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Journal of Hydrodynamics 2020年第1期32卷 107-115页

作者： Xin zhao Chao Wei Shi-hua Yuan Science and Technology on Vehicle Transmission Laborator Bejing Institute of TechnologyBeijing 10081China

A new slip velocity model based on molecular potential theory and macro-force analysis,which is applied in Couette flow with pressure gradient,is built *** model is validated by later being introduced in hydrodynamic system to predict film distribution,which shows a good agreement with experimental data obtained from multi-beam intensity-based tests with Fe and Cu ball materials under accurate controlled temperature,load and different wall *** show that the slip length for Fe case is ignorable so it seems like no slip,but for Cu case,the slip length is large to make 20%discrepancy with no slip simulation and also behaves ***,during the experimental cases when both Fe and Cu ball velocities rise from-133 mm/s to 1330 mm/s,the slip velocity changes its direction with entrainment velocity and thus contributes to first enhance and then diminish the hydrodynamic film,but due to slip length on Cu case varying largely than that on Fe case,the film from Cu case and from Fe case has a clear cross-point between uh=80 mm/s and uh=220 m m/s(ub is the ball speed).The results above support strongly that Cu surface will lead to stronger slip than Fe case because of its smaller solid-liquid interaction,and obviously slip will influence hydrodynamic characteristics prominently.

关键词： Slip Couette flow with pressure gradient hydrodynamic characteristic

Alteration of microbial properties and community structure in soils exposed to napropamide

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Journal of Environmental Sciences 2009年第4期21卷 494-502页

作者： GUO hua CHEN Guofeng LV zhaoping zhao hua YANG Hong Department of Applied Chemistry College of Science Nanjing Agricultural University Nanjing 210095 China Guizhou Provincial Center for Diseases Prevention and Control Guizhou 550004 China

The effect of pesticide napropamide （N,N-diethyl-2-（1-naphthalenyloxy） propanamide） on soil microorganisms for long-term （56 d） was assessed by monitoring changes in soil microbial biological responses. Soils were treated with napropamide at 0, 2, 10, 20, 40, and 80 mg/kg soil and sampled at intervals of 1, 3, 7, 14, 28, 42, and 56 d. The average microbial biomass C declined in napropamide-treated soils as compared to control. The same trend was observed on microbial biomass N after napropamide application. We also determined the basal soil respiration （BSR） and observed a high level in soils treated with napropamide during the first 7 d of experiment. But with the passage of incubation time, BSR with napropamide decreased relatively to control. Application of napropamide at 2-80 mg/kg soil had inhibitory effects on the activity of urease and invertase. Activity of catalase was enhanced during the initial 7 d of napropamide application, but soon recovered to the basal level. The depressed enzyme activities might be due to the toxicity of napropamide to the soil microbial populations. To further understand the effect of napropamide on microbial communities, a PCR- DGGE-based experiment and cluster analysis of 16S rDNA community profiles were performed. Our analysis revealed an apparent difference in bacterial-community composition between the napropamide treatments and control. Addition of napropamide apparently increased the number of bands during the 7-14 d of incubation. These results imply that napropamide-induced toxicity was responsible for the disturbance of the microbial populations in soil.

关键词： napropamide microbial respiration microbial biomass soil enzyme PCR-DGGE bacterial community

Regulating the coordination environment of Ru single-atom catalysts and unravelling the reaction path of acetylene hydrochlorination

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Green Energy & Environment 2023年第4期8卷 1141-1153页

作者： Yang Yang Chaoyue zhao Xianliang Qiao Qingxin guan Wei Li State Key Laboratory of Elemento-Organic Chemistry Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)College of ChemistryNankai UniversityNo.94 Weijin RoadTianjin300071China

In this work,DFT calculations were used firstly to simulate the nitrogen coordinated metal single-atom catalysts(M-N_(x)SACs,M=Hg,Cu,Au,and Ru) to predict their catalytic activities in acetylene *** DFT results showed that Ru-N_(x)SACs had the best catalytic performance among the four catalysts,and Ru-N_(x)SACs could effectively inhibit the reduction of ruthenium *** verify the DFT results,Ru-N_(x)SACs were fabricated by pyrolyzing MOFs in-situ spatially confined metal *** N coordination environment could be controlled by changing the pyrolysis *** performance tests indicated that low N coordination number(Ru-N_(2),Ru-N_(3))exhibited excellent catalytic activity and stability compared to RuCl_(3)*** calculations further revealed that Ru-N_(2)and Ru-N_(3)had a tendency to activate HCl at the first step of reaction,whereas Ru-N4tended to activate C_(2)H_(2).These findings will serve as a reference for the design and control of metal active sites.

