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An end-to-end 3d seismic simulation of underground structures due to point dislocation source by using

Zhenning BA; Jisai FU; Zhihui ZHU; Hao ZHONG

《结构与土木工程前沿(英文)》 2022年 第16卷 第12期   页码 1515-1529 doi: 10.1007/s11709-022-0887-0

摘要: Based on the domain reduction idea and artificial boundary substructure method, this paper proposes an FK-FEM hybrid approach by integrating the advantages of FK and FEM (i.e., FK can efficiently generate high-frequency three translational motion, while FEM has rich elements types and constitutive models). An advantage of this approach is that it realizes the entire process simulation from point dislocation source to underground structure. Compared with the plane wave field input method, the FK-FEM hybrid approach can reflect the spatial variability of seismic motion and the influence of source and propagation path. This approach can provide an effective solution for seismic analysis of underground structures under scenario of earthquake in regions where strong earthquakes may occur but are not recorded, especially when active faults, crustal, and soil parameters are available. Taking Daikai subway station as an example, the seismic response of the underground structure is simulated after verifying the correctness of the approach and the effects of crustal velocity structure and source parameters on the seismic response of Daikai station are discussed. In this example, the influence of velocity structure on the maximum interlayer displacement angle of underground structure is 96.5% and the change of source parameters can lead to the change of structural failure direction.

关键词: source-to-structure simulation     FK-FEM hybrid approach     underground structures     point dislocation source    

STRENGTHENING NON-POINT SOURCE POLLUTION CONTROL TO PROMOTE AGRICULTURAL GREEN DEVELOPMENT

《农业科学与工程前沿(英文)》 2023年 第10卷 第4期   页码 503-509 doi: 10.15302/J-FASE-2023528

摘要:

STRENGTHENING NON-POINT SOURCE POLLUTION CONTROL TO PROMOTE AGRICULTURAL GREEN DEVELOPMENT

关键词: GREEN     AGRICULTURAL     PROMOTE     POLLUTION     SOURCE     DEVELOPMENT     POINT     STRENGTHENING     CONTROL    

DITCHES AND PONDS CAN BE THE SOURCES OR SINKS OF NON-POINT SOURCE POLLUTION: OBSERVATIONS IN AN UPLAND

《农业科学与工程前沿(英文)》 2023年 第10卷 第4期   页码 607-626 doi: 10.15302/J-FASE-2023517

摘要:

As the common features of agroecosystems, ditches and ponds benefit the irrigation and drainage, as well as intercepting non-point source pollutants. However, most ditch-pond studies have been conducted in lowland areas. To test this source-sink assumption in upland areas, this study made observations on the ecological function of the ditch and pond system in a typical catchment in China. First, the changes in ponds in the catchment were analyzed using high-resolution remote sensing data. Then, the migration of agricultural pollutants in ditches and ponds were analyzed by field sampling and laboratory detection. The results showed that over the past 15 years the length of ditches in the catchment and the number of small ponds (< 500 m2) have increased by 32% and 75%, respectively. The rate of change in nutrient concentrations in the ditches and ponds were mostly from −20% to 20%, indicating ditches and ponds can be both sources and sinks for agricultural pollutants. Lastly, the contributing factors were explored and it was found that ditches and ponds are important sinks in dry season. However, during the rainy season, ditches and ponds become sources of pollutants, with the rapid drainage of ditches and the overflow of ponds in upland areas. The results of this study revealed that the ditches and ponds could be used for ecological engineering in upland catchments to balance drainage and intercept pollutants.

关键词: ditches     ponds     non-point source pollution     mountainous areas     nitrogen     phosphorus    

REDUCTION OF NON-POINT SOURCE POLLUTION IN THE YONG’AN RIVER BY CONSTRUCTED WETLAND BASED ON 9 YEARS

《农业科学与工程前沿(英文)》 2023年 第10卷 第4期   页码 627-638 doi: 10.15302/J-FASE-2023516

摘要:

