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Synthesis and characterization of castor oil-based polymeric surfactants

Xujuan HUANG,He LIU,Shibin SHANG,Zhaosheng CAI,Jie SONG,Zhanqian SONG

《农业科学与工程前沿(英文)》 2016年 第3卷 第1期   页码 46-54 doi: 10.15302/J-FASE-2016083

摘要: Dehydrated castor oil was epoxidized using phosphoric acid as a catalyst and acetic acid peroxide as an oxidant to produce epoxidized castor oil (ECO). Ring-opening polymerization with stannic chloride was used to produce polymerized ECO (PECO), and sodium hydroxide used to give hydrolyzed PECO (HPECO). The HPECO was characterized by Fourier transform infrared, H and C nuclear magnetic resonance spectroscopies, gel permeation chromatography, and differential scanning calorimetry. The weight-average molecular weight of soluble PECO and HPECO were 5026 and 2274 g·mol , respectively. PECO and HPECO exhibited glass transition. Through neutralizing the carboxylic acid of HPECO with different counterions, castor oil-based polymeric surfactants (HPECO-M, where M= Na , K or triethanolamine ion) exhibited high efficiency to reduce the surface tension of water. The critical micelle concentration (CMC) values of HPECO-M ranged from 0.042 to 0.098 g·L and the minimum equilibrium surface tensions at CMC ( ) of HPECO-M ranged from 25.6 to 30.0 mN·m . The water-hexadecane interfacial energy was calculated from measured surface tension using harmonic and geometric mean methods. Measured values of water-hexadecane interfacial tension agreed well with those calculated using the harmonic and geometric mean methods.

关键词: epoxidized vegetable oil     ring-opening polymerization     interfacial tension     polymeric surfactant    

Behavior of dam concrete under biaxial compression-tension and triaxial compression-compression-tension

WANG Huailiang, SONG Yupu

《结构与土木工程前沿(英文)》 2008年 第2卷 第4期   页码 323-328 doi: 10.1007/s11709-008-0043-5

摘要: In order to meet the requirement for nonlinear analysis and design of mass concrete structures, the deformation behavior and strength of three-graded concrete specimens 250 mm × 250 mm × 400 mm with a maximum aggregate size of 80 mm and the corresponding wet-screened concrete specimens 150 mm × 150 mm × 300 mm with a maximum aggregate size of 40 mm were studied experimentally. Specimens subjected to biaxial compression-tension (C-T) and triaxial compression-compression-tension (C-C-T) stress states. Test data indicate that both the deformation and strength of the mass concrete specimens are lower than those of the corresponding wet-screened concrete small specimens, but the initial tangent modulus of the stress-strain curve of the former is greater than that of the latter. Test results show that the wet-screened effect and size effect of the specimens under complex stress states are obvious such that these should be considered in the design of mass concrete structures. In addition, respective failure criteria for mass concrete in principal stress space and octahedron stress space are proposed.

关键词: requirement     wet-screened concrete     compression-tension     maximum aggregate     principal    

Seismic stability of earth slopes with tension crack

Yundong ZHOU, Fei ZHANG, Jingquan Wang, Yufeng GAO, Guangyu DAI

《结构与土木工程前沿(英文)》 2019年 第13卷 第4期   页码 950-964 doi: 10.1007/s11709-019-0529-3

摘要: Cracks at the crest of slopes frequently occur during earthquakes. Such cracks result from limited tension strength of the soil. A tension cut-off in Mohr-Coulomb shear strength can represent this limited strength. Presented is an extension of variational analysis of slope stability with a tension crack considering seismicity. Both translational and rotational failure mechanisms are included in a pseudo-static analysis of slope stability. Developed is a closed-form to assess the seismic stability of slopes with zero tensile strength. The results indicate that the presence of the tension crack has significant effects on the seismic stability of slopes, i.e. leading to small value of the yield acceleration. Considering soil tension strength in seismic slope analysis may lead to overestimation on the stability, as much as 50% for vertical slopes. Imposing tension crack results in transit of the critical failure mode to a straight line from a log-spiral, except for flat slopes with small soil cohesion. Under seismic conditions, large cohesion may increase the depth of crack, moving it closer to the slope.

