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Heat prices for public buildings in Tianjin

Boyuan HAO,Zhe TIAN,Yan DING,Peng PENG

《能源前沿(英文)》 2016年 第10卷 第3期   页码 249-259 doi: 10.1007/s11708-016-0412-z

摘要: Energy-saving awareness of heat users and heating enterprises can be stimulated by implementing heat metering for public buildings and by establishing scientific and reasonable policies for heat prices in China. In this paper, a two-part heat price for public buildings in Tianjin is introduced, which divides the heat price into a basic part and a metering part. According to the statistical analysis of information collected from two pilot heating enterprises, the specific heat load for public buildings in Tianjin is calculated, and three candidate schemes of heat price are proposed. A simulation of heat cost is also conducted, and the benefits for both heat users and heating enterprises are balanced. Finally, the two-part heat price for public buildings in Tianjin is determined: the basic heat price is recommended to be 20 CNY/m , and the metering heat price is recommended to be 76.10 CNY/GJ. Such a price could be implemented in the initial stage of heat metering for public buildings in Tianjin.

关键词: heat metering     public buildings     two-part heat price     specific heat load    

Application of a weakly compressible smoothed particle hydrodynamics multi-phase model to non-cohesive embankment breaching due to flow overtopping

Rasoul MEMARZADEH, Gholamabbas BARANI, Mahnaz GHAEINI-HESSAROEYEH

《结构与土木工程前沿(英文)》 2018年 第12卷 第3期   页码 412-424 doi: 10.1007/s11709-017-0432-8

摘要:

The subject of present study is the application of mesh free Lagrangian two-dimensional non-cohesive sediment transport model applied to a two-phase flow over an initially trapezoidal-shaped sediment embankment. The governing equations of the present model are the Navier-Stocks equations solved using Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) method. To simulate the movement of sediment particles, the model considers a powerful two-part technique; when the sediment phase has rigid behavior, only the force term due to shear stress in the Navier-Stokes equations is used for simulation of sediment particles’ movement. Otherwise, all the Navier-Stokes force terms are used for transport simulation of sediment particles. In the present model, the interactions between different phases are calculated automatically, even with considerable difference between the density and viscosity of phases. Validation of the model is performed using simulation of available laboratory experiments, and the comparison between computational results and experimental data shows that the model generally predicts well the flow propagation over movable beds, the induced sediment transport and bed changes, and temporal evolution of embankment breaching.

关键词: WCSPH method     non-cohesive sediment transport     rheological model     two-part technique     two-phase dam break    

A two-stage deep freezing chemisorption cycle driven by low-temperature heat source

Yuanyang HU, Liwei WANG, Lu XU, Ruzhu WANG, Jeremiah KIPLAGAT, Jian WANG

《能源前沿(英文)》 2011年 第5卷 第3期   页码 263-269 doi: 10.1007/s11708-011-0152-z

摘要: A two-stage chemisorption cycle suitable for deep-freezing application driven by low- temperature heat source was proposed. Through two-stage desorption processes, the two-stage cycle can break through the limitations of the heating temperature and ambient cooling temperature. The two-stage cycle based on CaCl /BaCl -NH working pair can utilize the heat source with a temperature of above 75°C, and simultaneously realize deep-freezing all the year round. Experimental results and performance prediction show that the adsorption quantity of calcium, theoretical coefficient of performance (COP) and optimized specific cooling power (SCP) of the CaCl /BaCl -NH chemisorption system are 0.489 kg/kg (salt), 0.24 and 120.7 W/kg, when the heating temperature, ambient cooling temperature, pseudo-evaporating temperature and mass ratio of reacting salt and expanded graphite are 85, 30, -20, and 4∶1, respectively.

