检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

基于二型模糊逻辑控制的半挂车轨迹跟踪研究

汽车工程 2025年第1期47卷 55-66页

作者：陈鹏蔡英凤原海波陈龙孙晓强江苏大学汽车工程研究院镇江212013

自动驾驶商用半挂车可以显著提升干线物流效率。然而半挂商用车是典型的欠驱动系统,在大曲率运动工况下难以同时兼顾牵引车和挂车的横向轨迹跟踪精度。随着车辆速度和负载的提升,挂车质心转移及载荷转移加剧,对铰接处产生更强烈的不确... 详细信息

自动驾驶商用半挂车可以显著提升干线物流效率。然而半挂商用车是典型的欠驱动系统,在大曲率运动工况下难以同时兼顾牵引车和挂车的横向轨迹跟踪精度。随着车辆速度和负载的提升,挂车质心转移及载荷转移加剧,对铰接处产生更强烈的不确定性影响,造成挂车与牵引车之间行驶轨迹的偏差进一步加大,增加了轨迹跟踪难度,影响了行驶安全性。为提高半挂商用车牵引车与挂车的横向安全性,本文提出一种基于二型模糊控制的鲁棒路径跟踪策略。首先,在MATLAB/Simulink中建立了半挂车辆的7自由度动力学模型,精确模拟牵引车与挂车的横-纵向运动动力学特性。其次,利用二型模糊逻辑控制理论中输入隶属度函数对系统不确定性的覆盖特性,设计了同时调控牵引车和挂车横向轨迹跟踪精度的二型模糊控制器。为提高不确定因素影响下横向轨迹跟踪控制的精度,降低控制器设计难度,采用粒子群优化算法对二型模糊控制器的输入隶属度函数参数进行优化。最后,利用MATLAB/Simulink与TruckSim的联合仿真平台,分别在不同车速和负载条件下进行车辆轨迹跟踪的仿真,以验证本文提出的控制策略,并与一型模糊控制和预瞄控制结果进行对比。结果表明:在双移线这种轨迹曲率发生变化的工况下,本文提出的二型模糊控制器对牵引车和挂车的横向轨迹跟踪精度有明显提升。

关键词：自动驾驶半挂车轨迹跟踪二型模糊逻辑控制

Rendering acceleration method based on JND and sample gradient

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2025年第3期21卷 177-182页

作者： ZHANG Ripei chen Chunyi School of Computer Science and Technology Qinghai Normal University School of Computer Science and Technology Changchun University of Science and Technology

Currently, the main idea of iterative rendering methods is to allocate a fixed number of samples to pixels that have not been fully rendered by calculating the completion rate. It is obvious that this strategy ignores the changes in pixel values during the previous rendering process, which may result in additional iterative operations.

关键词： Pixels

单县表层土壤重金属污染特征、健康风险及溯源解析

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

环境科学 2025年第1期46卷 442-452页

作者：赵庆令李清彩马龙贾琛陈娟山东省鲁南地质工程勘察院(山东省地质矿产勘查开发局第二地质大队) 济宁272100 自然资源部采煤沉陷区综合治理与生态修复工程技术创新中心济宁272100 山东农业大学资源与环境学院泰安271018

掌握土壤重金属污染风险特征及定量解析潜在来源,对精准防控、科学管理与安全利用土壤资源具有重要意义.以单县表层土壤为研究对象,采集并测定了330件表层土壤样品As、Cd、Cr、Cu、Hg、Ni、Pb和Zn等8种重金属含量,借助地累积指数和富集... 详细信息

掌握土壤重金属污染风险特征及定量解析潜在来源,对精准防控、科学管理与安全利用土壤资源具有重要意义.以单县表层土壤为研究对象,采集并测定了330件表层土壤样品As、Cd、Cr、Cu、Hg、Ni、Pb和Zn等8种重金属含量,借助地累积指数和富集指数评价了重金属污染程度,利用生态环境部指定的健康风险模型评价了重金属所产生的致癌风险和非致癌风险,运用绝对主成分得分-多元线性回归模型(APCS-MLR)定量解析了表层土壤中重金属的来源.结果表明,单县表层土壤样品中8种重金属的平均值均低于菏泽市表层土壤背景值和国家农用地土壤污染风险筛选值,Hg含量的变异系数达40.26%,其他7种元素含量的变异系数均低于15.2%;经Igeo和EF评价,仅Hg元素约5%的样点为轻微污染,其他7种重金属均为无污染或轻微污染状态;表层土壤中As对成人及儿童的致癌风险和非致癌风险为可耐受水平,其他7种重金属对成人及儿童的致癌风险和非致癌风险均可忽略;表层土壤中Cd、Cu、Zn、Ni和As的主要物质来源为自然背景源,Cr和Hg的主要物质来源分别为农业养殖源和工业燃煤源,Pb的主要污染来源包括其他未知源和自然背景源,自然背景源、农业养殖源、工业燃煤源和其他未知源平均贡献率分别为51.69%、27.18%、6.83%和14.31%,说明单县表层土壤中重金属来源主要为自然背景源,其次为农业养殖源.

