资源类型

期刊论文 150

年份

2023 10

2022 14

2021 19

2020 6

2019 1

2018 14

2017 7

2016 4

2015 5

2014 8

2013 7

2012 8

2011 7

2010 2

2009 5

2008 4

2007 7

2006 5

2005 2

2004 1

展开 ︾

关键词

并联机构 3

新一代智能制造 3

分解水 2

基本范式 2

大规模并行处理 2

并行推进 2

融合发展 2

BSP) 1

CBC-MAC模式 1

CCM模式 1

CMAC神经网络 1

CTR模式 1

GPU;密度峰值;聚类;并行计算 1

HeNe激光器 1

MCMC 1

MINLP 1

MSJPDA 1

PAM 1

PMAC模式 1

展开 ︾

检索范围:

排序: 展示方式:

Dynamic failure analysis on granite under uniaxial impact compressive load

ZHAI Yue, MA Guowei, HU Changming, ZHAO Junhai

《结构与土木工程前沿(英文)》 2008年 第2卷 第3期   页码 253-260 doi: 10.1007/s11709-008-0042-6

摘要: High strain-rate uniaxial compressive loading tests were produced in the modified split Hopkinson pressure bar (SHPB) with pulse shaper on granite samples. It was shown that the failure of the granite cylinder was typical tensile splitting failure mode by sudden splitting parallel to the direction of uniaxial compressive loading at different strain rates. Besides, it was concluded that not only the strength of granite increased, but also the fragment size decreased and the fragment numbers increased with the increasing strain rate. To quantitatively analyze the failure phenomena, the numerical calculation based on a dynamic interacting sliding microcrack model was adopted to investigate the influence of microcrack with the different initial crack length, crack angle, crack space and friction coefficient on the macro-mechanical properties of granite under different strain rates. Accordingly, the strain-dependency of the compression strength and the fragmentation degree of granite was explained reasonably.

关键词: numerical calculation     coefficient     cylinder     splitting parallel     strain-dependency    

Generation of enhanced stability of SnO/In(OH)/InP for photocatalytic water splitting by SnO protection

《能源前沿(英文)》 2021年 第15卷 第3期   页码 710-720 doi: 10.1007/s11708-021-0764-x

摘要: InP shows a very high efficiency for solar light to electricity conversion in solar cell and may present an expectation property in photocatalytic hydrogen evolution. However, it suffers serious corrosion in water dispersion. In this paper, it is demonstrated that the stability and activity of the InP-based catalyst are effectively enhanced by applying an anti-corrosion SnO layer and In(OH)3 transition layer, which reduces the crystal mismatch between SnO and InP and increases charge transfer. The obtained Pt/SnO/In(OH)3/InP exhibits a hydrogen production rate of 144.42 µmol/g in 3 h under visible light illumination in multi-cycle tests without remarkable decay, 123 times higher than that of naked In(OH)3/InP without any electron donor under visible irradiation.

关键词: SnO/In(OH)3/InP photocatalyst     enhanced activity and stability for water splitting     corrosion inhibition     enhancing charge transfer and decreasing crystal mismatch    

Approaching the commercial threshold of solar water splitting toward hydrogen by III-nitrides nanowires

《能源前沿(英文)》 doi: 10.1007/s11708-023-0870-z

摘要: Approaching the commercial threshold of solar water splitting toward hydrogen by III-nitrides nanowires

关键词: threshold solar water     splitting hydrogen III    

An overview and recent advances in electrocatalysts for direct seawater splitting

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1408-1426 doi: 10.1007/s11705-021-2102-6

摘要: In comparison to pure water, seawater is widely accepted as an unlimited resource. The direct seawater splitting is economical and eco-friendly, but the key challenges in seawater, especially the chlorine-related competing reactions at the anode, seriously hamper its practical application. The development of earth-abundant electrocatalysts toward direct seawater splitting has emerged as a promising strategy. Highly efficient electrocatalysts with improved selectivity and stability are of significance in preventing the interference of side reactions and resisting various impurities. This review first discusses the macroscopic understanding of direct seawater electrolysis and then focuses on the strategies for rational design of electrocatalysts toward direct seawater splitting. The perspectives of improved electrocatalysts to solve emerging challenges and further development of direct seawater splitting are also provided.

