STUDIES ON BIS(ALKENYLCYCLOPENTADIENYL) IVB GROUP METAL DERIVATIVES

A series of new bis(allyleyclopentadienyl) and bis(2-butenylcyelopentadienyl) dichlorides of titanium, zirconium and hafnium have been synthesized by reacting sodium allyl or 2-butenylcyclopentadienide with IVB group metal chlorides. The substituted bis-cyclopentadienyl metal dichlorides treated with inorganic halides, aryllithium, potassium thiocyanate or hydrogen sulfide, bis(alkenylcyclopentadienyl)metal dihalides, and that of diaryl, dithiocyanato and dimercaptometal derivatives were obtained. Addition reaction on allyl group in bis(allylcyclopentadienyl) dihalides of titanium, zirconium and hafnium with hydrogen halide, halogen was studied. It was found that the addition of HX followed Markovnikov's rule.The reactivity of electrophilic addition increased in the order HCl相似文献   

ADENYLATE CYCLASE-MODULATING MEDIATORS OF INSULIN

Plasma membranes prepared from pig liver incubated with insulin (50—300 μU/ml) resulted in the release of at least two insulin chemical mediators. They appeared to modulate the activity of adenylate cyclase in liver plasma membrances of pig. One of them was fraction 1 of insulin mediator (M. W. about 3700—4000 dalton) which markedly stimulated the activity of the enzyme, the other was fraction 2 of insulin mediator (M. W. about 1000 dalton) which inhibited the enzyme activity. The results showed that the inhibitor of fraction 2 generated was significantly higher than that of fraction 1 when the membranes were incubated with insulin of low concentration (50—100 μU/ml). On the other hand, the generation of stimulator of fraction 1 from plasma membranes incubated with insulin of high concentration (200 μU/ml) was higher than that of fraction 2. So the ratio of yield between two mediators produced from the membranes was dependent on the concentration of insulin added. The results also showed that the     

基于矩阵分裂的广义逆A_（T，S）~（2）的表示及其应用

本文首先给出基于矩阵分裂的广义逆Ａ_（Ｔ，Ｓ）~（２）的表示，并将其应用于某些线性方程组迭代格式。本文的结果是一般性的，推广了文［３，４］中的结论。     

Coherence Measurement of White Light Emission from Femtosecond Laser Propagation in Air

Strong white light emission is observed from femtosecond laser propagation in air. The divergence angle of the white light emission is measured to be about 5mrad. Young＇s double-slits and a Michelson interferometer are used to investigate the coherence. The wavelength components of the white light emission are identified to have a good spatial coherence and a coherence time of about 0.5ps.     

生物小分子的电分析化学研究：Ⅳ.维生素K3的电化学性质和光谱电化…

研究了维生素Ｋ３在热解石墨电极上的电化学行为，分子定向和分子间的相互作用，用紫外吸收光谱电化学验证了它的电化学还原机理。实验结果表明维生素Ｋ３在热解石墨电极上的反应是受吸附作用控制的３ｅ，２Ｈ＾＋准可逆过程，维生素Ｋ３分子是Ｃ（６，７）位上的Ｈ按垂直向方吸附于热解石墨电极表面的，且吸附分子间存在着相斥的相互作用，其吸附平衡常数约为１．１１×１０＾５，吸附能约为２８．８ＫＪ．ｍｏｌ＾－＾１。吸收光谱     

高速云纹摄影的一些应用

云纹法与高速摄影相结合是解决动态力学量测量的有效手段之一。本文介绍了高速云纹摄影在动态应变场测量、应力波波形及速度测量、动态应力集中现象、动态断裂问题等方面的应用。     

加氢裂化催化剂反应酸性的表征方法及研究

本文报导了用邻二甲苯异构化反应活性表征加氢裂化催化剂及其载体酸性的方法,以邻二甲苯的总转化率表示在反应条件下的反应酸性。用这种方法可将催化剂及载体的反应酸性分成三类:含分子筛或氟的加氢裂化催化剂的反应酸性在55%以上;以无定形硅—铝为载体的加氢裂化催化剂和含氟的无定形硅—铝载体反应酸性大约在10—40%之间;无定形硅—铝载体的反应酸性一般在10%以下。用本方法考察了某些因素对一些加氢裂化催化剂反应酸性的影响。结果表明,硫化型加氢裂化催化剂的反应酸性比氧化型的略低;催化剂上活性金属的含量对反应酸性有明显的影响。     

答关于测力计的几个问题

把一条绳子的两端拉紧时,绳子上每相邻两部分间都有着一对作用力和反作用力,称为绳子的张力。如果绳子是不能伸长的而且绳子的质量可以忽略不计,那么对绳子的每个部分由牛顿第二定律得到: T-T=ma=0 (∵m=0),即得 T=T.如图1所示: 如果把绳子剪开将测力计系在绳子中间,则测力计的读数便可以看成是张力T的量值。下面再结合一些读者来问,具体地说明有关问题。 1.用圆环把测力计系于墙上的钉子上,而在测力计另一端的钩子系一条绳子,当男孩A拉绳时,测力计指示的读数是42千克重。它的意义是什么? 如我们以F代表男孩A作用到绳子上的力,且我们已经知道测力计的读数可以看成是绳的张力T的量值;由于此时绳子不能伸长,且F和T处于平衡状态,则很容易得到:     

树脂催化法合成糖醇酯的研究

利用大孔阳离子交换树脂为催化剂，催化合成乙酸糖醇酯，丙酸糠醇酯，丁酸糠醇酯，乙酸四氢糠醇酯，丙酸四氢糠醇酯，丁酸四氢糠醇酯，对影响反应的诸因素进行了讨论。     

一种基于Zernike多项式的波前探测和重构方法

运用Ｎｏｌｌ建议的Ｚｅｒｎｉｋｅ多项式形式表征大气扰动的波面，求出由两个离焦面上的光强分决定的Ｚｅｒｎｉｋｅ多项式的前ｎ项在特定的探测器上的响应矩阵Ｒ。由Ｒ和输入的随机波面在两个离焦面上的光强分布，可方便地求出其Ｚｅｒｎｉｋｅ多项式的系数，从而实现了波前的探测和重构。采用光线追迹的变方法，用计算机模拟验证了这种方法的原理和可行性。