先进复合材料与力学

先进复合材料有着与常规材料完全不同的材料的概念,它本质上是结构物＾［１￣３］。这种需要用新的观念来应用和发展先进复合材料＾［４,５］,力不分析在这里起着十分重要的作用。     

气相催化法合成氯化亚砜

气相催化法合成氯化亚砜唐杜陵，张曼征，黄文丰，周忠信，李建新（湖北省化学研究所．武汉４３００７４）氯化亚砜［１］在有机合成上很重要，如氯化［２］、羧酸酰氯化［３］并醇解或氨（胺）解生成酯或酰胺，胺环化生成噻唑［４］和噻吩［５］等化合物，氯磺化及硫化物...     

分离装置的设计

分离装置的设计ｄｅｓｉｇｎｏｆｓｅｐａｒａｔｉｏｎｆａｃｉｌｉｔｙ四川轻化工学院饶安平译Ａ、除尘装置１．旋风除尘器［设计条件］分离在空气中含有密度为ρｐ［ｋｇ／ｍ￣３］的微粒子，风量为Ｑ［ｍ￣３／ｓ］，温度为ｔ［℃］。［设计计算］（１）形状不管选定图...     

气敏材料DBTAA及其衍生物的合成

本文报道ＤＢＴＡＡ（５，１４－二氢二苯并［ｂ，１］［１，４，８，１１］四氮杂［１４］轮烯）及其衍生物的合成实验结果。     

酸性离子液体催化合成三醋酸甘油酯

合成了［HSO₃-pmim］Cl、［HSO₃-pmim］［H₂PO₄］、［HSO₃-pmim］［BF₄］和［HSO₃-pmim］ ［HSO₄］离子液体，用1H-NMR和FT-IR对离子液体的结构进行了确定。将几种酸功能化离子液体应用于三醋酸甘油酯的合成反应中，筛选出了一种催化效果好又可以重复使用的离子液体［HSO₃-pmim］［HSO₄］。考察了催化剂用量、原料配比和反应时间对反应的影响，得到了较佳反应条件：n(甘油)∶n（醋酸）=1∶8，催化剂用量为醇酸总质量的5.8%，反应时间6 h，反应温度(80~90) ℃。对该功能化离子液体的重复使用性进行了考察，重复使用10次后，三醋酸甘油酯的收率仍大于90%。     

多聚磷酸作用下由硫代氨基脲合成1,3,4-二唑

多聚磷酸作用下由硫代氨基脲合成１，３，４┐二唑任仲皎＊李云李建有（中南民族学院化学系，武汉４３００７４）１，３，４－二唑化合物是重要的光敏物质，它们可作荧光剂［１］、激光染料［２］、闪烁体［３］，尤其作为感光高分子材料应用于电发光仪器［４～６］。...     

阴离子碳菁染料的合成与聚集动力学研究

自从１９３８年，Ｓｃｈｅｉｂｅ［１］发现了菁染料聚集体中的能量传递现象，人们对菁染料的聚集行为展开了大量的研究［２，３］．由于菁染料聚集体对乳剂具有特殊的增感作用，人们主要研究聚集体在乳剂中的增感机理［４，５］以及菁染料聚集的溶剂效应与浓度效应［６］...     

