四重

The presence of REE tetrad effects in apatites and whole rocks of S-type granites has been reported by Sha and Chappell (1999) and Zhao et al.(1999), respectively. The REE tetrad effect in minerals, such as apatite, spessartite, beryl, alkali feldspar and spodumene, from all zones of Altay No. 3 pegmatite has been found remarkable, and the fractionations among isovalent incompatible elements in these minerals are also significant. This paper puts forward that the REE tetrad effect is one of the basic features of peraluminous melts and the origin of REE tetrad effect might be probably related to some processes prior to the formation of pegmatite magma. The immiscibile liquid separation between silicate melt and hydrosaline melt may be responsible for it.

由于阿尔泰3号伟晶岩脉各带磷灰石以及与其共生的石榴石、绿柱石、碱性长石、锂辉石矿物均存在明显的稀土"四重效应"以及相同电价、相似离子半径的不相容元素间存在显著的分异，并结合最近赵振华等(1999)和Sha and Chappell(1999)报道S型花岗岩全岩和单矿物(磷灰石、独居石、长石、黄玉等)均存在稀土"四重效应"这一现象，本文研究提出，稀土"四重效应"是富挥发分过铝质岩浆体系的一个基本特征，其机制既不可能由含稀土的副矿物早期结晶引起残余熔体相中REE含量变化的结果，也不能定性地归因于流体相与熔体相相互作用过程中稀土元素在流体/熔体之间分异的结果，而很可能与伟晶岩岩浆形成之前某些过程密切相关，S型花岗岩岩浆在液相线以上存在硅酸盐熔体与高盐熔体的不混溶液相分离有可能是过铝质岩浆体系产生稀土"四重效应"的主要原因。

In contrast, the increases of the ellipticity of outgoing optical waves are obvious with the raise of Faraday rotation in non-fourfold-symmetry structures.

结果表明：在这些结构中，光波均被局域在中心缺陷处；同时，对于具有四重对称轴结构的材料，在其法拉第旋转角增加的同时，出射光波的椭圆率没有明显的增加；但对于不具有四重对称轴结构的材料，其法拉第旋转角增加的同时，出射光波的椭圆率也在增加。

Any repertoire for Piano Trio/Quartet/Quintet, any combination of string/wind instruments within 20 minutes

钢琴三重/四重/五重奏，任何管弦乐器组合不限，不超过20分钟之曲目

Besides these, the present calculations indicate that the epoxidation of ethylene is slightly endothermic or exothermic in sextet and quartet states, respectively.

另外，我们的计算结果显示乙烯环氧化反应在六重态下是微弱吸热的，而在四重态下是微弱放热的。

The calculated results are in accordance with the experimental observation that OsO〓 is unreactive to methane under the experimental condition.Ⅱ. The mechanism of the reaction of FeO〓 with ethylene For the oxidation reaction of gas-phase FeO〓 with ethylene, PESs in sextet, quartet and doublet states for various reaction channels are obtained.

二FeO〓与乙烯的反应机理通过对气相FeO〓与乙烯的反应的各种可能的低能量路径进行研究，得到了各种反应通道在二重态、四重态和六重态等三个自旋态下的势能面。

All the stationary points on the doublet, quartet, and sextet potential energy surfaces have been fully optimized. The reaction undergoes preferentially on the quartet PES. The whole reaction can be divided into two stages.

对二重态、四重态和六重态势能面上各驻点进行了全优化，发现反应易于沿四重态势能面发生。

The calculation results show that W(superscript +) initially closes to CO2 on the sextet surface, then the products, WO(superscript +) and CO. exit the channel on the quartet surface. The process involves an intersystem crossing from the sextet to the quartet state.

计算结果表明，W活化CO2分解反应以六重态进入反应通道，经过六重态势能面到四重态势能面的系间窜越，最后产物WO和CO以四重态离开反应通道。

It is indicated that theinfluence of the two sort of multiplets is a synthetic effect and does not obey the linearsuperposition theorem; the influence of the quartets plays a leading role; and theinfluence of the doublets on the 6S state is realized by means of the intermediate effect ofthe quartets.

指出两者的影响是一种综合效应，不服从线性迭加原理；四重态的影响占主导地位；二重态对~6S态的影响是通过四重态的中介作用而间接实现的。

Silver Tatsu campus card system is characterized by "quadruple", that is, re-finance applications, heavy self-help applications, re-expansion of applications, re-inclusive, this is the silver Tatsu in the years to meet the banking needs of services continue to sum up the process, improve and formed.

银达校园一卡通系统的突出特点是&四重&，即重金融应用、重自助应用、重扩展应用、重包容性，这是银达在多年为满足银行需求服务的过程中不断总结、完善和形成的。

We also simulate the environment of photon experiment, and calculate the effect by use of fourfold symmetry torsion pendulum, we find that the double frequency effect caused by gravitational gradient is reduced a magnitude when we buildup the symmetry of measurement system.

我们还对二重对称扭秤的光子实验数据进行了分析，结果发现二倍频的效应为10~(-12)Nm 的量级，通过计算分析我们发现扭秤周围环境的不对称所引入的引力梯度效应是不容忽视的，因此针对喻家山人防山洞的具体情况，我们对光子实验的实际环境进行了模拟计算，理论分析结果表明对于二重对称的扭秤而言，环境不对称的影响引起的力矩效应为5.4940×10~(-10) Nm，对于四重对称的扭秤来说，效应为1.8668×10~(-11)Nm，可以看到随着扭秤对称性的增加，引力梯度的效应减小了一个数量级。

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。