激光激活化学反应分离同位素反应池参数确定及其影响

在气体分子运动论、碰撞理论、流体力学和光化学反应、热化学反应及高斯光束理论基础上建立了位于激光器腔内外的反应池的设计尺寸同各相关参量和同位素产物产率、同位素分离系数间的关系，并给出了一些计算结果。     

交联剂在碳／碳复合材料沥青基体中的作用

本文从C/C复合合材料的基体入手，分析了交联剂在沥青中的交联机理，并以此为基础对中温煤沥青在催化剂作用下进行交联反应。结果表明，交联剂在C/C复合材料基体中的交联作用非常明显，不仅基体本身的残碳率及耐热程度有很大提高，而且，以它制成的C/C复合材料的抗压强度也有显著增加。     

Carbon fibre cloth as an electrode material: electrical conductivity and mass transfer

The paper deals with carbon fibre cloth electrodes, employed in the fabrication of composite materials. The electrical conductivity of single bundles, groups of bundles and cloth is studied. Ohm's law applies to the electrical conduction in the direction of the fibre length, but bundle conductivity decreases with the number of fibres in the bundle. Electrochemical mass transfer between a flowing electrolyte and a cloth arranged as a flow-through or a flow-by porous electrode indicates the existence of double porosity in the material. Due to double porosity, only the external surface of the cloth works as an electrode. This finding shows that the material is not suitable for such an application.     

Evolution of BET internal surface area in glassy carbon powder during thermal oxidation

It is demonstrated that glassy carbon powder can be thermochemically activated. During activation, a film with open pores is created on the glassy carbon particles. This film has a large internal surface area, which is accessible to liquids and gases. A simple model for the evolution of the internal surface area in glassy carbon powder during thermochemical gas-phase oxidation is also presented and compared with experimental data. Experimental results are in qualitative agreement with the model. We found that a sharp particle size distribution is desirable with regard to potential technical applications.     

Three‐dimensionally braided carbon fiber–epoxy composites,a new type of material for osteosynthesis devices. I. Mechanical properties and moisture absorption behavior

In recent years, three‐dimensionally (3D) braided composites have attracted a great deal of attention because of their high‐impact damage tolerance and fatigue life, superior fracture toughness, and so forth, and have been used in aeronautics, military, and transportation. These advantages make them strong candidates for osteosynthesis devices. In this study, 3D braided carbon fiber–epoxy (C_3D/EP) composites were produced via a simple vacuum impregnation technique. The load‐deflection curve, mechanical properties, and influence of fiber volume fraction, braiding angle, and axial reinforcing fibers were examined to determine their suitability for internal fixation devices. It is found that the C_3D/EP composites have excellent toughness and do not show brittleness when fractured because of their relatively high void content. The flexural, shear, and impact strengths of the C_3D/EP composites are excellent. It was shown that a C_3D/EP composite with a stiffness similar to load‐bearing bones can be made while maintaining enough strength. It is concluded that a relatively higher void content and braiding angle is more suitable for the C_3D/EP composites from the viewpoint of requirements of fracture fixation materials. The moisture absorption behavior and changes in mechanical properties caused by moisture uptake were evaluated. Results show that absorbed moisture slightly decreases mechanical properties of the C_3D/EP composites. Contrary to the unreinforced epoxy, the moisture absorption behavior of the C_3D/EP composites cannot be described with Fick's law of diffusion, probably because of the presence of voids and/or 3D fiber structure. The exact mechanisms should be proposed in further investigations. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1031–1039, 2002     

低浓度CO合成甲酸甲酯中试研究

进行了低浓度CO合成甲酸甲酯的中试研究,探讨了温度、压力、流速、催化剂浓度等因素对反应的影响,在优化条件下考察了系统的稳定性。结果表明,低浓度CO(体积分数15%)合成甲酸甲酯CO的单程转化率达到50%以上,粗品中甲酸甲酯含量达到7%～9%,可以满足工业浓缩要求,且整个合成系统未发生母液堵塞的问题,与高浓度CO羰基合成甲酸甲酯相比,单位生产成本可降低30%,具有良好的技术先进性。     

炭/炭复合材料抗氧化涂层厚度的光学测量

选用A,B,C,D4种炭/炭复合材料试样进行抗氧化涂层厚度的光学测量研究。其中:试样A,B孔隙度相同,均为15.85％,对其涂覆粒径分别为1μm和10μm的B_4C涂层;试样C,D孔隙度分别为13.52％和16.78％,对其均涂覆粒径为10μm的B_4C涂层。然后通过金相光学测量其涂层厚度,在抗氧化涂层厚度的计算过程中,对试样组织的内部未渗入抗氧化涂层的孔隙进行图像处理。结果表明:当试样孔隙度相同时,涂层材料粒径越小,其涂层越厚;当抗氧化涂层材料粒径相同时,试样孔隙度越大,涂层越厚。     

Vapor-liquid equilibrium and volumetric properties calculations for solutions in the supercritical carbon dioxide

The calculations of gas solubilities in supercritical solvents require equations of state remaining accurate in the critical range, which are difficult to obtain with classical models. In this work, the Helmholtz energy of a mixture is considered as the sum of the Helmholtz energies of pure components taken at a constant packing fraction and of a residual term which may have the form of a RedlichKister, Van Laar, NRTL, UNIQUAC, or UNIFAC function. Thus it is possible to assign to a given component an equation of state whose form is different from that of the others. This model has been applied to binary systems containing supercritical carbon dioxide. The results are improved with respect to those obtained with the classical model for vapor-liquid equilibria and for volumetric properties.     

大型预焙铝电解槽使用碳化硅砖与普通碳砖复合块的探讨

碳化硅砖和碳化硅砖与普通碳砖复合侧块，在上世纪末期我国铝电解槽上开始推广应用。使用后各厂家普遍发现碳化硅砖及碳化硅砖与普通碳块复合侧块均出现不同程度的断裂、上抬和脱落现象，该文对断裂、上抬和脱落原因进行了分析，并提出了改进措施。     

新型SiMnCr系高强度粗钢筋材料的研制

针对高强度钢筋的性能要求和钢筋生产的工艺特点 ,设计了一种新型的低碳SiMnCr系高强度钢。测定了该钢种的CCT曲线及其力学性能。在锻造或轧态下 ,可获得以低碳马氏体为主含少量贝氏体、残留奥氏体的复相组织 ,经低温回火 ,可获得高的强度 (σb>12 30MPa)和良好的塑性 (δ5≥ 8% )。