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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    

Global perspectives and future research directions for the phytoremediation of heavy metal-contaminated soil: A knowledge mapping analysis from 2001 to 2020

《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    

A comparative review of the state and advancement of Site-Specific Crop Management in the UK and China

Zhenhong LI, James TAYLOR, Lynn FREWER, Chunjiang ZHAO, Guijun YANG, Zhenhai LI, Zhigang LIU, Rachel GAULTON, Daniel WICKS, Hugh MORTIMER, Xiao CHENG, Chaoqing YU, Zhanyi SUN

《农业科学与工程前沿(英文)》 2019年 第6卷 第2期   页码 116-136 doi: 10.15302/J-FASE-2018240

摘要:

Precision agriculture, and more specifically Site-Specific Crop Management (SSCM), has been implemented in some form across nearly all agricultural production systems over the past 25 years. Adoption has been greatest in developed agricultural countries. In this review article, the current situation of SSCM adoption and application is investigated from the perspective of a developed (UK) and developing (China) agricultural economy. The current state-of-the art is reviewed with an emphasis on developments in position system technology and satellite-based remote sensing. This is augmented with observations on the differences between the use of SSCM technologies and methodologies in the UK and China and discussion of the opportunities for (and limitations to) increasing SSCM adoption in developing agricultural economies. A particular emphasis is given to the role of socio-demographic factors and the application of responsible research and innovation (RRI) in translating agri-technologies into China and other developing agricultural economies. Several key research and development areas are identified that need to be addressed to facilitate the delivery of SSCM as a holistic service into areas with low precision (PA) agriculture adoption. This has implications for developed as well as developing agricultural economies.

关键词: remote sensing     decision support     responsible research and innovation     digital soil mapping    

Mercury source zone identification using soil vapor sampling and analysis

David WATSON,Carrie MILLER,Brian LESTER,Kenneth LOWE,George SOUTHWORTH,Mary Anna BOGLE,Liyuan LIANG,Eric PIERCE

《环境科学与工程前沿(英文)》 2015年 第9卷 第4期   页码 596-604 doi: 10.1007/s11783-014-0709-2

摘要: Development and demonstration of reliable measurement techniques that can detect and help quantify the nature and extent of elemental mercury (Hg(0)) in the subsurface are needed to reduce uncertainties in the decision-making process and increase the effectiveness of remedial actions. We conducted field tests at the Y-12 National Security Complex in Oak Ridge, Tennessee, USA, to determine if sampling and analysis of Hg(0) vapors in the shallow subsurface (<0.3 m depth) can be used to as an indicator of the location and extent of Hg(0) releases in the subsurface. We constructed a rigid polyvinyl chloride push probe assembly, which was driven into the ground. Soil gas samples were collected through a sealed inner tube of the assembly and were analyzed immediately in the field with a Lumex and/or Jerome Hg(0) analyzer. Time-series sampling showed that Hg vapor concentrations were fairly stable over time, suggesting that the vapor phase Hg(0) was not being depleted and that sampling results were not sensitive to the soil gas purge volume. Hg(0) vapor data collected at over 200 push probe locations at 3 different release sites correlated very well to areas of known Hg(0) contamination. Vertical profiling of Hg(0) vapor concentrations conducted at two locations provided information on the vertical distribution of Hg(0) contamination in the subsurface. We conclude from our studies that soil gas sampling and analysis can be conducted rapidly and inexpensively at large scales to help identify areas contaminated with Hg(0).

关键词: push probe     spill     characterization     mapping     gas    

用航空航天影像更新地形图地物要素的栅格化方法

林宗坚

《中国工程科学》 2000年 第2卷 第4期   页码 43-47

摘要:

文章针对当前我国1:5和1:1万地形图更新的大规模生产的迫切需求,提出在原有地形图栅格式数字化的基础上,叠加经过精密纠正配准的航空或卫星遥感影像,以栅格方式更新地物要素的全过程方法。文中特别阐述了:1)地形图栅格数字化不同于矢量数字化的扫描采样分辨率问题;2)区别于传统的“针孔式”控制点概念的图像图形阵列控制点技术;3)由于DEM(数字高程模型)数据缺乏或精度不足引起的航空航天影像与地形图图形配准误差的局部纠正方法;4)定性指导定量的影像判读方法;5)从遥感影像提取地物结构信息的半自动化方法。文章最后列出

