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Hot deformation behavior and microstructure evolution of GH3536-TiB_(2) composites fabricated by powder metallurgy

Science China(Technological Sciences) 2024年第7期67卷 2107-2124页

作者： zhou shipeng WANG Shuai HUANG LuJun ZHANG Rui CHEN Xin MENG FanChao CHEN Run SUN FengBo WANG CunYu GENG Lin School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Waikato Centre for Advanced Materials and Manufacturing School of EngineeringUniversity of WaikatoHamilton 3240New Zealand State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

The hot deformation behavior and microstructure evolution of GH3536-TiB2composites fabricated by powder metallurgy(PM)were examined in the temperature range of 950–1150℃ and strain rate range of 0.001–1 s^(-1). The hot compression stress-strain curves and the constitutive equation were obtained. In addition, the hot processing map was drawn, which indicated that the appropriate hot working window was 950–1050℃/0.001–0.1 s^(-1)and 1050–1100℃/0.001–0.01 s^(-1). The microstructure analysis showed that the splitting and spheroidization of M3B2led to a decrease in size and volume fraction at 950–1100℃. At 1150℃,the eutectic microstructure of M_(3)B_(2)+ γ was formed due to the dissolution of M_(3)B_(2), which caused macroscopic cracking of the deformed sample. Additionally, the deformation temperature and the strain rate had little effect on the size and volume fraction of M_(3)B_(2). Besides, discontinuous dynamic recrystallization(DDRX) and continuous dynamic recrystallization(CDRX) were found in the deformed microstructure, while the former was dominant. Within the test range of this work, the dynamic recrystallization(DRX) fraction of the deformed composites was high due to the bulging nucleation of numerous interfaces. The DRX grain size increased with increasing deformation temperature or decreasing strain rate. Texture analysis showed that the deformation texture of //compression direction RD existed in the matrix when the deformation temperature was below 1100℃, and the texture type became //RD at 1100℃. Additionally, it was also found that the //RD texture was formed in M3B2under the strain rates of 0.1 and 0.01 s^(-1).

关键词： GH3536 alloy matrix composites powder metallurgy hot deformation behavior microstructure evolution

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Industrialization, Modernization and Self-Organization

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Journal of Systems Engineering and Electronics 1994年第2期5卷 53-59页

作者： zhou, shipeng Beijing Research Inst of Engineering & Technology Beijing China

This paper studies the industrialization of China, a key problem of Chinese economic development with self-organization theory in system science. The dual economic structure of modern industry and traditional agriculture existing simultaneously is the typical economic structure for most developing countries. How can we break the dual economic structure? After China has carried out the peasant family output-related system of contracted responsibilities, the rural enterprises which develop swiftly and violently are setting up a bridge between traditional agriculture and modern industry. This paper models the triple economic structure formed by traditional agriculture, rural enterprises and modern industry. From the study of structure evolution, we obtain the important relationship between economic growth rate, the rate of technological progress, the growth rate of capital and the growth rate of population, deduce three critical points of population growth, and find out the conditions under which the national economic system forms a stable and orderly self-organized structure. On the basis of quantitative analysis, we propose an approach to the strategies of industrialization of China, especially to the problem of rural enterprise development and rural labor transfer, and give three conclusions and four developmental strategies about national economic system.

关键词： Adaptive systems Agriculture Economic and social effects Industrial economics Mathematical models Modernization System stability Technology transfer

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ON SPECTRUM OF NETWORKS BASED ON MATRIX OF LINK-STATE AND ITS SYMMETRY

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Journal of Systems Science & Complexity 2009年第2期22卷 243-251页

作者： Liuqing XIAO shipeng zhou Department of Mathematics Shanghai Jiao Tong University Shanghai 200030 China. School of Business University of Shanghai for Science and Technology Shanghai 200093 China.

This paper constructs a new spectrum of networks by means of the matrix of link-state ofthe network,which can reveal the characteristics of the correlation between the degrees of the ***,the computation of this spectrum of networks is usually more feasible and more efficient due tothe much lower order of its matrix of link-state than its adjacent matrix in *** estimatesfor the bounds of the key eigenvalues in the spectrum are obtained,the corresponding inequalities arepresented and *** the sake of its application,the authors define spectrum of networks in twoways,and all theorems are given in parallel for both kinds of *** addition,the authors finda symmetry in the spectrum,which is relative to the characteristic of structure of its network to someextent.

