资源类型

期刊论文 495

会议视频 7

年份

2024 3

2023 31

2022 29

2021 39

2020 35

2019 25

2018 35

2017 18

2016 27

2015 20

2014 21

2013 21

2012 20

2011 20

2010 20

2009 23

2008 36

2007 34

2006 6

2005 3

展开 ︾

关键词

一阶分析法 2

应力状态 2

技术路线 2

数值模拟 2

机器学习 2

碳中和 2

ADV 1

ARMA模型 1

Arrhenius模型 1

CCUS 1

CFD 1

CO2利用 1

Cas12a 1

Chebyshev多项式 1

Colebrook隐式方程 1

HY-2 卫星 1

Hugoniot 1

ISO14000标准 1

LED,颜色漂移,光通量衰减,流明衰减 1

展开 ︾

检索范围:

排序: 展示方式:

Influence of boundary conditions and turntable speeds on the stability of hydrostatic oil cavity

Zhaomiao LIU, Chengyin ZHANG, Feng SHEN

《机械工程前沿(英文)》 2011年 第6卷 第3期   页码 359-368 doi: 10.1007/s11465-011-0222-2

摘要:

The flow, bearing, and carrying capacity of the cycloidal hydrostatic oil cavity in hydrostatic turntable systems are numerically simulated, considering the rotation speeds of a turntable from 0 to 5 m/s and different boundary conditions. The vortex effect is weakened, and the stability of the oil cavity is enhanced with the increase in lubricant viscosity. However, the increase in inlet speed, depth, and inlet radius of the oil cavity causes the vortex effect to increase and the stability of oil cavity to reduce. With the increase in the oil film thickness, the carrying capacity of the oil cavity diminishes. The oil cavity pressure increases along the direction of the motion of the turntable; it is distributed unevenly because of the rotation of the turntable. With the increase in turntable speed, the location and size of the vortex scope in the oil cavity flow field and the strength of the vortex near the entrance gradually weaken and move away from the entry. The distribution of pressure is determined by the locations of the vortex. When the vortex is close to the wall, the wall pressure increases at its location. Otherwise, the wall pressure decreases first and then increases after the center of the vortex.

关键词: hydrostatic oil cavity     flow state     oil cavity pressure     stability     vortex    

Numerical study of internal flow field and flow passage improvement of an inlet particle separator

Florian PAOLI, Tong WANG

《能源前沿(英文)》 2011年 第5卷 第4期   页码 386-397 doi: 10.1007/s11708-011-0156-8

摘要: By performing gas flow field numerical simulations for several inlet Reynolds numbers (from 2 × 10 to 9 × 10 ) and byflow ratios (from 10% to 20%), the present study has proposed to improve the flow passage of an inlet particle separator. An adjacent objective of the study is to lower pressure losses of the inlet particle separator (IPS). No particle has been included in the gas flow for a -epsilon turbulence model. The velocity distribution in different sections and the pressure coefficient along the duct have been analyzed, which indicates that there exist important low-velocity regions and vortices in the separation area. Therefore, the profile of streamlines along the original passage has been considered. This profile illustrated a vacuum region in the same area. All investigations suggest that the separation area is the most critical one for fulfilling the objective on pressure losses limitation. Then the flow passage improvement method has focused on the separation area. An improved shape has been designed in order to suit smoothly to the streamlines in this region. Similar numerical studies as those for the original shape have been conducted on this improved shape, confirming some considerable enhancements compared with the original shape. The significant vortices which appear in the original shape reduce in amount and size. Besides, pressure losses are greatly decreased in both outlets (up to 30% for high Reynolds number) and the flow is uniform at the main outlet. Subsequent engineering surveys could rely on expressions obtained for in both outlets which extend the pressure losses for a wide range of inlet Reynolds numbers. As a result, the numerical calculations demonstrate that the flow passage improvement method applied in this study has succeeded in designing a shape which enhances the flow behavior.

