检索结果-南通市图书馆

Impact resistance performance and optimization of the sand-EPE composite cushion in rock sheds

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第2期21卷 676-689页

作者： yu Bingxin ZHOU Xiaojun TANG jianhui ZHANG yujin ZHANG yuefeng School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China

Rock sheds are widely used to prevent rockfall disasters along roads in mountainous areas.To improve the capacity of rock sheds for resisting rockfall impact,a sand and expandable polyethylene(EPE)composite cushion was proposed.A series of model experiments of rockfall impact on rock sheds were conducted,and the buried depth of the EPE foam board in the sand layer was considered.The impact load and dynamic response of the rock shed were investigated.The results show that the maximum impact load and dynamic response of the rock shed roof are all significantly less than those of the sand cushion.Moreover,as the distance between the EPE foam board and rock shed roof decreases,the maximum rockfall impact force and impact pressure gradually decrease,and the maximum displacement,acceleration and strain of the rock shed first decrease and then change little.In addition,the vibration acceleration and vertical displacement of the rock shed roof decrease from the centre to the edge and decrease faster along the longitudinal direction than that along the transverse direction.In conclusion,the buffering effect of the sand-EPE composite cushion is better than that of the pure sand cushion,and the EPE foam board at a depth of 1/3 the thickness of the sand layer is appropriate.

关键词： Rockfall Rock shed Impact Composite cushion Buffering effect Dynamic response

Preparation,Characterization and Photothermal Study of PVA/Ti_(2)O_(3) Composite Films

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 658-663页

作者：尚蒙娅 HE Yanyan yu jianhui YAN Jiahui XIE Haodi 李金玲 School of Material Science&Engineering Henan University of TechnologyZhengzhou 450001China College of Advanced Interdis-ciplinary Science and Technology Henan University of TechnologyZhengzhou 450001China

In this work,flexible photothermal PVA/Ti_(2)O_(3) composite films with different amount(0 wt%,5 wt%,10 wt%,15 wt%)of Ti_(2)O_(3) particles modified by steric acid were prepared by a simple solution casting method.The microstructures,XRD patterns,FTIR spectra,UV-Vis-NIR spectra thermo-conductivity,thermo-stability and photothermal effects of these composite films were all characterized.These results indicated that Ti_(2)O_(3) particles were well dispersed throughout the polyvinyl alcohol(PVA)matrix in the PVA/Ti_(2)O_(3) composite films.And Ti_(2)O_(3) particles could also effectively improve the photothermal properties of the composite films which exhibited high light absorption and generated a high temperature(about 57.4℃for film with 15 wt%Ti_(2)O_(3) amount)on the surface when it was irradiated by a simulated sunlight source(1 kW/m^(2)).

关键词： Ti_(2)O_(3)particles solution casting method composite film photothermal conversion

Recent progress in bio-inspired macrostructure array materials with special wettability—from surface engineering to functional applications

在线全文

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第1期6卷 208-256页

作者： Zhongxu Lian jianhui Zhou Wanfei Ren Faze Chen Jinkai Xu Yanling Tian Huadong yu School of Mechanical and Aerospace Engineering Jilin UniversityChangchun 130022People’s Republic of China Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing Changchun University of Science and TechnologyChangchun 130022People’s Republic of China College of Mechanical and Electrical Engineering Changchun University of Science and TechnologyChangchun 130022People’s Republic of China School of Mechanical Engineering Tianjin UniversityTianjin 300350People’s Republic of China School of Engineering University of WarwickCoventry CV47ALUnited Kingdom

