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Tensile behavior of Ti-6Al-4V alloy fabricated by selective laser melting: effects of microstructures and as-built surface quality

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China Foundry 2018年第4期15卷 243-252页

作者： pan tao huai-xue li bai-ying huang quan-dong hu shui-li gong qing-yan xu Key Laboratory for Advanced Materials Processing Technology（MOE） School of Materials Science and EngineeringTsinghua UniversityBei/ing 100084China Science and Technology on Power Beam Processes Laboratory AVIC MamoCacturing Technology InstituteBei/ing 100024China Key Laboratory of Aeronautical Technology on additive manufacturing A VIC Manufacturing Technology InstituteBeijing 100024China

Selective laser melting （SLM） is a powerful additive manufacturing （AM） technology, of which the most prominent advantage is the ability to produce components with a complex geometry. The service performances of the SLM-processed components depend on the microstructure and surface quality. In this work, the microstructures, mechanical properties, and fracture behaviors of SLM-processed Ti-6AI-4V alloy under machined and as-built surfaces after annealing treatments and hot isostatic pressing （HIP） were investigated. The microstructures were analyzed by optical microscope （OM）, scanning electron microscope （SEM） and transmission electron microscopy （TEM）. The mechanical properties were measured by tensile testing at room temperature. The results indicate that the as-deposited microstructures are characterized by columnar grains and fine brittle martensite and the as- deposited properties present high strength, low ductility and obvious anisotropy. After annealing at 800-900~C for 2-4 h and HIP at 920~C/100MPa for 2 h, the brittle martensite could be transformed into ductile lamellar （a＋~） microstructure and the static tensile properties of SLM-processed Ti-6AI-4V alloys in the machined condition could be comparable to that of wrought materials. Even after HIP treatment, the as-built surfaces could decrease the ductility and reduction of area of SLM-processed fi-6AI-4V alloys to 9.2% and 20%, respectively. The crack initiation could occur at the columnar grain boundaries or at the as-built surfaces. The lamellar （a＋13） microstructures and columnar grains could hinder or distort the crack propagation path during tensile tests.

关键词： selective laser melting Ti-6Al-4V microstructure mechanical properties fracture surface quality

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Asymmetric Reduction of Aromatic Ketones Catalyzed by Using (αs,4s)-2-Dichloromethyl-4,5-Dihydro-α-(4-Nitrophenyl)-4- Oxazolemethanol-Borane Complex

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Wuhan University Journal of Natural Sciences 2002年第1期7卷 113-116页

作者： Shi Yu, hu quan-yuan, Yang Shao-rong, hu Xian-ming College of Pharmacy, Wuhan University, Wuhan 430072, hubei, China College of Pharmacy Wuhan University Wuhan Hubei China

Chiral oxazoborolidine borane complex was prepared from (αs, 4s)-2-dichloromethyl-4, 5-dihydro-α-(4-nitrophenyl)-4-oxazolemethanol with Borane in THF. The borane modified by chiral oxazoborolidine enantioselectively reduced aromatic ketones to second-alcohol with about 95%yield and medium optical yields. In the end of article, results are discussed and reduction mechanism is shown which proves the resulting major isomers fit very well.

关键词： asymmetric reduction prochiral ketones chiral oxazoborolidine borane chloramphenicol oxazoline

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A mathematical diffusion model of carbon isotopic reversals inside ultra-tight Longmaxi shale matrixes

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Petroleum Science 2022年第5期19卷 2014-2026页

作者： Bao-Jian Shen Zhi-Liang He Cheng Tao Jin-Cai Shen Zong-quan hu Zhi-Ming Li Yuan-Hao Cao Wei Chen State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development SINOPECBeijing100083China Wuxi Petroleum Geology Institute SINOPEC Petroleum Exploration and Production Research InstituteWuxiJiangsu 214126China China Petroleum&Chemical Corporation Beijing100728China Chongqing Fuling Shale Gas Exploration and Development Co. Ltd.SINOPECChongqing408014China Petroleum Exploration and Production Research Institute SINOPECBeijing100083China School of Energy Soochow UniversitySuzhouJiangsu 215006China