关键词: adsorption     freezing     desorption     heat source    

Can the Shanghai LNG Price Index indicate Chinese market?An econometric investigation using price discovery theory

Yeli ZENG, Cong DONG, Mikael HÖÖK, Jinhua SUN, Danyang SHI

《能源前沿(英文)》 2020年 第14卷 第4期   页码 726-739 doi: 10.1007/s11708-020-0701-4

摘要: China became the world’s second largest liquefied natural gas (LNG) importer in 2018 but has faced extremely high import costs due to a lack of bargaining power. Assessments of the Shanghai LNG Price Index, first released in 2015, are vital for improving the understanding of these cost dynamics. This paper, using the LNG price index data from the Shanghai Petroleum and Gas Exchange (SHPGX) coupled with domestic and international LNG prices from July 1, 2015 to December 31, 2018, estimates several econometric models to evaluate the long-term and short-term equilibriums of the Shanghai LNG Price Index, the responses to market information shocks and the leading or lagging relationships with LNG and alternative energy prices from other agencies. The results show that the LNG price index of the SHPGX has already exhibited a long-term equilibrium and short-term adjustment mechanisms to reflect the average price level and market movements, but the market information transparency and price discovery efficiency of the index are still inadequate. China’s LNG market is still relatively independent of other natural gas markets, and marketization reforms are under way in China. The influence of the SHPGX LNG price index on the trading decisions of market participants is expected to improve with further development of China’s LNG reforms, the formation of a natural gas entry-exit system, and the increasing liquidity of the hub.

关键词: liquefied natural gas     price index     Shanghai Petroleum and Gas Exchange     price discovery     market reforms    

Exploring price effects on the residential water conservation technology diffusion process: a case study

Junying CHU, Hao WANG, Can WANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第5期   页码 688-698 doi: 10.1007/s11783-013-0559-3

摘要: Reforms of the water pricing management system and the establishment of a flexible water pricing system are significant for cities in northern China to tackle their critical water issues. The WATAP (Water conservation Technology Adoption Processes) model is developed in order to capture the water conservation technology adoption process under different price scenarios with disaggregate water demands down to the end use level. This model is explicitly characterized by the technological selection process under maximum marginal benefit assumption by different categories of households. In particular, when households need to purchase water devices in the provision market with the consideration of complex factors such as the life span, investment and operating costs of the device, as well as the regulated water price by the government. Applied to Tianjin city, four scenarios of water price evolutions for a long-term perspective (from year 2011 to 2030) are considered, including BAU (Business As Usual), SP1 (Scenario of Price increase with constant annual rate), SP2 (Scenario of Price increase every four years) and SP3 (Scenario of Price increase with affordable constraint), considering many factors such as historic trends, affordability and incentives for conservation. Results show that on aggregate 2.3%, 11.0% and 18.2% of fresh water can be saved in the residential sector in scenario SP1, SP2 and SP3, respectively, compared with the BAU scenario in the year 2030. The water price signals can change the market shares of different water appliances, as well as the water end use structure of households, and ultimately improve water use efficiency. The WATAP model may potentially be a helpful tool to provide insights for policy makers on water conservation technology policy analysis and assessment.

关键词: technology selection     model optimization     water price     scenario analysis     consumer behavior    

Does oil price affect the value of firms? Evidence from Tunisian listed firms

Kaouther ZAABOUTI,Ezzeddine BEN MOHAMED,Abdelfettah BOURI

《能源前沿(英文)》 2016年 第10卷 第1期   页码 1-13 doi: 10.1007/s11708-016-0396-8

摘要: A new debate on the potential impact of oil price changes on the value of firms was initiated in this paper. Using a stochastic frontier approach, an attempt was made to derive the optimal value * of firms and calculate the value observed. Then the shortfall ( *– ) which represents the inefficiency term was explained. Starting from 19 industrial Tunisian firms listed on the Tunis Stock Exchange between 2007 and 2011, the fact that variation of oil prices can largely explain distortions in the value of firms was empirically demonstrated.

关键词: industrial Tunisian firms     oil price     value of firm     stochastic frontier approach    

Macroeconomic impacts of oil price volatility: mitigation and resilience

Zoheir EBRAHIM, Oliver R. INDERWILDI, David A. KING

《能源前沿(英文)》 2014年 第8卷 第1期   页码 9-24 doi: 10.1007/s11708-014-0303-0

摘要: Dependency on oil-derived fuels in various sectors, most notably in mobility, has left the global economy vulnerable to several macroeconomic economic side effects. Numerous studies have addressed the effect of price volatility on specific economic parameters. However, the current literature lacks a comprehensive review of the interactions between global macroeconomic performance and oil price volatility (OPV). Price volatility is intrinsic in commodity markets, but has been advancing at a faster rate in the crude oil market in comparison to other commodities over the past decade, reflecting the status of oil as the most globalised commodity. In this paper, the analytical literature review and analysis of the behavioral responses of macroeconomic agents to OPV shows that such volatility has several damaging and destabilizing macroeconomic impacts that will present a fundamental barrier to future sustainable economic growth if left unchecked. To ensure macroeconomic isolation from OPV, a combination of supply and demand-side policies have been recommended that can help to mitigate and build resilience to the economic uncertainty advanced by OPV.

