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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    

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A computational toolbox for molecular property prediction based on quantum mechanics and quantitativestructure-property relationship

《化学科学与工程前沿（英文）》 2022年 第16卷 第2期   页码 152-167 doi: 10.1007/s11705-021-2060-z

摘要： Chemical industry is always seeking opportunities to efficiently and economically convert raw materials to commodity chemicals and higher value-added chemical-based products. The life cycles of chemical products involve the procedures of conceptual product designs, experimental investigations, sustainable manufactures through appropriate chemical processes and waste disposals. During these periods, one of the most important keys is the molecular property prediction models associating molecular structures with product properties. In this paper, a framework combining quantum mechanics and quantitative structure-property relationship is established for fast molecular property predictions, such as activity coefficient, and so forth. The workflow of framework consists of three steps. In the first step, a database is created for collections of basic molecular information; in the second step, quantum mechanics-based calculations are performed to predict quantum mechanics-based/derived molecular properties (pseudo experimental data), which are stored in a database and further provided for the developments of quantitative structure-property relationship methods for fast predictions of properties in the third step. The whole framework has been carried out within a molecular property prediction toolbox. Two case studies highlighting different aspects of the toolbox involving the predictions of heats of reaction and solid-liquid phase equilibriums are presented.

关键词： molecular property     quantum mechanics     quantitative structure-property relationship     heat of reaction     solid-liquid phase equilibrium    

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Mercury emission and adsorption characteristics of fly ash in PC and CFB boilers

Li JIA, Baoguo FAN, Xianrong ZHENG, Xiaolei QIAO, Yuxing YAO, Rui ZHAO, Jinrong GUO, Yan JIN

《能源前沿（英文）》 2021年 第15卷 第1期   页码 112-123 doi: 10.1007/s11708-020-0682-3

摘要： The mercury emission was obtained by measuring the mercury contents in flue gas and solid samples in pulverized coal (PC) and circulating fluidized bed (CFB) utility boilers. The relationship was obtained between the mercury emission and adsorption characteristics of fly ash. The parameters included unburned carbon content, particle size, and pore structure of fly ash. The results showed that the majority of mercury released to the atmosphere with the flue gas in PC boiler, while the mercury was enriched in fly ash and captured by the precipitator in CFB boiler. The coal factor was proposed to characterize the impact of coal property on mercury emissions in this paper. As the coal factor increased, the mercury emission to the atmosphere decreased. It was also found that the mercury content of fly ash in the CFB boiler was ten times higher than that in the PC boiler. As the unburned carbon content increased, the mercury adsorbed increased. The capacity of adsorbing mercury by fly ash was directly related to the particle size. The particle size corresponding to the highest content of mercury, which was about 560 ng/g, appeared in the range from 77.5 to 106 µm. The content of mesoporous (4–6 nm) of the fly ash in the particle size of 77.5–106 µm was the highest, which was beneficial to adsorbing the mercury. The specific surface area played a more significant role than specific pore volume in the mercury adsorption process.

关键词： mercury     combustion modes     coal property     fly ash     particle size    

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Convective heat transfer in helical coils for constant-property and variable-property flows with high

Yufei MAO, Liejin GUO, Bofeng BAI, Ximin ZHANG

《能源前沿（英文）》 2010年 第4卷 第4期   页码 546-552 doi: 10.1007/s11708-010-0116-8

摘要： Forced convection heat transfer of single-phase water in helical coils was experimentally studied. The testing section was constructed from a stainless steel round tube with an inner diameter of 10 mm, coil diameter of 300 mm, and pitch of 50 mm. The experiments were conducted over a wide Reynolds number range of 40000 to 500000. Both constant-property flows at normal pressure and variable-property flows at supercritical pressure were investigated. The contribution of secondary flow in the helical coil to heat transfer was gradually suppressed with increasing Reynolds number. Hence, heat transfer coefficients of the helical tube were close to those of the straight tube under the same flow conditions when the Reynolds number is large enough. Based on the experimental data, heat transfer correlations for both incompressible flows and supercritical fluid flows through helical coils were proposed.

