期刊文献+
共找到6,095篇文章
< 1 2 250 >
每页显示 20 50 100
Impact of COVID-19 on College Students’Non-intellectual Factors and Corresponding Countermeasures
1
作者 HE Tong-tong HU Xin-yun +1 位作者 JIANG Dan ZHANG Shun-sheng 《Journal of Literature and Art Studies》 2023年第2期110-116,共7页
The outbreak of COVID-19 in December 2019 has exerted a wide and everlasting impact on the world,which has also influenced education enormously.The adjustment of objective learning environment during the COVID-19 pand... The outbreak of COVID-19 in December 2019 has exerted a wide and everlasting impact on the world,which has also influenced education enormously.The adjustment of objective learning environment during the COVID-19 pandemic makes the influence of non-intellectual factors on college students worthy of investigation,research and analysis.Based on this,we have launched a questionnaire survey on 500 college students who have witnessed the pandemic,and referred to related literature,network documents,news reports,contrast and analysis of college students’non-intelligence factors before and after the outbreak of the different levels of change,summing up some new measures to promote the development of college students’non-intelligence factors under the COVID-19 outbreak for online learning and autonomous learning. 展开更多
关键词 COVID-19 college students’non-intellectual factors impact learning enlightenment
下载PDF
An Evaluation of the Critical Success Factors in Sustainable Food Supply Chains in Developing Countries
2
作者 Muhammad Ahasan Habib Deen Islam Preyo +1 位作者 Muhammad Kamruzzaman Ahasan Md. Maruf Hossain 《World Journal of Engineering and Technology》 2024年第3期466-492,共27页
Food is one of the biggest industries in developed and underdeveloped countries. Supply chain sustainability is essential in established and emerging economies because of the rising acceptance of cost-based outsourcin... Food is one of the biggest industries in developed and underdeveloped countries. Supply chain sustainability is essential in established and emerging economies because of the rising acceptance of cost-based outsourcing and the growing technological, social, and environmental concerns. The food business faces serious sustainability and growth challenges in developing countries. A comprehensive analysis of the critical success factors (CSFs) influencing the performance outcome and the sustainable supply chain management (SSCM) process. A theoretical framework is established to explain how they are used to examine the organizational aspect of the food supply chain life cycle analysis. This study examined the CSFs and revealed the relationships between them using a methodology that included a review of literature, interpretative structural modeling (ISM), and cross-impact matrix multiplication applied in classification (MICMAC) tool analysis of soil liquefaction factors. The findings of this research demonstrate that the quality and safety of food are important factors and have a direct effect on other factors. To make sustainable food supply chain management more adequate, legislators, managers, and experts need to pay attention to this factor. In this work. It also shows that companies aiming to create a sustainable business model must make sustainability a fundamental tenet of their organization. Practitioners and managers may devise effective long-term plans for establishing a sustainable food supply chain utilizing the recommended methodology. 展开更多
关键词 Supply Chain Collaboration Interpretative Structural Modeling Cross-impact Matrix Multiplication SUSTAINABILITY Critical Success factors Multi-Criteria Decision Making Technique for Order of Preference by Similarity to Idea Solution
下载PDF
Changing Process and Impact Factors of Ecosystem in Shuangtaizi Estuary Wetland of China 被引量:1
3
作者 王永洁 郑冬梅 罗金明 《Journal of Landscape Research》 2011年第5期45-48,51,共5页
