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Optimization of Hot Workability in Superaustenitic Stainless Steel 654SMO

Journal of Iron and Steel Research International 2014年第10期21卷 975-982页

作者： En-xiang pu Wen-jie zheng Zhi-gang SONG Jin-zhong XIANG Xian-ping WEI School of Physics Science and Technology Yunnan University Central Iron and Steel Research Institute

Hot compression tests were conducted on a Gleeble-3800 machine in a temperature range of 950 to 1200 ℃ and a strain rate range of 0. 001 to 10 s-1 in order to study the hot deformation behaviour of superaustenitic stainless steel 654SMO. The results show that peak stress increases with decreasing temperature and increasing strain rate, and the apparent activation energy of this alloy was determined to be about 494 kJ/mol. The constitutive equation which can be used to relate the peak stress to the absolute temperature and strain rate was obtained. The processing maps for hot working developed on the basis of flow stress data and the dynamic materials model were adopted to op- timize the hot workability. It is found that the features of the maps obtained in the strain range of 0.2 to 1.0 are fun- damentally similar, indicating that the strain does not have a substantial influence on processing map. The combina- tion of processing map and mierostructural observations indicates that the favorable hot deformation conditions are located in two domains of processing map. The first domain occurs in the temperature range of 980 to 1035 ℃ and strain rate range of 0. 001 to 0.01 s-1 with a peak efficiency of 55%. The second domain appears in the temperature range of 1 120 to 1 180 ℃ and strain rate range of 0.3 to 3 s-1 with peak efficiency of 35%. Compared to other stable domains, the specimens deformed in these two domains exhibit full dynamic recrystallization grains with finer and more uniform sizes. An instability domain occurs at temperatures below 1 100 ℃ and strain rate above 0.1 s-1 , and flow instability is manifested in the form of flow localization.

关键词： 654SMO steel superaustenitic stainless steell processing mapl hot deformationl dynamic recrystallization

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Properties,combustion behavior,and kinetic triplets of coke produced by low-temperature oxidation and pyrolysis:Implications for heavy oil in-situ combustion

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Petroleum Science 2021年第5期18卷 1483-1491页

作者： Shuai Zhao Wan-fen pu Lei Su Ce Shang Yang Song Wei Li Hui-Zhuo He Yi-Gang Liu Zhe-Zhi Liu State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengduSichuan610500China Post-Doctorate R&D Base Southwest Petroleum UniversityChengduSichuan610500China E&D Research Institute of Liaohe Oilfield CNPC PanjinLiaoning124000China School of Oil and Gas Engineering Chongqing University of Science and TechnologyChongqing401331China

This work aimed at investigating the crucial factor in building and maintaining the combustion front during in-situ combustion(ISC),oxidized coke and pyrolyzed *** surface morphologies,elemental contents,and non-isothermal mass losses of the oxidized and pyrolyzed cokes were thoroughly *** results indicated that the oxidized coke could be combusted at a lower temperature compared to the pyrolyzed coke due primarily to their differences in the molecular polarity and *** triplets of coke combustion were determined using iso-conversional models and one advanced integral master plots *** activation energy values of the oxidized and pyrolyzed cokes varied in the range of 130-153 k J/mol and 95-120 kJ/mol,*** most appropriate reaction model of combustion of the oxidized and pyrolyzed cokes followed three-dimensional diffusion model(D_(3)) and random nucleation and subsequent growth model(F_(1)),*** observations assisted in building the numerical model of these two types of cokes to simulate the ISC process.

关键词： Oxidized coke Pyrolyzed coke Heavy oil In-situ combustion Kinetic triplets

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The third-party regulation on food safety in China:A review

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Journal of Integrative Agriculture 2015年第11期14卷 2176-2188页

作者： ZHANG Man QIAO Hui WANG Xu pu Ming-zhe YU Zhi-jun zheng feng-tian School of Agricultural Economics and Rural Development Renmin University of China School of Continuing Education Renmin University of China

Stakeholders in the field of food safety management in China can be classified into three categories, government, food producers （farmers and enterprises）, and the third-party regulatory bodies. The third-party regulation has experienced rapid development in past twenty years, and recently received considerable attention from consumers and the central government. This paper provides a review about the development, problems and future trend of the third-party regulation on food safety in China. To be specific, five forms of the third-party regulation are assessed, including media exposure, the third-party certification, regulation by consumer associations, social movements promoted by non-governmental organiza- tions （NGOs）, and regulation by industry associations. The study concludes that media and consumer associations are the major players in the third-party regulation and are highly repudiated among customers. The food certification industry has developed rapidly, but is now facing crises of confidence among consumers because of its lack of self-regulation. NGOs and industry associations still remain in the early development stages of food safety management, and therefore, are of little importance in current regulatory bodies.

