资源类型

期刊论文 242

会议视频 8

年份

2023 23

2022 19

2021 21

2020 19

2019 19

2018 10

2017 11

2016 9

2015 9

2014 17

2013 9

2012 9

2011 14

2010 10

2009 9

2008 12

2007 13

2006 2

2005 2

2003 1

展开 ︾

关键词

能源 2

2型糖尿病 1

Chebyshev多项式 1

Inconel 718合金 1

Rosenthal方程 1

一维材料 1

一阶分析法 1

三向受力状态 1

三塔双跨悬索桥 1

三维有限元分析 1

下穿施工 1

不利荷载 1

不等围压 1

业主 1

中间塔 1

久坐时间 1

五螺箍 1

人为地形变化 1

人员行为 1

展开 ︾

检索范围：

排序： 展示方式：

Concepts and implementation of strain-based criteria in design codes for steel structures

Reidar BJORHOVDE

《结构与土木工程前沿（英文）》 2012年 第6卷 第3期   页码 210-216 doi: 10.1007/s11709-012-0165-7

摘要： A uniaxial tension test is commonly used to determine the mechanical properties of steel, but it has no meaning for the response of the material in a structure. The test was developed as a consensus solution by producers, fabricators, designers and code writers, to have a standard by which similar materials could be compared to a common base. It does not represent the actual behavior of the steel in a structure, and was never intended to do so. To study the true behavior of the structure and how the material responds it would be better to determine the strains and deformations that will take place during actual service condition. Such characteristics reflect the real behavior, whether in the elastic or inelastic range. If stresses or forces are needed, these are easily determined by the value of the strain and the relevant material modulus, along with the type of cross section, whether elastic or inelastic. The paper addresses the properties of a range of structural steels, how these are incorporated into design standards and how the standards define deformation characteristics and demands for bolted and welded connections.

关键词： steel     stress-strain characteristics     tension test     strain design     actual behavior     improved design codes    

HTML PDF 收藏

Integration of renewable energies, flexible loads and storages into the German power grid: Actual situation

Harald SCHWARZ, Xiaoshu CAI

《能源前沿（英文）》 2017年 第11卷 第2期   页码 107-118 doi: 10.1007/s11708-017-0470-x

摘要： Starting from the late 1990’s, the German government decided to change the national electric power supply system dramatically. The main stimulating instrument was the German Law on Renewable Energies (Erneuerbare Energien Gesetz (EEG)), which guaranteed a fixed feed-in tariff to everyone who was willing to invest into renewable generation. Based on the year of commissioning, defined revenues per kWh were fixed for the next 20 years. Due to a very attractive over-funding, more than 1.5 million renewable generation units were connected to the German grid up to the end of 2015. According to the EEG, renewable generation units can feed to the grid wherever they are located and whenever they are able to produce. The old physical principle was and is still neglected, which clearly stated that generation always has to follow the demand—simply due to the limited availability of storages in the power system. Only in cases, when temporarily renewable overproduction exceeds the tolerable loading of lines or transformers respectively endangers the system stability in total, are German grid operators allowed to announce curtailments by emergency measures. Even in such cases, the “not produced energy” from renewable sources has to be funded. Although the installed capacity from renewables is much higher than the peak load in Germany, it contributes only about 32% to German average annual energy. Unfortunately, the regional distribution of renewable generation and load is very different, e.g. in the northeast of Germany, this Renewable Energy (RE)-ratio meanwhile exceeds 100% due to the high RE-penetration and low load. High transits of renewable overproduction from the north to the south will be necessary at nearly every day per year. Therefore, a tremendous change is needed within the German power grid. This paper will give a first overview followed by several others, describing possible solutions on how to overcome this critical situation.

关键词： grid integration     renewable energies     system stability     storages     flexible loads     new market design    

HTML PDF 收藏

Impact of renewable energies on the operation and economic situation of coal fired power stations: Actual

Hans-Joachim KRAUTZ, Alexander LISK, Joachim POSSELT, Christian KATZER

《能源前沿（英文）》 2017年 第11卷 第2期   页码 119-125 doi: 10.1007/s11708-017-0468-4

摘要： Due to the fluctuating character of the renewable energy sources the demand of conventional power plants for flexibility is increasing. In the recent years, in Germany there has been a fast rise of production capacity of renewable energies, especially from wind turbines, photovoltaic installations, and biomass plants. The installed nominal power of wind turbines is actually (December 2016) 42 GW and of photovoltaic installations 40?GW. The renewable electric energy production in Germany is about 190?TWh/a, which represents a share of 33% of the yearly demand. The increased need for flexibility affects both the power gradients as well as the minimum load of conventional power plants. Due to this flexibility behaviour, conventional power plants are faced with problems concerning the durability of power plant components, corrosion, more maintenance effort and consequently the overall life expectancy. Another consequence of the increasing share of renewable energies is the decreasing full load operating hours, especially of coal fired and gas power plants. Along with decreasing revenues from the energy exchange market, coal fired power plants are faced with new economically challenges.

