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In situ time-resolved FTIRS study of adsorption and oxidation of ethylene glycol on Pt(100) electrod
Adsorption and oxidation of ethylene glycol (EG) on Pt(100) electrode were studied by in situ time- resolved FTIRS (TRFTIRS). The TRFTIR spectra recorded at 0.10 V illustrate that an IR band appears near 2050 cm-1 at t > 5 s, corresponding to linearly bonded CO formed in dissociative adsorption of EG. The TRFTIR results have confirmed also that CO species are distributed uniformly on Pt(100) surface. Another band appears near 2342 cm-1 at t > 70 s, associating with IR absorption of CO2 produced in the direct oxidation of EG. With the increase of electrode potential, the direct oxidation of EG becomes gradually the main reaction. When the potential is above 0.40 V, the oxidation of EG occurs mainly via the reactive intermediates, i.e. species containing -COOH determined by in situ TRFTIRS....
2020-12-22 21:24:13浏览：95
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Stability Analysis for Stochastic Optimization Problems
Stochastic optimization offers a means of considering the objectives and constrains with stochastic parameters. However, it is generally difficult to solve the stochastic optimization problem by employing conventional methods for nonlinear programming when the number of random variables involved is very large. Neural network models and algorithms were applied to solve the stochastic optimization problem on the basis of the stability theory. Stability for stochastic programs was discussed. If random vector sequence converges to the random vector in the original problem in distribution, the optimal value of the corresponding approximation problems converges to the optimal value of the original stochastic optimization problem....
2020-12-06 21:11:24浏览：58
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Isolation and phylogenetic analysis of heterotrophic nitrobacteria
A method about the isolation of heterotrophic nitrosebactria and the characteristics of heterotrophic nitrosobaetria were studied, it can be seen from the fluorescence in situ hybridization results of the bio-mem-brahe sample from the bio-ceramic reactor, the spots of green nitrosobacteria are obviously more than those of orange nitrohaeteria. Two heterotrophic nitrohacteria were isolated from the bio-ceramic reactor. By sequencing 16SrDNA and establishing the phylogenic tree, they were identified physiologically and biochemically as Pseudomonas sp.. After 12 d, the COD removal efficiency of wgy55 and wgy68 were 45.03% and 50.85% , the NH4-N removal efficiency of them were 80.12% and 85.93%, and the TN removal efficiency of them were 69.71% and 64.7%. The final concentration of NO2-N of wgy55 and wgy68 was 0.753 mg/L and 0.601 mg/ L, and that of NO3-N was 3.21 mg/L and 3.38 mg/L. These results show that wgy55 and wgy68 have the ca-pability of nitrification and they are heterotrophic nitrobacteria....
2020-11-22 17:58:37浏览：69
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Analysis on the Individual Discrepancy in English Teaching
Pecently,a great tide of English teaching reform swept across China,advocating the innovation of educational concept and teaching mode.However,the phenomenon of rigid uniformity in teaching process is still commonly seen,neglecting the individual discrepancy of students.The individual discrepancy is manifested by both the congenital heredity and the acquired disposition.Supported by the Chinese traditional theory of teaching students in accordance with their aptitude and Vygotsky's "the zone of proximal development" theory,this paper illustrates the importance of paying attention to the individual discrepancy from the perspective of students' growing background and personality.In addition,standing on the point of view of relevant authority and English teacher,the author tries to put forward some countermeasures....
2020-11-22 17:58:37浏览：69
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河南省粮食“九连增”后的思考
在分析河南省粮食“九连增”影响因素的基础上，指出了粮食持续增产面临的问题，提出了促进河南省粮食持续增产的相关对策。...