关键词: seawater splitting     electrocatalysts     oxygen evolution reaction     hydrogen evolution reaction     chlorine chemistry    

Acoustic emissions evaluation of the dynamic splitting tensile properties of steel fiber reinforced concrete

《结构与土木工程前沿(英文)》   页码 1341-1356 doi: 10.1007/s11709-023-0988-4

摘要: This study empirically investigated the influence of freeze–thaw cycling on the dynamic splitting tensile properties of steel fiber reinforced concrete (SFRC). Brazilian disc splitting tests were conducted using four loading rates (0.002, 0.02, 0.2, and 2 mm/s) on specimens with four steel fiber contents (0%, 0.6%, 1.2%, and 1.8%) subjected to 0 and 50 freeze–thaw cycles. The dynamic splitting tensile damage characteristics were evaluated using acoustic emission (AE) parameter analysis and Fourier transform spectral analysis. The results quantified using the freeze–thaw damage factor defined in this paper indicate that the degree of damage to SFRC caused by freeze–thaw cycling was aggravated with increasing loading rate but mitigated by increasing fiber content. The percentage of low-frequency AE signals produced by the SFRC specimens during loading decreased with increasing loading rate, whereas that of high-frequency AE signals increased. Freeze–thaw action had little effect on the crack types observed during the early and middle stages of the loading process; however, the primary crack type observed during the later stage of loading changed from shear to tensile after the SFRC specimens were subjected to freeze–thaw cycling. Notably, the results of this study indicate that the freeze–thaw damage to SFRC reduces AE signal activity at low frequencies.

关键词: steel fiber reinforced concrete     freeze–thaw cycling     Brazilian disc splitting test     acoustic emission technique     dynamic splitting tensile acoustic emission properties    

Enhanced photocatalytic water splitting with surface defective SrTiO

Junying LIU, Zhidong WEI, Wenfeng SHANGGUAN

《能源前沿(英文)》 2021年 第15卷 第1期   页码 700-709 doi: 10.1007/s11708-021-0735-2

摘要: Surface reconstructed SrTiO nanocrystals were synthesized by a thermal treatment process in presence of NaBH and SrTiO nanocrystals. The surface reconstruction of SrTiO nanocrystals is attributed to the introduction of surface oxygen vacancies or Ti sites (such as Ti and Ti ) during the hydrogenation treatment process. The light absorption and the charge transfer ability of SrTiO nanocrystals are simultaneously enhanced due to surface oxygen vacancies or Ti sites (such as Ti and Ti ), which are beneficial to photocatalytic water splitting. Meanwhile, these defects also change the redox potential of the photocatalysts. Since there existed a synergistic effect between the three, the ratio of hydrogen to oxygen production was also regulated.

关键词: SrTiO3     surface reconstruction     oxygen vacancies     photocatalytic water splitting    

polarization enhanced bismuth ferrate photoelectrode: fabrication and boosted photoelectrochemical water splitting

《能源前沿(英文)》 2021年 第15卷 第3期   页码 781-790 doi: 10.1007/s11708-021-0782-8

摘要: In this paper, the fabrication of a highly orientated Bi2Fe4O9 (BFO) photoelectrode in the presence of two-dimensional (2D) graphene oxide (GO) was reported. It was found that the GO can be used as a template for controlling the growth of BFO, and the nanoplate composites of BFO/reduced graphene oxide (RGO) with a high orientation can be fabricated. The thickness of the nanoplates became thinner as the ratio of GO increased. As a result, the ferroelectric spontaneous polarization unit arranges itself in the space in a periodic manner, leading to the formation of a polarization field along a special direction. Therefore, the created built-in electric field of the nanoplate composites of BFO/RGO is improved upon the increase of the amount of RGO. As expected, carrier separation is enhanced by the built-in electric field, therefore substantially enhancing the photoelectrochemical (PEC) activity of water splitting compared to pure BFO under the irradiation of visible-light.