关键词: slope stability     tension     crack     limit equilibrium     seismic effect    

Surface tension of liquid metal: role, mechanism and application

Xi ZHAO, Shuo XU, Jing LIU

《能源前沿(英文)》 2017年 第11卷 第4期   页码 535-567 doi: 10.1007/s11708-017-0463-9

摘要: Surface tension plays a core role in dominating various surface and interface phenomena. For liquid metals with high melting temperature, a profound understanding of the behaviors of surface tension is crucial in industrial processes such as casting, welding, and solidification, etc. Recently, the room temperature liquid metal (RTLM) mainly composed of gallium-based alloys has caused widespread concerns due to its increasingly realized unique virtues. The surface properties of such materials are rather vital in nearly all applications involved from chip cooling, thermal energy harvesting, hydrogen generation, shape changeable soft machines, printed electronics to 3D fabrication, etc. owing to its pretty large surface tension of approximately 700 mN/m. In order to promote the research of surface tension of RTLM, this paper is dedicated to present an overview on the roles and mechanisms of surface tension of liquid metal and summarize the latest progresses on the understanding of the basic knowledge, theories, influencing factors and experimental measurement methods clarified so far. As a practical technique to regulate the surface tension of RTLM, the fundamental principles and applications of electrowetting are also interpreted. Moreover, the unique phenomena of RTLM surface tension issues such as surface tension driven self-actuation, modified wettability on various substrates and the functions of oxides are discussed to give an insight into the acting mechanism of surface tension. Furthermore, future directions worthy of pursuing are pointed out.

关键词: surface tension     liquid metal     soft machine     printed electronics     electrowetting     self-actuation    

Correlation between tension softening relation and crack extension resistance in concrete

Xiufang ZHANG , Shilang XU ,

《结构与土木工程前沿(英文)》 2009年 第3卷 第3期   页码 323-329 doi: 10.1007/s11709-009-0041-2

摘要: Changes of the material fracture energy consumption with crack propagation can be described by a crack extension resistance curve, one of the fundamental fracture criteria in crack mechanics. Recently, experimental observation of the fracture behavior in concrete was used to develop a new fracture criterion, the crack extension resistance curve, to analyze crack propagation during the entire concrete fracture process. The variation of the crack extension resistance is mainly associated with the energy consumption in the fracture process zone ahead of the stress-free crack tip. The crack extension resistance is then a function of the softening curve, which is a basic mechanical property in the fracture process zone. The relationship between the softening curve and the crack extension resistance curve is then analyzed based on results of three-point bending beams tests. The results indicate that the characteristic points of the crack extension resistance curve is closely related to the characteristic point on used tension softening curve.

关键词: concrete     fracture process zone     crack extension GR resistance     tension softening curve    

Calculation method of load distribution on pipe threaded connections under tension load

Shoujun CHEN, Lianxin GAO, Qi AN

《机械工程前沿(英文)》 2011年 第6卷 第2期   页码 241-248 doi: 10.1007/s11465-011-0219-x

摘要:

This paper presents a new calculation method that can calculate the load distribution on pipe threaded connections under tension load. On the basis of elastic mechanics, the new method was developed by analyzing each thread tooth, and a new deformation and covariant equation by making a mechanics analysis on each thread tooth was obtained. Compared with the traditional method proposed by the previous references, the new deformation and covariant equation could be used to describe the relation between the previous and the next thread tooth. By applying the new method on the sample of P-110S pipe threaded connection, the obtained results show that the load on thread tooth mainly concentrates on the four or five threads engaged and the middle teeth were not utilized well to bear the loads. The model offers a new way to calculate the loads carried on the thread teeth under tension load.

关键词: load distribution     calculation method     pipe threaded connections     tension load    

The effects of interfacial strength on fractured microcapsule

Luthfi Muhammad MAULUDIN, Chahmi OUCIF

《结构与土木工程前沿(英文)》 2019年 第13卷 第2期   页码 353-363 doi: 10.1007/s11709-018-0469-3

摘要: The effects of interfacial strength on fractured microcapsule are investigated numerically. The interaction between crack and microcapsule embedded in mortar matrix is modeled based on cohesive approach. The microcapsules are modelled with variation of core-shell thickness ratio and potential cracks are represented by pre-inserted cohesive elements along the element boundaries of the mortar matrix, microcapsules core, microcapsule shell, and at the interfaces between these phases. Special attention is given to the effects of cohesive fracture on the microcapsule interface, namely fracture strength, on the load carrying capacity and fracture probability of the microcapsule. The effect of fracture properties on microcapsule is found to be significant factor on the load carrying capacity and crack propagation characteristics. Regardless of core-shell thickness ratio of microcapsule, the load carrying capacity of self-healing material under tension increases as interfacial strength of microcapsule shell increases. In addition, given the fixed fracture strength of the interface of microcapsule shell, the higher the ratio core-shell thickness, the higher the probability of microcapsules being fractured.