关键词：重金属(HMs) 地累积指数富集指数健康风险源解析

Soil colloids can significantly enhance spreading of polybromodiphenyl ethers in groundwater by serving as an effective carrier

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2025年第1期147卷 93-100页

作者： Lin Duan Min Li Jiameng Liu Wei chen College of Environmental Science and Engineering Ministry of Education Key Laboratory of Pollution Processes and Environmental CriteriaTianjin Key Laboratory of Environmental Remediation and Pollution ControlNankai UniversityTianjin 300350China

Polybromodiphenyl ethers(PBDEs),the widely used flame retardants,are common contaminants in surface soils at e-waste recycling *** association of PBDEs with soil colloids has been observed,indicating the potential risk to groundwater due to colloid-facilitated ***,the extent to which soil colloidsmay enhance the spreading of PBDEs in groundwater is largely ***,we report the co-transport of decabromodiphenyl ester(BDE-209)and soil colloids in saturated porous *** colloids released froma soil sample collected at an e-waste recycling site in Tianjin,China,contain high concentration of PBDEs,with BDE-209 being the most abundant conger(320±30 mg/kg).The colloids exhibit relatively high mobility in saturated sand columns,under conditions commonly observed in groundwater ***,under all the tested conditions(i.e.,varying flow velocity,pH,ionic species and ionic strength),the mass of eluted BDE-209 correlates linearly with that of eluted soil colloids,even though the mobility of the colloids varies markedly depending on the specific hydrodynamic and solution chemistry conditions ***,the mass of BDE-209 retained in the columns also correlates strongly with themass of retained ***,the PBDEs remain bound to soil colloids during transport in porous *** in this study indicate that soil colloidsmay significantly promote the transport of PBDEs in groundwater by serving as an effective *** might be the reason why the highly insoluble and adsorptive PBDEs are found in groundwater at some PBDE-contaminated sites.

关键词： Polybromodiphenyl ethers Soil colloids E-waste recycling sites Groundwater Facilitated transport

The mechanisms of pH regulation on promoting volatile fatty acids production from kitchen waste

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

Journal of Environmental Sciences 2025年第1期147卷 414-423页

作者： Feng Liu Tingting Wang Leiyu Feng Yinguang chen College of Environmental Science and Engineering Tongji UniversityShanghai 200092China TUS-Environmental Science and Technology Development Co. Ltd.Beijing 100084China

The anaerobic acid production experiments were conducted with the pretreated kitchen waste under pH *** results showed that pH 8 was considered to be the most suitable condition for acid production,especially for the formation of acetic acid and propionic *** average value of total volatile fatty acid at pH 8 was 8814 mg COD/L,1.5 times of that under blank *** average yield of acetic acid and propionic acid was 3302 mg COD/L and 2891 mg COD/L,*** activities of key functional enzymes such as phosphotransacetylase,acetokinase,oxaloacetate transcarboxylase and succinylcoA transferase were all *** further explore the regulatory mechanisms within the system,the distribution of microorganisms at different levels in the fermentation system was obtained by microbial sequencing,results indicating that the relative abundances of Clostridiales,Bacteroidales,Chloroflexi,Clostridium,Bacteroidetes and Propionibacteriales,which were great contributors for the hydrolysis and acidification,increased rapidly at pH 8 compared with the blank ***,the proportion of genes encoding key enzymes was generally increased,which further verified the mechanism of hydrolytic acidification and acetic acid production of organic matter under pH regulation.

关键词： Kitchen waste Acid fermentation Volatile fatty acids pH regulation Functional genes

Synthesis of ternary geopolymers using prediction for effective solidification of mercury in tailings

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

Journal of Environmental Sciences 2025年第1期147卷 392-403页

作者： Xuan Lu Jinfa Guo Fang chen Mengkui Tian School of Chemistry and Chemical Engineering Guizhou UniversityGuiyang 550025China

This study used steel slag,fly ash,and metakaolin as raw materials(SFM materials)to create silica-alumina-based geopolymers that can solidify Hg^(2+)when activated with sodiumbased water *** experiments began with a triangular lattice point mixing design experiment,and the results were fitted,analyzed,and *** optimum SFM material mass ratio was found to be 70%steel slag,25%fly ash,and 5%*** optimum modulus of the activator was identified by comparing the unconfined compressive strength and solidifying impact on Hg^(2+)of geosynthetics with different *** SFM geopolymer was then applied in the form of potting to cure the granulated mercury *** inclusion of 50%SFM material generated a geosynthetic that reduced mercury transport to the surface soil by roughly 90%.The mercury concentration of herbaceous plant samples was also reduced by 78%.It indicates that the SFM material can effectively attenuate the migration transformation of ***,characterization methods such as XPS and FTIR were used to investigate the mechanism of Hg^(2+)solidification by geopolymers generated by SFM *** possible solidification mechanisms were proposed as alkaline environment-induced mercury precipitation,chemical bonding s,surface adsorption of Hg^(2+)and its precipitates by the geopolymer,and physical encapsulation.

