THE DEAD BURNING OF DOLOMITE—II1

There are many large deposits of dolomite in the United States. These range from the very pure dolomite of Ohio and the eastern states, notably New York and Pennsylvania which correspond very closely to the theoretical formula CaCO₃ MgCO₃ to dolomites which are very low in MgO content.     

单基团保护法制备三氯蔗糖的研究

三氯蔗糖是蔗糖的一种衍生物,是目前己知被发现的一种甜度极高、味觉特性最好的蔗糖三氯衍生物,口感与蔗糖相似,其研究及应用都有着广阔的前景。从工业化的角度出发,在讨论甜味剂三氯蔗糖的各种合成方法的基础上展开了研究。     

Stability of Homogeneous Fluidization Under Extreme Conditions of Operation

Recently reported results for the behaviour of fluidized beds under extreme conditions of operation are shown to be in good quantitative agreement with the predictions of a long established fluid‐dynamic criterion for the onset of instability of the homogeneously fluidized state. The four sets of experiments relate to fluidization under very high pressure conditions (by supercritical fluids), at very high and very low effective gravitational field strengths, and at very low particle concentrations.     

铸造钛上直接镀镍工艺的研究

钛及其钛合金是非常活泼的金属,由于在其上容易形成一种自然的氧化膜,很难获得结合力良好的镀层。在铸造钛上镀镍的关键是如何保证镍镀层与基体的结合力,这样对铸造钛材的前处理研究就显得非常重要。为此研究了铸造钛合金镀前的浸蚀和活化工艺,研究了浸蚀液和活化液的组成及其对镀层结合力的影响,确定了最佳的工艺。     

Drag force on a circular cylinder midway between two parallel plates at very low Reynolds numbers—Part 1: Poiseuille flow (numerical)

At very low Reynolds numbers, we calculate the drag force exerted on a circular cylinder in cross flow fixed midway between two parallel plane walls which are fixed while the fluid experiences a Poiseuille profile at upstream and downstream. The drag wall correction factor is numerically investigated from a very weak interaction to the lubrication regime. The Navier-Stokes and continuity equations are expressed in the stream function and vorticity formulation and are rewritten in an orthogonal system of curvilinear co-ordinates. These equations are solved with using a finite differences method. The generation of the grid was carried out by the singularities method. We calculated the separate contributions of the pressure and viscous forces numerically. At very weak interactions, our numerical results are in good agreement with those obtained analytically by Harrison (Trans. Camb. Phil. Soc. 23 (1924) 71) and Faxèn (Proc. Roy. Swed. Acad. Eng. Sci. 187 (1946) 1). In the lubrication regime these numerical calculations are in very good agreement with those we carried out by asymptotic expansion. So that, the accuracy of the numerical code is tested. This analysis allowed us to show how that the pressure term prevails over the viscosity term in the lubrication regime. At very weak interaction, these forces have the same value.     

Heat transfer by radiation and convection in fire testing

Fire safety engineers, especially those experts writing fire test standards, often have different understandings of the concepts of heat transfer from a fire to a surface by radiation and convection. The concepts are therefore often not very well defined, in e.g. ISO and CEN standards, leading in many cases to confusions, misunderstandings and considerable errors. This paper is an effort, in a very simple way, to make the issue a little clearer, particularly for use in international standardization work. ISO/TC92 and the International FORUM of Fire Research Directors are currently endorsing very important work on procedures to calibrate heat flux meters. The two entities, heat transfer by radiation and convection, may be treated independently. The presentation below is deliberately very short and basic avoiding many phenomena that are not immediately needed in most fire standardization work. Recommendations are reached on how to define and measure heat transfer in fire testing. Copyright © 2004 John Wiley & Sons, Ltd.     

荧光探针及其典型品种

荧光探针是一种典型的精细化学品,具有产量小（全球只需要几公斤）、附加值高（100美圆／毫克左右）、投资小（生产车间仅几百平米）、技术含量高的特点。文中给出了一些常见的、典型的品种以及它们的合成方法与应用领域。     

Measurement of particle size distribution by image analyser

Image analysis provides a very useful method for the measurement of the size distribution of granular materials. The method is very useful when the grains to be measured are very small (1 ? 25 μm), or are imbedded in a solid matrix. The techniques of measurement are described and the analytical methods for the transformation of random chord measurements made on section to three-dimensional size are provided in a convenient form. An example is given using data obtained from a modern automatic image analyser. Traditionally, this technique is applicable only to spherical particles, but the method presented in this paper can be used for particles of irregular shape which enhances its utility considerably.     

Synthesis of very highly dispersed platinum catalysts supported on carbon xerogels by the strong electrostatic adsorption method

Highly dispersed Pt/carbon xerogel catalysts are obtained by applying the “strong electrostatic adsorption” (SEA) of hexachloroplatinic acid to carbon xerogels (PZC = 9.4) and platinum tetraammine chloride to oxidized carbon xerogels (PZC = 2.4). After the reduction step, all these Pt/carbon xerogel catalysts display a very high level of metal dispersion: very small platinum particles (1.1–1.3 nm) are observed by TEM. Pt particle sizes obtained by CO chemisorption are in good agreement with TEM micrographs, which shows that the metal is accessible to reactants. These Pt/carbon xerogel catalysts are very active for the hydrogenation of benzene into cyclohexane.     

