资源类型

期刊论文 137

会议视频 2

年份

2023 13

2022 15

2021 8

2020 10

2019 11

2018 10

2017 11

2016 4

2015 8

2014 4

2013 3

2012 4

2011 8

2010 2

2009 8

2008 7

2007 4

2006 3

2005 1

2003 1

展开 ︾

关键词

数学模型 2

表面活性剂 2

Pm21 1

Pm40 1

LED灯具;加速老化测试;中位寿命;滑动平均误差 1

一维应力波 1

三相界面 1

中压变频 1

中国近海 1

中小企业 1

产乙酸菌 1

传播与演化 1

低压变频 1

信息安全;优化技术;数字版权;水印技术 1

免疫学 1

全球创新与产业高地 1

共性使能技术 1

内源抗性 1

农业生态工程 1

展开 ︾

检索范围:

排序: 展示方式:

Possible role of power-to-heat and power-to-gas as flexible loads in German medium voltage networks

Mark KUPRAT, Martin BENDIG, Klaus PFEIFFER

《能源前沿(英文)》 2017年 第11卷 第2期   页码 135-145 doi: 10.1007/s11708-017-0472-8

摘要: Germany’s energy transition triggered a rapid and unilateral growth of renewable energy sources (RES) in the electricity sector. With increasing shares of intermittent RES, overcapacities during periods of strong wind and photovoltaic electricity generation occur. In the face of insufficient transmission capacities, due to an inhibited network extension, the electricity generation has to be curtailed. This curtailment of RES leads to economic losses and could be avoided through flexible loads. As an option to cope with those problems, the technologies of power-to-gas (PtG) and power-to-heat (PtH) are presented in this paper. First, the alkaline electrolyzer (AEL), polymer electrolyte membrane electrolyzer (PEMEL), and solid oxide electrolyzer cell (SOEC) are investigated regarding their operational parameters. Second, the electric boiler, electrode heating boiler, and heat pumps are considered. Ultimately, the network-supporting abilities and the potential to provide ancillary services, such as control power, load sequence operation, cold start and part load capability, are compared among one another.

关键词: power-to-gas     power-to-heat     flexible loads     ancillary services     coherent energy systems    

Micro/nanofluidics-enabled energy conversion and its implemented devices

Yang YANG, Jing LIU

《能源前沿(英文)》 2011年 第5卷 第3期   页码 270-287 doi: 10.1007/s11708-010-0126-6

摘要: Most people were not aware of the role of energy as a basic force that drives the development and economic growth of the world until the two great oil crises occurred. According to the conservation law, energy not only exists in various forms but is also capable of being converted from one form to another. The common forms of energy are mechanical energy, chemical energy, internal energy, electrical energy, atomic energy, and electromagnetic energy, among others. The fluids in nature serve as the most common carriers and media in the energy conversion process. Following the rapid development of microelectromechanical systems (MEMS) technology, the energy supply and conversion issue in micro/nano scale has also been introduced in research laboratories worldwide. With unremitting efforts, great quantities of micro/nano scale energy devices have been investigated. Micro/nanofluid shows distinct features in transporting and converting energy similar to their counterpart macroscale tasks. In this paper, a series of micro/nanofluid-enabled energy conversion devices is reviewed based on the transformation between different forms of energy. The evaluation and contradistinction of their performances are also examined. The role of micro/nanofluid as media in micro/nano energy devices is summarized. This contributes to the establishment of a comprehensive and systematic structure in the relationship between energy conversion and fluid in the micro/nano scale. Some fundamental and practical issues are outlined, and the prospects in this challenging area are explored.