By introducing geological and natural conditions of Shuangtaizi Estuary Wetland,a national nature reserve,and borrowing Landsat5 TM wetland data of the year 1987 and 2005,the core area of Shuangtaizi Estuary Wetland i... By introducing geological and natural conditions of Shuangtaizi Estuary Wetland,a national nature reserve,and borrowing Landsat5 TM wetland data of the year 1987 and 2005,the core area of Shuangtaizi Estuary Wetland is studied,areas of its natural water,mudflat,seepweed beach,culture zone,reservoir and swag,reed field,rice field and non-wetland landscape are respectively analyzed,as well as the changes of wetland community,water quality,waterfowl quantity and species.It is found that the study area is suffering from serious fragmentation of wetland,reducing reed yield,degrading water quality,decreasing bird species and amount,which implies that the degraded wetland environment has imposed threats on the survival of some wetland species.Root causes of such a result are analyzed from the perspectives of regional climate changes and human interventions;while regional climate changes include obvious temperature increase and precipitation decrease,human interventions include oil exploration,reclamation of land from the lake,overuse of biotic resources,environment pollution.Due to the interactive influence of these two factors,ecosystem of Shuangtaizi Estuary Wetland has experienced drastic changes,which should be attached sufficient importance by relevant departments so as to enhance its protection and management. 展开更多
关键词 WETLAND ECOSYSTEM CHANGING process impact factors Shuangtaizi ESTUARY WETLAND
下载PDF
Impact factors identification of spatial heterogeneity of herbaceous plant diversity on five southern islands of Miaodao Archipelago in North China 被引量:8
4
作者 池源 石洪华 +3 位作者 王晓丽 覃雪波 郑伟 彭士涛 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第5期937-951,共15页
Herbaceous plants are widely distributed on islands and where they exhibit spatial heterogeneity.Accurately identifying the impact factors that drive spatial heterogeneity can reveal typical island biodiversity patter... Herbaceous plants are widely distributed on islands and where they exhibit spatial heterogeneity.Accurately identifying the impact factors that drive spatial heterogeneity can reveal typical island biodiversity patterns.Five southern islands in the Miaodao Archipelago,North China were studied herein.The spatial distribution of herbaceous plant diversity on these islands was analyzed,and the impact factors and their degree of impact on spatial heterogeneity were identified using CCA ordination and ANOVA.The results reveal 114 herbaceous plant species,belonging to 94 genera from 34 families in the50 plots sampled.The total species numbers on different islands were significantly positively correlated with island area,and the average a diversity was correlated with human activities,while the(3 diversity among islands was more affected by island area than mutual distances.Spatial heterogeneity within islands indicated that the diversities were generally high in areas with higher altitude,slope,total nitrogen,total carbon,and canopy density,and lower moisture content,pH,total phosphorus,total potassium,and aspect.Among the environmental factors,pH,canopy density,total K,total P,moisture content,altitude,and slope had significant gross effects,but only canopy density exhibited a significant net effect.Terrain affected diversity by restricting plantation,plantation in turn influenced soil properties and the two together affected diversity.Therefore,plantation was ultimately the fundamental driving factor for spatial heterogeneity in herbaceous plant diversity on the five islands. 展开更多
关键词 Island ecology herbaceous plant biodiversity spatial heterogeneity impact factor identification PLANTATION
下载PDF
Impacting Factors of Elemental Mercury Re-emission across a Lab-scale Simulated Scrubber 被引量:11
5
作者 武成利 曹晏 +1 位作者 董众兵 潘伟平 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第3期523-528,共6页
Elemental mercury(Hg^0)re-emissions from slurries and solutions were evaluated in a lab-scale simulated scrubber.Oxidized mercury(Hg^2 +)standard solution was injected into the simulated scrubber at a desired rat... Elemental mercury(Hg^0)re-emissions from slurries and solutions were evaluated in a lab-scale simulated scrubber.Oxidized mercury(Hg^2 +)standard solution was injected into the simulated scrubber at a desired rate to simulate absorbing and dissolving of Hg^2 +in the flue gas across wet flue gas desulfurization(WFGD)systems. PS analytical mercury analyzer was used to continuously determine Hg0re-emission concentrations in the carrier gas from the scrubber.Sulfite ion in the slurry of CaSO3 was validated to reduce Hg ^2+to Hg^ 0,while no Hg ^0 re-emission occurred from slurries of CaSO4 and CaO.Transitional metal ions with low chemical valence such as Fe^2 +,Pb ^2+,Ni ^2+, AsO2^-and Cu ^+were used to prepare solutions with concentration levels of mmol·L^-1.Reduction reaction of Hg^2 +to Hg 0was observed from these solutions.Reduction capabilities for the different transitional metal ions in the solutions were:Pb^2 +〉Cu ^+〉Fe^ 2+〉 AsO2^-〉Ni ^2+. 展开更多
