bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Simulation on goaf with different vertical distances in high-drainage roadways
Authors: Yang Rili , Cui Jianbin , Yang Fengfeng , Zhang Jufeng , Yu Lan
Published: October 2020

High drainage roadway horizon parameters not only influence goaf drainage effect, but also have effect on the air leakage field and spontaneous combustion three zones’ distribution in the goaf. Combined with mine fire-prevention and goaf spontaneous combustion three zones recognition, it was put forward to stimulate the distribution law of goaf air leakage field and spontaneous combustion three zones with fluid mechanics software FLUENT. The results showed that the width of goaf oxidization and heat accumulation zone increased with high drainage roadway vertically. Through stimulation study, it supplies a certain method to reasonablely optimizatate high drainage roadway vertical parameters, which to a great extent ensures mine safety production, fire and gas prevention.
Experimental Measurement of Thermal Conductivities in a Thin Heterogeneous Structure of Thermal Diodes
Authors: Zhou Jieyang , Wang Zhe , Wang Yun
Published: October 2020

Thermal diode has a wide application in the field of thermal management and thermal control. This article reports experimental results about measurement of the thermal conductivities of a novel thin layer (the thickness is about 0.3mm) for thermal diode applications. The layer consists printing paper, nylon mesh and liquid water, which are sealed between two pieces of aluminum, thus has a heterogeneity sublayers structure. It is shown that the thermal conductances are different in the two opposite through-plane directions. At 75 ˚C, the thermal conductivity is 0.457 W/mK in the conductive direction, more than 3 times larger than that in the opposite direction (0.133 W/mK). This phenomenon is due to the one-direction flow of working fluid. The thermal performance is dependent on the operating temperature and liquid water content in the structure.
Preparation of in-situ compatibilized PLA/starch composites and its non-isothermal pyrolysis kinetics
Authors: Chong Li , Zhiyuan Sun , Xiaohong He , Lin Peng , Jingmei Lv , Shijing Zhan , Hongbo Liu , Zhiyong Xiong , Bingzhi Guo , Zhengfu Liao , Qingze Jiao
Published: October 2020

A fully degradable PLA/starch composite was prepared by one-step in-situ compatibilization method. The effects of raw materials ratio and maleic anhydride （MAH） dosage were studied by thermogravimetric analyzer (TG) and scanning electron microscopy (SEM). The thermal stability and microstructure of the composites were investigated, and the non-isothermal thermal decomposition kinetics of the composites were discussed. The DTG results show that there are two distinct maximum decomposition rate peaks in the unmodified composites. After the MAH is added, the maximum decomposition rate peaks of the composites are close to each other. In addition, as the MAH dosage increases, the maximum rate of decomposition peak gradually shifts to a lower temperature. The SEM results show that the compatibility of the composites is improved after the addition of MAH. And both the Kissinger and Flynn-Wall-Ozawa methods are well described for the non-isothermal thermal decomposition kinetics of PLA and PLA/starch composites.
Development status and Prospect of directional hydraulic fracturing technology for coal mine roof
Authors: Liangwei LI
Published: October 2020

Aiming at the harm and control methods of thick and hard roof in coal mine, the paper firstly analyzes the advanced control methods of thick and hard roof, such as directional shaped charge blasting roof control technology, hydraulic fracturing roof control technology, abrasive water jet directional cutting roof technology, large-scale special roof cutting machine, etc Control hole fracturing, transverse slotting fracturing and longitudinal slotting fracturing are compared and analyzed; finally, the shortcomings of current research are analyzed. According to the current research results, the analysis shows that: the method of controlling roof by blasting in the future will be limited, while the method of hydraulic fracturing, especially directional hydraulic fracturing, has obvious advantages; the longitudinal slotting fracturing has the best control over fractures in the directional hydraulic fracturing technology; the guiding mechanism and fracture extension mechanism of longitudinal slotting hydraulic fracturing in thick and hard roof need to be further studied; lack of field application research and corresponding equipment development, lack of field effect evaluation method after longitudinal slotting fracturing.
Low Temperature Solar-driven Biogas Steam Reforming in a Membrane Reactor
Authors: Shen Jianqi , Yao Yali , Liu Xinying
Published: October 2020

A prototype for a low temperature solar-driven biogas steam reforming process was designed by coupling a hydrogen selective membrane reactor and linear Fresnel collector technology. To verify the prototype, the membrane reactor model was established by using ASPEN Plus and was studied using a modelled biogas in the temperature range 450 to 500oC. The methane conversion was significantly enhanced by applying the H2 selective membrane. Based on the actual Direct Normal Irradiation in South Africa, the capability of linear Fresnel collector was verified for the required heat duty in this study, which varying from 90.1 to 366.4 kW/m2. This novel work constitutes a reference study for new developments with reactor designs and solar energy application in biogas steam reforming processes.
Feasibility study of emission policy for photovoltaic integrated building microgrids
Authors: Gong Xundong , Xue Mingfeng , Yang Bo , Wang Deshun , Guo Xu , Ge Yuanfei , Zhang Xiongwen
Published: October 2020

