金属切削技术的发展与展望

本文概要阐述了金属切削技术在矛性自动化加工、超精密加工、高效切削加工及刀具技术方面的发展现状,分析了应重氏削民刀具技术这种机械制造基础工艺与基本技术的理由,最后简单介绍了该领域的发展方面与趋势。     

Synthesis,Characterization, Luminescent and Thermal Properties of a Hybrid Inorganic–Organic Polymeric Framework Formed by Lead (II) Pyridinecarboxylate

Abstract  

A coordination polymer of formula [Pb_0.5(pyc)] _n , 1, where Hpyc = pyridine-3-carboxylic acid, has been synthesized and structurally characterized by X-ray single crystal diffraction analysis. Every Pb(II) centre demonstrate trigonal dodecahedron geometry. The ligand i.e. pyridine-3-carboxylate offers μ _{3 -} η ² : η ¹ coordination pattern using its hetero donor centres. The complex initially forms an infinite 1D chain (c-axis) which is turned to 2D sheet and finally a 3D network is recognized through ligand connectivity. Stabilization of 3D structure is further reinforced by π–π stacking interaction. An open channel is identified along c-axis. TG analysis has been performed for the complex. Emission study demonstrates the existence of intraligand and metal-to-ligand charge transfer transition in 1.     

Production of first and second generation biofuels: A comprehensive review

Sustainable economic and industrial growth requires safe, sustainable resources of energy. For the future re-arrangement of a sustainable economy to biological raw materials, completely new approaches in research and development, production, and economy are necessary. The ‘first-generation’ biofuels appear unsustainable because of the potential stress that their production places on food commodities. For organic chemicals and materials these needs to follow a biorefinery model under environmentally sustainable conditions. Where these operate at present, their product range is largely limited to simple materials (i.e. cellulose, ethanol, and biofuels). Second generation biorefineries need to build on the need for sustainable chemical products through modern and proven green chemical technologies such as bioprocessing including pyrolysis, Fisher Tropsch, and other catalytic processes in order to make more complex molecules and materials on which a future sustainable society will be based. This review focus on cost effective technologies and the processes to convert biomass into useful liquid biofuels and bioproducts, with particular focus on some biorefinery concepts based on different feedstocks aiming at the integral utilization of these feedstocks for the production of value added chemicals.     

中波广播发射天线的类型及维护技术分析

随着科学技术的进步,世界开始朝着数字化、信息化、智能化方向发展,广播技术作为生活娱乐的重要媒介,也实现了技术上的革新。天线是传输广播发射设备的重要元素,其功能非常重要,因为有了传输天线,作为一种电磁波的中波才能完成中波电波的发射,终端设备才能接收到信号,人们才能收听广播节目。如今,广播已经走进千家万户,与日常生活息息相关。天线技术的好坏决定了广播信号的覆盖范围和信号质量。因此,文中分析了中波广播发射天线的类型和维护方案,以期为相关工作人员更好地开展工作提供参考。     

衍射增强成像技术在粘虫结构形态学研究中的初步应用

本文利用衍射增强峰位成像技术研究全变态类蛹期粘虫的发育,得到了清晰的粘虫蛹的内部结构的相衬图像,清楚地观察到蛹发育的整个过程以及粘虫从幼虫到成虫部分器官、组织内细微结构的形成与演变,成像分辨率可达到5μm.     

Synthesis of BaCO<Subscript>3</Subscript> with different morphologies using amphiphilic PS-PAA copolymer as medium

Barium carbonate (BaCO₃) with multiple morphologies were synthesized using BaCl₂ and Na₂CO₃ in the presence of a copolymer of poly(styrene) (PS) and poly(acrylic acid) (PAA), an amphiphilic copolymer, by a simple solvent reaction route. X-ray powder diffraction and field emission scanning electron microscopy were used to characterize the obtained products. The mole ratio of the PS/PAA was found to play an important role in determining the morphologies of the final products.     

基于虚拟仪器的汽车燃油蒸发污染物排放测试系统开发

利用虚拟仪器开发平台Labview,开发了PC-DAQ方案的汽车燃油蒸发污染物排放测试系统.对该系统进行性能试验研究,结果表明该系统运行良好,具有较高的自动化程度和测试精度,结果符合国家标准规定的要求.     

境外EPC工程建设的几点体会

我国在境外进行水泥厂建设已有较长的历史．进入21世纪以来．随着我国综合国力的提高．基础工业的增强．行业技术水平的进步．在境外进行水泥厂EPC工程建设取得了突飞猛进的发展．在国际市场占有一定的份额．具有相当的竞争力。仅在沙特阿拉伯．我国承担的已投产和正在建设的3000～10000td水泥生产线就有11条．生产能力超过沙特水泥总产量的1／3。我院从2005年开始承接第一条EPC水泥厂建设工程．目前已有6条生产线投产和通过性能考核．部分拿到工程验收证书．目前在建的国内外生产线还有17条。虽然我们在水泥厂EPC工程建设方面取得了辉煌的成绩．但与发达国家的先进技术相比．的确存在一些问题．本文结合在沙特NAJRAN6000t／d水泥生产线的建设经验．谈一些体会．     

碳氮化钛基金属陶瓷刀具的切削性能试验研究

通过系统切削实验，研究了碳氮化钛基金属陶瓷刀具的切削性能特点和规律，对比分析了碳氮化钛基金属陶瓷与传统的碳化钨基硬质合金刀具在耐磨性、抗冲击性、切削力、刀－屑摩擦系数和加工质量等方面的性能差异，所得实验数据及回归经验公式有助于这一新型刀具材料的合理推广使用．