资源类型

期刊论文 158

年份

2024 1

2023 16

2022 10

2021 11

2020 6

2019 9

2018 5

2017 7

2016 8

2015 7

2014 13

2013 6

2012 12

2011 5

2010 10

2009 7

2008 3

2007 5

2006 4

2005 1

展开 ︾

关键词

影响因素 12

风险因素 2

驱动因素 2

21世纪海上丝绸之路 1

ACE2 1

CO2排放 1

GPS浮标精度 1

Logistic分析 1

SARS-CoV-2 1

ε-不敏感损失函数 1

三塔悬索桥 1

不良妊娠结局 1

个人价值观 1

个体抗缺氧能力 1

主成分 1

二维插值 1

人为因素 1

人工流产 1

人工神经网络 1

展开 ︾

检索范围:

排序: 展示方式:

Factors influencing peak bone mass gain

Xiaowei Zhu, Houfeng Zheng

《医学前沿(英文)》 2021年 第15卷 第1期   页码 53-69 doi: 10.1007/s11684-020-0748-y

摘要: Bone mass is a key determinant of osteoporosis and fragility fractures. Epidemiologic studies have shown that a 10% increase in peak bone mass (PBM) at the population level reduces the risk of fracture later in life by 50%. Low PBM is possibly due to the bone loss caused by various conditions or processes that occur during adolescence and young adulthood. Race, gender, and family history (genetics) are responsible for the majority of PBM, but other factors, such as physical activity, calcium and vitamin D intake, weight, smoking and alcohol consumption, socioeconomic status, age at menarche, and other secondary causes (diseases and medications), play important roles in PBM gain during childhood and adolescence. Hence, the optimization of lifestyle factors that affect PBM and bone strength is an important strategy to maximize PBM among adolescents and young people, and thus to reduce the low bone mass or osteoporosis risk in later life. This review aims to summarize the available evidence for the common but important factors that influence bone mass gain during growth and development and discuss the advances of developing high PBM.

关键词: peak bone mass     children     adolescents     genetic     risk factors    

Factors influencing the photodegradation of

Bingbing XU, Zhonglin CHEN, Fei QI, Jimin SHEN, Fengchang WU

《环境科学与工程前沿(英文)》 2009年 第3卷 第1期   页码 91-97 doi: 10.1007/S11783-009-0013-8

摘要: In order to provide basic data for practical application,photodegradation experiment of -nitrosodimethylamine (NDMA) in aqueous solution was carried out with a low-pressure Hg lamp. Effects of the initial concentration of NDMA, solution pH, dissolved oxygen, and the presence of humic acid on NDMA photodegradation were investigated. NDMA at various initial concentrations selected in this study was almost completely photodegraded by UV irradiation within 20 min, except that at 1.07 mmol/L, NDMA could be photodegraded almost completely in the acidic and neutral solutions, while the removal efficiency decreased remarkably in the alkaline solution. Dissolved oxygen enhanced the NDMA photodegradation, and the presence of humic acid inhibited the degradation of NDMA. Depending on the initial concentration of NDMA, NDMA photodegradation by UV obeyed the pseudo-first-order kinetics. Dimethylamine, nitrite, and nitrate were detected as the photodegradation products of NDMA. O was found to be the reactive oxygen species present in the NDMA photodegradation process by UV, based on the inhibiting experiments using tert-butanol and sodium azide.

关键词: N-nitrosodimethylamine (NDMA)     ultraviolet irradiation     degradation kinetic     dimethylamine     photodegradation product    

Characteristics and Influencing Factors of Microplastics in Snow in the Inner Mongolia Plateau, China