关键词： convective heat transfer     helical coils     high Reynolds number     supercritical pressure     variable property    

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A review on the application of nanofluids in enhanced oil recovery

《化学科学与工程前沿（英文）》 2022年 第16卷 第8期   页码 1165-1197 doi: 10.1007/s11705-021-2120-4

摘要： Enhanced oil recovery (EOR) has been widely used to recover residual oil after the primary or secondary oil recovery processes. Compared to conventional methods, chemical EOR has demonstrated high oil recovery and low operational costs. Nanofluids have received extensive attention owing to their advantages of low cost, high oil recovery, and wide applicability. In recent years, nanofluids have been widely used in EOR processes. Moreover, several studies have focused on the role of nanofluids in the nanofluid EOR (N-EOR) process. However, the mechanisms related to N-EOR are unclear, and several of the mechanisms established are chaotic and contradictory. This review was conducted by considering heavy oil molecules/particle/surface micromechanics; nanofluid-assisted EOR methods; multiscale, multiphase pore/core displacement experiments; and multiphase flow fluid-solid coupling simulations. Nanofluids can alter the wettability of minerals (particle/surface micromechanics), oil/water interfacial tension (heavy oil molecules/water micromechanics), and structural disjoining pressure (heavy oil molecules/particle/surface micromechanics). They can also cause viscosity reduction (micromechanics of heavy oil molecules). Nanofoam technology, nanoemulsion technology, and injected fluids were used during the EOR process. The mechanism of N-EOR is based on the nanoparticle adsorption effect. Nanoparticles can be adsorbed on mineral surfaces and alter the wettability of minerals from oil-wet to water-wet conditions. Nanoparticles can also be adsorbed on the oil/water surface, which alters the oil/water interfacial tension, resulting in the formation of emulsions. Asphaltenes are also adsorbed on the surface of nanoparticles, which reduces the asphaltene content in heavy oil, resulting in a decrease in the viscosity of oil, which helps in oil recovery. In previous studies, most researchers only focused on the results, and the nanoparticle adsorption properties have been ignored. This review presents the relationship between the adsorption properties of nanoparticles and the N-EOR mechanisms. The nanofluid behaviour during a multiphase core displacement process is also discussed, and the corresponding simulation is analysed. Finally, potential mechanisms and future directions of N-EOR are proposed. The findings of this study can further the understanding of N-EOR mechanisms from the perspective of heavy oil molecules/particle/surface micromechanics, as well as clarify the role of nanofluids in multiphase core displacement experiments and simulations. This review also presents limitations and bottlenecks, guiding researchers to develop methods to synthesise novel nanoparticles and conduct further research.

关键词： nanofluid     EOR mechanism     nanoparticle adsorption     interface property     internal property    

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Experimental study on compaction-induced anisotropic mechanical property of rockfill material

Xiangtao ZHANG, Yizhao GAO, Yuan WANG, Yu-zhen YU, Xun SUN

《结构与土木工程前沿（英文）》 2021年 第15卷 第1期   页码 109-123 doi: 10.1007/s11709-021-0693-0

摘要： The anisotropy of rockfill materials has a significant influence on the performance of engineering structures. However, relevant research data are very limited, because of the difficulty with preparing specimens with different inclination angles using traditional methods. Furthermore, the anisotropy test of rockfill materials is complex and complicated, especially for triaxial tests, in which the major principal stress plane intersects with the compaction plane at different angles. In this study, the geometric characteristics of a typical particle fraction consisting of a specific rockfill material were statistically investigated, and the distribution characteristics of particle orientation in specimens prepared via different compaction methods were examined. For high-density rockfill materials, a set of specimen preparation devices for inclined compaction planes was developed, and a series of conventional triaxial compression tests with different principal stress direction angles were conducted. The results reveal that the principal stress direction angle has a significant effect on the modulus, shear strength, and dilatancy of the compacted rockfill materials. Analysis of the relationship between the principal stress direction angles, change in the stress state, and change in the corresponding dominant shear plane shows that the angle between the compacted surface and dominant shear plane is closely related to interlocking resistance associated with the particle orientation. In addition, different principal stress direction angles can change the extent of the particle interlocking effect, causing the specimen to exhibit different degrees of anisotropy.

