摘要：
地聚物是通过化学激发生成的具有低碳属性的新型胶凝材料, 具有部分取代水泥的巨大潜力。本文通过压汞试验表征了偏高岭土-矿渣地聚物净浆及砂浆的孔隙结构, 分析了液固比、砂体积分数等因素对孔结构特性的影响, 明确了孔结构特性与面分形维数的相关性。采用氯离子非稳态电迁移试验、非稳态自然扩散试验和水分扩散试验, 研究了偏高岭土-矿渣地聚物净浆与砂浆的抗渗透性能, 分析了液固比、砂体积分数及孔面分形维数与浆体介质传输性能的相关性。结果表明: 随着液固比增大, 地聚物净浆的孔隙率和最可几孔径均增大, 抗渗透性能降低; 地聚物砂浆的抗渗透性能优于水泥砂浆, 砂体积分数增加时, 地聚物砂浆的最可几孔径和介质传输系数均先减小后增大, 抗渗透性能先增强后减弱; 孔面分形维数能较好地表征地聚物浆体孔结构特性, 并与抗渗透性能相关性良好。 Geopolymer is a novel cementitious material with low carbon properties produced by chemical activation, which has great potential to partially replace cement. The pore structure of metakaolin-slag geopolymer paste and mortar was characterized by mercury intrusion porosimetry tests. The effects of liquid-solid ratio and sand volume fraction on pore structure properties were analyzed, the correlation between pore structure properties and surface fractal dimension was clarified, and the permeability resistance of metakaolin-slag geopolymer paste and mortar was investigated using chloride unsteady electromigration test, unsteady natural diffusion test and moisture diffusion test. The correlation between liquid-solid ratio, sand volume fraction, pore surface fractal dimension, and slurry media transport performance was analyzed. The results show that with the increase of liquid-solid ratio, the porosity and the most available pore size of geopolymer paste increase and the permeability resistance decreases. The permeability resistance of geopolymer mortar is superior to that of cement mortar. The most available pore size and media transfer coefficient of geopolymer mortar decrease first and then increase with the increase of sand volume fraction, and the permeability resistance increases first and then decreases. Furthermore, the pore surface fractal dimension can well characterize the pore structure properties of geopolymer slurry and has a good correlation with permeability resistance.
期刊：
Advances in Transportation Studies,2023年1(Special Issue):111-122 ISSN：1824-5463
通讯作者：
He, C.
作者机构：
[Xiong H.H.] School of Architecture and Urban planning, Hunan City University, Yiyang, 413000, China;Department of Architecture and Art, Central south University, Changsha, 410012, China;[He C.] School of Architecture, Changsha University of Science and Technology, Changsha, 410114, China;[Dissanayake S.] College of Engineering, Kansas State University, Manhattan, KS 66506, United States;[Jiang J.S.] School of Architecture and Urban planning, Hunan City University, Yiyang, 413000, China, Department of Architecture and Art, Central south University, Changsha, 410012, China
通讯机构：
[He, C.] S;School of Architecture, China
关键词：
balanced distribution;fuzzy ant colony algorithm;mixed traffic flow;urban roads
关键词：
Sustainable urban management;Digital twin;Solar and wind renewable energy resources;Time-of-use;Microgrid
摘要：
This paper proposes a sustainable energy management method for microgrids (MGs) in the urban area while taking into account energy storage systems (ESSs) and renewable energy (RE). This study integrates RE, such as solar and wind energy production, into the power grid, and formulates the optimum dispatch scheme of hybrid energy production, based on ESS charge and discharge planning using their digital models. Electricity is exchanged among the MG systems and the utilities on a daily basis. MG systems' cost-effective dispatch per day is solved by an improved pigeon-inspired optimization algorithm (IPIOA) considering the time-of-use (TOU) and other technical limitations. IPIOA can be modified in various ways for finding possible spaces with greater efficiency. This study uses IPIOA to manage power costs economically for Islanding and non-Islanding cases and compares the outcomes with other methods. Additionally, it uses micro-turbines as well as REs, ESSs, and Islanding and non-Islanding cases to schedule MGs optimally. In comparison to a number of existing algorithms, the new approach has proven to be more robust, reliable, and efficient.
期刊：
Journal of Cleaner Production,2023年413:137467 ISSN：0959-6526
通讯作者：
Zou, F
作者机构：
[Long, Meiqin; Zou, Fang] Changsha Univ Sci & Technol, Sch Architecture, Changsha, Peoples R China.;[Che, Erzhuo] Oregon State Univ, Sch Civil & Construction Engn, Corvallis, OR USA.
通讯机构：
[Zou, F ] C;Changsha Univ Sci & Technol, Sch Architecture, Changsha, Peoples R China.
