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。

A chemical bond consisting of a hydrogen atom between two electronegative atoms (e.g., oxygen or nitrogen) with one side be a covalent bond and the other being an ionic bond .

一种化学键：由两个负电原子及其间的氢原子组成，其中一边是共价键，另一边是离子键。

May be an electrovalent bond , covalent bond and metallic bond mark like chemistry key.

化学键一般可分为离子键、共价键和金属键。

Gemini surfactants are novel surfactant with especial molecule structure, which are made up of at least two hydrophilic groups and two hydrophobic groups. They are connected at the level of the head groups by a spacer groups through chemical bond (covalent bond or electrovalent bond).

孪连表面活性剂是一种结构较为特殊的新型表面活性剂，其分子中至少含有两个亲水基和两条疏水链，在其亲水基或靠近亲水基处，由联接基团通过化学键联接在一起。

The chemical bonding is formed the between coating and the substrate. The bond shows a mixed property of covalent bond and ionic bond.

镍晶格和基体粒子之间产生了键合作用，形成的键显示出共价键和离子键的混合性质。

Usually, they are suitable to mixed crystals with metallic bond but not to those with covalent bond or ionic bond.

上述近似方法通常适用于金属键混晶系统，但对于共价键或离子键混晶系统计算结果则不理想。

There are many factors that determine the ionic bond and covalent bond. What kind of chemical bond is formed between two atoms does not only have connections to the atom itself.It is related to the price attitude of the iton.

决定离子键、共价键的因素比较多，两原子之间形成哪种类型化学键不仅与原子本身性质有关，还与形成的化合物中离子的价态有关。

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 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。

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。