检索结果-南通市图书馆

Multi-objective parameter optimization for a single-shaft series-parallel plug-in hybrid electric bus using genetic algorithm

引用

Science China(Technological Sciences) 2016年第8期59卷 1176-1185页

作者： CHEN Zheng zhou liyan SUN Yong MA ZiLin HAN ZongQi State Key Laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China College of Vehicles and Energy Yanshan University Qinhuangdao 066004 China College of Information Science and Engineering Ocean University of China Qingdao 266100 China

Recently, the single-shaft series-parallel powertrain of Plug-in Hybrid Electric Bus （PHEB） has become one of the most popu- lar powertrains due to its alterable operating modes, excellent fuel economy and strong adaptability for driving cycles. Never- theless, for configuring the PHEB with single-shaft series-parallel powertrain in the development stage, it still faces greater challenge than other configurations when choosing and matching the main component parameters. Motivated by this issue, a comprehensive multi-objectives optimization strategy based on Genetic Algorithm （GA） is developed for the PHEB with the typical powertrain. First, considering repeatability and regularity of bus route, the methods of off-line data processing and mathematical statistics are adopted, to obtain a representative driving cycle, which could well reflect the general characteristic of the real-world bus route. Then, the economical optimization objective is defined, which is consist of manufacturing costs of the key components and energy consumption, and combined with the dynamical optimization objective, a multi-objective op- timization function is put forward. Meanwhile, GA algorithm is used to optimize the parameters, for the optimal components combination of the novel series-parallel powertrain. Finally, a comparison with the prototype is carried out to verify the per- formance of the optimized powertrain along driving cycles. Simulation results indicate that the parameters of powertrain com- ponents obtained by the proposed comprehensive multi-objectives optimization strategy might get better fuel economy, meanwhile ensure the dynamic performance of PHEB. In contrast to the original, the costs declined by 18%. Hence, the strat- egy would provide a theoretical guidance on parameter selection for PHEB manufacturers.

关键词： multi-objective parameter optimization single-shaft series-parallel powertrain plug-in hybrid electric bus (PHEB) genetic algorithm (GA) driving cycle city bus route

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

Tropospheric NO_2 vertical column densities retrieved from ground-based MAX-DOAS measurements at Shangdianzi regional atmospheric background station in China

引用

Journal of Environmental Sciences 2019年第6期31卷 186-196页

作者： Siyang Cheng Jianzhong Ma Weiping Cheng Peng Yan Huaigang zhou liyan zhou Peng Yang State Key Laboratory of Severe Weather & CMA Key Laboratory of Atmospheric Chemistry Chinese Academy of Meteorological Sciences China Waterborne Transport Research Institute CMA Meteorological Observation Centre Shangdianzi Regional Air Background Station Beijing Meteorological Bureau Meteorological Bureau of Shijiazhuang

Ground-basedMulti-AXis Differential Optical Absorption Spectroscopy(MAX-DOAS)measurements were performed at Shangdianzi(SDZ)regional atmospheric background station in northern China from March 2009 to February *** tropospheric NO_2vertical column densities(VCDs)were retrieved to investigate the background condition of the Beijing–Tianjin–Hebei developed economic circle in *** seasonal variation of mean NO_2tropospheric VCDs(VCD_(Trop))at SDZ is apparent,with the maximum(1.3×10^(16)molec/cm^2)in February and the minimum(3.5×10^(15)molec/cm^2)in August,much lower than those observed at the Beijing city *** average daytime diurnal variations of NO_2VCD_(Trop )are rather consistent for all four seasons,presenting the minimum at noon and the higher values in the morning and *** largest and lowest amplitudes of NO_2VCD_(Trop)diurnal variation appear in winter and in summer,*** diurnal pattern at SDZ station is similar to those at other less polluted stations,but distinct from the ones at the urban or polluted *** NO_2VCDs at SDZ are strongly dependent on the wind,with the higher values being associated with the pollution plumes from Beijing *** NO_2VCDs derived from ground-based MAX-DOAS at SDZ show to be well correlated with corresponding OMI(Ozone Monitoring Instrument)satellite products with a correlation coefficient R=***,the OMI observations are on average higher than MAX-DOAS NO_2VCDs by a factor of 28%,probably due to the OMI grid cell partly covering the south of SDZ which is influenced more by the pollution plumes from the urban areas.

