检索结果-南通市图书馆

Defence Technology（防务技术） 2024年第1期31卷 288-294页

作者： Er-hai An Xiao-xia Li Cun-juan Yu Ying-xin Tan Zi-jun Fan Qing-xia Li Peng Deng Xiong Cao school of Environment and safety engineering North University of ChinaTaiyuan030051PR China College of safety and emergency management engineering Taiyuan University of Science and TechnologyTaiyuan030024PR China

Fe/N-based biomass porous carbon composite(Fe/N-p Carbon) was prepared by a facile high-temperature carbonization method from biomass,and the effect of Fe/N-p Carbon on the thermal decomposition of energetic molecular perovskite-based material DAP-4 was *** porous carbonaceous materials was considered as the micro/nano support layers for in situ deposition of Fe/N ***/Np Carbon was prepared simply by the high-temperature carbonization *** was found that it showed the inherent catalysis properties for thermal decomposition of *** heat release of DAP-4/Fe/N-p Carbon by DSC curves tested had increased slightly,compared from DAP-4/Fe/N-p *** decomposition temperature peak of DAP-4 at the presence of Fe/N-p Carbon had reduced by 79°C from384.4°C(pure DAP-4) to 305.4°C(DAP-4/Fe/N-p Carbon-3).The apparent activation energy of DAP-4thermal decomposition also had decreased by 29.1 J/*** possible catalytic decomposition mechanism of DAP-4 with Fe/N-p Carbon was proposed.

关键词： Biomass materials Porous carbon DAP-4 Thermal decomposition Facile method

A state-of-the-art review of the development of self-healing concrete for resilient infrastructure

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil engineering 2024年第2期18卷 151-169页

作者： Dong LU Xi JIANG Yao ZHANG Shaowei ZHANG Guoyang LU Zhen LENG Department of Civil and Environmental engineering The Hong Kong Polytechnic UniversityHong Kong 999077China Laboratory of Fire safety School of Safety Engineering and Emergency ManagementShijiazhuang Tiedao UniversityShijiazhuang 050043China Department of Architecture and Civil engineering City University of Hong KongHong Kong 999077China

The brittleness of cement composites makes cracks almost inevitable,producing a serious limitation on the lifespan,resilience,and safety of concrete *** address this brittleness,self-healing concrete has been developed for regaining its mechanical and durability properties after becoming cracked,thereby promising sustainable development of concrete *** paper provides a comprehensive review of the latest developments in self-healing *** begins by summarizing the methods used to evaluate the self-healing efficiency of ***,it compares strategies for achieving healing *** then discusses the typical approaches for developing self-healing ***,critical insights are proposed to guide future studies on the development of novel self-healing *** review will be useful for researchers and practitioners interested in the field of self-healing concrete and its potential to improve the durability,resilience,and safety of concrete infrastructure.

关键词： resilient infrastructure sustainable concrete self-healing cracks

Acoustic emission characteristics of damage evolution of multi-scale fiber reinforced rubberized concrete under uniaxial compression and tension after being subjected to high temperatures

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 Structural and Civil engineering 2024年第8期18卷 1237-1266页

作者： Shaoqi ZHANG Yao ZHANG Qianru LEI Yumeng YANG Yichao WANG Fei XU Zhiguo YAN Hehua ZHU Laboratory of Fire safety School of Safety Engineering and Emergency ManagementShijiazhuang Tiedao UniversityShijiazhuang 050043China Structural Health Monitoring and Control Key Laboratory of Hebei Province Shijiazhuang Tiedao UniversityShijiazhuang 050043China Department of Geotechnical engineering Tongji UniversityShanghai 200092China

