资源类型

期刊论文 1538

年份

2024 1

2023 97

2022 109

2021 103

2020 119

2019 112

2018 78

2017 87

2016 58

2015 89

2014 77

2013 66

2012 58

2011 65

2010 65

2009 61

2008 54

2007 62

2006 43

2005 24

展开 ︾

关键词

技术预见 5

有限元法 4

节能减排 4

S-N曲线 2

一阶分析法 2

上限法 2

优化设计 2

参数估计 2

可靠性 2

多目标优化 2

大菱鲆 2

悬索桥 2

数学模型 2

数据驱动方法 2

智能制造 2

最小二乘法 2

析出强化 2

模态 2

海上风电场 2

展开 ︾

检索范围：

排序： 展示方式：

Stability analysis of a high loess slope reinforced by the combination system of soil nails and stabilization piles

Jiu-jiang WU,Qian-gong CHENG,Xin LIANG,Jian-Lei CAO

《结构与土木工程前沿（英文）》 2014年 第8卷 第3期   页码 252-259 doi: 10.1007/s11709-014-0260-z

摘要： While the soil nails and the corresponding compound technology are widely used as the support techniques for deep foundation pit and normal slopes, few related engineering cases are found for high loess slopes. By utilizing the finite element software of PLAXIS 8.5, the behavior of a high loess slope reinforced by the combination of soil nails and stabilization piles (hereinafter for CSNSP) is studied in this paper. It can be found that the potential slide surface of the slope moves to deeper locations during the process of the multi-staged excavations. The measure of reducing the weight of the top of the slope is a positive factor to the stability of the loess slope, while the rainfall is a negative factor. The slope can’t be stable if it’s reinforced only by stabilization piles or soil nails during the process of the multi-staged excavations. The soil nail contributes greater to the overall system stability when the excavation depth is relatively shallow, while the stabilization pile takes it over when the excavation depth reaches a large value. Compared to the results from the Sweden circular slip surface, the data derived from the method of phi/c reduction is relatively large when the slope is unreinforced or reinforced only by stabilization pile, and the data turns to be small when the slope is strengthened by soil nails or the combination system of soil nails and stabilization piles.

关键词： high loess slope     CSNSP     PLAXIS     phi/c strength reduction method     Sweden circular slip surface    

HTML PDF 收藏

Development of an H reduction and moderate oxidation method for 3,5-dimethylpyridine hydrogenation in

《化学科学与工程前沿（英文）》 2022年 第16卷 第12期   页码 1807-1817 doi: 10.1007/s11705-022-2243-2

摘要： The Ru/C catalyst prepared by impregnation method was used for hydrogenation of 3,5-dimethylpyridine in a trickle bed reactor. Under the same reduction conditions (300 °C in H2), the catalytic activity of the non-in-situ reduced Ru/C-n catalyst was higher than that of the in-situ reduced Ru/C-y catalyst. Therefore, an in-situ H2 reduction and moderate oxidation method was developed to increase the catalyst activity. Moreover, the influence of oxidation temperature on the developed method was investigated. The catalysts were characterized by Brunauer–Emmett–Teller method, hydrogen temperature programmed reduction H2-TPR, hydrogen temperature-programmed dispersion (H2-TPD), X-ray diffraction, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, O2 chemisorption and oxygen temperature-programmed dispersion (O2-TPD) analyses. The results showed that there existed an optimal Ru/RuOx ratio for the catalyst, and the highest 3,5-dimethylpyridine conversion was obtained for the Ru/C-i1 catalyst prepared by in-situ H2 reduction and moderate oxidation (oxidized at 100 °C). Excessive oxidation (200 °C) resulted in a significant decrease in the Ru/RuOx ratio of the in-situ H2 reduction and moderate oxidized Ru/C-i2 catalyst, the interaction between RuOx species and the support changed, and the hard-to-reduce RuOx species was formed, leading to a significant decrease in catalyst activity. The developed in-situ H2 reduction and moderate oxidation method eliminated the step of the non-in-situ reduction of catalyst outside the trickle bed reactor.

