Studies on the Structure and Catalytic Properties for Heck Reaction of Troxerutin Supported Palladium Catalyst

Theoretical Foundations of Chemical Engineering - Troxerutin supported palladium (TXT-Pd) catalyst was prepared readily by using one-step synthetic method. As-fabricated TXT-Pd catalyst was...     

Improved thermal conductivity of β-Si3N4 ceramics by lowering SiO2/Y2O3 ratio using YH2 as sintering additive

A two-step sintering process was conducted to produce β-Si₃N₄ ceramics with high thermal conductivity. During the first step, native SiO₂ was eliminated, and Y₂O₃ was in situ generated by a metal hydride reduction process, resulting in a high Y₂O₃/SiO₂ ratio. The substitution YH₂ for Y₂O₃ endow Si₃N₄ ceramics with an increase of 29% in thermal conductivity from 95.3 to 123 W m⁻¹ K⁻¹ after sintered at 1900°C for 12 hours despite an inferior sinterability. This was primarily attributed to the purified enlarged grains, devitrified grain boundary phase, and reduced lattice oxygen content in the YH₂-MgO-doped material.     

煤泥浮选中矿物颗粒间相互作用力的研究进展

煤泥浮选是选煤流程中的一个重要环节,改善煤泥浮选效果是提高煤炭高效洁净利用和企业经济效益的关键,煤泥浮选过程的强化越来越受到选煤行业的重视。论文总结了当前煤泥浮选体系中矿物颗粒间相互作用力的最新研究方法和研究进展,综述了浮选药剂、电解质、矿浆pH值、钙镁离子、机械搅拌、磁化处理、电化学处理、超声波处理以及微生物对矿物颗粒间相互作用力的影响规律及机理,对实现煤泥的高效分选有重要的参考价值。     

高边坡开挖卸荷过程强度折减法分析

针对露天矿开采过程中边坡变形破坏严重影响露天矿安全生产的问题，采用数值模拟的方法，应用MidasGTS NX软件建立重钢太和露天铁矿黄家山高边坡三维模型，进行开挖卸荷过程中的应力应变、位移及安全系数变化的数值模拟分析。结果表明：边坡岩体开挖卸荷过程中，随着采场的延深，边坡角的增大,塑性应力带的逐渐向边坡岩体内部扩大，风化破碎层及上部冰碛土层之间产生塑性应变贯通区，破坏面形成。开挖完成后整体边坡坡脚处发生剪切破坏，坡顶后缘形成张拉破坏区，边坡上部冰碛土层形成 “坐落—滑移”式滑动。边坡安全系数随向下开挖过程逐级降低，最终达到1.15稍显偏低。后期开采过程中，需对边坡中上部风化破碎岩层及冰碛土进行加固措施。     

Lower temperature hydrothermal pretreatment improves the anaerobic digestion performance of spent cow bedding

The anaerobic digestion (AD) performance of spent cow bedding was investigated with different hydrothermal pretreatment (HP) conditions. Spent cow bedding was pretreated with low temperatures (50, 70, and 90℃) and different pretreatment times (2-72 h) with ammonia and without ammonia. The results showed that spent cow bedding was a good raw material for AD. After pretreatment, the concentration of volatile fatty acids (VFAs) in the group of hydrothermal pretreatments with ammonia (HPA) was higher than that in the HP group at the same pretreatment temperature and time. The optimal pretreatment condition was achieved with an HPA of 50℃ holding for 72 h. At the optimal condition, the highest concentration of VFAs was 1.58-10.85 times higher than that of the other pretreated groups. The highest hemicellulose and lignin removal rates were 58.07% and 10.32%, respectively. The highest methane yield was 163.0 ml·(g VS)^-1, which was 48.9% higher than that of the untreated group. The VFAs, pH, and reducing sugars showed positive relationships with the methane yield. Therefore, HP at low temperature can enhance the AD performance of spent cow bedding.     

Preface to the Special Issue on Semiconductor Optoelectronic Integrated Circuits

The past 20 years have witnessed the rapid growth of photonic integration circuits(PIC)technology,which has been warmly embraced by both academia and the industry.Powered by the advanced development in material growth,processing,and design capability,the PIC technology now covers multiple material platforms,including III–V(InP,GaAs),silicon,silica,lithium niobate on insulator(LNOI)polymer,etc.The integration level has evolved from a single functional device to thousands of components on-chip.The increase in the performance and the complexity of the PICs have become an energetic booster for communication and information technology.     

有机元素检测仪器在石油化工行业的需求和应用现状

本文通过对国内外石油及石化产品分析检测相关标准技术的调研与收集,以及相关检测仪器特点的分析,对目前包括润滑油、汽油、柴油、煤油、石蜡、石化聚合物、原油等样品类型,共计80个样品在现有仪器上进行测试,使用标准方法对样品中碳、氢、氮、硫元素进行检测,获取样品的检测时间、含量结果、仪器条件等参数,为相关仪器检测提供数据基础.     

低成本火箭弹弹载计算机的设计

低成本制导火箭弹是一种对点目标具有较高命中概率的低成本灵巧弹药，具有较高的作战效费比。弹载计算机是火箭弹制导控制系统的核心，本文从弹载计算机的运算和接口处理要求出发，充分考虑相关电路低成本、高可靠性的实现方法，为火箭弹低成本、制导化的实施提供参考。     

Dual action bactericides: Quaternary ammonium/N‐halamine‐functionalized cellulose fiber

Bi‐functional antibacterial material was prepared by co‐grafting N‐halamine and quaternary ammonium salt monomers from cellulose fiber. The grafted fiber was characterized by Fourier transform infrared spectra, and X‐ray photoelectron spectra. The N‐halamine derived from the precursor 4‐[(acryloxy)methyl]‐4‐ethyl‐2‐oxazolidinone via chlorination treatment and the oxidative chlorine (Cl⁺) leaching behavior were investigated. The antibacterial activities of singly (only QAs‐functionalized or only Cl⁺‐releasing) and dual (QAs‐functionalized and Cl⁺‐releasing) functional cellulose fibers were tested against Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus. Compared to singly functionalized formulations, the bi‐functional cellulose fiber exhibited excellent and rapid bactericidal performance against both E. coli and S. aureus. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40070.