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Abstract: Through sampling reed in Shuangtai estuary wetland in April, 2009 and simulation test in Shenyang Agricultural University, we analyze the removal efficiency of Cu, Zn, Pb and Cd during different growth period of reed and distribution of them in various parts of reed. The results show that the removal efficiency is best in jointing stage, the removal of Pb largest with 21% increase and 30% in sprout and exhibition leaf period, the removal of Zn largest with 53% and 29% increase in jointing stage and the maturity period, the removal of Cd largest with 40% increase in the different growing season. The absorption amount of Cu, Zn, Pb and Cd in roots of reed reaches maximum during the growth, followed by in stems and in leaves. Absorptive capacity in the whole plant for Cu, Zn, Pb and Cd exists extremely significant difference (p <0.01). The order is Pb>Zn>Cu>Cd. The absorption in root is higher than in stems and in leaves (p <0.05), but Zn and Cd absorption amount has no significant differences in stems and leaves (p >0.05). [Copyright &y& Elsevier]

Data-driven three-dimensional (3D) mineral prospectivity modeling (MPM) employs diverse 3D exploration indicators to express geological architecture and associated characteristics in ore systems. The integration of 3D geological models with 3D computational simulation data enhances the effectiveness of 3D MPM in representing the geological architecture and its coupled geodynamic processes that govern mineralization. Despite variations in modality (i.e., data source, representation, and information abstraction levels) between geological models and simulation data, the cross-modal gap between these two types of data remains underexplored in 3D MPM. This paper presents a novel 3D MPM approach that robustly fuses multimodal information from geological models and simulation data. Acknowledging the coupled and correlated nature of geological architectures and geodynamic processes, a joint fusion strategy is employed, aligning information from both modalities by enforcing their correlation. A joint fusion neural network is devised to extract maximally correlated features from geological models and simulation data, fusing them in a cross-modality feature space. Specifically, correlation analysis (CCA) regularization is utilized to maximize the correlation between features of the two modalities, guiding the network to learn coordinated and joint fused features associated with mineralization. This results in a more effective 3D mineral prospectivity model that harnesses the strengths from both modalities for mineral exploration targeting. The proposed method is evaluated in a case study of the world-class Jiaojia gold deposit, NE China. Extensive experiments were carried out to compare the proposed method with state-of-the-art methods, methods using unimodal data, and variants without CCA regularization. Results demonstrate the superior performance of the proposed method in terms of prediction accuracy and targeting efficacy, highlighting the importance of CCA regularization in enhancing predictive power in 3D MPM. • Casting 3D mineral prospectivity modeling (MPM) as a deep multimodal fusion problem. • Joint fusion network for integrating features of 3D geological models and simulation data. • Canonical correlation analysis regularization to guide network fusion of the cross-modal gap. • Maximizing the correlation of multimodal information boosts the performance of 3D MPM. [ABSTRACT FROM AUTHOR]

Abstract A new high-order statistical moment based on multi-scale (MSHOM) is proposed for researching traditional statistics in this paper. In addition, the indispensable theoretical basis and derivation are illustrated in detail. With the help of three simulated time series, two kinds of situations of MSHOM analysis are mainly discussed in this work. One is accomplished by Gaussian white noise (GWN) and the other is fulfilled with Logistic map and autoregressive fractionally integrated moving-average (ARFIMA). Due to the insufficient performance of MSHOM, we propose an improved MSHOM, which is called MSHOM with control (C-MSHOM). Meanwhile, its performance is tested by the data of US and Chinese stock markets. However, C-MSHOM also brings an extra preprocess stage of data and the uncertainty of selection. To solve these problems, a more generic method, that is, generalized multi-scale high-order moments (G-MSHOM) is given in this paper. Highlights • A new high-order statistical moment is proposed based on multi-scale (MSHOM). • Two improved methods are proposed to widen extent of applications. • The analytic properties of the MSHOM method are presented in detail. • Simulation results show the stability and precision of the MSHOM method. • Benefits of MSHOM and G-MSHOM are shown using US and Chinese stock markets data. [ABSTRACT FROM AUTHOR]

When modeling the energy performance of existing buildings, model calibration always serves as an essential and necessary step to ensure the accuracy and applicability of building models. Model calibration for detailed energy models, which is also known as calibrated simulation (CS), refers to the process of tuning model's input parameters to narrow down the mismatch between the simulation result and the real-monitored data of building energy consumptions. Two major problems of current CS are: (1) a successful calibration requires HVAC domain knowledge of modelers. (2) Traditional building calibration process is labor-intensive and time-consuming. To solve these problems, a normative energy modeling based quick auto-calibration approach is proposed in this study. This approach is able to reduce the modeling time and simplify the calibration procedures. Firstly, this paper demonstrates the working principles and the credibility of Normative Energy Modeling (NEM). Then, the methodology of the proposed quick auto-calibration approach is elaborated. The energy performance model of a large hotel located in Shanghai, China with NEM is used as a case study to investigate the effectiveness of the proposed quick auto-calibration approach. The simulation result of the case study suggests that the proposed approach can significantly simplify the procedures of model calibrations while still achieve a good accuracy specified by ASHRAE Guideline 14 [1]. Besides, the results further confirm that such method requires much less time and computational power for modeling, compared with other counterparts (e.g., “Autotune” calibration [2]). With the advantage of speed and accuracy, the auto-calibration proposed in this paper is promising to be applied in both engineering and research field. [ABSTRACT FROM AUTHOR]

As an ingredient of the marine economy, the marine fishery has the dual attributes of carbon source and carbon sink. Marine fisheries are vital to the sustainable development of the marine economy and pivotal to the dual carbon goals. To explore the new mode of low carbon development of marine fishery, this paper utilizes system dynamics to establish the simulation model of low carbon development complex system of Chinese marine fishery for 2010 to 2019. Then, the carbon emission process of Chinese marine fishery is characterized from the perspectives of mariculture, marine fishing, marine processing industry, and marine shellfish carbon sink. This paper also performs policy simulation applying the system dynamics model to forecast and analyze marine fishery carbon emission development trends in adjusting GDP growth rate, fishery industry structure, and marine employment ratio. The simulation results indicate that the socio-economic system can influence marine fishery system development, which is an essential factor driving marine fishery carbon emissions. The number of marine fishery employment is associated with the scale of marine fishery development, which is the primary positive driving factor of carbon emissions from the marine fishery. Under the premise of excluding the heterogeneity of aquatic products, the energy consumption of the marine fishing industry is significantly higher than that of the mariculture industry in producing a unit of marine products, i.e., adjusting the structure of the marine industry can cause an inhibitory effect on the carbon emission of the marine fishery. Our findings contribute to policy implications for policymakers to reasonably restructure the marine fishery industry and the ratio of marine capture to mariculture to facilitate the low-carbon development of marine fishery. [ABSTRACT FROM AUTHOR]