关键词： rockfill     inclination of specimen preparation     anisotropy     mechanical property     mechanism    

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Experimental research on the mechanical property of prestressing steel wire during and after heating

ZHENG Wenzhong, HU Qiong, ZHANG Haoyu

《结构与土木工程前沿（英文）》 2007年 第1卷 第2期   页码 247-254 doi: 10.1007/s11709-007-0031-1

摘要： The mechanical property of prestressing steel wire during and after heating is the key factor in the design of fire resistance and after-fire damage evaluation of prestressed structures. Tensile experiment of 16 prestressing steel wires ( = 1770 N/mm, = 5 mm, low relaxation of stress) at high temperature and tensile experiment of 14 prestressed steel wires after heating are carried out. According to the experiment, the shapes of stress-strain curves of steel wire at high temperature go smooth and the mechanical property indexes of the steel wire such as strength, modulus of elasticity, etc., degenerate continuously as temperature increased. According to the experiment after heating, the mechanical property of steel wire varies little when the highest temperature that the steel wire has ever been heated to is lower than 300vH; while the stress-strain curves of steel wire become more ductile and the mechanical property indexes of the steel wire degenerate gradually when the highest temperature is higher than 300vH. By applying the theory of viscoelastic mechanics, stress-strain curves of steel wire at high temperatures without loading rate influence are obtained. The law of mechanical property indexes of the wire is presented. The mathematical models of the stress-strain relationship of the pre-stressed steel wire are established. All can serve as basic data for the analysis of fire resistance and after-fire damage evaluation of pre-stressed structures.
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深圳城市供水系统产权结构重组模式及评价

肖文,欧阳芳锐,王先甲

《中国工程科学》 2004年 第6卷 第7期   页码 48-52

摘要：

提出了城市供水系统产权结构重组的两种基本模式，运用制度经济学和管理学理论，提出产权结构模式评价的指标与方法，分析了这两种产权结构模式的特性和在这两种模式下不同利益主体的行为与利益关系的变化特点及优缺点，并提出了缓解劣势的手段与方法。

关键词： 城市供水     产权结构     产权重组     产权模式评价    

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novel strategy for the construction of silk fibroin–SiO composite aerogel with enhanced mechanical property

《化学科学与工程前沿（英文）》 2023年 第17卷 第3期   页码 288-297 doi: 10.1007/s11705-022-2222-7

摘要： The practical application of silica aerogels is an enormous challenge due to the difficulties in improving both mechanical property and thermal insulation performance. In this work, silk fibroin was used as scaffold to improve the mechanical property and thermal insulation performance of silica aerogels. The ungelled SiO2 precursor solution was impregnated into silk fibroin to prepare silk fibroin–SiO2 composite aerogels via sol−gel method followed by freeze-drying. By virtue of the interfacial hydrogen-bonding interactions and chemical reactions between silk fibroin and silica nanoparticles, SiO2 was well-dispersed in the silk fibroin aerogel and composite aerogels exhibited enhanced mechanical property. By increasing the loading of silk fibroin from 15 wt % to 21 wt %, the maximum compressive stress was enhanced from 0.266 to 0.508 MPa when the strain reached 50%. The thermal insulation performance of the composite aerogels was improved compared with pure silica aerogel, as evidenced that the thermal conductivity was decreased from 0.0668 to 0.0341 W∙m‒1∙K‒1. Moreover, the composite aerogels exhibited better hydrophobicity and fire retardancy compared to pure silica aerogel. Our work provides a novel approach to preparing silk fibroin–SiO2 composite aerogels with enhanced mechanical property and thermal insulation performance, which has potential application as thermal insulation material.

