Mössbauer Spectroscopic Studies of Chlorostannate(II) Complexes in Frozen Aqueous Solutions

Mössbauer parameters of frozen aqueous solutions of Sn(ClO₄)₂ in 0.5 M HClO₄ did not change with the concentration of NaClO₄, so that it was used to keep the ionic strength at the desired level. When NaCl was added into Sn(ClO₄)₂ solutions, isomer shift did not change, but quadrupole splitting did. Therefore, stability constants were calculated from the quadrupole splitting data, which were in good agreement with the published values. The observed spectra could be resolved into components.     

固相萃取-气相色谱-质谱分析肉样中盐酸克伦特罗的残留量

建立了固相萃取 气相色谱 质谱联机分析肉样中盐酸克伦特罗残留量的方法。对盐酸克伦特罗在C1 8和离子交换固相萃取柱上的保留行为进行了研究 ,发现不同浓度盐酸克伦特罗的固相萃取回收率在 75 %～ 95 %之间 ;肉样中的加标回收率在 70 %～ 83 % ;相对标准偏差在 4 .95 %～ 1 3 .4 % ;最低检出限为 1 μg kg。盐酸克伦特罗的硅烷化产物 ,采用选择离子的模式进行检测 ( 86、2 4 3、2 62、2 77) ,衍生物的峰面积与样品浓度在0 .0 0 2 5 2～ 2 .0 2mg L范围内呈良好的线性关系 ,线性回归系数大于 0 .9999。     

马齿苋及其籽中脂肪酸的比较研究

本实验利用ＧＣ－ＭＳ分析技术对马齿苋全草及其籽中的脂肪酸（以甲酯的形式）进行了分析，共鉴定出８种脂肪酸。全草中以亚麻酸（４７．１６％）、亚油酸（２２．００％）及棕榈酸（１７．４％）为主，籽中以亚油酸（４５．８６％）及亚麻酸（３０．６１％）为主。     

Pore size distributions in low‐k dielectric thin films from X‐ray porosimetry

X‐ray reflectivity has been used to determine the mass uptake of probe molecules in porous thin films supported on thick silicon wafers. The adsorption occurs by capillary condensation when the films are exposed to probe vapor at controlled partial vapor pressures. The probe solvent partial pressure was varied by mixing saturated air and dry air at constant temperature or by changing sample temperature at a constant vapor concentration. Pore size distribution in the films can be calculated from the probe uptake with typical porosimetric approaches such as the application of the Kelvin equation to convert partial pressure into pore size. For illustration, the pore size distribution of three different nanoporous thin films, the primary candidate of ultra‐low‐k interlevel dielectrics in the next generation of integrated circuit chips, was determined with this technique. These samples represent different generations of low‐k dielectrics developed by industry. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2170–2177, 2002     

紫外分光光度法测定蔬菜鲜样中的硝酸盐

建立了紫外分光光度法测定蔬菜鲜样中硝酸盐含量的方法，经t检验证明，该方法的测定结果与酚二磺酸法无显著性差异，RSD小于4．5％，方法操作简便，适用于蔬菜中硝酸盐含量的测定。     

中空纤维催化膜反应器中环戊二烯的选择加氢反应

将聚乙烯吡咯烷酮（ＰＶＰ）负载钯催化剂（ＰＶＰ－Ｐｄ）镶嵌到三种醋酸纤维（ＣＡ）中空膜（ＣＡ－Ｉ，ＣＡ－Ⅱ，ＣＡ－Ⅲ）内制各中空纤维催化膜，并进一步制成催化膜反应器，在４０℃和０．１ＭＰａ的反应条件下，在催化膜反应器中进行了环戊二烯的选择加氢反应，考察了具有不同氢气渗透率的醋酸纤维丝组成的三种膜反应器对反应的转化率及选择性的影响，并在此基础上考察了各种反应参数对反应的影响，ＣＡ中空纤维催化膜对环戊     

精神分裂症患者头发5种元素含量变化及临床意义

采用原子吸收光谱法测定了９６例精神分裂症患者和１０１名正常对照组的头发Ｚｎ、Ｃｕ、Ｆｅ、Ｃａ、Ｍｇ元素含量。结果发现，精神分裂症患者头发ｎ和Ｍｇ元素含量明显低于对照组，而Ｃｕ、Ｆｅ和Ｃａ元素含量明显高于对照组。提示精神分裂症的发病，可能与Ｚｎ和Ｍｇ元素含量降低，Ｃｕ、Ｆｅ和Ｃａ元素含量升高有关。     

Oscillation condition for a series piezoelectric sensor. Application to the determination of urease activity in plant seeds

The oscillating conditions for a series piezoelectric quartz crystal (SPQC) are proposed and verified experimentally. The influence of the cell constant and oscillator phase on the oscillational ability of the SPQC was investigated. It is shown that the SPQC possesses excellent oscillational ability in low or high conductivity solutions, but in solution of intermediate conductivity, the oscillational ability decreases with increasing oscillator phase or decreasing cell constant, sometimes resulting in a cease-to-oscillate zone. The SPQC was applied to determine the urease activity in plant seeds with a detection limit of 0.004 U ml⁻¹, based on the change in conductivity.     

Radiation Effects on Concentrated Potassium Hexacyanoferrate(III) Solutions

The neutron irradiated potassium hexacyanoferrate(III) solutions were analyzed for Fe(CN)₆^4?, Fe(CN)₆^3?, and Prussian blue. The retention values (1.1%) were constant throughout the pH and concentration ranges studied, and did not change with the length of irradiation. The complex behavior of the radiochemical yield of the Fe(CN)₆^4? and Prussian blue was attributed to the competition of the various reactions involved in the irradiation.     

GC/MS法分析奶油中的脂肪酸

利用气相色谱/质谱/计算机联用技术分析人造奶油、天然奶油和新西兰奶油中的脂肪酸,从中鉴定出7种酸:棕榈酸、棕榈油酸、硬脂酸、油酸、亚油酸、亚麻油酸及花生酸。人造奶油含亚油酸比天然奶油含的高。