[Objective] In this study, the performance and blood biochemical indices in lamps fed on milk replacer were researched, the feasibility of early weaned in lamps was discussed. [Method] 37 of 10 days lambs of Suffolk...[Objective] In this study, the performance and blood biochemical indices in lamps fed on milk replacer were researched, the feasibility of early weaned in lamps was discussed. [Method] 37 of 10 days lambs of Suffolk(♂) x XiaoWeiHanYang( ♀ ) were randomly divided into group A, B, C, D for this experiment. Group A, B, C were fed by 3 milk-replacers containing milk for different protein source respectively, and ten Iambs in each group; group D (seven lambs) were fed by ewes as the control. The performance and blood biochemical indices of the lamps were determined. [ Result] The results showed that the average daily gains of 10 - 15 days of age was not significantly different between group A and D ( P 〉 O. 05 ), the control were higher significandy than the group B,C (P 〈0.05). The average daily gains of 16 -25, 26 -35 days of age were not significantly different in group A, B, C, D. The daily weight gains of Group A, B, C in 45 - 55 days of age were higher significantly than the control (P〈0.05 ). Plasma urea nitrogen (PUN) of group B and C were higher than group A significantly (P〈0.05 ) ;Total protein ( TP), Plasma albumin (ALB) and Plasma total amino acid were no significant difference among the other 3 groups (P〉0.05 ). [Conclusion] So, the milk-replacers were available for early-weaned lamb.展开更多
[Objective] This study aimed to investigate the effects of different padding on ammonia concentration in broiler house and growth performance and blood indi- cators of broilers. [Method] A total of 480 one-day-old 817...[Objective] This study aimed to investigate the effects of different padding on ammonia concentration in broiler house and growth performance and blood indi- cators of broilers. [Method] A total of 480 one-day-old 817 broilers were selected. They were randomly divided into four groups with different paddings, and each group was in triplicate. The weights of broilers and feed were weighed weekly. The growth performance of broilers was determined. On day 30, the ammonia concentra- tions in broiler houses were determined. On day 35, 6 broilers were randomly se- lected from each group, and their vein blood was sampled. In the sampled vein blood, the concentrations of ammonia, glucose, globulin, serum total protein and urea nitrogen were determined. [Result] There were significant differences in ammo- nia concentration among broiler houses laid with different paddings (P〈0.05). The ammonia concentration in group 1 was significantly lower than those in group 3 and group 4 (P〈0.05). No significant difference was found in ammonia concentrations in broiler houses between group 2 and group 3 (P〉0.05). The ammonia concentration in group 4 was significantly higher than those in group1, group 2 and group 3 (,0〈 0.05). There were also significant differences in blood indicators among different groups (P〈0.05). The blood ammonia, blood glucose and serum urea nitrogen con- centrations in group 1 were significantly lower than those in other groups (P〈0.05), the serum total protein concentration was significantly higher than those in group 3 and group 4 (P〈0.05), and the serum globulin concentration was significantly higher than those in group 2, group 3 and group 4 (P〈0.05). Significant differences were observed in feed intake, body weight gain and slaughter weight between different groups (P〈0.05), but there were no significant differences in feed to grain ratio (P〉 0.05). [Conclusion] Under the experimental conditions, the padding of Chinese medicine residue showed better effect on reducing ammonia concentration in broiler house, which was conducive to play of production potential of broilers.展开更多
In order to investigate the effects of probiotics on growth performance, blood biochemical indexes and economic benefits of Cherry Valley ducks, different probiotics were added into the feed of Cherry Valley ducks. To...In order to investigate the effects of probiotics on growth performance, blood biochemical indexes and economic benefits of Cherry Valley ducks, different probiotics were added into the feed of Cherry Valley ducks. Total 240 1-d-old Cherry Valley ducks were selected, and they were randomly divided into 4 groups, including 1 control group and 3 treatment groups. There were 3 replicates for each group and there were 20 ducks for each replicate. The ducks in the control group were fed the basal diet, and the ducks in the 3 treatment groups were fed the basal diet added with Lactobacillus, Bacillus natto and florfenicol, respectively. The test lasted for 42 d. The results showed that the addition of Lactobacillus and Bacillus natto could improve the average daily weight gain and final average weight (P〈0.05) of Cherry Valley ducks, and reduce the glutamic-pyruvic transaminase ac- tivity, alkaline phosphatase activity and serum urinary nitrogen content in duck blood (P〈0.05) and reduce the creatinine content and total cholesterol content in Cherry Valley ducks (P〉0.05); at the same time, adding probiotics to feed could also in- crease the grass economic benefits of Cherry Valley ducks. In overall, the effects of adding probiotics were better than those of adding antibiotic.展开更多
