四价

The soluble tetra-alkyl phthalocyanine compounds have the following general structure, wherein Rn represents straight-chain or branching chain alkane, n represents the number of straight-chain or branching chain alkane, M represents center ligand of bivalence or more, L represents axial ligand, X represents the number of L.

该可溶性四烷基酞菁化合物符合如下结构通式：结构通式中，Rn代表直链或支化链的烷烃，n代表直链或支化链的烷烃的数目，M代表二价或二价以上的中心配体，L代表轴向配体，X代表L的数目。

In addition, some modifications on several computational methods are also presented. Using LMTO method the electronic structure of several systems are studied, and some results are obtained. They are: The ideal Nb (100) surface has three surface states, the multi-layer relaxed surface has two surface states. The surface energy of the ideal surface is higher than that of the relaxed surface, that means that the multi-layer relaxed surface is more stable than the former one, which supports the LEED results. The mono-layer relaxed Ag (111) surface is the most stable one among several" stable surface models"presented by several researchers. The surface energy of Ag (111) surface is higher than that of surface Ag (001), which supports some experimental results such as different reaction rate at different surface orientations for the same material. The surafce states of Si (111) surface not only locate near the Fermi level, but also in the valence band, which agrees well with Cohen's conclusion. Si (111)-H is an effective model for analysing the surface states and H adsorbed on the back surface is a good method for improving the convincingness of the results obtained on thinner slab models. The surface stability depends on three different kinds of MoSi〓(001) surfaces, the surface with mono-layer Si is the most stable one, and the surface with Mo at the first layer is the most unstable one among them. These are consistant with the Kemoda's experimental results. The valence bands of clean or K adsorbed CdTe (111) surface agrees well with the synchrotron radiation studies. The surface of CdTe (111) consists of four kinds of surface models which show different surface electronic structures and different surface structure stabilities. The conclusion agrees well with Wu's experimental work. The different absorbed alkali metals on the CdTe (111) surface give different adsorption characteristics which have relations not only with the valence electrons, but also with the core ones of the alkali metals. The electonic structures of Si-C alloys are different from that of Si-Ge alloys, and the energy band gaps of Si-C alloys do not increase linearly with Carbon concentration, our conclusion supports Alexander's results, but conflicts with Soref's one.

现分述如下： LMTO方法及其应用方面：1）通过对Nb（100）表面电子态分析发现清洁理想表面有三个表面态，多层弛豫表面有两个表面态；表面能大小说明多层弛豫表面更稳定，支持了LEED结果。2）通过对采用不同方法获得的几种不同Ag（111）表面稳定结构的表面能计算分析，给出了单层弛豫表面为Ag（111）表面的最稳定结构；从Ag（111）单层弛豫表面和Ag（001）表面的表面能比较，发现了Ag（001）表面表面能要比Ag（111）小的，表明了同种物质不同表面取向将表现出不同物理、化学性质，这是与实验中得出的结论是吻合的，3）通过对Si（111）表面态分析，不仅发现了Si（111）表面不仅具有居于费米能级附近的悬挂键所对应的表面态，而且还有很多表面态位于价带能量范围内，与Cohen等结果一致，H饱和slab模型背表面相当于增加了slab层的厚度，是一有效的变相增加slab层厚的方法，弛豫表面较清洁理想表面价带谱们低能端的少许移动，预示着总能降低，说明弛豫表面较清洁理想表面稳定。4）MoSi〓具有三种表面，从费米能级上态密度值大小得到单层Si表面最稳定，Mo原子为表层原子的表面最不稳定，双层Si原子表面居中的结论，这与Kemoda等人实验结果是一致的。5）通过对CdTe（111）表面表面电子态、表面结构稳定性及表面H、碱金属吸附的电子结构系列研究，不仅得出了CdTe（111）清洁及碱金属K吸附价带谱与同步辐射光电子谱相吻合的结果，而且发现了CdTe（111）表面具有四类不同原子近邻特征，表现出四类不同的表面结构及电子结构特征：不同表面态分布、不同的表面结构稳定性（表层原子与次层原子成三键有一悬挂键的表面要比表层原子与次层原子成一键有三悬挂键稳定（与Wu等人实验结果一致））、不同的H吸附特性。

Besides, it makes some modifications for the model and puts forward a new rule of multi-case variable substitution to solve the problems posed by the Chinese constructions called "JianYu", which are similar to the object control constructions in Chomsky's model of Principle and Parameter Theory.

同时，汉语一价动词、二价动词和三价动词的词项行为也是解释代词隐现的重要基础。本章验证了第四章解析模型中对汉语一般计算规则的限制条件，证明了对汉语词项行为的刻画是合理的。

The result showed that the plant of Maicao No. 9 was tall, with good fecundity, fully filled grain and vigorous growth. The chromosome number of the root cells was 2n=56, through the observation of pollen mother cells meiosis, there were a certain amount of univalents, ring bivalents and bar bivalents in PMCM. Different numbers of lagging chromosomes, chromosome bridges and micronucleus were found in anaphaseⅠ, anaphaseⅡ and tetraspore.

