检索结果-南通市图书馆

Mechanochemical reactions of gaN-Al_(2)O_(3) interface at the nanoasperity contact:Roles of crystallographic polarity and ambient humidity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2022年第7期10卷 1005-1018页

作者： Jian gUO Jian gaO chen XIAO Lei chen Linmao QIAN School of Mechanical Engineering University of South ChinaHengyang 421001China Tribology Research Institute State Key Laboratory of Traction PowerSouthwest Jiaotong UniversityChengdu 610031China Advanced Research Center for Nanolithography(ARCNL) Science Park 106Amsterdam 1098XGthe Netherlands Technology and Equipment of Rail Transit Operation and Maintenance Key Laboratory of Sichuan Province Southwest Jiaotong UniversityChengdu 610031China

Mechanochemical reactions of the gaN-Al_(2)O_(3) interface offer a novel principle for scientific and technological merits in the micro-/nano-scale ultra-precision surface *** this work,the mechanochemical reactions on ga-and N-faced gaN surfaces rubbed by the Al_(2)O_(3) nanoasperity as a function of the environmental humidity were *** results indicate that the N-face exhibits much stronger mechanochemical removal over the relative humidity range of 20%-80%than the *** water molecules in environmental conditions significantly promotes the interfacial mechanochemical reactions and hence accelerates the atomic attrition on *** hypothesized mechanism of the selective water-involved mechanochemical removal is associated with the dangling bond configuration,which affects the mechanically-stimulated chemical reactions via altering the activation energy barrier to form the bonding bridge across the sliding *** findings can enrich the understanding of the underlying mechanism of mechanochemical reactions at gaN-Al_(2)O_(3) interface and a broad cognition for regulating the mechanochemical reactions widely existing in scientific and engineering applications.

关键词： crystallographic polarity ambient humidity mechanochemical removal gaN-Al_(2)O_(3)interface

Arabidopsis WRKY45 Interacts with the DELLA Protein RgL1 to Positively Regulate Age- Triaaered Leaf Senescence

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2017年第9期10卷 1174-1189页

作者： Liga.g chen University of Chinese Academy of Sciences Beijing 100049 China

Leaf senescence can be triggered and promoted by various environmental stressors, developmental cues, and endogenous hormone signals. Several lines of evidence have suggested the involvement of WRKY transcription factors in regulating leaf senescence, but the underlying mechanisms and signaling pathways involved remain elusive. In this study, we identified Arabidopsis thaliana WRKY DNA-binding protein 45 （WRKY45） as a positive regulator of age-triggered leaf senescence. Loss of W^KY45 function resulted in increased leaf longevity in age-triggered senescence, whereas overexpression of WRKY45 significantly accelerated age-triggered leaf senescence. Consistently, expression of SENESCENCE- ASSOCIATED gENEs （SAgs） was significantly reduced in wrky45 mutants but markedly enhanced in transgenic plants overexpressing WRKY45. Chromatin immunoprecipitation assays revealed that WRKY45 directly binds the promoters of several SAgs such as SAg12, SAg13, SAg113, and SEN4. Both in vivo and in vitro biochemical analyses demonstrated that WRKY45 interacts with the DELLA pro- tein Rga-LIKE1 （RgL1）, a repressor of the gibberellin （ga） signaling pathway. We found that RgL1 repressed the transcription activation function of WRKY45, thereby attenuating the expression of its reg- ulon. Consistent with this finding, overexpression of RgL1 resulted in significantly increased leaf longevity in age-triggered senescence. Taken together, our results provide compelling evidence that WRKY45 functions as a critical component of the ga-mediated signaling pathway to positively regulate age-triggered leaf senescence.

