资源类型

期刊论文 300

年份

2023 14

2022 29

2021 27

2020 24

2019 26

2018 24

2017 24

2016 12

2015 14

2014 15

2013 11

2012 16

2011 6

2010 4

2009 13

2008 6

2007 11

2006 2

2005 1

2004 3

展开 ︾

关键词

调节性T细胞 3

三峡工程 2

三点弯曲梁 2

基因编辑 2

增材制造 2

新冠病毒肺炎 2

横梁 2

癌症 2

1T/2H-MoS2 1

3D打印 1

5G 1

7815 1

ANSYS 1

ATSC 1

CA 1

CAR19 1

CART19 1

CAR设计 1

CRISPR 1

展开 ︾

检索范围：

排序： 展示方式：

Ultimate load analysis of pretensioned inverted T-beams with circular web openings

Hock Tian CHENG , Bashar S. MOHAMMED , Kamal Nasharuddin MUSTAPHA ,

《结构与土木工程前沿（英文）》 2009年 第3卷 第3期   页码 262-271 doi: 10.1007/s11709-009-0031-4

摘要： The provision of transverse openings in floor beams to facilitate the passage of utility pipes and service ducts not only results in a more systematic layout of pipes and ducts, it also translates into substantial economic savings in the construction of a multi-storey building. In this paper, ultimate load analysis of statically loaded simply supported pretensioned inverted T-beams with circular web openings is presented. Major findings relevant to ultimate load analysis of pretensioned beams with circular web openings are summarized. An attempt has been made to answer the frequently asked questions related to ultimate load analysis on multiple circular web openings. It has been shown that the analysis method for pretensioned beams with multiple large circular web openings can be further simplified without sacrificing rationality.

关键词： pretensioned inverted T-beam     web opening    

HTML PDF 收藏

Finite element analysis and structural design of pretensioned inverted T-beams with web openings

Hock Tian CHENG, Bashar S. MOHAMMED, Kamal Nasharuddin MUSTAPHA

《结构与土木工程前沿（英文）》 2009年 第3卷 第2期   页码 148-157 doi: 10.1007/s11709-009-0030-5

摘要： This paper presents the results of a research project aimed at providing standard circular web openings to the popular precast pretensioned inverted T-beam. Opening size and placement and required materials strengths were investigated. In this paper the nonlinear analysis and design of simply supported pretensioned inverted T-beam with circular web openings are presented. Two design parameters are varied: opening location and number of openings. The results from nonlinear finite element analysis were substantiated by test results from five pretensioned inverted T-beams with web opening and one solid beam. Good agreement is shown between the theoretical and the experimental results. The test results obtained from this investigation show that the performance of the specimens with web openings is almost identical to that of the specimen without web openings. A simple design method for pretensioned inverted T-beam with circular web openings is proposed.

关键词： prestressed concrete     inverted-T beam     web opening    

HTML PDF 收藏

高速铁路900 t简支箱梁建造成套技术与装备

王清明,刘林生

《中国工程科学》 2011年 第13卷 第4期   页码 75-80

摘要：

全面介绍了高速铁路900 t简支箱梁建造的成套技术与装备，包括900 t简支箱梁的预制技术和装备、运输技术和装备、架设技术和装备及特殊工况下900 t简支箱梁建造技术及装备，可供从事高速铁路和桥梁工程技术人员参考。

关键词： 高速铁路     简支箱梁     建造技术    

HTML PDF 收藏

Damage assessment of laminated composite beam structures using damage locating vector (DLV) method

T. VO-DUY,N. NGUYEN-MINH,H. DANG-TRUNG,A. TRAN-VIET,T. NGUYEN-THOI

《结构与土木工程前沿（英文）》 2015年 第9卷 第4期   页码 457-465 doi: 10.1007/s11709-015-0303-0

摘要： In this paper, the damage locating vector (DLV) method using normalized cumulative energy ( ) is employed to locate multiple damage sites in laminated composite beam structures. Numerical simulations of two laminated composite beams are employed to investigate several damage scenarios in which the degradation of elements is modeled by the reduction in the longitudinal Young’s modulus and transverse Young’s modulus of beam layers. The results show that the DLV method gives good performance for this kind of structure.