The train platforming problem is one of the most investigated topics in the train operation field. However, a systematic understanding of how train platforming improves the convenience of passenger transfer procedures is still lacking. To face the rapidly growing transfer demands in the high-speed railway station, this paper proposes a transfer-facilitating-oriented train platforming approach based on a multi-agent train operation simulation model. By evaluating the transfer connection quality using an indicator named Transfer Connection Strength(TCS), which considers transfer distance and transfer time, the proposed transfer-facilitating-oriented train platforming strategies can establish more convenient transfer connections and so improve the transfer service. A track occupation horizon based on the modelling of accurate train running processes is utilized to detect route conflicts and guarantee conflict-free train operations in the simulation model, enabling the solutions' feasibility of train platforming to be taken into account. A series of simulation experiments are conducted using real data of Zhengzhou East station in China. The experiment results show that, the proposed transfer-facilitating-oriented train platforming strategies are capable of obtaining a greater number of convenient transfer connections. The feasibility can be guaranteed by permitted train delays and route conflict detection for the succeeding trains in a forward-looking period. Additionally, the platform assignment plans can be generated with a specified priority of transfer distance or transfer time. [ABSTRACT FROM AUTHOR]

• Calculation unit division induced soil spatial aggregation in SWAT model. • Effect of soil spatial aggregation on simulation was separated and quantified.Soil spatial aggregation caused a significant increase in annual runoff and sediment load. • The effect of soil spatial aggregation on sediment load was greater than on runoff. • Optimal sub-watershed division scheme was discussed. Distributed hydrological model divides watersheds into distinct calculation units to simulate hydrological processes. Within the model, different calculation unit division schemes induce input elements, such as soil and land use, to certain degrees of generalization, thus affecting the simulation result. Analyzing the effect of the calculation unit division on the simulation result is an important methodology to reduce uncertainty and improve the simulation accuracy of the model. Previous researchers have focused on the comprehensive effect of underlying surface generalization (such as soil, land use, and terrain generalization) caused by the calculation unit division on the simulation results, while it did not separate the effect of the generalization of the individual input factor on the simulation result. In this paper, the Dongjiang headwater region in southern China was selected as the study area. The single type of land use and slope were input into the Soil and Water Assessment Tool (SWAT) model to fix the effects of land use and terrain caused by calculation unit division on the simulation results. Eleven calculation unit division schemes were used to analyze the impact of soil spatial aggregation on runoff and sediment load simulations. The calculation unit division schemes included 11 sub-watershed division schemes and their hydrological response unit (HRU) thresholds were set at 8 %. The drainage area thresholds of the 11 sub-watershed division schemes were 30 ha, 60 ha, 120 ha, 240 ha, 480 ha, 1000 ha, 1600 ha, 2200 ha, 2800 ha, 3400 ha and 4000 ha. The results demonstrated that the soil spatial distribution showed an obvious aggregation with an increase in the drainage area threshold in the SWAT model. Of these, the Krasnozem soil type which covers the largest area in the watershed, increased significantly with an increase in the drainage area threshold. However, the areas of all the other soil types decreased significantly. The Lioth soil type covers the smallest area in the watershed decreased and even disappeared when the threshold in the SWAT model was greater than 1000 ha. Furthermore, soil spatial aggregation caused a significant increase in the annual runoff and sediment load (P < 0.05), with the sediment load (Re = 29.78 %) increasing at a greater rate compared to runoff (Re = 1.74 %). Increased soil aggregation significantly increased the sediment loads in the maximum 1-day, the continuous maximum 5-day, the continuous maximum 7-day, and the sediment load in flood processes (P < 0.001). Refining the calculation unit division scheme will cause a significant increase in the number of calculation units. Due to the computer processing power limitations, we cannot further refine the calculation unit division scheme. Based on our current operational calculation unit division scheme, we did not identify the optimal division scheme in the study region. These results can provide reference information for future research into hydrological model uncertainty and can improve the SWAT model simulation accuracy. [ABSTRACT FROM AUTHOR]

China will enact a national emissions trading system in 2017. The rules for the initial allocation of emission allowances have not been settled yet. This paper assesses the effect of auctioning as an initial emission allowance allocation methods of the China electricity power generation sector. This study employs a combined model with modified Trans-log production function, dynamic simulation model and multi-objective linear programming to provide more realistic results. After estimating the optimal electric power sources structure and technological structure under different auctioning rates, this paper calculates the abatement cost of the China’s electric power generation sector. When the allowance is free, the carbon shadow price will be 206.12 Yuan/ton. When 5% allowance is auctioned, the price will be 216.91 Yuan/ton. When the auctioning rate increases, the carbon emission abatement cost increases accordingly, as does the growth rate. The results also show that when the allowance auction rate is 5%, the marginal abatement costs for coal-fired power generation and clean power generation are 0.123 Yuan/kW h and 0.121 Yuan/kW h respectively, and thus, the total additional cost of the electric power generation sector will increase by 0.244 Yuan/kW h, which would be a heavy burden to China’s electric power generation sector and the forward progress of auctioning in the near future may be hindered. [ABSTRACT FROM AUTHOR]

In the process of coal mining safety inspection in China, the different interests and influences of stakeholders and their complicated dynamic interactions make the coal mining safety laws and regulations less effective. Moreover, the existing literature on China’s coal mining safety inspection is short of research on revealling the dynamic interactions that can occur under the bounded rationality and also on proposals for effective interactions that will lead to improved safety outcomes. Therefore, this paper explores the use of evolutionary game theory to describe the interactions between the stakeholders in China’s coal mining safety inspection system, which includes the State Administration of Coal Mine Safety (SACMS), the Local Regulation Departments of Coal Mine Safety (LRDCMS), and coal enterprises. Moreover, the paper also explores dynamic simulations of the evolutionary game model to analyze the stability of stakeholder interactions and to identify equilibrium solutions. The simulation results show that the strategy selections of the three stakeholders fluctuate repeatedly, which indicates that the evolutionary stable strategy does not exist in the current interactions between the stakeholders. Therefore, the dynamic penalty control scenario and an optimized dynamic penalty-incentive control scenario were proposed to control the fluctuations and then simulated again. And the simulation results indicated that the dynamic penalty control scenario can effectively restrain the fluctuations and make stakeholder interactions more stable. Furthermore, the optimized dynamic penalty-incentive control scenario can not only restrain the fluctuations effectively but also present an ideal evolutionary stable strategy in which coal enterprises could nearly choose safety production as their optimal strategy. [ABSTRACT FROM AUTHOR]