关键词： Complex network Laplacian matrix matrix of link-state spectrum of networks symmetry

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1990—2020年黄河源区林地面积与生态需水量的时空变化

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福建农林大学学报（自然科学版） 2024年第3期53卷 345-354页

作者：周诗鹏杨颖张小燕卢素锦秦碧玉张文黄晖陈娅玲青海大学生态环境工程学院青海西宁810016

【目的】探讨1990—2020年黄河源区林地面积与林地生态需水量的时空变化规律,为黄河源区林地生态需水量的合理调配提供依据。【方法】基于黄河源区1990—2020年的遥感影像数据和野外实测资料,通过目视解译确定黄河源区土地利用类型,通... 详细信息

【目的】探讨1990—2020年黄河源区林地面积与林地生态需水量的时空变化规律,为黄河源区林地生态需水量的合理调配提供依据。【方法】基于黄河源区1990—2020年的遥感影像数据和野外实测资料,通过目视解译确定黄河源区土地利用类型,通过计算得到林地面积和林地生态需水量数据;采用ArcGIS 10.8绘制林地面积与生态需水量的时空分布图,分别运用Canoco 5.0和SPSS 27作冗余分析和主成分分析。【结果】黄河源区1990—2020年的林地面积变化不大,林地主要分布于黄河源区中东部,以灌木林地为主;林地生态需水量的变化较小,总体上生态需水量表现为西多东少、北多南少。不同类型林地的生态需水量大小表现为灌木林地>有林地>疏林地>其他林地;影响源区生态需水量的最主要指标是斑块周长-面积比(mean perimeter-area ratio,PARA_MN),其次是斑块连通度指数(patch cohesion index,COHESION)。影响黄河源区生态需水量的主要因素为人口数量、经济水平、产业发展结构,自然环境因素的驱动力弱于社会环境因素。【结论】黄河源区1990—2020年林地面积呈小幅下降趋势,林地生态需水量变化不大;黄河源区景观水平多样性较低;黄河源区受人类活动的影响较大。

关键词：黄河源区景观格局林地生态需水量冗余分析驱动因素

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UNCONDITIONAL CONVERGENCE AND ERROR ESTIMATES OF A FULLY DISCRETE FINITE ELEMENT METHOD FOR THE MICROPOLAR NAVIER-STOKES EQUATIONS

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Journal of Computational Mathematics 2024年第1期42卷 71-110页

作者： shipeng Mao Jiaao Sun Wendong Xue NCMIS LSECInstitute of Computational Mathematics and Scientific/Enginnering ComputingAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

In this paper,we consider the initial-boundary value problem(IBVP)for the micropolar Naviers-Stokes equations(MNSE)and analyze a first order fully discrete mixed finite element *** first establish some regularity results for the solution of MNSE,which seem to be not available in the ***,we study a semi-implicit time-discrete scheme for the MNSE and prove L2-H1 error estimates for the time discrete ***,certain regularity results for the time discrete solution are establishes *** on these regularity results,we prove the unconditional L2-H1 error estimates for the finite element solution of ***,some numerical examples are carried out to demonstrate both accuracy and efficiency of the fully discrete finite element scheme.

关键词： Micropolar fluids Regularity estimates Euler semi-implicit scheme Mixed finite element methods Unconditional convergence

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Ferroptosis:a critical mechanism of N^(6)-methyladenosine modification involved in carcinogenesis and tumor progression

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Science China(Life Sciences) 2024年第6期67卷 1119-1132页

作者： Qingqing Wei Changning Xue Mengna Li Jianxia Wei Lemei Zheng shipeng Chen Yumei Duan Hongyu Deng Faqing Tang Wei Xiong Ming zhou NHC Key Laboratory of Carcinogenesis Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of MedicineCentral South UniversityChangsha 410013China Cancer Research Institute and School of Basic Medical Sciences Central South UniversityChangsha 410078China The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education Central South UniversityChangsha 410078China Hunan Key Laboratory of Oncotarget Gene Hunan Key Laboratory of Cancer MetabolismHunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of MedicineCentral South UniversityChangsha 410013China