杯［6］芳烃热解及热动力学特性分析

在氮气氛围中，利用热失重分析方法对杯［6］芳烃与对叔丁基杯［6］芳烃的热解特性进行了研究，同时采用热分解动力学分析方法计算了反应过程对应的活化能以及最优机理函数方程。结果表明，对叔丁基杯［6］芳烃由于叔丁基的不稳定性导致其初始热分解温度同杯［6］芳烃相比提前约160 ℃，此之后的分解过程同杯［6］芳烃基本一致（即发生桥联的亚甲基断裂与母体苯环的热裂解），整体上残炭量杯［6］芳烃略高10 %；热解动力学分析表明，依据Kissinger和Flynn?Wall?Ozawa方法求出的杯［6］芳烃反应活化能分别是387.87 kJ/mol和376.28 kJ/mol，对叔丁基杯［6］芳烃脱叔丁基过程的化学反应活化能分别为223.56 kJ/mol和240.97 kJ/mol；依据Coats?Redfern方法求出杯［6］芳烃热解机理函数为g（α）=［-ln（1-α）］^2/5，反应级数n=2/5，对应非等温热解机理为随机成核和随后生长反应，对叔丁基杯［6］芳烃脱叔丁基过程的热解机理函数为g（α）=［-ln（1-α）］^1/2，反应级数n=1/2，对应非等温热解机理为随机成核和随后生长反应。     

几种新的环脲化合物的合成与硝化

本文报道６，６＇－乙撑二［３、７－二氧代－２、４、６、８－四氮杂双环［３、３、０］辛烷］，７、７＇－乙撑二［８－氧代－２、５、７、９－四氮杂双环［４、３、０］壬烷］和５，１１－二硫代－２、４、６、８、１０、１２－六氮杂三环［７、３、０、０（３．７）］十二烷］三种新环脲化合物的合成与硝化。硝化产物６，６＇－乙撑二［３、７－二氧代－２、４、８－三硝基－２、４、６、８－四氮杂双环［４、３、０］辛烷］，７，７＇－乙撑二［８－氧代－２、５、９－三硝基－２、５、７、９－四氮杂双环［４、３、０］壬烷］是新的环脲硝胺炸药，它们具有相当高的能量和改善的水解安定性。     

β—酮酸酯合成法的改进

β－酮酸酯是有机合成中应用极为广泛的原料和中间体［１］，其制备方法已有文献报道［１～５］。其中较为典型的方法有：１．Ｃｌａｉｓｅｎ缩合［３］；２．Ｍｉｃｈａｅｌ合成，即在－７８℃用ＬＤＡ处理乙酸乙酯后同酰氯反应［４］。前者产物复杂，收率过低；后者条件...     

催化加氢法制备4,4′-二氨基二苯乙烯-2,2′-二磺酸

INTRODUCTION 4,4′-Diaminostilbene-2,2′-disulfonic acid(DAS) is an important intermediate which is widely used in synthesis of fluorescent whitening agents, direct dyes and reactive dyes[1,2].So far, the conventional procedure using Fe as catalyst for the production of DAS in China is greatly limited, due to industrial waste water, high labor intensity and low production capability. The electrochemical reduction method has been reported[3] overseas, but it is not suitable for China considering its large equipment investment, lower yield and great power consumption. Compared with the methods mentioned above, the catalytic hydrogenation method has attracted a great deal of attention in view of its simple and easy operation, high production capacity and high production efficiency[4-6].The relatively cheap Raney nickel is not used here since it shows a low safety performance in preparing DAS at a high reaction temperature and high pressure. In this paper, highly reactive and recyclable palladium-carbon is chosen as the catalyst. DAS of high purity and high yield is prepared under mild conditions. The catalytic hydrogenation method is a prospective method in producing DAS.     

多面系统的辐射传热——净热流密度方程组法

本文讨论了间隔透明介质的多面系统辐射传热,它是Поляк法,在多面系统中的引伸.在这方面,Jakob做过详细分析.本文则进一步得出了较为简明的净热流密度方程组,并分析了它的实用方法.它可用来直接施加已知条件,联解各面未知量,包括诸传热面的净热流密度(或热流)和散热面(耐火材料面)的黑辐射热流密度(或温度).各面要求是漫散面,但不限于灰体,其中耐火材料面的面数亦不限于一个,净散热热流密度亦不限于为零.和近期Hottel等、Sparrow等的出射热流密度方程组法相比,引出较简,易于直接施加已知条件和得解.由整理后的系数矩阵求逆,可直接得未知量算式.对于双面系统和多面系统中的简单情况,本法所得的算式解和一般书载相同;对于复杂情况,易于电算求值,已用例说明,并和简化面系作了对比.最后还讨论了散热面的分区和传热面温度的不均匀性等影响.     

