资源类型

期刊论文 964

会议视频 19

会议专题 1

年份

2023 73

2022 106

2021 78

2020 49

2019 51

2018 44

2017 41

2016 47

2015 52

2014 51

2013 42

2012 54

2011 38

2010 48

2009 39

2008 31

2007 34

2006 20

2005 11

2004 10

展开 ︾

关键词

水资源 16

细水雾 14

可持续发展 6

泥水盾构 6

反渗透 5

水环境 4

环境 4

砂卵石地层 4

超滤 4

三峡工程 3

农业节水 3

半旱地农业 3

绿色化工 3

GIS 2

Preissmann格式 2

中国西北地区 2

京津冀 2

优化 2

创新 2

展开 ︾

检索范围:

排序: 展示方式:

System engineering for water pollution control at the watershed level in China

Wei MENG,

《环境科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 443-452 doi: 10.1007/s11783-009-0037-0

摘要: The present water pollution situation at watershed level in China has been systematically analyzed. The causes of water pollution are attributed to the extensive economic developmental pattern, poor wastewater treatment, and a lack of nonpoint pollution control. The problems of water pollution control at watershed level include a lack of thought and approach, developmental delay in the environmental standard system, an inadequate monitoring ability, and an inefficient implementation of laws and regulations. From 2006 to 2020, water pollution control and governance will be a national key specific project of science and technology in China. The strategies of this project include establishing a water pollution control system at watershed level, orienting a healthy aquatic ecosystem, conducting risk management, and using comprehensive methods. The goal is to establish and complete a technological system of pollution control and management in three five-year phases. The main tasks are to develop common technologies, management systems, and mechanisms for lake eutrophication control, river pollution control, urban water environmental pollution control, potable water safety, and water environmental management. The bottlenecks of water pollution control and management in China could be systematically removed, and the demonstration of the system engineering approach will be conducted at selected key watersheds.

关键词: water pollution control     watershed     system engineering     sustainability     integrated watershed management     key specific project of science and technology    

Three-dimensional fluorescence spectral characterization of soil dissolved organic matters in the fluctuating water-level

Fang FANG, Yan YANG, Jinsong GUO, Hong ZHOU, Chuan FU, Zhe LI

《环境科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 426-434 doi: 10.1007/s11783-010-0264-4

摘要: Three-dimensional fluorescence spectroscopy was used to investigate the fluorescent properties of soil dissolved organic matter (DOM) in the water-level-fluctuation zone (WLFZ) of Kai County, Three Gorges Reservoir (TGR). Most of the soil DOM analyzed in this study was found to contain four fluorescence peaks. Peaks A and C represent humic-like fluorescence, whereas peaks B and D represent tryptophan-like fluorescence. Peaks E and F, which represent tyrosine-like fluorescence, only appeared in certain soils. Soil humus was the main source of DOM in soil, and higher concentration of soil DOM was found in the exposed soil than submerged soil. Compared to the peaks A and B, the fluorescence intensities of peaks C and D were strongly influenced by the fluctuating water level. Analysis of fluorescence intensities of different peaks in soil DOM showed that WLFZ soil was not contaminated significantly. Soil DOM contained at least two types of humic-like fluorescence groups and two types of protein-like fluorescence groups. The proportion of the content of peak A in soil organic matter was quite stable. The soil DOM in exposed soil had relatively high humification and aromaticity, and periodic submerging and exposure of soil had an impact on the humification of soil DOM.

关键词: water-level-fluctuation zone (WLFZ)     soil     dissolved organic matter (DOM)     three-dimensional fluorescence spectra    

Water-level based discrete integrated dynamic control to regulate the flow for sewer-WWTP operation

Zhengsheng Lu, Moran Wang, Mingkai Zhang, Ji Li, Ying Xu, Hanchang Shi, Yanchen Liu, Xia Huang

