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LINKING CROP WATER PRODUCTIVITY TO SOIL PHYSICAL, CHEMICAL AND MICROBIAL PROPERTIES

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期   页码 545-558 doi: 10.15302/J-FASE -2020349

摘要：

Agriculture uses a large proportion of global and regional water resources. Due to the rapid increase of population in the world, the increasing competition for water resources has led to an urgent need in increasing crop water productivity for agricultural sustainability. As the medium for crop growth, soils and their properties are important in affecting crop water productivity. This review examines the effects of soil physical, chemical, and microbial properties on crop water productivity and the quantitative relationships between them. A comprehensive view of these relationships may provide important insights for soil and water management in arable land for agriculture in the future.

 

关键词： crop water productivity     crop yield     soil chemical properties     soil microbial properties     soil physical properties     water consumption    

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LINKING CROP WATER PRODUCTIVITY TO SOIL PHYSICAL, CHEMICAL AND MICROBIAL PROPERTIES

Di WU, Allan A. ANDALES, Hui YANG, Qing SUN, Shichao CHEN, Xiuwei GUO, Donghao LI, Taisheng DU

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期   页码 545-558 doi: 10.15302/J-FASE-2020349

摘要： Agriculture uses a large proportion of global and regional water resources. Due to the rapid increase of population in the world, the increasing competition for water resources has led to an urgent need in increasing crop water productivity for agricultural sustainability. As the medium for crop growth, soils and their properties are important in affecting crop water productivity. This review examines the effects of soil physical, chemical, and microbial properties on crop water productivity and the quantitative relationships between them. A comprehensive view of these relationships may provide important insights for soil and water management in arable land for agriculture in the future.

关键词： crop water productivity     crop yield     soil chemical properties     soil microbial properties     soil physical properties     water consumption    

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Effect of land-use management systems on coupled physical and mechanical, chemical and biological soilprocesses: how can we maintain and predict soil properties and functions?

Rainer HORN, Winfried E. H. BLUM

《农业科学与工程前沿（英文）》 2020年 第7卷 第3期   页码 243-245 doi: 10.15302/J-FASE-2020334

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Analysis of physical properties of gas hydrate-bearing unconsolidated sediment samples from the ultra-deepwater

《能源前沿（英文）》 2022年 第16卷 第3期   页码 509-520 doi: 10.1007/s11708-021-0786-4

摘要： Marine natural gas hydrate has recently attracted global attention as a potential new clean energy source. Laboratory measurements of various physical properties of gas hydrate-bearing marine sediments can provide valuable information for developing efficient and safe extraction technology of natural gas hydrates. This study presents comprehensive measurement results and analysis of drilled hydrate-bearing sediments samples recovered from Qiongdongnan Basin in the South China Sea. The results show that the gas hydrate in the core samples is mainly methane hydrate with a methane content of approximately 95%, and the other components are ethane and carbon dioxide. The saturation of the samples fluctuates from 2%–60%, the porosity is approximately 38%–43%, and the water content is approximately 30%–50%, which indicate that high water saturation means that timely drainage should be paid attention to during hydrate extraction. In addition, the median diameter of the sediment samples is mainly distributed in the range of 15 to 34 μm, and attention should be paid to the prevention and control of sand production in the mining process. Moreover, the thermal conductivity is distributed in the range of 0.75 to 0.96 W/(m∙K) as measured by the flat plate heat source method. The relatively low thermal conductivity of hydrates at this study site indicates that a combined approach is encouraged for natural gas production technologies. It is also found that clay flakes and fine particles are attached to the surface of large particles in large numbers. Such characteristics will lead to insufficient permeability during the production process.

关键词： natural gas hydrates     physical properties analysis     hydrate-bearing sediments    

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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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Investigation of effects of Cocamide Diethanolamide chemical on physical and rheological properties of

