检索结果-南通市图书馆

Earthquake Engineering and Engineering Vibration 2021年第2期20卷 495-504页

作者： Anand M.Gharad Ranjan S.Sonparote Civil Engineering Department Shri Ramdeobaba College of Engineering and ManagementNagpur 440013India Department of Applied Mechanics Visvesvaraya National Institute of TechnologyNagpur 440010India

In the railway bridge analysis and design method,dynamic train loads are regarded as static loads enhanced by an impact factor(IF).The IF coefficients for various railway bridges have been reported as a function of span length or frequency of the bridges in Eurocode(2003).However,these IF coefficient values neglect the effects of very high speeds(>200 km/h)and soil-structure interaction(SSI).In this work,a comprehensive study to assess the impact factor coefficients of mid-span vertical displacements for continuous and integral railway bridges subjected to high-speed moving loads is *** different configurations,each for the three-dimensional(3D)continuous and integral bridge,are ***,single-track(1-T)and two-track(2-T)“real train”loading cases for both these bridge types are ***,finite element analysis of the full-scale 3D bridge models,to identify their IF values,considering the effects of SSI for three different soil conditions,is *** IF values obtained from the study for both bridge types are comparable and are greater than the values recommended by Eurocode(2003).The results reveal that with a loss of soil stiffness,the IF value reduces;thus,it confirms the importance of SSI analysis.

关键词： impact factor dynamic soil-structure interaction high-speed moving loads finite element analysis continuous bridge integral bridge

Calculation of impact factor of vibrator oscillation in offset printing based on fuzzy controller and genetic algorithm

在线全文

学校读者我要写书评

暂无评论

High Technology Letters 2015年第1期21卷 15-21页

作者：初红艳 Yang Junjing Cai Ligang College of Mechanical Engineering and Applied Electronics Technology Beijing University of Technology

In the inking system of an offset printing press,a vibrator roller distributes ink not only in the circumferential direction but also in the axial *** the control process,if ink amount is determined only by the dot area coverage without considering the impact of vibrator roller's oscillation,the printing colour quality will be *** paper describes a method of calculating the impact factor of vibrator roller' s ***,the oscillation performance is analyzed and sample data of impact factor is ***,a fuzzy controller used for the calculation of the impact factor is designed,and genetic algorithm is used to optimize membership functions and obtain the fuzzy control rules *** fuzzy controller can be used to calculate impact factors for any printing condition,and the impact factors can be used for ink amount control in printing process and it is important for higher printing colour quality and lowering ink and paper waste.

关键词： offset printing colour quality control impact factor fuzzy control genetic algorithm

impact factor analysis of post-operation life quality according to KPS in adult supratentorial superficial low-grade glioma

在线全文

学校读者我要写书评

暂无评论

Impact factor analysis of post-operation life quality accord...

Willingness of Farmer Households for Forest Management and Its impact factor Analysis after Collective Forest Tenure Reform

中国抗癌协会神经肿瘤专业委员会第八届学术会议

作者： Lu Ma,Qing Mao Department of Neurosurgery,West China hospital,Sichuan University,Chengdu,Sichuan Province,P.R.China

Objective:We assessed the life quality of adult supratentorial superficial low-grade glioma（ASS-LGG） patients according to Karnofsky Performance Scale（KPS） and analyzed the relevant *** benefit factors were found through this research to guide the therapeutic strategy and improve the patients’ prognosis after glioma ***:One hundred and four adults with ASS-LGG were collected and analyzed retrospectively from 2008 to *** follow-up time was from three months to half of a *** logistic regression was used to discuss the relationship between the life quality after surgery according to KPS and the impact factors such as age,gender,operation time,size and location of the tumor,degree of resection,and tumor grade before ***:We found that four out of ten candidate factors have pertinence with the improvement of the life quality after *** are age more than 40 years,the size of tumor less than 5cm,tumor located in the right hemisphere and limited resection of tumor in functional ***:It’s seems more significant to judge ASS-LGG patients’ prognosis on the base of life quality because of the patients’ long-time *** ASS-LGG patients,we could predict the life quality according to KPS after surgery depending on the patients’ age,and size and location of the *** is benefit to the improvement of life quality if the tumor is resected at early *** the size of the tumor and acquiring the pathological diagnosis should be recommended instead of the en bloc resection in functional area.

