关于Petrov-Galerkin方法的两点注记

本文讨论了Ｐｅｔｒｏｖ－Ｇａｌｅｒｋｉｎ方法的解存在且唯一的双线性泛函弱强制性条件与刚度矩阵的非奇异性之间的关系，证明了有界双线性泛函的弱强制性是存在唯一的解的充要条件。本文还用不同于文献〖１〗的方法严格讨论了Ｐｅｔｒｏｖ－Ｇａｌｅｒｋｉｎ方法的收敛性和误差估计。     

溶剂光氯化法生产氯蜡-70的研究

本文提出了以氯化石蜡－40和氯气为原料，在塔式反应器中采用MB为溶剂，光氯化合成氯化石蜡－70的制备方法，并用正交设计法系统地考察了影响反应的主要因素，并确定了目前较宜的反应条件。     

A New Synthesis Method of Single Crystalline CuO Nanoribbons

One-dimensional (1D) nanoscale materials (nanotubles, nanorods, nanowires and nanobelts or nanoribbons and so on) are currently of a matter of much interest. Due to their unique properties in electronics, magnetics, optics, and mechanics, they can be used to design and fabricate nanosensors, switches, nanolasers, transistors and other nanodevices[1]. In order to obtain desired one-dimensional materials, many techniques and methods have been developed[2].……     

提高企业数控机床使用效率的思考

数控加工技术的开发和应用已经成为工业制造业确保产品质量和效益的必备手段，如何发挥数控机床的使用功能，提高设备潜力与使用效率成为许多企业的迫切要求。简述了数控机床对企业发展的作用，针对企业数控机床的使用现状，对其优势和不足进行了分析，并提出一些改善措施。     

CONTROLLING DARKENING REACTIONS DURING MECHANICAL PULPING WITH ADDITIVES - A POSSIBLE APPROACH TO IMPROVING BRIGHTNESS AND BLEACHABILITY

The first part of this paper summarizes relevant literature information, which rationalizes our selection of chemicals. The second part reports some preliminary screening results. We have investigated a wide range of reagents, chosen for their different chemistries and divided into seven classes: (1)reducing agents, (2) reduced sulfur compounds, (3)hydrogen donors, (4) antioxidants and radical scavengers, (5) nucleophiles, (6) chelating agents,and (7) oxidizing bleaching agents. It is noted that some chemical reagents fall into more than one class.The obtained results will be discussed with respect to the effectiveness of each class.     

预电镀铁对活性钢热镀锌层的影响

研究了5种含硅钢板（含硅量分别为0．04％，0．09％，0．14％，0．28％和0．36％）预电镀铁后热浸锌时镀层中合金相的形成和生长规律．结果表明：预电镀铁能够显著抑制活性钢镀锌合金层的快速生长．对于Sandelin钢、薄的过Sandelin钢和含硅量较低（约0．28％）的过Sandelin钢，可在其表面预电镀厚度不超过10μm的铁层再热镀锌，以解决其镀层超厚问题．电子探针显微分析（EPMA）结果表明：钢中的硅会在钢基表面富集；随着钢基／镀层界面向钢基方向移动，富硅的α-Fe破碎成粒子或絮状物，以类似克根达尔效应中惰性标记物的方式穿过Г层进入δ层，从而促进δ层向钢基方向生长并吞并附近的Г层，令Г层逐渐消失．含硅钢预电镀铁后延缓并减弱了硅对热镀锌合金相的影响，故能在一定浸锌时间内抑制活性钢热浸镀锌层的快速生长，抑制时间随预电镀铁层厚度的增加而增加。     

Biomedical Application of Laser

INTRODUCTIONLasershaverevolutionizedresearchanddevelopmentinmedicineanddentistry .Theyhaveledtode velopmentandproductionofmanynewproducts .Laserapplicationsindiagnosis,treatmentandsurgeryareenormousandhaveledtospeedyandmoreefficientresults,aswellasbetterandquickerhealingProcesses.Theapplicationscouldbeclassifiedintermsofareasofusesorintermsofinstruments/products.Inthispa per,discussionswillnotbegroupedinaparticularfashion ,butwi1lbeonspecificapplications .Alotofin formationontheseapplica…     

跨国营销道德状况及影响因素分析

跨国营销道德是用来判定跨国营销活动正确与否的道德标准。文章从两个方面分析了跨国营销的道德问题：一是违反公司及行业道德规范的行为。包括营销方面的隐瞒和欺诈、胁迫和腐败行为及逃避纳税义务等；二是跨文化价值观冲突引起的道德困境，突出表现为母国和东道国在法律和规范上存在的冲突。制约跨国营销道德性决策的因素有很多，可概括为外部因素与内部因素两大类。要提高跨国营销道德水准，防止不道德的营销行为，必须同时从内外两方面着手。     

一种改进的快速全局k均值聚类分割算法

针对k均值聚类算法的聚类结果易受初始中心随机选择和噪声的影响,本文提出了一种改进的快速全局k均值聚类算法,该方法将聚类中心选择转化为一系列子问题,解决了k均值原始聚类中心的随机选择而导致聚类结果不正确的问题,通过中值方法选择新一轮聚类中心,缓解了k均值聚类结果易受噪声影响的问题.实验结果表明,本文提出方法提高了图像聚类分割的准确性.     

Crystal structure of the human beta2 adrenergic G-protein-coupled receptor

Structural analysis of G-protein-coupled receptors (GPCRs) for hormones and neurotransmitters has been hindered by their low natural abundance, inherent structural flexibility, and instability in detergent solutions. Here we report a structure of the human beta2 adrenoceptor (beta2AR), which was crystallized in a lipid environment when bound to an inverse agonist and in complex with a Fab that binds to the third intracellular loop. Diffraction data were obtained by high-brilliance microcrystallography and the structure determined at 3.4 A/3.7 A resolution. The cytoplasmic ends of the beta2AR transmembrane segments and the connecting loops are well resolved, whereas the extracellular regions of the beta2AR are not seen. The beta2AR structure differs from rhodopsin in having weaker interactions between the cytoplasmic ends of transmembrane (TM)3 and TM6, involving the conserved E/DRY sequences. These differences may be responsible for the relatively high basal activity and structural instability of the beta2AR, and contribute to the challenges in obtaining diffraction-quality crystals of non-rhodopsin GPCRs.