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Photoredox-catalyzed [4+2] annulation of cyclobutylanilines with alkenes, alkynes, and diynes in continuous flow

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Science China Chemistry 2016年第2期59卷 180-183页

作者： jiang Wang Theresa h.Nguyen Nan zheng Department of Chemistry and Biochemistry University of Arkansas

Continuous flow has recently emerged as a powerful enabling technology that greatly improves many reactions' efficiency. here, we apply the technology to intermolecular [4+2] annulation of cyclobutylanilines with alkenes, alkynes, and diynes by photoredox catalysis. An across-the-board improvement in the annulation's efficiency is noticed. Moreover, a gram-scale annulation is successfully demonstrated in continuous flow using a much lower catalyst loading.

关键词： photocatalysis continuous flow N-cyclobutylanfline [4+2] annulation visible light

Melting, Oxidation, Evaporation of Particle in-Flight in Plasma Spray Processes

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journal of Materials Science & Technology 2003年第z1期19卷 49-52页

作者： h.B.Xiong L.L.zheng Department of Mechanical Engineering State University of New York at Stony Brook Stony Brook NY 11794-2300 USA Department of Mechanical Engineering State University of New York at Stony Brook Stony Brook NY 11794-2300 USA

A comprehensive numerical model has been developed to investigate the transient behaviors of particle characteristics, such as temperature, melting, evaporation, and oxidation status during argon-hydrogen DC plasma *** model includes heat, momentum and mass transfer of carrier gas, and particle heating, melting, evaporationand oxidation. Special attentions have been paid to the evaporation-induced mass transfer and oxidation-inducedevaporation as well as variable non-continuum phenomena.

关键词： Melting, Oxidation, Materials processing, Multi-components reacting flow, Computational heat transfer

EIS ANALYSIS ON ThE ANODIC PROCESS OF ZINC IN AN ALKALINE SOLUTION

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Acta Metallurgica Sinica(English Letters) 2004年第6期17卷 912-922页

作者： Y.zheng j.M.Wang h.Chen j.Q.Zhang C.N.Cao DepartmentofChemistry ZhejiangUniversityHangzhou310027China DepartmentofChemistry ZhejiangUniversityHangzhou310027China／／ChineseStateKeyLaboratoryforCorrosionandProtectionInstituteofMetalReseachTheChineseAcademyofSciencesShenyang110016China

yThe　EIS　on　theanodic　process　of　pure　Zn　in　an　alkaline　solution　wereperformed　and　fitted　using　the　expression　of　Faradic　admittance,based　on　which　the　mechanism　of　the　process　was　***　results　showed　that　besides　electrode　potential　E　the　electrochemical　reaction　rate　was　affected　by　the　adsorption　of　Zn(Oh)ads　on　the　electrode　surface　and　the　diffusion　of　in　the　electrolyte　in　active　region,and　only　by　the　covering　of　passivation　layer　on　the　electrode　surface　in　both　transitive　and　passivation　***　equivalent　circuit　sapplied　in　these　various　circumstances　were　proposed　and　the　variation　of　some　parameters　and　state　variables　was　also　discussed.

关键词： Zn alkalinesolution anodicprocess EIS

PLASMA SPRAYED Ti AND hA COATINGS: A COMPARATIVE STUDY BETWEEN APS AND VPS

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 339-344页

作者： X.B.zheng h.ji j.Q.huang C.X.Ding ShanghaiInstituteofCeramics TheChineseAcademyofSciencesShanghai200050China

Titanium (Ti) and hydroxyapatite (hA) coatings have been prepared via air (APS) and vacuum plasma spraying (VPS), and then their composition, structure, bonding strength and bioactivity were examined. The results obtained reveal that in APS process many of Ti were oxidized, but in VPS the oxidization was avoided. VPS T i coating possesses better bonding condition than APS Ti coating. As for hA coat ing, higher crystallinity has been obtained while the coating was deposited by V PS as compared with APS. The simulated body fluid (SBF) tests show that both of APS and VPS hA coatings possess good bioactivity. As compared with APS, VPS is r ecommended as a better method to deposit Ti and hA coatings that can be applied as hard tissue replacement implants.

关键词： vacuum plasma spray Ti hA biocoating

The use of environmentally sustainable bio-derived solvents in solvent extraction applications——A review

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Chinese journal of Chemical Engineering 2016年第2期24卷 215-220页

作者： zheng Li Kathryn h.Smith Geoffrey W.Stevens Particulate Fluids Processing Centre Department of Chemical and Biomolecular EngineeringThe University of Melbourne

Replacement of volatile organic compounds （VOCs） by greener or more environmentally sustainable solvents is becoming increasingly important due to the increasing health and environmental concerns as well as economic pressures associated with VOCs. Solvents that are derived from biomass, namely bio-derived solvents, are a type of green solvent that have attracted intensive investigations in recent years because of their advantages over con- ventional VOCs, such as low toxicity, biodegradability and renewability. This review aims to summarize the use of bio-derived solvents in solvent extraction applications, with special emphasis given to utilization of biodiesels and terpenes. Compared with the conventional VOCs, the overall performance of these bio-derived solvents is comparable in terms of extraction yields and selectivity for natural product extraction and no difference was found for metal extraction. To date most researchers have focused on laboratory scale thermodynamics studies. Future work is required to develop and test new bio-derived solvents and understand the kinetic performance as well as solvent extraction nilnt nlant studies.

