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On Meromorphic Solutions of Nonlinear Complex Differential Equations

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Communications in Mathematical Research 2018年第2期34卷 149-160页

作者： Su Xian-feng Zhang qing-cai School of Information Renmin University of China School of Information Huaibei Normal University

Applying the Nevanlinna theory of meromorphic function, we investigate the non-admissible meromorphic solutions of nonlinear complex algebraic differential equation and gain a general result. Meanwhile, we prove that the meromorphic solutions of some types of the systems of nonlinear complex differential equations are non-admissible. Moreover, the form of the systems of equations with admissible solutions is discussed.

关键词： non-admissible solution complex differential equation value distribution meromorphic function

Photoluminescent biodegradable polyorganophosphazene: A promising scaffold material for in vivo application to promote bone regeneration

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Bioactive Materials 2020年第1期5卷 102-109页

作者： Yiqian Huang Zhaohui Huang Huanhuan Liu Xu Zhang qing cai Xiaoping Yang State Key Laboratory of Organic-Inorganic Composites Beijing Laboratory of Biomedical MaterialsBeijing University of Chemical TechnologyBeijing100029China Department of Endodontics School and Hospital of StomatologyTianjin Medical UniversityTianjin300070China

Tissue engineering scaffolds made of conventional aliphatic polyesters are inherently non-fluorescent,which results in their in vivo degradation hard to be *** biodegradable polyorganophosphazenes(PPOPs)are synthesized by introducing fluorophores onto the polyphosphazene backbone via nucleophilic substitution *** this study,a fluorophore(termed as TPCA),derived from citric acid and 2-aminoethanethiol,was co-substituted with alanine ethyl ester onto the polyphosphazene backbone to obtain a photoluminescent biodegradable POPP(termed as PTA).The scaffolds made of PTA demonstrated non-cytotoxicity and cell affinity,particularly,capacity in promoting osteogenic differentiation of bone marrow mesenchymal stromal cells(BMSCs).In vivo evaluations using the rat calvarial defect model confirmed its strong potential in enhancing osteogenesis,more importantly,the in vivo degradation of the PTA scaffold could be monitored via its fluorescence intensity alongside implantation time.

关键词： Tissue regeneration Biodegradation Photoluminescent Polyorganophosphazene

Electrical conductivity of molten LiF–DyF3–Dy2O3–Cu2O system for Dy–Cu intermediate alloy production

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International Journal of Minerals,Metallurgy and Materials 2019年第6期26卷 701-709页

作者： Shu-mei Chen Chun-fa Liao Jue-yuan Lin Bo-qing cai Xu Wang Yun-fen Jiao Institute of Metallurgy and Chemical Engineering Jiangxi University of Science and Technology

Dy–Cu intermediate alloys have shown substantial potential in the field of magnetostrictive and magnetic refrigerant ***,this study focused on investigating the electrical conductivity of molten-salt systems for the preparation of Dy–Cu alloys and on optimizing the corresponding operating *** electrical conductivity of molten LiF–DyF3–Dy2O3–Cu2O systems was measured from 910 to 1030°C using the continuously varying cell constant *** dependencies of the LiF–DyF3–Dy2O3–Cu2O system conductivity on the melt composition and temperature were examined *** optimal operating conditions for Dy–Cu alloy production were determined via analyses of the electrical conductivity and activation energies for conductance,which were calculated using the Arrhenius *** conductivity of the molten system regularly increases with increasing temperature and decreases with increasing concentration of Dy2O3 or Cu2O or *** activation energy Eκof the LiF–DyF3–Dy2O3 and LiF–DyF3–Cu2O molten-salt systems increases with increasing Dy2O3 or Cu2O *** regression functions of conductance as a function of temperature(t)and the addition of Dy2O3(W(Dy2O3))and Cu2O(W(Cu2O))can be expressed asκ=-2.08435+0.0068t-0.18929W(Dy2O3)-0.07918W(Cu2O).The optimal electrolysis conditions for preparing the Dy–Cu alloy in LiF–DyF3–Dy2O3–Cu2O molten salt are determined to be 2.0wt%≤W(Dy2O3)+W(Cu2O)≤3.0wt%and W(Dy2O3):W(Cu2O)=1:2 at 970 to 1000°C.

关键词： electrical conductivity molten salt Dy–Cu alloy dysprosium oxide cuprous oxide

Relationship between Dislocation Density in P91 Steel and Its Nonlinear Ultrasonic Parameter

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Journal of Iron and Steel Research International 2015年第11期22卷 1024-1030页

作者： Ye-qing cai Jin-zhong SUN Cheng-jie LIU Shi-wei MA Xi-cheng WEI School of Materials Science and Engineering Shanghai University School of Mechatronics Engineering and Automation Shanghai University

P91 steel is an important bearing material used in nuclear power plants. The study of its mechanical degradation behavior is important for ensuring safe operation. The relationship between the dislocation density of P91 steel under different strains and the corresponding nonlinear ultrasonic parameter β was studied. The dislocation density of strained samples was estimated by X-ray diffraction. Nonlinear ultrasonic testing was conducted to evaluate β, showing that this value increased with increasing dislocation density induced by different tensile elongations. It was shown that the ultrasonic secondharmonic generation technique can effectively evaluate the degradation behavior of metallic materials, and the prediction of the residual life of bearing parts in service can be made based on β and the dislocation density.