关键词: bismuth ferrate     ferroelectric polarisation     photoelectrochemical (PEC) water splitting     graphene oxide (GO)     high orientation    

Ga(X)N/Si nanoarchitecture: An emerging semiconductor platform for sunlight-powered water splitting toward

《能源前沿(英文)》 doi: 10.1007/s11708-023-0881-9

摘要: Sunlight-powered water splitting presents a promising strategy for converting intermittent and virtually unlimited solar energy into energy-dense and storable green hydrogen. Since the pioneering discovery by Honda and Fujishima, considerable efforts have been made in this research area. Among various materials developed, Ga(X)N/Si (X = In, Ge, Mg, etc.) nanoarchitecture has emerged as a disruptive semiconductor platform to split water toward hydrogen by sunlight. This paper introduces the characteristics, properties, and growth/synthesis/fabrication methods of Ga(X)N/Si nanoarchitecture, primarily focusing on explaining the suitability as an ideal platform for sunlight-powered water splitting toward green hydrogen fuel. In addition, it exclusively summarizes the recent progress and development of Ga(X)N/Si nanoarchitecture for photocatalytic and photoelectrochemical water splitting. Moreover, it describes the challenges and prospects of artificial photosynthesis integrated device and system using Ga(X)N/Si nanoarchitectures for solar water splitting toward hydrogen.

关键词: Ga(X)N/Si nanoarchitecture     artificial photosynthesis     water splitting     solar toward hydrogen    

Enhanced photoelectrochemical water splitting with a donor-acceptor polyimide

《能源前沿(英文)》 doi: 10.1007/s11708-023-0910-8

摘要: Polyimide (PI) has emerged as a promising organic photocatalyst owing to its distinct advantages of high visible-light response, facile synthesis, molecularly tunable donor-acceptor structure, and excellent physicochemical stability. However, the synthesis of high-quality PI photoelectrode remains a challenge, and photoelectrochemical (PEC) water splitting for PI has been less studied. Herein, the synthesis of uniform PI photoelectrode films via a simple spin-coating method was reported, and their PEC properties were investigated using melamine as donor and various anhydrides as acceptors. The influence of the conjugate size of aromatic unit (phenyl, biphenyl, naphthalene, perylene) of electron acceptor on PEC performance were studied, where naphthalene-based PI photoelectrode exhibited the highest photocurrent response. This is resulted from the unification of wide-range light absorption, efficient charge separation and transport, and strong photooxidation capacity. This paper expands the material library of polymer films for PEC applications and contributes to the rational design of efficient polymer photoelectrodes.

关键词: polyimide (PI) film     photoelectrochemistry     band structure engineering     aromatic unit    

design on photoelectrodes and devices to boost photoelectrochemical performance of solar-driven water splitting

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 777-798 doi: 10.1007/s11705-022-2148-0

摘要: As an eco-friendly, efficient, and low-cost technique, photoelectrochemical water splitting has attracted growing interest in the production of clean and sustainable hydrogen by the conversion of abundant solar energy. In the photoelectrochemical system, the photoelectrode plays a vital role in absorbing the energy of sunlight to trigger the water splitting process and the overall efficiency depends largely on the integration and design of photoelectrochemical devices. In recent years, the optimization of photoelectrodes and photoelectrochemical devices to achieve highly efficient hydrogen production has been extensively investigated. In this paper, a concise review of recent advances in the modification of nanostructured photoelectrodes and the design of photoelectrochemical devices is presented. Meanwhile, the general principles of structural and morphological factors in altering the photoelectrochemical performance of photoelectrodes are discussed. Furthermore, the performance indicators and first principles to describe the behaviors of charge carriers are analyzed, which will be of profound guiding significance to increasing the overall efficiency of the photoelectrochemical water splitting system. Finally, current challenges and prospects for an in-depth understanding of reaction mechanisms using advanced characterization technologies and potential strategies for developing novel photoelectrodes and advanced photoelectrochemical water splitting devices are demonstrated.

