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Evolution and Determinants of Population Agglomeration in Less Developed Metropolitan Areas:A Case Study of the Taiyuan Metropolitan Area,China
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作者 QIN Zhiqin LIANG Ye +1 位作者 AN Shuwei DOU Yongjing 《Chinese Geographical Science》 SCIE CSCD 2024年第4期739-751,共13页
It is of importance to enhance the urban areas'capacity for population aggregation in underdeveloped regions,aiming to rectify the imbalanced and insufficient pattern of economic development in China.Taking the Ta... It is of importance to enhance the urban areas'capacity for population aggregation in underdeveloped regions,aiming to rectify the imbalanced and insufficient pattern of economic development in China.Taking the Taiyuan Metropolitan Area(TMA)in central China as a case study,this paper examines the evolutionary process and characteristics of population agglomeration from 2000 to 2020,and identifies factors associated with agglomeration and their spatial effects.The findings indicated that:1)against the background of sustained population shrinkage in the provincial area,the TMA showed a demographic trend of steady increase,albeit with a decelerated growth rate.In the metropolitan area,urban population size continued to grow rapidly,whereas the rural areas endured sustained losses.Disparities in city size continued to widen,and the polarization of concentrated population in the core cities kept increasing.2)Agglomerations in both secondary and service industries had significant positive effects on local population agglomeration,with the former effect being stronger.Regional economic development,government fiscal expenditure,and financial advancement all contributed to facilitating local population clustering.From a spatial spillover perspective,service agglomeration and financial development promoted population agglomeration in surrounding areas.Conversely,fiscal expenditure inhibited such agglomeration.As for industrial agglomeration and regional economic development,their spatial spillover effects were non-significant.The results obtained reveal several policy implications aimed at enhancing the population agglomeration capacity of the metropolitan area in underdeveloped regions during the new era. 展开更多
关键词 population agglomeration population shrinkage spatial spillover effects Taiyuan Metropolitan Area(TMA) China
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Hydrochemical characteristics and the ecological effect of algal carbonic anhydrase in carbon cycle in the Taiyuan section of Fenhe River
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作者 Jing YANG Xin LI +1 位作者 Shulian XIE Jia FENG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第5期1507-1524,共18页
Water scarcity and pollution pose a threat to the sustainable development of cities and society.Therefore,it is crucial to analyze the hydrochemical characteristics and carbon dynamics of waterdeficient areas.Taking t... Water scarcity and pollution pose a threat to the sustainable development of cities and society.Therefore,it is crucial to analyze the hydrochemical characteristics and carbon dynamics of waterdeficient areas.Taking the Taiyuan section of Fenhe River as the research object,we systematically explored the hydrochemical characteristics of surface water and its evolutionary processes,as well as the ecological effect of algal carbonic anhydrase in carbon cycle using the hydrochemical evolution method and correlation analysis.The ternary diagram demonstrates that the main water chemical type in Fenhe River was