资源类型

期刊论文 1568

年份

2024 1

2023 108

2022 119

2021 105

2020 99

2019 91

2018 92

2017 90

2016 66

2015 83

2014 56

2013 55

2012 39

2011 52

2010 57

2009 50

2008 52

2007 64

2006 53

2005 38

展开 ︾

关键词

指标体系 12

系统工程 10

开放的复杂巨系统 7

系统集成 7

钱学森 7

技术体系 6

仿真 5

系统科学 5

人工智能 4

可持续发展 4

战略性新兴产业 4

智能制造 4

标准体系 4

电力系统 4

电动汽车 4

系统 4

Agent 3

互联网 + 3

农产品 3

展开 ︾

检索范围:

排序: 展示方式:

An autonomous system for thermal convection of viscoelastic fluids in a porous layer using a thermal

Qi WEI, Xiaohui ZHANG

《能源前沿(英文)》 2010年 第4卷 第4期   页码 507-516 doi: 10.1007/s11708-010-0017-x

摘要: Thermal convection of viscoelastic fluids saturating a horizontal porous layer heated from below is analyzed using a thermal nonequilibrium model to take account of the interphase heat transfer between the fluid and the solid. The viscoelastic character of the flow is considered by a modified Darcy’s law. An autonomous system with five differential equations is deduced by applying the truncated Galerkin expansion to the momentum and heat transfer equations. The effects of interphase heat transfer on the thermal convection of viscoelastic fluids in a porous medium are analyzed and discussed. The results show that the weak interphase heat transfer tends to stabilize the steady convection.

关键词: thermal convection     porous media     viscoelastic fluid     thermal nonequilibrium model    

Electrochemical performance of thermally-grown SiO

X. D. HUANG, X. F. GAN, Q. A. HUANG, J. Z. YANG

《能源前沿(英文)》 2018年 第12卷 第2期   页码 225-232 doi: 10.1007/s11708-018-0556-0

摘要: Direct integration of lithium-ion battery (LIB) with electronic devices on the same Si substrate can significantly miniaturize autonomous micro systems. For achieving direct integration, a barrier layer is essential to be inserted between LIB and the substrate for blocking Li diffusion. In this paper, the feasibility of thermal SiO film as the barrier layer is investigated by electrochemical characterization and X-ray photoelectron spectroscopy (XPS). Due to the negligible side reactions of thermal SiO with electrolyte, the solid electrolyte interphase (SEI) layer formed on the surface of the barrier layer is thin and the SEI content mainly consists of hydrocarbon together with slight polyethylene oxide (PEO), Li PO F , and Li CO . Although 8-nm thermal SiO effectively prevents the substrate from alloying with Li , the whole film changes to Li silicate after electrochemical cycling due to the irreversible chemical reactions of SiO with electrolyte. This degrades the performance of the barrier layer against the electrolyte penetration, thus leading to the existence of Li (in the form of F-Si-Li) and solvent decompositions (with the products of hydrocarbon and PEO) near the barrier layer/substrate interface. Moreover, it is found that the reaction kinetics of thermal SiO with electrolyte decrease significantly with increasing the SiO thickness and no reactions are found in the bulk of the 30-nm SiO film. Therefore, thermal SiO with an appropriate thickness is a promising barrier layer for direct integration.

关键词: autonomous micro system     direct integration     barrier layer     thermal SiO2 film     X-ray photoelectron spectroscopy (XPS)    

A smooth co-ordination control for a hybrid autonomous power system (HAPS) with battery energy storage

C. K. ARAVIND,G. SARAVANA ILANGO,C. NAGAMANI

《能源前沿(英文)》 2015年 第9卷 第1期   页码 31-42 doi: 10.1007/s11708-015-0347-9

摘要: The standalone hybrid power system constitutes a synchronous generator driven by a diesel engine, renewable energy source (wind) apart from a battery energy storage system. A coherent control strategy to regulate the voltage and frequency of the standalone grid is proposed in this paper. The system is simulated using Matlab/Simulink for preliminary validation and further tested on a laboratory prototype which involves a TMS320LF2407A DSP controller to digitally implement the control strategy. The dynamic behavior of the system is perused through the direct connection of an induction machine. The control strategy is verified for step changes in load and variation in wind power.

