资源类型

期刊论文 35

年份

2024 1

2023 3

2022 3

2021 2

2020 1

2019 1

2018 2

2017 1

2016 2

2015 1

2014 3

2013 2

2012 2

2011 1

2010 2

2009 2

2008 2

2005 1

2003 1

展开 ︾

关键词

HBV相关疾病 1

个体抗缺氧能力 1

元素硫 1

关键状态 1

功能弹性 1

加压浸出 1

医疗资源利用率 1

半工业试验 1

固砂剂 1

室内试验 1

岩石动力学 1

工程水压爆破 1

应变测试 1

延性 1

影响因素 1

承载力 1

斜拉桥 1

核岛 1

模型试验 1

展开 ︾

检索范围:

排序: 展示方式:

Nonlinear experimental response of non-conventional composite steel and concrete connection

Tobia ZORDAN, Bruno BRISEGHELLA

《结构与土木工程前沿(英文)》 2009年 第3卷 第1期   页码 42-49 doi: 10.1007/s11709-008-0058-y

摘要: An experiment was carried out on a set of full-scale specimens of a non-conventional connection between a concrete column and a composite steel and concrete beam defined on the basis of a number of requirements. The proposed connection, conceived in the ambit of semi-rigid joints, is aimed at combining general ease of construction with a highly simplified assembly procedure with a satisfying transmission of hogging moment at supports in continuous beams. For this purpose, the traditional shear studs used at the interface between the steel beam and the upper concrete slab, are also employed at the ends of the steel profiles welded horizontally to the end plates. The test is aimed at investigating the hogging moment response of the connection under incremental loads until failure.

关键词: composite connections     nonlinear behaviour     hogging moment     monotonic tests    

Investigation of the interior RC beam-column joints under monotonic antisymmetrical load

Fei GAO, Zhiqiang TANG, Biao HU, Junbo CHEN, Hongping ZHU, Jian MA

《结构与土木工程前沿(英文)》 2019年 第13卷 第6期   页码 1474-1494 doi: 10.1007/s11709-019-0572-0

摘要: The paper presents numerical findings of reinforced concrete interior beam-column joints under monotonic antisymmetrical load. The finite element models considered compression and tension damage were calibrated by test results in terms of the load-displacement, failure modes, and strains of longitudinal steel. The emphasis was put on studying the effects of hoop reinforcement ratio in joint core and the axial compression ratio on the responses of the joints. The results show that, in addition to the truss and strut-and-tie mechanisms, the confinement mechanism also existed in the joint core. A certain amount of stirrup is not only able to enhance the confinement in joint core, undertake a part of shear force and thus to increase the shear capacity, prevent the outward buckling of steel bars in column, improve the stress distribution in joint core, delay cracking and restrain the propagation of cracks, but also to increase the yield load, decrease the yield displacement of beam and improve the joint ductility. However, excessive horizontal stirrups contribute little to the joint performance. In a certain range, larger axial compression ratio is beneficial for the joint mechanical behavior, while it is negative when axial compression ratio is too large.

关键词: RC beam-column joint     reinforcement ratio in joint core     axial compression ratio     finite element     test    

Study of base friction simulation tests based on a complicated engineered bridge slope

Liu HE, Guang WU, Hua WANG

《结构与土木工程前沿(英文)》 2012年 第6卷 第4期   页码 393-397 doi: 10.1007/s11709-012-0174-6

摘要: In this paper, a physical base friction test model of a slope is established. The model is based on similarity principles and the geological conditions of a complicated bridge slope during construction, deformation and failure. The behavior of the slope in both its natural state and during excavation loading is qualitatively analyzed through base friction tests. The base friction test results are then subjected to comparison and analysis using finite element numerical simulation. The findings show that the whole engineered slope tends to stabilize in its natural state, whereas instabilities will arise at faulted rock masses located near bridge piers during excavation loading. Therefore, to ensure normal construction operation of bridge works, it is suggested that pre-reinforcement of faulted rock masses be performed.

