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Physical properties of WSTi3515S burn-resistant titanium alloy

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Rare Metals 2016年第5期35卷 361-366页

作者： Yun-Jin Lai ping-xiang zhang Xue-Min zhang xiang-Hong Liu Yong Feng Hong-Chao Kou Fan-Jiao Ma Wei-Dong Zeng State Key Laboratory of Solidification Processing Northwestern Polytechnical University Western Superconducting Technologies Co. Ltd. School of Materials Science and Engineering Chang’an University

Development of burn-resistant titanium alloys is the most direct way of mitigating the ignition and propagation of titanium fires in jet engines. WSTi3515S alloy（Ti–35V–15Cr–0.3Si–0.1C） is a new high alloying beta type burn-resistant titanium alloy, belonging to Ti–V–Cr type alloys which have been made significant progress in engineering technology in the past 5 years. The physical properties of WSTi3515S burn-resistant titanium alloy such as the elastic properties and thermal properties were measured and analyzed in different conditions. The results show that both the Young＇s modulus and shear modulus of WSTi3515S alloy decrease slightly with the temperature increasing at the tested temperature range. The Poisson＇s ratio of WSTi3515S alloy is around 0.36. However, the thermal properties such as the specific heat, thermal diffusivity, thermal conductivity and thermal expansion increase with the temperature increasing, which results from the strengthening of lattice heat vibration at elevated temperature. And the room temperature density of WSTi3515S alloy is 5.295 gácm^（-3）.

关键词： Physical properties WSTi3515S alloy Extrusion Burn-resistant

Recrystallization behavior of Ti40 burn-resistant titanium alloy during hot working process

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International Journal of Minerals,Metallurgy and Materials 2016年第5期23卷 581-587页

作者： Yun-jin Lai She-wei Xin ping-xiang zhang Yong-qing Zhao Fan-jiao Ma xiang-hong Liu Yong Feng State Key laboratory of Solidification Processing Northwestern Polytechnical University Xi'an 710072 China Western Superconducting Technologies Co. Ltd. Xi'an 710018 China Northwest Institute for Nonferrous Metal Research Xi'an 710016 China

The recrystallization behavior of deformed Ti40 alloy during a heat-treatment process was studied using electron backscatter dif- fraction and optical microscopy. The results show that the microstructural evolution of Ti40 alloy is controlled by the growth behavior of grain-boundary small grains during the heating process. These small grains at the grain boundaries mostly originate during the forging proc- ess because of the alloy＇s inhomogeneous deformation. During forging, the deformation first occurs in the grain-boundary region. New small recrystallized grains are separated from the parent grains when the orientation between deformation zones and parent grains exceeds a certain threshold. During the heating process, the growth of these small recrystallized grains results in a uniform grain size and a decrease in the av- erage grain size. The special recrystallization behavior of Ti40 alloy is mainly a consequence of the alloy＇s high β-stabilized elemeutal con- tent and high solution strength of the β-grains, which partially explains the poor hot working ability of Ti-V-Cr-type bum-resistant titanium alloys. Notably, this study on Ti40 bum-resistant titanium alloy yields important information related to the optimization of the microstruc- tures and mechanical properties.

关键词： titanium alloys hot working recrystallization microstructural evolution

Optimization of sintering parameters for fabrication of Ag-sheathed FeSe superconducting wires

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Rare Metals 2018年第5期37卷 433-438页

作者： Jian-Qing Feng Sheng-Nan zhang Ji-Xing Liu Bo-Tao Shao Cheng-Shan Li Ming Liang ping-xiang zhang Superconducting Materials Research Center Northwest Institute for Non-Ferrous Metal Research School of Materials Science and Engineering Northeastern University School of Materials Science and Engineering Xi'an University of Technology

Ag-sheathed Fe1.05Se superconducting wires were fabricated with ex-situ powder in tube （PIT） process. Fe and Se powders with molar ratio of 1.05 were firstly mixed and sintered under 600 ℃ for 12 h to form precursor powders. Owing to the complex Fe-Se binary phase diagram, both superconducting tetragonal FeSe and nonsuperconducting hexagonal FeSe could be formed simultaneously during sintering. Aiming at the reduction of hexagonal FeSe phase content and higher superconducting phase volume, the influences of key parameters, including sintering time, cooling rate and heating rate, on the phase composition of sintered wires were systematically studied. Optimal sintering parameters are obtained, and the maximum tetragonal FeSe phase content of ~ 97% is achieved. Meanwhile, the effects of packing density of precursor powders on the phase composition of final wires were also discussed. Owing to the shorter length of diffusion path, more tetragonal FeSe was formed with higher packing density. The superconducting transition signal with critical temperature of ~ 7.5 K was obtained, which proved the effectiveness of our optimal sintering process.

