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Mechanical Evaluation of AZ80 Magnesium Alloy in Cast Wrought Form
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作者 Peilin Ying Anita Hu +1 位作者 Wutian Shen Henry Hu 《Journal of Materials Science and Chemical Engineering》 2024年第4期119-125,共7页
Wrought magnesium alloy AZ80 with a thick section of 20 mm was prepared by squeeze casting (SC) and permanent steel mold casting (PSMC). The porosity measurements of the SC and PSMC depicted that SC AZ80 had a pore co... Wrought magnesium alloy AZ80 with a thick section of 20 mm was prepared by squeeze casting (SC) and permanent steel mold casting (PSMC). The porosity measurements of the SC and PSMC depicted that SC AZ80 had a pore content of 0.52%, which was 77% lower than 2.21% of PSMC AZ80 counterpart. The YS, UTS, e<sub>f</sub>, E and strengthening rate of cast AZ80 were determined by mechanical pulling. The engineering stress versus strain bended lines showed that SC AZ80 had a YS of 84.7 MPa, a UTS of 168.2 MPa, 5.1% in e<sub>f</sub>, and 25.1 GPa in modulus. But, the YS, UTS and e<sub>f</sub> of the PSMC AZ80 specimen were only 71.6 MPa, 109.0 MPa, 1.9% and 21.9 GPa. The findings of the mechanical pulling evidently depicted that the YS, UTS, e<sub>f</sub> and E of SC AZ80 were 18%, 54%, 174% and 15% higher than PSMC counterpart. The computed resilience and toughness suggested that the SC AZ80 exhibited greater resistance to tensile loads during elastic deformation and possessed higher capacity to absorb energy during plastic deformation compared to the PSMC AZ80. At the beginning of permanent change, the strengthening rate of SC AZ80 was 10,341 MPa, which was 9% greater than 9489 MPa of PSMC AZ80. The high mechanical characteristics of SC AZ80 should be primarily attributed to its low porosity level. . 展开更多
关键词 Squeeze Casting Wrought Magnesium Alloy AZ80 POROSITY Tensile Prop-erties
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Explanation of Ball Lightning by Plasma Oscillations
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作者 Auguste Meessen 《Journal of Modern Physics》 2023年第11期1355-1381,共27页
Ball Lightning (BL) is a “plasma bubble” that has very remarkable properties. Its membrane contains a higher density of charged particles than the ambient medium. They are held together by mutually attracting surfac... Ball Lightning (BL) is a “plasma bubble” that has very remarkable properties. Its membrane contains a higher density of charged particles than the ambient medium. They are held together by mutually attracting surface charges, generated by collective oscillations of all unbound electrons inside the membrane. Energy losses by collisions and emission of radiation, as well as losses of charged particles by recombination, are compensated by extracting other ones from atmospheric air. Since that occurs in a special rhythmic way, this leads to “parametric amplification” of the oscillations of all unbound electrons in the plasma membrane. Moreover, BL is attracted by higher concentrations of charged particles in atmospheric air. Too much of them leads to explosion and too few to extinction of visible BL. Since the electric charge of BL is oscillating, it is also attracted by metals, water and glass. It can then heat, melt and vaporize these materials without stored energy. BL is even able to pass through window panes in 3 different ways, but that can also be explained. 展开更多
关键词 Ball Lightning Electronic Plasma Oscillations Parametric Amplification Prop-erties of Ball Lightning
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REVIEW AND PROSPECT OF HIGH STRENGTH LOW ALLOY TRIP STEEL 被引量:13
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作者 L.Li P.Wollants +3 位作者 Y.L.He B.C.DeCooman X.C.Wei Z.Y.Xu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2003年第6期457-465,共9页
Research status of high strength low alloy TRIP (transformation induced plasticity) steels for automobile structural parts is briefly described. Composition and microstruc-ture factors especially the morphology, size ... Research status of high strength low alloy TRIP (transformation induced plasticity) steels for automobile structural parts is briefly described. Composition and microstruc-ture factors especially the morphology, size and volume fraction of retained austenite, which largely influence the strength and ductility of the steel, are reviewed and discussed one after another. Modelling of the inter-critical annealing and martempering processes as well as the designing of the TRIP steel aided by commercial software are introduced. Some special aspects of the dynamic mechanical properties of TRIP steel are firstly reported. 展开更多
