X-射线荧光仪熔片法测定石灰石中各组分

本文介绍了一种用X荧光熔片法测定石灰石中各组分的快速分析方法。用国家级石灰石标样绘制工作曲线,消除基体效应及吸收增强效应,分析速度快,操作简单,对快速冶炼起到了很好的指导作用。     

Removal of cadmium using acid-treated activated carbon in the presence of nonionic and/or anionic surfactants

The adsorption of cadmium ions on granular activated carbon treated with nitric acid (NGAC), and untreated regular granulated activated carbon (RGAC) is reported in the absence and presence of mixtures of anionic (sodium dodecyl sulfate, SDS) and nonionic (Triton X-100, TX100) surfactants. In the absence of surfactants, NGAC adsorbed 8.7 times more Cd (0.165 mmol/g) than did RGAC (0.019 mmol/g). In RGAC suspensions, the amount of Cd sorbed increased significantly with increasing dose of SDS, to a maximum of 0.112 mmol/g. This increase was due to increased binding of Cd with sorbed SDS. However, in NGAC suspension, the amount of Cd sorbed was not increased further by the addition of SDS. It suggested that addition of SDS blocked the availability of surface functional groups in the microporous structure of NGAC.     

4π(PPC)X-γ数字符合法测量88Y活度

本文介绍了采用4π(PPC)X-γ数字符合测量装置绝对测量⁸⁸Y放射性活度的方法。为提高对X射线的探测效率,实验采用高气压正比计数器,测量比较了甲烷和氩甲烷作为其工作气体的坪曲线,后者具有探测效率高、起始坪电压低的优势,因此采用氩甲烷为工作气体。采集原始谱数据后,选择不同的感兴趣γ窗进行离线数字符合计算,并分析了效率外推的结果和测量的不确定度。     

一元和多元醇对非离子表面活性剂的雾点和临界胶束浓度的影响

测定了乙醇、丙醇、丙三醇、季戊四醇和甘露醇对ＴｒｉｔｏｎＸ １００（ＴＸ１００）水溶液的雾点和ＣＭＣ的影响，结果表明，丙醇使ＴＸ１００溶液的雾点升高最多，其次是乙醇，季戊四醇几乎无影响，丙三醇使雾点稍有下降，而甘露醇使雾点下降最多，雾点与各添加物的浓度都近似成线性关系。除了ＴＸ１００的ＣＭＣ随甘露醇浓度的增大单调下降外，其余四种添加物的影响都与其浓度有关，即ＴＸ１００的ＣＭＣ都随添加物浓度的增大先降后升。这些结果说明，添加物对雾点的影响和对ＣＭＣ的影响之间并不存在相应的关系，根据胶束化是表面活性分子之间的疏水相互作用引起的，而雾点现象是胶束聚集造成的，对上述结果作了可能的解释。     

Neutrino properties studied with a triton source and a large spherical TPC

The purpose of the present paper is to study the neutrino properties as they may appear in the low-energy neutrinos emitted in triton decay:

with maximum neutrino energy of 18.6 keV. The technical challenges to this end can be summarized as building a very large Time Projection Counters (TPC) capable of detecting low-energy recoils, down to 100 eV, within the required low background constraints. More specifically we propose the development of a spherical gaseous TPC of about 10-m in radius and a 200 Mcurie triton source in the center of curvature. One can list a number of exciting studies, concerning fundamental physics issues, that could be made using a large-volume TPC and low-energy antineutrinos: (1) The oscillation length involving the small angle δ=sin θ₁₃, directly measured in our ν_e disappearance experiment, is fully contained inside the detector. Measuring the counting rate of neutrino–electron elastic scattering as function of the distance of the source will give a precise and unambiguous measurement of the oscillation parameters free of systematic errors. In fact first estimations show that even with a year's of data taking a sensitivity of a few percent for the measurement of the above angle will be achieved. (2) The low-energy detection threshold offers a unique sensitivity for the neutrino magnetic moment which is about two orders of magnitude beyond the current experimental limit of 10⁻¹⁰μ_B. (3) Scattering at such low neutrino energies has never been studied and any departure from the expected behavior may be an indication of new physics beyond the standard model. We present a summary of various theoretical studies and possible measurements, including a precise measurement of the Weinberg angle at very low momentum transfer.     

NON-DESTRUCTIVE MEASUREMENTS OF LEAD AND BARIUM IN ARCHAEOLOGICAL BONE SAMPLES USING XRF

The lead and barium contents in sixteen archaeological bone samples from 10 persons buried in Dalsby, Sweden, were determined by means of X- ray fluorescence analysis using two "Co sources for excitation and a planar Ge detector for registration of the X- rays. The lead concentrations were found to be less than 168μ g/g, and the barium concentrations were in the range of 15- 97μg/g.     

钪—5-Br-PADAP-Triton X-100显色体系的研究

本文研究了钪-5-Br-PADAP-Triton X-100显色体系的光度特性,并确定了钪测定的最佳条件.用单双波长法测定时,钪浓度均在0—11μg/10ml范围内遵循比尔定律,其表现摩尔吸光系数分别为5.9×10~4和7.5×10~4.Triton X-100的加入未能增敏,但能增溶,并显著提高了体系的选择性.从而建立了在水相中测定钪的新方法.用于镁基合成试样中钪的测定,结果满意.     

Influence of surfactants on an extracellular lipase fromPythium ultimum

The activity of an extracellular lipase from the fungusPythium ultimum was studied as a function of emulsion properties, and the amount and type of surfactants used in preparing the emulsions. The highest emulsified globule surface area as a function of surfactant concentration and emulsion stability were in the order taurocholic acid >Triton X-100>3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). Lipase activity was dependent on both the type and the concentration of surfactant, with taurocholic acid and CHAPS giving tenfold stimulation over the control at 0.1 and 0.8 mM, respectively. The evidence suggests that the influence of surfactant is related more to interaction with the enzyme at the oil-water interface than to providing greater interfacial surface area.     

亚音速火焰喷涂钛-生物玻璃涂层组织与性能研究

采用亚音速火焰喷涂方法及涂层处理技术,以Ti6A14V为基体,喷涂钛-生物玻璃,涂层经700℃晶化处理．用扫描电子显微镜（SEM）观察涂层显微结构,X射线衍射法（XRD）测试涂层相组成,采用基于GIXRD的残余应力分析方法测量涂层残余应力．结果表明：亚音速火焰喷涂钛-生物玻璃涂层沿裂纹处有晶态析出物TiO2,起到弥合裂纹的作用．添加生物玻璃G后,涂层表面有针状结构晶体Na2RO。,析出,新相Na2Ti60。,具有一定的有生物活性．涂层残余应力均为压应力,其值与生物玻璃含量成正比．     

给水管道腐蚀管垢的特征分析

使用扫描电镜(SEM)、X射线能谱分析(EDAX)和X射线衍射分析(XRD)对给水管网中灰口铸铁管和焊接钢管上的管内壁腐蚀管垢进行外观特征、微观形态、化学元素组成和化合物构成等物理化学特征分析。发现管垢外部平滑而致密,内部为疏松多孔结构。铁是管垢最重要的化学组成,管垢基本上由各种含铁的化合物组成。焊接钢管管垢腐蚀表层可能的化学组成为α-FeOOH和γ-FeOOH,硬壳层主要的化学组成为Fe_3O_4。