Virtual synchronous generators(VSGs)are widely introduced to the renewable power generation,the variablespeed pumped storage units,and so on,as a promising gridforming solution.It is noted that VSGs can provide virtua...Virtual synchronous generators(VSGs)are widely introduced to the renewable power generation,the variablespeed pumped storage units,and so on,as a promising gridforming solution.It is noted that VSGs can provide virtual inertia for frequency support,but the larger inertia would worsen the synchronization stability,referring to keeping synchronization with the grid during voltage dips.Thus,this paper presents a transient damping method of VSGs for enhancing the synchronization stability during voltage dips.It is revealed that the loss of synchronization(LOS)of VSGs always accompanies with the positive frequency deviation and the damping is the key factor to remove LOS when the equilibrium point exists.In order to enhance synchronization stability during voltage dips,the transient damping is proposed,which is generated by the frequency deviation in active power loop.Additionally,the proposed method can realize seamless switching between normal state and grid fault.Moreover,detailed control design for transient damping gain is given to ensure the synchronization stability under different inertia requirements during voltage dips.Finally,the experimental results are presented to validate the analysis and the effectiveness of the improved transient damping method.展开更多
Pre-harvest sprouting(PHS)is one of the serious global issues in wheat production.Identification of quantitative trait loci(QTL)and closely-linked markers is greatly helpful for wheat improvement.In the present study,...Pre-harvest sprouting(PHS)is one of the serious global issues in wheat production.Identification of quantitative trait loci(QTL)and closely-linked markers is greatly helpful for wheat improvement.In the present study,a recombinant inbred line(RIL)population derived from the cross of Zhongmai 578(ZM578)/Jimai 22(JM22)and parents were phenotyped in five environments and genotyped by the wheat 50 K single-nucleotide polymorphism(SNP)array.Two QTL of germination index(GI),QGI.caas-3A and QGI.caas-5A,were detected,explaining 4.33%–5.58%and 4.43%–8.02%of the phenotypic variances,respectively.The resistant effect of QGI.caas-3A was contributed by JM22,whereas that of QGI.caas.5A was from ZM578.The two QTL did not correspond to any previously identified genes or genetic loci for PHSrelated traits according to their locations in the Chinese Spring reference genome,indicating that they are likely to be new loci for PHS resistance.Four kompetitive allele-specific PCR(KASP)markers K_AX-109605367and K_AX-179559687 flanking QGI.caas-3A,and K_AX-111258240 and K_AX-109402944flanking QGI.caas-5A,were developed and validated in a natural population of 100 wheat cultivars.The distribution frequency of resistance alleles at Qphs.caas-3A and Qphs.caas-5A loci were 82.7%and57.1%,respectively,in the natural population.These findings provide new QTL and tightly linked KASP markers for improvement of PHS resistance in wheat.展开更多
This paper presents a 3D simulator used for studying the motion control and autonomous navigation of robotic fish. The simulator’s system structure and computation flow are presented. Simplified kinematics and hydrod...This paper presents a 3D simulator used for studying the motion control and autonomous navigation of robotic fish. The simulator’s system structure and computation flow are presented. Simplified kinematics and hydrodynamics models for a virtual robotic fish are proposed. Many other object models are created for water, obstacles, sonar sensors and a swimming pool. Experimental results show that the simulator provides a realistic and convenient way to develop autonomous navigation algorithms for robotic fish.展开更多
Vitamin B is essential for maintaining normal life activities in humans and animals who have to intake the microelement from the outside, especially from cereal products. In the present study 166 Chinese and foreign w...Vitamin B is essential for maintaining normal life activities in humans and animals who have to intake the microelement from the outside, especially from cereal products. In the present study 166 Chinese and foreign wheat cultivars planted in two environments were characterized for variation in vitamin B1 and B2 contents. A genome-wide association study(GWAS) using the wheat 90 K SNP assay identified 17 loci for vitamin B1 and 7 for vitamin B2 contents. Linear regression analysis showed a significantly positive correlation of the number of favorable alleles with vitamin B1 and B2 contents. Marker-trait associations(MTAs) at IWB43809(6AS, 0cM) and IWB69903(6AS, 13cM) were new and stable, and significantly associated with vitamin B1 content across two environments. The loci identified in this study and associated SNP markers could be used for improvement of vitamin B1 and B2 contents to obtain superior quality along with grain yield in wheat.展开更多
