资源类型

期刊论文 294

会议视频 3

年份

2023 10

2022 19

2021 13

2020 16

2019 11

2018 12

2017 13

2016 7

2015 7

2014 11

2013 26

2012 11

2011 33

2010 21

2009 13

2008 16

2007 13

2006 5

2005 6

2004 6

展开 ︾

关键词

三峡工程 38

升船机 11

三峡升船机 10

三塔悬索桥 4

混凝土 4

三峡库区 3

施工技术 3

横梁 3

设计 3

2021全球十大工程成就 2

三塔两跨悬索桥 2

三点弯曲梁 2

三相界面 2

三维 2

创新 2

动力特性 2

升船机塔柱 2

南京长江第四大桥 2

工程管理 2

展开 ︾

检索范围：

排序： 展示方式：

Simulation of cross-flow-induced vibration of tube bundle by surface vorticity method

WANG Fenghao, JIANG Gedong, Lin John Zhang

《能源前沿（英文）》 2008年 第2卷 第3期   页码 243-248 doi: 10.1007/s11708-008-0049-7

摘要： A fluid-structure interaction model based on Surface Vorticity Method (SVM) was used to study flow-induced vibrations of tube bundles in medium space ratio. The flow-induced vibrations of four tubes in a rotated square and a staggered tube bundle in three-row and five-column arrangements were simulated in the high sub-critical Reynolds number () range. The results on fluid forces, tube responses and vorticity maps were presented. The vorticity maps of the four rotated-square tubes changed dramatically when the rigid tubes were replaced by the flexible tubes. From the vorticity maps and vibration responses of the staggered tube bundle of different structural parameters, it was found that with the decrease of tube natural frequency, the maximal vibration response moved from the third row to the first. The results also showed that when more flexible tubes are used, the flow pattern changed drastically and the fluid-structure interaction imposed a dominant impact on the flow.

关键词： dominant     sub-critical Reynolds     staggered     Vorticity     three-row    

HTML PDF 收藏

General closed-form inverse kinematics for arbitrary three-joint subproblems based on the product of

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0681-7

摘要： The inverse kinematics problems of robots are usually decomposed into several Paden–Kahan subproblems based on the product of exponential model. However, the simple combination of subproblems cannot solve all the inverse kinematics problems, and there is no common approach to solve arbitrary three-joint subproblems in an arbitrary postural relationship. The novel algebraic geometric (NAG) methods that obtain the general closed-form inverse kinematics for all types of three-joint subproblems are presented in this paper. The geometric and algebraic constraints are used as the conditions precedent to solve the inverse kinematics of three-joint subproblems. The NAG methods can be applied in the inverse kinematics of three-joint subproblems in an arbitrary postural relationship. The inverse kinematics simulations of all three-joint subproblems are implemented, and simulation results indicating that the inverse solutions are consistent with the given joint angles validate the general closed-form inverse kinematics. Huaque III minimally invasive surgical robot is used as the experimental platform for the simulation, and a master–slave tracking experiment is conducted to verify the NAG methods. The simulation result shows the inverse solutions and six sets given joint angles are consistent. Additionally, the mean and maximum of the master–slave tracking experiment for the closed-form solution are 0.1486 and 0.4777 mm, respectively, while the mean and maximum of the master–slave tracking experiment for the compensation method are 0.3188 and 0.6394 mm, respectively. The experiments results demonstrate that the closed-form solution is superior to the compensation method. The results verify the proposed general closed-form inverse kinematics based on the NAG methods.

关键词： inverse kinematics     Paden–Kahan subproblems     three-joint subproblems     product of exponential     closed-form solution    

HTML PDF 收藏

and Innovate Environmental Protection Measures, Promote Green Protection of Cultural Relics in the Three

Fu-qing Liang,Yong-ping Sun

《工程管理前沿（英文）》 2014年 第1卷 第4期   页码 330-335 doi: 10.15302/J-FEM-2014055

摘要： The subject is implementing and innovating environmental protection measures, and promoting green protection of cultural relics in the Three Gorges area. This thesis states its significance and effect in the beginning, and then summarizes seven pieces of main practice, includes five pieces of main effect. In the end, this thesis produces some relevant conclusions and suggestions about the subject.