关键词： senescence WRKY transcription factor DELLA protein gibberellin

Thin-film composite forward osmosis membranes with substrate layer composed of polysulfone blended with PEg or polysulfone grafted PEg methyl ether methacrylate

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2016年第4期10卷 562-574页

作者： Baicang Liu chen chen Pingju Zhao Tong Li Caihong Liu Qingyuan Wang Yongsheng chen John Crittenden College of Architecture and Environment Sichuan University Chengdu 610065 China Institute of New Energy and Low Carbon Technology Siehnan University Chengdu 610207 China Litree Purifying Technology Co. Ltd Haikou 571126 China Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin 150090 China School of Civil and Environmental Engineering Georgia Institute of Technology Atlanta GA 30332 USA

To advance commercial application of forward osmosis （FO）, we investigated the effects of two additives on the performance of polysulfone （PSf） based FO membranes： one is poly（ethylene glycol）（PEg）, and another is PSf grafted with PEg methyl ether methacrylate （PSf-g-PEgMA）. PSf blended with PEg or PSf-g- PEgMA was used to form a substrate layer, and then polyamide was formed on a support layer by interfacial polymerization. In this study, NaC1 （1 mol·L^-1） and deionized water were used as the draw solution and the feed solution, respectively. With the increase of PEg content from 0 to 15 wt-%, FO water flux declined by 23.4% to 59.3% compared to a PSf TFC FO membrane. With the increase of PSf-g-PEgMA from 0 to 15 wt-%, the membrane flux showed almost no change at first and then declined by about 52.0% and 50.4%. The PSfwith 5 wt-% PSf-g-PEgMA FO membrane showed a higher pure water flux of 8.74 L·m^-2·h^-1 than the commercial HTI membranes （6-8 L·m^-2·h^-1） under the FO mode. Our study suggests that hydrophobic interface is very important for the formation ofpolyamide, and a small amount of PSf- g-PEgMA can maintain a good condition for the formation of polyamide and reduce internal concentration polarization.

关键词： thin-film composite forward osmosis amphi-philic copolymer interfacial polymerization poly(ethyleneglycol)

Reactivity of Al-rich Alloys with Water Promoted by Liquid Al grain Boundary Phases

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2017年第4期33卷 397-403页

作者： Tiantian He Wei Wang Wei chen Demin chen Ke Yang Institute of Metal Research Chinese Academy of Sciences

Al–ga–Sn, Al–ga–In and Al–ga–In–Sn alloys were prepared using arc melting technique. Their microstructures were investigated by X-ray diffraction and scanning electron microscopy with energy dispersed X-ray. Based on microstructure analysis, the phase constituents of alloys at Al grain boundaries were identified. The melting points of Al grain boundary phases were measured using differential scanning *** reactivities of Al–water at different water temperatures indicate that liquid Al grain boundary phases promote Al–water reactions of alloys. The melting points of Al grain boundary phases affect the reaction temperatures of Al–water, leading to different reaction temperatures of alloys. The measured H2 generation rate and yields of alloys are related to the compositions of alloys. The theory of microgalvanic cell is used to explain the observed different H2 generation rates of alloys.

关键词： AI alloy Microstructure Composition Reaction Hydrogen generation rate

Electrophoretic deposition of silk fibroin coatings with pre-defined architecture to facilitate precise control over drug delivery

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2021年第11期6卷 4243-4254页

作者： Xian cheng Dingpei Long Lili chen John A.Jansen Sander C.g.Leeuwenburgh Fang Yang Department of Dentistry-Biomaterials Radboud Institute for Molecular Life SciencesRadboud University Medical CenterPhilips van Leydenlaan 256525EX Nijmegenthe Netherlands Jiangsu Key Laboratory of Oral Diseases Nanjing Medical UniversityNanjing210029PR China Institute for Biomedical Sciences Center for Diagnostics&TherapeuticsGeorgia State UniversityAtlantaGA30302USA Department of Stomatology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022PR China

