期刊文献+
共找到30篇文章
< 1 2 >
每页显示 20 50 100
日本最新制动加力系统
1
作者 张维福 《汽车与配件》 1998年第21期21-21,共1页
日本的丰田和日产两大汽车公司在贸易和技术上竞争非常激烈,但是他们对一件事情的意见一致:某些人由于身体条件的局限性,在紧急情况下不能充分接合制动器,从而使自己和他人处于危险之中。这个问题在日本和东南亚国家也许更加突出,因为... 日本的丰田和日产两大汽车公司在贸易和技术上竞争非常激烈,但是他们对一件事情的意见一致:某些人由于身体条件的局限性,在紧急情况下不能充分接合制动器,从而使自己和他人处于危险之中。这个问题在日本和东南亚国家也许更加突出,因为这些国家的人民身材较小,而且体质比其它国家的人民弱。 丰田汽车公司对年龄在18~70岁之间的208名驾车者进行了调查,结果表明其中53%的人能够胜任使用制动器,42%的人不足以胜任,而余下的5%仅能勉强地使用它们。为解决这个问题。 展开更多
关键词 汽车 制动加力系统 日本
下载PDF
发动机加力系统发明背景
2
作者 孙连成 《黑龙江交通科技》 1996年第4期35-38,共4页
发动机加力系统发明背景本发明是一个利用高压液体为汽车发动机加力的系统。在汽车减速和刹车时,低压液体以高压的形式被存储起来,而后在汽车加速时,该部分液体释放出高压来驱动车轮。已经发现一种简单、易于安装、操纵和保养、使用... 发动机加力系统发明背景本发明是一个利用高压液体为汽车发动机加力的系统。在汽车减速和刹车时,低压液体以高压的形式被存储起来,而后在汽车加速时,该部分液体释放出高压来驱动车轮。已经发现一种简单、易于安装、操纵和保养、使用工业化零部件、相当便宜的实用系统,... 展开更多
关键词 汽车发动机 液压马达 信号电路 加力系统 动力输出轴 液压泵 储存器 控制装置 信号开关 刹车机构
下载PDF
航空发动机加力控制系统典型故障研究 被引量:10
3
作者 杨福刚 黄猛 范世新 《航空发动机》 2012年第3期34-37,57,共5页
为分析采用电子-液压机械式调节的某型航空发动机加力控制系统的故障部位,以加力状态控制的调节规律和工作原理为基础,建立了以"不能正确进入加力状态"为顶事件的故障树。按照该故障树进行发动机试车典型故障分析,使该故障有... 为分析采用电子-液压机械式调节的某型航空发动机加力控制系统的故障部位,以加力状态控制的调节规律和工作原理为基础,建立了以"不能正确进入加力状态"为顶事件的故障树。按照该故障树进行发动机试车典型故障分析,使该故障有效排除。 展开更多
关键词 加力控制系统 故障树 航空发动机 故障分析
下载PDF
加力调节器故障检测在线测试系统设计
4
作者 王一舒 陆小龙 +1 位作者 黄玉波 张涛 《航空发动机》 北大核心 2021年第3期91-96,共6页
喷口-加力调节器故障检测涉及的零部件来自不同的令号、附件号及机型,工艺要求各不相同,传统纸质履历方式造成加力调节器故障检测现场零件检测数据管理复杂、反馈及时性差、质量追溯困难。针对这些问题,提出基于信息化测试设备及检测技... 喷口-加力调节器故障检测涉及的零部件来自不同的令号、附件号及机型,工艺要求各不相同,传统纸质履历方式造成加力调节器故障检测现场零件检测数据管理复杂、反馈及时性差、质量追溯困难。针对这些问题,提出基于信息化测试设备及检测技术,以网络数据库实时传递反馈检测数据的智能测试方式满足加力调节器故障检测维修中零部件内径、外径参数测量、数据管理、质量追溯的需求。通过生产者/消费者设计模式使用LabVIEW语言实现气动量仪、数显比较仪、脚踏开关与工控机间的通信,提高了测量数据读取与处理效率。为验证系统性能,在维修现场对系统样机进行了测试。结果表明:该系统操作简便,运行稳定可靠,能显著提高检测效率,有效降低现场测试数据的管理难度。 展开更多
关键词 喷口-加力调节器 故障检测 加力控制系统 测试系统 航空发动机
下载PDF
军用航空发动机加力控制系统的研究和发展 被引量:9
5
作者 朴英 张绍基 《推进技术》 EI CAS CSCD 北大核心 2001年第2期89-91,96,共4页
对国外军用航空发动机加力控制系统的研制现状和今后的发展方向进行了归纳和分析 ,讨论了加力燃油泵、加力燃油调节器、加力燃油计量和分配装置、喷口油源泵和喷口调节器的技术特点、方案选择和研究动向。全权限数字电子控制技术的研究... 对国外军用航空发动机加力控制系统的研制现状和今后的发展方向进行了归纳和分析 ,讨论了加力燃油泵、加力燃油调节器、加力燃油计量和分配装置、喷口油源泵和喷口调节器的技术特点、方案选择和研究动向。全权限数字电子控制技术的研究和应用 ,将会对军用航空发动机的研究和发展产生巨大的影响。 展开更多
关键词 航空发动机 加力燃烧室 燃料系统 发动机控制 加力控制系统
下载PDF
航空涡扇发动机加力供油系统排故测试技术
6
作者 董英萃 《计算机测量与控制》 2020年第5期5-9,共5页
