含官能团的取代烯烃的硼氢化反应——Ⅰ.巴豆醛的硼氢化反应

巴豆醛在过量乙硼氢的硼氢化反应中得到的主要产物是正丁醇。本文论证这一反应的历程,其中包括有“二硼酸”型的β-消除反应。还讨论有电负性元素取代的烯烃的硼氢化反应。巴豆醛在低温(-25°)硼氢化,可使这类消除反应大为减少,主要得到硼氢化的正常产物——丁二醇。     

APPLICATION OF FLUX-VECTOR-SPLITTING SCHEME TO A DILUTE GAS–PARTICLE JPL NOZZLE FLOW

A time-dependent numerical algorithm is developed for the two-fluid model Euler of TLNS (thin layer Navier–Stokes) equations. The analysis is based on a MUSCL (monotone upstream central scheme for conservation laws)-type flux-vector-splitting scheme with the multi-level technique. This algorithm is applied to investigate JPL (Jet Propulsion Laboratory) nozzle flow. Calculated results for both one- and two-phase flows are given to show the accuracy, the computational efficiency and the particle influence on the flow field.     

Comparison of some multireference electronic structure methods in illustrative applications

The performances of several multireference electronic structure methods including complete active space self-consistent field (CASSCF)-based second-order perturbation theory (CASPT2), multireference configuration interaction with single and double excitations (MR-CISD), MR-CISD with the Davidson correction (MR-CISD+Q), and the CASSCF-based block-correlated coupled cluster method (CAS-BCCC4) we developed recently are compared by applying them to study several different chemical problems involving computation...     

对Maron理论处理高分子稀溶液的一点修改

近年来应用Maron溶液理论处理高分子溶液的一系列关于溶剂的热力学性貭,得到满意的結果。現有的例子都属高分子-良溶剂溶液。对稀溶液渗透压数据的处理,作者等巳指出可用π/c(1+qc)对c(1+qc)的作图法,得到直线关系,其中(符号均按Maron的写法,参阅文献[4])     

聚二甲基硅氧烷-溴代环己烷体系沉降系数的压力改正与s-M,[η]-M单分散关系

对聚二甲基硅氧烷-溴代环己烷θ溶液(28℃)体系进行了沉降速度法测定分子量分布及沉降系数压力改正的研究。提出了一种新的直接测定沉降系数的压力改正的方法,即在沉降池中加入不同量的溶液以得到不同的液柱高来改变静压,测定溶液界面在不同静压下的浮升速度计算压力系数。所得适用 于静压为200大气压以下的沉降系数的压力改正系数α=1.44×10~(-3)_(大气压)~(-1)。从沉降系数分布、(?)_ω、[η]_θ及[η]_(甲苯)的测定,订定了聚二甲基硅氧烷在28℃θ条件下的s-M,[η]_θ-M及在甲苯(25℃,良溶剂)中的[η]-M单分散关系为。 s_1=6.30×10~(16)M~(0.50)(溴代环己烷,28℃) [η]=7.41×10~(-2)M~(0.50)(溴代环己烷,28℃) [η]=9.53×10~(-3)M~(0.71)(甲苯,25℃)     

聚酰胺6的红外光谱

根据对聚酰胺类高聚物红外光谱的类比和对聚酰胺6试样进行氘化和碘处理后红外光谱的改变,以及根据对拉伸过的聚酰胺6薄膜试样的偏振红外光谱的观察,我们对聚酰胺6红外光谱中400cm^-1—1400cm^-1之间的主要吸收带,作了如下解释:1370cm^-1吸收带为ν_(cщN);1265cm^-1和1205cm^-1吸收带为δ_N-H+ν_(cщN)(酰胺Ⅲ);1170cm^-1吸收带为ν_(cN);730cm^-1吸收带为γ_(CH2)[当(CH₂)_n的n≥4时];690cm^-1吸收带为δ_N-H(面外);580cm^-1吸收带亦为δ_N-H(面外)。