关键词： environmental science     the Three Gorges cultural relics     innovate environmental protection measures     green protection    

HTML PDF 收藏

Distributed energy management for networked microgrids in a three-phase unbalanced distribution network

《能源前沿（英文）》 2023年 第17卷 第3期   页码 446-446 doi: 10.1007/s11708-022-0851-7

摘要： Owing to increased penetration of three-phase and single-phase microgrids, distributed energy resources (DERs), and responsive loads, the maintenance of a three-phase balance by distribution networks is a significant challenge. Existing literature on distributed energy management for networked microgrids generally neglects the distribution network or employs a simplified phase balanced distribution network; thus, these evaluations are not applicable. Further, the underlying mutual coupling between the different phases of distribution feeders results in a more challenging situation. To solve this issue, this study sought to propose distributed energy management based on a three-phase unbalanced distribution network. Various three-phase or single-phase microgrids, utility-owned DERs, and responsive loads were coordinated through iteratively adjusted price signals. Based on the price signals received, the microgrid controllers (MCs) and distribution management system (DMS) updated the schedules of the DERs and responsive loads under their jurisdiction separately. The price signals were then updated according to the generation-load mismatch at each node and distributed to the corresponding MCs and DMS for the next iteration. The iteration continued until a sufficiently small generation-load mismatch was achieved at all nodes, that is, a balanced generation and load at all nodes under the agreed price signals. Considering a three-phase unbalanced distribution network, the price signals were determined per phase per node. Overall, the proposed distributed energy management coordinates microgrids, utility-owned DERs, responsive loads with guaranteed network constraints, and preserves the privacy of microgrid customers. This distributed energy management method was further demonstrated through various case studies on a three-phase networked microgrid test system.

关键词： distributed optimization     energy management     networked microgrids     three-phase distribution network     distributed energy resources    

HTML PDF 收藏

Three-dimensional fluorescence spectral characterization of soil dissolved organic matters in the fluctuatingwater-level zone of Kai County, Three Gorges Reservoir

Fang FANG, Yan YANG, Jinsong GUO, Hong ZHOU, Chuan FU, Zhe LI

《环境科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 426-434 doi: 10.1007/s11783-010-0264-4

摘要： Three-dimensional fluorescence spectroscopy was used to investigate the fluorescent properties of soil dissolved organic matter (DOM) in the water-level-fluctuation zone (WLFZ) of Kai County, Three Gorges Reservoir (TGR). Most of the soil DOM analyzed in this study was found to contain four fluorescence peaks. Peaks A and C represent humic-like fluorescence, whereas peaks B and D represent tryptophan-like fluorescence. Peaks E and F, which represent tyrosine-like fluorescence, only appeared in certain soils. Soil humus was the main source of DOM in soil, and higher concentration of soil DOM was found in the exposed soil than submerged soil. Compared to the peaks A and B, the fluorescence intensities of peaks C and D were strongly influenced by the fluctuating water level. Analysis of fluorescence intensities of different peaks in soil DOM showed that WLFZ soil was not contaminated significantly. Soil DOM contained at least two types of humic-like fluorescence groups and two types of protein-like fluorescence groups. The proportion of the content of peak A in soil organic matter was quite stable. The soil DOM in exposed soil had relatively high humification and aromaticity, and periodic submerging and exposure of soil had an impact on the humification of soil DOM.

关键词： water-level-fluctuation zone (WLFZ)     soil     dissolved organic matter (DOM)     three-dimensional fluorescence spectra    

HTML PDF 收藏

Development of rocking constraint device with vertical damping capacity for three-dimensional base-isolated

《结构与土木工程前沿（英文）》 2023年 第17卷 第3期   页码 350-367 doi: 10.1007/s11709-022-0923-0

摘要： A new rocking constraint device (RCD) is developed for three-dimensional (3D) base-isolated frame structures by connecting a custom-designed cylinder pair to provide vertical damping with replaceable damping components installed outside the cylinders when the superstructure undergoes translational motion, and rocking constraint capacity when the superstructure is susceptible to rocking. Theoretical formulas for calculating the damping and rocking constraint stiffness of the RCD are proposed. Two series of sinusoidal loading tests are conducted at different loading frequencies and amplitudes to verify the damping and rocking constraint performance of the RCD. The test results show that the cylinder without orifices on its piston can provide the desired damping with a replaceable damping component, and that the RCD can effectively suppress rocking. Although the vertical stiffness of an individual cylinder is affected by the location of the replaceable damping component and loading frequency, the average vertical stiffness of the two cylinders, which determines the rocking constraint stiffness of the RCD, is independent of the two factors. Comparisons of the test and theoretical results indicate that the errors of the proposed formulas for calculating the damping and rocking constraint stiffness of the RCD do not exceed 12.9% and 11.0%, respectively.