关键词 HSLA TRIP steel retained austenite dynamic mechanical prop-erty THERMODYNAMICS KINETICS
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Direct evidence of high temperature superconductivity in one-unit-cell FeSe films on SrTiO_3 substrate by transport and magnetization measurements 被引量:2
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作者 邢颖 王健 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第11期15-22,共8页
Zero resistance and Meissner effect are two crucial experimental evidences of superconductivity in determining a new kind of superconductor, which can be detected by transport and diamagnetic measurements. In this pap... Zero resistance and Meissner effect are two crucial experimental evidences of superconductivity in determining a new kind of superconductor, which can be detected by transport and diamagnetic measurements. In this paper, we briefly review the main transport and magnetization results on the one unit cell (1-UC) FeSe films grown on SrTiO3 (STO) substrates from our team in recent years, which identify the high temperature superconductivity in 1-UC FeSe films. 展开更多
关键词 two-dimensional superconductivity one-unit-cell FeSe transport measurement diamagnetic prop-erty
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Effects of Metal Oxide Modifications on Photoelectrochemical Properties of Mesoporous TiO2 Nanoparticles Electrodes for Dye-Sensitized Solar Cells
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作者 Tian-you Peng Ke Fan +2 位作者 De Zhao Li-juan Yu Ren-jie Li 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第5期609-616,I0004,共9页
Mesoporous TiO2 (m-TiO2) nanoparticles were used to prepare the porous film electrodes for dye-sensitized solar cells, and a second metal oxide (MgO, ZnO, A1203, or NiO) modifi- cation was carried out by dipping t... Mesoporous TiO2 (m-TiO2) nanoparticles were used to prepare the porous film electrodes for dye-sensitized solar cells, and a second metal oxide (MgO, ZnO, A1203, or NiO) modifi- cation was carried out by dipping the m-TiO2 electrode into their respective nitrate solution followed by annealing at 500 ℃. Experimental results indicated that the above second metal oxide modifications on m-TiO2 electrode are shown in all cases to act as barrier layer for the interracial charge transfer processes, but film electron transport and interfacial charge recombination characteristics under applied bias voltage were dependent significantly on the existing states and kinds of these second metal oxides. Those changes based on sec- ond metal oxide modifications showed good correlation with the current-voltage analyses of dye-sensitized solar cell, and all modifications were found to increase the open-circuit photo- voltage in various degrees, while the MgO, ZnO, and NiO modifications result in 23%, 13%, and 6% improvement in cell conversion efficiency, respectively. The above observations indi- cate that controlling the charge transport and recombination is very important to improve the photovoltaic performance of TiO2-based solar cell. 展开更多
关键词 Dye-sensitized solar cell Metal oxide modification Photoelectrochemical prop-erty Mesoporous TiO2 nanoparticle
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Precise Synthesis of Acrylate Copolymer via RAFT Polymerization and Its Application
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作者 Lei Li Jinxing Song +4 位作者 Xin Yang Shengpeng Wang Zuguang Li Yingying Chen Aiyuan You 《Journal of Materials Science and Chemical Engineering》 2021年第6期59-67,共9页
<div style="text-align:justify;"> A series of different sequence structure containing stearyl acrylate (SA) and hydroxyethyl acrylate (HEA) copolymer were synthesized via reversible addition-fragmentat... <div style="text-align:justify;"> A series of different sequence structure containing stearyl acrylate (SA) and hydroxyethyl acrylate (HEA) copolymer were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The crystallization property of PHEA-<em>b</em>-PSA, PHEA-<em>b</em>-PSA-<em>b</em>-PHEA, PSA-<em>b</em>-PHEA-<em>b</em>-PSA, PHEA-<em>co</em>-PSA, and PHEA-<em>grad-b</em>-PSA were characterized by Differential Scanning Calorimetry (DSC). The condensed structure of different sequence copolymers were investigated using small-angle X-ray scattering (SAXS). A series of copolymers with different sequence structure were coated on the surface of polyester fabric, which can be found that PHEA-b-PSA-b-PHEA block copolymer has good water repellency. </div> 展开更多
