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81.
建立火焰原子吸收光谱法测定锌合金中镁含量。选用10 mL盐酸溶液(1+1)溶解样品,加入5 mL质量浓度为100 g/L的LaCl3溶液,以消除铝对镁的化学干扰,在选定的仪器工作条件下进行测定。结果表明,镁的质量浓度在0~1.238 mg/L范围内与与吸光度具有良好的线性关系,相关系数为0.999 4,线性方程为Y=1.086 4X+0.018 5,方法测定下限为0.010 mg/L。样品测定结果的相对标准偏差为1.61%~3.45%(n=6),加标回收率为91.3%~94.7%。该方法准确度高,精密度好,满足锌合金中镁含量的日常检测要求。 相似文献
82.
室内装修材料中的有害物质 总被引:4,自引:0,他引:4
本文对室内装修材料中的有害物质———甲醛、苯、氨气、放射性物质氡,从它们的来源、性质、对人体的危害作用、中毒机理等方面做了论述,提出了在室内装修中创造“绿色环境”的具体措施。 相似文献
83.
反相高效液相色谱法测定紫草素衍生物 总被引:8,自引:0,他引:8
紫草(gromwell)为紫草科多年生草本植物,是常用中药,因其根呈紫色而得名。药理学研究发现紫草提取物具有抑菌、抗炎、抗肿瘤以及抗生育等作用。对紫草素衍生物的测定方法主要有比色法、重量法、紫外-可见分光光度法、薄层扫描法、薄层-分光光度法、单扫描极谱法以及正相高效液相色谱法。所有这些方法主要用于测定紫草提取物中的萘醌类化合物总量或主要单体含量。本文建立了一种分离快、柱效高、准确度高、重现性好的反相高效液相色谱(RP—HPLC)同时测定紫草素衍生物的新方法。 相似文献
84.
Nong Yue HE Hui Shi GUO Di YANG Chun Rong GU Ji Nan ZHANG 《中国化学快报》2006,17(2):235-238
Cardiac troponin I (cTnI) is a cardiac muscle protein and forms a protein complextogether with troponin T and troponin C in heart. The troponin complex is broken upfollowing myocardial damage, and the individual protein components are released intothe blo… 相似文献
85.
Bibhu P. Swain Bhabani S. Swain Seung M. Yang Nong M. Hwang 《Applied Surface Science》2009,255(11):6033-6037
Nanocrystalline silicon (nc-Si) films were deposited by hot wire chemical vapor deposition with applying positive or negative filament biases. These films were characterized by Raman spectroscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy. Plasmon loss of the Si(2p) band region was shifted to higher energy due to dielectric changes with applied filament biases from negative to positive voltage. A semi-quantitative study of the valence band structure was employed to analyze the bias effect of the valance band in nc-Si networks. Nc-Si with a positive filament bias shows better microstructural properties than those with a negative bias and without biasing nc-Si films. 相似文献
86.
Ngo Van Nong 《Solid State Communications》2006,139(5):232-234
Polycrystalline samples of (Ca1−xRx)3Co2O6 with R = Gd, Tb, Dy and Ho at x=0-0.1 were synthesized and the effects of rare earth substitution on their thermoelectric properties were investigated. In the high-temperature region, the rare earth substitution resulted in an increase in the Seebeck coefficients (S), and the S values increased with decreasing ionic radius of rare earth elements in the order Gd3+>Tb3+>Dy3+>Ho3+. In contrast, the influence of rare earth substitution on the electrical resistivity was small. The high-temperature power factor was thereby improved by the late rare earth substitutions, particularly those with Ho3+ for Ca2+. For the Ho-doped samples (x≤0.05), the power factor was significantly improved by increasing Ho concentration. 相似文献
87.
Ruihong Kong Xiaobin Shan Sisheng Wang Yunwu Zhang Liusi Sheng Liqing Hao Zhenya Wang 《Journal of Electron Spectroscopy and Related Phenomena》2007,160(1-3):49-53
The photoionization of Ne·CO complex in the energy region of 13.8–14.2 eV was investigated with photoionization mass spectrometry using a synchrotron radiation source in Hefei. The ionization energy (IE) of Ne·CO is determined to be 13.965 eV from its photoionization efficiency curve whose characterization is affected by the photoabsorption of CO molecule. The equilibrium geometry and harmonic vibrational frequencies of Ne·CO and Ne·CO+ are calculated using cc-pVTZ basis sets at the QCISD level of theory. The results indicate that they are of a skewed T-shaped structure and show the configuration changes accompanying the ionization of Ne·CO complex. The parameters of thermo-chemistry of Ne·CO and Ne·CO+ are calculated using Gaussian-2 method, which provide information concerning the reduction of the ionization potentials of CO in the Ne·CO complex, relative to that of the bare molecule. 相似文献
88.
Jun Jie Niu Jian Nong Wang 《Physica E: Low-dimensional Systems and Nanostructures》2007,39(2):244-247
The growth mechanism for synthesizing large scales of one-dimensional silicon nano-structures (silicon nano-wires (SiNWs) or silicon oxide nano-wires (SiO2-NWs)) by a simple evaporation of sulfur-contained powders on silicon wafer is discussed. A novel sulfide-assisted mechanism referring to oxygen-assisted mechanism is proposed. Amongst this simple method, sulfide or pure sulfur can both assist the formation of SiNWs. The growth is fast and some SiNWs are easily oxidized to be amorphous structure of SiO2-NWs under the low-vacuum system. The simple method suggests a useful route to achieve plenty of one-dimensional silicon nano-structures for further research. 相似文献
89.
Bin Lin DAI Ai Nong FANG 《数学学报(英文版)》2005,21(3):465-472
In this paper, we will study the nonelementary groups of MSbius transformations in R^n and some properties are obtained. Also in this paper we will prove several theorems about discreteness criteria and group convergence of nonelementary groups of M(R^n). 相似文献
90.
毛细管电泳电化学检测法测定红葡萄酒中的多元酚 总被引:1,自引:0,他引:1
目前 ,人类各种疾病约 89%起因于活性氧 .因此消除活性氧基团 ,使过氧化物对机体的损伤降到最低限度已成为研究的热点 [1] . Maxwell等 [2 ] 测试了红葡萄酒在人体血液中的抗氧化能力 .发现从刚喝下红葡萄酒时起 ,抗氧化活性就开始上升 ,90 min后达到最大 ,抗氧化活性平均上升约 1 5 % .葡萄酒中的多酚含量与活性氧消除能力的相关系数高达 0 .9686,所以确立葡萄酒中多元酚的分析方法有重要意义 .红葡萄酒中含有酚酸类、儿茶素类、黄酮类等多酚类化合物 ,通常采用气相色谱[3] 、高效液相色谱 [4 ] 测定 .毛细管电泳 ( CE)应用于葡萄酒中多… 相似文献