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1.
我们用激光轰击石墨靶成功地制备出类金刚石无氢非晶碳薄膜.测量了光学吸收、光致发光及其随入射光强度的变化关系.结果表明,这种薄膜具有类金刚石的性质,光学带隙在1.67-2.25eV,发光在可见光区呈宽带结构.低激发强度下发光强度超线性变化,而在高激发强度下则为线性发光.我们用非成对载流子复合的模型对结果给出了合理的解释.用带尾态饱和的模型解释了发光峰值随激发光强增加而蓝移的现象.  相似文献   
2.
A series of diorganotin(IV) and dichlorotin(IV) derivatives of 4-X-benzohydroxamic acids, [HL(1) (X = Cl) or HL(2) (X = OCH(3))] formulated as [R(2)SnL(2)] (R = Me, Et, nBu, Ph or Cl; L = L(1) or L(2)), along with their corresponding mixed-ligand complexes [R(2)Sn(L(1))(L(2))] have been prepared and characterized by FT-IR, (1)H, (13)C, and (119)Sn NMR spectroscopy, mass spectrometry, elemental analysis, and melting points. In addition, single-crystal X-ray diffraction analyses were carried out for [Me(2)SnL(2)] (L = L(1) or L(2)), which show coordination structures intermediate between distorted octahedra and bicapped tetrahedra. The hydroxamate ligands are asymmetrically coordinated by the oxygen atoms, the carbonyl oxygen atom is further away from the metal center than the other oxygen atom. The complexes are stable monomeric species; most of them are soluble not only in chlorohydrocarbon solvents, but also in alcohols and hydroalcoholic solutions. In polar solvents, the mixed-ligand complexes gradually decompose into the corresponding single-ligand complex couples. The complexes exhibit in vitro antitumor activities (against a series of human tumor cell lines) which, in some cases, are identical to, or even higher than, that of cisplatin. For the dialkyltin complexes, the activity increases with the length of the carbon chain of the alkyl ligand and is higher in the case of the chloro-substituted benzohydroxamato ligand. The [nBu(2)Sn(L(1))(2)] complex displays a high in vivo activity against H22 liver and BGC-823 gastric tumors, and has a relatively low toxicity.  相似文献   
3.
Ni(OH)2 hollow microspheres with beta-Ni(OH)2 nanosheets as the in situ formed building units were fabricated via a novel template-free approach in a strong alkaline solution of glycine, and can be converted into NiO hollow microspheres by a thermal decomposition process.  相似文献   
4.
Summary Dipole Cauchy moments of the atoms through Ar are calculated using the hydrodynamic formulation of time-dependent Kohn-Sham theory. The exchange-correlation energy density functional is approximated by the gradient expansion for atoms. Using variational trial functions that contain both linear and nonlinear variational parameters, we are able to reproduce (to three or four significant figures) the static dipole polarizabilities obtained by explicitly solving the relevant differential equations. The resulting dipole Cauchy moments provide a convenient starting point for calculating other properties which result from the linear interaction of atoms with a time varying electric field.  相似文献   
5.
Love波免疫传感器在免疫分析中的研究   总被引:1,自引:0,他引:1  
Love波免疫传感器是一种以免疫反应为识别方式的新型声表面波传感器。与其它压电声波免疫传感技术相比,水平剪切型表面波、高的压电晶体基频以及声波导层的存在使Love波免疫传感器在可用于气液两相检测的同时具有更高的灵敏度,从而可以成为免疫分析中的一种重要的工具。本文分别从Love波传感器的构造、原理、发展现状和以抗体作为探针在传感器表面的固定化方法两方面综述了Love波免疫传感器的研究进展。  相似文献   
6.
刘百祥  李青山 《分析化学》1998,26(11):1365-1368
铂比互铂化处理后,形成疏松,粗糙的表面,将四硫富瓦烯-四氰基奎诺二甲烷导电有机盐入到铂化的铂黑微粒中。将3-羰基丁酸吡咯与吡咯按适当的比例在其表面用电化学聚合方法,将葡萄糖氧化酶固定于聚合形成的杂聚膜中制成微酶电极。该微酶电极测定时几乎不受氧分压影响,灵敏度高,响应快。  相似文献   
7.
TiO2 and Fe-doped TiO2 thin films were prepared on the substrates (glass plates and glass microballs) after dipped in colloid and calcined at 500°C. The films have been characterized by UV-absorption, x-ray diffraction and atomic force microscopy (AFM). The investigated Fe-doped TiO2 (A nominal 10 wt% Fe2O3 was impregnated) thin films were obtained by sol-gel method. The characterization results suggest that the calcined thin films primarily consist of TiO2 anatase. And the light absorption curve of the TiO2 films modified with Fe showed that red shift had happened by the dope of Fe. TiO2/beads as photocatalyst were used to degrade the simulated dyeing water which contains reactive deep-blue dye (K-R). Through the degradation experiment, we found that the dope of Fe promoted the photocatalytic activities. The results showed that the dyeing water can be decomposed more effectively by the photocatalytic oxidation of Fe/TiO2 film on glass micro-balls than glass plates.  相似文献   
8.
比较了不同体系下离子色谱法测定考核样中氟离子的准确度。在碳酸盐–碳酸氢盐体系下分析氟标准样品,进行甲酸根、乙酸根加标试验,讨论了甲酸根、乙酸根对氟定量准确性的影响。考核样品色谱峰处理前氟测定结果为0.273 mg/L,与统计均值0.240 mg/L相比偏高,色谱峰处理后结果为0.243 mg/L,在统计Z值偏差范围内。同时在氢氧根体系下分析考核样品,有效改善了氟离子与乙酸、甲酸的分离度。在氢氧根体系下分析环境水样中低浓度氟离子快速、方便。  相似文献   
9.
以甲氧基和卤素取代的苯甲酸为起始原料,经过羧酸酰基化、傅克酰基化、芳香环卤代等反应合成了12个卤代甲氧基二苯甲酮类化合物,其结构经ESI-MS、1H NMR、13C NMR进行了表征和确认。通过考察其对H2O2诱导的人脐静脉内皮细胞(HUVECs)损伤的保护活性,讨论了此类化合物的构效关系。体外活性实验表明,浓度为12.5μmol/L时,化合物7a和9a对HUVECs有一定的保护活性,保护率超过50%。  相似文献   
10.
We have studied the timing jitter in dispersion-managed soliton systems with a Gaussian pulse by two methods. Firstly, the timing jitter expressions for dispersion-managed soliton are derived by use of the perturbed variational method. By analyzing and simulating the timing jitter expressions, one can find that the timing jitter is induced by the amplifier spontaneous emission noise, the frequency shift, etc. The chirp sign, the soliton self-frequency shift, and the filters action also have effects on the timing jitter. Secondly, the timing jitter is calculated and analyzed by the moment method. The results of the two methods are proved to be consistent.  相似文献   
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