关键词： normalized cumulative energy     structural health monitoring (SHM)     damage locating vector method (DLV)     laminated composite beam structure    

HTML PDF 收藏

Free vibration analysis of laminated FG-CNT reinforced composite beams using finite element method

T. VO-DUY, V. HO-HUU, T. NGUYEN-THOI

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 324-336 doi: 10.1007/s11709-018-0466-6

摘要： In the present study, the free vibration of laminated functionally graded carbon nanotube reinforced composite beams is analyzed. The laminated beam is made of perfectly bonded carbon nanotubes reinforced composite (CNTRC) layers. In each layer, single-walled carbon nanotubes are assumed to be uniformly distributed (UD) or functionally graded (FG) distributed along the thickness direction. Effective material properties of the two-phase composites, a mixture of carbon nanotubes (CNTs) and an isotropic polymer, are calculated using the extended rule of mixture. The first-order shear deformation theory is used to formulate a governing equation for predicting free vibration of laminated functionally graded carbon nanotubes reinforced composite (FG-CNTRC) beams. The governing equation is solved by the finite element method with various boundary conditions. Several numerical tests are performed to investigate the influence of the CNTs volume fractions, CNTs distributions, CNTs orientation angles, boundary conditions, length-to-thickness ratios and the numbers of layers on the frequencies of the laminated FG-CNTRC beams. Moreover, a laminated composite beam combined by various distribution types of CNTs is also studied.

关键词： free vibration analysis     laminated FG-CNTRC beam     finite element method     first-order shear deformation theory     composite material    

HTML PDF 收藏

Inverted duplication including

Ming TIAN,Suyun FANG,Yanqiang WANG,Xiaorong GU,Chungang FENG,Rui HAO,Xiaoxiang HU,Ning LI

《农业科学与工程前沿（英文）》 2014年 第1卷 第2期   页码 121-129 doi: 10.15302/J-FASE-2014026

摘要： The dermal hyperpigmentation phenotype in chickens is controlled by the dominant fibromelanosis allele. One of the ten unique characteristics of Silkie chickens is the fibromelanosis phenotype, which is pigmentation in the dermal layer of the skin and connective tissue. In this study, we found a mutation of fibromelanosis, a genomic rearrangement that included an inverted duplication of ( ), is responsible. We show that, as a stimulator of melanoblast proliferation, expression was increased in silkie embryos and in both skin and muscle throughout adulthood. expression led to an increase in expression of the downstream genes and and was closely relate with the hyperpigmentation phenotype. We examined eight different Chinese chicken breeds showing hyperpigmentation and conclude that this structural genetic variant exists in all fibromelanosis chicken breeds.

关键词： dermal hyperpigmentation     duplication     endothelin 3     Silkie chicken    

HTML PDF 收藏

Scaling up of cluster beam deposition technology for catalysis application

《化学科学与工程前沿（英文）》 2021年 第15卷 第6期   页码 1360-1379 doi: 10.1007/s11705-021-2101-7

摘要： Many research works have demonstrated that the combination of atomically precise cluster deposition and theoretical calculations is able to address fundamental aspects of size-effects, cluster-support interactions, and reaction mechanisms of cluster materials. Although the wet chemistry method has been widely used to synthesize nanoparticles, the gas-phase synthesis and size-selected strategy was the only method to prepare supported metal clusters with precise numbers of atoms for a long time. However, the low throughput of the physical synthesis method has severely constrained its wider adoption for catalysis applications. In this review, we introduce the latest progress on three types of cluster source which have the most promising potential for scale-up, including sputtering gas aggregation source, pulsed microplasma cluster source, and matrix assembly cluster source. While the sputtering gas aggregation source is leading ahead with a production rate of ~20 mg·h–1, the pulsed microplasma source has the smallest physical dimensions which makes it possible to compact multiple such devices into a small volume for multiplied production rate. The matrix assembly source has the shortest development history, but already show an impressive deposition rate of ~10 mg·h–1. At the end of the review, the possible routes for further throughput scale-up are envisaged.

关键词： nanoparticle     cluster     cluster beam deposition     magnetron sputtering     heterogeneous catalysis    

HTML PDF 收藏

Is there an inverted U-shaped curve?

Fei LI,Suocheng DONG,Fujia LI,Libiao YANG

《环境科学与工程前沿（英文）》 2016年 第10卷 第2期   页码 276-287 doi: 10.1007/s11783-014-0700-y

摘要： As the largest contributor to water impairment, agriculture-related pollution has attracted the attention of scientists as well as policy makers, and quantitative information is being sought to focus and advance the policy debate. This study applies the panel unit root, heterogeneous panel cointegration, and panel-based dynamic ordinary least squares to investigate the Environmental Kuznets Curve on environmental issues resulting from use of agricultural synthetic fertilizer, pesticide, and film for 31 provincial economies in mainland China from 1989 to 2009. The empirical results indicate a positive long-run co-integrated relationship between the environmental index and real GDP per capita. This relationship takes on the inverted U-shaped Environmental Kuznets Curve, and the value of the turning point is approximately 10,000–13,000, 85,000–89,000 and over 160,000 CNY, for synthetic fertilizer nitrogen indicator, fertilizer phosphorus indicator and pesticide indicator, respectively. At present, China is subject to tremendous environmental pressure and should assign more importance to special agriculture-related environmental issues.