关键词: base friction test     slope stability evaluation     bridge slope    

Strain localization analyses of idealized sands in biaxial tests by distinct element method

Mingjing JIANG, Hehua ZHU, Xiumei LI,

《结构与土木工程前沿(英文)》 2010年 第4卷 第2期   页码 208-222 doi: 10.1007/s11709-010-0025-2

摘要: This paper presents a numerical investigation on the strain localization of an idealized sand in biaxial compression tests using the distinct element method (DEM). In addition to the dilatancy and material frictional angle, the principal stress field, and distributions of void ratio, particle velocity, and the averaged pure rotation rate (APR) in the DEM specimen are examined to illustrate the link between microscopic and macroscopic variables in the case of strain localization. The study shows that strain localization of the granular material in the tests proceeds with localizations of void ratio, strain and APR, and distortions of stress field and force chains. In addition, both thickness and inclination of the shear band change with the increasing of axial strain, with the former valued around 10–14 times of mean grain diameter and the later overall described by the Mohr-Coulomb theory.

关键词: idealized sand     strain localization     numerical analyses     distinct element method (DEM)    

Extension of pilot tests of cyanide elimination by ozone from blast furnace gas washing water through

Ismael Matino, Valentina Colla, Teresa A. Branca

《化学科学与工程前沿(英文)》 2018年 第12卷 第4期   页码 718-730 doi: 10.1007/s11705-018-1771-2

摘要:

For improving wastewater quality, one of the dare of steelworks is reducing cyanide in wastewater of gas washing treatment of blast furnaces. Costs of existing treatments, stringent environmental regulations and changeable composition of water from gas treatment, have led to study how available treatments can be modified and to examine new ones. Ozonation is one of cyanide treatments, tested within a European project. A process model was set up with Aspen Plus®, to assess operating conditions and wastewater distinctive characteristics and to demonstrate treatment robustness. Process was modeled by theoretical reactors, taking into account all more affecting reactions. A genetic algorithm was exploited to find kinetic parameters of these reactions. After validation, the model was used to analyse scenarios, by considering also real contexts. Pilot tests were extended, process knowledge was enhanced and suggestions were obtained. To promote cyanide removal with ozone, temperature and pH values were 30°C and 10, respectively. With an ozone (mg/h)/water (L/h) ratio of 100 mg/L, batch mode ensure reaching cyanide regulation limit (0.2 mg/L) after maximum 4.5 h, if initial amount was less than 20 mg/L. Higher removal was obtained than in continuous mode due to constraints related to this last run. Higher wastewater contamination needed further time and more ozone.

关键词: blast furnace     cyanide removal     gas washing water     modeling and simulation     ozonation    

砂质边坡安全保障新技术研究

牛笑笛,杨广庆,刘伟超

《中国工程科学》 2017年 第19卷 第6期   页码 86-91 doi: 10.15302/J-SSCAE-2017.06.013

摘要:

砂质边坡稳定性差,常规防护措施的防护效果较差。为了有效地对砂质边坡进行防护,笔者研制了一种新型固砂剂——TD–1。为了验证TD–1的固砂效果,笔者进行了配比优化试验、渗透试验、干湿循环试验和现场试验。试验结果表明:在磷酸硅、硅酸锂、硅溶胶掺入比例相同的条件下,固砂试样的强度随钾水玻璃模数的增加而增大;钾水玻璃的最佳添加量为固化砂质量的3%;加入改性剂的试样,强度有明显的增长;使用低模数钾水玻璃的试样,渗透能力相对更好;随着干湿循环次数的增加,试样的强度逐渐下降,经过3次循环之后,试样的强度基本趋于稳定。TD–1固砂剂还可与客土喷播技术结合使用,进行边坡绿化防护,固化产物有利于植物生长。

关键词: 砂质边坡     固砂剂     室内试验     现场试验    

高铁闪锌矿精矿加压浸出半工业试验研究

王吉坤,周廷熙,吴锦梅

《中国工程科学》 2005年 第7卷 第1期   页码 60-64

摘要:

高铁闪锌矿经二段加压浸出,锌浸出率97.09%,铁浸出率15.2%,元素硫产率93%,浸出液残酸3.95g/L,经简单中和、净化,生产合格硫酸锌新液供应锌电积。为了研究比较,闪锌矿经一段加压浸出,锌的浸出率98.09%,铁浸出率37.88%,元素硫产率96%,浸出液残酸高(46.4g/L),可并入现有传统湿法炼锌工艺流程处理。

