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Journal of Iron and Steel Research International 2020年第11期27卷 1294-1302页

作者： Xiang Wang Ren-guo Guan yuan-dong li Ti-jun Chen State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050GansuChina School of Materials Science and Engineering Northeastern UniversityShenyang 110819LiaoningChina

A hypereutectic Al-3Fe(wt.%)alloy was subjected by rheo-extrusion,and the effect of sub-rapid cooling and shear deformation on the refinement of Fe-rich phase was *** results showed that both the primary Fe-rich phase and eutectic Fe-rich phase in the solidified Al-Fe alloy were finer than the platelike Fe-rich phase in the as-cast Al-Fe alloy with the same content of *** solidified Al-Fe alloy was subjected to three stages of shear deformation,and both the primary Fe-rich phase and eutectic Fe-rich phase were fractured and the average length was refined to 400 nm,while Fe-rich phase in the as-cast Al-3Fe(wt.%)alloy was platelike and its average length was 40 *** tensile strength and elongation of the hypereutectic Al-3Fe(wt.%)alloy containing nanosized Fe-rich phase were 162 MPa and 25.78%while those of the as-cast AI-3Fe(wt.%)alloy containing coarse platelike Fe-rich phase were 102 MPa and 16.84%,*** the refineme nt of Fe-rich phase in hypereutectic Al-Fe alloy during rheo-extrusion,the three stages of shear deformation contributed more than sub-rapid cooling.

关键词： Fe-rich phase Hypereutectic Al-Fe alloy Refinement Sub-rapid cooling Shear deformation

A New Stilbene from Cercis chinensis Bunge

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Journal of Integrative Plant Biology 2005年第8期47卷 1021-1024页

作者： yuan li dong-Ming ZHANG Shi-Shan YU Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100050 China

To study new natural products, we used ODS （YMC, Kyoto, Japan） and silica gel column chromatography to separate compounds in Cercis chinensis Bunge （Leguminosae）. A new stilbene, trans- 3, 5, 3＇, 4＇-tetrahydroxy-4-methylstilbene （1）, along with 10 known compounds, namely piceatannol （2）, dihydromyricetin （3）, catechin （4）, dihydrorobinetin （5）, menisdaurin （6）, lithospermoside （7）, teatannin （8）, dasycarponin （9）, β-sitosterol （10）, and daucosterin （11）, was isolated from C. chinensis. Their structures were elucidated on the basis of spectroscopic evidence. Compounds 2-6 and 9 were isolated from the genus Cercis linn. for the first time.

关键词： Cercis chinensis Leguminosae trans-3, 5, 3', 4'-tetrahydroxy-4-methylstilbene.

STUDY OF DYE-SENSITIZED SYSTEMS FOR PHOTOIMAGING

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Chinese Journal of Polymer Science 2001年第1期19卷 79-83页

作者： Fang Gao Chun-ying Zhao Yong-yuan Yang li-dong li Insatute of Photographic Chemistry Chinese Academy of Sciences Beijing 100101 China Insatute of Photographic Chemistry Chinese Academy of Sciences Beijing 100101 China Insatute of Photographic Chemistry Chinese Academy of Sciences Beijing 100101 China Insatute of Photographic Chemistry Chinese Academy of Sciences Beijing 100101 China

o-Chloro-hexaarylbiimidazole (o-CI-HABI) can be sensitized efficiently by cyanine dyes, the cyclopentanone and cyclohexanone dyes, when exposed to xenon lamp (use filter cut lambda less than or equal to 400 nm). The photoreaction between the photoinitiator and the dyes was completed through an electron transfer process. Excellent results have been obtained in photoimaging studies, e.g. the resolution of the image can reach 7 mum. The influence of the content of the dyes and the heat after the exposure on the resolution of the image was investigated.

关键词： photopolymer photoimaging hexaarylbiimidazole printing plate

Microstructural evolution and age-hardening behavior of quasicrystal-reinforced Mg-Dy-Zn alloy

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Rare Metals 2019年第8期38卷 739-745页

作者： Guang-li Bi Yu-Xiang Han Jing Jiang Chun-Hong Jiang yuan-dong li Ying Ma State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of Technology Lanzhou 730050 China Key Laboratory of Nonferrous Metal Alloys and Processing Ministry of Education Lanzhou University of Technology Lanzhou 730050 China Lanshi Foundry Co. Ltd. Lanzhou 730050 China

Microstructural evolution and age-hardening behavior of Mg-2 Dy-6 Zn(at%)alloy during solid-solution and aging treatment were *** microstructure of as-cast alloy is composed of a-Mg,Mg3 DyZn6(Ⅰ)phase,Mg3 Dy2 Zn3(W)phase,Mg(Zn,Dy)phase and a small amount of Mg0.97Zn0.03 *** solid-solution treatment(480℃,12 h),all the I phases and most W phases dissolve into a-Mg matrix and the remainder W phases transform into Mg(Dy,Zn)phase and MgDy3 *** aging treatment,I phase and small amounts of W phases co-precipitate from α-Mg matrix,*** alloy exhibits a peak hardness of HV 77.5 at 200 ℃ for 8 *** excellent age-hardening behavior of alloy is mainly attributed to the co-precipitation strengthening of I and W phases.

