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Soil-water interaction in unsaturated expansive soil slopes

ZHAN Liangtong

《结构与土木工程前沿（英文）》 2007年 第1卷 第2期   页码 198-204 doi: 10.1007/s11709-007-0023-1

摘要： The intensive soil-water interaction in unsaturated expansive soil is one of the major reasons for slope failures. In this paper, the soil-water interaction is investigated with the full-scale field inspection of rainwater infiltration and comprehensive experiments, including wetting-induced softening tests, swelling, and shrinkage tests. It is demonstrated that the soil-water interaction induced by seasonal wetting-drying cycles is very complex, and it involves coupled effects among the changes in water content, suction, stress, deformation and shear strength. In addition, the abundant cracks in the expansive soil play an important role in the soil-water interaction. The cracks disintegrate the soil mass, and more importantly, provide easy pathways for rainfall infiltration. Infiltration of rainwater not only results in wetting-induced softening of the shallow unsaturated soil layers, but also leads to the increase of horizontal stress. The increase of horizontal stress may lead to a local passive failure. The seasonal wetting-drying cycles tend to result in a down-slope creeping of the shallow soil layer, which leads to progressive slope failure.

关键词： strength     intensive soil-water     comprehensive     Infiltration     wetting-induced softening    

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Influence of direct electric current on wetting behavior during brazing

Kirsten BOBZIN, Wolfgang WIETHEGER, Julian HEBING, Lidong ZHAO, Alexander SCHMIDT, Riza ISKANDAR, Joachim MAYER

《机械工程前沿（英文）》 2020年 第15卷 第3期   页码 496-503 doi: 10.1007/s11465-019-0582-6

摘要： The wetting behavior of liquid metals is of great importance for many processes. For brazing, however, a targeted modification beyond the adjustment of conventional process parameters or the actual set-up was not possible in the past. Therefore, the effect of direct electric current along the surface of a steel substrate on the wetting behavior and the formation of the spreading pattern of an industrial nickel-based filler metal was investigated at a temperature above = 1000 °C in a vacuum brazing furnace. By applying direct current up to = 60 A the wetted surface area could be increased and the spreading of the molten filler metal could be controlled in dependence of the polarity of the electric current. The electric component of the Lorentz force is supposed to be feasible reasons for the observed dependence of the electrical polarity on the filler metal spreading direction. To evaluate the influence of the electric current on the phase formation subsequent selective electron microscope analyses of the spreading pattern were carried out.

关键词： brazing     electric current assisted wetting     Lorentz force    

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review on membrane distillation in process engineering: design and exergy equations, materials and wetting

《化学科学与工程前沿（英文）》 2022年 第16卷 第5期   页码 592-613 doi: 10.1007/s11705-021-2105-3

摘要： One of the problems that most afflicts humanity is the lack of clean water. Water stress, which is the pressure on the quantity and quality of water resources, exists in many places throughout the World. Desalination represents a valid solution to the scarcity of fresh water and several technologies are already well applied and successful (such as reverse osmosis), producing about 100 million m3·d−1 of fresh water. Further advances in the field of desalination can be provided by innovative processes such as membrane distillation. The latter is of particular interest for the treatment of waste currents from conventional desalination processes (for example the retentate of reverse osmosis) as it allows to desalt highly concentrated currents as it is not limited by concentration polarization phenomena. New perspectives have enhanced research activities and allowed a deeper understanding of mass and heat transport phenomena, membrane wetting, polarization phenomena and have encouraged the use of materials particularly suitable for membrane distillation applications. This work summarizes recent developments in the field of membrane distillation, studies for module length optimization, commercial membrane modules developed, recent patents and advancement of membrane material.