关键词 RAFT Polymerization Different Sequence Structure Crystallization prop-erty Water Repellency
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Investigation of mechanical properties of twin gold crystal nanowires under uniaxial load by molecular dynamics method 被引量:1
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作者 张国伟 杨在林 罗刚 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第8期279-283,共5页
Twin gold crystal nanowires, whose loading direction is parallel to the twin boundary orientation, are simulated.We calculate the nanowires under tensile or compressive loads, different length nanowires, and different... Twin gold crystal nanowires, whose loading direction is parallel to the twin boundary orientation, are simulated.We calculate the nanowires under tensile or compressive loads, different length nanowires, and different twin boundary nanowires respectively. The Young modulus of nanowires under compressive load is about twice that under tensile load.The compressive properties of twin gold nanowires are superior to their tensile properties. For different length nanowires,there is a critical value of length with respect to the mechanical properties. When the length of nanowire is greater than the critical value, its mechanical properties are sensitive to length. The twin boundary spacing hardly affects the mechanical properties. 展开更多
关键词 molecular dynamics twinned crystal boundary gold nanowires uniaxial load mechanical prop-erties
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Synthesis of nano crystalline spatulae of lead zirconate titanate (PbZr0.52Ti0.48O3) 被引量:1
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作者 S. S. Bhatt S. C. Chaudhry +1 位作者 Neeraj Sharma Sonia Gupta 《Natural Science》 2010年第1期12-17,共6页
A simple and effective method for the synthesis of nano-crystalline PZT spatulae has been re-ported near MPB via a new Solution-Ignition Synthesis route and has been characterized by FT-IR, XRD, TG/DTG/DTA and SEM tec... A simple and effective method for the synthesis of nano-crystalline PZT spatulae has been re-ported near MPB via a new Solution-Ignition Synthesis route and has been characterized by FT-IR, XRD, TG/DTG/DTA and SEM techniques. X-ray line broadening and Scherrer formula show crystallite size to be^20 nm. Densities of nano-crystalline spatulae of PZT in pellet form made by using 2% PVA and without PVA have been found to be 5.35 and 7.51 gm/cm3 respec-tively compared to the theoretical value of 7.78 gm/cm3. Dielectric constants of 83 and 227 of these spatulae with dielectric loss 0.118 and 0.0609 at 1 MHz and a high resistivity value of 3.043 * 107 Ω cm for PZT pellets made without PVA suggest these nano-crystalline PZT spatu-lae to be the potential candidates for high fre-quency applications. 展开更多
关键词 NANOSTRUCTURES Chemical Synthesis INFRARED Spectroscopy X-RAY DIFFRACTION DIELECTRIC Prop-erties
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Structural, electrical, and optical properties of ZnInO alloy thin films
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作者 才玺坤 原子健 +4 位作者 朱夏明 王雄 张兵坡 邱东江 吴惠桢 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第10期340-344,共5页
Indium zinc oxide (IZO) thin films with different percentages of In content (In/[In+Zn]) are synthesized on glass substrates by magnetron sputtering, and the structural, electrical and optical properties of IZO t... Indium zinc oxide (IZO) thin films with different percentages of In content (In/[In+Zn]) are synthesized on glass substrates by magnetron sputtering, and the structural, electrical and optical properties of IZO thin films deposited at different In2O3 target powers are investigated. IZO thin films grown at different In2O3 target sputtering powers show evident morphological variation and different grain sizes. As the In2O3 sputtering power rises, the grain size becomes larger and electrical mobility increases. The film grown with an In2O3 target power of 100 W displays the highest electrical mobility of 13.5 cm.V-1-s-1 and the lowest resistivity of 2.4× 10^-3 Ω.cm. The average optical transmittance of the IZO thin film in the visible region reaches 80% and the band gap broadens with the increase of In2O3 target power, which is attributed to the increase in carrier concentration and is in accordance with Burstein-Moss shift theory. 展开更多