关键词: standalone hybrid power system     battery energy storage system (BESS)     power conversion    

Diagnosis and therapy of lacrimal system diseases by micro lacrimal endoscope

Nan XIANG, Weikun HU, Jing YUAN, Guigang LI, Haixia LIU

《医学前沿(英文)》 2009年 第3卷 第1期   页码 113-117 doi: 10.1007/s11684-009-0001-1

摘要: The lacrimal endoscope is applied to the diagnosis and therapy of the disorders of the lacrimal system in combination with laser or micro drills under orthophoria. The changes of mucous membranes, the characteristics of pathological changes and the predilection sites of lacrimal system diseases were initially approached. One hundred and forty six pairs of eyes of 128 patients with lacrimal system disease were observed by the lacrimal endoscope in the Ophthalmology Department of Tongji Hospital from June 2006 to March 2007. The dynamic changes in mucous membranes, lesion sites, secreted substances and formation of membrane could be observed under orthophoria. Combined with laser or micro drill, the endoscope was applied to the therapy of lacrimal system disorders and the difference before and after the treatment was observed. Results are as follows: (1) The examination and therapy using the lacrimal endoscope were completed under topical anesthesia in 122 patients, and 6 patients of neonatorum dacryocystitis were examined and treated under general anaesthesia. All patients reported painless. (2) Sharp images of the lacrimal system were obtained by the endoscope. Normal lacrimal mucosal membrane was smooth and light pink, expanded and unobstructed during irrigation. In chronic dacryocystitis patients, the inhomogeneous colour of mucosal membranes was red and white, with different degrees of fibrotic membranes at the superior, middle and inferior parts of the nasolacrimal canals and secreted substances at sac could be observed. The lacrimal ducts could not be expanded and obstructed during irrigation. The patients with lacrimal system obstruction had different extents of membrane formation, and stenosis or complete obstruction of the lacrimal duct could be observed, and the corresponding mucosal membrane was not smooth which could not be expanded and obstructed during irrigation. (3) After the treatment by the endoscope combined with laser or micro drill, the major proliferation of the membrane disappeared and the lacrimal duct was unobstructed during irrigation. The cure rate and effective rate were 80.1% and 93.1%, respectively. The lacrimal endoscope is a new method in the diagnosis of lacrimal system diseases. Through a combination with laser or micro drill to carry out the therapy under orthophoria, it will bring a great change to the diagnosis and therapy of lacrimal system diseases.

关键词: lacrimal apparatus diseases     endoscopes    

Technological development of multi-energy complementary system based on solar PVs and MGT

Xiaojing LV, Yu WENG, Xiaoyi DING, Shilie WENG, Yiwu WENG

《能源前沿(英文)》 2018年 第12卷 第4期   页码 509-517 doi: 10.1007/s11708-018-0598-3

摘要:

The complementary micro-energy network system consisting of solar photovoltaic power generation (solar PVs) and micro-gas turbine (MGT), which not only improves the absorption rate and reliability of photovoltaic power, but also has the advantages of low emission, high efficiency, and good fuel adaptability, has become one of the most promising distributed power systems in the field of micro grid. According to the development of current technology and the demand of actual work, this research described the domestic and foreign development of micro-energy network system based on solar PVs and MGT. Moreover, it analyzed the challenges and future development regarding the micro-energy network system in planning and design, energy utilization optimization and dispatching management, and system maintenance, respectively. Furthermore, it predicted the future development of the key technology of the multi-energy complementary system. These results will be beneficial for the progress of this field both in theory and practice.

