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

Jiwei ZHU, Hua GAO, Jiangrui WANG

Frontiers of Engineering Management 2021, Volume 8, Issue 3, Pages 402-411 doi: 10.1007/s42524-020-0098-0

Abstract: The mechanism and factors that influence the degree of management synergy are analyzed on the basis ofanalysis is utilized to identify the key factors that affect the synergy degree.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 majorrestriction on the further improvement of the synergy degree of EPC project management.

Keywords： hydropower project EPC mode synergy degree model grey relational analysis

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Study on Distribution Method of Auto-control Valves in Water Supply Network

Zhang Hongwei,Guo Yiping,Niu Zhiguang,Zhang Li

Strategic Study of CAE 2005, Volume 7, Issue 7, Pages 71-75

Abstract: presented a new approach to realize the optimal distribution of auto-control valves in water supply networkFirstly, the local headloss of the auto-control valve was introduced to the pipe network's hydraulicThen, the valve was supposed to be set on each pipe with different opening degree, following which theinfluencing degree on network was calculated under each situation.Last, this approach was tried on an example water supply network, and a general principle for the optimal

Keywords： auto-control valve water supply network distribution influencing degree on network

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Factors influencing peak bone mass gain

Xiaowei Zhu, Houfeng Zheng

Frontiers of Medicine 2021, Volume 15, Issue 1, Pages 53-69 doi: 10.1007/s11684-020-0748-y

Abstract: 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.

Keywords： peak bone mass children adolescents genetic risk factors

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Microbial self-healing of cracks in cement-based materials and its influencing factors

Frontiers of Structural and Civil Engineering doi: 10.1007/s11709-023-0986-6

Abstract: Cement-based materials are brittle and crack easily under natural conditions. Cracks can reduce service life because the transport of harmful substances can cause corrosion damage to the structures. This review discusses the feasibility of using microbial self-healing agents for crack healing. Tubular and spherical carriers can be used to load microbial self-healing agents and protect microbes, which prolongs the self-healing time. The area self-healing ratio, permeability, mechanical strength, precipitation depth method, numerical modeling, and ultrasonic method can be employed to identify the self-healing effect of cracks. Moreover, the self-healing mechanism is systematically analyzed. The results showed that microbial self-healing agents can repair cracks in cement-based materials in underground projects and dam gates. The difficulties and future development of self-healing cracks were analyzed. A microbial self-healing agent was embedded in the cement-based material, which automatically repaired the developing cracks. With the development of intelligent building materials, self-healing cracks have become the focus of attention.

Keywords： cement-based materials cracks microbial self-healing agent mechanism intelligent building materials

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Factors influencing the photodegradation of

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

Frontiers of Environmental Science & Engineering 2009, Volume 3, Issue 1, Pages 91-97 doi: 10.1007/S11783-009-0013-8

Abstract: 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.

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

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

Frontiers of Agricultural Science and Engineering 2023, Volume 10, Issue 1, Pages 83-94 doi: 10.15302/J-FASE-2022472

Abstract:

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

Keywords： university students food waste behavior theory of planned behavior university canteen

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

Xiao XU, Lijuan XIE, Yibin YING

Frontiers of Agricultural Science and Engineering 2019, Volume 6, Issue 2, Pages 105-115 doi: 10.15302/J-FASE-2019255

Abstract: However, there are still more than 40 error sources influencing the robustness and accuracy of its calibration

Keywords： agro-product error source influence factor near infrared spectroscopy

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Analysis of Influencing Factor of Brand Competitiveness

Bing Hongyan

Strategic Study of CAE 2002, Volume 4, Issue 5, Pages 79-83

Abstract: The author tries to discuss countermeasures to improve brand competitiveness by analyzing the influencing

Keywords： brand competitiveness influencing factor analysis countermeasure

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Indoor carbonyl compounds in an academic building in Beijing, China: concentrations and influencing factors