This paper presents a multi-agent robotic fish system used for mariculture monitoring. Autonomous robotic fish is designed to swim underwater to collect marine information such as water temperature and pollution level...This paper presents a multi-agent robotic fish system used for mariculture monitoring. Autonomous robotic fish is designed to swim underwater to collect marine information such as water temperature and pollution level. Each robotic fish has 5 degrees of freedom for controlling its depth and speed by milnicking a sea carp. Its bionic body design enables it to have high swimming efficiency and less disturbance to the surrounding sea lives. Several onboard sensors are equipped for autonomous 3D naviga- tion tasks such as path planning, obstacle avoidance and depth maintenance. A robotic buoy floating on the water surface is deployed as a control hub to communicate with individual robots, which in turn form a multi-agent system to monitor and cover a large scale sea coast cooperatively. Both laboratory experiments and field testing have been conducted to verify the feasibility and performance of the proposed multi-agent system.展开更多
Sex allocation theory predicts the optimal investment to male and female offspring.However,a biased sex ratio requires explanations as to why the deviation occurs.Rhesus macaque(Macaca mulatta)is the most widely distr...Sex allocation theory predicts the optimal investment to male and female offspring.However,a biased sex ratio requires explanations as to why the deviation occurs.Rhesus macaque(Macaca mulatta)is the most widely distributed nonhuman primate species and the Taihangshan macaque(Macaca mulatta tcheliensis)occupies the northern limit of all rhesus macaque natural populations worldwide.We observed one macaque troop(Wangwu-1[WW-1])inhabiting Taihangshan Macaque National Nature Reserve and recorded all birth events and the sex of newborn macaques from 2004 to 2013.Our aim was to apply the Trivers–Willard hypothesis to this free-ranging rhesus macaque troop,and to understand the relationship between climatic parameters(precipitation and temperature)and birth sex ratio.We found that the total newborn macaques showed a female-biased sex ratio at birth in the WW-1 troop,but there were no significant biased birth sex ratios in all matriarchs and in high-ranking and middle-ranking matrilineal units.However,the low-ranking macaque matrilineal unit was significantly female-biased.Moreover,we found that the annual precipitation of the previous year was positively associated with the birth sex ratio,and there was an interactive effect of troop size and current winter temperature on the birth sex ratio.The underlying mechanisms for the effects of social and climatic factors on birth sex ratio could be complex,and we discuss several plausible explanations.展开更多
Carotenoid content of wheat is an important criterion for prediction of the commercial and nutritional value of products made from bread wheat(Triticum aestivum) cultivars.The objective of this study was to determine ...Carotenoid content of wheat is an important criterion for prediction of the commercial and nutritional value of products made from bread wheat(Triticum aestivum) cultivars.The objective of this study was to determine the major components of carotenoids in Chinese wheat using ultra performance liquid chromatography(UPLC) including lutein,zeaxanthin,α-carotene andβ-carotene.Grain carotenoid content was investigated in217 cultivars from three major Chinese wheat regions and from seven other countries grown in two environments.Genotype contributed to the majority of variation in carotenoid components.Lutein,zeaxanthin and β-carotene concentrations varied from 18.3 to 100.1,4.9 to 12.0 and0.9 to 48.7 μg per 100 g in wheat flour with an average of40.2,7.2 and 18.2 μg per 100 g,respectively.Lutein(61.3%) was the main carotenoid component,followed byβ-carotene(27.7%) and zeaxanthin(11.0%).No α-carotene was detected.Total carotenoids,lutein,zeaxanthin andβ-carotene were all higher in cultivars with the 1BL.1RS translocation compared to those without the translocation.This is the first report on assay of lutein,zeaxanthin andβ-carotene concentrations for a large number of wheat cultivars.These data will be useful for genetic improvement of wheat carotenoid content and for understanding of the carotenoid biosynthetic pathway in wheat.展开更多
文摘Virtual synchronous generators(VSGs)are widely introduced to the renewable power generation,the variablespeed pumped storage units,and so on,as a promising gridforming solution.It is noted that VSGs can provide virtual inertia for frequency support,but the larger inertia would worsen the synchronization stability,referring to keeping synchronization with the grid during voltage dips.Thus,this paper presents a transient damping method of VSGs for enhancing the synchronization stability during voltage dips.It is revealed that the loss of synchronization(LOS)of VSGs always accompanies with the positive frequency deviation and the damping is the key factor to remove LOS when the equilibrium point exists.In order to enhance synchronization stability during voltage dips,the transient damping is proposed,which is generated by the frequency deviation in active power loop.Additionally,the proposed method can realize seamless switching between normal state and grid fault.Moreover,detailed control design for transient damping gain is given to ensure the synchronization stability under different inertia requirements during voltage dips.Finally,the experimental results are presented to validate the analysis and the effectiveness of the improved transient damping method.
