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Ginkgolide B promotes the proliferation and differentiation of neural stem cells following cerebral ischemia/reperfusion injury,both in vivo and in vitro

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Neural Regeneration Research 2018年第7期13卷 1204-1211页

作者： Pei-dong zheng Rajneesh Mungur Heng-Jun Zhou Muhammad Hassan Sheng-Nan Jiang Jie-Sheng zheng Department of Neurosurgery the First Affiliated HospitalCollege of MedicineZhejiang University

Neural stem cells have great potential for the development of novel therapies for nervous system ***,the proliferation of endogenous neural stem cells following brain ischemia is insufficient for central nervous system *** B has a robust neuroprotective *** this study,we investigated the cell and molecular mechanisms underlying the neuroprotective effect of ginkgolide B on focal cerebral ischemia/reperfusion injury in vitro and in *** stem cells were treated with 20,40 and 60 mg/L ginkgolide B in *** staining was used to assess cellular expression of neuron-specific enolase,glial fibrillary acid protein and suppressor of cytokine signaling *** treatment with 40 and 60 mg/L ginkgolide B,cells were large,with long ***,the proportions of neuron-specific enolase-,glial fibrillary acid protein-and suppressor of cytokine signaling 2-positive cells increased.A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery *** hours after ischemia,ginkgolide B（20 mg/kg） was intraperitoneally injected,once a *** Longa＇s method was used to assess neurological *** was performed to evaluate the proportion of nestin-,neuron-specific enolase-and glial fibrillary acid protein-positive ***-time quantitative polymerase chain reaction was used to measure m RNA expression of brain-derived neurotrophic factor and epidermal growth *** blot assay was used to analyze the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling *** B decreased the neurological deficit score,increased the proportion of nestin-,neuron-specific enolase-and glial fibrillary acid protein-positive cells,increased the m RNA expression of brain-derived neurotrophic factor and epidermal growth factor,and increased the expression levels of brain-derived neurotrophic factor and suppressor of cytokine sig

关键词： nerve regeneration brain-derived neurotrophic factor epidermal growth factor suppressor of cytokine signaling 2 neuron-specific enolase glial fibrillary acid protein nestin bromodeoxyuridine neurological function middle cerebral artery occlusion astrocytes neural regeneration

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Long-term Stable 2D Dion-Jacobson Phase Perovskite Photodiode with Low Dark Current and High On/off Ratio

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Chinese Journal of Structural Chemistry 2021年第12期40卷 1621-1630,1553页

作者： GU Hao CHEN Shan-Ci zheng Qing-dong College of Chemistry Fuzhou UniversityFuzhou 350000China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China

A two-dimensional(2D)organic-inorganic hybrid perovskite(OIHP)material is considered as a promising candidate for a long-term stable photodetector owing to its outstanding phase and environmental ***,we demonstrate a perovskite photodiode based on the DJ phase 2D perovskite(PDA)(MA)_(n-1)Pb_(n)I_(3n+1)(where PDA is 1,3-propylenediamine,MA is methylamine,nominal n=4).The best-performance device exhibits a high detectivity of 4.57×10^(11) Jones,a responsivity of 0.25 A·W^(-1) at 480 nm,a low dark current density of 9.60×10^(-4) mA cm^(-2),and a remarkable on/off ratio of 3.10×10^(5).The unencapsulated device can maintain 95%of the initial photocurrent density after 90 days under an ambient atmosphere with relative humidity(RH)of 65%,demonstrating its improved stability than the 3D *** excellent stability of the photodiode based on 2D perovskite promises its bright commercial application ftiture.

