手性液相色谱同时测定土壤中两种二苯醚类除草剂对映体

建立了土壤中两种二苯醚类除草剂对映体的手性液相色谱测定方法.样品用乙腈提取和氯化钠盐析后,上层乙腈经弗罗里硅土固相萃取柱净化后,用手性液相色谱检测.结果表明:两种农药各自对映体的回收率在84.4％-98.3％之间,相对标准偏差在3.2％-12.5％之间.在实际样品中的检出限在0.013-0.016mg/kg之间,定量限在0.043-0.053mg/kg之间.     

微波消解-石墨炉原子吸收光谱法测定3种中药中的铬

百合、龙眼和桂皮3种中药样品用硝酸-过氧化氢(3+2)混合溶液浸泡过夜,微波消解.并用石墨炉原子吸收光谱法(GF-AAS)测定了铬的含量.在优化的试验条件下,方法的回收率在97.3％-103.9％之间,相对标准偏差(n=6)在1.9％-4.1％之间.     

ICP-AES测定长柄扁桃仁油渣中的多种微量元素

用ICP-AES测定了长柄扁桃仁油渣中含有的11种人体所需的微量元素.实验结果表明,方法相对标准偏差在0.3％-1.7％之间,回收率在80.4％-119.2％之间.与常规方法相比较,方法具有简单、快速、灵敏度高、准确性好、检出限低和精密度高等优点,可用于植物种子中多种微量元素的快速测定.     

火焰原子吸收光谱法测定羊血中铁、铜和锌3种微量元素

建立了湿法消解-火焰原子吸收光谱法对羊血中Fe、Cu和Zn 3种微量元素测定的方法.方法的校准曲线线性关系良好（r=0.9965-0.9999）,方法加标回收率（n=5）在96.2％-98.5％之间,RSD值（n=5）在1.3％-4.9％之间.为了解动物微量元素含量提供参考,也为进一步研究畜禽疾病与微量元素的相关性提供基础资料.     

HPLC测定葡萄和葡萄酒中花色苷

采用反相高效液相色谱法对欧亚种葡萄(Vitis viniferaL.)和葡萄酒中的三种基本花色苷进行分离.矢车菊色素3-O-葡萄糖苷,芍药色素3-O-葡萄糖苷和锦葵色素3-O-葡萄糖苷的方法检出限分别为1,0.2,1mg/kg;线性范围分别为1-100,0.2-20,1-100mg/kg;方法回收率在84％-95％之间;方法的精密度RSD(％)在0.6844-2.7092之间.方法简单、快速,便于实现对花色苷类物质的准确定性、定量分析.     

火焰原子吸收光谱法测定大豆中的6种微量元素

用硝酸-高氯酸消解样品,采用火焰原子吸收法测定了大豆中Mg、Mn、Zn、Na、Ca、Fe 6种微量元素的含量.结果表明:在选定的实验条件下,测得大豆中6种元素的含量为Mg ＞Na＞Ca＞Fe＞Zn＞Mn.该方法的相对标准偏差RSD为0.632％-1.623％,平均回收率在91.7％-100.5％之间.     

青海省海东地区主要农产品中微量元素的测定

以电感耦合等离子体发射光谱法（ICP-OES）测定青海省海东地区主要农产品中10种元素含量.方法的回收率在96.4％-101.3％之间,相对标准偏差0.90％-2.98％之间（n=7）.实验证明,建立的方法简单快速,精密度高,满足对农产品中微量元素的监测要求.     

ICP-AES测定工厂废酸液中的8种元素

工厂废酸液经过处理后,采用电感耦合等离子体-原子发射光谱法(ICP-AES)测定其中铝、钾、锶、钡、锰、钴、钼、硒8种元素的含量.对仪器的工作条件进行了优化,选择各元素的分析线,测定各元素的检出限,样品的加标回收率在95.1％-101.5％之间,对2个工厂废酸液样品进行分析,8种元素测定的相对标准偏差RSD值(n=9)在0.087％-7.6％之间.     

HPLC-MS/MS测定保健食品中的镇静催眠类药物

建立了液相色谱串联质谱法测定保健食品中苯巴比妥、艾司唑仑、地西泮等13种镇静催眠类药物的方法,优化了样品前处理方法及液相色谱串联质谱测定条件.采用甲醇为提取溶剂,超声处理,液相色谱串联质谱检测.结果表明：本方法测定13种镇静催眠类药物的线性范围均为0.04-5.0μg/mL,检出限在1.0-10.0mg/kg之间,3个水平的加标回收率在82.5％-96.9％％之间.     

ICP-AES测定玩具中17种元素的特定迁移量

建立了电感耦合等离子体-原子发射光谱法(ICP-AES),可同时测定玩具中17种元素(铝、锑、砷、钡、硼、镉、铬、钻、铜、铅、锰、汞、镍、硒、锶、锡和锌)迁移量.砷、镉、铬、钴、铅、镍和硒的线性范围在0.01-10.0mg·L-1,铝、钡、铜、锰、锶、锌、锑、锡和硼的线性范围在0.1-20.0mg·L-1,汞的线性范围在o.01-1.0mg·L-1,仪器检出限(3s)在o.0003-0.03mg·L-1之间.方法用于玩具中17种元素特定迁移量分析,方法定量限在o.2-5mg·kg-1之间,回收率在88.4％-114.0％之间.重复性测定相对标准偏差(n=6)在0.08％-3.97％之间.方法快速,简单,可靠性高,可多元素同时测定,适用于欧盟玩具安全新指令检测要求.     