关键词： Mg-Dy-Zn alloy Microstructure I phase Age-hardening behavior

Solidification behavior and rheo-diecasting microstructure of A356 aluminum alloy prepared by self-inoculation method

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China Foundry 2017年第1期14卷 1-9页

作者： Ming li yuan-dong li Xiao-feng Huang Chi Cao Ying Ma State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050China Key Laboratory of Non-ferrous Metal Alloys and Processing Ministry of EducationLanzhou University of TechnologyLanzhou 730050China

Semisolid slurry of A356 aluminum alloy was prepared by self-inoculation method, and the microstructure and solidification behavior during rheo-diecasting process were investigated. The results indicate that the semisolid slurry of A356 aluminum alloy can be prepared by self-inoculation method at 600℃. Primary a-AI particles with fine and spherical morphologies are uniformly distributed when the isothermal holding time of slurry is 3 min. liquid phase segregation occurs during rheo-diecasting process of semisolid slurry and the primary particles （α1） show obvious plastic deformation in the area of high stress and low cooling rate. A small amount of dendrites resulting from the relatively low temperature of the shot chamber at the initial stage of secondary solidification are fragmented as they pass through the in-gate during the mould filling process. The amount of dendrite fragments decreases with the increase of filling distance. During the solidification process of the remaining liquid, the nucleation rate of secondary particles （α2） increases with the increase of cooling rate, and the content of Si in secondary particles （α2） are larger than primary particles （α1）. With the increase of cooling rate, the content of Si in secondary particles （α2） gradually increases. The morphologies of eutectic Si in different parts of die casting are noticeably different. The low cooling rate in the first filling positions leads to coarse eutectic structures, while the high cooling rate in the post filling positions promotes small and compact eutectic structures.

关键词： semisolid self-inoculation method secondary solidification dendrite fragments primary particles eutectic structure

Effects of Cu addition on microstructureand mechanical properties of as-cast Mg-6Znmagnesium alloy

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China Foundry 2017年第4期14卷 251-257页

作者： Yu Zhang Xiao-feng Huang Ying Ma Ti-jun Chen yuan-dong li yuan Hao State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050China

The application of Mg-Zn binary alloys is restricted due to their developed dendritic microstructure and poor mechanical properties. In this study, an alloying method was used to improve the mechanical properties of Mg-Zn alloy. The Mg-6Zn magnesium alloys microalloyed with varying Cu content(0, 0.8, 1.5, 2.0 and 2.5wt.%) were fabricated by permanent mould casting, and the effects of Cu content on the microstructure and mechanical properties of as-cast Mg-6Zn alloys were studied using OM, SEM, XRD and tensile tests at room temperature. The obtained results show that the addition of Cu not only can refine the grains effectively, but also can modify the eutectic morphology and improve the mechanical properties of the alloys. The main phases of the studied alloys include α-Mg, MgZn_2, Mg_2Cu and CuMgZn. When the content of Cu exceeds 0.8wt.%, Mg_2Cu phase appears. Meanwhile, the eutectic morphology is modified into dendritic shape or lamellar structure, which has an adverse effect on the tensile properties. Furthermore, among the investigated alloys, the alloy containing 0.8% Cu shows an optimalultimate tensile strength of 196 MPa, while the alloy with 1.5wt.% Cu obtains an excellent elongation of 7.22%. The experimental alloys under different Cu contents show distinguishing fracture behaviors: the fracture of the alloy with 0.8wt.% Cu reveals a mixed mode of inter-granular and quasi-cleavage, while in other investigated alloys, the fracture behaviors are dominated by cleavage fracture.

关键词： Mg-Zn magnesium alloy Cu addition microstructure mechanical property fracture mode

Validation concurrency control protocol in parallel real-time database systems

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Journal of Central South University of Technology 2002年第3期9卷 197-201页

作者： LEI Xiang-dong(雷向东) yuan Xiao-li(袁晓莉) College of Information Science and Engineering Central South University Changsha 410083 China College of Information Science and Engineering Central South University Changsha 410083 China

In parallel real-time database systems, concurrency control protocols must satisfy time constraints as well as the integrity constraints. The authors present a validation concurrency control(VCC) protocol, which can enhance the performance of real-time concurrency control mechanism by reducing the number of transactions that might miss their deadlines, and compare the performance of validation concurrency control protocol with that of HP2PL(High priority two phase locking) protocol and OCC-TI-WAIT-50(Optimistic concurrency control-time interval-wait-50) protocol under shared-disk architecture by simulation. The simulation results reveal that the protocol the author presented can effectively reduce the number of transactions restarting which might miss their deadlines and performs better than HP2PL and OCC-TI-WAIT-50. It works well when arrival rate of transaction is lesser than threshold. However, due to resource contention the percentage of missing deadline increases sharply when arrival rate is greater than the threshold.

