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Rare Metals 2013年第4期32卷 338-346页

作者： Yan Xu lian-Xi hu Yu Sun School of Materials Science and Engineering Harbin Institute of Technology School of Mechanical Engineering Beihua University

The deformation behavior and the microstruc-ture evolution of as-cast AZ91D magnesium alloy without pre-homogenization treatment were systematically inves-tigated. The flow stress behavior was studied by com-pression tests in strain rate range of 0.001-1.000 s^-1 and deformation temperature range of 220-380 ℃ with a maximum deformation strain of 60 %. The dependence of flow stress on deformation temperature and strain rate was described by hyperbolic sine constitutive equation. Through regression analysis, the average apparent activa- tion energy and coefficient of strain rate sensitivity were estimated to be 181.98 ***^-1 and 0.14, respectively. The results also reveal that the variation of peak stress depends on strain rate and deformation temperature. Microstructure observation shows that, at temperatures higher than 300 ℃ and strain rates lower than 0.01 s^-1, DRX developed extensively at the grain boundaries and in the core of coarse grains, resulting in a more homogeneous microstructure. Furthermore, the effects of strain, defor-mation temperature, strain rate, and eutectic β phase on the microstructure evolution of as-cast AZ91D magnesium alloy were discussed.

关键词： AZ91D magnesium alloy Isothermalcompression Constitutive equation Peak stress Microstructure evolution

Furazolidone,amoxicillin,bismuth and rabeprazole quadruple rescue therapy for the eradication of Helicobacter pylori

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World Journal of Gastroenterology 2009年第7期15卷 860-864页

作者： Hong Cheng Fu-lian hu Department of Gastroenterology Peking University First Hospital Beijing 100034 China

AIM： To compare the efficacy and side effect profiles of three furazolidone and amoxicillin-based quadruple rescue therapies for the eradication of Helicobacter pylori （H pylonS. METHODS： Patients who failed in the Hpylori eradication therapy for at least one course were randomly allocated into three groups. Group A received rebaprazole 10 mg＋ amoxicillin 1 g ＋ furazolidone 100 mg, and bismuth subcitrate 220 mg, twice daily for 1 wk; group B received the same regimen of group A but for 2 wk; and group C received the same regimen of group B, but furazolidone was replaced by furazolidone 100 mg three times daily. To record the side effect profiles at the end of the treatment, Hpylori eradication was assessed with 13C-urea breath test 4 wk after therapy. RESULTS： Sixty patients were enrolled including 28 males, and 20 patients in each group. The average age of the patients was 49.2 years, ranging from 18 to 84 years. H pylori eradication rates with per-protocol analysis were 82%, 89% and 90% in the three groups, respectively. Side effects were found in 11 patients, including mild dizziness, nausea, diarrhea and increased bowel movement. None of the 11 patients needed treatment for their side effects. CONCLUSION： One- or two-week furazolidone and amoxicillin-based quadruple rescue therapy with a low dose furazolidone （100 mg bid） for the eradication of Hpylori is effective. Extending the antibiotic course to 14 d could improve the eradication rates.

关键词： Helicobacter pylori Rescue therapy Quadruple therapy Furazolidone Low dose

Synthesis and Crystal Structure of a Co(II) Complex with Schiff Base and Imidazole Ligand

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Chinese Journal of Structural Chemistry 2006年第5期25卷 567-571页

作者： WU lian-Bin hu Zi-Qiang LAI Guo-Qiao Key Laboratory of Organosilicon Chemistry and Material Technology of Education Ministry Hangzhou Teachers University Hangzhou 310012 China

