含一维阶梯状[CuI]_n链配位聚合物[CuI(Hna)]_n的合成及晶体结构

以吡啶-2,3-二甲酸和碘化亚铜为原料,利用真空封管法,合成了一个含有一维阶梯状[CuI]n链的配位聚合物[CuI(Hna)]n(Hna为烟酸),其中配体吡啶-2,3-二甲酸发生脱羧作用生成了另一配体烟酸(Hna)。用红外光谱、元素分析和单晶X射线衍射分析对配合物进行了表征。晶体结构分析结果表明该配合物属于三斜晶系,空间群为P-1,晶胞参数:a=0.42020(10)nm,b=0.78661(14)nm,c=1.31179(18)nm,α=85.623(2)°,β=87.101(2),°γ=76.0660(10)°,V=0.41937(14)nm3,Z=2。配合物的中心Cu(I)与三个μ3-I-离子和烟酸中的一个氮原子配位,形成四配位的变形四面体构型。相邻的一维链通过分子间的氢键形成了二维超分子结构。     

经历金融风暴的中国PCB行业百强

金融风暴下的中国PCB行业 我国PCB行业自2002年开始公布行业排行榜,至今已9届了。新的一届（第九届）行业排行榜与上年不同的是,排出了本行业最强的100家印制电路板制造企业,20家覆铜箔板生产企业,20家专用材料和工具企业，10家专用设备仪器企业，     

一种富于启发性的热机实验演示与分析

利用试管、玻璃球、器、圆盘等易取材料研制了使玻璃球通过重力作用原理来转移工作物质的方法，并可用燃烧热、电阻热和光转化热作为高温热源的动力的热机实验演示，同时我们给出了相应的理论分析。     

ADSORPTION OF CAFFEINE BY HYDROGEN DONATING ADSORBENTS BASED ON HYDROGEN BONDING

1. INTRODUCTIONHydrogen bonding is a useful mechanism for adsorptive separation. The low enemy of thisbond ensures reversibility, while the directionality and the short range of this bond conferselectivity. The adsorption of hydrogen donating solutes onto an adsorbent capable of acceptinghydrogenedmberlite XAD-7, an adsorbent consisted of polycarboxylic ester--based onhydrogen bonding has been examined in detail 11-41. However, the adsorption of hydrogenaccepting solutes onto polymeric a…     

一种嵌入式协处理器的设计

文章介绍了嵌入式协处理器LSC87的结构和控制方式，LSC87为与Intel8087指令功能全兼容的嵌入式协处理器，研制中采用了Top-down完全正向设计流程，选择微程序作LSC87数据路径的控制以便于支持所有7种类型定浮点操作数与6种异常的屏蔽和非屏蔽处理，其中部分数据路径部件还组合了硬连线控制，使LSC87不仅对复杂操作的处理可控性好，而且有利于数值迭代计算的简单快速实现。     

辐照三烷基氧化膦萃取锶和铯的研究

研究了γ辐照后的３０％％ＲＰＯ－煤油－ＨＮＯ３体系萃取Ｓr和Ｃs的性能。利用ＩＣＰ－ＡＥＳ及ＡＡＳ分别测定两相中Ｓr和Ｃs浓度，分配比。试验了辐照剂量对分配比的影响。结果表明，γ射线辐照对ＴＲＰＯ的萃取笥能无显著影响。     

MgO(001) barrier based magnetic tunnel junctions and their device applications

Spintronics has received a great attention and significant interest within the past decades,and provided considerable and remarked applications in industry and electronic information etc.In spintronics,the MgO based magnetic tunnel junction(MTJ) is an important research advancement because of its physical properties and excellent performance,such as the high TMR ratio in MgO based MTJs.We present an overview of more than a decade development in MgO based MTJs.The review contains three main sections.(1) Research of several types of MgO based MTJs,including single-crystal MgO barrier based-MTJs,double barrier MTJs,MgO based MTJs with interlayer,novel electrode material MTJs based on MgO,novel barrier based MTJs,novel barrier MTJs based on MgO,and perpendicular MTJs.(2) Some typical physical effects in MgO based MTJs,which include six observed physical effects in MgO based MTJs,namely spin transfer torque(STT) effect,Coulomb blockade magnetoresistance(CBMR) effect,oscillatory magnetoresistance,quantum-well resonance tunneling effect,electric field assisted magnetization switching effect,and spincaloric effect.(3) In the last section,a brief introduction of some important device applications of MgO based MTJs,such as GMR & TMR read heads and magneto-sensitive sensors,both field and current switching MRAM,spin nano oscillators,and spin logic devices,have been provided.     

二维抛物型问题的Strang型交替分段区域分裂格式

给出求解二维抛物型方程的Strang型的交替分段区域分裂格式。交替分段思想可以将区域分为一些不重叠的子区域，Strang型算子分裂技巧通过将高维问题的求解分解为几个低维问题的求解来降低其求解的复杂度。方法是无条件稳定的，理论分析了截断误差。数值算例说明格式的有效性及时空的二阶精度.     

SMT生产线中贴片机平衡优化方法研究

贴片机是SMT生产线中的核心设备,其生产效率的高低直接决定着整条生产线的产出,因此提高其生产效率具有十分重要的意义。根据SMT生产模式以及生产线优化对象的不同,分别从单机优化、线体平衡、归组优化和生产计划优化四个方面进行阐述,着重探讨了SMT生产线中贴片机平衡优化的思想、方法以及经验,并结合具体的案例进行分析。