作者机构：
[Long, Yuehong; Qin, Jianxin] Hunan Normal Univ, Sch Geog Sci, Changsha 410081, Peoples R China.;[Long, Yuehong; Wu, Yang] Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Peoples R China.;[Wang, Ke] Hunan City Univ, Sch Informat & Elect Engn, Yiyang 413000, Peoples R China.
通讯机构：
[Qin, JX ] H;Hunan Normal Univ, Sch Geog Sci, Changsha 410081, Peoples R China.
关键词：
urban park;accessibility;space syntax;Changsha urban area
摘要：
Park green space is an important part of the green infrastructure in a city, and urban park space accessibility is an important indicator for measuring the city’s comprehensive strength, living environment, and resident happiness, which greatly affects the sustainable development and construction of the city. The spatial syntax method can discuss the accessibility of urban parks from the perspective of topology, which inherits the objective stability of the topological relationship. There are few research studies on the accessibility of urban parks. Therefore, with the support of space syntax theory and the spatial statistics method, this paper combined the data of park green space and road network to complete the accessibility evaluation of urban parks in the Changsha City urban area. This paper evaluates the accessibility of urban parks in the study area from four aspects, namely global accessibility, perceptual accessibility, local accessibility, and psychological accessibility, by using five quantitative indexes of space syntax, namely connectivity, depth, integration, selection, and synergy. The conclusions are as follows: The spatial layout area of the park is roughly consistent with the areas that have good global and local accessibility of the road network, and the global accessibility and local accessibility of the park in the study area are relatively high. The global spatial structure can be better perceived by the local space at a radius scale greater than or equal to 3000 m, and the perceptual accessibility of the park is high. Most of the urban parks in the Changsha urban area are located in sections with high space efficiency. The park space penetration is good, and nearly 70% of the parks have high psychological accessibility. Based on the overall spatial layout of urban parks, the space syntax method quantitatively and comprehensively evaluates the accessibility of urban parks from the perspective of topology. The conclusion is reliable and has important application value in the evaluation of park accessibility. It can be used as an important supplement to improve the evaluation model of accessibility.
期刊：
INTERNATIONAL JOURNAL OF EXERGY,2023年40(4):365-391 ISSN：1742-8297
通讯作者：
Xiang, XA
作者机构：
[Peng, Deyong; Zhou, Jun; Xiang, Xianan; Zhou, Xuehua; Deng, Zhiya; Li, Yongsuo] Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Hunan, Peoples R China.;[Wang, Chenhua] Univ Tianjin, Sch Civil Engn, Tianjin 300072, Peoples R China.
通讯机构：
[Xiang, XA ] H;Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Hunan, Peoples R China.
关键词：
exergy;AHP-FCE;rural solid waste;gasification;fixed bed
摘要：
An analytic hierarchy process-fuzzy comprehensive evaluation method (AHP-FCE) based on exergy analysis is proposed to evaluate the rural solid waste fixed-bed gasification process. The influence of gasification temperature, equivalence ratio (ER) and gasification agent on the gasification evaluation score are studied. Firstly, the exergy efficiency of gasification system is calculated by exergy analysis. Secondly, the AHP method is used to establish the optimal gasification process model, and the weight of the selected evaluation indexes is determined. The evaluation indexes include exergy efficiency, gas production rate, lower heating value (LHV) of producer gas, greenhouse gas emissions and waste residue emissions. Finally, the priority ranking of different gasification processes is obtained by the FCE method. The results show that when the gasification temperature is 1,000°C and the ER is 0.35, the gasification score is the highest. The oxygen/steam gasification is better than steam gasification and air gasification.
作者机构：
[Xue, Yun; Huang, Changjun; Cao, Yuanzhi; Liu, Fenliang] Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.;[Zhou, Lv] Guilin Univ Technol, Sch Geomat & Geoinformat, Guilin 541004, Peoples R China.;[Liu, Zhong] Hunan Remote Sensing Geol Survey & Monitoring Inst, Changsha 411000, Peoples R China.