关键词： food safety China the third-party regulation media certification

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Nitrogen and atomic Fe dual-doped porous carbon nanocubes as superior electrocatalysts for acidic H2-O_(2) PEMFC and alkaline Zn-air battery

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Journal of Energy Chemistry 2021年第8期30卷 388-395,I0008页

作者： Xiudong Shi Zonghua pu Bin Chi Mingrui Liu Siyan Yu Long zheng Lijun Yang Ting Shu Shijun Liao The Key Laboratory of Fuel Cell Technology of Guangdong Province&the Key Laboratory of New Energy Technology of Guangdong Universities School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510641China Ballard Power Systems 9000 Glenlyon ParkwayBurnaby V5J 5J8Canada

Air cathodes with high electrocatalytic activity are vital for developing H2/O_(2) proton exchange membrane fuel cells(PEMFC)and Zn-air ***,the state-of-the-art air cathodes suffer from either limited catalytic activity or high cost,which thus hinder their ***,we designed ZIF-8 derived nitrogen and atomic iron dual-doped porous carbon nanocubes as high-quality catalysts for ORR,through a novel gas-doping *** porous carbon nanocubic architecture and abundant Fe-Nxactive species endow ZIF-8 derived single atomic iron catalyst(PCN-A@Fe SA)with superior catalytic activity,and surpass Pt/C and a majority of the reported *** XAS and DFT calculations suggest that Fe2+N4 moieties are the main active centers that are favorable for oxygen affinity and OH*intermediate desorption,which can result in promising catalytic *** importantly,PCNA@Fe SA can achieve power density of 514 m W cm^(-2) as cathodic catalyst in a PEMFC and discharge peak power density of 185 m W cm^(-2) in an alkaline Zn-air *** outstanding performance is derived from both the high specific surface area and high-density of iron single atom in nitrogen doped nanocubic carbon matrix.

关键词： Gaseous doping Fe-Nx sites Fe single atoms Oxygen reduction reaction Electrocatalysts

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Al-enabled properties distribution prediction for high-pressure die casting Al-Si alloy

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Advances in Manufacturing 2024年第3期12卷 591-602页

作者： Yu-Tong Yang Zhong-Yuan Qiu Zhen zheng Liang-Xi pu Ding-Ding Chen Jiang zheng Rui-Jie Zhang Bo Zhang Shi-Yao Huang Key Laboratory for Light-Weight Materials Nanjing Tech UniversityNanjing211816People’s Republic of China Xi’an Jiaotong-Liverpool University Suzhou215000JiangsuPeople’s Republic of China Materials Academy JITRI Suzhou215100JiangsuPeople’s Republic of China Key Laboratory for Light-weight Materials Nanjing University of Science and TechnologyNanjing210009People’s Republic of China College of Materials Science and Engineering Chongqing UniversityChongqing400044People’s Republic of China Collaborate Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083People’s Republic of China Chongqing Millison Technologies Inc. Chongqing401321People’s Republic of China

High-pressure die casting(HPDC)is one of the most popular mass production processes in the automotive industry owing to its capability for part ***,the nonuniform distribution of mechanical properties in large-sized HPDC products adds complexity to part property ***,a methodology for property prediction must be *** characterization,simulation technologies,and artificial intelligence(AI)algorithms were ***,an image recognition technique was employed to construct a temperature-microstructure characteristic model for a typical HPDC Al7Si0.2Mg ***,a porosity/microstructure-mechanical property model was established using a machine learning method based on the finite element method and representative volume element model ***,the computational results of the casting simulation software were mapped with the porosity/microstructure-mechanical property model,allowing accurate prediction of the property distribution of the HPDC Al-Si *** AI-enabled property distribution model developed in this study is expected to serve as a foundation for intelligent HPDC part design platforms in the automotive industry.

关键词： Artificial intelligence(AI) Properties prediction High-pressure die-casting(HPDC) Image recognition Machine learning

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Plasmid-based generation of neural cells from human fibroblasts using non-integrating episomal vectors

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Neural Regeneration Research 2019年第3期14卷 501-505页

作者： Shao-Bing Dai Ting Shen Ting-Ting zheng Jia-Li pu Xin-Zhong Chen Department of Anesthesiology Women's Hospital School of Medicine Zhejiang University Department of Neurology Second Affiliated Hospital College of Medicine Zhejiang University