关键词： Ground-basedMAX-DOAS Tropospheric NO2 Satellite validation Pollution plume Regional atmospheric background station

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

A scalable sulfuration of WS2 to improve cyclability and capability of lithium-ion batteries

引用

Nano Research 2016年第3期9卷 857-865页

作者： liyan zhou Shancheng Yan Lijia Pan Xinran Wang Yuqiao Wang Yi Shi ing University Nanjing 210093 China School of Geography and Biological Information Nanjing University of Posts and Telecommunications Nanjing 210023 China National Laboratory of Solid State Microstructures School of Electronic Science and Engineering Nanjing University Nanjing 210093 China Jiangsu Optoelectronic Functional Materials and Engineering Laboratory School of Chemistry and Chemical Engineering Southeast University Nanjing 211189 China

Two-dimensional transition-metal dichalcogenides （WS2 and SnS2） have recently joined the family of energy storage materials （for lithium-ion batteries and supercapacitors） as a result of their favorable ion intercalation. So far, challenges in the synthesis of phase-pure WS2, restacking between WS2 nanosheets, low electronic conductivity, and the brittle nature of WS2, severely limit its use Li-ion battery application. Herein, we develop a facile low temperature solution sulfuration process to improve battery performance dramatically. The sulfuration process is demonstrated to be effective in converting WO3 impurities to WS2, and in repairing the sulfur vacancies, to improve cyclability and rate capability. Lithium-ion battery measurements demonstrate that the stable capacity of the WS2 anode could be enhanced by 48.4% via sulfuration reprocessing, i.e., from 381.7 to 566.8 rnAh/g at a relatively high current density of 0.8 A/g after 50 cycles. We further show that the sulfuration process can be readily extended to other dichalcogenides, and may provide a class of versatile electrode materials for lithium-ion batteries with improved electrochemical characteristics.

关键词： lithium-ion batteries tungsten disulfide sulfuration process anode

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

In-situ measurement of atmospheric CFC-11 at the Shangdianzi Global Atmosphere Watch(GAW) Regional Station

引用

Science China Earth Sciences 2011年第2期54卷 298-304页

作者： ZHANG Fang zhou LingXi YAO Bo ZHANG XiaoChun XU Lin ZHANG XiaoLing zhou HuaiGang DONG Fan zhou liyan Key Laboratory for Atmospheric Chemistry Centre for Atmosphere Watch and Services (CA WAS) Chinese Academy of Meteorological Sciences (CAMS) China Meteorological Administration ( CMA ) Beijing 100081 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Institute of Urban Meteorology (IUM) China Meteorological Administration (CMA) Beijing 100089 China Miyun County Meteorological Bureau Beijing 101500 China

An in-situ GC-ECD system was used to measure halocarbons at Shangdianzi （SDZ） GAW regional station. In this paper, we reported observational results of atmospheric CFC- 11 （CCI3F） mixing ratios from April 2007 to March 2008. The CFC- 11 time series showed large variability. Approximately 62% observed values were filtered as non-background data. The median, 10% and 90% percentiles of CFC-11 background mixing ratios were 245.4 ppt （10-12 mol/mol）, 244.6 ppt and 246.1 ppt, respectively; whereas those of non-background CFC- 11 mixing ratios were 254.7, 246.6 and 272.1 ppt, respectively. Significant differences in background and non-background CFC-11 mixing ratios were observed between summer and autumn, mainly because of the CFC-11 stored in loam being prone to atmospheric release in hot seasons. Comparison of tile SDZ data with the five AGAGE stations suggested agreement with mid-high latitude Northern Hemisphere stations MHD, THD and RPB. The SDZ data were higher than that of Southern Hemisphere stations CGO and SMO. Higher CFC-11 mixing ratios measured in different seasons were always associated with winds from the W-WSW-SW sector, indicating that the airflow coming from this wind sector has a positive contribution to CFC- 11 concentrations. The CFC-11 mixing ratios were higher in autumn and summer than in spring and winter, in which its mixing ratios were very close to the atmospheric background level. This was happened especially when airflow originated from the NNE-NE-ENE-E sector, indicating the air masses coming from these wind directions was relatively clean.