关键词： three-dimensional isolation     rocking behavior     rocking constraint device     replaceable damping component     sinusoidal test    

HTML PDF 收藏

Seasonal variation of nitrogen and phosphorus in Xiaojiang River—A tributary of the Three Gorges Reservoir

Zhe LI , Jinsong GUO , Man LONG , Fang FANG , Jinping SHENG , Hong ZHOU ,

《环境科学与工程前沿（英文）》 2009年 第3卷 第3期   页码 334-340 doi: 10.1007/s11783-009-0039-y

摘要： A yearlong monitoring program in the backwater area of Xiaojiang River (XBA) was launched in order to investigate the eutrophication of backwater areas in tributaries of the Yangtze River in the Three Gorges Reservoir (TGR) in China, starting after the impoundment water level of the TGR reached 156 m. From March 2007 to March 2008, the average concentration of total nitrogen (TN) and total phosphorus (TP) were (1553 ± 484) μg·L and (62 ± 31) μg·L, respectively. The mean value of chlorophyll was (9.07 ± 0.91) μg·L. The trophic level of XBA was meso-eutrophic, while the general nutrient limitation was phosphorus. The results indicated that XBA has a strong ability to purify itself and has non-point source pollution from terrestrial runoff. The variation of TN/TP ratio was caused by a variation in TN rather than in TP when TN/TP<22. N-fixation from cyanobacteria occurred and became an important process in overcoming the nitrogen deficit under a low TN/TP ratio. When TN/TP ≥ 22, the variation of TP affected the TN/TP ratio more significantly than TN. The increase of TP in XBA was caused mainly by particulate phosphorus, which could originate from a non-point source as adsorptive inorganic forms after heavy rainfall and surface runoff. An increase in the river’s flow could also contribute to an unstable environment for the growth of phytoplankton.

关键词： Three Gorges Reservoir     eutrophication     nitrogen     phosphorus     seasonal variation     chlorophyll    

HTML PDF 收藏

Fabrication of Si-based three-dimensional microbatteries: A review

Chuang YUE, Jing LI, Liwei LIN

《机械工程前沿（英文）》 2017年 第12卷 第4期   页码 459-476 doi: 10.1007/s11465-017-0462-x

摘要：

High-performance, Si-based three-dimensional (3D) microbattery systems for powering micro/nano-electromechanical systems and lab-on-chip smart electronic devices have attracted increasing research attention. These systems are characterized by compatible fabrication and integratibility resulting from the silicon-based technologies used in their production. The use of support substrates, electrodes or current collectors, electrolytes, and even batteries used in 3D layouts has become increasingly important in fabricating microbatteries with high energy, high power density, and wide-ranging applications. In this review, Si-based 3D microbatteries and related fabrication technologies, especially the production of micro-lithium ion batteries, are reviewed and discussed in detail in order to provide guidance for the design and fabrication.

关键词： three-dimensional (3D)     wafer-scale     Si-based anode     micro-LIBs     thin-film deposition    

HTML PDF 收藏

Performance investigation of artificial intelligence based controller for three phase four leg shunt

J. JAYACHANDRAN,R. MURALI SACHITHANANDAM

《能源前沿（英文）》 2015年 第9卷 第4期   页码 446-460 doi: 10.1007/s11708-015-0378-2

摘要： In this paper, the choice of power quality compensator is a DSTATCOM which constitutes a three phase four leg voltage source converter (VSC) with a DC capacitor. The control strategy proposed for the DSTATCOM is a neural network based one cycle control (OCC). This control strategy involves neural network block, digital circuits and linear elements, which eliminates the sensors required for sensing the load current and coupling inductor current in addition to the multiplier employed in the conventional method. The calculation of harmonic and reactive currents for the reference current generation is also eliminated, thus minimizing the complexity in the control strategy. The control strategy mitigates harmonic/reactive currents, ensures balanced and sinusoidal source current from the supply mains that are nearly in phase with the supply voltage, compensates neutral current, and maintains voltage across the capacitor under unbalanced source and load conditions. The performance of the DSTATCOM with the proposed artificial neural network (ANN) controllers is validated and investigated through simulations using Matlab software. The simulation results prove the efficacy of the proposed neural network based control strategy under varying source and load conditions.