关键词： Mercury Geopolymer Solidification Tailings

Seismic isolation design and resilience improvement of railway station considering the influence of near-fault pulse-like ground motions

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

Earthquake Engineering and Engineering Vibration 2025年第1期24卷 257-270页

作者： Pan Yi Song Jiayu chen Qi Liu Yongxin School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of Seismic Engineering of Sichuan Province Chengdu 610031China

To improve the resilience of railway stations,a typical station was selected as the research object,and an isolation design was ***-four groups of near-fault pulse-like ground motions were *** seismic resilience of the no-isolation railway stations(NIRS)and the isolation railway stations(IRS)were compared to provide a numerical result of the improvement in *** results show that in the station isolation design,the station's functional requirements and structural characteristics should be considered and the appropriate placement of isolation bearings is under the waiting *** the action of a rare earthquake,the repair cost,repair time,rate of harm and death of the IRS were decreased by 8.04 million,18.30 days,6.93×10^(-3)and 1.21×10^(-3),respectively,when compared to the *** IRS received a seismic resilience grade of three-stars and the NIRS only one-star,indicating that rational isolation design improves the seismic resilience of ***,for the design of stations close to earthquake faults,it is suggested to utilize appropriate isolation techniques to improve their seismic resilience.

关键词： railway station near-fault pulse-like ground motion isolation design seismic resilience resilience improvement

Boron shielding design for neutron and gamma detectors of a pulsed neutron tool

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2025年第1期36卷 115-126页

作者： Xin-Yang Wang Jun-Yan chen Qiong Zhang University of Electronic Science and Technology of China Chengdu 611731China

Shielding materials are critical for downhole pulsed neutron tool design because they directly influence the accuracy of formation measurements.A well-designed shield configuration ensures that the response of the tool is maximally representative of the formation without being affected by the tool and borehole *** study investigated the effects of boron-containing materials on neutron and gamma detectors based on a newly designed logging-while-drilling tool that is currently undergoing *** the boron content increased,the ability to absorb thermal neutrons increased *** simulation,it was proven that boron carbide(B_(4)C)can be used as an effective boron shielding material for thermal neutrons,and is therefore employed in this *** shield against thermal neutrons migrating from the mud pipes,the optimal shielding thicknesses for the near-and far-neutron detectors were determined to be 5 and 4 *** a porosity of 25 p.u.,near-neutron sensitivity exhibited a 5.6%***,to shield the capture gamma generated by thermal neutrons once they enter the tool from the mud pipe and formation,internal and external shields for the gamma detector were *** results show that the internal shield requires a boron content of 75%,whereas the external shield has a thickness of 14.2 mm thickness and a boron content of 25%to minimize the tool effect.

关键词： Nuclear well logging Pulsed neutron tool Boron shielding

Carbon Nanofiber/Polyaniline Composite Aerogel with Excellent Electromagnetic Interference Shielding,Low Thermal Conductivity,and Extremely Low Heat Release

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第4期17卷 77-95页

作者： Mingyi chen Jian Zhu Kai Zhang Hongkang Zhou Yufei Gao Jie Fan Rouxi chen Hsing-Lin Wang School of Textile Science and Engineering Tiangong UniversityTianjin 300387People’s Republic of China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055People’s Republic of China School of Innovation and Entrepreneurship Southern University of Science and TechnologyShenzhen 518055People’s Republic of China Guangdong Provincial Key Laboratory of Energy Materials for Electric Power Southern University of Science and TechnologyShenzhen 518055People’s Republic of China Ministry of Education Key Laboratory of Advanced Textile Composite Materials Tiangong UniversityTianjin 300387People’s Republic of China

The rapid development of communication technology and high-frequency electronic devices has created a need for more advanced electromagnetic interference(EMI)shielding *** response to this demand,a study has been conducted to develop multifunctional carbon nanofibers(CNFs)/polyaniline(PANI)aerogels with excellent electromagnetic interference shielding,flame retardancy,and thermal insulation *** process involved freeze-drying of electrospun CNFs and PANI nanoparticles followed by in situ growth PANI to coat the CNFs,creating the core-shell structured CNFs/PANI composite fiber and its hybrid aerogels(CP-3@PANI).The interaction between PANI and aniline(ANI)provides attachment sites,allowing additional ANI adsorption into the aerogel for in situ *** results in PANI uniformly covering the surface of the CNFs,creating a core-shell composite fiber with a flexible CNF core and PANI *** process enhances the utilization rate of the ANI monomer and increases the PANI content loaded onto the ***,effective connections are established between the CNFs,forming a stable,conductive three-dimensional network *** prepared CP-3@PANI aerogels exhibit excellent EMI shielding efficiency(SE)of 85.4 dB and specific EMI SE(SE d^(-1))of 791.2 dB cm^(3)g^(-1)in the *** to the synergistic flame-retardant effect of CNFs,PANI,and the dopant(phytic acid),the CP-3@PANI aerogels demonstrate outstanding flame-retardant and thermal insulation properties,with a peak heat release rate(PHRR)as low as 7.8 W g^(-1)and a total heat release of only 0.58 kJ g^(-1).This study provides an effective strategy for preparing multifunctional integrated EMI shielding materials.

关键词： CNFs/PANI hybrid aerogels EMI shielding Flame retardancy Thermal insulation