检索结果-南通市图书馆

Characterization of Fe-containing particles in Chengdu,southwest China,using single-particle aerosol mass spectrometry

引用

Journal of Environmental sciences 2024年第2期136卷 110-120页

作者： Renjiang He Junke Zhang Luyao Chen Wei Zhang Yingwei Xi School of Public Health Southwest Medical UniversityLuzhou 646000China Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China sichuan Environmental Monitoring Center Chengdu 610074China

Single-particle aerosol mass spectrometry was used to study the characteristics of Fecontaining particles during winter in Chengdu,southwest *** mass concentrations of PM_(2.5)and PM_(10)during the study period were 64±38 and 89±49μg/m~3,respectively,and NO_(2)and particulate matter were high compared with most other regions of *** Fecontaining particles were divided into seven categories with different mass spectra,sources and aging *** highest contribution was from Fe mixed with carbonaceous components(Fe-C,23.1%)*** was more mixed with sulfate than nitrate and therefore the contribution of Fe mixed with sulfate(Fe-S,20.7%)particles was higher than that of Fe mixed with nitrate(Fe-N,12.5%)*** contributions from Fe-containing particles related to primary combustion were high in the small particle size range,whereas aged Fecontaining particles and dust-related particles were mostly found in the coarse particle size *** air masses mainly originated from the west and east of Chengdu,and the corresponding PM_(2.5)concentrations were 79±36 and 55±36μg/m~3,*** west and east air masses showed stronger contributions of Fe-containing particles related to biomass burning(Fe-B)and fossil fuel combustion(Fe-C and Fe-S)particles,*** southwest area contributed the most Fe-containing *** assessments of the effects of Fe-containing particles during heavy pollution period should pay more attention to Fe-C and Fe-S ***-reduction of Fe-containing particles should consider both local emissions and short-distance transmission from the surrounding areas.

关键词： Fe-containing particles Particle composition Potential source areas Evolution Chengdu

来源：

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

Contact Stress Reliability Analysis Model for Cylindrical Gear with Circular Arc Tooth Trace Based on an Improved Metamodel

引用

Computer Modeling in Engineering & sciences 2024年第7期140卷 593-619页

作者： Qi Zhang Zhixin Chen Yang Wu Guoqi Xiang Guang Wen Xuegang Zhang Yongchun Xie Guangchun Yang School of Intelligent Manufacturing&Automobile Chengdu Industrial Vocational Technical CollegeChengdu610218China School of Intelligent Manufacturing Panzhihua UniversityPanzhihua617000China School of Electrical Engineering Chengdu Industry and Trade CollegeChengdu601165China School of Mechanical Engineering Sichuan UniversityChengdu601165China Chengdu Technological University Chengdu611730China

Although there is currently no unified standard theoretical formula for calculating the contact stress of cylindrical gears with a circular arc tooth trace(referred to as CATT gear),a mathematical model for determining the contact stress of CATT gear is essential for studying how parameters affect its contact stress and building the contact stress limit state equation for contact stress reliability *** this study,a mathematical relationship between design parameters and contact stress is formulated using the *** enhance the model’s accuracy,we propose a new hybrid algorithm that merges the genetic algorithm with the Quantum Particle Swarm optimization algorithm,leveraging the strengths of ***,the“parental inheritance+self-learning”optimization model is used to fine-tune the KrigingMetamodel’s *** this,amathematicalmodel for calculating the contact stress of Variable Hyperbolic Circular-Arc-Tooth-Trace(VH-CATT)gears using the optimized Kriging model was *** then examined how different gear parameters affect the VH-CATT gears’contact *** simulation results show:(1)Improvements in R2,RMSE,and RMAE.R2 rose from0.9852 to 0.9974(a 1.22%increase),nearing 1,suggesting the optimized Kriging Metamodel’s global error is ***,RMSE dropped from3.9210 to 1.6492,a decline of 57.94%.The global error of the GA-IQPSO-Kriging algorithm was also reduced,with RMAE decreasing by 58.69%from 0.1823 to 0.0753,showing the algorithm’s enhanced *** a comparison of ten experimental groups selected randomly,the GA-IQPSO-Kriging and FEM-based contact analysis methods were used to measure contact *** revealed a maximum error of 12.11667 MPA,which represents 2.85%of the real value.(2)Several factors,including the pressure angle,tooth width,modulus,and tooth line radius,are inversely related to contact *** descending order of their impact on the contact stress is:tooth line radius>modulus