《结构与土木工程前沿（英文）》 2022年 第16卷 第1期   页码 99-116 doi: 10.1007/s11709-021-0799-4

摘要： In this study, bituminous binder was modified with Cocamide Diethanolamide chemical, a non-ionic surfactant, and the physical and rheological properties of modified binders were investigated. In addition, Cocamide Diethanolamide has been used for the first time to modify bituminous binder, and this situation makes the study distinctive. Bituminous binder was modified more than once with the chemical by changing modification parameters and using certain additive ratios (1%, 3%, and 5%). The effects of different modification parameters and chemical additive on modified samples were investigated with conventional bitumen tests (softening point, penetration, ductility) and Superpave tests (rotational viscometer, rolling thin film oven test, pressure aging vessel, dynamic shear rheometer, bending beam rheometer). In addition, the structural characteristics of the reference binder and modified samples were examined by X-ray diffraction, Fourier Transform Infrared Spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The examinations showed that Cocamide Diethanolamide softens bituminous binder and lowers processing temperatures. In addition, compared to reference binder, rutting resistances of modified bituminous binders decreased with the increase of additive ratio. However, modification with Cocamide Diethanolamide increased the resistance to fatigue cracks and thermal cracks.

关键词： Cocamide Diethanolamide     bitumen modification     rheology     Superpave tests    

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Effect of extrusion temperature on the physical properties of high-silicon aluminum alloy

YANG Fuliang, GAN Weiping, CHEN Zhaoke

《机械工程前沿（英文）》 2007年 第2卷 第1期   页码 120-124 doi: 10.1007/s11465-007-0021-y

摘要： Light-weight high-silicon aluminum alloys are used for electronic packaging in the aviation and space-flight industry. Al-30Si and Al-40Si are fabricated with air-atomization and vacuum-canning hot-extrusion process. The density, thermal conductivity, hermeticity and thermal expansion coefficients of the material are measured, and the relationship between extrusion temperature and properties is obtained. Experimental results show that the density of high-silicon aluminum alloys prepared with this method is as high as 99.64% of the theory density, and increases with elevating extrusion temperature. At the same time, thermal conductivity varies between 104-140 W/(m " K); with the extrusion temperature, thermal expansion coefficient also increases but within 13?10 (at 100?C) and hermeticity of the material is high to 10 order of magnitude.

关键词： coefficient     hermeticity     temperature     relationship     air-atomization    

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Abundance, spatial distribution, and physical characteristics of microplastics in stormwater detention

《环境科学与工程前沿（英文）》 2023年 第17卷 第10期 doi: 10.1007/s11783-023-1724-y

摘要： Despite extensive research on microplastics (MP) in marine environments, little is known about MP abundance and transport in terrestrial systems. There is, therefore, still little understanding of the main mechanisms driving the substantial transport of MP across different environmental compartments. Storm events can transport MP beyond boundaries, such as from the land to groundwater or the ocean, as has already been discovered for organic carbon transport. Urban stormwater detention ponds are suitable environments to study the impact of stormwater on the environmental fate and transport of MP. Herein, we investigate the longitudinal and vertical distribution of MP within two detention ponds with different physical characteristics. Soil samples were collected at various locations and from multiple depths (surface and subsurface layers) for measuring MP concentrations using fluorescence microscopy. Our findings show that MP are retained more near the inlet of the ponds, and MP of larger sizes were found more abundantly near inlets than outlets. We also found that MP mass and sizes decrease from surface soil to subsurface soil. In the pond, where vegetation (grass root network) was more considerable, MP were found more evenly distributed along the depth. In terms of shape, the fragments were the most abundant MP shape.

关键词： Microplastic     Environmental transport     Soil pollution     Stormwater     Detention ponds    

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贵金属物理性质与原子结构的关系

陈景

《中国工程科学》 2000年 第2卷 第7期   页码 66-73

摘要：

按周期表位置排列的8个贵金属元素的物理性质，归纳出三种类型的规律，即原子半径相近，密度与比热接近倍比；熔点、沸点、硬度及其它力学性质呈线性变化；热导率和电导率呈不规则变化。文章用价键理论从原子结构特征对产生三类规律的原因进行了讨论。

关键词： 贵金属     物理性质     原子结构    

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Application of fractal theory to unsaturated soil mechanics

