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81.
82.
介绍一种以工业控制机为核心的空气压缩机实时监控系统。为防止电磁干扰,系统采取了有效的隔离保护措施。论述了系统结构、工作原理和硬软件配置。  相似文献   
83.
文中介绍一种一氧化碳检测报警器,利用恒电位电解法原理制成的传感器,并配以最新电子元器件组成检测仪。用于对矿井、化工、煤炭、电力、冶金、环保等有关部门的一氧化碳检测。  相似文献   
84.
Certain new sulfide-smelting processes and coal-gasification processes generate high-strength sulfur dioxide streams, for which a new process for converting sulfur dioxide to elemental sulfur needs to be developed because no process exists that is generally and economically applicable to the treatment of such streams. A thermodynamic and experimental investigation to develop a new process for converting sulfur dioxide to elemental sulfur by a cyclic process involving calcium sulfide and calcium sulfate without generating secondary pollutants was carried out. In this process, the starting raw material, calcium sulfate, is reduced by a suitable reducing agent, such as hydrogen, to produce calcium sulfide, which is used to reduce sulfur dioxide to elemental sulfur vapor and calcium sulfate. The latter is, in turn, reduced to regenerate calcium sulfide. In this Part I, detailed experimental results are presented on the kinetics of the reaction between sulfur dioxide and calcium-sulfide pellets, which produces elemental sulfur and calcium sulfate. The experiments were carried out at temperatures between 1023 and 1088 K and sulfur-dioxide partial pressures between 9 and 60 kPa by the use of a thermogravimetric analysis (TGA) technique. The rate of this reaction was demonstrated by the conversion of 40 pct calcium-sulfide pellets obtained from the hydrogen reduction of fresh calcium sulfate in 10 minutes at 1073 K under a sulfur-dioxide partial pressure of 43 kPa. The reactivity decreased somewhat during the first three cycles but remained largely unchanged thereafter up to the tenth cycle. This characteristic of the pellets is important because the solids must be reusable for repeated cycles to avoid generating secondary pollutants. A pore-blocking model was found to fit the reaction rate. The reaction is first order with respect to sulfur-dioxide partial pressure and has an activation energy of 101 to 134 kJ/mol (24 to 32 kcal/mol) for calcium-sulfide pellets reacted and regenerated several different times. Sulfur dioxide-containing streams from certain sources, such as the regenerator off-gas from an integrated-gasification, combined-cycle, desulfurization unit and new sulfide-smelting plants, contain much higher partial pressures of SO2. In these cases, the rate of the first reaction is expected to be proportionally higher than in the test conditions reported in this article. The reduction kinetics of calcium-sulfate pellets with hydrogen gas is reported in the accompanying Part II.  相似文献   
85.
油田污水中咪唑啉缓蚀剂浓度检测技术研究   总被引:5,自引:0,他引:5  
研究评价了油田污水中咪唑啉缓蚀剂浓度检测的七种方法 ,其中紫外光分析法和显色反应法适合于低浓度咪唑啉缓蚀剂检测 ,且方法简便、速度快、成本低 ,检测浓度范围 2~ 5 0mg/L。  相似文献   
86.
Microbiological denitrification of red beet juice   总被引:1,自引:0,他引:1  
The purpose of study was the determination of optimal conditions for red beet juice denitrification by Paracoccus denitrificans bacteria as well as the evaluation of the usefulness of microbiologically treated juice for the production of a natural colouring preparation for foods. Total reduction of nitrates was found during bacterial culturing at 25 and 30 °C, at an initial pH of 7.0-8.0 and juice osmotic pressure of 900-1100 mOsm/kg. Microbiological denitrification procedure affected colour, taste and aroma of the juice. However, the use of juice as food colouring and component was made feasible by acidification and partial evaporation of water together with volatile substances.  相似文献   
87.
离子交换铒掺杂磷酸盐玻璃波导特性研究   总被引:2,自引:0,他引:2  
郑杰  马少杰  张家骅 《中国激光》2002,29(5):447-449
给出有关离子交换铒掺杂磷酸盐玻璃波导的制备以及发光特性的基本结果。用Ag+ Na+ 离子交换在含有适量氧化钠的铒掺杂磷酸盐玻璃上很容易实现低损耗平面波导 ,并且离子交换过程对这种玻璃的光谱特性没有影响。  相似文献   
88.
89.
The paper discusses the postulated suspension force, by which it is possible to explain some enigmatic phenomena observed in different types of mass movements. This force is generated in thick suspensions as a result of friction between sinking solid particles and static water. The suspension force is related to the seepage force but they have opposite directions. Both forces form flow networks. Having explained the suspension force, the paper describes how this influences the movement of material, particularly in debris flows. Enigmatic features and the mechanism of debris flows and lahars are explained by virtue of the suspension force. Electronic Publication  相似文献   
90.
We consider the problem of rescheduling trains in the case where one track of a railway section consisting of two tracks in opposing directions is closed due to construction activities. After presenting an appropriate model for this situation we derive a polynomial algorithm for the subproblem of finding an optimal schedule with minimal latenesss if the subsequences of trains for both directions outside the construction site are fixed. Based on this algorithm we propose a local search procedure for the general problem of finding good schedules and report test results for some real world instances. Received: December 8, 1999 / Accepted: May 2, 2001  相似文献   
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