关键词： CATT gear contact stress finite element method metamodel hybrid algorithm influencing factors

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Protective effects of baffles with different positions,row spacings,heights on debris flow impact

引用

Journal of Mountain science 2024年第7期21卷 2352-2367页

作者： SUN Xinpo CHEN Min BI Yuzhang ZHENG Lu CHE Chi XU Ao TIAN Zijian JIANG Zheyuan College of Civil Engineering Sichuan University of Science and EngineeringZigong 643000China College of Resources and Environment Fujian Agriculture and Forestry UniversityFuzhou 350002China School of Civil Engineering Fuzhou UniversityFuzhou 350108China Jiangsu key Laboratory of Urban Underground Engineering&Environmental Safety Institute of Geotechnical EngineeringSoutheast UniversityNanjing 210096China Beijing Urban Construction science Technology Promoting Association Beijing 100055China SUSE-BZ Geoenvironmental Engineering Joint Laboratory Sichuan University of Science and EngineeringZigong 643000China

The baffle effectively slowed down debris flow velocity,reduced its kinetic energy,and significantly shortened the distance of debris flow ***,they are widely used for protection against natural hazards such as landslides and *** study,based on the threedimensional DEM(Discrete Element Method),investigated the impact of different baffle positions on debris flow *** flow velocity and kinetic energy variations were studied through single-factor *** baffle positions were preliminarily selected by analyzing the influence of the first-row baffle position on the impact force and accumulation mass of debris ***,based on the selected baffle positions and four factors influencing the effectiveness of baffle protection(baffle position(P),baffle height(h),row spacing(S_(r)),and angle of transit area(α)),an orthogonal design was employed to further explore the optimal arrangement of *** research results indicate that the use of a baffle structure could effectively slow down the motion velocity of debris flows and dissipate their *** the baffle is placed in the transit area,the impact force on the first-row baffle is greater than that when the baffle is placed in the deposition ***,when the baffle is placed in the transit area,the obstruction effect on debris flow mass is also greater than that when the baffle is placed in the deposition *** orthogonal experimental range analysis,when the impact on the first row of baffles is used as the evaluation criterion,the importance of each influencing factor is ranked asα>P>S_(r)>*** the mass of debris flow behind the baffle is regarded as the evaluation criterion,the rank is changed to P>α>S_(r)>*** experimental simulation results show that the optimal baffle arrangement is:P_(5),S_(r)=16,α=35°,h=9.

关键词： Debris flow Baffle Protective effect Discrete element

来源：

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

Experimental Study on Mixed-Mode(Ⅰ–Ⅱ)Fracture Toughness of Freshwater Ice

引用

Acta Mechanica Solida Sinica 2024年第2期37卷 252-264页

作者： Yaozhong Xu Mao Zhou Xian Yi Wen Hua Jiuzhou Huang Wenyu Zhang Shiming Dong key Laboratory of Deep Underground science and Engineering Ministry of EducationCollege of Architecture and EnvironmentSichuan UniversityChengdu610065China Failure Mechanics and Engineering Disaster Prevention key Laboratory of sichuan Province Sichuan UniversityChengdu610065China China Aerodynamics Research and Development Center/Low Speed Aerodynamics Research Institute Mianyang621000China College of Mechanical and Electrical Engineering Xichang UniversityXichang615000China

