This study was to investigate time-course effects of different types of dietary fiber on the energy values,fecal microbiota and short-chain fatty acid(SCFA)concentration in growing pigs.A total of 24 barrows(initial b...This study was to investigate time-course effects of different types of dietary fiber on the energy values,fecal microbiota and short-chain fatty acid(SCFA)concentration in growing pigs.A total of 24 barrows(initial body weight,19.8±0.5 kg)were assigned to 4 dietary treatments based on body weight(BW)in a completely randomized design,including a basal diet(CON)and 3 fiber-rich diets replacing corn,soybean meal and soybean oil in the CON diet with 20%sugar beet pulp(SBP),defatted rice bran(DFRB)or soybean hull(SBH),respectively.Fresh feces were sampled on d 7,14 and 21,followed by 5 d total feces and urine collections.The results showed that there were no differences in DE and ME between any of the fiber ingredients on d 7,14 or 21.However,fiber inclusion decreased the DE and ME of the diet(P<0.05)regardless of the time effect.Principal coordinate analysis(PCoA)revealed distinctly different microbial communities on the DFRB diet and SBH diet across different times(P<0.05)and the fecal microbiota of the 4 diet groups demonstrated notably distinct clusters at each time point(P<0.05).With adaptation time increased from 7 to 21 d,cellulose-degrading bacteria and SCFA-producing bacteria(e.g.,Ruminococcaceae_UCG-014,Rikenellaceae_RC9_gut_group and Bifidobacterium)increased in the fiber inclusion diets,and pathogenic genera(e.g.,Streptococcus and Selenomonas)were increased in the basal diet(P<0.05).Furthermore,the gut microbiota of growing pigs adapted more easily and quickly to the SBP diet compared to the DFRB diet,as reflected by the concentration of propionate,butyrate,isovalerate and total SCFA which increased with time for growing pigs fed the DFRB diet(P<0.05).Collectively,our results indicated at least 7 d adaptation was required to evaluate the energy values of fiber-rich ingredients,as the hindgut microbiota of growing pigs may need more time to adapt to a high fiber diet,especially for insoluble dietary fiber.展开更多
The objective of this study was to compare the energy values of high-fiber dietary ingredients with different solubility(sugar beet pulp[SBP]and defatted rice bran[DFRB])in growing pigs using the difference and the re...The objective of this study was to compare the energy values of high-fiber dietary ingredients with different solubility(sugar beet pulp[SBP]and defatted rice bran[DFRB])in growing pigs using the difference and the regression methods.A total of 21 barrows(initial BW,40.5±1.2 kg)were assigned to 3 blocks with BW as a blocking factor,and each block was assigned to a 7×2 incomplete Latin square design with 7 diets and two 13-d experimental periods.The 7 experimental diets consisted of a corn-soybean meal basal diet and 6 additional diets containing 10%,20%,or 30%SBP or DFRB in the basal diet,respectively.Each of the exper-imental periods lasted 12 d,with a 7 d dietary adaptation period followed by 5-d total fecal and urine collection.Results showed that the digestible energy(DE)and metabolizable energy(ME)of the SBP determined by the difference method with different inclusion levels(10%,20%,or 30%)were 2,712 and 2,628 kcal/kg,2,683 and 2,580 kcal/kg,and 2,643 and 2,554 kcal/kg DM basis,respectively.The DE and ME in the DFRB evaluated by the difference method with 3 different inclusion levels were 2,407 and 2,243 kcal/kg,2,687 and 2,598 kcal/kg,and 2,630 and 2,544 kcal/kg DM basis,respectively.Different inclusion levels had no effects on the energy values of each test ingredient estimated by the difference method.The DE and ME of the SBP and the DFRB estimated by the regression method were 2,562 and 2,472 kcal/kg and 2,685 and 2,606 kcal/kg DM basis,respectively.The energy values of each ingredient determined by the regression method were similar to the values estimated by the difference method with the 20%or 30%inclusion level.However,the energy values of the SBP and DFRB estimated by the difference method with the 10%inclusion level were inconsistent with the values determined by the regression method(P<0.05).In conclusion,the regression method was a robust indirect method to evaluate the energy values for high-fiber ingredients with different solubility in growing pigs.If the number of experimental animals was limited,the difference method with a moderate inclusion level(at least 20%)of the test high-fiber ingredient in the basal diet could be applied to substitute the regression method.展开更多
Owing to increasing environmental concerns and resource scarcity, integrated energy system shave become widely used in communities. Rural energy systems, as one of the important links of the energy network in China, s...Owing to increasing environmental concerns and resource scarcity, integrated energy system shave become widely used in communities. Rural energy systems, as one of the important links of the energy network in China, suffer from low energy efficiency and weak infrastructure. Therefore, it is particularly important to increase the proportion of electricity consumption and build an integrated energy system for rural electrification in China(IESREIC) with a rural distribution network as the core, in line with national conditions. In this study, by analyzing the Chinese regional differences and natural resource endowments, the development characteristics of the IESREIC are summarized. Then, according to the existing rural energy problems, key technologies are proposed for the IESREIC, such as those for planning and operation, value sharing, infrastructure, and a management and control platform. Finally, IESREIC demonstration projects and business models are introduced for agricultural production, rural industrial systems, and rural life. The purpose is to propose research concepts for the IESREIC, provide suggestions for the development of rural energy, and provide a reference for the construction of rural energy systems in countries with characteristics similar to those of China.展开更多