关键词： flexible load operation     minimal load     power gradients     power plant maintenance     corrosion     life expectancy    

HTML PDF 收藏

Theoretical analysis and actual experimental research on static characteristics of suspendome structure

CHEN Zhihua, YAN Xiangyu, SUN Ruirui, FENG Zhenchang, QIN Yali, ZHAO Jianbo

《结构与土木工程前沿（英文）》 2007年 第1卷 第3期   页码 286-292 doi: 10.1007/s11709-007-0037-8

摘要： The suspendome used as the roof of the VIP hall in Tianjin Museum was analyzed by ANASYS under the assumptions of hinged joints and rigid joints in up chord, respectively, and the results show that the member force and nodal displacement under the two assumptions have little difference. Thus, it is attained that the suspendome can be analyzed with the assumption of hinged joints. A full-scale test on the suspendome with half-cable and half-pipe was carried out. The loading system, arrangement of measuring points, and the test procedures are introduced. Also, a test on steel wire ropes for elastic module was carried out. The experimental and theoretical values of member forces and nodal displacements were compared and it showed that they accord well with each other under low-level load. While under high-level load, the experimental value was bigger than the theoretical value due to the influence of the test environment. With the increase of the load, tension of outside cables and looseness of inside cables occurred, which indicated that the prestressing value in inside cables should be properly assigned. Both the experimental and theoretical results verify that the suspendome has a wide application prospect with the advantages of perfect mechanical characteristics, low steel consumption, convenient construction and low cost.

关键词： Tianjin     influence     displacement     high-level     low-level    

HTML PDF 收藏

基于实际工作状态的多跨悬索桥中间塔静力试验模型设计

吉林,王陶,吴寒亮

《中国工程科学》 2012年 第14卷 第5期   页码 66-70

摘要：

与传统两塔悬索桥相比，多塔连跨悬索桥中间塔的约束条件、工作环境及荷载作用等均有较大差别，其对全桥安全性和使用性有显著影响。基于泰州大桥的实际工作状态（中间塔的纵向最不利工况），采用静力相似理论设计中间塔缩尺模型。通过对原桥中间塔和试验模型的数值仿真分析，从内力、位移及应变等方面比较分析原桥和试验模型的相似关系，结果表明，以几何尺寸和材料弹性模量为基本相似量所设计的试验模型，能满足中间塔主要静力性能的试验要求。

关键词： 悬索桥     中间塔     实际工作状态     相似理论     数值仿真     模型试验    

HTML PDF 收藏

Compressor performance of two-stage turbocharging system

HE Yituan, MA Chaochen, WEI Mingshan, ZHU Zhifu, HE Yituan

《机械工程前沿（英文）》 2008年 第3卷 第2期   页码 218-221 doi: 10.1007/s11465-008-0027-0

摘要： To study the performance of high and low stage compressors and that of the system as a whole, a two-stage turbocharging system was matched, and a special two-stage turbocharging system test bench was built. For each test curve, the speeds of the two stage turbochargers were adjusted to the fixed data, and a compressor performance experiment was performed. The results showed many differences between the corrected mass flow and the actual mass flow of the high pressure (HP) stage compressor. To find out the actual supercharging effect of the two-stage turbocharging system, it is better to adopt the actual mass flow. The two-stage turbocharging system in this paper has much higher efficiency under most operating conditions if the pressure ratio assignment is 1:1. The system can get very high supercharging pressure when the speeds of the two stage turbochargers are rather low, which ensures the system’s security and reliability.