关键词： neural network     DSTATCOM     neutral current mitigation     total harmonic distortion (THD)     three phase four wire distribution system     unbalanced and/or distorted source    

HTML PDF 收藏

The Environmental Impact of the Three Gorges Project and the Countermeasures

You-mei Lu,Cun-liang Shang

《工程管理前沿（英文）》 2014年 第1卷 第2期   页码 120-128 doi: 10.15302/J-FEM-2014019

摘要： The Three Gorges Project (TGP) is a landmark Chinese hydroelectric project with the goal of harnessing the Yangtze River and developing its water resources. Because of its enormous size and far-reaching influence, the project’s impact on the Yangtze River’s original ecological environment has been a concern to many people. This article examines the environmental effects of TGP with regard to reservoir-induced seismicity and bank stability, climate changes, sedimentation and bank erosion, the protection of aquatic species and water quality, and resettlement. Based on the operation monitoring data of TGP in 10 years (2003—2012), this article analyzes the tendency of reservoir-induced seismicity and bank stability, developing trend of sedimentation and bank erosion, the interplay between climate change and TGP, the distribution and cause of water contamination, the situation of aquatic species’ protection and living situation of resettled residents. At the same time, this article lists the comprehensive benefits of TGP in flood control, power generation, shipping, water supply, energy conservation and emission reduction. In the end, the authors deem that there is a dynamic and harmonious relationship between humankind and nature. The cognition about TGP will be progressed in practice, and harmonious relationship between the environment and TGP will be achieved through more practice.

关键词： the Three Gorges Project     ecosystem     aquatic species     water quality     flood control     disaster alleviation     energy saving     emission reduction    

HTML PDF 收藏

三峡枢纽水库运行调度

张曙光,周曼

《中国工程科学》 2011年 第13卷 第7期   页码 61-65

摘要：

三峡枢纽自2003年初步蓄水以来，工程建设进度、库区移民安置、地质灾害治理等较初步设计有所提前，泥沙淤积情况明显好于预期，三峡枢纽提前实现了分期蓄水目标。同时，随着运行条件的变化，三峡水库在汛限水位浮动、中小洪水调度、提前蓄水等方面进行了优化调度尝试，取得了较好的防洪、抗旱、航运、供水、生态等综合效益。尤其是2010年，汛期三峡水库实施了中小洪水调度，拦蓄洪量达到266亿m3，洪水资源利用充分；汛末采取了蓄水与汛期防洪运用相结合的方式，进一步利用汛末洪水资源，首次实现了175 m蓄水目标，枢纽开始全面发挥正常运行期的综合效益。

关键词： 运行调度     三峡枢纽    

HTML PDF 收藏

Design and calibration of a new high-definition three-dimensional laparoscopic system

Jia TANG,Li-qiang WANG,Bo YUAN,Hong JIANG,Qi-ming ZHU

《信息与电子工程前沿（英文）》 2015年 第16卷 第1期   页码 79-84 doi: 10.1631/FITEE.1400149

摘要： We present a high-definition (HD) 3D laparoscopic system including a dual channel optical system, two cameras, a camera control unit (CCU), and an HD 3D monitor. This laparoscopic system is capable of outputting dual high-definition videos and providing vivid 3D images. A modified pinhole camera model is used for camera calibration and a new method of depth measurement to improve precision. The average error of depth measurement measured by experiment (about 1.13 mm) was small in proportion to the large range in distance of the system (10-150 mm). The new method is applicable to any calibrated binocular vision system.

关键词： Dual optical channels     Three dimensional     Camera calibration     Pinhole model     Depth measurement     Laparoscopic system    

HTML PDF 收藏

Inner strain determination of three-dimensional braided preforms with co-braided optical fiber sensors

LI Xianghua, LIU Xiaohui, YUAN Shenfang

《机械工程前沿（英文）》 2008年 第3卷 第4期   页码 416-420 doi: 10.1007/s11465-008-0062-x

摘要： The experimental characterization of three-dimensional (3-D) braided composites is extremely important for their design and analysis. Because of their desirable attributes and outstanding performance, optical fiber sensors (OFSs) can be embedded to monitor mechanical properties of textile composites. This paper discusses two techniques to incorporate different OFSs into 3-D braided composite preforms. The operating principle of various sensor systems is first conducted. Experiments using Michelson interferometers, FBG sensors, and micro-bend sensors are performed to verify the concept of the proposed method. Strain curves of various OFSs tests are finally compared, and they all exhibit good linearity.