关键词： two-dimensional perovskite Dion-Jacobson photodiode on/off ratio stability

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Hot Deformation Behavior of GCr15 Steel

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Journal of Iron and Steel Research International 2013年第3期20卷 50-56页

作者： PENG Ning-qi TANG Guang-bo YAO Jun LIU zheng-dong Institute for Structural Materials Central Iron and Steel Research Institute

Hot deformation behavior of GCr15（ASTM 52100） steel was investigated using single-hit compression tests on Gleeble-1500 simulator at the temperature range of 850-1 100 ℃ and strain rate range of 0.1-10 *** flow stress constitutive equation of GCr15 steel during hot deformation was determined by stress-strain curves analysis on the basis of the hyperbolic sine *** the models of dynamic recrystallization fraction and dynamic recrystallization grain size of GCr15 steel were established by the measured curves and microstructure observation in different experimental *** mean activation energy and the time exponent of dynamic recrystallization kinetics equation in the range of experimental conditions were determined to be 356.2 kJ/mol and 2.12,***,the flow stress model was also established by the method of allocating flow stress curve with three main stress values,the saturation stress,the steady state stress and the stress when strain is *** flow stress curves predicted by the developed models under different deformation conditions are in good agreements with the measured ones.

关键词： GCr15 steel hot deformation flow stress dynamic recrystallization

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The role of dynamic transport in the formation of the inverted charge structure in a simulated hailstorm

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Science China Earth Sciences 2016年第7期59卷 1414-1426页

作者： XU Liang Tao ZHANG Yi Jun LIU Heng Yi zheng dong WANG Fei State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences College of Earth Sciences University of Chinese Academy of Sciences Laboratory of Lightning Physics and Protection Engineering Chinese Academy of Meteorological Sciences

The inverted charge structure formation of a hailstorm was investigated using the Advanced Weather Research and Forecasting(WRF-ARW) model coupled with electrification and discharge schemes. Different processes may be responsible for inverted charge structure in different storms and regions. A dynamical-derived mechanism of inverted charge structure formation was confirmed by the numerical model: the inverted structure was formed by strong updraft and downdraft under normal-polarity charging conditions such that the graupel charged negatively in the main charging region in the middle-upper level of the cloud. The simulation results showed the storm presented a normal charge structure before and after hail-fall; while during the hail-fall stage, it showed an inverted charge structure—negative charge region in the upper level of the cloud and a positive charge region in the middle level of the cloud—appearing at the front edge near the strong updraft in the hailstorm. The charging processes between the two particles mainly occurred at the top of the cloud, where the graupel charged negatively and ice crystals positively due to the strong updraft. When the updraft air reached the top of the storm, it would spread to the rear and front. The light ice crystals were transported backward and forward more easily. Meanwhile, the positively charged ice crystals were transported downward by the frontal subsidence, and then a positive charge region formed between the ?10 and ?25°C levels. Subsequently, a negative charge region materialized in the upper level of the cloud, and the inverted charge structure formed.

关键词： Severe storm Mesoscale model Inverted charge structure

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Three-Dimensional Microstructures and Tensile Properties of Pure Iron During Equal Channel Angular Pressing

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Journal of Iron and Steel Research International 2011年第12期18卷 40-44页

作者： YANG Gang YANG Mu-xin LIU zheng-dong WANG Chang Central Iron and Steel Research Institute Beijing 100081 China

Commercial pure iron billets having diameter of 60 mm and length of 180 mm were subjected to equal channel angular pressing（ECAP） at 350 ℃ for 1 to 4 passes via route *** evolutions on three planes（X,Y,Z planes） were characterized by optical microscopy and transmission electron microscopy（TEM）.It was found that after four passes an ultrafine microstructure could be formed on the X plane,but a band structure remained on the Z ***,the mechanical properties exhibited apparent dependence on the *** strength in the x and y directions was higher than that in the z *** microstructural refinement and mechanical properties were discussed in terms of experimental results.