关键词 indium-zinc oxide magnetron sputtering In content optical properties electrical prop-erties
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Density functional theory analysis of electronic structure and optical properties of La-doped Cd_2SnO_4 transparent conducting oxide
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作者 汤梅 尚家香 张跃 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第1期486-491,共6页
The electronic structural, effective masses of carriers, and optical properties of pure and La-doped Cd2SnO4 are calculated by using the first-principles method based on the density functional theory. Using the GGA+U... The electronic structural, effective masses of carriers, and optical properties of pure and La-doped Cd2SnO4 are calculated by using the first-principles method based on the density functional theory. Using the GGA+U method, we show that Cd2SnO4 is a direct band-gap semiconductor with a band gap of 2.216 eV, the band gap decreases to 2.02 eV and the Fermi energy level moves to the conduction band after La doping. The density of states of Cd2SnO4 shows that the bottom of the conduction band is composed of Cd 5s, Sn 5s, and Sn 5p orbits, the top of the valence band is composed of Cd 4d and O 2p, and the La 5d orbital is hybridized with the O 2p orbital, which plays a key role at the conduction band bottom after La doping. The effective masses at the conduction band bottom of pure and La-doped Cd2SnO4 are 0.18m0 and 0.092m0, respectively, which indicates that the electrical conductivity of Cd2SnO4 after La doping is improved. The calculated optical properties show that the optical transmittance of La-doped Cd2SnO4 is 92%, the optical absorption edge is slightly blue shifted, and the optical band gap is increased to 3.263 eV. All the results indicate that the conductivity and optical transmittance of Cd2SnO4 can be improved by doping La. 展开更多
关键词 transparent conducting oxides electronic band structure first-principle calculations optical prop-erties
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Effects of the sputtering power on the crystalline structure and optical properties of the silver oxide films deposited using direct-current reactive magnetron sputtering
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作者 郜小勇 张增院 +3 位作者 马姣民 卢景霄 谷锦华 杨仕娥 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第2期370-375,共6页
This paper reports that a series of silver oxide (AgzO) films are deposited on glass substrates by direct-current reactive magnetron sputtering at a substrate temperature of 250 ℃ and an oxygen flux ratio of 15:18... This paper reports that a series of silver oxide (AgzO) films are deposited on glass substrates by direct-current reactive magnetron sputtering at a substrate temperature of 250 ℃ and an oxygen flux ratio of 15:18 by modifying the sputtering power (SP). The AgxO films deposited apparently show a structural evolution from cubic biphased (AgO + Ag20) to cubic single-phased (Ag20), and to biphased (Ag20 + AgO) structure. Notably, the cubic single-phased Ag20 fihn is deposited at the SP = 105 W and an AgO phase with (220) orientation discerned in the Ag^O films deposited using the SP 〉 105 W. The transmissivity and refiectivity of the AgxO films in transparent region decrease with the increase the SP, whereas the absorptivity inversely increases with the increase of the SP. These results may be due to the structural evolution and the increasing film thickness. A redshift of the films' absorption edges determined in terms of Tauc formula clearly occurs from 3.1 eV to 2.73 eV with the increase of the SP. 展开更多
关键词 Ag2O film direct-current reactive magnetron sputtering x-ray diffraction optical prop-erties
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基于二十面体的新型B_(12)CN和B_(13)CN结构的第一性原理研究
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作者 朱莉 马梦冬 +8 位作者 熊美 高琦 武英举 应盼 魏旭东 赵智胜 辛圣炜 何巨龙 田永君 《Science China Materials》 SCIE EI CAS CSCD 2023年第11期4480-4488,共9页
以二十面体为基元的富硼化合物具有复杂多样的电子和机械性能.在本工作中,我们采用粒子群优化结构预测方法结合第一性原理计算,首次对二十面体基元的三元B_(12)CN和B_(13)CN化合物的晶体结构和性质进行了全面系统的研究.我们搜索得到了B... 以二十面体为基元的富硼化合物具有复杂多样的电子和机械性能.在本工作中,我们采用粒子群优化结构预测方法结合第一性原理计算,首次对二十面体基元的三元B_(12)CN和B_(13)CN化合物的晶体结构和性质进行了全面系统的研究.我们搜索得到了B_(13)CN和B_(12)CN化合物的新结构,其空间群均为Cmc21,与α-B的变体结构相比,新结构具有更优异的热力学稳定性.B_(12)CN的热力学稳定性和机械性能均稍逊于B_(13)CN.此外,B含量的微小差异造成了B_(12)CN与B_(13)CN两种三元化合物迥异的电学特性,即B_(13)CN具有半导体特性,而B_(12)CN具有空穴型导电特性.此外,在B_(12)CN与B_(13)CN系列新结构的拉伸过程中,由于二十面体的连续破坏和二十面体之间的连续断键造成的应力再增强、结构多级破坏和类蠕变变形等特殊变形机制也同样被揭示. 展开更多
关键词 B-C-N icosahedral-based structures physical prop-erties first principles