The photovoltaics (PV) based microgrids play important role in the development of green buildings. This work investigates the effects of emission policy on the PV integrated commercial and residential building microgrids. The component sizes of microgrid are determined by simulated optimal power dispatch with an optimization algorithm based on minimizing the cost of energy (COE). The COE is computed with consideration of the capital depreciation cost, fuel cost, emissions damage cost and maintenance cost. The simulation results show that the emission policy and photovoltaic subsidy have little effect on sizing the commercial microgrid system. However, the component sizing design for residential microgrid system is sensitive to the emission policy. Increasing emission taxes and photovoltaic subsidy can effectively raise the proportion of PV in the system. The most important factor of restricting PV usage in microgrids is the cost of batteries. Increasing the battery lifetime or selecting the lower cost of battery can significantly increase the installation of PV, thus rise the green building standard.
Study on Policy and Standard System of LED Lighting Industry in EU
Authors: Ding Qing , Liang Xiuying , Chen Haihong , Liu Meng , Yang Jie
Published: October 2020

This paper introduces the policy measures, regulations and standard systems of the LED lighting industry in EU, and analyzes the role of the EU’s policy measures in promoting the level of its LED lightning technologies and accelerating the industry development, as well as the positive significance of the EU’s standards and regulations in standardizing and leading the promotion and application of LED lighting products, realization of economic and social benefits, amongst others. In this paper, it is suggested that China should further enlarge policy-based support for promotion and application of key LED lighting technologies and products, enrich and improve the standard system, strengthen the implementation of standards, and set up a benign feedback mechanism for evaluation of standards.
Experimental investigation on the effect of mixed acids etched nickel foam electrode on performance of an alkaline direct ethanol fuel cell
Authors: Zhang Jiajia , Zhang Weiqi , Xing Lei , Su Huaneng , Xu Qian
Published: October 2020

The three-dimensional porous materials represented by nickel foam have broad application prospects in the fuel cell field due to their excellent physical properties (high conductivity, high porosity and high specific surface area, etc.). However, the smooth nickel foam skeleton not only limits the loadable amount of active materials, but also reduces the utilization efficiency of loaded active materials. Therefore, increasing the roughness of the nickel foam skeleton to improve the utilization of active materials has far-reaching significance for the practical application. In this paper, we used mixed acids solution to etch the nickel foam and investigated the effect of etched nickel foam electrode on the performance of an alkaline direct ethanol fuel cell. It was found that mixed acids etching treatment can significantly improve the roughness of nickel foam skeleton and had a great influence on the ethanol oxidation half-reaction (EOR), while the effect on the single cell performance can negligible. Therefore, we believe that the pretreatment method of nickel foam has little effect on the performance of high loading actual electrode.
Feasibility analysis of clean energy power generation and heating project under BOO mode
Authors: Zhang Zengqiang , Gao Ming , Fu Gaoshan , Xu Yelin , Xin Chaoshan
Published: October 2020

Clean energy for power generation and heating is an important route for clean energy consumption in the northern regions with abundant wind and solar resources. However, in the promotion of clean heating projects, there are problems such as high investment costs and high pressure from government financial subsidies. Therefore, it is urgent to explore new economically feasible business models suitable for clean energy power generation and heating. This paper first proposes a new business model of clean energy power generation and heating under the BOO operation mode of the PPP business model. Secondly, from the perspective of investment value, the net present value method is used to analyze the economic benefits of the project, and the cash flow of the clean energy power generation and heating project is analyzed. Finally, combined with actual cases in a certain area in Xinjiang, the net present value method is used to analyze the calculation examples, verify the economic feasibility of the proposed business model, and provide guidance for the further promotion of clean energy power generation and heating projects.
A multi-optimization model for the design of hydrogen supply chains
Authors: Li Miao , Yi , Baolian , Ming Pingwen , Xing Danmin , Liu Changfu
Published: October 2020

This paper presents a multi-objective optimization models which operating as time processes (2025-2035) for the design of hydrogen supply chain. The feasibility of the models are illustrated through a detail case study of Dalian, China. Furthermore, the case is evaluated with the total daily costs and CO2 emissions reduction constraints. The results show that with the increase of hydrogen demand, considering the environmental factors, SMR are mostly applied in hydrogen production link. Shahekou and Pulandian grids are suitable for the constructions of hydrogen production units. Tank trucks are the main modes of hydrogen transportation. The proposed design models can provide policy-makers with the selection of infrastructures pathways for strategic dynamic hydrogen development planning.
Two-population Asymmetric Evolutionary Game Dynamics-based Decision-making Behavior Analysis for A Supply-side Electric Power Bidding Market
Authors: Zeng Kaiwen , Cheng Lefeng , Liu Jianing , Wang Haizhu , Yu Tao
Published: October 2020

