期刊文献+
共找到13篇文章
< 1 >
每页显示 20 50 100
纯电动汽车龟速行驶故障诊断与排除方法
1
作者 刘建军 《汽车维修技师》 2023年第11期129-129,共1页
在汽车驾驶过程中,驾驶员驾驶车辆在道路上行驶时,车速明显低于车辆最大允许速度(40km/h)时,通常被称为“龟速行驶”。这类故障现象主要是由车辆电气系统引起的,应重点排查。如有必要,可通过测试方法检测判断。纯电动汽车因其动力电池... 在汽车驾驶过程中,驾驶员驾驶车辆在道路上行驶时,车速明显低于车辆最大允许速度(40km/h)时,通常被称为“龟速行驶”。这类故障现象主要是由车辆电气系统引起的,应重点排查。如有必要,可通过测试方法检测判断。纯电动汽车因其动力电池的特性,车辆行驶过程中容易发生“龟速行驶”现象,而造成这一现象的原因有很多,如车辆的驱动电机、电池、电控系统、整车电气系统等均可能导致该现象。 展开更多
关键词 行驶 故障现象 动力电池的特性
原文传递
关于集装箱船超大型化及慢速行驶的分析与思考 被引量:2
2
作者 钟子洋 《世界海运》 2017年第5期14-20,共7页
近年来,国际集装箱班轮的超大型化及慢速行驶趋势明显。为深入了解两种趋势,为有关部门掌握应对有关变化提供参考,通过对集装箱船超大型化以及慢速行驶趋势进行分析,探求变化背后的原因及利弊。认为集装箱船超大型化及慢速行驶趋势是航... 近年来,国际集装箱班轮的超大型化及慢速行驶趋势明显。为深入了解两种趋势,为有关部门掌握应对有关变化提供参考,通过对集装箱船超大型化以及慢速行驶趋势进行分析,探求变化背后的原因及利弊。认为集装箱船超大型化及慢速行驶趋势是航运界应对航运不景气及气候变化的手段,但是两种趋势各有利弊:总体上集装箱船超大型化是弊大于利,而慢速行驶则是利大于弊。有关部门及利益相关方应加强合作与研究,制定执行有效措施,引导上述趋势变化,促进航运业持续健康发展。 展开更多
关键词 集装箱船 船舶大型化 行驶
下载PDF
Suction characteristics of a thick material pump at high concentrations of coal slime 被引量:5
3
作者 MA Xing-min ZHAO Qiao-zhi +1 位作者 GAO Shao-gang WU Miao 《Journal of China University of Mining and Technology》 EI 2008年第2期210-213,共4页
A test system was designed to study the parameters affecting the volumetric efficiency of a thick-material pump for coal slime.The parameters studied included solid concentration,the slenderness ratio of the suction c... A test system was designed to study the parameters affecting the volumetric efficiency of a thick-material pump for coal slime.The parameters studied included solid concentration,the slenderness ratio of the suction cylinder and the running speed of the hydraulic cylinder.In the experiment the concentrations of coal slime were 75.7%,76.3%,74.4%,73.5%,72.1%and 70.63%;the running speeds were 0.23,0.18,0.13,0.10 and 0.08 m/s;and the slenderness ratios of the suction cylinder were 1.63,2.26,2.88,3.50,4.13,4.78 and 5.38.The results show that the suction volumetric efficiency decreases gradually with an increase in material concentration.The critical concentration value is 72%;below 72%the suction volumetric efficiency is above 90%,otherwise it decreases rapidly.When the solid concentration reaches 76.3%,the suction volumetric efficiency is only 40%.When the running speed of the piston is less than or equal to 0.23 m/s,the suction volumetric efficiency increases with an increase in running speed. 展开更多
关键词 suction volumetric efficiency coal sludge concentration running speed hydraulic cylinder slenderness ration
下载PDF
Development of a Data Acquisition System to Optimizing the Agricultural Tractor Performance 被引量:1
4
作者 J. M. Serrano J. O. Peca +3 位作者 S. Shahidian M. C. Nunes L. Ribeiro F. Santos 《Journal of Agricultural Science and Technology(B)》 2011年第5期756-766,共11页
A novel data acquisition system was successfully integrated on-board the Massey Ferguson 3,000 series agricultural tractors for measuring tractor-implement performance. A commercial load cell was incorporated into the... A novel data acquisition system was successfully integrated on-board the Massey Ferguson 3,000 series agricultural tractors for measuring tractor-implement performance. A commercial load cell was incorporated into the existing system for the needed tractor-implement performance, measurements. This system is capable of measuring, displaying and recording, in real-time, the tractor's theoretical travel speed, the actual travel speed, the engine speed, the fuel consumption rate, and the drawbar pull. Static calibration tests on various associated sensors for the required measurements show excellent linearity with correlation coefficients that are close to 1. The developed system was extensively and successfully field demonstrated for tractor-implement performance with offset disc harrows on dry, undisturbed loamy soils. Under these conditions, a ratio of tractor power to implement width