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Journal of Materials Science & Technology 2021年第11期70卷 73-82页

作者： K.Ma Z.y.liu S.Bi X.X.Zhang B.L.Xiao Z.y.Ma Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of ScienceShenyang110016China School of Materials Science and Engineering University of Science and Technology of China72 Wenhua RoadShenyang110016China School of Materials Science and Engineering Guilin University of TechnologyGuilin541004China

The hot deformation behaviors of the bimodal carbon nanotube reinforced 2009Al(CNT/2009Al)composite were studied by establishing processing map and characterizing the microstructure evolution.The results indicate that the grain size in the ultra-fine grained zones was stable during hot deformation,while the coarse grained zones were elongated with their long axis directions tending to be perpendicular to the compression direction.Low temperature with high strain rate(LTHR),as well as high temperature with low strain rate(HTLR)could increase the length/width ratio of the coarse grained zones.However,LTHR and HTLR could cause the instable deformation.The instable deformation at LTHR was induced by severe intragranular plastic deformation and the localized shear crack,while the instable deformation at HTLR resulted from the more deformation component at the coarse grained zones,and the micro-pore initiation due to CNT re-agglomeration at the boundaries between the coarse and the ultra-fine grained zones.

关键词： Carbon nanotube Bimodal Aluminum matrix composite Hot deformation Processing map

Response of lake phytoplankton to climate oscillation on the northeastern Tibetan Plateau: Evidence from a 1400-year-old sedimentary archive

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Science Bulletin 2024年第9期69卷 1208-1211页

作者： Zhang H. Zheng J. Wang R. Liu Y. Gao y. Wu F. Huo S. State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences Beijing 100012 China School of Geography and Ocean Science Nanjing University Nanjing 210023 China State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China Key Laboratory of Water and Sediment Science Ministry of Education College of Environmental Science and Engineering Peking University Beijing 100871 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

The Tibetan Plateau, also known as the Water Tower of Asia, is home to 1424 lakes with areas of greater than 1 km2, and supplies freshwater resources for more than 1.4 billion people [1,2]. In the context of recent global change, the warmer climate has caused prominent changes in the characteristics of the lake evolution on the Tibetan Plateau, such as changes in the hydrology.

关键词： Tibetan Plateau 青藏高原东北部

Modified Cam-Clay model incorporating unified nonlinear strength criterion

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Science China(Technological Sciences) 2011年第4期54卷 805-810页

作者： XIAO yang liu HanLong LIANG Robert y Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai University Nanjing 210098China 2 Geotechnical Research Institute Hohai UniversityNanjing 210098China Department of Civil Engineering University of AkronAkron 44325USA

A unified nonlinear strength criterion(i.e UNS criterion) is proposed,for the sake of versatility,to capture the complex strength behaviors of frictional materials in geotechnical field.It covers wide ranges on the meridian and octahedral planes to describe nonlinear strength behaviors of soils.The Modified Cam-Clay model,incorporating the unified nonlinear strength criterion,is employed as an example to derive working mathematical equations and to illustrate yielding surfaces in three-dimensional stress space for improving the model's predictive capability.The unified nonlinear strength criterion,demonstrated here,is capable of capturing the experimental results of different types of soils on the meridian and octahedral planes.In addition,the revised model,based on this unified nonlinear strength criterion,though very simple,is versatile to predict the true triaxial test results from literature when considering the influences of the intermediate principal stress on strength and deformation under complex stress conditions.

关键词：修正剑桥模型强度准则非线性标准规范预测能力真三轴试验复杂行为材料强度

Multi-scale simulation of columnar-to-equiaxed transition during laser selective melting of rare earth magnesium alloy

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Journal of Materials Science & Technology 2022年第24期119卷 11-24页

作者： W.L.Wang W.Q.liu X.yang R.R.Xu Q.y.Dai School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China

A model of coupling macro finite volume method(FVM) and cellular automata(CA) is proposed in this paper to explore the columnar-to-equiaxed transition(CET) during selective laser melting(SLM) of rare earth magnesium alloy.Taking into account the impact of recoil pressure and Marangoni convection on the molten pool temperature field,the grain structure is simulated.As suggested by the simulation results,with the undissolved Zr serving as heterogeneous nucleation sites,the liquid undercooled layer under the combined action of forced cooling,the temperature gradient and the liquid solute concentration gradient leads to CET.While considering the dissolution of Zr in magnesium matrix,the results demonstrate that the dissolution of element Zr is effective in significantly inhibiting the growth of columnar crystals and ensuring the sufficient constitutional supercooling(CS) required for nucleation.In addition,to raise the preheating temperature contributes to enhancing the outcome of nucleation and incresing the grain size.Invoking the interdependence model(IM),with the cooling rate gradually increasing in the SLM process of magnesium alloy,the nucleation-free zone(NFZ) reduces by decreasing the solute diffusion layer in the front of the solid/liquid(SL) interface and the temperature gradient.The reduction in temperature gradient can promote undercooling for nucleation and facilitate the development of equiaxed crystals.The simulation results are qualitatively verified as highly consistent through experimentation.

