检索结果-南通市图书馆

Molecular packing tuning via chlorinated end group enables efficient binary organic solar cells over 18.5%

Carbon Energy 2024年第3期6卷 196-203页

作者： Yafeng Li Zhenyu chen xingzheng Yan Ziyi Ge Zhejiang Business Technology Institute NingboZhejiangChina Zhejiang Engineering Research Center for Energy Optoelectronic Materials and Devices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingboZhejiangChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina

Designing novel nonfullerene acceptors(NFAs)is of vital importance for the development of organic solar cells(OSC).Modification on the side chain and end group are two powerful tools to construct efficient ***,based on the high-performance L8BO,we selected 3-ethylheptyl to substitute the inner chain of 2-ethylhexyl,obtaining the backbone of *** we introduced different halogen atoms of fluorine and chlorine on 2-(3-oxo-2,3-dihydro-1Hinden-1-ylidene)malononitrile end group(EG)to construct efficient NFAs named BON3-F and BON3-Cl,*** donor D18 was chosen to combine with two novel NFAs to construct OSC ***,D18:BON3-Cl-based device shows a remarkable power conversion efficiency(PCE)of 18.57%,with a high open-circuit voltage(V_(OC))of 0.907 V and an excellent fill factor(FF)of 80.44%,which is one of the highest binary PCE of devices based on D18 as the ***,BON3-F-based device shows a relatively lower PCE of 17.79%with a decreased FF of 79.05%.The better photovoltaic performance is mainly attributed to the red-shifted absorption,higher electron and hole mobilities,reduced charge recombination,and enhanced molecular packing in the D18:BON3-Cl ***,we performed stability tests on two binary systems;the D18:BON3-Cl and D18:BON3-F devices maintain 88.1%and 85.5%of their initial efficiencies after 169 h of storage at 85°C in an N2-filled glove box,*** work demonstrates the importance of selecting halogen atoms on EG and provides an efficient binary system of D18:BON3-Cl for further improvement of PCE.

关键词： binary organic solar cell chlorinated end group molecular packing

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

大豆玉米带状种植模式下玉米摘穗机设计与试验

引用

中国农机化学报 2024年第2期45卷 7-12,70页

作者：王鹏谢守勇李明生陈行政张小亮刘伟西南大学工程技术学院重庆市400715 丘陵山区农业装备重庆市重点实验室重庆市400715

针对丘陵山区大豆玉米带状种植模式的玉米果穗收获有机难用、无机可用的现状,设计一款自走式小型玉米摘穗机。该机采用纵卧式摘穗辊实现果穗摘取,并通过输送装置收集装袋;采用“Y”型布局的L型小甩刀实现茎秆粉碎。对摘穗过程进行动力... 详细信息

针对丘陵山区大豆玉米带状种植模式的玉米果穗收获有机难用、无机可用的现状,设计一款自走式小型玉米摘穗机。该机采用纵卧式摘穗辊实现果穗摘取,并通过输送装置收集装袋;采用“Y”型布局的L型小甩刀实现茎秆粉碎。对摘穗过程进行动力学分析、对粉碎过程进行静力学分析,确定其核心装置设计参数并进行样机试制。以茎秆粉碎长度合格率、果穗损失率、籽粒破碎率为试验指标进行田间试验,来验证该机设计的合理性。试验表明:在生产率为0.8 hm^(2)/d、果穗籽粒含水率为26.38%、茎秆含水量为71.25%的条件下进行试验,茎秆粉碎长度合格率为92.4%、果穗损失率为2.06%、籽粒破碎率为0.61%。该机设计各项指标符合国家相关标准,能够满足丘陵山地地区玉米机械化收获需求。

关键词：摘穗茎秆粉碎甩刀玉米大豆玉米带状种植

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Integrated Optimization of Structure and Control Parameters for the Height Control System of a Vertical Spindle Cotton Picker

引用

Chinese Journal of Mechanical Engineering 2021年第6期34卷 405-416页

作者： xingzheng chen Congbo Li Rui Hu Ning Liu Chi Zhang College of Engineering and Technology Southwest UniversityChongqing400715China State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing400044China Department of Mechanical Engineering National University of SingaporeSingapore119077Singapore

Vertical picking method is a predominate method used to harvest cotton ***,a vertical picking method may cause spindle bending of the cotton picker if spindles collide with stones on the cotton ***,how to realize a precise height control of the cotton picker is a crucial issue to be *** objective of this study is to design a height control system to avoid the *** design it,the mathematical models are established *** a multi-objective optimization model represented by structure parameters and control parameters is proposed to take the pressure of chamber without piston,response time and displacement error of the height control system as the opti-mization *** integrated optimization approach that combines optimization via simulation,particle swarm optimization and simulated annealing is proposed to solve the *** and experimental test results show that the proposed integrated optimization approach can not only reduce the pressure of chamber without piston,but also decrease the response time and displacement error of the height control system.

