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Industrial bio-based plant aggregates as hygric and insulating construction materials for energy efficient

Yunhong Jiang, Mike Lawrence, Meng Zhang, Jiandong Cui

《化学科学与工程前沿（英文）》 2022年 第16卷 第10期   页码 1532-1532 doi: 10.1007/s11705-020-1960-7

摘要： In this paper, the bulk density, microstructure, porosity and pore size distribution of the selected aggregates, including hemp shiv, flax shiv, rape shiv and wheat straw, are fully studied due to these properties are highly related to their excellent characteristics and more or less linked to the properties of the final product. The scanning electron microscope results showed all the selected aggregates have a highly porous and complex hierarchical structure, whereas the arrangement of pores and the thickness of cell wall are significantly different among these aggregates. All the selected aggregates had a low bulk density ranging from 30 to 130 kg∙m and a high porosity between 75.81% and 88.74%. The thermal conductivity of the selected bio-aggregates ranged from 0.04 to 0.06 W∙m ∙K . The thermal conductivity of the selected aggregates was not only depending on the bulk density of the sample but also depending on the raw material. Hemp shiv, rape shiv and flax shiv were excellent hygric regulators with moisture buffer value ( ) ranging from 2.07 to 2.36 g∙m ∙%RH , whereas, wheat straw had a lower MBV value ranging from 1.76 to 1.97 g∙m ∙%RH . The results showed that particle size does not affect the value. The value increases linearly with bulk density.

关键词： bio-based aggregates     density     porosity     thermal conductivity     hygric properties    

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Retraction note to: Industrial bio-based plant aggregates as hygric and insulating construction materials

Yunhong Jiang, Mike Lawrence, Meng Zhang, Jiandong Cui

《化学科学与工程前沿（英文）》 doi: 10.1007/s11705-021-2039-9

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Effect of different high viscosity modifiers on rheological properties of high viscosity asphalt

《结构与土木工程前沿（英文）》 2021年 第15卷 第6期   页码 1390-1399 doi: 10.1007/s11709-021-0775-z

摘要： High viscosity asphalt (HVA) has been a great success as a drainage pavement material. However, the larger porosity of drainage asphalt mixtures weakens the cohesion and adhesion and leads to premature rutting, water damage, spalling and cracking. The purpose of this study was to investigate the rheological properties of HVA prepared using different high viscosity modifiers through conventional tests, Brookfield viscosity tests, dynamic shear rheometer tests and bending beam rheometer tests. The conventional performance results demonstrated SBS + rubber asphalt (SRA-1/2) exhibited excellent elastic recovery and low-temperature flexibility. The 60°C dynamic viscosity results indicated TPS + rubber asphalt (TRA) had the excellent adhesion. The rotational viscosity results and rheological results indicated that SRA-2 not only exhibited excellent temperature stability and workability, as well as excellent resistance to deformation and rutting resistance, but also exhibited excellent low-temperature cracking resistance and relaxation performance. Based on rheological results, the PG classification of HVA was 16% rubber + asphalt for PG76-22, 20% rubber + asphalt for PG88-22, TRA and SRA-1/2 for PG88-28. From comprehensive evaluation of the viscosity, temperature stability and sensitivity, as well as high/low temperature performance of HVA, SRA-2 was found to be more suited to the requirements of drainage asphalt pavement materials.

关键词： high viscosity asphalt     rheological properties     rubber     modifier     viscosity    

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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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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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Mechanical properties and microstructure of multilayer graphene oxide cement mortar

《结构与土木工程前沿（英文）》 2021年 第15卷 第4期   页码 1058-1070 doi: 10.1007/s11709-021-0747-3

摘要： This study reports on the effects of multilayer graphene oxide (MGO) on compressive strength, flexural strength, and microstructure of cement mortar. The cement mortar was prepared with type P. II. 52.5 Portland cement, standard sand, and MGO. Four mixes were prepared with inclusion of MGO (0%, 0.02%, 0.04%, and 0.06% by weight of cement). The testing result shows that the compressive of GO-cement mortar increased by 4.84%–13.42%, and the flexural strength increased by 4.37%–8.28% at 3 d. GO-cement mortar’s compressive strength and flexural strength at 7 d increased by 3.84%–12.08% and 2.54%–13.43%, respectively. MGO made little contribution to the increases of compressive strength and flexural strength of cement mortar at 28 d. The results of X-ray diffraction (XRD), scanning electron microscope (SEM), and nitrogen (N2) adsorption/desorption tests show that the types of hydration products and crystal grain size did not change after adding MGO. Still, it can help to improve the microstructure of the cement mortar via regulating hydration products and can provide more condensed cores to accelerate hydration. Furthermore, the regulating action of MGO for the microstructure of cement mortar at an early age was better than that at 28 d.