关键词： SDZ background CFC-11 seasonal variation winds

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

A study of peroxyacetyl nitrate at a rural site in Beijing based on continuous observations from 2015 to 2019 and the WRFChem model

引用

Frontiers of Environmental Science & Engineering 2020年第4期14卷 189-199页

作者： Yulu Qiu Zhiqiang Ma Weili Lin Weijun Quan Weiwei Pu Yingruo Li liyan zhou Qingfeng Shi Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089China Beijing Shangdianzi Regional Atmosphere Watch Station Beijing 101507China Environmental Meteorology Forecast Center of Beijing-Tianjin-Hebei Beijing 100089China College of Life&Environmental Science Minzu University of ChinaBeijing 100081China

Peroxyacetyl nitrate(PA N)is one of the most important photochemical pollutants and has aroused much concern in China in recent ***,few studies described the long-term variations in PAN in *** this study,we continuously monitored the PAN,03 and NOx concentrations at a regional background site near Beijing from August 2015 to February *** on the observed concentrations and climate data,w e analyzed the seasonal PAN *** results revealed that the monthly mean PAN concentration ranged from 0.33-2.41 ppb,with an average value of 0.94 *** PAN concentration exhibited a distinct seasonal variation,with high values in spring and low values in *** analyzing the corresponding meteorological data,we found that stronger ultraviolet(UV)radiation,a relatively longer lifetime and a higher background PAN concentration contributed to the high PAN concentrations in *** addition,with the utilization of the WRF-Chem(Weather Research and Forecasting with Chemistry)model,the cause of the extremely high PAN concentration in spring 2018 wa s *** model results demonstrated that an anomalously low pressure and the southwesterly winds in northern China might be the main causes of the increased PAN concentration in Beijing and its surrounding area in spring 2018.

关键词： PAN Ozone Beijing WRF-Chem

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

Uniform Coverage of Fibres over Open-contoured Freeform Structure Based on Arc-length Parameter

引用

Chinese Journal of Aeronautics 2008年第6期21卷 571-577页

作者： Wang Xiaoping An Luling Zhang liyan zhou Laishui Jiangsu Key Laboratory of Precision and Micro-manufacturing Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

This article uses arc-length parameters for path planning to carry out robotic fibre placement （RFP） over open-contoured structures This allows representing the initial path and offset points using an identical mathematical equation and computation by more simple arithmetic. With the help of classical differential geometry, the calculation of fiber-placing paths may be reduced to solution of initial-value problems of first-order ordinary differential equations in the parametric domain （parametrically defined mould surface） or in 3D space （an implicitly defined mould surface）, thereby significantly improving on the existing methods. Compared with the conventional methods, the proposed method, besides its computational simplicity, has a better error control mechanism in computing the initial path and offset points. Numerical experiments are also carried out to demonstrate the feasibility of the new method in composite forming processes and also its potential application in computer numerical control （CNC） machining, surface trim, and other industrial practices.