In recent years,the issue of aircraft icing has gained widespread *** breaking and detachment of dynamic ice can pose a threat to flight ***,the shedding and fracture mechanisms of dynamic ice are unclear and cannot meet the engineering needs of ice-shedding hazard ***,studying the fracture toughness of ice bodies has extremely important practical *** address this issue,this article uses a centrally cracked Brazilian disk(CCBD)specimen to measure the pure modeⅠtoughness and pure modeⅡfracture toughness of freshwater ice at different loading *** mixed-mode(Ⅰ–Ⅱ)fracture characteristics of ice are discussed,and the experimental results are compared and analyzed with the theoretical values of the generalized maximum tangential stress(GMTS)criterion considering the influence of *** results indicated that as the loading rate increases,the pure modeⅠtoughness and pure modeⅡfracture toughness of freshwater ice decrease,and the fracture toughness of freshwater ice is more sensitive to the loading rate.Ⅰn terms of fracture criteria,the theoretical value of the ratio of pure modeⅡfracture toughness to pure modeⅠfracture toughness based on the GMTS criterion is in good agreement with the experimental value,while the theoretical value based on the maximum tangential stress(MTS)criterion deviates significantly from the experimental value,indicating that the GMTS criterion considering the influence of T-stress can better predict the experimental results.

关键词： Freshwater ice Fracture criteria Centrally cracked Brazilian disk(CCBD) Mixed-mode(Ⅰ-Ⅱ) Loading rate

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Preparation and Performance of Organically Modified Montmorillonite Composite Separation Membrane

引用

Journal of Wuhan University of Technology(Materials science) 2024年第5期39卷 1100-1107页

作者： LIU Peng BI Yuanyuan CHEN Shaowei WAN Ye YU Yunwu FANG Yanfeng GU Yaxin LI Feihong TANG Ning LI Xiangyu School of Materials science and Engineering Shenyang Jianzhu UniversityShenyang 110168China

A new composite separation membrane was developed by using organically modified montmorillonite(OMMT)as an *** effects of OMMT on the modification and properties of PVDF composite membranes were *** is found that different kinds and amounts of OMMT into the casting solution can obviously change the pure water flux,separation performance and hydrophilicity of composite membrane in varying *** the TA/PDA-MMT was 0.5 wt%,the pure water flux of the membrane reached the maximum,which was 584.7 L/(m^(2)·h),about 6 times that of the original *** OMMT/PVDF composite membrane had good hydrophilicity and stability in the treatment of oily *** development of novel OMMT/PVDF composite membrane will provide a new idea for solving the problem of oily wastewater treatment.

关键词： membrane montmorillonite composite wastewater

来源：

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

Analyze the Performance of Electroactive Anticorrosion Coating of Medical Magnesium Alloy Using Deep Learning

引用

Computers, Materials & Continua 2024年第4期79卷 263-278页

作者： Yashan Feng Yafang Tian Yongxin Yang Yufang Zhang Haiwei Guo Jing’an Li Advanced Functional Materials Laboratory Zhengzhou Railway Vocational and Technical CollegeZhengzhou450000China School of Materials science and Engineering Zhengzhou UniversityZhengzhou450000China

Electroactive anticorrosion coatings are specialized surface treatments that prevent or minimize corrosion. Thestudy employs strategic thermodynamic equilibriumcalculations to pioneer a novel factor in corrosion protection.A first-time proposal, the total acidity (TA) potential of the hydrogen (pH) concept significantly shapes medicalmagnesium alloys. These coatings are meticulously designed for robust corrosion resistance, blending theoreticalinsights and practical applications to enhance our grasp of corrosion prevention mechanisms and establisha systematic approach to coating design. The groundbreaking significance of this study lies in its innovativeintegration of the TA/pH concept,which encompasses the TA/pH ratio of the chemical environment. This approachsurpasses convention by acknowledging the intricate interplay between the acidity and pH levels within thecoating formulation, thereby optimizing metal-phosphate-based conversion coatings and transforming corrosionmitigation strategies. To authenticate the TA/pH concept, the study comprehensively compares its findings withexisting research, rigorously validating the theoretical framework and reinforcing the correlates among TA/pHvalues and observed corrosion resistance in the coatings. The influence of mutations that occur naturally inthe detergent solution on persistent phosphorus changes is shown by empirical confirmation, which improvescorrosion resistance. This realization advances the field ofmaterials and the field’s knowledge of coated generation,particularly anticorrosion converter layers.