This paper systematically discusses two-population asymmetric evolutionary games (2PAEGs) from the perspective of decision-making behavior characteristics, and applies these game models to a two-population supply-side electric power bidding market. First, a 2PAEG model is established. Then, complete evolutionary equilibrium rules of this model are revealed during decision-making processes. Discussion shows that final evolutionary game equilibria achieved in the 2PAEG model are only determined by some payoff parameters, which are defined as relative net payoff (RNP) parameters in this paper. Finally, a case study of supply-side bidding simulation for two generator populations is conducted, which can effectively verify the universality and effectiveness of the evolutionary dynamics results obtained in the established general 2PAEG model. Moreover, it shows that reasonable policies made by the government can guide more appropriate power bidding for onto-grid electricity.
Software Design of Intelligent Detection Platform for Electric Energy Measuring Equipment
Authors: Fu-yong CHENG , En WANG , Shao-lei ZHAI , Bo LI , Zheng CHEN , Bing-hui ZHAO
Published: October 2020

This paper aims to effectively detect and estimate the performance of various electric energy measuring equipments. We develop an intelligent detection platform for the electric energy measuring equipment which includes detection software, data storage, intelligent protocol library, virtual network and alarm program. By designing the intelligent protocol library and virtual network, data from different kinds of acquisition terminals can be collected by the proposed intelligent platform. Compared with the conventional electric energy measuring equipment, the intelligent electric energy measuring equipment can greatly save time and improve detection efficiency.
Analysis and Investigation on Causes of Voltage Sag Based on A Novel Apriori Algorithm
Authors: Liu Hao , Zeng Qinghui , Liu Shaohui , Wu Zhuojun , Li Lei , Ma Rongrong
Published: October 2020

As more and more power users are increasingly demanding the quality of electricity, the losses caused by voltage sags are becoming more and more serious. Therefore, it is very important to analyze the cause of the voltage sag to prevent the voltage sag in time. This paper proposes a new algorithm that combines Apriori correlation analysis algorithm and cluster analysis algorithm to analyze the causes of voltage sags. Because some typical climatic conditions also have an important influence on the cause of voltage dips, The data is initially processed using climate factors as clustering indicators, and then the correlation analysis between typical electrical characteristics and voltage sags is performed, and strong association rules are finally obtained. According to the calculation and analysis of examples, some factors with high correlation with the causes of voltage sag are found, which will provide theoretical support for the prevention of voltage sag and provide ideas for further research on the causes of voltage sag.
Study on Fault Analysis and early warning system of wind-induced disasters on transmission lines
Authors: Fanqin LIN , Ran JIA , Jingjing Yang , Huaming CAO , Hui LIU , Pengtao DONG
Published: October 2020

Wind-induced disaster has become one of the most important disasters affecting the safe operation of power grid. In order to improve the effect of prevention and treatment of wind-induced disasters, it is very important to give early warning and real-time warning. Therefore, based on the climate characteristics of Shandong power grid, this paper presents the wind speed statistical law and the distribution characteristics of the number of days with strong wind. By analysing the mechanism of wind-induced disasters and combining the fault data of five years, the characteristics and rules of wind deviation and foreign short-circuit fault are obtained. On this basis, an early warning model of wind deviation based on the calibration of minimum air gap and the determination of maximum wind speed is established. At the same time, there is a short circuit model based on visual image information. Based on GeoServer platform, we will develop an early warning system for wind-induced disasters of transmission lines, which can provide real-time warning and early warning for wind-induced disasters. The application of the system can reduce the impact of wind damage on the transmission line, and effectively improve the operation reliability of the line.
Design of output fluctuation smoothing strategy in photovoltaic power station
Authors: Zhang Yu , Shi Shanshan , Yang Qixing , Fang Chen , Xu Qin , Wang Yufei
Published: October 2020

The output power of photovoltaic (PV) power station has strong fluctuation and randomness. Large-scale photovoltaic grid connection will affect the safe operation of power grid. In this paper, the smoothing strategy of PV output fluctuation is designed based on the adaptive moving average algorithm, which combined with the PV power prediction technology. The energy storage system compensates the difference between the grid-connected reference power and the actual generation power in real time, smoothing the grid-connected power of PV power station. Firstly, the relationship between the length of fixed sliding window and smoothness, as well as volatility in the moving average algorithm is explored to provide theoretical basis for subsequent parameter selection. Then, in order to enhance the adaptive performance of the algorithm, an adaptive moving average algorithm is proposed to dynamically adjust the length of the sliding window according to the actual power volatility. The PV power prediction curve is smoothed based on the algorithm so that the grid-connected reference power curve can be obtained. Finally, three typical weather conditions of sunny day, cloudy day and overcast day are taken as examples to simulate. The results show both feasibility and effectiveness of the strategy designed to smooth output fluctuation of PV power station.
Optimization of Power Collector System for Large-scale Offshore Wind Farm Based on Topological Redundancy Assessment
Authors: Shurong Wei , Yuyao Feng , Kunlun Liu , Yang Fu
Published: October 2020