关键词： Solvent extraction Bio-derived solvents Green solvents Biodiesels Terpenes

Bi-block positive semidefiniteness of bi-block symmetric tensors

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Frontiers of Mathematics in China 2021年第1期16卷 141-169页

作者： zheng-hai h UANG Xia LI Yong WANG School of Mathematics Tianjin UniversityTianjin 300354China

The positive definiteness of elasticity tensors plays an important role in the elasticity *** this paper,we consider the bi-block symmetric tensors,which contain elasticity tensors as a ***,we define the bi-block M-eigenvalue of a bi-block symmetric tensor,and show that a bi-block symmetric tensor is bi-block positive(semi)definite if and only if its smallest bi-block M-eigenvalue is(nonnegative)***,we discuss the distribution of bi-block M-eigenvalues,by which we get a sufficient condition for judging bi-block positive(semi)definiteness of the bi-block symmetric tensor ***,we show that several classes of bi-block symmetric tensors are bi-block positive definite or bi-block positive semidefinite,including bi-block(strictly)diagonally dominant symmetric tensors and bi-block symmetric(B)*** give easily checkable sufficient conditions for judging bi-block positive(semi)definiteness of a bi-block symmetric *** a byproduct,we also obtain two easily checkable sufficient conditions for the strong ellipticity of elasticity tensors.

关键词： Bi-block symmetric tensor bi-block symmetric Z-tensor bi-block symmetric B 0-tensor diagonally dominant bi-block symmetric tensor bi-block M-eigenvalue

Density determination and simulation of Inconel 718 alloy at normal and metastable liquid states

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journal of Materials Science & Technology 2018年第3期34卷 436-439页

作者： h.P.Wang C.h.zheng P.F.Zou S.j.Yang L.hu B.Wei Department of Applied Physics Northwestern Polytechnical University

The density of liquid Incone1718 alloy was experimentally measured by electrostatic levitation technique, where the maximum undercooling of 100 K was realized for the commercial sample. The measured density of liquid lnconel 718 alloy is 7.39 g cm^-3 at the liquidus temperature of 1663 K which was confirmed by DSC experiment, with the linear temperature coefficient of -6.89 × 10^-4 gcm^-3 K^-1. Correspondingly, four ternary Ni-Cr-Fe compositions were designed to simulate the density of liquid lnconel 718 alloy with 16000 atoms, from which the liquid structure is revealed by pair distribution function, The predicted result shows a remarkable enhancement with the decrease of temperature at the first neighbor distance.

关键词： Undercooling Density Liquid metal and alloy Levitation

Rapid Growth of TiNi intermetallic compound within undercooled Ti_(50)Ni_(50)alloy under electrostatic levitation condition

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journal of Materials Science & Technology 2021年第18期77卷 82-89页

作者： P.F.Zou C.h.zheng L.hu h.P.Wang School of Physical Science and Technology Northwestern Polytechnical University.Xi'an710072China

The undercooling dependence of the solidification mechanism was systematically explored by the electrostatic levitation(ESL)*** the experiments,the maximum undercooling reached up to 406 K(0.26 T_L)and the growth velocity of the primary TiNi phase was in-situ determined at various *** the initial increase of alloy undercooling,the value of growth velocity sluggishly rose followed by a power *** this case,the primary TiNi phase preferentially developed as the equiaxed dendrite,then the remnant liquid participated as Ti_(2)Ni andα-Ti phases on the grain *** the undercooling exceeded the critical value of 350 K,the growth velocity of the primary phase displayed a sharply increase ***,the TEM results demonstrated that the precipitation of the intermetallic Ti_(2)Ni compound was gradually restrained during the rapid solidification and the R-phase existing in the TiNi matrix at large undercooling implied that the martensitic transformation was incomplete.

关键词： Undercooling Ti-Ni alloy Solidification Growth kinetics

ThE SYNThESIS OF STEROID-OLIGOPEPTIDE

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Chinese Chemical Letters 1995年第8期6卷 663-666页

作者： Zhang, X Weng, LL zheng, h Guangdong Med Coll Dept Biochem Zhanjiang 524023 Peoples R China W China Univ Med Sci Sch Pharm Chengdu 610041 Peoples R China

Six new compounds-steroid-oligopeptide were designed and synthesized with active ester method,their structures (CA-G(1), DCA-G(1), CA-G(2), DCA-G(2), CA-G(3), DCA-G(3)) were confirmed by spectra and elemental analysis. Preliminary study on their bioactivities showed that the DCA-G(3) his the ability of acid-inhibition and the others have the ability of promoting acid-secretion. The metabolic time of six title compounds are longer than the positive control(Boc-G(2)).

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