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Carbon Emission Effects Driven by Evolution of Chinese Dietary Structure from 1987 to 2020 被引量:1
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作者 ZHU Yuanyuan ZHANG Yan ZHU Xiaohua 《Chinese Geographical Science》 SCIE CSCD 2024年第1期181-194,共14页
Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research ob... Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research object(data excluding Hong Kong,Macao and Taiwan) and used the carbon emission coefficient method to quantitatively measure the food carbon emissions from 1987–2020,then analyzed the carbon emission effects under the evolution of dietary structure.The results showed that during the study period,the Chinese dietary structure gradually changed to a high-carbon consumption pattern.The dietary structure of urban residents developed to a balanced one,while that of rural residents developed to a high-quality one.During the study period,the per capita food carbon emissions and total food consumption of Chinese showed an increasing trend.The per capita food carbon emissions of residents in urban and rural showed an overall upward trend.The total food carbon emissions in urban increased significantly,while that in rural increased first and then decreased.The influence of beef and mutton on carbon emissions is the highest in dietary structure.Compared with the balanced dietary pattern,the food carbon emissions of Chinese residents had not yet reached the peak,but were evolving to a high-carbon consumption pattern. 展开更多
关键词 dietary structure structural evolution carbon emission effects carbon neutrality China
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Effect of strain on structure and electronic properties of monolayer C_(4)N_(4)
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作者 陈昊 徐瑛 +1 位作者 赵家石 周丹 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期595-600,共6页
The first-principles calculations are performed to examine structural,mechanical,and electronic properties at large strain for a monolayer C_(4)N_(4),which has been predicted as an anchoring promising material to atte... The first-principles calculations are performed to examine structural,mechanical,and electronic properties at large strain for a monolayer C_(4)N_(4),which has been predicted as an anchoring promising material to attenuate shuttle effect in Li–S batteries stemming from its large absorption energy and low diffusion energy barrier.Our results show that the ideal strengths of C_(4)N_(4)under tension and pure shear deformation conditions reach 13.9 GPa and 12.5 GPa when the strains are 0.07 and 0.28,respectively.The folded five-membered rings and diverse bonding modes between carbon and nitrogen atoms enhance the ability to resist plastic deformation of C_(4)N_(4).The orderly bond-rearranging behaviors under the weak tensile loading path along the[100]direction cause the impressive semiconductor–metal transition and inverse semiconductor–metal transition.The present results enrich the knowledge of the structure and electronic properties of C_(4)N_(4)under deformations and shed light on exploring other two-dimensional materials under diverse loading conditions. 展开更多
关键词 two-dimensional materials strain effect structural evolution electronic properties
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Electronic structure and effective mass of pristine and Cl-doped CsPbBr_(3)
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作者 魏志远 魏愉昊 +7 位作者 徐申东 彭舒婷 Makoto Hashimoto 路东辉 潘旭 匡泯泉 肖正国 何俊峰 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期167-171,共5页
Organic–inorganic lead halide perovskites(LHPs) have attracted great interest owing to their outstanding optoelectronic properties.Typically,the underlying electronic structure would determinate the physical properti... Organic–inorganic lead halide perovskites(LHPs) have attracted great interest owing to their outstanding optoelectronic properties.Typically,the underlying electronic structure would determinate the physical properties of materials.But as for now,limited studies have been done to reveal the underlying electronic structure of this material system,comparing to the huge amount of investigations on the material synthesis.The effective mass of the valance band is one of the most important physical parameters which plays a dominant role in charge transport and photovoltaic phenomena.In pristine CsPbBr_(3),the Fr?hlich polarons associated with the Pb–Br stretching modes are proposed to be responsible for the effective mass renormalization.In this regard,it would be very interesting to explore the electronic structure in doped LHPs.Here,we report high-resolution angle-resolved photoemission spectroscopy(ARPES) studies on both pristine and Cl-doped CsPbBr_(3).The experimental band dispersions are extracted from ARPES spectra along both ■ and ■ high symmetry directions.DFT calculations are performed and directly compared with the ARPES data.Our results have revealed the band structure of Cl-doped CsPbBr_(3) for the first time,which have also unveiled the effective mass renormalization in the Cl-doped CsPbBr_(3) compound.Doping dependent measurements indicate that the chlorine doping could moderately tune the renormalization strength.These results will help understand the physical properties of LHPs as a function of doping. 展开更多