关键词：
Geological hazard risk assessment;Hazard indexes;Mountainous areas
摘要：
To prevent and control geological hazards (geohazards), the intensity of geohazards compared to the frequency is more important in geohazard risk assessment. This has mostly been overlooked in previous studies. To address this deficiency, this study established different hazard indexes to comprehensively and quantitatively express the risks of geohazards. Moreover, human factors and anthropogenic activities characteristic of mountainous areas have been introduced into geohazard evaluation by different spatial autoregression models through a case study. The case is reported as follows: (1) Different hazard indexes can fully express the location, frequency and in-tensity of geohazards. (2) Areas with high incidence and high intensity of geohazards can be accurately identified in the case study area with an accuracy of 0.829 and 0.730, respectively. (3) Regions with the highest-risk and high-risk intensity and the highest-risk and high-risk frequency are not spatially consistent, accounting for 15.16% and 0.57% of the case areas, respectively. The hazard indexes developed in this work have the potential to increase comprehensive geohazard risk identification while also providing scientific support for hazard pre-vention and mitigation.
通讯机构：
[Li, C ] C;Cent South Univ, Sch Civil Engn, Changsha, Hunan, Peoples R China.
关键词：
Seismic metamaterial;Tuning fork;Finite element method;Surface waves
摘要：
BackgroundThe development of seismic metamaterials provides new inspiration for controlling the propagation of seismic waves. The unit cell of seismic metamaterials is generally designed as a column structure with a uniform cross-section. However, such column structure requires a large amount of rigid material to generate broadband band gaps in the low-frequency range.ObjectiveA novel tuning fork-shaped seismic metamaterial has been proposed for the utilization of the peculiar vibration modes of the tuning fork structure as the locally resonant to the dissipation of seismic energy.MethodsThe finite element method was applied to calculate the eigenmodes and the seismic shield effects in the commercial software COMSOL Multiphysics.ResultsThe types of eigenmodes with respect to the tuning fork structure have been determined, especially the special eigenmodes different from the traditional column structure. Through the parametric analysis, the vibration frequency of the tuning fork has been optimized to match the primary frequency of the seismic surface wave for enhancing the seismic energy dissipation. Finally, a numerical investigation of the seismic surface wave propagation through an array of tuning fork unit cells has been conducted to verify the seismic shield effects in band gaps.ConclusionThe proposed seismic metamaterial in the form of the optimized tuning fork structure can provide a good attenuation performance with lower steel consumption due to the locally resonant band gaps.
摘要：
A building with Trombe wall and phase change materials (PCMs) was designed, developed, tested and simulated to investigate the thermal comfort variation under various operation conditions. Eight models with different PCMs and ventilation modes were simulated and validated against experimental data. The thermal performance throughout the entire year was analyzed using indexes as integrated indoor discomfort degree-hour (IDH) and integrated indoor discomfort duration (ID). The findings indicate a strong correlation between the indoor thermal comfort and ventilation strategy, PCMs type and PCMs position. Ventilation with the presence of PCM25 at the inside layer of the Trombe wall is the most efficient approach to reduce the integrated indoor thermal discomfort degree-hour with a value of 12,857 & DEG;C & BULL;h with a penalty of longer indoor discomfort duration. However, for no ventilation condition, it is recommend to adopt the Trombe wall with PCM28 at the outside layer and PCM18 at the inside layer. The lowest integrated indoor thermal discomfort degree-hour was 13,914 & DEG;C & BULL;h. The lowest integrated indoor discomfort duration of 3009 h was obtained with the single Trombe wall without ventilation in the entire year.
作者机构：
[Chen, Mengjia; Zhang, Fupeng; Shi, Jiaqi; Ma, Qian; Liu, Simian; Shi, Lei] Cent South Univ, Sch Architecture & Art, Changsha 410075, Peoples R China.;[Chen, Mengjia; Zhang, Fupeng; Ma, Qian; Liu, Simian; Shi, Lei] Cent South Univ, Hlth Bldg Res Ctr, Changsha 410075, Peoples R China.;[Shi, Jiaqi] Changsha Univ Sci & Technol, Coll Architecture, Changsha 410076, Peoples R China.
通讯机构：
[Shi, JQ ] C;Cent South Univ, Sch Architecture & Art, Changsha 410075, Peoples R China.;Changsha Univ Sci & Technol, Coll Architecture, Changsha 410076, Peoples R China.
