Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 461

会议视频 25

会议信息 2

年份

2024 1

2023 42

2022 39

2021 53

2020 25

2019 23

2018 25

2017 17

2016 23

2015 23

2014 14

2013 19

2012 16

2011 22

2010 19

2009 27

2008 11

2007 18

2006 12

2005 8

展开︾

关键词

钢结构 8

建筑科学 7

三峡工程 3

优化设计 3

耐久性 3

飞机结构 3

DSM（设计结构矩阵） 2

DX桩 2

Quantitative structure 2

imge analysis 2

stereology 2

产业结构 2

关键技术 2

压力容器技术 2

可持续发展 2

城镇建设 2

数值分析 2

机械结构 2

疲劳寿命 2

展开︾

检索范围：

排序：展示方式：

Premature melt solidification during mold filling and its influence on the as-cast structure

M. WU, M. AHMADEIN, A. LUDWIG

《机械工程前沿（英文）》 2018年第13卷第1期页码 53-65 doi: 10.1007/s11465-017-0437-y

摘要：

Premature melt solidification is the solidification of a melt during mold filling. In this study, a numerical model is used to analyze the influence of the pouring process on the premature solidification. The numerical model considers three phases, namely, air, melt, and equiaxed crystals. The crystals are assumed to have originated from the heterogeneous nucleation in the undercooled melt resulting from the first contact of the melt with the cold mold during pouring. The transport of the crystals by the melt flow, in accordance with the so-called “big bang” theory, is considered. The crystals are assumed globular in morphology and capable of growing according to the local constitutional undercooling. These crystals can also be remelted by mixing with the superheated melt. As the modeling results, the evolutionary trends of the number density of the crystals and the volume fraction of the solid crystals in the melt during pouring are presented. The calculated number density of the crystals and the volume fraction of the solid crystals in the melt at the end of pouring are used as the initial conditions for the subsequent solidification simulation of the evolution of the as-cast structure. A five-phase volume-average model for mixed columnar-equiaxed solidification is used for the solidification simulation. An improved agreement between the simulation and experimental results is achieved by considering the effect of premature melt solidification during mold filling. Finally, the influences of pouring parameters, namely, pouring temperature, initial mold temperature, and pouring rate, on the premature melt solidification are discussed.

关键词： premature solidification mold filling as-cast structure modeling

HTML PDF 收藏

Propagation characteristics of transient waves in low-strain integrity testing on cast-in-situ concrete

Hanlong LIU, Xuanming DING

《结构与土木工程前沿（英文）》 2009年第3卷第2期页码 240-240 doi: 10.1007/s11709-009-0100-8

HTML PDF 收藏

中国钢筋混凝土空间网格结构新体系的开拓与发展（下）

马克俭,张华刚,肖建春,卢亚琴

《中国工程科学》 2008年第10卷第8期页码 22-34

摘要：

钢筋混凝土空间网格结构包括平板型的空腹网架结构、空腹夹层板结构、空腹双重网格结构、现浇混凝土空心大板楼盖结构。这些新型结构体系从20世纪80年代至今在跨度18～32 m公共建筑的屋盖和楼盖应用达100多万平方米，取得很好的社会与经济效益。有的已编制了相应的技术规程。我们研制了将钢筋混凝土空腹夹层板单向弯曲形成的钢筋混凝土空腹夹层网壳和网拱结构，双向弯曲形成的钢筋混凝土空腹夹层双曲扁网壳结构。这些拥有我国自主知识产权的空间网格结构新体系，均具有自身的特点和对建筑物的适应性，文章将按研制时间先后逐一介绍。其结构的“安全、合理、经济、先进”性，则通过工程实例予以剖析。

关键词：钢筋混凝土空腹夹层板现浇混凝土空心大板网架结构网壳结构

HTML PDF 收藏

Synergistic effects of sodium hypochlorite disinfection and iron-oxidizing bacteria on early corrosion in cast

《环境科学与工程前沿（英文）》 2022年第16卷第6期 doi: 10.1007/s11783-021-1506-3

摘要：

• The early corrosion process in the cast iron pipes was investigated.

关键词： Cast iron pipe corrosion Drinking water distribution systems Chlorine disinfection Iron-oxidizing bacteria Coupling effects

HTML PDF 收藏

基于可拓学的球墨铸铁石墨形态识别

陈智斌,余永权,杨少敏

《中国工程科学》 2005年第7卷第3期页码 84-89

摘要：

根据石墨的形态特征，运用物元分析方法建立起关于石墨形态识别的物元模型，提出了可拓分类树方法，讨论了可拓分类树的构造和实现途径，并将其应用于石墨形态的类型判别；给出了典型的实验结果，并对该方法与现有识别方法作出比较。

