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Chinese Chemical Letters 2003年第4期14卷 335-337页

作者： Wei ming XU li ming yu Xian HUANG Department of Chemistry Zhejiang University(Xixi Campus)Hangzhou 310028

Polystyrene-supported benzyl selenide has been prepared. This novel reagent was treated with LDA to produce a selenium stabilized carbanion, which reacted with alkyl halide, followed by selenoxide syn-elimination, to... 详细信息

关键词： Solid phase synthesis polystyrene-supported benzyl selenide substituted olefins.

Highly stable supramolecular hydrogels formed from 1,3,5-benzenetricarboxylic acid and hydroxyl pyridines

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Chinese Chemical Letters 2009年第10期20卷 1259-1262页

作者： li ming Tang yu Jiang Wang Laboratory of Advanced Materials Department of Chemical Engineering Tsinghua University Beijing 100084 China

New supramolecular hydrogels with the maximal sol-gel transition temperature （Tgel） of 95 ℃ were obtained by using gelators formed from 1,3,5-benzenetricarboxylic acid （BTA） and para-hydroxyl pyridine （PHP） or meta-hydroxyl pyridine （MHP）. The single crystal structure of the complex formed from BTA and ortho-hydroxyl pyridine （OHP） indicated that the molecules assembled into superstructure via both hydrogen bonds and π--π stacking interaction.

关键词： Supramolecular hydrogel Gelator Hydrogen bond

Morphology and quantitative analysis of O phase during heat treatment of hot-deformed Ti_2AlNb-based alloy

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International Journal of Minerals,Metallurgy and Materials 2018年第10期25卷 1191-1200页

作者： Hong-yu Zhang Chong li Zong-qing Ma li-ming yu Hui-jun li Yong-chang liu State Key Lab of Hydraulic Engineering Simulation and Safety School of Materials Science & Engineering Tianjin University

A 1040°C-hot-deformed Ti_2AlNb-based alloy solution-treated at 950°C and aged at different temperatures was quantitatively investigated. The microstructure, size of the phase, and microhardness of the deformed alloys were measured. The results indicated that the microstructure of the deformed Ti_2AlNb-based alloy specimens comprise coarse O lath, fine O lath, equiaxed O/α_2, and acicular O phase. More O phase was generated in the deformed alloy after heat treatment because the acicular O phase was more likely to nucleate and grow along the deformation-induced crystal defects such as dislocations and subgrain boundaries. After deformation and subsequent heat treatment, the acicular O phase of the resultant alloy became finer compared to that of the undeformed alloy, and the acicular O phase became coarser and longer with the elevated aging temperature, while the width of the O lath exhibited unobvious variations. The hot deformation facilitated the dissolution of the O lath but accelerated the precipitation of the acicular O phase. When the 950°C-solution-treated deformed Ti_2AlNb-based alloy was then aged at 750°C for different periods, the phase content was nearly invariable, O and B2 phases eventually reached equilibrium, and the microstructure became stable and homogeneous.

关键词： Ti2AlNb-based alloys hot deformation solution treatment aging microstructure

EFFECT OF DRILLPIPE ROTATION ON BOREHOLE CLEANING FOR EXTENDED REACH WELL

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Journal of Hydrodynamics 2009年第3期21卷 366-372页

作者： WANG Zhi-ming GUO Xiao-le li ming HONG yu-kui College of Oil and Gas Engineering China University of Petroleum Beijing 102249 China

Wellbore cleaning is a key technology for the Extended Reach Drilling （ERD）. The success of drilling extended reach wells depends directly upon the quality of wellbore cleaning. The rotation of the drillpipe, and hydraulic and rheological parameters, are the key factors for wellbore cleaning. In this study, Computational Fluid Dynamics （CFD） is applied to simulate solid-liquid two-phase flows in wellbore annulus. The annual flow field with the presence of drillpipe rotation is described through analyzing various rotation conditions. The results indicate that the quasi-spiral flow is the main flow pattern for liquid-solid transport in the horizontal annulus. The influence of rotation on the cuttings transport is also investigated, as the rotation of drillpipe increases the disturbance of liquid to solid in annulus. As a result, the solid flow becomes favorable and the solid volume is reduced. Comparisons with previously published results are also performed to prove the importance of drillpipe rotation in the wellbore clearing for the ERD.