《环境科学与工程前沿(英文)》 2020年 第14卷 第3期 doi: 10.1007/s11783-020-1222-4

摘要: A model-free sewer-WWTP integrated control was proposed. A dynamic discrete control based on the water level was developed. The approach could improve the sewer operation against flow fluctuation. The approach could increase transport capacity and enhance pump efficiency. This study aims to propose a multi-point integrated real-time control method based on discrete dynamic water level variations, which can be realized only based on the programmable logic controller (PLC) system without using a complex mathematical model. A discretized water level control model was developed to conduct the real-time control based on data-automation. It combines the upstream pumping stations and the downstream influent pumping systems of wastewater treatment plant (WWTP). The discretized water level control method can regulate dynamic wastewater pumping flow of pumps following the dynamic water level variation in the sewer system. This control method has been successfully applied in practical integrated operations of sewer-WWTP following the sensitive flow disturbances of the sewer system. The operational results showed that the control method could provide a more stabilized regulate pumping flow for treatment process; it can also reduce the occurrence risk of combined sewer overflow (CSO) during heavy rainfall events by increasing transport capacity of pumping station and influent flow in WWTP, which takes full advantage of storage space in the sewer system.

关键词: Sewer system     Integrated control     Discrete control     Water level    

Probabilistic stability analysis of Bazimen landslide with monitored rainfall data and water level fluctuations

Wengang ZHANG, Libin TANG, Hongrui LI, Lin WANG, Longfei CHENG, Tingqiang ZHOU, Xiang CHEN

《结构与土木工程前沿(英文)》 2020年 第14卷 第5期   页码 1247-1261 doi: 10.1007/s11709-020-0655-y

摘要: Landslide is a common geological hazard in reservoir areas and may cause great damage to local residents’ life and property. It is widely accepted that rainfall and periodic variation of water level are the two main factors triggering reservoir landslides. In this study, the Bazimen landslide located in the Three Gorges Reservoir (TGR) was back-analyzed as a case study. Based on the statistical features of the last 3-year monitored data and field instrumentations, the landslide susceptibility in an annual cycle and four representative periods was investigated via the deterministic and probabilistic analysis, respectively. The results indicate that the fluctuation of the reservoir water level plays a pivotal role in inducing slope failures, for the minimum stability coefficient occurs at the rapid decline period of water level. The probabilistic analysis results reveal that the initial sliding surface is the most important area influencing the occurrence of landslide, compared with other parts in the landslide. The seepage calculations from probabilistic analysis imply that rainfall is a relatively inferior factor affecting slope stability. This study aims to provide preliminary guidance on risk management and early warning in the TGR area.

关键词: reliability analysis     Bazimen landslide     rainfall     reservoir water level     slope stability    

New insights into the formation of ammonium nitrate from a physical and chemical level perspective

《环境科学与工程前沿(英文)》 2023年 第17卷 第11期 doi: 10.1007/s11783-023-1737-6

摘要:

● Factor analysis of ammonium nitrate formation based on thermodynamic theory.

关键词: Ammonium nitrate formation     Thermodynamic theory     Aerosol liquid water content     Source apportionment    

TRADE-OFFS IN THE DESIGN OF SUSTAINABLE CROPPING SYSTEMS AT A REGIONAL LEVEL: A CASE STUDY ON THE NORTH

《农业科学与工程前沿(英文)》 2022年 第9卷 第2期   页码 295-308 doi: 10.15302/J-FASE-2021434

摘要:

Since the Green Revolution cropping systems have been progressively homogenized and intensified with increasing rates of inputs such as fertilizers, pesticides and water. This has resulted in higher crop productivity but also a high environmental burden due to increased pollution and water depletion. To identify opportunities for increasing the productivity and reducing the environmental impact of cropping systems, it is crucial to assess the associated trade-offs. The paper presents a model-based analysis of how 30 different crop rotations practiced in the North China Plain could be combined at the regional level to overcome trade-offs between indicators of economic, food security, and environmental performance. The model uses evolutionary multi-objective optimization to maximize revenues, livestock products, dietary and vitamin C yield, and to minimize the decline of the groundwater table. The modeling revealed substantial trade-offs between objectives of maximizing productivity and profitability versus minimizing ground water decline, and between production of livestock products and vitamin C yield. Six strategies each defining a specific combination of cropping systems and contributing to different extents to the various objectives were identified. Implementation of these six strategies could be used to find opportunities to mitigate the trade-offs between objectives. It was concluded that a holistic analysis of the potential of a diversity cropping systems at a regional level is needed to find integrative solutions for challenges due to conflicting objectives for food production, economic viability and environmental protection.

