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Efficiency measurement for mixed two-stage nonhomogeneous network processes with shared extra intermediate

Qingxian AN, Xuyang LIU, Shijie DING

《工程管理前沿（英文）》 2020年 第7卷 第2期   页码 259-274 doi: 10.1007/s42524-019-0080-x

摘要： Unreasonable allocation of shared resources reduces the system efficiency and is a considerable operational risk. Sub-processes with insufficient portion of shared resources could not help accomplish complicated tasks, and overstaffing and idle resources will occur in the sub-processes assigned with redundant shared resources. This unfair portion distribution may cause internal contradictions among sub-processes and even lead to the collapsing of the entire system. This study proposes a data-driven, mixed two-stage network data envelopment analysis model. This method aims to reasonably define the allocation portion of shared extra intermediate resources among several nonhomogeneous subsystems and measure the overall system performance. A data set of 58 international hotels is used to test the features of the proposed model.

关键词： shared resource allocation     mixed two-stage system     data envelopment analysis     efficiency    

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Long-term observation of air pollution-weather/climate interactions at the SORPES station: a review and outlook

Aijun Ding,Wei Nie,Xin Huang,Xuguang Chi,Jianning Sun,Veli-Matti Kerminen,Zheng Xu,Weidong Guo,Tuukka Petäjä,Xiuqun Yang,Markku Kulmala,Congbin Fu

《环境科学与工程前沿（英文）》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0877-3

摘要： The concept design and detailed information of the SORPES station are introduced. Main scientific findings based 5-year measurements at the station are summarized. The future outlook of the development plan and its implications are discussed. The results improved understanding of interaction of physical and chemical processes. More SORPES-type stations are need to in different regions in China and the world. This work presents an overall introduction to the Station for Observing Regional Processes of the Earth System – SORPES in Nanjing, East China, and gives an overview about main scientific findings in studies of air pollution-weather/climate interactions obtained since 2011. The main results summarized in this paper include overall characteristics of trace gases and aerosols, chemical transformation mechanisms for secondary pollutants like O , HONO and secondary inorganic aerosols, and the air pollution – weather/climate interactions and feedbacks in mixed air pollution plumes from sources like fossil fuel combustion, biomass burning and dust storms. The future outlook of the development plan on instrumentation, networking and data-sharing for the SORPES station is also discussed.

关键词： Secondary pollution     Ground-based measurement     Planetary boundary layer meteorology     Earth system processes    

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Optimization and Management of Mining Engineering—Coordinative Operation and Optimal Management of Five processes

An-lin Shao,Rui-yu Yin

《工程管理前沿（英文）》 2014年 第1卷 第2期   页码 153-159 doi: 10.15302/J-FEM-2014023

摘要： In the view of engineering philosophy, the mining engineering is a dynamic operating process of ferrous material flow, in which the ferrous material flow is processed orderly through a series of continual coordinated procedures. It is also a process of discarding the dross, selecting the essential, and extracting the original metal. The object of management is to fulfill the multi-objective optimization. The proportion of lean ores in iron ore resources is 82% in the world and even 97% in China but their utilization is very low. Aiming at the bottleneck and weakness of China’s resource development, this paper analyzes and plans the mining engineering system as a whole based on the ideas and methods of system theory and engineering philosophical thinking. And the paper proposes the “grade decision-based multi-system integration” engineering management mode, which considers the relationship between engineering and environment and complies with the natural law. In the mode, the mining engineering, including geologic mining, ore blending, concentration and pelleting, can be viewed as a whole and the geological grade, mined ore grade, feed grade, concentrate grade and feed grade of blast furnace can be considered comprehensively. The mode reflected the overall structural optimization idea, realized the analysis, coordination and optimization among the multiple functions and processes, and thus drove the overall efficient and profit optimization throughout the processing flow. The establishment and the application of the “grade decision-based multi-system integration” mode have solved the lean iron ores exploitation problem and supported the “self-sufficiency” resource strategy.