SO^(2-)_(4)·Cl^(-)-Na^(+).The Gibbs and end-member diagrams of each ion display that the chemical composition of surface water was mainly controlled by silicate decomposition.The chemical ions originated mainly from dissolution of some minerals,such as plagioclase,halite,dolomite,calcite,and gypsum.The diatoms had a lower CO_(2)requirement because they exhibited a higher abundance at a lower partial pressure of CO_(2)(p CO_(2)).However,high CO_(2)concentration had a positive effect on cyanobacteria,which reduced the active transport of HCO_(3)^(-),saved the energy needed for this part of active transport,and indirectly improved the overall photosynthetic efficiency of algae.Carbonic anhydrase(CA)activity was significantly negatively correlated with p CO_(2)and positively correlated with HCO_(3)^(-)concentration,indicating that CA in water promoted the conversion of CO_(2)to HCO_(3)^(-).The HCO_(3)^(-)generated from this process continued to participate in the erosion of silicate rocks,sequestering CO_(2)in the form of Ca CO_(3),which has a non-negligible impact on the carbon sink in the Fenhe River.These consequences may have important implications for the biogeochemical cycling occurring in urban water. 展开更多
关键词 HYDROCHEMISTRY inorganic carbon phytoplankton community carbonic anhydrase Fenhe River
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Analysis of the carbon dioxide mole fraction variation and its transmission characteristics in Taiyuan 被引量:5
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作者 ZHANG Fengsheng ZHU Lingyun +2 位作者 YAN Shiming GAO Xing’ai PEI Kunning 《Atmospheric and Oceanic Science Letters》 CSCD 2020年第4期363-370,共8页
Based on the concentrations of CO2,PM2.5 and PM1.0,and conventional meteorological observation data from 2016 to 2018 at Taiyuan station,which belongs to the Shanxi greenhouse gas observation network,the CO2 concentra... Based on the concentrations of CO2,PM2.5 and PM1.0,and conventional meteorological observation data from 2016 to 2018 at Taiyuan station,which belongs to the Shanxi greenhouse gas observation network,the CO2 concentration monthly and daily distribution characteristics,the weekend effect,and the variation characteristics on haze days and non-haze days,are analyzed.By using the Hybrid Single-Particle Lagrangian Integrated Trajectorymodel(backward trajectory model)and surface wind data,the transmission characteristics of atmospheric CO2 in Taiyuan are studied in various seasons.The results show that,in Taiyuan,the CO2 mole fraction in autumn and winter is higher than that in spring and summer,and on haze days is higher than that on non-haze days.The diurnal variation characteristic of CO2mole fraction in each season is‘single peak and single valley’with the peak value around 0700(hereafter refers to Beijing Time)and the valley value around 1600.The CO2 mole fraction on workdays is slightly higher than that on non-workdays and obviously different around 0800 of the early peak.Horizontal diffusion can reduce the CO2 mole fraction,while breezy weather is not beneficial to CO2 diffusion.The wind direction and speed in the upper levels are different from those near the surface,and the close air masses in the southwest–west–northwest sector raise the CO2 concentration in Taiyuan obviously.This indicates that the CO2 in Taiyuan is mainly contributed by local sources. 展开更多
关键词 Atmospheric carbon dioxide mole fraction variation transmission characteristics Taiyuan
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Analysis of Changing Factors on Airborne Allergenic Pollens Distribution in Taiyuan Downtown, North China 被引量:1
