四面体的

The relationship between the orientation of tetrahedral [SO4]2- in sulfate crystals such as barite,anhydrite, epsomite and jarosite and their morphology was studied from the standpoint of crystal chemistry,and the formation inechanisin of their morphology was analysed according to the structural orientation of tetrahedral [SO4]2- and the bonding energy between [SO4]2- and metal ions [M2+] during growth.

本文从硫酸盐类晶体中负离子配位多面体的结晶方位和相互联结的稳定性出发，探讨了硫酸盐类晶体中[SO4]2-结晶方位与晶体结晶形貌之间的关系；认为[SO4]2-四面体与金属阳离子（Ba2+、Ca2+、Mg2+…）结合时，由于晶体结构和生长条件的不同，在晶体各族晶面上的叠合速率和取向不同；晶体的结晶形貌迥然有别。

In this state, theorists postulate, the liquid is made up of a continuously fluctuating mix of tetrahedral and more disordered structures, with the ratio of the two depending on temperature – just as Nilsson and his colleagues have found to be the case with water at the ambient temperatures important for life.

在这种状态下，理论家假设，这种液体是由一个不断波动的混合四面体和更加无序的结构构成的。两个比例主要取决于温度，-正如尼尔森和他的同事们发现，水的周围介质温度对生活的重要性。

It was proved that the area coordinates of plane triangle element and the volume coordinates of tetrahedron element are equivalent to the oblique Cartesian coordinates by the analytical and geometrical methods.

本文通过分析法和几何法证明：在有限元法和边界元法中，平面三角形单元的面积坐标或四面体单元的体积坐标与由这些单元的二边或三边构成的斜交笛卡儿二维坐标或三维坐标，尽管定义不同，而其内容却是完全对等的。

As the tetrahedral grids exist in the majority area, the pentahedral prism grids are adopted near the boundary, which meets the SST model's requirement of mesh in the boundary layer. Pressure recovery factors under different number of grids are calculated so as to decrease the error from coarse mesh, then the suitable number of grids is obtained.

流场大部分区域为四面体网格，在边界附近采用加密的五面体棱柱型网格，满足了SST模型对边界层网格的要求；为了减少网格过粗引起的汁算误差，还通过计算不同网格数下尾水管的压力恢复系数来优选出合适的网格数目。

The equations of two classes of 3D polynomial maps that are equivariant with respect to the rotational symmetries of either a regular tetrahedron group or a regular octahedron group are strictly given, on the basis of which the properties of the general Julia sets created by these 3D polynomial maps are discussed and proved.

从理论上分析并证明了三维多项式映射满足等变的条件，精确地给出了关于正四面体群和正八面体群具有旋转不变对称性的两类三维等变映射的具体公式，在此基础上讨论并证明了三维多项式映射的广义Julia集所具有的性质。

For two possible geometric structures,square and regular tetrahedron,the electronic structures of ground state and structure parameters of the O_4,O-_4 and O+_4 are calculated according to the principle of minimum energy.

计算了2种可能的空间结构——正方形和正四面体，分别得到了这2种结构的中性分子O4，正一价分子O+4和负一价分子O-4的基态电子结构，并根据能量最低原则确定了各自的结构参数，从而得到了O4分子2种结构的基态总能量、一价电离能及电子亲合势能。

The purpose is to calculate the butadiene's π MO by golden section relation and to get radio of positive and negative ions,whose coordination number is 4 by regular tetrahedron.

通过提出丁二烯πMO系数比的黄金分割系数和正四面体重心规律的具体应用，用黄金分割关系求出丁二烯的πMO；用重心规律求出配位数为4的正离子与负离子的半径比。

On the basis of shock wave characteristic of the supersonic projectile and the detailed analysis of measured datas,a method of decomposing and reconstructing the trajectory shock wave signal and muzzle blast wave signal is proposed and the characteristic parameters for positioning sound source and calculating trajectory vector with regular tetrahedron detection array are extracted.

根据空气动力学原理，在阐述超音速弹丸的弹道波特性的基础上，通过详细分析实测的声信号，提出了弹道波信号和枪口冲击波信号的小波分解和重构方法，提取了利用正四面体探测基阵进行声源定位和弹道矢量计算的特征参数，获得了满意的实验结果。

A map was achieved in detail for the optimal placement of ablation electrode. According to assumption of complete destruction of tumor and its 0.5 cm margin by 5.0 cm ablation device with this method, calculating results were obtained as follows: a tumor of 4.1 ～ 4.3 cm in diameter required 4 ablation at least by the regular tetrahedron way, a tumor of 4.4 ～ 5.6 cm in diameter required 5～8 ablation at least by the regular prism way, a tumor of 5.7 ～ 6.0 cm required 12 ablation at least by the three layers overlapping way.

根据RFA治疗原则消融范围须超越肿瘤周边 0 。5cm以上；按照覆盖类球体肿瘤的计算结果，采用伞径 5 。0cm的射频针，治疗 4.1～ 4.3cm的肿瘤须用正四面体法至少布针 4个点，治疗 4.4～5 。6cm的肿瘤用正棱柱法至少布针 5～ 8个点，治疗 5 。7～ 6 。0cm的肿瘤用三层重叠法至少布针 12个点，方能达到较彻底覆盖灭活肿瘤的效果。

Over the pillared saponite by the impulse reaction, while it was only ～4％ for the pillared montmorillonite, indicating that the substitutions in the tetrahedral sheets played an important role in the development of Bronsted acidity of the catalyst.

层柱皂石的异丙苯裂解转化率达到了65％；而层柱蒙脱土的转化率只有4％。这说明层材料的四面体取代对于层柱粘土Bronsted酸位的形成具有重要的决定作用。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了