产生金属的

In this thesis,based on the DFT+NEGF first-principles method,we construct a lead-molecule-lead sandwich system with single benzene-based molecule to investigate the relationship between the structure and properties of the molecular devices and the factors that influence properties of the molecular devices.Our computational investigations on these molecular devices are primarily concentrated on the effect of contact geometry between molecules and electrodes,the effect of side groups,the effect of different torsion angle between two phenyl rings and the effect of external electric field.This thesis consists of five chapters:In Chapter one,we mainly introduce the research background and development of the molecular electronics,including the experimental fabrication of molecular electronic components and theoretical simulation methods.Afterwards we discuss the questions that need to be solved in this area.Finally,the main contents of this thesis are listed.In Chapter two,we introduce the theoretical methods used in this thesis, including the main first-principles calculation methods,i.e.,the Density-Functionmethod and nonequilibrium Green\'s function.

本论文拟采用密度泛函理论和非平衡格林函数相结合的第一性原理计算方法，选取苯基小分子作为研究对象，构建了金属电极/有机小分子/金属电极三明治结构体系，系统地研究了苯基分子器件结构的改变与分子电输运性质之间的关系以及影响分子器件电输运性质的相关因素，其中重点研究了分子与电极间可能的接触结构改变、官能团、分子间的扭转角以及外电场对苯基分子电输运性质的影响，本论文主要包括以下五个章节的内容：第一章为综述部分，主要介绍了分子电子学产生的背景、分子器件的研究意义、当前研究分子器件的实验和主要理论方法，以及目前在研究分子器件中存在的一些问题，最后给出了本论文的主要研究内容和技术路线。

When struck with a sharp edge, the Misch Metal flint produces small balls of molten particles that burn hotter and have a longer burn time than the sparks made by a standard fire flint.

当你用锋利的到划它的时候，这种复合金属火石产生一些炽热的小球颗粒，比普通打火石产生的火花温度更高，燃烧时间更长。

He type of ossein in group B was mainly type Ⅰ collagen while that in group A type Ⅱ and it exhibited as a process of fiber formation in group C. The reason for why TGF-β〓 can promote ossification induced by BMP is that can promote the differentiation and proliferation of mesenchymal cells to supply more target cells for BMP, promote the differentiation and proliferation of mature osteocytes and chondrocytes, inhibit metalloproteinase to decrease the destruction of bone tissue and promote calcification of bone matrix.

GF-〓能促进BMP骨诱导作用主要因其能促进间充质细胞的分裂增殖为BMP提供丰富的靶细胞、促进成熟骨及软骨细胞的分裂增殖、促进骨细胞产生Ⅰ型胶原而抑制软骨细胞产生Ⅱ型胶原，抑制金属蛋白酶的活性以减少组织破坏、促进基质钙化等作用而使骨生成能力增加，提示它和BMP具有协同作用。

Li reduces the surface tension of aluminum luquid obviously, increases the ratio and rate of heterogeneous nucleation, which is the necessary condition of the formation of fine grains. However, a large amount of unmelted Al3Sc, Al3Zr TiAl3 particles dispersively distribute in the luquid metal along the edge of the molten pool, which is the sufficient condition of the formation of fine grains.

Li显著地降低了铝液表面张力，大大提高了异质形核率和形核速率，是细晶层产生的必要条件；而熔池边缘液态金属中弥散均匀分布大量未熔化的Al_3Sc、Al_3Zr和TiAl_3质点，则是细晶层产生的充分条件。

In addition, there are bond areas between the new and the primary coverage because of the growing up of the plating coat, which may lead to the emergence of micro crack on the coating owing to such causes as too big or uneven impact during plating process, little distortion of global granular zinc dust inside the plating coat, less tight coalescence of the zinc dust flecks.

由于形成镀层的过程处在酸性环境，在镀层增厚过程中不可避免把酸性溶液包裹在镀层里面，酸性溶液会与金属基体和镀层反应，产生氢气，必然会寻找通道选出，形成微气孔；镀层是逐渐形成的，新生镀层与原有镀层之间存在结合面；镀覆过程由于撞击力过大或者不均匀，镀层内部球形颗粒状锌粉变形较小，球形颗粒与球形颗粒的结合不严密等，这些原因会导致镀层产生微裂纹。

Soaps of metals heavier than sodium are not very soluble; the curdy precipitate made by soap in hard water is the calcium or magnesium salt of the fatty acid in the soap.

金属皂比钠重，可溶性不高。在硬水冷凝过程中产生的凝结物是肥皂中的脂肪酸产生的钙盐或镁盐。

The SEG's stators and rollers are magnetic components uniquely magnetized or imprinted with magnetic patterns and matched like a planetary gear. This magnetic arrangement along with the resulting radial currents from the Neodymium layer creates the roller's magnetomotive forces into motion at right angles to both the electric and magnetic vectors.

SEG的定子和转子是具有相反磁性的磁力部件，互相吸引起来就像一种行星齿轮，这种磁力装置通过金属钕涂层产生径向电流，这种电流产生的电场力和磁场力方向互相垂直，从而推动转子移动。

In this paper, mechanical analysis of over lap section of yieldable steel ribs is made. It describes how to deal with the overlap sections in calculation of internal forces in the support.It analyzes variation of shape of steel ribs and calculation of internal residual forces resulted from yielding of steel ribs. The theory for ca...

本文根据地下结构的特点，着重对可缩性金属支架的搭接段进行力学分析，并提出了在支架内力计算中搭接段的处理方法；分析了支架缩动引起的形状变化及支架由于缩动而产生的残余内力的计算，从而建立了可缩性金属支架的计算理论。

The analysis of decomposition mechanisms of the catalyst surface revealed that one of the mechanisms is that activated gas phase O2 captures the hydrogen of the organic pollutants to produce free radicals, which then initiate the catalytic reaction, and produce CO2 and H2O ultimately; and the other mechanism is that the activated organic compounds attack the crystal lattice oxygen, which reduces the valances of the transition metals, then the oxidant of the oxygen oxidizes the transition metals to high valances, which realize the self oxidation-reduction of the catalyst.

催化剂表面有机物降解的机理分析表明，一种反应机理为气相中的O2活化后直接夺取有机污染物的氢，产生自由基，并引发催化反应，最终生成CO2和H2O；另一种反应机理为活化后的有机物直接进攻催化剂的晶格氧，并且使得过渡金属由高价态变为低价态，反应气中的O2再将低价态的金属氧化为高价态，实现催化剂自身的氧化还原循环。

While a ball mill is working, balls in the mill are lifted, and then are thrown away with a certain velocity to collide raw material. But at the same time, balls and underboarding are also got collision which may make balls and underboarding fracture. Considering the tough lubrication condition and dust and prills have easy access to meshing zone of gears, the heavy abrasion on gear surface often appears in the upstage gear of open-gear transmission of ball mill.

当球磨机正常运转时，磨球被提升到一定高度后抛落，以一定的速度对物料产生冲击而粉碎物料，同时也对磨球和衬板自身产生冲击，这可能造成磨球和衬板的破球磨机的末级开式齿轮传动，由于润滑条件差，粉尘、金属颗粒容易进入啮合区，齿面常常出现严重磨损，导致齿廓形状发生变化，最后因齿厚磨损过多而折断。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。