Validating simulation model is one of the important aspects for modeling and simulation. Some methods of validating model are compared and analyzed. Several typical methods, such as TIC’s inequality coefficient, gray...Validating simulation model is one of the important aspects for modeling and simulation. Some methods of validating model are compared and analyzed. Several typical methods, such as TIC’s inequality coefficient, gray interconnected analysis, direct spectrum estimation, maximum entropy spectral estimation based on Burg or Marple, are chosen and programmed in C language. Some examples by using the program are given. The results show that the program is available and it is best to adopt multi methods for validating models.展开更多
[Objective] This study aimed to investigate the functions and properties of the preliminarily determined characteristics listed in DUS test guideline of Tagetes L., and explore the representativeness and comprehensive...[Objective] This study aimed to investigate the functions and properties of the preliminarily determined characteristics listed in DUS test guideline of Tagetes L., and explore the representativeness and comprehensiveness of this group of characteristics in DUS test. [Method] Based on the functions and properties of the characteristics, the described plant part (s), observation stage, expression pattern and observation method of each characteristic were analyzed to illustrate the representativeness and comprehensiveness of the combination of this group of characteristics in above functions and properties. [Result] As for described plant part(s), there are 5 characteristics describing plant as a whole, 3 characteristics describing stem, 6 characteristics describing leaf, 23 characteristics describing flower and 1 characteristic describing physiological feature. As for observation stage, there are 1 characteristic needing to be observed in the stage of seedling, 1 characteristic in the stage of beginning of flowering and other 36 characteristics in the stage of fully flowering. As for the expression pattern, there are 10 qualitative characteristics, 9 pseudo-qualitative characteristics and 19 quantitative characteristics. As for the observation method, there are 30 characteristics using VG as the observation method, and 8 characteristics using MS. [Conclusion] In view of the variation and morphological properties of marigold, this group of characteristics are representative and comprehensive, and ensure the accuracy and easiness of DUS test of Tagetes L., thereby achieving the reasonable combination of characteristics in described plant parts, observation stages, expression patterns and observation methods.展开更多
We apply reweighted inversion focusing to full tensor gravity gradiometry data using message-passing interface (MPI) and compute unified device architecture (CUDA) parallel computing algorithms, and then combine M...We apply reweighted inversion focusing to full tensor gravity gradiometry data using message-passing interface (MPI) and compute unified device architecture (CUDA) parallel computing algorithms, and then combine MPI with CUDA to formulate a hybrid algorithm. Parallel computing performance metrics are introduced to analyze and compare the performance of the algorithms. We summarize the rules for the performance evaluation of parallel algorithms. We use model and real data from the Vinton salt dome to test the algorithms. We find good match between model efficiency and feasibility of parallel computing gravity gradiometry data. and real density data, and verify the high algorithms in the inversion of full tensor展开更多
[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved re...[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved recently were taken as materials and relationship of plant characters including bud living rate and moth- er stem emergence rate of ratoon rice before harvest was explored, based on relat- ed data. [Result] The shorter rice with lower harvesting index is the main character of high emergence rate for first cropping rice; decline of plant height and increase of ear-bearing percentage would improve emergence of regenerative seedlings. [Conclusion] The research provided scientific reference for breeding of rice cultivars with high regenerative capacity.展开更多