Because of the bad environment of wind farms in the far -reaching sea, the cost of power collector system is high. The contradiction between economy and reliability of the power collector system planning is particularly prominent. According to the particularity of the wind farm in the far-reaching sea and the demand of the power collector system on higher reliability, this paper proposes the definition of topological redundancy of the power collector system and develops a multi-objective optimization model based on the topological redundancy. Thus, the contradictory variables of economy and reliability are optimized. Taking a large-scale offshore wind farm as an example, based on the topological redundancy assessment, the topology of its power collector system is optimized from the perspective of life cycle cost. The results show that, although the initial cost of the optimal redundancy topology is slightly higher than that of the radial structure, the advantage of life cycle cost after 8 years of operations is obvious, which can meet the actual engineering requirements of the power collector system for the wind farm in the far-reaching sea.
Evaluation of operation and management of Luocheng small municipal wastewater treatment plant
Authors: Wei Qiaoquan , Cheng Guanwen , Sun Bangzhou , Zhang Liao , Zhang Yuling , Wei Jiangzhou , Yang Xing
Published: October 2020

Operation efficiency, effect and operation energy consumption are the main basis for the evaluation of the operation and management level of wastewater treatment plant. The statistics of the operation data of the small municipal wastewater treatment plant in Luocheng County show that the operation rate of the facility is high, and the treated effluent reaches the Level A standard of the “Discharge standard of pollutants for municipal wastewater treatment plant” (GB18918-2002), and the various evaluation indicators of the urban wastewater treatment plant basically normal. However, the average operating load of some municipal wastewater treatment plant has not reached the index requirement for the operation period of production, and the load rates of CODCr and NH4+-N are mostly below 60%, and wastewater treatment plant unit wastewater volume, unit CODCr and NH4+-N load energy consumption is high. The reason is that the water quality of the design of the micro-municipal wastewater treatment plant is not reasonable, the construction scale is too large, and the operation fails to adopt effective management and control technology measures.
A risk assessment of leaching from artificial soil composed of fly ash and sludge
Authors: Wan Jie , Yang Xiaofan , Xu Xiaoping , Wei Xueyu
Published: October 2020

Mixture of fly ash (FA) and sewage sludge (SS) has been used as substrates to plant vegetables and turf grasses. Most studies chemically analyzed physiochemical properties of leachates from FA/SS mixtures, but did not considered the effects of plants growing on leaching properties, and the toxicity of leachates on aquatic animals were not well understood. In the present study, FA and SS were mixed in different ratios and then used to cultivate Zoysia matrella and Cynodon dactylon. After one month, these artificial soils were irrigated with water and leachates were collected for three months. Chemical analyses revealed that, although the heavy metal concentrations of FA and SS almost conformed to the relevant national standards, the levels of Cr, Zn, Cd, Pb and Cu in leachates still exceeded the limits in the Chinese Standard of Surface Water Quality, displaying potential environmental hazards. The effects of leachates on reproduction of Daphnia magna were evaluated and the results showed that leachates from high proportion of FA or SS would both negatively affect D. magna, demonstrating an environmental risk. However, leachates from mixture with FA: SS ratio from 1: 2 to 1: 6 did not significantly affect D. magna. Overall, the present results suggested that applications of FA/SS mixtures as artificial soil potentially contaminated aquatic environments and should be monitored carefully.
Influence of alkali earth metals on Ce/TiO2 catalyst for selective catalytic reduction of NO with NH3
Authors: Peng Hao , Guo Rui-tang , Lin He
Published: October 2020

The salts of alkali earth metals (Ca and Mg) in fly ash have a deactivation effect on SCR catalyst. In this study, the poisoning effect of Ca and Mg on Mn/TiO2 catalyst was investigated and explained based on experimental and characterization results of BET, XRD, H2-TPR, NH3-TPD and XPS. It was found that the deactivation effect of Ca is more obvious than that of Mg. The results showed that the drop of redox ability and Brønsted acidity, and the decrease of active oxygen species led to the decrease of Ca-Ce/TiO2 and Mg-Ce/TiO2.
Membrane bioreactors for wastewater treatment: A review of microbial quorum sensing and quenching to control membrane biofouling based on engineering quorum quenching bacteria
Authors: Jiao Xinmeng , Xie Kang , Qiu Liping
Published: October 2020

Membrane bioreactor (MBR) is a kind of reputable and prospective technology for wastewater treatment and reformation applications. However, membrane fouling caused by the formation of biofilm on the membrane surface, especially biofouling, is a major obstacle that limits the energy-saving operation and maintenance of the membrane bioreactor (MBR). Microbial communication (known as Quorum Sensing (QS)) is the cause of this fouling phenomenon. A new strategy called Quorum Quenching (QQ) seems to have been successfully used for biological pollution control in wastewater treatment MBR. This review summarizes the latest findings regarding membrane fouling, QS mechanisms and QQ applications. We discussed the opportunities for further practical application of self-cleaning engineering QQ bacteria in MBR.
Research on Identification of Land Damage Types and Analysis of Damage Process in Opencast Coal Mine of Steppe
Authors: Jiancheng Yan , Yong Liu , Junhai Gao
Published: October 2020

