Effects of Increased UV-B upon the Canopy's Structure of Wheat in China

Zheng, Youfei,He, Yuhong,Yang, Yuanyan,Li, Zhanqing Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

This paper is a part of the research into effects of increased UV-B (Ultraviolet-B, 280-320nm) upon the ecosystem of field wheat. Based on a 3-year project with intensified UV-B influencing the crop, observation and calculation were made of such factors and parameters as the morphology of a single wheat plant including its leaf area, leaf base angle and proportion of spacing between joints. The results show that the enhanced UV-B signifantly decreased wheat's SSLA, and the increased percentage of the lower LAI is associated with the change in leaf base angle and proportion of spacing between joints.

Catalytic coal partial gasification in an atmospheric fluidized bed

Hongcang Zhou,Youfei Zheng,Baosheng Jin,Zhaoping Zhong,Yaji Huang,Rui Xiao 한국화학공학회 2007 Korean Journal of Chemical Engineering Vol.24 No.3

Design Improvement of the Splitter Blade in the Centrifugal Pump Impeller Based on Theory of Boundary Vorticity Dynamics

Binjuan ZHAO,Chenghu ZHANG,Youfei ZHAO,Yanxia FU,Qi LIU,Huilong CHEN 한국유체기계학회 2018 International journal of fluid machinery and syste Vol.11 No.1

To improve the design of the splitter blade in the centrifugal pump impeller, inner flow numerical simulations are performed on the centrifugal pump impeller without splitter blades firstly, inner flow diagnoses are performed based on the theory of the boundary vorticity dynamics, and distributions of the boundary vorticity flux (BVF), friction force as well as vorticity on the inner walls of the impeller are carefully analyzed to find the location of bad flows and their dynamic sources. Later, according to the inner flow diagnosis results, splitter blades are designed and reformed for the original impeller. The inner flow filed in the impellers equipped with the preliminary splitter blade and reformed splitter blade are numerically simulated and diagnosed. Finally, comparisons are made among the three impellers, and it is found that, compared to the original impeller (impeller 0), the BVF, friction force and vorticity distribution in the impeller equipped with the preliminary splitter blade (impeller 1) has no obvious improvement, although the pump head increases, the efficiency decreases; the BVF, friction force and vorticity distribution in the impeller equipped with the reformed blade (impeller 2) has improved obviously, BVF peak decreases evidently and BVF distributes more uniformly, flow separation is inhibited, the hydraulic force acting on the impeller increases, with the pump head and efficiency increasing dramatically. It is proven that, flow diagnosis based on the theory of the boundary vorticity dynamics is an effective supplemental way for the design of the splitter blade in the centrifugal pump impeller, and will provide reference for the design of other turbo machinery as well.

mtDNA Diversity and Origin of Chinese Mongolian Horses

Li, Jinlian,Shi, Youfei,Fan, Caiyun,Manglai, Dugarjaviin Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.12

In order to learn the origin of the Chinese Mongolian horse, we analyzed polymorphisms within the mtDNA D-loop variable region in 305 horses of 6 types of 3 different breeds, including one imported breed, one cultivated breed and 4 types of one local breed. We detected 13 different haplotypes, and subsequent sequence analysis showed that all 6 horse types were genetically diverse. By constructing a cladogram of mtDNA D-loop sequences from the 6 horse types along with homologous sequences from several other horse types obtained from GenBank, we showed that Chinese Mongolian horses have a close genetic relationship with other horse types from Mongolia. We also speculate that several Chinese Mongolian horses descended from Przewalskii horse. Additionally, the 13 haplotypes were dispersed throughout the cladogram, suggesting that Chinese Mongolian horses likely originated from multiple female ancestors. A phylogenetic map of the 6 horse types showed that the genetic relationship between the local Wuzhumuqin and Wushen types were the closest. The Xinihe and Baerhu were also closely related to each other, and slightly more distantly related to the cultivated Sanhe breed. All five of the local Chinese horse types had a much more distant relationship with the imported Thoroughbred breed.