关键词： parallel database system real-time database concurrency control validation transactions

Microstructural evaluation and mechanical properties of 7075 aluminum alloy prepared by controlled diffusion solidification

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China Foundry 2019年第4期16卷 238-247页

作者： Xiong Yang yuan-dong li Xiao-mei Luo Hong-wei Zhou Qi-yong Cai Ming li Ying Ma State Key Laboratory ofAdvanced Processing and Recycling of Non-ferrous Metals Lanzhou University of Technology Lanzhou 730050 China Key Lab of Non-ferrous Metal Alloys and Processing Ministry of Education Lanzhou University of Technology L anzhou 730050 China

In the present work, 7075 aluminum alloy(Al-Zn-Mg-Cu) was produced by both conventional casting(CC) and controlled diffusion solidification(CDS) methods. Each sample was subjected to different heat-treatment conditions: as-cast, T4, and T6;and their microstructural and mechanical properties were investigated by optical microscopy(OM), scanning electron microscopy(SEM) and X-ray diffractometry(XRD). It was found that CDS promoted the formation of non-dendritic primary α-Al phase and reduced shrinkage porosity, thus resulting in improved mechanical properties. In addition, the eutectic phase of the CDS samples mainly consisted of T(Al-ZnMg-Cu) phase, which manifested a well-developed lamellar eutectic structure. However, in the CC samples, the T(Al-Zn-Mg-Cu) phase was composed of rod-like eutectics. Moreover, the θ(Al2 Cu) eutectic contents in the CC samples were greater than those in the CDS samples. Each element in the CC samples had an obvious change in the grain boundary, whereas the change in element content in the CDS samples was gradual. Therefore, the non-dendritic morphology of the primary phase and the presence of rod-like eutectics in the matrix of the CDS samples led to enhanced tensile strength and elongation under different heat treatment conditions.

关键词： primary α-Al phase eutectic phase solute atoms tensile strength elongation

Preparation of Tolterodine Metabolite Loaded Biodegradable PLGA Microspheres

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Chemical Research in Chinese Universities 2010年第1期26卷 75-80页

作者： TENG Le-sheng JIANG Chao-jun liN Xiang-you dong yuan-chen li Chun-mei MENG Qing-fan li You-xin College of life Science Jilin University Changehun 130012 P. R. China

Biodegradable polymer poly（lactic-co-glycolic acid）（PLGA） was used to encapsulate the pharmacological activity metabolite of tolterodine by means of O/W emulsion solvent evaporation method via homogenization in the emulsification process. The influences of preparation parameters were investigated. The results indicate that increa- sing PLGA concentration from 15% to 40% made the encapsulation efficiency of 5-hydroxymethyl derivative of tol- terodine（5-HMT） increased from 55.39% to 76.32%, and the particle size increased from 34.33 μm to 70,78 lain. In addition, when homogenization speed increased from 850 r/min to 2300 r/min, both particle size and encapsulation efficiency of microspheres decreased. An increase in the volume of aqueous phase led to higher encapsulation efficiency and bigger particle size. Increasing temperature made encapsulation efficiency and particle size change significantly. While reaction temperature increased from 20 ℃ to 50 ℃, the encapsulation efficiency decreased from 70.44% to 24.07%, and particle size increased from 38.66 μm to 69.38 μm. High reaction temperature（over 40 ℃） may lead to porous surface of microspheres. Porous surface, encapsulation efficiency and particle size influenced on the in vitro release of 5-HMT together.

关键词： Poly(lactic-co-glycolic acid) Microsphere Tolterodine Tolterodine metabolite

Application of Ground Phosphate Rock to Dimmish the Effects of Simulated Acid Rain on Soil Properties

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Pedosphere 1992年第2期2卷 147-152页

作者： dong yuan-VAN and li XUE-yuan Huazhong Agricultural University. Wuhan 430070 ( China)

The effects of simulated acid rain retained in soil on the properties of acid soil and its diminishing by application of ground phosphate rock were investigated by using the sorption method. Results show as follows: (1) For yellow brown soil, the effect of simulated acid rain on the properties of soil with a pH value of 5.9 was relatively small, except a great quantity of acid rain deposited on it. (2) For red soil, the effect of simulated acid rain on the properties of soil was significant. With the increase of the amount of acid deposition, the pH value of soil was declined, but the contents of exchangeable H+, Al3+ and Mn2+ and the amount of SO42- retention were increased. (3) Many properties of acid soils could be improved by applying ground phosphate rock. For example, pH value of soils and the amounts of available P and exchangeable Ca2+ and Mg2+ were increased, and the amounts of exchangeable H+ and Al3+ and SO42- retained was reduced. The application of ground posphate rock could effctively dimmish the pollution of acid rain to soil.

关键词： phosphate rock simulated acid rain soil properties