关键词： Single-atom catalyst Coordination environment Ru-based catalyst DFT calculations Acetylene hydrochlorination

Finite-time Control for a Class of Networked Control Systems with Short Time-varying Delays and Sampling Jitter

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International Journal of Automation and computing 2015年第4期12卷 448-454页

作者： Chang-Chun hua Shao-Chong Yu Xin-Ping guan Department of Electrical Engineering University of Yanshan Department of Automation Shanghai Jiaotong University

This paper is concerned with the finite-time control problem for a class of networked control systems(NCSs) with short time-varying delays and sampling *** a state feedback controller,the closed-loop NCS is described as a discrete-time linear system model,and the uncertain parts reflect the effect of the the network-induced delays and short sampling jitter of the system *** a robust approach is proposed to solve the finite-time stability and stabilization problems for the considered *** illustrative example is provided to demonstrate the effectiveness of the proposed theoretical results.

关键词： Networked control system(NCS) time-varying delay sampling jitter finite-time stability state feedback.

New flexible CsPbBr_(3)-based scintillator for X-ray tomography

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Nuclear Science and Techniques 2022年第8期33卷 34-44页

作者： Zhi-Wei Lü Gong-Xiang Wei Han-Qiu Wang Yu guan Ning Jiang Yun-Yan Liu zhao Li hua Qin Hui-Qiang Liu School of Physics and Optoelectronic Engineering Shandong University of TechnologyZibo 255000China

The evolution of lead halide perovskites used for X-ray imaging scintillators has been facilitated by the development of solution-processable semiconductors characterized by large-area,flexible,fast *** stability and durability of these new perovskites are insufficient to achieve extended computed tomography scanning times with hard *** this study,we fabricated a self-assembled CsPbBr_(3)-based scintillator film with a flexible large-area uniform thickness using a new roomtemperature solution-processable *** sensitivity and responsivity of X-ray photon conversion were quantitatively measured and showed a good linear response relationship suitable for X-ray *** also demonstrated,for the first time,that the self-assembled CsPbBr_(3)-based scintillator has good stability for hard X-ray ***,such an inexpensive solution-processed semiconductor easily prepared at room temperature can be used as a hard X-ray scintillator and equipped with flexible CsPbBr3-based X-ray *** has great potential in three-dimensional high-resolution phase-contrast X-ray-imaging applications in biomedicine and material science because of its heavy Pb and Br atoms.

关键词： X-ray scintillator X-ray illumination Computed tomography CsPbBr_(3)-based film perovskite Solution-processable semiconductor

Identification of multi-target anti-cancer agents from TCM formula by in silico prediction and in vitro validation

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Chinese Journal of Natural Medicines 2022年第5期20卷 332-351页

作者： ZHANG Bao-Yue ZHENG Yi-Fu zhao Jun KANG De WANG Zhe XU Lv-Jie LIU Ai-Lin DU guan-hua State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China School of Life Sciences Tsinghua UniversityBeijing 100084China

Cancer is a complex disease associated with multiple gene mutations and malignant phenotypes,and multi-target drugs provide a promising therapy idea for the treatment of *** products with abundant chemical structure types and rich pharmacological characteristics could be ideal sources for screening multi-target antineoplastic *** this paper,50 tumor-related targets were collected by searching the Therapeutic Target Database and Thomson Reuters Integrity database,and a multi-target anti-cancer prediction system based on mt-QSAR models was constructed by using naïve Bayesian and recursive partitioning algorithm for the first *** the multi-target anti-cancer prediction system,some dominant fragments that act on multiple tumor-related targets were analyzed,which could be helpful in designing multi-target anti-cancer ***-cancer traditional Chinese medicine(TCM)and its natural products were collected to form a TCM formula-based natural products library,and the potential targets of the natural products in the library were predicted by multi-target anti-cancer prediction *** a result,alkaloids,flavonoids and terpenoids were predicted to act on multiple tumor-related *** predicted targets of some representative compounds were verified according to literature review and most of the selected natural compounds were found to exert certain anti-cancer activity in vitro biological *** conclusion,the multi-target anti-cancer prediction system is very effective and reliable,and it could be further used for elucidating the functional mechanism of anti-cancer TCM formula and screening for multi-target anti-cancer *** anti-cancer natural compounds found in this paper will lay important information for further study.