Hongwei Yu,Junrong Shao,Huawei Jia,Diga Gang,Baiwen Ma,Chengzhi Hu,

《工程(英文)》 doi: 10.1016/j.eng.2023.02.007

摘要: Microplastics (MPs; < 5 mm) have become one of the most prominent global environmental pollution problems. MPs can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall, potentially threatening the structure and function of natural ecosystems. MPs in terrestrial and aquatic ecosystems alter the growth and functional characteristics of organisms. However, little attention has been given to the possible harm associated with MPs deposited in snow, particularly in the context of global climate warming. MPs collected from surface snow in the Inner Mongolia Plateau, China, were used for quantitative analysis and identification. The results showed that MPs were easily detected, and the related concentration was approximately 68 ± 10–199 ± 22 MPs·L−1 in snow samples. Fibers were the most common morphology, the polymer composition was largely varied, and the abundance and composition of MPs were linked to human activity to a great extent. High-throughput sequencing results showed that the composition and abundance of microorganisms also differed in snow samples from areas with different MP pollution characteristics, indicating a considerable difference in microbial functional diversity. MPs may have an interference effect on the individual growth and functional expression of microorganisms in snow. In addition, the results showed that functional living areas (e.g., landfills and suburban areas) in cities play an important role in the properties of MPs. For instance, the highest abundance of MPs was found in thermal power plants, whereas the abundance of polymers per sample was significantly lower in landfills. The MP contaminants hidden in snow can alter microbial structure and function and are therefore a potential threat to ecosystem health.

关键词: Human activities     Snow     Microplastics     Microbial community     Urban function     Environmental effect    

Influencing factors and control measures of excavation on adjacent bridge foundation based on analytic

Shuangxi FENG, Huayang LEI, Yongfeng WAN, Haiyan JIN, Jun HAN

《结构与土木工程前沿(英文)》 2021年 第15卷 第2期   页码 461-477 doi: 10.1007/s11709-021-0705-0

摘要: Many uncertain factors in the excavation process may lead to excessive lateral displacement or over-limited internal force of the piles, as well as inordinate settlement of soil surrounding the existing bridge foundation. Safety control is pivotal to ensuring the safety of adjacent structures. In this paper, an innovative method is proposed that combines an analytic hierarchy process (AHP) with a finite element method (FEM) to reveal the potential impact risk of uncertain factors on the surrounding environment. The AHP was adopted to determine key influencing factors based on the weight of each influencing factor. The FEM was used to quantify the impact of the key influencing factors on the surrounding environment. In terms of the AHP, the index system of uncertain factors was established based on an engineering investigation. A matrix comparing the lower index layer to the upper index layer, and the weight of each influencing factor, were calculated. It was found that the excavation depth and the distance between the foundation pit and the bridge foundation were fundamental factors. For the FEM, the FE baseline model was calibrated based on the case of no bridge surrounding the foundation pit. The consistency between the monitoring data and the numerical simulation data for a ground settlement was analyzed. FE simulations were then conducted to quantitatively analyze the degree of influence of the key influencing factors on the bridge foundation. Furthermore, the lateral displacement of the bridge pile foundation, the internal force of the piles, and the settlement of the soil surrounding the pile foundation were emphatically analyzed. The most hazardous construction condition was also determined. Finally, two safety control measures for increasing the numbers of support levels and the rooted depths of the enclosure structure were suggested. A novel method for combining AHP with FEM can be used to determine the key influencing aspects among many uncertain factors during a construction, which can provide some beneficial references for engineering design and construction.

关键词: deep foundation pit excavation     adjacent bridge foundation     influencing factors     analytic hierarchy process     finite element    

Analysis of synergy degree and its influencing factors in hydropower EPC project management

Jiwei ZHU, Hua GAO, Jiangrui WANG

《工程管理前沿(英文)》 2021年 第8卷 第3期   页码 402-411 doi: 10.1007/s42524-020-0098-0

摘要: The use of engineering procurement construction (EPC) mode is currently a trend in hydropower engineering construction. The clarification of the internal relationship between hydropower EPC projects and the realization of synergy has great significance in improving management efficiency and implementation effect. In this work, a three-dimensional system and a system model of hydropower EPC project management synergy are constructed. The mechanism and factors that influence the degree of management synergy are analyzed on the basis of management synergy theory. Furthermore, the evaluation index system and the degree of synergy model are established, and grey relational analysis is utilized to identify the key factors that affect the synergy degree. Thus, this study aims to facilitate the hydropower EPC project management synergy, provide a quantitative method for synergy degree evaluation, and propose corresponding promotion strategies. Results show that the order degree of each subsystem presents a steady upward trend. Specifically, the order degree of the subsystem at the trial operation stage is low, which is the major restriction on the further improvement of the synergy degree of EPC project management. The key factors in improving the synergy level of hydropower EPC project management are mainly concentrated in the information and organization synergy subsystems, including the construction degree of information platform, the performance of functions, the timeliness of information transfer, and the functions of the information platform.

