The accumulation of growth-promoting antibiotic residues in animal products and the resistance developed by bacteria in poultry farms has led to a search for natural compounds derived from plants. This study was desig...The accumulation of growth-promoting antibiotic residues in animal products and the resistance developed by bacteria in poultry farms has led to a search for natural compounds derived from plants. This study was designed to promote the production performance of broiler chickens using fresh Cupressus sempervirens leaves infusion. Fresh Cupressus sempervirens leaves were harvested, washed, chopped and ground to a paste using a blender and fermented for three days in a closed container at a rate of 500 g/L of water. The solution obtained was filtered and added at the rate of 2, 4, 6, 8 and 10 ml/L of drinking water. The chickens fed on the graded level of the solution were compared to a control ration without an additive and positive control group supplemented with 1 g antibiotic/kg feed. At the finisher phase and throughout the study period, water intake increased significantly (P < 0.05) with increasing levels of infusion. Feed intake decreased significantly (P < 0.05) with 2 and 4 ml of infusion/L drinking water. Live weight and weight gain were significantly (P < 0.05) higher with 6 ml/L, while feed conversion significantly (P < 0.05) decreased with the same treatment compared with the control treatment without additives (T0). Carcass characteristics were not significantly (P > 0.05) affected by the inclusion of Cupressus sempervirens infusion. Haematological parameters significantly (P < 0.05) increase independently of the rate of incorporation of the infusion into the drinking water, with the exception of RBCs, MCHT and PCT. Serum content in total protein, globulins, LDL cholesterol and triglycerides were significantly (P < 0.05) high with 8 and 10 ml Cupressus sempervirens infusion/litre drinking water as compared to all other treatments. AST, ALT, urea, creatine, albumin, total cholesterol and HDL-cholesterol were not significantly affected. The lactic acid bacteria load increased significantly (P E. coli and salmonella counts decreased significantly (P < 0.05) with infusion compared to the control without additive. In conclusion, 6 ml of Cupressus sempervirens infusion can be used as an alternative to antibiotic feed additives to promote growth performance in broilers.展开更多
In order to study the effects of geometric parameters of the rudder on the hydrodynamic performance of the propeller-rudder system,the surface panel method is used to build the numerical model of the steady interactio...In order to study the effects of geometric parameters of the rudder on the hydrodynamic performance of the propeller-rudder system,the surface panel method is used to build the numerical model of the steady interaction between the propeller and rudder to analyze the relevant factors.The interaction between the propeller and rudder is considered through the induced velocities,which are circumferentially averaged,so the unsteady problem is translated to steady state.An iterative calculation method is used until the hydrodynamic performance converges.Firstly,the hydrodynamic performance of the chosen propeller-rudder system is calculated,and the comparison between the calculated results and the experimental data indicates that the calculation program is reliable.Then,the variable parameters of rudder are investigated,and the calculation results show that the propeller-rudder spacing has a negative relationship with the efficiency of the propeller-rudder system,and the rudder span has an optimal match range with the propeller diameter.Futhermore,the rudder chord and thickness both have a positive correlation with the hydrodynamic performance of the propeller-rudder system.展开更多
A study was conducted to better understand how different parameters, namely, regression aging time and regression aging temperature, affect the creep aging properties, i.e., the creep deformation and performance of Al...A study was conducted to better understand how different parameters, namely, regression aging time and regression aging temperature, affect the creep aging properties, i.e., the creep deformation and performance of Al-Zn-MgCu alloy during regressive reaging. The corresponding creep strain and mechanical properties of samples were studied by conducting creep tests and uniaxial tensile tests. The electrical conductivity was measured using an eddy-current conductivity meter. The microstructures were observed by transmission electron microscopy(TEM). With the increase in regression aging time, the steady creep strain first increased and then decreased, and reached the maximum at 45 min.The steady creep strain increased with the increase in regression aging temperature, and reached the maximum at 200 ℃.The level of steady creep strain was determined by precipitation and dislocation recovery. Creep aging strengthens 7B50-RRA treated with regression aging time at 190 ℃ for 10 min, and the difference in the mechanical properties of alloy becomes smaller. The diffusion of solute atoms reduces the scattering of electrons, leading to a significant improvement in electrical conductivity and stress corrosion cracking(SCC) resistance after creep aging. The findings of this study could help in the application of creep aging forming(CAF) technology in Al-Zn-Mg-Cu alloy under RRA treatment.展开更多
In order to assess the effects of calibration data series length on the performance and optimal parameter values of a hydrological model in ungauged or data-limited catchments (data are non-continuous and fragmental ...In order to assess the effects of calibration data series length on the performance and optimal parameter values of a hydrological model in ungauged or data-limited catchments (data are non-continuous and fragmental in some catchments), we used non-continuous calibration periods for more independent streamflow data for SIMHYD (simple hydrology) model calibration. Nash-Sutcliffe efficiency and percentage water balance error were used as performance measures. The particle swarm optimization (PSO) method was used to calibrate the rainfall-runoff models. Different lengths of data series ranging from one year to ten years, randomly sampled, were used to study the impact of calibration data series length. Fifty-five relatively unimpaired catchments located all over Australia with daily precipitation, potential evapotranspiration, and streamflow data were tested to obtain more general conclusions. The results show that longer calibration data series do not necessarily result in better model performance. In general, eight years of data are sufficient to obtain steady estimates of model performance and parameters for the SIMHYD model. It is also shown that most humid catchments require fewer calibration data to obtain a good performance and stable parameter values. The model performs better in humid and semi-humid catchments than in arid catchments. Our results may have useful and interesting implications for the efficiency of using limited observation data for hydrological model calibration in different climates.展开更多
Effects of working parameters on performance characteristics of hydrostatic turntable are researched by applying the fluid-structure-thermal coupled model.Fluid-structure interaction(FSI)technique and computational fl...Effects of working parameters on performance characteristics of hydrostatic turntable are researched by applying the fluid-structure-thermal coupled model.Fluid-structure interaction(FSI)technique and computational fluid dynamics(CFD)method are both employed by this new model,and thermal effects are also considered.Hydrostatic turntable systems with a series of oil supply pressures,various oil recess depth and several surface roughness parameters are studied.Performance parameters,such as turntable displacement,system flow rate,temperature rise of lubrication,stiffness and damping coefficients,are derived from different working parameters(rotational speed of turntable and exerted external load)of the hydrostatic turntable.Numerical results obtained from this FSI-thermal model are presented and discussed,and theoretical predictions are in good agreement with the experimental data.Therefore,this developed model is a very useful tool for studying hydrostatic turntables.The calculation results show that in order to obtain better performance,a rational selection of the design parameters is essential.展开更多
