学科融合：由X射线晶体学揭示的生命进程中的化学基础

这篇文章是为国际化学年而写的总结.化学主导了几乎所有现代科学的分支,因为一旦深入到了分子水平上,就会涉及到化学事件.在生命科学领域里面,传统科学分支之间的界限实际上已经消失了,所以几乎所有的生物学问题都是以化学术语回答的.     

Synthesis,Crystal Structure,Magnetic Property and DFT Study of a Novel 2D Polymer [Cu(pdc)(bpy)]·H_2O

A new copper complex [Cu(pdc)(bpy)]·H2 O(1, H2 pdc = 3,5-pyridinedicarboxylic acid, bpy = 2,2-bipyridine) has been solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, UV-vis spectroscopy and magnetic measure- ments. Complex 1 crystallizes in monoclinic system, space group P21 /c, a = 10.893(2), b = 7.3641(15), c = 1.9921(4), β = 92.16(3), V = 1596.9(6)3, Dc = 1.676 g/cm3, Mr = 402.84, Z = 4, F(000) = 820, μ = 1.404 mm-1, the final R = 0.0237 and wR = 0.0693. The Cu(II) ion is five-coordinated by two O atoms from two pdc ligands, one N atom from another pdc ligand and two N atoms from the bpy ligand. The pdc anion, which acts as a tridentate ligand, links three Cu ions, forming(3,3)-connected two-dimensional(2D) sheets. We also studied the electronic structure and orbital energies of complex 1 by DFT methods, and the results are consistent with UV-vis spectrum.     

欢迎订阅中学数学

《中学数学》杂志旨在提高教学研究水平,构建教师发展平台,推进数学教育改革进程。主管:湖北省教育厅,主办:湖北大学、湖北省数学学会。国內刊号:CN42-1167/O1,国际刊号:ISSN1002-7572,邮发代号:上半月高中数学38-69、下半月初中数学38-225。本刊为全国优秀科技期刊、初等/中等教育类核心期     

欢迎订阅中学数学

正《中学数学》杂志旨在提高教学研究水平,构建教师发展平台,推进数学教育改革进程。主管:湖北省教育厅     

Linux的进程地址空间研究

本文研究了Linux进程的虚拟地址空间管理，包括页表结构、内存分配策略、线性地址区间结构，线性地址到物理地址的映射等。     

Exclusive γ（＊）γ processes

A short review of experimental and theoretical results on the large angle cross sections ＂γγ→ twomesons＂ and the form factors γ＊γ→ P = {π, η, η＇} is given.     

Resonance Conversion as a Catalyzer of Nuclear Reactions

It is shown that resonance internal conversion offers a feasible tool for mastering nuclear processes with laser or synchrotron radiation. The physics of the process is discussed in detail in a historical aspect. Possible experimental application is shown in the case of the M1 70.6-keV transition in nuclei of 169 Yb. The nuclear transition rate in hydrogen-like ions of this nuclide can be enhanced by up to four orders of magnitude.     

高考信息阅读题解说

数学是社会发展的产物，是人类文化的重要组成部分，它对推动社会进步和发展进程起着突出的主导作用．随着社会步入信息时代，掌握信息，领悟信息、利用信息已成为现代人必备的基本素质和能力．那么，作为具有选拔功能的高考又是怎样考查考生对信息的吸收、理解和运用能力的呢?     

Branch Processes of Vortex Filaments and Hopf Invariant Constraint on Scroll Wave

In this paper, by making use of Duan＇s topological current theory, the evolution of the vortex filaments in excitable media is discussed in detail. The vortex filaments are found generating or annihilating at the limit points and encountering, splitting, or merging at the bifurcation points of a complex function Z（x, t）. [t is also shown that the Hopf invariant of knotted scroll wave filaments is preserved in the branch processes （splitting, merging, or encountering） during the evolution of these knotted scroll wave filaments. Furthermore, it also revealed that the ＂exclusion principle＂ in some chemical media is just the special case of the Hopf invariant constraint, and during the branch processes the ＂exclusion principle＂ is also protected by topology.     

金刚石层厚度对复合片(PDC)残余应力的影响

通过X射线应力测试和有限元分析相结合的方法,研究了金刚石层厚度对聚晶金刚石复合片（PDC）残余应力的影响,并根据实验测试结果推导出了PDC表面中心与边缘的应力随金刚石层厚度变化的关系式。随着金刚石层厚度由0.5 mm增加到2.0 mm,PDC表面中心的压应力从1 800 MPa下降至700 MPa左右,而边缘部分的应力逐渐由压应力转为拉应力。金刚石层加厚虽然对边缘部分的最大拉应力影响不大,但使PDC边缘拉应力区宽度由0.76 mm增加到了2.85 mm。金刚石层厚度的增加还使得PDC边缘界面附近y方向的最大拉应力和位于界面边缘处的最大剪应力显著加大,这是金刚石层较厚的PDC界面容易产生裂纹的主要原因。