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作者 Kejun Zhang Binquan Wang +6 位作者 Yanli Zhang Yanli Zhang Nasha Cheng Changsheng Wang Chunming Zhang Wei Gao Ganggang Chen 《International Journal of Otolaryngology and Head & Neck Surgery》 2015年第2期148-155,共8页
To study and analyse 2 surveys on airborne allergenic pollens distribution in Taiyuan Downtown, North China 30 years apart, the surveys focused on the phenomenon and the influence factors on types, counts, drift patte... To study and analyse 2 surveys on airborne allergenic pollens distribution in Taiyuan Downtown, North China 30 years apart, the surveys focused on the phenomenon and the influence factors on types, counts, drift patterns, growth and decline rhythm and distribution features of airborne pollen with the same methods in the region in March 1977 to February 1978 and July 2008 to June 2009, respectively. The data of two airborne pollens surveys were treated with statistics, comparation and analysis, and the influence factors of pollen distribution in Taiyuan Downtown were explored. In the 2 surveys, 24 species and 35 species of pollen were collected in the region, respectively. Two pollen drift peaks were formed in spring and autumn in the two surveys. Artemisia L. is still the absolute dominant allergy airborne pollen. The types, counts, drift patterns and composition of pollen in air could be changed by the plants variation. Climate warming might affect pollen peak appearing time and lasting time, climate warming and Poplar & Willow contents changes in spring and autumn reversed the airborne pollen peak. It was found that Humulus L. had become the region’s main allergic pollen. Invasive strong allergen ragweed was spread to the inland city Taiyuan. Allergists should focus on exotic invasive harmful plants in the region. 展开更多
关键词 AIRBORNE POLLEN Identification of POLLEN POLLEN COUNT Seasonal DISTRIBUTION of AIRBORNE POLLEN Taiyuan
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The Taiyuan Lianhualao History and the Present Situation, Problems and Thinking
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作者 Liu Fang 《Review of Global Academics》 2014年第5期376-378,共3页
Taiyuan lian hua lao is the local of unique Shangcun of Tai Yuan in Chinese folk rap art breed, it is not a matter cultural heritage directory so far by column for Shanxi Province in 2006. This paper describes the dev... Taiyuan lian hua lao is the local of unique Shangcun of Tai Yuan in Chinese folk rap art breed, it is not a matter cultural heritage directory so far by column for Shanxi Province in 2006. This paper describes the development of Taiyuan Lian hua lao from the aspects of present situation, problems and thinking, then puts forward the relevant suggestions. 展开更多
关键词 taiyuan lianhualao present situation PROBLEMS THINKING
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Study on Ability of Ground Cover Plant of Taiyuan to Adsorb PM(2.5)
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作者 Baochun FU Guojie QIN +4 位作者 Ping CHANG Song WANG Min WU Lixiang ZUO Wei BO 《Agricultural Biotechnology》 CAS 2018年第2期85-88,100,共5页