关键词： membrane distillation     recent developments     heat and mass transfer     wetting     membrane material    

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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    

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Hypoplastic constitutive modeling of wetting deformation of weathered rockfill materials

Erich BAUER, Zhongzhi FU, Sihong LIU,

《结构与土木工程前沿（英文）》 2010年 第4卷 第1期   页码 78-91 doi: 10.1007/s11709-010-0011-8

摘要： The wetting deformation of weathered rockfill materials has been attracting growing attention from both engineers and scientists. The importance of realistic predictions of wetting deformations for high earth and rockfill dams is a strong motivation to establish a suitable constitutive model. Recently, the hypoplastic constitutive model by Gudehus and Bauer was extended by introducing solid hardness depending on the state of weathering. The extended model takes into account the influence of the current density, the effective stress state, the rate of deformation, and the time dependent process of degradation of the solid hardness. In the present paper, the performance of this model is evaluated by comparing numerical simulations with experiments obtained from a water sensitive rockfill material. In particular, triaxial compression paths and creep deformation under deviatoric stress states are considered. Finally, the constitutive model proposed is used to study the influence of a degradation of the solid hardness on the long term behavior of a hypothetical fill dam.

关键词： rockfill dams     weathered granular materials     hypoplasticity     solid hardness     creep     stress relaxation    

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Many-body dissipative particle dynamics simulation of wetting phenomena

Ying ZHAO, Ye YUE, Xianren ZHANG, Shuangyang LI, Atul SAJJANHAR,

《化学科学与工程前沿（英文）》 2010年 第4卷 第3期   页码 280-282 doi: 10.1007/s11705-009-0278-2

摘要： With the development of the simulation of particle dynamics, the traditional dissipative particle dynamics (DPD) method can not satisfy the needs of research in static or dynamic wetting phenomena. However, the Many-body DPD approach extends the ability of the traditional method to simulate the interface between solid and liquid or some other situation. In this paper, we propose a Many-body DPD program to simulate the solid-liquid interface and get satisfactory results.

关键词： development     satisfactory     traditional dissipative     phenomena     solid-liquid interface    

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Forward osmosis coupled with lime-soda ash softening for volume minimization of reverse osmosis

Jiandong Lu, Shijie You, Xiuheng Wang

《环境科学与工程前沿（英文）》 2021年 第15卷 第1期 doi: 10.1007/s11783-020-1301-6

摘要： Abstract • Forward osmosis (FO) coupled with chemical softening for CCI ROC minimization • Effective removal of scale precursor ions by lime-soda ash softening • Enhanced water recovery from 54% to 86% by mitigation of FO membrane scaling • High-purity CaCO3 was recovered from the softening sludge • Membrane cleaning efficiency of 88.5% was obtained by EDTA for softened ROC Reverse osmosis (RO) is frequently used for water reclamation from treated wastewater or desalination plants. The RO concentrate (ROC) produced from the coal chemical industry (CCI) generally contains refractory organic pollutants and extremely high-concentration inorganic salts with a dissolved solids content of more than 20 g/L contributed by inorganic ions, such as Na+, Ca2+, Mg2+, Cl−, and SO42−. To address this issue, in this study, we focused on coupling forward osmosis (FO) with chemical softening (FO-CS) for the volume minimization of CCI ROC and the recovery of valuable resources in the form of CaCO3. In the case of the real raw CCI ROC, softening treatment by lime-soda ash was shown to effectively remove Ca2+/Ba2+ (>98.5%) and Mg2+/Sr2+/Si (>80%), as well as significantly mitigate membrane scaling during FO. The softened ROC and raw ROC corresponded to a maximum water recovery of 86% and 54%, respectively. During cyclic FO tests (4 × 10 h), a 27% decline in the water flux was observed for raw ROC, whereas only 4% was observed for softened ROC. The cleaning efficiency using EDTA was also found to be considerably higher for softened ROC (88.5%) than that for raw ROC (49.0%). In addition, CaCO3 (92.2% purity) was recovered from the softening sludge with an average yield of 5.6 kg/m3 treated ROC. This study provides a proof-of-concept demonstration of the FO-CS coupling process for ROC volume minimization and valuable resources recovery, which makes the treatment of CCI ROC more efficient and more economical.

