Search | Engineering

订阅投稿

首页学术期刊学术焦点学术视频工程成就工程前沿联系我们 English

资源类型

期刊论文 187

会议视频 1

年份

2024 1

2023 4

2022 24

2021 14

2020 18

2019 15

2018 8

2017 11

2016 7

2015 4

2014 10

2013 4

2012 4

2011 8

2010 6

2009 14

2008 15

2007 13

2005 2

2003 1

展开︾

关键词

聚偏氟乙烯 2

3D生物打印 1

L1₀FePt 1

Anderson 模型 1

Cu(Inx 1

GDM过滤技术 1

Ga1–x)Se2 1

H7N9 1

HSLC钢 1

N3_C空位 1

S 特性 1

TBM 隧洞 1

U251细胞 1

iPS细胞 1

三峡工程 1

三维激发极化法 1

不确定时延 1

不良地质体 1

乙烷干重整 1

展开︾

检索范围：

排序：展示方式：

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

HTML PDF 收藏

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

HTML PDF 收藏

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

HTML PDF 收藏

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 G_R resistance tension softening curve

HTML PDF 收藏

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

HTML PDF 收藏

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

HTML PDF 收藏

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

HTML PDF 收藏
分享

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σ_s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

HTML PDF 收藏
分享

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

HTML PDF 收藏
分享

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

HTML PDF 收藏
分享

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

HTML PDF 收藏
分享

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

HTML PDF 收藏
分享

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

HTML PDF 收藏
分享

Vortex-induced vibration of stay cable under profile velocity using CFD numerical simulation method

Wenli CHEN, Hui LI,

《结构与土木工程前沿（英文）》 2009年第3卷第4期   页码 357-363 doi: 10.1007/s11709-009-0060-z

摘要： Vortex-induced vibration (VIV) of a stay cable subjected to a wind profile is numerically simulated through combining computational fluid dynamics (CFD) code CFX 10.0 and computational structural dynamics (CSD) code ANSYS 10.0. A stay cable with the inclined angle of 30° is used as the numerical model. Under a profile of mean wind speed, unsteady aerodynamic lift coefficients of the cable have been analyzed in both time domain and frequency domain when VIV occurs. The results indicate that the lift coefficient wave response of the stay cable under a wind profile is different from that of an infinitely long cable under a uniform flow in water (i.e., without consideration of profile) obtained by direct numerical simulation. Cable oscillations can severely affect the unsteady aerodynamic frequencies, change flow field distribution near the cable and affect the vortex shedding in the wake.

关键词： stay cable     fluid-structure interaction     numerical simulation     vortex-induced vibration

HTML PDF 收藏
分享

Numerical modeling of current-induced scour around multi-wall foundation using large-eddy simulation

《结构与土木工程前沿（英文）》 2023年第17卷第4期   页码 546-565 doi: 10.1007/s11709-023-0943-4

摘要： Scouring is one of the primary triggers of failure for bridges across rivers or seas. However, research concerning the scour mechanism of multi-wall foundations (MWFs) remains scarce, hindering the further application of MWFs. In this study, for the first time, the scouring effect caused by unidirectional flow around MWFs was examined numerically using FLOW-3D involving a large-eddy simulation. Initially, the applicability of the scouring model and input parameters was validated using a case study based on published measured data. Subsequently, the scouring effects of four MWFs with different wall arrangements and inflow angles, including the flow field analysis and scour pit and depth, were investigated thoroughly. It was found that the maximum scour depth of MWFs with an inflow angle of 0° was smaller than that of those with an inflow angle of 45°, regardless of the wall arrangement. Meanwhile, changing the inflow angle significantly affects the scour characteristics of MWFs arranged in parallel. In practical engineering, MWFs arranged in parallel are preferred considering the need for scouring resistance. However, a comparative analysis should be performed to consider comprehensively whether to adopt the form of a round wall arrangement when the inflow angle is not 0° or the inflow direction is changeable.

关键词： multi-wall foundation     current-induced scour     bridge foundation     large-eddy simulation     numerical analysis

HTML PDF 收藏
分享

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



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

Teng WU, Ahsan KAREEM

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



Vortex-induced vibration of stay cable under profile velocity using CFD numerical simulation method

Wenli CHEN, Hui LI,

期刊论文



Numerical modeling of current-induced scour around multi-wall foundation using large-eddy simulation

期刊论文