关键词: micro/nanofluid     different energy forms     energy conversion     medium role    

大中功率节能调速传动的合理电压等级

马小亮

《中国工程科学》 2001年 第3卷 第11期   页码 80-84

摘要:

大中功率风机和泵采用变频调速可节约大量电能,大部分功率在0.2~2 MW范围中。我国现在200 kW以上的电机多是中压,现行中压电网多为10 kV,选用10 kV直接变频从技术和经济角度看都不太合理。由于变频器输入侧都有变压器,因此电机和变频器没有必要和电网一致。文章讨论不同功率段的合理电压等级以及在电机电压和电网电压不同情况下当变频器出现故障时如何实现旁路工作。

关键词: 大中功率     节能调速     合理电压等级     低压变频     中压变频     旁路    

Uncoupled state space solution to layered poroelastic medium with anisotropic permeability and compressible

Zhiyong AI, Wenze ZENG, Yichong CHENG, Chao WU

《结构与土木工程前沿(英文)》 2011年 第5卷 第2期   页码 171-179 doi: 10.1007/s11709-011-0103-0

摘要: This paper presents an uncoupled state space solution to three-dimensional consolidation of layered poroelastic medium with anisotropic permeability and compressible pore fluid. Starting from the basic equations of poroelastic medium, and introducing intermediate variables, the state space equation usually comprising eight coupled state vectors is uncoupled into two sets of equations of six and two state vectors in the Laplace-Fourier transform domain. Combined with the continuity conditions between adjacent layers and boundary conditions, the uncoupled state space solution of a layered poroelastic medium is obtained by using the transfer matrix method. Numerical results show that the anisotropy of permeability and the compressibility of pore fluid have remarkable influence on the consolidation behavior of poroelastic medium.

关键词: uncoupled state space solution     layered poroelastic medium     three-dimensional consolidation     anisotropic permeability     compressible pore fluid    

Preparation of solar selective absorbing CuO coating for medium temperature application

HUANG Qunwu, WANG Yiping, LI Jinhua

《化学科学与工程前沿(英文)》 2007年 第1卷 第3期   页码 256-260 doi: 10.1007/s11705-007-0046-0

摘要: A new method of preparing CuO solar selective absorbing coating for medium temperature is presented. After pretreatment, brass was overlaid with CuO by chemical plating. The effects of reactant concentration, reaction temperature and reaction time on the absorptivity of CuO coating were investigated. The optimized condition of preparing CuO coating was obtained. The CuO coating was analyzed with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). In order to prolong the period of use, the CuO coating was protected by TiO. The experiment shows that the TiO/CuO coating is more heat-resistant, acid-resistant, and wear resistant than CuO coating, without losing absorptivity markedly. The TiO coating can reduce emissivity and protect the CuO coating.

关键词: photoelectron spectroscopy     temperature     pretreatment     absorptivity     microscopy    

Frontier of continuous structural health monitoring system for short & medium span bridges and condition

Ayaho MIYAMOTO, Risto KIVILUOMA, Akito YABE

《结构与土木工程前沿(英文)》 2019年 第13卷 第3期   页码 569-604 doi: 10.1007/s11709-018-0498-y

摘要: It is becoming an important social problem to make maintenance and rehabilitation of existing short and medium span(10-20 m) bridges because there are a huge amount of short and medium span bridges in service in the world. The kernel of such bridge management is to develop a method of safety(condition) assessment on items which include remaining life and load carrying capacity. Bridge health monitoring using information technology and sensors is capable of providing more accurate knowledge of bridge performance than traditional strategies. The aim of this paper is to introduce a state-of-the-art on not only a rational bridge health monitoring system incorporating with the information and communication technologies for lifetime management of existing short and medium span bridges but also a continuous data collecting system designed for bridge health monitoring of mainly short and medium span bridges. In this paper, although there are some useful monitoring methods for short and medium span bridges based on the qualitative or quantitative information, mainly two advanced structural health monitoring systems are described to review and analyse the potential of utilizing the long term health monitoring in safety assessment and management issues for short and medium span bridge. The first is a special designed mobile loading device(vehicle) for short and medium span road bridges to assess the structural safety(performance) and derive optimal strategies for maintenance using reliability based method. The second is a long term health monitoring method by using the public buses as part of a public transit system (called bus monitoring system) to be applied mainly to short and medium span bridges, along with safety indices, namely, “characteristic deflection” which is relatively free from the influence of dynamic disturbances due to such factors as the roughness of the road surface, and a structural anomaly parameter.

