Series of CdS/Ag2S composite photocatalysts with different Ag2S concentrations were prepared by the precipitation-grinding method. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, UVvisible spectroscopy, and photoluminescence spectroscopy. The catalyst particle size of CdS/Ag2S was proved to be smaller than the catalyst particle size of CdS. The reaction system was set under visible light irradiation to study the influence to the photocatalytic performance of CdS/Ag2S with different condentration of Ag2S. The CdS/Ag2S composite photocatalyst with the weight of 100% concentration of Ag2S showed the highest photocatalytic activity and the degradation of Rhodamine B was 71%.The presence of Ag2S also restrained the recombination rate of e-/h+ pairs.The photocatalytic activity of degradation of Rhodamine B was significantly improving.
The pneumatic transmit experiments with the size of sand of 1.2 mm were carried out with compressed air as pumped in the T pipeline experimental bench. Numerical simulation analysis is carried out of the pneumatic transmit process under different condition of the transmission flow and pressure, whereas the change of pressure drop and gassolid two phase volume fraction in branch pipe was achieved. Numerical simulation results show that, pressure drop is proportional to the transmission flow and pressure in the lower part of the pipe, whereas particle volume fraction is inversely proportional to the transmission flow but proportional to transmission pressure. Gas volume fraction is proportional to flow, but it is inversely proportional to pressure. The simulation results are in good accordance with the experiment results. The study provides relevant basis for the further research of the pneumatic conveying.
Since R.M.Butler developed the vapor extraction of heavy oil and bitumen (VAPEX) technology，the VAPEX has been found many advantages such as low energy consumption and costeffective. In addition, the VAPEX can also avoid the production of greenhouse gases and upgrade the crude oil. In brief, the VAPEX has become a promising and practical technology. In order to evaluate the oil recovery rate in different steps and optimize the field operation condition, solvent gas diffusion of the VAPEX has been attracted more and more attentions. This paper analyzes molecular diffusion and dispersion of solvent gas in heavy oil and bitumen, provides an important mathematical relation, and achieves an mathematical model for improving yield of heavy oil and bitumen, providing theoretical support for exploration of VAPEX, and could also predict the processes of VAPEX in efficient way in the meantime.The prospective of VAPEX technology has been raised in this paper.
A new protocol for the photoinduced addition reaction of sulfides with benzophenones has been extablished, affording the αfunctionalized products. The effects of UV wavelength, temperature, concentration of reactants, concentration of Lewis acid catalyst and other factors on the isolated product yield have been investigated. The optimum condition is: UV light wavelength of 313 nm, room temperature, 0.02 mmol of 4,4dimethoxybenzophenone, 0.002 mmol of the catalyst of AlCl3. Under optimum conditions, the isolated yield of the desired product (4methoxyphenyl) (2tetrahydrothienyl) methanol is 57%. Based on the experiment results and corresponding literature reports in this field, a possible mechanism is discussed.
In view of the problem of different oil pipelines leakage, using the finite volume method to build the three dimensional flow and mass transfer mathematical model of the soil porous media around underground pipeline, by the CFD soft to numerical simulate the range of different oil distribution of underground and the earth’s surface when petrol, diesel fuel or crude oil pipeline leakage, the simulation results showed that when the time was the same, the volume of diesel fuel leakage was the most, and the spread was more 20% than petrol or crude oil. After 2 hours’ leakage, the diffusion rates of both underground and surface cases tended to be stable. The simulation diffusion scopes of leakage oil had a guiding significance for repair work of contaminated soil.
Due to the oilgaswater threephase flow is extremely complex, the threephase hybrid interface is weak of stability, different delivery conditions exist a variety of flow patterns. Using the VOF model simulation, the mock object was oilgaswater threephase flow in mutation tube, studying the fluid flow in pipe when the parameters(volume gas fraction, oil viscosity and velocity) was different, thus it gotten the corresponding phase distribution nephogram. Through analyzing the results showed that the gas volume fraction and velocity had great effect on mutiphase flow pattern. The effect of crude oil viscosity on flow patterns was not very obvious. The size of the pipe diameter also affected the flow pattern.
In reference to previous research, the simulation software to simulate overhead gas pipeline leakage diffusion in the flat areas was used and the effects of four different leakage directions and speed on leakage diffusion process were analyzed.The results showed that the risky range of upwind area was bigger than the downwind area near the ground, the higher ground was relatively safe.The risky range of upward natural gas jet was the smallest,the risky ranges of windward and downward jet were the greatest.The impact of wind speed on the risky range of windward jet was less than downward jet.Natural gas leakage in the condition of lower wind speed and calm wind spread wider.The results could be used for the emergency evacuation and rescue of overhead natural gas pipeline leakage in the future.