针对传统测试技术对航空涡扇发动机可测量参数较少,导致排故测试精准度较低的问题;提出了航空涡扇发动机加力供油系统排故测试技术;依据航空涡扇发动机加力供油系统结构,分析加力供油系统工作原理;通过分析加力外涵计量活门位置的异常... 针对传统测试技术对航空涡扇发动机可测量参数较少,导致排故测试精准度较低的问题;提出了航空涡扇发动机加力供油系统排故测试技术;依据航空涡扇发动机加力供油系统结构,分析加力供油系统工作原理;通过分析加力外涵计量活门位置的异常波动情况,确定加力外涵供油流量不足原因;列出故障树,根据故障原因分析结果,确认线性可变差动变压器摩擦力异常;研究线性可变差动变压器结构,使用F150型号的内窥镜观察变压器底部存在的金属堆积物,完成加力供油系统计量活门摆动排故测试;根据加力启动供油装置,分析具体故障原因,并计算启动过程中损失的压力大小,获取航空涡扇发动机工作喷嘴燃油流量;对比分析模拟关闭电磁活门时的油泵出口压力和实际压力,排除加力供油系统启动点火故障;由实验结果可知,该技术测试精准度较高,最高可达到0.9815,为系统稳定工作裕度提供支持。 展开更多
关键词 航空 涡扇发动机 加力供油系统 排故测试
下载PDF
某涡喷发动机加力数控系统的仿真和试车验证
7
作者 马立明 张绍基 《航空发动机》 1993年第3期1-13,共13页
关键词 涡喷发动机 加力数控系统 仿真
下载PDF
加力燃油计量装置的AMESim仿真研究 被引量:17
8
作者 王彬 赵皓岑 叶志锋 《航空发动机》 2014年第5期62-66,共5页
为获得加力燃油系统数字化仿真与性能验证平台,采用功能划分的方法分析了典型计量装置的功能模块,确定了伺服阀-随动活塞、计量活门-等压差活门是决定计量装置动态特性的主要组成部分,对其进行了数学建模。鉴于获得的数学模型描述系统... 为获得加力燃油系统数字化仿真与性能验证平台,采用功能划分的方法分析了典型计量装置的功能模块,确定了伺服阀-随动活塞、计量活门-等压差活门是决定计量装置动态特性的主要组成部分,对其进行了数学建模。鉴于获得的数学模型描述系统特性时缺乏相关元件特性参数的设计依据,建立了由计量活门、等压差活门、电液伺服单元等组成计量装置的AMESim模型,计算主要结构参数后仿真分析了其稳态和动态特性。结果表明:基于控制系统构成的加力燃油计量装置功能划分与数学建模可为仿真研究与参数设计提供指导,AMESim可用于动态过程仿真与性能预测。 展开更多
关键词 加力燃油系统 计量装置 等压差活门 动态特性 参数设计 控制
下载PDF
关于某型发动机断应急放油时加力信号灯闪烁故障分析
9
作者 于鹏 《内燃机与配件》 2017年第2期81-83,共3页
某型发动机在断开应急放油开关后,出现接通加力信号,此故障涉及发动机调节系统较多,故障较为典型。本文主要通过对该型发动机应急放油系统和加力起动系统的工作原理进行分析研究,总结能够影响应急放油系统工作的主要因素,提出解决故障... 某型发动机在断开应急放油开关后,出现接通加力信号,此故障涉及发动机调节系统较多,故障较为典型。本文主要通过对该型发动机应急放油系统和加力起动系统的工作原理进行分析研究,总结能够影响应急放油系统工作的主要因素,提出解决故障的方法,提高排故效率,同时也为以后该类型故障的排除提供帮助。 展开更多
关键词 应急放油 加力起动系统 接通加力信号 加力
下载PDF
人工神经网络在某型航空发动机故障诊断中的应用 被引量:1
10
作者 孙涛 李本威 +1 位作者 李忠东 马力 《航空发动机》 2004年第3期52-55,共4页
介绍了神经网络在航空发动机故障诊断中的应用 ,给出了利用神经网络方法进行航空发动机故障诊断的方法和步骤及需注意的关键问题 。
关键词 神经网络 故障诊断 航空发动机 加力系统 非线性映射器
下载PDF
人眼角膜的双向加载实验研究
11
作者 赵梅生 孙力 董心 《试验技术与试验机》 2000年第1期71-72,共2页
由于生物软组织本身的结构特点,使其测试方法有别于一般工程中经常采用的方法,特别是二维实验,更不易实现。国外采用的是带有视频尺寸分析仪的二维加载装置,而国内目前尚不具备这种条件。故我们在现有设备的基础上,研制了一台简易生物... 由于生物软组织本身的结构特点,使其测试方法有别于一般工程中经常采用的方法,特别是二维实验,更不易实现。国外采用的是带有视频尺寸分析仪的二维加载装置,而国内目前尚不具备这种条件。故我们在现有设备的基础上,研制了一台简易生物软组织二维加力系统。实践证明效果还是较好的。 展开更多
关键词 人眼角膜 双向加载 二维加力系统 实验研究
下载PDF
System-Level Modeling and Simulation of Force-Balance MEMS Accelerometers 被引量:1
12
作者 张宇峰 刘晓为 陈伟平 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第5期917-922,共6页
This paper presents two approaches for system-level simulation of force-balance accelerometers. The derivation of the system-level model is elaborated and simulation results are obtained from the implementation of tho... This paper presents two approaches for system-level simulation of force-balance accelerometers. The derivation of the system-level model is elaborated