Evidence for non-site-isolation in ZSM-5 from ion-exchange and catalytic studies

Ion exchange of HZSM-5 samples with alkali metal cations, using metal chloride solutions, results in partially exchanged zeolites, MHZSM-5, M = Li, Na, K or Cs. The degree of exchange is found to increase with increasing ionic radius of the cations. The catalytic properties of the alkalized zeolites were evaluated using the reaction conditions under which the catalytic activity of the HZSM-5 samples in terms of n-hexane cracking is proportional to the aluminium content. From the residual catalytic activity exhibited by the Na-, K- and CsHZSM-5 samples it is concluded that each of the larger Na⁺, K⁺ and Cs⁺ ions is influencing more than one AlO ₄ ^– tetrahedron, implying that the aluminium sites in ZSM-5 are not isolated. The ion-exchange results are then interpreted in terms of non-isolated aluminium sites. The ion-exchange and catalytic properties of the zeolites as a function of aluminium content are also discussed.     

铝箔纸胶粘剂的制备

由醋酸乙烯和丙烯酸酯所制得的共聚物，能够极大地提高乳液对铝箔和纸张之间的粘合力，通过调整保护胶体聚乙烯醇的用量和增塑剂邻苯二甲酸二丁酯在反应过程中的不同加入方式，可以控制和生产所需要的乳液粘度，流平剂的加入，则改良了乳液在铝箔上胶时的流平性。     

韧性断裂准则在板料成形中应用研究进展

对板料成形中的成形极限应力图、最大变薄率、成形极限图以及韧性断裂准则等预测成形极限的方法进行了综述和分析,提出了利用韧性断裂准则能够较好地预测塑性差的板料成形极限,而且还能考虑应变路径的变化.利用有限元方法模拟时,韧性断裂准则既可以运用到完全耦合的弹塑性损伤模型的增量方法中,也可以运用到一步有限元逆算法中.指出了为准确地预测成形极限,除了提高有限元模拟精度外,应找到一种本质地反映材料性能的准则.     

Reserve estimation of an open pit mine under price uncertainty by real option approach

Reserve estimation is a key to find the correct NPV in a mining project. The most important factor in reserve estimation is the metal price. Metal price fluctuations in recent years were exaggerated, and imposed a high degree of uncertainty to the re-serve estimation, and in consequence to the whole mine planning procedure. Real option approach is an efficient method of deci-sion making in the uncertain conditions. This approach has been used for evaluation of defined natural resources projects until now. This study considering the metal price uncertainty used real option approach to prepare a methodology for reserve estimation in open pit mines. This study was done on a copper cylindrical deposit, but the achieved methodology can be adjusted for all kinds of deposits. This methodology was comprehensively described through the examples in such a manner that can be used by the mine planners.     

基于储氢合金的太阳能制冷系统理论研究

结合金属氢化物的特点,提出了一种新型太阳能吸附式制冷循环系统;具体介绍了系统结构形式,建立了系统能量转换与分析模型,并对构成系统的各部件进行了分析;根据具体算例,计算了系统各部件的效率与损失,结果表明,系统具有较好的节能效果,且系统优化应以太阳能辐射量为基准,以提高金属氢化物系统中的氢气转化率为目标进行。系统优化的另一方向在于发展与其他太阳能利用技术相结合的复合式系统。     

基于光纤像面全息的金属构件微位移测量

针对激光全息技术能处理常规方法难以解决的问题以及光纤具有环境适应性的特点,设计了一种基于光纤像面全息干涉计量对金属材料构件微小位移测量的方法.通过对不同芯径传像光纤束情况下的成像结果分析,得出了与材料力学相符合的结论.实验结果表明,提出的方案适用于对金属材料特性的高精度测量,可以解决阻碍激光全息技术推广应用和发展的环境要求.     

钯－银合金膜分离氢气的研究

采用厚为５０μｍ的Ｐｄ／Ａｇ（２３）合金膜进行了氢气渗透系数的测定和Ｈ＿２／Ｎ＿２混和气分离的研究，得出温度、压力、膜厚、进料气流量、膜的预处理和再活化及膜表面中毒等因素对氢气渗透的影响。分离Ｈ＿２／Ｎ＿２混和气可获得高纯氢气。     

Interfacial Microstructure and Mechanical Properties of Al/Mg Butt Joints Made by MIG Welding Process with Zn-Cd Alloy as Interlayer

Butt joints between Mg alloy AZ31 B and pure Al 1 060 sheets were produced via metal inert gas welding process with Zn-Cd alloy foil. Crack-free Al/Mg butt joints between AZ31 B Mg alloy and pure Al 1060 sheets were obtained. Intermetallic compound layer 1 and layer 2 had formed in fusion zone/Mg alloy and the average thickness of the layer 1 was about 50 μm. The intermetallic compound layer 1 consisted of Al12Mg17 and Mg2Si phases while layer 2 consisted of Al12Mg17, Mg2Si and Mg Zn2 phases. The crack started from the IMC layer at the bottom of the joint and propagated along the brittle IMC layer, then expanded into weld metal during the SEM in situ tensile test. The highest tensile strength of the dissimilar metal butt joints could reach 46.8 MPa and the effect ofinterfacial IMC layer on mechanical property of the joint was discussed in detail in the present study.     

Large magnetic-field-induced strains in rare earth polycrystalline Ni-Mn-Ga

The magnetic-field-induced strains (MFIS) of polycrystalline Ni50Mn29Ga21 alloys containing Tb were studied. A large MFIS of-1.10% was obtained under compressive prestress conditions. The addition of Tb can fine the crystal grains, enhance the bending strength obviously, and make MFIS increase further, indicating that a moderate amount of Tb does not hinder twin boundary motion and it conversely makes the material more practical.     

易溃散覆膜砂的应用及发展前景

介绍了覆膜砂用于轻合金铸件生产时溃散性差的原因和提出了改善的办法,并介绍了其发展前景.