关键词: photoelectrochemical water splitting     photoelectrodes     hydrogen production     charge separation     catalytic mechanism    

State-of-the-art progress in overall water splitting of carbon nitride based photocatalysts

Bing LUO, Yuxin ZHAO, Dengwei JING

《能源前沿(英文)》 2021年 第15卷 第1期   页码 600-620 doi: 10.1007/s11708-021-0737-0

摘要: Converting solar energy into hydrogen (H ) by photocatalytic water splitting is a promising approach to simultaneously address the increasing energy demand and environmental issues. Half decade has passed since the discovery of photo-induced water splitting phenomenon on TiO photoanode, while the solar to H efficiency is still around 1%, far below the least industrial requirement. Therefore, developing efficient photocatalyst with a high energy conversion efficiency is still one of the main tasks to be overcome. Graphitic carbon nitride (g-C N ) is just such an emerging and potential semiconductor. Therefore, in this review, the state-of-the-art advances in g-C N based photocatalysts for overall water splitting were summarized in three sections according to the strategies used, and future challenges and new directions were discussed.

关键词: photocatalysis     overall water splitting     carbon nitride     hydrogen    

Enhanced performance of NiF/BiVO photoanode for photoelectrochemical water splitting

《能源前沿(英文)》 2021年 第15卷 第3期   页码 760-771 doi: 10.1007/s11708-021-0781-9

摘要: The serious surface charge recombination and fatigued photogenerated carriers transfer of the BiVO4 photoanode restrict its photoelectrochemical (PEC) water splitting performance. In this work, nickel fluoride (NiF2) is applied to revamp pure BiVO4 photoanode by using a facile electrodeposition method. As a result, the as-prepared NiF2/BiVO4 photoanode increases the dramatic photocurrent density by approximately 180% compared with the pristine BiVO4 photoanode. Furthermore, the correlative photon-to-current conversion efficiency, the charge injection, and the separation efficiency, as well as the hydrogen generation of the composite photoanode have been memorably enhanced due to the synergy of NiF2 and BiVO4. This study may furnish a dependable guidance in fabricating the fluoride-based compound/semiconductor composite photoanode system.

关键词: BiVO4     NiF2     heterojunction     photoelectrochemical water splitting    

Structural optimization of typical rigid links in a parallel kinematic machine

Xinjun LIU, Zhidong LI, Xiang CHEN

《机械工程前沿(英文)》 2011年 第6卷 第3期   页码 344-353 doi: 10.1007/s11465-011-0227-x

摘要:

The motion dynamics and accuracy of parallel kinematic machines largely depend on the weights and rigidity of typical rigid links. Therefore, these parts should be designed in such a way that they are light but rigid. This work employs the techniques of topology and size optimization to design two typical rigid links of a parallel kinematic machine (PKM) and subsequently obtains applicable structures for them. The calculation models are established, and a new algorithm called the Guide-Weight method is introduced to solve topology optimization problems. The commercial software Ansys is used to perform size optimization.