The deformation performance index limits of high reinforced concrete (RC) shear wall components based on Chinese codes were discussed by the nonlinear finite element method. Two typical RC shear wall specimens in th...The deformation performance index limits of high reinforced concrete (RC) shear wall components based on Chinese codes were discussed by the nonlinear finite element method. Two typical RC shear wall specimens in the previous work were first used to verify the correctness of the nonlinear finite element method. Then, the nonlinear finite element method was applied to study the deformability of a set of high RC shear wall components designed according to current Chinese codes and with shear span ratio λ≥2.0. Parametric studies were made on the influence of shear span ratio, axial compression ratio, ratio of flexural capacity to shear capacity and main flexural reinforcement ratio of confined botmdary members. Finally, the deformation performance index and its limits of high RC shear wall components under severe earthquakes were proposed by the finite element model results, which offers a reference in determining the performance status of RC shear wall components designed based on Chinese codes.展开更多
In order to establish the quantitative relationship between equivalent strain and the performance index of the deformed material within the range of certain passes for equal channel angular processing (ECAP), a new ...In order to establish the quantitative relationship between equivalent strain and the performance index of the deformed material within the range of certain passes for equal channel angular processing (ECAP), a new approach to characterize the equivalent strain was proposed. The results show that there exists better accordance between mechanical property (such as hardness or strength) and equivalent strain after rolling and ECAP in a certain range of deformation amount, and Gauss equation can be satisfied among the equivalent strain and the mechanical properties for ECAP. Through regression analysis on the data of hardness and strength after the deformation, a more generalized expression of equivalent strain for ECAP is proposed as:ε=k0exp[-(k1M-k2)^2], where M is the strength or hardness of the material, k1 is the modified coefficient (k1∈ (0, 1)), ko and k2 are two parameters dependent on the critical strain and mechanical property that reaches saturation state for the material, respectively. In this expression the equivalent strain for ECAP is characterized novelly through the mechanical parameter relating to material property rather than the classical geometry equation.展开更多
The avian magnetic compass was analyzed in bird species of three different orders - Passeriforms, Columbiforms and Galliforms - and in three different behavioral contexts, namely migratory orientation, homing and dire...The avian magnetic compass was analyzed in bird species of three different orders - Passeriforms, Columbiforms and Galliforms - and in three different behavioral contexts, namely migratory orientation, homing and directional conditioning. The respective findings indicate similar functional properties: it is an inclination compass that works only within a functional window around the ambient magnetic field intensity; it tends to be lateralized in favor of the fight eye, and it is wavelength-dependent, requiring light from the short-wavelength range of the spectrum. The underlying physical mechanisms have been identified as radical pair processes, spin-chemical reactions in specialized photopigments. The iron-based receptors in the upper beak do not seem to be involved. The existence of the same type of magnetic compass in only very distantly related bird species suggests that it may have been present already in the common ancestors of all modem birds, where it evolved as an all-purpose compass mechanism for orientation within the home range [Current Zoology 56 (3): 265-276, 2010].展开更多
A novel chaotic search method is proposed,and a hybrid algorithm combining particle swarm optimization(PSO) with this new method,called CLSPSO,is put forward to solve 14 integer and mixed integer programming problems....A novel chaotic search method is proposed,and a hybrid algorithm combining particle swarm optimization(PSO) with this new method,called CLSPSO,is put forward to solve 14 integer and mixed integer programming problems.The performances of CLSPSO are compared with those of other five hybrid algorithms combining PSO with chaotic search methods.Experimental results indicate that in terms of robustness and final convergence speed,CLSPSO is better than other five algorithms in solving many of these problems.Furthermore,CLSPSO exhibits good performance in solving two high-dimensional problems,and it finds better solutions than the known ones.A performance index(PI) is introduced to fairly compare the above six algorithms,and the obtained values of(PI) in three cases demonstrate that CLSPSO is superior to all the other five algorithms under the same conditions.展开更多
Fast growth of mobile internet and internet-of-things has propelled the concept formation and research on 5G wireless communications systems which are to be standardized around 2020(IMT-2020).There will be diverse app...Fast growth of mobile internet and internet-of-things has propelled the concept formation and research on 5G wireless communications systems which are to be standardized around 2020(IMT-2020).There will be diverse application scenarios expected for 5G networks.Hence,key performance indicators(KPIs) of 5G systems would be very diverse,not just the peak data rate and average/edge spectral efficiency requirements as in previous generations.For each typical scenario,multiple technologies may be used independently or jointly to improve the transmission efficiency,to lower the cost,and to increase the number of connections,etc.Key enabling technologies are discussed which include massive MIMO,ultradense deployment specific techniques,nonorthogonal transmission,high frequency communications,etc.展开更多