关键词： Coal chemical industry     Forward osmosis     Chemical softening     Reverse osmosis concentrate    

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薄板坯连铸连轧铁素体+珠光体类型钢的强化与软化

傅杰,吴华杰,刘阳春

《中国工程科学》 2008年 第10卷 第4期   页码 65-72

摘要：

根据钢的综合强化理论，控制A1附近温度下钢中碳的析出，研究了HSLC钢的强化与软化问题。结果表明：薄板坯连铸连轧HSLC钢，强度还可进一步提高；通过回火缓冷，薄板坯连铸连轧HSLC钢ZJ330的σs从344 MPa降至225 MPa，能满足冷轧基板要求。讨论了有关铁素体轧制、超细晶粒钢以及一种可能的新型建筑材料等问题。

关键词： HSLC钢     强化     软化     冷轧基板     超级钢    

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Influence of pressure and density on the rheological properties of rockfills

Erich BAUER, Zhongzhi FU, Sihong LIU

《结构与土木工程前沿（英文）》 2012年 第6卷 第1期   页码 25-34 doi: 10.1007/s11709-012-0143-0

摘要： Long-term deformations of rockfill dams can be related to the type of dam, the pre-compaction achieved during the construction of the dam, the history of loading events, the rheological properties of the rockfill material used, the seepage behavior caused by defects of the sealing, the interactions of the dam building with the foundation, and the hydrothermal phenomena of the stressed rockfill material. The present paper investigates the rheological properties of coarse grained rockfill materials using a hypoplastic constitutive model. Particular attention is paid to wetting deformation under different deviatoric loading states and pre-compactions. To quantify the state of weathering a so-called “solid hardness” is used in the sense of a continuum description. It is shown that an appropriate modeling of wetting deformations requires a unified description of the interaction at least between the state of weathering, the stress state, the density and the rate of deformation. The results obtained from the numerical simulations are compared with available experimental data for a rockfill material used in Xiaolangdi earth dam.

关键词： rockfills     solid hardness     wetting deformation     hypoplasticity     creep    

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Treatment of gingival hyperplasia induced by cyclosporine A

MA Jingzhi, LI Ming, CAO Yingguang

《医学前沿（英文）》 2008年 第2卷 第3期   页码 290-294 doi: 10.1007/s11684-008-0055-5

摘要： The clinical therapy for cyclosporine A (CsA)-induced gingival hyperplasia (GH) and the pathological changes in hyperplastic gingival tissues were investigated. Nine cases of CsA-induced GH after renal transplantation were subjected to periodontal non-surgical treatment and surgical treatment and were followed up. Gingival index (GI), dental plaque index (PLI) and GH degree (GHD) at different time points were measured. Under light and electron microscopy, the pathological changes in hyperplastic gingival tissues were observed. The CsA concentrations in gingival tissues and blood were determined by using fluorescence polarization immunoassay with TDFL monoclonal antibody. The results showed that GI, PLI and GHD in patients with GH declined after periodontal treatment. Two patients suffered from different degrees of GH during the 6 months to 54 months post-transplantation. Under transmission electron microscopy, fibroblasts in the hyperplastic gingival tissues were enlarged, cytoplasmic rough endoplasmic reticula were abundant and expanded slightly, and a few fibroblasts with early apoptotic changes were seen. The concentrations of CsA in hyperplastic gingival tissues were from 351.00 to 1345.47 ng/mL, which were significantly higher than in the blood of the same patients taken at the same time points. It was concluded that GI and PLI declined after periodontal treatment in combination with surgical treatment in patients taking CsA for a long time, but in some patients, GH recurred. The fact that the concentration of CsA in hyperplastic gingival tissues is higher than in blood awaits further studies.