Four ground cover plant species of Taiyuan( Iris,Hemerocallis,Sedum,Hosta) were selected to study their capacities in adsorbing PM(2.5). Meanwhile,the concentration of PM(2.5) in Taiyuan between April 2017 and A... Four ground cover plant species of Taiyuan( Iris,Hemerocallis,Sedum,Hosta) were selected to study their capacities in adsorbing PM(2.5). Meanwhile,the concentration of PM(2.5) in Taiyuan between April 2017 and August 2017 was recorded,and the characteristics of PM(2.5) pollution in summer and autumn in Taiyuan were studied. The results showed that for the 4 plants,the ability to adsorb PM(2.5) was in the order from great to small of Hosta,Iris,Hemerocallis,Sedum,in which H. plantaginea had the best effect to adsorb PM(2.5). The fresh weight and dry weight per gram of H. plantaginea were 4. 4 times and 2 times higher than those of S. spectabile,while the mass quality of dust adsorption was 2.8 times higher. The sorting result was the same as the ability to adsorb PM(2.5) of unit leaf area. The result of the coefficient of purification showed that the purification coefficients of 3 vegetation structure were positive,and the combination of trees and shrubs in university campus had strong PM(2.5) adsorption capacity. By comparing the seasonal variation of PM(2.5) concentration in Taiyuan city,it found that the PM(2.5) concentration was particularly high in late spring and early summer of Taiyuan,when most of the ground cover plants were not fully grown. Therefore,ground cover plants played an important role in the construction of landscape and the regulation of ecological environment in Taiyuan. 展开更多
关键词 Taiyuan Ground cover plants PM2.5 Adsorption capacityHome
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Accident Analysis and Emergency Response Effect Research of the Deep Foundation Pit in Taiyuan Metro
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作者 ZHANG Xiaoshuang FENG Chao +1 位作者 HAN Yunshan ZHANG Jun 《Journal of Donghua University(English Edition)》 EI CAS 2020年第3期199-206,共8页
Taking the deep foundation pit accident occurring at a station of metro Line 2 in Taiyuan as an example,the influence of the seepage and inrush of the foundation pit on the retaining structure and surrounding environm... Taking the deep foundation pit accident occurring at a station of metro Line 2 in Taiyuan as an example,the influence of the seepage and inrush of the foundation pit on the retaining structure and surrounding environment were studied under the geological conditions of the confined aquifer on the east coast of Fenhe River.The causes of deep foundation pit accident were also analyzed systematically based on the monitoring data,and various emergency measures were proposed to control the occurrence of secondary accident for deep foundation pit.The results showed that the occurrence of inrush for foundation pit was mainly caused by the insufficient dewatering.The development of the accident was effectively controlled by the adding of the dewatering wells,local grouting of retaining structure to stop seepage,surface grouting to reinforcement and uplift soil.The successful experience can provide some guidance to the construction of similar projects in the proposal. 展开更多
关键词 metro station deep foundation pit inrush SEEPAGE grouting reinforcement
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Environmental Effects on the Performance of Polycrystalline Silicon Solar Cells under Long-Term Outdoor Exposure in Taiyuan, China
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作者 Kashif Ali Yanbing Jia +1 位作者 Muhammad Abbas Syed Arslan Bukhari 《Journal of Power and Energy Engineering》 2019年第11期15-27,共13页
