掺CdS_xSe_（1－x）玻璃波导分布反馈光学双稳器件

本文给出了掺ＣｄＳ_ｘＳｅ_(１－ｘ)玻璃平面波导分布反馈（ＤＦＢ）光学双稳器件的设计和制备方法，实现了低功耗、快速的本征光学双稳。     

Electrocatalytic Oxidation of Vitamin B6 by 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl

Introduction Nitroxides such as 2,2,6,6-tetramethylpiperidine-N- oxyl (TEMPO) are well-known stable free radicals which have been extensively used in spin labeling,1 spin trapping2 and as antioxidants.3 Nitroxides are also easy to undergo reversible one-electron oxidation to form the corresponding oxoammonium ions.4 Oxoammonium ions are mild one-electron oxidants which have been used in organic synthesis5-8 and to generate radical cations.9 We10 found recently that electrochemically generat…     

微波辐射下合成2-(未)取代苯甲酰胺基-5-(1-苯基-3-甲基-5-氯吡唑- 4-基)-1,3,4-噻二唑衍生物

分别在微波辐射和常规加热条件下, 通过2-氨基-5-(1-苯基-3-甲基-5-氯吡唑-4-基)-1,3,4-噻二唑(1)与(未)取代苯甲酰氯(2a～2j)反应, 合成了一系列未见文献报道的2-(未)取代苯甲酰胺基-5-(1-苯基-3-甲基-5-氯吡唑-4-基)-1,3,4-噻二唑衍生物(3a～3j). 标题化合物的结构经元素分析, IR, 1H NMR确证.     

二氢异喹啉类BACE1抑制剂的特征结构及结合模式研究

β-分泌酶(BACE1)是水解淀粉样前体蛋白生成β-淀粉样多肽的关键限速酶,近年来已成为治疗阿尔茨海默症的一个理想靶点。本文以34个二氢异喹啉类BACE1抑制剂为研究对象,采用比较分子相似性指数(CoMSIA)法定量研究其结构与生物活性间的构效关系,并建立可靠的3D-QSAR预测模型,运用分子对接法分析其与受体BACE1间的结合模式。结果显示,基于立体场、疏水场和氢键供体场建立的CoMSIA模型稳定性良好、预测能力强(Q~2=0.47,R_(ncv)~2=0.93,R_(pre)~2=0.95)。本研究所得模型和信息较好地解释了二氢异喹啉类BACE1抑制剂的结构特征及其与受体间的结合模式,为后续新型BACE1抑制剂的设计开发提供理论指导。     

Numerical simulation and analysis of complex patterns in a two-layer coupled reaction diffusion system

The resonance interaction between two modes is investigated using a two-layer coupled Brusselator model. When two different wavelength modes satisfy resonance conditions, new modes will appear, and a variety of superlattice patterns can be obtained in a short wavelength mode subsystem. We find that even though the wavenumbers of two Turing modes are fixed, the parameter changes have influences on wave intensity and pattern selection. When a hexagon pattern occurs in the short wavelength mode layer and a stripe pattern appears in the long wavelength mode layer, the Hopf instability may happen in a nonlinearly coupled model, and twinkling-eye hexagon and travelling hexagon patterns will be obtained. The symmetries of patterns resulting from the coupled modes may be different from those of their parents, such as the cluster hexagon pattern and square pattern. With the increase of perturbation and coupling intensity, the nonlinear system will convert between a static pattern and a dynamic pattern when the Turing instability and Hopf instability happen in the nonlinear system. Besides the wavenumber ratio and intensity ratio of the two different wavelength Turing modes, perturbation and coupling intensity play an important role in the pattern formation and selection. According to the simulation results, we find that two modes with different symmetries can also be in the spatial resonance under certain conditions, and complex patterns appear in the two-layer coupled reaction diffusion systems.     

Conformal invariance and conserved quantity of third-order Lagrange equations for non-conserved mechanical systems

This paper studies conformal invariance and conserved quantity of third-order Lagrange equations for non-conserved mechanical systems. Third-order Lagrange equations, the definition and a determining equation of conformal invariance of the system are presented. The conformal factor expression is deduced from conformal invariance and Lie symmetry. The necessary and sufficient condition that conformal invariance of the system would have Lie symmetry under single-parameter infinitesimal transformations is obtained. The corresponding conserved quantity of conformal invariance is derived with the aid of a structure equation. Lastly, an example is given to illustrate the application of the results.     

Cu/Ti超晶格薄膜的强紫外反射性能研究

采用直流磁控溅射方法制备了一维二组元Cu/Ti周期超晶格金属薄膜 ,研究了基片温度、膜周期数、基片取向与紫外反射的关系。当基片加热温度为 470℃时 ,在硅 (10 0 )晶面上生长的 30层Cu/Ti膜 ,层间膜厚控制在1∶3、膜总厚度控制为 30 0nm时 ,所制备的超晶格薄膜在 5°入射角下对 2 0 0nm的紫外光 ,其反射率可高达 90 %。     

基于磁珠分离的生物质谱技术用于急性白血病疗效评价

基于磁珠分离的生物质谱技术,建立急性白血病疗效的血清评价方法。通过对质控血清的连续检测分析,日间及日内重复性均达国际标准,确保血清多肽分析体系的稳定性及可靠性。以30例初发急性白血病血清及其治疗缓解血清为研究对象,经金属铜鳌合磁珠分离和基质辅助激光解吸电离飞行时间质谱仪(MAL-DI-TOF-MS)检测后获得血清多肽谱图。经过FlexAnalysis 2.4软件和Biosun_MS软件分析,在m/z1000～10000范围内,得到27个具有统计学意义(p<0.05)的差异峰,其中治疗缓解后表达上调峰10个,表达下调峰17个,利用上述差异峰建立的诊断模型获得了100%敏感性和90%的特异性。基于磁珠分离和MALDI-TOF-MS检测建立的诊断模型具有较高的敏感性和特异性,对差异峰进行测序鉴定将有助于急性白血病疗效评价和发病机理研究。     

P2Y12受体拮抗剂定量构效关系的研究

P2Y12受体拮抗剂是一类重要的抗血小板药物,研究分子活性与其结构参数的关系,对于合成新的P2Y12受体拮抗剂具有一定指导作用.选用178个结构多样的P2Y12受体拮抗剂分子作为数据集,随机选取了143个P2Y12受体拮抗剂作为训练集,剩余分子作为检验集.采用多元线性回归(MLR)方法和主成分回归分析(PCA)方法对每个分子的636个分子参数进行线性回归分析.MLR所建模型的结果为:训练集R2=0.800,检验集R2=0.834;PCA模型结果为:训练集R2=0.545,检验集R2=0.665.相比之下MLR法所建模型具有良好的预测性和可靠性.通过模型分析,确定了影响分子活性的关键因素.以上模型对筛选和合成新型高效P2Y12受体拮抗剂提供了一定理论指导.     

纳米TiO2光催化剂改性研究进展

TiO2光催化活性高,化学稳定性好,绿色环保及价廉等特点,在污水处理、有机污染物降解、催化制氢、抗菌抗癌及自清洁等方面有巨大的应用前景。然而TiO2半导体禁带宽,光谱范围小,光量子效率低等问题限制了其光催化性能。文章综述了TiO2光催化剂优化改性的研究进展,系统分析了TiO2半导体的结构特征与作用机理,以及TiO2光催化过程的影响因素,着重介绍了TiO2光催化剂多元优化改性方法的优势及不足,最后对未来发展新型TiO2基光催化剂提出了建议。