关键词： Superconductors FeSe Powder in tube Phase composition Superconducting transition

Oxidative Esterification of Methacrolein to Methyl Methacrylate over Supported Palladium Catalyst

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Chinese Chemical Letters 2006年第6期17卷 739-742页

作者： Wei ZHAO Wei Guo CHENG Zeng Xi LI Lei WANG xiang ping zhang Suo Jiang zhang Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 Graduate University of Chinese Academy of Sciences Beijing 100049

Supported palladium catalysts, which were used in the oxidative esterification of methacrolein to methyl methacrylate, have been prepared with different carriers and Pd precursors. Experimental results revealed that Pd catalysts with r-Al2O3 support and Na2PdC14 precursor showed good performance. Pd catalyst modified with Pb and Mg indicated that Pd-Mg bimetallic catalyst exhibited considerably higher activity and Pd-Pb exhibited both higher activity and selectivity. 92.27% methacrolein conversion and 90.57% methyl methacrylate selectivity were obtained on Pd-Pb-Mg catalyst.

关键词： Oxidative esterification methacrolein methyl methylcralate palladium alumina.

Effect of groove rolling on the microstructure and properties of Cu–Nb microcomposite wires

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International Journal of Minerals,Metallurgy and Materials 2021年第2期28卷 279-284页

作者： Peng-fei Wang Ming Liang Xiao-yan Xu Jian-qing Feng Cheng-shan Li ping-xiang zhang Jin-shan Li School of Materials Northwestern Polytechnical UniversityXi’an 710072China Northwest Institute for Nonferrous Metal Research Xi’an 710016China

Cu–Nb microcomposite wire was successfully prepared by a groove rolling *** effects of groove rolling on the diffraction peaks,microstructure,and properties of the Cu–Nb microcomposite were investigated and the microstructure evolutions and strengthening mechanism were *** tensile strength of the Cu–Nb microcomposite wire with a diameter of 2.02 mm was greater than 1 GPa,and its conductivity reached 68%of the International Annealed Copper Standard,demonstrating the Cu–Nb microcomposite wire with high tensile strength and high conductivity after groove *** results show that an appropriate groove rolling method can improve the performance of the Cu–Nb microcomposite wire.

关键词： groove rolling microstructure strengthening mechanism copper-niobium microcomposites

Prognostic impact of metastatic lymph node ratio in advanced gastric cancer from cardia and fundus

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World Journal of Gastroenterology 2008年第27期14卷 4383-4388页

作者： Chang-Ming Huang Bi-Juan Lin Hui-Shan Lu xiang-Fu zhang ping Li Jian-Wei Xie Department of Oncology Affiliated Union Hospital of Fujian Medical University Fuzhou 350001 Fujian Province China

AIM: To investigate the prognostic impact of the metastatic lymph node ratio (MLR) in advanced gastric cancer from the cardia and fundus. METHODS: Two hundred and thirty-six patients with gastric cancer from the cardia and fundus who underwent D2 curative resection were analyzed ret- rospectively. The correlations between MLR and the total lymph nodes, positive nodes and the total lymph nodes were analyzed respectively. The influence of MLR on the survival time of patients was determined with univariate Kaplan-Meier survival analysis and mul- tivariate Cox proportional hazard model analysis. And the multiple linear regression was used to identify the relation between MLR and the 5-year survival rate of the patients. RESULTS: The MLR did not correlate with the total lymph nodes resected (r = -0.093, P = 0.057). The 5-year overall survival rate of the whole cohort was 37.5%. Kaplan-Meier survival analysis identified that the following eight factors influenced the survival time of the patients postoperatively: gender (χ2 = 4.26, P = 0.0389), tumor size (χ2 = 18.48, P < 0.001), Borrmann type (χ2 = 7.41, P = 0.0065), histological grade (χ2 = 5.07, P = 0.0243), pT category (χ2 = 49.42, P < 0.001), pN category (χ2 = 87.7, P < 0.001), total number of re- trieved lymph nodes (χ2 = 8.22, P = 0.0042) and MLR (χ2 = 34.3, P < 0.001). Cox proportional hazard model showed that tumor size (χ2 = 7.985, P = 0.018), pTcategory (χ2 = 30.82, P < 0.001) and MLR (χ2 = 69.39, P < 0.001) independently influenced the prognosis. A linear correlation between MLR and the 5-year survival was statistically significant based on the multiple lin- ear regression (β = -0.63, P < 0.001). Hypothetically, the 5-year survival would surpass 50% when MLR was lower than 10%. CONCLUSION: The MLR is an independent prognostic factor for patients with advanced gastric cancer from the cardia and fundus. The decrease of MLR due to adequate number of total resected lymph nodes can improve the survival.