关键词: 高铁闪锌矿     加压浸出     半工业试验     元素硫    

Seismic tests of post-tensioned self-centering building frames with column and slab restraints

Chung-Che CHOU, Jun-Hen CHEN

《结构与土木工程前沿(英文)》 2011年 第5卷 第3期   页码 323-334 doi: 10.1007/s11709-011-0119-5

摘要: Post-tensioned (PT) self-centering moment frames have been developed as an alternative to typical moment-resisting frames (MRFs) for earthquake resistance. When a PT frame deforms laterally, gaps between the beams and columns open. However, the gaps are constrained by the columns and the slab in a real PT self-centering building frame. This paper presents a methodology for evaluating the column restraint and beam compression force based on the column deformation and gap openings at all stories. The method is verified by cyclic tests of a full-scale, two-bay by one-story PT frame. Moreover, a sliding slab is proposed to minimize restraints on the expansion of the PT frame. Shaking table tests were conducted on a reduced-scale, two-by-two bay one-story specimen, which comprises one PT frame and two gravitational frames. The PT frame and gravitational frames are self-centering throughout the tests, responding in phase with only minor differences in peak drifts caused by expansion of the PT frame. When the specimen is excited by a simulation of the 1999 Chi-Chi earthquake with a peak ground acceleration of 1.87 g, the maximum interstory drift and the residual drift are 7.2% and 0.01%, respectively.

关键词: post-tensioned frame     frame expansion     column restraint     sliding slab     frame test     shake table test    

enhancement for implementation in purification of modal frequency for extremely noisy ambient vibration tests

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI, Soheil MOHAMMADI

《结构与土木工程前沿(英文)》 2020年 第14卷 第2期   页码 446-472 doi: 10.1007/s11709-019-0605-8

摘要: The main purpose of the present study is to enhance high-level noisy data by a wavelet-based iterative filtering algorithm for identification of natural frequencies during ambient wind vibrational tests on a petrochemical process tower. Most of denoising methods fail to filter such noise properly. Both the signal-to-noise ratio and the peak signal-to-noise ratio are small. Multiresolution-based one-step and variational-based filtering methods fail to denoise properly with thresholds obtained by theoretical or empirical method. Due to the fact that it is impossible to completely denoise such high-level noisy data, the enhancing approach is used to improve the data quality, which is the main novelty from the application point of view here. For this iterative method, a simple computational approach is proposed to estimate the dynamic threshold values. Hence, different thresholds can be obtained for different recorded signals in one ambient test. This is in contrast to commonly used approaches recommending one global threshold estimated mainly by an empirical method. After the enhancements, modal frequencies are directly detected by the cross wavelet transform (XWT), the spectral power density and autocorrelation of wavelet coefficients. Estimated frequencies are then compared with those of an undamaged-model, simulated by the finite element method.

关键词: ambient vibration test     high level noise     iterative signal enhancement     wavelet     cross and autocorrelation of wavelets    

Axial compression tests and numerical simulation of steel reinforced recycled concrete short columns

Hui MA; Fangda LIU; Yanan WU; Xin A; Yanli ZHAO

《结构与土木工程前沿(英文)》 2022年 第16卷 第7期   页码 817-842 doi: 10.1007/s11709-022-0844-y

摘要: To research the axial compression behavior of steel reinforced recycled concrete (SRRC) short columns confined by carbon fiber reinforced plastics (CFRP) strips, nine scaled specimens of SRRC short columns were fabricated and tested under axial compression loading. Subsequently, the failure process and failure modes were observed, and load-displacement curves as well as the strain of various materials were analyzed. The effects on the substitution percentage of recycled coarse aggregate (RCA), width of CFRP strips, spacing of CFRP strips and strength of recycled aggregate concrete (RAC) on the axial compression properties of columns were also analyzed in the experimental investigation. Furthermore, the finite element model of columns which can consider the adverse influence of RCA and the constraint effect of CFRP strips was founded by ABAQUS software and the nonlinear parameter analysis of columns was also implemented in this study. The results show that the first to reach the yield state was the profile steel in the columns, then the longitudinal rebars and stirrups yielded successively, and finally RAC was crushed as well as the CFRP strips was also broken. The replacement rate of RCA has little effect on the columns, and with the substitution rate of RCA from 0 to 100%, the bearing capacity of columns decreased by only 4.8%. Increasing the CFRP strips width or decreasing the CFRP strips spacing could enhance the axial bearing capacity of columns, the maximum increase was 10.5% or 11.4%, and the ductility of columns was significantly enhanced. Obviously, CFRP strips are conducive to enhance the axial bearing capacity and deformation capacity of columns. On this basis, considering the restraint effect of CFRP strips and the adverse effects of RCA, the revised formulas for calculating the axial bearing capacity of SRRC short columns confined by CFRP strips were proposed.