Twenty four 7-day-old crossbred goslings (Chuan white×Tai lake) were divided randomly into control and treatment groups. Enzyme preparation was added in the diet of treatment group at dosage of 1 g/kg. The bloo...Twenty four 7-day-old crossbred goslings (Chuan white×Tai lake) were divided randomly into control and treatment groups. Enzyme preparation was added in the diet of treatment group at dosage of 1 g/kg. The blood samples were collected from 60 day-old goslings via the wing vein. During the fifty-three days experiment, body weights were adopted measured each week, related hormone contents and biochemical parameters in plasma were determined. The results were as following:(1) Compared with control, body weight of treatment group were significantly higher (P<0.05) since 3-week-old goslings. The weight gains were significant higher (P<0.05) in (4~7) week-old goslings too, feed intake were increased and the "feed: body weight gain" was decreased; (2) Compared with control, growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels were dramatically enhanced by 36.62% (P<0.01) and 66.55% (P<0.01) respectively, while the level of β-endorphin (β-END) decreased by 51.66% (P<0.01); (3) Thyroid-stimulating hormone (TSH) and 3,3′,5-triiodothyronine (T3) contents in treatment group were 24.39% (P<0.05) and (16.81%) (P<0.05) higher than those of control, whereas thyroxine (T4) contents was lower by 18.33% (P<0.05), ratios of T3/T4 were increased; (4) Compared with control, insulin contents were elevated by 36.75% (P<0.01), while level of glucagon was reduced by 23.11% (P<0.01),ratios of insulin/glucagon were increased; (5) The activity of glutamic-pyruvic transaminase (GTP) was 4.46 fold higher than those of control (P<0.01) and uric acid content was reduced by 57.50% (P<0.01).These results indicate that enzyme preparation added in barley based diet can promote the gosling growth by improving the barely digestibility, carbohydrate metabolism and influencing the hormone levels.展开更多
This experiment was conducted to evaluate the effects of dietary protein and fat levels on growth performance and serum biochemical parameters of male minks during the growing period. A total, of 90 healthy male minks...This experiment was conducted to evaluate the effects of dietary protein and fat levels on growth performance and serum biochemical parameters of male minks during the growing period. A total, of 90 healthy male minks at the age of 60 d were randomly assigned into six groups with 15 replicates per group and one mink per replicate. The minks were fed six experimental diets with two protein levels (32% and 36% ) and three fat levels ( 10% , 20% and 30% ) for a 7-day preliminary period and then for 60-day experimental period. The results showed that the final body weight and average daily weight gain (ADWG) were significantly higher in low-protein, middle-fat group and low-protein, high-fat group than those in low-protein, low-fat group and high-protein, low-fat group (P 〈 0. O1 ). The final weight and ADWG were increased with dietary fat level increasing, and the two indices of 20% and 30% fat groups were significantly higher than those of 10% fat groups ( P 〈 0. O1 ). The ratio of feed intake to weight gain (F/G) in low-protein, high-fat group was the lowest, which was significantly lower than that in low- protein, low-fat group and high-protein, high-fat group (P 〈 0.05 ). Serum urea nitrogen (UN) in low-protein, high-fat group was significantly lower than that in other groups (P 〈 0. 01 ). Serum alanine transaminase (ALT) activity in 32% protein groups was significantly higher than that in 36% protein groups (P 〈 O. 05). Serum triglyceride (TG) content in low-protein, high-fat group and high-protein, high-fat group was significantly higher than that in low-protein, low-fat group and high-protein, low-fat groups (P 〈 0.05 ). Serum TG, total cholesterol (TCHO) and high-density lipoprotein (HDL) contents increased with the increase in dietary fat level, and they were all the highest in low-protein, high-fat group. The growth performance and serum biochemical parameters of minks were not affected by the interaction between dietary protein and fat levels (P 〉 O. 05 ). Considering all the factors, when the dietary protein is 32% and the fat level is 20% to 30% under the condition of this experiment, the dietary protein and fat utilization rates are higher, and the male minks during the growing period can get a better growth performance.展开更多
The objective of this study was to investigate the effects of phytase supplementation on growth performance, slaughter performance, growth of internal organs and small intestine, and serum biochemical indices of broil...The objective of this study was to investigate the effects of phytase supplementation on growth performance, slaughter performance, growth of internal organs and small intestine, and serum biochemical indices of broilers. A total of 360 1-day-old Ross 308 broilers were randomly divided into 4 groups with 3 replicates and 30 broilers per replicate (15 male, 15 female). The treatments were fed with basal diet supplemented with 0%, 0.01%, 0.02% and 0.03% phytase. The results showed that: 1) Phytase supplementation increased the body weight gain and the body weight of Ross 308 broilers (P serum calcium (Ca) consistency was 0.02%. According to the above analysis, the feasible supplementation of phytase (enzyme activity for 5000 u/g) in broiler dietary was 0.02%.展开更多
[Objective] The aim was to evaluate the health of transgenic sFat-1 gene pigs in order to provide a reference for the breeding selection of pig excellent individuals. [Method] 15 physiological biochemical parameters a...[Objective] The aim was to evaluate the health of transgenic sFat-1 gene pigs in order to provide a reference for the breeding selection of pig excellent individuals. [Method] 15 physiological biochemical parameters and reproductive performances of 21 negative control pigs and 20 transgenic sFat-1 gene pigs were determined. [Result] The liver functions of some transgenic sFat-1 gene pigs were hurted lightly,and the reproductive performance also decreased lightly. [Conclusion] The determination of physiological biochemical parameters and reproductive performance in transgenic pigs could be taken as one of effective methods in environmental safety evaluation of transgenic pigs.展开更多
Rigid blocking masses are located in the typical base structure of a power cabin based on the impedance mismatch principle.By combining the acoustic-structural coupling method and statistical energy analysis,the full-...Rigid blocking masses are located in the typical base structure of a power cabin based on the impedance mismatch principle.By combining the acoustic-structural coupling method and statistical energy analysis,the full-band vibration and sound radiation reduction effect of vibration isolation masses located in a base structure was researched.The influence of the blocking mass’ cross-section size and shape parameters and the layout location of the base isolation performance was discussed.Furthermore,the effectiveness of rigid vibration isolation design of the base structure was validated.The results show that the medium and high frequency vibration and sound radiation of a power cabin are effectively reduced by a blocking mass.Concerning weight increment and section requirement,suitably increasing the blocking mass size and section height and reducing section width can result in an efficiency-cost ratio.展开更多