关键词: hydropower project     EPC mode     synergy degree model     grey relational analysis    

FACTORS INFLUENCING FOOD-WASTE BEHAVIORS AT UNIVERSITY CANTEENS IN BEIJING, CHINA: AN INVESTIGATION BASED

《农业科学与工程前沿(英文)》 2023年 第10卷 第1期   页码 83-94 doi: 10.15302/J-FASE-2022472

摘要:

● Investigate the actual situation of food waste at university canteens in Beijing, China.

关键词: university students     food waste behavior     theory of planned behavior     university canteen    

平朔东露天煤矿工业场地地下水位变化影响因素分析

林杜军,宫守才,张银洲

《中国工程科学》 2012年 第14卷 第2期   页码 49-53

摘要:

在地下水三维流数值模型研究的基础上,采用参数灵敏度分析的方法,对东露天煤矿工业场地地下水位变化影响因素进行定量分析。结果表明,场地内强风化砂泥岩的渗透性能、填土区大气降水补给能力、盲沟排水能力对工业场地因填土引起的地下水位变化有显著影响。针对这些主要影响因素,进行工业场地各地层渗透系数研究,为完善地面排水系统,控制盲沟质量等提供有力依据,控制工业场地的地下水位上升。

关键词: 数值模型     地下水位变化     影响因素     灵敏度分析    

Factors influencing near infrared spectroscopy analysis of agro-products: a review

Xiao XU, Lijuan XIE, Yibin YING

《农业科学与工程前沿(英文)》 2019年 第6卷 第2期   页码 105-115 doi: 10.15302/J-FASE-2019255

摘要:

The near infrared (NIR) spectroscopy technique has wide applications in agriculture with the advantages of being nondestructive, sensitive, safe and rapid. However, there are still more than 40 error sources influencing the robustness and accuracy of its calibration and operation. Environmental, sample and instrument factors that influence the analysis are discussed in this review, including temperature, humidity and other factors that introduce uncertainty. Error sources from livestock products, fruit and vegetables, which are the most common objects in the field of NIR analysis, are also emphasized in the second part. In addition, studies utilizing different instruments, spectral pretreatments, variable selection methods, wavelength ranges, detection modes and calibration methods are tabulated to illustrate the complications they introduce and how they influence NIR analysis. It is suggested that large scale of data with abundant varieties can be used to build a more robust calibration model, in order to improve the robustness and accuracy of the NIR analytical model, and overcome problems caused by confining analysis to too many uniform samples.

关键词: agro-product     error source     influence factor     near infrared spectroscopy    

Evaluation of factors influencing soluble microbial product in submerged MBR through hybrid ASM model

Fangyue LI, Joachim BEHRENDT, Knut WICHMANN, Ralf OTTERPOHL

《环境科学与工程前沿(英文)》 2009年 第3卷 第2期   页码 226-235 doi: 10.1007/s11783-009-0008-5

摘要: In this study, a mathematical model was established to predict the formation of the soluble microbial product (SMP) in a submerged membrane bioreactor. The developed model was calibrated under the reference condition. Simulation results were in good agreement with the measured results under the reference condition. The calibrated model was then used in the scenario studies to evaluate the effect of three chosen operating parameters: hydraulic retention time (HRT), dissolved oxygen concentration, and sludge retention time (SRT). Simulation results revealed that the SMP dominated the soluble organic substances in the supernatant. The scenario studies also revealed that the HRT can be decreased to 1 h without deteriorating the effluent quality; dissolved oxygen concentration in the reactor can be kept at 2-3 mg/L to maintain the effluent quality, reduce the content of SMP, and minimize operating costs; the optimal SRT can be controlled to 10-15 d to achieve complete nitrification process, less membrane fouling potential, and acceptable organic removal efficiency.