The title compound, [Co（C3H4N2）2（C22H18N2O4）]·5H2O （Mr = 659.56）, has been prepared and its crystal structure was determined by X-ray diffraction method. The crystal belongs to monoclinic, space group P21/n, a = 9.6808（2）, b = 26.7204（5）, c = 12.7993（3） A, β = 100.9340（10）°, V= 3250.75（12） A^3, Z = 4, Dc = 1.348 g/cm^3,μ = 0.586 mm^-1, F（000） = 1380, S = 1.131, R = 0.0689 and wR = 0.1883 for 4782 observed reflections （Ⅰ 〉 2σ（Ⅰ））. The title crystal consists of Co（Ⅱ） complex and lattice water molecules. The Co（Ⅱ） complex assumes a distorted octahedral coordination geometry, formed by one Schiff base dianion phenylenediamine-3-methoxysali-cylaldehyde and two imidazole ligands. The π-π stacking interaction occurs between nearly parallel benzene rings of the neighboring complexes.

关键词： cobalt(Ⅱ) complex Schiff base crystal structure π-π stacking

Interaction or relationship between Helicobacter pylori and non-steroidal anti-inflammatory drugs in upper gastrointestinal diseases

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World Journal of Gastroenterology 2006年第24期12卷 3789-3792页

作者： Kai-Yu Ji Fu-lian hu Department of Internal Medicine and Gastroenterology Beijing United Family Hospital Beijing 100016 China Peking University First Hospital Beijing 100034China

According to a meta-analysis, H pylori and non-steroidal anti-inflammatory drugs （NSAID） independently and significantly increase the risk of gastroduodenal ulcer and ulcer bleeding. Their coincidence is frequent, demonstration of a possible relationship and consequent attitude is of important implications. But unfortunately, no consensus has been approved in the past years and their interactions are still controversial. H pylori and NSAID are known to share a number of pathogenic mechanisms, but there is no evidence for the significant synergic action between these two risk factors. Their relationship is independent, additive, synergistic or antagonistic without considering the influence of other factors because studies on this subject are different in almost all aspects of their methodology, including the definition of a NSAID user as well as the types, doses, duration and their indications for NSAID use, as well as their end-points, definition of dyspepsia and regimes used for eradication of H pylori. These might contribute to the conflicting results and opinions. H pylori infection in humans does not act synergistically with NSAID on ulcer healing, and there is no need to eradicate it. This notion is supported by the finding that the eradication of H pylori does not affect NSAID induced gastropathy treated with omeprazole and that H pylori infection induces a strong cyclooxygenase-2 （COX-2） expression resulting in excessive biosynthesis of gastroprotective prostaglandin which in turn counteracts NSAID-induced gastropathy and heals the existing ulcer. Other investigators claimed that H pylori infection acts synergistically with NSAID on ulcer development, and H pylori should be eradicated, particularly at the start of long-term NSAID therapy. Eradication of H pylori prior to NSAID treatment does not appear to accelerate ulcer healing or to prevent recurrent ulcers in NSAID users. However, some recommendations can be drawn from the results of clinical trails.

关键词： Hpylori Aspirin NSAIDs Peptic ulcerdisease Cyclooxygenase-2

Photoelectron Imaging Spectroscopy of ZrO-Diatomic Anion

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Chinese Journal of Chemical Physics 2015年第4期28卷 -页

作者： Qing-yu Liu lian-rui hu hui Chen Sheng-gui He Beijing National Laboratory for Molecular Sciences State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100190China Beijing National Laboratory for Molecular Sciences Key Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

The diatomic ZrO− anion has been prepared by laser ablation and studied by photoelectron imaging spectroscopy combined with quantum chemistry calculations. The observed photoelectron spectra can be well assigned on the basis of reported optical spectroscopy and high-level ab initio calculations. The ground state of ZrO− is a 2Δ state with spin-orbit splitting of 578±12 cm−1. The electron affinity of ZrO is 1.249±0.005 eV. For the first time, the c3∑− state of ZrO has been experimentally observed at 13316±24 cm−1 with respect to the X1∑+ ground state. A comparison between ZrO and the isoelectronic molecule NbN has been made.