关键词: streamlines     pressure losses     flow passage improvement     inlet particle separator (IPS)    

Advances in tissue state recognition in spinal surgery: a review

Hao Qu, Yu Zhao

《医学前沿(英文)》 2021年 第15卷 第4期   页码 575-584 doi: 10.1007/s11684-020-0816-3

摘要: Spinal disease is an important cause of cervical discomfort, low back pain, radiating pain in the limbs, and neurogenic intermittent claudication, and its incidence is increasing annually. From the etiological viewpoint, these symptoms are directly caused by the compression of the spinal cord, nerve roots, and blood vessels and are most effectively treated with surgery. Spinal surgeries are primarily performed using two different techniques: spinal canal decompression and internal fixation. In the past, tactile sensation was the primary method used by surgeons to understand the state of the tissue within the operating area. However, this method has several disadvantages because of its subjectivity. Therefore, it has become the focus of spinal surgery research so as to strengthen the objectivity of tissue state recognition, improve the accuracy of safe area location, and avoid surgical injury to tissues. Aside from traditional imaging methods, surgical sensing techniques based on force, bioelectrical impedance, and other methods have been gradually developed and tested in the clinical setting. This article reviews the progress of different tissue state recognition methods in spinal surgery and summarizes their advantages and disadvantages.

关键词: spinal surgery     tissue state recognition     image     force sensing     bioelectrical impedance    

Effectiveness of state incentives for promoting wind energy: A panel data examination

Deepak SANGROYA,Jogendra NAYAK

《能源前沿(英文)》 2015年 第9卷 第3期   页码 247-258 doi: 10.1007/s11708-015-0364-8

摘要: Over the last decade, India has started to concentrate earnestly on renewable energy. The Indian government, as well as different state governments, are adopting policy instruments such as feed in tariff, captive consumption, renewable purchase obligation and generation based incentive etc. aimed at renewable energy development. This paper evaluates the effectiveness of state level incentives for the development of wind energy in India. Fixed effect panel data modelling technique of econometric analysis is used to analyse the data of 26 Indian states in 11 years. The results show that feed in tariff and captive consumption are the significant predictors of wind energy development. However, renewable purchase obligation does not affect wind energy significantly.

关键词: India     wind energy development     state incentives     econometric analysis     panel data    

Digital image correlation-based structural state detection through deep learning

《结构与土木工程前沿(英文)》 2022年 第16卷 第1期   页码 45-56 doi: 10.1007/s11709-021-0777-x

摘要: This paper presents a new approach for automatical classification of structural state through deep learning. In this work, a Convolutional Neural Network (CNN) was designed to fuse both the feature extraction and classification blocks into an intelligent and compact learning system and detect the structural state of a steel frame; the input was a series of vibration signals, and the output was a structural state. The digital image correlation (DIC) technology was utilized to collect vibration information of an actual steel frame, and subsequently, the raw signals, without further pre-processing, were directly utilized as the CNN samples. The results show that CNN can achieve 99% classification accuracy for the research model. Besides, compared with the backpropagation neural network (BPNN), the CNN had an accuracy similar to that of the BPNN, but it only consumes 19% of the training time. The outputs of the convolution and pooling layers were visually displayed and discussed as well. It is demonstrated that: 1) the CNN can extract the structural state information from the vibration signals and classify them; 2) the detection and computational performance of the CNN for the incomplete data are better than that of the BPNN; 3) the CNN has better anti-noise ability.

关键词: structural state detection     deep learning     digital image correlation     vibration signal     steel frame    

Biological pretreatment of corn stover by solid state fermentation of

Jian ZHANG, Xin REN, Wenqun CHEN, Jie BAO

《化学科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 146-151 doi: 10.1007/s11705-012-1220-6

摘要: Biological pretreatment is a promising way to overcome the biorecalcitrance of cleaving the supermolecular structure of lignocellulose by lignin degrading enzymes from microorganisms. Solid state fermentation of corn stover with the white-rot fungus was carried out and the efficiency of this pretreatment was evaluated. The enzymatic hydrolysis yield reached a maximum when the corn stover was biologically pretreated for nine days, and the hydrolysis yield decreased sharply if the solid state fermentation was carried out for more than nine days. A possible explanation for this sharp decrease is that not only the lignin degrading enzymes (LiP and MnP) were secreted, but also other metabolites, which were toxic or fatal to the hydrolysis enzymes resulting in the lower hydrolysis yield were generated during the prolonged period of biopretreatment. These results are useful to help determine the optimal timing and to understand the lignin structure and degradation mechanism in biological pretreatment processes.