基金funded by the Core Research Budget of the Nonprofit Governmental Research Institutions(S2022ZD04)the National Natural Science Foundation of China(31971929,31961143007)the Agricultural Science and Technology Innovation Program of CAAS(CAAS-ZDRW202002)。
文摘Pre-harvest sprouting(PHS)is one of the serious global issues in wheat production.Identification of quantitative trait loci(QTL)and closely-linked markers is greatly helpful for wheat improvement.In the present study,a recombinant inbred line(RIL)population derived from the cross of Zhongmai 578(ZM578)/Jimai 22(JM22)and parents were phenotyped in five environments and genotyped by the wheat 50 K single-nucleotide polymorphism(SNP)array.Two QTL of germination index(GI),QGI.caas-3A and QGI.caas-5A,were detected,explaining 4.33%–5.58%and 4.43%–8.02%of the phenotypic variances,respectively.The resistant effect of QGI.caas-3A was contributed by JM22,whereas that of QGI.caas.5A was from ZM578.The two QTL did not correspond to any previously identified genes or genetic loci for PHSrelated traits according to their locations in the Chinese Spring reference genome,indicating that they are likely to be new loci for PHS resistance.Four kompetitive allele-specific PCR(KASP)markers K_AX-109605367and K_AX-179559687 flanking QGI.caas-3A,and K_AX-111258240 and K_AX-109402944flanking QGI.caas-5A,were developed and validated in a natural population of 100 wheat cultivars.The distribution frequency of resistance alleles at Qphs.caas-3A and Qphs.caas-5A loci were 82.7%and57.1%,respectively,in the natural population.These findings provide new QTL and tightly linked KASP markers for improvement of PHS resistance in wheat.
文摘This paper presents a 3D simulator used for studying the motion control and autonomous navigation of robotic fish. The simulator’s system structure and computation flow are presented. Simplified kinematics and hydrodynamics models for a virtual robotic fish are proposed. Many other object models are created for water, obstacles, sonar sensors and a swimming pool. Experimental results show that the simulator provides a realistic and convenient way to develop autonomous navigation algorithms for robotic fish.
基金supported by National Key Research and Development Programs of China(2016YFD0101802,2016YFE0108600,2014CB1381050)Gene Transformation Projects(2016ZX08002003–003)Core Research Budget of the Non–profit Governmental Research Institutions(Y2016XT06)
文摘Vitamin B is essential for maintaining normal life activities in humans and animals who have to intake the microelement from the outside, especially from cereal products. In the present study 166 Chinese and foreign wheat cultivars planted in two environments were characterized for variation in vitamin B1 and B2 contents. A genome-wide association study(GWAS) using the wheat 90 K SNP assay identified 17 loci for vitamin B1 and 7 for vitamin B2 contents. Linear regression analysis showed a significantly positive correlation of the number of favorable alleles with vitamin B1 and B2 contents. Marker-trait associations(MTAs) at IWB43809(6AS, 0cM) and IWB69903(6AS, 13cM) were new and stable, and significantly associated with vitamin B1 content across two environments. The loci identified in this study and associated SNP markers could be used for improvement of vitamin B1 and B2 contents to obtain superior quality along with grain yield in wheat.