关键词: conventional oil     price volatility     macroeconomy     economic stability     energy security    

Direct energy rebound effect for road transportation in China

《工程管理前沿(英文)》   页码 597-611 doi: 10.1007/s42524-023-0276-y

摘要: The enhancement of energy efficiency stands as the principal avenue for attaining energy conservation and emissions reduction objectives within the realm of road transportation. Nevertheless, it is imperative to acknowledge that these objectives may, in part or in entirety, be offset by the phenomenon known as the energy rebound effect (ERE). To quantify the long-term EREs and short-term EREs specific to China’s road transportation, this study employed panel cointegration and panel error correction models, accounting for asymmetric price effects. The findings reveal the following: The long-term EREs observed in road passenger transportation and road freight transportation range from 13% to 25% and 14% to 48%, respectively; in contrast, the short-term EREs in road passenger transportation and road freight transportation span from 36% to 41% and 3.9% to 32%, respectively. It is noteworthy that the EREs associated with road passenger transportation and road freight transportation represent a partial rebound effect, falling short of reaching the magnitude of a counterproductive backfire effect. This leads to the inference that the upsurge in energy consumption within the road transportation sector cannot be solely attributed to advancements in energy efficiency. Instead, various factors, including income levels, the scale of commodity trade, and industrial structure, exert more substantial facilitating influences. Furthermore, the escalation of fuel prices fails to dampen the demand for energy services, whether in the domain of road passenger transportation or road freight transportation. In light of these conclusions, recommendations are proffered for the formulation of energy efficiency policies pertinent to road transportation.

关键词: road transportation     direct energy rebound effect     asymmetric price effects     panel data model    

Day-ahead electricity price forecasting using back propagation neural networks and weighted least square

S. Surender REDDY,Chan-Mook JUNG,Ko Jun SEOG

《能源前沿(英文)》 2016年 第10卷 第1期   页码 105-113 doi: 10.1007/s11708-016-0393-y

摘要: This paper proposes the day-ahead electricity price forecasting using the artificial neural networks (ANN) and weighted least square (WLS) technique in the restructured electricity markets. Price forecasting is very important for online trading, e-commerce and power system operation. Forecasting the hourly locational marginal prices (LMP) in the electricity markets is a very important basis for the decision making in order to maximize the profits/benefits. The novel approach proposed in this paper for forecasting the electricity prices uses WLS technique and compares the results with the results obtained by using ANNs. To perform this price forecasting, the market knowledge is utilized to optimize the selection of input data for the electricity price forecasting tool. In this paper, price forecasting for Pennsylvania-New Jersey-Maryland (PJM) interconnection is demonstrated using the ANNs and the proposed WLS technique. The data used for this price forecasting is obtained from the PJM website. The forecasting results obtained by both methods are compared, which shows the effectiveness of the proposed forecasting approach. From the simulation results, it can be observed that the accuracy of prediction has increased in both seasons using the proposed WLS technique. Another important advantage of the proposed WLS technique is that it is not an iterative method.

关键词: day-ahead electricity markets     price forecasting     load forecasting     artificial neural networks     load serving entities    

Two-dimensional modeling of sintering of a powder layer on top of nonporous substrate

Tiebing CHEN, Yuwen ZHANG,

《机械工程前沿(英文)》 2010年 第5卷 第2期   页码 143-148 doi: 10.1007/s11465-010-0006-0

摘要: Selective laser sintering (SLS) of a two-component metal powder layer on the top of multiple sintered layers by a moving Gaussian laser beam is modeled. The loose metal powder layer is composed of a powder mixture with significantly different melting points. The physical model that accounts the shrinkage induced by melting is described by using a temperature-transforming model. The effects of the porosity and the thickness of the atop loose powder layer with different numbers of the existing sintered metal powder layers below on the sintering process are numerically investigated. The present work will provide a better understanding to simulate much more complicated three-dimensional SLS process.