The therapeutic precision and clinical applicability of drug-eluting coatings can be substantially improved by facilitating tunable drug ***,the design of coatings which allows for precise control over drug release kinetics is still a major ***,a double-layered silk fibroin(SF)coating system was constructed by sequential electrophoretic deposition.A mixture of dissolved Bombyx mori SF(bmSF)molecules and pre-made bmSF nanospheres at different ratios was deposited as ***,this underlayer was covered by a top-layer comprising Antheraea pernyi SF(apSF)molecules(rich in arginylglycylaspartic acid,RgD)to improve the cellular response of the resulting double-layered ***,model drug doxycycline was either pre-mixed with dissolved bmSF molecules or pre-loaded into pre-made bmSF nanospheres at the same amount before their mixing and *** thickness and nanosphere content of the under-layer architecture were proportional to the deposition time and nanosphere concentration in precursor mixtures,*** surface topography,wettability,degradation rate and adhesion strength were comparable within the double-layered coating *** expected,RgD-rich apSF top-layer improved cell adhesion,spreading and proliferation compared with bmSF ***,the amount and duration of drug release increased linearly with increasing nanosphere concentration at fixed deposition time,whereas drug release amount increased linearly with increasing deposition *** results indicate that the dosage and kinetics of loaded drugs can be quantitatively tailored by altering nanosphere concentration and deposition time as main processing ***,this study illustrates the strong potential of pre-defining coating architecture to facilitate control over drug delivery.

关键词： Electrophoretic deposition Coating Drug delivery kinetics Silk fibroin Nanospheres

Influence of multi-photon excitation on the atomic above-threshold ionization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第4期24卷 138-142页

作者：田原野王春成李苏宇郭福明丁大军 Roeterdink Wim-ga 陈基根曾思良刘学深杨玉军 Institute of Atomic and Molecular Physics Jilin University Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy Jilin University Department of Physics and Materials Engineering Taizhou University Data Center for High Energy Density Physics Institute of Applied Physics and Computational Mathematics Science and Technology Computational Physics Laboratory Institute of Applied Physics and Computational Mathematics

Using the time-dependent pseudo-spectral scheme, we solve the time-dependent Schrodinger equation of a hydrogen- like atom in a strong laser field in momentum space. The intensity-resolved photoelectron energy spectrum in abovethreshold ionization is obtained and further analyzed. We find that with the increase of the laser intensity, the abovethreshold ionization emission spectrum exhibits periodic resonance structure. By analyzing the population of atomic bound states, we find that it is the multi-photon excitation of bound state that leads to the occurrence of this phenomenon, which is in fairly good agreement with the experimental results.

关键词： time-dependent pseudo-spectral scheme above-threshold ionization resonance structure

Paleo-to Mesoproterozoic Tectono-Magmatic Events Recorded in the Huwan Complex from the Dabie Orogen,Central China:Evidence from Petrology and U-Pb geochronology

在线全文

学校读者我要写书评

暂无评论

Acta geologica Sinica(English Edition) 2023年第4期97卷 1150-1162页

作者： ZHU Jiang chen Yuqiong chen Chao LI Zhanke SHI Xianbin chen Song ZOU Yuanbing College of Resources and Environment Yangtze UniversityWuhan 430100China Hubei Key Laboratory of Petroleum geochemistry and Environment Yangtze UniversityWuhan 430100China Hubei geological Survey Wuhan 430034China Hubei Key Laboratory of Resources and Eco-environment geology(Hubei geological Bureau) Wuhan 430034China School of Earth Resources China University of GeosciencesWuhan 430074China Sixth geological Brigade Hubei Geological BureauXiaoganHubei 432000China

To better understand the Paleo-to Mesoproterozoic tectonic evolution of the Dabie Orogen in the northern margin of Yangtze Block,we present geochronological data for metasedimentary and metavolcanic rocks in the Huwan complex.A total of 385 detrital zircon LA-ICP-MS analyses for metasedimentary rocks yielded three^(207)Pb/^(206)Pb age populations:1.50-1.80 ga,1.81-1.87 ga and 1.93-2.0 ga,providing a maximum depositional timing of ca.1.50 ga;while metafelsic volcanic gneisses yielded protolith U-Pb ages of 1893±54 *** peak ages are remarkably consistent with the tectonothermal events that occurred in the northern Yangtze Block,indicating the presence of Paleo-to Mesoproterozoic magmatism in the Dabie *** age range of 1.93-2.0 ga correlates with the Paleoproterozoic collision;the age range of 1.81-1.87 ga coincides with the period of the post-orogenic extension;and the age range of 1.50-1.80 ga is interpreted to associate with an extensional *** cores with age of 1732-1965 Ma haveε_(Hf)(t)values ranging from-11.70 to-2.47,indicating that juvenile crust involved in their magma *** to the similar age spectra,we proposed that the nucleus of the Dabie Orogen was close to the Yangtze Block since the *** Huwan complex has an intimate affiliation to the Yangtze Block,and implies multiple orogenic *** was not only experienced the Paleo-Tethys ocean subduction and collision,but also recorded Paleo-to Mesoproterozoic tectono-magmatic events in the Dabie Orogen.