With the development of high-speed and heavy-haul railway in China, problems like insufficient thickness of ballast bed and overlarge track stiffness are obvious. Ballast may break into small particles and their conta...With the development of high-speed and heavy-haul railway in China, problems like insufficient thickness of ballast bed and overlarge track stiffness are obvious. Ballast may break into small particles and their contact status will deteriorate under cyclic loading, resulting in ballast degradation. Discrete element method(DEM) was used to research improved performance of ballast bed using elastic sleeper. Clusters were generated by bonding spheres to model real ballasts, while broken bonds were utilized to distinguish breakage. Two kinds of ballast beds with elastic sleeper and conventional sleeper were established, respectively. After applying cyclic loading to the models, differences of mechanical properties between two models were analyzed by contrasting their dynamic behavior indexes, such as particle contact force, sleeper settlement, vibration velocity and acceleration, breakage characteristic. The results illustrate that compared with conventional sleeper, elastic sleeper increases sleeper settlement, while reduces ballast vibration and contact force between particles, which could depress ballast breakage.展开更多
The majority of existing papers about spectrum sensing have the assumption that secondary users(SUs) are stationary. However,mobility is an essential feature of mobile communications networks. In this paper,the detect...The majority of existing papers about spectrum sensing have the assumption that secondary users(SUs) are stationary. However,mobility is an essential feature of mobile communications networks. In this paper,the detection performance of spectrum sensing by mobile SUs was analyzed. Three performance metrics,i.e.,detection probability,miss detection probability and false alarm probability,were thoroughly investigated. In our analysis,a critical variable was the real-time received primary user signal power by a mobile SU. Its probability distribution and mathematical expectation were analytically derived. Moreover,the three performance metrics in single-node spectrum sensing and multi-node collaborative spectrum sensing systems were also derived. Extensive simulations were performed. The results are consistent with the theoretical analysis. And it is concluded that SU mobility has a significant impact on the detection probability and the miss detection probability,but not on the false alarm probability.展开更多
This paper presents a method for solving the attitude control problem of high altitude airship (HAA) with aerodynamic fin and vectored thruster control. The algorithm is based on the synthetic optimization of dynamic ...This paper presents a method for solving the attitude control problem of high altitude airship (HAA) with aerodynamic fin and vectored thruster control. The algorithm is based on the synthetic optimization of dynamic performance and energy consumption of airship. Firstly, according to the system overall configuration, the dynamic model of HAA was established and the HAA linearized model of longitudinal plane motion was obtained. Secondly, using the classic PID control theory, the HAA attitude control system was designed. Thirdly, through analyzing the dynamic performance of airship with fin or vectored thruster control, the synthetic performance index function with different weighting functions was determined. By means of optimizing the obtained performance index function, the attitude control of high altitude airship with good dynamic performance and low energy consumption was achieved. Finally, attitude control allocation strategy was designed for the airship station keeping at an altitude of 22 km. The simulation experiment proved the validity of the proposed algorithm.展开更多
The temperature of a solar cell subjected to the incident global solar radiation as a function of the local day time is determined. A heat balance equation is solved considering the heat losses due to convection and t...The temperature of a solar cell subjected to the incident global solar radiation as a function of the local day time is determined. A heat balance equation is solved considering the heat losses due to convection and thermal radiation. The cell efficiency is estimated as a measure of its performance. The results reveal that the temperature within the cell attains significant values. Nevertheless, the temperature dependence of its efficiency along the day time is not pronouncing. It slightly decreases with temperature.展开更多
