查询词典 covalent bond

The results show: the strongest bond is the Al-Al bond in the segregated cell without containing vacancy, where the Al atomic covalence radius is greater than that of Li atom in the cell; while the strongest bond is the Al-Li bond in the segregated cell containing vacancy, and the Al atomic covalence radius in the cell is less than that of Li atom. Since the difference of electronagativity between the Al and Li atoms is obvious, it is inclined to formed the Al-Li segregated cell of short range order structure in the condition of vacancy present. The short range order structure containing vacancy is probably the embryo or precursor structure of the metastable phase δ′(Al3Li). Because the strongest covalent bond in the Al-Li-vacancy segregated cell in alloy formed in quenching is the main strength reason for supersaturated solid solution of alloy. The bond net of succeeding precipitation of δ′(Al3Li) has the picture of anisotropic Al-Al bonding and the bond intensity enhanced. Since the δ′(Al3Li) is coherence with matrix, the bond net strength is enhanced by the precipitation of δ′(Al3Li) and so strengthen the alloy.

计算结果表明：不包含空位的偏聚晶胞的键络最强键为Al—Al键，其中Al原子的共价半径较Li原子的共价半径要大；而含空位的偏聚晶胞的最强键为Al—Li键， Al原子的共价半径要比Li原子的共价半径要小；在空位存在的情况下，由于Al原子与Li原子的电负性相差明显，促使Al和Li原子结合，倾向形成Al-Li短程序结构偏聚区，这种含空位的短程序结构很可能就是δ′(Al3Li)亚稳相的前兆结构和生长胚胎；由于Al-Li-空位有序偏聚晶胞的Al—Li键络比基体键络要强许多，因此，淬火过程中合金生成的Al-Li-空位偏聚晶胞对合金过饱和固溶体起主要强化作用；后续析出的δ′(Al3Li)亚稳相键络各项异性显著，键络强度明显提高；由于Al3Li与基体共格，其大量均匀弥散析出起到提升基体整体键络强度，同样对合金产生强化作用。

The results show: the strongest bond is the Al-Al bond in the segregated cell without containing vacancy, where the Al atomic covalence radius is greater than that of Li atom in the cell; while the strongest bond is the Al-Li bond in the segregated cell containing vacancy, and the Al atomic covalence radius in the cell is less than that of Li atom. Since the difference of electronagativity between the Al and Li atoms is obvious, it is inclined to formed the Al-Li segregated cell of short range order structure in the condition of vacancy present. The short range order structure containing vacancy is probably the embryo or precursor structure of the metastable phase δ'(Al3Li). Because the strongest covalent bond in the Al-Li-vacancy segregated cell in alloy formed in quenching is the main strength reason for supersaturated solid solution of alloy. The bond net of succeeding precipitation of δ'(Al3Li) has the picture of anisotropic Al-Al bonding and the bond intensity enhanced. Since the δ'(Al3Li) is coherence with matrix, the bond net strength is enhanced by the precipitation of δ'(Al3Li) and so strengthen the alloy.

计算结果表明：不包含空位的偏聚晶胞的键络最强键为Al-Al键，其中Al原子的共价半径较Li原子的共价半径要大；而含空位的偏聚晶胞的最强键为Al-Li键，Al原子的共价半径要比Li原子的共价半径要小；在空位存在的情况下，由於Al原子与Li原子的电负性相差明显，促使Al和Li原子结合，倾向形成Al-Li短程序结构偏聚区，这种含空位的短程序结构很可能就是δ'(Al3Li)亚稳相的前兆结构和生长胚胎；由於Al-Li-空位有序偏聚晶胞的Al-Li键络比基体键络要强许多，因此，淬火过程中合金生成的Al-Li-空位偏聚晶胞对合金过饱和固溶体起主要强化作用；后续析出的δ'(Al3Li)亚稳相键络各项异性显著，键络强度明显提高；由於Al3Li与基体共格，其大量均匀弥散析出起到提升基体整体键络强度，同样对合金产生强化作用。

By this way, it can be seen that the risks of natural disaster and accident can be transferred by construction insurance and that man-caused risks by construction bond. Furthermore, this paper studies the legal problems in the implementation of construction insurance and bond system and the correspondent laws that need to be improved. With reference to construction insurance, it is compulsive to carry out Contractor"s All Risks, Erection All Risks, Employer"s Liability Insurance, Supervisory Engineer/Designer Professional Liability Insurance and Maintenance Insurance. As for construction bond, it is suitable to take the method of surety bond and implement obligatorily Bid Bond, Performance Bond, Employer Payment Bond and Contractor Payment Bond. In addition, this paper analyses the problems in the implementation of construction insurance and bond system in China and presents corresponding solutions. In the end, it provides a method by option price theory to estimate the costs of construction bond.

本文首先借鉴国外工程保险和担保制度，通过工程保险可以有效的转移自然灾害和意外事故风险，通过工程担保转移各种人为风险；其次研究了在我国实行工程保险和担保制度存在的法律问题和需完善的相关法律，提出在工程保险方面，应强制实行建筑工程一切险、安装工程一切险、质量保修保险、设计/监理责任险，在工程担保方面，宜采取保证担保的方式，强制实行投标保证担保、履约保证担保、业主履约保证担保和付款保证担保，分析了在我国实行工程保险和担保制度存在的问题，提出相应对策；最后运用期权价格理论给出了确定工程担保费用的一种方法。

The second section analyzes the restraint conditions of establishing zero-coupon bond yield curve in China. In order to analyze the constraint conditions of establishing zero-coupon bond yield curve, we should firstly study the current situation and problems of Chinese bond market because the data estimating zero-coupon bond yield curve mainly come from bond market which can't be separated from the analysis of the development history of bond market. So the main content of this section includes the development history of bond market, the present problems of Chinese bond market and the restraint conditions of establishing zero-coupon bond yield curve in China.