Abstract: The coal under buildings accounts for 69% of the total in China, while more than 4.5 billion tons of solid waste is discharged to the ground over years. This paper studied the backfill with solid mining method. It is meaningful for the efficient exploitation of coal mining under buildings as well as reducing environmental pollution around the mining area. In this paper, we analyzed the plastic zone distribution of the face surrounding rock and the variation of surface subsidence systematically. According to the simulation results, backfill mining with solid reduce the damage to the surrounding rock of the goaf and diminish the effect on the stability of surrounding rock. It also can reduce the surface subsidence obviously. Taking the above study results as one of the important references, we research and design the matching equipments with fully-mechanized filling mining. The filling equipments mainly are the self-tamping backfilling hydraulic support and backfilling conveyor. These have been applied to an actual exploitation of coal mining under buildings, and achieved good results. It can control the surface deformation effectively and ensure the safety of buildings and the efficient exploitation of resources. Backfill mining with solid provides a new way for the mining under buildings. [Copyright &y& Elsevier]

Abstract: Firstly, this paper analyzes the basic principles and processes of the spatial pattern changes of land use in towns and villages, and the result shows that the land resource demands of urban development and population growth lead to the spatial pattern changes. Secondly, in order to grip land use changes better, the paper proposes a method for the simulation of spatial patterns. The simulating method can be divided into two parts: one is a quantitative forecast by using the Markov model, and the other is simulating the spatial pattern changes by using the CA model. The above two models construct the simulative model of the spatial pattern of land use in towns and villages. Finally, selecting Fangshan which is a district of Beijing as the experimental area, both the quantity and spatial pattern changing characteristics are investigated through building a changing dataset of land use by using spatial analysis methods based on the land use data in 2001, 2006 and 2008; CA–Markov is used to simulate the spatial pattern of land use in Fangshan for 2015. [Copyright &y& Elsevier]

Abstract: Snow cover is a common and relatively stable land cover condition in winter for cold north regions in China. Snow cover has significant effects on water and heat transfers in frozen soil; it needs to be considered in the study of frozen soil water–heat coupled movements. On the basis of previous research results and physical process analysis of water and heat movements in snow cover and soil, a snow cover–soil union water–heat coupled movements model is established in this paper. The numerical simulation was conducted by using a finite difference method. The results indicate that the simulated values have a similar trend to the measured values and the numerical simulation had big relative errors. However, the average absolute errors of the total and liquid moisture content in frozen soil were all less than 4%, and that of the frozen soil temperature was 1.37 °C. The errors of the numerical simulation were still within the acceptable range. Thus, the snow cover–soil union water–heat coupled movement model constructed in this paper is rational. [Copyright &y& Elsevier]

Abstract: Building cooling load prediction is one of the key factors in the success of energy-saving measures. Many computational models available in the industry today have been developed from either forward or inverse modeling approaches. However, most of these models require extensive computer resources and involve lengthy computation. This paper discusses the use of data-driven intelligent approaches, a probabilistic entropy-based neural (PENN) model to predict the cooling load of a building. Although it is common knowledge that the presence and activity of building occupants have a significant impact on the required cooling load of buildings, practices currently adopted in modeling the presence and activity of people in buildings do not reflect the complexity of the impact occupants have on building cooling load. In contrast to previous artificial neural network (ANN) models, most of which employ a fixed schedule or historic load data to represent building occupancy in simulating building cooling load, this paper introduces two input parameters, dynamic occupancy area and rate and uses it to mimic building cooling load. The training samples used include weather data obtained from the Hong Kong Observatory and building-related data acquired from an existing grade A mega office buildings in Hong Kong with tenants including many multi-national financial companies that require 24-h air conditioning seven days a week. The dynamic changes that occur in the occupancy of these buildings therefore make it very difficult to forecast building cooling load by means of a fixed time schedule. The performance of simulation results demonstrate that building occupancy data play a critical role in building cooling load prediction and that their use significantly improves the predictive accuracy of cooling load models. [Copyright &y& Elsevier]

Abstract: This paper investigates numerical method for predicting wind field and pollutant dispersion in an urban area with crowded buildings and heavy traffic. Large eddy simulation is employed in numerical computation with Lagrangian dynamic model to close the subgrid scale stress. The fine grids are required in numerical simulation of micro-atmospheric flows in an urban area with crowded and complex building-streets. To realize the numerical simulation on available computer resources a domain decomposition method and a combined model for the building-street layout are proposed that the computed domain of an urban area is decomposed into a central area, where the pollution is the major concern and a surrounding region where the pollutant distribution is not concerned. The combined flow model is proposed for the complex building-street layout that the fine grid mesh and exact flow boundary conditions are prescribed in the central area while the buildings are treated as roughness elements in the surrounding region where the coarse grids are used. The proposed numerical method is applied to simulate the wind field and pollutant dispersion from vehicle exhaust in the Rua Do Campo area of Macau (referred to the site hereafter). The wind speed and temperature fields are computed from 7 am on September 6 2005 to 7 am of the next day and the pollutant concentration field is computed from 7 am to 6 pm on September 6 2005. The results show fairly good agreement with the field observation. The wind field and pollutant concentration distribution are demonstrated in the site by proposed combined model and they are compared with those computed by drag element model in whole computational domain. The results show that the combined model is an appropriate method for predicting wind field and pollutant dispersion in the crowded building area. The paper also reveals the relevance of buoyancy effect in the prediction of urban atmospheric environment. [Copyright &y& Elsevier]

Summary: The rapid economic development has caused heavy pollution in the Pearl River Delta Region (PRDR) and neighboring regions. In order to investigate the polluted characteristics, a coupled modelling approach has been deployed and the study area in the Pear River Delta is divided into two modelling systems: a river network that is simulated by a 1D hydrodynamic and water quality model, and an estuary that is modelled by a 3D model. The 1D river network model is coupled with the 3D estuary model based on the mass conservation criteria. The hydrodynamic (HD) model is based on 1D hydrostatic shallow water equations, and is solved by the Alternating Direction Implicit Approach. The water quality (WQ) model component is based on advection–diffusion equations. Some physical and bio-chemical processes are included in the WQ model to address the water pollution problems by different pollution substances, in particular, to the chemical oxygen demand (COD). The water quality data of the main rivers from 2004 to 2007 were collected, processed and evaluated. Because no detailed water quality data in the river is available, the COD source pollution intensity in the water quality model is taking the pollutant load from the confluence of the main five outlets of the Pearl River Estuary (PRE) for 1996–2007 as surrogate. The results show that the pollutants from the PRDR have a large impact on the quality of the Hong Kong seawater and much more serious in the wet season with high river discharge. An insight of the flow and transportation mechanism in the river and estuary system has been obtained through the paper, and a reliable basis to control water pollution of the Pearl River Delta is provided in this paper. [Copyright &y& Elsevier]