关键词： Extended Reach Drilling (ERD) borehole cleaning solid-liquid two-phase flow drillpipe rotation simulation spiral flow

Assembling and releasing performance of supramolecular hydrogels formed from simple drug molecule as the hydrogelator

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Chinese Chemical Letters 2007年第8期18卷 1009-1012页

作者： yu Jiang Wang liang Yan li ming Tang Jian yu Laboratory of Advanced Materials Department of Chemical Engineering Tsinghua University Beijing 100084 China

A simple drug compound, 4-oxo-4-（2-pyridinylamino） butanoic acid （defined as AP）, was able to gel water at 4 wt% concentration under various conditions. In the superstructure, AP molecules assembled into fibrous aggregates driving by hydrogen bonds and π-π stacking interaction. The gels with different backbone structures released drug molecules in different speeds.

关键词： Supramolecular hydrogel Hydrogelator Releasing

Hot deformation behaviors of a 9Cr oxide dispersion-strengthened steel and its microstructure characterization

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International Journal of Minerals,Metallurgy and Materials 2019年第5期26卷 597-610页

作者： yu Shao li-ming yu Yong-chang liu Zong-qing Ma Hui-jun li Jie-feng Wu State Key Lab of Hydraulic Engineering Simulation and Safety Tianjin Key Lab of Composite and Functional Materials Tianjin University Institute of Plasma Physics Chinese Academy of Sciences

The hot deformation behaviors of a 9 Cr oxide dispersion-strengthened(9 Cr-ODS) steel fabricated by mechanical alloying and hot isostatic pressing(HIP) were investigated. Hot compression deformation experiments were conducted on a Gleeble 3500 simulator in a temperature range of 950–1100°C and strain rate range of 0.001–1 s^(-1). The constitutive equation that can accurately describe the relationship between the rheological stress and the strain rate of the 9 Cr-ODS steel was established, and the deformation activation energy was calculated as 780.817 kJ/mol according to the data obtained. The processing maps of 9 Cr-ODS in the strain range of 0.1–0.6 were also developed. The results show that the region with high power dissipation efficiency corresponds to a completely recrystallized structure. The optimal processing conditions were determined as a temperature range of 1000–1050°C with strain rate between 0.003 and 0.01 s^(-1).

关键词： hot deformation constitutive equations processing maps microstructural evolution

Phycocyanobilin accelerates liver regeneration and reduces mortality rate in carbon tetrachloride-induced liver injury mice

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World Journal of Gastroenterology 2015年第18期21卷 5465-5472页

作者： Jie liu Qing-yu Zhang li-ming yu Bin liu ming-Yi li Run-Zhi Zhu Department of Hepatobiliary Surgery Affiliated Hospital of Guangdong Medical College Department of Maxillofacial Surgery Affiliated Hospital of Guangdong Medical College

AIM: To investigate the hepatoprotective effects of phycocyanobilin(PCB) in reducing hepatic injury and accelerating hepatocyte proliferation following carbon tetrachloride(CCl4) ***: C57BL/6 mice were orally administered PCB 100 mg/kg for 4 d after CCl4 injection, and then the serum and liver tissue of the mice were collected at days 1, 2, 3, 5 and 7 after CCl4 treatment. A series of evaluations were performed to identify the curative effects on liver injury and recovery. Aspartate aminotransferase(AST), alanine aminotransferase(ALT), albumin and superoxide dismutase(SOD) were detected to indirectly assess the anti-inflammatory effects of PCB. Meanwhile, we detected the expressions of hepatocyte growth factor, transforming growth factor alpha(TGF-α), TGF-β, tumor necrosis factor-alpha(TNF-α) and interleukin-6(IL-6), the factors which are associated with inflammation and liver regeneration. The protein expressions of proliferating cell nuclear antigen(PCNA), TNF-α and cytochrome C were detected by western blot. Furthermore, the survivalrates were analyzed of mice which were administered a lethal dose of CCl4(2.6 mg/kg)with or without ***:In our research,PCB showed a strongly anti-inflammatory effect on CCl4-induced liver injury in *** ALT was significantly decreased after CCl4 treatment from day 1(Pliver SOD were increased from day2(P0.05).PCB protected the structure of liver from the injury by *** assay showed that PCB dramatically reduced the number of apoptotic cells after CCl4 treatment compared to the control(101.0±25.4 vs 25.7±6.4,Pliver failure(ALF)mice which were injecte