Bio-inspired macrostructure array(MAA,size:submillimeter to millimeter scale)materials with special wettability(MAAMs-SW)have attracted significant research attention due to their outstanding performance in many applications,including oil repellency,liquid/droplet manipulation,anti-icing,heat transfer,water collection,and oil–water separation.In this review,we focus on recent developments in the theory,design,fabrication,and application of bio-inspired MAAMs-SW.We first review the history of the basic theory of special wettability and discuss representative structures and corresponding functions of some biological surfaces,thus setting the stage for the design and fabrication of bio-inspired MAAMs-SW.We then summarize the fabrication methods of special wetting MAAs in terms of three categories:additive manufacturing,subtractive manufacturing,and formative manufacturing,as well as their diverse functional applications,providing insights into the development of these MAAMs-SW.Finally,the challenges and directions of future research on bio-inspired MAAMs-SW are briefy addressed.Worldwide efforts,progress,and breakthroughs from surface engineering to functional applications elaborated herein will promote the practical application of bio-inspired MAAMs-SW.

关键词： macrostructure arrays superhydrophobic 3D printing laser droplet manipulation

Females adopt sexual catalepsy to facilitate mating

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2024年第2期70卷 174-181页

作者： Jihe Liu Keke Liu yu Tang Weihua Wang Xiang Xu jianhui Liang Yonghong Xiao Mark A.Elgar College of Life Sciences Jinggangshan UniversityJi'anJiangxi 343009China Pharmaceutical Center Tsinghua UniversityBeijing 100084China College of Life Sciences Hunan Normal UniversityChangshaHunan 410081China School of Pharmaceutical Sciences Peking UniversityBeijing 100083China School of BioSciences University of MelbourneMelbourneVictoria 3010Australia School of Life Sciences and Technology Tongii UniversityShanghai 200092China

Theory predicts that males and females of dioecious species typically engage in an evolutionary sexual conflict over the frequency and choice of mating partner.Female sexual cannibalism,a particularly dramatic illustration of this conflict,is widespread in certain animal taxa including spiders.Nevertheless,females of some funnel weaving spiders that are generally aggressive to conspecifics enter a cataleptic state after male courtship,ensuring the males can mate without risk of attack.In this study,we demonstrated that the physical posture and duration,metabo-lites,and central neurotransmitters of females of Aterigena aculeata in sexual catalepsy closely resemble females in thanatosis but are distinct from those in anesthesia,indicating that the courted females feign death to eliminate the risk of potentially aggressive responses and thereby allow preferred males to mate.Unlike the taxonomically widespread thanatosis,which generally represents a deceptive visual signal that acts against the interest of the receivers,sexual catalepsy of females in the funnel weaving spiders may deliver a sexual-receptive signal to the courting males and thereby benefit both the signal senders and receivers.Therefore,sexual catalepsy in A.aculeata may not reflect a conflict butrather a confluence of interest betweenthe sexes.

关键词： female catalepsy funnel weaving spiders mate choice mating strategy sexual behavior.

Different responses of two adjacent artificial beaches to Typhoon Hato in Zhuhai,China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2024年第2期42卷 511-521页

作者： Jun ZHU Qing WANG Chao ZHAN Fengjuan SUN Wenhao HUA jianhui LIU Hongshuai QI yu YANG Coastal Research Institute Ludong UniversityYantai 264025China Third Institute of Oceanography Ministry of Natural ResourcesXiamen 261005China