Abstract: Full-scope digital instrumentation and controls system (I&C) technique is being introduced in Chinese new constructed Nuclear Power Plant (NPP), which mainly includes three parts: control system, reactor protection system and engineered safety feature actuation system. For example, SIEMENS TELEPERM XP and XS distributed control system (DCS) have been used in Ling Ao Phase II NPP, which is located in Guangdong province, China. This is the first NPP project in China that Chinese engineers are fully responsible for all the configuration of actual analog and logic diagram, although experience in NPP full-scope digital I&C is very limited. For the safety, it has to be made sure that configuration is right and control functions can be accomplished before the phase of real plant testing on reactor. Therefore, primary verification and validation (V&V) of I&C needs to be carried out. Except the common and basic way, i.e. checking the diagram configuration one by one according to original design, NPP engineering simulator is applied as another effective approach of V&V. For this purpose, a virtual NPP thermal-hydraulic model is established as a basis according to Ling Ao Phase II NPP design, and the NPP simulation tools can provide plant operation parameters to DCS, accept control signal from I&C and give response. During the test, one set of data acquisition equipments are used to build a connection between the engineering simulator (software) and SIEMENS DCS I/O cabinet (hardware). In this emulation, original diagram configuration in DCS and field hardware structures are kept unchanged. In this way, firstly judging whether there are some problems by observing the input and output of DCS without knowing the internal configuration. Then secondly, problems can be found and corrected by understanding and checking the exact and complex configuration in detail. At last, the correctness and functionality of the control system are verified. This method is also very convenient for expansion to other type digital I&C V&V. This paper is mainly focused on V&V of closed-loop control systems in full-scope DCS and several detailed reactor control (RRC) systems, including pressurizer pressure and water level control, steam generator water level control. The V&V works were carried out by applying engineering simulator. This paper describes the structure and function of the simulator, V&V procedure, results analysis and problems identified. Through the actual on-line virtual closed-loop testing on Ling Ao Phase II NPP project, many problems of DCS configuration were found and solved. And it proved that V&V based on engineering simulator enables significant time saving, improves economics and safety in the phase of engineering debugging. [Copyright &y& Elsevier]

Abstract: Wind energy is an important renewable energy source because of its reliability due to the maturity of the technology, good infrastructure and relative cost competitiveness. Rich wind resources and strong support in regulations by the Chinese government have enabled the wind power industry to grow at a fast speed and the primary market scale has been achieved, making it the second largest wind power market in the world. There has also been an increase in wind energy research in various regions in China during the last few years. As utility-size wind turbines increase in size, and correspondingly their initial capital investment cost, there is an increasing need to monitor the health of these structures. However, most of the research papers in China are about the manufacture and production, such as the simulation of the wind turbine generator system model, the systematic resonance and stability for the world turbine, the wind speed, wind power and pitch adjustment simulation model, and so on. Few papers focus on the structural health monitoring (SHM) techniques of the wind turbine. In this paper, we review the status of the current SHM techniques in wind turbine and analyze the problems of them in China. The aims of this paper are to let more scholars and experts know the status of the current SHM techniques and to do something for building a successful industry in China. [Copyright &y& Elsevier]

Abstract: This paper presents an investigation of the natural ventilation cooling potential (NVCP) of office buildings in the five generally recognised climate zones in China using the Thermal Resistance Ventilation (TRV) model, which is a simplified, coupled, thermal and airflow model. The acceptable operative temperature for naturally conditioned space supplied by the ASHARE Standard 55-2004 has been used for the comfort temperature setting. Dynamic simulations for a typical office room in the five representative cities, which are Harbin, Beijing, Shanghai, Kunming and Guangzhou, have been carried out. The study demonstrates that the NVCP depends on the multiple impacts of climate, the building''s thermal characteristics, internal gains, ventilation profiles and regimes. The work shows how the simplified method can be used to generate detailed, indoor, operative temperature data based on the various building conditions and control profiles which are used to investigate the NVCP at the strategic design stage. The simulation results presented in this paper can be used as a reference guideline for natural ventilation design in China. [Copyright &y& Elsevier]

Abstract: With the start up of West–East Natural Gas Transmission Project, the construction of natural gas-pipeline will enter on a new era in China. The development tendency will be towards large-diameter, high-pressure and long-distance for natural gas-pipelines. Correspondingly, the life cycle cost of natural gas-pipeline networks is increasing gradually. The mainline system is a vital part of natural gas network systems. The investment required for the mainline system is enormous, usually accounting for 80% of the total investment for this system. In general, the investment required for a gas-pipeline depends on its operating parameters. Therefore, based on the characteristics of gas networks, optimization for investment becomes indispensable to gas networks design. A comprehensive and optimal mathematic model of a gas networks system is established in this paper which considers all the factors influencing the total investment of a gas networks system (e.g. pipe diameter, thickness, pressure, length, compression ratio, etc). From the standpoint of the characteristics of a model comprising both continuous and discrete variables, a new methodology, rank-optimization, is presented. On the basis of this model, a simple and visual high-pressure networks optimization program has been compiled. Furthermore, the developed optimization program has been applied to a practical project and the effects of operating parameters on the total investment have been analyzed. The simulation model in this paper is shown to be an effective method to solve optimization on mainline system in high-pressure gas networks. [Copyright &y& Elsevier]

[Display omitted] • China's water footprint (WF) under the SSP-RCP scenario was predicted dynamically. • A new attempt to combine the system dynamic (SD) model with SSP-RCP was made. • The grey WF decreases significantly under all scenarios during the forecast year. • The agricultural WF is the main contributor to China's water footprint. • SSP1-2.6 is the best scenario to alleviate water shortages and water pollution. Under the dual influence of socioeconomic development and climate change, water resources in China are under increasing stress. It is of great significance to comprehensively explore the changing trend of China's water footprint (WF) in the future, clarify the water resource challenges that China will face, and alleviate water shortage and water pollution problems. This paper uses System Dynamics (SD) to build a simulation model of China's WF, calculate China's WF from 2000 to 2019, and for the first time, simulate and optimize China's WF from 2020 to 2050 under the SSP-RCP scenario matrix composed of Shared Socioeconomic Pathways (SSPs) and Representative Concentration Pathways (RCPs). The results are as follows. (1) From 2000 to 2019, China's WF increased to 2009 and began to decline. The main contributors are grey WF and agricultural WF. (2) During 2020–2050, China's total WF under the SSP1-2.6 scenario will always be at the lowest; compared with other scenarios, the simulation result of China's total WF under the SSP2-4.5 scenario is the closest to the actual situation in China in 2020, 2021 and 2022. China's total WF under the SSP4-6.0 scenario is close to that under the SSP2-4.5 scenario, but the numerical variation characteristics of the WF composition are different. China's total WF under the SSP3-7.0 and SSP5-8.5 scenarios is high. (3) Based on the changes in WF and water resources supply/demand ratio under different scenarios, the SSP1-2.6 scenario is the best scenario to mitigate a future water shortage and water pollution in China. The research results can help decision-makers formulate relevant management policies and socioeconomic development models for water resource utilization and provide decision support for alleviating water shortages and water pollution in China. [ABSTRACT FROM AUTHOR]

