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Coupled solid-fluid FE-analysis of an embankment dam

Michael PERTL, Matthias HOFMANN, Guenter HOFSTETTER

《结构与土木工程前沿（英文）》 2011年第5卷第1期页码 53-62 doi: 10.1007/s11709-010-0084-4

摘要： A coupled solid-fluid FE-model for partially saturated soils, characterized by modeling the soil as a three-phase material consisting of a deformable soil skeleton and the fluid phases water and air, is reviewed briefly. As a constitutive model for the soil skeleton, the well-known Barcelona Basic model (BBM) is employed, which is formulated in terms of net stress and matric suction. For the BBM, a computationally efficient return mapping algorithm is proposed, which only requires the solution of a scalar nonlinear equation at the integration point level. The coupled FE-model is applied to the coupled transient numerical simulation of the water flow and the deformations and stresses in an embankment dam.

关键词： multi-phase model unsaturated soil model Barcelona Basic model (BBM) return mapping algorithm embankment dam

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Financing climate-resilient infrastructure: Determining risk, reward, and return on investment

Peter B. MEYER, Reimund SCHWARZE

《工程管理前沿（英文）》 2019年第6卷第1期页码 117-127 doi: 10.1007/s42524-019-0009-4

摘要：

Urban infrastructure investment is needed for both, mitigation of climate risks and improved urban resiliency. Financing them requires the translation of those benefits into measurable returns on investment in the context of emerging risks that capital markets can understand and appreciate. This paper develops a generic framework to identify what are the necessary and sufficient factors to economically favor climate-change resilient infrastructure in private investment decisions. We specifically demonstrate that carbon pricing alone will not generate the needed will, because market prices at present systematically fail to account for climate change risks such as the costs of stranded assets and the national and local co-benefits of investments in climate resiliency. Carbon pricing is necessary, but not sufficient for an enhanced private financing of climate-resilient infrastructure. The Paris Agreement and other supra-local policies and actors including city networks can concretely help to generate the sufficient social and political will for investments into climate change mitigation and resiliency at the city level.

关键词： infrastructure urban finance climate low carbon economy

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Land use/cover change effects on floods with different return periods: a case study of Beijing, China

Yueling WANG, Xiaoliu YANG

《环境科学与工程前沿（英文）》 2013年第7卷第5期页码 769-776 doi: 10.1007/s11783-013-0542-z

摘要： In this study, an approach integrating digital land use/cover change (LUCC) analysis, hydraulic modeling and statistical methods was applied to quantify the effect of LUCC on floods in terms of inundation extent, flood arrival time and maximum water depth. The study took Beijing as an example and analyzed five specific floods with return periods of 20-year, 50-year, 100-year, 1000-year and 10000-year on the basis of LUCC over a nine-year period from 1996 to 2004. The analysis reveals that 1) during the period of analysis Beijing experienced unprecedented LUCC; 2) LUCC can affect inundation extent and flood arrival time, and floods with longer return periods are more influenced; 3) LUCC can affect maximum water depth and floods with shorter return periods are more influenced; and 4) LUCC is a major flood security stressor for Beijing. It warns that those cities having experienced rapid expansion during recent decades in China are in danger of more serious floods and recommends that their actual land use patterns should be carefully assessed considering flood security. This integrated approach is demonstrated to be a useful tool for joint assessment, planning and management of land and water.

关键词： inundation extent flood arrival time maximum water depth shallow flow model

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Chemical mapping of cement pastes by using confocal Raman spectroscopy

Fengjuan LIU,Zhihui SUN

《结构与土木工程前沿（英文）》 2016年第10卷第2期页码 168-173 doi: 10.1007/s11709-015-0323-9

摘要： In the present study, chemical mapping on the hydration process of cement paste with water-to-cement ( / ) ratio of 0.60 was implemented by Raman spectroscopy (RS). The RS was applied to study the paste from 12 hours after mixing to 28 days. Cement ingredients and hydration products, including calcium silicates (C S and C S), calcium hydroxide (CH), and ettringite, were quantitatively studied. From the research, it is observed that calcium silicates were consumed gradually with the increased hydration age. Calcium hydroxide increased and tended to cluster in the pore vicinity during hydration. Ettringite was found to form on the surface of the unreacted particles, which was shown as a mixed zone of ettringite and calcium silicates in the maps. It is concluded from the study that chemical mapping was an effective method to assist in visualizing particle dispersion and connection on top of the quantitative analysis.