Major differences in beach erosion between two neighboring artificial beaches Xiangluwan Beach(XL beach)and Meiliwan Beach(ML beach)in Zhuhai,China,were studied after Super Typhoon Hato.In this study,a fully nonlinear Boussinesq wave model(FUNWAVE)-Total Variation Diminishing(TVD)was used to distinguish the main impact factors,their relative contributions,and the hydrodynamic mechanisms underlying the different beach responses.Results show that compared to the ML beach,the main reason for the relatively weak erosion on Xiangluwan(XL)beach was the smaller beach berm height(accounting for approximately 75.9%of the erosion response).Regarding the beach with a higher berm,the stronger wave-induced undertow flow,along with the higher sediment concentration,led to a higher offshore sediment transport flux,resulting in more severe erosion relative to the beach with a smaller berm height.The second most important reason explaining the weak erosion on XL beach was the absence of seawalls(accounting for approximately 17.9%of the erosion response).Wave reflection induced by the seawall could cause higher suspended sediment concentration,resulting in a toe scouring near the seawall.The offshore submerged breakwater protected XL beach slightly(accounting for approximately 6.1%of the erosion response).Due to the higher water level induced by storm surge,most of the wave energy could penetrate through the submerged breakwater.The effect of the larger berm width of XL beach was negligible.Compared to the beach with a larger berm width,the erosion/deposition regions in the beach with a narrower berm width showed shoreward migration,without significant changes in the erosion/deposition extent.Despite of this,the larger berm width could reduce the wave energy reaching the shoreline.This study of the storm stability of artificial beaches may be applied to beach restoration design.

关键词： beach erosion berm height berm width seawall fully nonlinear Boussinesq wave model(FUNWAVE)

Strategies for improving extraction capacity through preorganization structure:A novel 5,6-bicyclicmalonamide extractant(THPPD)

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第4期42卷 768-774页

作者： Miaomiao Zhang Zhen Yang yuhua Cui jianhui Su Heng Zhao Chengjin Xu Xiaolei Liu Guoxin Sun Xiujing Peng yu Cui School of Chemistry and Chemical Engineering University of JinanJinan250022China Institute for Smart Materials&Engineering University of JinanJinan250022China Shandong Institute for Food and Drug Control Jinan250101China

Rational design of extractant structure to improve the extraction and separation capacity of rare earth elements(REEs)is a long-standing challenge.Herein,a new strategy was proposed to improve the stability of the chelating structure formed by malonamide and REEs.The stability of the chelating structure is greatly improved by using a double-ring framework structure which makes the two carbonyl groups of malonamide unable to rotate freely and both of them point to the metal ion position.Three benzyl groups were used to construct the hydrophobicity of the extractant and the organic shell of the extracted species.Tribenzylhexahydro-pyrrolo-pyridine-dione(THPPD)was designed and synthesized.The structure reduces the energy consumed by rotating carbonyl group in the coordination with metal ions and then improves the extraction ability of extractant.The crystal structure was preorganized as expected,with the two carbonyls pointing in a favorable coordination direction to the structural complement of the metal ion.The extraction behaviors of REEs with THPPD in a nitric acid medium were studied.Compared with N,N’-dibenzyl-N,N’-dimethylmalonamide(DBDM-MA)with a chain structure,the extraction capacity of THPPD is 360 times higher than that of DBDM-MA at 5.0 mol/L sodium nitrate.Furthermore,the binding energy and Gibbs free energy were investigated by density functional theory(DFT)in conjunction with the B3LYP.The theoretical results show that THPPD has more effective interaction with Pr(NO_(3))3 than DBDM-MA.The construction of chelating groups conformation is a worthy direction to improve the coordination ability and even selectivity of extractant.

关键词： Rare earth elements Extraction separation 5,6-bicyclicdiamide extractant

Effect of SiO_(2) nano film deposited on copper and aluminium electrodes on the power frequency breakdown voltage of SF_(6) gas

在线全文

学校读者我要写书评

暂无评论

High Voltage 2023年第4期8卷 791-798页

作者： yu Zheng Shengle Gong Lei Liu Zhihui Xiang Yichen Lv jianhui yu Wenjun Zhou School of Electrical Engineering and Automation Wuhan UniversityWuhanChina State Key Laboratory of HVDC Transmissions Technology China Southern Power GridGuangzhouChina