关键词 lead halide perovskites electronic structure effective mass
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Regulation effect of the grille spacing of a funnel-type grating water–sediment separation structure on the debris flow performance
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作者 LI Shuai GU Tianfeng +2 位作者 WANG Jiading WANG Fei LI Pu 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2283-2304,共22页
The size of pores or the grille spacing of water–sediment separation structures directly affects their regulation effect on the debris flow performance.A suitable pore size or grille spacing can effectively improve t... The size of pores or the grille spacing of water–sediment separation structures directly affects their regulation effect on the debris flow performance.A suitable pore size or grille spacing can effectively improve the water–sediment separation ability of the structure.The new funnel-type grating water–sediment separation structure(FGWSS)combines vertical and horizontal structures and provides a satisfactory water–sediment separation effect.However,the regulation effect of the grille spacing of the structure on the debris flow performance has not been studied.The regulation effect of the structure grille spacing on the debris flow performance is studied through a flume test,and the optimal structure grille spacing is obtained.An empirical equation of the relationship between the relative grille spacing of the structure and the sediment separation rate is established.Finally,the influence of the water–sediment separation structure on the regulation effect of debris flows is examined from two aspects:external factors(properties of debris flows)and internal factors(structural factors).The experimental results show that the gradation characteristics of solid particles in debris flows constitute a key factor affecting the regulation effect of the structure on the debris flow performance.The optimum grille spacing of the FGWSS matches the particle size corresponding to the material distribution curves d85~d90 of the debris flow.The total separation rate of debris flow particles is related to the grille spacing of the structure and the content of coarse and fine particles in the debris flow. 展开更多
关键词 Debris flow Water–sediment separation structure Grille spacing Performance regulation effect
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Analysis of the Application Effect of Structured Healthcare Education in Brittle Diabetic Patients
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作者 Na Deng 《Journal of Contemporary Educational Research》 2024年第6期44-49,共6页
Objective:To explore the application effect of structured healthcare education in patients with brittle diabetes mellitus.Methods:188 brittle diabetic patients admitted to our hospital from May 2021 to December 2023 w... Objective:To explore the application effect of structured healthcare education in patients with brittle diabetes mellitus.Methods:188 brittle diabetic patients admitted to our hospital from May 2021 to December 2023 were selected as the study subjects,and were divided into the control group(n=94)and the observation group(n=94)according to the random number table method.The control group used conventional nursing intervention and the observation group used structured healthcare education.The general information,glycemic indexes,self-efficacy,compliance,and nursing satisfaction of patients in the two groups were observed.Results:There was no statistical significance in the basic information of the two groups of patients(P>0.05);after the intervention,the fasting plasma glucose,2-hour postprandial blood glucose,and HbA1c of the patients in the observation group were lower than those of the control group(P<0.001);after the intervention,the self-efficacy scores of the patients in the two groups increased,and the scores of the observation group were significantly higher than those of the control group(P<0.001);the total adherence rate of the patients in the observation group(90/95.75%)was significantly higher than that of the control group(80/90.10%)(χ^(2)=6.144,P<0.05);and the total satisfaction rate of patients in the observation group(92/97.87%)was significantly higher than that of the control group(78/82.98%)(χ^(2)=12.042,P<0.05).Conclusion:In patients with brittle diabetes mellitus,structured healthcare education can effectively control patients’blood glucose levels,improve patients’self-efficacy and adherence,and enhance patient satisfaction. 展开更多