A 45-day growth trial was conducted to investigate the effects of 4 concentrations (0, 40, 80, 120 mg·kg^-1 Zinc- Methionine (Zn-Met) supplementation on growth and serum biochemical indexes of Jirong rabbits ...A 45-day growth trial was conducted to investigate the effects of 4 concentrations (0, 40, 80, 120 mg·kg^-1 Zinc- Methionine (Zn-Met) supplementation on growth and serum biochemical indexes of Jirong rabbits (60-day-old). A total of 72 Jirong rabbits were randomly divided into 4 groups, 3 replicates with 6 rabbits each. The Met value in the basal diet was 0.60%. ADGs of group Ⅱ, Ⅲ and Ⅳ were significantly different than that of control, increased by 3.16%, 7.53%, 8.14% during 0-15 days and 7.58%, 15.60%, 15.71% during 16-30 days and 8.27%, 12.43%, 11.44% during 31-45 days (P〈0.05), but it was not significantly different in ADG among group Ⅱ, Ⅲ and Ⅳ (P〉0.05). The fur area and the density of hair of groups Ⅱ, Ⅲ and Ⅳ were not significantly different than that of control (P〉0.05). The content of serum zinc, AKP, ALB for groups Ⅱ, Ⅲ and Ⅳ were significantly different than that of control (P〈0.05). The serum TP and SUN in group Ⅱ, Ⅲ and IV were not significantly different than that of control (P〉0.05). The results show that dietary supplementation of Zn-Met is much more efficient than dietary without Zn-Met for 60-day-old Jirong rabbits.展开更多
A total of 480 nursery pigs (Duroc x Landrace x Large White) were utilized in two experiments conducted to determine the effects of different ratios of standardized ileal digestible lysine (SID- Lys) to metaboliza...A total of 480 nursery pigs (Duroc x Landrace x Large White) were utilized in two experiments conducted to determine the effects of different ratios of standardized ileal digestible lysine (SID- Lys) to metabolizable energy (ME) ratio on the performance, nutrient digestibility, plasma urea nitrogen (PUN) ,and plasma free amino acids of 10 to 28 kg pigs. In Exp. 1, 192 pigs ( 10.58 kg) were assigned to one of four treatments. The treatments consisted of diets with a ME content of 3.2, 3.25, 3.3, or 3.35 Mcal/kg with a constant SID-Lys:ME ratio of 3.7 g/Mcal. The experiment lasted 28 days. Pigs which were fed the diets containing 3.3 and 3.35 Mcal/kg ME had lower feed intakes ( P 〈 0.05)than those fed 3.2 Mcal/kg. Feed efficiency was linearly improved with increasing dietary ME ( P 〈0.05). Increasing the dietary ME level also increased (P 〈0.05 ) dry matter and energy digestibility. Therefore,3.3 Mcal/kg ME was selected for Exp. 2 in which 288 pigs ( 10.60 kg) were assigned to one of six treatments. Treatments consisted of SID-Lys: ME ratios of 3.1,3.3,3.5,3.7,3.9, or 4.1 g/Mcal with all diets providing 3.3 Mcal of ME/kg. Weight gain and feed efficiency were increased (P 〈0.05 ) as the SID-Lys:ME ratio in diet increased. Based on a straight broken-line model ,the estimated SID-Lys:ME ratio to maximize weight gain was 3.74.展开更多
This study aimed at investigating effects of frying oils supplemented with vitamin E on blood parameters and growth performance of rats. Three experimental diets containing fresh corn oil or frying oil (FO) with or wi...This study aimed at investigating effects of frying oils supplemented with vitamin E on blood parameters and growth performance of rats. Three experimental diets containing fresh corn oil or frying oil (FO) with or without vitamin E were fed to Wistar rats over a 90-day. Blood Chemistry, blood parameters (hematocrit and erythrocyte osmotic fragility) and growth performance were determined. Neither FO alone nor vitamin E had any considerable impact on the growth performance. Hematocrit of FO group did not change significantly compared to animals fed fresh oil. Although, vitamin E increased hematocrit to 16.37%, but still it had no considerable effect on restoring hematocrit to normal values. Serum triacylglycerol (TAG) did not change significantly among FO animals, while significant increase in TAG was noted between FO and vitamin E treated animals compared with other treatments. Serum total cholesterol (TC) did not change significantly among experimental animals compared with the control. Vitamin E resulted in an insignificant increase in high-density lipoprotein (HDL-C) level compared to the control. Serum low-density lipoprotein (LDL-C) level did not display any considerable difference among the three treatments. Frying oil with or without vitamin E had no significant effects on growth performance, lipid chemistry, and blood parameters. The only significant effect of FO was shown on erythrocytes hemolysis at higher concentration. Vitamin E supplementation had no impacts on undesired effects caused by frying oil.展开更多
[Objective] This paper was to study effects of pelleted total mixed ration with different concentrate-roughage ratios on production performance and serum biochemical parameters of fattening Hainan black goats.[Method]...[Objective] This paper was to study effects of pelleted total mixed ration with different concentrate-roughage ratios on production performance and serum biochemical parameters of fattening Hainan black goats.[Method] Thirty-six fattening Hainan black goats with the same genetic background and similar initial weight of(14.08±0.13) kg were randomly assigned into three treatments. Goats were fed with Juncao + concentrate(control group), pelleted total mixed ration I(concentrate: roughage 50 ∶50, group Ⅰ) and Ⅱ(concentrate: roughage 45∶55, group Ⅱ), respectively. The test lasted 45 d.[Result] The final weight, daily gain and feed intake of rams in experimental group Ⅰ were significantly higher than those of control group and experimental group Ⅱ(P<0.05);the final weight and daily gain of rams in experimental group Ⅰ were also markedly higher than those of experimental group Ⅱ(P<0.05);the feed/gain of rams in experimental group Ⅰ was significantly lower than those in control group and experimental group Ⅱ(P<0.05). The feed gain cost of rams in experimental group Ⅰ was markedly lower than that in experimental group Ⅱ( P<0.05), but was significantly higher than that in experimental group Ⅰ(P<0.05);the gross profit of rams in experimental group Ⅰ was significantly higher than those in control group and experimental group Ⅱ(P<0.05). Compared with control group and experimental group Ⅱ, the serum total protein and glucose lev-els in experimental group Ⅱ increased significantly(P<0.05), but the urea nitrogen content reduced(P>0.05).[Conclusion] When the concentrateroughage ratio of pelleted total mixed ration was 50∶50, the fattening effect of Hainan black goat was better, and the serum total protein and glucose levels were evidently improved.展开更多
Target recognition performance can be affected by radar waveform parameters.In this paper,we established rigorous relationship between target recognition efficiency and the parameters of a repeatedly transmitted wavef...Target recognition performance can be affected by radar waveform parameters.In this paper,we established rigorous relationship between target recognition efficiency and the parameters of a repeatedly transmitted waveform.It is based on Kullback-Leibler Information Number of single observation(KLINs),which measures the dissimilarity between targets depicted by a range-velocity double spread density function in frequency domain.We considered two signal models which are different in the coherence of the observations.The method we proposed takes advantage of the methodology of sequential hypothesis test,and then the recognition performance in terms of correct classification rate is expressed by Receiver Operating Characteristic(ROC).Simulation results about the parameters of LFM signal show the validity of the method.展开更多