关键词: crop rotation / food security / multi-objective optimization / water use    

三峡工程对葛洲坝枢纽下游近坝段水位与航道影响研究

陆永军,陈稚聪,赵连白,邵学军,杨美卿,李云中

《中国工程科学》 2002年 第4卷 第10期   页码 67-72

摘要:

根据实测地形和水文泥沙资料,分析了葛洲坝枢纽运用后宜昌河段的河床冲淤变化、推移质和床沙的粗化以及枯水位的变化。由数学模型计算和物理模型试验成果,预测了三峡工程施工期及初期运用阶段葛洲坝枢纽近坝段水位下降及对通航的影响。

关键词: 葛洲坝枢纽     三峡工程     冲刷     水位下降     船闸与航道     数学模型     物理模型    

平朔东露天煤矿工业场地地下水位变化影响因素分析

林杜军,宫守才,张银洲

《中国工程科学》 2012年 第14卷 第2期   页码 49-53

摘要:

在地下水三维流数值模型研究的基础上,采用参数灵敏度分析的方法,对东露天煤矿工业场地地下水位变化影响因素进行定量分析。结果表明,场地内强风化砂泥岩的渗透性能、填土区大气降水补给能力、盲沟排水能力对工业场地因填土引起的地下水位变化有显著影响。针对这些主要影响因素,进行工业场地各地层渗透系数研究,为完善地面排水系统,控制盲沟质量等提供有力依据,控制工业场地的地下水位上升。

关键词: 数值模型     地下水位变化     影响因素     灵敏度分析    

Simulation of heterogeneous two-phase media using random fields and level sets

George STEFANOU

《结构与土木工程前沿(英文)》 2015年 第9卷 第2期   页码 114-120 doi: 10.1007/s11709-014-0267-5

摘要: The accurate and efficient simulation of random heterogeneous media is important in the framework of modeling and design of complex materials across multiple length scales. It is usually assumed that the morphology of a random microstructure can be described as a non-Gaussian random field that is completely defined by its multivariate distribution. A particular kind of non-Gaussian random fields with great practical importance is that of translation fields resulting from a simple memory-less transformation of an underlying Gaussian field with known second-order statistics. This paper provides a critical examination of existing random field models of heterogeneous two-phase media with emphasis on level-cut random fields which are a special case of translation fields. The case of random level sets, often used to represent the geometry of physical systems, is also examined. Two numerical examples are provided to illustrate the basic features of the different approaches.

关键词: microstructure     random fields     level sets     shape recovery     two-phase media    

The effect of sea level rise on beach morphology of caspian sea coast

M. A. Lashteh NESHAEI, F. GHANBARPOUR

《结构与土木工程前沿(英文)》 2017年 第11卷 第4期   页码 369-379 doi: 10.1007/s11709-017-0398-6

摘要: Study of beach morphology has been one of the most important issues in coastal engineering research projects. Because of the existence of two important coastal areas located in the north and south parts of the Iran, in the present study an analysis of the coastal zone behaviour is made. Bed level elevations are measured and compared with the theoretical equilibrium profile. It is shown that the behaviour of the coastal zone in the region is consistent with the Dean (1991) equilibrium profile. In the next stage, following extensive investigations, the bed level changes due to arise in sea level at different locations in the surf zone are estimated. The mechanism of beach re-treatment due to a rise in sea level is considered based on the simplified model of Dean (1991) in which the mass balance of the sediments is taken into account. Comparison of the equilibrium profiles for different cases of sea level rise, clearly shows that because of the sediment transport induced by the fluctuation of the water level, the beach profile in the surf zone changes accordingly resulting in an erosion in the inner region of the surf zone and an accumulation of sediments towards the offshore.