Environmental conditions such as wind, temperature and humidity affect the amount of solar irradiance received by the photovoltaic (PV) cells and thus have a significant effect on the PV output efficiency. This paper ... Environmental conditions such as wind, temperature and humidity affect the amount of solar irradiance received by the photovoltaic (PV) cells and thus have a significant effect on the PV output efficiency. This paper aims to analyze the power efficiency of Polycrystalline Silicon solar cells under China’s weather considering these environmental conditions. Performance of the Polycrystalline solar panel is analyzed through eight months of data emphasizing the maximum, average and minimum temperature acquired from a solar power plant installed at Taiyuan University of technology, China consisting of 78 PV panels with a total rated capacity of 20 KW and average module efficiency of 16.56% at an ambient temperature of 25°. The results of our practical investigations show that polycrystalline solar cells in October yield the best monthly average efficiency of 35.6% at an average temperature and humidity level of 14°C and 44%. In comparison to a maximum temperature of 27°C and humidity of 66% in summer, the efficiency is found to drop by 5%. Also, the power produced in winter at minimum temperature and the efficiency showed a decline of 15% compared to that of October. Consequently, this investigation leads to a conclusion that the increase in temperature and humidity together is found to have a negative effect on the efficiency whereas the increase in irradiance and wind speed showed an improvement in the output power of the polycrystalline solar cells. 展开更多
关键词 EFFICIENCY POLYCRYSTALLINE Photovoltaics WEATHER Effects
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Epidemiological studies on Legionella infection in Taiyuan area of Shanxi Province
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作者 WANGSuping 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1999年第3期241-241,共1页
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Forecast of peak infection and estimate of excess deaths in COVID-19 transmission and prevalence in Taiyuan City,2022 to 2023
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作者 Jia-Lin Wang Xin-Long Xiao +5 位作者 Fen-Fen Zhang Xin Pei Ming-Tao Li Ju-Ping Zhang Juan Zhang Gui-Quan Sun 《Infectious Disease Modelling》 CSCD 2024年第1期56-69,共14页
In this paper,with the method of epidemic dynamics,we assess the spread and prevalence of COVID-19 after the policy adjustment of prevention and control measure in December 2022 in Taiyuan City in China,and estimate t... In this paper,with the method of epidemic dynamics,we assess the spread and prevalence of COVID-19 after the policy adjustment of prevention and control measure in December 2022 in Taiyuan City in China,and estimate the excess population deaths caused by COVID-19.Based on the transmission mechanism of COVID-19 among individuals,a dynamic model with heterogeneous contacts is established to describe the change of control measures and the population's social behavior in Taiyuan city.The model is verified and simulated by basing on reported case data from November 8th to December 5th,2022 in Taiyuan city and the statistical data of the questionnaire survey from December 1st to 23rd,2022 in Neijiang city.Combining with reported numbers of permanent residents and deaths from 2017 to 2021 in Taiyuan city,we apply the dynamic model to estimate theoretical population of 2022 under the assumption that there is no effect of COVID-19.In addition,we carry out sensitivity analysis to determine the propagation character of the Omicron strain and the effect of the control measures.As a result of the study,it is concluded that after adjusting the epidemic policy on December 6th,2022,three peaks of infection in Taiyuan are estimated to be from December 22nd to 31st,2022,from May 10th to June 1st,2023,and from September 5th to October 13th,2023,and the corresponding daily peaks of new cases can reach 400000,44000 and 22000,respectively.By the end of 2022,excess deaths can range from 887 to 4887,and excess mortality rate can range from 3.06%to 14.82%.The threshold of the infectivity of the COVID-19 variant is estimated 0.0353,that is if the strain infectivity is above it,the epidemic cannot be control with the previous normalization measures. 展开更多