The paper analysed the current situation of municipal solid waste(MSW) quantity and quality in China and the changing tendencies of its composition. Further more, the energy value of MSW was discussed. To the point ...The paper analysed the current situation of municipal solid waste(MSW) quantity and quality in China and the changing tendencies of its composition. Further more, the energy value of MSW was discussed. To the point of the technical and economic aspects, the feasibility of the energy recovery from MSW was also analysed. The conclusion is that the energy can be effectively recovered through a landfill gas utilization process and the energy produced by an incineration process. Through a suitable energy recovery process, it is possible to improve the economic viability of a MSW treatment process.展开更多
In order to improve prediction accuracy of the grey prediction model and forecast China energy consumption and production in a short term, this paper proposes a novel com- prehensively optimized GM(1,1) model, also ...In order to improve prediction accuracy of the grey prediction model and forecast China energy consumption and production in a short term, this paper proposes a novel com- prehensively optimized GM(1,1) model, also named COGM(1,1), based on the grey modeling mechanism. First, the relationship of the background value formula and its whitenization equation is analyzed and a new method optimizing background values is proposed to eliminate systemic errors in the modeling process. Second, the solving process of the new model is derived. For parameter estimation, a set of auxiliary parameters are used to change grey equation's form. Then, original parameters are re- stored by an equations system. After solving the whitenization equation, initial value in time response function is established by least errors criteria. Finally, a numerical case and comparison with other grey prediction models are made to testify the new model's effectiveness, and the computational results show that the COGM(1,1) model has a better property and achieves higher precision. The new model is used to forecast China energy con- sumption and production, and the ability of energy self-sufficiency is further analyzed. Results indicate that gaps between consump- tion and production in future are predicted to decline.展开更多
The traditionally centralized approach of electricity networks is progressively undergoing a shift towards a decentralized, distributed structure. The local and crowd-based principle is transforming the existing suppl...The traditionally centralized approach of electricity networks is progressively undergoing a shift towards a decentralized, distributed structure. The local and crowd-based principle is transforming the existing supply chain and related activities into a value network (VN). Previous researches on crowd value network concepts focus on the activities of infrastructure and load management and neglect activities that generate collaboration. Collaboration with and within crowds particularly demands a different mindset and management of sharing values, information, benefit, and risks. Furthermore, these concepts must integrate technical, processual, and social aspects. Thus, this article proposes a holistic framework of electricity VN management for crowd energy. It redefines VN activities for infrastructure and load management while appending VN activities for social electricity handling. Additionally, the framework illustrates the interactions among these three elements and concludes with an adaption cycle for the crowd value network.展开更多
Transplutonium isotopes are scarce and need to be produced by irradiation in high flux reactors.However,their production is inefficient,and optimization studies are necessary.This study analyzes the physical nature of...Transplutonium isotopes are scarce and need to be produced by irradiation in high flux reactors.However,their production is inefficient,and optimization studies are necessary.This study analyzes the physical nature of transplutonium isotope produc-tion using ^(252)Cf,^(244)Cm,^(242)Cm,and ^(238)Pu as examples.Traditional methods based on the Monte Carlo burnup calculation have the limitations of many calculations and cannot analyze the individual energy intervals in detail;thus,they cannot sup-port the refined evaluation,screening,and optimization of the irradiation schemes.After understanding the physical nature and simplifying the complexity of the production process,we propose a rapid diagnostic method for evaluating radiation schemes based on the concepts“single energy interval value(SEIV)”and“energy spectrum total value(ESTV)”.The rapid diagnostic method not only avoids tedious burnup calculations,but also provides a direction for optimization.The optimal irradiation schemes for producing ^(252)Cf,^(244)Cm,^(242)Cm,and ^(238)Pu are determined based on a rapid diagnostic method.Optimal irradiation schemes can significantly improve production efficiency.Compared with the initial scheme,the optimal scheme improved the production efficiency of ^(238)Pu by 7.41 times;^(242)Cm,11.98 times;^(244)Cm,65.20 times;and ^(252)Cf,15.08 times.Thus,a refined analysis of transplutonium isotope production is conducted and provides a theoretical basis for improving production efficiency.展开更多
The single event effect of a silicon–germanium heterojunction bipolar transistor(SiGe HBT) was thoroughly investigated. By considering the worst bias condition, the sensitive area of the proposed device was scanned w...The single event effect of a silicon–germanium heterojunction bipolar transistor(SiGe HBT) was thoroughly investigated. By considering the worst bias condition, the sensitive area of the proposed device was scanned with a pulsed laser.With variation of the collector bias and pulsed laser incident energy, the single event transient of the SiGe HBT was studied.Moreover, the single event transient produced by laser irradiation at a wavelength of 532 nm was more pronounced than at a wavelength of 1064 nm. Finally, the impact of the equivalent linear energy transfer of the 1064 nm pulsed laser on the single event transient was qualitatively examined by performing technology computer-aided design simulations, and a good consistency between the experimental data and the simulated outcomes was attained.展开更多