Recently developed multi-scale fiber(i.e.,CaCO3 whisker,polyvinyl alcohol(PVA)fiber,and steel fiber)reinforced rubberized concrete exhibits excellent mechanical properties and spalling resistance at high *** of macro properties such as strength and Young’s modulus cannot reveal and characterize damage mechanisms,particularly those relating to the multi-scale fiber strengthening *** this study,acoustic emission(AE)technology is applied to investigate the impact of multi-scale fiber on the damage evolution of rubberized concrete exposed to high temperatures,under the uniaxial compression and tension loading *** mechanical properties,AE event location,peak frequency,b-value,the ratio of rise time to amplitude(RA),average frequency(AF)values,and AE energy of specimens are *** results show that the number of events observed using AE gradually increases as the loading *** crumb rubber and fibers inhibit the generation and development of the *** is concluded that both the peak frequency and b-value reflect the extension process of *** the cracks develop from the micro scale to the macro scale,the peak frequency tends to be distributed in a lower frequency range,and the b-value decreases *** the peak stress point,the AE energy increases rapidly and the b-value *** specimens without multi-scale fibers exhibit brittle failure,while the specimens with fibers exhibit ductile *** addition,adding multi-scale fibers and crumb rubber increases the peak frequency in the medium and high frequency ranges,indicating a positive effect on inhibiting crack *** being subjected to high temperatures,the maximum and minimum b-values decrease,reflecting an increase in the number of initial cracks due to thermal ***,the RA and AF values are used to classify tensile and shear *** specimens fracture with more shear cracks under compression,and there are more tensile

关键词： multi-scale fibers acoustic emission fracture damage evolution rubberized concrete

A model for aircraft cabin evacuation considering passenger type

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 safety Science and Resilience 2024年第1期5卷 83-90页

作者： Yaping Ma Jinfeng Yuan Lingling Tan Quanyi Liu Mengling Li Civil Aircraft Fire Science and safety engineering Key Laboratory of Sichuan Province Civil Aviation Flight University of ChinaGuanghan 618307China school of safety Science and emergency management Wuhan University of TechnologyWuhan 430070China

Pedestrian safety evacuation in aircraft cabins has been a challenging problem because of the aircraft’s unique characteristics,such as the diversity of passengers and the restricted evacuation *** is difficult to reproduce evacuation activities in aircraft cabin due to safety concerns and cost *** fill this gap,an improved cellular automaton model of crowd evacuation for aircraft cabin is established by incorporating the characteristics of cabin space structures and passenger *** are divided into healthy individual passengers and disabled-healthy group passengers,whose movement mechanisms are *** on the constructed model,simulation experiments are conducted using the configuration cabin layout of B737-800 as an *** results show that the evacuation time is prolonged with increased passenger density and the number of disabled ***,the overall evacuation time is insignificantly affected by whether disabled-healthy group passengers’seats are close to the aisle or window,and the evacuation efficiency is best when their seats are evenly distributed in the *** evacuation time is the shortest when all cabin doors are open,and pedestrians are evacuated the slowest when the central emergency doors are *** study pro-vides valuable insights into effective strategies for pedestrian evacuation and crowd emergency management of civil aircraft.

关键词： Aircraft cabin evacuation Passenger type Cellular automaton model Pedestrian distribution Evacuation efficiency

Seismic Risk Model for the Beijing–Tianjin–Hebei Region, China:Considering Epistemic Uncertainty from the Seismic Hazard Models

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2024年第3期15卷 434-452页

作者： Jian Ma Katsuichiro Goda Kai Liu Silva Vitor Anirudh Rao Ming Wang Key Laboratory of Earthquake engineering and engineering Vibration Institute of Engineering MechanicsChina Earthquake Administration Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency Management school of National safety and emergency management Beijing Normal University Shenzhen Key Laboratory of Urban Disasters Digital Twin Department of Earth Sciences Western University Global Earthquake Model Foundation

This study presents a probabilistic seismic risk model for the Beijing–Tianjin–Hebei region in China. The model comprises a township-level residential building exposure model, a vulnerability model derived from the Chinese building taxonomy,and a regional probabilistic seismic hazard model. The three components are integrated by a stochastic event-based method of the OpenQuake engine to assess the regional seismic risk in terms of average annual loss and exceedance probability curve at the city, province, and regional levels. The novelty and uniqueness of this study are that a probabilistic seismic risk model for the Beijing–Tianjin–Hebei region in China is developed by considering the impact of site conditions and epistemic uncertainty from the seismic hazard model.