关键词： iron ECAP UFG microstructure mechanical property

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Effect of Mn content on microstructure, tensile and impact properties of SA508Gr.4N steel for reactor pressure vessel

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Journal of Iron and Steel Research International 2020年第4期27卷 461-470页

作者： Xi-kou He Zhi-qiang Yang Zhen Wang Shi-bin Qiao zheng-dong Liu Institute for Special Steels Central Iron and Steel Research InstituteBeijing 100081China Technology Center of Ma’anshan Iron and Steel Co. Ltd.Ma’anshan 243000AnhuiChina

The effect of manganese(Mn)on the microstructure,tensile and impact properties of SA508Gr.4N steel has been experimentally *** influence of Mn content on the substructure of SA508Gr.4N steel was investigated using the scanning electron microscope,electron back-scattered diffractometer and transmission electron *** was found that the increased Mn content had a beneficial effect on both strength and *** of microstructure revealed smaller size of block and larger number of high-angle grain boundaries with higher Mn *** change of the ultimate tensile strength and toughness with increasing Mn content was attributed to the increased hardenability,the number of high-angle grain boundaries and the crack propagation path by the block refining.

关键词： Mn element SA508Gr.4N steel Microstructure Charpy impact toughness Substructure

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A 10-yr Rainfall and Cloud-to-Ground Lightning Climatology over Coastal and Inland Regions of Guangdong,China during the Pre-Summer Rainy Season

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Journal of Meteorological Research 2024年第3期38卷 469-488页

作者： Yuqing RUAN Rudi XIA Xinghua BAO dong zheng Yan SHEN Jinfang YIN State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing100081China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing210044China National Meteorological Information Centre China Meteorological AdministrationBeijing100081China

A comparative analysis of the spatiotemporal distribution characteristics of rainfall and lightning in coastal and inland areas of Guangdong Province of China during the pre-summer rainy season(PSRS)from 2008 to 2017 reveals distinct *** the inland target region(ITR),rainfall is concentrated in the central and eastern mountainous *** exhibits a bimodal diurnal variation,with peaks in the afternoon and *** afternoon peak becomes more pronounced during the post-monsoon-onset period because of the increased rainfall ***,in the coastal target region(CTR),rainfall concentrates around mountainous ***,CTR’s rainfall is weaker than ITR’s during the pre-monsoon-onset period,primarily associated with the lower-level moisture outflow in CTR,but it strengthens significantly during the post-monsoon-onset period owing to enhanced moisture ***’s diurnal rainfall variation transitions from bimodal to a single broad peak during the post-monsoon-onset period,influenced by changes in both rainfall frequency and *** contrast to rainfall,the spatiotemporal distribution of lightning centers remains relatively stable during the *** strongest center is located over ITR’s plains west of the rainfall center,with a secondary center in the western plains of *** activity significantly increases during the post-monsoon-onset period,particularly in ITR,primarily because of the increased lightning *** diurnal lightning flash density and lightning hours show a single afternoon peak in the two target regions,and the timing of the peak in ITR is approximately two hours later than in *** circulation analysis indicates that during early morning,the lower atmosphere is nearly neutral in *** advected warm,moist,unstable airflow,combined with topography,favors convection *** the afternoon,solar radiation increases thermal instability,further enhancing the convection frequency and in

关键词： rainfall lightning spatiotemporal distribution diurnal variation pre-summer rainy season

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Effect of Nd content on microstructure and mechanical properties of as-cast Mg-12Li-3Al alloy

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China Foundry 2017年第4期14卷 279-285页

作者： Tian-shun dong Xiao-dong zheng Tuo Wang Jin-hai Lliu Guo-lu Li School of Materials Science and Engineering Hebei University of TechnologyTianjin 300132China

