Advanced Materials Research Vols. 347-353

Abstract: With the theme of ecological environment and low-carbon economic of the 21st century, the environmental protection industry possesses a huge market potential. Strengthen our environmental protection industry can create enormous economic as a new industries. Our environmental protection industry has already achieved certain progress, but it has still a large margin from the reality of the claim and the level of developed countries. In view of the problems in our environmental protection industry, this paper analysis the development status of China’s environmental protection industry, based on the prospect of environmental protection industry, propose measures of accelerating the development of China's environmental protection industry, which will push China's environmental protection industry into a new development stage.

Abstract: Solar-coal complementary electric generation is a new way to utilize solar thermal, however, using solar thermal to replace the heat transfer of some heating surfaces will inevitably affects the stability and efficiency of boiler operation, and the running characteristics of the boiler will affects the utilization capacity of the solar thermal in turn. A 300MW unit thermal- circulation boiler has been studied. A research on calculation of heat transfer characteristic has been made. The influence of solar-energy utilization on heat transfer has been analyzed. Calculation and analysis indicate that using solar thermal to heat the feedwater can decrease coal consumption. 87.2% of the coal consumption decrement can be attributed to the replacement of coal by solar thermal, 12.8% of the coal consumption decrement is leaded by the boiler efficiency increment; Solar thermal should not be introduced into the boilers with low exhaust gas temperature and the boilers running at low load operation; Using solar thermal to heat the feedwater leads to decreasing spray water; Through the boiler calculation in this paper, the maximum solar thermal utilization capacity is 19.27MW.

Abstract: Charge storage is an important research topic in smart grid and distributed generation system, pumped storage as one of the most popular large-scale charge storage methods has attracted increasing attention. However, the motor generator of the pumped charge station has high input voltage and heavy load, so in order to get grid connected safely, being soft started by a high voltage converter is necessary. In the view of the existing high voltage high power converters, only the voltage source inverter Multi-stage Series-connection high voltage frequency converters are suitable for this application, and this paper gives analysis of such converters. Based on Carrier Wave Phase-Shifted modulation, this paper proposes a multi-stage Series-connection high voltage frequency converter with balanced output power of the step-down transformer’s secondary windings, in which a winding burdens three symmetry three-phase to single-phase MC outputs, and the same phase outputs of the MC are cascaded at the secondary side of the transformers, letting out one phase of high-voltage AC output. The circuit is consisted of a step-down industry frequency transformer at the network side, three-phase to single-phase MC arrays, a step-up high frequency transformer at the load side and filter components. The simulation result based on MATLAB/SIMULINK shows that the proposed multi-stage Series-connection high voltage frequency converter is feasible and low-cost.

Abstract: Quaternary compounds Cu2ZnSnSe4 is a promising candidates for low cost thin film solar cell with an optimal direct band-gap (0.85~1.65eV)and a high absorption coefficient (>104cm-1). In our study, we have been successfully synthesized Cu2ZnSnSe4 nanocrystals in ethylenediamine solution through solvothermal method using CuCl, ZnCl2, SnCl4•5H2O and Se powers as reaction reagents.The result demonstrated that Cu2ZnSnSe4 nanocrystals slightly polydispersed with most of the size of nanocrystals falling in the range 8-12 nm. Raman spectra of Cu2ZnSnSe4 nanocrystals have a redshifts as the smaller size effect. Photoluminescence spectra of Cu2ZnSnSe4 nanocrystals showed that one wide emission band with peak position around 1.40eV.