Chuanjia JIANG, Pengyi ZHANG

Frontiers of Environmental Science & Engineering 2012, Volume 6, Issue 2, Pages 184-194 doi: 10.1007/s11783-011-0309-3

Abstract: Carbonyl compounds in indoor air are of great concern for their adverse health effects. Between February and May, 2009, concentrations of 13 carbonyl compounds were measured in an academic building in Beijing, China. Total concentration of the detected carbonyls ranged from 20.7 to 189.1 μg·m , and among them acetone and formaldehyde were the most abundant, with mean concentrations of 26.4 and 22.6 μg·m , respectively. Average indoor concentrations of other carbonyls were below 10 μg·m . Principal component analysis identified a combined effect of common indoor carbonyl sources and ventilation on indoor carbonyl levels. Diurnal variations of the carbonyl compounds were investigated in one office room, and carbonyl concentrations tended to be lower in the daytime than at night, due to enhanced ventilation. Average concentrations of carbonyl compounds in the office room were generally higher in early May than in late February, indicating the influence of temperature. Carbonyl source emission rates from both the room and human occupants were estimated during two lectures, based on one-compartment mass balance model. The influence of human occupants on indoor carbonyl concentrations varies with environmental conditions, and may become significant in the case of a large human occupancy.

Keywords： carbonyl compounds indoor air ventilation human occupancy source emission rate (SER) principal component analysis (PCA)

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On the location of the secondary instantaneous poles in two-degree-of-freedom spherical mechanisms

Soheil ZARKANDI

Frontiers of Mechanical Engineering 2014, Volume 9, Issue 1, Pages 34-40 doi: 10.1007/s11465-014-0290-1

Abstract: presents a theorem showing analytically that the locus of an unknown secondary instant pole in two-degree-of-freedom

Keywords： spherical mechanisms instantaneous poles great circle angular velocity

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Stiffness of a 3-degree of freedom translational parallel kinematic machine

S. SHANKAR GANESH,A.B. KOTESWARA RAO

Frontiers of Mechanical Engineering 2014, Volume 9, Issue 3, Pages 233-241 doi: 10.1007/s11465-014-0312-z

Abstract:

In this paper, a typical 3-degree of freedom (3-DOF) translational parallel kinematic machine

Keywords： 3-DOF translational PKM inverse kinematics stiffness modeling translational stiffness

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A survey of instantaneous poles for a class of two-degree-of-freedom spherical mechanisms

Soheil ZARKANDI

Frontiers of Mechanical Engineering 2014, Volume 9, Issue 4, Pages 344-353 doi: 10.1007/s11465-014-0320-z

Abstract:

This paper is a detailed exploration of instantaneous poles for a class of two-degree-of-freedom (

Keywords： spherical mechanisms instantaneous poles Aronhold-Kennedy theorem great circles pencil of meridian

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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,

Engineering doi: 10.1016/j.eng.2023.02.007

Abstract: 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.

Keywords： Human activities Snow Microplastics Microbial community Urban function Environmental effect

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Error analysis and optimization of a 3-degree of freedom translational Parallel Kinematic Machine

S. SHANKAR GANESH,A. B. KOTESWARA RAO

Frontiers of Mechanical Engineering 2014, Volume 9, Issue 2, Pages 120-129 doi: 10.1007/s11465-014-0300-3

Abstract:

In this paper, error modeling and analysis of a typical 3-degree of freedom translational Parallel

Keywords： translational Parallel Kinematic Machine error modeling global error transformation index

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Study on high efficient and clean utilization of coal

Chen Yinying, Wang Shujuan, Chen Changhe, Xu Xuchang

Strategic Study of CAE 2011, Volume 13, Issue 6, Pages 51-56

Abstract: China were analyzed, and an index system for efficient and clean utilization of coal, including clean degree, eco-friendly degree, and low-carbon degree was developed.

Keywords： clean coal power generation clean degree energy sustainable development comprehensive index eco-friendlydegree low-carbon degree