关键词 Taiyuan city COVID-19 Dynamic model Epidemic scale Epidemic peak Excess death
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Magnetostratigraphy and paleoenvironmental record of late Cenozoic sediments in the Taiyuan Basin,North China
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作者 Zhi-Qiang Feng Qian Li +6 位作者 Wei Han Kun-Yuan Ma Yong-Jiang Liu Rong-Zhu Wei Yan-Wei Du Yong Lei Guang-Hui Li 《Journal of Palaeogeography》 SCIE CSCD 2024年第4期971-992,共22页
The Taiyuan Basin is of importance for intraplate tectonic deformation in North China and contains Cenozoic strata with a maximum thickness of 3800 m.A~853.5-m-deep borehole(ZK01)with an overall core recovery rate of ... The Taiyuan Basin is of importance for intraplate tectonic deformation in North China and contains Cenozoic strata with a maximum thickness of 3800 m.A~853.5-m-deep borehole(ZK01)with an overall core recovery rate of 85.09%was drilled at Yuci(37°35'37?N,112°39'47?E)in the central Taiyuan Basin,to obtain high-resolution records of paleomagnetism,paleoclimatic and paleoenvironmental conditions,and depositional environment of the sediments.The obtained magnetic polarity sequence consists of 13 normal and 12 reverse zones,which correspond to C1n-C4An.2n of the geomagnetic polarity time scale.Magnetostratigraphic data show that the evolution of ZK01 core covers the interval from 8.1 Ma to the present,and the bottoms of Pliocene,Quaternary,and Middle Pleistocene were identified in Taiyuan Basin,with a sedimentary accumulation rate ranging from 62.5 m/Ma to 175.9 m/Ma.Geochemical data reveal that the source rocks in the study area underwent intense weathering and the sediments mainly formed in a semi-arid and oxygen-rich conditions.In addition,paleoclimatic changes occurred at~7 Ma,3.8 Ma,and 1.7 Ma,which can be closely related to the tectonic uplift of the Loess Plateau and Tibetan Plateau,as well as the variations in the Asian monsoon and associated regional and global climatic change. 展开更多
关键词 Taiyuan Basin Core sediment MAGNETOSTRATIGRAPHY Climate change PALEOENVIRONMENT QUATERNARY
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Exploring the characteristics of microbial community and enzyme activity in the aged refuse landfill environment of Taiyuan,China
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作者 Fen HOU Junjie DU +1 位作者 Yuzhou MENG Xihui WU 《Pedosphere》 SCIE CAS CSCD 2024年第5期879-891,共13页
Municipal solid waste landfill is the main disposal option for domestic garbage,in which microbial activities play an important role.However,despite the widespread practice of landfilling,the metagenomic microbial pro... Municipal solid waste landfill is the main disposal option for domestic garbage,in which microbial activities play an important role.However,despite the widespread practice of landfilling,the metagenomic microbial profiles of landfill sites remain poorly characterized.In this study,we used a combination of physicochemical analysis,ultraviolet-visible spectrophotometry,and high-throughput Illumina shotgun sequencing to systematically investigate the changes in soil enzyme activities,microbial community structure,and functional attributes in aged refuse collected from the Xingou Municipal Solid Waste Landfill in