关键词： dislocation density P91 steel nonlinear ultrasonic second order harmonic

Weldability and Microstructure of Nickel-Silicon Based Alloys

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Journal of Iron and Steel Research International 2006年第3期13卷 61-67页

作者： LIU qing-cai LIU Yi YANG Jian J. W. Newkirk ZHANG Shan-hong State Key Laboratory of Mechanical Transmissions Chongqing University Chongqing 400044 China Department of Metallurgical Engineering University of Missouri-Rolla Rolla MO 65401 USA Yuanda Environmental Protection Co Ltd Chorgqing 400060 China

The NiSix based alloy typically has poor weldability due to its lower ductility. A limited amount of work has been performed on the weldability of NiSix based alloys. Therefore, the effect of heat treatment and welding parameters on weldability of the alloys, and the relationship between the weldability and microstructure were studied. The results show that the as-cast Ni-Si-Nb-B alloy （Ni 76. 5%, Si 20%, Nb 3%, and B 0. 5%） could be successfully welded after preheating at 600 ℃. The welding procedure should be performed on the alloys before any heat treatment and a preheating at 600 ℃ should be used. The fusion zone is harder than the matrix due to a large amount of 7 phase and a finer microstructure. The cracks are predominantly intergranular in heat affected zone and associated with the needle-like ）, phase. The heat treatment before welding increases the tendency of cracking in the fusion zone.

关键词： weldability Ni3Si based alloy heat treatment heat affected zone

Nanocrystallization of Amorphous Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 Irradiated by Laser

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Journal of Iron and Steel Research International 2005年第5期12卷 58-62页

作者： CHEN Sui-yuan LIU Chang-sheng ZHOU Li LI Hui-li cai qing-kui Northeastern Univcrsity Shenyang 110004 China

The surface nanocrystallization of amorphous Fe73.5 Cu1Nb3Si13.5B9 radiated by CO2 laser was studied by means of M（oe）ssbauer spectroscopy, transmission electro iroscope and X-ray diffraction. The result shows that under certain technical conditions, nanocrystalline is fiound on the surface of amorphous Fe73.5 Cu1Nb3Si13.5B9 radiated by laser; the crystallization phase is α-Fe（Si） crystalline, and its size is about 10-20 nm; the nanocrystalline is uniformly distributed on amorphous base to keep the amorphous and crystallized phase in balance; the a mount of crystallization reaches 23% when the laser power is 300 W, the diameter of light spot is 20 mm, and the radiation speed is 20 mm/s. The phase balance can be controlled by adjusting the laser technology parameter. Laser radiation on the amorphous Fe73.5 Cu1Nb3Si13.5B9 alloy is an important technique for surface nanocrystallization of the amorphous alloys.

关键词： CO2 laser amorphous alloy Fe73.5 Cu1Nb3Si13.5B9 nanocrystallization

Enzymatic Synthesis of Agmatine by Immobilized Escherichia coli Cells with Arginine Decarboxylase Activity

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Chemical Research in Chinese Universities 2011年第6期27卷 992-995页

作者： ZHANG Wei-guo ZHAO Gen-hai LIU Jun-zhong LIU Qian JIAO qing-cai State Key Laboratory of Pharmaceutical Biotechnology School of Life Science Nanjing University Nanjing 210093 P. R. China

A new method for the enzymatic synthesis of agmatine by immobilized Escherichia coli cells with arginine decarboxylase（ADC） activity was established and a series of optimal reaction conditions was set down. The arginine decarboxylase showed the maximum activity when the pyridoxal phosphate（PLP） concentration was 50 mmol/L, pH=7 and 45 °C. The arginine decarboxylase exhibited the maximum production efficiency when the substrate concentration was 100 mmol/L and the reaction time was 15 h. It was also observed that the appropriate concentration of Mg2＋, especially at 0.5 mmol/L promoted the arginine decarboxylase activity; Mn2＋ had little effect on the arginine decarboxylase activity. The inhibition of Cu2＋ and Zn2＋ to the arginine decarboxylase activity was significant. The immobilized cells were continuously used 6 times and the average conversion rate during the six-time usage was 55.6%. The immobilized cells exhibited favourable operational stability. After optimization, the maximally cumulative amount of agmatine could be up to 20 g/L. In addition, this method can also catalyze D,L-arginine to agmatine, leaving the pure optically D-arginine simultaneously. The method has a very important guiding significance to the enzymatic preparation of agmatine.

关键词： Arginine decarboxylase Agmatine Enzymatic resolution Immobilized cell

A novel ionic liquid based on small size cation

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Chinese Chemical Letters 2009年第1期20卷 62-65页

作者： qing Hai cai Ya Wei Hou Shen Yi Shi Bin Lu Yong Kui Shan Department of Chemistry East China Normal University Shanghai 200062 China Department of Chemustry Harbin Normal University Harbin 150080 China

An ionic liquid material containing small size cation was synthesized and its composition and structure was determined by FT- IR, ^1H NMR, ^13C NMR and element analysis. However, its physical properties such as melting point, viscosity, conductivity, etc. were measured and the results show that the novel ionic liquid is composed of small cation with highly symmetry and larger anion which is very rare among the reported ionic liquid family.

关键词： Ammonium diacetate Ionic liquid Synthesis Characterization

Charge recombination in dye-sensitized nanoporous TiO_(2)solar cell

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Chinese Science Bulletin 2005年第21期50卷 2408-2412页

作者： ZHANG Zhe ZHOU Baoxue GE Weijie XIONG Bitao ZHENG qing cai Weimin School of Environmental Science and Engineering Shanghai .liaotong University Shanghai 200240 China

DSSC has been a subject of intense study throughout the world. The efforts to investigate DSSC are mainly focused on how to increase light absorption, speed electron transport in circuit and reduce charge recombina-tion. In this article, the development of charge recombination in DSSC is discussed, and the investigating techniques, main paths, mechanism and main inhibiting methods of charge recombination in DSSC are also described.

关键词： TiO2 太阳能电池纳米材料多孔渗水性电子转移