The agricultural and livestock activities surrounding the rivers flowing into the lakes have caused non-point source pollution, leading to excessive amounts of nutrient salts in downstream rivers. Introducing river water into constructed wetlands along river course has proven to be an effective solution for decreasing nitrogen (N) and phosphorus (P) loads. This paper reports 9 years of monitoring the Yong’an River and its surrounding constructed wetlands in the upper reaches of Erhai Lake, located in Yunnan Province, China. This study analyzed the main types of pollutants in the river, and evaluated the removal efficiency of pollutants by the constructed wetlands. The findings indicate that total nitrogen (TN) and nitrate nitrogen (NO3-N) are the primary pollutants in the Yong’an River, which exhibit variation throughout the year corresponding to the alternating wet and dry seasons. Although constructed wetlands are effective in removing NO3-N and P, their efficacy in removing ammonium nitrogen (NH4+-N) and organic pollutants is limited. This limitation can be attributed to the lack of timely disposal of aquatic plant residues. This research contributes to the understanding of the potential issues that may arise during the extended use of constructed wetlands and provides solutions to address them.

关键词: inflowing rivers     surface-flow constructed wetland     nutrients     long-term monitoring    

Control division of agricultural non-point source pollution at medium-sized watershed scale in Southeast

HUANG Jinliang, HONG Huasheng, ZHANG Luoping

《环境科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 333-339 doi: 10.1007/s11783-008-0035-7

摘要: This paper presents the study carried out for controlling agricultural non-point source pollution (NSP) in a medium-sized watershed covering 1.47 × 10 km in Southeast China using quantitative analysis coupled with geographic information system (GIS), universal soil loss equation (USLE), soil conservation service-curve number (SCS-CN), nutrient loss equations, and annualized agricultural nonpoint source model (AnnAGNPS). Based on the quantitative results derived from GIS and environmental models, five control division units were generated for NSP control in Jiulong River watershed, namely, controlling unit for soil losses, controlling unit for livestock breeding and soil losses, controlling unit for excessive fertilizer use and livestock breeding, controlling unit for soil losses and fertilizer use, and controlling unit for excessive fertilizer use and soil losses. This study proved that integrating GIS with environmental models can be adopted to efficiently evaluate major sources and contributors of NSP, and identify the critical source areas of NSP, which enables adjusting measures to local conditions by further control division units developed through such study for control and management of water quality degradation induced by NSP in the Jiulong River watershed.

Modeling agricultural non-point source pollution in a high-precipitation coastal area of China

Zhiyi LI,Pengfei DU,Haiwei HUANG,Yong Ge,Xu LI

《环境科学与工程前沿(英文)》 2014年 第8卷 第6期   页码 922-928 doi: 10.1007/s11783-014-0720-7

摘要: Non-point source (NPS) pollution simulation in the high-precipitation coastal areas of China is difficult because varying annual typhoon incidence leads to highly contrasting rainfall patterns in dry years and wet years. An IMPULSE (Integrated Model of Non-point Sources Pollution Processes) based NPS model of the Changtan Reservoir watershed, which is a typical high-precipitation coastal area in China, was established based on the analysis of point and NPS pollution data, a digital elevation model, and data on land-use, soil, meteorology, economy, and agricultural management practice. Pre-processed pre-rainfall soil moisture levels were introduced during the simulation to model the effects of typhoons on hydrology. Rainfall events were simulated sequentially through the year and the model was calibrated and verified using hydrological and water quality data. Accuracy of the simulated rainfall runoff and water quality in the Changtan watershed was found to be acceptable. The study showed that the NPS modeling system could be applied to the simulation and prediction of NPS loadings in the Changtan Reservoir watershed.

关键词: Changtan Reservoir watershed     non-point source pollution modeling     pre-rainfall soil moisture     model calibration    

Role of rural solid waste management in non-point source pollution control of Dianchi Lake catchments

LU Wenjing, WANG Hongtao

《环境科学与工程前沿(英文)》 2008年 第2卷 第1期   页码 15-23 doi: 10.1007/s11783-008-0006-z

摘要: In recent years, with control of the main municipal and industrial point pollution sources and implementation of cleaning for some inner pollution sources in the water body, the discharge of point source pollution decreased gradually, while non-point source pollution has become increasingly distressing in Dianchi Lake catchments. As one of the major targets in non-point source pollution control, an integrated solid waste controlling strategy combined with a technological solution and management system was proposed and implemented based on the waste disposal situation and characteristics of rural solid waste in the demonstration area. As the key technology in rural solid waste treatment, both centralized plant-scale composting and a dispersed farmer-operated waste treating system showed promise in rendering timely benefits in efficiency, large handling capacity, high quality of the end product, as well as good economic return. Problems encountered during multi-substrates co-composting such as pathogens, high moisture content, asynchronism in the decomposition of different substrates, and low quality of the end product can all be tackled. 92.5% of solid waste was collected in the demonstration area, while the treating and recycling ratio reached 87.9%, which prevented 32.2 t nitrogen and 3.9 t phosphorus per year from entering the water body of Dianchi Lake after implementation of the project.

