高纯Tb4O7中痕量杂质元素的火花源质谱测定

本文采用同位素稀释和相对灵敏度因子法相结合，定量分析了高纯Ｔｂ４Ｏ７中的２０多种微量元素的含量，测定检测限０．０ｘ－０．００ｘμｇ／ｇ，大多数元素的相对标准偏差在３０％以内，用同位素稀释法分析了Ｃｕ，Ｂａ，Ｄｙ三元素，其相对标准偏差均在１０％以内。     

Aryl oxalate chemiluminescence detection for high-performance liquid chromatography

Aryl oxalate chemiluminescence detection for high-performance liquid chromatography offers ultrahigh sensitivity for interactive fluorophores. With optimal analytes, attomole limits of detection can be obtained with conventional instrumentation     

Studies on the New Constituents of Sal via Miltiorrhiza Bunge

Two novel constituents were isolated from the roots of Chinese medicinal herbs, Salvia miltiorrhiza. Their structures were determined by spectroscopic technique. The compounds were named 13,14-dihydroxy-15-methyl-benzo[2,3-a]-7,7-dimethyl-12-oxa-tricyclo[4,4,21.4,0]dodecane(1) and 16-methyl-tropono[2,3-c]-7,7-dimethyl-12-oxa-tricyclo[4,4,21.4,0]dodecane(2).     

GIANT MAGNETO-IMPEDANCE IN Fe-BASED SOFT FERROMAGNETIC RIBBONS

ＧＩＡＮＴＭＡＧＮＥＴＯ－ＩＭＰＥＤＡＮＣＥＩＮＦｅ－ＢＡＳＥＤＳＯＦＴＦＥＲＲＯＭＡＧＮＥＴＩＣＲＩＢＢＯＮＳＣｈｅｎＣｈｅｎＭｅｉＬｉａｎｇｍｏＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓ，ＳｈａｎｄｏｎｇＵｎｉｖｅｒｓｉｔｙ，Ｊｉｎａｎ２５０１００...     

Influence of MgO surface conditions on the in-plane crystal orientation and critical current density of epitaxial YBCO films

The effect of magnesium oxide (MgO) surface conditions on in-plane grain orientation and critical current density of epitaxial YBa₂Cu₃O₇ (YBCO) films was systematically investigated. The MgO substrates were either “as received” or stored for some time, cleaned using different methods and lithographically prepared for our step-edge junction devices. The YBCO films were grown via reactive thermal co-evaporation by Theva, GmbH. The surface characterisation of MgO substrates was studied using X-ray photoelectron spectroscopy (XPS). The in-plane grain orientation of the YBCO films was studied by means of X-ray diffraction (XRD) φ-scan and the critical current density was measured for the XRD scanned samples. The surface condition of the MgO substrates was found to have a strong influence on the in-plane grain orientation and the critical current density of the YBCO films. The MgO substrates with a degraded or contaminated surface gave rise to 45° grain misorientation in YBCO films and reduced the critical current density. A final process step using a low energy Ar ion beam etching (IBE) of the MgO substrates prior to the YBCO film deposition was found effective in removing the in-plane grain misorientation and promoting the growth of perfectly aligned c-axis YBCO films.     

5-Br-PADN光度法连续测定铸铁中铜和镍

研究了以溴代十六烷基吡啶和TritonX 100为增溶剂,以5 Br PADN为显色剂,在pH为9.7的氨 氯化铵介质下连续测定铜和镍的方法。铜、镍与5 Br PADN的配合物在547nm处均有较大的吸收,其表观摩尔吸光系数为εCu=3.94×104L·mol-1·cm-1,εNi=3.64×104L·mol-1·cm-1,配合物至少可稳定12h,铜、镍分别在0～10μg/10ml和0～8μg/10ml范围内服从比耳定律,方法用于铸铁中铜和镍的连续测定,结果满意。     

Superconductivity and the Anomalous Meissner Effect in La3CaBa3Cu7O15,5 + x Oxide

A superconducting oxide with a stoichiometry La₃CaBa₃Cu₇O_15.5+x, in which x = 0.75, was prepared. It had a tetragonal triple-perovskite structure with lattice parameters a = 3.879 Å and c = 11.637 Å. According to resistivity measurements, a sharp superconducting transition, ΔT_c(10-90%) = 1.5 K, and T_c(zero) = 80 K were observed. When it was measured at a small magnetic field (10-20 gauss) with field cooling, the sintered pellet showed a positive magnetic susceptibility, but the powdered sample exhibited (he diamagnetism of a typical superconductor. However, no peculiar shielding effect was found in both the sintered and powdered samples.     

CaAl3BO7：RE(RE=Ce,Gd,Tb)中稀土离子的光谱特性

采用固相反应法合成了CaAl₃BO₇RE(RE=Ce,Gd,Tb),研究了Ce³⁺,Gd³⁺和Tb³⁺的光谱特性。发现铈离子周围存在较强的晶场,使基态的4f能级劈裂较大,从而导致铈离子的特征发射峰重叠较大;Ce³⁺的5d能级明显低于Gd³⁺的⁶I、⁶P能级;Ce³⁺和Tb³⁺之间存在有效的能量传递。     

尿中氯硝西泮代谢物7-氨基氯硝西泮的薄层色谱检测法

采用高效薄层色谱法检测尿中氯硝西泮代谢物7－氨基氯硝西泮（7ACLZ），分析物斑点用弗路兰进行荧光显现，灵敏度高，检出限5μg/L，定量下限15μg/L，可以检测人口服2mg氯硝西泮后48h内排泄尿的7ACLZ,适用于麻醉抢劫犯罪案件中药物检测。     

Heat Capacities and Thermodynamic Properties of a H2O + Li2B4O7 Solution in the Temperature Range from 80 to 356 K

The molar heat capacities of an aqueous Li₂B₄O₇ solution were measured with a precision automated adiabatic calorimeter in the temperature range from 80 to 356 K at a concentration of 0.3492 mol⋅kg⁻¹. The occurrence of a phase transition was determined based on the changes in the curve of the heat capacity with temperature. A phase transition was observed at 271.72 K corresponding to the solid-liquid phase transition; the enthalpy and entropy of the phase transition were evaluated to be Δ H _m = 4.110 kJ⋅mol⁻¹ and Δ S _m = 15.13 J⋅K⁻¹⋅mol⁻¹, respectively. Using polynomial equations and thermodynamic relationship, the thermodynamic functions [H _T −H _298.15] and [S _T −S _298.15] of the aqueous Li₂B₄O₇ solution relative to 298.15 K were calculated in temperature range 80 to 355 K at intervals of 5 K. Values of the relative apparent molar heat capacities of the aqueous Li₂B₄O₇ solution, C _p,φ, were calculated at every 5 K in temperature range from 80 to 355 K from the experimental heat capacities of the solution and the heat capacities of pure water.