2020-11-06 10:55:48浏览：58
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Amplification process of a gas electron multiplier simulated by PIC-MCC model
The performance of a single gas electron multiplier (GEM) in pure Xe at an atmospheric pressure is investigated by Particle in Cell-Monte Carlo Collision (PIC-MCC) model.The micro development processes with electrons and ions distributions in space have been revealed.Based on the micro development processes,the macroscopic parameters such as GEM gain and the effective efficiency have also been obtained.The simulation results indicate that after tens of nanoseconds,electrons are collected by the readout electrode while the ions still exist in the gas space for several microseconds.The main signal current is formed by the electrons arriving at the readout electrode,but electrons and ions are also collected by the copper electrodes near the GEM hole and the thin Kapton film boundary.The simulated gain of GEM exponentially increases with the applied GEM voltage.With the PIC-MCC simulations,both the physical amplification and charging mechanisms in the GEM device can be well understood,which is beneficial to the device design....
2020-09-15 12:28:59浏览：78
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Study of 3-D Numerical Simulation for Gas Transfer in the Goaf of the Coal Mining
In order to simulate field distribution rules, mathematical models for 3-D air flows and gas transfer in the goaf of the coal mining are established, based on theories of permeability and dynamic dispersion through porous media. A gas dispersion equation in a 3-D field is calculated by use of numerical method on a weighted upstream multi-element balance. Based on data of an example with a U type ventilation mode, surface charts of air pressure distribution and gas concentration are drawn by Graphtool software. Finally, a comparison between actually measured results in the model test and the numerical simulation results is made to proves the numerical implementation feasible....
2020-09-15 12:28:59浏览：59
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Surface performance of workpieces processed by electrical discharge machining in gas
The surface performance of workpieces processed by electrical discharge machining in gas (dry EDM) was studied in this paper. Firstly, the composition, micro hardness and recast layer of electrical discharge machined (EDMed) surface of 45 carbon steels in air were investigated through different test analysis methods. The results show that the workpiece surface EDMed in air contains a certain quantity of oxide, and oxidation occurs on the workpiece surface. Compared with the surface of workpieces processed in kerosene, fewer cracks exist on the dry EDMed workpiece surface, and the surface recast layer is thinner than that obtained by conventional EDM. The micro hardness of workpieces machined by dry EDM method is lower than that machined in kerosene, and higher than that of the matrix. In addition, experiments were conducted on the surface wear resistance of workpieces processed in air and kerosene using copper electrode and titanium alloy electrode.The results indicate that the surface wear resistance of workpieces processed in air can be improved, and it is related with tool material and dielectric....
2020-09-15 12:28:59浏览：84
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Riemann problem for the zero-pressure flow in gas dynamics
The Riemann problem for zero-pressure flow in gas dynamics in one dimension and two dimensions is investigated. Through studying the generalized Rankine-Hugoniot conditions of delta-shock waves, the one-dimensional
Riemann solution is proposed which exhibits four different structures when the initial density involves Dirac measure. For
the two-dimensional case, the Riemann solution with two pieces of initial constant states separated at a smooth curve is
obtained....2020-09-15 12:28:59浏览：73
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Physical Simulation of Water Dissolved Gas (WDG)During Migration
By using the equipment designed and developed by ourselves, experiment of investigating the influence of dissolution on some geo-chemical parameters (such as Δ13c,Δd,and Ic4/Nc4 in water-dissolved gas (WDG) during migration) was performed. The result shows that, with the increase of distance, 1) the relative abundance of non-hydrocarbon (CO2) and hydrocarbon (CH4) increase while the relative abundance of hydrocarbon (C2+) decreases (the relative abundance of hydrocarbon (C5+) can be basically negligible); 2) the relative abundance of benzene and methylbenzene increase in the initial time and then decrease. The carbon and hydrogen isotopes of methane vary slightly, which can be regarded as indicators of gas dissolved in water formation....