关键词: interfacial strength     cohesive elements     microcapsule     core-shell thickness ratio     fracture properties    

Construction of interfacial dynamic bonds for high performance lignin/polymer biocomposites

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1372-1388 doi: 10.1007/s11705-023-2302-3

摘要: Lignin is the largest natural aromatic biopolymer, but usually treated as industrial biomass waste. The development of lignin/polymer biocomposites can promote the high value utilization of lignin and the greening of polymers. However, the weak interfacial interaction between industrial lignin and polymer induces poor compatibility and serious agglomeration in polymer owing to the strong intermolecular force of lignin. As such, it is extremely difficult to prepare high performance lignin/polymer biocomposites. Recently, we proposed the strategy of in situ construction of interfacial dynamic bonds in lignin/polymer composites. By taking advantage of the abundant oxygen-containing polar groups of lignin, we inserted dynamic bonding connection such as hydrogen bonds and coordination bonds into the interphase between lignin and the polymer matrix to improve the interfacial interactions. Meanwhile, the natural amphiphilic structure characteristics of lignin were utilized to construct the hierarchical nanophase separation structure in lignin/polymer composites. The persistent problems of poor dispersity and interfacial compatibility of lignin in the polymer matrix were effectively solved. The lignin-modified polymer composites achieved simultaneously enhanced strength and toughness. This concise review systematically summarized the recent research progress of our group toward building high-performance lignin/polymer biocomposites through the design of interfacial dynamic bonds (hydrogen bonds, coordination bonds, and dynamic covalent bonds) between lignin and different polymer systems (polar plastics, rubber, polyurethane, hydrogels, and other polymers). Finally, the future development direction, main challenges, and potential solutions of lignin application in polymers were presented.

关键词: lignin     polymer     interfacial dynamic bonds    

Comparing the effects of Bassini versus tension-free hernioplasty: 3 years’ follow-up

Yulong SHI, Zhongxue SU, Leping LI, Hongjun LIU, Changqing JING,

《医学前沿(英文)》 2010年 第4卷 第4期   页码 463-468 doi: 10.1007/s11684-010-0050-5

摘要: In order to compare the effects of Bassini and tension-free mesh hernioplasty, a total of 552 patients with inguinal hernia who were subjected to surgical treatment in our hospital were randomly divided into the following two groups: the Bassini group (=269) and the tension-free mesh group (=283). The recurrence rates, pain, discomfort, and other complications were recorded, and the causes of the complications were explored. The recurrence rate in the Bassini group was 8.9% (24/269), significantly higher than that in the tension-free repair group (2.8%, 8/283). In addition, the recurrence rates in the Bassini and tension-free groups before 2004 were 12.6% and 5.6%, respectively, which were markedly higher than the rates after 2004 (5.3% and 0.7%, respectively). The rate of post-operative discomfort and pain within the first three months was higher in the Bassini group compared to the tension-free group (25.7% 18.5%, respectively). However, there was no difference after three months in the rate of post-operative discomfort and pain, incidence of infection, or scrotal edema between the two groups. The average hospital stay in the Bassini group was longer than that in the tension-free repair group (7.6€±€1.2 4.5€±€2.2 days, respectively), but the cost was lower (4518.0€±€510 6221.3€±€578 yuan, respectively). Thus, tension-free mesh hernioplasty is indicated for most inguinal hernia patients due to the low recurrence rate, rapid recovery time, and treatment success, but the traditional Bassini procedure has lower cost and other beneficial effects and is still suitable for some patients.

关键词: hernioplasty     Bassini repair     tension-free repair     complication    

High-precision gyro-stabilized control of a gear-driven platform with a floating gear tension device

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 487-503 doi: 10.1007/s11465-021-0635-5