关键词: steel reinforced recycled concrete     CFRP strips     short columns     axial compression behavior     recycled aggregate concrete    

新冠病毒肺炎疫情肆虐——抗原检测能否挽救局面?

Peter Weiss

《工程(英文)》 2021年 第7卷 第1期   页码 3-5 doi: 10.1016/j.eng.2020.12.002

基于非参数检验的高原反应影响因素分析

常海娟,刘猛,庞丽萍,杨鹏 ,王浚

《中国工程科学》 2009年 第11卷 第2期   页码 65-69

摘要:

用一年的时间随青藏铁路列车采集了2 882样本数据,随机抽取其中的1 693份,利用非参数检验及 相关分析的方法从统计学上对可能影响耐缺氧反应的因素做分析,最后发现以前到高原时缺氧反应严重程 度、性别、吸烟习惯、肥胖度、年龄5个因素对个体的抗缺氧能力有着不可忽视的影响。该结论不仅可以为减 少旅客高原反应提供指导性意见,为高原旅客列车供氧系统设计和改进提供重要依据,也可以为后续的医学 研究提供统计学基础。

关键词: 高原反应     影响因素     青藏铁路     非参数检验     个体抗缺氧能力    

Model testing of tripod caisson foundations in silty clay subjected to eccentric lateral loads

《结构与土木工程前沿(英文)》 2023年 第17卷 第3期   页码 467-476 doi: 10.1007/s11709-023-0933-6

摘要: In this study, model tests were conducted to investigate the bearing capacities of tripod caisson foundations subjected to eccentric lateral loads in silty clay. Lateral load–rotation curves of five eccentric-shaped tripod suction foundations were plotted to analyze the bearing capacities at different loading angles. It was observed that the loading angle significantly influenced the bearing capacity of the foundations, particularly for eccentric tripod caisson foundations. Compared with eccentric tripod caisson foundations, the traditional tripod foundation has a relatively high ultimate lateral capacity at the omnidirectional loading angle. By analyzing the displacement of the caissons, a formula for the rotational center of the tripod caisson foundation subjected to an eccentric lateral load was derived. The depth of the rotation center was 0.68–0.92 times the height of the caisson when the bearing capacity reached the limit. Under the undrained condition, suction was generated under the lid of the “up-lift” caisson, which helps resist lateral forces from the wind and waves.

关键词: tripod caisson foundation     silty clay     eccentric lateral capacity     model tests    

Investigation of effects of Cocamide Diethanolamide chemical on physical and rheological properties of bituminous binder

《结构与土木工程前沿(英文)》 2022年 第16卷 第1期   页码 99-116 doi: 10.1007/s11709-021-0799-4

摘要: In this study, bituminous binder was modified with Cocamide Diethanolamide chemical, a non-ionic surfactant, and the physical and rheological properties of modified binders were investigated. In addition, Cocamide Diethanolamide has been used for the first time to modify bituminous binder, and this situation makes the study distinctive. Bituminous binder was modified more than once with the chemical by changing modification parameters and using certain additive ratios (1%, 3%, and 5%). The effects of different modification parameters and chemical additive on modified samples were investigated with conventional bitumen tests (softening point, penetration, ductility) and Superpave tests (rotational viscometer, rolling thin film oven test, pressure aging vessel, dynamic shear rheometer, bending beam rheometer). In addition, the structural characteristics of the reference binder and modified samples were examined by X-ray diffraction, Fourier Transform Infrared Spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The examinations showed that Cocamide Diethanolamide softens bituminous binder and lowers processing temperatures. In addition, compared to reference binder, rutting resistances of modified bituminous binders decreased with the increase of additive ratio. However, modification with Cocamide Diethanolamide increased the resistance to fatigue cracks and thermal cracks.