induced by interaction burning of tri-symmetric propane fires in open space based on weighted multi-pointsource model

Jie JI, Junrui DUAN, Huaxian WAN

《能源前沿(英文)》 2022年 第16卷 第6期   页码 1017-1026 doi: 10.1007/s11708-020-0716-x

摘要: The interaction of multiple fires may lead to a higher flame height and more intense radiation flux than a single fire, which increases the possibility of flame spread and risks to the surroundings. Experiments were conducted using three burners with identical heat release rates (HRRs) and propane as the fuel at various spacings. The results show that flames change from non-merging to merging as the spacing decreases, which result in a complex evolution of flame height and merging point height. To facilitate the analysis, a novel merging criterion based on the dimensionless spacing / was proposed. For non-merging flames ( / >0.368), the flame height is almost identical to a single fire; for merging flames ( / ≤0.368), based on the relationship between thermal buoyancy and thrust (the pressure difference between the inside and outside of the flame), a quantitative analysis of the flame height, merging point height, and air entrainment was formed, and the calculated merging flame heights show a good agreement with the measured experimental values. Moreover, the multi-point source model was further improved, and radiation fraction of propane was calculated. The data obtained in this study would play an important role in calculating the external radiation of propane fire.

关键词: flame interaction     air entrainment     flame height     multi-point source model     thermal radiation    

Loss coefficient of nitrogenous non-point source pollution under various precipitation conditions

CHENG Hongguang, HAO Fanghua, REN Xiyan, YANG Shengtian, XIONG Wen, LEI Shaoping

《环境科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 230-235 doi: 10.1007/s11783-008-0043-7

摘要: In this study, calibrations of non-point source (NPS) pollution models are performed based on Black River basin historical real-time runoff data, sedimentation record data, and NPS sources survey information. The concept of NPS loss

关键词: information     concept     non-point     historical real-time     sedimentation    

滇池流域点源污染负荷总量变化趋势及原因分析

何佳,徐晓梅,陈云波,张琨玲,李跃勋,李中杰

《中国工程科学》 2010年 第12卷 第6期   页码 75-79

摘要:

对滇池流域近20年来的点源污染负荷产生量和削减量进行了核算,分析了其变化的趋势和主要原因。在8个污水处理厂及两个截污泵站的共同运行下,滇池流域COD、总氮和总磷3种污染物的削减量从1993年的1 542 t,177 t和13 t,分别增加到2007年的40 581 t,5 193 t和637 t。总体而言,生活污染源是主要的污染源,是流域污染物产生量增长的主要因素,流域内经济的发展和城市化进程的加快,人口数量急剧增长,是滇池污染物产生量增加的主要原因

关键词: 滇池     点源污染    

INTERACTIVE KNOWLEDGE LEARNING BY ARTIFICIAL INTELLIGENCE FOR SMALLHOLDERS

《农业科学与工程前沿(英文)》 2023年 第10卷 第4期   页码 648-653 doi: 10.15302/J-FASE-2023505

摘要:

Enhancement of farming management relies heavily on enhancing farmer knowledge. In the past, both the direct learning approach and the personnel extension system for improving fertilization practices of smallholders has proven insufficiently effective. Therefore, this article proposes an interactive knowledge learning approach using artificial intelligence as a promising alternative. The system consists of two parts. The first is a dialog interface that accepts information from farmers about their current farming practices. The second part is an intelligent decision system, which categorizes the information provided by farmers in two categories. The first consists of on-farm constraints, such as fertilizer resources, split application times and seasons. The second comprises knowledge-based practices by farmers, such as nutrient in- and output balance, ratios of different nutrients and the ratios of each split nutrient amount to the total nutrient input. The interactive knowledge learning approach aims to identify and rectify incorrect practices in the knowledge-based category while considering the farmer’s available finance, labor, and fertilizer resources. Investigations show that the interactive knowledge learning approach can make a strong contribution to prevention of the overuse of nitrogen and phosphorus fertilizers, and mitigating agricultural non-point source pollution.