Taiyuan,China,with ordinary topsoil from an area within 5 km of the landfill as control soil.Except for neutral phosphatase(P=0.065),the activities of urease,laccase,dehydrogenase,sucrase,neutral protease,andβ-glucosidase were all significantly reduced(P<0.05)in the aged refuse compared with the control soil.Contrastingly,catalase activity was found to be significantly elevated in the aged refuse.Compared with the control soil,aged refuse was characterized by higher richness and diversity of microbial communities,as reflected by the higher values of community richness estimators(Chao 1 and ACE)and diversity indices(Shannon and Simpson).In total,186 phyla,4354 genera,and 34459 species were identified,with 132 phyla,1914 genera,and7369 species showing significantly different abundances between the aged refuse and the control soil.Actinobacteria and Acidobacteria were identified as the dominant phyla in the control soil,whereas Proteobacteria,Euryarchaeota(archaea),and Firmicutes were found to predominate in the aged refuse.Notably,Euryarchaeota and Methanoculleus were the major taxa detected in the aged refuse,but were almost completely absent in the control soil.Xenobiotic biodegradation and bacterial chemotaxis were the main functions of the microflora in the aged refuse,whereas the carbohydrate,amino acid,energy,and lipid metabolism pathways were significantly enriched in the control soil.Moreover,the aged refuse contained a high abundance of genes involved in quorum sensing.Our findings in this study revealed close associations between enzyme activities and variations in the microbial community structure and genes that were actively involved in biodegradation activities at landfill sites.It was found that the landfill environment was characterized by a more complex spectrum of microbial activities than expected.Further investigations are needed to gain a more comprehensive understanding of the microbial community structure and functional attributes as well as their potential influencing factors in the landfill environment. 展开更多
关键词 functional attribute metabolism pathway municipal solid waste landfll resource utilization soil microflora
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基于LabVIEW的拖拉机电气故障诊断系统设计 被引量:1
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作者 张扬 《农机化研究》 北大核心 2025年第2期239-243,248,共6页
设计了一种基于LabVIEW的拖拉机电气故障诊断系统,其采用模块化设计,可以自动检测和诊断拖拉机的电气故障,并提供可视化的诊断结果。系统由数据采集模块、信号处理模块、故障诊断模块和用户界面模块组成。数据采集模块负责采集拖拉机各... 设计了一种基于LabVIEW的拖拉机电气故障诊断系统,其采用模块化设计,可以自动检测和诊断拖拉机的电气故障,并提供可视化的诊断结果。系统由数据采集模块、信号处理模块、故障诊断模块和用户界面模块组成。数据采集模块负责采集拖拉机各个部件的电气参数数据,信号处理模块对采集到的数据进行处理和分析,故障诊断模块通过分析处理后的数据来判断拖拉机是否存在故障,并给出相应的诊断结果,用户界面模块提供友好的交互界面。试验结果表明:系统可以准确地诊断拖拉机的电气故障,具有良好的应用前景和推广价值。 展开更多
关键词 拖拉机 电气故障诊断 LABVIEW 数据采集 模块化设计
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高温下HMX热分解反应分子动力学模拟 被引量:1
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作者 陈芳 贾方硕 +3 位作者 陈瑶 李天浩 郭国琦 董羚 《原子与分子物理学报》 CAS 北大核心 2025年第2期105-110,共6页
本文采用ReaxFF-lg反应分子动力学方法研究了奥克托金(HMX)在六种不同温度下的初始反应热分解过程,验证了ReaxFF-lg势函数对HMX体系的适用性,计算了不同温度下HMX体系势能、总物种演化趋势、初始反应产物以及指前因子和活化能.结果表明,... 本文采用ReaxFF-lg反应分子动力学方法研究了奥克托金(HMX)在六种不同温度下的初始反应热分解过程,验证了ReaxFF-lg势函数对HMX体系的适用性,计算了不同温度下HMX体系势能、总物种演化趋势、初始反应产物以及指前因子和活化能.结果表明,HMX热分解过程主要有三种初始分解机理:N-NO_(2)键的断裂,HONO的解离和主环上C-N键的断裂,计算得到的初始分解阶段活化能Ea和指前因子ln(A),与实验值相吻合. 展开更多
关键词 HMX 反应分子动力学(RMD) ReaxFF-lg 热分解 温度
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基于P3HT的有机薄膜晶体管环境稳定性提升
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作者 李强 丁莉峰 +4 位作者 李磊磊 李禹文 李鑫旺 马佳楠 桑胜波 《半导体技术》 CAS 北大核心 2025年第1期23-31,共9页