关键词： chemical mapping Raman spectroscopy calcium silicates calcium hydroxide ettringite

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Independent continuous and mapping method of structural topology optimization based on the global stress

Yunkang SUI, Jili FENG, Hongling YE, Xirong PENG,

《机械工程前沿（英文）》 2010年第5卷第2期页码 130-142 doi: 10.1007/s11465-010-0011-3

摘要： There are three difficulties in topology optimization of continuum structures. 1) The topology under multiple load case is more difficult to be optimized than under single load case, because the former becomes a multiple objective based on compliance objective functions. 2) With local constraints, such as an elemental stress limit, the topology is more difficult to be solved than with global constraints, such as the displacement or frequency limits, because the sensitivity analysis of the former has very expensive computation. 3) With the phenomenon of load illness, which is similar with stiffness illness in the structural analysis, it is not easy to get the reasonable final topological structure, because it is difficult to consider different influences between the loads with small forces and big forces, and some topology paths of transferring small forces may disappear during the iteration process. To overcome difficulties above, four measures are adopted. 1) Topology optimization model is established by independent continuous mapping (ICM) method. 2) Based on the von Mises strength theory, all elements’ stress constraints are transformed into a structural energy constraint. 3) The phenomenon of load illness is divided to classify into three cases. 4) A strategy based on strain energy is proposed to adopt ICM method with stress globalization, and the problems of the above mentioned three cases of load illness are solved in terms of different complementary approaches. Several numerical examples show that the topology path of transferring forces can be obtained more easily by substituting global strain energy constraints for local stresses constraints, and the problem of load illness can be solved well by the weighting method that takes the structural energy as a weighting coefficient.

关键词： independent continuous mapping (ICM) method global stresses constraints topology optimization continuum structure load illness

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A survey of photon mapping state-of-the-art research and future challenges

Chun-meng KANG,Lu WAN,Yan-ning XU,Xiang-xu MENG

《信息与电子工程前沿（英文）》 2016年第17卷第3期页码 185-199 doi: 10.1631/FITEE.1500251

摘要： Global illumination is the core part of photo-realistic rendering. The photon mapping algorithm is an effective method for computing global illumination with its obvious advantage of caustic and color bleeding rendering. It is an active research field that has been developed over the past two decades. The deficiency of precise details and efficient rendering are still the main challenges of photon mapping. This report reviews recent work and classifies it into a set of categories including radiance estimation, photon relaxation, photon tracing, progressive photon mapping, and parallel methods. The goals of our report are giving readers an overall introduction to photon mapping and motivating further research to address the limitations of existing methods.

关键词： Global illumination Photon mapping Radiance estimation Photon relaxation Progressive photon mapping

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and future research directions for the phytoremediation of heavy metal-contaminated soil: A knowledge mapping

《环境科学与工程前沿（英文）》 2022年第16卷第6期 doi: 10.1007/s11783-021-1507-2

摘要：

• The overall global perspective of the PHMCS field was obtained.

关键词： Heavy metal-contaminated soil Hot topics Knowledge mapping analysis Knowledge base Phytoremediation

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偏振模色散对高速光码的影响

饶敏,孙小菡,张明德

《中国工程科学》 2002年第4卷第11期页码 67-70

摘要：

研究一阶、二阶偏振模色散（PMD）对10 Gb/s和40 Gb/s的光传输系统性能的影响，考虑PMD的统计特性，基于基本偏振态（PSP）理论数值模拟了非归零码（NRZ）和归零码（RZ）在传输过程中产生的脉冲畸变以及系统Q值的变化。结果表明，传输速率越高PMD对系统性能的影响越显著，二阶PMD也将不可忽略。另外，RZ码传输性能明显优于NRZ码并且可通过预啁啾进行改善。

关键词：偏振模色散（PMD）非归零码（NRZ）归零码（RZ）频率啁啾

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Economic Analysis of Residential Distributed Solar Photovoltaic

Xi Luo,Jia-ping Liu

《工程管理前沿（英文）》 2015年第2卷第2期页码 125-130 doi: 10.15302/J-FEM-2015031

摘要： Under the huge challenges of global energy conservation, emission reduction and energy security, distributed solar photovoltaic industry has become the key means to achieve economic restructuring and low carbon economy. Based on System Advisor Model software, the authors choose Baoji as the sample plot. Household load, unit investment, loan interest rate and loan fraction are used as influence factors to analyze the economic benefits of distributed solar photovoltaic in China. The result demonstrates that government incentives help to increase the profitability of distributed solar photovoltaic by a large extent; other factors that influence the profitability includes household load, unit investment cost, loan interest rate and loan fraction.