关键词： Cotton picker Height control system Structure parameters Control parameters Integrated optimization

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

Energy efficient cutting parameter optimization

引用

Frontiers of Mechanical Engineering 2021年第2期16卷 221-248页

作者： xingzheng chen Congbo LI Ying TANG Li LI Hongcheng LI College of Engineering and Technology Southwest UniversityChongqing 400715China State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing 400044China Department of Electrical and Computer Engineering Rowan UniversityGlassboroNJ 08028USA College of Advanced Manufacturing Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

Mechanical manufacturing industry consumes substantial energy with low energy efficiency. Increasing pressures from energy price and environmental directive force mechanical manufacturing industries to implement energy efficient technologies for reducing energy consumption and improving energy efficiency of their machining processes. In a practical machining process, cutting parameters are vital variables set by manufacturers in accordance with machining requirements of workpiece and machining condition. Proper selection of cutting parameters with energy consideration can effectively reduce energy consumption and improve energy efficiency of the machining process. Over the past 10 years, many researchers have been engaged in energy efficient cutting parameter optimization, and a large amount of literature have been published. This paper conducts a comprehensive literature review of current studies on energy efficient cutting parameter optimization to fully understand the recent advances in this research area. The energy consumption characteristics of machining process are analyzed by decomposing total energy consumption into electrical energy consumption of machine tool and embodied energy of cutting tool and cutting fluid. Current studies on energy efficient cutting parameter optimization by using experimental design method and energy models are reviewed in a comprehensive manner. Combined with the current status, future research directions of energy efficient cutting parameter optimization are presented.

关键词： energy efficiency cutting parameter optimization machining process

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

深松作业下多机协同任务分配优化方法

引用

农业工程学报 2023年第21期39卷 1-9页

作者：李丽侯兴华陈行政王五一周浩西南大学工程技术学院重庆400715 宜宾西南大学研究院宜宾644002

任务分配方式对农业机械作业油耗影响显著。在多机协同多任务分配过程中,与将完整田块作业任务分配给单台农业机械相比,拆分各任务田块作业量并采用多农机协同作业能进一步降低作业油耗。为实现农业机群高效节能协同作业,该研究以深松... 详细信息

任务分配方式对农业机械作业油耗影响显著。在多机协同多任务分配过程中,与将完整田块作业任务分配给单台农业机械相比,拆分各任务田块作业量并采用多农机协同作业能进一步降低作业油耗。为实现农业机群高效节能协同作业,该研究以深松作业为例,首先系统地分析机群协同作业过程油耗;然后建立以农机作业量为优化变量、以最低机群油耗和最短整体耗时为优化目标的多目标优化模型,并采用INSGA-Ⅱ算法对模型进行优化求解;最后基于实际深松作业案例,分析了所提模型的有效性和实用性。案例分析结果表明:与传统NSGA-Ⅱ算法相比,INSGA-Ⅱ算法可降低4.35%机群油耗及4.51%整体耗时;与传统作业方式相比,根据本文模型进行多机协同任务分配可降低5.51%机群油耗及42.65%整体耗时。研究结果可为无人农场多任务多农机作业分配提供科学依据。

关键词：农业机械油耗任务分配多机协同 INSGA-Ⅱ算法

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

基于SOM-Kmeans的机床能效等级评价方法

引用

机械工程学报 2023年第7期59卷 295-306页

作者：崔佳斌李聪波曹华军陈行政王军见戴涛重庆大学机械传动国家重点实验室重庆400044 西南大学工程技术学院重庆400715 国家机床质量监督检验中心北京101312 重庆第二机床厂有限责任公司重庆400072

机床能效等级评价是提高能源效率的基础。现有机床能效评价方法多运用能量利用率和比能等指标评价特定加工过程能效,未考虑加工能力对机床能效评价的影响,致使无法综合评价机床能效等级。为此,从机床加工能力和能耗特性角度构建机床能... 详细信息

机床能效等级评价是提高能源效率的基础。现有机床能效评价方法多运用能量利用率和比能等指标评价特定加工过程能效,未考虑加工能力对机床能效评价的影响,致使无法综合评价机床能效等级。为此,从机床加工能力和能耗特性角度构建机床能效等级评价指标,提出基于自组织映射神经网络-K均值(SOM-Kmeans)的机床能效等级评价方法。首先,分析机床加工能力特性和时段能耗特性,构建机床加工能力指标和多时段能耗特性指标;其次,运用SOM-Kmeans对机床能效信息进行聚类分析,并采用主成分分析法(PCA)对机床能效等级进行综合评价;最后,通过实际案例验证了所提方法的有效性和实用性。

关键词：机床能效等级加工能力能耗特性聚类分析

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

Meridional deflection of global eddy propagation derived from tandem altimetry: Mechanism and implication

引用

Science China Earth Sciences 2024年第3期67卷 811-825页

作者： Ge chen Xiaoyan chen Frontiers Science Center for Deep Ocean Multispheres and Earth System School of Marine TechnologyOcean University of ChinaQindao 266100China Laboratory for Regional Oceanography and Numerical Modeling Laoshan LaboratoryQindao 266237China

