广东土牛膝中微量元素的分析

应用电感耦合等离子体发射光谱仪（ICP-AEP）,对广东土牛膝中的微量元素进行了测定分析,结果表明,广东土牛膝中Al、ca、Fe、Mg、P、Mn等元素含量相对较高,变异系数范围在0．81％～7．26％之间,元素回收率在93．O％～104．O％之间。该法简便快速,可用于广东土牛膝中微量元素的测定。     

端视ICP-AES法测定茶叶中铅铜砷镉铬钴

研究了用ICP-AES法同时测定茶叶中6种重金属元素铅、铜、砷(为类金属元素)、镉、铬、钴的分析方法。方法回收率都在90％～104％之间，相对标准偏差在0．1％～8．3％之间，对茶叶标准物的测定值与推荐值基本一致，方法简便、准确，结栗满意。     

中药辛夷中微量元素含量的测定

应用电感耦合等离子体发射光谱仪（ICP—AEP）,对中药辛夷中的微量元素进行了测定分析。结果表明,辛夷中Ca、Al、Mg、P、Fe等元素含量相对较高,变异系数范围在0．87％-6．82％之间,元素回收率在95．02％～103．53％之间。该法操作简便、快速,可用于中药辛夷中微量元素的测定。     

ICP-AES法测定钢中的铈

建立了离子体发射光谱仪测定钢中铈元素的方法。为消除共存元素对铈分析游线的光谱干扰,选择Ce413．380nm作为分析线,铈含量在0．005％-0．50％之间工作曲线线性良好。对于含量范围在0．005％-0．10％的铈元素,回收率为85．6％-12．5％,测定结果的相对标准偏差小于9．74％（n=8）;对于含量范围在0．10％-0．50％的铈元素,回收率为99．5％-103．0％,测定结果的相对标准偏差小于3．52％（n=8）。该方法适宜钢中含量范围在O．005％-0．50％的铈元素的测定。     

ICP-AES法测定出口工业硅中11种杂质元素

利用ICP-AES分析技术,对试样溶解方法,元素分析谱线,共存元素干扰,仪器分析参数,无机酸介质影响等因素进行了研究,确定了最佳工作条件,建立了可同时测定出口金属硅中11种杂质元素的简单、快速和适用的分析方法,结果表明,该方法线性范围宽,检出限低,准确性高,操作步骤简单,11个元素测定回收率在85％～105％之间,相对标准偏差在1．9％～8．1％之间。     

电感耦合等离子体质谱测定高纯金属钐中25种杂质元素

研究建立了电感耦合等离子体质谱(ICP—MS)测定高纯金属钐中14种稀土及11种非稀土杂质的测定方法。考察了钐基体对杂质元素测定的各种干扰影响。对无干扰的杂质元素,采取了直接测量的方式;对有干扰的元素(Nd、Eu、Dy、Ho、Er、Tm),采用标准加入法的方式进行测定。选择内标元素Sc和Cs,有效补偿了由于基体效应带来的测量偏差。方法的检出限为0．012～83μg／L．加标回收率为88．6％～108．0％．测定精密度(RSD)为0．55％～2．53％,方法可满足99．9％纯度的金属钐中朵质元素的分析测定。     

电感耦合等离子体发射光谱法测定硅铝铁合金中的多种元素

本文应用电感耦合等离子体发射光谱法(ICP—AES)对硅铝铁合金的溶解和仪器参数进行了优化,确定了适宜的硅铝铁合金中多种元素的测定条件。测定结果的RSD在0．26％～5．1％之间,加标回收率在95．5％～102．7％之间,标准样品测定结果与推荐值接近。本文方法简便、准确、快速,有应用推广价值。     

ICP-MS法测定超细锆钇粉中多种杂质元素的研究

用电感耦合等离子体质谱(ICP-MS)直接测定超细锆钇粉中多种杂质元素,考察了基体效应对测定元素的影响。定量加入内标元素有效地校正了基体效应及仪器波动等因素引起的测量偏差。方法的固体检出限在0．01～10／zg／g;精密度在1．1％～4．7％;加标回收率在91．0％～110．5％范围。     

电感耦合等离子体质谱法测定水处理材料浸泡液中微量元素

提出了电感耦合等离子体质谱（ICP—MS）法测定水处理材料浸泡液中微量锰、铜、锌、镉、银、铅的方法。按国家标准GB／T5750所述方法对水处理材料进行浸泡,以铟作内标物质,用ICP-MS同时测定浸泡液中6种元素。上述6元素的检出限在0．006～0．252μg·L^-1之间,回收率在85％-107％之间。     

ICP-AES内标法测定钢铁及其合金样品中的化学成分

建立了内标法测定钢铁样品中化学成分的ICP-OES分析方法。利用铟元素作为内标物质,消除了铁基体元素对被测元素的干扰,减少了废气、废液的产生。钢铁样品中16种被测元素的检测范围在0．001％-20．00％之间,检出限为0．001-0．030μg／mL,回收率为97％-110％。该方法减少了高纯物质的使用。     