关键词： Cancer Multi-target mt-QSAR model Nave Bayesian Recursive partitioning TCM formulae

Modeling Soil Water Retention Curve with a Fractal Method

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Pedosphere 2006年第2期16卷 137-146页

作者： huaNG guan-hua ZHANG Ren-Duo huaNG Quan-Zhong Department of Irrigation and Drainage Chinese-Israeli International Center for Research and Training in Agriculture China Agricultural University Beijing 100083 （China）. Department of Renewable Resources University of Wyoming Laramie WY 82071-3354 （USA）

Many empirical models have been developed to describe the soil water retention curve (SWRC). In this study, a fractal model for SWRC was derived with a specially constructed Menger sponge to describe the fractal scaling behavior of soil; relationships were established among the fractal dimension of SWRC, the fractal dimension of soil mass, and soil texture; and the model was used to estimate SWRC with the estimated results being compared to experimental data for verification. The derived fractal model was in a power-law form, similar to the Brooks-Corey and Campbell empirical functions. Experimental data of particle size distribution (PSD), texture, and soil water retention for 10 soils collected at different places in China were used to estimate the fractal dimension of SWRC and the mass fractal dimension. The fractal dimension of SWRC and the mass fractal dimension were linearly related. Also, both of the fractal dimensions were dependent on soil texture, i.e., clay and sand contents. Expressions were proposed to quantify the relationships. Based on the relationships, four methods were used to determine the fractal dimension of SWRC and the model was applied to estimate soil water content at a wide range of tension values. The estimated results compared well with the measured data having relative errors less than 10% for over 60% of the measurements. Thus, this model, estimating the fractal dimension using soil textural data, offered an alternative for predicting SWRC.

关键词： fractal dimension soil texture soil water retention curve

Inheritance of social dominance is associated with global sperm DNA methylation in inbred male mice

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Current Zoology 2023年第2期69卷 143-155页

作者： guan-Mei Hou Yao-hua Zhang Jian-Xu Zhang The State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijing 100101China CAS Center for Excellence in Biotic Interactions University of Chinese Academy of SciencesBeijing 100101China

Dominance relationships between males and their associated traits are usually heritable and have implications for sexual selection in *** particular,social dominance and its related male pheromones are heritable in inbred mice;thus,we wondered whether epigenetic changes due to altered levels of DNA methylation determine ***,we used C57BL/6 male mice to establish a social dominance-subordination relationship through chronic dyadic encounters,and this relationship and pheromone covariation occurred in their offspring,indicative of *** transcriptome sequencing and whole-genome DNA methylation profiling of the sperm of both generations,we found that differential methylation of many genes was induced by social dominance-subordination in sires and could be passed on to the *** methylated genes were mainly related to growth and development processes,neurodevelopment,and cellular *** expression of the genes with similar functions in whole-genome methylation/bisulfite sequencing was also differentiated by social dominance-subordination,as revealed by *** particular,the gene Dennd1a,which regulates neural signaling,was differentially methylated and expressed in the sperm and medial prefrontal cortex in paired males before and after dominance-subordination establishment,suggesting the potential epigenetic control and inheritance of social dominance-related *** suggest that social dominance might be passed on to male offspring through sperm DNA methylation and that the differences could potentially affect male competition in offspring by affecting the development of thenervous system.