This study investigated the effects of dioscorea opposite waste(DOW) on the growth performance, blood parameters, rumen fermentation and rumen microbiota of weaned lambs. Sixty healthy weaned Small-Tailed Han lambs(ma...This study investigated the effects of dioscorea opposite waste(DOW) on the growth performance, blood parameters, rumen fermentation and rumen microbiota of weaned lambs. Sixty healthy weaned Small-Tailed Han lambs(male,(22.68±2.56) kg initially) were used as the experimental animals. Four levels of concentrate: 0(control, CON), 10%(DOW1), 15%(DOW2) and 20%(DOW3), were replaced with DOW in the basal diet as experimental treatments. The results showed that lambs fed the DOW2 diet had a higher(P<0.05) dry matter intake(DMI) than the other groups. There was no significant difference(P>0.05) among DOW groups in average daily weight gain(ADG), and replacing concentrate with DOW linearly or quadratically increased(P<0.05) the ADG, while lambs fed the DOW2 diet showed greater(P<0.05) ADG than the CON group. The relative plasma concentration of growth hormone(GH), insulin like growth factor-1(IGF-1) and insulin were affected by DOW, replacing concentrate with DOW linearly or quadratically(P<0.05) enhanced the plasma concentration of GH, IGF-1 and insulin, which was significantly higher(P<0.05) in the DOW2 group than in the CON, DOW1 and DOW3 groups. In addition, the DOW treatment showed a lower(P<0.05) concentration of blood urea nitrogen(BUN) than the CON group. Replacing concentrate with DOW quadratically decreased(P<0.05) the ruminal ammonia nitrogen(NH3-N) and increased(P<0.05) the total of volatile fatty acids(TVFAs) at 0 and 4 h after feeding as well as linearly decreased(P<0.05) the NH3-N at 8 h after feeding. Replacing concentrate with DOW linearly decreased(P<0.05) the propionate and increased the aceate before feeding, and linearly decreased(P<0.05) propionate and quadratically increased(P<0.05) the aceate at 4 and 8 h after feeding. Lambs fed the DOW2 diet increased the phylum Firmicutes and genera Succiniclasticum and Ruminococcus_1 groups, whereas decreased(P<0.05) the relative abundance of phylum Deferribacteres and genera intestinimonas and Ruminiclostridium. In summary, replacing the concentrate with 15% DOW was beneficial for improving the rumen fermentation and ADG by increasing the DMI and modulating the rumen microbial community.展开更多
The restriction of antibiotic growth promoters in livestock nutrition has led to a growing interest in plant feed additives. This study was designed to assess the production performance of broiler chickens fed on grad...The restriction of antibiotic growth promoters in livestock nutrition has led to a growing interest in plant feed additives. This study was designed to assess the production performance of broiler chickens fed on graded levels of<em> Pentadiplandra brazzeana</em> powder in drinking water. A total of 448 day-old Cobb 500 broiler chicks were randomly assigned to seven treatment groups with 4 replicates of 16 birds each (08 males and 08 females). <em>Pentadiplandra brazzeana</em> root was grounded and incorporated at 1, 2, 3, 4 and 5 g/L of drinking water. Control rations consisted of diet without any supplement (T0) and antibiotic (1 g/kg) medicated diet (T0+). Throughout the experimental period (49 days) feed intake was not significantly (p > 0.05) affected by graded levels of <em>Pentadiplandra brazzeana </em>except for 5 g/L of water that significantly (p < 0.05) decreased feed intake. Weight gain was significantly higher (p < 0.05) with 1, 2 and 3 g/L, while feed conversion ratio was significantly lower (p < 0.05) with the same treatments compared to the control group (T0). Chickens fed on 1 g <em>Pentadiplandra brazzeana</em>/L recorded a higher (p < 0.05) carcass yield compared to the control ration (T0). Haematological parameters were not significantly (p > 0.05) affected irrespective of the level of incorporation of the test spice in drinking water. Serum content in urea was significantly lower (p < 0.05) with 3 g <em>Pentadiplandra brazzeana</em>/L compared to all other treatments. ASAT, ALAT, creatinine, total cholesterol, triglycerides, HDL and LDL-cholesterol were not significantly affected by the inclusion of<em> Pentadiplandra brazzeana</em> powder in drinking water. Feeding chickens with up to 4 g of<em> Pentadiplandra brazzeana</em> significantly increased (p < 0.05) lactic acid bacteria count. E. coli and salmonella counts significantly (p < 0.05) decreased with the spice in water as compared to the control diet. In conclusion, the administration of up to 3 g of <em>Pentadiplandra brazzeana</em> powder through drinking water can be used as alternative to antibiotics to improve growth performance of broiler chickens.展开更多
To find out the influence of technological parameters on optical performance of fused optical fiber device, the fiber coupler was served as subject investigated by using the fused biconical taper machining as experime...To find out the influence of technological parameters on optical performance of fused optical fiber device, the fiber coupler was served as subject investigated by using the fused biconical taper machining as experimental setup. Fused fiber coupler's optical performances such as insertion loss, excess loss, directivity and uniformity were tested with the optical test system that was constituted of tunable laser and optical spectrum analyzer. Especially the relationship between optical performance and drawing speed was investigated. The experimental results show that the optical performance is closely related to process conditions. At fused temperature of 1 200 ℃, there exists a drawing speed of 150 μms, which makes the device's performance optimum. Out of this speed region, the optical performance drops quickly. At drawing speed of 200 μms, the excess loss is relatively small when the fused temperature is above 1 200 ℃. So the technological parameters have close relationship with optical performance of the coupler, and the good performance coupler can't get until the drawing speed and fused temperature match accurately.展开更多
financially supported by the Science and Technology Develop Project of Northern Jiangsu, China (BN2015136);the Priority Academic Program Development of Jiangsu Higher Education Institution, China
<span style="font-family:Verdana;">The present study was assigned to evaluate the Effect of </span><i><i><span style="font-family:Verdana;">Dracaena arborea</span&g...<span style="font-family:Verdana;">The present study was assigned to evaluate the Effect of </span><i><i><span style="font-family:Verdana;">Dracaena arborea</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;"> roots powder in</span><span style="color:red;"> </span><span style="font-family:Verdana;">ratio</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">n</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"><span style="font-family:Verdana;"> on growth performances and some hematological parameters in the guinea pig on diet supplemented with graded levels of incorporation. A total of 40 guinea pigs weaned of local breed and aged 3 weeks were divided into 4 identical batches. Each of the groups was randomly assigned one of 4 rations containing different levels of the powder from </span><i></i></span><i><i><span style="font-family:Verdana;">Dracaena arborea</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;"> (Da) roots: Da0;Da0.25;Da0.5 and Da0.75. The results at the 11th week of breeding showed that the highest intake (21.13</span></span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">g/d) was obtained with the Da0.5 ration. The highest live weight (372.50 g) and total weight gains were obtained with the Da0.25 ration. In addition, the highest commercial (161.75 g) and conventional (307.75 g) carcass weights and large intestine length (99.5 cm) were obtained with the D0.25 ration. The highest values for granulocytes (0.250</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">10</span><sup></sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><sup>3</sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">/μl), platelets (805</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">10</span><sup></sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><sup>3</sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">/μl) and lymphocytes (6.92</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">10</span><sup></sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><sup>3</sup></span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"><span style="font-family:Verdana;">/μl) were respectively, obtained with the rations containing Da0;D0.5 and D0.75. In view of the above, </span><i></i></span><i><i><span style="font-family:Verdana;">Dracaena arborea</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;"> roots powder can be used at a rate of 0.25% in the ration, to improve the productivity of the guinea pig (</span><i></i></span><i><i><span style="font-family:Verdana;">Cavia porcellus</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;">).</span></span></span>展开更多