Background: There are various fat sources with different energy values and fatty acid compositions that may affect growth performance and carcass composition of grow-finishing pigs. A higher net energy was recently re...Background: There are various fat sources with different energy values and fatty acid compositions that may affect growth performance and carcass composition of grow-finishing pigs. A higher net energy was recently reported in choice white grease compared with soybean oil. Therefore, two experiments were conducted to determine whether practical responses confirm that difference between choice white grease and soybean oil, and to extend the observations to other fat sources.Results: In Exp. 1, pigs fed fats had lower(P < 0.05) average daily feed intake in phase II and overall period,greater(P < 0.05) gain:feed in phase I, phase II, and overall period than pigs fed the control diet. Pigs fed fats tended(P = 0.057) to have thicker backfat depth at the last rib than those fed control. Pigs fed 6% fats had greater(P < 0.01) gain:feed in phase II and overall period than pigs fed 3% fats. During phase I, pigs fed choice white grease grew faster(P < 0.05) than pigs fed soybean oil. In Exp. 2, pigs fed dietary fats(soybean oil, choice white grease, animal-vegetable blend, palm oil, or tallow) had greater(P < 0.01) gain:feed in each phase and overall period, greater(P < 0.01) average daily gain in phase I, but lower(P < 0.01) average daily feed intake in phase II an overall than pigs fed the control diets. The choice white grease also increased(P < 0.05) average daily gain during phase I compared with soybean oil. Pigs fed palm oil had thicker(P < 0.05) backfat depth at the 10 thrib than those fed soybean oil, animal-vegetable blend, or tallow.Conclusions: Inclusion of 6% dietary fat improved feed efficiency of finishing pigs, while different fats produced different practical results that may be consistent with their different energy values. Results from the early stage indicate that dietary fats with relatively more saturated fatty acids may provide greater energy than those with relatively more unsaturated fatty acids for growing pigs.展开更多
The nutritive value of rangelands in Southern Darfur, Sudan could be improved by introduction and multiplication of nutritious forbs with the objective of increasing livestock production in the area. The present study...The nutritive value of rangelands in Southern Darfur, Sudan could be improved by introduction and multiplication of nutritious forbs with the objective of increasing livestock production in the area. The present study was conducted to evaluate the nutritive value and palatability of eleven range forbs collected at flowering stage from Gahzal Gawazat, Southern Darfur, Sudan using chemical analysis. The crude protein (CP) ranged from 6.8% in Oxygonum atriplicifolium with lowest digestible crude protein (DCP) 2.8% to 16.4% in Zornia diphylla with highest DCP 11.73%. The highest and the lowest crude fiber (CF) values were obtained in Commelina spp (56.4%) and Sesamum alatum (25.9%), respectively. NDF and DMI values were maximum and minimum for Zornia diphylla (44.9 and 2.67%) and Alysicarpus glumaceus (35.3 and 3.4%), respectively. The total digestible nutrients (TDN) ranged from 57.1% in Blepharis linariifolia to 69.3% in Tribulus terrestris with highest digestible energy (DE) in later while the lowest DE was obtained in Commelina spp (2.4%). The calculated in vitro organic matter digestibility (IVOMD) was highest for the Canavalia ensiformis (50.27%) and lowest value (43.17%) for Commelina spp. Zornia diphylla, Tribulus terrestris and Sesamum alatum showed highest nutritive value, while Alysicarpus glumaceus, Oldenlandia senegalensis and Chrozophora brocchiana showed highest palatability. It is concluded that these rangeland forbs are palatable and their CP and energy contents are sufficient to support different classes of livestock in South Darfur, Sudan.展开更多
In this paper, simulated experiment device of coal and gas outburst was employed to perform the experiment on gas-containing coal extrusion. In the experiment, coal surface cracks were observed with a high-speed camer...In this paper, simulated experiment device of coal and gas outburst was employed to perform the experiment on gas-containing coal extrusion. In the experiment, coal surface cracks were observed with a high-speed camera and then the images were processed by sketch. Based on the above description, the paper studied the fractal dimension values from different positions of coal surface as well as their changing laws with time. The results show that there is a growing parabola trend of crack dimension value in the process of coal extrusion. Accordingly, we drew the conclusion that extruded coal crack evolution is a process of fractal dimension value increase. On the basis of fractal dimension values taken from different parts of coal masses, a fractal dimension of the contour map was drawn. Thus, it is clear that the contour map involves different crack fractal dimension values from different positions. To be specific, where there are complicated force and violent movement in coal mass, there are higher fractal dimension values, i.e., the further the middle of observation surface is from the exit of coal mass, and the lower the fractal dimension value is. In line with fractal geometry and energy theory of coal and gas outburst, this study presents the relation between fractal dimension and energy in the process of extruding. In conclusion, the evolution of crack fractal dimension value can signify that of energy, which has laid a solid foundation for the quantification research on the mechanism of gas-containing coal extrusion.展开更多