关键词: artificial intelligence     extension system     non-point source pollution control     smallholders     fertilization    

FULL TIME-SPACE GOVERNANCE STRATEGY AND TECHNOLOGY FOR CROPLAND NON-POINT POLLUTION CONTROL IN CHINA

《农业科学与工程前沿(英文)》 2023年 第10卷 第4期   页码 593-606 doi: 10.15302/J-FASE-2023522

摘要:

Ensuring food safety while reducing agricultural non-point source pollution is quite challenging, especially in developing and underdeveloped countries. Effective systematic strategies and comprehensive technologies need to be developed for agricultural non-point source pollution control at the watershed scale to improve surface water quality. In this review, a proposal is made for a full time-space governance strategy that prioritizes source management followed by endpoint water pollution control. The 4R chain technology system is specifically reviewed, including source reduction, process retention, nutrient reuse and water restoration. The 4R chain technology system with the full time-space governance strategy was applied at the scale of an administrative village and proved to be a feasible solution for reducing agricultural non-point source pollution in China. In the future, a monitoring system needs to be established to trace N and P transport. Additionally, new smart fertilizer and intelligent equipment need to be developed, and relevant governance standards and supportive policies need to be set to enhance the efficacy of agricultural non-point source pollution control.

关键词: 4R chain technology system     agricultural non-point source pollution     case study     full time-space governance strategy    

Finite element simulation for elastic dislocation of the North-Tehran fault: The effects of geologic

Pooya ZAKIAN; Hossein ASADI HAYEH

《结构与土木工程前沿(英文)》 2022年 第16卷 第4期   页码 533-549 doi: 10.1007/s11709-022-0802-8

摘要: The present study uses the finite element method for simulating the crustal deformation due to the dislocation of a segment of the North-Tehran fault located in the Karaj metropolis region. In this regard, a geological map of Karaj that includes the fault segment is utilized in order to create the geometry of finite element model. First, finite element analysis of homogeneous counterpart of the fault’s domain with two different sections was performed, and the results were compared to those of Okada’s analytical solutions. The fault was modeled with the existing heterogeneity of the domain having been considered. The influences of both uniform and non-uniform slip distributions were investigated. Furthermore, three levels of simplification for geometric creation of geological layers’ boundaries were defined in order to evaluate the effects of the geometric complexity of the geological layering on the displacement responses obtained with the finite element simulations. In addition to the assessment of slip distribution, layering complexity and heterogeneity, the results demonstrate both the capability and usefulness of the proposed models in the dislocation analysis for the Karaj segment of North-Tehran fault.

关键词: finite element method     fault dislocation     slip distribution     the North-Tehran fault     heterogeneity     geological layering    

Adaptive simulation of wave propagation problems including dislocation sources and random media

Hassan YOUSEFI, Jamshid FARJOODI, Iradj MAHMOUDZADEH KANI

《结构与土木工程前沿(英文)》 2019年 第13卷 第5期   页码 1054-1081 doi: 10.1007/s11709-019-0536-4

摘要: An adaptive Tikhonov regularization is integrated with an h-adaptive grid-based scheme for simulation of elastodynamic problems, involving seismic sources with discontinuous solutions and random media. The Tikhonov method is adapted by a newly-proposed detector based on the MINMOD limiters and the grids are adapted by the multiresolution analysis (MRA) via interpolation wavelets. Hence, both small and large magnitude physical waves are preserved by the adaptive estimations on non-uniform grids. Due to developing of non-dissipative spurious oscillations, numerical stability is guaranteed by the Tikhonov regularization acting as a post-processor on irregular grids. To preserve waves of small magnitudes, an adaptive regularization is utilized: using of smaller amount of smoothing for small magnitude waves. This adaptive smoothing guarantees also solution stability without over smoothing phenomenon in stochastic media. Proper distinguishing between noise and small physical waves are challenging due to existence of spurious oscillations in numerical simulations. This identification is performed in this study by the MINMOD limiter based algorithm. Finally, efficiency of the proposed concept is verified by: 1) three benchmarks of one-dimensional (1-D) wave propagation problems; 2) P-SV point sources and rupturing line-source including a bounded fault zone with stochastic material properties.