Active sites in methanol oxidation on Cu(110) determined by STM and molecular beam measurements

STM has been combined with molecular beam rate measurements to gain an understanding of the oxidative dehydrogenation of methanol to produce formaldehyde, both at the macroscopic and microscopic level. From this a model of the reaction is developed where the methanol initial reacts at very few active oxygen sites located at the short sides of oxygen islands on the Cu(110) surface. Such sites are very much rarer on a surface which is saturated with 0.5 monolayers of oxygen and the reaction rate is initially very low, but shows autocatalytic behaviour, rising in time as vacancies are created in the oxygen layer.     

堆肥过程中产生的尾气

堆肥过程中产生大量的臭气，考察这些臭气的组成、含量对处理城市生活垃圾堆肥有重大意义。实验采用气相色谱质谱联用仪（GCMS）对收集的堆肥尾气进行检测，测得21种气体，其中含量较大的气体为NH3和H2S等。     

电厂主厂房灭火器的配置

主厂房是电厂的中枢纽带,其结构复杂,设备种类繁多,消防设计非常繁琐。文章对火力发电厂主厂房灭火器配置进行了简要概述,并对设置注意事项进行了讨论。正确、合理的配置建筑灭火器,可以有效地扑救厂房初起火灾,减少火灾损失,保护人身和财产的安全。     

工厂计划优化管理系统PIMS

详细叙述了过程工业经济规划系统（PIMS）的概念，应用及其产品。     

Diacetylene-Containing Polymers XIV: Poly(octa-3,5-diynylene-1,8-dicarboxyalates) containing some polar azo dyes

Abstract A series of novel polymers having polar azo dyes were synthesized and characterized. Although their chromophore contents are very high, their second order nonlinear (2-NLO) response was very poor. The poor 2-NLO responses are thought to be due to poor orientation because of their improper main chain conformations, as well as their low glass transition temperatures. They undergo slow cross-linking on standing at room temperature, and rapidly on heating at temperalures above 150°C, through the diacetylene units of the main chains. Nevertheless, these polymers are interesting materials as azo-polymers because of their very high concentration of azo dyes, which are distributed homogeneously in the polymers. Synthesis and characterization are described, and the most important factor for the 2-NLO polymers is discussed.     

Rheological behaviour of cement and silica suspensions: Particle aggregation modelling

Cement and silica suspension rheological behaviour is modelled by supposing that particle aggregation occurs. With two independent parameters, the variation of the shear viscosity as a function of the shear rate for cement or silica suspensions having different solid volume fractions can be predicted. The model is in good agreement with experimental data. Cement suspensions are initially very similar to unreactive silica suspensions. The values of adhesion forces obtained seem to show that the effective interaction areas are very small. It reflects the fact that in the dormant period the particles are contacting at points, which become progressively higher in surface as C-S-H precipitates at these contacts. The model used is consistent with the observed power law variation of static and dynamic yield stresses with solid volume fraction. The aggregates formed under shear seem to be very compact, which is presumably related to the large solid volume fractions of the studied suspensions.     

长距离管道化学清洗方法初探

长管道的化学清洗历来是清洗工程中的难点，它无法循环，热损失严重，放空、腐蚀难控制。笔者在长期实践中总结出5种清洗方式。     

Polymeric Inserts and Implants for the Controlled Release of Drugs

Because of the ability of polymers to exist in glassy, rubbery or solvent-swollen forms which have very different diffusion coefficients they are able to be used very effectively to control the release of incorporated drugs. As the polymers can vary from inert in vivo to biodegradable an even greater scope for versatile formulation is provided. The various parameters governing the design of controlled release implants are discussed.     

Electrochemical digital simulations with an exponentially expanding grid: General expressions for higher order approximations to spatial derivatives: The special case of four-point formulas and their application to multipulse techniques in planar and any size spherical electrodes

This paper deals with the consideration, in digital simulation, of a grid in which there is a geometrical relationship between the distances between neighbouring pairs of points, leading to an exponentially expanding sequence of intervals. We show that the expressions for derivatives for higher order spatial discretisations take a very simple form, with coefficients which are dependent on the number of points taken to the left and right of the point considered, but independent of the absolute position of the point in the grid. This enables convenient and efficient manipulation and incorporation in computer programs of these derivatives in the context of finite difference approach. Moreover, the explicit expressions obtained lead to very interesting particular situations. The most interesting is the optimal behaviour of the four-point spatial discretisation for very high expansion factors, which, in combination with fully implicit time-integration schemes, leads to very fast and accurate calculations both for planar and any size spherical electrodes, including microelectrodes. Applications of these coefficients in the simulation of some multipulse and square wave experiments are also presented.     

相转移催化Reimer-Tiemann法反应合成对羟基苯甲醛的研究进展

对羟基苯甲醛是一种十分重要的精细化工原料,其合成方法较多.其中的Reimer-Tiemann法反应机理明确、原料价格低廉易得、设备要求低,采用相转移催化剂后可有效减少副产物并提高产率.     

浅析防刺织物研究开发现状

目前安保人员面临的威胁主要来自小型火器和锐器,当前防弹装备技术已很成熟,且种类丰富,但防刺装备还很落后,亟需开发一种新型防刺织物在满足防刺要求的同时,兼顾轻质、穿戴舒适以及美观等功能。阐述了织物防刺机制及须具备的特性,并介绍了几种防刺织物研究开发应用的高性能纤维及开发途径。