Ferroptosis is an iron-dependent regulatory cell necrosis induced by iron overload and lipid *** occurs when multiple redoxactive enzymes are ectopically expressed or show abnormal ***,the precise regulation of ferroptosis-related molecules is mediated across multiple levels,including transcriptional,posttranscriptional,translational,and epigenetic levels.N^(6)-methyladenosine(m^(6)A)is a highly evolutionarily conserved epigenetic modification in *** m^(6)A modification is commonly linked to tumor proliferation,progression,and therapy resistance because it is involved in RNA metabolic ***,accumulating evidence suggests that dysregulated ferroptosis caused by the m^(6)A modification drives tumor *** this review,we summarized the roles of m^(6)A regulators in ferroptosis-mediated malignant tumor progression and outlined the m^(6)A regulatory mechanism involved in ferroptosis *** also analyzed the potential value and application strategies of targeting m^(6)A/ferroptosis pathway in the clinical diagnosis and therapy of tumors.

关键词： ferroptosis m6A modification RNA methylation m^(6)A regulator tumor progression

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Numerical study on ignition start-up process of an underwater solid rocket motor across a wide depth range

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Chinese Journal of Aeronautics 2024年第10期37卷 136-157页

作者： Deyou WANG shipeng LI Ge JIN Ruyao WANG Dian GUAN Ningfei WANG School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Beijing System Design Institute of Electro-mechanic Engineering Beijing 100854China

Solid rocket motors have important applications in the propulsion of trans-media vehicles and underwater launched *** this paper,the ignition start-up process of an underwater solid rocket motor across a wide depth range has been numerically studied.A novel multi-domain integrated model has been developed by combining the solid propellant ignition and combustion model with the volume of fluid multiphase *** integrated model enables the coupled simulation of the propellant combustion and gas flow inside the motor,along with the gas jet evolution in the external water *** detailed flow field developments in the combustion chamber,nozzle,and wake field are carefully *** variation rules of the internal ballistics and thrust performance are also *** effects of environmental medium and operating depth on the ignition start-up process are systematically *** results show that the influence of the operating environment on the internal ballistic characteristics is primarily reflected in the initial period after the nozzle closure *** development of the gas jet in water lags significantly compared with that in *** the water depth increases,the ignition delay time of the motor is shortened,and the morphology evolution of the gas jet is significantly compressed and ***,the necking and bulging of the jet boundary near the nozzle outlet and the consequent shock oscillations are intensified,resulting in stronger fluctuations in the wake pressure field and motor thrust.

关键词： Underwater propulsion Solid rocket motor Ignition start-up process Underwater gas jet Thrust oscillation

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Formation behaviors of rod-like reactive shaped charge penetrator and their effects on damage capability

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Defence Technology（防务技术） 2024年第2期32卷 242-253页

作者： Tao Sun Haifu Wang shipeng Wang Chao Ge Die Hu Pengwan Chen Yuanfeng Zheng Beijing Institute of Technology State Key Laboratory of Explosion Science and TechnologyBeijing100081China Xi'an Institute of Electromechanical Information Technology Xi'an710065China

Formation behaviors of rod-like reactive shaped charge penetrator(RRSCP)and their effects on damage capability are investigated by experiments and numerical *** pulsed X-ray technology and a spaced aluminum/steel plate with the thicknesses of 5 mm/100 mm are *** types of sphericalsegment aluminum-polytetrafluoroethylene-copper(Al-PTFE-Cu)reactive liners with Cu contents of 0%,46.6%,and 66%are fabricated and *** experimental results show that the reactive liners can form excellent rod-shaped penetrators with tail skirts under the shaped charge effect,but the tail skirts disappear over ***,rupturing damage to the aluminum plate and penetration to the steel plate are caused by the RRSCP *** simulation analysis,the RRSCP is formed by a mechanically and chemically coupled response with the reactive liner activated by shock in its outer walls and bottom and then backward overturning,forming a leading reactive penetrator and a following chemical energy *** unique formation structure determines the damage modes of the aluminum plate and the steel *** analysis indicates that the formation behaviors and damage capability of Al-PTFE-Cu RRSCP strongly depend on Cu *** increasing Cu content,the velocity,activation extent,and reaction extent of Al-PTFE-Cu RRSCP decrease,which contribute to elongation and alleviate the negative effects of chemical reactions on elongation,significantly increasing the length-diameter ratio and thus enhancing the capability of steel plate ***,the lower activation extent and energetic density will weaken the RRSCP's capability of causing rupturing damage to the aluminum plate.

