旺格维利采矿法矿柱合理尺寸数值模拟

为回收瓦厂坪铝土矿边角矿体并提高矿井资源回收率,本文基于简支梁、固定梁及两区约束理论,结合FLAC~(3D)数值模拟软件,对瓦厂坪铝土矿采用旺格维利采矿法回收边角矿体时刀间矿柱的合理尺寸进行模拟分析,得出刀间矿柱随采硐数目增加所受垂直应力和塑性区的变化规律。结果表明:较合理的刀间矿柱尺寸为1.0 m,1.0 m刀间矿柱能够保护当前回采采硐,且靠近工作面的三到四对刀间矿柱部分发生塑性破坏,能起到临时支撑顶板作用。     

可光－生降解聚乙烯薄膜的降解性能试验

用自然光照法、模拟光照法和堆肥法进行了可光一生降解聚乙烯薄顺和普通聚乙烯薄膜的光降解和微生物降解对比试验。结果表明，前者的光降解和微生物降解性能都明显优于后者。     

无缝钢管成形件偏心的原因和防治方法

结合无缝钢管冲孔 拔伸工艺 ,分析了钢管锻件产生偏心的原因 ,并从工艺和模具结构方面探讨了防治钢管产生偏心的措施 ,可为生产无缝钢管及其他孔径要求较高的长筒形零件的行业提供参考     

麻石泡沫脱硫除尘处理技术的工业应用

简介麻石泡沫脱硫除尘处理技术的基本原理、工艺系统主要特性。侧重介绍了麻石泡沫脱硫除尘处理技术应用在35t/h燃煤锅炉上的投资与效益分析。     

负载TiO2的泡沫镍网光催化降解甲醛的膜厚优化

采用负载TiO2的泡沫镍网光催化降解甲醛,考虑内部和外部质量传递,建立了可预测优化催化剂膜厚的数学模型.分析了TiO2膜厚对光催化降解甲醛的影响,并在模型基础上分析了催化剂层内光的衰减系数和污染物的有效扩散系数对最优催化剂膜厚的影响.结果表明,随着催化剂膜厚的增加,甲醛的降解先增加而后趋于平缓;最优催化剂膜厚受UV光衰减系数的影响较大,受污染物的有效扩散系数的影响较小;由于TiO2催化剂对254nmUV光的强烈吸收,优化的催化剂膜厚只有80nm左右.该模型对实验数据拟合较好.     

非晶态TiO2-W薄膜的光催化性能研究

采用磁控溅射技术在玻璃基片上制备了W掺杂的非晶态TiO2薄膜,用XRD、XPS和椭圆偏光测厚仪等对薄膜进行了微观分析.结果表明,TiO2-W薄膜为非晶态结构.Ti以 4价存在;W以0价和 6价形式存在,并且6价和0价W的原子浓度比为6.4:1;薄膜中Ti和W的原子浓度比为2.6:1.对5 mg·L-1的亚甲基蓝溶液光催化脱色试验表明,随着膜厚的增加,光催化降解率递增,当膜厚达到141 nm时,所制备的TiO2-W薄膜对亚甲基蓝的脱色率在2 h达到90%;当膜厚大于141 nm时,光催化降解率不再增加.     

微米级空心玻璃微珠三相泡沫稳定性研究

基于水成膜泡沫灭火剂(AFFF),用微米级空心微珠颗粒作为泡沫稳定剂,制成三相泡沫,并研究了泡沫组成因素对发泡能力和泡沫稳定性的影响。采用控制变量法,研究了颗粒浓度、颗粒粒径、AFFF原液浓度对发泡倍数和析液时间的影响。颗粒加入对发泡能力有抑制作用;因为颗粒存在影响,三相泡沫的发泡能力随AFFF原液浓度增大而减小;40μm粒径颗粒的抑制作用相对20μm和60μm颗粒最小。颗粒浓度和AFFF原液浓度增加,能够提升三相泡沫稳定性,且泡沫析液时间随颗粒浓度增加呈指数规律变化。当AFFF原液浓度为3.0%、颗粒浓度为9%左右时,三相泡沫稳定时间约为两相泡沫的3倍,该配方三相泡沫有较好的稳定性。     

Research on the recycling industry development model for typical exterior plastic components of end-of-life passenger vehicle based on the SWOT method

In-depth studies on the recycling of typical automotive exterior plastic parts are significant and beneficial for environmental protection, energy conservation, and sustainable development of China. In the current study, several methods were used to analyze the recycling industry model for typical exterior parts of passenger vehicles in China. The strengths, weaknesses, opportunities, and challenges of the current recycling industry for typical exterior parts of passenger vehicles were analyzed comprehensively based on the SWOT method. The internal factor evaluation matrix and external factor evaluation matrix were used to evaluate the internal and external factors of the recycling industry. The recycling industry was found to respond well to all the factors and it was found to face good developing opportunities. Then, the cross-link strategies analysis for the typical exterior parts of the passenger car industry of China was conducted based on the SWOT analysis strategies and established SWOT matrix. Finally, based on the aforementioned research, the recycling industry model led by automobile manufacturers was promoted.     

LDPE/EPDM Multilayer Films Containing Recycled LDPE for Greenhouse Applications

In this paper the reuse of recycled LDPE in combination with the incorporation of EPDM modifier in the production of greenhouse films has been investigated. A three-layer film (60-100-40 micron thickness) containing recycled LDPE in the middle layer and a high UV-stabilized 40-micron outer layer was developed and proven to be commercially successful. Films with 25% and 50% recycled material content were produced. The effect of natural weathering on the film properties over a period of 15 months has been observed. Changes in physical and mechanical property were determined. The addition of EPDM to the raw resin was found to improve the extrudability of the compound and improve the weather resistivity of the film. The EPDM-modified films containing 25% to 50% recycled material retained approximately 95% and 75%, respectively, of their original extensibility after 9 months' exposure to natural weathering. Optimization of EPDM and UV stabilizer concentration was carried out to develop a balanced film with excellent mechanical and physical properties and resistance to weathering conditions. The use of UV stabilizer concentrations slightly higher than commercial practice in the outer layer of the multilayer film can be justified by the cost reduction by the incorporation of recycled LDPE materials.     

Thermal Degradation Mechanism of Low-Density Polyethylene Plastic Wastes in Cyclohexane

The thermal LDPE degradation mechanism harnessing a high-pressure autoclave surrounded by a furnace was investigated in this work. Rates of formation of gas, liquid, and solid during degradation of PE plastic wastes in cyclohexane as solvent at 400 and 425°C have been experimentally determined. Four reaction mechanisms have been proposed and tested to estimates of gas, liquid, and solid. Proposed mechanisms are based on the assumption that the reactions are pseudo-first-order with respect to the reacting species. Pseudo-first-order rate constants for each of the indicated mechanistic steps have been calculated by nonlinear regression analysis. The best fit was obtained by model 2 (pure parallel reaction mechanism), and its activation energy was determined.