and simulation results are obtained from the implementation of those strategies on the fabricated silicon force-balance MEMS accelerometer. The mathematical model presented is implemented in VHDL- AMS and SIMULINK TM,respectively. The simulation results from the two approaches are compared and show a slight difference. Using VHDL-AMS is flexible,reusable,and more accurate. But there is not a mature solver developed for the language and this approach takes more time, while the simulation model can be easily built and quickly evaluated using SIMULINK. 展开更多
关键词 MEMS force-balance accelerometers system-level simulation mathematical model
下载PDF
发动机加力燃油调节系统故障树分析
13
作者 佟永军 王绍忠 +1 位作者 薛庆增 王威 《航空维修与工程》 2011年第4期52-54,共3页
以涡扇发动机中较为典型的加力燃油调节系统为例,在发动机修理过程中对系统进行故障树分析,确定引起故障事件的底事件和故障模式,找出系统薄弱环节并采取有针对性的措施,提高发动机的修理质量。
关键词 故障树 加力燃油调节系统 自动分析
原文传递
An Effective Differential Fault Analysis on the Serpent Cryptosystem in the Internet of Things 被引量:1
14
作者 LI Wei TAO Zhi +4 位作者 GU Dawu SUN Li QU Bo LIU Zhiqiang LIU Ya 《China Communications》 SCIE CSCD 2014年第6期129-139,共11页
Due to the strong attacking ability, fast speed, simple implementation and other characteristics, differential fault analysis has become an important method to evaluate the security of cryptosystem in the Internet of ... Due to the strong attacking ability, fast speed, simple implementation and other characteristics, differential fault analysis has become an important method to evaluate the security of cryptosystem in the Internet of Things. As one of the AES finalists, the Serpent is a 128-bit Substitution-Permutation Network(SPN) cryptosystem. It has 32 rounds with the variable key length between 0 and 256 bits, which is flexible to provide security in the Internet of Things. On the basis of the byte-oriented model and the differential analysis, we propose an effective differential fault attack on the Serpent cryptosystem. Mathematical analysis and simulating experiment show that the attack could recover its secret key by introducing 48 faulty ciphertexts. The result in this study describes that the Serpent is vulnerable to differential fault analysis in detail. It will be beneficial to the analysis of the same type of other iterated cryptosystems. 展开更多
关键词 internet of things CRYPTANALYSIS differential fault analysis serpent.