1-烯丙基-3-甲基咪唑氯盐[AMIM]Cl的回收

利用传统加热法合成1-烯丙基-3-甲基咪唑氯盐[AMIM]Cl,对稻杆进行预处理。采用常规减压蒸馏技术对[AMIM]Cl进行重复使用及回收。研究结果表明：使用五次的[AMIM]Cl的结构和组分基本保持一致;首次使用[AMIM]Cl对稻杆处理的还原糖收率可达82.08%,第2次和第3次还原糖收率为78.05%和76.11%;离子液体重复使用五次,仍具有良好的处理稻杆纤维素的能力,具有较好的应用前景。     

Synthesis of hexagonal structured wurtzite and chalcopyrite CuInS2 via a simple solution route

Wurtzite semiconductor CuInS₂ [CIS] has been reported in recent years. As a kind of metastable structure, it is a great challenge to synthesize pure wurtzite CIS at low temperature. In this paper, via a simple and quick solution route, we synthesize both wurtzite- and chalcopyrite-structure CIS. Well-controlled wurtzite CIS hexagonal plates are obtained when an appropriate agent is added. The influence of the used agent triethanolamine [TEA] has also been studied, and it turns out that without TEA, chalcopyrite CIS with a kind of rare morphology is formed through this method.     

A solution method for solving coupled nonlinear boundary-value problems

A Strum-Liouville integral transform technique is novelly applied to solve system of coupled nonlinear boundary-value problems approximately. The systems of differential equations consist of a linear differential operator and a nonlinear function of the dependent variables. To illustrate the potential of this technique we consider an example which comes from the modeling of diffusion and nonlinear chemical reaction systems in chemical engineering. The approximate solutions obtained by our technique agree surprising well with the numerically exact solutions obtained by the orthogonal collocation technique. To improve the approximation an iteration scheme in transform space is also defined.

Scope—Today, mathematical modeling of physical phenomena often produces (single or coupled) nonlinear differential equations. The true physical situation can, in many cases, be more closely described if the differential equations are allowed to be nonlinear. However, nonlinear differential equations are generally too difficult to be solved analytically apart from a few “tricks” or substitutions which apply only to a handful of equations [1]. An alternative approach is to look for a method which will reduce the problem, via analytical techniques, to a point where a “simple” computer program can solve the rest of the problem. The method introduced in this paper belongs to this class of solution techniques.

The method, which in this paper is applied to solving coupled nonlinear boundary-value problems, is a generalization of an idea in a paper by Do and Bailey [2] who apply it to a single nonlinear differential equation of boundary-value type. The equations, to which the technique is applied, arise from Fick's law diffusion into a porous solid and nonlinear reaction within the solid.

The solution method employs a Strum-Loiuville integral transform and to account for the nonlinear part an approximation is introduced. An iteration scheme is defined to improved the accuracy of the solution. The system of coupled nonlinear differential equations is reduced to a system of coupled nonlinear algebraic equations which is solved using a Newton-Raphson process. Finally, the solution is expressed as an infinite series, which is summed using a computer.

In response to papers by Do and Bailey [3] and Do and Weiland [4], Jerri [5] has tried to put this method on a more mathematical footing, and he shows that this method is a special case of a more general technique he has devised. Jerri uses the idea of Fourier transforms and convolution products to justify his method. The results for the example he considered are good, but he did not state how many iterations he required to obtain the solutions reported.