关键词： Environmental Kuznets Curve     agrochemical     China    

HTML PDF 收藏

三级倒立摆的云控制方法及动平衡模式

李德毅

《中国工程科学》 1999年 第1卷 第2期   页码 41-46

摘要：

文章提出了定性和定量之间转换的云模型的形式化表示方法，用来反映语言值中蕴涵的模糊性和随机性，给出云发生器的生成算法，解释多条定性推理规则同时被激活时的不确定性推理机制。利用这种智能控制方法有效地实现了单电机控制的一、二、三级倒立摆的多种不同动平衡姿态，显示其鲁棒性，并给出了详细试验结果。研究成果不仅可用于对太空飞行器以及机器人控制，而且对揭示定性定量转换规律和策略具有普遍意义。

关键词： 智能控制     云模型     定性推理     倒立摆    

HTML PDF 收藏

基于Lagrange方程建模的单级旋转倒立摆控制

吴爱国,张小明,张钊

《中国工程科学》 2005年 第7卷 第10期   页码 11-15

摘要：

介绍一种新型单级旋转倒立摆系统的构成，通过对其动力学特性的分析建立了基于Lagrange方程的数学模型。在平衡点附近给出系统的线性化模型，对系统的稳定性、能控性和能观性进行了分析。利用线性二次型最优控制策略LQR方法设计了控制器，并在仿真实验和实物实验中实现了倒立摆的平衡控制。实验表明，系统稳定性好、鲁棒性较强。

关键词： 旋转倒立摆     Lagrange方程     最优控制策略LQR    

HTML PDF 收藏

Processing parameter optimization of fiber laser beam welding using an ensemble of metamodels and MOABC

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0703-5

摘要： In fiber laser beam welding (LBW), the selection of optimal processing parameters is challenging and plays a key role in improving the bead geometry and welding quality. This study proposes a multi-objective optimization framework by combining an ensemble of metamodels (EMs) with the multi-objective artificial bee colony algorithm (MOABC) to identify the optimal welding parameters. An inverse proportional weighting method that considers the leave-one-out prediction error is presented to construct EM, which incorporates the competitive strengths of three metamodels. EM constructs the correlation between processing parameters (laser power, welding speed, and distance defocus) and bead geometries (bead width, depth of penetration, neck width, and neck depth) with average errors of 10.95%, 7.04%, 7.63%, and 8.62%, respectively. On the basis of EM, MOABC is employed to approximate the Pareto front, and verification experiments show that the relative errors are less than 14.67%. Furthermore, the main effect and the interaction effect of processing parameters on bead geometries are studied. Results demonstrate that the proposed EM-MOABC is effective in guiding actual fiber LBW applications.

关键词： laser beam welding     parameter optimization     metamodel     multi-objective    

HTML PDF 收藏

Application of consistent geometric decomposition theorem to dynamic finite element of 3D composite beam

Iman FATTAHI, Hamid Reza MIRDAMADI, Hamid ABDOLLAHI

《结构与土木工程前沿（英文）》 2020年 第14卷 第3期   页码 675-689 doi: 10.1007/s11709-020-0625-4

摘要： Analyzing static and dynamic problems including composite structures has been of high significance in research efforts and industrial applications. In this article, equivalent single layer approach is utilized for dynamic finite element procedures of 3D composite beam as the building block of numerous composite structures. In this model, both displacement and strain fields are decomposed into cross-sectional and longitudinal components, called consistent geometric decomposition theorem. Then, the model is discretized using finite element procedures. Two local coordinate systems and a global one are defined to decouple mechanical degrees of freedom. Furthermore, from the viewpoint of consistent geometric decomposition theorem, the transformation and element mass matrices for those systems are introduced here for the first time. The same decomposition idea can be used for developing element stiffness matrix. Finally, comprehensive validations are conducted for the theory against experimental and numerical results in two case studies and for various conditions.

