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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    

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    

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    

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    

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    

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    

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

Development of MCBurn and its application in the analysis of SCWR physical characteristics

Ganglin YU , Kan WANG ,

《能源前沿(英文)》 2009年 第3卷 第3期   页码 348-352 doi: 10.1007/s11708-009-0031-z

摘要: The MCBurn, a coupled code system linking the Monte Carlo N-particle transport code(MCNP) and Oak Ridge isotope generation and depletion code (ORIGEN), can resolve the basic calculation problems in reactor physical design and analysis, such as criticality, power distribution, nuclide burn up, and neutron fluence. It has been verified in the pressurized water reactor (PWR) pin model, fast reactor (FR) burn up model, and boiling water reactor(BWR) assemble model with benchmarked results. In supercritical water reactor (SCWR) physical calculations, the calculation conditions such as the geometry, the neutron spectrum, and the fuel materials, etc., are more complex than those in traditional reactors, which is a great challenge to reactor physics calculation code. However, the MCBurn code is a possible solution. In this paper, several update functions of the MCBurn in new neutron cross-section lib, code interface, and neutron flux distribution were described. The application of the MCBurn in SCWR were verified on a supercritical water reactor assemble. The calculation results show that the MCBurn is accurate and adaptable in the SCWR calculation.

关键词: Monte Carlo method     MCBurn     SCWR     neutron cross-section lib    

Physical and mechanical properties of municipal solid waste incineration residues with cement and coal

Toshifumi MUKUNOKI, Ta Thi HOAI, Daisuke FUKUSHIMA, Teppei KOMIYA, Takayuki SHIMAOKA

《结构与土木工程前沿(英文)》 2019年 第13卷 第3期   页码 640-652 doi: 10.1007/s11709-018-0502-6

摘要: A significant volume of Municipal Solid Waste incineration bottom ash and fly ash (i.e., incineration residues) are commonly disposed as landfill. Meanwhile, reclamation of landfill sites to create a new land space after their closure becomes an important goal in the current fewer and fewer land availability scenario in many narrow countries. The objective of this study is to reclaim incineration residue materials in the landfill site by using cement and coal fly ash as stabilizers aiming at performing quality check as new developed materials before future construction. Indeed, physical and mechanical properties of these new materials should be initially examined at the micro scale, which is the primary fundamental for construction at larger scale. This research examines quantitative influences of using the combination of cement and coal fly ash at different ratio on the internal structure and ability of strength enhancement of incineration residues when suffering from loading. Couple of industrial and micro-focus X-ray computed tomography (CT) scanners combined with an image analysis technique were utilized to characterize and visualize the behavior and internal structure of the incineration residues-cement-coal fly ash mixture under the series of unconfined compression test and curing period effect. Nine types of cement solidified incineration residues in term of different curing period (i.e., 7, 14, 28 days) and coal fly ash addition content (i.e., 0%, 9%, 18%) were scanned before and after unconfined compression tests. It was shown that incineration residues solidified by cement and coal fly ash showed an increase in compression strength and deformation modulus with curing time and coal fly ash content. Three-dimension computed tomography images observation and analysis confirmed that solidified incineration residues including incineration bottom and fly ash as well as cement and coal fly ash have the deliquescent materials. Then, it was studied that stabilized parts play a more important role than spatial void distribution in increment or reduction of compression strength.

关键词: mechanical property     municipal solid waste incineration residues     coal fly ash     unconfined compression test     image analysis     X-Ray Computed Tomography scanners    

Numerical analysis and experimental investigation of modal properties for the gearbox in wind turbine

Pengxing YI,Peng HUANG,Tielin SHI

《机械工程前沿(英文)》 2016年 第11卷 第4期   页码 388-402 doi: 10.1007/s11465-016-0404-z

摘要:

Wind turbine gearbox (WTG), which functions as an accelerator, ensures the performance and service life of wind turbine systems. This paper examines the distinctive modal properties of WTGs through finite element (FE) and experimental modal analyses. The study is performed in two parts. First, a whole system model is developed to investigate the first 10 modal frequencies and mode shapes of WTG using flexible multi-body modeling techniques. Given the complex structure and operating conditions of WTG, this study applies spring elements to the model and quantifies how the bearings and gear pair interactions affect the dynamic characteristics of WTGs. Second, the FE modal results are validated through experimental modal analyses of a 1.5 WM WTG using the frequency response function method of single point excitation and multi-point response. The natural frequencies from the FE and experimental modal analyses show favorable agreement and reveal that the characteristic frequency of the studied gearbox avoids its eigen-frequency very well.