Based on the theory of system energy-saving, a multilevel input-output computational model ot the iron and steel enterprise was established. And one example was calculated using this model to analyze the product energ...Based on the theory of system energy-saving, a multilevel input-output computational model ot the iron and steel enterprise was established. And one example was calculated using this model to analyze the product energy value, the process of energy consumption and energy consumption per ton of steel of an iron and steel enterprise. The influences of factory layout, steel ratio and production structure are calculated and analyzed. The calculation example indicates that reasonable factory layout is helpful to reduce its transportation energy consumption, decrease loss of heat, improve product rate and reduce environmental contamination; ore to steel ratio and iron to steel ratio decrease at the same degree; the influence of ore to steel ratio on energy intensity per ton is less than that of iron to steel ratio. The lord process product structure has a certain effect on comprehensive energy consumption per ton of steel.展开更多
The cost of feed represents an important part of the total cost in swine and poultry production(>60%)with energy accounting for at least 70%of feed cost.The energy value of ingredients or compound feeds can be esti...The cost of feed represents an important part of the total cost in swine and poultry production(>60%)with energy accounting for at least 70%of feed cost.The energy value of ingredients or compound feeds can be estimated as digestible(DE),metabolisable(ME)and net energy(NE)in pigs and ME and NE in poultry.The current paper reviews the different methods for evaluating DE,ME and NE of feeds for monogastric animals and their difficulties and limits,with a focus on NE.In pigs and poultry,energy digestibility depends on the chemical characteristics of the feed,but also on technology(pelleting,for instance)and animal factors such as their health and body weight.The ME value includes the energy losses in urine that are directly dependent on the proportion of dietary N excreted in urine resulting in the concept of ME adjusted for a zero N balance(MEn)in poultry.For poultry,the concept of true ME(TME,TMEn),which excludes the endogenous fecal and urinary energy losses from the excreta energy,was also developed.The measurement of dietary NE is more complex,and NE values of a given feed depend on the animal and environmental factors and also measurement and calculation methods.The combination of NE values of diets obtained under standardised conditions allows calculating NE prediction equations that are applicable to both ingredients and compound feeds.The abundance of energy concepts,especially for poultry,and the numerous feed and animal factors of variation related to energy digestibility or ME utilisation for NE suggest that attention must be paid to the experimental conditions for evaluating DE,ME or NE content.This also suggests the necessity of standardisations,one of them being,as implemented in pigs,an adjustment of ME values in poultry for an N retention representative of modern production conditions(MEs).In conclusion,this review illustrates that,in addition to numerous technical difficulties for evaluating energy in pigs and poultry,the absolute energy values depend on feed and animal factors,the environment,and the methods and concepts.Finally,as implemented in pigs,the use of NE values should be the objective of a more reliable energy system for poultry feeds.展开更多
It’s systematically analyzed that energy efficiency optimization technology has been applied in the field of steel industry. The fundamental principal of energy optimization technology is reasonably matching the qual...It’s systematically analyzed that energy efficiency optimization technology has been applied in the field of steel industry. The fundamental principal of energy optimization technology is reasonably matching the quality and price of energy as well as energy-dominated systematic energy efficiency management system. Specific measures of energy optimization have been put forward, which include taking high efficiency utilized technology such as energy saving from the original, the production process and recycling of waste heat and waste energy etc., integrating and configuring energy in an optimized way of high efficiency and excellent quality, fully realizing the function of different energy in order to optimize the utilization sequence of energy, and improving the energy medium system by themselves. Finally it is clearly pointed out that the steel industry should pay more consideration about the great deal of energy system which they have used now and an ideal energy evaluation methodology and standard should be built as soon as possible if they want to take full usage of the real role and function of energy in all aspects.展开更多
The effects of pH value on crystal size and optical property of zinc oxide nanoparticles prepared by chemical precipitation method were investigated.Prepared samples have been characterized by means of X-ray diffracti...The effects of pH value on crystal size and optical property of zinc oxide nanoparticles prepared by chemical precipitation method were investigated.Prepared samples have been characterized by means of X-ray diffraction,scanning electron microscopy,ultraviolet-visible spectrometer and photoluminescence spectrometer.From X-ray diffraction profile,it is found that the particle size of sample increases from 13.8 to 33 nm when the pH value of the solution was increased from 6 to 13.Microstructural study also shows that the particle size increases with pH value.Hexagonal shape of the zinc oxide nanoparticle has been confirmed by the scanning electron microscopy image.The recorded ultraviolet-visible spectrum shows excitonic absorption peaks around 381 nm.The energy gap of the prepared samples has been determined from the ultraviolet-visible absorption spectrum,effective mass model equation and Tauc's relation.It was found that the energy gap of the prepared samples decreases with increase in pH value.The recorded blue shift confirmed the quantum confinement effect in the prepared zinc oxide samples.Photoluminescence spectrum infers that the increase in pH value shifts the ultraviolet-visible emission but not the violet and green emissions.展开更多
基金This work was funded by Agricultural Science and Technology Innovation Program(ASTIP-IAS07)Guizhou Science and Technology Support Program(2021-149).