XU Yongfu, TONG Lixin

《结构与土木工程前沿（英文）》 2007年 第1卷 第4期   页码 411-421 doi: 10.1007/s11709-007-0056-5

摘要： The mechanical properties of unsaturated soils are a function of the saturation degree or matric suction, and can be obtained based on currently available procedures. However, each procedure has its limitations and consequently, care should be taken in the selection of a proper procedure. The fractal approach seems to be a potentially useful tool to describe hierarchical systems and is suitable to model the structure and hydraulic properties of unsaturated soils. In this paper, the soil-water characteristics, unsaturated hydraulic conductivity function, unsaturated shear strength, swelling deformation and compression were derived from the fractal model for the pore-size distribution, and were expressed by only two independent physical parameters, the fractal dimension and the air entry value. The predictions of the proposed soil-water characteristics, unsaturated hydraulic conductivity, unsaturated shear strength, swelling deformation and compression were in good agreement with published experimental data. Comparisons between the experimental results of unsaturated hydraulic conductivity and the predictions of the both fractal model and the van Genuchten-Mualem model were also performed, and it was found that the predictions of the fractal model were better than that of the van Genuchten-Mualem model.

关键词： selection     soil-water     independent physical     unsaturated     strength    

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Influence of the sewage irrigation on the agricultural soil properties in Tongliao City, China

Hong YAO, Shichao ZHANG, Xiaobo XUE, Jie YANG, Kelin HU, Xiaohua YU

《环境科学与工程前沿（英文）》 2013年 第7卷 第2期   页码 273-280 doi: 10.1007/s11783-013-0497-0

摘要： Increasing shortages of fresh water has led to greater use of treated wastewater for irrigation of crops. This study evaluates the spatial variability of soil properties after irrigation with wastewater and freshwater. Geostatistical techniques were used to identify the variability of soil properties at the different sites. A set of physical and chemical soil properties were measured including total nitrogen (TN), total phosphorus (TP), organic matter (OM) and soil moisture. The TN concentration levels varied from 567 to 700 mg·kg , while OC levels ranged from 7.3 to 16.3 mg·kg in wastewater-irrigated zones. The concentration levels of TP were between 371.53 and 402.88 mg·kg for the wastewater-irrigated sites. Wastewater irrigation resulted in higher TN, TP and OM concentrations by 18.4%, 8% and 25%, respectively. The highest TN and OM occurred along the wastewater trunk. It was also observed that nitrogen concentrations correlate with the soil's organic matter. The increase of salinity may be associated with the increase of pH, which might suggest that a reduction of pH will be beneficial for plant growth due to the decrease of salinity. The average concentrations of nitrogen in topsoil were higher than those in subsurface soils in irrigated areas. Such differences of the N profile might be due to variations in organic matter content and microbial populations. Consistent with TN and OM, soil C:N decreased significantly with an increase of depth. This phenomenon possibly reflects a greater degree of breakdown and the older age of humus stored in the deeper soil layers. The analysis of pH levels at different depths for the three sites showed that pH values for wastewater irrigation were slightly lower than the controlled sites at the same depths.

关键词： spatial variability     soil properties     groundwater and sewage irrigation    

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Effects of different types of biochar on the properties and reactivity of nano zero-valent iron in soil

《环境科学与工程前沿（英文）》 2021年 第15卷 第5期 doi: 10.1007/s11783-021-1388-4

摘要：

• Biochar enhanced the mobility and stability of zero-valent iron nanoparticles.

关键词： Nano zero-valent iron     Biochar     BDE209     Transport     Soil    

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Ultimate bearing capacity of strip footing resting on clay soil mixed with tire-derived aggregates

《结构与土木工程前沿（英文）》 2021年 第15卷 第4期   页码 1016-1024 doi: 10.1007/s11709-021-0751-7

摘要： This study investigated the use of recycled tire-derived aggregate (TDA) mixed with kaolin as a method of increasing the ultimate bearing capacity ( UBC) of a strip footing. Thirteen 1g physical modeling tests were prepared in a rigid box of 0.6 m × 0.9 m in plan and 0.6 m in height. During sample preparation, 0%, 20%, 40%, or 60% (by weight) of powdery, shredded, small-sized granular (G 1–4 mm) or large-sized granular (G 5–8 mm) TDA was mixed with the kaolin. A strip footing was then placed on the stabilized kaolin and was caused to fail under stress-controlled conditions to determine the UBC. A rigorous 3D finite element analysis was developed in Optum G-3 to determine the UBC values based on the experimental test results. The experimental results showed that, except for the 20% powdery TDA, the TDA showed an increase in the UBC of the strip footing. When kaolin mixed with 20% G (5–8 mm), the UBC showed a threefold increase over that for the unreinforced case. The test with 20% G (1–4 mm) recorded the highest subgrade modulus. It was observed that the UBC calculated using finite element modeling overestimated the experimental UBC by an average of 9%.

