检索结果-南通市图书馆

science china(Life sciences) 2009年第11期52卷 1030-1035页

作者： QU LuJiang, LIU Wei, YANG FangXi, HOU ZhuoCheng, ZHENG JiangXia, XU GuiYun & YANG Ning State Laboratory for Agrobiotechnology and Department of animal science and technology, china agricultural university, Beijing 100193, china 1. State Laboratory for Agrobiotechnology and Department of animal science and technology China Agricultural University Beijing 100193 China

In order to elucidate the domestication history of Peking ducks, 190 blood samples from six Chinese indigenous duck breeds were collected with186 individualsgenotyped by 15 microsatellite markers. Both the FST and Nei’s standard genetic distances (Ds) from the microsatellite data indicated high genetic differentiation between Peking duck and other Chinese indigenous breeds. The haplotype network with mtDNA data showed that most of the Peking duck haplotypes were distinctly different from those of other domestic breeds. Although the H01 haplotype was shared by all domesticated duck breeds, Peking ducks displayed 12 specific domestic duck haplotypes, including four similar haplotypes H02, H04, H08 and H22, that formed a single haplogroup (A). Both H02 and H22 haplotypes were also shared by mallard and Peking ducks, indicating that Peking ducks originated from wild mallard ducks.

关键词： Peking duck Chinese indigenous duck breeds microsatellite mitochondrial DNA genetic relationship

Pattern phenomena in an rf discharge dusty plasma system

在线全文

学校读者我要写书评

暂无评论

science china(Physics,Mechanics & Astronomy) 2006年第5期49卷 588-596页

作者： HUANG Feng1,2, YE Maofu2 & WANG Long2 1. College of science, china agricultural university, Beijing 100083, china 2. Institute of Physics, Chinese Academy of sciences, Beijing 100080, china 1. College of science China Agricultural University Beijing 100083 China 2. Institute of Physics Chinese Academy of Sciences Beijing 100080 China

Various dust patterns are observed in an rf discharge dusty plasma system. According to the dust growth process from small to large in size, the formation of different dust patterns can be divided into two stages: the small-particle stage (or dust cloud stage), and the large-particle stage (or dust crystal stage). The evolution relations between different dust patterns with gas pressure changing are investigated. Dust voids, dust acoustic waves and strong turbulence modes are presented at the small-particle stage. The self-organized dust lattices and dust clusters are investigated at the large-particle stage. The static structure of a dust lattice is characterized by means of the pair correlation function. Dust clusters formed by particles with different numbers and the regular evolution of the clusters with gas pressure are also investigated. The packing sequences of dust clusters are verified through two-dimensional confined molecular dynamics simulations.

关键词： dusty plasma dust patterns

The refined theory of deep rectangular beams for symmetrical deformation

在线全文

学校读者我要写书评

暂无评论

science china(Physics,Mechanics & Astronomy) 2009年第6期52卷 919-925页

作者： GAO Yang1 & WANG MinZhong2 1 College of science, china agricultural university, Beijing 100083, china 2 State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Aerospace Engineering, Peking university, Beijing 100871, china College of science China Agricultural University Beijing 100083 China State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Aerospace Engineering Peking University Beijing 100871 China

Based on elasticity theory, various one-dimensional equations for symmetrical deformation have been deduced systematically and directly from the two-dimensional theory of deep rectangular beams by using the Papkovich-Neuber solution and the Lur'e method without ad hoc assumptions, and they construct the refined theory of beams for symmetrical deformation. It is shown that the displacements and stresses of the beam can be represented by the transverse normal strain and displacement of the mid-plane. In the case of homogeneous boundary conditions, the exact solutions for the beam are derived, and the exact equations consist of two governing differential equations: the second-order equation and the transcendental equation. In the case of non-homogeneous boundary conditions, the approximate governing differential equations and solutions for the beam under normal loadings only and shear loadings only are derived directly from the refined beam theory, respectively, and the correctness of the stress assumptions in classic extension or compression problems is revised. Meanwhile, as an example, explicit expressions of analytical solutions are obtained for beams subjected to an exponentially distributed load along the length of beams.

关键词： deep rectangular beams the refined theory symmetrical deformation the Papkovich-Neuber solution the Lur’e method

Maschke-type theorem and Morita context over weak Hopf algebras

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2006年第5期49卷 587-598页

作者： ZHANG Liangyun College of science, Nanjing agricultural university, Nanjing 210095, china Department of Mathematics, Nanjing university, Nanjing 210008, china 1. College of science Nanjing Agricultural University Nanjing 210095 China 2. Department of Mathematics Nanjing University Nanjing 210008 China

This paper gives a Maschke-type theorem over semisimple weak Hopf algebras,extends the well-known Maschke-type theorem given by Cohen and Fishman and constructs a Morita context over weak Hopf algebras.

