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361.
能量色散偏振X射线荧光光谱法测定生铁中锰和钛 总被引:1,自引:0,他引:1
探讨了应用能量色散偏振X射线荧光光谱仪测定生铁中锰和钛进行炉前快速分析的方法.对测定锰及钛时仪器的工作条件,试样的制备以及工作曲线的制作等因素作了较系统的试验,该方法所得测定结果与化学法测定结果或标样标准值相吻合,相对标准偏差小于1.5%,与化学法相比,锰和钛的测定时间由50 min缩短到2 min. 相似文献
362.
The template-directed fabrication of highly-ordered porous film is of significant importance in implementation of the photonic band gap structure. The paper reports a simple and effective method to improve the electrodeposition of metal porous film by utilizing highly-ordered polystyrene spheres (PSs) template. By surface-modification method, the hydrophobic property of the PSs template surfaces was changed into hydrophilic one. It was demonstrated that the surface modification process enhanced the permeability of the electrolyte solution in the nanometer-sized voids of the colloidal template. The homogeneously deposited copper film with the highly-ordered voids in size of less than 500 nm was successfully obtained. In addition, it was found that large defects, such as microcracks in the template, strongly influenced the macroporous films quality. An obvious preferential growth in the cracked area was observed. 相似文献
363.
Lan Yang Xiao He Zhiying Zeng Jiakun Tang Dongmei Qi Huijie Ma Hui Chen Xinghai Ning Xuli Feng 《Chemical science》2021,12(24):8394
Nucleus-targeted therapy holds great promise in cancer treatment; however, a lack of effective nucleus-specific delivery significantly limits its application potential. Here, we report a nucleus-targeted synergistic chemo-photodynamic therapy based on the self-assembly of chlorin e6 (Ce6) and doxorubicin (DOX) tuned by clickable dibenzocyclooctyne (DIBO) functionalized lysine (D-K) and subsequent reaction with crosslinkers. The assembled nanodrugs with high loading efficiency and long-term stability show enhanced cellular uptake and accumulation in the nucleus, resulting in greatly improved in vitro and in vivo chemo-photodynamic efficacy. Notably, D-K can promote the rapid self-assembly of Ce6 and DOX in aqueous solution, avoiding the introduction of organic solvents or tedious preparations. In addition, the introduction of the DIBO group can effectively expand the types of self-assembly material and enhance the self-assembly behaviour through a copper-free click reaction. Therefore, we present an effective nucleus-targeted combination drug delivery strategy, which has great potential in the treatment of many diseases.A highly efficient nucleus-targeted multi-drug delivery nanoplatform based on clickable amino acid tuned self-assembly of chlorin e6 and doxorubicin has been prepared for enhanced photodynamic therapy and chemotherapy. 相似文献
364.
Quantized vortices are important topological excitations in Bose–Einstein condensates. The Gross–Pitaevskii equation is a widely accepted theoretical tool. High accuracy quantized-vortex solutions are desirable in many numerical and analytical studies. We successfully derive the Padéapproximate solutions for quantized vortices with winding numbers ω = 1, 2, 3, 4, 5, 6 in the context of the Gross–Pitaevskii equation for a uniform condensate. Compared with the numerical solutions, we find that(1) they approximate the entire solutions quite well from the core to infinity;(2) higher-order Padé approximate solutions have higher accuracy;(3) Padé approximate solutions for larger winding numbers have lower accuracy. The healing lengths of the quantized vortices are calculated and found to increase almost linearly with the winding number. Based on experiments performed with ~(87)Rb cold atoms, the healing lengths of quantized vortices and the number of particles within the healing lengths are calculated, and they may be checked by experiment. Our results show that the Gross–Pitaevskii equation is capable of describing the structure of quantized vortices and physics at length scales smaller than the healing length. 相似文献
365.
366.
Synthesis,Structures, and Luminescent Properties of Lanthanide Complexes with Triphenylphospine Oxide
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Yan Ma Shan Xu Xin Wang Min Liu Yue‐Xue Li Xiu‐Lan Xin Qiong‐Hua Jin 《无机化学与普通化学杂志》2017,643(12):780-788
Seven lanthanide complexes [Ln(OPPh3)3(NO3)3] ( 1 – 3 ) (OPPh3 = triphenylphosphine oxide, Ln = Nd, Sm, Gd), [Dy(OPPh3)4(NO3)2](NO3) ( 4 ), [Ln(OPPh3)3(NO3)3]2 ( 5 – 7 ) (Ln = Pr, Eu, Gd) were synthesized by the reactions of different lanthanide salts and OPPh3 ligand in the air. These complexes were characterized by single‐crystal X‐ray diffraction analysis, elemental analysis, IR and fluorescence spectra. Structure analysis shows that complexes 1 – 4 are mononuclear complexes formed by OPPh3 ligands and nitrates. The asymmetric units of complexes 5 – 7 consist of two crystallographic‐separate molecules. Complex 1 is self‐assembled to construct a 2D layer‐structure of (4,4) net topology by hydrogen bond interactions. The other complexes show a 1D chain‐like structure that was assembled by OPPh3 ligands and nitrate ions through C–H ··· O interactions. Solid emission spectra of compounds 4 and 6 are assigned to the characteristic fluorescence of Tb3+ (λem = 480, 574 nm) and Eu3+ (λem = 552, 593, 619, 668 nm). 相似文献
367.