关键词 simulated scrubber elemental mercur-y re-emission impacting factors SULFITE transitional metal ions
下载PDF
Calculation of Ecological Footprint Based on Modified Method and Quantitative Analysis of Its Impact Factors——A Case Study of Shanghai 被引量:4
6
作者 GAO Chengkang JIANG Dahe +1 位作者 WANG Dan YAN Jonathan 《Chinese Geographical Science》 SCIE CSCD 2006年第4期306-313,共8页
Ecological footprint (EF) has attracted much attention internationally as a potential indicator for sustainable development. In China, EF has also gained recognition in related fields and disciplines. Moreover, some... Ecological footprint (EF) has attracted much attention internationally as a potential indicator for sustainable development. In China, EF has also gained recognition in related fields and disciplines. Moreover, some scholars in these fields have proposed alternative methods to calculate EF and have made some progress. This paper, therefore, begins with the introduction and development of EF in China. However, the established methods of EF calculation hold some limitations, such as indicator variance and result abnormality. In order to resolve those problems, the authors make a further modification considering the demand of EF as a comprehensive indicator: 1) More accurate analysis has been done to divide EF into several parts: imported EF, exported EF, and producible EF, which is the solution to the problem of abnormality in original EF results and can explain abnormal phenomena reasonably. 2) Considering the actual situa- tion of Shanghai, emended equivalence factor is brought forward and a matrix is formed with equivalence factors. The measure can reduce the deviation between the fact and the results. 3) The calculation compares local yield with global average yield to analyze the effects of yields. And based on local yields in different years, the results are more accurate. Finally, the calculation method is applied to calculating EF of Shanghai from 1980 to 2003, and the subsequent detailed analysis is presented. Available data and results suggest a statistically significant correlation coefficient between EF and GDP, population density and urbaniTation level. Through analyzing the process of calculating EF and its results, it can be seen that EF, as a macro-indicator, can not exactly indicate whether development within a region can meet the re- quests of sustainable development, which can be explained by the fact that the result of EF is impacted greatly by sub- jective factors including national policy,available technology, population, etc. Nevertheless, EF can demonstrate, at least to some degree, the regional status in terms of resources and energy consumption, as well as developmental potential. The calculation of EF, therefore, deserves further research to achieve more far-reaching significance in application. 展开更多
关键词 ecological footprint quantitative analysis impact factors SHANGHAI
下载PDF
Impact Factors of Energy Productivity in China: An Empirical Analysis 被引量:2
7
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 《Chinese Journal of Population,Resources and Environment》 北大核心 2007年第2期28-33,共6页
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: tec... 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. 展开更多
关键词 energy productivity impact factor economic growth China
下载PDF
Bromate removal by activated carbon adsorption:material selection and impact factors study 被引量:2
8
作者 刘彤冕 赵志伟 +3 位作者 崔福义 刘冬梅 王欢 朱琦 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第5期81-85,共5页