Abstract: Based on uniaxial compression test, the mechanical properties of buffer/backfilling materials after different temperatures are studied. The study analyzed buffer/backfilling materials of stress-strain curve，peak stress，modulus of elasticity，peak strain, with the variation of temperature. The buffer/backfilling materials of strengthening and degradation in different temperature are discussed briefly. The test result show that below 200°C, buffer/backfilling materials of stress-strain curve of slope，peak stress，modulus of elasticity，peak strain ,are increase with increasing temperature increase. The main reason is that with increasing temperature, adsorbed water in the sample will evaporate, and brittleness of sample will improve; mineral particles of expansion lead to the original cracks closing, the porosity will reduce, and improve friction properties between particles. 300 °C,buffer / backfill materials of stress - strain curve of slope, peak stress, elastic modulus, decreased to varying degrees compared to 200 °C. the main reason is that thermal stress damage to the internal structure of the samples, resulting in new small cracks. The peak strain of buffer / backfill materials in the 25 °C～100 °C is increase with increasing temperature increase.100°C～200°C, peak strain is decrease with the increase of temperature. In the 200 °C～300 °C, the peak strain change little.

Abstract: The environment-friendly epoxy emulsion was synthesized by MAA, BA, St reacting as grafting monomer, while silane coupling agents played a role as functional monomer. Experimental results were characterized by Nano-particle size analyzer, EIS, UV-VIS spectrophotometer, FTIR and TGA. The results of Nano-particle size analyzer showed the average particle size lower than 300nm and emulsion had lowest water absorption when ω(KH560+KH550) was 7%. The results of EIS and UV-VIS spectrum showed the cured firm had the best corrosion resistance and weather resistance while n(KH560):n(KH550)=2:1. The results of FTIR showed the silane coupling agents had successfully grafted in the skeletal structure of epoxy molecules. The results of TGA showed the thermal stability were better than unmodified.

Abstract: Catalytic oxidation of NO with O2 over Pt/-Al2O3 and La0.8Sr0.2MnO3 was conducted with a tubular reactor in range of space time 0.090-0.720 second, inlet NO concentration 0.03-0.2 vol%, O2 concentration 2-10 vol% and at 473 K. Under the conditions of 0.720 s space time, 0.05 vol% NO and 5 vol% O2 concentrations, the steady-state conversion of NO oxidation over Pt/-Al2O3 and La0.8Sr0.2MnO3 reached 22.4 and 90.5 %, respectively. A kinetic model consisting of 12 elementary reactions fits the experimental data adequately, indicated that the rate-limiting step of NO oxidation over Pt/-Al2O3 was the reaction between gaseous NO with dissociately adsorbed O, and over La0.8Sr0.2MnO3 was the desorption of product NO2.

Abstract: Nanocrystalline silicon film has become the research hit of today’ s P-V solar technology. It’s optical band gap was controlled through changing the grain size and crystalline volume fraction for the quanta dimension effect. The crystalline volume fraction in nc-Si:H is modulated by varying the hydrogen concentration in the silane plasma. Also, the crystallinity of the material increases with increasing hydrogen dilution ratio, the band tail energy width of the nc-Si:H concurrently decreases. Two sets of nc-Si:H solar cells were made with different layer thicknesss, their electronic and photonic bandgap, absorption coefficient, optical band gap, nanocrystalline grain size(D), and etc have been stuied. In addition, we discussed the relationship between the stress of nc-Si thin films and H2 ratio. At last nc-Si:H solar cells have been designed and prepared successfully in the optimized processing parameters.

Abstract: This paper uses the theory of grey relational analysis to calculate the correlation between forest tourism and three industrial sectors in Eastern Liaoning from 2000 to 2009. The conclusion is that the forest tourism has remarkable effect on tertiary industry. The author further discusses the coordination of forest tourism and sub—industries and draws a conclusion: warehousing and transportation, hotels and catering services are most closely related to the forest tourism. At last, this article proposes the suggestion of industrial restructuring in rich forest areas.

Abstract: Wind energy will affect the reliability of power system for its randomness and fluctuation. In this paper, the steady state model for the asynchronous generator is established and wind farms are considered as special PQ buses during power flow calculation. Combining with state models of conventional generating units, transmission lines and transformers, a time-sequential Monte Carlo simulation based on wind farm reliability model is established to do reliability assessment of composite generation and transmission system with wind farm. Meanwhile, an optimal load shedding model is used to decrease shedding load. IEEE-RTS test system is used to prove the proposed method. Analysis and comparison of results show that reliability can be improved clearly after integration of wind farm.