关键词: 测绘遥感     地形图更新     数字栅格地图    

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    

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    

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    

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    

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    

Platform governance in the era of AI and the digital economy

《工程管理前沿(英文)》 2023年 第10卷 第1期   页码 177-182 doi: 10.1007/s42524-022-0241-1

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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    

Revisiting digital twins: Origins, fundamentals, and practices

《工程管理前沿(英文)》   页码 668-676 doi: 10.1007/s42524-022-0216-2

摘要: The digital twins (DT) has quickly become a hot topic since it was proposed. It appears in all kinds of commercial propaganda and is widely quoted by academic circles. However, the term DT has misstatements and is misused in business and academics. This study revisits DT and defines it to be a more advanced system/product/service modeling and simulation environment that combines most modern information communication technologies (ICTs) and engineering mechanism digitization and characterized by system/product/service life cycle management, physically geometric visualization, real-time sensing and measurement of system operating conditions, predictability of system performance/safety/lifespan, and complete engineering mechanisms-based simulations. The idea of DT originates from modeling and simulation practices of engineering informatization, including virtual manufacturing (VM), model predictive control, and building information modeling (BIM). On the basis of the two-element VM model, we propose a three-element model to represent DT. DT does not have its unique technical characteristics. The existing practices of DT are extensions of the engineering informatization embracing modern ICTs. These insights clarify the origin of DT and its technical essentials.

关键词: virtual manufacturing     digital twins     modeling and simulation     digitization     computational engineering    

Development trend of urban design in “digital age”: Pan-dimensionality and individual-ubiquity

《结构与土木工程前沿(英文)》 2021年 第15卷 第3期   页码 569-575 doi: 10.1007/s11709-021-0735-7

摘要: The wave of “digital age” featuring digital information is coming. Digital technology is profoundly changing the societal development direction and evolution paths. It also has significant bearing on production modes, social interactions and lifestyles. With regard to urban design, a system of knowledge about the creation and adaptation of material space forms that integrate humanities, art, technology and materials, digital technology has provided it with a brand-new and revolutionary scientific impetus for its evolution. The result of this evolution is “digital urban design paradigm based on human-computer interaction”, i.e., the urban development is moving toward “pan-dimensionality” and “individual ubiquity”. The future of urban design will construct a new approach to urban research and engineering, which is more complex, capable of accommodating and compatible with multiple goals of “instrumental rationality” and “value rationality”. Such a new approach shall be led by the probabilistic theory of “gray scale thinking”, reflecting quaternary synergetic view of “scientific rationality, ecological rationality, cultural rationality and technical rationality” to realize the cognitive progress of “engineering for the benefit of mankind”.

关键词: digital age     urban design     multiple objectives     human-computer interaction     pan-dimensionality     individual-ubiquity    

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    

标题 作者 时间 类型 操作

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

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

期刊论文

Global perspectives and future research directions for the phytoremediation of heavy metal-contaminated soil: A knowledge mapping analysis from 2001 to 2020

期刊论文

A comparative review of the state and advancement of Site-Specific Crop Management in the UK and China

Zhenhong LI, James TAYLOR, Lynn FREWER, Chunjiang ZHAO, Guijun YANG, Zhenhai LI, Zhigang LIU, Rachel GAULTON, Daniel WICKS, Hugh MORTIMER, Xiao CHENG, Chaoqing YU, Zhanyi SUN

期刊论文

Mercury source zone identification using soil vapor sampling and analysis

David WATSON,Carrie MILLER,Brian LESTER,Kenneth LOWE,George SOUTHWORTH,Mary Anna BOGLE,Liyuan LIANG,Eric PIERCE

期刊论文

用航空航天影像更新地形图地物要素的栅格化方法

林宗坚

期刊论文

Coupled solid-fluid FE-analysis of an embankment dam

Michael PERTL, Matthias HOFMANN, Guenter HOFSTETTER

期刊论文

Chemical mapping of cement pastes by using confocal Raman spectroscopy

Fengjuan LIU,Zhihui SUN

期刊论文

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

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

期刊论文

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

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

期刊论文

Quantifying and mapping spatial variability of Shanghai household carbon footprints

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

期刊论文

Platform governance in the era of AI and the digital economy

期刊论文

Mapping the structure-activity relationship of

Worawan PANPIPAT, Hasene KESKIN, Zheng GUO

期刊论文

Revisiting digital twins: Origins, fundamentals, and practices

期刊论文

Development trend of urban design in “digital age”: Pan-dimensionality and individual-ubiquity

期刊论文

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

期刊论文