关键词: wind turbine gearbox     modal analysis     finite element analysis     modal frequency     bearing equivalence    

Combination form analysis and experimental study of mechanical properties on steel sheet glass fiber

《结构与土木工程前沿(英文)》 2021年 第15卷 第4期   页码 834-850 doi: 10.1007/s11709-021-0743-7

摘要: The concept of steel sheet glass fiber reinforced polymer (GFRP) composite bar (SSGCB) was put forward. An optimization plan was proposed in the combined form of SSGCB. The composite principle, material selection, and SSGCB preparation technology have been described in detail. Three-dimensional finite element analysis was adopted to perform the combination form optimization of different steel core structures and different steel core contents based on the mechanical properties. Mechanical tests such as uniaxial tensile, shear, and compressive tests were carried out on SSGCB. Parametric analysis was conducted to investigate the influence of steel content on the mechanical properties of SSGCB. The results revealed that the elastic modulus of SSGCB had improvements and increased with the rise of steel content. Shear strength was also increased with the addition of steel content. Furthermore, the yield state of SSGCB was similar to the steel bar, both of which indicated a multi-stage yield phenomenon. The compressive strength of SSGCB was lower than that of GFRP bars and increased with the increase of the steel core content. Stress-strain curves of SSGCB demonstrated that the nonlinear-stage characteristics of SSGCB-8 were much more obvious than other bars.

关键词: steel sheet GFRP composite bar     combination form     numerical modeling     mechanical properties test     strength    

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    

Mechanical properties of stabilized artificial organic soil

XU Riqing, GUO Yin, LIU Zengyong

《结构与土木工程前沿(英文)》 2008年 第2卷 第2期   页码 161-165 doi: 10.1007/s11709-008-0023-9

摘要: In order to study the influence of organic matter on the mechanical properties of stabilized soil and the effect of XGL2005 on stabilizing organic soil, unconfined compressive strength tests were carried out. Test results indicated that the strength of stabilized soil decreased in the form of a logarithmic function as the organic matter content increased. In contrast, the strength increased in the form of a power function as the content of the stabilization agent increased. The strength of cement stabilized organic soil was reinforced greatly by adding the stabilizer XGL2005. Based on the law obtained from the test, a strength prediction model was established by regression analysis. The model included the influence of the curing time, the content of the cement, the organic matter content and the stabilization agent on the strength of stabilized soil.

关键词: compressive strength     stabilized     stabilization     regression analysis     stabilizer XGL2005    

Critical review of recent development in fiber reinforced adobe bricks for sustainable construction

Mahgoub M. SALIH, Adelaja I. OSOFERO, Mohammed S. IMBABI

《结构与土木工程前沿(英文)》 2020年 第14卷 第4期   页码 839-854 doi: 10.1007/s11709-020-0630-7

摘要: This paper presents a state-of-the-art review of research on the utilization of fibers (predominantly derived from waste materials) as reinforcement in adobe brick production. Recycling of these wastes provides sustainable construction materials and helps to protect the environment. Specimen preparation and test procedures are outlined. The effects of addition of these wastes on the physical and mechanical properties of adobe bricks as presented in the literature, are investigated. The main results for each additive are presented and discussed. It is concluded that improved adobe brick properties can be expected with the addition of combination of waste additives. The use of waste materials in the construction industry is generally of interest and useful for engineers and designers seeking sustainable solutions in construction. It is also of interest to researchers actively seeking to develop methodical approaches to quantifying, optimising and testing the performance in use of such waste material additives.

关键词: adobe bricks     fibre reinforced bricks     green     sustainable building material     physical and mechanical properties    

Response surface regression analysis on FeCrBSi particle in-flight properties by plasma spray

Runbo MA,Lihong DONG,Haidou WANG,Shuying CHEN,Zhiguo XING

《机械工程前沿(英文)》 2016年 第11卷 第3期   页码 250-257 doi: 10.1007/s11465-016-0401-2

摘要:

This work discusses the interactive effects between every two of argon flow rate, voltage, and spray distance on in-flight particles by plasma spray and constructs models that can be used in predicting and analyzing average velocity and temperature. Results of the response surface methodology show that the interactive effects between voltage and spray distance on particle in-flight properties are significant. For a given argon flow rate, particle velocity and temperature response surface are obviously bending, and a saddle point exists. With an increase in spray distance, the interactive effects between voltage and argon flow rate on particle in-flight properties appear gradually and then weaken. With an increase in voltage, the interactive effects between spray distance and argon flow rate on particle in-flight properties change from appearing to strengthening and then to weakening.

关键词: particle velocity     particle temperature     interactive effects     response surface    

标题 作者 时间 类型 操作

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

期刊论文

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

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

贵金属物理性质与原子结构的关系

陈景

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

Development of MCBurn and its application in the analysis of SCWR physical characteristics

Ganglin YU , Kan WANG ,

期刊论文

Physical and mechanical properties of municipal solid waste incineration residues with cement and coal

Toshifumi MUKUNOKI, Ta Thi HOAI, Daisuke FUKUSHIMA, Teppei KOMIYA, Takayuki SHIMAOKA

期刊论文

Numerical analysis and experimental investigation of modal properties for the gearbox in wind turbine

Pengxing YI,Peng HUANG,Tielin SHI

期刊论文

Combination form analysis and experimental study of mechanical properties on steel sheet glass fiber

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

Mechanical properties of stabilized artificial organic soil

XU Riqing, GUO Yin, LIU Zengyong

期刊论文

Critical review of recent development in fiber reinforced adobe bricks for sustainable construction

Mahgoub M. SALIH, Adelaja I. OSOFERO, Mohammed S. IMBABI

期刊论文

Response surface regression analysis on FeCrBSi particle in-flight properties by plasma spray

Runbo MA,Lihong DONG,Haidou WANG,Shuying CHEN,Zhiguo XING

期刊论文