关键词：物元模型可拓分类树石墨形态球墨铸铁

HTML PDF 收藏

Defect passivation on cast-mono crystalline screen-printed cells

Alison WENHAM,Lihui SONG,Malcolm ABBOTT,Iskra ZAFIROVSKA,Sisi WANG,Brett HALLAM,Catherine CHAN,Allen BARNETT,Stuart WENHAM

《能源前沿（英文）》 2017年第11卷第1期页码 60-66 doi: 10.1007/s11708-016-0443-5

摘要： Cast-mono crystalline silicon wafers contain crystallographic defects, which can severely impact the electrical performance of solar cells. This paper demonstrates that applying hydrogenation processes at moderate temperatures to finished screen print cells can passivate dislocation clusters within the cast-mono crystalline silicon wafers far better than the hydrogenation received during standard commercial firing conditions. Efficiency enhancements of up to 2% absolute are demonstrated on wafers with high dislocation densities. The impact of illumination to manipulate the charge state of hydrogen during annealing is investigated and found to not be significant on the wafers used in this study. This finding is contrary to a previous study on similar wafers that concluded increased H or H from laser illumination was responsible for the further passivation of positively charged dangling bonds within the dislocation clusters.

关键词： silicon solar cell dislocation cast-mono laser hydrogen passivation

HTML PDF 收藏

Influence of surface cracking, anchor head profile, and anchor head size on cast-in headed anchors in

《结构与土木工程前沿（英文）》页码 1163-1187 doi: 10.1007/s11709-023-0987-5

摘要： In this study, the concrete cone capacity, concrete cone angle, and load–displacement response of cast-in headed anchors in geopolymer concrete are explored using numerical analyses. The concrete damaged plasticity (CDP) model in ABAQUS is used to simulate the behavior of concrete substrates. The tensile behavior of anchors in geopolymer concrete is compared with that in normal concrete as well as that predicted by the linear fracture mechanics (LFM) and concrete capacity design (CCD) models. The results show that the capacity of the anchors in geopolymer concrete is 30%–40% lower than that in normal concrete. The results also indicate that the CCD model overestimates the capacity of the anchors in geopolymer concrete, whereas the LFM model provides a much more conservative prediction. The extent of the difference between the predictions by the numerical analysis and those of the above prediction models depends on the effective embedment depth of the anchor and the anchor head size. The influence of concrete surface cracking on the capacity of the anchor is shown to depend on the location of the crack and the effective embedment depth. The influence of the anchor head profile on the tensile capacity of the anchors is found to be insignificant.

关键词： cast-in anchor concrete cone capacity geopolymer concrete head size surface crack anchor profile

HTML PDF 收藏

铸钢粗晶的成因及消除方法的研究

邹安全,邓沛然

《中国工程科学》 2005年第7卷第4期页码 79-82

摘要：

通过对ZG32Cr06铸钢粗晶成因的分析及消除粗晶的工艺性能试验，探讨了粗晶导致铸件断裂的机理。试验证明，由于浇铸温度过高，水爆清砂时开箱过早而产生的粗晶可以用热处理方法消除，同时提出了铸件在浇铸时防止粗晶的措施。

关键词：铸钢粗晶水爆清砂消除方法

HTML PDF 收藏

DX桩群桩承载性状的数值分析

张清林,陈立宏

《中国工程科学》 2012年第14卷第1期页码 51-59

摘要：

通过数值计算对不同桩间距的DX桩群桩进行了分析研究。结果表明：DX桩的群桩效应随着桩间距的减小而逐渐明显，间距为6倍桩径的群桩极限承载力是间距为3倍桩径的群桩极限承载力的1.32倍；群桩间距由3倍桩径增大为6倍桩径时，群桩效应系数由0.59增大为0.78；群桩间土体沉降的最大值发生在两扩盘中间位置处，且随着桩间距的增大而减小。

关键词： DX桩群桩沉降数值分析

HTML PDF 收藏

DX旋挖挤扩灌注桩单桩抗拔承载性状的数值分析

陈立宏,张清林,袁希雨

《中国工程科学》 2012年第14卷第1期页码 31-36

摘要：

总结了DX桩的抗拔研究现状，采用FLAC3D对具有两个承力盘的DX单桩和相同直径与长度的普通直孔桩做了抗拔的数值计算分析，对DX单桩抗拔的性状进行了研究。模型参数依据土工试验获取并采用现场大比尺试验结果进行校验。通过模拟分级加载，得到了DX桩和直孔桩的抗拔承载力曲线，同时得到了沿桩身的轴力分布，依据这些计算结果展开分析，可以发现DX单桩的抗拔承载力比相同直径的普通直孔桩高出一倍以上，其上下承力盘的发挥作用是由上而下，但当荷载增大到一定程度时，下盘将发挥更大的作用。

