多取代5,6二氢-4-噻喃并咪唑酮类化合物的合成

在α-肉桂酰基二硫缩烯酮类化合物(1)的基础上,由2,3-二氢-4-噻喃酮化合物(2)与水合肼在温和条件下合成了多取代5,6-二氢-4-噻喃并咪唑酮类化合物(3),通过核磁共振、红外光谱、质谱及元素分析对所得化合物进行了表征,并对该反应机理进行了探讨.     

H.264视频编码在数码监控系统中的应用研究

目前数码视频监控系统大多采用MPEG1、MPEG2的编码标准,导致视频存储成本高,网络负载重.H.264比以前的视频编码标准可以节省50%以上的码率,因此在视频监控中具有很大的应用前景,但其编解码器也很复杂.为了达到实时压缩的目标,文章从三个方面来提高其运算速度:①优化帧间模式的选择;②调整内插算法的运行结构;③采用MMX、SSE汇编优化.     

2(5H)-呋喃酮的水相Diels-Alder反应

研究了2(5H)-呋喃酮、5-羟基-2(5H)-呋喃酮与环戊二烯发生Diels-Alder反应,产物用FT-IR、1HNMR、MS进行了表征。该反应在水相中进行时,反应时间为0.5 h,比在有机相反应的时间大大缩短。     

软盘特殊格式化及加密技术的研究

通过对软盘结构、物理参数、逻辑参数的分析,给出了一种实现软盘在不破坏原盘数据的基础上,通过使用Int 13H等中断技术,进行重新格式化、扩充软盘容量的方法及加密技术的实现.     

Recent results on hydrogen and hydration in biology studied by neutron macromolecular crystallography

Neutron diffraction provides an experimental method of directly locating hydrogen atoms in proteins, a technique complimentary to ultra-high-resolution [1, 2] X-ray diffraction. Three different types of neutron diffractometers for biological macromolecules have been constructed in Japan, France and the United States, and they have been used to determine the crystal structures of proteins up to resolution limits of 1.5-2.5 A. Results relating to hydrogen positions and hydration patterns in proteins have been obtained from these studies. Examples include the geometrical details of hydrogen bonds, H/D exchange in proteins and oligonucleotides, the role of hydrogen atoms in enzymatic activity and thermostability, and the dynamical behavior of hydration structures, all of which have been extracted from these structural results and reviewed. Other techniques, such as the growth of large single crystals, the preparation of fully deuterated proteins, the use of cryogenic techniques, and a data base of hydrogen and hydration in proteins, will be described.     

Molecular mechanisms in therapy of acid-related diseases

Inhibition of gastric acid secretion is the mainstay of the treatment of gastroesophageal reflux disease and peptic ulceration; therapies to inhibit acid are among the best-selling drugs worldwide. Highly effective agents targeting the histamine H2 receptor were first identified in the 1970s. These were followed by the development of irreversible inhibitors of the parietal cell hydrogen-potassium ATPase (the proton pump inhibitors) that inhibit acid secretion much more effectively. Reviewed here are the chemistry, biological targets and pharmacology of these drugs, with reference to their current and evolving clinical utilities. Future directions in the development of acid inhibitory drugs include modifications of current agents and the emergence of a novel class of agents, the acid pump antagonists. Received 30 May 2007; received after revision 15 August 2007; accepted 13 September 2007     

A Family of Reliable H_∞ State-Feedback Controllers for Nonlinear Systems with Strictly Redundant Actuators: the Full Information Case

1　 IntroductionInherited from state space linear H∞ control theory,a number of nonlinear H∞ solutionshave been presented in terms of various formulations.The nonlinear H∞ control problemcan be stated as follows:find a compensator,either state feedback ormore general outputfeedback such that( 1 ) the internal state of the closed-loop system is stable and( 2 ) the L2 -gain of the mapping from the exogenous input disturbance to the controlled output liketracking error or cost variables is mi…     

Radiolarians from the British North‐Polar Expedition (1875–1876): re‐examination of the H. B. Brady (1878) collection

The earliest report on radiolarians from the Arctic Ocean (north of the Arctic Circle) was provided by H. B. Brady (1878 Brady, H. B. 1878. On the reticularian and radiolarian Rhizopoda (Foraminifera and Polycystina) of the North‐Polar Expedition of 1875–76.. Annals and Magazine of Natural History, Series 5, 1: 425–440. [Taylor & Francis Online] , [Google Scholar]). He documented the occurrences of 10 genera from soundings in northern Baffin Bay and north of Greenland, but he did not illustrate any specimens in his report. We have re‐examined Brady's original slide collection, housed at the Natural History Museum, London (NHM), in order to refine his radiolarian identifications to species level. We have identified 11 radiolarian taxa in his slides, but some are definitely more characteristic of tropical oceans rather than high northern latitudes. We conclude that this is most likely due to sample contamination or misidentification of samples. Therefore, the actual occurrence of tropically affiliated radiolarians recorded from the Arctic is uncertain and should be regarded with suspicion.     

Revalidation of Hepsetus cuvieri (Castelnau, 1861) (Characiformes: Hepsetidae) from the Quanza,Zambezi and southern part of the Congo ichthyofaunal provinces

Hepsetus cuvieri (Castelnau, 1861 Castelnau, FL. 1861. Mémoire sur les poissons de l'Afrique australe, Paris: Mem Poiss Afr Australe. [Crossref] , [Google Scholar]), originally described from “lac N'gami” (Botswana) and synonymized with H. odoe (Bloch, 1794 Bloch, ME. 1794. Naturgeschichte der ausländischen Fische. Berlin., 8: 1–174.  [Google Scholar]) by Roberts (1984 Roberts, TR. 1984. “Hepsetidae”. In Check-list of the freshwater fishes of Africa (CLOFFA), Edited by: Daget, J, Gosse, JP and Thys van den Audenaerde, DFE. 138–139. Tervuren and Paris: ORSTOM. p.  [Google Scholar]), is revalidated. Hepsetus cuvieri can be readily distinguished from H. odoe based on a lower total number of gill rakers (8–13 versus 14–21); a generally higher number of scales between the dorsal fin and the lateral line (10½–11½ versus 7½–10½) and a higher number of scales between the adipose fin and the lateral line (6½–7½ versus 4½–6½) and other characters. A neotype is designated, as the holotype of this nominal species is apparently lost. Hepsetus cuvieri is restricted to the Quanza, Zambezi ichthyofaunal provinces and the southern part of the Congo Basin, i.e. the Congo ichthyofaunal province.     

一个已加强的Hardy-Hilbert不等式的改进

利用改进的Holder’s不等式,对一个已加强的Hardy-Hilbert不等式作了进一步改进,建立了一个新的不等式.