文摘This study was to investigate time-course effects of different types of dietary fiber on the energy values,fecal microbiota and short-chain fatty acid(SCFA)concentration in growing pigs.A total of 24 barrows(initial body weight,19.8±0.5 kg)were assigned to 4 dietary treatments based on body weight(BW)in a completely randomized design,including a basal diet(CON)and 3 fiber-rich diets replacing corn,soybean meal and soybean oil in the CON diet with 20%sugar beet pulp(SBP),defatted rice bran(DFRB)or soybean hull(SBH),respectively.Fresh feces were sampled on d 7,14 and 21,followed by 5 d total feces and urine collections.The results showed that there were no differences in DE and ME between any of the fiber ingredients on d 7,14 or 21.However,fiber inclusion decreased the DE and ME of the diet(P<0.05)regardless of the time effect.Principal coordinate analysis(PCoA)revealed distinctly different microbial communities on the DFRB diet and SBH diet across different times(P<0.05)and the fecal microbiota of the 4 diet groups demonstrated notably distinct clusters at each time point(P<0.05).With adaptation time increased from 7 to 21 d,cellulose-degrading bacteria and SCFA-producing bacteria(e.g.,Ruminococcaceae_UCG-014,Rikenellaceae_RC9_gut_group and Bifidobacterium)increased in the fiber inclusion diets,and pathogenic genera(e.g.,Streptococcus and Selenomonas)were increased in the basal diet(P<0.05).Furthermore,the gut microbiota of growing pigs adapted more easily and quickly to the SBP diet compared to the DFRB diet,as reflected by the concentration of propionate,butyrate,isovalerate and total SCFA which increased with time for growing pigs fed the DFRB diet(P<0.05).Collectively,our results indicated at least 7 d adaptation was required to evaluate the energy values of fiber-rich ingredients,as the hindgut microbiota of growing pigs may need more time to adapt to a high fiber diet,especially for insoluble dietary fiber.
基金the National Natural Science Foundation of China(31702119)Fundamental Research Funds for the Chinese Academy of Agricultural Sciences(2020-YWF-ZX-04)Agricultural Science and Technology Innovation Program(ASTIP-IAS07)
文摘The objective of this study was to compare the energy values of high-fiber dietary ingredients with different solubility(sugar beet pulp[SBP]and defatted rice bran[DFRB])in growing pigs using the difference and the regression methods.A total of 21 barrows(initial BW,40.5±1.2 kg)were assigned to 3 blocks with BW as a blocking factor,and each block was assigned to a 7×2 incomplete Latin square design with 7 diets and two 13-d experimental periods.The 7 experimental diets consisted of a corn-soybean meal basal diet and 6 additional diets containing 10%,20%,or 30%SBP or DFRB in the basal diet,respectively.Each of the exper-imental periods lasted 12 d,with a 7 d dietary adaptation period followed by 5-d total fecal and urine collection.Results showed that the digestible energy(DE)and metabolizable energy(ME)of the SBP determined by the difference method with different inclusion levels(10%,20%,or 30%)were 2,712 and 2,628 kcal/kg,2,683 and 2,580 kcal/kg,and 2,643 and 2,554 kcal/kg DM basis,respectively.The DE and ME in the DFRB evaluated by the difference method with 3 different inclusion levels were 2,407 and 2,243 kcal/kg,2,687 and 2,598 kcal/kg,and 2,630 and 2,544 kcal/kg DM basis,respectively.Different inclusion levels had no effects on the energy values of each test ingredient estimated by the difference method.The DE and ME of the SBP and the DFRB estimated by the regression method were 2,562 and 2,472 kcal/kg and 2,685 and 2,606 kcal/kg DM basis,respectively.The energy values of each ingredient determined by the regression method were similar to the values estimated by the difference method with the 20%or 30%inclusion level.However,the energy values of the SBP and DFRB estimated by the difference method with the 10%inclusion level were inconsistent with the values determined by the regression method(P<0.05).In conclusion,the regression method was a robust indirect method to evaluate the energy values for high-fiber ingredients with different solubility in growing pigs.If the number of experimental animals was limited,the difference method with a moderate inclusion level(at least 20%)of the test high-fiber ingredient in the basal diet could be applied to substitute the regression method.