关键词：
residential public space;microclimate;performance-driven optimization;genetic algorithm
摘要：
Residential public spaces are closely intertwined with residents’ lives as the outdoor thermal environment significantly influences the comfort and safety of outdoor activities. However, in modern designs, factors such as forms, aesthetics and functionalities often take precedence, resulting in the neglect of the microclimate of the settlement’s public spaces. In this paper, we established a workflow of “parametric simulation-performance simulation-genetic optimization”. By employing the octopus genetic algorithm tool, we conducted experiments on a typical model and set objectives to optimize the winter sunshine duration as well as the thermal comfort during the summer and winter. The results indicated that the average value of the UTCI was optimized for both the summer and winter. This study concludes that altering the layout of public spaces is beneficial for the outdoor microclimate. Additionally, the presence of evenly distributed open node spaces throughout the settlement can improve ventilation in all areas while also protecting it against the winter cold and the dissipation of summer heat. Moreover, it is advisable to position larger public spaces, such as plazas, in the south or southeast. The number of public spaces should gradually decrease in size from the southeast to northwest as this prevents excessive cold winds from traversing in the settlement during the winter.
作者：
Zou, Fang;Jiang, Hang;Che, Erzhuo;Wang, Jianling;Wu, Xuan
期刊：
International Journal of Disaster Risk Reduction,2023年90:103665 ISSN：2212-4209
通讯作者：
Fang Zou
作者机构：
[Jiang, Hang; Zou, Fang; Wu, Xuan; Wang, Jianling] Changsha Univ Sci & Technol, Sch Architecture, Changsha, Peoples R China.;[Che, Erzhuo] Oregon State Univ, Sch Civil & Construct Engn, Corvallis, OR USA.
通讯机构：
[Fang Zou] S;School of Architecture, Changsha University of Science and Technology, Changsha, China
关键词：
Evaluation of emergency shelters;Multiple scenarios;Emergency evacuation
摘要：
Accurate evaluation of urban emergency shelters is key to improving disaster response capacity and government emergency management ability, especially in mountainous areas where disasters are common. Most existing studies focus on evaluating material aspects, such as the capacity and accessibility of emergency shelters, ignoring the impact of different scenarios in the same area such as topographic, demographic, and population spatial-temporal distribution differences. Considering the multiple scenarios factors influencing emergency shelter practice, this study constructed a validity, efficiency, and security evaluation framework which was tested in Bian-cheng, Hunan, China. A combination of qualitative multiple scenario analysis and quantitative Network Analysis method were used to portray existing emergency shelters during emergency evacuations. The important conclusions are as follows: (1) there are significant differences in the evaluation of emergency shelters in the different scenarios. Scenario I (considering terrain) and Scenario II (considering demographics) decreased the evaluation results, while Scenario III (considering time-space) increased the evaluation results. (2) All three scenarios could cause variation in the validity indicators (A) and efficiency indicators (B), but A1 were unchanged in Scenario II and B2 remained constant in Scenario III, while none of the security indicators (C) were affected except in Scenario I. (3) While different emergency shelters performed differently in different scenarios, overall ID2 performed best and ID5 performed worst. Consideration of all scenarios was clearly necessary for us to scientifically evaluate the real use of emergency shelters, which can effectively guide emergency shelter planning and thus improve the abilities of urban disaster relief.
摘要：
The use of renewable energy and storage systems in energy sharing communities relieves the strain on the grid and reduces the cost of electricity, making the design of community energy management strategies particularly important. In this paper, a shared energy storage operation strategy considering the time-of-use tariff is proposed for the grid-connected PV-BESS system of hybrid building community including factories, offices and dormitories. Aiming at maximizing the photovoltaic self-consumption ratio, minimizing the payback period and power transportation loss, the system is optimized by non-dominated sequencing genetic algorithm II to obtain the optimal battery capacity of each building under the designed strategy. The results show that when the total battery capacity of the community is determined, the photovoltaic power generation of each building and the building load are the main factors that affect the allocation of battery capacity, and the proportion of battery allocation in each building changes little when the values of other influencing parameters are changed. The photovoltaic array area of the building, the difference between peak and valley electricity price and the power input and output limits of the grid are the main factors affecting the optimal battery capacity and system performance. When the photovoltaic array area increases from 65% to 80%, the difference between peak and valley price increases from 0.52RMB/kWh to 0.82RMB/kWh, and the grid power output limit increases from 7500 kW to 9000 kW, the total optimal battery capacity is increased by 9.8%, 20%, 2.2%, the corresponding payback period is increased by 4%, 3.1%, 2%, the photovoltaic self-consumption ratio is increased by 3.3%, 1.9%, 0.2%, and the electricity transportation loss is increased by 6%, 21%, 2.4%, respectively. On the contrary, when the grid power input limit increases from 5500 kW to 7000 kW, the optimal total battery capacity, the corresponding payback period, photovoltaic self-consumption ratio, and power transport loss are reduced by 2.8%, 2.5%, 0.3% and 3.3%, respectively. This study provides theoretical guidance for community battery capacity optimization and energy scheduling design under the peak-valley policy of power grid.