The glass forming ability, thermal and mechanical properties of some Zr Cu Al Ni bulk metallic glasses were analyzed. The compositions of the alloys were theoretically determined with the dense packing and kinetic fra...The glass forming ability, thermal and mechanical properties of some Zr Cu Al Ni bulk metallic glasses were analyzed. The compositions of the alloys were theoretically determined with the dense packing and kinetic fragility index models. Cylindrical and conical ingots were produced by copper mould suction-casting under Ar atmosphere. The conical ingots were characterized by means of X-ray diffraction in order to determine the glassy structure. It was found that both alloys have a critical glassy diameter, Dc, of 3 mm. Thermal behaviours were investigated by differential scanning calorimetry at heating rates of 0.5, 0.67 and 0.83 K/s. The gamma parameter γ, supercooled liquid region ΔTx, and reduced glass transition temperature Trg, of the experimentally obtained glasses indicated high glass forming ability. The glassy compositions showed a fragility index of ~40 GPa. The compression test of the investigated alloys was carried out at a strain rate of 0.016 s^-1, obtaining a elastic modulus of ~83 GPa, total deformation of ~5%, yield strength of 1.6 GPa and hardness of 4 GPa. It was concluded that the use of the dense packing and kinetic fragility index models helped to predict glass-forming compositions in the family alloy investigated.展开更多
基金Supported by Span Program of Ministry of Agriculture(KY2001-15)~~
文摘[Objective] In this study, the performance and blood biochemical indices in lamps fed on milk replacer were researched, the feasibility of early weaned in lamps was discussed. [Method] 37 of 10 days lambs of Suffolk(♂) x XiaoWeiHanYang( ♀ ) were randomly divided into group A, B, C, D for this experiment. Group A, B, C were fed by 3 milk-replacers containing milk for different protein source respectively, and ten Iambs in each group; group D (seven lambs) were fed by ewes as the control. The performance and blood biochemical indices of the lamps were determined. [ Result] The results showed that the average daily gains of 10 - 15 days of age was not significantly different between group A and D ( P 〉 O. 05 ), the control were higher significandy than the group B,C (P 〈0.05). The average daily gains of 16 -25, 26 -35 days of age were not significantly different in group A, B, C, D. The daily weight gains of Group A, B, C in 45 - 55 days of age were higher significantly than the control (P〈0.05 ). Plasma urea nitrogen (PUN) of group B and C were higher than group A significantly (P〈0.05 ) ;Total protein ( TP), Plasma albumin (ALB) and Plasma total amino acid were no significant difference among the other 3 groups (P〉0.05 ). [Conclusion] So, the milk-replacers were available for early-weaned lamb.
基金Supported by Innovation Project for Universities and Research Institutes in Jinan City(201303053)Shandong Provincial Science and Technology Plan Project(2014GGH210001)Program of Animal Husbandry and Veterinary Bureau of Shandong Province~~
文摘[Objective] This study aimed to investigate the effects of different padding on ammonia concentration in broiler house and growth performance and blood indi- cators of broilers. [Method] A total of 480 one-day-old 817 broilers were selected. They were randomly divided into four groups with different paddings, and each group was in triplicate. The weights of broilers and feed were weighed weekly. The growth performance of broilers was determined. On day 30, the ammonia concentra- tions in broiler houses were determined. On day 35, 6 broilers were randomly se- lected from each group, and their vein blood was sampled. In the sampled vein blood, the concentrations of ammonia, glucose, globulin, serum total protein and urea nitrogen were determined. [Result] There were significant differences in ammo- nia concentration among broiler houses laid with different paddings (P〈0.05). The ammonia concentration in group 1 was significantly lower than those in group 3 and group 4 (P〈0.05). No significant difference was found in ammonia concentrations in broiler houses between group 2 and group 3 (P〉0.05). The ammonia concentration in group 4 was significantly higher than those in group1, group 2 and group 3 (,0〈 0.05). There were also significant differences in blood indicators among different groups (P〈0.05). The blood ammonia, blood glucose and serum urea nitrogen con- centrations in group 1 were significantly lower than those in other groups (P〈0.05), the serum total protein concentration was significantly higher than those in group 3 and group 4 (P〈0.05), and the serum globulin concentration was significantly higher than those in group 2, group 3 and group 4 (P〈0.05). Significant differences were observed in feed intake, body weight gain and slaughter weight between different groups (P〈0.05), but there were no significant differences in feed to grain ratio (P〉 0.05). [Conclusion] Under the experimental conditions, the padding of Chinese medicine residue showed better effect on reducing ammonia concentration in broiler house, which was conducive to play of production potential of broilers.