关键词： graphene oxide     cement     mortar     mechanical properties     microstructure    

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Biological properties and clinical applications of berberine

Danyang Song, Jianyu Hao, Daiming Fan

《医学前沿（英文）》 2020年 第14卷 第5期   页码 564-582 doi: 10.1007/s11684-019-0724-6

摘要： Berberine, an isoquinoline alkaloid isolated from the Chinese herb and other plants, has a wide range of pharmacological properties. Berberine can be used to treat many diseases, such as cancer and digestive, metabolic, cardiovascular, and neurological diseases. Berberine has protective capacities in digestive diseases. It can inhibit toxins and bacteria, including , protect the intestinal epithelial barrier from injury, and ameliorate liver injury. Berberine also inhibits the proliferation of various types of cancer cells and impedes invasion and metastasis. Recent evidence has confirmed that berberine improves the efficacy and safety of chemoradiotherapies. In addition, berberine regulates glycometabolism and lipid metabolism, improves energy expenditure, reduces body weight, and alleviates nonalcoholic fatty liver disease. Berberine also improves cardiovascular hemodynamics, suppresses ischemic arrhythmias, attenuates the development of atherosclerosis, and reduces hypertension. Berberine shows potent neuroprotective effects, including antioxidative, antiapoptotic, and anti-ischemic. Furthermore, berberine exerts protective effects against other diseases. The mechanisms of its functions have been extensively explored, but much remains to be clarified. This article summarizes the main pharmacological actions of berberine and its mechanisms in cancer and digestive, metabolic, cardiovascular, and neurological diseases.

关键词： berberine     Coptis chinensis     pharmacological properties     mechanism     clinical applications    

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Aging properties and aging mechanism of activated waste rubber powder modified asphalt binder based onrheological properties and micro-characterization

《结构与土木工程前沿（英文）》 2023年 第17卷 第4期   页码 625-636 doi: 10.1007/s11709-023-0938-1

摘要： The research and development of high-performance pavement materials has been intensified owing to the demand for long-life pavements. This study is performed to develop a novel pavement material using waste rubber powder, waste lubricating by-product (LBP), and asphalt. Subsequently, the aging properties and aging mechanism of activated waste rubber powder modified asphalt (ARMA) are investigated based on its rheological properties and micro-characterization. The rheological results show that, compared with waste rubber powder modified asphalt (RMA), ARMA offers a higher aging resistance and a longer fatigue life. A comparison and analysis of the rheological aging parameters of ARMA and RMA show that LBP activation diminishes the aging sensitivity of ARMA. The micro-characterization result shows that the aging of ARMA may be caused by the fact that LBP-activated waste rubber powder is more reactive and can form a dense colloidal structure with asphalt. Therefore, the evaporation loss of asphalt light components by heat and the damage to the colloidal structure by oxygen during the aging process are impeded, and the thermal-oxidative aging resistance of ARMA is improved.

关键词： rubber powder modified asphalt     aging     mechanism     rheological     characterization    

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Mechanical properties of vanadium-alloyed austempered ductile iron for crankshaft applications

《机械工程前沿（英文）》 2023年 第18卷 第3期 doi: 10.1007/s11465-023-0746-2

摘要： This study focused on the development of austempered ductile iron (ADI) with desirable combination of mechanical properties for crankshaft applications by the combined effect of vanadium (V) alloying and an optimized heat treatment process. The produced unalloyed GGG60, 0.15% V-alloyed GGG60 (V-15), and 0.30% V-alloyed GGG60 samples were subjected to austenitizing at 900 °C for 1 h and subsequent austempering processes at 250, 300, and 350 °C for 15, 30, 60, 90, and 180 min. As a result of these austempering processes, different bainitic structures were obtained, which led to the formation of diverse combinations of mechanical properties. The mechanical properties of the austempered samples were tested comprehensively, and the results were correlated with their microstructures and the stability of the retained austenite phases. From the microstructural observations, the V-alloyed samples exhibited a finer microstructure and a more acicular ferrite phase than unalloyed samples. The V addition delayed the coarsening of the acicular ferrite structures and considerably contributed to the improvement of the mechanical properties of GGG60. Moreover, the X-ray diffraction results revealed that the retained austenite volume and the carbon enrichment of austenite phases in ADI samples were remarkably affected by the addition of vanadium. The increase in volume fraction of retained austenite and its carbon content provided favorable ductility and toughness to V-15, as confirmed by the elongation and impact test results. Consequently, the dual-phase ausferrite microstructure of V-15 that was austempered at 300 °C for 60 min exhibited high strength with substantial ductility and toughness for crankshaft applications.