关键词： life quality low-grade glioma adult supratentorial superficial surgical therapy Karnofsky Performance Scale(KPS) impact factor

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Forestry Science and Technology 2011年第4期10卷 21-35页

作者： Huang Lili Wang Dengju Research Institute of Forestry Policy and Information, Chinese Academy of Forestry, Beijing 100091, P. R. China

The study was conducted in Mangling Village under Dehong Perfecture, Yunnan Province, for thorough investigation of forest tenure structure, management mode and forestland transfer of collective forests as well as of farmers' preference for management and transfer intention. The impact factors of management orientation of farmer households were analyzed with Logistic Model. The results showed that tenure structure and management modes of collective forest have been diversified after the collective forest tenure reform, and 87.5% of farmer households preferred to independent or joint management while 12.5% of them would rather to transfer their forestland. The choice of farmer household for management mode was mainly influenced by their education background, production skill, household labors and household income sources. The main factors influencing farmer households' forestland transfer activities include the proportion of forestry revenues to the total revenues, farmers' experiences, amount of household labor and forest land area.

关键词： forest tenure structure management mode forestland transfer willingness for management impact factor

在线全文

学校读者我要写书评

暂无评论

impact factor

Hepatobiliary & Pancreatic Diseases International 2005年第4期4卷 508-508页

(From www. wame. org; posted April 7, 2004) impact factor is widely regarded by authors and academic programs to be a measure of a journal’s prestige and value and can be important for authors’ career advancement in academic medicine. However, impact factor can be affected by a number of aspects unrelated to journal quality, including self-citation by a journal, publication timing, and types of articles published. As a result, impact factor has become a highly discussed issue among journal authors and editors. The recent WAME list-serve discussion has addressed its benefits and fallacies. On the basis of this discussion, the WAME Board makes the following recommendations to WAME members:

关键词： impact factor AME As

Dynamic Response impact of Vehicle Braking on Simply Supported Beam Bridges with Corrugated Steel Webs Based on Vehicle-Bridge Coupled Vibration Analysis

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第6期139卷 3467-3493页

作者： Yan Wang Siwen Li Na Wei School of Civil Engineering Zhengzhou UniversityZhengzhou450001China

A novel approach for analyzing coupled vibrations between vehicles and bridges is presented,taking into account spatiotemporal effects and mechanical phenomena resulting fromvehicle *** modeling and solution of bridge vibrations induced by vehicle deceleration are realized using this *** method’s validity and reliability are substantiated through numerical examples.A simply supported beam bridge with a corrugated steel web is taken as an example and the effects of parameters such as the initial vehicle speed,braking acceleration,braking location,and road surface roughness on the mid-span displacement and impact factor of the bridge are *** results show that vehicle braking significantly amplifies mid-span displacement and impact factor responses in comparison to uniform vehicular motion across the ***,the influence of wheelto-bridge friction forces is of particular significance and cannot be *** the vehicle initiates braking near the middle of the span,both the mid-span displacement and impact factor of the bridge exhibit substantial increases,further escalating with higher braking *** favorable road surface conditions,the midspan displacement and the impact factor during vehicle braking may exceed the design values stipulated by *** is important to note that road surface roughness exerts a more pronounced effect on the impact factor of the bridge in comparison to the effects of vehicle braking.

关键词： Corrugated steel web girder bridges simply supported beam bridges vehicle-bridge coupled vibration braking impact factor

impact factors and dynamic simulation of tillage-layer temperature in frozen-thawed soil under different cover conditions

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

International Journal of Agricultural and Biological Engineering 2018年第2期11卷 101-107页

作者： Qiang Fu Zi’ao Ma Enliang Wang Tianxiao Li Renjie Hou School of Water Conservancy and Civil Engineering Northeast Agricultural UniversityHarbin 150030China

Based on a winter field experiment between 2016 and 2017,four treatments(bare land(BL),natural snowfall coverage(NS),5-cm-deep straw+natural snowfall coverage(SC5),and 10-cm-deep straw+natural snowfall coverage(SC10))were established to determine the effects of the different treatments on soil temperature at the soil surface and at depths of 10 cm,20 cm,and 30 *** environmental factors of ambient temperature,ambient humidity,water vapor pressure,10-min wind speed,total radiation,net radiation,and long wave radiation were obtained from the weather station in the study *** correlation,multiple regression,and stepwise regression analysis,models for dynamic simulation of the tillage-layer soil temperature were constructed for analyzing the relation between tillage-layer soil temperature and environmental *** results showed that the environmental factors were all significantly correlated with tillage-layer temperature at the 0.01 level;when the impacts of other environmental factors were excluded,the correlations decreased *** dynamic simulation models for tillage-layer soil temperature under different coverage conditions were different,and the larger the coverage amount,the fewer the environmental factors that could affect the tillage-layer *** coefficients of determination of the prediction results of the dynamic models for the tillage-layer soil temperature under the four treatments(BL,NS,SC5,and SC10)were 0.8385,0.7110,0.7283,and 0.6216,*** prediction had a high accuracy and can accurately depict the dynamic changes of the tillage-layer soil *** results provided a theoretical basis for the efficient utilization of farmland soil water and heat resources.

