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排序方式: 共有106条查询结果,搜索用时 15 毫秒
1.
Zhao Tianqi Luo Tianzi Fang Bo Shi Lijiang Jin Yongxing Zhou Pengwei Yao Dong Li Chenxia Jing Xufeng Hong Zhi 《Journal of Russian Laser Research》2021,42(5):586-597
Journal of Russian Laser Research - The zero-refractive-index metamaterials have excellent electromagnetic properties, which provide new ideas and methods to realize the control of electromagnetic... 相似文献
2.
Dake Hu Tianqi Zhao Xiaofan Ping Husong Zheng Lei Xing Xiaozhi Liu Jingying Zheng Lifei Sun Lin Gu Chenggang Tao Dong Wang Liying Jiao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(21):7051-7055
Two‐dimensional (2D) PtSe2 shows the most prominent layer‐dependent electrical properties among various 2D materials and high catalytic activity for hydrogen evolution reaction (HER), and therefore, it is an ideal material for exploring the structure–activity correlations in 2D systems. Here, starting with the synthesis of single‐crystalline 2D PtSe2 with a controlled number of layers and probing the HER catalytic activity of individual flakes in micro electrochemical cells, we investigated the layer‐dependent HER catalytic activity of 2D PtSe2 from both theoretical and experimental perspectives. We clearly demonstrated how the number of layers affects the number of active sites, the electronic structures, and electrical properties of 2D PtSe2 flakes and thus alters their catalytic performance for HER. Our results also highlight the importance of efficient electron transfer in achieving optimum activity for ultrathin electrocatalysts. Our studies greatly enrich our understanding of the structure–activity correlations for 2D catalysts and provide new insight for the design and synthesis of ultrathin catalysts with high activity. 相似文献
3.
In order to alleviate the contradiction between injectability of the profile control agent and its profile control performance, a novel core‐shell heterogeneous structure colloidal particles (CSA) were synthesized, and the mechanism of self‐aggregation plugging was proposed. Cross‐linking inside the nanoparticles and chain‐growth polymerization via capturing acrylamide in the aqueous phase result in the formation of core‐shell heterogeneous structures as proved by TEM observation and XPS analysis. Moreover, CSA nanoparticles exhibit good hydrophilic properties, outstanding thermal stability and limited expansion capacity. Effects of different metal cations and surface group on the self‐aggregation time of CSA nanoparticles were systematically studied. Results showed that divalent cations contributed to more significant aggregation of CSA nanoparticles in comparison to monovalent cations. The increasing cations concentration and valency decreased the thickness of electric double layer, which lead to a decrease in the zeta potential. Core flooding test shows that the injection of nanoparticles which diameter is much smaller that of pore‐throats into the target reservoir can not only successfully enter the depth of porous media, but also effectively block the high permeability areas by the formation of self‐aggregation particle clusters. This study provides a new method for the equilibrium between nanoparticles injectivity and in‐depth profile control of nanoparticles. 相似文献
4.
非连续边界元——有限元耦合方法分析 总被引:4,自引:0,他引:4
对边界元-有限元耦合方法进行了分析,采用非连续元离散边界积分方程,解决了耦合分析中自由度约束问题,给出了非连续边界元同有限元耦合的具体实施步骤,通过对二维弹性力学和流=固耦合问题分析,表明了该文方法的有效性。 相似文献
5.
Ouyang Jinbo Wang Yun Li Tianqi Zhou Limin Liu Zhirong 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(3):1419-1428
Journal of Radioanalytical and Nuclear Chemistry - The carboxyl-modified multiwalled carbon nanotubes were immobilized in chitosan-based composite membranes (CS-CNTs) which were used as efficient... 相似文献
6.
7.