A common view on meridional deflection of eddy propagation is poleward for cyclones and equatorward for anticyclones. This widely accepted polarity-sensitive pattern has been increasingly undermined given that it is systematically violated on both zonal and regional scales as recently reported. Here, we approach the problem by exploring these violations in terms of eddy effects of spatiotemporal geostrophy, thermal fading, and flow dragging, yielding the following main conclusions.(1) The polarity-dependent deflection discrepancy is a pseudo feature resulting from a biased fit to the normalized eddy tracks which are spatially asymmetric(though azimuthally symmetric) between the two signs;Instead, the primary pattern of eddy deflection appears to be geographically correlated and polarity independent.(2) Geostrophic adjustment plays a critical role in defining the meridional movement of an eddy. Specifically, a consistent poleward(equatorward) trajectory bending of spatially(temporally) ageostrophic eddies is observed irrespective of their polarity.(3) The mechanism of eddy deflection is also determined by its zonal propagation direction. Westward propagating eddies are substantially affected by thermal fading, while opposite ones by flow dragging. A realistic and comprehensive understanding of eddy deflection mechanisms serves as a significant contribution to the prediction of eddy trajectory, and the protection of ocean environment.

关键词： Mesoscale eddies Eddy propagation Eddy meridional deflection Satellite observation Geostrophic adjustment

来源：

维普期刊数据库

同方期刊数据库

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

A refined representation method of the particle size distribution curve based on grading entropy

引用

Particuology 2024年第5期88卷 302-311页

作者： Xing Li Qun chen Zhaozhao Liu cheng Zhou chen Wang chen chen State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China

The particle size distribution(PSD)curve is an important expression of the basic properties of the *** characteristic parameters such as median particle size D_(50),effective particle size D_(10),and some combinations of characteristic parameters can only represent some points of the PSD curve,failing to represent all information of the PSD *** this paper,a fraction characteristic parameter F that could reflect the fraction size variation of the PSD curve was introduced based on grading *** a new presentation method of the A-B-F three parameters was proposed for a refined representation of the PSD *** was found that the newly constructed model not only better represents the differences in the width of PSD curves but also has a higher sensitivity than the A-B two-parameter model proposed by Lő*** PSD curves with similar distributions,the new presentation method has a higher degree of discrimination than that of the D_(50)-C_(u)-C_(c) three-parameter or the four-parameter combination G_(c) proposed by ***,the application of this new method in describing the spatial nonuniformity distribution of depositions and predicting the soil hydraulic conductivity was *** research results can provide a reference for the refined representation of PSD curves.

关键词： Grading entropy Particle size distribution curve Refined representation

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

Track correlation algorithm based on CNN-LSTM for swarm targets

引用

Journal of Systems Engineering and Electronics 2024年第2期35卷 417-429页

作者： chen Jinyang WANG Xuhua chen Xian Research Institute for National Defense Engineering Academy of Military SciencesLuoyang 471023China Information Engineering University Zhengzhou 450001China School of Computer Science and Technology Xidian UniversityXi’an 710071China

The rapid development of unmanned aerial vehicle(UAV) swarm, a new type of aerial threat target, has brought great pressure to the air defense early warning system. At present, most of the track correlation algorithms only use part of the target location, speed, and other information for *** this paper, the artificial neural network method is used to establish the corresponding intelligent track correlation model and method according to the characteristics of swarm ***, a route correlation method based on convolutional neural networks (CNN) and long short-term memory (LSTM)Neural network is designed. In this model, the CNN is used to extract the formation characteristics of UAV swarm and the spatial position characteristics of single UAV track in the formation,while the LSTM is used to extract the time characteristics of UAV swarm. Experimental results show that compared with the traditional algorithms, the algorithm based on CNN-LSTM neural network can make full use of multiple feature information of the target, and has better robustness and accuracy for swarm targets.

关键词： track correlation correlation accuracy rate swarm target convolutional neural network(CNN) long short-term memory(LSTM)neural network

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

Aerial target threat assessment based on gated recurrent unit and self-attention mechanism

引用

Journal of Systems Engineering and Electronics 2024年第2期35卷 361-373页

作者： chen chen QUAN Wei SHAO Zhuang School of Automation Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Intelligent Control and Decision of Complex Systems Beijing 100081China

Aerial threat assessment is a crucial link in modern air combat, whose result counts a great deal for commanders to make decisions. With the consideration that the existing threat assessment methods have difficulties in dealing with high dimensional time series target data, a threat assessment method based on self-attention mechanism and gated recurrent unit(SAGRU) is proposed. Firstly, a threat feature system including air combat situations and capability features is established. Moreover, a data augmentation process based on fractional Fourier transform(FRFT) is applied to extract more valuable information from time series situation features. Furthermore, aiming to capture key characteristics of battlefield evolution, a bidirectional GRU and SA mechanisms are designed for enhanced ***, after the concatenation of the processed air combat situation and capability features, the target threat level will be predicted by fully connected neural layers and the softmax classifier. Finally, in order to validate this model, an air combat dataset generated by a combat simulation system is introduced for model training and testing. The comparison experiments show the proposed model has structural rationality and can perform threat assessment faster and more accurately than the other existing models based on deep learning.

关键词： target threat assessment gated recurrent unit(GRU) self-attention(SA) fractional Fourier transform(FRFT)

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

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：