关键词 structured healthcare education Brittle diabetes mellitus Application effect
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Molecular simulation study on the evolution process of hydrate residual structures into hydrate
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作者 Liwei Cheng Yunfei Li +4 位作者 Jinlong Cui Huibo Qin Fulong Ning Bei Liu Guangjin Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第5期79-91,共13页
The clathrate hydrate memory effect is a fascinating phenomenon with potential applications in carbon capture,utilization and storage(CCUS),gas separation,and gas storage as it can accelerate the secondary formation o... The clathrate hydrate memory effect is a fascinating phenomenon with potential applications in carbon capture,utilization and storage(CCUS),gas separation,and gas storage as it can accelerate the secondary formation of clathrate hydrate.However,the underlying mechanism of this effect remains unclear.To gain a better understanding of the mechanism,we conducted molecular dynamic simulations to simulate the initial formation and reformation processes of methane hydrate.In this work,we showed the evolution process of hydrate residual structures into hydrate cages.The simulation results indicate that the residual structures are closely related to the existence of hydrate memory effect,and the higher the contribution of hydrate dissociated water to the hydrate nucleation process,the faster the hydrate nucleation.After hydrate dissociation,the locally ordered structures still exist after hydrate dissociation and can promote the formation of cluster structures,thus accelerating hydrate nucleation.Additionally,the nucleation process of hydrate and the formation process of clusters are inseparable.The size of clusters composed of cup-cage structures is critical for hydrate nucleation.The residence time at high temperature after hydrate decomposition will affect the strength of the hydrate memory effect.Our simulation results provide microscopic insights into the occurrence of the hydrate memory effect and shed light on the hydrate reformation process at the molecular scale. 展开更多
关键词 Memory effect Molecular simulation Hydrate reformation Residual structures
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A hierarchically structured tin-cobalt composite with an enhanced electronic effect for high-performance CO_(2) electroreduction in a wide potential range 被引量:2
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作者 Xingxing Jiang Xuan Li +5 位作者 Yan Kong Chen Deng Xiaojie Li Qi Hu Hengpan Yang Chuanxin He 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第1期462-469,I0012,共9页
Earth-abundant and nontoxic Sn-based materials have been regarded as promising catalysts for the electrochemical conversion of CO_(2)to C1 products,e.g.,CO and formate.However,it is still difficult for Snbased materia... Earth-abundant and nontoxic Sn-based materials have been regarded as promising catalysts for the electrochemical conversion of CO_(2)to C1 products,e.g.,CO and formate.However,it is still difficult for Snbased materials to obtain satisfactory performance at low-to-moderate overpotentials.Herein,a simple and facile electrospinning technique is utilized to prepare a composite of a bimetallic Sn-Co oxide/carbon matrix with a hollow nanotube structure(Sn Co-HNT).Sn Co-HNT can maintain>90%faradaic efficiencies for C1 products within a wide potential range from-0.6 VRHE to-1.2 VRHE,and a highest 94.1%selectivity towards CO in an H-type cell.Moreover,a 91.2%faradaic efficiency with a 241.3 m A cm^(-2)partial current density for C1 products could be achieved using a flow cell.According to theoretical calculations,the fusing of Sn/Co oxides on the carbon matrix accelerates electron transfer at the atomic level,causing electron deficiency of Sn centers and reversible variation between Co^(2+)and Co^(3+)centers.The synergistic effect of the Sn/Co composition improves the electron affinity of the catalyst surface,which is conducive to the adsorption and stabilization of key intermediates and eventually increases the catalytic activity in CO_(2)electroreduction.This study could provide a new strategy for the construction of oxide-derived catalysts for CO_(2)electroreduction. 展开更多
关键词 Hierarchic structure Tin-cobalt bimetallic oxide Electronic effect CO_(2)electroreduction Wide potential range