关键词： special two-stage     HP     performance experiment     reliability     actual supercharging    

HTML PDF 收藏

Hyperbranched magnetic polymer: highly efficient removal of Cr(VI) and application in electroplating wastewater

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1568-1580 doi: 10.1007/s11705-023-2303-2

摘要： By using a two-step hydrothermal method and trithiocyanuric acid (TTCA), 2,4,6-trihydrazino-1,3,5-triazine (THT), and Fe3O4 as raw materials, a spherical magnetic adsorbent polymer (TTCA/THT@Fe3O4) was synthesized to achieve the efficient removal of Cr(VI) from wastewater. Under optimal adsorption conditions, the maximum adsorption capacity of TTCA/THT@Fe3O4 for Cr(VI) can reach 1340 mg∙g‒1. Notably, the removal efficiency can approach 98.9%, even at the lower concentration of 20 mg∙L‒1 Cr(VI). For actual wastewater containing Cr(VI), the Cr(VI) concentration was reduced from 25.8 to 0.4 mg∙L‒1, a remarkable 20% lower than the current industry discharge standard value. A mechanism for the high adsorption performance of Cr(VI) on TTCA/THT@Fe3O4 was investigated using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and density functional theory. It can be plausibly attributed to the formation of Cr/N and Cr/S coordination bonds. Additionally, surface electrostatic adsorption, reduction effects, and the spherical polymer structure increase the contact area with Cr(VI), maximizing adsorption. The synergistic effect of adsorption and reduction enhances the adsorption performance of TTCA/THT@Fe3O4 for Cr(VI) and total chromium in water. The resultant polymer has a simple preparation process, excellent adsorption performance, easy magnetic separation, and promising application for actual wastewater.

关键词： magnetic polymer     chromium removal     hydrogen bonding     recyclability     actual wastewater    

HTML PDF 收藏

Investigation on the integral output power model of a large-scale wind farm

BAO Nengsheng, MA Xiuqian, NI Weidou

《能源前沿（英文）》 2007年 第1卷 第1期   页码 67-78 doi: 10.1007/s11708-007-0006-x

摘要： The integral output power model of a large-scale wind farm is needed when estimating the wind farm s output over a period of time in the future. The actual wind speed power model and calculation method of a wind farm made up of many wind turbine units are discussed. After analyzing the incoming wind flow characteristics and their energy distributions, and after considering the multi-effects among the wind turbine units and certain assumptions, the incoming wind flow model of multi-units is built. The calculation algorithms and steps of the integral output power model of a large-scale wind farm are provided. Finally, an actual power output of the wind farm is calculated and analyzed by using the practical measurement wind speed data. The characteristics of a large-scale wind farm are also discussed.

关键词： power model     actual     energy     large-scale     practical measurement    

HTML PDF 收藏

Study on Big Data-based Behavior Modification in Metro Construction

Lie-yun Ding,Sheng-yu Guo

《工程管理前沿（英文）》 2015年 第2卷 第2期   页码 131-136 doi: 10.15302/J-FEM-2015037

摘要： With the rapid development of metro construction in China, construction accidents frequently happen, which are significantly attributable to workers’ unsafe behavior. Behavior-based safety (BBS) is an effective method to modify workers’ unsafe behavior. This paper introduces the study on big data-based metro construction behavior modification, aiming to solve the problem of current research without consideration of workers’ personal characters. First, the behavior modification pushing mechanism based on content-based personalized recommendation is studied. Secondly, the development of behavior modification system of metro construction (BMSMC) is introduced. Thirdly, BMSMC practical applications using the unsafe behavior rate, as a measuring indicator is implemented. Observations at one metro construction site in Wuhan indicate that the unsafe behavior rate of modified scaffolders at this work place decreased by 69.3%. At the same time, as of unmodified scaffolders at another work place for comparison, the unsafe behavior rate decreased by 56.9%, which validates the effectiveness of this system.

关键词： big data     unsafe behavior     behavior modification     behavior-based safety (BBS)     unsafe behavior rate    

HTML PDF 收藏

Flow behavior of non-spherical particle flowing in hopper

He TAO,Wenqi ZHONG,Baosheng JIN

《能源前沿（英文）》 2014年 第8卷 第3期   页码 315-321 doi: 10.1007/s11708-014-0331-9

摘要： Ellipsoidal particles flowing in the hopper were simulated by using the discrete element method (DEM), and described by the multi-element method. The contact detection algorithm and equations for ellipsoidal particle motion in hopper were developed. And the simulation results were confirmed by experiment. Additionally, the mass flow rate, pressure distribution and velocity distribution of two kinds of particles were examined. The results show that the mass flow rate of ellipsoidal particles is smaller than that of spherical particles. There is a maximum value of pressure drop at the top of the junction. Besides, the pressure drop decreases with the discharging time increasing. The velocity of spherical particle is larger than that of ellipsoidal.