关键词： aggression epigenetic inheritance pheromone social hierarchy WGBs

Homocysteine, hypertension, and risks of cardiovascular events and all-cause death in the Chinese elderly population: a prospective study

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Journal of Geriatric Cardiology 2021年第10期18卷 796-808页

作者： Zhong-Ying ZHANG Xiang GU Zhe TANG Shao-Chen guan Hong-Jun LIU Xiao-guang WU Yan zhao Xiang-hua FANG Geriatric Department Xuanwu HospitalCapital Medical UniversityBeijingChina Evidence-based Medical Center Xuanwu HospitalCapital Medical UniversityBeijingChina Medical Affair Department Beijing Friendship HospitalCapital Medical UniversityBeijingChina Beijing Geriatric Healthcare Center Xuanwu HospitalCapital Medical UniversityBeijingChina Education Department Xuanwu HospitalCapital Medical UniversityBeijingChina

BACKGROUND Increased homocysteine levels are associated with the risk of cardiovascular disease(CVD)and ***,their prevention has not been effective in decreasing CVD *** study investigated the individual and combined associations of hyperhomocysteinemia and hypertension with incident CVD events and all-cause death in the Chinese elderly population without a history of *** This prospective study was conducted among 1,257 elderly participants(mean age:69 years).A questionnaire survey,physical examinations,and laboratory tests were conducted to collect baseline *** was defined as homocysteine level≥15μmol/L.H-type hypertension was defined as concomitant hypertension and *** Cox regression analysis was used to evaluate individual and combined associations of hyperhomocysteinemia and hypertension with the risks of incident CVD events and all-cause *** Over a median of 4.84-year follow-up,hyperhomocysteinemia was independently associated with incident CVD events and all-cause *** hazard ratios(HRs)were 1.45(95%CI:1.01−2.08)for incident CVD events and 1.55(95%CI:1.04−2.30)for all-cause *** adjustment for confounding factors,H-type hypertension had the highest HRs for incident CVD events and all-cause *** fully adjusted HRs were 2.44 for incident CVD events(95%CI:1.28−4.65),2.07 for stroke events(95%CI:1.01−4.29),8.33 for coronary events(95%CI:1.10−63.11),and 2.31 for all-cause death(95%CI:1.15−4.62).CONCLUSIONS Hyperhomocysteinemia was an independent risk factor,and when accompanied by hypertension,it contrib-uted to incident CVD events and all-cause death in the Chinese elderly population without a history of CVD.

关键词： hypertension prospective prevention

Microstructure and Mechanical Properties in Friction Stir Welded Thick Al–Zn–Mg–Cu Alloy Plate

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Acta Metallurgica Sinica(English Letters) 2022年第8期35卷 1329-1342页

作者： Fei Qiang Wen Wang Ke Qiao Pai Peng Ting Zhang Xiao-Hu guan Jun Cai Qiang Meng hua-Xia zhao Kuai-She Wang School of Metallurgical Engineering National and Local Joint Engineering Research Center for Functional Materials ProcessingXi'an University of Architecture and TechnologyXi'an 710055China Northwest Institute for Non-Ferrous Metal Research Xian 710016China AVIC Manufacturing Technology Institute Bejing 100024China Beijing FSW Technology Co.Ltd Bejing 101107China

In this work, 20-mm-thick aluminum-alloy plates were joined via friction stir welding. The temperature gradient was reduced by reducing the surface welding heat input to achieve uniformity of the mechanical properties across the thick plate joints. The welding temperature was measured using thermocouples. The microstructures were observed via electron backscatter diff raction and transmission electron microscopy. The tensile properties of the samples sliced along the thickness direction of the joint were evaluated. The results show that the highest welding peak temperature is 430℃ on the advancing side on the top surface of the joint. The grain size gradually decreased along the thickness direction, and grain refi nement was due to the combination of continuous, discontinuous, and geometric dynamic recrystallization. The tensile properties of the sliced samples were found to be uniform, and the ultimate tensile strength reached 62% of that of the base metal. The main strengthening mechanism of the Al–Zn–Mg–Cu alloy joints consists of precipitation strengthening. In addition, the η ` → η phase transition and grain coarsening in the heat-affected zone were found to be responsible for the fracture of the joints.

关键词： Friction stir welding Aluminum alloy thick plate Dynamic recrystallization Mechanical properties Precipitated phase