Brij35／油酸钠／油酸／水体系的溶致液晶性质——应用偏光显微镜,SAXS,~2H-NMR和流变等方法

首先研究Brij35(十二烷基聚氧乙烯(23)醚)/油酸钠/油酸/水体系的拟三元相图, 发现该体系最大的特点是溶致液晶占相图总面积的2/3. 对O/W型微乳液进行流动曲线研究, 属于牛顿流体. 对溶致液晶体系开展了偏光显微镜, SAXS, ²H-NMR等方法的研究. 当体系组成沿着相图中AA¢线改变时, 其液晶结构变化的顺序是, 立方状液晶→立方状与层状液晶共存→层状液晶→层状液晶与六角状液晶共存→六角状液晶. 并且对上述体系系统地开展了流变性质的研究. 其结果再一次证实液晶结构随着体系中某组分的改变而发生变化. 同时还得到立方液晶和六角状液晶的晶格参数, 分别为10.53和5.68 nm.     

Cs改性X型沸石上甲苯和甲醇的侧链烷基化反应

研究了碱金属离子交换和CsNO₃负载改性X型沸石上甲苯和甲醇的侧链烷基化反应。实验结果显示碱金属离子交换X型沸石由于碱性较弱其碱催化脱氢能力和侧链烷基化反应活性较低，而在Cs负载改性X型沸石上，由于CsNO₃负载物形成新的强碱位，能有效催化甲醇脱氢，表现出高的侧链反应活性。实验发现侧链烷基化反应产物收率(Y_EB+Sty)与异丙醇分解产物丙酮选择性(Sel._A)之间有极好的关联。     

High efficient diode-pumped Tm:YAP laser at room temperature

A high efficient diode-pumped Tm:YAP laser is reported. The maximum output power at 1981 nm is 5.2 W and the slope efficiency is 30%. Unpolarized absorption near 800 nm and unpolarized fluorescence spectra near 1800 nm pumped by laser diode (LD) are measured. In addition, the relationship between operation temperature and output power is discussed.     

微小孔径激光器的工艺及器件功率和寿命特性分析

在650nm波长半导体激光器的基础上制造出了高输出功率的微小孔径激光器.驱动电流为25mA时， 输出功率达到0.4mW，最大功率可达１mW以上.叙述了微小孔径激光器的特殊的制造工艺，并分析了器件可能的失效机理. 关键词： 近场光学 微小孔径激光器 半导体激光器 失效分析     

Nonlinear dissipative dynamics of a two-component atomic condensate coupling with a continuum

We investigate the nonlinear dissipative coherence bifurcation and population dynamics of a two-component atomic Bose-Einstein condensate coupling with a continuum. The coupling between the two-component condensates and the continuum brings effective dissipations to the two-component condensates. The steady states and the coherence bifurcation depend on both dissipation and the nonlinear interaction between condensed atoms. The coherence among condensed atoms may be even enhanced by the effective dissipations. The combination of dissipation and nonlinearity allows one to control the switching between different self-trapped states or the switching between a self-trapped state and a non-self-trapped state.     

以硅为衬底的ZnO p-n结的制备及其结构、光学和电学特性

分别在n型半绝缘Si、弱n (n )以及强n (n+ )型Si片 (1 0 0 )面上用射频磁控反应溅射法和直流磁控反应溅射法制备了p型ZnO薄膜以及ZnO同质p n结。其中在生长p型ZnO时 ,反应室中通以过量的氧。对上述p型和n型ZnO薄膜进行了X射线衍射测量 ,在 34.1°附近得到了 0 .3°左右半峰全宽的ZnO(0 0 2 )衍射峰。ZnO薄膜的原子力显微镜图像上可见六角型的自组装结构。阴极射线荧光的测量显示了位于 390nm的紫外特征峰。用I V特性仪测量了上述ZnOp n结原型器件的I V电学输运曲线 ,其正向显示了约为 1 .1V的阈值 ,与日美科研人员用直流溅射和扩散法制备的ZnOp n结相似 ,但反向特性明显优于他们的     