关键词： discrete element method     ellipsoidal particle     flow behavior     hopper    

HTML PDF 收藏

Evaluation of the performance of a centralized ground-water heat pump system in cold climate region

Shilei LU,Zhe CAI,Li ZHANG,Yiran LI

《能源前沿（英文）》 2014年 第8卷 第3期   页码 394-402 doi: 10.1007/s11708-014-0310-1

摘要： The aim of this study is to evaluate the performance of a centralized open-loop ground-water heat pump (GWHP) system for climate conditioning in Beijing with a cold climate in China. Thus, a long-time test was conducted on a running GWHP system for the heating season from December 2011 to March 2012. The analysis of the testing data indicates that the average heat-pump coefficient of performance (COP) and the COP of the system (COPs) are 4.27 and 2.59. The low value and large fluctuation in the range of COP are found to be caused by the heat transfixion in the aquifer and the bypass in the circulation loop. Therefore, some suggestions are proposed to improve the performance for GWHPs in the cold climate region in China.

关键词： ground-water heat pump (GWHP)     actual coefficient of performance     heat transfixion    

HTML PDF 收藏

A simplified method for investigating the bending behavior of piles supporting embankments on soft ground

《结构与土木工程前沿（英文）》   页码 1021-1032 doi: 10.1007/s11709-023-0952-3

摘要： In recent years, concrete and reinforced concrete piles have been widely used to stabilize soft ground under embankments. Previous research has shown that bending failure, particularly during rapid filling on soft ground, is the critical failure mode for pile-supported embankments. Here, we propose an efficient two-stage method that combines a test-verified soil deformation mechanism and Poulos’ solution for pile–soil interaction to investigate the bending behavior of piles supporting embankments on soft ground. The results reveal that there are three possible bending failure scenarios for such piles: at the interface between the soft and firm ground layers, at mid-depths of the fan zone, and at the boundary of the soil deformation mechanism. The location of the bending failure depends on the position and relative stiffness of the given pile. Furthermore, the effect of embedding a pile into a firm ground layer on the bending behavior was investigated. When the embedded length of a pile exceeded a critical value, the bending moment at the interface between the soft and firm ground layers reached a limiting value. In addition, floating piles that are not embedded exhibit an overturning pattern of movement in the soft ground layer, and a potential failure is located in the upper part of these piles.

关键词： bending behavior     pile     embankment     soil−structure interaction     failure mode    

HTML PDF 收藏

Weakening behavior of waterproof performance in joints of shield tunnels under adjacent constructions

《结构与土木工程前沿（英文）》   页码 884-900 doi: 10.1007/s11709-022-0912-3

摘要： Groundwater leakage in shield tunnels poses a threat to the safety and durability of tunnel structures. Disturbance of adjacent constructions during the operation of shield tunnels frequently occurs in China, leading to deformation of tunnel lining and leakage in joints. Understanding the impact of adjacent constructions on the waterproofing performance of the lining is critical for the protection of shield tunnels. In this study, the weakening behavior of waterproof performance was investigated in the joints of shield tunnels under transverse deformation induced by adjacent construction. First, the relationship between the joint opening and transverse deformation under three typical adjacent constructions (upper loading, upper excavation, and side excavation) was investigated via elaborate numerical simulations. Subsequently, the evolution of the waterproof performance of a common gasket with a joint opening was examined by establishing a coupled Eulerian–Lagrangian model of joint seepage, and a formula describing the relationship between waterproof performance and joint opening was proposed. Finally, the weakening law of waterproofing performance was investigated based on the results of the aforementioned studies. It was determined that the joints with the greatest decline in waterproof performance were located at the tunnel shoulder in the upper loading case, tunnel crown in the upper excavation case, and tunnel shoulder in the side excavation case. When the waterproof performance of these joints decreased to 50% and 30%, the transverse deformations were 60 and 90 mm under upper loading, 90 and 140 mm under upper excavation, and 45 and 70 mm under side excavation, respectively. The results provide a straightforward reference for setting a controlled deformation standard considering the waterproof performance.