关键词： multi-system integration     engineering management     objective optimization     lean ores exploitation     engineering philosophy     mode    

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Effect of earth reinforcement, soil properties and wall properties on bridge MSE walls

《结构与土木工程前沿（英文）》 2021年 第15卷 第5期   页码 1209-1221 doi: 10.1007/s11709-021-0764-2

摘要： Mechanically stabilized earth (MSE) retaining walls are popular for highway bridge structures. They have precast concrete panels attached to earth reinforcement. The panels are designed to have some lateral movement. However, in some cases, excessive movement and even complete dislocation of the panels have been observed. In this study, 3-D numerical modeling involving an existing MSE wall was undertaken to investigate various wall parameters. The effects of pore pressure, soil cohesion, earth reinforcement type and length, breakage/slippage of reinforcement and concrete strength, were examined. Results showed that the wall movement is affected by soil pore pressure and reinforcement integrity and length, and unaffected by concrete strength. Soil cohesion has a minor effect, while the movement increased by 13–20 mm for flexible geogrid reinforced walls compared with the steel grid walls. The steel grid stresses were below yielding, while the geogrid experienced significant stresses without rupture. Geogrid reinforcement may be used taking account of slippage resistance and wall movement. If steel grid is used, non-cohesive soil is recommended to minimize corrosion. Proper soil drainage is important for control of pore pressure.

关键词： mechanically stabilized earth walls     precast concrete panels     backfill soil     finite element modeling     earth reinforcement    

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朝鲜半岛构造系统地质环境演化及动力学机制的地球卫星遥感影像解译研究

胡东生,张华京,徐冰,田新洪,张国伟

《中国工程科学》 2007年 第9卷 第12期   页码 31-38

摘要： 采用将东亚地区综合资料分析成果与地球卫星遥感影像解译相结合的方法，深入研究了全球构造域中典型的构造地段朝鲜地块。详细识别出朝鲜半岛地区的基本构造形式，其基本类型主要有环形构造（及辐射构造）、追踪构造、共轭构造、菱形构造、多米诺构造等；对其构造地质环境演化过程及地球动力学机制进行了宏观阐述， 晚古生代之前朝鲜半岛是由中国东部三个不同板块（华北板块、扬子板块、华南板块）贴拼焊接而成，中生代隆起成陆以后遭受了三期构造运动的影响（松林运动、大宝运动、佛国寺运动），新生代发生了玉岭运动。朝鲜地块基本构造形式的形成受

关键词： 地球卫星遥感影像解译；构造系统基本类型；地质环境演化过程；地球动力学机制；朝鲜半岛    

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Emerging electrochemical processes for materials recovery from wastewater: Mechanisms and prospects

Lingchen Kong, Xitong Liu

《环境科学与工程前沿（英文）》 2020年 第14卷 第5期 doi: 10.1007/s11783-020-1269-2

摘要： Abstract • Mechanisms for selective recovery of materials in electrochemical processes are discussed. • Wastewaters that contain recoverable materials are reviewed. • Application prospects are discussed from both technical and non-technical aspects. Recovering valuable materials from waste streams is critical to the transition to a circular economy with reduced environmental damages caused by resource extraction activities. Municipal and industrial wastewaters contain a variety of materials, such as nutrients (nitrogen and phosphorus), lithium, and rare earth elements, which can be recovered as value-added products. Owing to their modularity, convenient operation and control, and the non-requirement of chemical dosage, electrochemical technologies offer a great promise for resource recovery in small-scale, decentralized systems. Here, we review three emerging electrochemical technologies for materials recovery applications: electrosorption based on carbonaceous and intercalation electrodes, electrochemical redox processes, and electrochemically induced precipitation. We highlight the mechanisms for achieving selective materials recovery in these processes. We also present an overview of the advantages and limitations of these technologies, as well as the key challenges that need to be overcome for their deployment in real-world systems to achieve cost-effective and sustainable materials recovery.

关键词： Materials recovery     Electrosorption     Capacitive deionization     Redox processes     Electrochemical precipitation    

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Numerical analysis of nonlinear dynamic behavior of earth dams

Babak EBRAHIMIAN

《结构与土木工程前沿（英文）》 2011年 第5卷 第1期   页码 24-40 doi: 10.1007/s11709-010-0082-6

摘要： A numerical study is conducted to investigate the dynamic behavior of earth dams. The numerical investigation employs a fully nonlinear dynamic finite difference analysis incorporating a simple elastic perfectly plastic constitutive model to describe the stress-strain response of the soil and the Rayleigh damping to increase the level of hysteretic damping. The extended Masing rules are implemented into the constitutive model to explain more accurately the soil response under general cyclic loading. The soil stiffness and hysteretic damping change with loading history. The procedures for calibrating the constructed numerical model with centrifuge test data and also a real case history are explained. For the latter, the Long Valley (LV) earth dam subjected to the 1980 Mammoth Lake earthquake as a real case-history is analyzed and the obtained numerical results are compared with the real measurements at the site in both the time and frequency domains. Relatively good agreement is observed between computed and measured quantities. It seems that the Masing rules combined with a simple elasto-plastic model gives reasonable numerical predictions. Afterwards, a comprehensive parametric study is carried out to identify the effects of dam height, input motion characteristics, soil behavior, strength of the shell materials and dam reservoir condition on the dynamic response of earth dams. Three real earthquake records with different levels and peak acceleration values (PGAs) are used as input motions. The results show that the crest acceleration decreases when the dam height increases and no amplification is observed. Further, more inelastic behavior and more earthquake energy absorption are observed in higher dams.