Aiming at the situation of land damage caused by large Opencast Coal Mine in steppe, this paper took Borshil Opencast Coal Mine in Hulunbuir as the research object, identified the types of land damage caused by Opencast Coal Mine in the last 20 years, analysed the space-time sequence and quantity of land damage process, and calculated the coefficient of land damage based on the types of damage. We found that, since 1998 to 2018, the area of land improper excavation and land cover occupation increased year by year in Borshil Opencast Coal Mine, the area of land improper excavation changed inconspicuously between years, and the area of land cover occupation decreased between years; the area of land occupation increased first and then remained unchanged basically, and the proportion decreased from 36.5% to 16.2%. By 2018, the total area of land damage in Borshil Opencast Coal Mine was 5150.52 hm2, and the ratio of land improper excavation to land cover occupation to land piled up was about 3:5:2. In addition, the land damage coefficient of Borshil Opencast Coal Mine increased first and then decreased, reaching the maximum of 0.6425 hm2/104t in 2011, and it was 0.196hm2/104t in 1998-2018. The data combined with coal mine output can predict the future land damage area of mining area, and provide data support for land reclamation potential survey. It can also provide reference for the implementation of relevant national policies and plans.
Preliminary Study on Pollution Isolation of Civil Air Defence Underground Engineering
Authors: Yunzhe Ji , Xiaojie Wang , Jintian Li
Published: October 2020

In order to control the airborne spread of pollutants in civil air defences underground projects, the pollution source rooms are isolated. In this paper, CFD simulation technology is used to compare the effect of different positions of air supply and exhaust outlets on the removal of contaminants in the polluted isolation room. Pressure difference control is proposed to prevent the diffusion of polluted air from the isolation room to the clean area, and the realization of pressure difference control under emergency ventilation mode is discussed.
Development Trends of Non-thermal Plasma (NTP) Technology Used in Environmental Pollutants Treatment: A Patent-Bibiometric Analysis
Authors: Liyuan Liu , Yue Gong , Yang Chen , Qinzhong Feng
Published: October 2020

Non-thermal plasma Technology (NTP) has been widely used in various fields, especially in environmental pollutants treatment field. This paper provides an overview of the global NTP patent landscape by analyzing relative patents based on CNABS and DWPI, selected from 1987 to 2019, which covers patenting activity related to technologies in pollutant removal from the process in the above-mentioned areas. The most common technologies for each area were identified and their developments were analyzed over time. Information related to the main countries, key applicants, current activities and the technology strength were identified by synthesizing important findings from qualitative research and quantitative literature analysis.
Multi-sensor comparison of aerosol optical properties profiles observed during a pollution episode in a mega city of the North China Plain
Authors: Gao Lina , Zhang Yong , Chen Yubao , Bu Zhichao , Cheng Xinghong , Jing Junshan , Lv Shanshan
Published: October 2020

A fine aerosol particle pollution episode happened in mega city Beijing during February 25th – March 5th. Aerosol extinction coefficient profiles were observed at 7 L idar s ta ti ons. Different aerosol optical property instruments were used to verify Lidar retrievals. Ground visibility observations were used to verify near ground Lidar observations. High correlation coefficient was found (0.8) between visiometer and Lidar observations. Lidar’s Column integrated aerosol extinction coefficient was also verified by Himawari-8 aerosol optical depth (AOD) data. The correlation coefficient between two AOD retrievals was 0.4. And the mean bias was -0.17. CALIPSO aerosol property profiles was also used to verify Lidar retrievals. Lidar retrievals was inconsistent with CALIPSO in the boundary layer. Overall, the Lidar retrievals are consistent with other optical property sensors. And the retrials could be used for observation research and model validation.
Research on Dynamic Monitoring and Ecological Restoration of Mining Environment in the Source Region of the Yellow River
Authors: Yao Weiling , Xu Wenjia , Wang Jie , Wang Hao , Liu Xiaoyang , Jiang Cunhao
Published: October 2020

The source region of the Yellow River is facing with problems of local ecosystem degradation and reduction of water conservation function, and the ecological environment in the source region of the Yellow River is fragile. Mining development is one of the key factors affecting the ecological environment in the source region of the Yellow River. Based on the high-resolution remote sensing satellite data of 2015 and 2018, this paper carried out the monitoring of the current situation and dynamic changes of the mine environment in the source region. The results show that the main mine environmental problems, caused by mining development, in the source region are land excavation and land occupation, and the growth rate is pretty fast. At present, the recovery rate of mines is low, only 25.24%. According to the present situation of mining environment, regional physical geography and other factors, the mine damaged land in the source region of the Yellow River is divided into three types: the natural restoration areas, the general restoration areas and the key restoration areas. The ecological restoration of mines in the source region should adhere to the strategy of taking measures according to local conditions, and offer specific ecological restoration proposals for each type of areas. The ecological restoration of mines in the source region should focus on water conservation, strengthen the restoration of stocking mine damaged land, study the permitting mechanism of mining activities, and reinforce the function of regional ecological protection.
Remote sensing investigation of sand mining in Wenzhou based on domestic satellite data
Authors: Jie Wang , Yaqiu Yin , Yuhao Wang , Li Li , Dong Chen
Published: October 2020