关键词： different     experimental characterization     three-dimensional     composite     micro-bend    

HTML PDF 收藏

Numerical simulation of three-dimensional turbulent flow in multistage axial compressor blade row

JIANG Jian, LIU Bo, WANG Yangang, NAN Xiangyi

《能源前沿（英文）》 2008年 第2卷 第3期   页码 320-325 doi: 10.1007/s11708-008-0041-2

摘要： Numerical simulation of three-dimensional turbulent flow in a multistage axial compressor blade row is conducted. A high resolution, third-order ENN scheme is adopted to catch the shockwave and simulate the turbulent flow correctly,

关键词： simulation     compressor     multistage     third-order     three-dimensional turbulent    

HTML PDF 收藏

METABOLITE VARIATION AND FLAVONOID REGULATORY NETWORKS IN FRESH SHOOTS OF TEA (CAMELLIA SINENSIS) OVER THREE

《农业科学与工程前沿（英文）》 2021年 第8卷 第2期

摘要：

Metabolites, especially secondary metabolites, are very important in the adaption of tea plants and the quality of tea products. Here, we focus on the seasonal variation in metabolites of fresh tea shoots and their regulatory mechanism at the transcriptional level. The metabolic profiles of fresh tea shoots of 10 tea accessions collected in spring, summer, and autumn were analyzed using ultra-performance liquid chromatography coupled with quadrupole-obitrap mass spectrometry. We focused on the metabolites and key genes in the phenylpropanoid/flavonoid pathway integrated with transcriptome analysis. Multivariate statistical analysis indicates that metabolites were distinctly different with seasonal alternation. Flavonoids, amino acids, organic acids and alkaloids were the predominant metabolites. Levels of most key genes and downstream compounds in the flavonoid pathway were lowest in spring but the catechin quality index was highest in spring. The regulatory pathway was explored by constructing a metabolite correlation network and a weighted gene co-expression network.

 

HTML PDF 收藏

标题 作者 时间 类型 操作

Simulation of cross-flow-induced vibration of tube bundle by surface vorticity method

WANG Fenghao, JIANG Gedong, Lin John Zhang

期刊论文

General closed-form inverse kinematics for arbitrary three-joint subproblems based on the product of

期刊论文

and Innovate Environmental Protection Measures, Promote Green Protection of Cultural Relics in the Three

Fu-qing Liang,Yong-ping Sun

期刊论文

Distributed energy management for networked microgrids in a three-phase unbalanced distribution network

期刊论文

Three-dimensional fluorescence spectral characterization of soil dissolved organic matters in the fluctuatingwater-level zone of Kai County, Three Gorges Reservoir

Fang FANG, Yan YANG, Jinsong GUO, Hong ZHOU, Chuan FU, Zhe LI

期刊论文

Development of rocking constraint device with vertical damping capacity for three-dimensional base-isolated

期刊论文

Seasonal variation of nitrogen and phosphorus in Xiaojiang River—A tributary of the Three Gorges Reservoir

Zhe LI , Jinsong GUO , Man LONG , Fang FANG , Jinping SHENG , Hong ZHOU ,

期刊论文

Fabrication of Si-based three-dimensional microbatteries: A review

Chuang YUE, Jing LI, Liwei LIN

期刊论文

Performance investigation of artificial intelligence based controller for three phase four leg shunt

J. JAYACHANDRAN,R. MURALI SACHITHANANDAM

期刊论文

The Environmental Impact of the Three Gorges Project and the Countermeasures

You-mei Lu,Cun-liang Shang

期刊论文

三峡枢纽水库运行调度

张曙光,周曼

期刊论文

Design and calibration of a new high-definition three-dimensional laparoscopic system

Jia TANG,Li-qiang WANG,Bo YUAN,Hong JIANG,Qi-ming ZHU

期刊论文

Inner strain determination of three-dimensional braided preforms with co-braided optical fiber sensors

LI Xianghua, LIU Xiaohui, YUAN Shenfang

期刊论文

Numerical simulation of three-dimensional turbulent flow in multistage axial compressor blade row

JIANG Jian, LIU Bo, WANG Yangang, NAN Xiangyi

期刊论文

METABOLITE VARIATION AND FLAVONOID REGULATORY NETWORKS IN FRESH SHOOTS OF TEA (CAMELLIA SINENSIS) OVER THREE

期刊论文