Suppression of the Charge Density Wave State in Two-Dimensional 1T-TiSe2 by Atmospheric Oxidation 下载免费PDF全文
Lifei Sun Chuanhui Chen Dr. Qinghua Zhang Christian Sohrt Tianqi Zhao Dr. Guanchen Xu Jinghui Wang Prof. Dong Wang Prof. Kai Rossnagel Prof. Lin Gu Prof. Chenggang Tao Prof. Liying Jiao 《Angewandte Chemie (International ed. in English)》2017,56(31):8981-8985
Two-dimensional (2D) metallic transition-metal dichalcogenides (TMDCs), such as 1T-TiSe2, have recently emerged as unique platforms for exploring their exciting properties of superconductivity and the charge density wave (CDW). 2D 1T-TiSe2 undergoes rapid oxidation under ambient conditions, significantly affecting its CDW phase-transition behavior. We comprehensively investigate the oxidation process of 2D TiSe2 by tracking the evolution of the chemical composition and atomic structure with various microscopic and spectroscopic techniques and reveal its unique selenium-assisting oxidation mechanism. Our findings facilitate a better understanding of the chemistry of ultrathin TMDCs crystals, introduce an effective method to passivate their surfaces with capping layers, and thus open a way to further explore the functionality of these materials toward devices. 相似文献
8.
Dr. Zhongyuan Huang Prof. Haihui Zhou Feifei Sun Dr. Chaopeng Fu Dr. Fanyan Zeng Tianqi Li Prof. Yafei Kuang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(41):13720-13725
PdPt bimetallic nanotubes were prepared by the self‐assembly of Pt and Pd on Te nanowires at room temperature. The morphologies of the as‐prepared PdPt nanotubes were investigated by scanning electron microscopy and transmission electron microscopy, and the results display a large amount of PdPt bimetallic nanotubes with a diameter of 10–20 nm and a length of several micrometers. The composition and structure of the nanotubes were characterized by X‐ray diffraction, high‐resolution transmission electron microscopy, scanning transmission electron microscopy, and energy spectrum analysis, and the results display uniform compositional distributions of both elements (Pd and Pt). The mechanism of the formation of the nanotube structure was supposed. The electrocatalytic performance of PdPt nanotubes were studied by cyclic voltammetry and chronoamperometry. Electrochemical results show that the as‐prepared PdPt nanotube catalysts have not only high activity but also good stability for ethanol oxidation in alkaline medium. 相似文献
9.
Zidong He Aiqing Zhong Hui Zhang Linfeng Xiong Yang Xu Tianqi Wang Minghong Zhou Kun Huang 《Macromolecular rapid communications》2016,37(19):1566-1572
Here, a novel method is demonstrated for the preparation of three‐arm branched microporous organic nanotube networks (TAB‐MONNs) based on molecular templating of three‐arm branched core–shell bottlebrush copolymers and Friedel–Crafts alkylation reaction. The unique three‐arm branched bottlebrush copolymers are synthesized by a combination of atom transfer radical polymerization, reversible addition‐fragmentation chain transfer polymerization, and ring‐opening polymerization techniques. In this approach, the length and diameter of branched tube units can be well‐controlled by rational molecular design. Moreover, the as‐prepared TAB‐MONNs possess a high surface area and exhibit a superior adsorption capacity for Rhodamine 6G (R6G) and p‐cresol.
10.
咪唑丙酸可以通过哺乳动物雷帕霉素靶蛋白复合物1(mTORC1)路径引起人的胰岛素抵抗, 从而导致2型糖尿病(T2D), 因此, 咪唑丙酸的准确定量可辅助2型糖尿病的诊断. 本文利用NiO与咪唑基团之间的配位作用, 采用氧化镍沉积硅胶(NiO@SiO2)萃取材料对咪唑丙酸进行选择性富集和萃取. 首先对NiO@SiO2 固相萃取(SPE)条件进行优化: 吸附剂用量为200 mg, 上样液为20 mmol/L的磷酸盐缓冲溶液(pH=3.0), 解吸液为1.0 mL含1%(质量分数)NH3·H2O的水溶液; 然后, 对萃取液进行高效液相色谱-质谱(HPLC-MS)分离分析, 建立了血清中咪唑丙酸的检测方法. 结果表明, 咪唑丙酸浓度在0.05~10 ng/mL范围内对质谱响应值具有良好的线性关系(R 2≥0.996), 检出限和定量限分别为0.02和0.05 ng/mL, 加标回收率为84.0%~119%, 相对标准偏差RSD<17.2%. 将该方法用于检测2型糖尿病患者与正常人血清样品中的咪唑丙酸, 发现在2型糖尿病患者与正常人的血清中咪唑丙酸含量存在显著性差异, 说明咪唑丙酸的准确定量对2型糖尿病具有医学诊断上的潜力. 相似文献