is suggested. The data also show the existence of a linear relationship between fuel consumption per hectare and specific draught, for the 4 to 9 kN m^-1 range, which suggests the possibility of extending the American Society of Agricultural and Biological Engineers model of draught prediction to forecast fuel consumption. The configuration of the tractor-harrow combination, based on the measurement of the draught required under operational conditions, provides the manufacturers with a reliable indication of the recommended power required for each harrow model. With this type of information farmers can make decisions regarding selection of a suitable tractor-implement combination for their farms. As a consequence, there is improved tractor-harrow productivity and field efficiency. 展开更多
关键词 Data acquisition system datatronic TILLAGE tractor implement performance
下载PDF
Ship Resistance of Quadramaran With Various Hull Position Configurations 被引量:2
5
作者 Yanuar Gunawan +1 位作者 A. Muhyi A. Jamaluddin 《Journal of Marine Science and Application》 CSCD 2016年第1期28-32,共5页
Multihull ships are widely used for sea transportation, and those with four hulls are known as quadramarans. Hull position configurations of a quadramaran include the diamond, tetra, and slice. In general, multihull v... Multihull ships are widely used for sea transportation, and those with four hulls are known as quadramarans. Hull position configurations of a quadramaran include the diamond, tetra, and slice. In general, multihull vessels traveling at high speeds have better hydrodynamic efficiency than monohull ships. This study aims to identify possible effects of various quadramaran hull position configurations on ship resistance for hull dimensions of 2 m length, 0.21 m breadth, and 0.045 m thickness. We conducted a towing test in which we varied the hull spacing and speed at Fr values between 0.08 and 0.62 and measured the total resistance using a load cell transducer. The experimental results reveal that the lowest total resistance was achieved with a diamond quadramaran configuration at Fr = 0.1-0.6 and an effective interference factor of up to 0.35 with S/L = 3/10 and R/L = 1/2 at Fr = 0.62. 展开更多
关键词 multihull quadramaran ship resistance interference factor hull position configurations
下载PDF
Numerical Simulation of a Planing Vessel at High Speed 被引量:15
6
作者 Yumin Su Qingtong Chen +1 位作者 Hailong Shen Wei Lu 《Journal of Marine Science and Application》 2012年第2期178-183,共6页
Planing vessels are applied widely in civil and military situations.Due to their high speed,the motion of planning vessels is complex.In order to predict the motion of planning vessels,it is important to analyze the h... Planing vessels are applied widely in civil and military situations.Due to their high speed,the motion of planning vessels is complex.In order to predict the motion of planning vessels,it is important to analyze the hydrodynamic performance of planning vessels at high speeds.The computational fluid dynamic method(CFD) has been proposed to calculate hydrodynamic performance of planning vessels.However,in most traditional CFD approaches,model tests or empirical formulas are needed to obtain the running attitude of the planing vessels before calculation.This paper presents a new CFD method to calculate hydrodynamic forces of planing vessels.The numerical method was based on Reynolds-Averaged Navier-Stokes(RANS) equations.The volume of fluid(VOF) method and the six-degrees-of-freedom equation were applied.An effective process was introduced to solve the numerical divergence problem in numerical simulation.Compared with experimental results,numerical simulation results indicate that both the running attitude and hydrodynamic performance can be predicted well at high speeds. 展开更多