摘要: This study presents an improved compound control algorithm that substantially enhances the anti-disturbance performance of a gear-drive gyro-stabilized platform with a floating gear tension device. The tension device can provide a self-adjustable preload to eliminate the gap in the meshing process. However, the weaker gear support stiffness and more complex meshing friction are also induced by the tension device, which deteriorates the control accuracy and the ability to keep the aim point of the optical sensors isolated from the platform motion. The modeling and compensation of the induced complex nonlinearities are technically challenging, especially when base motion exists. The aim of this research is to cope with the unmeasured disturbances as well as the uncertainties caused by the base lateral motion. First, the structural properties of the gear transmission and the friction-generating mechanism are analyzed, which classify the disturbances into two categories: Time-invariant and time-varying parts. Then, a proportional-integral controller is designed to eliminate the steady-state error caused by the time-invariant disturbance. A proportional multiple-integral-based state augmented Kalman filter is proposed to estimate and compensate for the time-varying disturbance that can be approximated as a polynomial function. The effectiveness of the proposed compound algorithm is demonstrated by comparative experiments on a gear-drive pointing system with a floating gear tension device, which shows a maximum 76% improvement in stabilization precision.

关键词: inertially stabilized platform     floating gear tension device     nonlinear friction     disturbance compensation     proportional multiple-integral observer    

Studies on the liquid-liquid interfacial mass transfer process using holographic interferometry

ZHAO Chaofan, ZHU Chunying, MA Youguang

《化学科学与工程前沿(英文)》 2008年 第2卷 第1期   页码 1-4 doi: 10.1007/s11705-008-0006-3

摘要: This paper aims at the interfacial phenomena of liquid-liquid mass transfer and its characteristic. By using the real-time holographic technique, the concentration distributions on the aqueous side were obtained according to holographic diagrams of mass transfer of ethanol through the interface of oil and water at different initial concentrations. Furthermore, the concentrations near the interface and the mass transfer coefficients were attained. A correlation of concentration near the interface to the concentration of the solute in the oil side was proposed. An approach of interfacial energy with solute concentration was established, and the calculated results are at good agreement with the experimental data. It is indicated that the liquid-liquid mass transfer process is approximately in accordance with two-film theory, the interfacial performance may be changed by the addition of the solute, and the interface of liquid-liquid is non-equilibrium thermodynamically during the mass transfer process.

关键词: liquid-liquid     different     real-time holographic     addition     transfer    

Interfacial induction and regulation for microscale crystallization process: a critical review

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 838-853 doi: 10.1007/s11705-021-2129-8

摘要: Microscale crystallization is at the frontier of chemical engineering, material science, and biochemical research and is affected by many factors. The precise regulation and control of microscale crystal processes is still a major challenge. In the heterogeneous induced nucleation process, the chemical and micro/nanostructural characteristics of the interface play a dominant role. Ideal crystal products can be obtained by modifying the interface characteristics, which has been proven to be a promising strategy. This review illustrates the application of interface properties, including chemical characteristics (hydrophobicity and functional groups) and the morphology of micro/nanostructures (rough structure and cavities, pore shape and pore size, surface porosity, channels), in various microscale crystallization controls and process intensification. Finally, possible future research and development directions are outlined to emphasize the importance of interfacial crystallization control and regulation for crystal engineering.

关键词: interfacial crystallization     heterogeneous nucleation     supersaturation     micro/nanostructure     process control and intensification    

Controlling microbiological interfacial behaviors of hydrophobic organic compounds by surfactants in

ZHANG Dong,ZHU Lizhong

《环境科学与工程前沿(英文)》 2014年 第8卷 第3期   页码 305-315 doi: 10.1007/s11783-014-0647-z

摘要: Bioremediation of hydrophobic organic compounds (HOCs) contaminated soils involves several physicochemical and microbiological interfacial processes among the soil-water-microorganism interfaces. The participation of surfactants facilitates the mass transport of HOCs in both the physicochemical and microbiological interfaces by reducing the interfacial tension. The effects and underlying mechanisms of surfactants on the physicochemical desorption of soil-sorbed HOCs have been widely studied. This paper reviewed the progress made in understanding the effects of surfactant on microbiological interfacial transport of HOCs and the underlying mechanisms, which is vital for a better understanding and control of the mass transfer of HOCs in the biodegradation process. In summary, surfactants affect the microbiological interfacial behaviors of HOCs during three consecutive processes: the soil solution-microorganism sorption, the transmembrane process, and the intracellular metabolism. Surfactant could promote cell sorption of HOCs depending on the compatibility of surfactant hydrophile hydrophilic balance (HLB) with cell surface properties; while the dose ratio between surfactant and biologic mass (membrane lipids) determined the transmembrane processes. Although surfactants cannot easily directly affect the intracellular enzymatic metabolism of HOCs due to the steric hindrace, the presence of surfactants can indirectly enhanced the metabolism by increasing the substrate concentrations.