Developing mathematical models for high Knudsen number(Kn)flow for isotopic gas fractionation in tight sedimentary rocks is still *** this study,carbon isotopic reversals(δ^(13)C_(1)>δ^(13)C_(2))were found for four Longmaxi shale samples based on gas degassing *** in shale with higher gas content exhibits larger ***,a mathematical model was developed to simulate the carbon isotopic reversals of methane and *** model is based on these hypotheses:(i)diffusion flow is dominating during gas transport process;(ii)diffusion coefficients are nonlinear depending on concentration *** model not only shows a good agreement with isotopic reversals,but also well predicts gas production rates by selecting appropriate exponents m and m^(*) of gas pressure gradient,where m is for ^(12)C and m^(*)is for ^(13)***,the(m−m^(*))value has a positive correlation with fractionation level.(m1−m1^(*))of methane are much higher than that of ***,the predicted carbon isotopic reversal magnitude(δ^(13)C_(1)−δ^(13)C_(2))exhibits a positive relationship with total gas content since gas in shale with higher gas content experiences a more extensive high Kn number diffusion *** a result,our model demonstrates an impressive agreement with the experimental carbon isotopic reversal data.

关键词： Diffusion Isotopic fractionation Carbon isotopic reversal Modeling

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Direct synthesis of imines by 9-azabicyclo-[3,3,1]nonan-N-oxyl/KOH-catalyzed aerobic oxidative coupling of alcohols and amines

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Chinese Chemical Letters 2018年第8期29卷 1269-1272页

作者： Yan Wan Jia-Qi Ma Chao Hong Mei-Chao Li Li-Qun Jin Xin-quan hu Bao-Xiang hu Wei-Min Mo Nan Sun Zhen-Lu Shen College of Chemical Engineering Zhejiang University of Technology

A simple and efficient method for preparation of imines by the oxidative coupling of benzyl alcohols with aromatic amines or aliphatic amines was developed. The reaction was catalyzed by 9-azabicyclo[3.3.1]nonan-N-oxyl（ABNO）/KOH with air as the economic and green oxidant. Under the optimal reaction conditions, a variety of imines were obtained in 80%-96% isolated yields.

关键词： Imines Benzyl alcohols Amines ABNO Air

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Structure and properties of Tb_(0.3)Dy_(0.7)Fe_(2) alloys modified by surface nitriding

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Rare Metals 2021年第5期40卷 1198-1202页

作者： Hong-Chuan Yang Shi-Rong Zhang Dun-Bo Yu Kuo-She Li Yuan-Fei Yang quan-Xia hu Yang Luo Hong-Wei Li National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous MetalsBeijing 100088China Grirem Advanced Materials Co. Ltd.Beijing 100088China

The surface of Tb_(0.3)Dy_(0.7)Fe_(2) alloys was modified by microwave electron-cyclotron-resonance chemical vapor deposition(MW-ECR-CVD)and ion implantation technology,*** microstructure and corrosion resistance of nitrided layers were investigated by means of optical microscope(OM),X-ray diffractomer(XRD),auger electron spectroscopy(AES),and electrochemical *** modified by MW-ECR-CVD,the nitrogen concentration of the nitrided layers decreases gradually with the depth increasing,while the nitrogen concentration modified by ion implantation process exhibits Gaussian *** self-corrosion electric potential of the sample modified by ion implantation is higher than that modified by MW-ECR-CVD,which reveals that the samples modified by ion implantation process have a better resistance to *** magnetostrictions are assessed for the samples placed in the air for one year,which further confirms that the ion implantation process is more helpful to maintain the magnetostrictions.