关键词： earth dam     numerical     nonlinear response     dynamic analysis     earthquake     dam height    

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Deviation correction strategy for the earth pressure balance shield based on shield–soil interactions

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0676-4

摘要： The control system presently used in shield posture rectification is based on driver experience, which is marginally reliable. The study of the related theory is flawed. Therefore, a decision-making approach for the deviation correction trajectory and posture rectification load for an earth pressure balance (EPB) shield is proposed. A calculation model of posture rectification load of an EPB shield is developed by considering the interactions among the cutter head, shield shell, and ground. The additional position change during the shield attitude correction is highlighted. The posture rectification loads and shield behaviors results can be solved by the proposed method. The influences of the stratum distribution (i.e., bedrock height in the upper-soft and lower-hard strata) on shield behaviors and posture rectification loads are analyzed. Results indicated that the increase of pitch angle in the upper-soft and lower-hard strata causes a sharp rise in vertical displacement. The bedrock height increases the magnitudes of the required posture rectification moments when hr/D > 0.5. For a tunnel with hr/D ≤ 0.5, the variation of hr/D has little effect on the posture rectification moments. Finally, the posture rectifying curves based on the theoretical model are compared with the target ones based on the double circular arc interpolation method. The required results can be obtained regardless of the soil–rock compound stratum distribution. The maximum rectification moment in the rock layer is almost 12.6 times that in the soil layer. Overall, this study provides a valuable reference for moment determination and the trajectory prediction of posture rectification in compound strata.

关键词： additional position change     deviation correction trajectory     earth pressure balance shield     mechanical model     posture rectification    

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A new approach for scheduling of multipurpose batch processes with unlimited intermediate storage policy

Nikolaos Rakovitis, Nan Zhang, Jie Li, Liping Zhang

《化学科学与工程前沿（英文）》 2019年 第13卷 第4期   页码 784-802 doi: 10.1007/s11705-019-1858-4

摘要： The increasing demand of goods, the high competitiveness in the global marketplace as well as the need to minimize the ecological footprint lead multipurpose batch process industries to seek ways to maximize their productivity with a simultaneous reduction of raw materials and utility consumption and efficient use of processing units. Optimal scheduling of their processes can lead facilities towards this direction. Although a great number of mathematical models have been developed for such scheduling, they may still lead to large model sizes and computational time. In this work, we develop two novel mathematical models using the unit-specific event-based modelling approach in which consumption and production tasks related to the same states are allowed to take place at the same event points. The computational results demonstrate that both proposed mathematical models reduce the number of event points required. The proposed unit-specific event-based model is the most efficient since it both requires a smaller number of event points and significantly less computational time in most cases especially for those examples which are computationally expensive from existing models.

关键词： scheduling     multipurpose batch processes     simultaneous transfer     mixed-integer linear programming    

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Soil spatial variability impact on the behavior of a reinforced earth wall

Adam HAMROUNI, Daniel DIAS, Badreddine SBARTAI

《结构与土木工程前沿（英文）》 2020年 第14卷 第2期   页码 518-531 doi: 10.1007/s11709-020-0611-x

摘要： This article presents the soil spatial variability effect on the performance of a reinforced earth wall. The serviceability limit state is considered in the analysis. Both cases of isotropic and anisotropic non-normal random fields are implemented for the soil properties. The Karhunen-Loève expansion method is used for the discretization of the random field. Numerical finite difference models are considered as deterministic models. The Monte Carlo simulation technique is used to obtain the deformation response variability of the reinforced soil retaining wall. The influences of the spatial variability response of the geotechnical system in terms of horizontal facing displacement is presented and discussed. The results obtained show that the spatial variability has an important influence on the facing horizontal displacement as well as on the failure probability.