Fluctuations in number of photons in region of unstable behavior in process of intracavity generation of second harmonic

Quantum fluctuations of the number of photons of the fundamental mode and of the second harmonic in the process of intracavity generation of the second harmonic in the unstable region of the system are studied. The distribution functions of the number of photons of interacting modes are calculated in the positive P-representation. The functions of the joint distribution of the number of photons of the fundamental mode and the number of photons in the second harmonic are also studied.     

Correlation in calculations of density of states in thin films

The density of electronic states and its spatial distribution in thin films are considered including the electron correlations in the coherent phase approximation applied to the intra-atomic interaction. This new approach allows us to derive the line shape for electronic levels which is important from the point of view of the convergency for the density function in the case of systems with restricted dimensions. Detailed calculations are performed for 4s copper film functions with the fcc lattice and various crystallographic orientations of the surfaces.The authors are very grateful to Professor L. Valenta (Prague) for his kind interest in this paper and to Dr. J. Mizia (Cracow) for helpful discussions. We would like to express our gratitude to Professor M. Wonicki and Mrs M. Firszt (Toru) for their help in obtaining the computer program procedure for two-particle interaction integrals calculations.The paper has been done in the framework of the Problem M.R I-11.     

皮革中甲醛含量测量不确定度评估

依据GB/T 19941-2005标准,测定了皮革中的甲醛含量,对测量结果的不确定度来源进行了分析和评定,并计算出合成不确定度和有效自由度,最后根据JJF1059规范要求给出了甲醛测量不确定度表达式.     

一种在弱酸性介质中有电化学发光性能的鲁米诺衍生物

报道了一种鲁米诺的衍生物-3-(1-乙酰丙酮偶氮)苯二甲酰肼在酸性介质中的电化学发光行为,该化合物与鲁米诺类似,发生两步电化学氧化反应,但其氧化电位较鲁米诺低约0.5V,在氧化铟锡玻璃电极上具有良好的电化学发光性能,有效地避免了氧化铟锡玻璃电极本身的发光干扰.不仅在碱性介质中具有较高的电化学发光效率,而且在酸性介质中也产生较稳定的电化学发光,在1.0×10-6mol/L以上浓度,电化学发光强度与浓度有良好的线性关系.     

Inhibition of corrosion of aluminium in presence of fluorescein in basic medium

The influence of Fluorescein in conjunction with calcium oxide on the corrosion of Aluminium in 1.0 N NaOH was studied by galvanostatic studies and weight loss studies. It has been found that the inhibition of corrosion of aluminium increased with the increasing concentration of the inhibitor. The maximum inhibition efficiency of fluorescein alone was found to be 30.80%. However, the addition of calcium oxide increased the maximum inhibition efficiency to 53.71%. The corrosion process was found to be under the anodic control, in the presence or in the absence of inhibitor. The inhibition was found to be mixed type. Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, Inida, Nov. 28–30, 2003.     

Emergence of differences in potential in wood as a result of natural changes in temperature

The emergence of differences in potential in a natural macromolecular heterogeneous structure (wood) upon natural changes in temperature with allowance for humidity is considered. It is shown that the magnitude of the emerging difference in potential in the wood is proportional to the change in temperature and grows along with the humidity of the wood.     

Deflection of IR-radiation in n-InSb in the presence of temperature-electrical instability in a magnetic field

The formation of an S-shaped volt-ampere characteristic (VAC) during the heating of a specimen of n-type indium antimonide by a dc electric current in the presence of an external magnetic field is considered. In the calculation of the VAC the temperature dependences of the band gap width, the carrier density, the mobility, and the heat conductivity are taken into account. The angle of deflection of IR-radiation in indium antimonide is calculated using the density distribution over the cross section of the specimen derived from the integration of heat conductivity equation. The experimental and theoretical dependences of the deflection angle on the current are in agreement in order of magnitude and indicate that it is possible to use the temperature instability for the construction of laser radiation deflectors in the IR range.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 35–40, November, 1984.The authors are grateful to V. L. Bonch-Bruevich and I. P. Zvyagin for useful discussion and valuable critical remarks.     

The role of carbon in the precipitation of oxygen in silicon

Oxygen precipitates were formed in Czochralski-grown silicon samples at different temperatures and for different lenghts of times of heat treatment. Precipitation was evident from infrared(IR) analysis of so treated samples. These samples were irradiated with 2 MeV electrons at near room temperature (310 K). Deep level transient spectroscopy measurements and IR measurements were performed on these samples. The results show directly that a single carbon atom or a carbon-oxygen complex can serve as nucleation centers for the oxygen precipitation.