关键词： path planning fibre placement offset curve uniform coverage

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

Constructing G^2 Continuous Curve on Freeform Surface with Normal Projection

引用

Chinese Journal of Aeronautics 2010年第1期23卷 137-144页

作者： Wang Xiaoping,An Luling,zhou Laishui,Zhang liyan Jiangsu Key Laboratory of Precision and Macro-manufacturing Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China Jiangsu Key Laboratory of Precision and Macro-manufacturing Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

This article presents a new method for G2 continuous interpolation of an arbitrary sequence of points on an implicit or parametric surfaee with prescribed tangent direction and curvature vector, respectively, at every point. First, a G2 continuous curve is constructed in three-dimensional space. Then the curve is projected normally onto the given surface. The desired interpolation curve is just the projection curve, which can be obtained by numerieally solving the initialvalue problems for a system of first-order ordinary differential equations in the parametric domain for parametric case or in three-dimensional space for implicit ease. Several shape parameters are introduced into the resulting curve, which can be used in subsequent interactive modification so that the shape of the resulting curve meets our demand. The presented method is independent of the geometry and parameterization of the base surface. Numerical experiments demonstrate that it is effective and potentially useful in numerical control （NC） machining, path planning for robotic fibre placement, patterns design on surface and other industrial and research fields.

关键词： Hermite interpolation normal projection freeform surface G2 continuity ordinary differential equations

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

Variation in Sunshine Duration and Related Aerosol Influences at Shangdianzi GAW Station, China: 1958–2021

引用

Journal of Meteorological Research 2023年第4期37卷 551-563页

作者： Weijun QUAN Zhiqiang MA Ziming LI Xiaolan LI Yingruo LI Xiangao XIA Huaigang zhou Hujia ZHAO Zhenfa WANG Weiwei PU Fan DONG Di HE liyan zhou Qingfeng SHI Wenyan WANG Fang JIA Beijing Weather Forecast Center Beijing Meteorological ServiceBeijing 100097 Environmental Meteorology Forecast Center of Beijing–Tianjin–Hebei Beijing Meteorological ServiceBeijing 100097 Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089 Institute of Atmospheric Environment China Meteorological AdministrationShenyang 110116 Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029

Sunshine duration(SD) is adopted widely to study global dimming/brightening. However, long-term simultaneous measurements of SD and closely related impact factors require further analysis to elucidate how and why SD has varied during the past decades. In this study, a long-term(1958–2021) SD data series obtained from the Shangdianzi Global Atmosphere Watch(GAW) station in China was analyzed to detect linear trends, climatic jumps, and climatic periods in SD using linear fitting, the Mann–Kendall trend test, and the continuous wavelet transform method. Annual SD exhibited steady dimming(-67.3 h decade-1) before 2010, followed by a period of brightening(189.9 h decade-1)during 2011–2020. An abrupt jump in annual SD occurred in 1995, and the annual SD anomaly exhibited significant oscillation with ~3-yr periodicity during 1960–1978. Partial least squares analysis revealed that annual SD anomaly was associated with variations in relative humidity, gale days, cloud cover, and black carbon(BC). Further analysis of the clear-sky daily sunshine percentage(DSP) and simultaneous measurements of aerosol properties, including aerosol optical depth, aerosol extinction coefficient, single scattering albedo(SSA), BC, and total suspended particulates, suggested that variation in DSP was affected primarily by aerosol scattering and absorption. Furthermore, the hourly clear-sky SD at high aerosol loading was approximately 60% and 56% of that at middle and low aerosol loadings, respectively. The pattern of diurnal variation in clear-sky hourly SD, as well as the actual values, can be affected by the fine particulate concentration, aerosol extinction coefficient, and SSA.