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Systematic Review of Community Type 2 Diabetes Structured Health Education (CT2DSHE)
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作者 Gift Phiri 《Open Journal of Nursing》 2024年第8期377-400,共24页
Aim: This paper aims to evaluate disparities of type 2 diabetes structured health education programmes that is utilised within the communities. Design: systematic review, (a type of secondary research design) aiming t... Aim: This paper aims to evaluate disparities of type 2 diabetes structured health education programmes that is utilised within the communities. Design: systematic review, (a type of secondary research design) aiming to summarize the results of prior primary research studies on available evidence Community type 2 diabetes structured education (CT2DSHE). Methods: Research question: Type 2 diabetic structured health education within a community how effective is it? Qualitative Systematic review, defined as a way to get reliable and objective picture of current available evidence on the specific topic—(CT2DSHE), (Denscombe, 2021) through reflexivity synthesis of available data as an example. This is valuable in time constraints such as project assignments that must be met within specific time and also to bring together available evidence together [1]. Results: This review has shown that CT2DSHE is effective with seven out of the eleven authors supporting, three authors against and one was neutral, further showed that knowledge and skills acquired can last longer with patient activation improved among T2DM patients ideal for sustaining their self-management of T2DM. Conclusion: This research provides suggestive answers to the research question: “Type 2 diabetic structured health education within a community how effective is it?”, This has demonstrated CT2DSHE effectiveness in knowledge acquisition and improving T2DM awareness among T2DM patients, whilst evidencing long effects beyond the study times of 3 - 9 months period in relation to patient activation. Also Identified diabetes education self-management on newly diagnosed (DESMOND) patient as CT2DSHE program for recommendation. Patient or Public Contribution: This work aspires to contribute to CT2DSHE in these areas;Influencing policy decision-making for community diabetes care within the UK and world at large., Contributing to already vast knowledge on diabetes self-management and reasons why?, Influencing educators on how CT2DSHEP are designed, delivered by putting the patient at the Centre and bringing different perspectives on CT2DSHEP in one place that is serving users time of having to consult several resources especially busy clinicians [2] [3]. 展开更多
关键词 Community Health EDUCATION effectIVENESS Impact structured and Planned Type 2 Diabetes (T2DM)
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Structure and material study of dielectric laser accelerators based on the inverse Cherenkov effect
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作者 孙斌 何阳帆 +5 位作者 罗若云 章太阳 周强 王少义 王度 赵宗清 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期250-254,共5页
Dielectric laser accelerators(DLAs)are considered promising candidates for on-chip particle accelerators that can achieve high acceleration gradients.This study explores various combinations of dielectric materials an... Dielectric laser accelerators(DLAs)are considered promising candidates for on-chip particle accelerators that can achieve high acceleration gradients.This study explores various combinations of dielectric materials and accelerated structures based on the inverse Cherenkov effect.The designs utilize conventional processing methods and laser parameters currently in use.We optimize the structural model to enhance the gradient of acceleration and the electron energy gain.To achieve higher acceleration gradients and energy gains,the selection of materials and structures should be based on the initial electron energy.Furthermore,we observed that the variation of the acceleration gradient of the material is different at different initial electron energies.These findings suggest that on-chip accelerators are feasible with the help of these structures and materials. 展开更多
关键词 dielectric laser accelerator high gradient accelerator inverse Cherenkov effect accelerated structure and material
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Atomistic simulation of thermal effects and defect structures during nanomachining of copper 被引量:5
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作者 郭永博 梁迎春 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第11期2762-2770,共9页