文摘This paper presents a multi-agent robotic fish system used for mariculture monitoring. Autonomous robotic fish is designed to swim underwater to collect marine information such as water temperature and pollution level. Each robotic fish has 5 degrees of freedom for controlling its depth and speed by milnicking a sea carp. Its bionic body design enables it to have high swimming efficiency and less disturbance to the surrounding sea lives. Several onboard sensors are equipped for autonomous 3D naviga- tion tasks such as path planning, obstacle avoidance and depth maintenance. A robotic buoy floating on the water surface is deployed as a control hub to communicate with individual robots, which in turn form a multi-agent system to monitor and cover a large scale sea coast cooperatively. Both laboratory experiments and field testing have been conducted to verify the feasibility and performance of the proposed multi-agent system.
基金We acknowledge the editors for their effort in communication between us and reviewers.Thanks to the three anonymous reviewers for their constructive criticisms which help to improve the early version of our manuscript greatly.We are grateful to Wang Haofeng,Wang Yonghong,Hou Jiafu,Kong Maocai,and Hou Xiquan for assistance in the field.We appreciate Professor Paul A.Garber(University of Illinois,USA)for his editing and suggestion on our manuscript.We especially thank the Jiyuan Administration of Taihangshan Macaque National Nature Reserve for permission and logistic support to this research.This research was financially supported by the National Natural Science Foundation of China(No.30970378 and 31170503).The authors declare no conflict of interest.
文摘Sex allocation theory predicts the optimal investment to male and female offspring.However,a biased sex ratio requires explanations as to why the deviation occurs.Rhesus macaque(Macaca mulatta)is the most widely distributed nonhuman primate species and the Taihangshan macaque(Macaca mulatta tcheliensis)occupies the northern limit of all rhesus macaque natural populations worldwide.We observed one macaque troop(Wangwu-1[WW-1])inhabiting Taihangshan Macaque National Nature Reserve and recorded all birth events and the sex of newborn macaques from 2004 to 2013.Our aim was to apply the Trivers–Willard hypothesis to this free-ranging rhesus macaque troop,and to understand the relationship between climatic parameters(precipitation and temperature)and birth sex ratio.We found that the total newborn macaques showed a female-biased sex ratio at birth in the WW-1 troop,but there were no significant biased birth sex ratios in all matriarchs and in high-ranking and middle-ranking matrilineal units.However,the low-ranking macaque matrilineal unit was significantly female-biased.Moreover,we found that the annual precipitation of the previous year was positively associated with the birth sex ratio,and there was an interactive effect of troop size and current winter temperature on the birth sex ratio.The underlying mechanisms for the effects of social and climatic factors on birth sex ratio could be complex,and we discuss several plausible explanations.
基金supported by the International Collaboration Projects from Ministry of Science and Technology(2013DFG30530,2014DFG31690)
文摘Carotenoid content of wheat is an important criterion for prediction of the commercial and nutritional value of products made from bread wheat(Triticum aestivum) cultivars.The objective of this study was to determine the major components of carotenoids in Chinese wheat using ultra performance liquid chromatography(UPLC) including lutein,zeaxanthin,α-carotene andβ-carotene.Grain carotenoid content was investigated in217 cultivars from three major Chinese wheat regions and from seven other countries grown in two environments.Genotype contributed to the majority of variation in carotenoid components.Lutein,zeaxanthin and β-carotene concentrations varied from 18.3 to 100.1,4.9 to 12.0 and0.9 to 48.7 μg per 100 g in wheat flour with an average of40.2,7.2 and 18.2 μg per 100 g,respectively.Lutein(61.3%) was the main carotenoid component,followed byβ-carotene(27.7%) and zeaxanthin(11.0%).No α-carotene was detected.Total carotenoids,lutein,zeaxanthin andβ-carotene were all higher in cultivars with the 1BL.1RS translocation compared to those without the translocation.This is the first report on assay of lutein,zeaxanthin andβ-carotene concentrations for a large number of wheat cultivars.These data will be useful for genetic improvement of wheat carotenoid content and for understanding of the carotenoid biosynthetic pathway in wheat.