Based on the heat loss occurred when a pipeline to transport hightemperature steam vapor overhead, it is established physical and mathematical models of steam pipeline,and compared to the three commonly used insulation materials of overhead pipeline. Research results showed that the application results of nano airgel composite reflective insulation was the best. The different steam temperatures of the temperature field of pipeline and insulation layer in, different diameter and different insulation thickness distribution were simulated. By analyzing the temperature field indicated that changing the diameter effected the heat loss of overhead vapor line greatly. When the diameter changed from 126 mm to 132 mm unit length, the heat loss increased 10.702 62 kJ/(h •m).
According to the technology of situ electrical heating on oil shale, a physical model was established by FLUENT. Numerical analysis of temperature field distribution of oil shale was carried out. In this model, the healing efficiency was increased by time, which was obviously increased when the heating well and oil well exchange heating. When the heating time was less than 3 a, the temperature of oil shale layer was increased steadily. But it did not reach the temperature that oil shale pyrolysis required. When the heating time was greater than 3 a, the temperature of oil shale layer was reached to 350～500 ℃. And it reached the temperature that oil shale pyrolysis required. After pyrolysis, the thermal conductivity, porosity and permeability of oil shale were increased while the temperature was elevated. Therefore, the analysis and control of temperature field of oil shale was helpful to improve the heating efficiency and production of oil shale.
The finite element analysis software ANSYS was used to propose a parametric model of the quickopening structure with toothlocked sintering furnace cover. The structure design was optimized by using weight parameter as the objective function and using allowable stress as constraints. Based on the optimal sizes the intensity design requirements were met and the weight of the structure was reduced effectively. Data reference for the similar quickopening structure design was given in this paper.
Based on the theory of normalization of stiffness matrix, a linear flexible platform was established. Through the stiffness matrix of flexible platform normalization process, its flexibility matrix organization was gotten, and then judged the degree of freedom and constraints of the design agencies. Then through analyzing the finite element simulation for the designed flexible platform, the results showed that the results of the finite element analysis was consistent with the calculated theoretical. This could become the reference for the design and analysis of multiple degrees of freedom linear flexible mechanism.
Multidimension 01 knapsack problem is a typical NonDeterministic Polynomial problem. In view that ant colony algorithm solving often have local optimum and slow convergence speed problems, this article propose an improved ant colony algorithm. Based on the introduction of leap frog algorithm clustering thought, the ants have been developed into two groups with different culture, which improves the global search ability. The greedy strategy modified formula is applied in order to improve the accuracy of calculation. The formula is further simplified by roulette algorithm. Simulation results indicated that the modified algorithm improves the accuracy and global search ability.
Based on the analyses of complex modeling characteristic with special fireworks, this paper puts forward a multiparameter simulation function. Through different parameters combination, a variety of special fireworks simulation could be realized. And some special fireworks simulation was carried out using the multiparameter function based on particle system, the results show that a variety of special fireworks simulation can be easily completed. By taking the actual scene images as background, the very good special fireworks simulation effect was obtained.
The secondary development functional the electric principle graphics libraries is established in AutoCAD. A new method named "invisible boundary" is proposed to draw the electrical graphic symbols. The method has efficiently solved "interruption issue" problem occurred in the middle of reinserting electrical circuit drawing symbols. By utilizing this new type of database, the procedure of discontinuing conducting wire can be avoided, which is beneficial to symbols reediting and also improves drafting efficiency.
Credit rating is a comprehensive evaluation of the capability and the integrity of fulfilling economic commitments for the individual, the economy and financial instrument. The main function of credit rating lies in the credit risks revealment, which plays an irreplaceable role in increasing the efficiency of financial market. It is of great significance for the security of national finance and economy to have a proper credit rating. Different levels and time of default probability will be studied in this paper, which also includes further discussion on the risk premium and associated dependencies.
The diversification enterprises performance evaluation index system based on the perspective of shareholders was constructed, according to the characteristics of the performance evaluation of diversification enterprises. Combined with the economic added value and adjusting the different indicators, the system could fully display the various aspects of a listed company's financial situation and help manager thinking and deciding on the position of shareholders. The 10 listed companies which were close to the average net asset ratio were selected calculate their indicators. According to the above the index value, the coefficients of correlation between the various indicators were calculated and determined the weights using the SPSS software. Finally, the case of the CH listed companies was analyzed to gain a comprehensive review of the company operating conditions in 2013 and stated the advantages and shortcomings of this index system.
The budget expenditure performance appraisal system of the colleges is important to carry out the controlling the college resources and improves the management of budget.In most of the models of the budget expenditure performance appraisal system of the colleges，analytic hierarchy process(AHP) always was used to establish the evaluation indicators and analysis the weight.But in the budget expenditure performance evaluation in colleges，in order to evaluate the actual status of the various indicators，it needed to carry on comparative analysis to the index standard and the actual value.By using the efficacy function，efficacy coefficient method could reasonably achieve the translation between the index standard and the actual value，and through the analysis score, the budget expenditure performance situation could be understood.