基金supported by the National Natural Science Foundation of China(No.51977141)headquarters technology project of State Grid Corporation of China(No.5400-202025208A-0-0-00)
文摘Owing to increasing environmental concerns and resource scarcity, integrated energy system shave become widely used in communities. Rural energy systems, as one of the important links of the energy network in China, suffer from low energy efficiency and weak infrastructure. Therefore, it is particularly important to increase the proportion of electricity consumption and build an integrated energy system for rural electrification in China(IESREIC) with a rural distribution network as the core, in line with national conditions. In this study, by analyzing the Chinese regional differences and natural resource endowments, the development characteristics of the IESREIC are summarized. Then, according to the existing rural energy problems, key technologies are proposed for the IESREIC, such as those for planning and operation, value sharing, infrastructure, and a management and control platform. Finally, IESREIC demonstration projects and business models are introduced for agricultural production, rural industrial systems, and rural life. The purpose is to propose research concepts for the IESREIC, provide suggestions for the development of rural energy, and provide a reference for the construction of rural energy systems in countries with characteristics similar to those of China.
文摘The paper analysed the current situation of municipal solid waste(MSW) quantity and quality in China and the changing tendencies of its composition. Further more, the energy value of MSW was discussed. To the point of the technical and economic aspects, the feasibility of the energy recovery from MSW was also analysed. The conclusion is that the energy can be effectively recovered through a landfill gas utilization process and the energy produced by an incineration process. Through a suitable energy recovery process, it is possible to improve the economic viability of a MSW treatment process.
基金supported by the National Natural Science Foundation of China(710710777130106071371098)
文摘In order to improve prediction accuracy of the grey prediction model and forecast China energy consumption and production in a short term, this paper proposes a novel com- prehensively optimized GM(1,1) model, also named COGM(1,1), based on the grey modeling mechanism. First, the relationship of the background value formula and its whitenization equation is analyzed and a new method optimizing background values is proposed to eliminate systemic errors in the modeling process. Second, the solving process of the new model is derived. For parameter estimation, a set of auxiliary parameters are used to change grey equation's form. Then, original parameters are re- stored by an equations system. After solving the whitenization equation, initial value in time response function is established by least errors criteria. Finally, a numerical case and comparison with other grey prediction models are made to testify the new model's effectiveness, and the computational results show that the COGM(1,1) model has a better property and achieves higher precision. The new model is used to forecast China energy con- sumption and production, and the ability of energy self-sufficiency is further analyzed. Results indicate that gaps between consump- tion and production in future are predicted to decline.
文摘The traditionally centralized approach of electricity networks is progressively undergoing a shift towards a decentralized, distributed structure. The local and crowd-based principle is transforming the existing supply chain and related activities into a value network (VN). Previous researches on crowd value network concepts focus on the activities of infrastructure and load management and neglect activities that generate collaboration. Collaboration with and within crowds particularly demands a different mindset and management of sharing values, information, benefit, and risks. Furthermore, these concepts must integrate technical, processual, and social aspects. Thus, this article proposes a holistic framework of electricity VN management for crowd energy. It redefines VN activities for infrastructure and load management while appending VN activities for social electricity handling. Additionally, the framework illustrates the interactions among these three elements and concludes with an adaption cycle for the crowd value network.
基金sponsored by Natural Science Foundation of Shanghai (NO.22ZR1431900)Science and Technology on Reactor System Design Technology Laboratory.
文摘Transplutonium isotopes are scarce and need to be produced by irradiation in high flux reactors.However,their production is inefficient,and optimization studies are necessary.This study analyzes the physical nature of transplutonium isotope produc-tion using ^(252)Cf,^(244)Cm,^(242)Cm,and ^(238)Pu as examples.Traditional methods based on the Monte Carlo burnup calculation have the limitations of many calculations and cannot analyze the individual energy intervals in detail;thus,they cannot sup-port the refined evaluation,screening,and optimization of the irradiation schemes.After understanding the physical nature and simplifying the complexity of the production process,we propose a rapid diagnostic method for evaluating radiation schemes based on the concepts“single energy interval value(SEIV)”and“energy spectrum total value(ESTV)”.The rapid diagnostic method not only avoids tedious burnup calculations,but also provides a direction for optimization.The optimal irradiation schemes for producing ^(252)Cf,^(244)Cm,^(242)Cm,and ^(238)Pu are determined based on a rapid diagnostic method.Optimal irradiation schemes can significantly improve production efficiency.Compared with the initial scheme,the optimal scheme improved the production efficiency of ^(238)Pu by 7.41 times;^(242)Cm,11.98 times;^(244)Cm,65.20 times;and ^(252)Cf,15.08 times.Thus,a refined analysis of transplutonium isotope production is conducted and provides a theoretical basis for improving production efficiency.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61574171, 61704127, 11875229,51872251, and 12027813)。
文摘The single event effect of a silicon–germanium heterojunction bipolar transistor(SiGe HBT) was thoroughly investigated. By considering the worst bias condition, the sensitive area of the proposed device was scanned with a pulsed laser.With variation of the collector bias and pulsed laser incident energy, the single event transient of the SiGe HBT was studied.Moreover, the single event transient produced by laser irradiation at a wavelength of 532 nm was more pronounced than at a wavelength of 1064 nm. Finally, the impact of the equivalent linear energy transfer of the 1064 nm pulsed laser on the single event transient was qualitatively examined by performing technology computer-aided design simulations, and a good consistency between the experimental data and the simulated outcomes was attained.