基金Supported by Project of Jiangsu Agri-animal Husbandry Vocational College(NSFZN1309)~~
文摘In order to investigate the effects of probiotics on growth performance, blood biochemical indexes and economic benefits of Cherry Valley ducks, different probiotics were added into the feed of Cherry Valley ducks. Total 240 1-d-old Cherry Valley ducks were selected, and they were randomly divided into 4 groups, including 1 control group and 3 treatment groups. There were 3 replicates for each group and there were 20 ducks for each replicate. The ducks in the control group were fed the basal diet, and the ducks in the 3 treatment groups were fed the basal diet added with Lactobacillus, Bacillus natto and florfenicol, respectively. The test lasted for 42 d. The results showed that the addition of Lactobacillus and Bacillus natto could improve the average daily weight gain and final average weight (P〈0.05) of Cherry Valley ducks, and reduce the glutamic-pyruvic transaminase ac- tivity, alkaline phosphatase activity and serum urinary nitrogen content in duck blood (P〈0.05) and reduce the creatinine content and total cholesterol content in Cherry Valley ducks (P〉0.05); at the same time, adding probiotics to feed could also in- crease the grass economic benefits of Cherry Valley ducks. In overall, the effects of adding probiotics were better than those of adding antibiotic.
文摘Validating simulation model is one of the important aspects for modeling and simulation. Some methods of validating model are compared and analyzed. Several typical methods, such as TIC’s inequality coefficient, gray interconnected analysis, direct spectrum estimation, maximum entropy spectral estimation based on Burg or Marple, are chosen and programmed in C language. Some examples by using the program are given. The results show that the program is available and it is best to adopt multi methods for validating models.
基金Supported by Special R&D Fund for National Public Service Sectors(Agriculture)of China(200903008-14)National 948 Project of China(2009-Z11)~~
文摘[Objective] This study aimed to investigate the functions and properties of the preliminarily determined characteristics listed in DUS test guideline of Tagetes L., and explore the representativeness and comprehensiveness of this group of characteristics in DUS test. [Method] Based on the functions and properties of the characteristics, the described plant part (s), observation stage, expression pattern and observation method of each characteristic were analyzed to illustrate the representativeness and comprehensiveness of the combination of this group of characteristics in above functions and properties. [Result] As for described plant part(s), there are 5 characteristics describing plant as a whole, 3 characteristics describing stem, 6 characteristics describing leaf, 23 characteristics describing flower and 1 characteristic describing physiological feature. As for observation stage, there are 1 characteristic needing to be observed in the stage of seedling, 1 characteristic in the stage of beginning of flowering and other 36 characteristics in the stage of fully flowering. As for the expression pattern, there are 10 qualitative characteristics, 9 pseudo-qualitative characteristics and 19 quantitative characteristics. As for the observation method, there are 30 characteristics using VG as the observation method, and 8 characteristics using MS. [Conclusion] In view of the variation and morphological properties of marigold, this group of characteristics are representative and comprehensive, and ensure the accuracy and easiness of DUS test of Tagetes L., thereby achieving the reasonable combination of characteristics in described plant parts, observation stages, expression patterns and observation methods.
基金supported by the Sino-Probe09(No.201011078)National High-tech R&D Program(No.863 and2014AA06A613)
文摘We apply reweighted inversion focusing to full tensor gravity gradiometry data using message-passing interface (MPI) and compute unified device architecture (CUDA) parallel computing algorithms, and then combine MPI with CUDA to formulate a hybrid algorithm. Parallel computing performance metrics are introduced to analyze and compare the performance of the algorithms. We summarize the rules for the performance evaluation of parallel algorithms. We use model and real data from the Vinton salt dome to test the algorithms. We find good match between model efficiency and feasibility of parallel computing gravity gradiometry data. and real density data, and verify the high algorithms in the inversion of full tensor
基金Supported by Sichuan Financial and Engineering Foundation for the Young(2007QNJJ-020)Sichuan Cultivation Foundation for Academy leaders+3 种基金Sichuan Key Project of Rice BreedingConstruction of Rice Industry System in SouthwestNational Crop-harvesting ProjectSichuan Financial Promotion~~
文摘[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved recently were taken as materials and relationship of plant characters including bud living rate and moth- er stem emergence rate of ratoon rice before harvest was explored, based on relat- ed data. [Result] The shorter rice with lower harvesting index is the main character of high emergence rate for first cropping rice; decline of plant height and increase of ear-bearing percentage would improve emergence of regenerative seedlings. [Conclusion] The research provided scientific reference for breeding of rice cultivars with high regenerative capacity.