Studies are conducted by using activated carbon process aimed at bromate removal from the raw water.Screening of activated carbon for bromate removal was performed in different activated carbons.GAC Merck possesses th... Studies are conducted by using activated carbon process aimed at bromate removal from the raw water.Screening of activated carbon for bromate removal was performed in different activated carbons.GAC Merck possesses the highest iodine number and surface area,the highest number of basic groups and Vmeso,thereby contains the highest adsorption velocity and adsorption capacity.Impact factors of bromate removal on activated carbon were studied.Through static absorption experiments we studied the effect of adsorption time,pH,temperature,anions and organic matter on bromate removal.With the decrease of pH,removal of bromate enhanced,suggests that it may be possible to increase bromate reduction through pH control.The increase of temperature will be favorable to adsorption of bromate on activated carbon.Anions and organic matter can inhibit the adsorption of bromate on activated carbon through competing active sites.Bromate removal can be improved by controlling key water quality parameters. 展开更多
关键词 BROMATE activated carbon ADSORPTION impact factors
下载PDF
Seasonal dynamics and impact factors of urban forest CO2 concentration in Harbin,China 被引量:2
9
作者 Wenyu Zheng Yunwei Zhou +1 位作者 Han Gu Zhongping Tian 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第1期125-132,共8页
CO2 concentrations in different plant communities (larch, birch, lilac, and grassland) were measured during the growing season in the Heilongjiang Forest Botanical Garden to study diurnal variation, seasonal and ann... CO2 concentrations in different plant communities (larch, birch, lilac, and grassland) were measured during the growing season in the Heilongjiang Forest Botanical Garden to study diurnal variation, seasonal and annual dynamics and factors that impact CO2 concentration in different spaces. CO2 concentration in different communities in green lands had an obvious diurnal variation, chronically decreasing, and temperature influenced the lilac area and the grassland. Seasonally, CO2 was lowest in the larch green land (344.03 ±23.03 μmol/mol) and highest in the grassland (360.13 ± 22.43 μmol/mol). The overall trend in CO2 concentration was autumn 〉 spring 〉 summer; temperature is the main factor controlling variation in CO2 concentrations during the growing season; the CO2 concentration at the larch, birch, lilac, and grassland types of sites was negatively correlated with land surface temperature and air temperature, and the CO2 concentration at the larch and birch sites was positively correlated with atmospheric pressure. Without any obvious annual change law, further study and observation are needed. 展开更多
关键词 CO2 concentration Ecological benefits Green land impact factors Plant communities
下载PDF
Degradation of chlorothalonil by ultrasonic irradiation:Kinetics and impact factors 被引量:2
10
作者 郭洪光 高乃云 +2 位作者 黎雷 金玄雄 陈喆 《Journal of Central South University》 SCIE EI CAS 2011年第4期1068-1073,共6页
Factors on degradation of chlorothalonil(CLT) in water by high frequency ultrasonic irradiation were investigated.The effects of initial concentration of chlorothalonil,dosages of tertiary butyl alcohol,humic acid and... Factors on degradation of chlorothalonil(CLT) in water by high frequency ultrasonic irradiation were investigated.The effects of initial concentration of chlorothalonil,dosages of tertiary butyl alcohol,humic acid and initial pH value on degradation of chlorothalonil,as well as the reaction mechanism were studied.The results reveal that chlorothalonil could be effectively degradated by ultrasonic irradiation.The reaction constant value kapp decreased from 0.014 1 to 0.010 2 min-1 with the initial concentration increasing from 50 to 400 μg/L during 180 min irradiation.Tertiary butyl alcohol had negative effect on chlorothalonil degradation,while lower concentration of humic acid promoted the sonolysis,and kapp declined with the further concentration increasing.The kapp varied little when the pH value ranged from 3.10 to 10.28.It may be concluded that mechanical and pyrolysis process played main roles on the degradation of chlorothalonil in ultrasonic irradiation rather than ·OH attack.The electrical energy per order(EEo) values for sonolysis degradation of CLT were also calculated to evaluate the cost of the process. 展开更多
关键词 ultrasonic irradiation CHLOROTHALONIL KINETICS impact factors
下载PDF
Study on the Spreading of Environmental Impact of Human Being' s Activities and Its Crucial Factors in Upper Minjiang River 被引量:1
11