Taking the domestic high-resolution satellite image data obtained in 2018 as the information source, the remote sensing image was processed, and part of the map spots were verified in the field. Combined with the natural environment, topography and geomorphology of Wenzhou City, the sand mining of Oujiang, Feiyun and Aojiang in Wenzhou City was investigated and monitored by remote sensing. Through the application research, the current situation of sand mining in Wenzhou City is found out, which can provide scientific basis for the government to make the next decision of sand mining restoration and management and the reasonable development and utilization planning of mineral resources.
Effects of ZnO nanoparticles on microbial biomass and enzyme activity in soils containing cellulose and lignin
Authors: Jiang Hao , Wang Hui , Yang Baoshan , Cao Xinlei , Liu Xingyue
Published: October 2020

In order to investigate the effect of ZnO nanoparticles (ZnONPs) on soil ecosystem in soil with added cellulose and lignin, five treatments were set up: cellulose, cellulose + ZnONPs, lignin, lignin + ZnONPs, and no addition. The soil respiration, microbial biomass, and the activities of soil enzymes were explored during a 56-day incubation time after the addition of ZnONPs. The results showed that when cellulose and lignin were added to the soil, the CO2 efflux increased by 90.9% and 18.2%, respectively, compared with the control soil. The microbial biomass carbon and the activity of peroxidase, polyphenol oxidase, β-glucosidase and cellulase were increased. Compared with the treatment with the addition of cellulose and lignin only, the exposure of ZnONPs increased the CO2 efflux, microbial biomass carbon, β-glucosidase and cellulase activities, but decreased the peroxidase and polyphenol oxidase activities. We concluded that the addition of cellulose and lignin to farmland soil increased respiration, microbial biomass and soil enzyme activity, but the degradation degree of cellulose was higher than lignin. The ZnONPs promote soil respiration, microbial biomass, and hydrolase activity throughout the culture period, but inhibited the activity of redox enzymes.
Correlations of Socio-economic Backgrounds and Flood Preventive Behavioral Attitudes for Taipei
Authors: Lee Yung-Jaan , Lin Shih-Ying
Published: October 2020

Under the impact of climate change, the world is facing various extreme weather challenges. Cities face higher frequency and severity of these challenges due to high population density and high levels of business and commerce activities. How to reduce disaster risk has become an important connotation of risk city governance. People’s attitudes toward disaster prevention can help reduce disaster risk and management efforts and reduce mortality and economic losses. Using a stratified random sampling method, this study selected 600 respondents from four different environmentally sensitive districts in Taipei to examine the relationships between their socio-economic backgrounds (age and residence duration) and flood preventive behavioral attitudes. The analyses of the Chi-squared test indicate that there is a high correlation between residents’ age and flood preventive behavioral attitudes, while a low correlation in different regions. There are moderate to low correlations between the prevention behavioral attitudes and age of the residents in Zhongshan and Wenshan districts with low natural vulnerability / low social vulnerability. The relationship between residence duration and flood prevention behavioral attitudes was only associated in districts with high natural vulnerability / high social vulnerability, while the respondents in other districts did not show correlation relationships. It is recommended to increase the residents’ flood prevention behavioral attitudes to encourage positive behavior in the reduction of flood risk in different areas and similar environments.
Protection and Renewal Strategy of Historical Remains Landscape in Urban Reconstruction -- A case study of Guilin ring water system
Authors: Qin Ping , Huang Ying , Gan Yu
Published: October 2020

In recent years, with the rapid development of urban landscape, more and more attention has been paid to urban landscape protection. In this paper, based on the perspective of protection and renewal of historical monument landscape, a study was conducted in the Guilin ring city water system, and it was found that the water system has the problems of scattered historical relics, damaged historical spatial pattern, serious water pollution and lake waterlogging. To address these issues, this paper proposes strategies such as improving the historical space organization system, continuing the historical form and function of the city’s water system, integrating historical and cultural resources, restoring the historical space pattern of the city’s water system, formulating historical heritage conservation plans and continuing cultural practices. This article provides a beneficial discussion on creating an ideal environment with rich history and culture, suitable for human habitation, and shaping the region and character of the city.
The relationship between Liaoning urban agglomeration based on Gravity Model
Authors: Jing Zhi
Published: October 2020

.This paper simulates the economic gravitation between 14 prefecture level cities of Liaoning province by gravity model, and achieves data visualization through ArcMap and Ucinet . It is concluded that the central city group of Liaoning is composed of Shenyang, Liaoyang, Benxi, Anshan, Fushun and Tieling.The southern city group of Liaoning is composed of Dalian, Yingkou, Panjin, Huludao and Jinzhou.
Site selection for EVCSs by GIS-based AHP method
Authors: SUN Linzhao
Published: October 2020