通讯机构：
[Changjun Huang] S;School of Municipal and Surveying Engineering, Hunan City University, Yiyang 413000, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
Dam deformation monitoring data are generally characterized by non-smooth and no-saturated S-type fluctuation. The grey Verhulst model can get better results only when the data series is non-monotonic swing development and the saturated S-shaped sequence. Due to the limitations of the grey Verhulst model, the prediction accuracy will be limited to a certain extent. Aiming at the shortages in the prediction based on the traditional Verhulst model, the optimized grey Verhulst model is proposed to improve the prediction accuracy of the dam deformation monitoring. Compared with those of the traditional GM (1,1) model, the DGM (2,1) model, and the traditional Verhulst (1,1) model, the experimental results show that the new proposed optimized Verhulst model has higher prediction accuracy than the traditional gray model. This study offers an effective model for dealing with the non-saturated fluctuation sequence to predict dam deformation under uncertain conditions.
关键词：
fluvial process;climate change;Late Quaternary;upper Huaihe River
摘要：
Research into river processes in different climatic and geomorphic areas is vital for a clearer understanding of the non-linear responses of rivers to climate change. The Huaihe River (HHR) Basin, located in China's North-South Transition Zone (NSTZ), provides an ideal environment in which to explore river responses to climate change within a humid/semi-humid transitional area. Based on optically stimulated luminescence (OSL) and C-14 dating, combined with sedimentary stratigraphic analyses, we reconstructed the river processes of three sedimentary sequences in the upper HHR since the Late Quaternary. Our results showed that the upper HHR was characterized by aggrading meandering channels from the Last Glacial Maximum (LGM) to 0.5 ka, and an aggrading wandering channel from 0.2 ka to the present. Two periods of downcutting occurred during 5.8-3.0 and 0.5-0.2 ka, respectively. The river incision is potentially linked to changes in the climate during the Mid-Late Holocene transition and the Little Ice Age (LIA). However, there have been no marked changes in channel patterns in the upper HHR since the LGM. This phenomenon reflects the influence of vegetation on channel patterns during climate change. Our results showed that the fluvial processes in different climatic and geomorphic areas are controlled by the local hydroclimatic regime.
摘要：
Residential building space cooling and heating energy consumption account for approximately 15% of the total social energy consumption. Occupant behaviour is the primary factor influencing energy consumption for cooling and heating in residential buildings. This study used extensive face-to-face questionnaire surveys and actual measurements for typical households to study the cooling and heating energy consumption of high-rise residential buildings in Changsha. Statistical analysis was conducted on the influencing factors of participant information, architecture, occupant behaviour, and energy conservation awareness in the questionnaire survey. The household energy bills for cooling and heating were clustered, and PCA models were proposed between the influencing factors and the energy consumption, and were verified by measured data of typical households. The results demonstrated that the household energy bills could be divided into five categories. The PCA models show the mode of ventilation during the cooling period and the mode of air conditioner (AC) turning on/off during the heating period are the most important component, accounting for 46.7% and 35.9%, respectively. The statistical parameters provided a reference for the energy consumption simulation software, and the PCA models achieved energy consumption prediction through data of principal components, which are significant for building energy efficiency and carbon reduction.
期刊：
Transactions of the Indian Institute of Metals,2023年76(5):1221-1227 ISSN：0972-2815
通讯作者：
Bozhi Ren
作者机构：
[Ren, Bozhi; Wang, Xin] Hunan Univ Sci & Technol, Sch Civil Engn, Xiangtan 411201, Hunan, Peoples R China.;[Wang, Xin; Zhang, Chun] Hunan City Univ, Sch Municipal & Mapping Engn, Yiyang 413000, Hunan, Peoples R China.;[Ren, Bozhi] Hunan Prov Key Lab Shale Gas Resource Exploitat, Xiangtan 411201, Hunan, Peoples R China.;[Zhou, Yingying] ChongQing Univ, Coll Environm & Ecol, Chongqing 400044, Peoples R China.
通讯机构：
[Bozhi Ren] S;School of Civil Engineering, Hunan University of Science and Technology, Xiangtan, People’s Republic of China<&wdkj&>Hunan Provincial Key Laboratory of Shale Gas Resource Exploitation, Xiangtan, People’s Republic of China
摘要：
Abandoned tailings are one of the important sources of heavy metal pollution in regions surrounding mining areas. In this study, the speciation and kinetic characteristics of Mn and Pb were analyzed in waste rocks from a manganese mining area. The results show that under different experimental conditions, Mn mainly occurs in the residual state and the iron-manganese oxide-bound state, accounting for more than 90%, and Pb mainly occurs in the residual state, accounting for more than 99%. The cumulative release data in the dynamic leaching experiment can be fitted with a quadratic function. This research aims to provide a scientific basis for relevant decision-making departments to formulate environmental governance and protection strategies in mining areas.