作者 FanHong ZhaoHong-da 《Wuhan University Journal of Natural Sciences》 CAS 2003年第03B期949-956,共8页
This paper focuses on the historical transition of human being's activities and the eco-environment in the upper reaches of Minjiang River. The history is divided into 4 periods, each with its own feature. During ... This paper focuses on the historical transition of human being's activities and the eco-environment in the upper reaches of Minjiang River. The history is divided into 4 periods, each with its own feature. During the period of nomad immigration, the top-line of the subalpine forest was forced downward by the expanding subalpine meadow. During the period of farming nationality immigration, the bottom-line of middle mountain forest had moved upward forced by the needs for land or timber of the increasing population in the valley basia During the period of the early exploiting, the focus resource was the timber. The total output was limited, comparing with the later period, because of the bad accessibility. But it was large enough to impact the forest ecosystem of the deforesting area. The recent 50 years is the crucial period of economic development and eco-environment degradation. This paper points out that the impact of human being's activities for environment lies on 3 factors: 1) physical features control the location and tendency eco-environmental change; 2) population and productivity control the scale and speed of eco-environmental change; 3) regional accessibility controls the time and location of eco-environmental change. 展开更多
关键词 historical period human being's activities environmental impact crucial factors
下载PDF
Pore scale performance evaluation and impact factors in nitrogen huff-n-puff EOR for tight oil 被引量:2
12
作者 Yi-Lei Song Zhao-Jie Song +4 位作者 Yun-Fei Zhang Ze-Hui Xie Li-Chao Zhang Dai-Gang Wang Gang Hui 《Petroleum Science》 SCIE CAS CSCD 2022年第6期2932-2940,共9页
Nitrogen huff-n-puff(N_(2)HnP) appears to be an economical and high-efficiency enhanced oil recovery(EOR) technique for tight oil reservoirs.There is however a lack of understanding of the pore-level EOR performance o... Nitrogen huff-n-puff(N_(2)HnP) appears to be an economical and high-efficiency enhanced oil recovery(EOR) technique for tight oil reservoirs.There is however a lack of understanding of the pore-level EOR performance of N2HnP under tight reservoir conditions.In this work,a non-magnetic reactor was created and combined with a nuclear magnetic resonance(NMR) device for real-time monitoring of oil distribution in the HnP experiment.N_(2)HnP experiments were then performed in a tight sandstone core sample at a temperature of 353 K and an injection pressure≥ 24 MPa.The pore-level oil distribution under reservoir conditions was monitored and the EOR performance of N2HnP in specific pores was analyzed.The pore throat structures of the core sample and the phase behavior of the N_(2)-Oil system were analyzed to elucidate the EOR mechanism of N_(2)HnP.An oil recovery factor of 37.52% can be achieved after four cycles,which proves the EOR potential of N_(2)HnP for tight reservoirs.The highest recoveries after N_(2)HnP are obtained in the large pores,followed by the medium pores,the small pores,and finally the micro pores.Increases in soaking time and injection pressure resulted in slight and pronounced increases in oil recovery,respectively,both of which are mainly reflected in the first cycle.Specifically,increasing the soaking time only slightly improves the cumulative oil recovery in the small pores while increasing the injection pressure significantly improves the cumulative oil recovery in the small,medium,and large pores simultaneously.However,variations in both injection pressure and soaking time have a negligible effect on the cumulative oil recovery of the micro pores. 展开更多
关键词 Tight oil reservoirs N_(2)huff-n-puff Pore-level production characteristics impact factors Nuclear magnetic resonance
下载PDF
Evaluating the impact and significance of meteorological factors upon dust storm occurrence 被引量:1
13
作者 WanYuan Li ShiHua Lv +3 位作者 Ye Yu ZhiBao Dong ZhiBao Shen YuChun Chen 《Research in Cold and Arid Regions》 2011年第2期161-171,共11页