关键词： Multi-scale simulation Columnar-to-equiaxed transition Selective laser melting Rare earth magnesium alloy Constitutional supercooling

Rational design of AgGaS/ZnS/ZnS quantum dots with a near-unity photoluminescence quantum yield via double shelling scheme

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Journal of Materials Science & Technology 2024年第2期169卷 235-242页

作者： H.X.Lu H.liu Z.Z.Fu y.y.Chen H.Q.Dai Z.Hu W.L.Zhang R.Q.Guo Institute for Electric Light Sources School of Information Science and TechnologyFudan UniversityShanghai 200433China Institute of Future Lighting Academy for Engineering and TechnologyFudan UniversityShanghai 200433China yiwu Research Institute of Fudan University YiwuZhejiang 322000China Zhongshan-Fudan Joint Innovation Center Zhongshan 528437China

In this study,a two-step method was used to synthesize highly luminescent AgGaS/ZnS/ZnS quantum dots(QDs).In the first step,an inner ZnS shell was formed via a one-pot method,which resulted in a smaller lattice mismatch between the AgGaS core and the outer ZnS shell,thereby facilitating the formation of a thick outer shell.After the two-step shelling process,the synthesized AgGaS/ZnS/ZnS QDs showed an excellent photoluminescence quantum yield(PLQy)of 96.4%with a peak wavelength of 508 nm,repre-senting the highest PLQy reported thus far for AgGaS QDs.Furthermore,the effect of halogen ions in Zn precursors on the shelling process was investigated.It was proposed that the capacity of halogen ions to coordinate with the QDs influenced the balance between Zn cation diffusion and ZnS shelling reaction.Specifically,the ZnS shelling reaction was dominant when ZnCl_(2)was employed,while Zn cation diffusion was the dominant process under the I^(−)-rich environment.This work provides insights into the interfacial restructuring during the ZnS shelling and offers a clear map for the tailored synthesis of core/shell QDs.

关键词： AgGaS Quantum dots Photoluminescence Core/shell Alloyed core/shell interface

2018—2019年度中国医务人员流感疫苗接种情况网络调查

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中华预防医学杂志 2020年第2期54卷 138-138页

作者：谭亚运(编译) liu H Tan y Zhang M 苏州市疾病预防控制中心传染病防治科不详

中国医务人员流感疫苗接种率较低,为了促进医务人员接种流感疫苗,2018年10月国家卫生健康委员会要求医院要为医务人员免费提供流感疫苗接种。为了解2018—2019年度医务人员流感疫苗接种情况及可能的影响因素,该研究利用丁香园注册医务... 详细信息

中国医务人员流感疫苗接种率较低,为了促进医务人员接种流感疫苗,2018年10月国家卫生健康委员会要求医院要为医务人员免费提供流感疫苗接种。为了解2018—2019年度医务人员流感疫苗接种情况及可能的影响因素,该研究利用丁香园注册医务人员进行抽样调查,共调查了4078名医务人员。

关键词：医务人员流感疫苗接种卫生健康抽样调查接种流感疫苗丁香园

Association of polymorphisms in the vascular endothelial growth factor gene and its serum levels with diabetic retinopathy in Chinese patients with type 2 diabetes： A cross-sectional study

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Chinese Medical Journal 2014年第4期127卷 651-657页

作者： Fan XH Wu QH Li y Hao yH Ning N Kang Z Cui y liu RH Department of Social Medicine School of Health ManagementHarbin Medical University Harbin Heilongjiang 150081 China Second Hospital of Harbin Heilongjiang 150001 China Second Hospital of Harbin Heilongjiang i50001 China Wenhua Community Clinics Qiqihar Heilongjiang 161005 China

Background Vascular endothelial growth factor （VEGF） is a major mediator of angiogenesis,and plays a key role in the pathogenesis of diabetic retinopathy （DR）.This study was designed to identify the possible role of VEGF gene polymorphisms in the development of DR in type 2 diabetic patients in Chinese and clarify the relationship between VEGF serum levels and the risk of DR.Methods This cross-sectional study included 1 040 Chinese subjects with type 2 diabetes mellitus.There were 372 patients diagnosed with DR in the case group and 668 patients without DR in the control group.DNA from each patient was analyzed for VEGF polymorphisms of-2578A/C （rs699947）,-1154G/A （rs1570360）,-460C/T （rs833061）,＋405C/G （rs2010963）,and ＋936C/T （rs3025039） using MassARRAy compact analyzer.The VEGF serum levels were quantified by enzyme-linked immunosorbent assay （ELISA）.Results No evidence of association was observed between-2578 A/C （rs699947）,＋405C/G （rs2010963）,＋936C/T （rs3025039）,and DR risk under stringent Bonferroni＆#39;s correction.However,VEGF serum levels were significantly higher in DR patients than those of control group.The genetic variation of VEGF polymorphisms influenced VEGF serum levels; subjects carrying the VEGF-2578 C/C （rs699947） genotype had greater VEGF serum levels than those carrying the C/A genotype and VEGF serum levels were significantly higher in CC genotype of the ＋405C/G （rs2010963） compared with those of the other genotypes.Conclusions The data did not suggest significant association between the VEGF polymorphisms and DR risk under stringent Bonferroni＆#39;s correction.However,our study indicated that DR patients have higher VEGF levels than diabetic patients without retinopathy,and-2578A/C （rs699947） and ＋405C/G （rs2010963） may be important factors in determining serum VEGF levels.

