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Hot Deformation Behavior of an Ultra-High-Strength Fe–Ni–Co-Based Maraging Steel

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Acta Metallurgica Sinica(English Letters) 2019年第9期32卷 1161-1172页

作者： Le Zhang Wei Wang M. Babar Shahzad yi-yin shan Ke Yang Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Hot processing behavior of an ultra-high-strength Fe–Ni–Co-based maraging steel was studied in temperature range of 900–1200℃and strain rate range of 0.001–10 s^-*** processing parameters and optimum hot working window were characterized via flow stress analysis,constitutive equation construction,hot processing map calculation and microstructure evolution,*** strain value for dynamic recrystallization was determined through theoretical mathematical differential method:the inflection point ofθ–σand-αθ/ασ-σ*** was found that the flow stress increased with the decrease in deformation temperature and increase in the strain *** power dissipation maps in the strain range of 0.1–0.6 were entirely similar with the tendency of contour lines which implied that strain had no strong effect on the dissipation ***,the instability maps showed obvious strain sensitivity with increasing strain,which was ascribed to the flow localization and *** optimized hot processing window of the experimental steel was obtained as 1100–1200℃/0.001–1 s^-1 and 1000–1100℃/0.001–0.1 s^-1,with the efficiency range of 20–40%.Owing to high Mo content in the experimental steel,high dynamic activation energy,Q=439.311 kJ mol^-1,was achieved,indicating that dynamic recrystallization was difficult to occur in the hot deformation process,which was proved via microstructure analysis under different hot deformation conditions.

关键词： Maraging steel Hot working Dynamic recrystallization Constitutive equation Hot processing map

Immunotherapy in liver transplantation for hepatocellular carcinoma:Pros and cons

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World Journal of Gastrointestinal Oncology 2022年第1期14卷 163-180页

作者： yi Luo Fei Teng Hong Fu Guo-shan Ding Department of Liver Surgery and Organ Transplantation Changzheng HospitalNaval Medical UniversityShanghai 200003China

Liver transplantation(LT)has emerged as a curative strategy for hepatocellular carcinoma(HCC),but contributes to a higher predisposition to HCC recurrence in the immunosuppression context,especially for tumors beyond the Milan *** immunotherapy has dramatically improved survival for immunocompetent patients and has become the standard of care for a variety of tumors,including HCC,it is mainly used outside the scope of organ transplantation owing to potentially fatal allograft ***,accumulative evidence has expanded the therapeutic paradigms of immunotherapy for HCC,from downstaging or bridging management in the pretransplant setting to the salvage or adjuvant strategy in the posttransplant ***,immunotherapy mainly includes immune checkpoint inhibitors(ICIs),adoptive cell transfer(ACT)and vaccine ***,followed by ACT,have been most investigated in LT,with some promising *** of the complex tumor microenvironment and immunoreactivity when immunosuppressants are combined with immunotherapy,it is difficult to reach formulations for immunosuppressant adjustment and the optimal selection of immunotherapy as well as *** addition,the absence of effective biomarkers for identifying rejection and tumor response is still an unresolved barrier to successful clinical immunotherapy applications for *** this review,we comprehensively summarize the available evidence of immunotherapy used in LT that is specific to ***,we discuss clinically concerning issues regarding the concurrent goals of graft protection and antitumor response.

关键词： Hepatocellular carcinoma Liver transplantation Immunotherapy Immune checkpoint inhibitors Adoptive cell transfer Immunosuppressant

Tomographic PIV investigation on coherent vortex structures over shark-skin-inspired drag-reducing riblets

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Acta Mechanica Sinica 2016年第2期32卷 284-294页

作者： Shao-Qiong Yang shan Li Hai-Ping Tian Qing-yi Wang Nan Jiang Department of Mechanics Tianjin UniversityTianjin 300072 China Tianjin Key Laboratory of Modern Engineering Mechanics Tianjin 300072 China School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore 639805 Singapore

Nature has shown us that the microstructure of the skin of fast-swimming sharks in the ocean can reduce the skin friction drag due to the well-known shark-skin *** the present study,the effect of shark-skin-inspired riblets on coherent vortex structures in a turbulent boundary layer（TBL） is *** is done by means of tomographic particle image velocimetry（TPIV） measurements in channel fl ws over an acrylic plate of drag-reducing riblets at a friction Reynolds number of *** turbulent fl ws over drag-reducing riblets are verifie by a planar time-resolved particle image velocimetry（TRPIV） system initially,and then the TPIV measurements are ***-dimensional（2D） experimental results with a dragreduction rate of around 4.81% are clearly visible over triangle riblets with a peak-to-peak spacing s＋of 14,indicating from the drag-reducing performance that the buffer layer within the TBL has thickened;the logarithmic law region has shifted upward and the Reynolds shear stress decreased.A comparison of the spatial topological distributions of the spanwise vorticity of coherent vortex structures extracted at different wall-normal heights through the improved quadrant splitting method shows that riblets weaken the amplitudesof the spanwise vorticity when ejection（Q2） and sweep（Q4） events occur at the near wall,having the greatest effect on Q4 events in *** so-called quadrupole statistical model for coherent structures in the whole TBL is verified Meanwhile,their spatial conditional-averaged topological shapes and the spatial scales of quadrupole coherent vortex structures as a whole in the overlying turbulent fl w over riblets are changed,suggesting that the riblets dampen the momentum and energy exchange between the regions of near-wall and outer portion of the TBL by depressing the bursting events（Q2 and Q4）,thereby reducing the skin friction drag.