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Fiducial inference in the pivotal family of distributions 被引量:17
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作者 XU Xingzhong & LI Guoying Department of Mathematics, Beijing Institute of Technology, Beijing 100081, China Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100080, China 《Science China Mathematics》 SCIE 2006年第3期410-432,共23页
In this paper a family, called the pivotal family, of distributions is considered.A pivotal family is determined by a generalized pivotal model. Analytical results show that a great many parametric families of distrib... In this paper a family, called the pivotal family, of distributions is considered.A pivotal family is determined by a generalized pivotal model. Analytical results show that a great many parametric families of distributions are pivotal. In a pivotal family of distributions a general method of deriving fiducial distributions of parameters is proposed. In the method a fiducial model plays an important role. A fiducial model is a function of a random variable with a known distribution, called the pivotal random element, when the observation of a statistic is given.The method of this paper includes some other methods of deriving fiducial distributions. Specially the first fiducial distribution given by Fisher can be derived by the method. For the monotone likelihood ratio family of distributions, which is a pivotal family, the fiducial distributions have a frequentist property in the Neyman-Pearson view. Fiducial distributions of regular parametric functions also have the above frequentist property. Some advantages of the fiducial inference are exhibited in four applications of the fiducial distribution. Many examples are given, in which the fiducial distributions cannot be derived by the existing methods. 展开更多
关键词 CONFIDENCE bounds fiducial distributions fiducial model frequentist prop-erty GENERALIZED pivotal model pivotal FAMILY of distributions testing hypotheses.
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SICA for Cox's Proportional Hazards Model with a Diverging Number of Parameters 被引量:4
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作者 Yue-Yong SHI Yong-Xiu CAO +1 位作者 Yu-Ling JIAO Yan-Yan LIU 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2014年第4期887-902,共16页
The smooth integration of counting and absolute deviation (SICA) penalized variable selection procedure for high-dimensional linear regression models is proposed by Lv and Fan (2009). In this article, we extend th... The smooth integration of counting and absolute deviation (SICA) penalized variable selection procedure for high-dimensional linear regression models is proposed by Lv and Fan (2009). In this article, we extend their idea to Cox's proportional hazards (PH) model by using a penalized log partial likelihood with the SICA penalty. The number of the regression coefficients is allowed to grow with the sample size. Based on an approximation to the inverse of the Hessian matrix, the proposed method can be easily carried out with the smoothing quasi-Newton (SQN) algorithm. Under appropriate sparsity conditions, we show that the resulting estimator of the regression coefficients possesses the oracle property. We perform an extensive simulation study to compare our approach with other methods and illustrate it on a well known PBC data for predicting survival from risk factors. 展开更多
关键词 Cox proportional hazards models penalized partial likelihood diverging parameters oracle prop-erty smoothing quasi-Newton
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Electron structures and non-linear optical properties of tert butyl-nitro-phthalocyanines 被引量:1
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作者 Tianli Zhang Jimin Yan +1 位作者 Yunqi Liu Daoben Zhu 《Chinese Science Bulletin》 SCIE EI CAS 1999年第8期694-698,共5页
The electron structures and the non-linear optical properties of phthalocyanines and asymmetrically substituted phthalocyanines are studied with the AM1 method. The results show that the fertbutyl-nitro-phthalocyanine... The electron structures and the non-linear optical properties of phthalocyanines and asymmetrically substituted phthalocyanines are studied with the AM1 method. The results show that the fertbutyl-nitro-phthalocyanines have much higher second order non-linear optical coefficients . 展开更多
关键词 phthalocyanine. asymmetrically SUBSTITUTED PHTHALOCYANINE PUSH-PULL electron effect non-linear optical prop-erty.