关键词： vascular endothelial growth factor polymorphism genetics diabetic retinopathy

Comparison of cultivation characteristics between a wild Sanghuangporus vaninii strain and domestic three Sanghuangporus species

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Mycosystema 2023年第4期42卷 896-906页

作者： yang y. Zhang Z. liu J. Li C. liu P. Li y. Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi Jilin Agricultural University Jilin Changchun 130118 China Jilin Sanghuang Biotechnology Co. Ltd. Jilin Yanbian 133500 China

A wild strain of Sanghuangporus collected from Quanshuidong forest farm of yanbian Korean Autonomous Prefecture in Jilin Province was identified as Sanghuangporus vaninii according to morphological and phylogenetic evidences. The effects of carbon and nitrogen source, pH value, and temperature on the mycelial growth of the wild strain were investigated by single factor test and optimized by orthogonal experiments. The results showed that the optimal carbon source and nitrogen source was sucrose and yeast extract powder respectively, the optimal pH was 5.0, and the optimal temperature was 29 °C. The domestic cultivation study of the wild strain was carried out, and the mycelial growth rate, primordium differentiation time, agronomic traits and yield of the strain were compared with those of domestically cultivated strains of S. vaninii, S. baumii and S. sanghuang. The comparison results showed that under the same culture conditions, the hyphae of the wild S. vaninii had the fastest growth rate and the best growth vigour; the primordia were rapidly differentiated. The agronomic traits showed excellent and high yielding. S. baumii showed the slowest in hyphal growth, and less in basidiomata yield. S. sanghuang comparatively grow fast but the yield of fruiting bodies was lowest. The wild strain of S. vaninii was named as SH14, and it might become a substitute for the current cultivars of S. vaninii. Copyright © 2023 Institute of Microbiology, CAS. All rights reserved.

关键词： biological characteristics cultivation domestication phylogeny Sanghuangporus

Comparative in vitro Study on Pure Metals(Fe,Mn,Mg,Zn and W) as Biodegradable Metals

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Journal of Materials Science & Technology 2013年第7期29卷 619-627页

作者： J.Cheng B.liu y.H.Wu y.F.Zheng Center for Biomedical Materials and Tissue Engineering Academy for Advanced Interdisciplinary StudiesPeking University State Key Laboratory for Turbulence and Complex System and Department of Materials Science and Engineering College of EngineeringPeking University

Five pure metals including Fe, Mn, Mg, Zn and W have been investigated on their corrosion behavior and in vitro biocompatibility by electrochemical measurement, static immersion test, contact angle measurement, cytotoxicity and hemocompatibility tests. It is found that the sequence of corrosion rate of five metals in Hank＇s solution from high to low is： Mg 〉 Fe 〉 Zn 〉 Mn 〉 W. Fe, Mg and W show no cytotoxicity to L929 and ECV304 cells, Mn induces significant cytotoxicity to both L929 and ECV304 cells, and Zn has almost no inhibition effect on the metabolic activities of ECV304 while largely reduces the cell viability of L929 cells. The hemolysis percentage of five pure metals is lower than 5% except for Mg and platelets adhered on Zn has been activated and pseudopodia-like structures can be observed while platelets on the other four metals keep normal.

关键词： Biodegradable metals Cytotoxicity Corrosion Biocompatibflity

Numerical study on the ozone formation inside street canyons using a chemistry box model

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Journal of Environmental Sciences 2008年第7期20卷 832-837页

作者： Chun-Ho liu Dennis y.C.Leung Department of Mechanical Engineering The University of Hong KongHong Kong.

Tropospheric ozone is a secondary air pollutant produced in the presence of nitrogen oxides (NO_x),volatile organic compounds (VOCs),and solar radiation.In an urban environment,ground-level vehicular exhaust is the major anthropogenic source of ozone precursors.In the cases of street canyons,pollutant dilution is weakened by the surrounding buildings that creates localized high concentration of NO_x and VOCs,and thus leads to high potential of ozone formation.By considering the major physical and chemical p...

关键词： volatile organic compounds VOCs-to-NO_x ratio air quality vehicular emission chemistry box model