Molecular dynamics (MD) simulations of monocrystalline copper (100) surface during nanomachining process were performed based on a new 3D simulation model. The material removal mechanism and system temperature dis... Molecular dynamics (MD) simulations of monocrystalline copper (100) surface during nanomachining process were performed based on a new 3D simulation model. The material removal mechanism and system temperature distribution were discussed. The simulation results indicate that the system temperature distribution presents a roughly concentric shape, a steep temperature gradient is observed in diamond cutting tool, and the highest temperature is located in chip. Centrosymmetry parameter method was used to monitor defect structures. Dislocations and vacancies are the two principal types of defect structures. Residual defect structures impose a major change on the workpiece physical properties and machined surface quality. The defect structures in workpiece are temperature dependent. As the temperature increases, the dislocations are mainly mediated from the workpiece surface, while the others are dissociated into point defects. The relatively high cutting speed used in nanomachining results in less defect structures, beneficial to obtain highly machined surface quality. 展开更多
关键词 monocrystalline copper atomistic simulation thermal effects molecular dynamics simulation nanomachining temperature distribution defect structures dislocations VACANCIES
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Effects of Tropical Storm on Mangroves Forest Structure of Dongzhai Harbor in Hainan Island
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作者 邱治军 王旭 +2 位作者 杨怀 张永明 周光益 《Meteorological and Environmental Research》 CAS 2010年第5期80-83,共4页
The effects of tropical storm on the community structure of Sonneratia caseolaris-Sonneratia apetala(S.caseolaris-S.apetala) artificial mangroves and Ceriops tagal-Rhizophora stylosa(C.tagal-R.stylosa) natural mangrov... The effects of tropical storm on the community structure of Sonneratia caseolaris-Sonneratia apetala(S.caseolaris-S.apetala) artificial mangroves and Ceriops tagal-Rhizophora stylosa(C.tagal-R.stylosa) natural mangroves were analyzed in Dongzhai Harbor in Hainan Island,and the results showed that the average tree height,crown width(CW) in east-west direction(E-W) and north-south direction(N-S) of S.caseolaris-S.apetala artificial mangroves were decreased by 2.8%,14.3% and 12.1% respectively,but the average clear bole height was increased by 60.0% after tropical storm.For C.tagal-R.stylosa natural mangroves,the average tree height and clear bole height were increased by 8.3% and 20.0%,but there was no change in CW(E-W) and CW(N-S).Therefore,tropical storm had greater effects on artificial mangroves than natural mangroves.After tropical storm,tree heights of different species increased in the following sequence:C.tagal>R.stylosa>S.apetala>S.caseolaris,and the sequence of effect degree on CW was C.tagal>R.stylosa>S.caseolaris>S.apetala,while it was C.tagal < R.stylosa < S.caseolaris < S.apetala for clear bole height.Under the effect of tropical storm,the average biomass loss and dry biomass loss of S.caseolaris-S.apetala artificial mangroves were 0.22 and 0.13 t/hm2 respectively,while there was a minimal biomass loss in C.tagal-R.stylosa natural mangroves.On the whole,the wind resistance of natural mangroves was better than artificial mangroves,and that of C.tagal was stronger than R.stylosa,while S.caseolaris was better than S.apetala. 展开更多
关键词 Tropical storm MANGROVES Forest structure effect China
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Quantum Effects on Global Structure of Liquid Water
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作者 林珂 胡乃银 +2 位作者 周晓国 刘世林 罗毅 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第2期127-132,I0003,共7页
The structure difference between light and heavy liquid water has been systematically in- vestigated by high precision Raman spectroscopy over the temperature range of 5-85℃. Distinct difference between the Raman spe... The structure difference between light and heavy liquid water has been systematically in- vestigated by high precision Raman spectroscopy over the temperature range of 5-85℃. Distinct difference between the Raman spectral profiles of two different liquid waters is clearly observed. By analyzing the temperature-dependent Raman spectral contour using global fitting procedure, it is found that the micro-structure of heavy water is more ordered than that of light water at the same temperature, and the structure difference between the light and heavy water decreases with the increase of the temperature. The temperature off- set, an indicator for the structure difference, is determined to vary from 28 ℃ to 18 ℃ for the low-to-high temperature. It indicates that quantum effect is significantly not only at low temperature, but also at room temperature. The interaction energy among water molecules has also been estimated from van't Hoff's relationship. The detailed structural information should help to develop reliable force fields for molecular modeling of liquid water. 展开更多