关键词: biodegradation     sorption     transmembrane transport     microbiological interfaces     surfactants    

A state-of-the-art review on interfacial behavior between asphalt binder and mineral aggregate

Meng GUO, Yiqiu TAN, Linbing WANG, Yue HOU

《结构与土木工程前沿(英文)》 2018年 第12卷 第2期   页码 248-259 doi: 10.1007/s11709-017-0422-x

摘要: The interface between asphalt binder and mineral aggregate directly affects the service life of pavement because the defects and stress concentration occur more easily there. The interaction between asphalt binder and mineral aggregate is the main cause of forming the interface. This paper presents an extensive review on the test technologies and analysis methods of interfacial interaction, including molecular dynamics simulation, phase field approach, absorption tests, rheological methods and macro mechanical tests. All of the studies conducted on this topic clearly indicated that the interfacial interaction between asphalt binder and mineral aggregate is a physical-chemical process, and can be qualitatively characterized by microscopical technique (such as SEM and AFM), and also can be quantitatively evaluated by rheological methods and interfacial mechanical tests. Molecular dynamics simulation and phase field approach were also demonstrated to be effective methods to study the interfacial behavior and its mechanism.

关键词: Asphalt binder     Mineral aggregate     Interfacial behavior     Multiscale    

Simulation of interfacial Marangoni convection in gas-liquid mass transfer by lattice Boltzmann method

Shuyong CHEN, Xigang YUAN, Bo FU, Kuotsung YU

《化学科学与工程前沿(英文)》 2011年 第5卷 第4期   页码 448-454 doi: 10.1007/s11705-011-1142-8

摘要: Interfacial Marangoni convection has significant effect on gas-liquid and/or liquid-liquid mass transfer processes. In this paper, an approach based on lattice Boltzmann method is established and two perturbation models, fixed perturbation model and self-renewable interface model, are proposed for the simulation of interfacial Marangoni convection in gas-liquid mass transfer process. The simulation results show that the concentration contours are well consistent with the typical roll cell convection patterns obtained experimentally in previous studies.

关键词: interfacial Marangoni convection     lattice Boltzmann method     gas-liquid mass transfer    

标题 作者 时间 类型 操作

Synthesis and characterization of castor oil-based polymeric surfactants

Xujuan HUANG,He LIU,Shibin SHANG,Zhaosheng CAI,Jie SONG,Zhanqian SONG

期刊论文

Behavior of dam concrete under biaxial compression-tension and triaxial compression-compression-tension

WANG Huailiang, SONG Yupu

期刊论文

Seismic stability of earth slopes with tension crack

Yundong ZHOU, Fei ZHANG, Jingquan Wang, Yufeng GAO, Guangyu DAI

期刊论文

Surface tension of liquid metal: role, mechanism and application

Xi ZHAO, Shuo XU, Jing LIU

期刊论文

Correlation between tension softening relation and crack extension resistance in concrete

Xiufang ZHANG , Shilang XU ,

期刊论文

Calculation method of load distribution on pipe threaded connections under tension load

Shoujun CHEN, Lianxin GAO, Qi AN

期刊论文

The effects of interfacial strength on fractured microcapsule

Luthfi Muhammad MAULUDIN, Chahmi OUCIF

期刊论文

Construction of interfacial dynamic bonds for high performance lignin/polymer biocomposites

期刊论文

Comparing the effects of Bassini versus tension-free hernioplasty: 3 years’ follow-up

Yulong SHI, Zhongxue SU, Leping LI, Hongjun LIU, Changqing JING,

期刊论文

High-precision gyro-stabilized control of a gear-driven platform with a floating gear tension device

期刊论文

Studies on the liquid-liquid interfacial mass transfer process using holographic interferometry

ZHAO Chaofan, ZHU Chunying, MA Youguang

期刊论文

Interfacial induction and regulation for microscale crystallization process: a critical review

期刊论文

Controlling microbiological interfacial behaviors of hydrophobic organic compounds by surfactants in

ZHANG Dong,ZHU Lizhong

期刊论文

A state-of-the-art review on interfacial behavior between asphalt binder and mineral aggregate

Meng GUO, Yiqiu TAN, Linbing WANG, Yue HOU

期刊论文

Simulation of interfacial Marangoni convection in gas-liquid mass transfer by lattice Boltzmann method

Shuyong CHEN, Xigang YUAN, Bo FU, Kuotsung YU

期刊论文