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).     

新型含金属元素二胺的合成与表征

本文分别用液相法和固相法合成了一系列含不同金属元素的二胺,并通过红外光谱,~1HNMR、~(13)CNMR,紫外光谱,电化学分析及元素分析对其进行表征,还通过DSC和TG对其热性能进行了研究,结果发现这些二胺具有良好的耐热性,是合成一些耐热高聚物的优良原料.     

Cyanex272-P507浸渍树脂协同萃取色层分离铥镱镥的研究

以Cyanex272-P507浸渍树脂采用萃取色层法对铥镱镥富集物进行了吸附和淋洗分离研究,考察了淋洗剂浓度、稀土负载量、淋洗液流速等因素对分离铥镱镥富集物的影响。结果表明,在充填的树脂粒度为0.3~0.6 mm的色层柱中,以0.2 ml.cm-2.min-1进料流速时能得到较大的吸附率;在稀土负载量为树脂重量的0.6%,淋洗液流速为1.0 ml.cm-2.min-1,温度为30℃,装柱树脂高度为400 mm(高径比为25∶1)的条件下,用1.0,1.5,2.0 mol.L-1盐酸梯度淋洗Tm,Yb,Lu,可实现铥镱镥富集物三者的完全分离。