He Yanfang Niu Xiangheng Shi Libo Zhao Hongli Li Xin Zhang Wenchi Pan Jianming Zhang Xifeng Yan Yongsheng Lan Minbo 《Mikrochimica acta》2017,184(7):2181-2189
Microchimica Acta - The authors describe a photometric method for the determination of free cholesterol based on the oxidation of cholesterol by the catalytic action of the enzyme... 相似文献
368.
Ming-Qi Wang Zi-Yu Wang Yi-Fan Yang Gui-Ying Ren Xiao-Ning Liu Shuo Li Jian-Wei Wei Lan Zhang 《Tetrahedron letters》2017,58(33):3296-3300
The development of small-molecule G-quadruplex DNA probes has attracted significant attention in recent years. However, G-quadruplexes can display a wide variety of topologies, which process different structures and functions. Therefore, selective discrimination one G-quadruplex structure over another is promising. Herein, we reported the design, synthesis and biological evaluation of a long-chain fatty amine functionalized triphenylamine-quinolinium conjugate 1b. Significant enhancement of the fluorescence intensity (over 180 fold) was observed when 1b bound with HRAS G-quadruplex DNA, while much weaker enhancements were presented in the presence of other G-quadruplexes (45–90-fold) and single/double-stranded DNAs (less than 20-fold), indicating 1b had an excellent selectivity to HRAS. The details of the interactions were investigated by UV–Vis, FID and CD analysis. The results show 1b could interact and stabilize HRAS structure mainly by π-π stacking binding mode. The introduced amine chain of the structure core was found to be better in the terms of inducing selectivity toward G-quadruplex structure. In addition, the application of 1b as a fluorescent agent for living cell imaging was also demonstrated. 相似文献
369.
Li Ruifen Cao Xiaojun Zhao Haogui Liu Chunxia Li Zheng Wang Jinhua Zhang Lan Li Qinguan 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(3):1715-1725
Di-1-methyl heptyl methyl phosphonate (DMHMP) is a promising alternative extractant for Th-U fuel reprocessing, in which the irradiation stability of extractant should be systematically studied. In this paper, the radiolysis products of DMHMP were analyzed qualitatively and quantitatively with gas and ion chromatograph, the possible radiolysis mechanism of DMHMP was also concluded. Moreover, the effect of structure on the radiolysis products and irradiation stability of neutral organophosphorus compound extractant was also discussed.
相似文献370.
Lan Luo Ziyi Zhang Yanhua Chen Lixia Zhang Xiangfeng Bu Hanqi Zhang 《International journal of environmental analytical chemistry》2017,97(12):1178-1191
A simple and sensitive surface-enhanced Raman spectroscopy (SERS) method for the detection of safranine T (ST) and Hg2+ using silver nanoparticles (AgNPs) as substrate was developed. ST can absorb on the surface of AgNPs through electrostatic interaction, the electromagnetic effect combined with chemical adsorption effect give a notable Raman enhancement for ST. The presence of Hg2+ well decreased the absorbed ST molecules on AgNPs, leading to a significant decrease of SERS signals thus enabling to detect Hg2+. The determination conditions for SERS, including the amount of AgNPs, the concentration of NaCl, the concentration of HCl, the concentration of ST and the reaction time, were optimised. Under the optimised experimental conditions, good linear responses were obtained for ST and Hg2+ in the concentration ranges of 0.01–4.0 μmol L?1 (3.5–1403.4 ng mL?1) and 0.01–2.0 μmol L?1 (2.0–401.2 ng mL?1), the limit of detection were 3.0 nmol L?1 (1.1 ng mL?1) and 2.0 nmol L?1 (0.4 ng mL?1), respectively. The present method was subsequently applied to the determination of ST in tomato sauces and Hg2+ in environmental waters, the recoveries of ST and Hg2+ in spiked samples are 95.5–107.8% and 91.4–110.8 %, respectively. 相似文献