作者机构：
[Chi, Nianping; Yang, Zhenwen] Hunan City Univ, Hunan Prov Engn &Technol Res Ctr Rural Water Qual, Sch Municipal & Geomatics Engn, Yiyang 413000, Hunan, Peoples R China.;[Li, Xuhao; Feng, Li] Guangdong Univ Technol, Sch Civil & Transportat Engn, Guangzhou 510006, Peoples R China.;[Zhu, Junren] Chongqing City Management Coll, Chongqing 401331, Peoples R China.;[Jiang, Zhenzhen] Chongqing Vocat Inst Engn, Chongqing 402260, Peoples R China.;[Zheng, Huaili] Chongqing Univ, Key Lab Three Gorges Reservoir Reg Ecoenvironm, Minist Educ, Chongqing 400045, Peoples R China.
通讯机构：
[Li Feng] S;School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, 510006, China
关键词：
Biodegradability;Dyeing wastewater;Electro- Ce(III) process;Energy consumption;Medium oxidation;Reactive red 2
摘要：
Reactive red 2 (RR2) azo dye wastewater poses a serious hazard to the water environment health, so using a novel and efficient Electro- Ce(III) (E- Ce(III)) process takes on a critical significance in treating RR2 dye wastewater. In this study, the effects of a variety of single-factor conditions on RR2 removal efficiency were evaluated in depth. The results indicated that the optimal experimental conditions are as reaction temperature of 25°C, Na(2)SO(4) concentration of 25mM, Ce(III) concentration of 0.3mM, pH of 4.0, and current density of 40.0mA/cm(2). When the RR2 dye wastewater was treated for 40min under the optimal experimental conditions, a high removal rate of 99.8% for RR2 was obtained. It is suggested that the background ion PO(4)(3-) in the dye wastewater inhibits the E-Ce (III) process, whereas Cl- facilitates this process. Moreover, the yield of Ce(IV) increases with the increase of the current density. At the current density of 40.0mA/cm(2), a reasonable energy consumption of 3.85kW h/gTOC for the process was obtained after the 3-h treatment. The effects of different degradation processes (including Direct Electrooxidation (DEO), single Ce(III), and E-Ce (III)) on RR2 removal efficiency and TOC change were compared. The types of oxidizing substances in the E-Ce (III) process were detected, and the mechanism of RR2 oxidative degradation in the E-Ce (III) process was summarized. The result suggests that the E-Ce (III) process has low power consumption. Meanwhile, in the E-Ce (III) process, free reactive Ce(IV) with strong oxidation is continuously generated, RR2 can be efficiently degraded. And the continuous cycle transformation between Ce(III) and Ce(IV) maintains the strong oxidation of the process. The contribution of free reactive Ce(IV) and DEO to RR2 degradation was obtained as 58.8% and 39.8%, respectively. The combined effect of Ce(IV) and DEO played a major role in the E-Ce (III) process, while ·OH exhibited a relatively weak effect (nearly 1.4%). RR2 was comprised of 13 major intermediates, and the biodegradability of wastewater was improved significantly after treatment, thus facilitating the further mineralization and biodegradation of the products. The E- Ce(III) process is novel, efficient, and environment-friendly, and has a large market application space, suggesting that it can be applied as an efficient, economic, and sustainable water treatment process.
摘要：
The development of remote sensing technology has accumulated a large number of remote sensing image time series data for human monitoring of surface vegetation change, which provides a basis for vegetation change prediction. In order to improve the prediction accuracy of vegetation change, this paper uses discrete wavelet to decompose remote sensing image sequences at multiple scales, to explore the difference of influence of different temporal scale change characteristics on vegetation spatio-temporal change prediction, and find the best decomposition scale for vegetation change prediction. In this paper, the research object is the MODIS 13Q1 EVI image data of Hunan Province from 2001 to 2021. The discrete wavelet is adopted to obtain multi-scale vegetation trend components and detailed component sequences, and then complete the LSTM modeling prediction and comparison. The following are the experimental findings: the predictive ability of the discrete wavelet decomposition sequence group is better than that of the original EVI time series to varying degrees. The order of prediction accuracy is: monthly scale > seasonal scale > annual scale > original EVI time series. Thus, it is of reference significance to the research of application scenarios of change prediction of other regionalized variables with multi-scale characteristics.