关键词: Cocamide Diethanolamide     bitumen modification     rheology     Superpave tests    

ROUTE DEVELOPMENT, ANTIVIRAL STUDIES, FIELD EVALUATION AND TOXICITY OF AN ANTIVIRAL PLANT PROTECTANT NK0238

《农业科学与工程前沿(英文)》 2022年 第9卷 第1期 doi: 10.15302/J-FASE- 2021390

摘要:

It has previously been shown that tryptophan, the biosynthesis precursor of Peganum harmala alkaloids, and its derivatives have anti-TMV activity both in vitro and in vivo. Further exploration of this led to the identification of NK0238 as a highly effective agent for the prevention and control of diseases caused by plant viruses, but the existing routes are unsuitable for its large-scale synthesis. This study optimized a route for two-step synthesis of this virucide candidate via reaction of l-tryptophan with triphosgene to produce l-tryptophan-N-carboxylic anhydride, which then reacts with n-octylamine to give NK0238 at up to 94% yield and nearly 97% HPLC purity. In addition, the route was used for the preparation of NK0238 on a>40 g scale permitting further assessment of its antivirus activity in the greenhouse and field experiments, and toxicity tests. NK0238 exhibited useful antiviral activities against a variety of viruses both in greenhouse and field experiments. The toxicity tests showed that NK0238 was not acutely toxic to birds, fish, honey bees and silkworms. The optimized route provides a solid foundation for its large-scale synthesis and subsequent efficacy and toxicity studies, its excellent activity and safety make NK0238 a promising drug candidate for further development.

 

关键词: antiviral plant protectant / antiviral in the greenhouse / field evaluation / l-trp-NCA / synthesis optimization / toxicity tests    

标题 作者 时间 类型 操作

Nonlinear experimental response of non-conventional composite steel and concrete connection

Tobia ZORDAN, Bruno BRISEGHELLA

期刊论文

Investigation of the interior RC beam-column joints under monotonic antisymmetrical load

Fei GAO, Zhiqiang TANG, Biao HU, Junbo CHEN, Hongping ZHU, Jian MA

期刊论文

Study of base friction simulation tests based on a complicated engineered bridge slope

Liu HE, Guang WU, Hua WANG

期刊论文

Strain localization analyses of idealized sands in biaxial tests by distinct element method

Mingjing JIANG, Hehua ZHU, Xiumei LI,

期刊论文

Extension of pilot tests of cyanide elimination by ozone from blast furnace gas washing water through

Ismael Matino, Valentina Colla, Teresa A. Branca

期刊论文

砂质边坡安全保障新技术研究

牛笑笛,杨广庆,刘伟超

期刊论文

高铁闪锌矿精矿加压浸出半工业试验研究

王吉坤,周廷熙,吴锦梅

期刊论文

Seismic tests of post-tensioned self-centering building frames with column and slab restraints

Chung-Che CHOU, Jun-Hen CHEN

期刊论文

enhancement for implementation in purification of modal frequency for extremely noisy ambient vibration tests

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI, Soheil MOHAMMADI

期刊论文

Axial compression tests and numerical simulation of steel reinforced recycled concrete short columns

Hui MA; Fangda LIU; Yanan WU; Xin A; Yanli ZHAO

期刊论文

新冠病毒肺炎疫情肆虐——抗原检测能否挽救局面?

Peter Weiss

期刊论文

基于非参数检验的高原反应影响因素分析

常海娟,刘猛,庞丽萍,杨鹏 ,王浚

期刊论文

Model testing of tripod caisson foundations in silty clay subjected to eccentric lateral loads

期刊论文

Investigation of effects of Cocamide Diethanolamide chemical on physical and rheological properties of bituminous binder

期刊论文

ROUTE DEVELOPMENT, ANTIVIRAL STUDIES, FIELD EVALUATION AND TOXICITY OF AN ANTIVIRAL PLANT PROTECTANT NK0238

期刊论文