关键词: topology optimization     size optimization     parallel kinematic machine (PKM)    

Optimal design of a linkage–cam mechanism-based redundantly actuated parallel manipulator

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 451-467 doi: 10.1007/s11465-021-0634-6

摘要: A redundantly actuated parallel manipulator (RAPM) with mixed translational and rotational degrees of freedom (DOFs) is challenged for its dimensionally homogeneous Jacobian modeling and optimal design of architecture. In this paper, a means to achieve redundant actuation by adding kinematic constraints is introduced, which reduces the DOFs of the end-effector (EE). A generic dimensionally homogeneous Jacobian is developed for this type of RAPMs, which maps the generalized velocities of three points on the EE to the joint velocities. A new optimization algorithm derived from this dimensionally homogeneous Jacobian is proposed for the optimal design of this type of RAPMs. As an example, this paper presents a spatial RAPM involving linkages and cam mechanisms. This RAPM has 4 DOFs and 6 translational actuations. The linkage lengths and the position of the universal joints of the RAPM are optimized based on the dimensionally homogeneous Jacobian.

关键词: redundant actuation     parallel manipulator     linkage–cam mechanism     Jacobian     optimal design    

Variable identification and automatic tuning of the main module of a servo system of parallel mechanism

YANG Zhiyong, XU Meng, HUANG Tian, NI Yanbing

《机械工程前沿(英文)》 2007年 第2卷 第1期   页码 82-88 doi: 10.1007/s11465-007-0014-x

摘要: The variables of the main module of a servo system for miniature reconfigurable parallel mechanism were identified and automatically tuned. With the reverse solution module of the translation, the module with the exerted translation joint was obtained, which included the location, velocity and acceleration of the parallelogram carriage-branch. The rigid dynamic reverse model was set as the virtual work principle. To identify the variables of the servo system, the triangle-shaped input signal with variable frequency was adopted to overcome the disadvantages of the pseudo-random number sequence, i.e., making the change of the vibration amplitude of the motor dramatically, easily impact the servo motor and make the velocity loop open and so on. Moreover, all the variables including the rotary inertia of the servo system were identified by the additive mass. The overshoot and rise time were the optimum goals, the limited changing load with the attitude was considered, and the range of the controller variables in the servo system was identified. The results of the experiments prove that the method is accurate.

关键词: acceleration     reconfigurable parallel     additive     sequence     parallel mechanism    

标题 作者 时间 类型 操作

Dynamic failure analysis on granite under uniaxial impact compressive load

ZHAI Yue, MA Guowei, HU Changming, ZHAO Junhai

期刊论文

Generation of enhanced stability of SnO/In(OH)/InP for photocatalytic water splitting by SnO protection

期刊论文

Approaching the commercial threshold of solar water splitting toward hydrogen by III-nitrides nanowires

期刊论文

An overview and recent advances in electrocatalysts for direct seawater splitting

期刊论文

Acoustic emissions evaluation of the dynamic splitting tensile properties of steel fiber reinforced concrete

期刊论文

Enhanced photocatalytic water splitting with surface defective SrTiO

Junying LIU, Zhidong WEI, Wenfeng SHANGGUAN

期刊论文

polarization enhanced bismuth ferrate photoelectrode: fabrication and boosted photoelectrochemical water splitting

期刊论文

Ga(X)N/Si nanoarchitecture: An emerging semiconductor platform for sunlight-powered water splitting toward

期刊论文

Enhanced photoelectrochemical water splitting with a donor-acceptor polyimide

期刊论文

design on photoelectrodes and devices to boost photoelectrochemical performance of solar-driven water splitting

期刊论文

State-of-the-art progress in overall water splitting of carbon nitride based photocatalysts

Bing LUO, Yuxin ZHAO, Dengwei JING

期刊论文

Enhanced performance of NiF/BiVO photoanode for photoelectrochemical water splitting

期刊论文

Structural optimization of typical rigid links in a parallel kinematic machine

Xinjun LIU, Zhidong LI, Xiang CHEN

期刊论文

Optimal design of a linkage–cam mechanism-based redundantly actuated parallel manipulator

期刊论文

Variable identification and automatic tuning of the main module of a servo system of parallel mechanism

YANG Zhiyong, XU Meng, HUANG Tian, NI Yanbing

期刊论文