关键词： Beijing–Tianjin–Hebei region Epistemic uncertainty Seismic risk assessment Seismic risk model

Preparation of TiO_(2) Nano-Flower Coating on Ti Substrates with Good Physical Sterilization Effect and Biocompatibility

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1581-1589页

作者： Ruoyu Di Yonghua Sun Runhua Yao Sen Pei Xiaohong Yao Ruiqiang Hang Shanxi Key Laboratory of Biomedical Metal Materials College of Materials Science and EngineeringTaiyuan University of TechnologyTaiyuan030024China College of safety and emergency management engineering Taiyuan University of TechnologyTaiyuan030024China

We report a facile solution method to form titanium oxide(TiO_(2))nano-flower structure on the titanium(Ti)substrates for realizing good physical sterilization and *** first prepare TiO_(2) nanotubes(NT)with a diameter of about 80-100 nm and a length of about 5μm on Ti substrates by anodization,which is utilized as ***,we employ immersion treatment in different concentrations of phosphoric acid solution at 75℃ for 5 h to realize the transformation from TiO_(2) NT to TiO_(2) nano-flower *** addition,we studied the effects of phosphoric acid concentration(1 wt%,2.5 wt%,5 wt% and 10 wt%)on the TiO_(2) nano-flower structure,and the antibacterial properties and biocompatibility of the TiO_(2) nano-flower *** results show that TiO_(2) nano-flower structure become larger and thicker with the increase in the phosphoric acid concentration,and the thickness of the coating can reach 6.88μ***,the TiO_(2) nano-flower structure shows good physical sterilization effect,especially for the TiO_(2) nano-flower structure formed in 10 wt%H^(3)PO_(4) solution,the antibacterial rate can reach 95%.In addition,the TiO_(2) nano-flower structure have no toxicity to the osteoblasts and support cell growth.

关键词： Anodization Biocompatibility Physical sterilization TiO_(2)nano-flower

emergency management capacity assessment for urban rail transit-an example of Beijing Metro Line 13

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transportation safety and Environment 2024年第1期6卷 109-115页

作者： Jiao Liu Yun Qi Wei Wang school of emergency management and safety engineering China University of Mining&Technology(Beijing)Beijing 100083China China safety Science Journal Editorial Department China Occupational Safety and Health AssociationBeijing 100011China College of mechanical engineering and automation Liaoning University of TechnologyJinzhou 121001LiaoningChina

In order to improve the emergency management capability of urban rail transit system and reduce accidents during metro operation,an emergency management capability evaluation method combining analytic hierarchy process(AHP)and technique for order preference by similarity to ideal solution(TOPSIS)is *** on the Prevention Preparation Response Recovery(PPRR)model,factors influencing the emergency management capability of the urban rail transit system are summarized from the perspective of‘human,machine,environment and management’.Then,an emergency management capability evaluation index system containing of 20 secondary indicators is constructed in four stages:emergency prevention,emergency preparation,emergency response and emergency *** weights of indicators are calculated using the AHP method,and the closeness of each indicator to the optimal solution is analysed with the TOPSIS ***,take the Beijing Metro Line 13 as an example to investigate the level of emergency management capability of urban rail *** results show that the emergency management capability of Beijing’s urban rail transit system is‘well’,among which hazard prevention measures(0.31)and emergency response team(0.34)have a greater weight on the emergency management capability of rail *** model can more accurately assess the emergency management capability of urban rail transit and provide a basis for emergency management.

关键词： urban rail transit emergency management capability analytic hierarchy process(AHP) technique for order preference by similarity to ideal solution(TOPSIS) prevention preparation response recovery(PPRR)model

A strategy to synthesize phosphorus-containing nickel phyllosilicate whiskers to enhance the flame retardancy of epoxy composites with excellent mechanical and dry-friction properties

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and engineering 2024年第3期18卷 39-50页

作者： Shibin Nie Zongquan Zhao Yuxuan Xu Wei He Wenli Zhai Jinian Yang school of Public Security and emergency management Anhui University of Science and TechnologyHefei231131China school of safety Science and engineering Anhui University of Science and TechnologyHuainan232001China school of Materials Science and engineering Anhui University of Science and TechnologyHuainan232001China Institute of Energy Hefei Comprehensive National Science CenterHefei230000China

To enhance the fire safety and wear resistance of epoxy,phosphorus-containing nickel phyllosilicate whiskers(FP-NiPS)were synthesized using a facile hydrothermal technology,with 9,10-dihydro-9-oxa-10-phosphaphenanthrene as the organic *** impacts of FP-NiPS on the thermal stability,flame retardancy,and mechanical and tribological properties of EP composites were *** findings demonstrated that 5 wt%FP-NiPS elevated the limiting oxygen index of the EP composite from 23.8%to 28.4%,achieving a V-0 rating during vertical burning ***-NiPS could enhance the thermal stability of epoxy resin(EP)and facilitate the development of a dense and continuous carbon layer,thereby significantly improving the fire safety of the EP *** FP-NiPS led to an 8.2%increase in the tensile strength and a 38.8%increase in the elastic modulus of the EP composite,showing outstanding mechanical ***,FP-NiPS showed remarkable potential in enhancing the wear resistance of *** wear rate of 1 wt%FP-NiPS is 2.34×10^(−5) mm^(3)·N^(−1)·m^(−1),a decrease of 66.7%compared to *** work provides a novel promising modification method to enhance the fire safety,mechanical and wear resistance properties of EP.