关键词： austempered ductile iron (ADI)     vanadium alloying     mechanical properties     crankshafts     retained austenite    

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Synthesis, characterization and assessment thermal properties of clay based nanopigments

Mohammad Banimahd KIEVANI, Milad EDRAKI

《化学科学与工程前沿（英文）》 2015年 第9卷 第1期   页码 40-45 doi: 10.1007/s11705-015-1505-7

摘要： Nano-clay based pigments (NCP) are new type of pigments composed of organic dyes and layered silicate-clay nano-particles, and have already been used in polymeric coatings to improve mechanical thermal and stability properties. In this paper, the basic blue 41(BB41) was intercalated into Na - montmorillonite in an aqueous medium. The dye-intercalated montmorillonite was centrifuged, dried, and milled to prepare the nanopigment particles. X-ray diffraction showed an increase in the basal spacing, thus confirming intercalation of the BB41 molecules within the nanostructures of the interlayer spaces. Fourier transform infrared spectroscopy was used for identifying the functional groups and chemical bounding of Na -montmorillonite, BB41 and montmorillonite-BB41. The morphology of NCP was also studied by transmission electron microscopy. Finally, thermo-gravimetric analysis and differential thermograms suggested the thermal stability of the intercalated dye was improved.

关键词： nanopigment     layered silicate     cationic dye     thermal properties    

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Assessment and prediction of the mechanical properties of ternary geopolymer concrete

Jinliang LIU; Wei ZHAO; Xincheng SU; Xuefeng XIE

《结构与土木工程前沿（英文）》 2022年 第16卷 第11期   页码 1436-1452 doi: 10.1007/s11709-022-0889-y

摘要： This paper utilized granulated blast furnace slag (GBFS), fly ash (FA), and zeolite powder (ZP) as the binders of ternary geopolymer concrete (TGC) activated with sodium silicate solution. The effects of alkali content (AC) and alkaline activator modulus (AAM) on the compressive strength, flexural tensile strength and elastic modulus of TGC were tested and the SEM micrographs were investigated. The experimental results were then compared with the predictions based on models of mechanical properties, and the amended models of TGC were proposed taking account of the effects of AC and AAM. The results indicated that increasing AC and reducing AAM which were in the specific ranges (5% to 7% and 1.1 to 1.5, respectively) had positive effects on the mechanical properties of TGC. In addition, the flexural tensile strength of TGC was 27.7% higher than that of OPC at the same compressive strength, while the elastic modulus of TGC was 25.8% lower than that of OPC. Appropriate prediction models with the R2 of 0.945 and 0.987 for predicting flexural tensile strength and elastic modulus using compressive strength, respectively, were proposed. Fitting models, considering the effects of AC and AAM, were also proposed to predict the mechanical properties of TGC.

关键词： Ternary Geopolymer Concrete (TGC)     alkaline activator modulus     alkali content     mechanical properties     assessment    

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Molecular dynamics investigation of mechanical properties of single-layer phagraphene

Ali Hossein Nezhad SHIRAZI

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 495-503 doi: 10.1007/s11709-018-0492-4

摘要： Phagraphene is a very attractive two-dimensional (2D) full carbon allotrope with very interesting mechanical, electronic, optical, and thermal properties. The objective of this study is to investigate the mechanical properties of this new graphene like 2D material. In this work, mechanical properties of phagraphene have been studied not only in the defect-free form, but also with the critical defect of line cracks, using the classical molecular dynamics simulations. Our study shows that the pristine phagraphene in zigzag direction experience a ductile behavior under uniaxial tensile loading and the nanosheet in this direction are less sensitive to temperature changes as compared to the armchair direction. We studied different crack lengths to explore the influence of defects on the mechanical properties of phagraphene. We also investigated the temperature effect on the mechanical properties of pristine and defective phagraphene. Our classical atomistic simulation results confirm that larger cracks can reduce the strength of the phagraphene. Moreover, it was shown the temperature has a considerable weakening effect on the tensile strength of phagraphene. The results of this study may be useful for the design of nano-devices using the phagraphene.

