含环氧基的丙烯酸酯共聚物改性环氧树脂

合成了一系列含环氧基团的丙烯酸酯聚合物（ＨＧＭＢ），并对其改性环氧树脂／４，４‘－二氨基二苯基甲烷的抗冲性能，动态力学行为进行了考察，结果表明：当必性体系中加入质量分数为１５％的ＨＧＭＢ（甲基丙烯酸缩水甘油酯、甲基丙烯酸羟乙基酯、甲基丙烯酸甲酯、丙烯酸丁酯的摩尔分数分别为４．３％、５％、２５．７％、６５％）时，与空白体系相比，改性体系的冲击强度提高５０％，且玻璃化有所提高，模量没有降低。     

CH3与NO在单、三态势能面上的反应机理

用从头算分了轨道法，在ＵＨＦ／６－３１Ｇ，水平上研究了ＣＨ３Ｏ与ＮＯ在单、三态势能面上的反应机理，发现该反应在两个势能面上均在两个彼此平行的反应途径，分别生产成产物ＣＨ３ＯＮ（ａ）和ＨＣＨＯ＋ＨＮＯ（ｂ），优化了四个途径的所有驻点的几何构型，用Ｍｏｒｏｋｕｍａ的数值分析方法计算了它们的内禀反应坐标（ＩＲＣ），各途径经零点能（ＺＰＥ）校正的活化位垒，单重态途径（ａ）为８６．８６ｋＪ．ｍｏｌ＾－１途径     

Theoretical calculations of the unimolecular canonical rate constants

Microcanonical rate constants k(E) and canonical rate constants k(T) for unimolecular reactions have been obtained through the calculations of cumulative reaction probabilities N(E) with the unsymmetrical Eckart potential tunneling correction. By way of example, the reactions HCN→CNH (I) and FNC→NCF (II) have been employed. For reaction (I), the calculated rate constants are in agreement with the experimental data; for reaction (II), the results are in accordance with the rate constants kCVT/MEPSAG(T) calculated by the common program POLYRATE.     

钛酸盐ATiO3 钙钛矿的铁电和反铁畸变

钛酸盐钙钛矿氧化物体系的研究对理解具有铁电极化的功能材料具有非常重要的科学意义.本文对ATiO3(A= Ca,Sr,Ba,Pb,Cd)体系的低温相、结构相变、及其对应的位移模式进行综述.我们着重比较了该体系存在的两类不稳定声子模式,即铁电极化模式(Ferroelectric,FE)和反铁畸变模式(Antiferrodistortive,AFD),在不同体系中所起到的作用.我们举例阐述了晶格失配应变、人工构造超晶格和化学掺杂等方法对这两种模式的调控思路.最后我们给出本文的总结讨论及研究展望.     

溶胶-凝胶杂化整体柱修饰及在多环芳烃检测中的应用

利用点击反应对含叠氮基的溶胶-凝胶整体柱进行了表面修饰,制备了C₆-硅胶杂化整体萃取柱。实验以多环芳烃为分析对象,考察了制备和修饰条件对萃取效率的影响,在优化的条件下,新制备的整体柱对萘、菲、芘和苯并[a]芘的萃取富集倍数分别达到95.9、114.2、103.2和57.8。萃取实验的日内和日间精密度(RSD)分别小于5.5%(n=8)和7.3%(n=10)。建立的管内固相微萃取-高效液相色谱检测16种常见多环芳烃方法的检出限(S/N=3)达到0.08~3.72 μg/L,定量限(S/N=10)达到0.26~12.40 μg/L。土壤中多环芳烃分析的加标回收率为82.4%~110.6%, RSD为2.6%~7.9%(n=3)。与美国国家环境保护局检测土壤中多环芳烃的方法比较,结果一致,准确性高。实验表明,该方法萃取效率高,灵敏可靠,操作简便,重现性好,可满足土壤等样品中痕量多环芳烃检测的要求。     

极大平面图结构研究

为采用常规数学方法研究“四色问题”,本文先对极大平面图的结构进行分析.提出了极大平面图的判断定理、有关性质及构成算法.     

光电经纬仪的跟踪误差及其检测

本文开头指出了跟踪性能是光电经纬仪第一重要技术指标，接着叙述了跟踪原理和跟踪误差的检测方法，并对跟踪误差进行了较深入的分析讨论文章最后，将跟踪误差分门别类，介绍了降低跟踪误差，提高跟踪性能的途径。     

半自动胶片判读仪的校正与标定

指出判读仪有三大核心问题;判读误差、输片误差和控制的正确性.简要地介绍了判读仪的“口”字调整、“田”字检验,以及“十”标定和判读误差的“井”字校正方法.最后给出了一个例子.     

Synthesis and biodistribution of the 99mTc nitrido complex with 2-(4-nitro-1H-imidazolyl)ethyl dithiocarbamate (NIET)

Sodium and chlorine measurements were made by instrumental neutron activation analysis (INAA) on stratigraphically dated ice core samples from Byrd Station, Antarctica, for the last three centuries. The time period between 1969 and 1989 showed an enhanced impact on the Antarctic ice sheets from oceans in the form of marine aerosols. A disturbed ocean-atmosphere interface due to El Niño Southern Oscillation (ENSO) events seems to be a candidate for this observation in Antarctica.     

Theoretical study of PhCH2O4CH2Ph: intermediate in the PhCH2O2 self-reaction

As a possible important intermediate during the oxidation of toluene in gas phase, the PhCH₂O₄CH₂Ph molecule has been invested on the structural parameters at CAM-B3LYP/6-311+g(df,pd) level, the vibrational frequencies at B3LYP-D3(BJ)/6-311+g(df,pd) level, and the potential energy surface of isomerization between main isomers at CCSD(T)-F12/cc-pVDZ-F12 level of theory. Ten PhCH₂O₄CH₂Ph isomers were located, in which the structural parameters of C-O₄-C skeleton are close to those in HO₄H and C₂H₅O₄C₂H₅. However, due to larger steric hindrance of aromatic groups, PhCH₂O₄CH₂Ph has a more open geometry with larger bond angles and dihedral angles in individual isomers. Meanwhile, it seems that the hyperconjugation appears to be stronger between the O-O bonds and aromatic groups, since the O-O bond lengths are slightly shorter than those found in HO₄H and C₂H₅O₄C₂H₅. Harmonic vibrational frequencies of PhCH₂O₄CH₂Ph isomers were first reported here and we found that the frequencies of O₄ torsion and O-O/C-O stretches in PhCH₂O₄CH₂Ph are consistent with those of CH₃O₄CH₃ and C₂H₅O₄C₂H₅. In the progress of isomerization, three transition states were located and a thermodynamic equilibrium between three main isomers may achieve at ambient temperature concerning the characters of energy barrier.