三环己基和三苯基锡化合物的质谱重排反应及配位效应

研究了１８种新合成的有机锡化合物的电子轰击质谱，利用Ｂ／Ｅ联动扫描及碰撞诱导解离技术，研究了该类化合物的几种特殊的重排反应机理，同时探讨了与锡配位的基团对其断裂规律的影响。     

Preparation and properties of GaN films on Si(111) substrates

High-quality gallium nitride (GaN) films were prepared on Si(111) substrates by sputtering post-annealing-reaction technique. XRD, XPS, and SEM measurement results indicate that polycrystalline GaN with hexagonal structure was successfully prepared. Intense room- temperature photoluminescence that peaked at 354 nm of the films is observed. The bandgap of these films has a blueshift with respect to bulk GaN.     

叔胺催化的Sulfa-Michael-Aldol串联反应合成羟基取代的四氢噻吩类化合物

探究了叔胺1,4-二氮杂二环[2.2.2]辛烷(DABCO)催化的2,5-二羟基-1,4-二噻烷和羟基取代查尔酮的sulfa-Michael-aldol串联环化反应。考察了催化剂对反应收率的影响，以最高79%的收率合成了15个多取代的四氢噻吩化合物。 其代表产物的结构经X-ray单晶衍射实验确证，化合物结构经¹H NMR, ¹³C NMR, IR和HR-MS(ESI)表征。      

高平均功率调Q准连续Nd:YAG激光器

通过选用低掺杂浓度的Nd:YAG晶体棒、热近非稳腔优化设计、双棒串接热致双折射补偿技术以及双Q开关正交放置结构，在LD抽运功率1116W时，实现调Q准连续全固态Nd:YAG激光器1064nm输出，平均功率达258W，光束质量M²～15.5，重复频率为10kHz，脉冲宽度为64ns，峰值功率达0.4GW，光光转换效率达23.1%. 关键词： Nd:YAG激光器 准连续波 激光二极管抽运 固体激光器     

腔内倍频Nd:YVO4晶体激光获得的大功率671nm红光

本文报道了由双端泵浦Nd:YVO4晶体产生1342nm基频光，经过非线性晶体LBO腔内产生的671nm的红光光源。泵浦功率19.5W时，产生的671nm的红光平均功率是2.9W。光光转换效率为14.9%。分析了最近泵浦光斑尺寸，最佳聚焦位置，减少热透镜效应对输出功率的影响。双端泵浦结构和准连续运行模式大大减弱了热透镜效应。     

C60结构的对称群（I）Ih群的坐标表示

本文提供一种直观简便的方法，用矢量分析导出正二十面体特殊点的空间位置，从而给出正二十面体对称群的坐标表示。     

FINITE ELEMENT ANALYSIS OF FREE VIBRATION OF LIQUID－FILLED AXISYMMETRIC TANKS

ＦＵＲＵＤＥ（符儒德）；ＵＳＨＩＪＩＭＡＴＥＲＵＯ（牛岛照夫）（ＤｅｐａｒｔｍｅｎｔｏｆＣｏｍｐｕｔｅｒＳｃｉｅｎｃｅ＆ＩｎｆｏｒｍａｔｉｏｎＭａｔｈｅｍａｔｉｃｓ，ＵｎｉｖｅｒｓｉｔｙｏｆＥｌｅｃｔｒｏ－Ｃｏｍｍｕｎｉｃａｔｉｏｎｓ，Ｔｏｋｙｏ１８...     

Thermal Decomposition Behaviour of ZB3N2 Powder

Thermal gravimetric analysis (TGA) and differential thermal analysis (DTA) are employed to investigate the thermal decomposition behaviour of zinc nitride powder, which indicated that the thermal oxidation of zinc nitride powder in air follows the two-step reaction model. When the temperature is between 200 and 500℃,compact ZnO or ZnxOyNx layers in the surface of zinc nitride powder will begin to form, and prevent the interior of zinc nitride powder from the thermal oxidation. When the temperature is higher than 500℃, fast thermal oxidation occurs in the interior of zinc nitride powder. Over 750℃, all the zinc nitride will turn into zinc oxide.The x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) of the zinc nitride powder annealed at different temperature in air are consistent with the two-step reaction model.     

不同惯性系间电磁场变换关系的特殊推导方法

电场和磁场是电磁场的特殊存在形式,由于历史的原因人们对电磁场的认识是从它的上述两个侧面分别进行的。这种认识到一定程度上很有必要进行一次由片面到全面的提高,完成这种提高的有效途径是考虑电磁场的表达式在不同参照系间的转换。做为普通     

A Room-Temperature Multiwavelength Erbium-Doped Fibre Laser by Exploiting Polarization Hole Burning

Multiwavelength operation of a linear cavity erbium-doped fibre laser (EDFL) is proposed and demonstrated. A 3-dB fibre loop mirror and a high birefringence (HiBi) fibre loop mirror are utilized as the cavity reflectors. By utilizing the wavelength-dependent polarization rotation induced by the HiBi fibre loop mirror and by using a fibre polarizer to control the intracavity polarization state, the polarization states of different wavelengths are diversified. Therefore, the polarization hole burning (PHB) effect has been greatly enhanced and the homogeneous broadening of erbium-doped fibre is suppressed to a large extent. By simply tuning a polarization controller, we experimentally obtained simultaneous lasing of four and five wavelengths with wavelength spacing of ～1.8nm and less than 2nm at room temperature, respectively. The repeated scans show that all of these lasers have good stability.