关键词： Turbulent boundary layer(TBL) Coherent vortex structure Flow control Drag reduction Shark-skininspired riblet Tomographic particle image velocimetry(TPIV)

Progress in the Study of Molecular Genetic Improvements of Poplar in China

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Journal of Integrative Plant Biology 2006年第9期48卷 1001-1007页

作者： shan-Zhi Lin Zhi-yi Zhang Qian Zhang Yuan-Zhen Lin Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education Beijing Forestry University Beijing 100083 China

The poplar is one of the most economically important and intensively studied tree species owing to its wide application in the timber industry and as a model material for the study of woody plants. The natural resource of poplars in China is replete. Over the past 10 years, the application of molecular biological techniques to genetic improvements in poplar species has been widely studied in China. Recent advances in molecular genetic improvements of poplar, including cDNA library construction, gene cloning and identification, genetic engineering, gene expression, genetic linkage map construction, mapping of quantitative trait loci （QTL） and molecular-assisted selection, are reviewed in the present paper. In addition, the application of modern biotechnology to molecular improvements in the genetic traits of the poplar and some unsolved problems are discussed.

关键词： poplar gene engineering genetic improvement genetic linkage maps molecular marker quantitative trait loci (QTL) mapping

Parameterized expressions for an improved Rouse equation

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International Journal of Sediment Research 2013年第4期28卷 523-534页

作者： Chen CHENG Zhi-yao SONG yi-gang WANG Jin-shan ZHANG School of Marine Sciences Nanjing University of Information Science&Technology Key Laboratory of Virtual Geographic Environment under Ministry of Education and Jiangsu Key Laboratory for Numerical Simulation of Large-Scale Complex SystemNanjing Normal University College of Harbor Coastal and Offshore EngineeringHohai University River Harbor Engineering Department Nanjing Hydraulic Research Institute

The equilibrium profile of suspended sediment concentration（SSC） in steady,uniform turbulent flow has been extensively studied since the proposition of Rouse equation（Rouse,1937）.Many researchers keep studying and attempting to improve the Rouse equation by modifying the mixing length *** and Dey（2009） improved Rouse equation based on the modified sediment diffusivity,however,their proposed sediment diffusivity has two parameters,the depth modification factor α and the reciprocal of the sediment Schmidt number β=1/S;,and the corresponding expressions were not given properly in their *** paper aims to parameterize the relevant coefficients,the results shows:（1）α is parameterized from a reasonable approximation by the analysis of surface boundary condition of SSC;（2） considering some effect factors on the settling velocity,β can be expressed by an extended and modified Montcs-Ippen formula,and its related parameters are calibrated by substantial data about the relationship between the primary Rouse parameter Z.= ω;/*** its counterpart Z.’=ω;/β*** verification with some experimental and field datasets,and comparison with related formula,the results show that the sediment diffusivity and SSC profiles have a good agreement with measured data used the present parameterized expressions of a and β,so the present improved Rouse equation is reasonable,and can be applied in practical ***,an approximation and simplified expression of the improved Rouse equation is deduced by using the approach of perturbation,which can be applied easily for the estimation of suspended sediment transport rate.

关键词： Improved Rouse equation Parameterization Sediment transport

Two New Group 3 LEA Genes of Wheat and Their Functional Analysis in Yeast

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Journal of Integrative Plant Biology 2005年第11期47卷 1372-1381页

作者： Jia-Ning YU Jin-Song ZHANG Lun shan Shou-yi CHEN Department of Life Sciences Northwest Sci- Tech University of Agriculture and Forestry Yangling 712100 China Key Laboratory of Plant Biotechnology Institute of Genetics and Developmental Biology the Chinese Academy of Sciences Beijing 100101 China

The group 3 late embryogenesis abundant （LEA） proteins are thought to protect cells from stresses associated with dehydration during periods of water deficit. To investigate the functions of different members of the group 3 LEA genes, we isolated and characterized two new group 3 LEA genes, namely TaLEA2 and TaLEA3, from wheat （Triticum aestivum L.） and introduced TaLEA2 and TaLEA3 into Saccharmyces cerevisiae to examine the effect of these genes on yeast cell tolerance to osmotic, salt, and cold stresses. The TaLEA2 gene encoded a protein of 211 amino acids and possessed five repeats of 11-mer amino acid motifs. The TaLEA3 gene encoded a polypeptide of 211 amino acids with nine repeated units. Overexpression of TaLEA2 and TaLEA3 improved stress tolerance in transgenic yeast cells when cultured in medium containing sorbitol, salt and-20℃ freezing treatments respectively. However, the yeast transformants with TaLEA2 seemed to be more tolerant to hyperosmotic and freezing stress than transformants with TaLEA3. This implies that a close relationship exists between function and the number of repeats of the 11- mer amino acid motif in the group 3 LEA protein.