关键词: renewable energy     solar photovoltaic power generation     micro gas turbine     multi-energy complementary system     micro-energy network    

Experimental investigation of a novel micro gas turbine with flexible switching function for distributedpower system

Xiaojing LV, Weilun ZENG, Xiaoyi DING, Yiwu WENG, Shilie WENG

《能源前沿(英文)》 2020年 第14卷 第4期   页码 790-800 doi: 10.1007/s11708-020-0691-2

摘要: Micro gas turbine (MGT) is widely used in small-scale distributed power systems because of its low emissions and fuel flexibility. However, the under-utilization of its exhaust heat and the low electric efficiency are the main bottlenecks that restrict its application. Additionally, the flexible switching between the power generated by the MGT and the power grid is also a key factor for keeping the secure operation of a distributed power station. Therefore, this paper conducted some experimental investigations of a 30 kW MGT to provide reference solutions for the above issues. This MGT is located at Shanghai Jiao Tong University (SJTU), which is designed by the Gas Turbine Research Institute of SJTU, and is manufactured by a turbo-machinery factory in Chongqing, China. The demonstration prototype is mainly composed of a single stage centrifugal compressor, a radial turbine, a combustor, a high-speed permanent magnet generator, and a control system. The results show that the MGT can achieve steady operation at a low rotational speed from 10000 r/min to 34000 r/min in the case of using oil lubricated bearings, which can greatly reduce the economic cost compared with the use of air bearings. At the same time, the ignition success rate of combustion chamber (CC) reaches 98% at a low rotational speed, and a wide range of stable combustion area can be obtained, because of the novel design method of combustor by referencing the way applied in an axial flow aero-engine. The MGT generating set can achieve functions, such as starting up, ignition, stable operation, loaded operation, grid-connection and stopping. This system also can realize flexibly switching from the start motor mode to the generator mode, and from grid-connected mode to off-grid mode, because the innovative multi-state switching control system is adopted. The above research work can make our state master independent intellectual property rights of micro gas turbine, rather than continue to be subject to the technological monopoly of the developed states, which can provide theoretical and experimental support for the industrialization of MGT in China.

关键词: gas turbine     flexible switching system     control system     distributed power system     emission test    

导航星座自主导航技术研究

帅平,曲广吉,陈忠贵

《中国工程科学》 2006年 第8卷 第3期   页码 22-30

摘要:

导航星座自主导航日益成为新一代卫星导航系统的主要研究方向。在系统地论述导航星座自主导航的信息处理流程的基础上,重点提出了导航星座自主导航的关键技术,包括卫星星历与时钟参数的长期预报技术、星间测距与通信链路的建立和维持技术、星座卫星自主时间同步技术、星座卫星自主星历更新技术、自主导航信息处理的鲁棒滤波技术、星座整体旋转建模技术,以及地球自转及极移参数的长期预报技术。详细分析了关键技术实施途径,论证了相关数学模型。最后,对星座卫星自主时间同步与星历更新算法进行了系统仿真,结果表明:通过星载滤波器处理星间双向测量数据,不断地修正卫星时钟和星历参数,能够高精度实现星座卫星时间同步和星历更新,初步展示星座自主导航信息处理流程及其关键技术算法的合理性和可行性。

关键词: 导航星座     自主导航     信息处理流程     系统仿真    

An autonomous miniature wheeled robot based on visual feedback control

CHEN Haichu

《机械工程前沿(英文)》 2007年 第2卷 第2期   页码 197-200 doi: 10.1007/s11465-007-0033-7

摘要: Using two micro-motors, a novel omni-direction miniature wheeled robot is designed on the basis of the bi-corner driving principle. The robot takes advantage of the Bluetooth technology to wirelessly transmit data at a short distance. Its position and omni-direction motion are precise. A Charge Coupled Device (CCD) camera is used for measuring and for visual navi gation. A control system is developed. The precision of the position is 0.5 mm, the resolution is about 0.05 mm, and the maximum velocity is about 52 mm/s. The visual navigation and control system allow the robot to navigate and track the target and to accomplish autonomous locomotion.

