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In particular, when thereis an alternating group A_5 action on a Spin 4-manifold X, we obtain: If X is smooth Spin4-manifold with non-positive signature and b_1=0, denote k=-σ/16 and m=b_2~+,then 2k+3≤m if b_2~++b_2~+≠2b_2~+(Z/A_5) and b_2~+≠0,where and are subgroups of A_5 generated by the elements s=∈A_5and t=∈A_5 respectively.

特别地，在Spin 4-流形具有非交换群A_5作用时，我们得到了：若X为光滑的具有非正符号差的Spin 4-流形，b_1=0，令k=-σ／16，m=b_2~+，如果X上具有Spin交错群A_5作用，且满足b_2~++b_2~+≠2b_2~+(X／A_5)，b_2~+≠0，则2k+3≤m，其中和分别为s=∈A_5和t=∈A_5生成的A_5的子群。

XRD shows: when the value of x is between 0.1 and 0.3, the alloying thin film remains the structure of hexagonal wurtzite and the angle of (002) diffraction peak becomes bigger as the value of X increases; The photoluminescence spectra at room temperature shows that the PL spectra of the alloying thin film is composed of the stronger UV emission band and weaker visible band, and UV emission peak will have the blue shift with the content of Mg increasing and the visible emission weakened.

XRD衍射测试表明：在0.1＜x＜0.3范围内，合金薄膜仍然保持氧化锌六角型纤锌矿结构，(002)衍射峰位随x的增大向大角度方向移动，在X≥0.3的范围内，合金薄膜的结构则为氧化锌和氧化镁的混合结构；室温光致发光谱表明：ZnMgO合金薄膜PL谱都是由较强的紫外发射带组成，且随着Mg含量的增加紫外发射峰位发生蓝移，同时可见发射增强。

Detailed contents are given as follows:(1)In views of the x-ray laser target chamber on the SG-II high-power laser facility and the experimentally physical demands, the key influencing factors, such as the elliptical eccentricity and the spectral detection angle, on the angular dispersion, the spectral resolution,and the photometric parameter were studied by the elliptical self-focusing geometric principle. In order to increase the spectral and spatial resolution, using ray tracing code and optical path function, optimization calculation was carried out for an elliptical crystal spectrometer.

进一步以此为核心开发出了一种新型的X射线测量与诊断系统，取得了一些新的科研成果，可为王王淦淦昌昌院士、王大珩院士二老倡导研制成的用于国防科研、激光惯性约束聚变、强激光与物质相互作用、X射线激光等物理研究的大型钕玻璃高功率"神光II"激光装置上的物理实验提供更有效的诊断X射线谱手段，扩充了其应用范围，也对激光等离子体辐射keV以上能区段的X光发射和吸收的原子物理过程与机制、占据动力学、谱形态结构等方面做了深入一步的理论和实验研究。

The aim of this thesis is to explore new MWDC with cation-deficient perovskite structure in A_5B_4O_(15) system. According to the characteristic of A_5B_4O_(15) perovskite structure, series of new titanates / tantalates Ba_(5-x)La_xTi_xTa_(4-x)O_(15)(x=1~3) were prepared, characterized. The dielectric properties were measured. Furthermore, the effects of Nb~(5+) substitution Ta~(5+) at B-site in Ba_3La_2Ti_2Ta_2O_(15) ceramic on structure and dielectric properties were studied.

本论文的主要目的是在A_5B_4O_(15)系列中探索新型类钙钛矿结构高性能微波介质陶瓷，进行了Ba_(5-x)La_xTi_xTa_(4-x)O_(15)(x=1～3)系列钛钽酸盐陶瓷的制备、结构与介电性能研究工作，并研究了材料Ba_3La_2Ti_2Ta_2O_(15)的B位Nb~(5+)离子取代Ta~(5+)离子对材料结构和介电性能的影响。

Then by using FEM to calculate the direct and quadrature axis magnetic fields, the steady-state reactances x〓 and x〓 are determined with definition method and vector potential method when μ〓 equals ∞ and voltage equals 0.1U〓 and U〓 respectively.

接下来，以有限元为工具，在直轴和交轴磁场下，用定义法和矢量位法，分别确定μ〓=∞、0.1U〓和U〓状态下的稳态电抗x〓和x〓以及在额定负载下确定x〓和x〓的饱和值，并研究了直、交轴间的耦合电抗以及用路的方法确定稳态电抗。

As x was increased, the transition of B-site cation ordered perovskites from 1:2 (x = 0) to 1:1 (x = 0.1) and disordered (x = 0.5) types was observed and related to the variation in the proportion of cation-oxygen octahedra.

此有序结构相转换与各阳离子之氧八面体之比率的变化有关。1：2 有序程度主导 x = 0 ~ 0.10 之 Qxf 值随著 x 的增加而降低的趋势。

In the first part of this thesis, I will give a general description to synchrotron radiation source and beamline design; and then the comparison to the difference in the designs of hard X ray and soft X ray beamline is given; some detailed features on hard X ray beamline design is also discussed especially in this part.

本文第一部分对同步辐射光源特点及光束线设计作了概述，并对硬X光束线与软X光束线的设计特点作了比较，这一部分中还着重讨论了硬X光束线的不同设计路线。

It was found that CaZr4 (PO4)6(X＝0) and BaZr4(PO4)6 (X= 1) had opposite anisotropies in their respective axial thermal expansion,therefore,the near-zero thermal expansion can be obtained by selecting X value.

研究发现CaZr(PO4)6(X=0)及BaZr4(PO4)6(X＝1)时的轴膨胀特性正好相反，因此当X为某一值时热膨胀系数将为零。

But this is not new - the X-11 and X-12 from the 1950s were going to be prototypes of the Atlas intercontinental ballistic missile, and the still-born Lockheed X-27 was always intended as a prototype of a production aircraft.

不过，这并不是新的-在X - 11和X - 12由20世纪50年代将被原型的Atlas洲际弹道导弹，并仍在出生洛克希德的X 27总是作为原型，生产的飞机。

In the second chapter, during the study of compound x-ray refractive lenses, diffraction function of compound lens is derived in the light of refraction and absorption effect and the design theory of X-ray is deduced using diffraction theory in connection with the characteristic of X-ray band.

在第二章X射线聚焦组合透镜的研究中，针对X射线波段的特性，综合考虑折射和吸收效应得出组合透镜的衍射屏函数，利用衍射理论推导出X射线聚焦组合透镜的设计理论并进行结构设计与微细加工制作技术研究。

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。