关键词： Ru/C catalyst     in-situ H2 reduction and moderate oxidation     in-situ reduction     non-in-situ reduction     hydrogenation of 3     5-dimethylpyridine    

HTML PDF 收藏

Strength reduction factors for structural rubbercrete

Bashar S. MOHAMMED,N. J. AZMI

《结构与土木工程前沿（英文）》 2014年 第8卷 第3期   页码 270-281 doi: 10.1007/s11709-014-0265-7

摘要： Many researches have been carried out to study the fresh and hardened properties of concrete containing crumb rubber as replacement to fine aggregate by volume, yet there is no specific guideline has been developed on the mix design of the rubbercrete. The experimental program, which has been developed and reported in this paper, is designed and executed to provide such mix design guidelines. A total of 45 concrete mixes with three different water to cement ratio (0.41, 0.57 and 0.68) were cast and tested for fresh and mechanical properties of rubbercrete such as slump, air content, unit weight, compressive strength, flexural strength, splitting tensile strength and modulus of elasticity. Influence of mix design parameters such as percentage of crumb rubber replacement, cement content, water content, fine aggregate content, and coarse aggregate content were investigated. Three levels of slump value (for conventional concrete mixes) has been selected; low, medium and high slump. In each slump level, water content was kept constant. Equations for the reduction factors (RFs) for compressive strength, flexural strength, splitting tensile strength and modulus of elasticity have been developed. These RFs can be used to design rubbercrete mixes based on the conventional mix (0% crumb rubber content)

关键词： crumb rubber     recycled tire     mix design     reduction factor     strength     modulus elasticity    

HTML PDF 收藏

Structure improvement and strength finite element analysis of VHP welded rotor of 700°C USC steam turbine

Jinyuan SHI,Zhicheng DENG,Yong WANG,Yu YANG

《能源前沿（英文）》 2016年 第10卷 第1期   页码 88-104 doi: 10.1007/s11708-015-0387-1

摘要： The optimized structure strength design and finite element analysis method for very high pressure (VHP) rotors of the 700°C ultra-super-critical (USC) steam turbine are presented. The main parameters of steam and the steam thermal parameters of blade stages of VHP welded rotors as well as the start and shutdown curves of the steam turbine are determined. The structure design feature, the mechanical models and the typical position of stress analysis of the VHP welded rotors are introduced. The steady and transient finite element analysis are implemented for steady condition, start and shutdown process, including steady rated condition, 110% rated speed, 120% rated speed, cold start, warm start, hot start, very hot start, sliding-pressure shutdown, normal shutdown and emergency shutdown, to obtain the temperature and stress distribution as well as the stress ratio of the welded rotor. The strength design criteria and strength analysis results of the welded rotor are given. The results show that the strength design of improved structure of the VHP welded rotor of the 700°C USC steam turbine is safe at the steady condition and during the transient start or shutdown process.

关键词： 700°C ultra-super-critical unit     steam turbine     very high pressure rotor     structure strength design     strength design criteria     finite element analysis    

HTML PDF 收藏

Electrochemical CO reduction to C products over CuZn intermetallic catalysts synthesized by electrodeposition

《能源前沿（英文）》 doi: 10.1007/s11708-023-0898-0

摘要： Electrocatalytic CO2 reduction (ECR) offers an attractive approach to realizing carbon neutrality and producing valuable chemicals and fuels using CO2 as the feedstock. However, the lack of cost-effective electrocatalysts with better performances has seriously hindered its application. Herein, a one-step co-electrodeposition method was used to introduce Zn, a metal with weak *CO binding energy, into Cu to form Cu/Zn intermetallic catalysts (Cu/Zn IMCs). It was shown that, using an H-cell, the high Faradaic efficiency of C2+ hydrocarbons/alcohols (FEC2+) could be achieved in ECR by adjusting the surface metal components and the applied potential. In suitable conditions, FEC2+ and current density could be as high as 75% and 40 mA/cm2, respectively. Compared with the Cu catalyst, the Cu/Zn IMCs have a lower interfacial charge transfer resistance and a larger electrochemically active surface area (ECSA), which accelerate the reaction. Moreover, the *CO formed on Zn sites can move to Cu sites due to its weak binding with *CO, and thus enhance the C–C coupling on the Cu surface to form C2+ products.

