装药条件对弹道性能一致性的影响

总结了多年来时有发生的装药与初速呈异常关系的现象 ,经分析和验证 ,认定是由于装药条件变化引起挥发份含量不同所致 。

我国聚甲醛改性研究进展

基于我国聚甲醛改性对相关领域的重要影响,通过对聚甲醛改性的研究进展进行系统分析,主要采用理论概述、进展分析、应用研究等方法,对聚甲醛改性的实际应用、性能发挥等进行阐明,为下一步工作开展提供依据参考。

Simultaneous removal of ethyl acetate, benzene and toluene with gliding arc gas discharge

The simultaneous removal of ethyl acetate, benzene and toluene with relatively low or high initial concentration is studied using a laboratory scale gliding arc gas discharge (GA) reactor. Good decomposition efficiencies are obtained which proves that the GA is effective for the treatment of volatile organic compounds (VOCs) with either low or high concentration. A theoretical decomposition mechanism is proposed based on detection of the species in the plasma region and analysis of the decomposition by-products. This preliminary investigation reveals that the GA has potential to be applied to the treatment of exhaust air during color printing and coating works, by either direct removal or combination with activated carbon adsorption/desorption process.

The Effect of Non-acidified Wastewater on Expanded Granular Sludge Bed （EGSB） Reactors Performance

The textile processing plants utilize a wide variety of dyes and other chemicals such as acids, bases, salts, detergents, sizes, oxidants, mercerizing and finishing chemicals. Many of these are not retained in the final product and are discharged in the effluent. Therefore, the objective of this study was to assess the performance of EGSB （Expanded Granular Sludge Bed） reactor to treat non-acidifie wastewater. Several experiments using starch and volatile fatty acids as model substrates were conducted. The problems of piston formation were evaluated at a variety of relevant operational conditions, such as substrate concentration, organic and hydraulic loading rates. The results showed that newly grown acidogenic biomass diluted original methanogenic biomass and the granular sludge in the EGSB reactor deteriorated. The piston formation in the EGSB reactor that was fed with non-acidified wastewater occurred due to high growth of acidogenic biomass and high upflow velocity applied in the system.

Gut Fermentation and Growth Performance of Pigs Fed High Fiber Diet

Ninety six pigs average weight 9.15 kg were used to study the effects of feeding diets containing multiple sources of dietary fiber （DF） on weight gain and concentration of fermentation products in the digestive tract. The experiment employed four diets and four pens diet1. Diets included a low fiber diet （LFD）, as control and three antibiotic free high-fiber diets （HFD） containing a 1：2, 1：1 or 2：1 oats：barley ratios. At the end of the 70 d feeding trial three pigs of comparable weight diefI were slaughtered. Digesta taken from the stomach, cecum and colon were used for the determination of volatile fatty acids （VFA）. Results indicated that inclusion of HFD increased （P 〈 0.05） feed intake but not weight gain. As revealed by the higher feed intake the nutritional value of HFD was approximately 88% of LFD. Also, as the amount of oats in the diet was increased, VFA concentration was also increased while isobutyrate decreased （P 〈 0.05）. Lower concentration of isobutyrate may indicate parallel reduction in other putatively toxic products of protein fermentation in the digestive tract. Thus, inclusion of multiple sources of fiber in the diet impacted feed intake and the products of gut fermentation in growing pigs.

Changes in sulfur form during coal desulfurization with microwave:Effect on coal properties

The changes in sulfur form in coal were analyzed by sulfur K-XANES(K-edge X-ray absorption near edge structures) spectra before and after the coal microwave desulfurization in a Na OH solution. After the desulfurization, the pyritic sulfur content of coal decreased significantly from 53.6% to 39.2%, while the sulfate sulfur content increased from 17.3% to 34.6%. Only a small amount of thiophene sulfur(20.1–16.1%) was removed. Some sulfur-containing components were oxidized to sulfate sulfur. Under the optimum conditions, the ash content decreased, while the volatile content increased. The calorific value of coal slightly decreased with a slight variation in the amplitudes. The overall structure of coal did not change significantly based on Fourier transform infrared(FTIR) spectral analyses. Thus, the desulfurization of coal with microwave irradiation in a Na OH solution did not significantly change the properties of coal.