关键词： Diatomic molecules Electronic structure Spin-orbit splitting Photoelectron imaging spectroscopy ab initio calculations

Ca-P Conversion Coating on AZ60 Magnesium Alloy for Biomedical Application

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Chemical Research in Chinese Universities 2014年第4期30卷 543-548页

作者： CHENG Zhongji lian Jianshe hu Xiaoli YANG Xiaohong LI Guangyu Key Laboratory of Automobile Materials Ministry of Education College of Materials Science and Engineering Jilin University Changchun 130022 P. R. China

To improve the anti-corrosion behaviors of magnesium alloy in the inner environment of human body,a bioactive Ca-P coating was deposited on the AZ60 magnesium alloy by a novel simple *** morphologies of the Ca-P coatings formed under different treatment time were studied by scanning electron microscopy（SEM）.The corrosion behaviors of Ca-P coating were investigated by electrochemical polarization test and electrochemical impedance spectroscopy in both 3％（mass fraction） NaCl solution and simulated body fluid（SBF）.Immersion test in SBF was performed to evaluate the corrosion rate of Ca-P coated magnesium alloy.X-Ray diffraction（XRD） analysis result shows that the coating mentioned above mainly consists of dicalcium phosphate dehydrate（CaHPO4·2H2O,DCPD） and β-tricalcium phosphate dehydrate[β-TCP,Ca3（PO4）2],which exhibits good corrosion *** magnesium alloy was immersed in 1 mol/L NaOH solution at 80 ℃ for 2 h,hydroxyapatite [Ca10（PO4）6（OH）2,HA]appeared on the magnesium alloy substrate,which can further decrease the corrosion rate of AZ60 magnesium alloy in SBF.

关键词： Ca-P coating Deposited method Magnesium alloy Corrosion rate Simulated body fluid(SBF)

Influence of Strong Electron-Electron Interaction on the Peierls Transition

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Chinese Physics Letters 1997年第1期14卷 63-66页

作者： hu lian K.Y.Szeto SUN Xin Department of Physics South China Normal UniversityGuangzhou 510631 Department of Physics The Hong Kong University of Science and TechnologyHong Kong Department of Physics Fudan UniversityShanghai 200433

The influence of short-ranged Coulomb repulsion of strongly correlated electrons on the Peierls transition for a quasi-one-dimensional system is *** shows that the influence varies with the band filling and proves that the condition of single-occupation leads to a singularity on the density of states at half-filling which enhances *** also shows that dimerization is suppressed by the increase of U in the region of large-U and proves that increasing nearest-neighbor interaction V will suppress the Peierls transition temperature at half-filling,and strongly enhance it for band-filling at n≈1/4,which means the enhancement of tetramer-ization for a quarter-filled band.

关键词： Electron Peierls singularity

Microstructure,wear and friction behavior of CoCrAITaY-xCNTs composite coatings deposited by laser-induction hybrid cladding

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Rare Metals 2024年第4期43卷 1815-1827页

作者： Sheng-Feng Zhou Yu Long Yan-liang Yi Cheng Deng lian-Xi hu Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou510632China Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and TechnologyWuhan430074China MOE Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured MaterialsGuangxi UniversityNanning530004China School of Mechatronics Engineering Guangdong Polytechnic Normal UniversityGuangzhou510635China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

To improve the wear performance of CoCrAlYTa coating,part of the carbon nanotubes(CNTs)chemically reacted with Ta to form reinforcement phase(TaC),while the other CNTs were retained as lubrication ***,the CoCrAlYTa-xCNTs(x=0,1,2,and 4;wt%)composite coatings were prepared by laserinduction hybrid cladding(LIHC),and the microstructure and wear resistance of coatings were systematically *** show that the coatings are mainly composed of TaC,y-(Co,Cr)andβ-(Co,Cr)*** the CNTs content increases from 0 wt%to 4 wt%,the volume fraction of TaC increases from 13.11 vol%to 16.12 vol%.Meanwhile,the nano-hardness ofγ-(Co,Cr)andβ-(Co,Cr)Al are improved from 7.49 and 9.72 to 9.36 and 11.19 GPa,*** a result,the microhardness of coating increases from HV536.25 to HV 738.16,the wear rate decreases from32.4×10^(-3)to 6.1×10^(-3)mg·m^(-1),and the average friction coefficient decreases from 0.55 to *** good wear performance of the coating is attributed to the formation of TaC and the existence of remained CNTs lubricant film.