关键词： nickel phyllosilicate epoxy resin flame retardant wear resistance mechanical property

Automatic detection and assessment of crack development in ultra-high performance concrete in the spatial and Fourier domains

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 Structural and Civil engineering 2024年第3期18卷 350-364页

作者： Jixing CAO Yao ZHANG Haijie HE Weibing PENG Weigang ZHAO Zhiguo YAN Hehua ZHU school of safety engineering and emergency management Shijiazhuang Tiedao UniversityShijiazhuang 050043China College of Civil engineering and Architecture Zhejiang UniversityHangzhou 310058China College of Civil and Architectural engineering Taizhou UniversityTaizhou 318000China College of Civil engineering and Architecture Zhejiang University of TechnologyHangzhou 310014China Department of Geotechnical engineering Tongji UniversityShanghai 200092China

Automatic detection and assessment of surface cracks are beneficial for understanding the mechanical performance of ultra-high performance concrete(UHPC).This study detects crack evolution using a novel dynamic mode decomposition(DMD)*** this method,the sparse matrix‘determined’from images is used to reconstruct the foreground that contains cracks,and the global threshold method is adopted to extract the crack *** application of the DMD method to the three-point bending test demonstrates the efficiency in inspecting cracks with high ***,the geometric features,including the area and its projection in two major directions,are evaluated over *** relationship between the geometric properties of cracks and load-displacement curves of UHPC is *** to the irregular shape of cracks in the spatial domain,the cracks are then transformed into the Fourier domain to assess their *** indicate that crack patterns in the Fourier domain exhibit a distinct concentration around a central ***,the power spectral density of cracks exhibits an increasing trend over *** investigation into crack evolution in both the spatial and Fourier domains contributes significantly to elucidating the mechanical behavior of UHPC.

关键词： dynamic mode decomposition ultra-high performance concrete crack detection geometric features Fourier domain

Hybrid stacking ensemble algorithm and simulated annealing optimization for stability evaluation of underground entry-type excavations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Underground Space 2024年第4期17卷 25-44页

作者： Leilei Liu Guoyan Zhao Weizhang Liang Zheng Jian school of Resources and safety engineering Central South UniversityChangsha 410083China

The stability of underground entry-type excavations(UETEs)is of paramount importance for ensuring the safety of mining *** more engineering cases are accumulated,machine learning(ML)has demonstrated great potential for the stability evaluation of *** this study,a hybrid stacking ensemble method aggregating support vector machine(SVM),k-nearest neighbor(KNN),decision tree(DT),random forest(RF),multilayer perceptron neural network(MLPNN)and extreme gradient boosting(XGBoost)algorithms was proposed to assess the stability of ***,a total of 399 historical cases with two indicators were collected from seven ***,to pursue better evaluation performance,the hyperparameters of base learners(SVM,KNN,DT,RF,MLPNN and XGBoost)and meta learner(MLPNN)were tuned by combining a five-fold cross validation(CV)and simulated annealing(SA)*** on the optimal hyperparameters configuration,the stacking ensemble models were constructed using the training set(75%of the data).Finally,the performance of the proposed approach was evaluated by two global metrics(accuracy and Cohen’s Kappa)and three within-class metrics(macro average of the precision,recall and F1-score)on the test set(25%of the data).In addition,the evaluation results were compared with six base learners optimized by *** hybrid stacking ensemble algorithm achieved better comprehensive performance with the accuracy,Kappa coefficient,macro average of the precision,recall and F1-score were 0.92,0.851,0.885,0.88 and 0.883,*** rock mass rating(RMR)had the most important influence on evaluation ***,the critical span graph(CSG)was updated based on the proposed model,representing a significant improvement compared with the previous *** study can provide valuable guidance for stability analysis and risk management of ***,it is necessary to consider more indicators and collect more extensive and balanced dataset to validate the model in futur

关键词： Underground entry-type excavations(UETEs) Hybrid stacking ensemble Machine learning Simulated annealing Critical span graph Base and meta learners