关键词: laser     sintering     melting     solidification     heat transfer    

SPH原理、发展现状及热传导问题模型

王玉恒,刘峰,宋凤梅

《中国工程科学》 2008年 第10卷 第11期   页码 47-51

摘要:

对光滑粒子流体动力学方法(smoothed particle hydrodynamics,SPH)的基本技术原理及发展现状进行了综述,利用SPH方法对两个典型二维非线性动力学算例进行了数值模拟。同时,利用国外学者提出的方法初步探索了有关热传导问题的SPH模型。

关键词: SPH     二维非线性动力学     热传导模型     数值模拟    

An approach to locational marginal price based zonal congestion management in deregulated electricity

Md SARWAR,Anwar Shahzad SIDDIQUI

《能源前沿(英文)》 2016年 第10卷 第2期   页码 240-248 doi: 10.1007/s11708-016-0404-z

摘要: Congestion of transmission line is a vital issue and its management pose a technical challenge in power system deregulation. Congestion occurs in deregulated electricity market when transmission capacity is not sufficient to simultaneously accommodate all constraints of power transmission through a line. Therefore, to manage congestion, a locational marginal price (LMP) based zonal congestion management approach in a deregulated electricity market has been proposed in this paper. As LMP is an economic indicator and its difference between two buses across a transmission line provides the measure of the degree of congestion, therefore, it is efficiently and reliably used in deregulated electricity market for congestion management. This paper utilizes the difference of LMP across a transmission line to categorize various congestion zones in the system. After the identification of congestion zones, distributed generation is optimally placed in most congestion sensitive zones using LMP difference in order to manage congestion. The performance of the proposed methodology has been tested on the IEEE 14-bus system and IEEE 57-bus system.

关键词: locational marginal price (LMP)     distributed generation     pool market     deregulated electricity market     congestion management    

Residual stresses in coating-based systems, part I: Mechanisms and analytical modeling

ZHANG Xiancheng, WU Yixiong, XU Binshi, WANG Haidou

《机械工程前沿(英文)》 2007年 第2卷 第1期   页码 1-12 doi: 10.1007/s11465-007-0001-2

摘要: Thin films and multi-layered coatings comprised of different classes of materials are often used for various functional devices. The thermo-mechanical integrity of these systems is becoming a major concern and is strongly related to the residual stresses because of the fabrication processes. In this paper, the sources of the residual stresses in the coating-based systems and the concept of misfit strain were briefly reviewed. Analytical models were developed to predict the residual stresses in multi-layered film structures or coating-based systems using the force and moment balances. In addition, the residual stress distributions in the func tionally and compositionally graded coatings were also analyzed.

关键词: briefly     different     thermo-mechanical integrity     addition     residual    

Process development for green part printing using binder jetting additive manufacturing

Hadi MIYANAJI, Morgan ORTH, Junaid Muhammad AKBAR, Li YANG

《机械工程前沿(英文)》 2018年 第13卷 第4期   页码 504-512 doi: 10.1007/s11465-018-0508-8

摘要:

Originally developed decades ago, the binder jetting additive manufacturing (BJ-AM) process possesses various advantages compared to other additive manufacturing (AM) technologies such as broad material compatibility and technological expandability. However, the adoption of BJ-AM has been limited by the lack of knowledge with the fundamental understanding of the process principles and characteristics, as well as the relatively few systematic design guideline that are available. In this work, the process design considerations for BJ-AM in green part fabrication were discussed in detail in order to provide a comprehensive perspective of the design for additive manufacturing for the process. Various process factors, including binder saturation, in-process drying, powder spreading, powder feedstock characteristics, binder characteristics and post-process curing, could significantly affect the printing quality of the green parts such as geometrical accuracy and part integrity. For powder feedstock with low flowability, even though process parameters could be optimized to partially offset the printing feasibility issue, the qualities of the green parts will be intrinsically limited due to the existence of large internal voids that are inaccessible to the binder. In addition, during the process development, the balanced combination between the saturation level and in-process drying is of critical importance in the quality control of the green parts.