关键词： phaqraphene     mechanical properties     crack propaqation     molecular dynamics     thermal effects    

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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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Radiative properties of materials with surface scattering or volume scattering: A review

Qunzhi ZHU, Hyunjin LEE, Zhuomin M. HANG

《能源前沿（英文）》 2009年 第3卷 第1期   页码 60-79 doi: 10.1007/s11708-009-0011-3

摘要： Radiative properties of rough surfaces, particulate media and porous materials are important in thermal engineerit transfer between surfaces and volume elements in participating media, as well as for accurate radiometric temperature measurements. In this paper, recent research on scattering of thermal radiation by rough surfaces, fibrous insulation, soot, aerogel, biological materials, and polytetrafluoroethylene (PTFE) was reviewed. Both theoretical modeling and experimental investigation are discussed. Rigorous solutions and approximation methods for surface scattering and volume scattering are described. The approach of using measured surface roughness statistics in Monte Carlo simulations to predict radiative properties of rough surfaces is emphasized. The effects of various parameters on the radiative properties of particulate media and porous materials are summarized.

关键词： aerogel     fiber     particle scattering     radiative properties     soot     surface roughness    

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Unified calculation method and its application in determining the uniaxial mechanical properties of concrete

Faxing DING, Xiaoyong YING, Linchao ZHOU, Zhiwu YU

《结构与土木工程前沿（英文）》 2011年 第5卷 第3期   页码 381-393 doi: 10.1007/s11709-011-0118-6

摘要： This paper presents a unified calculation method and its application in determining the uniaxial mechanical properties of concrete with concrete strengths ranging from 10 to 140 MPa. By analyzing a large collection of test results of the uniaxial mechanical properties of normal-strength, high-strength and super high-strength concrete in China and performing a regression analysis, unified calculation formulas for the mechanical indexes of concrete are proposed that can be applied to various grades of concrete for determining the size coefficient, uniaxial compressive strength, uniaxial tensile strength, elastic modulus, and strain at peak uniaxial compression and tension. Optimized mathematical equations for the nonlinear stress-strain relationship of concrete, including the ascending and descending branches under uniaxial stress, are also established. The elastic modulus is almost constant throughout the elastic stage for the ascending branches of the stress-strain relationship for concrete. The proposed stress-strain relationship of concrete was applied to the nonlinear finite element analysis of both a steel-concrete composite beam and a concrete-filled steel tubular stub column. The analytical results are in good agreement with the experiment results, indicating that the proposed stress-strain relationship of concrete is applicable. The achievements presented in this paper can be used as references for the design and nonlinear finite element analysis of concrete structures.

关键词： concrete     mechanical properties     stress-strain relationship     uniaxial stress     application    

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标题 作者 时间 类型 操作

Industrial bio-based plant aggregates as hygric and insulating construction materials for energy efficient

Yunhong Jiang, Mike Lawrence, Meng Zhang, Jiandong Cui

期刊论文

Retraction note to: Industrial bio-based plant aggregates as hygric and insulating construction materials

Yunhong Jiang, Mike Lawrence, Meng Zhang, Jiandong Cui

期刊论文

Effect of different high viscosity modifiers on rheological properties of high viscosity asphalt

期刊论文

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

期刊论文

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

期刊论文

Mechanical properties and microstructure of multilayer graphene oxide cement mortar

期刊论文

Biological properties and clinical applications of berberine

Danyang Song, Jianyu Hao, Daiming Fan

期刊论文

Aging properties and aging mechanism of activated waste rubber powder modified asphalt binder based onrheological properties and micro-characterization

期刊论文

Mechanical properties of vanadium-alloyed austempered ductile iron for crankshaft applications

期刊论文

Synthesis, characterization and assessment thermal properties of clay based nanopigments

Mohammad Banimahd KIEVANI, Milad EDRAKI

期刊论文

Assessment and prediction of the mechanical properties of ternary geopolymer concrete

Jinliang LIU; Wei ZHAO; Xincheng SU; Xuefeng XIE

期刊论文

Molecular dynamics investigation of mechanical properties of single-layer phagraphene

Ali Hossein Nezhad SHIRAZI

期刊论文

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

期刊论文

Radiative properties of materials with surface scattering or volume scattering: A review

Qunzhi ZHU, Hyunjin LEE, Zhuomin M. HANG

期刊论文

Unified calculation method and its application in determining the uniaxial mechanical properties of concrete

Faxing DING, Xiaoyong YING, Linchao ZHOU, Zhiwu YU

期刊论文