关键词： reinforced earth wall     geosynthetic     random field     spatial variability     Monte Carlo simulation    

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Upper bound solution to seismic active earth pressure of submerged backfill subjected to partial drainage

《结构与土木工程前沿（英文）》 2021年 第15卷 第6期   页码 1480-1493 doi: 10.1007/s11709-021-0776-y

摘要： In waterfront geotechnical engineering, seismic and drainage conditions must be considered in the design of retaining structures. This paper proposes a general analytical method to evaluate the seismic active earth pressure on a retaining wall with backfill subjected to partial steady seepage flow under seismic conditions. The method comprises the following steps: i) determination of the total head, ii) upper bound solution of seismic active earth thrust, and iii) deduction for the earth pressure distribution. The determination of total head h(x,z) relies on the Fourier series expansions, and the expressions of the seismic active earth thrust and pressure are derived by using the upper bound theorem. Parametric studies reveal that insufficient drainage and earthquakes are crucial factors that cause unfavorable earth pressure. The numerical results confirm the validity of the total head distribution. Comparisons indicate that the proposed method is consistent with other relevant existing methods in terms of predicting seismic active earth pressure. The method can be applied to the seismic design of waterfront retaining walls.

关键词： seismic active earth pressure     partial seepage flow     pore pressure     anisotropy     upper bound theorem    

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Rare-earth separation based on the differences of ionic magnetic moment via quasi-liquid strategy

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1584-1594 doi: 10.1007/s11705-022-2189-4

摘要： The separation of rare earth elements is particularly difficult due to their similar physicochemical properties. Based on the tiny differences of ionic radius, solvent extraction has been developed as the “mass method” in industry with hundreds of stages, extremely intensive chemical consumption and large capital investments. The differences of the ionic magnetic moment among rare earths are greater than that of ionic radius. Herein, a novel method based on the large ionic magnetic moment differences of rare earth elements was proposed to promote the separation efficiency. Rare earths were firstly dissolved in the ionic liquid, then the ordering degree of them was improved with the Z-bond effect, and finally the magnetic moment differences between paramagnetic and diamagnetic rare earths in quasi-liquid system were enhanced. Taking the separation of Er/Y, Ho/Y and Er/Ho as examples, the results showed that Er(III) and Ho(III) containing ionic liquids had obvious magnetic response, while ionic liquids containing Y(III) had no response. The separation factors of Er/Y and Ho/Y were achieved at 9.0 and 28.82, respectively. Magnetic separation via quasi-liquid system strategy provides a possibility of the novel, green, and efficient method for rare earth separation.

关键词： rare earth element     different magnetic moment     magnetic separation     ionic liquid    

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Modeling of hydrological processes in arid agricultural regions

Jiang LI,Xiaomin MAO,Shaozhong KANG,David A. BARRY

《农业科学与工程前沿（英文）》 2015年 第2卷 第4期   页码 283-294 doi: 10.15302/J-FASE-2015076

摘要： Understanding of hydrological processes, including consideration of interactions between vegetation growth and water transfer in the root zone, underpins efficient use of water resources in arid-zone agriculture. Water transfers take place in the soil-plant-atmosphere continuum, and include groundwater dynamics, unsaturated zone flow, evaporation/transpiration from vegetated/bare soil and surface water, agricultural canal/surface water flow and seepage, and well pumping. Models can be categorized into three classes: (1) regional distributed hydrological models with various land uses, (2) groundwater-soil-plant-atmosphere continuum models that neglect lateral water fluxes, and (3) coupled models with groundwater flow and unsaturated zone water dynamics. This review highlights, in addition, future research challenges in modeling arid-zone agricultural systems, e.g., to effectively assimilate data from remote sensing, and to fully reflect climate change effects at various model scales.

关键词： hydrological processes     irrigation area     SPAC     crop growth     groundwater     canal seepage    

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Membrane bioreactors for hospital wastewater treatment: recent advancements in membranes and processes

《化学科学与工程前沿（英文）》 2022年 第16卷 第5期   页码 634-660 doi: 10.1007/s11705-021-2107-1

摘要： Discharged hospital wastewater contains various pathogenic microorganisms, antibiotic groups, toxic organic compounds, radioactive elements, and ionic pollutants. These contaminants harm the environment and human health causing the spread of disease. Thus, effective treatment of hospital wastewater is an urgent task for sustainable development. Membranes, with controllable porous and nonporous structures, have been rapidly developed for molecular separations. In particular, membrane bioreactor (MBR) technology demonstrated high removal efficiency toward organic compounds and low waste sludge production. To further enhance the separation efficiency and achieve material recovery from hospital waste streams, novel concepts of MBRs and their applications are rapidly evolved through hybridizing novel membranes (non hydrophilic ultrafiltration/microfiltration) into the MBR units (hybrid MBRs) or the MBR as a pretreatment step and integrating other membrane processes as subsequent secondary purification step (integrated MBR-membrane systems). However, there is a lack of reviews on the latest advancement in MBR technologies for hospital wastewater treatment, and analysis on its major challenges and future trends. This review started with an overview of main pollutants in common hospital wastewater, followed by an understanding on the key performance indicators/criteria in MBR membranes (i.e., solute selectivity) and processes (e.g., fouling). Then, an in-depth analysis was provided into the recent development of hybrid MBR and integrated MBR-membrane system concepts, and applications correlated with wastewater sources, with a particular focus on hospital wastewaters. It is anticipated that this review will shed light on the knowledge gaps in the field, highlighting the potential contribution of hybrid MBRs and integrated MBR-membrane systems toward global epidemic prevention.