关键词: biological pretreatment     Phanerochaete chrysosporium     solid state fermentation     biorecalcitrance     hydrolysis yield    

物质流分析的跟踪观察法

陆钟武

《中国工程科学》 2006年 第8卷 第1期   页码 18-25

摘要:

流动,是物质(如铜、铝等)流动和流体流动二者所具有的基本特征,基于这个论点,简要地回顾了流体力学中研究流体流动的两种方法,即拉格朗日法和欧拉法;相应地提出了物质流分析的两种方法,即跟踪观察法和定点观察法。由于前者在文献中未见报道,因此对它进行了重点说明。强调了物质流的跟踪观察法既适用于稳态物质流(产品产量不变),也适用于非稳态物质流(产品产量增长或下降)。以钢铁产品生命周期的铁流图为例,说明了物质流的跟踪模型。在引入了物质流的非稳度后,提出了物质流各项指标的计算式,以及它们之间的相互关系。以瑞典铅酸电池系统为对象,计算了其中铅流的各项指标,并进行了必要的分析。

关键词: 物质流的研究方法     物质流的跟踪观察法     物质流的基本公式     物质流的非稳度    

UPFC setting to avoid active power flow loop considering wind power uncertainty

Shenghu LI, Ting WANG

《能源前沿(英文)》 2023年 第17卷 第1期   页码 165-175 doi: 10.1007/s11708-020-0686-z

摘要: The active power loop flow (APLF) may be caused by impropriate network configuration, impropriate parameter settings, and/or stochastic bus powers. The power flow controllers, e.g., the unified power flow controller (UPFC), may be the reason and the solution to the loop flows. In this paper, the critical existence condition of the APLF is newly integrated into the simultaneous power flow model for the system and UPFC. Compared with the existing method of alternatively solving the simultaneous power flow and sensitivity-based approaching to the critical existing condition, the integrated power flow needs less iterations and calculation time. Besides, with wind power fluctuation, the interval power flow (IPF) is introduced into the integrated power flow, and solved with the affine Krawcyzk iteration to make sure that the range of active power setting of the UPFC not yielding the APLF. Compared with Monte Carlo simulation, the IPF has the similar accuracy but less time.

关键词: active power loop flow (APLF)     unified power flow controller (UPFC)     wind power uncertainty     interval power flow (IPF)    

Development of a constitutive model for rockfills and similar granular materials based on the disturbed state

Mehdi VEISKARAMI, Ali GHORBANI, Mohammadreza ALAVIPOUR

《结构与土木工程前沿(英文)》 2012年 第6卷 第4期   页码 365-378 doi: 10.1007/s11709-012-0178-2

摘要: Behavior of rockfills was investigated experimentally and theoretically. A series of standard triaxial compression tests were carried out on a quarried rockfill material at different stress levels. It was found that both the stress level and the shear stress ratio, like most of granular materials, controls the behavior of rockfill materials. At lower shear stress ratios the behavior is much more similar to a nonlinear elastic solid. When the shear stress goes further, the stress-strain curve shows an elasto-plastic behavior which suggests using the disturbed state concept to develop a constitutive model to predict the stress-strain behavior. The presented constitutive model complies reasonably with the experimental data.

关键词: constitutive model     granular material     rockfill     plasticity     disturbed state concept     stress level    

A novel flow electrode capacitive deionization device with spindle-shaped desalting chamber

《环境科学与工程前沿(英文)》 2023年 第18卷 第4期 doi: 10.1007/s11783-024-1800-y

摘要:

● A spindle-shaped influent chamber was designed and equipped in FCDI system.