如何有效维护计算机硬件

无论什么样的计算机它的性能和工作寿命是有限的,如果维护的不好,那么计算机的性能随着时间的推移将会大大减少。本文重点研究计算机硬件的常见问题与维护方法,使计算机的性能得到充分的发挥,寿命得到最大限度的提高。

浅谈防渗漏的施工技术

在建筑工程中,建筑施工企业要想控制建筑工程施工质量,在施工中应用防渗漏施工技术,才能把建筑的使用性能最大化的发挥。因为渗漏是建筑工程中普通的质量问题。因而本文正是基于这一视角,主要就建筑防渗漏施工技术要点进行了探讨。

预制装配式建筑给水排水系统设计分析

现今我国建筑行业正处于巅峰时期,尤其是在预制装配式建筑出现以后,这为我国建筑行业的发展带来了较大助力。本文重点对预制装配式建筑给排水系统设计进行分析和探讨,希望对预制装配式建筑性能的发挥有所帮助。

Vapor-liquid equilibrium properties for confined binary mixtures involving CO_2,CH_4,and N_2 from Gibbs ensemble Monte Carlo simulations

The effects of solid-fluid interactions on the vapor-liquid phase diagram,coexistence density,relative volatility and vaporization enthalpy have been investigated for confined binary systems of CO 2-CH 4,CO 2-N 2 and CH 4-N 2.The Gibbs ensemble Monte Carlo(GEMC) simulation results indicate that the confinement and the solid-fluid interaction have significant influences on the vapor-liquid equilibrium properties.The confinement and the strength of the solid-fluid interaction make the p-x i phase diagram move to higher pressure regions.They also make the two-phase region become narrower for each binary mixture.The strength of the solid-fluid interactions can cause increases in the coexistence liquid and vapor densities,and cause the decrease of the relative volatility and the vaporization enthalpy for the systems studied.As the pore width is decreased,the two-phase region of the binary mixture becomes narrower.

Secondary aerosol formation and oxidation capacity in photooxidation in the presence of Al_2O_3 seed particles and SO_2

To investigate the sensitivity of secondary aerosol formation and oxidation capacity to NOx in homogeneous and heterogeneous reactions, a series of irradiated toluene/NOx/air and ?-pinene/NOx/air experiments were conducted in smog chambers in the absence or presence of Al2O3 seed particles. Various concentrations of NOx and volatile organic compounds(VOCs) were designed to simulate secondary aerosol formation under different scenarios for NOx. Under "VOC-limited" conditions, the increasing NOx concentration suppressed secondary aerosol formation, while the increasing toluene concentration not only contributed to the increase in secondary aerosol formation, but also led to the elevated oxidation degree for the organic aerosol. Sulfate formation was suppressed with the increasing NOx due to a decreased oxidation capacity of the photooxidation system. Secondary organic aerosol(SOA) formation also decreased with the presence of high concentration of NOx, because organo-peroxy radicals(RO2) react with NOx instead of with peroxy radicals(RO2 or HO2), resulting in the formation of volatile organic products. The increasing concentration of NOx enhanced the formation of sulfate, nitrate and SOA under "NOx-limited" conditions, in which the heterogeneous reactions played an important role. In the presence of Al2O3 seed particles, a synergetic promoting effect of mineral dust and NOx on secondary aerosol formation in heterogeneous reactions was observed in the photooxidation. This synergetic effect strengthened the positive relationship between NOx and secondary aerosol formation under "NOx-limited" conditions but weakened or even overturned the negative relationship between NOx and secondary aerosol formation under "VOC-limited" conditions. Sensitivity of secondary aerosol formation to NOx seemed different in homogeneous and heterogeneous reactions, and should be both taken into account in the sensitivity study. The sensitivity of secondary aerosol formation to NOx was further investigated under "winter-like" and NH3-rich conditions. No obvious difference for the sensitivity of secondary aerosol formation except nitrate to NOx was observed.

Enhanced open-circuit voltage in methoxyl substituted benzodithiophene-based polymer solar cells

The open-circuit voltage(V_(oc))is one of the important parameters that influence the power conversion efficiency(PCE)of polymer solar cells.Its value is mainly determined by the energy level offset between the highest occupied molecular orbital(HOMO)of the donor and the lowest unoccupied molecular orbital(LUMO)of the acceptor.Therefore,decreasing the HOMO value of the polymer could lead to a high V_(oc)and thus increasing the cell efficiency.Here we report a facile way to lower the polymer HOMO energy level by using methoxyl substituted-benzodithiophene(BDT)unit.The polymer with the methoxyl functionl group(POBDT(S)-T1)exhibited a HOMO value of-5.65 eV,which is deeper than that(-5.52 eV)of polymer without methoxyl unit(PBDT(S)-T1).As a result,POBDT(S)-T1-based solar cells show a high V_(oc)of 0.98 V and PCE of 9.2%.In contrast,PBDT(S)-T1-based devices show a relatively lower V_(oc)of 0.89 V and a moderate PCE of 7.4%.The results suggest that the involvement of methoxyl group into conjugated copolymers can efficiencly lower their HOMO energy levels.