INCREASED UV EXPOSURE IN FINLAND IN 1993

Abstract—
Exceptionally low total ozone, up to 40% below the normal level, was measured over Northern Europe during winter and spring in 1992 and 1993. In 1993 the depletion persisted up to the end of May, resulting in a significant increase of biologically effective UV radiation. The increases were significantly smaller in 1992 and 1994 than in 1993. The UV exposure of the Finnish population was evaluated through measurements and theoretical calculations. The increase in measured erythemal (International Lighting Commission) UV falling onto horizontal surfaces on clear days was determined relative to model calculations for an average ozone amount. The increase was on average 10% from April to May 1993, and the maximal measured increase was 34%. Theoretical calculations for both erythemal and carcinogenic (Skin Cancer Utrecht-Philadelphia) UV indicated that in 1993 the theoretical annual increase to a vertical (cylinder) surface ranged from 8 to 13% in Finland. The reflection of UV from snow considerably increases facial UV doses in Northern Finland.     

COLLOID CHEMISTRY IN PETROLEUM INDUSTRY IN CHINA

Wool-wax alcohols are remarkably effective in stabilization of water-in-oil emulsions. The structural changes in the continuous phase have been analysed by X-ray diffraction technique between the emulsification temperature, when the alcohol phase is liquid, down to room temperature. Evidence is given for the formation of sterol multilayer structure at the oil/water interface. The bilayer thickness of the sterols is 34,3 Å, and at about 37 °C there is a transition into a phase with X-ray data in close agreement with these of anhydrous cholesterol. The aliphatic alcohol molecules, which thus separate from the sterol molecules, start to form an ordered structure at about 50 °C. First a lamellar liquid-crystalline phase is formed with a bilayer thickness of 41,1 Å. Ano α-crystal phase, with hexagonal chain packing and vertical molecules is formed at further cooling to about 40 °C. The relation between emulsion stability and ordered interfacial structure is discussed.     

中国硫回收技术进展(英文)

综述了国内硫回收技术的现状,并对今后１０－１５年内硫回收技术的发展进行了展望。     

RHODOPSIN-PHOSPHOLIPID INTERACTION IN DETERGENT AND IN THE DISK

Abstract— Solubilization of cattle disk membrane in deoxycholate shifted the fluorescence emission maximum from 324 to 331 nm without changing the intensity. Tryptophyl residues are probably located at the hydrophobic interface between rhodopsin and phospholipid. Depletion of deoxycholate concentration from the solubilized disk by Sephacryl 200 column chromatography produced rhodopsin-phospholipid complexes with different characteristics that are the intermediate stages of membrane formation from homogeneous molecular solution. Association of rhodopsin takes place in a two-dimensional way even in the appreciably low content of phospholipid.
Sedimentation velocity studies showed that reassociation of lipid and rhodopsin occurs in 0.2% deoxycholate as well as in 0.05% sodium dodecylsulfate.
By using Sephacryl column we can now prepare, within 60 min, the rhodopsin-lipid complex that can form large vesicles in response to the addition of MgCl₂ without dialysis. This type of lipoprotein complex will be useful to the study of the mechanism of the two dimensional membrane formation.     

TRANSPORT OF LIGHT IN TISSUE IN PHOTODYNAMIC THERAPY

Abstract The dose rate in photodynamic therapy is proportional to the energy fluence rate and the concentration of the photosensitizer. Calculations of the energy fluence rate have been performed in slab, cylindrical and spherical geometries with the discrete ordinates transport method and diffusion theory. The attentuation of the energy fluence rate is least in slab geometry and greatest in spherical geometry. Violet (405 nm) light is attenuated much more rapidly than red (630 nm) light. Small tissue dimensions or narrow beam irradiation further decrease the energy fluence rate with radius and depth. Anisotropic scattering increases the energy fluence rate at large depths, but decreases it near the source. Measurements of the absolute energy fluence rate vs depth in a mouse tumor model exhibit an order of magnitude attenuation through the skin and a 3 mm thick tumor. Calculations of the energy fluence rate of the DHE fluorescence have been carried out to guide measurement of the concentration. Violet light excitation is much more efficient than red light excitation.     

PHOTOLUMINESCENT PROPERTIES OF OCTADECYLRHODAMINE B IN WATER, IN ALCOHOLS AND IN MIXED WATER-ALCOHOL SOLUTIONS

Abstract Fluorescence, excitation and absorption spectra of octadecylrhodamine B (ORB) have been observed in solutions of water, methanol, ethanol and other simple alcohols. A remarkable increase in the ORB fluorescence intensity occurs when the probe is transferred from water to the alcohols. This effect is ascribed to the release of ORB fluorescent monomers from nonfluorescent multimers, which exist predominantly in water. The dependence of the fluorescence intensity on the composition of water-alcohol binary solvent systems shows that hydrophobic interactions play an important role in the monomer = multimer equilibrium of ORB in these solutions. The fluorescence lifetimes of ORB in the alcohols are also reported.     

食品中氯丙醇测定方法研究进展

对食品中氯丙醇的检测方法进行了探讨,包括气相色谱法、气相色谱-质谱联用法、顶空-气相色谱法等,并针对样品处理所用衍生化方法作了详细介绍及对比。