关键词: measuring     distance     autonomous locomotion     advantage     navigation    

Strengthening of polysulfone membranes using hybrid mixtures of micro- and nano-scale modifiers

Peyman P. Selakjani, Majid Peyravi, Mohsen Jahanshahi, Hamzeh Hoseinpour, Ali S. Rad, Soodabeh Khalili

《化学科学与工程前沿(英文)》 2018年 第12卷 第1期   页码 174-183 doi: 10.1007/s11705-017-1670-y

摘要: Polysulfone (PSf) membranes were modified by either a new organic modifier (sulfonated poly(ether sulfide sulfone), SPESS) or a traditional modifier (rice hulk). These membranes were further reinforced with either multi-walled carbon nanotubes (MWCNTs) or silica nanoparticles. Having a dye rejection of 98.46%, the reinforced membranes increased more than 50% in strength but no change in solution flux was observed. The morphological and roughness studies were conducted using scanning electron microscopy and atomic force microscopy. Moreover, the PSF membranes were also characterized by differential scanning calorimetry. Modifying the membranes with organic modifier or nanofiller increases the glass transition temperature ( ). The highest and strength were observed for the PSf-SPESS-MWCNT membrane. SPESS decreases surface roughness but MWCNT increases roughness on the nanoscale. All membranes show a bimodal pore size distribution, whereas the PSf-SPESS-MWCNT membrane exhibits a relatively uniform distribution of macroscopic and microscopic pores.

关键词: polysulfone membrane     mechanical properties     micro- and nano-modification     binary and ternary system     dye removal    

Toward autonomous mining: design and development of an unmanned electric shovel via point cloud-based

《机械工程前沿(英文)》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0686-2

摘要: With the proposal of intelligent mines, unmanned mining has become a research hotspot in recent years. In the field of autonomous excavation, environmental perception and excavation trajectory planning are two key issues because they have considerable influences on operation performance. In this study, an unmanned electric shovel (UES) is developed, and key robotization processes consisting of environment modeling and optimal excavation trajectory planning are presented. Initially, the point cloud of the material surface is collected and reconstructed by polynomial response surface (PRS) method. Then, by establishing the dynamical model of the UES, a point to point (PTP) excavation trajectory planning method is developed to improve both the mining efficiency and fill factor and to reduce the energy consumption. Based on optimal trajectory command, the UES performs autonomous excavation. The experimental results show that the proposed surface reconstruction method can accurately represent the material surface. On the basis of reconstructed surface, the PTP trajectory planning method rapidly obtains a reasonable mining trajectory with high fill factor and mining efficiency. Compared with the common excavation trajectory planning approaches, the proposed method tends to be more capable in terms of mining time and energy consumption, ensuring high-performance excavation of the UES in practical mining environment.

关键词: autonomous excavation     unmanned electric shovel     point cloud     excavation trajectory planning    

智能无人自主系统发展趋势 Review

Tao ZHANG,Qing LI,Chang-shui ZHANG,Hua-wei LIANG,Ping LI,Tian-miao WANG,Shuo LI,Yun-long ZHU,Cheng WU

《信息与电子工程前沿(英文)》 2017年 第18卷 第1期   页码 68-85 doi: 10.1631/FITEE.1601650

摘要: 智能无人自主系统是人工智能的重要应用之一,其发展可大大推动人工智能技术的创新。本文通过其主要成就介绍了智能无人自主系统的发展趋势。并且,本文将相关技术分成了7个领域,包括人工智能技术、无人车、无人机、服务机器人、空间机器人、海洋机器人和无人车间/智能工厂。本文对每个领域的发展趋势进行了介绍。

