孔洞缺陷对B炸药性能影响的理论计算

为探究孔洞缺陷及其大小对B炸药性能的影响,建立了3种空位缺陷浓度一致但孔洞大小不同的B炸药缺陷模型.采用分子动力学方法,计算得到了不同B炸药模型与感度、结合能、爆轰性能和力学性能相关的参数并进行了比较.结果表明,缺陷模型的键连双原子作用能和内聚能密度下降了9.93～23.88 kJ·mol~(-1)和0.0082～0.0254 kJ·cm~(-3),表明孔洞缺陷的存在使B炸药更敏感,且孔洞越大,敏感程度越高.缺陷模型的结合能下降了368.43～391.46 kJ·mol~(-1),表明孔洞缺陷导致B炸药的稳定性下降,且孔洞越大,稳定性越差.孔洞缺陷对B炸药的爆轰性能影响比较微弱,受密度下降的影响,爆速和爆压轻微下降.孔洞缺陷导致B炸药的弹性模量、体积模量、剪切模量和柯西压分别下降0.21～1.24 GPa、0.23～1.46 GPa;0.08～0.48 GPa以及0.09～0.44 GPa,体积模量与剪切模量的比值几乎不变,表明孔洞缺陷导致B炸药的抗变形能力和延展性变差.     

一苯氧基二氯化钕四氢呋喃络合物和三氯化钕酚合物对丁二烯聚合的催化活性

<正> 脂肪族三烷氧基稀土化合物作为双烯烃定向聚合的主催化剂只有少数专利。最近,单成基等以Nd(OR)_(3-n)Cl_n-AlEt_3催化体系对双烯烃聚合进行了研究。三氯化钕醇合物与烷基铝组成的双烯烃聚合催化体系已有报导。本文着重研究一苯氧基二氯化钕四氢呋喃络合物和三氯化稀土酚合物与烷基铝组成的催化体系对丁二烯聚合的催化活性。     

Synthesis, Crystal Structure and Photoluminescent Property of a Novel Silver(I) Compound {[Ag(bpp)]_2(Hphth)(NO_3)·(H_2O)_2}_n

Self-assembly of Ag(I) nitrate, 1,3-bis(4-pyridyl)propane (bpp) and phthalic acid monopotassium salt (KHphth) in CH3OH-H2O solution produced the title complex, {[Ag(bpp)]2(Hphth)(NO3)·(H2O)2}n, which was characterized by single-crystal X-ray diffraction, elemental analysis, IR spectrum, and photoluminescent spectrum. Single-crystal X-ray analysis revealed that the complex crystallizes in a monoclinic system, space group P21/c, with a = 15.4174(5), b = 8.6398(2), c = 25.2466(8) , β = 91.072(1)o, V = 3362.34(17) 3, Z = 4, C34H37N5O9Ag2, Mr = 875.43, Dc = 1.729 g/cm3, μ = 1.228 mm-1, F(000) = 1768, the final R = 0.0749 and wR = 0.1580 for 5754 reflections with I > 2σ(I). The Ag atom is coordinated by two N atoms from two bpp molecules in an approximately linear geometry. The Ag(I) ions are linked by the bpp molecules to form one-dimensional zigzag chains propagating along the c axis. The Hphth- and nitrate counter-ions are bridged by solvent water molecules through hydrogen bonds to generate a one-dimensional chain extending along the b axis. Electrostatic interactions between cations and anions, extensive hydrogen bonds and π-π interactions are responsible for the three-dimensional supramolecular structure. In the solid state, the compound exhibits blue photoluminescence with the maximum at 436 nm upon excitation at 344 nm.     

幕墙石材红砂岩测试评价方法的探讨

红砂岩板材作建筑物幕墙,在国内外非常少见,其测试评价方法标准和验收规程在国内几乎是空白。本文参照《金属与石材幕墙工程技术规范》(JGJ 133-2001)和根据红砂岩的特性,提出了红砂岩作幕墙板材需进行测试的指标,包括物性指标和强度指标等;对初步选定的满足设计要求的红砂岩石材,特别需进行大气稳定性试验。同时对其有关指标进行必要的鉴定和评价,才能找出符合要求的红砂岩板材作幕墙。     

苯胺在SnO_2/Ti电极上的电化学氧化

研究了以SnO_2/Ti为阳极降解苯胺的电化学降解特性.实验结果表明,同Pt电极比较,掺F的SnO_2/Ti电极对苯胺的降解表现了明显的效果.苯胺在SnO_2/Ti电极上氧化降解速率主要决定于其中间产物的阳极溶解行为.由中间产物构成的有机膜的阳极溶解是反应的慢步骤.研究了苯胺溶液的浓度、pH和电流密度对苯胺降解速率的影响规律,对反应中间产物的复杂性及构成“膜”的理化性质进行了初步分析.     

实验教具的改进──多孔试管夹

普通试管夹在某些情况下使用起来很不方便.经我改进的试管夹有双孔的、三孔的——多孔的试管夹,如图.     

Hydrothermal Synthesis, Crystal Structure and Magnetic Property of a Novel Pentanuclear Copper(II) Complex:[Cu_5(SIP)_2(HSIP)_2(H_2O)_(18)](H_2O)_5

The pentanuclear complex, Cu5(SIP)2(HSIP)2(H2O)18(H2O)5(H3SIP = 5-sulfoi-sophthalic acid), has been synthesized by the hydrothermal reaction of CuCl2 with NaH2SIP at 160 ℃, and characterized by single-crystal X-ray diffraction and IR spectrum.The crystal of the complex crystallizes in a triclinic system, space group P1-, with a = 7.0018(5), b = 11.9725(8), c = 19.0424(13) , α = 78.8540(10), β = 85.1710(10), γ = 83.6080(10)o, V = 1553.24(19) 3, Z = 1, C32H60O51S4Cu5, Mr = 1706.74, Dc = 1.825 g/cm3, μ = 1.937 mm-1, F(000) = 869, the final R = 0.0709 and wR = 0.1503 for 4235 observed reflections with I > 2σ(I).The five Cu2+ ions are connected by two symmetry-related tridentate SIP3-ligands and charge-balanced by two monodentate HSIP2-ligands, giving a discrete pentanuclear structure.The pentanuclear copper molecules are linked by hydrogen bonds to form a three-dimensional supramolecular structure.The temperature-dependent magnetic susceptibility data revealed weak ferromagnetic magnetic interactions between the Cu2+ ions.