关键词： silica aerogel     silk fibroin     impregnation     thermal insulation     mechanical property    

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新一代煤化工和洁净煤技术利用现状分析与对策建议

谢克昌

《中国工程科学》 2003年 第5卷 第6期   页码 15-24

摘要：

在论述煤炭的战略地位、利用现状和分析新一代煤化工技术与洁净煤技术利用现状的基础上，以科学规划所应遵循的原则，结合作者的科研实践，提出了我国发展新一代煤化工和洁净煤利用技术的建议。

关键词： 煤化工     洁净煤技术     对策    

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Meshing stiffness property and meshing status simulation of harmonic drive under transmission loading

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0674-6

摘要： The multitooth meshing state of harmonic drive (HD) is an important basic characteristic of its high transformation precision and high bearing capacity. Meshing force distribution affects the load sharing of the tooth during meshing, and theoretical research remains insufficient at present. To calculate the spatial distributed meshing forces and loading backlashes along the axial direction, an iterative algorithm and finite element model (FEM) is proposed to investigate the meshing state under varied transmission loading. The displacement formulae of meshing point under tangential force are derived according to the torsion of the flexspline cylinder and the bending of the tooth. Based on the relationship of meshing forces and circumferential displacements, meshing forces and loading backlashes in three cross-sections are calculated with the algorithm under gradually increased rotation angles of circular spline, and the results are compared with FEM. Owing to the taper deformation of the cup-shaped flexspline, the smallest initial backlash and the earliest meshing point appear in the front cross-section far from the cup bottom, and then the teeth in the middle cross-section of the tooth rim enter the meshing and carry most of the loading. Theoretical and numerical research show that the flexibility is quite different for varied meshing points and tangential force amplitude because of the change of contact status between the flexspline and the wave generator. The meshing forces and torsional stiffness of the HD are nonlinear with the torsional angle.

关键词： harmonic drive     meshing flexibility matrix     meshing force     loading backlash     flexspline     contact analysis    

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Modeling and analysis of controllable output property of cantilever-beam inertial sensors based on magnetic

Guixiong LIU, Peiqiang ZHANG, Chen XU

《机械工程前沿（英文）》 2009年 第4卷 第2期   页码 129-133 doi: 10.1007/s11465-009-0035-8

摘要： Magnetic fluid is first introduced into the traditional cantilever-beam senor. Based on the property of the cantilever-beam and the novel controllable mag-viscosity of magnetic fluid, the output of cantilever-beam sensors is under control so that the controllable output of the sensors can be realized. The mathematical model of the sensors is established and analyzed. The dynamic control function and the following educational results, which include the two curves of the displacement ratio and phase function with the different damping ratio and frequency ratio, are obtained based on the model. The result shows that it is valid to realize the controllable output of the sensors by controlling the viscosity of the magnetic fluid, and finally the expanded measurement range can be realized.

关键词： sensors     magnetic fluid     property of mag-viscosity     controllable output    

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of photolysis half-lives of dyes in a continuous-flow system with the aid of quantitative structure-property

Davoud BEIKNEJAD,Mohammad Javad CHAICHI

《环境科学与工程前沿（英文）》 2014年 第8卷 第5期   页码 683-692 doi: 10.1007/s11783-014-0680-y

摘要： In this paper the photolysis half-lives of the model dyes in water solutions and under ultraviolet (UV) radiation were determined by using a continuous-flow spectrophotometric method. A quantitative structure-property relationship (QSPR) study was carried out using 21 descriptors based on different chemometric tools including stepwise multiple linear regression (MLR) and partial least squares (PLS) for the prediction of the photolysis half-life ( ) of dyes. For the selection of test set compounds, a K-means clustering technique was used to classify the entire data set, so that all clusters were properly represented in both training and test sets. The QSPR results obtained with these models show that in MLR-derived model, photolysis half-lives of dyes depended strongly on energy of the highest occupied molecular orbital ( ), largest electron density of an atom in the molecule ( ) and lipophilicity (log ). While in the model derived from PLS, besides aforementioned and descriptors, the molecular surface area ( ), molecular weight ( ), electronegativity ( ), energy of the second highest occupied molecular orbital ( ) and dipole moment ( ) had dominant effects on logt values of dyes. These were applicable for all classes of studied dyes (including monoazo, disazo, oxazine, sulfonephthaleins and derivatives of fluorescein). The results were also assessed for their consistency with findings from other similar studies.