关键词: 智能无人自主系统;无人车;人工智能;机器人学;发展趋势    

Analysis and control of micro-stepping characteristics of ultrasonic motor

Ning CHEN, Jieji ZHENG, Xianliang JIANG, Shixun FAN, Dapeng FAN

《机械工程前沿(英文)》 2020年 第15卷 第4期   页码 585-599 doi: 10.1007/s11465-019-0577-3

摘要: Micro-stepping motion of ultrasonic motors satisfies biomedical applications, such as cell operation and nuclear magnetic resonance, which require a precise compact-structure non-magnetization positioning device. When the pulse number is relatively small, the stopping characteristics have a non-negligible effect on the entire stepwise process. However, few studies have been conducted to show the rule of the open-loop stepwise motion, especially the shutdown stage. In this study, the modal differences of the shutdown stage are found connected with amplitude and velocity at the turn-off instant. Changes of the length in the contact area and driving zone as well as the input currents, vibration states, output torque, and axial pressure are derived by a simulation model to further explore the rules. The speed curves and vibration results in functions of different pulse numbers are compared, and the stepwise motion can be described by a two-stage two-order transfer function. A test workbench based on the Field Programmable Gate Array is built for acquiring the speed, currents, and feedback voltages of the startup–shutdown stage accurately with the help of its excellent synchronization performances. Therefore, stator vibration, rotor velocity, and terminal displacements under different pulse numbers can be compared. Moreover, the two-stage two-order model is identified on the stepwise speed curves, and the fitness over 85% between the simulation and test verifies the model availability. Finally, with the optimization of the pulse number, the motor achieves 3.3 µrad in clockwise and counterclockwise direction.

关键词: ultrasonic motor     stepping characteristics     pulse number control     synchronous acquisition system     precise positioning    

Performance analysis of cogeneration systems based on micro gas turbine (MGT), organic Rankine cycle

Zemin BO, Kai ZHANG, Peijie SUN, Xiaojing LV, Yiwu WENG

《能源前沿(英文)》 2019年 第13卷 第1期   页码 54-63 doi: 10.1007/s11708-018-0606-7

摘要: In this paper, the operation performance of three novel kinds of cogeneration systems under design and off-design condition was investigated. The systems are MGT (micro gas turbine) + ORC (organic Rankine cycle) for electricity demand, MGT+ ERC (ejector refrigeration cycle) for electricity and cooling demand, and MGT+ ORC+ ERC for electricity and cooling demand. The effect of 5 different working fluids on cogeneration systems was studied. The results show that under the design condition, when using R600 in the bottoming cycle, the MGT+ ORC system has the lowest total output of 117.1 kW with a thermal efficiency of 0.334, and the MGT+ ERC system has the largest total output of 142.6 kW with a thermal efficiency of 0.408. For the MGT+ ORC+ ERC system, the total output is between the other two systems, which is 129.3 kW with a thermal efficiency of 0.370. For the effect of different working fluids, R123 is the most suitable working fluid for MGT+ ORC with the maximum electricity output power and R600 is the most suitable working fluid for MGT+ ERC with the maximum cooling capacity, while both R600 and R123 can make MGT+ ORC+ ERC achieve a good comprehensive performance of refrigeration and electricity. The thermal efficiency of three cogeneration systems can be effectively improved under off-design condition because the bottoming cycle can compensate for the power decrease of MGT. The results obtained in this paper can provide a reference for the design and operation of the cogeneration system for distributed energy systems (DES).

关键词: cogeneration system     different working fluids     micro gas turbine (MGT)     organic Rankine cycle (ORC)     ejector refrigeration cycle (ERC)    

Extended model predictive control scheme for smooth path following of autonomous vehicles

《机械工程前沿(英文)》 2022年 第17卷 第1期   页码 4-4 doi: 10.1007/s11465-021-0660-4

摘要: This paper presents an extended model predictive control (MPC) scheme for implementing optimal path following of autonomous vehicles, which has multiple constraints and an integrated model of vehicle and road dynamics. Road curvature and inclination factors are used in the construction of the vehicle dynamic model to describe its lateral and roll dynamics accurately. Sideslip, rollover, and vehicle envelopes are used as multiple constraints in the MPC controller formulation. Then, an extended MPC method solved by differential evolution optimization algorithm is proposed to realize optimal smooth path following based on driving path features. Finally, simulation and real experiments are carried out to evaluate the feasibility and the effectiveness of the extended MPC scheme. Results indicate that the proposed method can obtain the smooth transition to follow the optimal drivable path and satisfy the lateral dynamic stability and environmental constraints, which can improve the path following quality for better ride comfort and road availability of autonomous vehicles.