关键词： farmland cover condition frozen-thawed soil tillage-layer temperature impact factor dynamic simulation stepwise regression

impact factors of Energy Productivity in China: An Empirical Analysis

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

Chinese Journal of Population,Resources and Environment 2007年第2期5卷 28-33页

作者： Wei Chu1,2, Shen Manhong2 1. College of Economics and Management, Zhejiang Sci-Tech University, Hangzhou Zhejiang 310018, China 2. College of Economics, Zhejiang University, Hangzhou Zhejiang 310017, China College of Economics and Management Zhejiang Sci-Tech University Zhejiang 310018 Hangzhou China College of Economics Zhejiang University Zhejiang 310017 Hangzhou China

This article developed a decomposition model of energy productivity on the basis of the economic growth model. Four factors were considered which may influence China’s energy productivity according to this model: technology improvement, resource allocation structure, industrial structure and institute arrangement. Then, an econometric model was employed to test the four factors empirically on the basis of China’s statistical data from 1978 to 2004. Results indicated that capital deepening con- tributes the most (207%) to energy efficiency improvement, and impact from labor forces (13%) is the weakest one in resource factor; industrial structure (7%) and institute innovation (9.5%) positively improve the energy productivity.

关键词： energy productivity impact factor economic growth China

Regional difference and influencing factors of the green development level in the urban agglomeration in the middle reaches of the Yangtze River

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2022年第8期65卷 1449-1462页

作者： Lei ZOU Huiyuan LIU Feiyu WANG Ting CHEN Yi DONG Key Laboratory of Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China

The urban agglomeration in the middle reaches of the Yangtze River(UAMRYR)is a key area to promote the central region rise and the green development of the Yangtze River Economic *** this paper,an evaluation index system was comprehensively constructed for the green development level of the UAMRYR from five aspects:resource utilization,green environment,green economy,green life,and support *** weight-TOPSIS method and multivariate statistical method,including spatial autocorrelation analysis and geographic detectors,were used to analyze the regional differences and influencing factors of the green development level of the UAMRYR from 2008 to *** results showed that:(1)the overall green development level of the UAMRYR showed a fluctuating upward trend from 2008 to 2018,among which the provincial capital cities such as Wuhan,Changsha,and Nanchang,as well as the cities covered by the Poyang Lake urban agglomeration had relatively higher green development levels.(2)The green development level of the 31 cities in the UAMRYR showed insignificant spatial heterogeneity within the study *** with other areas,the green development levels varied greatly among the regions of the Wuhan metropolitan area,which was a typical high-low aggregation type.(3)Green economy,green life,and support mechanisms were the highly influential aspects of the green development of the UAMRYR,and the main influencing factors were the total value added of secondary and tertiary industries,urbanization rate,and fixed asset *** explanatory power of the interaction of influencing factors on the green development of the UAMRYR was greater than that of a single *** study is intended to provide a reference for the green transformation development and the coordinated development of the“resources-environment-economy”in the UAMRYR.

关键词： Green development Regional difference impact factor Entropy weight-TOPSIS Geographic detector UAMRYR

Regional variation of urban air quality in China and its dominant factors

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 2022年第5期32卷 853-872页

作者： ZHAO Yanyan ZHANG Xiaoping CHEN Mingxing GAO Shanshan LI Runkui College of Resources and Environment University of Chinese Academy of SciencesBeijing100049China Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing100101China

It is of great theoretical and practical importance to carry out research on the spatio-temporal evolution of urban air pollution and its driving forces,which helps to facilitate a deeper understanding of the mutual feedback mechanisms between the urban environment and socio-economic *** of these mechanisms will contribute to the design and implementation of efficient environmental policies that ultimately will improve the quality of urbanization *** paper illustrates the spatio-temporal evolutionary characteristics of six urban ambient air pollutant concentrations,namely,CO,NO_(2),O_(3),PM_(10),PM_(2.5),SO_(2),in 286 sample cities above the prefecture level in China from 2014 to *** interactions between the pollutant concentrations are analyzed based on panel regression models.A random forest model is then employed to explore the correlations between the concentrations of these six pollutants and 13 natural and socio-economic impact factors to isolate the most crucial *** results reveal three ***,within the research period,the average annual concentration of O_(3)increased while that of other pollutants decreased year by ***,there were significant interactions between concentrations of the six pollutants,leading to obvious compound air pollution in urban ***,the impact of natural and socio-economic factors on urban air quality varied greatly among different air pollutants,with air temperature,vegetation coverage,urbanization level and traffic factors ranking high and the different response thresholds to the dominant influencing *** light of the limited ability of humans to control the natural environment and meteorological conditions,it is recommended that urban air quality be further improved by optimizing urban density,controlling anthropogenic emission sources,and implementing strict air pollution prevention and control measures.

关键词： urban air quality spatio-temporal evolution random forest model impact factor