关键词： kaolin     physical modeling tests     stabilization     numerical modeling    

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Using a systems modeling approach to improve soil management and soil quality

Enli WANG, Di HE, Zhigan ZHAO, Chris J. SMITH, Ben C. T. MACDONALD

《农业科学与工程前沿（英文）》 2020年 第7卷 第3期   页码 289-295 doi: 10.15302/J-FASE-2020337

摘要：

Soils provide the structural support, water and nutrients for plants in nature and are considered to be the foundation of agriculture production. Improving soil quality and soil health has been advocated as the goal of soil management toward sustainable agricultural intensification. There have been renewed efforts to define and quantify soil quality and soil health but establishing a consensus on the key indicators remains difficult. It is argued that such difficulties are due to the former ways of thinking in soil management which largely focus on soil properties alone. A systems approach that treats soils as a key component of agricultural production systems is promoted. It is argued that soil quality must be quantified in terms of crop productivity and impacts on ecosystems services that are also strongly driven by climate and management interventions. A systems modeling approach captures the interactions among climate, soil, crops and management, and their impacts on system performance, thus helping to quantify the value and quality of soils. Here, three examples are presented to demonstrate this. In this systems context, soil management must be an integral part of systems management practices that also include managing the crops and cropping systems under specific climatic conditions, with cognizance of future climate change.

关键词： APSIM     available water capacity     nitrogen management     soil functional properties     soil health     soil-plant modeling    

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δ-TRIP 钢的物理与力学冶金

易红亮,陈蓬,王国栋,马鸣图

《中国工程科学》 2014年 第16卷 第2期   页码 18-30

摘要：

δ-相变诱发塑性（TRIP）钢具有高的强韧性，可达到第三代汽车钢性能要求，且可电阻点焊，是一种新型的具有较高产业化前景的先进汽车钢。主要阐述了δ-TRIP钢的发展、组织与性能、相变与组织演化机理、强韧性机理、电阻点焊工艺与物理冶金机理。

关键词： TRIP钢     δ铁素体     贝氏体相变     组织演化     性能    

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标题 作者 时间 类型 操作

LINKING CROP WATER PRODUCTIVITY TO SOIL PHYSICAL, CHEMICAL AND MICROBIAL PROPERTIES

期刊论文

LINKING CROP WATER PRODUCTIVITY TO SOIL PHYSICAL, CHEMICAL AND MICROBIAL PROPERTIES

Di WU, Allan A. ANDALES, Hui YANG, Qing SUN, Shichao CHEN, Xiuwei GUO, Donghao LI, Taisheng DU

期刊论文

Effect of land-use management systems on coupled physical and mechanical, chemical and biological soilprocesses: how can we maintain and predict soil properties and functions?

Rainer HORN, Winfried E. H. BLUM

期刊论文

Analysis of physical properties of gas hydrate-bearing unconsolidated sediment samples from the ultra-deepwater

期刊论文

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

期刊论文

Investigation of effects of Cocamide Diethanolamide chemical on physical and rheological properties of

期刊论文

Effect of extrusion temperature on the physical properties of high-silicon aluminum alloy

YANG Fuliang, GAN Weiping, CHEN Zhaoke

期刊论文

Abundance, spatial distribution, and physical characteristics of microplastics in stormwater detention

期刊论文

贵金属物理性质与原子结构的关系

陈景

期刊论文

Application of fractal theory to unsaturated soil mechanics

XU Yongfu, TONG Lixin

期刊论文

Influence of the sewage irrigation on the agricultural soil properties in Tongliao City, China

Hong YAO, Shichao ZHANG, Xiaobo XUE, Jie YANG, Kelin HU, Xiaohua YU

期刊论文

Effects of different types of biochar on the properties and reactivity of nano zero-valent iron in soil

期刊论文

Ultimate bearing capacity of strip footing resting on clay soil mixed with tire-derived aggregates

期刊论文

Using a systems modeling approach to improve soil management and soil quality

Enli WANG, Di HE, Zhigan ZHAO, Chris J. SMITH, Ben C. T. MACDONALD

期刊论文

δ-TRIP 钢的物理与力学冶金

易红亮,陈蓬,王国栋,马鸣图

期刊论文