As an alternative to fossil-fuelled vehicles, electric vehicles (EVs) are eco-friendly which can reduce carbon emissions and improve energy efficiency. However, there are still some barriers to the development of EVs. One of the main problems is lacking scientific planning of charging stations considering social, technological and environmental factors. To solve the problem, our paper proposes a Geographic Information System (GIS)-based AHP method to find optimal locations of electric vehicle charging stations (EVCSs) in Nanshan District, Shenzhen City. From the experimental result, the middle and southeast are more suitable to locate charging stations than other areas.18 alternative stations are selected considering the reality and existed charging stations.
Ecological Strategies of Urban Ecological Parks – A case of Bishan Ang Mo Kio Park and Kallang River in Singapore
Authors: An Zhongfang , Chen Qingchang , Li Jian
Published: October 2020

In order to deal with the negative effect of ecological environment caused by the rapid urbanization process, much more attention has been paid to urban ecological parks with the functions such as restoring urban natural ecological environment, building sustainable stable ecosystems, improving biodiversity and spreading ecological culture. On the basis of explaining the concept of urban ecological parks, this paper sums up the ecological strategies of the restoration case of Bishan Ang Mo Kio Park and Kallang River in Singapore, and puts forward ecological strategies of urban ecological parks in the aspects of planning, design and maintenance, involving site selection, layout, planting, techniques, facilities, education and management.
Numerical study on the effect of shaft position on natural smoke exhaust in tunnels with one closed portal
Authors: Pengqiang GENG , Zihao WANG , Miaocheng WENG , Fang LIU
Published: October 2020

.This paper uses Fire Dynamics Simulator (FDS) to study the effect of the longitudinal distance from the shaft to the fire source on the natural smoke exhaust of the tunnel fire with one closed portal, and analyzes the temperature distribution of the smoke and the shaft’s smoke exhaust efficiency. The results show that when the shaft is located downstream of the fire source (Ds<0), with the increase of the distance from the shaft to the fire source, the smoke exhaust efficiency decreases first and then stabilizes at a fixed value. At this time, the ceiling temperature attenuation’s coefficient at upstream of the fire source is only related to the heat release rate of the fire source (HRR). When the shaft is located upstream of the fire source (Ds>0), the smoke exhaust efficiency increases slightly with the increase of the distance from the shaft to the fire source, but the overall value is relatively small. When HRR is fixed, the shaft located downstream of the fire source has a higher smoke exhaust efficiency. As the distance between the shaft and the fire source increases, the plug phenomenon decreases.
Laboratory Test Research on Collapsible Loess Foundation Treatment
Authors: Shao Yan , Yuan Man , Hao Yong , Sun Xiaohong
Published: October 2020

Combined with the Dingxi-Lintao Expressway, this paper discusses the method of strengthening the collapsible loess foundation, and conducts the indoor California Bearing Ratio (CBR) test research according to the characteristics of the highway project. Under the optimal water content, through the comparison analysis of the test results of the plain soil California Bearing Ratio test and the lime soil California Bearing Ratio test after the ash mixing ratio reaches 5%, it can be found that under the condition that the compaction degree reaches 96%, the test result after ash mixing is 5% The CBR value of this kind has been greatly improved, and the expansion amount has been drastically reduced. It is proved that this treatment method can eliminate the adverse effects of collapsible loess, significantly increase the bearing capacity of the foundation, and provide good guidance for the subsequent roadbed treatment design and construction.
Resource utilization of composite insulator silicone rubber
Authors: Jiang Yuze , Zhang Yong , Jiang Diwen , Wang Chao , Chen Yimin
Published: October 2020

Composite insulators provide highly effective insulation support, and their application in power transmission lines has seen rapid growth in recent years. However, every year, a large quantity of composite insulators are scrapped on reaching the end of their service life. Due to the exceptional chemical inertness of the silicone rubber in the insulators, they have poor self-degradation characteristics, and end up filling landfills and occupying a lot of space, which inadvertently endangers the ecological environment. So far, there has not been any effective means to recycle composite insulators. This paper analyzes the material composition and characteristics of the silicone rubber in the core and housing of composite insulators, and proposes a resource utilization approach for the application of the pulverized silicone rubber powder from the insulators in the following three applications: use in producing silicone rubber asphalt at a blending ratio of 15%–18%—the corresponding market demand is large enough to meet the disposal needs of scrapped composite insulators; use in modification of waste rubber powder and blending with ethylene propylene diene monomer rubber (EPDM) at a blending ratio of 10%—as the annual production capacity of EPDM is more than 850,000 tons in China, thousands of tons of waste insulators can be thus disposed; and use as an aggregate for non-slip coatings, which accounts for more than 40% of the coatings material. Thus, there is tremendous scope for recycling waste insulator.
Composite right/left-handed transmission line with array of thermocouples for generating terahertz radiation
Authors: Beiranvand Behrokh , Sobolev Alexander S. , Kudryashov Anton V.
Published: October 2020