关键词： Lymph node metastasis Metastatic lymph node ratio Lymphadenectomy Prognosis

Effect of lymphadenectomy extent on advanced gastric cancer located in the cardia and fundus

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World Journal of Gastroenterology 2008年第26期14卷 4216-4221页

作者： Chang-Ming Huang Bi-Juan Lin Hui-Shan Lu xiang-Fu zhang ping Li Jian-Wei Xie Department of Oncology Affiliated-Union Hospital of Fujian Medical University Fuzh-ou350001 Fujian Province China

AIM： To analyze the prognostic impact of lymphade-nectomy extent in advanced gastric cancer located in the cardia and fundus. METHODS： Two hundred and thirty-six patients with advanced gastric cancer located in the cardia and fundus who underwent D2 curative resection were analyzed retrospectively. Relationships between the numbers of lymph nodes （LNs） dissected and survival was analyzed among different clinical stage subgroups. RESULTS： The 5-year overall survival rate of the entire cohort was 37.5%. Multivariate prognostic variables were total LNs dissected （P 〈 0.0001; or number of negative LNs examined, P 〈 0.0001）, number of positive LNs （P 〈 0.0001）, T category （P 〈 0.0001） and tumor size （P = 0.015）. The greatest survival differences were observed at cutoff values of 20 LNs resected for stage Ⅱ（p = 0.0136）, 25 for stage Ⅲ（P 〈 0.0001）, 30 for stage Ⅳ（P = 0.0002）, and 15 for all patients （P = 0.0024）. Based on the statistically assumed linearity as best fit, linear regression showed a significant survival enhancement based on increasing negative LNs for patients of stages Ⅲ （P = 0.013） and Ⅳ（P = 0.035）. CONCLUSION： To improve the long-term survival of patients with advanced gastric cancer located in the cardia and fundus, removing at least 20 LNs for stage Ⅱ,25 LNs for stage Ⅲ, and 30 LNs for stage N patients during D2 radical dissection is recommended.

关键词： Stomach neoplasms Lymph node meta-stasis Surgery Lymphadenectomy Prognosis

Effect of high magnetic field on solidification microstructure evolution of a Cu-Fe immiscible alloy

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China Foundry 2022年第4期19卷 335-341页

作者： Yu-jie Yan Chen Wei Yi-xuan He Chao Li ping-xiang zhang Jin-shan Li Jun Wang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China Xi'an Superconducting Magnet Technology Co. Ltd.Xi'an 710018China Northwest Institute for Nonferrous Metal Research Xi'an 710016China

The liquid phase separation behavior and the evolution of the solidification microstructure of a binary Cu_(50)Fe_(50) alloy were investigated under the conditions of without and with a 10 T magnetic field,with different undercooling during the solidification *** show that the combined effect of Stokes motion and Marangoni convection leads to the formation of the core-shell structure under the condition without the magnetic *** addition,specific gravity segregation is reinforced by increasing the undercooling,resulting in Fe-rich phase drifts towards the sample *** the 10 T magnetic field,the Fe-rich phase is elongated in the parallel direction of the magnetic field under the action of demagnetization energy due to the difference of static magnetic energy and surface *** the vertical direction,through the action of Lorentz force,the convection in the melt is inhibited and Fe-rich phase becomes more ***,the diffusion of the two phases and the coagulation of the Fe-rich phases are also restrained under the magnetic field,therefore,the phase volume fraction of the Fe-rich phase decreases at the same undercooling in the 10 T magnetic *** magnetic field inhibits the segregation behavior in the vertical direction of the magnetic field,and at the same time,improves the gravitational segregation to a certain extent,which has a very important impact on microstructure regulation.

关键词： high magnetic field Cu-Fe immiscible alloy undercooling solidification

Advanced Materials for NH_(3)Capture:Interaction Sites and Transport Pathways

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Nano-Micro Letters 2024年第11期16卷 119-155页

作者： Hai‑Yan Jiang Zao‑Ming Wang Xue‑Qi Sun Shao‑Juan Zeng Yang‑Yang Guo Lu Bai Ming‑Shui Yao xiang‑ping zhang Key Laboratory of Green Process and Engineering State Key Laboratory of Mesoscience and EngineeringBeijing Key Laboratory of Ionic Liquids Clean ProcessInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190People’s Republic of China School of Future Technology University of Chinese Academy of SciencesBeijing 100049People’s Republic of China China University of Petroleum Beijing 102249People’s Republic of China Institute for Integrated Cell‑Material Sciences(iCeMS) Kyoto UniversitySakyo‑KuYoshidaKyoto 606‑8501Japan

Ammonia(NH3)is a carbon-free,hydrogen-rich chemical related to global food safety,clean energy,and environmental *** an essential technology for meeting the requirements raised by such issues,NH3 capture has been intensively explored by researchers in both fundamental and applied *** four typical methods used are(1)solvent absorption by ionic liquids and their derivatives,(2)adsorption by porous solids,(3)abadsorption by porous liquids,and(4)membrane *** in the development of advanced materials for NH3 capture,we conducted a coherent review of the design of different materials,mainly in the past 5 years,their interactions with NH3 molecules and construction of transport pathways,as well as the structure–property relationship,with specific examples ***,the challenges in current research and future worthwhile directions for NH3 capture materials are proposed.

关键词： Ammonia capture Solvents Porous solids Porous liquids Membranes