In this article, the quantitative impact and significance of factors on dust storm occurrence have been analyzed in detail, based on spring daily data sets of 17 meteorological factors and dust storm records during th... In this article, the quantitative impact and significance of factors on dust storm occurrence have been analyzed in detail, based on spring daily data sets of 17 meteorological factors and dust storm records during the period of 1954-2005 for 60 gauge stations distributed over Gansu Province of China. Results show that daily mean and maximum wind speeds and evaporation have a positive effect on dust storm occurrence, i.e., their increase can result in an increase of dust storm occurrence. Inversely, daily mean and minimum relative humidity, lowest surface air pressure, vapor pressure and number of sunny hours have a negative effect on dust storm occurrence. However, daily mean and highest surface air pressure; mean, highest and lowest surface air temperature; and precipitation of 20:00-08:00, 08:00-20:00 and 20:00-20:00 have a positive effect on dust storm occurrence in some places but negative in other places. On average, daily maximum and mean wind speeds, direction of the maximum wind, number of sunny hours and evaporation have a significant effect on dust storm occurrence in Gansu Province, but precipitation of 20:00--08:00, 08:00-20:00 and 20:00-20:00, and mean surface air pressure and temperature all have a minor influence upon dust storm occurrence. 展开更多
关键词 Gansu Province meteorological factor spring dust storm occurrence impact and significance
下载PDF
Physical, Psychological, and Social Health Impact of Temperature Rise Due to Urban Heat Island Phenomenon and Its Associated Factors 被引量:3
14
作者 Li Ping WONG Haridah Alias +2 位作者 Nasrin Aghamohammadi Sima Aghazadeh Nik Meriam Nik Sulaiman 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2018年第7期545-550,共6页
The Urban Heat Island Effect(UHI)has now become a commonly observed phenomenon worldwide.Indeed,it has become a significant environmental effect of urbanisation.In Malaysia,research results showed that UHI effects a... The Urban Heat Island Effect(UHI)has now become a commonly observed phenomenon worldwide.Indeed,it has become a significant environmental effect of urbanisation.In Malaysia,research results showed that UHI effects are very evident in several cities such as Kuala Lumpur and Putrajaya.UHI effect has long been observed to cause temperature of cities. 展开更多
关键词 AS UHI PSYCHOLOGICAL and Social Health impact of Temperature Rise Due to Urban Heat Island Phenomenon and Its Associated factors PHYSICAL
下载PDF
A novel approach to the dynamic response analysis of Euler-Bernoulli beams resting on a Winkler soil model and subjected to impact loads
15
作者 Adolfo Foriero Filippo Santucci de Magistris Giovanni Fabbrocino 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第2期389-401,共13页
This work presents a novel approach to the dynamic response analysis of a Euler-Bernoulli beam resting on a Winkler soil model and subjected to an impact loading.The approach considers that damping has much less impor... This work presents a novel approach to the dynamic response analysis of a Euler-Bernoulli beam resting on a Winkler soil model and subjected to an impact loading.The approach considers that damping has much less importance in controlling the maximum response to impulsive loadings because the maximum response is reached in a very short time,before the damping forces can dissipate a significant portion of the energy input into the system.The development of two sine series solutions,relating to different types of impulsive loadings,one involving a single concentrated force and the other a distributed line load,are presented.This study revealed that when a simply supported Euler-Bernoulli beam,resting on a Winkler soil model,is subject to an impact load,the resulting vertical displacements,bending moments and shear forces produced along the span of the beam are considerably affected.In particular,the quantification of this effect is best observed,relative to the corresponding static solution,via an amplification factor.The computed impact amplification factors,for the sub-grade moduli used in this study,were in magnitude greater than 2,thus confirming the multiple-degree-of-freedom nature of the problem. 展开更多
关键词 beam-Winkler-soil model sub-grade moduli impact load impact distributed line load dynamic solution impact amplification factor
下载PDF