关键词： DX桩抗拔数值分析

HTML PDF 收藏

三峡升船机塔柱混凝土施工测量技术

罗琛,晏春波

《中国工程科学》 2013年第15卷第9期页码 97-101

摘要：

针对三峡垂直升船机高薄壁塔柱结构混凝土形体及内置埋件施工精度指标要求，对三峡升船机塔柱混凝土及内置埋件施工测量中的平面、高程基准传递及埋件定位测量方法进行了研究。分别将天顶仪投点、电磁波测距及中心带照准标志的圆柱螺帽型定位装置施工测量技术运用于混凝土结构尺寸控制测量以及内置埋件定位测量。通过对实测数据的统计与分析，证明三峡升船机塔柱混凝土施工测量技术方案具有可靠性和可行性。

关键词：施工测量天顶仪投点电磁波测距套管空间定位测量三峡升船机

HTML PDF 收藏

Influence of pore structure on biologically activated carbon performance and biofilm microbial characteristics

《环境科学与工程前沿（英文）》 2021年第15卷第6期 doi: 10.1007/s11783-021-1419-1

摘要：

• Pore structure affects biologically activated carbon performance.

关键词： Granular activated carbon Biologically activated carbon filter Bacterial community structure Pore structure

HTML PDF 收藏

Hierarchical fractal structure of perfect single-layer graphene

T. Zhang, K. Ding

《机械工程前沿（英文）》 2013年第8卷第4期页码 371-382 doi: 10.1007/s11465-013-0279-1

摘要：

The atomic lattice structure of perfect single-layer graphene that can actually be regarded as a kind of hierarchical fractal structure from the perspective of fractal geometry was studied for the first time. Three novel and special discoveries on hierarchical fractal structure and sets were unveiled upon examination of the regular crystal lattices of the single-layer graphene. The interior fractal-type structure was discovered to be the fifth space-filling curve from physical realm. Two efficient methods for calculating the fractal dimension of this fresh member was also provided. The outer boundary curve had a fractal dimension equal to one, and a multi-fractal structure from a naturally existing material was found for the first time. A series of strict self-similar hexagons comprised a rotating fractal set. These hexagons slewed at a constant counterclockwise angle of 19.1° when observed from one level to the next higher level. From the perspective of fractal geometry, these pioneering discoveries added three new members to the existing regular fractal structures and sets. A fundamental example of a multi-fractal structure was also presented.

关键词： hierarchical fractal structure fractal dimension the fifth space-filling curve multi-fractal structure

HTML PDF 收藏

Floating forest: A novel breakwater-windbreak structure against wind and wave hazards

《结构与土木工程前沿（英文）》 2021年第15卷第5期页码 1111-1127 doi: 10.1007/s11709-021-0757-1

摘要： A novel floating breakwater-windbreak structure (floating forest) has been designed for the protection of vulnerable coastal areas from extreme wind and wave loadings during storm conditions. The modular arch-shaped concrete structure is positioned perpendicularly to the direction of the prevailing wave and wind. The structure below the water surface acts as a porous breakwater with wave scattering capability. An array of tubular columns on the sloping deck of the breakwater act as an artificial forest-type windbreak. A feasibility study involving hydrodynamic and aerodynamic analyses has been performed, focusing on its capability in reducing wave heights and wind speeds in the lee side. The study shows that the proposed 1 km long floating forest is able to shelter a lee area that stretches up to 600 m, with 40%–60% wave energy reduction and 10%–80% peak wind speed reduction.

关键词： floating structure breakwater windbreak hydrodynamic CFD

HTML PDF 收藏

Bicontinuous porous membranes with micro-nano composite structure using a facile atomization-assisted

《化学科学与工程前沿（英文）》 2022年第16卷第8期页码 1268-1280 doi: 10.1007/s11705-022-2143-5

摘要： The micro-nano composite structure can endow separation membranes with special surface properties, but it often has the problems of inefficient preparation process and poor structural stability. In this work, a novel atomization-assisted nonsolvent induced phase separation method, which is also highly efficient and very simple, has been developed. By using this method, a bicontinuous porous microfiltration membrane with robust micro-nano composite structure was obtained via commercially available polymers of polyacrylonitrile and polyvinylpyrrolidone. The formation mechanism of the micro-nano composite structure was proposed. The microphase separation of polyacrylonitrile and polyvinylpyrrolidone components during the atomization pretreatment process and the hydrogen bonding between polyacrylonitrile and polyvinylpyrrolidone molecules should have resulted in the nano-protrusions on the membrane skeleton. The membrane exhibits superhydrophilicity in air and superoleophobicity underwater. The membrane can separate both surfactant-free and surfactant-stabilized oil-in-water emulsions with high separation efficiency and permeation flux. With excellent antifouling property and robust microstructure, the membrane can easily be recycled for long-term separation. Furthermore, the scale-up verification from laboratory preparation to continuous production has been achieved. The simple, efficient, cost-effective preparation method and excellent membrane properties indicate the great potential of the developed membranes in practical applications.

关键词： atomization nonsolvent induced phase separation bicontinuous porous structure micro-nano composite structure oil-water separation