结果表明：麦草9号植株高大，结实性较好，籽粒饱满，生长旺盛；根尖细胞染色体数目为2n=56，对其进行花粉母细胞减数分裂观察，中期Ⅰ具有一定数量的单价体、环状二价体、棒状二价体；后期Ⅰ、后期Ⅱ与四分体时期都出现不同数量的落后染色体、染色体桥、微核等现象。

The paper obtains some conclusions after many theories analysis and empirical tests: Firstly, Volume-price relativity is extensive: total volume or it's change, disassembled volume promoting price movement or it's change all has plus relativity to equilibria price. Secondly, there is unilateralisms Granger casuality in bullmarket, while there is bidirectional Granger casuality in bearmarket. There is not nonlinear Granger casuality in both markets. Third, Behavior finance has remarkable effects after contrasting to different investment conditions. Moreover, causality research by moving tendency can reflect the stable relation while usual causality research can't do. Fourth, it can be ture forecasing key period of tendency reversion by building volume-price elasticity coefficient containing composite information of volume-price and analysis methods of moving tendency.

本文大量的理论分析和实证研究得到以下结果：第一，量价之间的相关性具有广泛性，总成交量及变化、分解的促进股价变化的成交量及变化都与均衡价格收益有正相关关系；第二，在牛市中，收益和成交量之间存在单向的Granger因果关系，而在熊市中，收益和成交量之间存在双向的Granger因果关系，不论熊市和牛市，上证和深证量价间均没有非线性因果关系；第三，不同市场环境的比较中还发现行为金融在股市中的作用明显，通过比较发现依据运行趋势的因果关系分析能反映量价间的稳定关系，而常规因果分析方法却反映不出来；第四，通过建立包含量价信息的量价弹性系数指标和依据运行趋势的关键区域研究法，可以实现对趋势转变关键区域的预测。

A tetravalent nonmetallic element; next to oxygen it is the most abundant element in the earth's crust; occurs in clay and feldspar and granite and quartz and sand; used as a semiconductor in transistors.

一种四价非金属元素，地壳中含量仅次于氧，见于粘土、长石、石英和沙中，在晶体管中用作半导体。

Seven inactivated tetravalent vaccines of Riemerella anatipestifer,of which three (1#,3#,7#) employed oil-emulsion,two(4#,6#) employed propolis,two(8#,10#) employed aluminum hydroxide as their basic adjuvants,were developed and compared by the methods as follows:challenges were performed by homologous virulent RA strains to measure their protective abilities;indirect enzyme-linked immunosorbent assay was used to monitor antibody production;lymphocyte transformation test was performed to study the expression of cell-mediated immunity.

本实验通过对供试鸭的攻毒保护试验、通过用ELISA方法对供试鸭特异性抗体消长规律的研究以及通过用~3H-TdR掺入法对供试鸭T细胞免疫水平的检测三个方面对所研制的七种不同佐剂类型的鸭疫里氏杆菌四价灭活苗的免疫原性进行了比较研究。

The results showed that: at metaphase I, the homoeologous chromosome pairing among different F1 hybrids ranged from 2.0 to 11.4 bi-valents formed by homoeologous chromosomes per pollen mother cell, and very few multivalents, and even very few bivalents were formed by two chromosomes within one genome rather than homoeologous chromosomes in some PMCs; at anaphase I, all biva-lents were disjoined and most univalents were divided.

结果表明在中期I阶段，这些杂种一代的近缘染色体联会变化很大，每个花粉母细胞中二价体形成的数目从平均2个到11.4个不等，甚至在某些花粉母细胞中，还发现极少的多价体和非部分同源染色体所形成的单基因组内二价体；在后期I时，所有的二价体分离，同时多数单价体也分离，分离的二价体和分离的单价体都移向两极，从而形成两组染色体；因为这时完整花粉母细胞中分离的二价体在两组染色体中总是对应出现，从而根据半二价体上染色体重组的位置可以分析在二价体的四分体时期发生在非姊妹染色体之间的多种染色体交换类型，如单交换、三线双交换、四线双交换、四线三交换和四线多交换。

Carbon has 4 valencies.

碳的化合价是四价。

In the Purex process, the separation of plutonium from uranium is achieved by using reductants which can quickly and quantitatively reduce Pu to Pu.Up to now the reductant U-N2H4 is still used widely for separation of Pu from U in the rep...

目前动力堆乏燃料后处理中广泛采用的钚还原剂还是由肼支持的四价铀，而醛、肼、羟胺类有机无盐还原剂在Purex流程中的应用目前还停留在实验室研究阶段。

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。