Gypsum/anhydrite: some engineering problems

 The engineering properties of gypsum/anhydrite change as a consequence of groundwater, pressure and heat. Gypsum and anhydrite may experience dissolution in the near-surface zone and along the discontinuities, creating karst terrain to depths related to present and/or past groundwater levels. This paper reviews the problems of constructing on gypsum/anhydrite and their engineering significance and provides short case histories to illustrate some of the problems encountered. Received: 19 February 2000 · Accepted: 13 May 2000     

论就地浸矿法与传统采矿法的矿块结构参数的异同点

考虑到就地溶浸开采法的前半部分的工艺过程和矿块结构参数与传统的采矿方法（如留矿矿法）有相似之处,同时考虑到从事这个采矿方法研究,设计和生产的不少技术人员比较熟悉传统采矿法,运用两类方法对比,讨论就地浸溶开采法的优点及矿块结构参数的影响因素,确定原则及与传统方法的不同点,同时重点阐述了这个新采矿法的3个结构参数特点,即矿块的封闭性,淋浸系统的覆盖性及集液系统的完整性。     

Second law analysis of a disturbed flow in a thin slit with wall suction or injection

Fully-developed laminar flow in a horizontal thin slit having plates at different temperature is considered for the case of lower plate movement and/or the pressure gradient-and-upper plate movement. The flow under these conditions is analyzed in terms of entropy generations as function of the Prandtl number, the Eckert number, cross-flow Reynolds number and dimensionless temperature difference. In this context, the governing equations for distributions of temperature, the dimensionless entropy generation number and Bejan number are analytically derived with the aid of expressions for velocity distributions. The effect of each parameter on the temperature and the entropy generation are investigated by varying one of the parameters and keeping the rest of them constant for each flow case. The effects of viscous dissipation, rates of mass suction/injection and dimensionless temperature differences on the fluid temperature and entropy generation are examined. The magnitudes of mass suction and/or injection have a large influence on the temperature profile of the fluid. It is observed that the Prandtl number and the Eckert number affect fluid temperature in similar way. It is found that an increase in values of the cross-flow Reynolds number (mass suction/injection) enhances the entropy generation in boundary layer. The velocity profiles are found to be in agreement with the distributions of the dimensionless entropy generation number (N_S) for two flow cases.     

油井效益评价系列图版的研制及应用

结合孤东油田生产状况,人经济盈亏分析原理了,开发出油井效益评价系列图版,图版包括单井次措施增油效益评价图版,单井日产油效评价图版及单井阶段性投入产出效益评价图版3部分。利用图版可科学评价各类增产措施的经济效果及生产的效益状况,为优越,优化各类增产措施和油井生产状况提供有效手段。     

广西大新锰矿选矿厂洗矿溢流的回收利用

广西大新锰矿选矿厂,由于其洗矿作业的溢流跑粗且含锰品位偏高,影响选矿厂锰金属回收率。通过对洗矿作业的查定及产品粒度组成和回收试验结果的分析,论证从溢流中回收流失的锰矿物的必要性和可能性。     

醇类合成催化剂Cu/Mn/ZrO_2产物分布结构的调控

考察了镍助剂调变的Cu/Mn/ZrO2 催化剂在一氧化碳加氢反应过程中的反应行为。结果表明 ,Cu/Mn/ZrO2是活性较好的合成甲醇催化剂 ,在一定范围内镍组元的加入大大促进了催化剂的反应活性 ,如在一定的条件下 ,n(Ni) /n(Cu) =0 2的催化剂液相时空产率可达 2 2 g/ (mlcat·h) ,虽然镍成分含量很高 ,催化剂并没有表现出明显的甲烷化倾向。在此催化剂中加入钾会促使催化剂转变为生成混合醇为主的催化体系。液相产物组成可分别控制以生成甲醇 /异丁醇为主或符合S F分布的正构混合醇为主 ,同时保留相当高的混合醇时空产率。因此 ,可通过控制反应条件及添加少量的助剂 ,有目的地调整催化剂反应产物的分布情况     

Hβ中添加WOx／ZrO2对Pt／WZr—Hβ催化剂正庚烷临氢异构化性能的影响

采用机械混合法将WOx/ZrO2引入Hβ制备Pt/WZr-Hβ催化剂。比较其与Pt/WOx-ZrO2,Pt/Hβ以及两者简单加合的Pt/WZr-Pt/Hβ催化剂上正庚烷（n-C7)加氢异构化的性能。结果表明,Pt/WZr-Hβ上的n-C7转化率较Pt/Hβ略有下降,但异构化选择性显著提高。Pt/WZr-Pt/Hβ上的n-C7转化率比Pt/WOx-ZrO2和Pt/Hβ均明显下降,但异构化选择性比Pt/WOx-ZrO2低,而比Pt/Hβ显著提高,Pt/WZr-Hβ上的n-C7转化率及异构化选择性比Pt/WZr-Pt/Hβ均高,说明Pt/WZr-Hβ并非是Pt／WOx-ZrO2和Pt/Hβ的简单加合。     

Effect of Nuclear Data Libraries on Tritium Breeding in a (D–T) Fusion Driven Reactor

In design a Deuterium–Tritium (D–T) fusion driven hybrid reactor, neutronics and nuclear data libraries have an essential role for reliable neutronics calculations. Therefore, nuclear data libraries are very important to calculate of the neutronic parameters and selection of tritium breeder materials to be used in the blanket. In this study tritium breeding performances of candidate tritium breeding materials, namely, Li₂O, LiH, Li₂TiO₃, Li₂ZrO₃ and Li₄SiO₄ in a (D–T) driven fusion–fission (hybrid) reactor is investigated based on three dimensional (3-D) and one dimensional (1-D) neutronic calculations. 3-D and 1-D neutron transport calculations are performed with Monte Carlo transport code (MCNP 4C), SCALE 5 and ANISN nuclear data codes to determine the tritium breeding ratio (TBR) of the blanket. The effects of different nuclear data libraries on TBR are examined and TBR calculation results are comparatively investigated.     

南钢公司焦炭质量的提高及措施

根据南钢公司焦炭质量的现状 ,总结了提高焦炭质量的具体措施 ,并指出了存在的问题 ,对强化高炉冶炼有一定现实意义。     

TiO2材料的半导化机理探讨

研究了表面掺杂和高温烧结对ＴiO2材料的半导化的影响,结果表明：ＴiO2材料在高温条件下可产生间隙离子和氧空位;掺入与Ｔi^4 离子半径相近的Ｖ^5 ,Nb^5 ,Mg^2 ,Li^ 等离子可与ＴiO2生成固熔体,从而增加材料的导电粒子数目,改变了ＴiO2材料的能带结构,降低材料的固有阻值,使ＴiO2材料的半导化。