关键词： membrane technology     membrane bioreactor     hospital wastewater     hybrid MBR     integrated MBR-membrane system    

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低轨卫星导航增强技术——机遇与挑战

王磊,李德仁,陈锐志,付文举,沈欣,江昊

《中国工程科学》 2020年 第22卷 第2期   页码 144-152 doi: 10.15302/J-SSCAE-2020.02.018

摘要：

在我国北斗卫星导航系统（北斗系统）初步实现全球能力覆盖的背景下，低轨卫星导航增强（LEO-NA）技术因其易于与北斗系统协同来提高全球自主导航精度、拓展全球卫星导航应用市场的巨大潜力而成为研究热点。本文梳理了发展导航增强技术的现实需求，分析了导航增强技术以及LEO-NA技术的发展现状，重点介绍了我国“珞珈一号”关键技术在轨验证的进展情况。在此基础上，研判了LEO-NA系统未来发展面临的技术挑战，如导航增强频率的兼容互操作、通信/导航信号一体化设计、低轨卫星星座管控、高动态导航增强信号捕获与跟踪、与现有导航系统的融合等。研究提出，针对我国发展LEO-NA技术的迫切需求，可着重在以下方面开展工作：加强系统顶层设计并充分利用现有资源，注重LEO-NA系统与北斗系统的协同增效；促进通信、导航、遥感功能融合，分步骤分层次构建天基信息实时服务系统；将卫星工程与地面基础设施统一规划考虑，实行星地一体化建设。

关键词： 卫星导航增强     低轨卫星星座     北斗系统     协同建设     星地一体化    

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标题 作者 时间 类型 操作

Efficiency measurement for mixed two-stage nonhomogeneous network processes with shared extra intermediate

Qingxian AN, Xuyang LIU, Shijie DING

期刊论文

Long-term observation of air pollution-weather/climate interactions at the SORPES station: a review and outlook

Aijun Ding,Wei Nie,Xin Huang,Xuguang Chi,Jianning Sun,Veli-Matti Kerminen,Zheng Xu,Weidong Guo,Tuukka Petäjä,Xiuqun Yang,Markku Kulmala,Congbin Fu

期刊论文

Optimization and Management of Mining Engineering—Coordinative Operation and Optimal Management of Five processes

An-lin Shao,Rui-yu Yin

期刊论文

Effect of earth reinforcement, soil properties and wall properties on bridge MSE walls

期刊论文

朝鲜半岛构造系统地质环境演化及动力学机制的地球卫星遥感影像解译研究

胡东生,张华京,徐冰,田新洪,张国伟

期刊论文

Emerging electrochemical processes for materials recovery from wastewater: Mechanisms and prospects

Lingchen Kong, Xitong Liu

期刊论文

Numerical analysis of nonlinear dynamic behavior of earth dams

Babak EBRAHIMIAN

期刊论文

Deviation correction strategy for the earth pressure balance shield based on shield–soil interactions

期刊论文

A new approach for scheduling of multipurpose batch processes with unlimited intermediate storage policy

Nikolaos Rakovitis, Nan Zhang, Jie Li, Liping Zhang

期刊论文

Soil spatial variability impact on the behavior of a reinforced earth wall

Adam HAMROUNI, Daniel DIAS, Badreddine SBARTAI

期刊论文

Upper bound solution to seismic active earth pressure of submerged backfill subjected to partial drainage

期刊论文

Rare-earth separation based on the differences of ionic magnetic moment via quasi-liquid strategy

期刊论文

Modeling of hydrological processes in arid agricultural regions

Jiang LI,Xiaomin MAO,Shaozhong KANG,David A. BARRY

期刊论文

Membrane bioreactors for hospital wastewater treatment: recent advancements in membranes and processes

期刊论文

低轨卫星导航增强技术——机遇与挑战

王磊,李德仁,陈锐志,付文举,沈欣,江昊

期刊论文