下载PDF
Discussion of skill improvement in marine ecosystem dynamic models based on parameter optimization and skill assessment 被引量:1
15
作者 沈程程 石洪华 +2 位作者 刘永志 李芬 丁德文 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第4期683-696,共14页
Marine ecosystem dynamic models(MEDMs) are important tools for the simulation and prediction of marine ecosystems. This article summarizes the methods and strategies used for the improvement and assessment of MEDM ski... Marine ecosystem dynamic models(MEDMs) are important tools for the simulation and prediction of marine ecosystems. This article summarizes the methods and strategies used for the improvement and assessment of MEDM skill, and it attempts to establish a technical framework to inspire further ideas concerning MEDM skill improvement. The skill of MEDMs can be improved by parameter optimization(PO), which is an important step in model calibration. An effi cient approach to solve the problem of PO constrained by MEDMs is the global treatment of both sensitivity analysis and PO. Model validation is an essential step following PO, which validates the effi ciency of model calibration by analyzing and estimating the goodness-of-fi t of the optimized model. Additionally, by focusing on the degree of impact of various factors on model skill, model uncertainty analysis can supply model users with a quantitative assessment of model confi dence. Research on MEDMs is ongoing; however, improvement in model skill still lacks global treatments and its assessment is not integrated. Thus, the predictive performance of MEDMs is not strong and model uncertainties lack quantitative descriptions, limiting their application. Therefore, a large number of case studies concerning model skill should be performed to promote the development of a scientifi c and normative technical framework for the improvement of MEDM skill. 展开更多
关键词 marine ecosystem dynamic models global optimization CALIBRATION model skill VALIDATION UNCERTAINTY
下载PDF
Analysis of the Power System from an Electron Beam Accelerator and the Correlation with the Theoretical Dosimetry for Radiation Processing
16
作者 Samir Luiz Somessari Elizabeth S. Ribeiro Somessari Carlos Gaia da Silveira Wilson Aparecido Parejo Calvo 《Journal of Physical Science and Application》 2015年第5期356-366,共11页
Dynamitron DC1500/25/04 type EBA (Electron beam accelerator), model JOB 188, was manufactured by IBA Industrial (Radiation Dynamics, Inc.) and installed at IPEN-CNEN/SP, in 1978. The technical specifications of th... Dynamitron DC1500/25/04 type EBA (Electron beam accelerator), model JOB 188, was manufactured by IBA Industrial (Radiation Dynamics, Inc.) and installed at IPEN-CNEN/SP, in 1978. The technical specifications of the EBA are: energy 0.5 to 1.5 MeV; beam current: 0.3 to 25.0 mA; beam scanning: 60 to 120 cm; beam width: 25.4 mm and frequency: 100 Hz. Nowadays, this accelerator has been used for innumerable applications, such as: For sterilization of medical, pharmaceutical and biological products, treatment of industrial and domestic effluents and sludge, preservation and disinfestations of foods and agricultural products. Other important application are lignocellulosic material irradiation as a pre-treatment to produce ethanol bio-fuel, decontamination of pesticide packing, solid residues remediation, organic compounds removal from wastewater, treatment of effluent from petroleum production units, crosslinking of foams, wires and electric cables. Electron accelerator JOB 188 is, also, very important composite and nanocomposite materials and carbon fibers irradiation, irradiated grafting ion-exchange membranes for fuel cells application, natural polymers and multilayer packages irradiation and biodegradable blends production. The energy of the electron beam is calculated as a function of the current in the accelerator high-voltage divisor, taking into account the thickness and density of the material to be irradiated. This energy is calculated considering the electron through the entire material and the distance from the titanium foil window, so that the absorbed doses at the points of entrance and exit are equivalent on the material. The dose is directly proportional to the beam current and the exposure time of the material under the electron beam and inversely proportional to the scan width. The aim of this paper is to analyze the power system parameters of the EBA Dynamitron DC 1500/25/04, such as, voltage and RMS (Root-mean-square) current in the oscillator system, high voltage generator and waveform. For this purpose software developed in the Radiation Technology Center at IPEN/CNEN-SP to simulate the energy efficiency of this industrial accelerator. Finally, it is also targeted to compare theoretical dosimetry using parameters of energy and beam current with data from the accelerator power system. This knowledge and technology will be very useful and essential for the control system upgrade of EBA, mainly Dynamitron DC 1500/25/04 taking into consideration that radiation processing technology for industrial and environmental applications has been developed and used worldwide. 展开更多
关键词 Electron beam accelerator industrial dosimetry radiation processing accelerator power system Dynamitron DC 1500/25/04 accelerator.
