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101.
From the changes in energy band, density of state (DOS) and electronic structure calculated by the DFT/B3LYP method, the conductivity of carbon doped boron‐nitride nanotube (BNNT), which is formed by C‐C bond substituting B‐N bond, was discussed. The results indicate that the substitution will strengthen the conductivity of the tube, and its semi‐conductivity might be adjusted by controlling the substitution. 相似文献
102.
We optimized the hot water extraction of polysaccharides from the root of Henry wood betony (RHWPs) using a uniform test and explored their anti-tumor activities in vitro and in vivo. The optimal extraction conditions were as follows: 40 min extraction time, liquid/solid ratio 30 mL/g, 100 min soaking time, two extraction cycles, 100% ethanol concentration, and extraction temperature of 80 °C. The molecular weight distribution of RHWPs with MWs was 228,600 g/mol and 5001 g/mol. The IR spectrum further indicated that RHWPs are acidic polysaccharides containing pyranose and furan rings. The main monosaccharides found in RHWPs were mannose, ribose, l-rhamnose monohydrate, glucuronic acid, galacturonic acid, glucose, galactose, xylose, arabinose, and fucose. RHWPs inhibited the proliferation of S180 tumor cells and induced apoptosis in vitro. Oral administration of RHWPs to tumor-bearing mice significantly inhibited the growth of the S180 xenografts, accelerated apoptosis in tumor cells, and expanded the necrotic regions. Furthermore, RHWPs also markedly increased the levels of TNF-α, IFN-γ, and IL-2 in the sera of tumor-bearing mice, and activated immune cells such as lymphocytes, NK cells, and macrophages, thereby inducing tumor cell apoptosis. Taken together, RHWPs are a promising anti-tumor agent that ought to be explored further. 相似文献
103.
Wen Ma Yu-Peng Tian Sheng-Yi Zhang Jie-Ying Wu Hoong-Kun Fun Suchada Chantrapromma 《Transition Metal Chemistry》2006,31(1):97-102
A new diferrocenyl-substituted macrocyclic ligand (H2L) and its complexes ML(M = CuII, NiII, ZnII, CdII) were prepared and characterized by IR, elemental analysis, absorption spectra and FAB mass spectra. The ferrocenyl-substituted
macrocyclic ligand was characterized by single crystal X-ray diffraction analysis. The superconjugative effect of the cyclopentadienyl
(CP) rings increase the activity of the hydrogen atoms in the tetra-azacyclotetradecane macrocyclic ligand. The imine nitrogen
atoms lose two protons and coordinate to the metal. The electrochemical properties of these compounds are discussed. 相似文献
104.
Chunsheng Tian Stefan Gara Gerhard Hobler Gerhard Stingeder 《Mikrochimica acta》1992,107(3-6):161-169
The axial channeling behaviour of boron implants in <100>, <110> and <111> silicon wafers is investigated by SIMS. Large differences of channeling characteristics such as channeled projected range (the projected range of channeled ions or channeling peak) and the fraction of channeled to implanted ions are observed among the three major crystal orientations. Within the critical angle, the channeling behaviour is very sensitive to the incidence beam angle with respect to crystal orientations. SIMS measurements are performed at different positions along several critical directions over a whole wafer. Well channeled profiles with an incidence beam angle to crystal orientations of 0 ° are obtained for each ion implantation energy and orientation. The results are used to test various models of ion implantation by simulation. A 3-parameter model for electronic stopping power of boron in silicon was proposed. 相似文献
105.
Hexagonal ZnO group whiskers synthesized from Zn(NH3)42+ precursor at 145°C in a structure-directing template solvent (2.5% v/v alcohol) show strong photoluminescence at 409 and 420 nm. FE-SEM and TEM observation reveals that the ZnO group whiskers consist of uniform pencil-like whiskers with the diameter of around 1.5 μm and the length of up to 6 μm. 相似文献
106.
107.
SAPO—11分子筛用i—Pr2NH导向合成及其酸性研究 总被引:3,自引:0,他引:3
以AlPO4、H3PO4、SiO2等为原料采用单一模板剂iPr2NH合成了SAPO11分子筛,利用Avrami方程等对合成过程进行了定量描述。还利用红外(IR)、程序升温脱附(TPD)、线性丁烯骨架异构反应催化活性测试等手段表征了SAPO11的酸性。结果表明,合成过程随温度有明显变化,晶化阶段的活化能远高于核化阶段的值。可用Avrami方程的参数来表征合成过程的难易程度。分子筛中存在B酸和L酸位,主要在中等强度范围,从而对线性丁烯骨架异构反应有较好的催化活性。提高分子筛中硅含量可明显增大酸位浓度,酸强度也有轻度增强。 相似文献
108.
Reactions in a Mixture of CH4 and CO2 under the Aciton of Microwave Discharge at Atmospheric Pressure
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Reactions between CH4 and CO2 under the action of continuous microwave discharge at atmospheric pressure were studied in a special homemade reactor,The main products were CO and H2,while acetylene and ethylene were also found in the products.Experimental results show that conversions of CH4 and CO2 could be higher than 90% without the presence of any catalyst,Effects of CO2/CH4 molar ratio and total flow rate of the feed gas on the reaction were also investigated. 相似文献
109.
[reaction: see text] A molecular shuttle containing an alpha-CD macrocycle, an azobenzene unit, and two different fluorescent naphthalimide units was synthesized. The cis-trans photoisomerization of the azobenzene unit resulted in the motion of the CD macrocycle on the track. Because of the easy regulation and full reversibility of the fluorescence change of the two stopper units, the molecular shuttle could be used as a molecular storage medium or switch with all-optical inputs and outputs. 相似文献
110.