关键词: wave     coastal zone     beach morphology     evolution     equilibrium profile     sea level rise    

Level set band method: A combination of density-based and level set methods for the topology optimization

Peng WEI, Wenwen WANG, Yang YANG, Michael Yu WANG

《机械工程前沿(英文)》 2020年 第15卷 第3期   页码 390-405 doi: 10.1007/s11465-020-0588-0

摘要: The level set method (LSM), which is transplanted from the computer graphics field, has been successfully introduced into the structural topology optimization field for about two decades, but it still has not been widely applied to practical engineering problems as density-based methods do. One of the reasons is that it acts as a boundary evolution algorithm, which is not as flexible as density-based methods at controlling topology changes. In this study, a level set band method is proposed to overcome this drawback in handling topology changes in the level set framework. This scheme is proposed to improve the continuity of objective and constraint functions by incorporating one parameter, namely, level set band, to seamlessly combine LSM and density-based method to utilize their advantages. The proposed method demonstrates a flexible topology change by applying a certain size of the level set band and can converge to a clear boundary representation methodology. The method is easy to implement for improving existing LSMs and does not require the introduction of penalization or filtering factors that are prone to numerical issues. Several 2D and 3D numerical examples of compliance minimization problems are studied to illustrate the effects of the proposed method.

关键词: level set method     topology optimization     density-based method     level set band    

钢塔节段水平预拼装关键技术研究

张永利,顾碧峰

《中国工程科学》 2010年 第12卷 第4期   页码 48-52

摘要:

通过对泰州长江公路大桥钢塔柱预拼装方案的选择和关键工艺的研究,提出结构形式复杂的钢塔节段预拼装工艺选择原则。在研究了钢塔节段预拼环境的影响、支撑条件、金属接触率等水平预拼装关键工艺控制项点后,成功地解决了泰州桥钢塔节段水平预拼装中的技术难题。钢塔节段水平预拼装填补了我国钢塔制造的技术空白,为后续复杂钢塔节段水平预拼装方案选择提供了有力基础。

关键词: 钢塔     水平预拼装     支撑控制     水平力施加    

Two-level uncapacitated lot-sizing problem considering the financing cost of working capital requirement

Yuan BIAN, David LEMOINE, Thomas G. YEUNG, Nathalie BOSTEL

《工程管理前沿(英文)》 2020年 第7卷 第2期   页码 248-258 doi: 10.1007/s42524-019-0069-5

摘要: During financial crisis, companies constantly need free cash flows to efficiently react to any uncertainty, thus ensuring solvency. Working capital requirement (WCR) has been recognized as a key factor for releasing tied up cash in companies. However, in literatures related to lot-sizing problem, WCR has only been studied in the single-level supply chain context. In this paper, we initially adopt WCR model for a multi-level case. A two-level (supplier–customer) model is established on the basis of the classic multi-level lot-sizing model integrated with WCR financing cost. To tackle this problem, we propose sequential and centralized approaches to solve the two-level case with a serial chain structure. The ZIO (Zero Inventory Ordering) property is further confirmed valid in both cases. This property allows us to establish a dynamic programming-based algorithm, which solves the problem in O(T ). Finally, numerical tests show differences in optimal plans obtained by both approaches and the influence of varying delays in payment on the WCR of both actors.

关键词: two-level ULS problem     lot-sizing     working capital requirement     ZIO property     infinite production capacity    

Understanding the demand predictability of bike share systems: A station-level analysis