关键词： carbon dioxide electroreduction     electrochemistry     co-electrodeposition     intermetallic catalysts     value-added chemicals    

HTML PDF 收藏

Shear design of high strength concrete prestressed girders

C. HSU,Y. L. MO

《结构与土木工程前沿（英文）》 2014年 第8卷 第4期   页码 373-387 doi: 10.1007/s11709-014-0087-7

摘要： Normal strength prestressed concrete I-girders are commonly used as the primary superstructure components in highway bridges. However, shear design guidelines for high strength PC girders are not available in the current structural codes. Recently, ten 7.62 m (25 feet) long girders made with high strength concrete were designed, cast, and tested at the University of Houston (UH) to study the ultimate shear strength and the shear concrete contribution ( ) as a function of concrete strength ( ). A simple semi-empirical set of equations was developed based on the test results to predict the ultimate shear strength of prestressed concrete I-girders. The UH-developed set of equations is a function of concrete strength ( ), web area ( ), shear span to effective depth ratio ( / ), and percentage of transverse steel ( ). The proposed UH-Method was found to accurately predict the ultimate shear strength of PC girders with concrete strength up to 117 MPa (17000 psi) ensuring satisfactory ductility. The UH-Method was found to be not as overly conservative as the ACI-318 (2011) code provisions, and also not to overestimate the ultimate shear strength of high strength PC girders as the AASHTO LRFD (2010) code provisions. Moreover, the proposed UH-Method was found fairly accurate and not exceedingly conservative in predicting the concrete contribution to shear for concrete strength up to 117 MPa (17000 psi).

关键词： shear design     high strength concrete     prestressed girders     full-scale tests    

HTML PDF 收藏

Nanomaterials for environmental burden reduction, waste treatment, and nonpoint source pollution control

SURAMPALLI , Tian C. ZHANG

《环境科学与工程前沿（英文）》 2009年 第3卷 第3期   页码 249-264 doi: 10.1007/s11783-009-0029-0

摘要： Nanomaterials are applicable in the areas of reduction of environmental burden, reduction/treatment of industrial and agricultural wastes, and nonpoint source (NPS) pollution control. First, environmental burden reduction involves green process and engineering, emissions control, desulfurization/denitrification of nonrenewable energy sources, and improvement of agriculture and food systems. Second, reduction/treatment of industrial and agricultural wastes involves converting wastes into products, groundwater remediation, adsorption, delaying photocatalysis, and nanomembranes. Third, NPS pollution control involves controlling water pollution. Nanomaterials alter physical properties on a nanoscale due to their high specific surface area to volume ratio. They are used as catalysts, adsorbents, membranes, and additives to increase activity and capability due to their high specific surface areas and nano-sized effects. Thus, nanomaterials are more effective at treating environmental wastes because they reduce the amount of material needed.

关键词： nanomaterials     industrial     agricultural     nonpoint source pollution     environmental burden reduction    

HTML PDF 收藏

In situ DRIFTS study of photocatalytic CO 2 reduction under UV irradiation

Jeffrey C. S. WU, Chao-Wei HUANG,

《化学科学与工程前沿（英文）》 2010年 第4卷 第2期   页码 120-126 doi: 10.1007/s11705-009-0232-3

摘要： Photocatalytic reduction of CO on TiO and Cu/TiO photocatalysts was studied by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) under UV irradiation. The photocatalysts were prepared by sol-gel method via controlled hydrolysis of titanium (IV) butoxide. Copper precursor was loaded onto TiO during sol-gel procedure. A large amount of adsorbed HO and surface OH groups was detected at 25°C on the TiO photocatalyst after being treated at 500°C under air stream. Carbonate and bicarbonate were formed rapidly due to the reaction of CO with oxygen-vacancy and OH groups, respectively, on TiO surface upon CO adsorption. The IR spectra indicated that, under UV irradiation, gas-phase CO further combined with oxygen-vacancy and OH groups to produce more carbonate or bicarbonate. The weak signals of reaction intermediates were found on the IR spectra, which were due to the slow photocatalytic CO reduction on photocatalysts. Photogenerated electrons merge with H ions to form H atoms, which progressively reduce CO to form formic acid, dioxymethylene, formaldehyde and methoxy as observed in the IR spectra. The well-dispersed Cu, acting as the active site significantly increases the amount of formaldehyde and dioxymethylene, thus promotes the photoactivity of CO reduction on Cu/TiO. A possible mechanism of the photocatalytic CO reduction is proposed based on these intermediates and products on the photocatalysts.