关键词: Spindle-shaped chamber     Desalination performance     Flow electrode capacitive deionization    

Machine learning and neural network supported state of health simulation and forecasting model for lithium-ion

《能源前沿(英文)》 doi: 10.1007/s11708-023-0891-7

摘要: As the intersection of disciplines deepens, the field of battery modeling is increasingly employing various artificial intelligence (AI) approaches to improve the efficiency of battery management and enhance the stability and reliability of battery operation. This paper reviews the value of AI methods in lithium-ion battery health management and in particular analyses the application of machine learning (ML), one of the many branches of AI, to lithium-ion battery state of health (SOH), focusing on the advantages and strengths of neural network (NN) methods in ML for lithium-ion battery SOH simulation and prediction. NN is one of the important branches of ML, in which the application of NNs such as backpropagation NN, convolutional NN, and long short-term memory NN in SOH estimation of lithium-ion batteries has received wide attention. Reports so far have shown that the utilization of NN to model the SOH of lithium-ion batteries has the advantages of high efficiency, low energy consumption, high robustness, and scalable models. In the future, NN can make a greater contribution to lithium-ion battery management by, first, utilizing more field data to play a more practical role in health feature screening and model building, and second, by enhancing the intelligent screening and combination of battery parameters to characterize the actual lithium-ion battery SOH to a greater extent. The in-depth application of NN in lithium-ion battery SOH will certainly further enhance the science, reliability, stability, and robustness of lithium-ion battery management.

关键词: machine learning     lithium-ion battery     state of health     neural network     artificial intelligence    

Simulation of horizontal slug-flow pneumatic conveying with kinetic theory

GU Zhengmeng, GUO Liejin

《能源前沿(英文)》 2007年 第1卷 第3期   页码 336-340 doi: 10.1007/s11708-007-0050-6

摘要: Wavelike slug-flow is a representative flow type in horizontal pneumatic conveying. Kinetic theory was introduced to establish a 3D kinetic numerical model for wavelike slug gas-solid flow in this paper. Wavelike motion of particulate slugs in horizontal pipes was numerically investigated. The formation and motion process of slugs and settled layer were simulated. The characteristics of the flow, such as pressure drop, air velocity distribution, slug length and settled layer thickness, and the detailed changing characteristics of slug length and settled layer thickness with air velocity were obtained. The results indicate that kinetic theory can represent the physical characteristics of the non-suspension dense phase flow of wavelike slug pneumatic conveying. The experiment in this paper introduced a new idea for the numerical calculation of slug-flow pneumatic conveying.

关键词: velocity distribution     detailed     slug-flow     gas-solid     theory    

Characterization and comparison of organic functional groups effects on electrolyte performance for vanadium redox flow

《化学科学与工程前沿(英文)》 2023年 第17卷 第9期   页码 1221-1230 doi: 10.1007/s11705-023-2298-8

摘要: The vanadium redox flow battery with a safe and capacity-controllable large-scale energy storage system offers a new method for the sustainability. In this case, acetic acid, methane sulfonic acid, sulfonic acid, amino methane sulfonic acid, and taurine are used to overcome the low electrolyte energy density and stability limitations, as well as to investigate the effects of various organic functional groups on the vanadium redox flow battery. When compared to the pristine electrolyte (0.22 Ah, 5.0 Wh·L–1, 85.0%), the results show that taurine has the advantage of maintaining vanadium ion concentrations, discharge capacity (1.43 Ah), energy density (33.9 Wh·L–1), and energy efficiency (90.5%) even after several cycles. The acetic acid electrolyte is more conducive to the low-temperature stability of the V(II) electrolyte (177 h at −25 °C) than pristine (82 h at −2 °C). The –SO3H group, specifically the coaction of the –NH2 and –SO3H groups, improves electrolyte stability. The –NH2 and –COOH additive groups improved conductivity and electrochemical activity.