In order to reveal the effect of insulating nano film on the insulation strength of SF_(6) gas gap,SiO_(2) nano film was deposited on the electrode surface by the plasma-enhanced chemical vapour deposition technique.The power frequency breakdown characteristics of SF_(6) gas under Cu and Al electrodes were obtained before and after coating.The results showed that when the Cu electrode was coated,the breakdown voltage was up to at most 11.5% higher than that of an uncoated Cu electrode in the pressure range of 0.2-0.5 MPa.When the Al electrode was coated,the breakdown voltage of SF_(6) gas was lower than that of an uncoated one in the pressure range of 0.2-0.5 MPa.The breakdown voltage of SF_(6) gas under the Cu electrode was slightly lower than that under the Al electrode,but the breakdown voltages under the coated Cu electrode were significantly higher than that under the coated Al electrode.Through SEM tests,it was found that the surface roughness of the electrode decreases after coating,but particles were formed on the surface of the Al electrode.The content of metal fluoride formed on the coated Al electrode under multiple breakdowns was significantly higher than that on the coated Cu electrode.The research results could provide references for improving insulation performance of GIS equipment.

关键词： coating electrode film

Identifying interlinkages between urbanization and Sustainable Development Goals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geography and Sustainability 2022年第4期3卷 339-346页

作者： Mingxing Chen Liangkan Chen Jiafan Cheng jianhui yu Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Resource and Environment University of Chinese Academy of SciencesBeijing 100049China

Urbanization and Sustainable Development Goals(SDGs)are important global issues in the current“Anthropocene”.Climate change and the COVID-19 pandemic have exacerbated global urban problems and hindered the ability to meet SDGs on time,while the broad interlinkages between urbanization and the SDGs remain poorly understood.This study shows that among the interlinkages of urbanization with 17 SDGs,synergies are observed with 151 targets(89%),among which 67(40%)have stronger synergies,and trade-offs are observed with 66 targets(39%),among which 31(18%)have stronger trade-offs.Furthermore,the synergies and trade-offs between urbanization and the achievement of SDGs are specifically analyzed based on four fundamental interaction fields:(a)public health and social welfare equality;(b)energy consumption and economic growth;(c)natural resource use and ecological/environmental impacts;and(d)international cooperation for development.Finally,based on these analyses,we propose four recommendations for sustainable urbanization,including(a)shared well-being and spatial justice for urban and rural residents;(b)guiding green and low-carbon urban development;(c)building resilient cities;and(d)promoting multilateral cooperation in cities,which can contribute to the achievement of SDGs by 2030.

关键词： Urbanization Sustainable Development Goals(SDGs) Synergies Trade-offs Well-being Anthropocene

Methods for alleviation of impacts of axial diffusion on decomposition products monitoring in gas‐insulated transmission lines

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Voltage 2022年第1期7卷 41-51页

作者： Rui Qiu Weijiang Chen Wenjun Zhou Ming Liu Jianming Zou yu Zheng Han Li Shizhuo Hu jianhui yu School of Electrical Engineering and Automation Wuhan UniversityWuhanChina State Grid Corporation of China BeijingChina Central China Branch of State Grid Corporation of China WuhanChina

Considering the long length of gas‐insulated transmission lines(GILs),novel methods are required to alleviate the impacts of axial diffusion on decomposition products'moni-toring.The diffusion process of two typical decomposition products,SO2 and SO2F2,was studied.During the diffusion experiments,SO2 and SO2F2 were generated by partial discharges.Based on Fick’s law,an axial diffusion model of SO2 and SO2F2 was proposed.By combining the experiment and simulation results,it was found that the diffusion coefficient of SO2 was greater than that of SO2F2.In addition,the concentration variation at different positions would experience some delay and decay in axial direction.The delay and decay were inversely related to the diffusion coefficient and increased with prolongation of the distance.Based on the diffusion characteristics determined,methods for optimising the monitoring positions,correcting concentration,and using the concentration ratio and generation rate were proposed to alleviate the impacts of diffusion.The methods could allow the decomposition products to be monitored in 1 month and reduce the monitoring error to 10%or less.The diffusion model and the methods could be useful for monitoring decomposition products in GILs.

关键词： diffusion axial positions