关键词： Magnetostriction Nitriding Corrosion resistance Ion implantation Microwave electron-cyclotron-resonance chemical vapor deposition

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Robotic-assisted Laparoscopic Nephrectomy with Vein Thrombectomy:Initial Experience and Outcomes from a Single Surgeon

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Current Medical Science 2018年第5期38卷 834-839页

作者： Xin-wen KE Xing ZENG Xian WEI Yuan-qing SHEN Jia-hua GAN Ji-hua TIAN Zhi-quan hu Department of Urology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuha430030China Department of Urology the Central Hospital of WuhanWuhan 430014China

This study was designed to explore the safety and feasibility of robotic-assisted laparoscopic nephrectomy with vein thrombectomy (RAL-NVT) for the treatment of renal cell carcinoma (RCC)with venous tumor thrombus (VTT).Clinical data of 6 patients treated with RAL-NVT between July 2016 and November 2017 in our hospital were retrospectively collected and *** were 5 males and 1 female with their age ranging from 48 years to 68 *** renal tumors were right-sided and one left-sided. Three cases fell in level 0 VTT,one in level I and two in level Ⅱ.preoperative imaging revealed lymph node involvement in 1 case and distant metastasis in 2 *** RCC with level 0 VTT,the renal vein of the affected side was adequately and carefully dissected around the thrombus to the proximity of inferior vena cava (IVC)and was ligated with Hem-o-loks without cross-clamping the *** level Ⅰ and Ⅱ VTT,the IVC was cross-clamped cephalically and caudally around the tumor thrombus and all tributaries were sequentially blocked to ensure the safe retrieval of *** operations were successfully completed without conversion to open *** mean operative time was 150(115-230)***-clamping of the IVC happened in 3 cases,and the blocking time was 14, 19 and 20min,*** mean estimated blood loss during the operation was 400 (200-580)*** peritoneal drainage tube was removed 5 to 9 days after the operation, and all patients were postoperatively discharged at 6 to 11 *** pathological analysis confirmed that the RCCs were comprised of 4 clear cell RCCs,1 papillary cell RCC,and 1 medullary cell RCC;2 cases were Fuhrman grade Ⅱ,3 cases grade Ⅲ,and 1 case undefined *** recurrence or progression was observed during the follow-up of 4.2(3-6)*** concluded that RAL-NVT is highly challenging but safe and feasible for the treatment of RCC with VTT.

关键词： robotics laparoscopy renal cell carcinoma venous tumor thrombus thrombectomy

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Simulation Research of Transient Over-voltage on High-voltage Shunt Capacitor Banks

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高压电器 2011年第9期47卷 37-43页

作者： hu quan-wei ZHOU Xing-xing SI Wen-rong ZHANG Yang LI Jun-hao LI Yan-ming Power Equipment State Key Laboratory of Electrical Insulation Xi'an Jiaotong University Xi'an 710049 China Electric Power Research Institute of East China Shanghai 200437 China Yichang Power Supply Company Yichang 443000 China

With the development of power systems,a large number of shunt capacitors are used to improve power quality in the distribution *** shunt capacitor banks are operated much frequently,as a result,the capacitor banks will bear large numbers of over-voltage *** the over-voltage exceeds certain amplitude,the capacitor will be *** paper aims at the capacitor banks in the 35 kV side of Shanghai Xu-xing 500 kV substation,and applies ATP-EMTP to simulate the over-voltages generated by operating the switches under different angles of the ***,according to the results of simulation and theoretical analysis,a best choice(*** of the source) to switch on capacitor banks is *** this case the over-voltage on the capacitor will be limited to lowest.

关键词： capacitor banks operating over-voltage EMTP simulation

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N6-methyladenosine modification of hypoxia-inducible factor-1α regulates Helicobacter pylori-associated gastric cancer via the PI3K/AKT pathway

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WORLD JOURNAL OF GASTROINTESTINAL ONCOLOGY 2024年第7期16卷 3270-3283页

作者： An, Tong-Yan hu, quan-Man Ni, Peng hua, Yan-Qiao Wang, Di Duan, Guang-Cai Chen, Shuai-Yin Jia, Bin Zhengzhou Univ Coll Publ Hlth Dept Epidemiol 100 Kexue Rd Zhengzhou 450001 Henan Province Peoples R China Zhengzhou Univ Dept Oncol Affiliated Hosp 1 Zhengzhou 450052 Henan Province Peoples R China

