N′-四氮唑基-N-取代苯氧乙酰基硫脲的合成及生物活性

通过4-氯苯氧乙酸、2,4-二氯苯氧乙酸与硫氰酸钾反应合成取代苯氧异硫氰酸酯,再分别与5-氨基-1,2,3,4-四氮唑发生亲核加成反应,合成了2种未见报道的酰基硫脲衍生物.其结构经元素分析、IR和1H NMR确证,并初步测定了其生物活性.     

1-苯基-3-甲基-5-吡唑酮酰化反应的密度泛函研究

采用酰化方法对1-苯基-3-甲基-5-吡唑酮进行合成得到二茂铁基吡唑酮,并用密度泛函方法计算了它的3种互变异构体,解释了酮式是最稳定异构体的原因.同时,根据计算得到的分子轨道图推测出1-苯基-3-甲基-5-吡唑酮的酰化反应位置,计算结果得到实验结果验证.     

用二-2-乙基己基磷酸和P2O5混合物从硝酸溶液中萃取Am（Ⅲ）

用二-2-乙基己基磷酸（HDEHP）和P2O5混合物做萃取剂^241 Am^3＋为示踪剂,做了从硝酸溶液中液-液萃取Am的实验研究。完成了硝酸浓度和震荡时间的变化影响^241 Am^3＋萃取效率的条件实验。发现P20,的浓度≥0．0125mol／L时,^241 Am^3＋ 的萃取效率大干98％;震荡时间≥30s,两相便可达到萃取平衡。分别用二乙撑三胺五乙酸（DTPA）-乳酸以及N％CO3溶液对^241 Am^3＋进行反萃取。结果显示N％CO,溶液能给出很高的反萃效率。而且,在很短的震荡时间内,两相都能达到反萃平衡。     

基于DM642的网络视频服务器设计与实现

本文提出了一种基于DM642的网络视频服务器设计。系统以DM642为核心实现了视频数据的采集、本地显示、H．264编码和网络传输。介绍了系统的硬件结构和软件设计,重点给出了各个模块的程序设计。实验结果表明,该系统能够满足网络视频服务器实时性和稳定性的要求,具有良好的推广应用价值。     

5维转动黑洞中有质量标量粒子的Hawking辐射

从有两个不同角动量参数的5维转动黑洞的线元出发,首先明显地计算出其不为零的协变度规分量和相应的逆变度规分量以及度规行列式,然后将有质量的Klein-Gordon标量场方程分离变量,得到径向方程与角向方程.最后利用径向方程讨论了5维黑洞中有质量的Klein-Go,do.标量场的Hawking辐射.     

On Fuzzy <Emphasis Type="Italic">h</Emphasis>-Ideals of Hemirings

The concept of quasi-coincidence of a fuzzy interval value in an interval valued fuzzy set is considered. In fact, this concept is a generalized concept of the quasi-coincidence of a fuzzy point in a fuzzy set. By using this new concept, the authors define the notion of interval valued （∈, ∈ Vq）fuzzy h-ideals of hemirings and study their related properties. In addition, the authors also extend the concept of a fuzzy subgroup with thresholds to the concept of an interval valued fuzzy h-ideal with thresholds in hemirings.     

Glutamine stimulates translation of uncoupling protein 2mRNA

Uncoupling protein 2 (UCP2) belongs to a family of transporters/exchangers of the mitochondrial inner membrane. Using cell lines representing natural sites of UCP2 expression (macrophages, colonocytes, pancreatic beta cells), we show that UCP2 expression is stimulated by glutamine at physiological concentrations. This control is exerted at the translational level. We demonstrate that the upstream open reading frame (ORF1) in the 5’ untranslated region (5’UTR) of the UCP2 mRNA is required for this stimulation to take place. Cloning of the 5’ UTR of the UCP2 mRNA in front of a GFP cDNA resulted in a reporter gene with which GFP expression could be induced by glutamine. An effect of glutamine on translation of a given mRNA has not been identified before, and this is the first evidence for a link between UCP2 and glutamine, an amino acid oxidized by immune cells or intestinal epithelium and playing a role in the control of insulin secretion. Received 26 January 2007; received after revision 16 April 2007; accepted 8 May 2007 C. Hurtaud, C. Gelly: These authors contributed equally to this work.     

Influence of temperature on taste perception

Daily experience tells us that temperature has a strong influence on how we taste. Despite the longstanding interest of many specialists in this aspect of taste, we are only starting to understand the molecular mechanisms underlying the temperature dependence of different taste modalities. Recent research has led to the identification of some strong thermosensitive molecules in the taste transduction pathway. The cold activation of the epithelial Na⁺ channel and the heat activation of the taste variant of the vanilloid receptor (TRPV1t) may underlie the temperature dependence of salt responses. Heat activation of the transient receptor potential channel TRPM5 explains the enhancement of sweet taste perception by warm temperatures. Current development of methods to study taste cell physiology will help to determine the contribution of other temperature-sensitive events in the taste transduction pathways. Vice versa, the analysis of the thermodynamic properties of these events may assist to unveil the nature of several taste processes. Received 29 August 2006; received after revision 5 October 2006; accepted 20 November 2006     

2-甲基-3,5-吡啶二甲酸的制备及其结构表征

多羧酸类化合物在配位聚合物的合成中是很有价值的配体之一.本文通过高锰酸钾氧化法意外地制备了2-甲基-3,5-吡啶二甲酸,它具有很好的三角形对称结构,是理想的配位体.对它的结构进行了红外和核磁共振结构表征,结果与目标结构能够较好地吻合.     

Delphi高级接口技术及其在数据处理中的应用

在Delphi7.0环境下利用OLE Automation技术实现了Delphi,Fortran,Surfer和AutoCAD的无缝集成,并编制出一套地震面波频散曲线自动成图以及频散数据自动读取的应用软件,同时给出了在地震海量数据处理方面的应用实例.