文摘The accumulation of growth-promoting antibiotic residues in animal products and the resistance developed by bacteria in poultry farms has led to a search for natural compounds derived from plants. This study was designed to promote the production performance of broiler chickens using fresh Cupressus sempervirens leaves infusion. Fresh Cupressus sempervirens leaves were harvested, washed, chopped and ground to a paste using a blender and fermented for three days in a closed container at a rate of 500 g/L of water. The solution obtained was filtered and added at the rate of 2, 4, 6, 8 and 10 ml/L of drinking water. The chickens fed on the graded level of the solution were compared to a control ration without an additive and positive control group supplemented with 1 g antibiotic/kg feed. At the finisher phase and throughout the study period, water intake increased significantly (P < 0.05) with increasing levels of infusion. Feed intake decreased significantly (P < 0.05) with 2 and 4 ml of infusion/L drinking water. Live weight and weight gain were significantly (P < 0.05) higher with 6 ml/L, while feed conversion significantly (P < 0.05) decreased with the same treatment compared with the control treatment without additives (T0). Carcass characteristics were not significantly (P > 0.05) affected by the inclusion of Cupressus sempervirens infusion. Haematological parameters significantly (P < 0.05) increase independently of the rate of incorporation of the infusion into the drinking water, with the exception of RBCs, MCHT and PCT. Serum content in total protein, globulins, LDL cholesterol and triglycerides were significantly (P < 0.05) high with 8 and 10 ml Cupressus sempervirens infusion/litre drinking water as compared to all other treatments. AST, ALT, urea, creatine, albumin, total cholesterol and HDL-cholesterol were not significantly affected. The lactic acid bacteria load increased significantly (P E. coli and salmonella counts decreased significantly (P < 0.05) with infusion compared to the control without additive. In conclusion, 6 ml of Cupressus sempervirens infusion can be used as an alternative to antibiotic feed additives to promote growth performance in broilers.
基金Supported by the China Postdoctoral Science Foundation(Grant No.2012M512133)the National Natural Science Foundation of China(Grant NO.41176074)the Fundamental Research Funds for the Central University(Grant No.T013513015)
文摘In order to study the effects of geometric parameters of the rudder on the hydrodynamic performance of the propeller-rudder system,the surface panel method is used to build the numerical model of the steady interaction between the propeller and rudder to analyze the relevant factors.The interaction between the propeller and rudder is considered through the induced velocities,which are circumferentially averaged,so the unsteady problem is translated to steady state.An iterative calculation method is used until the hydrodynamic performance converges.Firstly,the hydrodynamic performance of the chosen propeller-rudder system is calculated,and the comparison between the calculated results and the experimental data indicates that the calculation program is reliable.Then,the variable parameters of rudder are investigated,and the calculation results show that the propeller-rudder spacing has a negative relationship with the efficiency of the propeller-rudder system,and the rudder span has an optimal match range with the propeller diameter.Futhermore,the rudder chord and thickness both have a positive correlation with the hydrodynamic performance of the propeller-rudder system.
基金Project(2017YFB0306300) supported by the National key R&D Program of ChinaProjects(51675538, 51905551)supported by the National Natural Science Foundation of ChinaProject(ZZYJKT2019-11) supported by Free Exploration Project of State Key Laboratory of High performance Complex Manufacturing,China。
文摘A study was conducted to better understand how different parameters, namely, regression aging time and regression aging temperature, affect the creep aging properties, i.e., the creep deformation and performance of Al-Zn-MgCu alloy during regressive reaging. The corresponding creep strain and mechanical properties of samples were studied by conducting creep tests and uniaxial tensile tests. The electrical conductivity was measured using an eddy-current conductivity meter. The microstructures were observed by transmission electron microscopy(TEM). With the increase in regression aging time, the steady creep strain first increased and then decreased, and reached the maximum at 45 min.The steady creep strain increased with the increase in regression aging temperature, and reached the maximum at 200 ℃.The level of steady creep strain was determined by precipitation and dislocation recovery. Creep aging strengthens 7B50-RRA treated with regression aging time at 190 ℃ for 10 min, and the difference in the mechanical properties of alloy becomes smaller. The diffusion of solute atoms reduces the scattering of electrons, leading to a significant improvement in electrical conductivity and stress corrosion cracking(SCC) resistance after creep aging. The findings of this study could help in the application of creep aging forming(CAF) technology in Al-Zn-Mg-Cu alloy under RRA treatment.
基金supported by the National Basic Research Program of China (the 973 Program,Grant No.2010CB951102)the National Supporting Plan Program of China (Grants No.2007BAB28B01 and 2008BAB42B03)the National Natural Science Foundation of China (Grant No. 50709042),and the Regional Water Theme in the Water for a Healthy Country Flagship
文摘In order to assess the effects of calibration data series length on the performance and optimal parameter values of a hydrological model in ungauged or data-limited catchments (data are non-continuous and fragmental in some catchments), we used non-continuous calibration periods for more independent streamflow data for SIMHYD (simple hydrology) model calibration. Nash-Sutcliffe efficiency and percentage water balance error were used as performance measures. The particle swarm optimization (PSO) method was used to calibrate the rainfall-runoff models. Different lengths of data series ranging from one year to ten years, randomly sampled, were used to study the impact of calibration data series length. Fifty-five relatively unimpaired catchments located all over Australia with daily precipitation, potential evapotranspiration, and streamflow data were tested to obtain more general conclusions. The results show that longer calibration data series do not necessarily result in better model performance. In general, eight years of data are sufficient to obtain steady estimates of model performance and parameters for the SIMHYD model. It is also shown that most humid catchments require fewer calibration data to obtain a good performance and stable parameter values. The model performs better in humid and semi-humid catchments than in arid catchments. Our results may have useful and interesting implications for the efficiency of using limited observation data for hydrological model calibration in different climates.
基金Projects (51175518,51705147) supported by the National Natural Science Foundation of China
文摘Effects of working parameters on performance characteristics of hydrostatic turntable are researched by applying the fluid-structure-thermal coupled model.Fluid-structure interaction(FSI)technique and computational fluid dynamics(CFD)method are both employed by this new model,and thermal effects are also considered.Hydrostatic turntable systems with a series of oil supply pressures,various oil recess depth and several surface roughness parameters are studied.Performance parameters,such as turntable displacement,system flow rate,temperature rise of lubrication,stiffness and damping coefficients,are derived from different working parameters(rotational speed of turntable and exerted external load)of the hydrostatic turntable.Numerical results obtained from this FSI-thermal model are presented and discussed,and theoretical predictions are in good agreement with the experimental data.Therefore,this developed model is a very useful tool for studying hydrostatic turntables.The calculation results show that in order to obtain better performance,a rational selection of the design parameters is essential.