基金Project(2009ZA04) supported by the Independent Research Foundation of State Key Laboratory of Subtropical Architecture Science,China
文摘The deformation performance index limits of high reinforced concrete (RC) shear wall components based on Chinese codes were discussed by the nonlinear finite element method. Two typical RC shear wall specimens in the previous work were first used to verify the correctness of the nonlinear finite element method. Then, the nonlinear finite element method was applied to study the deformability of a set of high RC shear wall components designed according to current Chinese codes and with shear span ratio λ≥2.0. Parametric studies were made on the influence of shear span ratio, axial compression ratio, ratio of flexural capacity to shear capacity and main flexural reinforcement ratio of confined botmdary members. Finally, the deformation performance index and its limits of high RC shear wall components under severe earthquakes were proposed by the finite element model results, which offers a reference in determining the performance status of RC shear wall components designed based on Chinese codes.
基金Projects(50471102,50671089) supported by the National Natural Science Foundation of China
文摘In order to establish the quantitative relationship between equivalent strain and the performance index of the deformed material within the range of certain passes for equal channel angular processing (ECAP), a new approach to characterize the equivalent strain was proposed. The results show that there exists better accordance between mechanical property (such as hardness or strength) and equivalent strain after rolling and ECAP in a certain range of deformation amount, and Gauss equation can be satisfied among the equivalent strain and the mechanical properties for ECAP. Through regression analysis on the data of hardness and strength after the deformation, a more generalized expression of equivalent strain for ECAP is proposed as:ε=k0exp[-(k1M-k2)^2], where M is the strength or hardness of the material, k1 is the modified coefficient (k1∈ (0, 1)), ko and k2 are two parameters dependent on the critical strain and mechanical property that reaches saturation state for the material, respectively. In this expression the equivalent strain for ECAP is characterized novelly through the mechanical parameter relating to material property rather than the classical geometry equation.
基金supported by the Deutsche Forschungsgemeinschaftthe Human Frontiers Sciences Program
文摘The avian magnetic compass was analyzed in bird species of three different orders - Passeriforms, Columbiforms and Galliforms - and in three different behavioral contexts, namely migratory orientation, homing and directional conditioning. The respective findings indicate similar functional properties: it is an inclination compass that works only within a functional window around the ambient magnetic field intensity; it tends to be lateralized in favor of the fight eye, and it is wavelength-dependent, requiring light from the short-wavelength range of the spectrum. The underlying physical mechanisms have been identified as radical pair processes, spin-chemical reactions in specialized photopigments. The iron-based receptors in the upper beak do not seem to be involved. The existence of the same type of magnetic compass in only very distantly related bird species suggests that it may have been present already in the common ancestors of all modem birds, where it evolved as an all-purpose compass mechanism for orientation within the home range [Current Zoology 56 (3): 265-276, 2010].
基金Projects(50275150,61173052) supported by the National Natural Science Foundation of ChinaProject(14FJ3112) supported by the Planned Science and Technology of Hunan Province,ChinaProject(14B033) supported by Scientific Research Fund Education Department of Hunan Province,China
文摘A novel chaotic search method is proposed,and a hybrid algorithm combining particle swarm optimization(PSO) with this new method,called CLSPSO,is put forward to solve 14 integer and mixed integer programming problems.The performances of CLSPSO are compared with those of other five hybrid algorithms combining PSO with chaotic search methods.Experimental results indicate that in terms of robustness and final convergence speed,CLSPSO is better than other five algorithms in solving many of these problems.Furthermore,CLSPSO exhibits good performance in solving two high-dimensional problems,and it finds better solutions than the known ones.A performance index(PI) is introduced to fairly compare the above six algorithms,and the obtained values of(PI) in three cases demonstrate that CLSPSO is superior to all the other five algorithms under the same conditions.
文摘Fast growth of mobile internet and internet-of-things has propelled the concept formation and research on 5G wireless communications systems which are to be standardized around 2020(IMT-2020).There will be diverse application scenarios expected for 5G networks.Hence,key performance indicators(KPIs) of 5G systems would be very diverse,not just the peak data rate and average/edge spectral efficiency requirements as in previous generations.For each typical scenario,multiple technologies may be used independently or jointly to improve the transmission efficiency,to lower the cost,and to increase the number of connections,etc.Key enabling technologies are discussed which include massive MIMO,ultradense deployment specific techniques,nonorthogonal transmission,high frequency communications,etc.