作者机构：
[Xue, Yun; Xi, Zhen; Liu, Fenliang; Huang, Changjun] Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Peoples R China.;[Gao, Hongshan] Lanzhou Univ, Coll Earth & Environm Sci, Key Lab Western Chinas Environm Syst, Minist Educ, Lanzhou 730000, Peoples R China.;[Li, Zongmeng] Xinyang Normal Univ, Sch Geog Sci, Xinyang 464000, Peoples R China.
通讯机构：
[Liu, FL ] H;Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Peoples R China.
关键词：
lacustrine sediment;terrace;river evolution;Jinsha River
摘要：
The formation of the Jinsha River drainage is a significant subject of concern in the geological and geomorphological fields. Among them, one key question is whether there was a regional paleo lake into which Lower Jinsha River drainage drained during the late Pliocene to early Pleistocene, due to massive fluvio-lacustrine sediments widely distributed in the Lower Jinsha River. Nevertheless, there has yet to be a consensus on the genesis of those fluvio-lacustrine sediments due to poor sedimentological and chronological data. In this study, to unravel the origin of those fluvio-lacustrine sediments and the formation model of the Lower Jinsha River, sedimentary characteristics, including spatial distribution, lithological composition, and stratigraphic contact relationship of those fluvio-lacustrine sediments were analyzed, and chronological determination of the fluvio-lacustrine sediments using Electron Spin Resonance and Optically stimulated luminescence method was conducted. The results show that in the Lower Jinsha River, the lacustrine sediments are mainly composed of silt and clay, with apparent horizontal bedding, stacked with fluvial cobble-gravel and sand, and are in unconformable contact with the underlying bedrock strata or paleo soil. The lacustrine sediments are spatially discontinuous and mainly distributed in the Shigu, Taoyuan, Panzhihua, and Longjie reaches. Downstream of these reaches are deeply incised gorges with an average slope >30 degrees, and many landslide landforms and deposits can be identified here. In each reach, the lacustrine sediments were closely distributed along the trunk and tributary channels in the plane and were distributed at different altitudes, forming a sequence of lacustrine terraces. Chronological analysis shows that in different reaches, the deposition ages of lacustrine sediments are significantly different. In each reach, the deposition age of the lacustrine terraces of high altitude is older than that of low altitude. The above characteristics collectively indicate that the lacustrine sediments in the Lower Jinsha River were locally deposited by individual dammed lakes, probably induced by landslide rather than a regional paleo lake by tectonic activities. During the incision process of the river valley, landslides continuously block the river channel, forming dammed lakes, and then deposited lacustrine sediments at different elevations, forming lacustrine terraces. The lacustrine sediment of the topmost lacustrine terrace in Panzhihua reach was dated to be 1.78 Ma, combined with previous studies on the fluvial terraces, indicating the Lower Jinsha River existed and started to incise its valley before the early Pleistocene. The widespread dammed lake sediment indicates that the formation of the Jinsha River valley follows the pattern of "incision-landslide-damming-aggradation-incision".
摘要：
This paper examined the impacts of different pretreatments on the characteristics of biochar and its adsorption behavior for Pb(2+). Biochar with combined pretreatment of water-washing and freeze-drying (W-FD-PB) performed a maximum adsorption capacity for Pb(2+) of 406.99mg/g, higher than that of 266.02mg/g on water-washing pretreated biochar (W-PB) and 188.21mg/g on directly pyrolyzed biochar (PB). This is because the water-washing process partially removed the K and Na, resulting in the relatively enriched Ca and Mg on W-FD-PB. And the freeze-drying pretreatment broke the fiber structure of pomelo peel, favoring the development of a fluffy surface and large specific surface area during pyrolysis. Quantitative mechanism analysis implied that cation ion exchange and precipitation were the driving forces in Pb(2+) adsorption on biochar, and both mechanisms were enhanced during Pb(2+) adsorption on W-FD-PB. Furthermore, adding W-FD-PB to Pb-contaminated soil increased the soil pH and significantly reduced the availability of Pb.
