关于高维系统中Poincαre—Bendixson定理的反例

本文给出了在n(n≥4)维系统中,Poincare-Bendixson定理不成立的多项式系统的反例。     

Isolation and purification of BVⅠ-2H from bee venom and analysis of its biological action

The medical use of bee venom for rheumatoid arthritis ( RA ) has a very long tradition. In this study, isolation and purification of polypeptides from bee venom were carried out on sephadex chromatography, heparin sepharose CL-6B chromatography and HPLC. Several fractions were extracted, and their effects on activation of splenocyte and THP-1 cell were studied. The inhibitory fraction was selected for further studies. Finally, BVⅠ-2H that the HPLC elution profiles was a single peak was isolated by C8 column. ESI- MS detection results showed that BVⅠ-2H was a fraction of bee venom, and the molecular weight of the major component was 644.8. BVⅠ-2H could inhibit ConA-induced splenocyte proliferation, IL-1 production and interfere with splenocyte cycle in mice. Moreover, BVⅠ-2H could inhibit PMA-induced TNFα production in THP-1 cells, which was due to its inhibitory effects on TNFα mRNA expression and protein phosphorylation of IκBα. Our studies indicated that BVⅠ-2H was one of the anti-inflammatory components of bee venom.     

作物高产性的光合碳同化生理限制因子分析

对影响作物高产的光合作用碳同化的生理限制因子进行了分析，提出内外因子结合考虑是提高作物的光合效率和产量的关键．     

L型连续退火炉退火工艺的模拟实验

结合唐钢镀锌线退火炉的工艺特点，热模拟了退火工艺，检验了退火后带钢的力学性能和金相组织，为实际生产提供了理论依据。     

三峡库区兴山县平邑口滑坡稳定性及其工程治理研究

利用极限平衡方法,针对各种不同的库水位运行工况,对平邑口滑坡治理前后的稳定性进行了分析计算,对比分析计算结果说明了工程采用压脚回填处治措施是合理有效的.     

Genetic and photoperiodic control of an avian reproductive cycle

European blackcaps,Sylvia atricapilla, with one breeding season per year, have a single-peaked annual testes cycle. However, African conspecifics from the Cape Verde Islands with two breeding seasons per annum demonstrate a two-peaked cycle. Both population-specific cycles reflect differences in the respective endogenous circannual rhythms. Experimental hybridization of birds of the two populations resulted in an intermediate pattern of testes cycle, thus demonstrating that there are genetic components for some temporal aspects in an avian reproductive cycle. Another characteristic of the African birds, their extremely rapid juvenile development and early sexual maturity (at an age of 5–6 months) proved largely to be a photoperiodic (short-day) effect in birds hatched in autumn. The same effect could also be induced in European conspecifics exposed to correspondingly short day-lengths.     

S桶空间的几个性质(Ⅱ)

讨论了S桶空间在归纳限和稠密子空间方面的一些基本性质．     

原子核稳定线、液滴模型和核电荷上限的研究

探求原子核稳定线公式,结合液滴模型,得出核电荷的上限.     

MAPLE在微积分教学中的应用

极限是微积分的重点和难点。本文简述了数学软件MAPLE在极限教学中的应用。     

基于企业自身发展的核心能力管理

企业之间的竞争体现为核心能力的竞争，企业的多元化战略应围绕核心能力来进行。人们通过用户价值、独特性、延展性、难以模仿和替代性来识别企业的核心能力。对企业核心能力进行管理的基础在于核心能力具有生命周期。