关键词： Carbon nanotube MCrAlY coating Friction and wear performance Laser-induction hybrid cladding

Thermoelectric properties of Al substituted misfit cobaltite Ca_3(Co_(1-x)Al_x)_4O_9 at low temperature

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International Journal of Minerals,Metallurgy and Materials 2014年第7期21卷 720-725页

作者： Yi Liu Hong-mei Chen Jin-lian hu Xu-bing Tang Hai-jin Li Wei Wang School of Mathematics and Physics Anhui University of Technology Institute of Optoelectronic Information Materials and Technologies Anhui University of Technology School of Materials Science & Engineering Anhui University of Technology

Thermoelectric properties of Al substituted compounds Ca3（Co1-xAlx）4O9 （x=0, 0.03, 0.05）, prepared by a sol-gel process, have been investigated in the temperature range 305-20 K. The results indicate that after Al substitution for Co in Ca3（Co1-xAlx）4O9, the direct current electrical resistivity and thermopower increase due to the reduction of carrier concentration. Experiments show that Al substitution results in decreased lattice thermal conductivity. The figure of merit of temperature behavior suggests that Ca3（Co0.97Al0.03）4O9 would be a promising candidate thermoelectric material for high-temperature thermoelectric application.

关键词： transition metal oxides sol-gel process thermoelectricity electrical properties substitution

Analysis of the track system in bumpy unstructured hard road environment by vibration test

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International Journal of Agricultural and Biological Engineering 2022年第4期15卷 163-171页

作者： Mutong Li Junlue Li Lin He Jie He lian hu Chengxu Lyu Key Laboratory of Modern Agricultural Intelligent Equipment in South China Ministry of Agriculture and Rural AffairsChina/Guangdong Institute of Modern Agricultural EquipmentGuangzhou 510630China College of Engineering South China Agricultural UniversityGuangzhou 510642China Chinese Academy of Agricultural Mechanization Sciences Beijing 100083China

The complex terrain environment in the hilly land directly affects the operational reliability of agricultural *** order to study the impact of road irregularity on walking chassis vibration,the 3CYLZ-750 remote-controlled weeding machine which is applied to orchards was taken as the object of study,and the rear roller was selected as the object of observation to reveal the rules under which the vibration of the track chassis changes as there is a sudden change in road surface elevation.A column-type test-to-pass method based on unit excitation was proposed in this *** excitation behavior and action process were analyzed by category.A critical acceleration prediction model was built and verified by virtual simulation and hard road surface excitation *** results showed that at the forward velocity of 0-2.5 km/h and exciter height of 20-100 mm,the vertical vibration acceleration of the target roller was significantly affected by Track Contact Point Centrifugal Acceleration(TCPCA).As TCPCA increased,the change rate of vertical vibration acceleration decreased,reaching a minimum of[−13.8,28.8];as TCPCA decreased,the vertical vibration acceleration tended to increase positively at a maximum variation range of[−13.3,42.2].The measured and simulated macroscopic change rules were consistent with the theoretical analysis,further verifying the correctness of variable extraction,and providing a research basis for the accurate modification and improvement of the *** research conclusions can lay a theoretical foundation for analyzing the walking reliability of the track chassis,and provide a design basis and technical support for the development of a tracked agricultural robot chassis for the hilly land in the future.

关键词： track system unstructured road vibration test simulation analysis hilly land agricultural robot