关键词： composite beam     dynamic finite element     degrees of freedom coupling     experimental validation     numerical validation    

HTML PDF 收藏

Experimental and numerical analysis of beam to column joints in steel structures

Gholamreza ABDOLLAHZADEH, Seyed Mostafa SHABANIAN

《结构与土木工程前沿（英文）》 2018年 第12卷 第4期   页码 642-661 doi: 10.1007/s11709-017-0457-z

摘要： The behaviors such as extreme non-elastic response, constant changes in roughness and resistance, as well as formability under extreme loads such as earthquakes are the primary challenges in the modeling of beam-to-column connections. In this research, two modeling methods including mechanical and neural network methods have been presented in order to model the complex hysteresis behavior of beam-to-column connections with flange plate. First, the component-based mechanical model will be introduced in which every source of transformation has been shown only with geometrical and material properties. This is followed by the investigation of a neural network method for direct extraction of information out of experimental data. For the validation of behavioral curves as well as training of the neural network, the experiments were carried out on samples with real dimensions of beam-to-column connections with flange plate in the laboratory. At the end, the combinational modeling framework is presented. The comparisons reveal that the combinational modeling is able to display the complex narrowed hysteresis behavior of the beam-to-column connections with flange plate. This model has also been successfully employed for the prediction of the behavior of a newly designed connection.

关键词： beam to column connections     experiments     component method     neural network model     combinational modeling    

HTML PDF 收藏

disrupting chemicals from water through urethane functionalization of microfiltration membranes via electron beam

《环境科学与工程前沿（英文）》 2023年 第18卷 第4期 doi: 10.1007/s11783-024-1805-6

摘要：

● Urethane functionalities created on PES membranes via electron beam irradiation.

关键词： Surface functionalization     Electron beam irradiation     Microfiltration     Endocrine disrupting chemicals    

HTML PDF 收藏

Deubiquitinases as pivotal regulators of T cell functions

null

《医学前沿（英文）》 2018年 第12卷 第4期   页码 451-462 doi: 10.1007/s11684-018-0651-y

摘要：

T cells efficiently respond to foreign antigens to mediate immune responses against infections but are tolerant to self-tissues. Defect in T cell activation is associated with severe immune deficiencies, whereas aberrant T cell activation contributes to the pathogenesis of diverse autoimmune and inflammatory diseases. An emerging mechanism that regulates T cell activation and tolerance is ubiquitination, a reversible process of protein modification that is counter-regulated by ubiquitinating enzymes and deubiquitinases (DUBs). DUBs are isopeptidases that cleave polyubiquitin chains and remove ubiquitin from target proteins, thereby controlling the magnitude and duration of ubiquitin signaling. It is now well recognized that DUBs are crucial regulators of T cell responses and serve as potential therapeutic targets for manipulating immune responses in the treatment of immunological disorders and cancer. This review will discuss the recent progresses regarding the functions of DUBs in T cells.

关键词： deubiquitinase     ubiquitination     T cell activation     T cell differentiation     T cell tolerance    

HTML PDF 收藏

标题 作者 时间 类型 操作

Ultimate load analysis of pretensioned inverted T-beams with circular web openings

Hock Tian CHENG , Bashar S. MOHAMMED , Kamal Nasharuddin MUSTAPHA ,

期刊论文

Finite element analysis and structural design of pretensioned inverted T-beams with web openings

Hock Tian CHENG, Bashar S. MOHAMMED, Kamal Nasharuddin MUSTAPHA

期刊论文

高速铁路900 t简支箱梁建造成套技术与装备

王清明,刘林生

期刊论文

Damage assessment of laminated composite beam structures using damage locating vector (DLV) method

T. VO-DUY,N. NGUYEN-MINH,H. DANG-TRUNG,A. TRAN-VIET,T. NGUYEN-THOI

期刊论文

Free vibration analysis of laminated FG-CNT reinforced composite beams using finite element method

T. VO-DUY, V. HO-HUU, T. NGUYEN-THOI

期刊论文

Inverted duplication including

Ming TIAN,Suyun FANG,Yanqiang WANG,Xiaorong GU,Chungang FENG,Rui HAO,Xiaoxiang HU,Ning LI

期刊论文

Scaling up of cluster beam deposition technology for catalysis application

期刊论文

Is there an inverted U-shaped curve?

Fei LI,Suocheng DONG,Fujia LI,Libiao YANG

期刊论文

三级倒立摆的云控制方法及动平衡模式

李德毅

期刊论文

基于Lagrange方程建模的单级旋转倒立摆控制

吴爱国,张小明,张钊

期刊论文

Processing parameter optimization of fiber laser beam welding using an ensemble of metamodels and MOABC

期刊论文

Application of consistent geometric decomposition theorem to dynamic finite element of 3D composite beam

Iman FATTAHI, Hamid Reza MIRDAMADI, Hamid ABDOLLAHI

期刊论文

Experimental and numerical analysis of beam to column joints in steel structures

Gholamreza ABDOLLAHZADEH, Seyed Mostafa SHABANIAN

期刊论文

disrupting chemicals from water through urethane functionalization of microfiltration membranes via electron beam

期刊论文

Deubiquitinases as pivotal regulators of T cell functions

null

期刊论文