基金Item supported by international develop-ment research centre of Canada (No.92-1300)national sciencefoundation of China(No.39270500)
文摘Twenty four 7-day-old crossbred goslings (Chuan white×Tai lake) were divided randomly into control and treatment groups. Enzyme preparation was added in the diet of treatment group at dosage of 1 g/kg. The blood samples were collected from 60 day-old goslings via the wing vein. During the fifty-three days experiment, body weights were adopted measured each week, related hormone contents and biochemical parameters in plasma were determined. The results were as following:(1) Compared with control, body weight of treatment group were significantly higher (P<0.05) since 3-week-old goslings. The weight gains were significant higher (P<0.05) in (4~7) week-old goslings too, feed intake were increased and the "feed: body weight gain" was decreased; (2) Compared with control, growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels were dramatically enhanced by 36.62% (P<0.01) and 66.55% (P<0.01) respectively, while the level of β-endorphin (β-END) decreased by 51.66% (P<0.01); (3) Thyroid-stimulating hormone (TSH) and 3,3′,5-triiodothyronine (T3) contents in treatment group were 24.39% (P<0.05) and (16.81%) (P<0.05) higher than those of control, whereas thyroxine (T4) contents was lower by 18.33% (P<0.05), ratios of T3/T4 were increased; (4) Compared with control, insulin contents were elevated by 36.75% (P<0.01), while level of glucagon was reduced by 23.11% (P<0.01),ratios of insulin/glucagon were increased; (5) The activity of glutamic-pyruvic transaminase (GTP) was 4.46 fold higher than those of control (P<0.01) and uric acid content was reduced by 57.50% (P<0.01).These results indicate that enzyme preparation added in barley based diet can promote the gosling growth by improving the barely digestibility, carbohydrate metabolism and influencing the hormone levels.
基金Supported by Natural Foundation of Jilin Provincial Department of Science and Technology(20150101112JC)The Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences
文摘This experiment was conducted to evaluate the effects of dietary protein and fat levels on growth performance and serum biochemical parameters of male minks during the growing period. A total, of 90 healthy male minks at the age of 60 d were randomly assigned into six groups with 15 replicates per group and one mink per replicate. The minks were fed six experimental diets with two protein levels (32% and 36% ) and three fat levels ( 10% , 20% and 30% ) for a 7-day preliminary period and then for 60-day experimental period. The results showed that the final body weight and average daily weight gain (ADWG) were significantly higher in low-protein, middle-fat group and low-protein, high-fat group than those in low-protein, low-fat group and high-protein, low-fat group (P 〈 0. O1 ). The final weight and ADWG were increased with dietary fat level increasing, and the two indices of 20% and 30% fat groups were significantly higher than those of 10% fat groups ( P 〈 0. O1 ). The ratio of feed intake to weight gain (F/G) in low-protein, high-fat group was the lowest, which was significantly lower than that in low- protein, low-fat group and high-protein, high-fat group (P 〈 0.05 ). Serum urea nitrogen (UN) in low-protein, high-fat group was significantly lower than that in other groups (P 〈 0. 01 ). Serum alanine transaminase (ALT) activity in 32% protein groups was significantly higher than that in 36% protein groups (P 〈 O. 05). Serum triglyceride (TG) content in low-protein, high-fat group and high-protein, high-fat group was significantly higher than that in low-protein, low-fat group and high-protein, low-fat groups (P 〈 0.05 ). Serum TG, total cholesterol (TCHO) and high-density lipoprotein (HDL) contents increased with the increase in dietary fat level, and they were all the highest in low-protein, high-fat group. The growth performance and serum biochemical parameters of minks were not affected by the interaction between dietary protein and fat levels (P 〉 O. 05 ). Considering all the factors, when the dietary protein is 32% and the fat level is 20% to 30% under the condition of this experiment, the dietary protein and fat utilization rates are higher, and the male minks during the growing period can get a better growth performance.
文摘The objective of this study was to investigate the effects of phytase supplementation on growth performance, slaughter performance, growth of internal organs and small intestine, and serum biochemical indices of broilers. A total of 360 1-day-old Ross 308 broilers were randomly divided into 4 groups with 3 replicates and 30 broilers per replicate (15 male, 15 female). The treatments were fed with basal diet supplemented with 0%, 0.01%, 0.02% and 0.03% phytase. The results showed that: 1) Phytase supplementation increased the body weight gain and the body weight of Ross 308 broilers (P serum calcium (Ca) consistency was 0.02%. According to the above analysis, the feasible supplementation of phytase (enzyme activity for 5000 u/g) in broiler dietary was 0.02%.
基金Supported by National GMO Cultivation of New Varieties of Major Projects Subproject Environmental Safety Assessment of Genetically Modified Pigs Technology (2008ZX08011-004)~~
文摘[Objective] The aim was to evaluate the health of transgenic sFat-1 gene pigs in order to provide a reference for the breeding selection of pig excellent individuals. [Method] 15 physiological biochemical parameters and reproductive performances of 21 negative control pigs and 20 transgenic sFat-1 gene pigs were determined. [Result] The liver functions of some transgenic sFat-1 gene pigs were hurted lightly,and the reproductive performance also decreased lightly. [Conclusion] The determination of physiological biochemical parameters and reproductive performance in transgenic pigs could be taken as one of effective methods in environmental safety evaluation of transgenic pigs.
基金Supported by the International Cooperation Program under Grant No.2007DFR80340the National Natural Science Foundation of China under Grant No.50779007
文摘Rigid blocking masses are located in the typical base structure of a power cabin based on the impedance mismatch principle.By combining the acoustic-structural coupling method and statistical energy analysis,the full-band vibration and sound radiation reduction effect of vibration isolation masses located in a base structure was researched.The influence of the blocking mass’ cross-section size and shape parameters and the layout location of the base isolation performance was discussed.Furthermore,the effectiveness of rigid vibration isolation design of the base structure was validated.The results show that the medium and high frequency vibration and sound radiation of a power cabin are effectively reduced by a blocking mass.Concerning weight increment and section requirement,suitably increasing the blocking mass size and section height and reducing section width can result in an efficiency-cost ratio.
基金the National Science Foundation for Postdoctoral Scientists of China (20060390909)
文摘A 45-day growth trial was conducted to investigate the effects of 4 concentrations (0, 40, 80, 120 mg·kg^-1 Zinc- Methionine (Zn-Met) supplementation on growth and serum biochemical indexes of Jirong rabbits (60-day-old). A total of 72 Jirong rabbits were randomly divided into 4 groups, 3 replicates with 6 rabbits each. The Met value in the basal diet was 0.60%. ADGs of group Ⅱ, Ⅲ and Ⅳ were significantly different than that of control, increased by 3.16%, 7.53%, 8.14% during 0-15 days and 7.58%, 15.60%, 15.71% during 16-30 days and 8.27%, 12.43%, 11.44% during 31-45 days (P〈0.05), but it was not significantly different in ADG among group Ⅱ, Ⅲ and Ⅳ (P〉0.05). The fur area and the density of hair of groups Ⅱ, Ⅲ and Ⅳ were not significantly different than that of control (P〉0.05). The content of serum zinc, AKP, ALB for groups Ⅱ, Ⅲ and Ⅳ were significantly different than that of control (P〈0.05). The serum TP and SUN in group Ⅱ, Ⅲ and IV were not significantly different than that of control (P〉0.05). The results show that dietary supplementation of Zn-Met is much more efficient than dietary without Zn-Met for 60-day-old Jirong rabbits.