关键词： distributed solar photovoltaic internal rate of return price ladder government incentives

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Electromagnetic induction mapping at varied soil moisture reveals field-scale soil textural patterns

Hiruy ABDU, David A. ROBINSON, Janis BOETTINGER, Scott B. JONES

《农业科学与工程前沿（英文）》 2017年第4卷第2期页码 135-145 doi: 10.15302/J-FASE-2017143

摘要： Knowledge of the spatial distribution of soil textural properties is important for determining soil moisture storage and soil hydraulic transport properties. Capturing field heterogeneity without exhaustive sampling and costly sample analysis is difficult. Our objective was to employ electromagnetic induction (EMI) mapping in low apparent electrical conductivity (EC ) soils at varying soil water contents to capture time invariant properties such as soil texture. Georeferenced EC measurements were taken using a ground conductivity meter on six different days where volumetric water content ( ) varied from 0.11 to 0.23. The 50 m × 50 m field included a subsurface gravelly patch in an otherwise homogeneous silt-loam alluvial soil. Ordinary block kriging predicted EC at unsampled areas to produce 1-m resolution maps. Temporal stability analysis was used to divide the field into three distinct EC regions. Subsequent ground-truthing confirmed the lowest conductivity region correlated with coarse textured soil parent materials associated with a former high-energy alluvial depositional area. Combining maps using temporal stability analysis gives the clearest image of the textural difference. These maps could be informative for modeling, experimental design, sensor placement and targeted zone management strategies in soil science, ecology, hydrology, and agricultural applications.

关键词： soil electrical conductivity soil texture mapping temporal stability analysis

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Quantifying and mapping spatial variability of Shanghai household carbon footprints

Shangguang YANG,Chunlan WANG,Kevin LO,Mark WANG,Lin LIU

《能源前沿（英文）》 2015年第9卷第1期页码 115-124 doi: 10.1007/s11708-015-0348-8

摘要： Understanding the spatial variability of household carbon emissions is necessary for formulating sustainable and low-carbon energy policy. However, data on household carbon emissions is limited in China, the world’s largest greenhouse gases emitter. This study quantifies and maps household carbon emissions in Shanghai using a city-wide household survey. The findings reveal substantial spatial variability in household carbon emissions, especially in transport-related emissions. Low emission clusters are founded in Hongkou, Xuhui, Luwan, Jinshan, and Fengxian. High emission clusters are located in Jiading and Pudong. Overall, the spatial pattern of household carbon emissions in Shanghai is donut-shaped: lowest in the urban core, increasing in the surrounding suburban areas, and declining again in the urban fringe and rural regions. The household emissions are correlated with a number of housing and socioeconomic factors, including car ownership, type of dwelling, size of dwelling, age of dwelling, and income. The findings underscore the importance of a localized approach to low-carbon policy-making and implementation.

关键词： household carbon emissions spatial variability energy policy Shanghai China

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Management innovation of Chang’e-5 project

《工程管理前沿（英文）》 2021年第8卷第4期页码 620-626 doi: 10.1007/s42524-021-0165-1

关键词： lunar exploration sample return systems engineering project management

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Mapping the structure-activity relationship of