关键词 planing vessel RANS equations running attitude six degrees of freedom equations VOF
下载PDF
Performance and Adaptation of the Vallerani Mechanized Water Harvesting System in Degraded Badia Rangelands
7
作者 I.A. Gammoh T.Y. Oweis 《Journal of Environmental Science and Engineering》 2011年第10期1370-1380,共11页
Rainwater harvesting in micro-catchments such as contour ridges and semicircular bunds is an option for utilizing the limited rainfall, improving productivity and combating land degradation in dry rangeland areas (Ba... Rainwater harvesting in micro-catchments such as contour ridges and semicircular bunds is an option for utilizing the limited rainfall, improving productivity and combating land degradation in dry rangeland areas (Badia). However, implementation of this practice using manual labor or traditional machinery is slow, tedious and costly, and often impractical on a large scale. These limitations can be overcome using the "Vallerani" plow for quickly constructing continuous and intermittent ridges. The plow (model Delfino (50 MI/CM), manufactured by Nardi, Italy) was tested and adapted to dry steppe (Badia) conditions in Jordan. The performance of the machine, its weaknesses and potential improvements were assessed in the 2006/07 season at three sites on 165 hectares of various terrain, slope and soil conditions. The performance parameters included effective field capacity (EFC), machine efficiency (ME) and fuel consumption (FC). Field tests were carried out at different tractor (134 HP) traveling speeds, pit sizes and contour spacings. Overall mean performance indicators gave an EFC of 1.2 ha/h, 51% ME and an average FC of 5.15 liter/ha. Increasing ridge spacing had a small effect on ME where, increasing traveling speed had a greater effect. A guide table was developed, relating performance parameters with ridge spacing, speed, and bund size setting. This could be a useful reference for the implementation and management of mechanized micro-catchment construction in the Badia. The system performed well in the construction of continuous ridges. However, it was unable to construct intermittent ridges at speeds over 4km/h; problems were encountered in properly staggering the bunds at successive contours. 展开更多
关键词 Land degradation contour micro-catchments Vallerani system machine capacity machine efficiency Badia.
下载PDF
Vehicle Speed Observation Models Based on the Data on the Smartphone GPS
8
作者 Gede Herdian Setiawan I Made Oka Widyantara Made Sudarma 《Computer Technology and Application》 2016年第6期300-307,共8页
The development of GPS (global positioning system) receiver now can be integrated on a smartphone. GPS receiver on smartphones has been developed for location-based applications. Smartphones are very suitable to be ... The development of GPS (global positioning system) receiver now can be integrated on a smartphone. GPS receiver on smartphones has been developed for location-based applications. Smartphones are very suitable to be used as an experimental tool, because smartphones are usually equipped with various types of sensors. This paper proposes a model observation vehicle speed on a road section based on the GPS data on the smartphone. Observations made by calculating the speed of the speed of vehicles moving through the data transfer at the GPS location of the smartphone, the data are then sent periodically to the server and server processing and storage of vehicle speed data. After tested with test reliability indicators use RMSE, observations with model observations speed, speed based on GPS data on a smartphone are relevant when compared with the speed directly from the vehicle's speedometer with the difference between the value of the difference of speed that is 3.1785 km/h. 展开更多
关键词 GPS SMARTPHONE vehicle speed observations.
