Crystal and Molecular Structure of a New Mono－substituted Titanocene Complex，｛（η~5－Cp）［η~5－（1－（4－OCH_3）C_6H_4）C_6H_（10）Cp］（TiCl_2）｝·0．3（n－C_6H_（14））

ＣｒｙｓｔａｌａｎｄＭｏｌｅｃｕｌａｒＳｔｒｕｃｔｕｒｅｏｆａＮｅｗＭｏｎｏ－ｓｕｂｓｔｉｔｕｔｅｄＴｉｔａｎｏｃｅｎｅＣｏｍｐｌｅｘ，｛（η~５－Ｃｐ）［η~５－（１－（４－ＯＣＨ_３）Ｃ_６Ｈ_４）Ｃ_６Ｈ_（１０）Ｃｐ］（ＴｉＣｌ_２）｝·０．３（ｎ－...     

C1桥联的茂金属化合物(Cp)CR1R2(Flu)MCl2的合成及其催化烯烃聚合活性

合成了6种单碳桥联的含芴(Flu)茂(Cp)基B族茂金属催化剂,研究了它们催化烯烃聚合的能力.通过IR,¹HNMR,EI-MS和元素分析对化合物进行了表征.用所合成的茂金属化合物与MAO所组成的催化体系对乙烯、丙烯的聚合进行了研究.其中金属为Ti的催化剂没有聚合活性或活性极低.金属为Zr的催化剂有一定的催化活性,用不同的催化剂得到的聚合物性质有一定的差异.     

Robust adaptive synchronization of chaotic neural networks by slide technique

In this paper, we focus on the robust adaptive synchronization between two coupled chaotic neural networks with all the parameters unknown and time-varying delay. In order to increase the robustness of the two coupled neural networks, the key idea is that a sliding-mode-type controller is employed. Moreover, without the estimate values of the network unknown parameters taken as an updating object, a new updating object is introduced in the constructing of controller. Using the proposed controller, without any requirements for the boundedness, monotonicity and differentiability of activation functions, and symmetry of connections, the two coupled chaotic neural networks can achieve global robust synchronization no matter what their initial states are. Finally, the numerical simulation validates the effectiveness and feasibility of the proposed technique.     

实际气体R134a在离心叶轮内部流动的数值研究

使用实际气体模型对R134a在半开式离心压缩机叶轮内部三维湍流进行了数值计算,比较了比容比相等情况下实际及理想气体模型对压缩过程的差异.研究表明二者设计流量系数基本相等,但实际气体的多变效率低于相应的理想气体计算值;数值计算能够较好地预测实际气体的流动结构和性能参数的变化规律,对实际气体制冷压缩机气动热力设计具有理论及工程意义.     

The structural transformation and properties of spin-on poly(silsesquioxane) films by thermal curing

In this study, the structural transformation and properties of five commercially available poly(silsesquioxanes) by thermal curing were investigated, including poly(hydrogen silsesquioxanes) (HSQ and T12), and poly(methylsilsesquioxanes) (MSQ, T7 and T9). These materials with a different cage/network ratio and side groups (Si-H and Si-CH₃). The FTIR spectra show that the poly(silsesquioxane) films have different contents of the Si-O-Si cage and network structures, which significantly affects the refractive index and dielectric constant. The shifting of the Si-O-Si network band in the FTIR spectra can be correlated with their molecular structures. The refractive indices and dielectric constants of the studied poly(silsesquioxane) films increase with increasing the Si-O-Si network content. The retention of the Si-H or Si-CH₃ side group suggests the existence of the cage structures in the poly(silsesquioxane) films. The Si-O-Si cage structure results in a larger free volume than the Si-O-Si network structure in the poly(silsesquioxane) films and thus reduces the refractive index and dielectric constant. It is supported by the porosity result. The order of the refractive index in the studied poly(silsesquioxanes) films is T12>HSQ for the Si-H side group and T7>T9>MSQ with the Si-CH₃ side group, which can be correlated with the Si-O-Si network content. The poly(silsesquioxane) film with the Si-CH₃ side group has a lower refractive index than the Si-H side group at the same Si-O-Si network content, which is probably due to the steric hindrance effect of the CH₃ group.     

Linear matrix inequality approach to exponential synchronization of a class of chaotic neural networks with time-varying delays

In this paper, a synchronization scheme for a class of chaotic neural networks with time-varying delays is presented. This class of chaotic neural networks covers several well-known neural networks, such as Hopfield neural networks, cellular neural networks, and bidirectional associative memory networks. The obtained criteria are expressed in terms of linear matrix inequalities, thus they can be efficiently verified. A comparison between our results and the previous results shows that our results are less restrictive.     

微波法合成2,2′-二苯-1,4-苯并噁嗪-3(4H)-酮及其结构表征

苯并噁嗪酮化合物广泛存在于禾本科植物中,这类化合物在前药合成和生物活性研究方面具有广泛的应用前景[1～4].目前已知的合成方法中,大多都是采用邻氨基酚与ClC(R1R2)COCl(氯酰氯)在碱性条件下长时间回流制得的,反应时间较长;除反应原料外,还需要加入其它碱性物质和溶剂[5～7]     

A delay-decomposition approach for stability of neural network with time-varying delay

This paper studies delay-dependent asymptotical stability problems for the neural system with time-varying delay. By dividing the whole interval into multiple segments such that each segment has a different Lyapunov matrix, some improved delay-dependent stability conditions are derived by employing an integral equality technique. A numerical example is given to demonstrate the effectiveness and less conservativeness of the proposed methods.     

松香基甜菜碱两亲分子构筑多维Ni(OH)2/NiOOH微纳米复合材料

采用自制脱氢松香基甜菜碱功能性两亲分子构筑得到3种形貌均匀的Ni(OH)₂/NiOOH微纳米复合材料, 分别为孔径约2 μm的三维珊瑚状、花状空心微球和宽度约100 nm的二维纳米片, 对复合材料的物相组成和形貌结构采用X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)等技术手段分析表征。结合自制松香基甜菜碱两亲分子红外光谱(FT-IR)、核磁(NMR)结构表征和优异的表面活性推测得到松香基甜菜碱两亲分子构筑3种不同形貌微纳米复合材料的机理;研究表明, 在松香基甜菜碱两亲分子稳定刚性结构的作用下, 通过反应温度控制其吸附能力可构筑出3种形貌分散性较好的氢氧化镍复合材料。     

松香基甜菜碱两亲分子构筑多维Ni(OH)2/NiOOH微纳米复合材料

采用自制脱氢松香基甜菜碱功能性两亲分子构筑得到3种形貌均匀的Ni(OH)_2/NiOOH微纳米复合材料,分别为孔径约2μm的三维珊瑚状、花状空心微球和宽度约100 nm的二维纳米片,对复合材料的物相组成和形貌结构采用X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)等技术手段分析表征。结合自制松香基甜菜碱两亲分子红外光谱(FT-IR)、核磁(NMR)结构表征和优异的表面活性推测得到松香基甜菜碱两亲分子构筑3种不同形貌微纳米复合材料的机理;研究表明,在松香基甜菜碱两亲分子稳定刚性结构的作用下,通过反应温度控制其吸附能力可构筑出3种形貌分散性较好的氢氧化镍复合材料。