2020-09-15 12:28:59浏览：83
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Source-Contacting Gas:Accumulation Mechanism and Distribution in China
Source-contacting gas, which is also called basin-center gas, deep basin gas, is the tight-sand gas accumulation contacting closely to its source rocks. Having different accumulation mechanisms from conventional gas reservoirs that are formed by replacement way, the typical source-contacting gas reservoirs are formed by piston-typed migration forward way. Source-contacting gas accumulations exhibit a series of distinctly mechanic characteristics. According to the valid combination of these characteristics, the estimation for the type of discovered gas reservoirs or distributions of source-contacting gas reservoirs can be forecasted. The source-contacting gas is special for having no edge water or bottom water for gas and complicated gas-water relationships, which emphasizes the intimate association of reservoir rocks with source rocks, which is called the root of the gas reservoir. There are many basins having the mechanic conditions for source-contacting gas accumulations in China, which can be divided into three regions. Most of the basins with favorable accumulation conditions are located mainly in the central and western China. According to the present data, basins having source-contacting gas accumulations in China can be divided into three types, accumulation conditions and configuration relationships are the best in type A basins and they are the larger basins in central China. Type B basins with plain accumulation conditions exist primarily in eastern China and also the basins in western China. Accumulation conditions and exploration futures are worse in type C basins, which refer mainly to the small basins in southern China and China Sea basins. Main source-contacting gas basins in China are thoroughly discussed in this paper and the distribution patterns of source-contacting gas in five huge basins are discussed and forecasted....
2020-09-13 23:35:02浏览：98
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Division of Gas Accumulation System and Laws Controlling Distribution of Natural Gas in Typical Petr
Considering the existing problems of the petroleum system, this paper brings forward the concept of natural gas accumulation system and presents the dividing principles. Then detailed statistics on the accumulation factors of the 32 typical natural gas accumulation systems in China and studies on the laws controlling distribution of gas are collected. The research shows that the petroleum accumulation system is the basic unit controlling petroleum generation, migration and accumulation. Generating intensity, generating amount, accumulating efficiency and migration distance plays an important role in the distribution of natural gas. Through analysis on results of resources evaluation, discovered reserves and residual reserves, potential areas in middle-scaled petroliferous basins in China are forecasted in this paper. Ordos, Sichuan, Tarim and Qaidam basins are found out to be the main basins developing and enriching gas accumulation systems....
2020-09-13 23:35:02浏览：60
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聚乙二醇6000对间尼索地平溶解性能的影响
目的：研究聚乙二醇6000对间尼索地平溶解度和体外溶出度的影响,为间尼索地平剂型的选择提供参考。方法以聚乙二醇(PEG)6000为载体,采用溶剂-熔融法制备间尼索地平固体分散体。应用差示扫描量热分析法( DSC)、X射线粉末衍射光谱( XRD)对固体分散体进行鉴定,紫外分光光度法测定固体分散体的溶解度和体外溶出度。结果固体分散体的DSC、XRD图谱与原料药及其物理混合物均不同,不同比例的间尼索地平-聚乙二醇固体分散体的溶解度及体外溶出度均高于原料药,2 h的溶出百分率：原料药26.80%,固体分散体(13,15,17)分别为35.31%,38.71%,41.48%,比例相同的固体分散体的溶出率高于其物理混合物。结论间尼索地平与聚乙二醇6000形成了低共熔物,聚乙二醇6000作为间尼索地平的载体,可加速其体外溶出。...
2020-07-10 14:39:05浏览：57
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宝钢电厂4号机组循环水泵房控制系统
该文介绍了宝钢电厂4号机组循环水泵房现场控制系统设计,内容主要包括监控内容、控制原则、PLC现场站设计、主要控制功能和控制系统供电设计.由于所涉被监控设备地理位置分散和电厂运行要求高可靠性,系统设计与常规市政泵站相比有一定的复杂性及特异性.系统采用远方DCS及就地PLC相结合的构架,各环节均采用冗余系统,采用符合循环水泵特点的控制逻辑及有效的保护措施,实现了泵房的可靠运行.几年来运行结果表明,该控制系统设计符合使用方的要求....
2020-07-10 14:39:05浏览：68
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