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991.
基本解方法与边界节点法求解Helmholtz方程的比较研究 总被引:4,自引:4,他引:0
基本解方法和边界节点法是基于径向基函数的两种重要无网格边界离散数值技术。针对Helmholtz方程,本文比较研究这两种数值方法在不同计算区域问题上的计算精度、插值矩阵对称性、病态性及计算成本。数值试验结果表明,两种方法都可以有效求解边界数据准确的Helmholtz问题。在数值离散过程中,两种方法都可以通过调整配置点的位... 相似文献
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The chiral phosphoric acid catalyzed asymmetric[3+2]annulation of substituted 2-vinylindoles with azlactones has been established.This reaction represented a practical approach for the synthesis of structurally diverse pyrrolo[1,2-a]indoles with two vicinal stereocenters including one tetrasubstituted stereocenter in good yields and good stereoselectivities under mild conditions. 相似文献
997.
Feng Gao Juan Song Bin Zhang Hidekazu Tanaka Fei Gao Weiwei Qiu Qingxiang Wang 《中国化学快报》2020,31(1):181-184
The core-shell structured Au@Bi2S3 nanorods have been prepared through direct in-situ growth of Bi2S3 at the surface of pre-synthesized gold nanorods.The product was characterized by X-ray diffraction,transmission electron microscopy and energy-dispersive X-ray spectroscopy.Then the obtained Au@Bi2S3 nanorods were coated onto glassy carbon electrode to act as a scaffold for fabrication of electrochemical DNA biosensor on the basis of the coordination of-NH2 modified on 5’-end of probe DNA and Au@Bi2S3.Electrochemical characterization assays demonstrate that the Au@Bi2S3 nanorods behave as an excellent electronic transport channel to promote the electron transfer kinetics and increase the effective surface area by their nanosize effect.The hybridization experiments reveal that the Au@Bi2S3 matrix-based DNA biosensor is capable of recognizing complementary DNA over a wide concentration ranging from 10 fmol/L to 1 nmol/L.The limit of detection was estimated to be 2 fmol/L(S/N=3).The biosensor also presents remarkable selectivity to distinguish fully complementa ry sequences from basemismatched and non-complementary ones,showing great promising in practical application. 相似文献
998.
Chuncheng Zou Yuanyuan Han Chuikun Zeng Tony Y. Zhang Jinxing Ye Gonghua Song 《中国化学快报》2020,31(2):377-380
An organocatalytic asymmetric [3+2] cycloaddition of trifluoromethyl-containing azomethine ylides with cyclic 2,4-dienones was developed.The process enables efficient incorporation of CF3 groups into functionalized spiro [pyrro lid in-3,2'-oxindoles] in high yields with good to excellent enantio-and diastereoselectivities. 相似文献
999.
Meng Ding Juanjuan Zhou Hongcen Yang Ruya Cao Shouwei Zhang Minghui Shao Xijin Xu 《中国化学快报》2020,31(1):71-76
Graphene-like C3N4/Ag3PO4 photocatalysts are synthesized by calcination and solutions precipitating method.The obtained g-C3N4/Ag3PO4 composites display excellent photocatalytic activity for the degradation of methylene orange(MO),rhodamine B(RhB)and tetracycline(TC)under visible light irradiation.The solutions containing RhB(10 mg/L)and MO(10 mg/L)can be efficiently degraded within15 min and 30 min.Especially,nearly 80%of TC(50 mg/L)is degraded within 20 min.which are much better than those of pure g-C3N4 nanosheets and Ag3PO4,implying that strong interaction and reasonable energy band alignment in the contact interface can effectively transfer the carries.Furthermore,the g-C3N4/Ag3PO4 composites exhibit the improved stability,and only a slight decrease is observed after three recycling runs.Moreover,the impact of inorganic ions and PH values on the degradation performance is rather small.The Z-scheme photocatalytic mechanism of the g-C3N4/Ag3PO4 composites based on the active species trapping experimental is proposed.This work demonstrates the promising applications of the g-C3N4/Ag3PO4 composites in environmental issues. 相似文献
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Xiaofang Lu Qi Zheng Shijia Gu Rui Guo Li Su Jiancheng Wang Zhenxing Zhou Yuchi Fan Wan Jiang Lianjun Wang 《中国化学快报》2020,31(3):880-884
Cu@Ag/Bi2Te3 nanocomposites were prepared for the first time by ultrasonic dispersion-rapid freezedrying method combined with spark plasma sintering(SPS).By changing the content of Cu@Ag nanoparticle,we could modulate the temperature dependent thermoelectric properties.The highest ZT value can be obtained at 450 K for 1 vol%Cu@Ag/Bi2Te3,which is benefited from the decoupling of electrical and thermal properties.With the increase of electrical conductivity,the absolute value of Seebeck coefficient lifts while the thermal conductivity declines.Meanwhile,the average ZT value between 300 K and 475 K was 0.61 for 1 vol%Cu@Ag/Bi2Te3,which is much higher than that of pristine Bi2 Te3.Therefore,the decoupling effect of Cu@Ag nanoparticles incorporation could be a promising method to broaden the application of Bi2Te3 based thermoelectric materials. 相似文献