检索结果-南通市图书馆

High-throughput Procedure for Single Pollen Grain Collection and Polymerase Chain Reaction in Plants

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2008年第3期50卷 375-383页

作者： Ping-Hua Chen Yong-bao Pan Ru-Kai Che USDA-ARS Southem Regional Research Center Sugarcane Research Laboratory Houma LA 70360 USA Key Laboratory of Eco-physiology & Genetic Improvement for Sugarcane Ministry of Agriculture Fujian Agriculture and Forestry University Fujian Normal University Fuzhou 350002 China

Single pollen grain polymerase chain reaction （PCR） has succeeded in several species, however only limited numbers of pollen grains were involved due to difficulties in pollen isolation and lysis. This has limited its application in genetic analysis and mapping studies in plants. A high-throughput （HT） procedure for collecting and detecting genetic variation in a large number of individual pollen grains by PCR is reported. The HT procedure involved the collection of individual pollen grains by a pair of special forceps and the lysis of pollen grains in a heated alkali/detergent solution followed by neutralization with a tris-ethylenediamine tetraacetic acid （TE） buffer. These resulting template solutions yielded PCR reactions involving the 5S ribosomal RNA intergenic spacers, randomly amplified polymorphic DNA, and simple sequence repeats markers. Using this procedure, one person with experience could collect and process up to 288 single pollen grain PCR reactions per day. The method worked well on sugarcane, corn, Miscanthus spp., snap bean, sorghum, and tomato. The ability to collect and conduct PCR on individual pollen grains on a large scale offers a new approach to genetic analyses and mapping studies in an easily controllable environment with a considerable cost reduction. The method will also significantly benefit studies in species that are difficult subjects for classical genetic research.

关键词： DNA marker high-throughput polymerase chain reaction single pollen grain

Some Properties of Two-mode Displaced Excited Squeezed Vacuum States

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第9期52卷 493-499页

作者： MENG Xiang-Guo WANG Ji-Suo LIANG bao-Long Department of Physics Liaocheng University Liaocheng 252059 China

In this paper,two-mode displaced excited squeezed vacuum states (TDESVS) are constructed and theirnormalization and completeness are *** the entangled state representation and Weyl ordering formof the Wigner operator,the Wigner functions of TDESVS are obtained and the variations of Wigner functions withthe parameters m,n and r are ***,two marginal distributions of Wigner functions of TDESVS areobtained,which exhibit some entangled properties of the two-particle's system in TDESVS.

关键词： two-mode displaced excited squeezed vacuum state Weyl ordering Wigner function marginal distribution entangled state representation

CIDNP Study of Photoinduced [2+2] Cycloadditions (the Paterno- Büchi Coupling) of Arylacetylenes and Quinone

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2003年第3期14卷 270-273页

作者： Xin Yan WANG bao Zhen YAN Ting WANG Department of Applied Chemistry Beijing University of Chemical TechnologyBeijing 100029

CIDNP techniques were applied to study the mechanism of photocycloadditions of 2-chloro-5-methoxybenzoquinone 1 with arylacetylenes 2-5 in benzene-d6 and acetonitrile-d6 respectively.

关键词： Paterno-Büchi reaction 1, 4-biradicals photo-CIDNP arylacetylenes quinones.

Casimir Effect for a Massless Spin-3/2 Field in Minkowski Spacetime

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2007年第3X期48卷 457-460页

作者： LIU Wen-Biao XIAO Kui ZHANG Hong-bao Department of Physics Beijing Normal University Beijing 100875 China Department of Astronomy Beijing Normal University Beijing 100875 China CCAST (World Laboratory) P.O. Box 8730 Beijing 100080 China

The Casimir effect has been studied for various quantum fields in both fiat and curved spacetimes. As a further step along this line, we provide an explicit derivation of Casimlr effect for massless spin-3/2 field with periodic boundary condition imposed in four-dimensional Minkowski spacetime. The corresponding results with Dirichlet and Neumann boundary conditions are also discussed.

关键词： Casimir effect massless spin-3/2 field

Fabrication of wear-resistant layers with lamellar eutectic structure by laser surface alloying using the in situ reaction between Cr and B_4C

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第11期23卷 1294-1301页

作者： You-zheng Sun Jin-bao Li Daniel Wellburn Chang-sheng Liu Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education) Northeastern University

To improve the wear resistance of Cr5 steel, wear-resistant layers with lamellar eutectic microstructure were fabricated by laser surface alloying（LSA）, which is dependent on the in situ reaction between Cr and B_4C. Our results indicated that the hypoeutectic structures of the LSA layers were divided into interdendritic eutectic structures and dendrites. The area fraction of the eutectic structures increased with increasing laser scanning speed, which improved the hardness and wear resistance of the LSA layers. The average hardness of the LSA layer prepared at a scanning speed of 8 mm/s was HV_（0.2） 883.9, which was 1.8 times greater than that of the traditional quenched layer（approximately HV 480）. After sliding for 659.4 m, the specimen prepared at a scanning speed of 8 mm/s exhibited a volume loss of 0.0323 mm^3, which was only 29.5% of the volume loss of the traditional quenched specimen.