The paper presents simulation results of an inland container vessel designed to be operated in the inland waters of China. Initially, calm water simulations are performed in open water with varying draft and speed to determine the possible propulsion power required by the vessel for regular operations. Next, static drift simulations are performed with a heave and pitch-free motion at varying drift angles and drafts. Encountered hull resistance and linear derivatives are determined from the drift results to assess the vessel's maneuvering capabilities. Finally, simulations are performed in restricted water following possible operating channel geometry to assess the vessel's performance in restricted operating conditions. The required propulsion power of the vessel has been calculated for each case and compared. Cases that showed maximum resistance was re-stimulated in full scale to discard the scaling effect from predictions. The results show that a significant increase in resistance is observed when the vessel operates in shallow and narrow channels, which limits its possible operating speed. The study concludes that model-scale simulations are efficient for preliminary studies. However, for the required power prediction, full-scale simulations should be considered. • The paper presents simulation results of an inland container vessel designed to be operated in the inland waters of China. • Calm water simulations are performed in open water with varying draft and speed to determine the propulsion power required. • Static drift simulations are performed with a heave and pitch-free motion at varying drift angles and drafts. • Hull resistance and linear derivatives are determined from the drift results to assess the manoeuvring capabilities. • Simulations are performed in restricted water following possible operating channel geometry. [ABSTRACT FROM AUTHOR]

Coal-fired generation units in China often operate under off-design loads. The off-design performance has important influence on operation energy consumption of generation units. An all-condition model is of critical importance for studying the off-design performance. In this paper, an all-condition simulation model of the steam turbine system for a 600 MW generation unit is built. Based on the actual system composition, the steam turbine system is divided into several sub equipment. A sub model is established for each device. In the turbine model, a parameter M is defined as the intermediate variable to calculate the extraction pressure of turbine. The operating data from a 600 MW generation unit are used to verify the all-condition model. The heater fouling conditions are also calculated. The result shows that the model successfully predicts the operation parameters under different loads and forecasts the thermal performance of typical equipment failure. [ABSTRACT FROM AUTHOR]

Photovoltaic shading systems which can act as power generators and external shading devices in buildings have been widely used in recent years. In order to obtain the optimum tilt angles of photovoltaic shading systems in China, this paper develops a simulation model for PV shading systems based on EnergyPlus. Five cities, viz. Harbin, Beijing, Changsha, Kunming, and Guangzhou, are selected as representative cities for different climatic regions in this study. The annual and monthly optimum tilt angles of PV shading systems are investigated and analyzed for maximizing electricity generation and minimizing net energy consumption. The results show that PV shading panels installed with monthly optimum tilt angles are superior to those installed with annual optimum tilt angles. Moreover, PV panels mounted in the south orientation have larger energy-saving potential than those mounted in the east and west for all climatic regions. The conclusions of this study provide a theoretical basis for PV shading systems’ design and installation. [ABSTRACT FROM AUTHOR]

Based on a public building in China, this paper built a benchmark model and analyzed the influence of main thermal performance of building envelopes on energy consumption in different climatic regions by EnergyPlus. The results showed that in the order of hot summer and warm winter region, hot summer and cold winter region, cold region, severe cold region, the energy-saving effect was getting better and better with the increase of roof insulation, exterior wall insulation and exterior window insulation. If SHGC of exterior window was reduced, building energy consumption decreased in hot summer and warm winter region, hot summer and cold winter region, but it increased in cold region and severe cold region. For hot summer and warm winter region, hot summer and cold winter region, the factors that affected energy consumption was as follows: SHGC > K win > K wal > K ro, for cold region and severe cold region, it was as follows: K win > K wal > SHGC > K ro . [ABSTRACT FROM AUTHOR]

In recent years, Beijing rural “coal to electricity” is more and more attention. Among them, the air source heat pump as a clean energy is vigorously promoted, but due to of its low water supply temperature. So, for what kind of terminal equipment need to be researched. In this paper, the two terminal equipment of PE-X pipe are adopted as the low-temperature floor radiant heating and four-post 760 cast iron radiator in the bedroom of a Beijing farmhouse are simulated. The performance of two kinds of terminal equipment is analyzed from four aspects: indoor temperature field distribution, indoor air cleanliness, indoor air velocity distribution and energy consumption. The commercial CFD software was used to simulate the characteristics of two heating terminal equipment. The simulation results show that PE-X pipes as the low-temperature floor radiant heating is better than that the four-post 760 cast iron radiator heating, it has good heating effect. [ABSTRACT FROM AUTHOR]

Although microclimate effects of the urban fabric and the urban green are known, they are rarely considered in energy performance studies of buildings in their specific context. The microclimate in the urban environment is effective on human well-being and on the energy demand of buildings. Especially the temperatures surrounding buildings in summer and, in case these buildings are air conditioned, the resulting energy demand for cooling are effected. However microclimatic design strategies are evaluated (if at all) qualitatively or based on short periods of ‘representative conditions’, while thermal building simulation studies are usually performed with climate datasets from weather stations remote from the real urban context. This paper introduces and applies an algorithm to translate available EPW climate data into annual climate datasets containing urban microclimate effects of the specific location through multiple application of the microclimate simulation model ENVI-met. The resulting annual microclimate information is able to be applied in thermal simulation studies with TRNSYS to determine the course of the temperatures in a building over the year as well as the resulting annual cooling demand. 56 detailed 24h-simulation runs are performed to represent the climatic conditions each week of the year and four additional extreme climate situations. From the results of these ENVI-met calculations an 8760h-dataset is constructed as input for an annual thermal simulation study. The algorithm has been tested for 26 locations in China through comparison of the original dataset with a model representing a ‘neutral’ site environment for calibration. It then has been applied for urban context models with green coverage. Differences in maximum temperatures as well as the impact of the urban context on the annual cooling demand are reported for the 26 locations. From these results also the CO2-emission reduction potentials are calculated. [ABSTRACT FROM AUTHOR]