Design Improvement of the Splitter Blade in the Centrifugal Pump Impeller Based on Theory of Boundary Vorticity Dynamics

ZHAO, Binjuan,ZHANG, Chenghu,ZHAO, Youfei,FU, Yanxia,LIU, Qi,CHEN, Huilong Korean Society for Fluid machinery 2018 International journal of fluid machinery and syste Vol.11 No.1

To improve the design of the splitter blade in the centrifugal pump impeller, inner flow numerical simulations are performed on the centrifugal pump impeller without splitter blades firstly, inner flow diagnoses are performed based on the theory of the boundary vorticity dynamics, and distributions of the boundary vorticity flux (BVF), friction force as well as vorticity on the inner walls of the impeller are carefully analyzed to find the location of bad flows and their dynamic sources. Later, according to the inner flow diagnosis results, splitter blades are designed and reformed for the original impeller. The inner flow filed in the impellers equipped with the preliminary splitter blade and reformed splitter blade are numerically simulated and diagnosed. Finally, comparisons are made among the three impellers, and it is found that, compared to the original impeller (impeller 0), the BVF, friction force and vorticity distribution in the impeller equipped with the preliminary splitter blade (impeller 1) has no obvious improvement, although the pump head increases, the efficiency decreases; the BVF, friction force and vorticity distribution in the impeller equipped with the reformed blade (impeller 2) has improved obviously, BVF peak decreases evidently and BVF distributes more uniformly, flow separation is inhibited, the hydraulic force acting on the impeller increases, with the pump head and efficiency increasing dramatically. It is proven that, flow diagnosis based on the theory of the boundary vorticity dynamics is an effective supplemental way for the design of the splitter blade in the centrifugal pump impeller, and will provide reference for the design of other turbo machinery as well.

DUAL-MOTOR FULL-WEIGHT ELECTRIC POWER STEERING SYSTEM FOR COMMERCIAL VEHICLE

Yaohua Li,Qianlong Feng,Yangsen Zhang,Youfei Nan 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.3

In order to study the electric power steering system (EPS) which is suitable for the steering characteristics of commercial vehicles, the effect of weight on steering performance is analyzed, and a dual-motor full-weight EPS system is proposed. Firstly, the full-weight assist characteristics are studied, and two current distribution schemes and corresponding fault-tolerant control strategies are proposed according to the structural characteristics of dual-motor EPS system. By comparing with the traditional single-weight EPS system, it is proved that the full-weight EPS system improves the control stability and makes the driver get a better road feeling. Through the double line change test and step test, the effectiveness of the two current distribution schemes are verified, and it has better fault-tolerance performance. By comparison, the faulttolerance performance of scheme two is better than that of scheme one.

Peroxisome Proliferator-Activated Receptor-Alpha Deficiency Protects Aged Mice from Insulin Resistance Induced by High-Fat Diet

Cha, Dae Ryong,Han, Jee Young,Su, Dong Ming,Zhang, Yahua,Fan, Xuefeng,Breyer, Matthew D.,Guan, Youfei S. Karger AG 2007 American journal of nephrology Vol.27 No.5

<P><I>Background/Aims:</I> Insulin resistance is a central feature of the metabolic syndrome and progressively increases with age, resulting in excessively high incidence of type II diabetes in the elderly population. Peroxisome proliferator-activated receptor-α (PPARα) is widely expressed in insulin target tissues, including those of the liver, kidney, and muscle, where it mediates expression of genes promoting fatty acid β-oxidation. The aim of this study was to evaluate the potential role of PPARα in insulin resistance in aging mice induced by a high-fat diet. <I>Methods:</I> We used male PPARα knockout (KO) mice and wild-type (WT) littermates that were 18 months old. Animals were fed with a high-fat diet (HFD) for 4 weeks, and metabolic parameters associated with insulin sensitivity were assessed. <I>Results:</I> Following HFD treatment, WT mice showed more severe insulin resistance than did mice lacking the PPARα gene, as assessed by both the glucose tolerance test (GTT) and insulin tolerance test (ITT). In addition, WT mice exhibited significantly higher HOMA-IR, plasma total cholesterol levels and urinary albumin-creatinine ratio but less liver weight than did PPARα KO mice. <I>Conclusion:</I> These data suggest that PPARα gene deficiency may protect aged mice from developing insulin resistance and albuminuria induced by a HFD.</P><P>Copyright © 2007 S. Karger AG, Basel</P>