Differentiation of human fibroblasts into functional neurons depends on the introduction of viral-mediated transcription factors, which present risks of viral gene integration and tumorigenicity. In recent years, although some studies have been successful in directly inducing neurons through sustained expression of small molecule compounds, they have only been shown to be effective on mouse-derived cells. Thus, herein we delivered vectors containing Epstein-Barr virus-derived oriP/Epstein-Barr nuclear antigen 1 encoding the neuronal transcription factor, Ascl1, the neuron-specific microRNA, miR124, and a small hairpin directed against p53, into human fibroblasts. Cells were incubated in a neuron-inducing culture medium. Immunofluorescence staining was used to detect Tuj-1, microtubule-associated protein 2, neuron-specific nucleoprotein NeuN and nerve cell adhesion molecules in the induced cells. The proportion of Tuj1-positive cells was up to 36.7% after induction for 11 days. From day 21, these induced neurons showed neuron-specific expression patterns of microtubule-associated protein 2, NeuN and neural cell adhesion molecule. Our approach is a simple, plasmid-based process that enables direct reprogramming of human fibroblasts into neurons, and provides alternative avenues for disease modeling and neurodegenerative medicine.

关键词： nerve regeneration induced neurons plasmid-based human fibroblasts nucleofection Ascl1 miR124 p53 reprogramming neural regeneration

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Evaluation of harmonious development for economy-environment system in coastal cities: a case study of Tianjin Municipality

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Ecological Economy 2006年第2期2卷 152-160页

作者： Li fen Zhang Yuan zheng Binghui Wang Xiqin School of Environment and Natural Resources Renmin University of China Beijing 100873 P. R. China River and Coastal Environmental Research Center. Chinese Research Academy of Environmental Sciences. Beijing 100012. P. R. China

With the aim of the harmonious development of economy-environment system in coastal cities in China. an index ,system used to evaluate the economy-environment system is built up in this paper, which includes four aspects： economy, environment, resources, and ocean industry. Based on the analysis on present condition and future trends of economic development in Tianjin and the quantification of various evaluation indices, the aathor applies integrated index valuation model to valuate the harmonious development af economy-environment of Tianjin. The results show that the coordinated degree of economy-environment would drop down in the future, from 0.95（superior level of harmonious development） in 2000 to 0.59（inferior level of harmonious development） in 2015. under the circumstance of the current economic development mode. The level of comprehensive development of Tianjin also presents to descend. Based on the analyzing of status and future trends of environment-economy coordinated development, the paper puts forward the countermeasures such as industry, structure adjustment, increasing the level of environmental protection investment, strengthening the enforcement of en vironmental policies to improve the coordinated development of environment-economy in Tianjin municipality.

关键词： Coastal cities Economy-environment system Harmonious development Coordination degree Tianjin Municipality

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Tuning the Molecular Weight of Chlorine-Substituted Polymer Donors for Small Energy Loss

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Chinese Journal of Chemistry 2021年第6期39卷 1651-1658页

作者： Tingxing Zhao Huan Wang Mingrui pu Hanjian Lai Hui Chen Yulin Zhu Nan zheng feng He Shenzhen Grubbs Institute and Department of Chemistry Southern University of Science and TechnologyShenzhenGuangdong 518055China Academy for Advanced Interdisciplinary Studies Southern University of Science and TechnologyShenzhenGuangdong 518055China Institute of Polymer Optoelectronic Materials and Devices State Key Loborotory of Luminescent Materials and DevicesSouth China University of TechnologyGuangzhouGuangdong 510640China Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and TechnologyShenzhenGuangdong 518055China

The molecular weight of polymers plays a major role in their aggregation and miscibility in active layer,which eventually dominate the energy loss and device performance.A series of chlorine-substituted PBD-CI polymers with controlled molecular weight have been synthesized as templates to discern a relationship between molecular weight and the optical properties,energy levels,morphologies,energy loss and photovoltaic *** it has similar optical and electrochemical properties,when blended with acceptor N3,the low molecular weight polymer PBD-CI_(L) gives the biggest energy loss value,and a PCE of 12.06%.PBD-CI_(H) shows a moderate energy loss,but displays the lowest PCE of 9.00%as a result of excessive ***-CI_(M) with a medium molecular weight gives the smallest energy loss and achieves a PCE of 17.17%,which is among one of the highest values recorded to date for the C卜substituted polymer solar ***,the molecular weight mainly affects the nonradiative energy loss(△E_(3)), PBD-CI_(M) also shows the smallest value of 0.252 eV among three polymer *** results show the effect of controlling the molecular weight to achieve a small energy loss and provide guidelines which can lead to an understanding of the real photovoltaic performance of new materials.