关键词 Light and heavy water Quantum effect Raman spectra structure Temperature offset
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The structural characteristics of dietary fibers from Tremella fuciformis and their hypolipidemic effects in mice 被引量:9
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作者 Shanshan Zhang Xinle Xu +1 位作者 Xu Cao Tingting Liu 《Food Science and Human Wellness》 SCIE CSCD 2023年第2期503-511,共9页
In this study,Tremella fuciformis residues as raw material,dietary fibers from tremella were prepared by multiple enzymes.The structure of dietary fibers from tremella was studied by Fourier transform infrared(FTIR),X... In this study,Tremella fuciformis residues as raw material,dietary fibers from tremella were prepared by multiple enzymes.The structure of dietary fibers from tremella was studied by Fourier transform infrared(FTIR),X-ray diffraction analysis(XRD)and scanning electron microscopy(SEM).We analyzed their lipidlowering properties in vitro(water holding,oil holding swelling cholesterol and sodium cholate binding capacitises)and the hypolipidemic effects in mice.The results showed that tremella dietary fibers presented the infrared absorption spectrum characteristics of polysaccharides and the characteristic diffraction peaks of cellulose type I.SEM results indicated that the surface of insoluble dietary fiber(IDF)was porous,while the soluble dietary fiber(SDF)was relatively compact and spongy.IDF exhibited significantly higher water holding,oil holding,and swelling binding capacities than the corresponding SDF.However,SDF exhibited significantly higher viscosity than IDF.The results showed tremella dietary fibers were significant in swelling,water holding and oil holding,cholesterol and bile acids.In vivo experiment results in mice indicated that SDF has the best effect on hyperlipidemia mice than IDF and total dietary fiber(TDF).SDF showed that the total cholesterol(TC),triglyceride(TG)and low density lipoprotein cholesterol(LDL-C)contents dropped by 28.33%,18.65%,and 48.97%,respectively,while high density lipoprotein cholesterol(HDL-C)content increased by 43.80%.Compared with the high-fat control(HCM)group,the arteriosclerosis index(AI)and liver index(LI)of the SDF group mice showed significant differences,indicating that SDF has a good auxiliary effect of lowering blood lipids.The administration of tremella fibers improved the lipid metabolism disorderly situation of hyperlipidemia mice.These results provide a reference for further research and rational development of T.fuciformis. 展开更多
关键词 Tremella fuciformis Dietary fiber structural characterization Hypolipidemic effects
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The corridor effect of metropolitan spatialextension and optimization of landscape structure—the case of Beijing 被引量:10
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作者 ZONG Yue-guang, TANG Yan-bing, CHEN Hong-chun, GUO Rui-hua(Dept. of Resources & Environment, Beijing Normal University, Beijing 100875, China) 《Journal of Geographical Sciences》 SCIE CSCD 1999年第4期319-325,共7页
Because of the existence of gradient field of the urban center and the corridor effect. underthe drive of going merely after economic benefit, the city intrinsically has the trend of massive growth, and this will se... Because of the existence of gradient field of the urban center and the corridor effect. underthe drive of going merely after economic benefit, the city intrinsically has the trend of massive growth, and this will seriously destroy the urban reasonable landscape structure and the ecological equilibrium.By applying the theory of corridor effect. this paper studies the interactive process between artificialcorridors and natural corridors. At the same time, by studying the Beijing's spatial extension pattern in central urban area during different periods. this paper analyses the corridors extension volume.extension velocity and variant tendency of urban landscape on & directions. Moreover. this paperbrings forward the idea of incorporating the systen of natural corridors into the Beijing'smetropolitan planning, namely to form a star-shaped scattering-group pattern in which artificialcorridors and natural corridors are alternately distributed in order to effectively prevent built-up areafrom massive growth . 展开更多
关键词 metropolitan area corridor effect urban landscape structure
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Crust-Mantle Structure and Coupling Effects on Mineralization : An Example from Jiaodong Gold Ore Deposits Concentrating Area, China 被引量:17