关键词: adaptive wavelet     adaptive smoothing     discontinuous solutions     stochastic media     spurious oscillations     Tikhonov regularization     minmod limiter    

农业面源污染现状及防控技术

武淑霞, 刘宏斌, 刘申, 王耀生, 谷保静, 金书秦, 雷秋良, 翟丽梅, 王洪媛

《中国工程科学》 2018年 第20卷 第5期   页码 23-30 doi: 10.15302/J-SSCAE-2018.05.004

摘要:

农业面源污染是造成我国水环境污染的主要因素之一,具有随机性强、污染排放不固定、污染负荷变化大等特点,防治较点源污染更为困难,了解农业面源污染现状及其防控技术是进行面源污染治理的前提。本文概述了农业面源污染成因及其现状,指出种植业中肥料的不合理施用和规模化畜禽养殖排污是当前最重要的农业面源污染来源,较全面地介绍了种植业和畜禽养殖业中较为成熟的面源污染防控技术,提出“源头控制为主、过程阻控与末端治理相结合”是当前进行农业面源污染防控的主要途径,应因地制宜地采用相应的面源污染防控技术,实现环境效益、经济效益和社会效益的同步发展。

关键词: 农业面源污染     农田养分流失     畜禽养殖排污     防控技术    

标题 作者 时间 类型 操作

An end-to-end 3d seismic simulation of underground structures due to point dislocation source by using

Zhenning BA; Jisai FU; Zhihui ZHU; Hao ZHONG

期刊论文

STRENGTHENING NON-POINT SOURCE POLLUTION CONTROL TO PROMOTE AGRICULTURAL GREEN DEVELOPMENT

期刊论文

DITCHES AND PONDS CAN BE THE SOURCES OR SINKS OF NON-POINT SOURCE POLLUTION: OBSERVATIONS IN AN UPLAND

期刊论文

REDUCTION OF NON-POINT SOURCE POLLUTION IN THE YONG’AN RIVER BY CONSTRUCTED WETLAND BASED ON 9 YEARS

期刊论文

Control division of agricultural non-point source pollution at medium-sized watershed scale in Southeast

HUANG Jinliang, HONG Huasheng, ZHANG Luoping

期刊论文

Modeling agricultural non-point source pollution in a high-precipitation coastal area of China

Zhiyi LI,Pengfei DU,Haiwei HUANG,Yong Ge,Xu LI

期刊论文

Role of rural solid waste management in non-point source pollution control of Dianchi Lake catchments

LU Wenjing, WANG Hongtao

期刊论文

induced by interaction burning of tri-symmetric propane fires in open space based on weighted multi-pointsource model

Jie JI, Junrui DUAN, Huaxian WAN

期刊论文

Loss coefficient of nitrogenous non-point source pollution under various precipitation conditions

CHENG Hongguang, HAO Fanghua, REN Xiyan, YANG Shengtian, XIONG Wen, LEI Shaoping

期刊论文

滇池流域点源污染负荷总量变化趋势及原因分析

何佳,徐晓梅,陈云波,张琨玲,李跃勋,李中杰

期刊论文

INTERACTIVE KNOWLEDGE LEARNING BY ARTIFICIAL INTELLIGENCE FOR SMALLHOLDERS

期刊论文

FULL TIME-SPACE GOVERNANCE STRATEGY AND TECHNOLOGY FOR CROPLAND NON-POINT POLLUTION CONTROL IN CHINA

期刊论文

Finite element simulation for elastic dislocation of the North-Tehran fault: The effects of geologic

Pooya ZAKIAN; Hossein ASADI HAYEH

期刊论文

Adaptive simulation of wave propagation problems including dislocation sources and random media

Hassan YOUSEFI, Jamshid FARJOODI, Iradj MAHMOUDZADEH KANI

期刊论文

农业面源污染现状及防控技术

武淑霞, 刘宏斌, 刘申, 王耀生, 谷保静, 金书秦, 雷秋良, 翟丽梅, 王洪媛

期刊论文