关键词: vanadium redox flow battery     functional groups     organic additives     energy density     stability    

Firm Innovation Systems: Perspectives of Researches on State-owned Key Enterprises

Jin Chen,Shu-fang Huang,Qing-rui Xu

《工程管理前沿(英文)》 2015年 第2卷 第1期   页码 64-70 doi: 10.15302/J-FEM-2015017

摘要: Based on the origin of the innovation theory and the technological innovation models of Rothwell, this paper puts forward four-generations of evolutionary models using the firm innovation system: “Internal R&D-Oriented Innovation System”, “Internal and External Collaborative Innovation System”, “Highly Strategic-Oriented Innovation System” and “Ecological Innovation System”. This paper dwells on the characteristics and relationship between each innovation system, and the role in the enterprise innovation especially the State-owned Key Enterprises innovation, so as to provide a theoretical and practical basis for the design and improvement of the State-owned Key Enterprises innovation system.

关键词: firm innovation system     state-owned key enterprises     ecology     evolution    

Modeling and analysis of steady-state vibration induced by backlash in servo rotary table

Xiao YANG,Dun LU,Sanli LIU,Jun ZHANG,Wanhua ZHAO

《机械工程前沿(英文)》 2015年 第10卷 第1期   页码 43-47 doi: 10.1007/s11465-015-0327-0

摘要:

Backlash cannot be always avoided in mechanical systems because of wear or looseness. Steady-state vibration may be induced by backlash in closed loop feed drive systems. This paper presents a mathematical model of a servo rotary table, considering the effect of backlash. The accuracy of this model is verified by an experiment. The influences of the parameters, such as position controller gain, velocity controller gain, load and the magnitude of backlash, on steady-state vibration are discussed. The steady-state vibration amplitude increases with the position controller gain, load and the magnitude of backlash. The steady-state vibration frequency increases with the position controller gain and the velocity controller gain, while an increase in load leads to a decrease in the frequency.

关键词: backlash     servo rotary table     steady-state vibration    

标题 作者 时间 类型 操作

Influence of boundary conditions and turntable speeds on the stability of hydrostatic oil cavity

Zhaomiao LIU, Chengyin ZHANG, Feng SHEN

期刊论文

Numerical study of internal flow field and flow passage improvement of an inlet particle separator

Florian PAOLI, Tong WANG

期刊论文

Advances in tissue state recognition in spinal surgery: a review

Hao Qu, Yu Zhao

期刊论文

Effectiveness of state incentives for promoting wind energy: A panel data examination

Deepak SANGROYA,Jogendra NAYAK

期刊论文

Digital image correlation-based structural state detection through deep learning

期刊论文

Biological pretreatment of corn stover by solid state fermentation of

Jian ZHANG, Xin REN, Wenqun CHEN, Jie BAO

期刊论文

物质流分析的跟踪观察法

陆钟武

期刊论文

UPFC setting to avoid active power flow loop considering wind power uncertainty

Shenghu LI, Ting WANG

期刊论文

Development of a constitutive model for rockfills and similar granular materials based on the disturbed state

Mehdi VEISKARAMI, Ali GHORBANI, Mohammadreza ALAVIPOUR

期刊论文

A novel flow electrode capacitive deionization device with spindle-shaped desalting chamber

期刊论文

Machine learning and neural network supported state of health simulation and forecasting model for lithium-ion

期刊论文

Simulation of horizontal slug-flow pneumatic conveying with kinetic theory

GU Zhengmeng, GUO Liejin

期刊论文

Characterization and comparison of organic functional groups effects on electrolyte performance for vanadium redox flow

期刊论文

Firm Innovation Systems: Perspectives of Researches on State-owned Key Enterprises

Jin Chen,Shu-fang Huang,Qing-rui Xu

期刊论文

Modeling and analysis of steady-state vibration induced by backlash in servo rotary table

Xiao YANG,Dun LU,Sanli LIU,Jun ZHANG,Wanhua ZHAO

期刊论文