BACKGROUND Helicobacter pylori (H. pylori) colonizes the human gastric mucosa and is implicated in the development of gastric cancer (GC). The tumor microenvironment is characterized by hypoxia, where hypoxia-inducible factor-1 alpha (HIF-1 alpha) plays a key role as a transcription factor, but the mechanisms underlying H. pylori-induced HIF-1 alpha expression and carcinogenesis remain unclear. AIM To explore the underlying mechanism of H. pylori-induced HIF-1 alpha expression in promoting the malignant biological behavior of gastric epithelial cells (GES-1). METHODS The study was conducted with human GES-1 cells in vitro. Relative protein levels of methyltransferase-like protein 14 (METTL14), HIF-1 alpha, main proteins of the PI3K/AKT pathway, epithelial-mesenchymal transition (EMT) biomarkers, and invasion indicators were detected by Western blot. Relative mRNA levels of METTL14 and HIF-1 alpha were detected by quantitative reverse transcription-polymerase chain reaction. mRNA stability was evaluated using actinomycin D, and the interaction between METTL14 and HIF-1 alpha was confirmed by immunofluorescence staining. Cell proliferation and migration were evaluated by cell counting kit-8 assay and wound healing assay, respectively. RESULTS H. pylori promoted HIF-1 alpha expression and activated the PI3K/AKT pathway. Notably, METTL14 was downregulated in H. pylori-infected gastric mucosal epithelial cells and positively regulated HIF-1 alpha expression. Functional experiments showed that the overexpression of HIF-1 alpha or knockdown of METTL14 enhanced the activity of the PI3K/AKT pathway, thereby driving a series of malignant transformation, such as EMT and cell proliferation, migration, and invasion. By contrast, the knockdown of HIF-1 alpha or overexpression of METTL14 had an opposite effect. CONCLUSION H. pylori-induced underexpression of METTL14 promotes the translation of HIF-1 alpha and accelerates tumor progression by activating the PI3K/AKT pathway. These

关键词： Helicobacter pylori Gastric cancer Methyltransferase-like protein 14 Hypoxia-inducible factor-1 alpha N6-methyladenosine PI3K/AKT pathway

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Genetic analysis of Chinese families reveals a novel truncation allele of the retinitis pigmentosa GTPase regulator gene

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International Journal of Ophthalmology(English edition) 2014年第5期7卷 753-758页

作者： Fang hu Xiang-Yun Zeng Lin-Lin Liu Yao-Ling Luo Yi-Ping Jiang hui Wang Jing Xie Cheng-quan hu Lin Gan Liang huang Department of Ophthalmology the First Affiliated HospitalGannan Medical University Flaum Eye Institute and Department of Ophthalmology School of Medicine and DentistryUniversity of Rochester

AIMTo make comprehensive molecular diagnosis for retinitis pigmentosa (RP) patients in a consanguineous Han Chinese family using next generation sequencing based Capture-NGS screen technology.

关键词： retinitis pigmentosa GTPase regulator retinitis pigmentosa next-generation sequencing genetic diagnosis

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Synthesis of Chiral Amino Cyclic Phosphoric Acids

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Wuhan University Journal of Natural Sciences 2000年第4期5卷 497-499页

作者： Zhang Zhan, hu quan-yuan, Deng Fa-da, Shu Jia-you, He Jian-she, hu Xian-ming College of Chemistry and Environmental Science, Wuhan University, Wuhan 430072 College of Chemistry and Environmental Science Wuhan University Wuhan

Chiral amino cyclic phosphoric acids, 5-amino-2-hydroxy-4-(4-nitrophenyl)-1,3,2-dioxaphosphorinane 2-oxide and 2-hydroxy-4-(4-methylsulfonylphenyl)-5-phthalimido-1,3,2-dioxaphos phorinane 2-oxide are synthesized in good over yields (64.2%and 72.8%respectively) from 2-amino-1-aryl-1,3-propanediols. The different reaction conditions are necessary in hydrolysis reactions of amino cyclic phosphonyl chlorides.

关键词： chiral amino cyclic phosphoric acid amino diols synthesis

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