基金Project(U1234211)supported by the National Natural Science Foundation of ChinaProject(2013G009-B)supported by China Railway Corporation
文摘With the development of high-speed and heavy-haul railway in China, problems like insufficient thickness of ballast bed and overlarge track stiffness are obvious. Ballast may break into small particles and their contact status will deteriorate under cyclic loading, resulting in ballast degradation. Discrete element method(DEM) was used to research improved performance of ballast bed using elastic sleeper. Clusters were generated by bonding spheres to model real ballasts, while broken bonds were utilized to distinguish breakage. Two kinds of ballast beds with elastic sleeper and conventional sleeper were established, respectively. After applying cyclic loading to the models, differences of mechanical properties between two models were analyzed by contrasting their dynamic behavior indexes, such as particle contact force, sleeper settlement, vibration velocity and acceleration, breakage characteristic. The results illustrate that compared with conventional sleeper, elastic sleeper increases sleeper settlement, while reduces ballast vibration and contact force between particles, which could depress ballast breakage.
基金supported by National Natural Science Foundation of China under Grand No.61671183
文摘The majority of existing papers about spectrum sensing have the assumption that secondary users(SUs) are stationary. However,mobility is an essential feature of mobile communications networks. In this paper,the detection performance of spectrum sensing by mobile SUs was analyzed. Three performance metrics,i.e.,detection probability,miss detection probability and false alarm probability,were thoroughly investigated. In our analysis,a critical variable was the real-time received primary user signal power by a mobile SU. Its probability distribution and mathematical expectation were analytically derived. Moreover,the three performance metrics in single-node spectrum sensing and multi-node collaborative spectrum sensing systems were also derived. Extensive simulations were performed. The results are consistent with the theoretical analysis. And it is concluded that SU mobility has a significant impact on the detection probability and the miss detection probability,but not on the false alarm probability.
文摘This paper presents a method for solving the attitude control problem of high altitude airship (HAA) with aerodynamic fin and vectored thruster control. The algorithm is based on the synthetic optimization of dynamic performance and energy consumption of airship. Firstly, according to the system overall configuration, the dynamic model of HAA was established and the HAA linearized model of longitudinal plane motion was obtained. Secondly, using the classic PID control theory, the HAA attitude control system was designed. Thirdly, through analyzing the dynamic performance of airship with fin or vectored thruster control, the synthetic performance index function with different weighting functions was determined. By means of optimizing the obtained performance index function, the attitude control of high altitude airship with good dynamic performance and low energy consumption was achieved. Finally, attitude control allocation strategy was designed for the airship station keeping at an altitude of 22 km. The simulation experiment proved the validity of the proposed algorithm.
文摘The temperature of a solar cell subjected to the incident global solar radiation as a function of the local day time is determined. A heat balance equation is solved considering the heat losses due to convection and thermal radiation. The cell efficiency is estimated as a measure of its performance. The results reveal that the temperature within the cell attains significant values. Nevertheless, the temperature dependence of its efficiency along the day time is not pronouncing. It slightly decreases with temperature.
基金the financial support from UNAM-DGAPA-PAPIIT thorough the project 101016CONACYT for the 232312 Ph D scholarship grant
文摘The glass forming ability, thermal and mechanical properties of some Zr Cu Al Ni bulk metallic glasses were analyzed. The compositions of the alloys were theoretically determined with the dense packing and kinetic fragility index models. Cylindrical and conical ingots were produced by copper mould suction-casting under Ar atmosphere. The conical ingots were characterized by means of X-ray diffraction in order to determine the glassy structure. It was found that both alloys have a critical glassy diameter, Dc, of 3 mm. Thermal behaviours were investigated by differential scanning calorimetry at heating rates of 0.5, 0.67 and 0.83 K/s. The gamma parameter γ, supercooled liquid region ΔTx, and reduced glass transition temperature Trg, of the experimentally obtained glasses indicated high glass forming ability. The glassy compositions showed a fragility index of ~40 GPa. The compression test of the investigated alloys was carried out at a strain rate of 0.016 s^-1, obtaining a elastic modulus of ~83 GPa, total deformation of ~5%, yield strength of 1.6 GPa and hardness of 4 GPa. It was concluded that the use of the dense packing and kinetic fragility index models helped to predict glass-forming compositions in the family alloy investigated.