关键词: hybrid activated sludge model (ASM)     membrane bioreactor (MBR)     soluble microbial product (SMP)    

海上风电场规划的主要影响因素分析

何杰,赵鑫,杨家胜

《中国工程科学》 2010年 第12卷 第11期   页码 16-19

摘要:

 

海上风电是新能源发展的一个战略重点,目前我国沿海地区正在积极开展大规模海上风电的规划。对中国近海风电场规划与开发现状进行了介绍,总结了近海风电场规划的主要内容,分析了近海风电场在规划中的主要影响因素和解决方法。

关键词: 海上风电     风资源     规划     影响因素    

The influencing factors of the WTP for the risk reduction of chemical industry accidents in China

Lei HUANG, Zhijuan SHAO, Weiliang BAO, Bailing DUAN, Jun BI, Zengwei YUAN

《环境科学与工程前沿(英文)》 2012年 第6卷 第6期   页码 860-868 doi: 10.1007/s11783-012-0467-y

摘要: To explore the factors that influence respondents’ willingness to pay (WTP) for the risk reduction of chemical industry accidents, a questionnaire survey combined with contingent valuation and psychometric paradigm methods were conducted in the city of Yancheng, Jiangsu Province, China. Both traditional socioeconomic variables and perceived characteristics of the hazards were considered in this study, and a Tobit model was used to find the factors influencing WTP under three risk reduction scenarios. The results showed that three demographic characteristics, , , and , significantly affected the WTP for chemical risk reduction. In addition, three extracted public risk perception factors, , , and , also strongly affected the WTP. The mean WTP value increased as the magnitude of the risk reduction increased. The number of factors influencing the WTP decreased as the reduction level improved, and only the factor had a significant influence on the WTP for a higher level (80%) of risk reduction. The cost for chemical safety management of Yancheng was calculated, and the optimized risk reduction level was determined. These findings can assist governments and policy makers to formulate suitable strategies for risk control, to reach target groups of people to develop effective communication, and to provide specific references for the best investment for the security of local residents.

关键词: risk perception     willingness to pay     contingent valuation method     risk management school of the environment    

Changes in major factors affecting the ecosystem health of the Weihe River in Shaanxi Province, China

Qi LI, Jinxi SONG, Anlei WEI, Bo ZHANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第6期   页码 875-885 doi: 10.1007/s11783-013-0568-2

摘要: Maintenance of the ecosystem health of a river is of great importance for local sustainable development. On the basis of both qualitative and quantitative analysis of the influence of natural variations and human activities on the ecosystem function of the Weihe River, the changes in major factors affecting its ecosystem health are determined, which include: 1) Deficiency of environment flow: since the 1960s, the incoming stream flow shows an obvious decreasing tendency. Even in the low flow period, 80% of the water in the stream is impounded by dams for agriculture irrigation in the Baoji district. As a result, the water flow maintained in the stream for environmental use is very limited. 2) Deterioration of water quality: the concentrations of typical pollutants like Chemical Oxygen Demand (COD) and NH -N are higher than their maximum values of the Chinese environmental quality standard. Very few fish species can survive in the River. 3) Deformation of water channels: the continuous channel sedimentation has resulted in the decrease in stream gradient, shrinkage of riverbed and the decline in the capability for flood discharge. 4) Loss of riparian vegetation: most riparian land has been occupied by urban construction activities, which have caused the loss of riparian vegetation and biodiversity and further weakened flood control and water purification functions.

关键词: influencing factors     ecosystem health     ecological and environmental functions     the Weihe River     Shaanxi Province    

Antibiotic resistance genes in manure-amended paddy soils across eastern China: Occurrence and influencingfactors

《环境科学与工程前沿(英文)》 2022年 第16卷 第7期 doi: 10.1007/s11783-021-1499-y

摘要:

• Manure fertilization resulted in antibiotic residues and increased metal contents.

关键词: Pig manure     Antibiotics     Metals     Antibiotic resistance genes     Paddy fields    

对影响我国汽车整车产品开发能力若干因素的分析

张宁,姚群,张文杰,姜英

《中国工程科学》 2009年 第11卷 第11期   页码 37-44

摘要:

“中国汽车整车企业产品开发能力研究”课题研究内容包括两个方面:第一,运用当前国际同类研究通行方法,结合我国国情,建立我国汽车整车产品开发能力评价体系,并借此分析影响整车企业产品开发能力形成的关键因素究竟是什么;第二,摸清我国整车企业技术能力的底数,了解企业整车开发技术的掌握情况,为此课题组沿着整车开发流程提炼出了具备整车开发能力的企业必须掌握的190项关键技术,并希望借此在产品开发能力建设方向上对企业给予必要的引导。课题组历时一年多的研究工作中,共对102家国内整车生产企业进行了问卷调查。