关键词： Reactive materials Al-PTFE composites Reactive liner X-ray Penetration

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Key role of interferon regulatory factor 1(IRF-1)in regulating liver disease:progress and outlook

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第6期25卷 451-470页

作者： Tao CHEN shipeng LI Dewen DENG Weiye ZHANG Jianjun ZHANG Zhongyang SHEN First Central Clinical School Tianjin Medical UniversityTianjin 300192China Department of Organ Transplant Tianjin First Central HospitalTianjin 300192China Research Institute of Transplant Medicine Nankai UniversityTianjin 300192China Department of Hepatobiliary Surgery Henan Provincial People’s HospitalZhengzhou 450000China Key Laboratory of Organ Transplant Tianjin First Central HospitalTianjin 300192China

Interferon regulatory factor 1(IRF-1)is a member of the IRF *** is the first transcription factor to be identified that could bind to the interferon-stimulated response element(ISRE)on the target gene and displays crucial roles in the interferoninduced signals and ***-1,as an important medium,has all of the advantages of full cell cycle regulation,cell death signaling transduction,and reinforcing immune surveillance,which are well *** studies indicate that IRF-1 is of vital importance to the occurrence and evolution of multifarious liver diseases,including but not limited to inhibiting the replication of the hepatitis virus(A/B/C/E),alleviating the progression of liver fibrosis,and aggravating hepatic ischemiareperfusion injury(HIRI).The tumor suppression of IRF-1 is related to the clinical characteristics of liver cancer patients,which makes it a potential indicator for predicting the prognosis and recurrence of liver cancer;additionally,the latest studies have revealed other effects of IRF-1 such as protection against alcoholic/non-alcoholic fatty liver disease(AFLD/NAFLD),cholangiocarcinoma suppression,and uncommon traits in other liver diseases that had previously received little ***,several compounds and drugs have featured a protective function in specific liver disease models in which there is significant involvement of the IRF-1 *** this paper,we hope to propose a prospective research basis upon which to help decipher translational medicine applications of IRF-1 in liver disease treatment.

关键词： Interferon regulatory factor(IRF-1) Hepatitis virus Liver fibrosis Hepatic ischemia-reperfusion injury(HIRI) Liver cancer

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Three-dimensionally ordered macroporous(3DOM) structure promoted the activity and H_(2)O poisoning resistance of Ce Mn/3DOM-TiO_(2) catalyst in NH_(3)-SCR

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Journal of Rare Earths 2024年第3期42卷 523-533,I0004页

作者： Yaqin Hu shipeng Ding Chenchen Tan Peng Wu Guobo Li Sheng Wang Hongqiang Yang Yaping Zhang Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing210096China State Power Environmental Protection Research Institute Nanjing210031China

NH_(3)-SCR is an effective mean of NOxremoval in the non-electric industry, however, the high activation temperature and poor H_(2)O resistance of SCR catalysts posed a barrier to its application. In this work, a series of three-dimensionally ordered macroporous(3DOM) catalysts were synthesized via a colloidal crystal template(CCT) method, and various characterizations were carried out to explore the physicochemical property of catalysts. The experiment results reveal that Ce_(0.2)Mn_(0.2)/3DOM-TiO_(2) catalyst presents the excellent low-temperature catalytic activity of nearly 100% at 100℃. Furthermore, the enhanced H_(2)O resistance is achieved, certified by the unaffected NO remove at 150℃ in the participation of 15 vol% H_(2)O. The characterizations results exhibit that the improved dispersion of the active component and enhanced redox ability are conducive to the low-temperature catalytic activity. N_(2) adsorption and desorption experiments indicate that catalyst with 3DOM support possesses a larger pore diameter and specific surface area, which may weaken the condensation of H_(2)O in the microporosity of catalysts and improved the H_(2)O resistance of the catalyst. In situ DRIFTS results manifest that Ce_(0.2)Mn_(0.2)/3DOM-TiO_(2) catalyst could not only absorb more NH_(3) and generate more surface-active sites, but inhibit the competitive adsorption between H_(2)O and SCR reactants.

关键词： 3DOM material NH_(3)-SCR H_(2)O resistance Low-temperature Cerium Rare earths

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