文摘Background: There are various fat sources with different energy values and fatty acid compositions that may affect growth performance and carcass composition of grow-finishing pigs. A higher net energy was recently reported in choice white grease compared with soybean oil. Therefore, two experiments were conducted to determine whether practical responses confirm that difference between choice white grease and soybean oil, and to extend the observations to other fat sources.Results: In Exp. 1, pigs fed fats had lower(P < 0.05) average daily feed intake in phase II and overall period,greater(P < 0.05) gain:feed in phase I, phase II, and overall period than pigs fed the control diet. Pigs fed fats tended(P = 0.057) to have thicker backfat depth at the last rib than those fed control. Pigs fed 6% fats had greater(P < 0.01) gain:feed in phase II and overall period than pigs fed 3% fats. During phase I, pigs fed choice white grease grew faster(P < 0.05) than pigs fed soybean oil. In Exp. 2, pigs fed dietary fats(soybean oil, choice white grease, animal-vegetable blend, palm oil, or tallow) had greater(P < 0.01) gain:feed in each phase and overall period, greater(P < 0.01) average daily gain in phase I, but lower(P < 0.01) average daily feed intake in phase II an overall than pigs fed the control diets. The choice white grease also increased(P < 0.05) average daily gain during phase I compared with soybean oil. Pigs fed palm oil had thicker(P < 0.05) backfat depth at the 10 thrib than those fed soybean oil, animal-vegetable blend, or tallow.Conclusions: Inclusion of 6% dietary fat improved feed efficiency of finishing pigs, while different fats produced different practical results that may be consistent with their different energy values. Results from the early stage indicate that dietary fats with relatively more saturated fatty acids may provide greater energy than those with relatively more unsaturated fatty acids for growing pigs.
文摘The nutritive value of rangelands in Southern Darfur, Sudan could be improved by introduction and multiplication of nutritious forbs with the objective of increasing livestock production in the area. The present study was conducted to evaluate the nutritive value and palatability of eleven range forbs collected at flowering stage from Gahzal Gawazat, Southern Darfur, Sudan using chemical analysis. The crude protein (CP) ranged from 6.8% in Oxygonum atriplicifolium with lowest digestible crude protein (DCP) 2.8% to 16.4% in Zornia diphylla with highest DCP 11.73%. The highest and the lowest crude fiber (CF) values were obtained in Commelina spp (56.4%) and Sesamum alatum (25.9%), respectively. NDF and DMI values were maximum and minimum for Zornia diphylla (44.9 and 2.67%) and Alysicarpus glumaceus (35.3 and 3.4%), respectively. The total digestible nutrients (TDN) ranged from 57.1% in Blepharis linariifolia to 69.3% in Tribulus terrestris with highest digestible energy (DE) in later while the lowest DE was obtained in Commelina spp (2.4%). The calculated in vitro organic matter digestibility (IVOMD) was highest for the Canavalia ensiformis (50.27%) and lowest value (43.17%) for Commelina spp. Zornia diphylla, Tribulus terrestris and Sesamum alatum showed highest nutritive value, while Alysicarpus glumaceus, Oldenlandia senegalensis and Chrozophora brocchiana showed highest palatability. It is concluded that these rangeland forbs are palatable and their CP and energy contents are sufficient to support different classes of livestock in South Darfur, Sudan.
基金the National Natural Science Foundation of China (Nos. 50904067 and 51104156)the New Century Excellent Talents in University (No. NCET-10-0768) for their support of this project
文摘In this paper, simulated experiment device of coal and gas outburst was employed to perform the experiment on gas-containing coal extrusion. In the experiment, coal surface cracks were observed with a high-speed camera and then the images were processed by sketch. Based on the above description, the paper studied the fractal dimension values from different positions of coal surface as well as their changing laws with time. The results show that there is a growing parabola trend of crack dimension value in the process of coal extrusion. Accordingly, we drew the conclusion that extruded coal crack evolution is a process of fractal dimension value increase. On the basis of fractal dimension values taken from different parts of coal masses, a fractal dimension of the contour map was drawn. Thus, it is clear that the contour map involves different crack fractal dimension values from different positions. To be specific, where there are complicated force and violent movement in coal mass, there are higher fractal dimension values, i.e., the further the middle of observation surface is from the exit of coal mass, and the lower the fractal dimension value is. In line with fractal geometry and energy theory of coal and gas outburst, this study presents the relation between fractal dimension and energy in the process of extruding. In conclusion, the evolution of crack fractal dimension value can signify that of energy, which has laid a solid foundation for the quantification research on the mechanism of gas-containing coal extrusion.