Social economy of China has been rapidly developing for more than 30 years with efficient reforms and policies being issued. Societal developments have resulted in a greater use of many natural resources to the extent that the ecosystem can no longer self-regulate, thus severely damaging the balance of the ecosystem itself. This in turn has led to a deterioration in people's living environments. Our research is based on a combination of climate scenarios presented in the fifth report of the Intergovernmental Panel on Climate Change (IPCC) and policy scenarios, including the one-child policy and carbon tax policy. We adopted Land Change Modeler of IDRISI software to simulate and analyze land-use change under 16 future scenarios in 2050. Carbon sequestration, soil conservation and water yields were quantified, based on those land-use maps and different ecosystem models. We also analyzed trade-offs and synergy among each ecosystem service and discussed why those interactions happened. The results show that: (1) Global climate change has a strong influence on future changes in land-use. (2) Carbon sequestration, water yield and soil conservation have a mutual relationship in the Guanzhong-Tianshui economic region. (3) Climate change and implementation of policy have a conspicuous impact on the changes in ecosystem services in the Guanzhong-Tianshui economic region. This paper can be used as a reference for further related research, and provide a reliable basis for achieving the sustainable development of the ecosystem. [ABSTRACT FROM AUTHOR]

Successful policy-making for an emerging industry relies on two key factors: adopting a scientific perspective and accurately forecasting the policy's potential effects. By combining Mitchell's score-based approach and expert grading method, this paper identifies the key stakeholders of the Chinese electric vehicle (EV) industry, and proposes a key stakeholder-based policy research framework (G-MIC: Government — Manufacturers, Infrastructure, Consumers). Furthermore, a system dynamics (SD) model is outlined, focusing on financial subsidy (FS) policy and the three groups of programs that are set to simulate level of FS, FS allocation, and the demand for realizing the CAO (Civilian Auto Ownership) goal of the Chinese EV industry by 2020. The findings reveal that the following show that a key stakeholder perspective is a better approach to policy research; the SD model constructed under the G-MIC framework extends the methodology of SD; and a “bottom-up” policy-making path is more likely to improve policy outcomes. [ABSTRACT FROM AUTHOR]

This paper employs complex network theory to assess the structural vulnerability of high speed railway networks subjected to two different malicious attacks. Chinese, US and Japanese high speed railway networks are used to discuss the vulnerable characteristics of systems. We find that high speed railway networks are very fragile when suffering serious disturbances and two attack rules can cause analogous damages to one high speed railway network, which illustrates that the station with large degree possesses high betweenness, vice versa. Meanwhile, we discover that Japanese high speed railway network has the best global connectivity, but Chinese high speed railway network has the best local connectivity and possesses the largest transport capacity. Moreover, we find that there exist several redundant paths in Chinese high speed railway network and discover the critical stations of three HSRNs. Furthermore, the nearest-link method is adopted to implement topological interventions and to improve the connectivity and reliability of high speed railway networks. In addition, the feasibility and effectiveness of topological interventions are shown by simulations. [ABSTRACT FROM AUTHOR]

A bottom-up subnational physics-based model has been developed in this paper to estimate the residential heating energy consumption in China's Hot Summer–Cold Winter climate region. This model is constituted of data collecting module, core calculation module (including occupant behavior modeling component, building simulation component and aggregation component), calibration module and prediction module. In order to investigate occupant heating behaviors in this area, a field measurement and questionnaire survey has been carried out. This model is validated by comparing the modeled heating energy consumption with the investigated. It is calculated that currently the residential heating energy usage is 9.8 kWh/m 2 and is predicted to rise by 31% due to the increase of residents’ expectation for indoor environment. Sensitivity analysis shows that residential heating energy consumption is significantly influenced by heating triggering/set-point temperature. The households with the retired consume averagely 47% more heating energy than those without the retired. [ABSTRACT FROM AUTHOR]

This paper presents a holistic approach for safety and protection of historical buildings adjacent to tunneling excavation. A finite element model is built to simulate the impact of tunneling excavation on the distribution of structural stress of historical buildings, in order to determine stress concentration regions in materials and structures subjected to forces or loads. Some corresponding reinforcement measures are proposed according to simulative results, aiming to improve its structural integrity and rigidity of historical buildings to satisfy the load-bearing requirements prior to construction. The effectiveness of the adoption of reinforcement measures against tunnel-induced building damage is validated using a two-stage numerical simulation process, where the impact of the tunneling excavation on the deformation of surrounding soils and building foundations is simulated separately, given the reinforcement measures are implemented. A case in relating to the protection of a historical building of Roots’ formal residence (RFR) adjacent to the construction of a twin tunnel, Wuhan Yangtze River Tunnel (WYRT) in China, is presented, where the tunnel in the east line passes under the foundation of RFR, and the nearest receiving shaft foundation in the west line is only 1.4 m away from the building foundation edge of RFR. Results demonstrate the feasibility of the proposed approach, as well as its application potential. The proposed approach can be used as a decision tool to provide some positive guidelines on the protection of historical buildings, and thus increase the likelihood of a successful project in tunneling environments. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive analysis of the Schumann resonance (SR) parameters observed at low latitude stations in China for the first time. Variations of SR peak frequency and intensity on different timescales (from minutes to years) are analyzed in detail. Diurnal and seasonal variations are shown and the source-observer distance is calculated to confirm the contributions of lightning activity. Differences in the profiles of SR intensity between the NS and EW components are due to the effects of the source-observer distance and the relative position of the observer to the sources. Diurnal frequency variations are more complicated and cannot be directly linked with the three thunderstorm centers. Seasonal variations are clear for intensity but not for frequency. The differences in the diurnal and seasonal variations between the SR intensity and frequency show that the greatest contributor to SR intensity is global lightning activity, while the SR frequency is not affected solely by lightning, as certain other factors involving ionosphere properties may play non-negligible roles. We also emphasize that our observations do not show a distinct day–night change in the SR parameters, and that the SR intensity does not show abrupt changes across terminators. This observation is consistent with previous simulations. Finally, the response of the SR to a solar flare is discussed. The flare leads to a sudden increase of about 0.2 Hz relative to the 2 σ level of the SR frequencies in the first three modes, which is in agreement with other works in the literature. This frequency enhancement is explained using theoretical calculations. [ABSTRACT FROM AUTHOR]

The current refueling system of China Lead-based Research Reactor (CLEAR-I) is still in the developing stage and requires frequent changes of the refueling design scenarios. This paper presents a virtual simulation prototype which contributes to the complex refueling system for CLEAR-I. The proposed simulation system focuses on utilizing a desktop virtual environment to simulate the complex mechanical movement of triple crank connecting rod mechanism which consists of large rotating plug, small rotating plug and transfer machine. Main features of the proposed simulation system are: (1) automatic refueling scene modeling, (2) XML-based management for refueling scenario, (3) motion simulation and collision detection, (4) record and evaluation of refueling simulation process. The system architecture, features and capabilities of the developed virtual simulation prototype system were described. And the refueling simulation tests were carried out in order to meet the frequently updated engineering design for refueling scenarios of CLEAR-I. [ABSTRACT FROM AUTHOR]