We present a new concept of the thermoelectric structure that generates microwave and terahertz signals when illuminated by femtosecond optical pulses. The structure consists of a series array of capacitively coupled thermocouples. The array acts as a hybrid type microwave transmission line with anomalous dispersion and phase velocity higher than the velocity of light. This allows for adding up the responces from all the thermocouples in phase. The array is easily integrable with microstrip transmission lines. Dispersion curves obtained from both the lumped network scheme and numerical simulations are presented. The connection of the thermocouples is a composite right/left-handed transmission line, which can receive terahertz radiation from the transmission line ports. The radiation of the photon to the surface of the thermocouple structure causes a voltage difference with the bandwidth of terahertz. We examined a lossy composite right/left-handed transmission line to extract the circuit elements. The calculated properties of the design are extracted by employing commercial software package CST STUDIO SUITE.
Order and disorder in intellectual history. Spinoza’s case in the light of complexity
Authors: Rovere Maxime
Published: October 2020

This article presents the conception of order and disorder developed by the philosopher B. Spinoza (1632-1677), and shows how this theory supports the intelligibility of nature without attributing any kind of organization to nature. From these principles, the author questions the use of causality in intellectual history, and sketches the possibility of a complex history based upon the disorder of interactions.
Critical temperatures of the Ising model on Sierpiñski fractal lattices
Authors: Perreau Michel
Published: October 2020

We report our latest results of the spectra and critical temperatures of the partition function of the Ising model on deterministic Sierpiñski carpets in a wide range of fractal dimensions. Several examples of spectra are given. When the fractal dimension increases (and correlatively the lacunarity decreases), the spectra aggregates more and more tightly along the spectrum of the regular square lattice. The single real rootvc, comprised between 0 and 1, of the partition function, which corresponds to the critical temperatureTcthrough the formulavc= tanh(1/Tc), reliably fits a power law of exponentkwherekis the segmentation step of the fractal structure. This simple expression allows to extrapolate the critical temperature fork→ ∞. The plot of the logarithm of this extrapolated critical temperature versus the fractal dimension appears to be reliably linear in a wide range of fractal dimensions, except for highly lacunary structures of fractal dimensions close from 1 (the dimension of a quasilinear lattice) where the critical temperature goes to 0 and its logarithm to −∞.
Vortex lines in a cubic magnetic nanodot: structure and dynamics
Authors: Depondt Ph. , Lévy J.-C. S.
Published: October 2020

Langevin simulations of cubic magnetic nanodots were performed using the Landau-Lifshitz equation with exchange and dipolar interactions. Vortices tend to organize as lines: we establish the structure and dynamics thereof for a large range of the dipolar versus exchange ratiod. These lines tend to be bent and twisted. For large values of the dipolar interaction, a complex network of vortex lines arises. Dynamics evidences low frequency collective gyrotropic motions of vortex lines which maintain their distance during motion.
Magnetic excitations in assemblies of dipolar coupled nanoparticles
Authors: Boust Fabrice , Vukadinovic Nicolas
Published: October 2020

The equilibrium magnetization configurations and the associated microwave susceptibility spectra of dipolar coupled nanoplatelets are explored using three-dimensional (3D) micromagnetic simulations. First, the case of periodic arrangements of nanoplatelets on square arrays is considered. As a result, a macro-vortex state defined as a flux closure pattern spreading over the whole array with or without a vortex core can be stabilized starting from an initial orthoradial magnetization configuration. For macro-vortex states with a vortex core, the linear excitation spectrum exhibits a sub-GHz resonance line ascribed to the vortex core dynamics at the array center. The features of this line (spectral position and amplitude) depend on the array size and the strength of the dipolar coupling through the interplatelet spacing. This resonance is also observed for macro-vortex states without a vortex core but only in the regime of a strong dipolar coupling. The effect of disorder is then investigated by numerically generating assemblies of nanoplatelets with a position disorder and, shape and size distributions. The micromagnetic simulations reveal flux closure magnetization configurations as well but without a vortex core. A low-frequency resonance appears in the susceptibility spectra for quite high surface contents of nanoplatelets but its amplitude is weaker compared to the case of periodic arrays. This line arises from a collective mode extended over a few nanoplatelets.

A large variety of static and dynamical behaviors is thus evidenced resulting in a great complexity even in such model systems.
Technological advancements in evaluating the performance of the pulverized coal injection through tuyeres in blast furnace
Authors: Agrawal Ashish , Tiwari Rohit Kumar , Kumar Sanjiv , Chatterjee Rajeswar , Singh Basant Kumar , Singh Rama Shankar , Tripathi Vineet Ranjan , Kundu Subhashis , Padmapal  , Ramna R.V. , Singh Manish Kumar
Published: October 2020

The pulverized coal injection (PCI) is pursued to reduce the hot metal production cost by replacing the expensive metallurgical coke with the non-coking coal. Increasing the PCI rate causes various difficulties in the blast furnace (BF) operation. In the present work, an attempt is made to review the various aspects of PC injection in BF such as the challenges with increasing the PCI rate and modifications in the injection system to circumvent the concerns related to higher PCI rate. Various methods for detecting the tuyere blockage and failure caused due to the high PCI rate are elaborated. The factors influencing the combustion of coal in front of tuyeres have been discussed and their impact in the replacement ratio has been discussed. Further, recommendations are made to improve the coal combustibility in front of tuyeres.