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51.
用高密度等离子体模型可以计算出一整套输运参数,并且在很宽的等离子体温度和密度范围内有合理的精度,可广泛应用于Z箍缩等离子体、激光聚变和磁约束聚变等领域,并将这个模型计算出的各种输运参数拟合成了实用的公式。 相似文献
52.
53.
c轴定向氮化铝薄膜的制备 总被引:3,自引:0,他引:3
利用电子回旋共振 (ECR)微波增强化学气相沉积法 (PECVD)并使用氮气 (N2 ) ,氩气 (Ar)和AlCl3蒸气作为气源在直径为 6 .35cm的 (10 0 )单晶硅片表面制备了c轴定向氮化铝 (AlN)薄膜 ,并使用X射线衍射仪及其X射线特征能谱和扫描电镜 (SEM)分析了薄膜特征 ,研究了微波功率、基板温度和N2 流量对薄膜c轴定向的影响 ,得到了c轴偏差角小于 5°的高质量大面积AlN薄膜。 相似文献
54.
Guido Momerency Karel Van Cauwenberghe Ernst A. De Bruijn Allan T. Van Oosterom Martin S. Highley Peter G. Harper 《Journal of separation science》1994,17(9):655-661
A method is described for the determination of the antitumor agent iphosphamide and seven of its metabolites in the plasma of cancer patients by multiple ion monitoring (MIM) GC-MS, mainly using the electron capture chemical ionization mode, of stable methyl and/or trifluoroacetyl derivatives. The metabolites determined were 2- and 3-dechloroethyliphosphamide, 4-ketoiphosphamide, carboxyiphosphamide, iphosphamide mustard, and two previously undetected metabolites, chloroethylamine and 1,3-oxazolidine-2-one. The isolation of the acidic and neutral metabolites was performed by solid phase extraction on to C18 adsorbent at pH 4. The weakly acidic iphosphamide mustard, isolated under these conditions with a yield of ca 50%, was measured as a stable methyltrifluoroacetyl derivative, in contrast to the corresponding phosphoramide mustard of the isomer cyclophosphamide which decomposes during derivatization. Chloroethylamine and 1,3-oxazolidine-2-one were isolated with high yield by liquid extraction with ethyl acetate at pH 10. Selective measurement of several metabolite derivatives with similar retention times was performed by multiple ion monitoring MS of specific ion masses, using a methyl phenyl siloxane capillary column previously employed in the study of cyclophosphamide metabolites. Quantitation of metabolites in patient plasma samples could be performed in the concentration range 3 ng to 20 μg per ml of original plasma. 相似文献
55.
Chemisorption of polybenzimidazole on silver and copper etched with nitric acid has been observed by surface-enhanced Raman scattering (SERS). The polymer is found to react chemically with silver, forming a complexed film on the surface. The SERS spectra show that polybenzimidazole film inhibits oxidation of the metal at high temperature, unlike chemisorbed benzimidazole, benzotriazole, and poly(4-vinyl pyridine). © 1992 John Wiley & Sons, Inc. 相似文献
56.
ZhengBin Zhang Chunying Liu Peifeng Li Zhenzhen Wu Cai Lin Huawei Huang Lei Xing Liansheng Liu 《Frontiers of Chemistry in China》2006,1(1):86-97
Many food algae and red tide algae were cultivated in the f/2 medium, and the nitric oxide (NO) concentration of the medium
and the cell density were determined. The experiments on algae were conducted when different concentrations of NO were added
into the medium using two methods. The results show that low concentrations of NO were self-produced by marine algae during
the exponential growth period and were about nmol/L level. But at the end of the period, i.e., 2 or 3 days before the cell
density reaches the maximum, an NO peak appeared, with the NO concentration reaching 10 nmol/L. The NO threshold concentration
exists according to the influence of exogenous NO on the marine phytoplankton growth. One type is the threshold concentration
that can promote algae growth, and its value is between 10 and 1 nmol level, or even lower. The other type can inhibit the
phytoplankton growth, which is about μmol level or higher. The results indicate that red tide algae are far more sensitive
to NO than are food algae. The fundamental experimental outcome above may provide a new clue for red tide chemical forecast
by inspecting the NO change. 相似文献
57.
Reduction of tetranuclear heterometallic complex Mo2Mg2 was simulated using the B3LYP and PBE density functional methods. The results of geometry calculations of the initial complex
[MoVIO2Mg(MeOH)2(OMe)4]2 and a partially reduced MoV complex are in good agreement with experimental data. The reduced MoIII complex is characterized by a decrease in the binding energy of aqua ligands. Structural rearrangement of the complex with
release of a coordination position at the Mo atoms requires small energy expenditure. One can assume that the reduction of
the polynuclear complex causes overcrowding of its coordination sphere, which favors formation of dinitrogen complexes.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 441–457, March, 2008. 相似文献
58.
以一种新型的醌类光敏剂—菌生素 (HMB)为模型化合物 ,利用量子化学从头算HF/ 6 31G和含时密度泛函TD B3LYP/ 6 31G方法计算研究了卤代作用对醌类光敏剂分子性质和光敏活性的影响 .结果发现 ,卤代作用降低了HMB母体的HOMO和LUMO能级 (EHOMO和ELUMO)及其差值△E ,随卤族元素从上到下 ,EHOMO和ELUMO呈增大趋势 ,而△E呈减小趋势 ,使得分子激发光谱有不同程度的红移 ,在增加PQP三重态量子产率的同时降低了分子最低三重激发态的能量 ,两种作用相互抵消 ,使得卤代物的 1O2 量子产率与母体相似 ;增加了分子的绝热电子亲合势 ,使分子产生O2 -的能力下降 ;卤原子的引入 ,降低了HMB母体分子内氢键的强度 ,同时使顺式构型的分子内质子传递势垒增大 ,而使反式构型势垒减小 . 相似文献
59.
介绍了电泳技术制备YBCO高温超导厚膜的实验方法和YBCO高温超导厚膜的电学性质测量 ,讨论了在学生小型科研实验或设计实验中开展此实验的学时安排、注意事项和实验内容的扩展 . 相似文献
60.
医疗和危险废物高温洁净热处理及环境力学 总被引:3,自引:0,他引:3
结合2003年中国的突发危害公众健康的事件,分析了医疗、化学战剂及危险废物的分类、特性,比较了各种高温热处理技术的基本要求,方法分类和设备特点,包括:各类焚烧炉、热解炉和等离子体裂解装置.还对前处理工艺要求,尾气处理工艺等进行了分析讨论,讨论了防止二次污染的技术手段,特别介绍了二噁英等高危险性产物的特性.还介绍了发达国家的医疗废物和危险废物的管理、处置和二次污染防治等情况. 相似文献