基金Item Sponsored by National Science and Technology Support Plan(863)of China(2008AA042901)
文摘Based on the theory of system energy-saving, a multilevel input-output computational model ot the iron and steel enterprise was established. And one example was calculated using this model to analyze the product energy value, the process of energy consumption and energy consumption per ton of steel of an iron and steel enterprise. The influences of factory layout, steel ratio and production structure are calculated and analyzed. The calculation example indicates that reasonable factory layout is helpful to reduce its transportation energy consumption, decrease loss of heat, improve product rate and reduce environmental contamination; ore to steel ratio and iron to steel ratio decrease at the same degree; the influence of ore to steel ratio on energy intensity per ton is less than that of iron to steel ratio. The lord process product structure has a certain effect on comprehensive energy consumption per ton of steel.
文摘The cost of feed represents an important part of the total cost in swine and poultry production(>60%)with energy accounting for at least 70%of feed cost.The energy value of ingredients or compound feeds can be estimated as digestible(DE),metabolisable(ME)and net energy(NE)in pigs and ME and NE in poultry.The current paper reviews the different methods for evaluating DE,ME and NE of feeds for monogastric animals and their difficulties and limits,with a focus on NE.In pigs and poultry,energy digestibility depends on the chemical characteristics of the feed,but also on technology(pelleting,for instance)and animal factors such as their health and body weight.The ME value includes the energy losses in urine that are directly dependent on the proportion of dietary N excreted in urine resulting in the concept of ME adjusted for a zero N balance(MEn)in poultry.For poultry,the concept of true ME(TME,TMEn),which excludes the endogenous fecal and urinary energy losses from the excreta energy,was also developed.The measurement of dietary NE is more complex,and NE values of a given feed depend on the animal and environmental factors and also measurement and calculation methods.The combination of NE values of diets obtained under standardised conditions allows calculating NE prediction equations that are applicable to both ingredients and compound feeds.The abundance of energy concepts,especially for poultry,and the numerous feed and animal factors of variation related to energy digestibility or ME utilisation for NE suggest that attention must be paid to the experimental conditions for evaluating DE,ME or NE content.This also suggests the necessity of standardisations,one of them being,as implemented in pigs,an adjustment of ME values in poultry for an N retention representative of modern production conditions(MEs).In conclusion,this review illustrates that,in addition to numerous technical difficulties for evaluating energy in pigs and poultry,the absolute energy values depend on feed and animal factors,the environment,and the methods and concepts.Finally,as implemented in pigs,the use of NE values should be the objective of a more reliable energy system for poultry feeds.
文摘It’s systematically analyzed that energy efficiency optimization technology has been applied in the field of steel industry. The fundamental principal of energy optimization technology is reasonably matching the quality and price of energy as well as energy-dominated systematic energy efficiency management system. Specific measures of energy optimization have been put forward, which include taking high efficiency utilized technology such as energy saving from the original, the production process and recycling of waste heat and waste energy etc., integrating and configuring energy in an optimized way of high efficiency and excellent quality, fully realizing the function of different energy in order to optimize the utilization sequence of energy, and improving the energy medium system by themselves. Finally it is clearly pointed out that the steel industry should pay more consideration about the great deal of energy system which they have used now and an ideal energy evaluation methodology and standard should be built as soon as possible if they want to take full usage of the real role and function of energy in all aspects.
文摘The effects of pH value on crystal size and optical property of zinc oxide nanoparticles prepared by chemical precipitation method were investigated.Prepared samples have been characterized by means of X-ray diffraction,scanning electron microscopy,ultraviolet-visible spectrometer and photoluminescence spectrometer.From X-ray diffraction profile,it is found that the particle size of sample increases from 13.8 to 33 nm when the pH value of the solution was increased from 6 to 13.Microstructural study also shows that the particle size increases with pH value.Hexagonal shape of the zinc oxide nanoparticle has been confirmed by the scanning electron microscopy image.The recorded ultraviolet-visible spectrum shows excitonic absorption peaks around 381 nm.The energy gap of the prepared samples has been determined from the ultraviolet-visible absorption spectrum,effective mass model equation and Tauc's relation.It was found that the energy gap of the prepared samples decreases with increase in pH value.The recorded blue shift confirmed the quantum confinement effect in the prepared zinc oxide samples.Photoluminescence spectrum infers that the increase in pH value shifts the ultraviolet-visible emission but not the violet and green emissions.