关键词： eutectic wear resistance laser alloying hardness

Indirect Flow Injection Chemiluminescence Method for the Determination of Tetracyclines Using Cu(Ⅱ) as a Probe Ion

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2005年第8期16卷 1067-1070页

作者： Su Qin HAN Er bao LIU Hua LI Institute of Analytical Science Northwest University Xi＇an 710069 School of Chemistry and Material Science Shanxi Normal University Linfen 041004 College of Chemistry and Life Science Tianjin Normal University Tianjin 300074

This paper reported an indirect flow injection chemiluminescence （FI-CL） method for the determination of the drugs tetracycline （TC）, chlortetracycline （CTC） and oxytetracycline（OTC） using Cu（ Ⅱ ） as a probe ion. The CL reaction was induced on-line and after injection of the sample the negative peaks appeared as a result of complexation. The method was applied to the determination of TCs in pharmaceuticals and human urine with recoveries in the range95-105%.

关键词： Cu(Ⅱ) probe ion inhibitory chemiluminescence tetracyclines.

寄主植物对植食性昆虫抗性的研究进展——以云杉八齿小蠹为例

在线全文

学校读者我要写书评

暂无评论

环境昆虫学报 2024年第2期46卷 326-331页

作者：程彬暴峰陈思羽刘冬梅高军勇吉林省林业科学研究院长春130033 吉林省通化县国有林总场吉林通化134100

云杉八齿小蠹Ips typographus是针叶林中最具破坏性的物种之一。雄虫以寄主挥发物作为嗅觉信号搜寻和定位寄主,然后释放信息素吸引同性或异性小蠹群集攻击寄主。寄主植物在受到云杉八齿小蠹为害后,不同寄主植物对云杉八齿小蠹的抗性反... 详细信息

云杉八齿小蠹Ips typographus是针叶林中最具破坏性的物种之一。雄虫以寄主挥发物作为嗅觉信号搜寻和定位寄主,然后释放信息素吸引同性或异性小蠹群集攻击寄主。寄主植物在受到云杉八齿小蠹为害后,不同寄主植物对云杉八齿小蠹的抗性反应不同,但都能够利用其自身的物理结构、分泌物及挥发性化学物质等抵御小蠹的危害,并合成产生大量的防御化学物质来使其免受侵害,寄主植物这种应对小蠹侵害的能力可能有助于它们的长期生存,这是树木的一种可持续的防御策略。寄主植物对云杉八齿小蠹入侵的有效防御是多阶段系统防御,包括一系列组成和诱导的机制来抵御入侵的云杉八齿小蠹和限制入侵的真菌病原体的传播。寄主植物对植食性昆虫的抗性反应为研发植物诱导剂、植食性昆虫及其天敌的行为调控剂等害虫治理手段开辟了新途径。

关键词：云杉八齿小蠹组成抗性诱导抗性防御反应

A local pseudo arc-length method for hyperbolic conservation laws

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2014年第6期30卷 956-965页

作者： Xing Wang Tian-bao Ma Hui-Lan Ren Jian-Guo Ning State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology

A local pseudo arc-length method（LPALM）for solving hyperbolic conservation laws is presented in this *** key idea of this method comes from the original arc-length method,through which the critical points are bypassed by transforming the computational *** method is based on local changes of physical variables to choose the discontinuous stencil and introduce the pseudo arc-length parameter,and then transform the governing equations from physical space to arc-length *** order to solve these equations in arc-length coordinate,it is necessary to combine the velocity of mesh points in the moving mesh method,and then convert the physical variable in arclength space back to physical *** examples have proved the effectiveness and generality of the new approach for linear equation,nonlinear equation and system of equations with discontinuous initial ***-oscillation solution can be obtained by adjusting the parameter and the mesh refinement number for problems containing both shock and rarefaction waves.

关键词： Numerical method Local pseudo arc-length method Hyperbolic conservation laws Mesh adaptation

2T-PERIODIC SOLUTION FOR m ORDER NEUTRAL TYPEDIFFERENTIAL EQUATIONS WITH TIME DELAYS

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2002年第1期23卷 100-106页

作者： ZHANG bao-sheng(张保生) ZHU Guang-hui(朱光辉) Department of Mathematics Yunnan Nationalities InstituteKunming 650031 P R China Department of Mathematics Yunnan Nationalities InstituteKunming 650031 P R China

Periodic solution of m order linear neutral equations with constant coefficient and time delays was studied. Existence and uniqueness of 2 T-periodic solutions for the equation were discussed by using the method of Fourier series. Some new necessary and sufficient conditions of existence and uniqueness of 2 T-periodic solutions for the equation are obtained. The main result is used widely. It contains results in some correlation paper for its special case, improves and extends the main results in them. Existence of periodic solution for the equation in larger number of particular case can be checked by using the result, but cannot be checked in another paper. In other words, the main result in this paper is most generalized for (1) the better result cannot be found by using the same method.

关键词： neutral type equation 2T-periodic solution Fourier series