关键词： weak Hopf algebra, smash product, Maschke-type theorem, Morita context.

Lie comodules and the constructions of Lie bialgebras

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2008年第6期51卷 1017-1026页

作者： ZHANG LiangYun College of science,Nanjing agricultural university,Nanjing 210095,china College of science Nanjing Agricultural University Nanjing 210095 China

In this paper,we first give a direct sum decomposition of Lie comodules,and then accord- ing to the Lie comodule theory,construct some(triangular)Lie bialgebras through Lie coalgebras.

关键词： Lie coalgebras Lie comodules Lie bialgebras triangular Lie bialgebras 16W30

ALLOYING BEHAVIOUR OF Ca IN STEEL 58CrV

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1992年第6期5卷 449-453页

作者： LU Feng CAO Fengyu LI Chengji university of science and technology Beijing,Beijing,chinaZHANG Yongxiang CHEN Yonggang Beijing Institute of Machine Tools,Beijing,china faculty of Metallograph,university of science and technology Beijing,Beijing 100083,china Beijing Univ of science and Technology Beijing China

Effect of Ca on hardenability and CCT diagram of steel 58CrV has been investigated by means of end-quenching and thermal *** addition of 0.006 wt-%Ca to the steel may improve the hardenability,reduce the critical cooling rate of transformation of pearlite or bainite under continuous cooling and increase the M_*** analysis showed that Ca segre- gates markedly along austenitie grain boundaries,and accelecrates the segregation of C,Cr and *** is believed that besides towards deoxidizing and desulphurizing as well as improving sulphide morphology,a trace of Ca in steel 58CrV behaves towards microalloying.

关键词： Ca steel 58CrV microalloying hardenability CCT diagram

Artificial Induction of Twinning by an Active Immunization of Beef Cows Against Inhibin Partially Purified from Porcine Seminal Plasma

在线全文

学校读者我要写书评

暂无评论

agricultural sciences in china 2002年第4期1卷 466-471页

作者： YANG Li-guo, ZHANG Ju-nong, WANG Jin-rong, YE Rong, SANG Run-zi, NIU Shu-li and LIU Cheng-hai( Research Laboratory of animal Reproduction , College of animal science and technology, Nanjing agricultural university,Nanjing 210095 , china College of animal science and technology, Shihezi agricultural university, Shihezi 832003 ,china Department of animal Husbandry and Veterinary Medicine , Xinjiang agricultural university,Wulumuqi 830000 , china Department of animal Husbandry and Veterinary Medicine ,Hebei agricultural university, Baoding 071001 , P.R. china) Research Laboratory of animal Reproduction College of Animal Science and Technology Nanjing Agricultural University Nanjing 210095 China College of animal science and technology Shihezi Agricultural University Shihezi 832003 China Department of animal Husbandry and Veterinary Medicine Xinjiang Agricultural University Wulumuqi 830000 China Department of animal Husbandry and Veterinary Medicine Hebei Agricultural University Baoding 071001P.R. China

Two hundred and seventy multiparous Chinese Yellow cattle (beef) were selected at 1 to 3 months postpartum and divided into three groups (90 cows for each). animals were given both a primary and booster immunizations with a total dose of 3 mg (Group Th) or 1.5 mg (Group Tl) of seminal preparation containing inhibin activity, emulsified with Freund's complete adjuvant and incomplete adjuvant (for booster) , at 3 or 4-week intervals. Other cows were treated with the same volume of seminal preparation without inhibin activity as procedures mentioned above to serve as a control (Group C). Artificial inseminations were given twice at 8 - 12 h intervals when the cow was in heat. Jugular venous blood samples were collected from each cow and used to assay the presence of antibody against seminal preparation by double-diffusion in agar precipitation test and to detect the titer of inhibin antibody by an ELISA method. Data from 247 cows showed that 83.9% (73/87) of cows were in estrus and ovulated 89 ova altogether, of which 19 cows ovulated twin ova and 15 cows produced twins in Group Th (n = 87). However, only 61.1% (44/72) of cows in Group TI (n = 72) and 62.5% (55/88) of cows in Group C were in estrus and ovulated 46 and 52 ova altogether respectively. The ovulation rate (1.27 ± 0.03), calving rate (126.3%) and twinning rate (26.3%) in Group Th were greater than those in Groups Tl or C (Panimals (r = 0.7507, P<0.01). These results indicate that active immunization of postpartum cows against inhibin purified from porcine seminal plasma may increase the ovulation rate and induce twinning, suggesting the potential to develop a method to improve fertility in cows.