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Tuning optical properties of MOF-based thin films by changing the ligands of MOFs 被引量:1
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作者 殷文昌 陶呈安 +3 位作者 王芳 黄坚 曲天良 王建方 《Science China Materials》 SCIE EI CSCD 2018年第3期391-400,共10页
The preparation and development of novel optical thin films are of great importance to functional optical and opto-electric components requiring a low refractive index.In this study, a typical metal-organic framework... The preparation and development of novel optical thin films are of great importance to functional optical and opto-electric components requiring a low refractive index.In this study, a typical metal-organic framework(MOF), MIL-101(Cr), is selected as the research model. The corresponding MOF nanoparticles are prepared by a hydrothermal method and the optical thin films are successfully prepared by spincoating. The optical properties of the corresponding MOF thin films are controlled by changing the type of functional groups on the benzene ring of the ligand(terephthalic acid) on MOFs.The functional groups are hydrogen atoms(H),electron donating groups(-NH_2,-OH) and electron withdrawing groups(-NO_2,-(NO_2)_2 or F_4), respectively. It is found that the effective refractive index(n_(eff)) of MOF thin films decreases along with the increasing voids among MOF nanoparticles. In addition, the extinction coefficient(k) increases with the addition of electron donating groups, and decreases with the addition of electron withdrawing groups. Among the MOFs used in this study, the n_eff of NO_2-MIL-101(Cr) containing electron withdrawing groups is as low as ~1.2, and value of k is particularly low, which suggests its potential application in antireflective devices. In addition, the intrinsic refractive index(n_(dease)) of the dense MOF materials evaluated according to their porosity increases with the number of the functional groups, and the n_(dense) of the two nitro-substituted MOFs is greater than that of the single nitro-substituted one, and the latter is bigger than that of hydroxyl-substituted one, which is close to that of amino-functionalized one. The diversity of ligands in MOFs makes them a promising new generation of optical materials. 展开更多
关键词 metal-organic frameworks thin film optical prop-erty refractive index changing of ligand
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Coupled modified Kd V equations, skew orthogonal polynomials, convergence acceleration algorithms and Laurent property
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作者 Xiangke Chang Yi He +3 位作者 Xingbiao Hu Shihao Li Hon-wah Tam Yingnan Zhang 《Science China Mathematics》 SCIE CSCD 2018年第6期1063-1078,共16页
In this paper, we show that the coupled modified Kd V equations possess rich mathematical structures and some remarkable properties. The connections between the system and skew orthogonal polynomials,convergence accel... In this paper, we show that the coupled modified Kd V equations possess rich mathematical structures and some remarkable properties. The connections between the system and skew orthogonal polynomials,convergence acceleration algorithms and Laurent property are discussed in detail. 展开更多
关键词 integrable system skew orthogonal polynomial convergence acceleration algorithm Laurent prop-erty
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Promoted porous Co_3O_4-Al_2O_3 catalysts for ammonia decomposition 被引量:2
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作者 Zhe-Shan Zhang Xin-Pu Fu +3 位作者 Wei-Wei Wang Zhao Jin Qi-Sheng Song Chun-Jiang Jia 《Science China Chemistry》 SCIE EI CAS CSCD 2018年第11期1389-1398,共10页
Transition metal catalysts have been considerably used for NH3 decomposition because of the potential application in COx-free H2 generation for fuel cells. However, most transition metal catalysts prepared via traditi... Transition metal catalysts have been considerably used for NH3 decomposition because of the potential application in COx-free H2 generation for fuel cells. However, most transition metal catalysts prepared via traditional synthetic approaches performed the inferior stability due to the agglomeration of active components. Here, we adopted an efficient method, aerosol-assisted self- assembly approach (AASA), to prepare the optimized cobalt-alumina (C0304-A1203) catalysts. The C0304-A1203 catalysts exhibited excellent catalytic performance in the NH3 decomposition reaction, which can reach 100% conversion at 600 ℃and maintain stable for 72 h at a gaseous hourly space velocity (GHSV) of 18000 cm3 gcat-1 h-1. The catalysts were characterized by various techniques including transmission electron microscope (TEM), scanning electron microscope (SEM), nitrogen sorption, temperature-programmed reduction by hydrogen (H2-TPR), ex-situ/in-situ Raman and ex-situ/in-situ X-ray diffraction (XRD) to obtain the information about the structure and property of the catalysts. H2-TPR and in-situ XRD results show that there is strong interaction between the cobalt and alumina species, which influences the redox properties of the catalysts. It is found that even a low content of alumina (10 at%) is able to stabilize the catalysts due to the adequate dispersion and rational interaction between different components, which ensures the high activity and superior stability of the cobalt-alumina catalysts. 展开更多