China’s photovoltaic industry developed sharply, and now it is the only country whose production covers the installed. Since R&D policy and deployment policy of China’s PV industry should not increase its production, this paper focuses on impact of investment policy, regarded as subsidy, on the photovoltaic industry. Feedback model of China’s photovoltaic industry is built, and the parameters of the model were estimated. And then simulation is done based on the model. The results show that the expansion is mainly caused by overreaction to the potential of the industry, but not the investment policy. In fact, investment policy only causes price fluctuations and industry overcapacity to some extent. Therefore, China’s investment policy on PV industry investment should be reduced properly or even canceled, or at least it should be combined with deployment and R&D. [ABSTRACT FROM AUTHOR]

The top-coal caving mining method, developed steadily in the past two decades, has become the main method for thick seam coal mining in China. In recent years, the core research areas in the top-coal caving mining are the mechanisms of top-coal caving and the improvement of top-coal recovery ratio. In this paper, the mechanisms of the top-coal caving are illustrated by a large number of physical simulation experiments and numerical modelings of actual cases. The marker method, which has sufficient accuracy to calculate the top-coal recovery ratio, is also described in detail. [ABSTRACT FROM AUTHOR]

Abstract: In order to simulate the wheel wear behaviour of freight cars, the rail vehicle's multi-body dynamical model and wheel wear simulation programme were combined as a wheel wear simulation tool in this paper. Multi-body dynamical models of China's heavy haul freight cars such as the C80, C80H, C70 and C70H, were built in SIMPACK software and the track system was built based on the China's Ring-line. For the wheel/rail rolling contact, the semi-Hertzian method and FASTSIM algorithm were applied to solve the normal and tangential problem respectively. The shapes of worn wheel profiles in the simulation agree well with the field measurements, but wear rates from the simulation are larger than those found in field measurements. This discrepancy is contributed to two factors. The first factor is the wheel material. The CL60 wheel steel used in China's freight car, is harder than the BS11 wheel steel used in Zobory's wheel/rail wear experiments. The second factor is the impact of a material's elastic shear deformation on the slip velocity in contact patch. This impact will increase the wear rate and was considered in the present wear simulation. [Copyright &y& Elsevier]

Abstract: Green roofs could act as a thermal buffer in buildings and offer potential energy savings. However, the energy benefits from green roofs are not usually properly recognised by traditional building energy regulations. Building energy regulations are traditionally over-simplistic during the assessment of the energy performance of complex building constructions. In the case of green roof designs, it is essential that the assessment mechanisms should not ignore the complex heat and moisture balances within the green roof layers. In this paper, dynamic energy modelling that considers the complexity within the green roof layers is adopted to guide policy makers in China on the relationship between using specific thicknesses of roof insulation against green roof layers. Simulations are run for a residential building type by also considering different thermal envelope characteristics across eight large Chinese cities and within the five main climatic zones of China. Results that link the green roof characteristics with respective traditional insulation layers are produced for all cities and it is found that optimising the plant and soil characteristics of green roofs in some climates could substitute more than 125 mm of roof insulation, while less optimum green roof types could only replace about 25 mm of roof insulation. [Copyright &y& Elsevier]

Abstract: In order to analyze the dynamic evolutionary process of Chinese emerging housing market, the paper defines the behavioral functions of household agents in terms of demand generation, information search and price negotiation, and incorporates multi-agent technique and geographic information system to conduct a series of simulation studies on Beijing housing market. By setting different market scenarios, the impacts of new housing supply and information level on Beijing housing market are addressed. The findings show that, Beijing housing market is characterized by the prominent urban expansion with the formation of consolidated residential zones outside the 5th ring road; the growth in new housing supply can reduce the buyer search duration significantly, and lead the buyer search flow to the new housing market; higher information level can increase the sales of resale housing market, but inhibit the sales and time on market for new-built houses to some extent. [Copyright &y& Elsevier]

Abstract: This paper assesses the impact of climate change on China''s agricultural production at a cross-provincial level using the Ricardian approach, incorporating a multilevel model with farm-level group data. The farm-level group data includes 13,379 farm households, across 316 villages, distributed in 31 provinces. The empirical results show that, firstly, the marginal effects and elasticities of net crop revenue per hectare with respect to climate factors indicated that the annual impact of temperature on net crop revenue per hectare was positive, and the effect of increased precipitation was negative when looking at the national totals; secondly, the total impact of simulated climate change scenarios on net crop revenues per hectare at a Chinese national total level, was an increase of between 79 USD per hectare and 207 USD per hectare for the 2050s, and an increase from 140 USD per hectare to 355 USD per hectare for the 2080s. As a result, climate change may create a potential advantage for the development of Chinese agriculture, rather than a risk, especially for agriculture in the provinces of the Northeast, Northwest and North regions. However, the increased precipitation can lead to a loss of net crop revenue per hectare, especially for the provinces of the Southwest, Northwest, North and Northeast regions. [Copyright &y& Elsevier]

Abstract: Urban growth boundaries (UGBs) have been extensively studied and applied in the USA as an effective tool to curb urban sprawl. The “People’s Republic of China Town and Country Planning Act” requires the establishment of urban construction boundaries (UCBs) in Chinese city master and detail plans. We consider planned UCBs in China to be Chinese UGBs, as they have similar implementation mechanisms to their counterparts in the USA. However, different from UGBs in the USA, Chinese UGBs often resemble “artwork” by urban designers. Accordingly, they lack sound analytical basis and fail to sufficiently accommodate market mechanisms of land use. When measured by the criterion that the UGB should result in a spatial pattern that corresponds to its map, the Chinese UGBs are not well implemented. In this paper, we propose a method to support establishing UGBs through constrained cellular automata (CA). Our approach takes into account influence factors related to urban growth and generates UGBs based on spatiotemporally dynamic simulations. This method is applied to establish UGBs for the central city, new cities and small towns in the Beijing Metropolitan Area. The results indicate that there are significant differences between the UGBs based on constrained CA simulations and those in the previously established city master plan. We argue that our method could be a helpful planning tool for the establishment of UGBs in Chinese cities. [Copyright &y& Elsevier]