基金support received from the State Key Laboratory of Animal Nutrition of China ( No .2004DA125184-0810)National Natural Science Foundation of China(No .31072040)+1 种基金Guangdong Cooperation Project be-tween Industry-Academia-Research of China ( No .2009B090300110)the Ministry of Science and Technology of the People’s Republic of China ( No .2006BAD12B05-10and No . Nyhyzx07-34)
文摘A total of 480 nursery pigs (Duroc x Landrace x Large White) were utilized in two experiments conducted to determine the effects of different ratios of standardized ileal digestible lysine (SID- Lys) to metabolizable energy (ME) ratio on the performance, nutrient digestibility, plasma urea nitrogen (PUN) ,and plasma free amino acids of 10 to 28 kg pigs. In Exp. 1, 192 pigs ( 10.58 kg) were assigned to one of four treatments. The treatments consisted of diets with a ME content of 3.2, 3.25, 3.3, or 3.35 Mcal/kg with a constant SID-Lys:ME ratio of 3.7 g/Mcal. The experiment lasted 28 days. Pigs which were fed the diets containing 3.3 and 3.35 Mcal/kg ME had lower feed intakes ( P 〈 0.05)than those fed 3.2 Mcal/kg. Feed efficiency was linearly improved with increasing dietary ME ( P 〈0.05). Increasing the dietary ME level also increased (P 〈0.05 ) dry matter and energy digestibility. Therefore,3.3 Mcal/kg ME was selected for Exp. 2 in which 288 pigs ( 10.60 kg) were assigned to one of six treatments. Treatments consisted of SID-Lys: ME ratios of 3.1,3.3,3.5,3.7,3.9, or 4.1 g/Mcal with all diets providing 3.3 Mcal of ME/kg. Weight gain and feed efficiency were increased (P 〈0.05 ) as the SID-Lys:ME ratio in diet increased. Based on a straight broken-line model ,the estimated SID-Lys:ME ratio to maximize weight gain was 3.74.
文摘This study aimed at investigating effects of frying oils supplemented with vitamin E on blood parameters and growth performance of rats. Three experimental diets containing fresh corn oil or frying oil (FO) with or without vitamin E were fed to Wistar rats over a 90-day. Blood Chemistry, blood parameters (hematocrit and erythrocyte osmotic fragility) and growth performance were determined. Neither FO alone nor vitamin E had any considerable impact on the growth performance. Hematocrit of FO group did not change significantly compared to animals fed fresh oil. Although, vitamin E increased hematocrit to 16.37%, but still it had no considerable effect on restoring hematocrit to normal values. Serum triacylglycerol (TAG) did not change significantly among FO animals, while significant increase in TAG was noted between FO and vitamin E treated animals compared with other treatments. Serum total cholesterol (TC) did not change significantly among experimental animals compared with the control. Vitamin E resulted in an insignificant increase in high-density lipoprotein (HDL-C) level compared to the control. Serum low-density lipoprotein (LDL-C) level did not display any considerable difference among the three treatments. Frying oil with or without vitamin E had no significant effects on growth performance, lipid chemistry, and blood parameters. The only significant effect of FO was shown on erythrocytes hemolysis at higher concentration. Vitamin E supplementation had no impacts on undesired effects caused by frying oil.
基金Supported by Major Science and Technology Program of Hainan Province(ZDKJ2016017-01,ZDKJ2016017-03)Youth Science and Technology Talents Innovation Project of Hainan Science&Technology Association(QCXM201802)
文摘[Objective] This paper was to study effects of pelleted total mixed ration with different concentrate-roughage ratios on production performance and serum biochemical parameters of fattening Hainan black goats.[Method] Thirty-six fattening Hainan black goats with the same genetic background and similar initial weight of(14.08±0.13) kg were randomly assigned into three treatments. Goats were fed with Juncao + concentrate(control group), pelleted total mixed ration I(concentrate: roughage 50 ∶50, group Ⅰ) and Ⅱ(concentrate: roughage 45∶55, group Ⅱ), respectively. The test lasted 45 d.[Result] The final weight, daily gain and feed intake of rams in experimental group Ⅰ were significantly higher than those of control group and experimental group Ⅱ(P<0.05);the final weight and daily gain of rams in experimental group Ⅰ were also markedly higher than those of experimental group Ⅱ(P<0.05);the feed/gain of rams in experimental group Ⅰ was significantly lower than those in control group and experimental group Ⅱ(P<0.05). The feed gain cost of rams in experimental group Ⅰ was markedly lower than that in experimental group Ⅱ( P<0.05), but was significantly higher than that in experimental group Ⅰ(P<0.05);the gross profit of rams in experimental group Ⅰ was significantly higher than those in control group and experimental group Ⅱ(P<0.05). Compared with control group and experimental group Ⅱ, the serum total protein and glucose lev-els in experimental group Ⅱ increased significantly(P<0.05), but the urea nitrogen content reduced(P>0.05).[Conclusion] When the concentrateroughage ratio of pelleted total mixed ration was 50∶50, the fattening effect of Hainan black goat was better, and the serum total protein and glucose levels were evidently improved.
文摘Target recognition performance can be affected by radar waveform parameters.In this paper,we established rigorous relationship between target recognition efficiency and the parameters of a repeatedly transmitted waveform.It is based on Kullback-Leibler Information Number of single observation(KLINs),which measures the dissimilarity between targets depicted by a range-velocity double spread density function in frequency domain.We considered two signal models which are different in the coherence of the observations.The method we proposed takes advantage of the methodology of sequential hypothesis test,and then the recognition performance in terms of correct classification rate is expressed by Receiver Operating Characteristic(ROC).Simulation results about the parameters of LFM signal show the validity of the method.
