Picosecond third-harmonic light generation inβ-BaB2O4

The type-II phase-matched third-harmonic light generation in a -BaB₂O₄ crystal is studied experimentally. A passively mode-locked Nd: phosphate glass laser is used as a pump source. At a pump pulse peak intensity ofI ₁₀=5×10¹⁰W/cm² a third-harmonic conversion efficiency of a percent is obtained. A theoretical discussion of phase-matched third-harmonic generation in crystals of the symmetry group of -BaB₂O₄ (trigonal class 3) is given. The effective nonlinear susceptibility _eff for type-II phase-matching is determined.On leave from the Shanghai Institute of Optics and Fine Mechanics, Academia Sinica, Shanghai, P.R. China     

AnX α study of the laser crystal MgF2:V2+

The electronic structures of the laser crystal MgF₂:V²⁺ were obtained with the spinpolarized MS-X method. The calculated value of 10Dq and the energies of the lowest doublet states were given for the first time. The relations between the laser properties and the electronic structures were discussed.     

穿过液膜的自发电势振荡

An artificial membrane consisting of pricramic acid in nitrobenzene was used as an oil phase imposed between two aqueous phases. The right one contained trimethyl-slearylammonium chloride and aicohol; and the left contained sucrose solution (or H_2O). We found that this system exhibited rhythmic oscillation of electrical potential. The amplitude of the oscillations was between 20—150 mV. The oscillations were observed even when ethyl alcohol was absent in the aqueous of trimethylslearylammonium Chloride, and the increase in amplitude of oscillation with time was found to be less in the presence of sucrose. Some of the expremental results have been explained.     

54例白血病患者血清硒含量分析

以催化极谱法测定了５４例白血病患者血清硒含量。结果表明，急淋、急粒患者血清硒含量均低于正常对照组，慢粒及急、慢粒经治疗缓解者血清硒含量与正常对照组间均无显著性差异，提示低硒状态只存在于急性患者，且随病情缓解后血硒水平趋于正常，慢粒与血硒含量没有明显的相关关系。     

SUPER TOUGH GELS WITH A DOUBLE NETWORK STRUCTURE

 Living tissues work with fantastic functions in soft and wet gel-like state. Thus, hydrogels have attracted much attention as excellent soft & wet materials, suitable for making artificial organs for medical treatments.However, conventional hydrogels are mechanically too weak for practical uses. We have created double network (DN) hydrogels with extremely high mechanical strength in order to overcome this problem. DN gels are interpenetrating network (IPN) hydrogels consisting of rigid polyelectrolyte and soft neutral polymer. Their excellent mechanical properties cannot be explained by the standard fracture theories. In this paper, we discuss about the toughening mechanism of DN gels in accordance with their characteristic behavior, such as large hysteresis and necking phenomenon. We also describe the results on tissue engineering application of DN gels.     

稀土复合型柴油催化助燃剂的研制及应用

采用铈、铂的有机配合物及碳酸酯制备出一种稀土复合型柴油催化助燃剂.通过发动机台架试验,表明添加剂可有效降低碳烟PM和NOz排放,并且发动机热效率有所提高.     

A microfluidic device using a green organic light emitting diode as an integrated excitation source

A simply fabricated microfluidic device using a green organic light emitting diode (OLED) and thin film interference filter as integrated excitation source is presented and applied to fluorescence detection of proteins. A layer-by-layer compact system consisting of glass/PDMS microchip, pinhole, excitation filter and OLED is designed and equipped with a coaxial optical fiber and for fluorescence detection a 300 microm thick excitation filter is employed for eliminating nearly 80% of the unwanted light emitted by OLEDs which has overlaped with the fluorescence spectrum of the dyes. The distance between OLED illuminant and microchannels is limited to approximately 1 mm for sensitive detection. The achieved fluorescence signal of 300 microM Rhodamine 6G is about 13 times as high as that without the excitation filter and 3.5 times the result of a perpendicular detection structure. This system has been used for fluorescence detection of Rhodamine 6G, Alexa 532 and BSA conjugates in 4% linear polyacrymide (LPA) buffer (in 1 x TBE, pH 8.3) and 1.4 fmol and 35 fmol mass detection limits at 0.7 nl injection volume for Alexa and Rhodamine dye have been obtained, respectively.     

Statistics aided optimization for high-performance liquid chromatographic analysis of organic acids in tobacco

HPLC analysis for organic acids in tobacco was optimized with the aid of statistical experimental design, a central composite face-centered design. In the design, only thirteen HPLC analyses were needed for identifying two optimal separation parameters. A Bio-Rad Aminex HPX-87H column was used for the analyses. An optimal separation for seven acids in tobacco was found at a temperature of 57 degrees C and a mobile phase of 0.032 N sulfuric acid solution, or at a temperature of 70 degrees C and a mobile phase of 0.024 N sulfuric acid solution, with a flow rate of 0.6 ml min(-1).     

甲醇与乙醇一步合成异丁醛用CuO-ZnO/Al2O3催化剂

在ＣｕＯ－ＺｎＯ／Ａｌ２Ｏ３催化剂上，甲醇与乙醇在常压和２１０￣３６０℃温度下一步反应合成异丁醛。利用正交设计方法，研究了ＣｕＯ－ＺｎＯ／Ａｌ２Ｏ３体系催化剂组成和制备条件等因素对催化剂催化性能的影响。结果表明，催化剂中ＣｕＯ含量对催化剂的催化活性影响最大，而ＺｎＯ含量则主要影响催化剂对异丁醛的选择性。催化剂制备条件，如沉淀温度、陈化时间等，也不同程度也影响催化剂的催化性能。ＸＲＤ和ＢＥＴ表征结果     

四种溴代甲苯异构体的质谱区分

本工作用四种较新的质谱技术(碰撞诱导解离(CID),电荷剥离(CS),电荷分离(CSe),电子捕获诱导解离(ECID)谱研究了邻、间、对溴甲苯和溴化苄四种异构体。四种技术在一定程度上都可区分这些异构体。其中比较四种异构体ECID谱中ECID峰的相对强度可得到满意的区分效果。