关键词： shield tunnel     waterproof performance     horizontal transverse deformation     joint opening     weakening behavior    

HTML PDF 收藏

Effects of herding behavior of tradable green certificate market players on market efficiency: Insights

《能源前沿（英文）》 2023年 第17卷 第2期   页码 266-285 doi: 10.1007/s11708-021-0752-1

摘要： Tradable green certificate (TGC) scheme promotes the development of renewable energy industry which currently has a dual effect on economy and environment. TGC market efficiency is reflected in stimulating renewable energy investment, but may be reduced by the herding behavior of market players. This paper proposes and simulates an artificial TGC market model which contains heterogeneous agents, communication structure, and regulatory rules to explore the characteristics of herding behavior and its effects on market efficiency. The results show that the evolution of herding behavior reduces information asymmetry and improves market efficiency, especially when the borrowing is allowed. In addition, the fundamental strategy is diffused by herding evolution, but TGC market efficiency may be remarkably reduced by herding with borrowing mechanism. Moreover, the herding behavior may evolve to an equilibrium where the revenue of market players is comparable, thus the fairness in TGC market is improved.

关键词： tradable green certificate     herding behavior     evolution     heterogeneous agent model     complex network    

HTML PDF 收藏

Adsorption behavior of antibiotic in soil environment: a critical review

Shiliang WANG,Hui WANG

《环境科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 565-574 doi: 10.1007/s11783-015-0801-2

摘要： Antibiotics are used widely in human and veterinary medicine, and are ubiquitous in environment matrices worldwide. Due to their consumption, excretion, and persistence, antibiotics are disseminated mostly via direct and indirect emissions such as excrements, sewage irrigation, and sludge compost and enter the soil and impact negatively the natural ecosystem of soil. Most antibiotics are amphiphilic or amphoteric and ionize. A non-polar core combined with polar functional moieties makes up numerous antibiotic molecules. Because of various molecule structures, physicochemical properties vary widely among antibiotic compounds. Sorption is an important process for the environment behaviors and fate of antibiotics in soil environment. The adsorption process has decisive role for the environmental behaviors and the ultimate fates of antibiotics in soil. Multiply physicochemical properties of antibiotics induce the large variations of their adsorption behaviors. In addition, factors of soil environment such as the pH, ionic strength, metal ions, and organic matter content also strongly impact the adsorption processes of antibiotics. Review about adsorption of antibiotics on soil can provide a fresh insight into understanding the antibiotic-soil interactions. Therefore, literatures about the adsorption mechanisms of antibiotics in soil environment and the effects of environment factors on adsorption behaviors of antibiotics in soil are reviewed and discussed systematically in this review.

关键词： adsorption     antibiotics     environment factors     soil    

HTML PDF 收藏

标题 作者 时间 类型 操作

Concepts and implementation of strain-based criteria in design codes for steel structures

Reidar BJORHOVDE

期刊论文

Integration of renewable energies, flexible loads and storages into the German power grid: Actual situation

Harald SCHWARZ, Xiaoshu CAI

期刊论文

Impact of renewable energies on the operation and economic situation of coal fired power stations: Actual

Hans-Joachim KRAUTZ, Alexander LISK, Joachim POSSELT, Christian KATZER

期刊论文

Theoretical analysis and actual experimental research on static characteristics of suspendome structure

CHEN Zhihua, YAN Xiangyu, SUN Ruirui, FENG Zhenchang, QIN Yali, ZHAO Jianbo

期刊论文

基于实际工作状态的多跨悬索桥中间塔静力试验模型设计

吉林,王陶,吴寒亮

期刊论文

Compressor performance of two-stage turbocharging system

HE Yituan, MA Chaochen, WEI Mingshan, ZHU Zhifu, HE Yituan

期刊论文

Hyperbranched magnetic polymer: highly efficient removal of Cr(VI) and application in electroplating wastewater

期刊论文

Investigation on the integral output power model of a large-scale wind farm

BAO Nengsheng, MA Xiuqian, NI Weidou

期刊论文

Study on Big Data-based Behavior Modification in Metro Construction

Lie-yun Ding,Sheng-yu Guo

期刊论文

Flow behavior of non-spherical particle flowing in hopper

He TAO,Wenqi ZHONG,Baosheng JIN

期刊论文

Evaluation of the performance of a centralized ground-water heat pump system in cold climate region

Shilei LU,Zhe CAI,Li ZHANG,Yiran LI

期刊论文

A simplified method for investigating the bending behavior of piles supporting embankments on soft ground

期刊论文

Weakening behavior of waterproof performance in joints of shield tunnels under adjacent constructions

期刊论文

Effects of herding behavior of tradable green certificate market players on market efficiency: Insights

期刊论文

Adsorption behavior of antibiotic in soil environment: a critical review

Shiliang WANG,Hui WANG

期刊论文