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排序方式: 共有1341条查询结果,搜索用时 62 毫秒
61.
Zhang Ning Zhang Bin Pang Yong Yang Hong-Sheng Zong Lu Duan Yong-Xin Zhang Jian-Ming 《高分子科学》2022,40(4):373-383
Chinese Journal of Polymer Science - Macromolecule nanocrystal network and strong interfacial interaction are always beneficial to enhance the mechanical property of polymer-based nanocomposites.... 相似文献
62.
Synthesis,properties and mechanism of photodegradation of core–shell structured upconversion luminescent NaYF4:Yb3+,Er3+@BiOCl
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Shiyu Zhou Qiyan Zhang Deqiang Zhao Wenjuan Zong Zihong Fan Yaofang Sun Xuan Xu 《应用有机金属化学》2018,32(4)
Microspherical bismuth oxychloride (BiOCl) can only utilize ultraviolet (UV) light to promote photocatalytic reactions. To overcome this limitation, a uniform and thin BiOCl nanosheet was synthesized with a particle size of about 200 nm. As results of UV–visible diffuse reflectance spectroscopy showed, the band gap of this nanostructure was reduced to 2.78 eV, indicating that the BiOCl nanosheet could absorb and utilize visible light. Furthermore, the upconversion material NaYF4 doped with rare earth ions Yb3+ and Er3+ emitted visible light at 410 nm following excitation with near‐infrared (NIR) light (980 nm), which could be utilized by BiOCl to produce a photocatalytic reaction. To produce a high‐efficiency photocatalyst (NaYF4:Yb3+,Er3+@BiOCl), BiOCl‐loaded NaYF4:Yb3+,Er3+ was successfully synthesized via a simple two‐step hydrothermal method. The as‐synthesized material was confirmed using X‐ray diffraction, scanning electron microscopy, X‐ray photoelectron spectroscopy as well as other characterizations. The removal ratio of methylene blue by NaYF4:Yb3+,Er3+@BiOCl was much higher than that of BiOCl alone. Recycling experiments verified the stability of NaYF4:Yb3+,Er3+@BiOCl, which demonstrated excellent adsorption, strong visible‐light absorption and high electron–hole separation efficiency. Such properties are expected to be useful in practical applications, and a further understanding of the NIR‐light‐responsive photocatalytic mechanism of this new catalytic material would be conducive to improving its structural design and function. 相似文献
63.
Sheng Xia Shan Yin Shimin Tao Yanhui Shi Liangce Rong Xianyong Wei Zhimin Zong 《Research on Chemical Intermediates》2012,38(9):2435-2442
One-pot, multicomponent reaction for the synthesis of novel substituted pyrimidine derivatives: 4-amino-5-carbonitrile-2-nitroaminopyrimidine from aromatic aldehydes, 1-nitroguanidine, and malononitrile under ethanol is described. Because of containing many active functional groups, such as amino, cyan and nitro, these products are important intermediate of organic synthesis. The advantages of this procedure include the short reaction time, mild reaction conditions, and excellent yields. 相似文献
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Dr. Zhen Lei Zong‐Jie Guan Dr. Xiao‐Li Pei Shang‐Fu Yuan Xian‐Kai Wan Jin‐Yuan Zhang Prof.Dr. Quan‐Ming Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(32):11156-11160
A red–near‐IR dual‐emissive nanocluster with the composition [Au10Ag2(2‐py?C≡C)3(dppy)6](BF4)5 ( 1 ; 2‐py?C≡C is 2‐pyridylethynyl, dppy=2‐pyridyldiphenylphosphine) has been synthesized. Single‐crystal X‐ray structural analysis reveals that 1 has a trigonal bipyramidal Au10Ag2 core that contains a planar Au4(2‐py?C≡C)3 unit sandwiched by two Au3Ag(dppy)3 motifs. Cluster 1 shows intense red–NIR dual emission in solution. The visible emission originates from metal‐to‐ligand charge transfer (MLCT) from silver atoms to phosphine ligands in the Au3Ag(dppy)3 motifs, and the intense NIR emission is associated with the participation of 2‐pyridylethynyl in the frontier orbitals of the cluster, which is confirmed by a time‐dependent density functional theory (TD‐DFT) calculation. 相似文献
66.
An immersed smoothed point interpolation method (IS‐PIM) for fluid‐structure interaction problems
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An immersed smoothed point interpolation method using 3‐node triangular background cells is proposed to solve 2D fluid‐structure interaction problems for solids with large deformation/displacement placed in incompressible viscous fluid. In the framework of immersed‐type method, the governing equations can be decomposed into 3 parts on the basis of the fictitious fluid assumption. The incompressible Navier‐Stokes equations are solved using the semi‐implicit characteristic‐based split scheme, and solids are simulated using the newly developed edge‐based smoothed point interpolation method. The fictitious fluid domain can be used to calculate the coupling force. The numerical results show that immersed smoothed point interpolation method can avoid remeshing for moving solid based on immersed operation and simulate the contact phenomenon without an additional treatment between the solid and the fluid boundary. The influence from information transfer between solid domain and fluid domain on fluid‐structure interaction problems has been investigated. The numerical results show that the proposed interpolation schemes will generally improve the accuracy for simulating both fluid flows and solid structures. 相似文献
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68.
Hongmei Yang Zong‐Jun Li Debin Wan Wenhui Lian Shuying Liu 《Journal of mass spectrometry : JMS》2013,48(5):539-543
In this work, laser‐enhanced in‐source decay (LEISD) technique of matrix‐assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI‐FT‐ICR‐MS) was used to distinguish reducing and nonreducing carbohydrates. Interestingly, easier cleavage of (1 → 2)‐linked glycosidic bonds for nonreducing carbohydrates containing D‐fructofuranosyl units was observed in MALDI‐FT‐ICR‐MS, which was in agreement with the result of theoretical calculation by the software package Gaussian 09. Importantly, no cross‐ring cleavage of fructofuranosyl residues was detected in the LEISD spectra of nonreducing carbohydrates. LEISD method therefore offers an attractive alternative for fast and efficient differentiation of reducing and nonreducing carbohydrates, and the positions of nonreducing monosaccharide residues in a carbohydrate chain could be easily speculated. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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A series of cyclophanes composed of two triarylelement caps linked by two-atom bridges has been synthesized. The bridgehead functional groups include phosphines in combination with amines, hydrosilanes, methylsilanes, and ethoxysilanes. Computational studies accurately predicted that when the bridgehead substituents are small (lone pairs or protons), an in,in bridgehead stereochemistry is strongly favored, but larger bridgehead substituents favor the formations of in,out stereoisomers. The X-ray structures, spectra, and reactivity of these compounds are discussed, as well as the resolution of one of the cyclophanes into pure enantiomers. 相似文献