关键词： post-transplantation     Gingival     cytoplasmic     CsA-induced     further    

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Influence of fluid-structure interaction on vortex induced vibration and lock-in phenomena in long span

Nazim Abdul NARIMAN

《结构与土木工程前沿（英文）》 2016年 第10卷 第4期   页码 363-384 doi: 10.1007/s11709-016-0353-y

摘要： In this paper, deck models of a cable stayed bridge are generated in ABAQUS-finite element program once using only CFD model (one-way fluid-structure interaction) and another by using both the CFD model and the CSD model together (two-way fluid-structure interaction) in a co-simulation. Shedding frequencies for the associated wind velocities in the lock-in region are calculated in both approaches. The results are validated with Simiu and Scanlan results. The lift and drag coefficients are determined for the two approaches and the latter results are validated with the flat plate theory results by Munson and coauthors. A decrease in the critical wind velocity and the shedding frequencies considering two-way approach was determined compared to those obtained in the one-way approach. The results of the lift and drag forces in the two-way approach showed appreciable decrease in their values. It was concluded that the two-way approach predicts earlier vortex induced vibration for lower critical wind velocities and lock-in phenomena will appear at lower natural frequencies of the long span bridges. This helps the designers to efficiently plan and consider for the design and safety of the long span bridge against this type of vibration.

关键词： vortex-induced vibration     fluid-structure interaction     Strouhal number     lock-in     kinetic energy    

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Formation of microporous polymeric membranes via thermally induced phase separation: A review

Min Liu,Shenghui Liu,Zhenliang Xu,Yongming Wei,Hu Yang

《化学科学与工程前沿（英文）》 2016年 第10卷 第1期   页码 57-75 doi: 10.1007/s11705-016-1561-7

摘要： A review of recent research related to microporous polymeric membranes formed via thermally induced phase separation (TIPS) and the morphologies of these membranes is presented. A summary of polymers and suitable diluents that can be used to prepare these microporous membranes via TIPS are summarized. The effects of different kinds of polymer materials, diluent types, cooling conditions, extractants and additive agents on the morphology and performance of TIPS membranes are also discussed. Finally new developments in TIPS technology are summarized.

关键词： polymer     microporous membrane     thermally induced phase separation    

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An overview of vortex-induced vibration (VIV) of bridge decks

Teng WU, Ahsan KAREEM

《结构与土木工程前沿（英文）》 2012年 第6卷 第4期   页码 335-347 doi: 10.1007/s11709-012-0179-1

摘要： A brief overview of vortex-induced vibration (VIV) of circular cylinders is first given as most of VIV studies have been focused on this particular bluff cross-section. A critical literature review of VIV of bridge decks that highlights physical mechanisms central to VIV from a renewed perspective is provided. The discussion focuses on VIV of bridge decks from wind-tunnel experiments, full-scale observations, semi-empirical models and computational fluids dynamics (CFD) perspectives. Finally, a recently developed reduced order model (ROM) based on truncated Volterra series is introduced to model VIV of long-span bridges. This model captures successfully salient features of VIV at “lock-in” and unlike most phenomenological models offers physical significance of the model kernels.

关键词： vortex-induced vibration (VIV)     Volterra series     bridge    

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Synthesis and ultraviolet/aggregation-induced emission investigation of novel tetraphenylvinyl hydrazone

《化学科学与工程前沿（英文）》 2023年 第17卷 第12期   页码 2061-2073 doi: 10.1007/s11705-023-2366-0

摘要： Herein, three novel tetraphenylethylene hydrazone chemosensors TC12, SC16, and TC16 are prepared for the selective detection of F−. Two NH and one C=N units are incorporated into the sensors for better colorimetric responses, whereas the tetraphenyl unit is in charge of the aggregation-induced emission effect. Among them, compounds SC16 and TC16 form stable gels with some organic solvents. All the tetrahydrofuran/H2O solutions of the three compounds exhibit aggregation-induced emission effect, whereby the fluorescence emission increases by varying degrees with the volume of poor solvent water. Moreover, good aggregation-induced emission effects are observed in the self-assembly of SC16 and TC16. As a sample chemosensor, TC12 in tetrahydrofuran responds to F− selectively with high sensitivity, with the colorimetric and fluorometric detection limits of 8.25 × 10−7 mol·L–1 and 2.69 × 10−7 mol·L–1, respectively. The reversible gel-sol-gel phase transition and color changes indicate that both SC16-dimethyl sulfoxide and TC16-ethyl acetate gels specifically respond to F– with good sensitivity. The detection results are well supported by ultraviolet-visible spectroscopy, fluorescent spectroscopy, and 1H nuclear magnetic resonance. More importantly, the driving forces of gelation are visually clarified through the single crystal X-ray analysis of compound TOMe.