关键词: autonomous vehicles     vehicle dynamic modeling     model predictive control     path following     optimization algorithm    

Flexible micro flow sensor for micro aerial vehicles

Rong ZHU, Ruiyi QUE, Peng LIU

《机械工程前沿(英文)》 2017年 第12卷 第4期   页码 539-545 doi: 10.1007/s11465-017-0427-0

摘要:

This article summarizes our studies on micro flow sensors fabricated on a flexible polyimide circuit board by a low-cost hybrid process of thin-film deposition and circuit printing. The micro flow sensor has merits of flexibility, structural simplicity, easy integrability with circuits, and good sensing performance. The sensor, which adheres to an object surface, can detect the surface flow around the object. In our study, we install the fabricated micro flow sensors on micro aerial vehicles (MAVs) to detect the surface flow variation around the aircraft wing and deduce the aerodynamic parameters of the MAVs in flight. Wind tunnel experiments using the sensors integrated with the MAVs are also conducted.

关键词: micro flow sensor     flexible sensor     surface flow sensing     aerodynamic parameter     micro aerial vehicle (MAV)    

标题 作者 时间 类型 操作

An autonomous system for thermal convection of viscoelastic fluids in a porous layer using a thermal

Qi WEI, Xiaohui ZHANG

期刊论文

Electrochemical performance of thermally-grown SiO

X. D. HUANG, X. F. GAN, Q. A. HUANG, J. Z. YANG

期刊论文

A smooth co-ordination control for a hybrid autonomous power system (HAPS) with battery energy storage

C. K. ARAVIND,G. SARAVANA ILANGO,C. NAGAMANI

期刊论文

Diagnosis and therapy of lacrimal system diseases by micro lacrimal endoscope

Nan XIANG, Weikun HU, Jing YUAN, Guigang LI, Haixia LIU

期刊论文

Technological development of multi-energy complementary system based on solar PVs and MGT

Xiaojing LV, Yu WENG, Xiaoyi DING, Shilie WENG, Yiwu WENG

期刊论文

Experimental investigation of a novel micro gas turbine with flexible switching function for distributedpower system

Xiaojing LV, Weilun ZENG, Xiaoyi DING, Yiwu WENG, Shilie WENG

期刊论文

导航星座自主导航技术研究

帅平,曲广吉,陈忠贵

期刊论文

An autonomous miniature wheeled robot based on visual feedback control

CHEN Haichu

期刊论文

Strengthening of polysulfone membranes using hybrid mixtures of micro- and nano-scale modifiers

Peyman P. Selakjani, Majid Peyravi, Mohsen Jahanshahi, Hamzeh Hoseinpour, Ali S. Rad, Soodabeh Khalili

期刊论文

Toward autonomous mining: design and development of an unmanned electric shovel via point cloud-based

期刊论文

智能无人自主系统发展趋势

Tao ZHANG,Qing LI,Chang-shui ZHANG,Hua-wei LIANG,Ping LI,Tian-miao WANG,Shuo LI,Yun-long ZHU,Cheng WU

期刊论文

Analysis and control of micro-stepping characteristics of ultrasonic motor

Ning CHEN, Jieji ZHENG, Xianliang JIANG, Shixun FAN, Dapeng FAN

期刊论文

Performance analysis of cogeneration systems based on micro gas turbine (MGT), organic Rankine cycle

Zemin BO, Kai ZHANG, Peijie SUN, Xiaojing LV, Yiwu WENG

期刊论文

Extended model predictive control scheme for smooth path following of autonomous vehicles

期刊论文

Flexible micro flow sensor for micro aerial vehicles

Rong ZHU, Ruiyi QUE, Peng LIU

期刊论文