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作者 YangLiqiang DengJun +2 位作者 ZhangZhongjie WangGuangjie WangJianping 《Journal of China University of Geosciences》 SCIE CSCD 2003年第1期42-51,共10页
Based on the results of two dimension velo city structure, 1∶100 000 aeromagnetic anomaly, 1∶200 000 bouguer gravity anom aly and seismic anisotropy of Jiaodong and neighboring region in Shandong, China , the info... Based on the results of two dimension velo city structure, 1∶100 000 aeromagnetic anomaly, 1∶200 000 bouguer gravity anom aly and seismic anisotropy of Jiaodong and neighboring region in Shandong, China , the information of geophysical field was divided into two parts: deep and sh allow focus fields. And then, the information of two different fields was c ombined with that of deep seated geology and ore deposit features. The syntheti c result was adopted to analyze three dimension structure, to probe into crust mantle coupling effects of mineralization and dynamics of ore formation system . 展开更多
关键词 geophysical field crust mantle structure coupling effect dynamics of mineralization Jiaodong area of China.
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Mesh Size Effect in Numerical Simulation of Blast Wave Propagation and Interaction with Structures 被引量:25
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作者 师燕超 李忠献 郝洪 《Transactions of Tianjin University》 EI CAS 2008年第6期396-402,共7页
Numerical method is popular in analysing the blast wave propagation and interaction with structures.However,because of the extremely short duration of blast wave and energy trans-mission between different grids,the nu... Numerical method is popular in analysing the blast wave propagation and interaction with structures.However,because of the extremely short duration of blast wave and energy trans-mission between different grids,the numerical results are sensitive to the finite element mesh size.Previous numerical simulations show that a mesh size acceptable to one blast scenario might not be proper for another case,even though the difference between the two scenarios is very small,indicating a simple numerical mesh size convergence test might not be enough to guarantee accu-rate numerical results.Therefore,both coarse mesh and fine mesh were used in different blast scenarios to investigate the mesh size effect on numerical results of blast wave propagation and interaction with structures.Based on the numerical results and their comparison with field test re-sults and the design charts in TM5-1300,a numerical modification method was proposed to correct the influence of the mesh size on the simulated results.It can be easily used to improve the accu-racy of the numerical results of blast wave propagation and blast loads on structures. 展开更多
关键词 mesh size effect numerical simulation sensitivity blast wave propagation blast load structureS
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Effect of Landform on Seasonal Temperature Structures across China in the Past 52 Years 被引量:8
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作者 LU Aigang PANG Deqian +3 位作者 GE Jianping HE Yuanqing PANG Hongxi YUAN Lingling 《Journal of Mountain Science》 SCIE CSCD 2006年第2期158-167,共10页
The data of 16o national meteorological observatory stations including the long-term monthly temperature data in China were analyzed to study the seasonal variation of the spatial temperature structures across China i... The data of 16o national meteorological observatory stations including the long-term monthly temperature data in China were analyzed to study the seasonal variation of the spatial temperature structures across China in the past half century. It is found that temperature structures differ between seasons: a latitude temperature pattern in winter and a landform temperature pattern in summer, which indicate that the effect of landform on temperature structure is much stronger in summer than that in winter and the effect of latitudinal temperature is much stronger in winter than that in summer. The mechanisms of the seasonal difference in temperature structures are also discussed in this paper. 展开更多
关键词 Landform effect latitude effect seasonal variation temperature structure climate change mechanism China
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Hierarchical structure observation and nanoindentation size effect characterization for a limnetic shell 被引量:4
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作者 Jingru Song Cuncai Fan +1 位作者 Hansong Ma Yueguang Wei 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2015年第3期364-372,共9页