关键词： late embryogenesis abundant (LEA) protein Saccharmyces cerevisiae stress tolerance wheat.

Aggregate Characteristics during Natural Revegetation on the Loess Plateau

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Pedosphere 2008年第6期18卷 809-816页

作者： AN Shao-shan HUANG yi-Mei ZHENG Fen-Li YANG Jian-Guo State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources Yangling 712100 （China） Northwest Agriculture and Forestry University Yangling 712100 （China） College of Water Conservancy and Civil Engineering China Agricultural University Beijing 100083 （China） Institute of Agricultural Resources and Environment Ningxia Academy of Agriculture and Forestry Sciences Yinchuan 750002 （China）

Field investigations and laboratory analysis were conducted to study the characteristics of soil water-stable aggregates during vegetation rehabilitation in typical grassland soils of the hilly-gullied loess area. The relationship between water- stable aggregates and other soil properties was analyzed using canonical correlation analysis and principal component analysis. The results show that during the natural revegetation, the aggregates 〉 5 mm dominated and constituted between 50% and 80% of the total soil water-stable aggregates in most of the soil layers. The 2-5 mm aggregate class was the second main component. The mean value of water-stable aggregates 〉 5 mm within the 0-2 m soil profile under different plant communities decreased in the following order： Stipa grandis 〉 Stipa bungeana Trin. 〉 Artemisia sacrorum Ledeb. 〉 Thymus mongolicus Ronn. 〉 Hierochloe odorata （L.） Beauv. Clay, organic matter, and total N were the key factors that influenced the water stability of the aggregates. Total N and organic matter were the main factors that affected the water stability of the aggregates 〉 5 mm and 0.5-1 mm in size. The contents of Fe2O3, Al2O3, and physical clay （〈 0.01 mm） were the main factors which affected the water stability of the 1-2 and 0.25-0.5 mm aggregates.

关键词： canonical correlation analysis loess area natural revegetation principal component analysis soil water- stable aggregates

El Nio–Southern Oscillation and its impact in the changing climate

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National Science Review 2018年第6期5卷 840-857页

作者： Song Yang Zhenning Li Jin-yi Yu Xiaoming Hu Wenjie Dong shan He School of Atmospheric Sciences Sun Yat-sen University Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University Institute of Earth Climate and Environment System Department of Earth System Science University of CaliforniaIrvine CAUSA

Extensive research has improved our understanding and forecast of the occurrence, evolution and global impacts of the El Nio–Southern Oscillation(ENSO). However, ENSO changes as the global climate warms up and it exhibits different characteristics and climate impacts in the twenty-first century from the twentieth century. Climate models project that ENSO will also change in the warming future and have not reached an agreement about the flavor, as to the intensity and the frequency, of future ENSO *** article presents the conventional view of ENSO properties, dynamics and teleconnections, and reviews the emerging understanding of the diversity and associated climate impacts of ENSO. It also reviews the results from investigations into the possible changes in ENSO under the future global-warming scenarios.

关键词： El Nino–Southern Oscillation(ENSO) diversity teleconnections climate impacts ENSO projection

EXPERIMENTAL STUDY ON THE SECOND-ORDER DIFFRACTION WAVE PRESSURE AND FORCE ON A CIRCULAR CYLINDER UNDER STOKES WAVE ACTION

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Journal of Hydrodynamics 1993年第2期5卷 94-103页

作者： Zhou, Zhi-li Tian, Yong-an Dai, yi-shan Huang, Wei-li Harbin Shipbuilding Engineering Inst Harbin China

This paper presents the model test to measure the second-order wave pressure and forces on a circular cylinder fixed in Stokes wave with a given draught. The distributions of second-order oscillating and steady wave pressure on the wet surface of the cylinder and second order oscillating wave forces were obtained in this test, but the second-order steady wave force was not able to be measured due to its very small magnitude. The test results also show that third-order wave force may be greater than the second-order force when wave frequencies are high. The experimental results were compared with the corresponding calculation results of Reference [3].

关键词： Cylinders (shapes) Diffraction Fluid structure interaction Force measurement Hydrodynamics Loads (forces) Mathematical models Pressure effects