关键词: condition assessment     short & medium span bridge     structural health monitoring(SHM)     long-term data collection     system     maintenance     bridge performance     information technology     loading vehicle(public bus)     in-situ loading    

Deeply missing my career idol and role model ― Professor Perry L. McCarty

《环境科学与工程前沿(英文)》 2023年 第17卷 第9期 doi: 10.1007/s11783-023-1717-x

大中型水利工程建设管理的实践和体会

张基尧

《中国工程科学》 2011年 第13卷 第8期   页码 22-25

摘要: 水利工程建设是基础设施建设的重要组成部分。加强水利工程建设管理是提高水利投资效益和社会、经济、生态效益的重要途经,是工程管理科学研究的重要内容。文章主要阐述了不同阶段大中型水利工程建设管理的责任主体、管理重点、有效做法和成功案例。

关键词: 大中型水利工程;项目管理;实践体会    

Appreciating the role of big data in the modernization of environmental governance

《工程管理前沿(英文)》 2022年 第9卷 第1期   页码 163-169 doi: 10.1007/s42524-021-0185-x

The role of EcoCampus in addressing sustainability in UK universities

Peter REDFERN, Hua ZHONG

《工程管理前沿(英文)》 2017年 第4卷 第2期   页码 193-200 doi: 10.15302/J-FEM-2017038

摘要: Universities are key drivers of sustainable development and are well-positioned to contribute to the sustainability agenda. Universities in the United Kingdom (UK) are themselves large and influential organisations, and because of their size, can have a significant impact on the environment. Their challenge, however, is to practice what they preach and to manage their own estates and procurement decisions to reduce their impact on the environment and meet carbon reduction targets. In the UK, higher education (HE) sector Scopes 1 and 2 carbon CO e emissions have, over recent years, been falling considerably short of the emission reduction targets set by the Higher Education Funding Council for England (HEFCE) in all but a few institutions. Setting sector specific targets, therefore, does not guarantee success in addressing climate change. However, in those institutions adopting the EcoCampus management system approach, Scopes 1 and 2 carbon CO e emissions have fallen by up to 5% over the latest reporting period (2013/2014–2014/2015). This contrasts with the increase in emissions from those institutions who currently do not have a certified management system and are currently at the bottom of the People and Planet University League Table. (This is an independent league table of UK universities ranked by environmental and ethical performance). Environmental management systems (EMSs) are increasingly being used by organisations to improve their environmental performance. EMSs deliver many benefits such as reducing resource use and pollution, complying with relevant environmental legislation, managing risks, improving corporate reputation and saving costs. The aim of this research was to assess the carbon management performance of universities in the UK and China and relate this to the level of uptake of EMSs in these universities. The results of this research informed the development of the EMS support and awards programme called EcoCampus. EcoCampus addresses the challenges faced by universities in reducing their carbon emissions by developing an EMS in simple stages with support in a variety of different forms. This self-financing programme has now been operating successfully for over ten years. During this time, EcoCampus has worked with over 60 universities and colleges in the UK. Eighteen participants have currently achieved the highest phase of EcoCampus and certification to the international EMS standard ISO14001. There are currently 40 universities, one research institute and three colleges enrolled on the various phases of the EcoCampus programme. There are five universities from the Russell Group including Cambridge University, Imperial College London, Nottingham University, Newcastle University and University College London. The EcoCampus programme is highly successful in the UK and there is growing interest from international universities wishing to join the programme. Seven of the top ten universities in the UK’s People and Planet University League Table are EcoCampus members. All the top ten universities in the League Table have shown a reduction in their carbon emissions. In contrast, the ten institutions at the bottom of the League don’t have a certified EMS and have increased their carbon emissions. By identifying the benefits of an EMS, particularly in relation to carbon management, it is hoped that this paper will encourage organisations to develop, implement and operate an EMS. This should lead to a more sustainable sector able to lead by example.