基金supported by the Key R&D Project of Hebei Province of China (21322907D and 21322910D)the Natural Science Foundation of Hebei Province, China (C2022204174)the China Agriculture Research System (CARS-38 and CARS-39-23)。
文摘This study investigated the effects of dioscorea opposite waste(DOW) on the growth performance, blood parameters, rumen fermentation and rumen microbiota of weaned lambs. Sixty healthy weaned Small-Tailed Han lambs(male,(22.68±2.56) kg initially) were used as the experimental animals. Four levels of concentrate: 0(control, CON), 10%(DOW1), 15%(DOW2) and 20%(DOW3), were replaced with DOW in the basal diet as experimental treatments. The results showed that lambs fed the DOW2 diet had a higher(P<0.05) dry matter intake(DMI) than the other groups. There was no significant difference(P>0.05) among DOW groups in average daily weight gain(ADG), and replacing concentrate with DOW linearly or quadratically increased(P<0.05) the ADG, while lambs fed the DOW2 diet showed greater(P<0.05) ADG than the CON group. The relative plasma concentration of growth hormone(GH), insulin like growth factor-1(IGF-1) and insulin were affected by DOW, replacing concentrate with DOW linearly or quadratically(P<0.05) enhanced the plasma concentration of GH, IGF-1 and insulin, which was significantly higher(P<0.05) in the DOW2 group than in the CON, DOW1 and DOW3 groups. In addition, the DOW treatment showed a lower(P<0.05) concentration of blood urea nitrogen(BUN) than the CON group. Replacing concentrate with DOW quadratically decreased(P<0.05) the ruminal ammonia nitrogen(NH3-N) and increased(P<0.05) the total of volatile fatty acids(TVFAs) at 0 and 4 h after feeding as well as linearly decreased(P<0.05) the NH3-N at 8 h after feeding. Replacing concentrate with DOW linearly decreased(P<0.05) the propionate and increased the aceate before feeding, and linearly decreased(P<0.05) propionate and quadratically increased(P<0.05) the aceate at 4 and 8 h after feeding. Lambs fed the DOW2 diet increased the phylum Firmicutes and genera Succiniclasticum and Ruminococcus_1 groups, whereas decreased(P<0.05) the relative abundance of phylum Deferribacteres and genera intestinimonas and Ruminiclostridium. In summary, replacing the concentrate with 15% DOW was beneficial for improving the rumen fermentation and ADG by increasing the DMI and modulating the rumen microbial community.
文摘The restriction of antibiotic growth promoters in livestock nutrition has led to a growing interest in plant feed additives. This study was designed to assess the production performance of broiler chickens fed on graded levels of<em> Pentadiplandra brazzeana</em> powder in drinking water. A total of 448 day-old Cobb 500 broiler chicks were randomly assigned to seven treatment groups with 4 replicates of 16 birds each (08 males and 08 females). <em>Pentadiplandra brazzeana</em> root was grounded and incorporated at 1, 2, 3, 4 and 5 g/L of drinking water. Control rations consisted of diet without any supplement (T0) and antibiotic (1 g/kg) medicated diet (T0+). Throughout the experimental period (49 days) feed intake was not significantly (p > 0.05) affected by graded levels of <em>Pentadiplandra brazzeana </em>except for 5 g/L of water that significantly (p < 0.05) decreased feed intake. Weight gain was significantly higher (p < 0.05) with 1, 2 and 3 g/L, while feed conversion ratio was significantly lower (p < 0.05) with the same treatments compared to the control group (T0). Chickens fed on 1 g <em>Pentadiplandra brazzeana</em>/L recorded a higher (p < 0.05) carcass yield compared to the control ration (T0). Haematological parameters were not significantly (p > 0.05) affected irrespective of the level of incorporation of the test spice in drinking water. Serum content in urea was significantly lower (p < 0.05) with 3 g <em>Pentadiplandra brazzeana</em>/L compared to all other treatments. ASAT, ALAT, creatinine, total cholesterol, triglycerides, HDL and LDL-cholesterol were not significantly affected by the inclusion of<em> Pentadiplandra brazzeana</em> powder in drinking water. Feeding chickens with up to 4 g of<em> Pentadiplandra brazzeana</em> significantly increased (p < 0.05) lactic acid bacteria count. E. coli and salmonella counts significantly (p < 0.05) decreased with the spice in water as compared to the control diet. In conclusion, the administration of up to 3 g of <em>Pentadiplandra brazzeana</em> powder through drinking water can be used as alternative to antibiotics to improve growth performance of broiler chickens.
基金Project (50605063) supported by the National Natural Science Foundation of ChinaProject(NCET-040753) supported by New Century Excellent Talents in University of ChinaProject (20050533037) supported by the Doctoral Program of Higher Education of China
文摘To find out the influence of technological parameters on optical performance of fused optical fiber device, the fiber coupler was served as subject investigated by using the fused biconical taper machining as experimental setup. Fused fiber coupler's optical performances such as insertion loss, excess loss, directivity and uniformity were tested with the optical test system that was constituted of tunable laser and optical spectrum analyzer. Especially the relationship between optical performance and drawing speed was investigated. The experimental results show that the optical performance is closely related to process conditions. At fused temperature of 1 200 ℃, there exists a drawing speed of 150 μms, which makes the device's performance optimum. Out of this speed region, the optical performance drops quickly. At drawing speed of 200 μms, the excess loss is relatively small when the fused temperature is above 1 200 ℃. So the technological parameters have close relationship with optical performance of the coupler, and the good performance coupler can't get until the drawing speed and fused temperature match accurately.
基金financially supported by the Science and Technology Develop Project of Northern Jiangsu, China (BN2015136)the Priority Academic Program Development of Jiangsu Higher Education Institution, China
文摘financially supported by the Science and Technology Develop Project of Northern Jiangsu, China (BN2015136);the Priority Academic Program Development of Jiangsu Higher Education Institution, China
文摘<span style="font-family:Verdana;">The present study was assigned to evaluate the Effect of </span><i><i><span style="font-family:Verdana;">Dracaena arborea</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;"> roots powder in</span><span style="color:red;"> </span><span style="font-family:Verdana;">ratio</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">n</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"><span style="font-family:Verdana;"> on growth performances and some hematological parameters in the guinea pig on diet supplemented with graded levels of incorporation. A total of 40 guinea pigs weaned of local breed and aged 3 weeks were divided into 4 identical batches. Each of the groups was randomly assigned one of 4 rations containing different levels of the powder from </span><i></i></span><i><i><span style="font-family:Verdana;">Dracaena arborea</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;"> (Da) roots: Da0;Da0.25;Da0.5 and Da0.75. The results at the 11th week of breeding showed that the highest intake (21.13</span></span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">g/d) was obtained with the Da0.5 ration. The highest live weight (372.50 g) and total weight gains were obtained with the Da0.25 ration. In addition, the highest commercial (161.75 g) and conventional (307.75 g) carcass weights and large intestine length (99.5 cm) were obtained with the D0.25 ration. The highest values for granulocytes (0.250</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">10</span><sup></sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><sup>3</sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">/μl), platelets (805</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">10</span><sup></sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><sup>3</sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">/μl) and lymphocytes (6.92</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">10</span><sup></sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><sup>3</sup></span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"><span style="font-family:Verdana;">/μl) were respectively, obtained with the rations containing Da0;D0.5 and D0.75. In view of the above, </span><i></i></span><i><i><span style="font-family:Verdana;">Dracaena arborea</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;"> roots powder can be used at a rate of 0.25% in the ration, to improve the productivity of the guinea pig (</span><i></i></span><i><i><span style="font-family:Verdana;">Cavia porcellus</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;">).</span></span></span>