动物活体NMR技术在脑研究中的应用

近十余年来核磁共振技术在生物医学研究中的应用取得了巨大的进展。动物活体NMR技术得到了广泛的重视,已成为生理学、生物化学、药理学、和神经化学研究中的新的重要手段,该技术有如下几个特点:1.非损伤性,即对被测的活体动物的组织和细胞没有破坏性,可以对同一动物进行多次测定,2.可同时直接测定动物活体内数种化合物,不需解剖、匀浆、分离提取和生化分析等繁琐步骤,因此较为方便省时。3.可在正常生理状态下连续进行实时动态测定,有利于药物代谢动力学研究。4.可对同一动物测定给药前和给药后的NMR指标进行自身比较,减少统计学处理,节省实验动物数目.为药理研究和药效评估提供一种崭新的方法。本文就我国和国外最近几年有关动物活体高分辨NMR技术在脑研究中的应用情况进行综述。     

时间参量法(Ⅳ)──对峙反应的热动力学研究

根据热动力学基本理论和对峙反应的通用微分动力学方程,将时间作为已知参量,建立了对峙反应热动力学时间参量法的数学模型,并利用该法分别研究了硝基乙烷与氨和三(羟甲基)氨基甲烷反应的热动力学.     

兴国红鲤卵巢发育的研究

在274尾兴国红鲤材料上,于1976—1983年进行了卵巢发育的研究,记述了卵巢在第一次性周期内发育的时序。雌鱼的性成熟年龄为2周龄,为多次产卵类型。探讨了性成熟后卵巢发育的周年变化,描述了原始生殖细胞和各种时相卵母细胞的形态特征及不同发育时期卵巢的组织学成分。根据其细     

Die chemische Industrie auf dem Weg in eine grüne Zukunft? Sustainable Development und Responsible Care

In literature as well as in environmental reports of many companies of the chemical industry, phrases like „sustainability”︁ and „sustainable development”︁ are proposed strategies for a better future. Such strategies should be the solution for global environmental problems with regard to economic and social needs of the present and future generations. In order to be successful, these strategies should include integrated pollution control as well as responsibility for both resources and products. Examples for new approaches are cleaner production and green chemistry.     

Size shrinking of composite bosons for increasing density in the BCS to Bose-Einstein crossover

We consider a system of fermions in the continuum case at zero temperature, in the strong-coupling limit of a short-range attraction when composite bosons form as bound-fermion pairs. We examine the density dependence of the size of the composite bosons at leading order in the density (“dilute limit”), and show on general physical grounds that this size should decrease with increasing density, both in three and two dimensions. We then compare with the analytic zero-temperature mean-field solution, which indeed exhibits the size shrinking of the composite bosons both in three and two dimensions. We argue, nonetheless, that the two-dimensional mean-field solution is not consistent with our general result in the “dilute limit”, to the extent that mean field treats the scattering between composite bosons in the Born approximation which is known to break down at low energy in two dimensions. Received 3 June 1999 and Received in final form 29 July 1999     

网上技术市场发展模式与运行管理机制--以中国浙江网上技术市场为例

网上技术市场正逐步发展成为技术交易的主要形式.本文以中国浙江网上技术市场为例,从其定位和动力模式两方面探讨了网上技术市场的发展模式,以及从信息资源管理、技术交易管理和市场运作三方面探讨了网上技术市场的运行管理机制.     

论工科高等数学精品课程建设

系统论述了工科高等数学精品课程建设产生的历史背景、指导思想、建设内容和在建设中所应遵循的基本原则.     

最短时限运输问题的推广

在目前文献所讨论的最短时限运输问题中,从一个发点到一个收点的运输时间为常数,与运输量无关.这有一定的局限性.本文从实际出发,在已有模型中加入运输量对运输时间的影响,使其更具一般性.实际上,可把时间函数推广到单调递增函数.文中给出了推广模型的多项式时间算法,它能相对快速地找到最优运输方案.     

Application of energy dispersive X-ray fluorescence spectrometry as multielemental analysis to determine the elemental composition of crumb rubber samples

The elemental content of different rubber samples was analyzed using different analytical methods (inductively coupled atomic emission spectroscopy and non-polarized energy dispersive X-ray fluorescent spectroscopy). A new application of energy dispersive X-ray spectrometry as an analytical method for the determination of elemental content of rubber samples was investigated. Control analyses were also carried out to compare the results by ICP-AES. In one hand four samples contained same quality of elements (Mg, Si, P, S, Ca, Fe, Zn), while another four samples were without phosphorous. On the other hand there were significant differences in the ratio of C/H in the case of each sample. Based on the results, it was concluded that the X-ray spectrometry as an analytical method is well-applicable to determine the elemental composition of rubber samples, but the calibration is a key part of the analysis. A good correlation was observed between the different methods, but the correlation was the function of characteristic of matrices. Significant matrix effect from the presence of phosphor was observed in the case of some samples, while the change of C/H ratio could not result notable matrix effect.     

关注职前化学教师实践性知识的主题教学研修——以师范生“化学肥料”课堂教学为例

为了探索职前化学教师实践性知识生成的指导和培养,由化学师范生、化学教学论教师和初高中化学教师组成的教师学习共同体开展主题教学研修。在关注师范生试教“化学肥料”的基础上,从不同角度开展评析和指导。基于共同体的研修活动指出化学师范生应回归学科知识,职前指导需要多元化补充,来自不同层面的师生组成学习共同体利于共同成长。该活动从实践层面开拓教师教育课程改革的新方向。