关键词: EcoCampus     environmental management     sustainable development     carbon management    

The critical role of autophagy in plant responses to abiotic stresses

Yu WANG,Jie ZHOU,Jingquan YU

《农业科学与工程前沿(英文)》 2017年 第4卷 第1期   页码 28-36 doi: 10.15302/J-FASE-2017130

摘要: Autophagy is an evolutionary conserved recycling process in eukaryotes whereby intracellular components are engulfed by autophagosomes, which are subsequently transferred to the vacuoles for further degradation and reuse. In organisms like yeast and metazoans, autophagy is actively engaged during environmental perturbation either by degrading denatured proteins and organelles or by interfacing with stress related signaling molecules. Studies over the last decade have also revealed numerous important mechanisms where autophagy is widely involved in plant abiotic stress responses. Autophagy serves as a pivotal route for nutrient remobilization by the degradation of superfluous or damaged cellular cytoplasmic material and organelles. It is also reported to regulate the accumulation of reactive oxygen species, to maintain the cellular redox balance of plants under stressful conditions. Furthermore, autophagy is essential in regulating cellular toxicity by removing aggregated and/or denatured proteins and thereby improving plant stress tolerance. In this review, recent advances in our understanding of autophagy, along with pathways and regulatory networks through which it influences many aspects of plant growth and development in response to nutrient starvation, oxidative stress, osmotic stress and extreme temperatures are discussed.

关键词: abiotic stresses     autophagy     extreme temperature     nutrient starvation     osmotic stress     oxidative stress    

The role of lipids in fermentative propionate production from the co-fermentation of lipid and food waste

《环境科学与工程前沿(英文)》 2023年 第17卷 第7期 doi: 10.1007/s11783-023-1686-0

摘要:

● Lipid can promote PA production on a target from food waste.

关键词: Acidogenic fermentation     Microbial community     Volatile fatty acid     Propionate     Food waste     Lipid    

Liquid metal as energy transportation medium or coolant under harsh environment with temperature below

Yunxia GAO, Lei WANG, Haiyan LI, Jing LIU

《能源前沿(英文)》 2014年 第8卷 第1期   页码 49-61 doi: 10.1007/s11708-013-0285-3

摘要: The current highly integrated electronics and energy systems are raising a growing demand for more sophisticated thermal management in harsh environments such as in space or some other cryogenic environment. Recently, it was found that room temperature liquid metals (RTLM) such as gallium or its alloys could significantly reduce the electronics temperature compared with the conventional coolant, like water, oil or more organic fluid. However, most of the works were focused on RTLM which may subject to freeze under low temperature. So far, a systematic interpretation on the preparation and thermal properties of liquid metals under low temperature (here defined as lower than 0°C) has not yet been available and related applications in cryogenic field have been scarce. In this paper, to promote the research along this important direction and to overcome the deficiency of RTLM, a comprehensive evaluation was proposed on the concept of liquid metal with a low melting point below zero centigrade, such as mercury, alkali metal and more additional alloy candidates. With many unique virtues, such liquid metal coolants are expected to open a new technical frontier for heat transfer enhancement, especially in low temperature engineering. Some innovative ways for making low melting temperature liquid metal were outlined to provide a clear theoretical guideline and perform further experiments to discover new materials. Further, a few promising applied situations where low melting temperature liquid metals could play irreplaceable roles were detailed. Finally, some main factors for optimization of low temperature coolant were summarized. Overall, with their evident merits to meet various critical requirements in modern advanced energy and power industries, liquid metals with a low melting temperature below zero centigrade are expected to be the next-generation high-performance heat transfer medium in thermal managements, especially in harsh environment in space.

