排序方式: 共有38条查询结果,搜索用时 31 毫秒
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Lanqin Tang Bing Zhou Jingzhe Zhao Xiaotang Lv Fang Sun Zichen Wang 《Colloids and surfaces. A, Physicochemical and engineering aspects》2009,332(1):43-49
In this study, a facile solution-based chemical method has been developed to produce ZnO particles in the presence of triethanolamine (TEA) and NaOH. In this novel method, TEA acted as complexing reagents, and NaOH contributed to the transformation of ZnO precursor (Zn–TEA complex) into ZnO particles. The core of this new strategy is to transform Zn–TEA complex into morphological ZnO particles directly by a facile solution method. The results from transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM) analysis revealed that the morphologies of the as-prepared ZnO samples evolved from slices to quasi-spheres by increasing the amount of TEA. X-ray diffraction (XRD), Raman and room-temperature photoluminescence (PL) tests showed that these ZnO samples had wurtzite structures. A reasonable mechanism for the transformation of Zn–TEA complex into morphological ZnO particles was supplied. 相似文献
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In this paper, we demonstrate a simple and general "dispersion-decomposition" approach to the synthesis of metal sulfide nanocrystals with the assistance of alkylthiol. This is a direct heating process without precursor injection. By using inorganic metal salts and alkylthiol as the raw materials, high-quality Ag(2)S, Cu(2)S, PbS, Ni(3)S(4), CdS, and ZnS nanocrystals were successfully synthesized. The mechanism study shows that the reaction undergoes two steps. A key intermediate compound, metal thiolate, is generated first. It melts and disperses into the solvent at a relatively low temperature, and then it decomposes into metal sulfide as a single precursor upon heating. This method avoids using toxic phosphine agent and injection during the reaction process. The size and shape of the nanocrystal can be also controlled by the concentration of the reactant and ligands. Furthermore, the optical properties and assembly of the nanocrystals have also been studied. This report provides a facile, direct-heating "dispersion-decomposition" approach to synthesize metal sulfides nanocrystals that has potential for future large-scale synthesis. 相似文献
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激光-钨靶耦合效应的二维模拟研究 总被引:1,自引:0,他引:1
利用二维ESCL-CASTOR磁流体力学三温激光靶程序,对激光-钨靶进行了计算机模拟研究。得到了密度、温度(T_e,T_i,T_R)和速度的空间分布以及随时间的变化规律;特别是得到了临界面的运动规律、辐射谱和X光转换效率等结果,并与实验结果进行了比较。 相似文献
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建立了氢还原重量法测定三氯化钌产品大样中钌含量的新方法,研究并优化了测定条件,结合原子吸收光谱法(AAS)、电感耦合等离子体原子发射光谱法(ICP-AES)和氯化铵纯度考察了杂质元素对了分析结果的误差影响。结果表明,钌含量为0.3~0.6g的三氯化钌与5~7g氯化铵能完全形成(NH4)2RuCl6配合物,于约100℃烘干水分、350℃分解铵盐、750℃氢还原为海绵钌和105℃干燥水气的条件下,测定3.94%,5.88%,7.32%,9.47%,10.84%和12.93%含量的钌,极差、标准偏差(S)、相对标准偏差(RSD,n=22)和重复性限(r)分别为±0.01%,0.0030%~0.0050%,0.0369%~0.0761%和0.008%~0.014%。样品加标回收率99.96%~99.98%。方法的结果准确,精密度好,且与YS/T562—2009标准分析方法的吻合。 相似文献
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Tong Guo Hong Chang Jinping Chen Xing Fu Xiaotang Hu 《Optics and Lasers in Engineering》2009,47(3-4):512-517
A computer-controlled micro-motion analyzer (MMA) to study the dynamic behavior of movable structures of MEMS is described in this paper. It employs two optical nondestructive methods—computer microvision for in-plane motion measurement and phase-shifting interferometry for out-of-plane motion measurement. This fully integrated system includes a high-performance imaging system, drive electronics, data acquisition and data analysis software. This system can freeze the fast motions of MEMS devices using strobed illumination and measure motions in three dimensions with nanometer accuracy. The static measurement accuracy and repeatability of the system is calibrated by a step height standard which is certified by National Institute of Standards and Technology (NIST). The capabilities of this system are illustrated with a study of the dynamic behaviors of a surface micromachined polysilicon micro-resonator. 相似文献
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Xiaotang Gan Zuqi Fu Lixin Liu Yani Yan Chao Chen Yongbo Zhou Jianyu Dong 《Tetrahedron letters》2019,60(32):150906
A metal-free and two-phase protocol for the Meyer-Schuster isomerization of propargyl alcohols to the corresponding α,β-unsaturated carbonyl compounds has been achieved in the presence of stoichiometric phosphorous acid aqueous solution, which produces the desired products in high yields with excellent stereoselectivity. Compared with the traditional methods, the procedure features broad scope of the substrates, mild conditions, and easy separation, providing an appealing alternative to the Meyer-Schuster reaction. 相似文献
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Manipulation and behavior modeling of one-dimensional nanomaterials on a structured surface 总被引:2,自引:0,他引:2
Sen Wu Author Vitae Xing Fu Author VitaeAuthor Vitae Xiaotang Hu Author Vitae 《Applied Surface Science》2010,256(14):4738-4744
Different diameters of multiwall carbon nanotubes (CNTs) are manipulated by a cantilever tip of an atomic force microscope (AFM) to investigate the motion properties of one-dimensional nanomaterials on a structured surface. To describe the mechanical behaviors of this kind of samples, two mechanical models based on continuum mechanics are proposed. Through foreseeable manipulation procedures, we are able to position the tubes onto pre-etched micro trenches, and then measure their Young's moduli by the three-point bending method. Both string-like and beam-like deformation forms are observed on the tested samples. Additionally, we present a reparable ‘collapse’ phenomenon of the nanotube bridges. 相似文献