In order to improve the mechanical properties of Mg-Li alloy with single β phase structure, Mg-12Li-3Al-xNd(x=0.3, 0.7, 1.1, 2.0wt.%) alloy was prepared. Subsequently, the as-cast microstructure and mechanical properties were observed and tested. The results showed that the structure of Mg-12Li-3Al-xNd(x=0.3, 0.7, 1.1, 2.0wt.%) as-cast alloy was composed of β phase matrix and Al_2Nd, Al_(11)Nd_3, MgLiAl_2, Al_4Li_9 and AlLi phases. With the increase of Nd content in the alloy, the Al-Nd intermetallic compounds have a trend to change from needle-like Al_(11)Nd_3 to granular Al_2Nd. The hardness of as-cast Mg-12Li-3Al-xNd(x=0.3, 0.7, 1.1, 2.0wt.%) alloy was stable at room temperature. The tensile strength of Mg-12Li-3Al-1.1Nd was as high as 180 MPa, the elongation rate of Mg-12Li-3Al-0.7Nd reached 53.7%, and the comprehensive mechanical properties of Mg-12Li-3Al-2.0Nd was the best. PLC phenomenon occurred during the tensile process of the alloys at room temperature. Therefore, the β-based Mg-Li alloy with good plasticity as well as enhanced strength can be obtained by a moderate addition of Nd and Al.

关键词： Mg-Li β Nd microstructure mechanical properties

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Towards full-stack deep learning-empowered data processing pipeline for synchrotron tomography experiments

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The Innovation 2024年第1期5卷 127-138页

作者： Zhen Zhang Chun Li Wenhui Wang zheng dong Gongfa Liu Yuhui dong Yi Zhang National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

Synchrotron tomography experiments are transitioning into multifunctional,cross-scale,and dynamic characterizations,enabled by new-generation synchrotron light sources and fast developments in beamline ***,with the spatial and temporal resolving power entering a new era,this transition generates vast amounts of data,which imposes a significant burden on the data processing ***,as a highly accurate and efficient data processing method,deep learning shows great potential to address the big data challenge being encountered at future synchrotron *** this review,we discuss recent advances employing deep learning at different stages of the synchrotron tomography data processing *** also highlight how applications in other data-intensive fields,such as medical imaging and electron tomography,can be migrated to synchrotron ***,we provide our thoughts on possible challenges and opportunities as well as the outlook,envisioning selected deep learning methods,curated big models,and customized learning strategies,all through an intelligent scheduling solution.

关键词： processing pipeline outlook

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Effects of interface adhesive and resin cohesive strength on tensile strength of resin sand based on numerical analysis

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China Foundry 2019年第6期16卷 406-413页

作者： Yun-dong Ji Zi-han Liu Kai-dong zheng Jia-bo Li Hai-xiao Hu dong-feng Cao School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Zhangwu Country Lian Xin Foundry Silica Sand Co. Ltd.Fuxin 123200China

A plane-strain unit-cell finite element model was proposed to study the effects of resin/sand interface adhesive and resin cohesive strength on the overall tensile strength of resin sand,as well as the fracture *** main micro-scale characteristics of the numerical model were extracted from the micrograph of resin sand specimens by three-dimensional X-ray microscopy(3 D-XRM).The extended finite element method(XFEM)and cohesive behavior method were employed to explicitly describe the resin fracture and sand/resin interface debonding,*** corresponding experimental observation of micro-scale failure behavior based on the scanning electron microscopy(SEM)was presented for a *** numerical results show that the initial failure of the model occurs at the sand/resin interface,followed by consequent resin *** on the resin cohesive strength,the location of resin failure varies from the central zones to resin neck arc zones.A typical mixed mode fracture is observed,which is consistent with the corresponding micro-scale experimental *** the resin cohesive strength ranges between 8 and 12 MPa,the resin cracks occur at the central zone of resin bridges and propagate perpendicularly to the tensile direction until through cracks *** a higher range(between 12 and 16 MPa),interface cracks cross with resin cracks,bonding bridges of resin sand are *** interface adhesive strength has a more significant effect on the overall tensile strength of resin sand than the resin cohesive *** overall tensile strength of resin sand increases first then keeps stable with the increase of the resin cohesive *** work attempts to establish a numerical model which accurately describes the complicated mixed mode fracture of resin sand,which is beneficial to understand deeply the fracture mechanism of resin sand.

关键词： resin sand microstructure interface debonding resin crack fracture mode

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