Dynamic Response Impact of Vehicle Braking on Simply Supported Beam Bridges with Corrugated Steel Webs Based on Vehicle-Bridge Coupled Vibration Analysis
16
作者 Yan Wang Siwen Li Na Wei 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期3467-3493,共27页
A novel approach for analyzing coupled vibrations between vehicles and bridges is presented,taking into account spatiotemporal effects and mechanical phenomena resulting fromvehicle braking.Efficient modeling and solu... A novel approach for analyzing coupled vibrations between vehicles and bridges is presented,taking into account spatiotemporal effects and mechanical phenomena resulting fromvehicle braking.Efficient modeling and solution of bridge vibrations induced by vehicle deceleration are realized using this method.The 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 analyzed.The results show that vehicle braking significantly amplifies mid-span displacement and impact factor responses in comparison to uniform vehicular motion across the bridge.Notably,the influence of wheelto-bridge friction forces is of particular significance and cannot be overlooked.When 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 acceleration.Under favorable road surface conditions,the midspan displacement and the impact factor during vehicle braking may exceed the design values stipulated by codes.It 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. 展开更多
关键词 Corrugated steel web girder bridges simply supported beam bridges vehicle-bridge coupled vibration BRAKING impact factor
下载PDF
Characterization of Aquabacterium parvum sp. Strain B6 during Nitrate-Dependent Fe(Ⅱ) Oxidation Batch Cultivation with Various Impact Factors 被引量:2
17
作者 Xiaoxin Zhang Ulrich Szewzyk Fang Ma 《Transactions of Tianjin University》 EI CAS 2017年第4期315-324,共10页
In order to assess the capacity of Aquabacterium parvum sp. strain B6 for nitrate-dependent Fe(II) oxidation, batch cultivation was conducted, and its ability to oxidize Fe(II) coupled to nitrate reduction in the pres... In order to assess the capacity of Aquabacterium parvum sp. strain B6 for nitrate-dependent Fe(II) oxidation, batch cultivation was conducted, and its ability to oxidize Fe(II) coupled to nitrate reduction in the presence of diverse organic substrates was studied. Meanwhile, the nitrate-removal rate of B6 with various impact factors was further optimized by the response surface methodology (RSM). The results show that strain B6 is capable of utilizing different organic compounds as substrates for nitrate reduction. Compared with yeast extract, B6 showed a greater potential of chemical oxygen demand (COD) degradation and cell proliferation with acetate and glucose mediums, respectively, while citrate was not beneficial for this process due to its low consumption rate. RSM analysis demonstrated that the maximum nitrate-reduction rate of 30.64% could be achieved with an initial pH of 7.4, incubation temperature of 25.0 °C, and carbon source concentration of 266.10 mg/L. © 2017, Tianjin University and Springer-Verlag Berlin Heidelberg. 展开更多
关键词 Carbon Cell proliferation Iron compounds NITRATES Optimization OXIDATION
下载PDF
Changing Characteristics and Impact factors of Pan Evaporation in Benxi County
18
作者 Wang Fuchun Wu Yingjie Han Mei 《Meteorological and Environmental Research》 CAS 2014年第8期1-3,6,共4页
Based on data of monthly pan evaporation,temperature,precipitation,sunshine hours,wind speed,relative humidity,etc. in Benxi County during 1958-2012 from Meteorological Bureau of Benxi County,annual,seasonal and month... Based on data of monthly pan evaporation,temperature,precipitation,sunshine hours,wind speed,relative humidity,etc. in Benxi County during 1958-2012 from Meteorological Bureau of Benxi County,annual,seasonal and monthly changes and impact factors of pan evaporation in Benxi County in recent 55 years were analyzed. The results showed that annual evaporation in Benxi County showed a decreasing trend from 1958 to 2012,with the linear tendency rate of-12. 18 mm/10 a. Except that evaporation in spring decreased obviously,but evaporation in other seasons increased slightly in recent 55 years. Moreover,evaporation changes correlated with changes of average temperature,daily range of temperature,precipitation,sunshine hours,average wind speed and relative humidity,but the correlations between evaporation and each meteorological element were different in various seasons. 展开更多
