表面活性剂双水相界面性质的研究

表面活性剂双水相是指正、负离子表面活性剂混合水溶液在一定浓度及混合比 范围内，自发分离形成的两个互不相溶的水相。前文报道了将其作为一种新型萃取 体系，用于生物活性物质的分离。目前有关其相行为、化学物质和生物大分子的分 配方面已有较多研究，但未见两相之间界面化学性质研究的报道。表面活性剂双水 相的形成是一种奇特的相分离现象，两个稀水溶液（含水量可高达99%以上）互不 相溶、平衡共存，其界面结构和界面张力必有其特殊性。     

Wetting and adsorption: II. Adsorption of Triton X-100 and Triton X-305 onto carbon black from water and cyclohexane solutions

The adsorption isotherms of nonionic surfactants Triton X-100 and Triton X-305 from water and cyclohexane on carbon black have been determined at 15 and 30°C. The Langmuir-type and BET-type isotherms are obtained for adsorption of Triton X-100 and Triton X-305 from water and cyclohexane respectively. Both the contact angles of water for graphite/water/air and graphite/water/cyclohexane decrease monotonously with increasing surfactant concentration. From these results, it is proposed that the adsorption of Triton X-100 and Triton X-305 on carbon black or graphite from water is monolayer. For the adsorption from cyclohexane solutions, the ethyleneoxide group of the surfactant molecules may be adsorbed onto the polar spot at the surface of carbon black, and the hydrophobic group of adsorbed molecules may direct toward the liquid phase or attaches to the nonpolar surface region around the polar spot. As the concentration increases, the ethylene oxide groups of the adsorbed molecules can be aggregated with each other via polar interactions to form hemi-reversed micelle.     

30MeV医用回旋加速器气体靶束流线的研制

中国原子能科学研究院于1994年研究建成我国第一台医用强流回旋加速器CYCIAE-30及配套放射性同位素生产线,目前为了增加气体靶以生产新品种医用同位素,在原有束流输运线的基础上开展了束流输运系统的升级改造方案设计,包括束流线的总体布局考虑和光学设计,并根据束流光学设计的结果,进行了新增柬流线上电磁元件的设计.在物理设计的基础上,还进行了施工设计以及各分系统的加工、调试、安装,并以物理设计得到的参数为依据进行了束流调试,靶上得到的束斑与理论值有较好的符合,满足设计要求.     

Optimal design of temperature-insensitive long period fiber gratings for athermal refractive-index sensor

Based on coupled-mode theory of long-period fiber grating (LPFG), a theoretical analysis and simulations for the optimal design of a temperature-insensitive LPFG is presented in order to achieve an athermal condition for sensing the refractive index of the external medium. Effects of the variation of the cladding radius and grating period on the temperature sensitivity of the LPFG are discussed. Both of these parameters are found to be important to control the temperature sensitivity when the thermo-optic coefficients of core and cladding materials are of the same order. Other grating parameters are also optimized in order to achieve a good contrast of the grating period with resonance wavelength in the 1.5 μm region and to sense the external medium refractive index over a wide range. Variation of external medium refractive index from 1.0 to 1.45 results a red-shift in the LPFG resonance wavelength by 86 nm with its temperature sensitivity as low as 0.008 nm/°C over a temperature range of 0–80 °C for this optimally designed LPFG.     

A two-fold interpenetrating 3D metal-organic framework material constructed from helical chains linked via 4,4′-H2bpz fragments

A 3-connected dia-f-type metal-organic framework compound {[Ag(L)_3/2H₂PO₄]}_n (1) has been synthesized by self-assembly of 4,4′-H₂bpz (L=4,4′-H₂bpz=3,3′,5,5′-tetramethyl-4,4′-bipyrazole) and Ag₄P₂O₇ under hydrothermal conditions. It crystallizes in the tetragonal space group I4₁/acd with a=21.406(4) Å, b=21.406(4) Å, c=36.298(8) Å, Z=32. X-ray single-crystal diffraction reveals that 1 has a three-dimensional framework with an unprecedented alternate left- and right-handed helices structure, featuring a non-uniform two-fold interpenetrated (4.14²) net. Photoluminescent investigation reveals that the title compound displays interesting emissions in a wide region, which shows that the title compound may be a good potential candidate as a photoelectric material.     

基于Fe3O4@SiO2/Ni-NTA磁性微球的His-tag融合蛋白纯化体系的建立

合成了表面共价结合Ni-氨基三乙酸(Ni-NTA)基团的Fe3O4@ SiO2微球,这种磁性微球可用于分离含有His-tag标签的融合蛋白.微球中心由尺寸约402 nm的Fe3O4微粒组成,赋予了微球极好的磁性分离和离心分离的特性.应用Fe3O4@ SiO2/Ni-NTA磁性微球对含有6×His-tag(6聚组氨酸)标签的蛋白进行了分离纯化,结果表明,10 mg Fe3O4@ SiO2/Ni-NTA微球能够从10mL重组蛋白裂解液中纯化出约1 mg带有6×His-tag标签的融合蛋白.微球的高效分离效果使其能够用于含量较低的带有6×His-tag标签蛋白的分离纯化.     

一种扑翼运动的模型实验及流场测量方法

俯旋、下拍、仰旋、上挥是一般昆虫运动的四个典型运动过程 ,本文通过研制三维和二维扑翼流场模拟装置以及相应的运动控制系统 ,实现了对昆虫扑翼飞行的上述过程的模拟。在测量方面 ,流场信息主要是通过自研制的 2D -DPIV(二维粒子速度成像仪 )来获得。该系统装备了高分辨率的高速CCD摄像机能够较为精细地动态量化流场 ,3维和 2维流场的动态流动显示以及量化测量都是通过它来实现。初步实验结果表明 ,模拟装置能成功地刻画昆虫翼的典型运动特征 ,2D -DPIV系统也能捕捉和反映强非定常特性的流场。本文还显示了实验中发现的一些有趣的现象 ,这些现象将作为我们进一步研究的重点     

吹脱捕集气相色谱-质谱法测定挥发性有机物条件优化

讨论了吹脱捕集气相色谱-质谱法测定挥发性有机物条件及其优化。     

高重复频率水冷Nd:YAG激活镜放大器的温度特性

为解决高重复频率大能量激光放大器的热管理问题,采用数值模拟与实验分析的方法,对背面水冷Nd:YAG激活镜放大器的流体散热进行了研究.基于低雷诺数k-e湍流模型,建立了流-固共轭传热多物理场耦合分析模型,对比分析了近壁面处理方法对流体流动、对流扩散和热传导过程及温度分布的影响,分析研究了不同冷却液流量和泵浦参数对流场特性...     

固相微萃取气相色谱-质谱法测定自来水中的挥发性卤代烃

采用固相微萃取技术萃取水中的挥发性有机物,用气相色谱-质谱仪检测。