关键词： organogelator     tetraphenylvinyldrazone     single crystal     aggregation-induced emission effect     ion sensing    

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Cellular changes in bronchoalveolar lavage fluid in hyperoxia-induced lung injury

HE Xinbiao, ZHAO Wei

《医学前沿（英文）》 2008年 第2卷 第4期   页码 370-373 doi: 10.1007/s11684-008-0071-5

摘要： It is well known that high concentration oxygen exposure is a model of acute lung injury (ALI). However, controversy exists over the mechanism. This study was designed to clarify the cellular characteristics in bronchoalveolar lavage fluid (BALF) and body weight loss of rats exposed to oxygen(> 90%). Young male Wistar rats, aged 6 weeks, were divided into three groups: (1) room air group (exposed to room air, = 22); (2) hyperoxia < 48 h group (exposed to over 90% oxygen for less than 48 h, = 18); (3) hyperoxia 66–72 h group (exposed to over 90% oxygen for 66–72 h group, = 7). Compared to the room air group, the total cell counts in the hyperoxia 66–72 h group decreased, whereas the neutrophils increased significantly. The body weights of the rats exposed to room air continued to increase. However, the body weights of oxygen-exposed rats increased slightly on the first day and weight loss was seen from the second day. All rats were noted to have bilateral pleural effusion in the hyperoxia 66–72 h group. The data suggests that (1) an increase in neutrophil count is an evident feature of hyperoxia-induced lung injury; (2) high concentration oxygen exposure can give rise to anorexia and malnutrition, which may play a role in hyperoxia-induced lung injury. Blocking neutrophil influx into lung tissue in the early phase and improving malnutrition are two effective methods to reduce hyperoxic lung injury.
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标题 作者 时间 类型 操作

Soil-water interaction in unsaturated expansive soil slopes

ZHAN Liangtong

期刊论文

Influence of direct electric current on wetting behavior during brazing

Kirsten BOBZIN, Wolfgang WIETHEGER, Julian HEBING, Lidong ZHAO, Alexander SCHMIDT, Riza ISKANDAR, Joachim MAYER

期刊论文

review on membrane distillation in process engineering: design and exergy equations, materials and wetting

期刊论文

Correlation between tension softening relation and crack extension resistance in concrete

Xiufang ZHANG , Shilang XU ,

期刊论文

Hypoplastic constitutive modeling of wetting deformation of weathered rockfill materials

Erich BAUER, Zhongzhi FU, Sihong LIU,

期刊论文

Many-body dissipative particle dynamics simulation of wetting phenomena

Ying ZHAO, Ye YUE, Xianren ZHANG, Shuangyang LI, Atul SAJJANHAR,

期刊论文

Forward osmosis coupled with lime-soda ash softening for volume minimization of reverse osmosis

Jiandong Lu, Shijie You, Xiuheng Wang

期刊论文

薄板坯连铸连轧铁素体+珠光体类型钢的强化与软化

傅杰,吴华杰,刘阳春

期刊论文

Influence of pressure and density on the rheological properties of rockfills

Erich BAUER, Zhongzhi FU, Sihong LIU

期刊论文

Treatment of gingival hyperplasia induced by cyclosporine A

MA Jingzhi, LI Ming, CAO Yingguang

期刊论文

Influence of fluid-structure interaction on vortex induced vibration and lock-in phenomena in long span

Nazim Abdul NARIMAN

期刊论文

Formation of microporous polymeric membranes via thermally induced phase separation: A review

Min Liu,Shenghui Liu,Zhenliang Xu,Yongming Wei,Hu Yang

期刊论文

An overview of vortex-induced vibration (VIV) of bridge decks

Teng WU, Ahsan KAREEM

期刊论文

Synthesis and ultraviolet/aggregation-induced emission investigation of novel tetraphenylvinyl hydrazone

期刊论文

Cellular changes in bronchoalveolar lavage fluid in hyperoxia-induced lung injury

HE Xinbiao, ZHAO Wei

期刊论文