关键词： Medical magnesium alloys hydrogen gas anticorrosion total acidity potential of the hydrogen(pH)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Responses of growth performance,antioxidant function,small intestinal morphology and mRNA expression of jejunal tight junction protein to dietary iron in yellow-feathered broilers

引用

Journal of Integrative Agriculture 2024年第4期23卷 1329-1337页

作者： Kaiwen Lei Hao Wu Jerry W Spears Xi Lin Xi Wang Xue Bai Yanling Huang key Laboratory of Animal science of State Ethnic Affairs Commission Southwest Minzu UniversityChengdu 610041China key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Southwest Minzu UniversityChengdu 610041China Department of Animal science North Carolina State UniversityRaleighNC 27695-7621USA

This study aimed to investigate the dose-effect of iron on growth performance,antioxidant *** morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers.A total of 7201-d-old yellow-feathered maleb roilers were allocated to 9 treatments with 8 replicate cages of 10 birds per *** dietary treatments were consisted of a basal diet(contained 79.6 mg Fe kg^(-1))supplemented with 0,20,40,60,80,160,320,640,and 1,280 mg Fe kg^(-1)in the form of FeSO_(4)·7H_(2)*** with the birds in the control group,birds supplemented with 20mg Fe kg^(-1)had higher average daily gain(ADG)(P<0.0001).Adding 640 and 1,280 mg Fe kg^(-1)significantly decreased ADG(P<0.0001)and average daily feed intake(ADFI)(P<0.0001)compared with supplementation of 20mg Fe kg^(-1).Malondialdehyde(MDA)concentration in plasma and duodenum increased linearly(P<0.0001),but MDA concentration in liver and jejunum increased linearly(P<0.05)or quadratically(P<0.05)with increased dietary Fe *** villus height(VH)in duodenum and jejunum,and the ratio of villus height to crypt depth(V/C)in duodenum decreased linearly(P?0.05)as dietary *** dietary Fe increased,the jejunal relative mRNA abundance of claudin-1 decreased linearly(P=0.001),but the jejunal relative mRNA abundance of zona occludens-1(ZO-1)and occludin decreased linearly(P?0.05)or quadratically(P?0.05).Compared with the supplementation of 20 mg Fe kg^(-1),the supplementation of640 mg Fe kg^(-1)or higher increased(P?0.05)MDA concentrations in plasma,duodenum,and jejunum,decreased VH in the duodenum and jejunum,and the addition of 1,280 mg Fe kg^(-1)reduced(P?0.05)the jejunal tight junction protein(claudin-1,ZO-1,occludin)mRNA *** summary,640 mg of supplemental Fe kg^(-1)or greater was associated with decreased growth performance,increased oxidative stress,disrupted intestinal morphology,and reduced mRNA expression of jejunal tight junction protein.

关键词： iron yellow-feathered broiler antioxidant function intestinal morphology tight junction protein

来源：

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

Effects of water molecules on luminescence in europium and terbium coordination polymers with p-fluorobenzoic acid as ligand

引用

Journal of Rare Earths 2024年第7期42卷 1258-1264,I0003页

作者： Xiaoqi Zhao Puyan Hao Yami Ling Mengzhen Jia Rui Zhu Jiawen Liu Qiang Xu Jianhong Zhou Collaborative Innovation Center of Rare-Earth Optical Functional Materials and Devices Development Baoji Key Laboratory of Micro-Nano Optoelectronics and Terahertz TechnologySchool of Physics and Opto-Electronic TechnologyBaoji University of Arts and SciencesBaoji721016China