关键词： dye     photolysis half-life     quantitative structure-property relationship     continuous-flow     stepwise multiple linear regression     partial least squares    

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Preparation and property of porous hydroxyapatite as an inorganic dispersant used in suspension polymerization

XU Kaqiu, XU Jiale, WANG Yuhong

《化学科学与工程前沿（英文）》 2008年 第2卷 第1期   页码 49-54 doi: 10.1007/s11705-008-0004-5

摘要： The porous hydroxyapatite (HAP) for suspension polymerization dispersant was prepared using calcium carbonate and phosphoric acid as raw materials. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and BET nitrogen adsorption. The results show that the prepared HAP has a porous structure, low particle density, large specific surface area, uniform particle size and does not agglomerate easily between the particles. The preparation conditions for the HAP were optimized as follows: solid content of calcium carbonate aqueous suspension 90 g/L, concentration of phosphoric acid 1.0 mol/L, reaction/aging temperature 50°C, and aging time 3 h. The HAP prepared under optimal preparation conditions has 106.8 m·g of specific surface area, which is about 1.5–1.8 times as much as that of Japanese HAP or commercial HAP. Its application result in the suspension polymerization of styrene show that the porous HAP dispersant has high surface activity, excellent suspension dispersibility and stability and can markedly improve the quality of polystyrene beads.

关键词： diffraction     stability     nitrogen adsorption     phosphoric     aqueous suspension    

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标题 作者 时间 类型 操作

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

A computational toolbox for molecular property prediction based on quantum mechanics and quantitativestructure-property relationship

期刊论文

Mercury emission and adsorption characteristics of fly ash in PC and CFB boilers

Li JIA, Baoguo FAN, Xianrong ZHENG, Xiaolei QIAO, Yuxing YAO, Rui ZHAO, Jinrong GUO, Yan JIN

期刊论文

Convective heat transfer in helical coils for constant-property and variable-property flows with high

Yufei MAO, Liejin GUO, Bofeng BAI, Ximin ZHANG

期刊论文

A review on the application of nanofluids in enhanced oil recovery

期刊论文

Innovative approach of low carbon and efficient utilization of coal resources: The polygeneration systemof a combination of the gasified coal gas and the pyrolyzed coal gas to form the synthetic gas

Kechang XIE, Fan LI

期刊论文

Experimental study on compaction-induced anisotropic mechanical property of rockfill material

Xiangtao ZHANG, Yizhao GAO, Yuan WANG, Yu-zhen YU, Xun SUN

期刊论文

Experimental research on the mechanical property of prestressing steel wire during and after heating

ZHENG Wenzhong, HU Qiong, ZHANG Haoyu

期刊论文

深圳城市供水系统产权结构重组模式及评价

肖文,欧阳芳锐,王先甲

期刊论文

novel strategy for the construction of silk fibroin–SiO composite aerogel with enhanced mechanical property

期刊论文

新一代煤化工和洁净煤技术利用现状分析与对策建议

谢克昌

期刊论文

Meshing stiffness property and meshing status simulation of harmonic drive under transmission loading

期刊论文

Modeling and analysis of controllable output property of cantilever-beam inertial sensors based on magnetic

Guixiong LIU, Peiqiang ZHANG, Chen XU

期刊论文

of photolysis half-lives of dyes in a continuous-flow system with the aid of quantitative structure-property

Davoud BEIKNEJAD,Mohammad Javad CHAICHI

期刊论文

Preparation and property of porous hydroxyapatite as an inorganic dispersant used in suspension polymerization

XU Kaqiu, XU Jiale, WANG Yuhong

期刊论文