关键词: liquid metal     cryogenics     low melting point     thermal management     aircraft     liquid cooling     space exploration    

The role of microRNAs in adipocyte differentiation

null

《医学前沿(英文)》 2013年 第7卷 第2期   页码 223-230 doi: 10.1007/s11684-013-0252-8

摘要:

Adipocytes differentiate from mesenchymal stem cells (MSCs) in a process known as adipogenesis. The programme of adipogenesis is regulated by the sequential activation of transcription factors and several signaling pathways. There is growing evidence indicating that a class of small non-coding single-stranded RNAs known as “microRNAs (miRNAs)” also are involved in this process. In this review, we summarize the biology and functional mechanisms of miRNAs in adipocyte differentiation. In addition, we further discuss the miRNAs profiling, the miRNAs function and miRNAs target prediction in the adipogenesis.

关键词: microRNA     adipocyte     differentiation     adipogenesis    

Organizational dynamics in adaptive distributed search processes: effects on performance and the role

Friederike WALL

《信息与电子工程前沿(英文)》 2016年 第17卷 第4期   页码 283-295 doi: 10.1631/FITEE.1500306

摘要: In this paper, the effects of altering the organizational setting of distributed adaptive search processes in the course of search are investigated. We put particular emphasis on the complexity of interactions between partial search problems assigned to search agents. Employing an agent-based simulation based on the framework of NK landscapes we analyze different temporal change modes of the organizational set-up. The organizational properties under change include, for example, the coordination mechanisms among search agents. Results suggest that inducing organizational dynamics has the potential to increase the effectiveness of distributed adaptive search processes with respect to various performance measures like the final performance achieved at the end of the search, the chance to find the optimal solution of the search problem, or the average performance per period achieved during the search process. However, results also indicate that the mode of temporal change in conjunction with the complexity of the search problem considerably affects the order of magnitude of these beneficial effects. In particular, results suggest that organizational dynamics induces a shift towards more exploration, i.e., discovery of new areas in the fitness landscape, and less exploitation, i.e., stepwise improvement.

关键词: Agent-based simulation     Complexity     Coordination     Distributed search     NK landscapes    

标题 作者 时间 类型 操作

Possible role of power-to-heat and power-to-gas as flexible loads in German medium voltage networks

Mark KUPRAT, Martin BENDIG, Klaus PFEIFFER

期刊论文

Micro/nanofluidics-enabled energy conversion and its implemented devices

Yang YANG, Jing LIU

期刊论文

大中功率节能调速传动的合理电压等级

马小亮

期刊论文

Uncoupled state space solution to layered poroelastic medium with anisotropic permeability and compressible

Zhiyong AI, Wenze ZENG, Yichong CHENG, Chao WU

期刊论文

Preparation of solar selective absorbing CuO coating for medium temperature application

HUANG Qunwu, WANG Yiping, LI Jinhua

期刊论文

Frontier of continuous structural health monitoring system for short & medium span bridges and condition

Ayaho MIYAMOTO, Risto KIVILUOMA, Akito YABE

期刊论文

Deeply missing my career idol and role model ― Professor Perry L. McCarty

期刊论文

大中型水利工程建设管理的实践和体会

张基尧

期刊论文

Appreciating the role of big data in the modernization of environmental governance

期刊论文

The role of EcoCampus in addressing sustainability in UK universities

Peter REDFERN, Hua ZHONG

期刊论文

The critical role of autophagy in plant responses to abiotic stresses

Yu WANG,Jie ZHOU,Jingquan YU

期刊论文

The role of lipids in fermentative propionate production from the co-fermentation of lipid and food waste

期刊论文

Liquid metal as energy transportation medium or coolant under harsh environment with temperature below

Yunxia GAO, Lei WANG, Haiyan LI, Jing LIU

期刊论文

The role of microRNAs in adipocyte differentiation

null

期刊论文

Organizational dynamics in adaptive distributed search processes: effects on performance and the role

Friederike WALL

期刊论文