关键词: binder jetting     additive manufacturing     green part     process optimization     process development    

Improvement of part-load performance of gas turbine by adjusting compressor inlet air temperature and

《能源前沿(英文)》 2022年 第16卷 第6期   页码 1000-1016 doi: 10.1007/s11708-021-0746-z

摘要: A novel adjusting method for improving gas turbine (GT) efficiency and surge margin (SM) under part-load conditions is proposed. This method adopts the inlet air heating technology, which uses the waste heat of low-grade heat source and the inlet guide vane (IGV) opening adjustment. Moreover, the regulation rules of the compressor inlet air temperature and the IGV opening are studied comprehensively to optimize GT performance. A model and calculation method for an equilibrium running line is adopted based on the characteristic curves of the compressor and turbine. The equilibrium running lines calculated through the calculation method involve three part-load conditions and three IGV openings with different inlet air temperatures. The results show that there is an optimal matching relationship between IGV opening and inlet air temperature. For the best GT performance of a given load, the IGV could be adjusted according to inlet air temperature. In addition, inlet air heating has a considerable potential for the improvement of part-load performance of GT due to the increase in compressor efficiency, combustion efficiency, and turbine efficiency as well as turbine inlet temperature, when inlet air temperature is lower than the optimal value with different IGV openings. Further, when the IGV is in a full opening state and an optimal inlet air temperature is achieved by using the inlet air heating technology, GT efficiency and SM can be obviously higher than other IGV openings. The IGV can be left unadjusted, even when the load is as low as 50%. These findings indicate that inlet air heating has a great potential to replace the IGV to regulate load because GT efficiency and SM can be remarkably improved, which is different from the traditional viewpoints.

关键词: inlet air temperature     inlet guide vane (IGV) opening     part-load     equilibrium running line     gas turbine (GT) efficiency     surge margin (SM)    

标题 作者 时间 类型 操作

Heat prices for public buildings in Tianjin

Boyuan HAO,Zhe TIAN,Yan DING,Peng PENG

期刊论文

Application of a weakly compressible smoothed particle hydrodynamics multi-phase model to non-cohesive embankment breaching due to flow overtopping

Rasoul MEMARZADEH, Gholamabbas BARANI, Mahnaz GHAEINI-HESSAROEYEH

期刊论文

A two-stage deep freezing chemisorption cycle driven by low-temperature heat source

Yuanyang HU, Liwei WANG, Lu XU, Ruzhu WANG, Jeremiah KIPLAGAT, Jian WANG

期刊论文

Can the Shanghai LNG Price Index indicate Chinese market?An econometric investigation using price discovery theory

Yeli ZENG, Cong DONG, Mikael HÖÖK, Jinhua SUN, Danyang SHI

期刊论文

Exploring price effects on the residential water conservation technology diffusion process: a case study

Junying CHU, Hao WANG, Can WANG

期刊论文

Does oil price affect the value of firms? Evidence from Tunisian listed firms

Kaouther ZAABOUTI,Ezzeddine BEN MOHAMED,Abdelfettah BOURI

期刊论文

Macroeconomic impacts of oil price volatility: mitigation and resilience

Zoheir EBRAHIM, Oliver R. INDERWILDI, David A. KING

期刊论文

Direct energy rebound effect for road transportation in China

期刊论文

Day-ahead electricity price forecasting using back propagation neural networks and weighted least square

S. Surender REDDY,Chan-Mook JUNG,Ko Jun SEOG

期刊论文

Two-dimensional modeling of sintering of a powder layer on top of nonporous substrate

Tiebing CHEN, Yuwen ZHANG,

期刊论文

SPH原理、发展现状及热传导问题模型

王玉恒,刘峰,宋凤梅

期刊论文

An approach to locational marginal price based zonal congestion management in deregulated electricity

Md SARWAR,Anwar Shahzad SIDDIQUI

期刊论文

Residual stresses in coating-based systems, part I: Mechanisms and analytical modeling

ZHANG Xiancheng, WU Yixiong, XU Binshi, WANG Haidou

期刊论文

Process development for green part printing using binder jetting additive manufacturing

Hadi MIYANAJI, Morgan ORTH, Junaid Muhammad AKBAR, Li YANG

期刊论文

Improvement of part-load performance of gas turbine by adjusting compressor inlet air temperature and

期刊论文