Conclusions and Significance—This paper has presented a very powerful method of solving boundary-value problems with linear operators and a nonlinear function of the dependent variable. The method works well for a single equation or coupled equations and can handle any kind of nonlinear function. We have shown through extensive numerical calculation the accuracy of this solution method, where the accuracy is measured in terms of a ratio of norms. In most cases an error of 4% can be achieved with just one iteration (Tables 2 and 3). Even though the present method has been applied to problems which have arisen from the modeling of chemical engineering problems, it would also be applicable to differential equations arising in other areas, provided they are of the same form.     

Materials based on aluminum and iron oxides obtained by the hydrothermal method

The influence of the relation [Al³⁺] : [Fe³⁺] on the phase composition and morphology of the products obtained by the hydrothermal method using solutions of salts of metals and combined sols of aluminum and iron (3+) hydroxides has been studied. The hydrothermal treatment of solutions of salts of aluminum and iron (3+) results in the formation of hematite of a cylindrical or capsular shape, while by the treatment of sols, depending on the relation [Al³⁺] : [Fe³⁺], it is possible to obtain particles of hematite with an ellipsoidal shape or bundles of amorphous AlOOH.     

Critique of dielectric cure monitoring in epoxy resins – Does the method work for commercial formulations?

Dielectric techniques can be used as an in situ monitor of resin cure. This study reports measurements on two commercial resin formulations and aims to establish the extent to which identifiable turning points in the dielectric behaviour are dependent of the formulation used. Complementary curometer and differential scanning calorimetry data are used to monitor the progress of cure and are compared with the dielectric data. System [A] is a simple epoxy amine system, whilst system [B] is a blend of both epoxy and amine resins. It is clear that without calibration of the dielectric data against other methods it is difficult to unambiguously derive absolute cure information on a system not previously studied. However, dielectric data does allow identification of the points at which gelation and vitrification occur and demonstrates its utility as an in situ monitoring method for the cure process.     

An analysis of switch stresses in two-dimensional bunkers

The method of characteristics, used in previous paper [7, 8] to calculate limiting stress fields in two-dimensional bins and hoppers containing granular material, is used to solve the switch stress problem, i.e. to find the stress field associated with a change in state from active to passive. The solution involves a discontinuity which, at the centre-line, is vertical rather than horizontal as has previously been assumed in other analyses. The peak stress does not occur at the transition but below it where the discontinuity reaches the wall.Wall stresses given by the present method are compared with those by the approximate methods of Walker [11], Walter [4], Enstad [5] and Jenike and Johanson [2, 3]. Substantial differences are found in the form of stress distribution and in the location and magnitude of the peak stresses. It is concluded that the approximate methods leave much to be desired.     

On a relationship between Quasi-Newton and dominant eigenvalue methods for the numerical solution of non-linear equations

In order to compare Quasi-Newton methods with the dominant eigenvalue (DE) method of convergence acceleration, the latter is modified so that an acceleration step is taken at every iteration and the method of calculation of the required coefficients can be suitably chosen.A relationship is derived between the class of rank-one Quasi-Newton methods (QN1) and modified DE methods such that each QN1 method corresponds to a particular modified DE method. However, it was not possible to find a QN1 formula which would correspond to the DE method applied at every iteration. Such a formula would appear to require information in advance, from iteration yet to be done.The advantages of using the equivalent modified DE method instead of Broyden's QN1 method are examined. A new algorithm of QN1 methods is proposed, based on the equivalent modified DE method, which was at least one order of magnitude faster, for Broyden's mehtod[1] on an example problem, than the conventional implementation.     

电真空玻璃熔窑内三维数学模型研究

电真空玻璃熔窑内三维数学模型研究祁建伟，胡桅林，过增元（清华大学工程力学系　１０００８４）ＴｈｒｅｅＤｉｍｅｎｓｉｏｎａｌＮｕｍｅｒｉｃａｌＳｉｍｕｌａｔｉｏｎｉｎａｎＥｌｅｃｔｒｉｃＶａｃｕｕｍＧｌａｓｓＭｅｌｔｉｎｇＦｕｒｎａｃｅ￥ＱｉＪｉａｎｗ...