关键词: 汽车     开发     能力     影响因素    

Factors influencing water quality indices in a typical urban river originated with reclaimed water

Jiao Zhang, Zhen Wei, Haifeng Jia, Xia Huang

《环境科学与工程前沿(英文)》 2017年 第11卷 第4期 doi: 10.1007/s11783-017-0943-5

摘要: The water quality in a typical urban river segment originated with reclaimed water in Beijing was monitored for two years to investigate the evolution of water quality along the river, and statistical analysis was applied to determine factors influencing water quality of such river recharged by reclaimed water. It was found that no significant change in pollutant concentrations (including COD, NH -N, TN and TP) was observed during this time, and their average values were close to those of the original reclaimed water. However, turbidity and algal contents fluctuated temporally in the direction of river flow. Statistical analysis showed that turbidity was strongly positively correlated with algal contents for flow rate<0.1 m·s , whereas it was strongly positively correlated with both algal contents and TOC for flow rate>0.1 m·s . It was observed that diatom was the absolute predominant phyla with as the major species. In terms of algal bloom control, the specific growth rate of algae was strongly correlated to temperature, and was influenced by flow rate as well. Compared with two other rivers originated with reclaimed water and one originated with natural water, the Shannon–Wiener index in the objective river was the lowest, with values between 0.7 and 1.6, indicating a high risk for algal bloom. Statistics showed that Shannon–Wiener index was strongly negatively correlated to nutrient salts and cations.

关键词: Reclaimed water     Urban river     Turbidity     Algae     Flow rate    

标题 作者 时间 类型 操作

Factors influencing peak bone mass gain

Xiaowei Zhu, Houfeng Zheng

期刊论文

Factors influencing the photodegradation of

Bingbing XU, Zhonglin CHEN, Fei QI, Jimin SHEN, Fengchang WU

期刊论文

Characteristics and Influencing Factors of Microplastics in Snow in the Inner Mongolia Plateau, China

Hongwei Yu,Junrong Shao,Huawei Jia,Diga Gang,Baiwen Ma,Chengzhi Hu,

期刊论文

Influencing factors and control measures of excavation on adjacent bridge foundation based on analytic

Shuangxi FENG, Huayang LEI, Yongfeng WAN, Haiyan JIN, Jun HAN

期刊论文

Analysis of synergy degree and its influencing factors in hydropower EPC project management

Jiwei ZHU, Hua GAO, Jiangrui WANG

期刊论文

FACTORS INFLUENCING FOOD-WASTE BEHAVIORS AT UNIVERSITY CANTEENS IN BEIJING, CHINA: AN INVESTIGATION BASED

期刊论文

平朔东露天煤矿工业场地地下水位变化影响因素分析

林杜军,宫守才,张银洲

期刊论文

Factors influencing near infrared spectroscopy analysis of agro-products: a review

Xiao XU, Lijuan XIE, Yibin YING

期刊论文

Evaluation of factors influencing soluble microbial product in submerged MBR through hybrid ASM model

Fangyue LI, Joachim BEHRENDT, Knut WICHMANN, Ralf OTTERPOHL

期刊论文

海上风电场规划的主要影响因素分析

何杰,赵鑫,杨家胜

期刊论文

The influencing factors of the WTP for the risk reduction of chemical industry accidents in China

Lei HUANG, Zhijuan SHAO, Weiliang BAO, Bailing DUAN, Jun BI, Zengwei YUAN

期刊论文

Changes in major factors affecting the ecosystem health of the Weihe River in Shaanxi Province, China

Qi LI, Jinxi SONG, Anlei WEI, Bo ZHANG

期刊论文

Antibiotic resistance genes in manure-amended paddy soils across eastern China: Occurrence and influencingfactors

期刊论文

对影响我国汽车整车产品开发能力若干因素的分析

张宁,姚群,张文杰,姜英

期刊论文

Factors influencing water quality indices in a typical urban river originated with reclaimed water

Jiao Zhang, Zhen Wei, Haifeng Jia, Xia Huang

期刊论文