第二节分析中国零息票债券收益率曲线构造的约束条件，由于估计零息票债券收益率曲线所需要的数据主要来自债券市场，这样，要研究零息票债券收益率曲线构造的约束条件，首先必须研究中国债券市场的现状和问题，而这一切又离不开对中国债券市场发展历史的分析，因此本节的内容包括中国债券市场发展的历史沿革、中国债券市场目前存在的主要问题和中国零息票债券收益率曲线构造的约束条件三个部分。

The results show that the major contribution to DOS of Mg and Pb are the 2p orbit of Mg and the 5d orbit of Pb, followed by the 3s orbit of Mg and the 6p orbit of Pb, the 6s orbit of Pb is the smallest one. There are a large number of charges around Mg, it has the characteristics of typical metal bond. Mg and Pb share some charges to form covalent bond, but the distortion of the charge at the junction is little; the proportion of covalent bond is less than the metal bond, Mg2Pb is semimetal. The elastic modulus and shear modulus of Mg2Pb are 68.6 and 27.9 GPa, respectively. Based on Pugh empirical criterions and Poisson's ratio, Mg2Pb is brittle in nature.

结果表明：Mg和Pb对态密度的贡献主要是Mg的2p轨道和Pb的5d轨道，其次为Mg的3s轨道和Pb的6p轨道，Pb的6s轨道贡献最小；在Mg原子周围有大量的电荷存在，呈典型的金属键特征，Mg、Pb之间存在共用的电荷，有较强的离域性，以共价键形式存在，但交界电荷的畸变不大，故共价键所占比例较少，金属键所占比例较大，Mg2Pb化合物呈半金属性；Mg2Pb的弹性模量和切变模量分别为68.6和27.9 GPa，Pugh经验判据和泊松比均表明Mg2Pb具有脆性。

The bonding energy of the mixed covalent/metallic Ti-Al bond for the Ti-terminated Al/TiB_2 interface is larger than that of the polar covalent Al-B bond with partial ionic-like feature for the B-terminated interface. Metallic bond between Al atoms forms across the Al/AlB_2 interface, which results in weaker interfacial adhesion than that for the Al/TiB_2 interface. The interfacial energy for Al/TiB_2 depends on the interfacial chemical potential.

Al熔体中仅存在TiB_2粒子，而无多余溶质Ti时，α-Al在TiB_2粒子上异质形核产生的Al/TiB_2界面能大于α-Al从Al熔体中直接形核时的液-固界面能，不满足TiB_2粒子充当α-Al有效异质形核核心的能量条件，这从理论上解释了Al熔体内仅存在TiB_2粒子时无晶粒细化效果的实验现象。

The weak base anion exchange resin with covalent bond side chains which contain donator atom N offering unshared electron pairs, is able to form a coordinative covalent bond to heavy metal in which unsaturated vacant orbits exist in its electron shells.

在天然淡水水体的环境下，重金属被树脂吸附源于树脂胺基官能团上的N原子有孤对电子，水中所含重金属的价电子层有空轨道。

Synthesis of organic sulfuric compounds in aqueous media is carried out by: using thio-olefin compounds with carbonyl compounds, acetal/keltone, hydrazone, oxime, osazone and enamine to synthesize mercaptal/keltone compounds in aqueous media; using thio-olefin compounds with alpha-hydroxyaldehyde/keltone or alpha-halogenated aldehyde/keltone to synthesize thia-olefin derivatives in a queous media; using thio-olefin compounds with alpha, beta-unsaturated hydroxy compounds, C-C treble bond, C-N treble bond, C-C double bond, N-N double bond, C-N double bond, C-S double bond, epoxy and its derivatives, aziridine and its derivatives, cyclopropane and its derivatives and halogenated carboxy to synthesize sulfoether compounds in a queous media.

含水介质中有机硫化合物的合成方法，本发明属于有机合成方法，用硫缩烯酮类化合物与羰基化合物、缩醛/酮、腙、肟、脎、烯胺在含水介质中合成缩硫醛/酮化合物，与α-羟基醛/酮或α-卤代醛/酮在含水介质中合成噻烯类衍生物，与α，β-不饱和羰基化合物、碳碳叁键、碳氮叁键、碳碳双键、氮氮双键、碳氮双键、碳硫双键、环氧乙烷及其衍生物、氮杂环丙烷及其衍生物、环丙烷及其衍生物、卤代烃等在含水介质，中合成硫醚化合物。

But unique difference handling middle, enterprise bond and corporate bond in reality is lain in, enterprise bond government credit with being, enterprise bond distribution needs to examine and approve and issue the procedure examining and verifying two process forehead degree, corporate bond enterprise debenture bond with being's, the distribution is from Securities Regulatory Commission leading factor then, can adopt the pattern criticizing as reporting therefore.

在现实操作中，企业债券与公司债券的唯一区别在于，企业债券用的是政府信用，企业债券的发行需要经过额度审批和发行审核两道程序，而公司债券用的是企业信用，公司债券的发行则是由证监会主导，因此可以采取随报随批的模式。

Reversible covalent modification The activity of many enzymes is alterd by the reversible making and breaking of a covalent bond between the enzyme and a small nonprotein group.

可逆共价修饰许多酶的活性随酶和小的非蛋白质基团之间共价键可逆性的生成和断裂而改变。

Objective To study the effect of chitosan in the prevention of fibrous scar formation in the epidural space after laminectomy.

目的 观察选择性脊神经后根切除术椎板切除后硬膜外几种防瘢痕粘连物质的作用并探讨其机制。

On his way to the lift, he looked back to us or was it me his eyes pointing?

当他要进电梯时，他回头看我们（或者说是我，他的眼光？