Our previous experimental observations show that the crystal structure of lanthanide luminescent complexes synthesized in aqueous solution usually contains a large number of coordination water molecules or free water *** order to probe the influence of water molecules on luminescent processes of lanthanide complexes,the photoluminescence properties of Ln-FBA(Ln=Eu and Tb,FBA=p-fluorobenzoic acid)coordination polymers at different ambient temperatures,in different solvents and aqueous DMSO solutions with different volume concentrations were systematically *** experiment results show that the presence of water molecules can promote the energy transfer from FBA ligand to Ln3+,at the same time,can cause luminescent non-radiation quenching of lanthanide *** addition,the variation of emission intensity ratio of 615 nm/591 nm peaks of Eu^(3+)with increasing the volume concentration of H_(2)O can be potentially used for the quantitatively detection of water traces in organic *** order to suppress the non-radiation quenching caused by the water molecules,Ln-FBA(Ln=Eu and Tb)coordination polymers were embedded into the PVP matrix to prepare Ln-FBA@PVP hybrid *** photoluminescence investigation indicates that PVP can not only block the quenching effect of water molecules on luminescence,but also effectively sensitize Eu^(3+)and Tb^(3+)*** experimental conclusions are useful for probing the influence of water molecules on luminescent processes of lanthanide complexes,quantitatively detecting water traces in organic solvents and enhancing the photoluminescence intensity in lanthanide complexes.

关键词： Lanthanide complexes Photoluminescence Luminescent quenching Rare earths

来源：

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

Dynamical behaviors in discrete memristor-coupled small-world neuronal networks

引用

Chinese Physics B 2024年第4期33卷 729-734页

作者：鲁婕妤谢小华卢亚平吴亚联李春来马铭磷 School of Automation and Electronic Information Xiangtan UniversityXiangtan 411105China School of Computer science School of Cyberspace science Xiangtan UniversityXiangtan 411105China

The brain is a complex network system in which a large number of neurons are widely connected to each other and transmit signals to each *** memory characteristic of memristors makes them suitable for simulating neuronal synapses with *** this paper,a memristor is used to simulate a synapse,a discrete small-world neuronal network is constructed based on Rulkov neurons and its dynamical behavior is *** explore the influence of system parameters on the dynamical behaviors of the discrete small-world network,and the system shows a variety of firing patterns such as spiking firing and triangular burst firing when the neuronal parameterαis *** results of a numerical simulation based on Matlab show that the network topology can affect the synchronous firing behavior of the neuronal network,and the higher the reconnection probability and number of the nearest neurons,the more significant the synchronization state of the *** addition,by increasing the coupling strength of memristor synapses,synchronization performance is *** results of this paper can boost research into complex neuronal networks coupled with memristor synapses and further promote the development of neuroscience.

关键词： small-world networks Rulkov neurons memristor synchronization

来源：

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

Fine-grained grid computing model for Wi-Fi indoor localization in complex environments

引用

Journal of Electronic science and Technology 2024年第1期22卷 42-52页

作者： Yan Liang Song Chen Xin Dong Tu Liu School of Computer Engineering Chengdu Technological UniversityChengdu611730China HAN Networks Corporation Limited Beijing100094China

The fingerprinting-based approach using the wireless local area network(WLAN)is widely used for indoor ***,the construction of the fingerprint database is quite *** when the position of the access point(AP)or wall changes,updating the fingerprint database in real-time is *** appropriate indoor localization approach,which has a low implementation cost,excellent real-time performance,and high localization accuracy and fully considers complex indoor environment factors,is preferred in location-based services(LBSs)*** this paper,we proposed a fine-grained grid computing(FGGC)model to achieve decimeter-level localization *** points(RPs)are generated in the grid by the FGGC ***,the received signal strength(RSS)values at each RP are calculated with the attenuation factors,such as the frequency band,three-dimensional propagation distance,and walls in complex *** a result,the fingerprint database can be established automatically without manual measurement,and the efficiency and cost that the FGGC model takes for the fingerprint database are superior to previous *** proposed indoor localization approach,which estimates the position step by step from the approximate grid location to the fine-grained location,can achieve higher real-time performance and localization accuracy *** mean error of the proposed model is 0.36 m,far lower than that of previous ***,the proposed model is feasible to improve the efficiency and accuracy of Wi-Fi indoor *** also shows high-accuracy performance with a fast running speed even under a large-size *** results indicate that the proposed method can also be suitable for precise marketing,indoor navigation,and emergency rescue.

关键词： Fine-grained grid computing (FGGC) Indoor localization Path loss Random forest Reference points(RPs)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：