关键词： Beef cows Seminal inhibin Active immunization Twinning Ovulation rate

Molecular characterization and expression analysis of caveolin-1 in pig tissues

在线全文

学校读者我要写书评

暂无评论

science china(Life sciences) 2008年第7期51卷 655-661页

作者： WANG Chong1,MEI YingJie 1,LI Li 1,MO DeLin 2,LI JiaQi 1,ZHANG Hao 1,TIAN XingGuo 1 &CHEN YaoSheng2 1College of animal science,South china agricultural university,Guangzhou 510642,china 2School of Life science,Sun Yat-Sen university,Guangzhou 510006,china 1. College of animal science South China Agricultural University Guangzhou 510642 China 2. School of Life science Sun Yat-Sen University Guangzhou 510006 China

Members of the caveolin family played important roles during fundamental cellular processes,such as regulation of cell morphology,migration,and gene expression in muscle *** this study,caveolin-1 (Cav-1),one of the caveolins,was identified from longissimus dorsi muscle of Large Yorkshire pig and Chinese indigenous Lantang pig based on the results of mRNA differential display *** deduced amino acids sequence of the porcine Cav-1 contained a caveolin domain,and was very conservative among different *** Cav-1 mRNA was widely expressed in the eight tissues in this study,including heart,liver,kidney,encephalon,spleen,lung,longissimus dorsi muscle,and back fat, and the highest expression quantity was found in back fat of the two pig *** expression quantity of porcine Cav-1 in back fat and longissimus dorsi muscle of Lantang pig was significantly higher than that of Large Yorkshire(Panimal model of pig.

关键词： caveolin family clone expression analysis real-time quantify PCR

Layer-by-layer assembly carbon nanotubes thin film based gas sensors for ammonia detection

在线全文

学校读者我要写书评

暂无评论

science china(Information sciences) 2011年第12期54卷 2700-2706页

作者： SUN Ping 1,2 , JIANG YaDong 1* , XIE GuangZhong 1 , DU XiaoSong 1 , LI Xian 1 & HU Jia 1 1 School of Optoelectronic Information, State Key Laboratory of Electronic Thin Films and Integrated Devices, university of Electronic science and technology of china (UESTC), Chengdu, 610054, china 2 Life and Physical science College, Sichuan agricultural university, Ya’an 625014, china 1. School of Optoelectronic Information State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China (UESTC) Chengdu 610054 China2. Life and Physical Science College Sichuan Agricultural University Ya’an 625014 China

Single walled carbon nanotubes (SWNTs) were deposited on interdigital electrode (IDE) devices and quartz crystal microbalance (QCM) devices through layer-by-layer self-assembly method to fabricate resistance sensitive and mass sensitive gas sensors, respectively. Their ammonia gas-sensitive characteristics were detected at different temperature. It is revealed that the SWNTs based mass sensitive gas sensor has good sensing properties at room temperature. However, the SWNTs based resistance sensitive gas sensor has irreversible response for ammonia gas. When the temperature increases, the noise of SWNTs based mass sensitive gas sensor increases and the gas sensitive characteristic decreases. Meanwhile, the humidity effect is also discussed. It is important to optimize gas sensor by making it work at an appropriate external environment.

关键词： layer-by-layer self-assembly carbon nanotube gas sensor

Nonsingularity in second-order cone programming via the smoothing metric projector

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china Mathematics 2010年第4期53卷 1025-1038页

作者： WANG Yun 1,& ZHANG LiWei 2 1 College of Information sciences and Engineering,Shandong agricultural university,Tai’an 271018,china 2 Department of Applied Mathematics,Dalian university of technology,Dalian 116024,china 1. College of Information sciences and Engineering Shandong Agricultural University Tai’an 271018 China2. Department of Applied Mathematics Dalian University of Technology Dalian 116024 China

Based on the differential properties of the smoothing metric projector onto the second-order cone,we prove that,for a locally optimal solution to a nonlinear second-order cone programming problem,the nonsingularity of the Clarke's generalized Jacobian of the smoothing Karush-Kuhn-Tucker system,constructed by the smoothing metric projector,is equivalent to the strong second-order sufficient condition and constraint nondegeneracy,which is in turn equivalent to the strong regularity of the Karush-Kuhn-Tucker ***,this nonsingularity property guarantees the quadratic convergence of the corresponding smoothing Newton method for solving a Karush-Kuhn-Tucker ***,the analysis does not need the strict complementarity condition.

关键词： second-order cone programming problem smoothing metric projector B-subdifferential Clarke’s generalized Jacobian smoothing Newton method