关键词： sunshine duration global dimming/brightening multitemporal-scale variation partial least squares Shangdianzi

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

Bioinformatics analysis of human kallikrein 5 (KLK5) expression in metaplastic triple‐negative breast cancer

引用

Cancer Innovation 2023年第5期2卷 376-390页

作者： Yue Song Guiying Bai Xiaoqing Li liyan zhou Yiran Si Xiaohui Liu Yilin Deng Yehui Shi Department of Phase I Clinical Trial Tianjin Medical University Cancer Institute and HospitalTianjinChina Medical Oncology Department of Breast Cancer Tianjin Medical University Cancer Institute and HospitalTianjinChina National Clinical Research Center for Cancer TianjinChina

Background:Metaplastic breast carcinoma(MBC)is a rare breast cancer subtype;most cases are triple‐negative breast cancers(TNBCs)and are poorly responsive to conventional systemic *** potential diagnostic and prognostic markers for distinguishing between metaplastic TNBC and nonmetaplastic TNBC have been *** performed bioinformatic analysis to explore the underlying mechanism by which metaplastic TNBC differs from nonmetaplastic TNBC and provides potential pathogenic genes of metaplastic ***:Differentially expressed genes(DEGs)in metaplastic tumors and nonmetaplastic tumors from TNBC patients were screened using *** GSE76275 data set and The Cancer Genome Atlas(TCGA)database were used to screen DEGs in TNBC and non‐*** and DAVID were used for the Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis and Gene Ontology(GO)analysis of *** databases,including UALCAN,GEPIA,HPA,Breast Cancer Gene‐Expression Miner,and quantitative PCR and western blot,were used to examine KLK5 messenger RNA and protein expression in breast *** of KLK5‑associated genes was performed with TCGA data,and the LinkedOmics database was used to detect the genes co‐expressed with ***(Search Tool for the Retrieval of Interacting Genes)and Cytoscape were used to screen for hub ***‑Meier plotter was used for survival ***:KLK5 was identified among the DEGs in nonmetaplastic TNBC and metaplastic *** KLK5 gene was overexpressed in nonmetaplastic TNBC but downregulated in metaplastic *** and GO analyses revealed that epithelial‐to‐mesenchymal transition was a pathogenic mechanism in metaplastic TNBC and an important pathway by which KLK5 and its associated genes DSG1and DSG3 influence metaplastic TNBC progression. Prognosis analysis showedthat only low expression of KLK5 in metaplastic TNBC had clinical ***: Our research indicated that KLK5 may be a pivotal moleculewit

关键词： bioinformatics analysis differentially expressed genes EMT KLK5 metaplastic breast carcinoma

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

一种制备新生隐球菌单细胞的方法

引用

微生物学报 2019年第2期59卷 326-333页

作者：周利艳付钰中国科学院微生物研究所微生物资源前期开发国家重点实验室北京100101 中国科学院大学存济医学院北京100049

【目的】建立流式细胞仪分选新生隐球菌单细胞的方法,确定新生隐球菌单细胞恢复生长的条件和能力。【方法】利用Moflo XDP流式细胞分析分选仪,体外测定不同条件下新生隐球菌恢复生长的比率。【结果】建立了流式细胞仪新生隐球菌单细胞... 详细信息

【目的】建立流式细胞仪分选新生隐球菌单细胞的方法,确定新生隐球菌单细胞恢复生长的条件和能力。【方法】利用Moflo XDP流式细胞分析分选仪,体外测定不同条件下新生隐球菌恢复生长的比率。【结果】建立了流式细胞仪新生隐球菌单细胞分选流程。确定流式细胞仪分选得到的新生隐球菌单细胞具有恢复生长的能力,恢复生长的能力受营养条件和菌株差异的影响。在营养丰富的条件下,新生隐球菌JEC21和H99单细胞恢复生长比率分别为74%和89%。在寡营养条件下,JEC21和H99单细胞恢复生长比率分别为37%和80%。JEC21生长比率随细胞数的增加而升高,细胞数为100个时,生长比率为55%;细胞数为1000个时,生长比率为97%。【结论】流式细胞仪分选得到新生隐球菌单细胞具有恢复生长的能力,生长能力受营养条件、菌株差异的影响。

关键词：单细胞分选技术流式细胞仪新生隐球菌

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：