动力猫道提升过程动力学建模与分析

举升式动力猫道在提升过程中,拉力的变化较大,设计时需要确定提升过程中拉力的变化规律以及所需的最大拉力值.基于此,结合动力猫道提升过程的边界条件,推导了动力猫道提升各阶段的几何方程,应用达朗贝尔原理建立了4个阶段的动力学方程.通过建立的4个阶段的动力学模型,采用C#软件调用Matlab程序求解方程,编写了动力猫道提升动力学的软件.应用该软件分析了所设计动力猫道提升过程中拉力的变化规律,并对其规律进行了分析,相关计算结果表明所设计的动力猫道满足现场使用的要求,为动力猫道的现场使用提供了重要的参考,为动力猫道进一步的优化、性能提升奠定了基础.     

Diode-pumped laser performance of Tm:Sc_2SiO_5 crystal at 1971 nm

The 4-at.% Tm:Sc_2SiO_5 (Tm:SSO) crystal is successfully obtained by the Czochralski method. The optical properties and thermal conductivity of the crystal are investigated. The broad continuous wave(CW) laser output of(100)-cut Tm:SSO with the dimensions of 3 mm×3 mm×3 mm under laser diode(LD)-pumping is realized. The full width at half maximum(FWHM) of the laser emitting reaches up to 21 nm. The laser threshold of Tm:SSO is measured to be 0.43 W. Efficient diode-pumped CW laser performance of Tm:SSO is demonstrated with a slope efficiency of 25.9% and maximum output power of 934 mW.     

Roles of voltage in semi-insulating GaAs photoconductive semiconductor switch

An experimental study of leakage current is presented in a semi-insulating(SI) Ga As photoconductive semiconductor switch(PCSS) with voltages up to 5.8 kV(average field is 19.3 kV/cm). The leakage current increases nonlinearly with the bias voltage increasing from 1.2×10~(-9)A to 3.6×10~(-5)A. Furthermore, the dark resistance, which is characterized as a function of electric field, does not monotonically decrease with the field but displays several distinct regimes. By eliminating the field-dependent drift velocity, the free-electron density n is extracted from the current, and then the critical field for each region of n(E) characteristic of PCSS is obtained. It must be the electric field that provides the free electron with sufficient energy to activate the carrier in the trapped state via multiple physical mechanisms, such as impurity ionization, fielddependent EL2 capture, and impact ionization of donor centers EL10 and EL2. The critical fields calculated from the activation energy of these physical processes accord well with the experimental results. Moreover, agreement between the fitting curve and experimental data of J(E), further confirms that the dark-state characteristics are related to these field-dependent processes. The effects of voltage on SI-Ga As PCSS may give us an insight into its physical mechanism.     

饲料蛋白质水平对日本无针乌贼生长性能和肌肉营养成分的影响

为研究饲料中不同蛋白质水平对日本无针乌贼生长性能及肌肉营养成分的影响, 试验配制了蛋白质水平为35%、40%、45%、50%、55%共5组试验饲料, 对初始体重为(37.86±5.63)g的(P>0.05). 当饲料蛋白质水平为50%时, 肌肉中粗蛋白(82.09%)、氨基酸总量(80.45%)达最大值, 而肌肉粗脂肪在饲料蛋白质55%组达到最大(6.33%), 均显著高于其他4组(P<0.05). 对肌肉氨基酸和脂肪酸的分析结果表明: 肌肉中必需氨基酸量(28.29%)和鲜味氨基酸量(33.03%)在45%和50%两组间无显著性差异(P>0.05),但显著高于其他3组(P<0.05); 总不饱和脂肪酸(EPA+DHA)呈先降后升的趋势, 在45%组和50%组显著低于其他组(P<0.05). 根据SGR折线模型拟合回归方程分析得出, 日本无针乌贼对饲料蛋白质的需求量为44.73%