电子设备领域对高稳定性有机薄膜晶体管(OTFT)的需求日益增长。为了解决有机材料在环境因素作用下影响晶体管稳定性的问题,制备了一种新型OTFT,并同时采用两种方法来提高其环境稳定性:对晶体管进行表面钝化处理,利用钝化层的高化学稳定... 电子设备领域对高稳定性有机薄膜晶体管(OTFT)的需求日益增长。为了解决有机材料在环境因素作用下影响晶体管稳定性的问题,制备了一种新型OTFT,并同时采用两种方法来提高其环境稳定性:对晶体管进行表面钝化处理,利用钝化层的高化学稳定性隔绝空气中的氧分子和水分子;利用聚(3-己基噻)(P3HT)共混聚甲基丙烯酸甲酯(PMMA)有源层获得高抗氧化性和抗水解能力。测试结果表明,经过60d后器件载流子迁移率仅降低到原始值的87.91%,电流开关比降低到原来的81.90%,说明本文提出的环境稳定性提升方法优于其他方法。 展开更多
关键词 聚(3-己基噻吩)(P3HT) 有机薄膜晶体管(OTFT) 稳定性提升 表面钝化 有源层共混
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参数带宽化的双摆桥式起重机线性自抗扰控制
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作者 邵雪卷 韩雨豪 +3 位作者 周亮亮 孙来庆 陈志梅 张井岗 《振动与冲击》 北大核心 2025年第4期82-90,共9页
桥式起重机作为工业上广泛应用的运输设备,在实际起动时,台车移动势必会带动吊钩以及负载产生两级摆角,增加小车定位与实时消摆的难度。针对这种情况,提出一种参数基于带宽调节的线性自抗扰控制方法,以消除初始负载摆角、内部不确定状... 桥式起重机作为工业上广泛应用的运输设备,在实际起动时,台车移动势必会带动吊钩以及负载产生两级摆角,增加小车定位与实时消摆的难度。针对这种情况,提出一种参数基于带宽调节的线性自抗扰控制方法,以消除初始负载摆角、内部不确定状态以及外界扰动对系统的影响。首先,将系统解耦成三个控制量互不包含的子系统;其次,对解耦后的子系统分别设计线性扩张状态观测器和线性控制器;最后,结合Lyapunov方法将设计的扩张状态观测器和控制器参数带宽化并进行收敛性和稳定性分析。仿真结果表明,所提控制方法能够在强扰动影响下准确平稳地将负载运输到目标位置并快速消除两级摆动,同时对模型参数变化具有较强的鲁棒性。 展开更多
关键词 双摆桥式起重机 带宽法 自抗扰 线性扩张状态观测器
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碳钢表面碳原子偏聚对锡原子热扩散的影响
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作者 李海斌 徐惠婷 +3 位作者 闫岳涛 陈璇 帅美荣 王强 《中国有色冶金》 北大核心 2025年第1期96-104,共9页
巴氏合金与轴承(碳钢)的紧密结合对轴承运行效率至关重要,目前主要采用铁锡化合物作为中间材料来提高轴承寿命。目前相关文献关于碳钢中碳原子含量对锡原子向铁中的扩散影响还没有报道,本研究对25^(#)和35^(#)钢基体表面进行了一系列热... 巴氏合金与轴承(碳钢)的紧密结合对轴承运行效率至关重要,目前主要采用铁锡化合物作为中间材料来提高轴承寿命。目前相关文献关于碳钢中碳原子含量对锡原子向铁中的扩散影响还没有报道,本研究对25^(#)和35^(#)钢基体表面进行了一系列热镀锡试验,分析了310℃条件下,Fe-Sn反应平衡时间、锡原子扩散系数和扩散厚度等关键指标对锡原子向碳钢中扩散的影响。结果表明,锡原子扩散到碳钢表面的距离随着保温时间的增加而增大,在310℃时,锡原子进入25^(#)钢的扩散系数为6.6×10^(-9),约为35^(#)钢的两倍;碳原子向25^(#)和35^(#)钢表面的扩散距离比与碳钢表面碳浓度商的平方根成反比。此外,Fe_(3)C的键能为-133 eV/atom,而FeSn和Fe_(3)Sn_(2)的键能分别仅为-7.4和-6.9 eV/atom;可知碳原子易与铁原子结合,即碳钢表面碳含量高会阻碍锡原子向钢中扩散。因此,锡原子容易向25^(#)钢表面扩散,25^(#)钢为理想的巴氏合金轴承材料。 展开更多
关键词 巴氏合金 轴承 铁锡化合物 碳钢 锡原子 扩散距离 扩散系数 结合能
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自动化专业学生创新实践能力培养模式改革与实践
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作者 王健安 赵志诚 +2 位作者 谢刚 柏艳红 何秋生 《控制工程》 北大核心 2025年第2期372-376,共5页
在地方高校自动化专业的教学中,加强创新型应用型人才的培养是提升教育质量与适应行业需求的迫切任务。因此,探索强化学生创新素质和实践能力的有效途径和方式十分必要。以“厚基础、重实践、强能力、高素质”为核心理念,以自动化人才... 在地方高校自动化专业的教学中,加强创新型应用型人才的培养是提升教育质量与适应行业需求的迫切任务。因此,探索强化学生创新素质和实践能力的有效途径和方式十分必要。以“厚基础、重实践、强能力、高素质”为核心理念,以自动化人才培养为目标,建立了“理实相融、产教相融、科教相融、资源共享”的创新实践能力培养体系,形成以“学生为中心、项目为抓手、平台为依托、制度为保障”的创新实践能力培养模式,致力于通过创新素质的提升和工程实践能力的强化,最终实现学生在面对复杂工程挑战时具备更强的应对能力和创新能力,从而提升学生的核心竞争力。 展开更多
关键词 自动化专业 创新实践能力 人才培养模式 地方高校
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“双碳”背景下制度安排对碳排放的影响 被引量:1
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作者 李佳佳 王鹏鑫 杨婉童 《生态经济》 北大核心 2025年第1期60-69,共10页
在探析制度安排对碳排放影响机理的基础上,构建并行多重中介模型,从产权制度、对外开放、金融制度、环境规制四个方面,实证检验了制度安排通过能源消费结构低碳化、产业结构合理化和高级化、技术进步三条路径影响碳排放的影响效应和作... 在探析制度安排对碳排放影响机理的基础上,构建并行多重中介模型,从产权制度、对外开放、金融制度、环境规制四个方面,实证检验了制度安排通过能源消费结构低碳化、产业结构合理化和高级化、技术进步三条路径影响碳排放的影响效应和作用机制。结果表明:产权制度主要通过推动产业结构合理化与促进技术进步实现碳减排;对外开放增加了碳排放,但中介路径有助于其转向碳减排;金融制度可以直接促进碳减排,其中介路径不显著;环境规制则完全通过推动产业结构合理化和技术进步来抑制碳排放。而且,沿海地区以制度安排抑制碳排放的效果比沿边地区与内陆地区更佳。因此,在尊重市场规律的条件下制定合理的激励相容制度对于促进企业低碳转型具有重要意义。 展开更多
关键词 制度安排 碳排放 并行多重中介模型 影响路径
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电动汽车多参数模型预测制动能量跟踪策略
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作者 张巍 高妍 张红娟 《汽车技术》 北大核心 2025年第1期20-25,共6页
针对电机制动能量回收率低和直流母线电压波动大的问题,提出了考虑电机功率、双向DC/DC变换器效率、超级电容电压等多个参数实时调整超级电容电流参考值的制动能量跟踪策略。采用储能单元的离散状态空间模型预测超级电容的电流和电压,... 针对电机制动能量回收率低和直流母线电压波动大的问题,提出了考虑电机功率、双向DC/DC变换器效率、超级电容电压等多个参数实时调整超级电容电流参考值的制动能量跟踪策略。采用储能单元的离散状态空间模型预测超级电容的电流和电压,并结合系统中多个参数计算超级电容的电流参考值。使用基于比例积分(PI)的电流环控制超级电容电流实时跟踪参考值,实现超级电容对电机能量的跟踪。通过仿真分析和对比试验,结果表明:所提出的策略能够将制动能量的回收效率由55.93%提升至86.76%,直流母线的电压波动范围抑制在0.9%以内。 展开更多
关键词 状态空间模型 双向DC/DC 变换器 制动能量跟踪
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