关键词： irradiation     oxygen-vacancy     Photocatalytic reduction     Carbonate     butoxide    

HTML PDF 收藏

Effect of environment change on the strength of cement/lime treated clays

Takenori HINO, Rui JIA, Seiji SUEYOSHI, Tri HARIANTO

《结构与土木工程前沿（英文）》 2012年 第6卷 第2期   页码 153-165 doi: 10.1007/s11709-012-0153-y

摘要： The field strengths of cement/lime treated clays were investigated in the Ariake Sea costal lowlands. The deposition environment of the investigation location is reconstructed and compared to the present ground environment. The mechanism of the ground environment change and its effect on the strength of cement/lime treated soil are discussed. The strength development of improved soil using cement and lime in different curing environments was investigated in the laboratory for studying the effect of environment change on the strength also. It has been found that the strength deterioration of improved soil in deep mixing method is due to 1) the ground environment change due to the secondary oxidation which results in low pH value and high organic content, and 2) the formations of the porous structures result from the elution of the calcium ions. Also, it has been found that the initial strength increase of the improved soil is related to the dissolved silica and that the dissolution of the silica in clay minerals needs long time. When examining the long-term strength for preventing strength degradation, the effect of environmental change has to be considered. The importance of measuring pH and oxidation-reduction potential (ORP) of the ground for cement/lime solidification method is explained.

关键词： soil solidification     ground environment     strength deterioration     pH     oxidation-reduction potential (ORP)     silica    

HTML PDF 收藏

用有限元强度折减法进行边坡稳定分析

郑颖人,赵尚毅,张鲁渝

《中国工程科学》 2002年 第4卷 第10期   页码 57-61

摘要：

通过对边坡非线性有限元模型进行强度折减，使边坡达到不稳定状态时，非线性有限元静力计算将不收敛，此时的折减系数就是稳定安全系数，同时可得到边坡破坏时的滑动面。传统条分法无法获得岩质边坡的滑动面与稳定安全系数。该方法开创了求岩质边坡滑动面与稳定安全系数的先例。文章对此法的计算精度以及影响因素进行了分析。算例表明采用摩尔-库仑等面积圆屈服准则求得的稳定安全系数与简化Bishop法的误差为3%～8%，与Spencer法的误差为1%～4%，证实了其实用于工程的可行性。

关键词： 边坡稳定分析     有限元强度折减法     屈服准则    

HTML PDF 收藏

Border-search and jump reduction method for size optimization of spatial truss structures

Babak DIZANGIAN, Mohammad Reza GHASEMI

《结构与土木工程前沿（英文）》 2019年 第13卷 第1期   页码 123-134 doi: 10.1007/s11709-018-0478-2

摘要： This paper proposes a sensitivity-based border-search and jump reduction method for optimum design of spatial trusses. It is considered as a two-phase optimization approach, where at the first phase, the first local optimum is found by few analyses, after the whole searching space is limited employing an efficient random strategy, and the second phase involves finding a sequence of local optimum points using the variables sensitivity with respect to corresponding values of constraints violation. To reach the global solution at phase two, a sequence of two sensitivity-based operators of border-search operator and jump operator are introduced until convergence is occurred. Sensitivity analysis is performed using numerical finite difference method. To do structural analysis, a link between open source software of OpenSees and MATLAB was developed. Spatial truss problems were attempted for optimization in order to show the fastness and efficiency of proposed technique. Results were compared with those reported in the literature. It shows that the proposed method is competitive with the other optimization methods with a significant reduction in number of analyses carried.

关键词： optimum design     sensitivity analysis     reduction method     spatial trusses     OpenSees    

HTML PDF 收藏

Achieving air pollutant emission reduction targets with minimum abatement costs: An enterprise-levelallocation method with constraints of fairness and feasibility

《环境科学与工程前沿（英文）》 2022年 第16卷 第2期 doi: 10.1007/s11783-021-1459-6

摘要：

• Quantification of efficiency and fairness of abatement allocation are optimized.

关键词： Pollutant emission reduction allocation     Emission reduction measures     Total abatement cost     Economic efficiency     Abatement space    

HTML PDF 收藏

带约束条件的C-Bézier曲面最优降多阶逼近 Article

Lian ZHOU, Xin-hui LIN, Hong-yan ZHAO, Jun CHEN

《信息与电子工程前沿（英文）》 2017年 第18卷 第12期   页码 2009-2016 doi: 10.1631/FITEE.1700458

摘要： 本文提出了一种在L2范数下C-Bézier曲面带约束条件的降多阶逼近最优方法。利用C-Bézier基函数的转换矩阵，得到了降阶曲面控制顶点的显式矩阵表示。

关键词： C-Bézier曲面；降阶；边界约束    

HTML PDF 收藏

An improved design method to predict the E-modulus and strength of FRP composites at different temperatures