关键词 EVAPORATION Climatic change impact factors China
下载PDF
Analysis of Impact Factors on Agricultural SMEs′ Technological Innovation Capacity——Case Study of Wenzhou City 被引量:1
19
作者 LI Yan-yan1, ZENG Wen-jin2 1.Wenzhou Vocational College of Science and Technology, Wenzhou 325000, China 2.Wenzhou Agricultural Bureau, Wenzhou 325000, China 《Asian Agricultural Research》 2010年第9期10-12,16,共4页
The paper investigates impact factors of agricultural SMEs′ technological innovation by questionnaire on the survey of more than 100 agricultural SMEs of Wenzhou City of Jiangsu Province. It selects 14 major factors ... The paper investigates impact factors of agricultural SMEs′ technological innovation by questionnaire on the survey of more than 100 agricultural SMEs of Wenzhou City of Jiangsu Province. It selects 14 major factors that influence agricultural SMEs′ technological innovation, they are capital source, enterprise culture, support from leaders, government policy support, effect of key research personnel, communication inside organization, enterprise strategy, technological development level, organizing and coordination inside organization, related information acquisition capacity, external cooperation, association and communication with consumers, change of external market and incentive measures to research personnel. Putting these factors in introductionance ordering by scores, we find out comparatively big impact factors influence agricultural SMEs′ technological innovation among them, they are technological development level, incentive measures to research personnel, capital source, government policy support and enterprise strategy. The paper also puts forward corresponding measures and suggestions: further enhance innovation consciousness and improve technological innovation level of agricultural SMEs; increase incentive measures, strengthen construction of talents team of technological innovation; express scientific research strength of local scientific research institutes and agricultural institution of higher learning, realize integration of industries, universities and research; sound government guiding and pushing mechanism, improve new policy environment of agricultural SMEs′ technological innovation. 展开更多
关键词 AGRICULTURAL SMES TECHNOLOGICAL INNOVATION capacit
下载PDF
A quantitative BP neural network analysis of the relationships between ΣREE content and impact factors in the Beibu Gulf
20
作者 ZHANG Wen-li HU Hao +2 位作者 LONG Jiang-ping XU Dong ZHOU Meng-jia 《Marine Science Bulletin》 CAS 2017年第1期52-66,共15页
The distribution characteristics of rare earth elements (REE) in bottomsediments are influenced by many factors. Hence, conducting a quantitative analysis isdifficult. A qualitative analysis of the relationships bet... The distribution characteristics of rare earth elements (REE) in bottomsediments are influenced by many factors. Hence, conducting a quantitative analysis isdifficult. A qualitative analysis of the relationships between ΣREE content andprovenance, hydrodynamics, grain size and mineral distribution in the Beibu Gulf showsthat terrestrial rocks control the ΣREE composition. Both weaker hydrodynamics andfiner grain size lead to a higher ΣREE content. Relative curves revealing therelationships between individual impact factors and ΣREE content were obtained fromthe combination of qualitative and quantitative analyses of the BP neural network,which trained the position of samples, gravel content, sand content, silt content, claycontent and clay mineral content. The results are consistent with those of thequantitative analysis. The self-learning algorithm is automatically determined andcalculated quantitatively. The impact of each factor on REEs and how each factorcontrols the ΣREE distribution is identified. Thus, environmental changes and thegeological evolution of the region can be inferred based on curve variation and the geological evolution of the region can be inferred based on curve variation and theactual situation. This method also provides useful theoretical guidance for the analysisof REE enrichment and dispersion. 展开更多
关键词 REE impact factors quantitative analysis BP neural network controlvariable method
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部