晶体

SiC polytypes of 6H and 15R and a transition zone between the two were observed under HREM and TEM and discussed from the point view of the crystal structures; the clear evidence of Al〓C〓 nucleated in the SiC particle was provided, indicating the aluminum penetrating the SiC grains is already carbon-saturated and, consequently, Al〓C〓 crystals grow in the particles wherever a temporary local supersaturating is produced; The experimental observation indicated that the types of the interface between SiC and Al are variable and the distribution feature of reaction product, Al〓C〓, were also given in the present work: to be nucleated on SiC, to be aggregated at SiC/Al interface zone or to be aggregated at the crystal boundaries.

通过高分辨透射电镜，本文观察到SiC增强体中6H和15R同质多晶现象及6H-15R SiC转变区，以及另外一种无序的SiC同质多晶，并从其晶体结构的角度解释了6H和15R在晶体内共存的现象。通过高分辨透射电镜，本文给出了Al〓C〓在SiC颗粒内部形核的明证，表明Al〓C〓形核是Al渗透到SiC颗粒内部在C过饱和处在SiC的（0006）面上而形核，而且一种可能的位相关系为A1〓C〓[11〓0]∥SiC[11〓0]。研究结果同时给出了SiC/Al复合材料的界面反应产物A1〓C〓的分布特征：在SiC上形核并生长，聚集于SiC/Al界面去附近，或者聚集于晶界上。

For wurtzite-type crystal, [Zn-S4]6- and [Zn-S4]6+ with different crystal positions distribute in the form of layers along c axis, where the two layers of tetrahedrons whirl 60 around c axis, so the crystal is mainly like hexagonal cone.

在纤锌矿型晶体中，[Zn-S_4]~(6-)和[Cd-S_4]~(6-)四面体沿c轴呈层状分布，上下两层四面体的结晶方位不同，两层四面体绕c轴旋转60°，晶体的结晶形貌为六方锥状。

The tremendous application foreground of photonic crystals upsurges the research in fabricating periodic artificial structures in many famous labs all over the world during the last decade, which has been a very important research direction in the field of photonics.

光子晶体巨大的应用前景令世界很多著名实验室在近十年来掀起了光子晶体制作的研究热潮，已经成为光学领域一个非常重要的研究方向。

Both crystal and ceramics show typical Ce3+ absorption bands at 230,340 and 460 nm and a 540 nm emission peak.

Ce：YAG晶体和陶瓷都具有位于230，340和460 nm波段的Ce3+离子的特征吸收带和540 nm附近的发射峰，但Ce：YAG晶体同时存在296和370 nm的色心吸收，其发射峰位于398 nm，而透明陶瓷中不存在。

Common lifetime measurement methods for minority carrier of crystalline silicon and crystalline silicon solar cells were introduced, including microwave photoconductivity decay, quasi-steady state photo-conductance, surface photoelectric voltage, infrared carrier density imaging, modulation free-carrier absorption and laser beam-induced current microscopy.

分别介绍了常用的测量晶体硅和晶体硅太阳电池少子寿命的各种方法，包括微波光电导衰减法，准稳态光电导方法，表面光电压，IR浓度载流子浓度成像，调制自由载流子吸收和光束诱导电流，并指出了各种方法的优点和不足。

A systematic study on the crystallization process of ammonium sulphate has been performed in this thesis.

为了改善饱和器结晶硫酸铵过程中，生成的晶体颗粒较小，粒度分布不均匀，色度不理想，并伴有晶体聚结现象发生等问题。

The high-efficiency SRS in barium nitrate Ba(NO32 crystal was obtained pumped by a Q-switched Nd:YAG laser (532 nm) operated at 30 Hz.

报道了利用重复频率为30 Hz，波长为532 nm 的Nd∶YAG倍频激光单次通过抽运硝酸钡（Ba(NO3)2）晶体（晶体由水溶液降温法生长，长度为48 mm，横截面为10 mm×10 mm），获得高效率的一阶（563 nm），二阶（599 nm）和三阶（639 nm）斯托克斯光的实验结果。

A harmonic of Nd:YAG laser(532 nm) pumped barium nitrate crystal in external resonator and excited stimulated Raman laser.Experimental setup adopted the Raman shifter consisted of external cavity and two prisms spectrometer.The external cavity was composed of diachronic mirrors with optimal reflectivity for Stokes components.

采用单端泵浦的外置拉曼振荡腔与双棱镜分光装置进行了硝酸钡晶体拉曼激光实验，泵浦源为倍频Nd： YAG的532 nm激光，硝酸钡晶体通过水溶液降温法生长，尺寸为10 mm×10 mm×48 mm，采用特殊镀膜的腔镜对各阶斯托克斯光进行优化选择。

A harmonic of Nd:YAG laser (532nm) pumped barium nitrate crystal in external resonator and excited stimulated Raman laser. Experimental setup adopted the Raman shifter consisted of external cavity and two prisms spectrometer. The external cavity was composed of diachronic mirrors with optimal reflectivity for Stokes components. Barium nitrate crystal was grown by the aqua-solution cooling method with the size of 48mm×10mm×10mm.

采用单端泵浦的外置拉曼振荡腔与双棱镜分光装置进行了硝酸钡晶体拉曼激光实验，泵浦源为倍频Nd：YAG的532nm激光，硝酸钡晶体通过水溶液降温法生长，尺寸为10mm×10mm×48mm，采用特殊镀膜的腔镜对各阶斯托克斯光进行优化选择。

Thus by using longer crystal and focused pump beam in OPA or OPO, the gain of amplification can be increased and oscillation threshold be reduced.

本文从理论上和实验上证实，OBNC对OPA和OPO参量作用有特别重要的意义，它可以使泵光束和信号光束在非线性晶体中实现最大的交叠并允许泵光束有较大的发散度，从而可以通过加长非线性晶体的长度或会聚泵光以增加参量作用的增益和降低振荡的阈值。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。