关键词： liver injury Hepatoprotective Tumor necrosis factor-alpha Phycocyanobilin Cytochrome C

Effect of microstructure variation on the corrosion behavior of high-strength low-alloy steel in 3.5wt% NaCl solution

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International Journal of Minerals,Metallurgy and Materials 2015年第6期22卷 604-612页

作者： yu-bing Guo Chong li Yong-chang liu li-ming yu Zong-qing Ma Chen-xi liu Hui-jun li State Key Laboratory of Hydraulic Engineering Simulation and Safety School of Materials Science and EngineeringTianjin University

The effect of microstructure variation on the corrosion behavior of high-strength low-alloy（HSLA） steel was investigated. The protective property of the corrosion product layer was also explored. Experimental results reveal that the type of microstructure has significant effect on the corrosion resistance of HSLA steel. The measurement results of weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy indicate that the steel with acicular ferrite microstructure exhibits the lowest corrosion rate. Martensite exhibits a reduced corrosion resistance compared with polygonal ferrite. It is found that the surface of the acicular ferrite specimen uniformly covered by corrosion products is seemingly denser and more compact than those of the other two microstructures, and can provide some amount of protection to the steel; thus, the charge transfer resistance and modulus values of the acicular ferrite specimen are the largest. However, corrosion products on martensite and polygonal ferrite are generally loose, porous, and defective, and can provide minor protectiveness; thus, the charge transfer resistance values for polygonal ferrite and martensite are lower.

关键词： high-strength low-alloy steel microstructure corrosion sodium chloride solutions

Magnesium based degradable biomaterials： A review

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Frontiers of Materials Science 2014年第3期8卷 200-218页

作者： Xue-Nan GU Shuang-Shuang li Xiao-ming li yu-Bo FAN Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education School of Biological Science and Medical Engineering Beihang University Beijing 100191 China

Magnesium has been suggested as a revolutionary biodegradable metal for biomedical applications. The corrosion of magnesium, however, is too rapid to match the rates of tissue healing and, additionally, exhibits the localized corrosion mechanism. Thus it is necessary to control the corrosion behaviors of magnesium for their practical use. This paper comprehensively reviews the research progress on the development of representative magnesium based alloys, including Mg-Ca, Mg-Sr, Mg-Zn and Mg-REE alloy systems as well as the bulk metallic glass. The influence of alloying element on their microstructures, mechanical properties and corrosion behaviors is summarized. The mechanical and corrosion properties of wrought magnesium alloys are also discussed in comparison with those of cast alloys. Furthermore, this review also covers research carried out in the field of the degradable coatings on magnesium alloys for biomedical applications. Calcium phosphate and biodegradable polymer coatings are discussed based on different preparation techniques used. We also compare the effect of different coatings on the corrosion behaviors of magnesium alloys substrate.

关键词： magnesium alloy degradable biomaterial coating degradation corrosion

Effect of cold rolling and first precipitates on the coarsening behavior of γ″-phases in Inconel 718 alloy

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International Journal of Minerals,Metallurgy and Materials 2016年第9期23卷 1087-1096页

作者： Jing-ling Zhang Qian-ying Guo Yong-chang liu Chong li li-ming yu Hui-jun li State Key Lab of Hydraulic Engineering Simulation and Safety School of Materials Science & Engineering Tianjin University

The coarsening behaviors of γ″-phase particles in Inconel 718 alloy aged at 750, 800, and 850℃ were investigated by scanning electron microscopy（SEM）. Detailed observations and quantitative measurements were conducted to characterize the coarsening behavior of the γ″-phase under various aging conditions. The experimental results indicate that the existence of the δ-phase retards the formation and coarsening of the γ″-phase, without influencing its final particle size or amount. Moreover, when cold rolled with a reduction of 50%, the dimensions of the γ″ particles in Inconel 718 alloy decrease with increasing aging time. Furthermore, the coarsening behavior of the γ″-phase in the Inconel 718 alloy after a normal aging treatment（sample A） and that of the primary δ-phase（sample B） follow the lifshitz–Slyozov–Wagner（LSW） diffusion-controlled growth theory; the thus-obtained activation energies for the γ″-phase are 292 k J·mol^-1 and 302 k J·mol^-1, respectively.

关键词： nickel base superalloys cold rolling precipitates coarsening