Mohammed FARUQI, Gobishanker RAJASKANTHAN, Breanna BAILEY, Francisco AGUINIGA

《结构与土木工程前沿（英文）》 2022年 第16卷 第12期   页码 1654-1654 doi: 10.1007/s11709-020-0622-7

HTML PDF 收藏

Direct acting antiviral-induced dynamic reduction of serum

Tung Huynh, Ke-Qin Hu

《医学前沿（英文）》 2019年 第13卷 第6期   页码 658-666 doi: 10.1007/s11684-019-0707-7

摘要： Direct acting antiviral (DAA) treatments may reduce the elevated α fetoprotein (AFP), but data on how these treatments affect elevated AFP in patients with chronic hepatitis C (CHC) remain insufficient. In the present study, the frequency of baseline AFP elevations and their related factors, AFP dynamics during and after DAA treatment, and factors associated with AFP reduction was assessed. This retrospective study included 141 patients with CHC without hepatocellular carcinoma who received DAA and achieved sustained virological response. The details are as follows: mean post-treatment follow-up was 99 weeks (12–213); mean age, 57.8 years old; 52%, males; 79%, genotype (GT) 1; and 47%, cirrhosis. Pre-treatment AFP elevation (>5.5 ng/mL) was seen in 48.2% patients. On multivariate analysis, baseline AFP>5.5 was associated with the presence of cirrhosis ( =0.001), co-existing non-alcoholic steatohepatitis (NASH) ( = 0.035), and GT 1 ( = 0.029). AFP normalization was seen in 28.2% patients at treatment week 2, in 52% at the end of treatment, and in 73.4% at the end of follow-up. Post-treatment week 24 AFP normalization was associated with the absence of cirrhosis ( = 0.003), Child–Pugh score<6 ( = 0.015), and baseline AFP<10 ( = 0.015). AFP elevation is common in patients with CHC and independently associated with NASH, cirrhosis, and GT 1. DAA treatment resulted in AFP normalization as early as treatment week 2. Post-treatment week 24 AFP normalization is independently associated with the absence of cirrhosis, Child–Pugh score<6, and baseline AFP<10.

关键词： chronic hepatitis C     α fetoprotein     direct acting antiviral treatment     cirrhosis    

HTML PDF 收藏

标题 作者 时间 类型 操作

Stability analysis of a high loess slope reinforced by the combination system of soil nails and stabilization piles

Jiu-jiang WU,Qian-gong CHENG,Xin LIANG,Jian-Lei CAO

期刊论文

Development of an H reduction and moderate oxidation method for 3,5-dimethylpyridine hydrogenation in

期刊论文

Strength reduction factors for structural rubbercrete

Bashar S. MOHAMMED,N. J. AZMI

期刊论文

Structure improvement and strength finite element analysis of VHP welded rotor of 700°C USC steam turbine

Jinyuan SHI,Zhicheng DENG,Yong WANG,Yu YANG

期刊论文

Electrochemical CO reduction to C products over CuZn intermetallic catalysts synthesized by electrodeposition

期刊论文

Shear design of high strength concrete prestressed girders

C. HSU,Y. L. MO

期刊论文

Nanomaterials for environmental burden reduction, waste treatment, and nonpoint source pollution control

SURAMPALLI , Tian C. ZHANG

期刊论文

In situ DRIFTS study of photocatalytic CO 2 reduction under UV irradiation

Jeffrey C. S. WU, Chao-Wei HUANG,

期刊论文

Effect of environment change on the strength of cement/lime treated clays

Takenori HINO, Rui JIA, Seiji SUEYOSHI, Tri HARIANTO

期刊论文

用有限元强度折减法进行边坡稳定分析

郑颖人,赵尚毅,张鲁渝

期刊论文

Border-search and jump reduction method for size optimization of spatial truss structures

Babak DIZANGIAN, Mohammad Reza GHASEMI

期刊论文

Achieving air pollutant emission reduction targets with minimum abatement costs: An enterprise-levelallocation method with constraints of fairness and feasibility

期刊论文

带约束条件的C-Bézier曲面最优降多阶逼近

Lian ZHOU, Xin-hui LIN, Hong-yan ZHAO, Jun CHEN

期刊论文

An improved design method to predict the E-modulus and strength of FRP composites at different temperatures

Mohammed FARUQI, Gobishanker RAJASKANTHAN, Breanna BAILEY, Francisco AGUINIGA

期刊论文

Direct acting antiviral-induced dynamic reduction of serum

Tung Huynh, Ke-Qin Hu

期刊论文