关键词： Molecular weight Chlorine Miscibility Energy loss Renewable resources

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Overexpression of transcription factor 3 drives hepatocarcinoma development by enhancing cell proliferation via activating Wnt signaling pathway

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Hepatobiliary & Pancreatic Diseases International 2022年第4期21卷 378-386页

作者： Xing-Yu pu Dao-feng zheng Tao Lv Yong-Jie Zhou Jia-Yin Yang Li Jiang Department of Liver Surgery and Liver Transplantation Center West China HospitalSichuan UniversityChengdu 610041China Laboratory of Liver Transplantation Frontiers Science Center for Disease-Related Molecular NetworkWest China HospitalSichuan UniversityChengdu 610041China

Background:Transcription factor 3(TCF3)plays pivotal roles in embryonic development,stem cell maintenance and ***,its role in hepatocellular carcinoma(HCC)remains largely *** study aimed to analyze the correlation between TCF3 expression and clinicopathological features of HCC,and further explore the underlying mechanism in HCC ***:The expression of TCF3 was collected from the Cancer Genome Atlas(TCGA)and the Gene Expression Omnibus(GEO)HCC datasets,and further confirmed by immunostaining and Western blotting *** correlation between TCF3 expression and the clinicopathological features was *** analysis and in vitro experiments were conducted to explore the potential role of TCF3 in HCC ***:Both the mRNA and protein levels of TCF3 were significantly higher in HCC tumor tissues compared to tumor adjacent tissues(P<0.001 and P<0.01).Analysis based on TCGA datasets showed that TCF3 was positively correlated with tumor clinical stage and grade,and patients with high TCF3 expression had shorter overall survival(P=0.012),disease-specific survival(P=0.022)and progression-free survival(P=0.013).Similarly,the immunostaining results revealed that the high expression of TCF3 was closely correlated with tumor size(P=0.001)and TNM stage(P=0.002),and TCF3 was an independent risk factor of *** vitro study exhibited that TCF3 knockdown dramatically suppressed cancer cell proliferation,and the underlying mechanism might be that the silencing of TCF3 reduced the expression of critical regulating proteins towards cell cycle and proteins involved in Wnt signaling ***:TCF3 expression is significantly elevated in HCC and positively associated with the tumor size and TNM stage,as well as poor prognosis of HCC *** mechanism might be that TCF3 promotes cancer cell proliferation via activating Wnt signaling pathway.

关键词： Hepatocellular carcinoma Proliferation Cell and molecular biology

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Plasma thrombomodulin changes in acute cerebral infarction or hypertension patients An observation for verification

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Neural Regeneration Research 2008年第1期3卷 71-74页

作者： pu feng Hui Zhang Bingyi Yang Yonggang zheng Jinhui Xie Ying Wang Jinchuan Li Department of Internal Medicine Yuquan Hospital of Tsinghua University （Second Affiliated Hospital of Tsinghua University） Beijing100049 China

BACKGROUND： Thrombomodulin concentration greatly increases in plasma when vascular endothelial cells are injured, and it is one of the specific molecular markers for endothelial injury. OBJECTIVE： To analyze the plasma levels of thrombomodulin after cerebral infarction or hypertension, and to compare levels with those from healthy control subjects. DESIGN： A case-controlled observation. SETTING： Yuquan Hospital of Tsinghua University. PARTICIPANTS： Patients with hypertension （n = 37） and acute cerebral infarction （n = 26） were selected from the outpatient and inpatient Department of Neurology, Yuquan Hospital of Tsinghua University from February 2003 to February 2006. The cerebral infarction group consisted of 24 males and 2 females, 36-77 years of age, with a mean age of 62 years. All patients fulfilled the diagnosis criteria for cerebral infarction, according to the diagnostic standards revised by the Second National Academic Meeting for Cerebrovascular Disease, and were confirmed by CT or MRI. The hypertension group consisted of 27 males and 10 females, 36-77 years of age, with a mean age of 56 years. These patients fulfilled the diagnostic criteria for hypertension set by WHO. In addition, 43 healthy physical examinees were selected as the control group, consisting of 23 males and 20 females, 35-67 years of age. Informed consent was obtained from all participants. METHODS： In the cerebral infarction group, thrombomodulin plasma levels were determined by enzyme-linked immunoabsorbent assay at days 1, 3, 7, and 14 after attack. Thrombomodulin plasma levels were determined only once in the hypertension group and the control group. The results from the cerebral infarction group were compared with those from the hypertension group and the control group. MAIN OUTCOME MEASURES： Level of thrombomodulin in plasma. RESULTS： All 63 patients and 43 healthy volunteers were included in the final analysis of results. （1） At 7 days after the attack, the plasma levels of thrombo

关键词： thrombomudulin cerebral infarction MRI

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