《工程管理前沿(英文)》   页码 551-565 doi: 10.1007/s42524-023-0279-8

摘要: Predicting demand for bike share systems (BSSs) is critical for both the management of an existing BSS and the planning for a new BSS. While researchers have mainly focused on improving prediction accuracy and analysing demand-influencing factors, there are few studies examining the inherent randomness of stations’ observed demands and to what degree the demands at individual stations are predictable. Using Divvy bike-share one-year data from Chicago, USA, we measured demand entropy and quantified the station-level predictability. Additionally, to verify that these predictability measures could represent the performance of prediction models, we implemented two commonly used demand prediction models to compare the empirical prediction accuracy with the calculated entropy and predictability. Furthermore, we explored how city- and system-specific temporally-constant features would impact entropy and predictability to inform estimating these measures when historical demand data are unavailable. Our results show that entropy of demands across stations is polarized as some stations exhibit high uncertainty (a low entropy of 0.65) and others have almost no check-out demand uncertainty (a high entropy of around 1.0). We also validated that the entropy and predictability are a priori model-free indicators for prediction error, given a sequence of bike usage demands. Lastly, we identified that key factors contributing to station-level entropy and predictability include per capita income, spatial eccentricity, and the number of parking lots near the station. Findings from this study provide more fundamental understanding of BSS demand prediction, which can help decision makers and system operators anticipate diverse station-level prediction errors from their prediction models both for existing stations and for new ones.

关键词: bike share systems     demand prediction     prediction errors     machine learning     entropy    

水电站叠梁门多层取水下泄水温公式

高学平,陈弘,宋慧芳

《中国工程科学》 2011年 第13卷 第12期   页码 63-67

摘要:

对于温度成层型水库,水电站进水口分层取水方式通常被采用,目的是有选择地取用水库的不同层水体,减免下泄低温水对下游河流环境的负面影响。目前缺乏简单实用的分层取水下泄水温的预测公式。笔者针对糯扎渡水电站工程,试验模拟水库水温分布,量测下泄水温;依据大量的试验数据,建立下泄水温预测公式;所提出的公式得到了锦屏一级电站下泄水温试验数据的验证。

关键词: 温度成层型水库     水电站进水口     叠梁门     下泄水温公式     模型试验    

标题 作者 时间 类型 操作

System engineering for water pollution control at the watershed level in China

Wei MENG,

期刊论文

Three-dimensional fluorescence spectral characterization of soil dissolved organic matters in the fluctuating water-level

Fang FANG, Yan YANG, Jinsong GUO, Hong ZHOU, Chuan FU, Zhe LI

期刊论文

Water-level based discrete integrated dynamic control to regulate the flow for sewer-WWTP operation

Zhengsheng Lu, Moran Wang, Mingkai Zhang, Ji Li, Ying Xu, Hanchang Shi, Yanchen Liu, Xia Huang

期刊论文

Probabilistic stability analysis of Bazimen landslide with monitored rainfall data and water level fluctuations

Wengang ZHANG, Libin TANG, Hongrui LI, Lin WANG, Longfei CHENG, Tingqiang ZHOU, Xiang CHEN

期刊论文

New insights into the formation of ammonium nitrate from a physical and chemical level perspective

期刊论文

TRADE-OFFS IN THE DESIGN OF SUSTAINABLE CROPPING SYSTEMS AT A REGIONAL LEVEL: A CASE STUDY ON THE NORTH

期刊论文

三峡工程对葛洲坝枢纽下游近坝段水位与航道影响研究

陆永军,陈稚聪,赵连白,邵学军,杨美卿,李云中

期刊论文

平朔东露天煤矿工业场地地下水位变化影响因素分析

林杜军,宫守才,张银洲

期刊论文

Simulation of heterogeneous two-phase media using random fields and level sets

George STEFANOU

期刊论文

The effect of sea level rise on beach morphology of caspian sea coast

M. A. Lashteh NESHAEI, F. GHANBARPOUR

期刊论文

Level set band method: A combination of density-based and level set methods for the topology optimization

Peng WEI, Wenwen WANG, Yang YANG, Michael Yu WANG

期刊论文

钢塔节段水平预拼装关键技术研究

张永利,顾碧峰

期刊论文

Two-level uncapacitated lot-sizing problem considering the financing cost of working capital requirement

Yuan BIAN, David LEMOINE, Thomas G. YEUNG, Nathalie BOSTEL

期刊论文

Understanding the demand predictability of bike share systems: A station-level analysis

期刊论文

水电站叠梁门多层取水下泄水温公式

高学平,陈弘,宋慧芳

期刊论文