关键词 cobalt-alumina catalyst aerosol-assisted self-assembly approach ammonia decomposition anti-sintering redox prop-erties
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Novel 2H-pyrazolo[4,3-c]hexahydropyridine derivatives: Synthesis, crystal structure, fluorescence properties and cytotoxicity evaluation against human breast cancer cells 被引量:1
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作者 PANG ChunCheng SUN ChuanWen +3 位作者 WANG Jing XIAO Di DING Li BU HongFei 《Science China Chemistry》 SCIE EI CAS 2013年第6期702-715,共14页
A series of novel 2H-pyrazolo[4,3-c]hexahydropyridine derivatives (II) have been designed and synthesized. The target com- pounds have been identified by elemental analysis and spectral (1H NMR, IR, and MS) data a... A series of novel 2H-pyrazolo[4,3-c]hexahydropyridine derivatives (II) have been designed and synthesized. The target com- pounds have been identified by elemental analysis and spectral (1H NMR, IR, and MS) data and the absolute configuration of compound (IIl) was confirmed by single crystal X-ray diffraction. The cytotoxicity of the target compounds have been evalu- ated in vitro against two human breast cancer cell lines MCF-7 and MDA-MB-231 by MTT assay. Most compounds exhibited good inhibition, and compounds II21 (IC50 = 4.7 μM for MCF-7 and IC50 = 9.3 μM for MDA-MB-231), 1133 (IC50 = 2.4 μM for MCF-7 and IC50 = 4.2 gM for MDA-MB-231) and 114o (IC50 = 3.3 μM for MCF-7 and IC5o =8.6 μM for MDA-MB-231) dis- played better inhibitory activity than 5-fluorouracil (IC50 = 4.8 μM for MCF-7 and IC50 = 9.6 I, tM for MDA-MB-231, respec- tively). Flow cytometric analysis and DNA fragmentation suggest that II33 is cytotoxic and able to induce the apoptosis of MCF-7 cells. The fluorescence properties of compounds IIl, II6, II11,II16, II23, Il2s, and II3s were also studied and compound Ilzs afforded the highest photoluminescence quantum yield (38%). 展开更多
关键词 PYRAZOLOPYRIDINE SYNTHESIS crystal structure breast cancer cells cytotoxicity evaluation apoptosis fluorescence prop-erties
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Influence of Strain Rate on Tensile Characteristics of SUS304 Metastable Austenitic Stainless Steel 被引量:1
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作者 Xifeng LI Jun CHEN +2 位作者 Liyan YE Wei DING Pengchao SONG 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2013年第6期657-662,共6页
The microstructure characteristics and plastic deformation behavior of SUS304 metastable austenitic stainless steel sheets have been investigated during tensile process at different strain rates at room temperature. T... The microstructure characteristics and plastic deformation behavior of SUS304 metastable austenitic stainless steel sheets have been investigated during tensile process at different strain rates at room temperature. The yield stress continuously increases with strain rates due to low fraction of martensite transformed from austenite at 0.2% plastic stain. While the ultimate tensile stress (UTS) and elongation gradually decreases and then slightly increases with increase in strain rate from 0.0005 s-1 to 0.i s-1, which is attributed to the variation of the martensite fraction that is affected seriously by adiabatic heating. A higher temperature increase in the tensile specimens restricts the martensitic transformation at high strain rate. The strain rate of 0.1 s-1 is considered as a transition deformation rate from quasi-static state to plastic forming, where the transformed martensitic content is very small in a higher strain rate range. Anomalous stress peaks in the later half stage of deformation occur at a very low strain rate (i.e., 0.0005 s-1) result from X-shaped strain localization repeatedly sweeping over the specimen. With increasing strain rates, the variation of dimple number density follows similar trend as that of UTS and ductility because martensite fraction mostly influences void nucleation and growth. 展开更多
关键词 SUS304 metastable austenitic stainless steel Strain rate Mechanical prop-erties Martensite fraction DIMPLE
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