Worawan PANPIPAT, Hasene KESKIN, Zheng GUO

《化学科学与工程前沿（英文）》 2015年第9卷第1期页码 105-113 doi: 10.1007/s11705-015-1502-x

摘要： The phase behavior of twelve synthesized -sitosteryl fatty acid esters with acyl moieties with different chain lengths (C2:0-C18:0) and different degrees of unsaturation (C18:1-C18:3) were investigated in pure and mixed Langmuir monolayers with phospholipids. The surface-pressure isotherms showed that short chain -sitosteryl fatty acid esters gave smaller mean molecular areas and had decreased monolayer stability and the long chain steryl esters did not produce collapsed plateaus. All the steryl esters displayed strong condensing effects, but there was a pronounced structural dependency: medium chain esters (C8 and C10) were less efficient than short and long chain esters. Atomic force microscopy imaging demonstrated that monolayers mixed with dipalmitoyl phosphatidylcholine (DPPC) displayed both DPPC-rich and steryl lipid-rich domains. However, the height and area differences between the two phases and the roughness and morphologic patterns were very dependent on the steryl lipid concentrations as well as the length, the degree of unsaturation and the molecular conformations of the acyl segments. These findings not only provide a better understanding of the interactions between phytosteryl hydrophobic derivatives and biomembranes, but also may be of general use for the design and engineering of phytosterol structural derivations for specific food and pharmaceutical applications.

关键词： β-sitosteryl fatty acid esters dipalmitoyl phosphatidylcholine Langmuir monolayer condensing effect structure-activity relationship

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Mapping the trends and prospects of battery cathode materials based on patent landscape

《能源前沿（英文）》页码 822-832 doi: 10.1007/s11708-023-0900-x

摘要： Advancing portable electronics and electric vehicles is heavily dependent on the cutting-edge lithium-ion (Li-ion) battery technology, which is closely linked to the properties of cathode materials. Identifying trends and prospects of cathode materials based on patent analysis is considered a kernel to optimize and refine battery related markets. In this paper, a patent analysis is performed on 6 popular cathode materials by comprehensively considering performance comparison, development trend, annual installed capacity, technology life cycle, and distribution among regions and patent assignees. In the technology life cycle, the cathode materials majorly used in electric vehicle have entered maturity stage, while the lithium cobalt oxide (LCO) cathode that is widely used in portable electronics is still in the growth stage. In global patent distributions, China holds more than 50% of total patents. In the top 10 patent assignees of 6 cathode materials, 2 institutes are from China with the rest being Japan (6) and Republic of Korea (2), indicating that the technology of cathode materials in China is relatively scattered while cathode research is highly concentrated in Japan and Republic of Korea. Moreover, the patent distribution has to consider practical issues as well as the impacts of core patents. For example, the high cost discourages the intention of applying international patents. This paper is expected to stimulate battery research, understand technical layout of various countries, and probably forecast innovative technology breakthroughs.

关键词： patent analysis cathode batteries technology life cycle

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新阶段巩固拓展脱贫攻坚成果面临的挑战与政策建议

程国强,邓秀新

《中国工程科学》 2021年第23卷第5期页码 148-156 doi: 10.15302/J-SSCAE-2021.05.019

摘要：

巩固拓展脱贫攻坚成果，防止规模性返贫，是“十四五”时期必须守住的底线任务，为此要强化返贫风险治理，实施“分类施策、精准帮扶”策略，促进建立巩固脱贫攻坚成果的长效机制。本文分析了新发展阶段巩固拓展脱贫攻坚成果面临的挑战，主要有脱贫人口返贫风险成因复杂、扶贫产业可持续发展能力不强、乡村卫生健康事业发展仍然滞后、脱贫地区农村饮用水安全保障不足、乡村治理不能适应新形势要求等，总结了巩固拓展扶贫攻坚成果的基本思路，从注重增加制度供给、破解资源环境约束、激发脱贫人口内生动力等3 个方面提出了巩固拓展脱贫攻坚成果的关键任务，并针对性地提出了政策建议。本文从构建农村低收入人口识别机制、实施扶贫产业提质增效工程、提升乡村治理能力、实施乡村名医堂工程、加强农村饮水质量安全保障等5 个方面提出了巩固拓展脱贫攻坚成果的政策建议。

关键词：返贫，农村低收入人口，乡村振兴，扶贫产业，脱贫攻坚

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标题作者时间类型操作

Coupled solid-fluid FE-analysis of an embankment dam

Michael PERTL, Matthias HOFMANN, Guenter HOFSTETTER

期刊论文

Financing climate-resilient infrastructure: Determining risk, reward, and return on investment

Peter B. MEYER, Reimund SCHWARZE

期刊论文

Land use/cover change effects on floods with different return periods: a case study of Beijing, China

Yueling WANG, Xiaoliu YANG

期刊论文