Abstract: Pisha Sandstone area is located in an adjacent region close to Inner Mongolia Autonomous Region, Shaanxi and Shanxi province of northwestern China, which covers an area of more than 11,000km2. Pisha Sandstone is a kind of loosely bonded sandstone formed during the tertiary period. It is very hard when it is dry but becomes loose when wet. Due to the nature of that, this area of northwestern China is plagued with a high erosion rate (over 20,000tkm−2 yr−1) as well as poor vegetation. In order to reforest gullies and to control erosion in this area, the seabuckthorn flexible dam that is actually a new biological measure focused on by many people was successfully used to reduce the erosion rate of the area. This paper aims at the identification and/or determination of the major impact factors which essentially influence the sediment retention effects of the seabuckthorn flexible dam. Firstly, the sediment retention effects of the single seabuckthorn flexible dam were simulated using one-dimensional sediment-flow model in this study. Then, based on the computational results, two major impact factors, i.e. roughness and dam length of the seabuckthorn flexible dam, were found. Finally, according to the sediment retention effects under various roughness and dam lengths condition, a series of the suitable length ranges of the seabuckthorn flexible dam were given in corresponding to a series of the seabuckthorn flexible dam''s roughness. The results show that the seabuckthorn flexible dam can strikingly and effectively reduce sediment loss from the gully. An emphasis is placed on widely spreading and planting of the seabuckthorn flexible dam in the Pisha Sandstone area in the future to prevent soil and water loss and to achieve at least good ecological status. [Copyright &y& Elsevier]

Abstract: The Geographic Information System (GIS) has been extensively integrated into hydrology and non-point source (H/NPS) pollution modeling. However, few studies have been carried out on the effect of GIS inputs on NPS modeling and the prediction uncertainty related to the combination of different GIS inputs. In this paper, the effect of GIS data on H/NPS simulation was investigated by re-sampling the initial GIS data into new grid sizes and grouping the available GIS maps in all possible ways. The effect of GIS inputs was then quantified by the Soil and Water Assessment Tool (SWAT) in the Daning watershed, China. Based on the results, the GIS inputs had a limited impact on runoff and nitrogen (N) predictions, while sediment and phosphorus (P) simulations were sensitively biased by GIS data. This study further demonstrated that a level (threshold) of GIS resolution existed, within which more precise data would not be of benefit to SWAT prediction. To reduce prediction uncertainty, the digital elevation model (DEM) should be tackled to determine at which resolution the model would perform optimally. [Copyright &y& Elsevier]

Abstract: Because of the complexity of urban systems, the dynamic process of urban expansion is filled with uncertainty. Although many studies have been done on cellular automata (CA)-based urban expansion models, the measurements of uncertainties and uncertainty propagation were commonly neglected when constructing CA models. The cloud model can express uncertainty and its propagation, and coherently integrates fuzziness and randomness as well as overcoming the limitations of fuzzy theory and the Monte Carlo method. A cloud-based CA (cloud-CA) model is presented in this paper to represent uncertainty propagation and show the dependence of simulation results on different degrees of uncertainty represented by hyper-entropy (He). We implemented the cloud-CA model and applied it on the simulation of the urban expansion in Jiangxia, Wuhan, China. After constructing the appropriate parameter settings for the cloud-CA model, a comparison of cloud-CA with the fuzzy-set-based CA (fuzzy-CA) model, and the hybrid CA model based on fuzzy set and the Monte Carlo method (FSMC-CA) was made by simulating spatial patterns of urban growth in Jiangxia from 2002 to 2007. The experiment indicated that the cloud-CA model has a better performance than the other two CA models, with higher kappa indices and figure of merit, proving the effectiveness of the cloud-CA model. [Copyright &y& Elsevier]

Abstract: Beijing has a unique spatial pattern that is characterized by an inverted U-shape building height curve and geometrically developed transportation network (rings of highways and axial roads). The inverted U-shape curve of building heights is mainly the outcome of building height restrictions in inner city for historical preservation. This paper estimates the economic costs of the building height restrictions by using land development data. Through comparing land development without building height restrictions and simulations, we show that the economic costs are substantial. The impacts of the building height restrictions include land price decrease by up to 60%, housing output decrease by up to 70%, and land investment decrease by 85%. To accommodate the loss of housing output, the city edge has to expand, causing urban sprawl (given all other things equal). In order to offset building space reduction, housing prices rise by 20% and the city edge expands by 12%. Finally, induced travel costs resulting from urban sprawl and low density caused by building height restrictions may not be trivial. [Copyright &y& Elsevier]

Abstract: The performance evaluation and analysis of PF5 conductor of the ITER Project in China have been performed using the Gandalf code (Bottura [1]). This study focuses on the T cs and MQE of PF5 conductor with Cu–non Cu ratio of 2.3 NbTi strands from WST. The PF5 conductor samples have been measured in SULTAN at CRPP for evaluating the performance successfully. The measurement results are also presented with the evaluation results in the paper. The evaluation results related to T cs and MQE are agreed well with the measurement results. The simulation with Gandalf code can predict the performance of PF5 conductor effectively and provide the helpful method for ITER conductor design and analysis. [Copyright &y& Elsevier]

Abstract: The Qinghai–Tibet Railway (QTR), the longest high-altitude railway in the world, is frequently damaged by windblown sand because of strong winds and abundant sand. Based on detailed wind data, in situ observations of windblown sand and field wind tunnel simulations along the QTR, this paper aims to clarify the characteristics of windblown sand with increasing altitude, and to show the dynamical environment of sand activities. The predominant wind is unidirectional along the QTR. In cold-high environments, sand transport rate increases with increasing wind velocity, but decreases exponentially with increasing height in the windstream. As the altitude increases, the threshold velocity for sand movement linearly increases with altitude, and the sand transport per unit width decreases gradually. The results can be used to guide the design of sand-control structures both in the study area and in other areas suffering from windblown sand. [Copyright &y& Elsevier]

Abstract: The performance of Power System Stabilizer (PSS) strongly depends on its parameters. For fast-changing power systems, some well-tuned PSSs might not provide the expected damping performance after great changes in system structure and operating mode. Therefore, these PSSs need to be tuned again. However, considering the system stability issue, a PSS should not be taken offline once it has been put into service in actual power systems. Under that situation, if a PSS needs to be re-tuned, existing tuning methods cannot be applied since the phase compensation cannot be measured conveniently or even calculated with the PSS in service. This paper proposes a novel PSS-online re-tuning method in order to solve this problem, using local local phasor measurement unit (PMU) measurements. The system closed-loop transfer function (CTF) taking PSS as feedback compensation is identified using the standard Prony analysis. Then, the open-loop transfer function (OTF), which is essentially required for determining PSS parameters, is calculated based on the CTF identification result. The performance of this online re-tuning method is verified by a simulation study of a typical 2-area system. The priority research is also addressed in the same simulation study. Finally, this online-method has been applied to GuiZhou Power Grid (GZPG), which is a provincial grid located in Southwest China. The results from both simulations and field tests in GZPG demonstrate that this online re-tuning method is effective and can be applied to interconnected grids. [Copyright &y& Elsevier]