关键词： geochronology detrital zircon Huwan complex Precambrian Yangtze block

Porosity Prediction from Well Logs Using Back Propagation Neural Network Optimized by genetic Algorithm in One Heterogeneous Oil Reservoirs of Ordos Basin, China

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2021年第4期32卷 828-838页

作者： Lin chen Weibing Lin Ping chen Shu Jiang Lu Liu Haiyan Hu Wuhan Center China Geological SurveyWuhan 430205China Energy and geoscience Institute University of UtahSalt Lake City 84108USA Hubei Key Laboratory of Marine geological Resources China University of GeosciencesWuhan 430074China College of Marine Science and Technology China University of GeosciencesWuhan 430074China Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education China University of GeosciencesWuhan 430074China Exploration and Development Institute Huabei Branch Company of SINOPECZhengzhou 450006China School of geosciences Yangtze UniversityWuhan 430100China

A reliable and effective model for reservoir physical property prediction is a key to reservoir characterization and *** present,using well logging data to estimate reservoir physical parameters is an important means for reservoir *** on the characteristics of large quantity and complexity of estimating process,we have attempted to design a nonlinear back propagation neural network model optimized by genetic algorithm(BPNNga)for reservoir porosity *** model is with the advantages of self-learning and self-adaption of back propagation neural network(BPNN),structural parameters optimizing and global searching optimal solution of genetic algorithm(ga).The model is applied to the Chang 8 oil group tight sandstone of Yanchang Formation in southwestern Ordos *** to the correlations between well logging data and measured core porosity data,5 well logging curves(gamma ray,deep induction,density,acoustic,and compensated neutron)are selected as the input neurons while the measured core porosity is selected as the output *** number of hidden layer neurons is defined as 20 by the method of multiple calibrating *** results demonstrate that the average relative error of the model output is 10.77%,indicating the excellent predicting effect of the *** predicting results of the model are compared with the predicting results of conventional multivariate stepwise regression algorithm,and BPNN *** average relative errors of the above models are 12.83%,12.9%,and 13.47%,*** show that the predicting results of the BPNNga model are more accurate than that of the other two,and BPNNga is a more applicable method to estimate the reservoir porosity parameters in the study area.

关键词： porosity prediction well logs back propagation neural network genetic algorithm Ordos Basin Yanchang Formation

同方期刊数据库

ga-based liquid metal as an extreme pressure lubricant for steel-ceramic pairs

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2022年第5期65卷 1107-1115页

作者： YANg DongSheng chen WenYuan chen Jiao SUN QiChun TAN Hui cheng Jun State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China

Extreme pressure lubrication is a crucial engineering problem for many mechanical ***,an extraordinary and novel functional material,ga-based liquid metal(gLM),is found to be a promising extreme pressure lubricant for steel-ceramic sliding pairs and bears applied load above 1500 N.A ga-rich metallic tribofilm forms on the frictional interface during sliding,providing good lubricity and bearing *** addition,the lubrication performance of gLM strongly depends on its composition and the contacting *** ga-In-Sn alloy has superior lubrication to binary ga-In *** lubrication is more effective on the interfaces of AISI52100/Si_(3)N_(4)than on those of AISI52100/SiC sliding pairs.

关键词： liquid metal sliding wear tribochemistry boundary lubrication