下载PDF
STUDY ON THE CONTROL SYSTEM OF HYDRAULIC MOMENT-ADJUSTED BRAKE FOR DOWNWARD BELT CONVEYOR
17
作者 孟国营 徐志强 +1 位作者 霍森 方佳雨 《Journal of Coal Science & Engineering(China)》 1997年第1期60-63,共4页
Having analyzed the drawbacks on the design of control system of hydraulic moment-adjusted brake system, the author presents a closed loop control system in the process of start and braking of the conveyer. On the bas... Having analyzed the drawbacks on the design of control system of hydraulic moment-adjusted brake system, the author presents a closed loop control system in the process of start and braking of the conveyer. On the basis of the concept of the critical time and the critical ac-celeration and its deductions, the working mode of the conveyer can be identified and controlled in feedback, furthermore, thus realize the process of soft start. ln the deceleration process, the author points out the problems that exist in the present control system and sets forward the control process that acted by the combined function of brake moment of motor and the drag torque of hy-draulic brake at the beginning of deceleration, it will further improved reliability of conveyor sys-tem. 展开更多
关键词 hydraulic moment-adjusted brake critical acceleration soft start closed-loop control
下载PDF
CFD modelling of Iongwall goaf gas flow to improve gas capture and prevent goaf self-heating 被引量:1
18
作者 REN Ting-xiang 《Journal of Coal Science & Engineering(China)》 2009年第3期225-228,共4页
CFD models have been developed to investigate the Iongwall goaf gas flow patternsunder different mining and geological control conditions.The Iongwall goaf wastreated as porous regions and gas flow was modelled as a m... CFD models have been developed to investigate the Iongwall goaf gas flow patternsunder different mining and geological control conditions.The Iongwall goaf wastreated as porous regions and gas flow was modelled as a momentum sink added to themomentum equation.Gas desorption from the caved goaf and destressed coal seamswithin the mining disturbed area was modelled as additional mass sources in the continuityequation.These CFD models were developed according to specific Iongwall layoutsand calibrated against field monitoring data.Two case studies were presented demonstratingthe application of CFD modelling of goaf gas flow characteristics for improved goafgas capture and the reduction of oxygen ingress into the goaf areas for self-heating prevention.Results from the case studies indicate that the optimum goaf drainage strategywould be a combination of shallow (near the face) and deep holes to improve the overalldrainage efficiency and gas purity.For gassy Iongwall faces retreating against the seam dip,it is recommended to conduct cross-measure roof hole drainage targeting the fracturedzones overlying the return corner,rather than high capacity surface goaf drainage deep inthe goaf. 展开更多
关键词 CFD modelling Iongwall goaf gas goaf drainage self-heating prevention
下载PDF
Numerical and Experimental Study on Dynamic Performance of Heat Pump Water Heater with Electronic Expansion Valve
19
作者 Liang Zhang Xianmin Guo Weiguo Li Weihua Wang 《Journal of Energy and Power Engineering》 2012年第10期1582-1588,共7页
A series of experiments on the dynamic performance of the HPWH (heat pump water heater) unit with EXV (electronic expansion valve) under different environmental conditions were conducted. The dynamic heating capac... A series of experiments on the dynamic performance of the HPWH (heat pump water heater) unit with EXV (electronic expansion valve) under different environmental conditions were conducted. The dynamic heating capacity and COP (coefficient of performance) of the HPWH unit under different EXV openings were measured. The effects of the EXV opening on the performance of the HPWH unit were analyzed. Meanwhile, the dynamic performance of the HPWH with EXV was simulated and the results were compared with the experimental one. The experimental results indicate that during heating process, the COP increases firstly and then decreases for a fixed EXV opening, which is in good agreement with the numerical result. For different EXV openings, the COP and heating capacity of the system using larger EXV opening are superior to those using the smaller one in the initial heating stage. While in the late stage, the performance of system using smaller EXV opening is better. It is found that the system performance is improved significantly by changing the EXV opening in the different heating period and the average COP of the HPWH system is increased by 7.6%. 展开更多
关键词 Heat pump water heater electronic expansion valve experimental investigation simulation.
下载PDF
Dependency of Electrical Demand of Bangladesh Power System on the Weather of the Country
20
作者 Nahid-Al-Masood Md. Quamrul Ahsan 《Journal of Energy and Power Engineering》 2012年第6期960-964,共5页
The variation of electrical demand above its base value is its common characteristic. The weather dependent variation of demand, especially where the weather is severe in nature, requires a significant reserve margin ... The variation of electrical demand above its base value is its common characteristic. The weather dependent variation of demand, especially where the weather is severe in nature, requires a significant reserve margin of the generation system. The evaluation of the weather dependent component of the electric demand is the basic tool for the planning of the reserve margin. This paper evaluates the weather dependent portion of the load of BPS (Bangladesh power system). The evaluation of the weather dependent portion of the demand is based on the EMD (empirical mode decomposition) technique. 展开更多
关键词 Weather sensitive component of load reserve margin load forecasting empirical mode decomposition temperature-humidity index generation capacity.
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部