In the present research, hierarchical structure observation and mechanical property characterization for a type of biomaterial are carried out. The investigated bioma- terial is Hyriopsis cumingii, a typical limnetic ... In the present research, hierarchical structure observation and mechanical property characterization for a type of biomaterial are carried out. The investigated bioma- terial is Hyriopsis cumingii, a typical limnetic shell, which consists of two different structural layers, a prismatic "pillar" structure and a nacreous "brick and mortar" structure. The prismatic layer looks like a "pillar forest" with variationsection pillars sized on the order of several tens of microns. The nacreous material looks like a "brick wall" with bricks sized on the order of several microns. Both pillars and bricks are composed of nanoparticles. The mechanical properties of the hierarchical biomaterial are measured by using the nanoindentation test. Hardness and modulus are measured for both the nacre layer and the prismatic layer, respectively. The nanoindentation size effects for the hierarchical structural materials are investigated experimentally. The results show that the prismatic nanostructured material has a higher stiffness and hardness than the nacre nanostructured material. In addition, the nanoindentation size effects for the hierarchical structural materials are described theoretically, by using the trans-scale mechanics theory considering both strain gradient effect and the surface/interface effect. The modeling results are consistent with experimental ones. 展开更多
关键词 Biomaterial Hierarchical structure - Mechan-ical property Nanoindentation size effect Trans-scalemechanics
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Nonlinear effect of the structured light profilometry in the phase-shifting method and error correction 被引量:3
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作者 张万祯 陈浙泊 +2 位作者 夏彬峰 林斌 曹向群 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第4期324-329,共6页
Digital structured light (SL) profilometry is increasingly used in three-dimensional (3D) measurement technology. However, the nonlinearity of the off-the-shelf projectors and cameras seriously reduces the measure... Digital structured light (SL) profilometry is increasingly used in three-dimensional (3D) measurement technology. However, the nonlinearity of the off-the-shelf projectors and cameras seriously reduces the measurement accuracy. In this paper, first, we review the nonlinear effects of the projector-camera system in the phase-shifting structured light depth measurement method. We show that high order harmonic wave components lead to phase error in the phase-shifting method. Then a practical method based on frequency domain filtering is proposed for nonlinear error reduction. By using this method, the nonlinear calibration of the SL system is not required. Moreover, both the nonlinear effects of the projector and the camera can be effectively reduced. The simulations and experiments have verified our nonlinear correction method. 展开更多
关键词 structured light profilometry depth measurement phase-shifting algorithm nonlinear effect
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The cooling effect of crushed rock structures on permafrost under an embankment 被引量:5
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作者 QingBai Wu MingYong Li YongZhi Liu 《Research in Cold and Arid Regions》 2009年第1期39-50,共12页
Based on the analysis and comparison of soil temperature, thermal regime and permafrost table under the experimental embankment of crushed rock structures in Beiluhe, results show that crushed rock structures provide ... Based on the analysis and comparison of soil temperature, thermal regime and permafrost table under the experimental embankment of crushed rock structures in Beiluhe, results show that crushed rock structures provide an extensive cooling effect, which produces a rising permafrost table and decreasing soil temperatures. The rise of the permafrost table under the embankment ranges from an increase of 1.08 m to 1.67 m, with an average of 1.27 m from 2004 to 2007. Mean annual soil temperatures under the crushed rock layer embankment decreased significantly from 2005 to 2007, with average decreases of ?1.03 °C at the depth of 0.5 m, ?1.14 °C at the depth of 1.5 m, and ?0.5 °C at the depth of 5 m. During this period, mean annual soil temperatures under the crushed rock cover embankment showed a slight decrease at shallow depths, with an average decrease of ?0.2 °C at the depth of 0.5 m and 1.5 m, but a slight rise at the depth of 5 m. After the crushed rock structures were closed or crammed with sand, the cooling effect of the crushed rock layer embankment was greatly reduced and that of the crushed rock cover embankment was just slightly reduced. 展开更多
关键词 cooling effect crushed rock structure PERMAFROST
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