下载PDF
Econnect Germany -Testing of an Electric Minibus Designed for Public Transportation
9
作者 Felix Topler Lutz Eckstein +1 位作者 Gerrit Geulen Jerome Homann 《Journal of Energy and Power Engineering》 2014年第7期1258-1264,共7页
Within the econnect project (funded by the German Ministry of Economics and Technology), a battery electric passenger bus on the basis of a Mercedes Sprinter City 65 has been tested on public roads. Driving without ... Within the econnect project (funded by the German Ministry of Economics and Technology), a battery electric passenger bus on the basis of a Mercedes Sprinter City 65 has been tested on public roads. Driving without local emissions, high energy efficiency and reduced energy costs are the main advantages of electric drivetrains. Otherwise the limited energy content of the battery reduces range and availability of electric propelled vehicles. Passenger buses in public transportation systems are usually driving on inner-urban routes and have an average driving speed of app. 20 km/h. Next to that breaks at the end of service offer the possibility to recharge the battery so that the average daily driving distance can be easily covered by electric buses. This paper presents the results of test drives on urban and extra-urban bus routes for the electric bus and a second bus with a conventional diesel engine. 展开更多
关键词 Battery-electric vehicle public transportation energy consumption emissions.
下载PDF
Effects of flashing green on driver's stop/go decision at signalized intersection 被引量:2
10
作者 沈家军 王炜 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第2期771-778,共8页
The primary objective of this work is to explore how drivers react to flashing green at signalized intersections. Through video taping and data procession based on photogrammetry, the operating speeds of vehicles befo... The primary objective of this work is to explore how drivers react to flashing green at signalized intersections. Through video taping and data procession based on photogrammetry, the operating speeds of vehicles before and after the moment when flashing green started was compared using paired-samples T-test. The critical distances between go and stop decisions was defined through cumulative percentage curve. The boundary of dilemma zone was determined by comparing stop distance and travel distance.Amber-running violation was analyzed on the basis of the travel time to the stop line. And finally, a logistic model for stop and go decisions was constructed. The results shows that the stopping ratios of the first vehicles of west-bound and east-bound approaches are 41.3% and 39.8%, respectively; the amber-light running violation ratios of two approaches are 31.6% and 25.4%, respectively;the operating speed growth ratios of first vehicles selecting to cross intersection after the moment when flashing green started are26.7% and 17.7%, respectively; and the critical distances are 48 m and 46 m, respectively, which are close to 44 m, the boundary of dilemma zone. The developed decision models demonstrate that the probability of go decision is higher when the distance from the stop line is shorter or operating speed is higher. This indicates that flashing green is an effective way to enhance intersection safety,but it should work together with a strict enforcement. In addition, traffic signs near critical distance and reasonable speed limitation are also beneficial to the safety of intersections. 展开更多
关键词 signalized intersections flashing green critical distance dilemma zone amber-running violation logistic decision model
下载PDF
Collision Simulation of Minibus at High Speed
11
作者 LIN Fan-guo ZHAO Li 《International English Education Research》 2015年第1期99-102,共4页
Collision properties of minibus when traveling at high speed are studied. Based on the display dynamics and basic theoretical of contact collision analysis, the front crash finite element model of minibus is built by ... Collision properties of minibus when traveling at high speed are studied. Based on the display dynamics and basic theoretical of contact collision analysis, the front crash finite element model of minibus is built by Hypermesh. The model is simulated under the 50 km/h by ANSYS/Ls-Dyna solver. Finally, the deformation of the front rail, B pillar acceleration curve and the steering column intrusion are got. It is important to improve safety design for minibus. 展开更多
关键词 MINIBUS COLLISION simulation analysis steering column
下载PDF
魁北克赏鲸
12
《航空港》 2009年第4期76-79,共4页
5月底,圣劳伦斯湾的冰雪在暖风吹拂中开始消融。随着夏季来临,水温逐渐上升到11℃。这时,成群结队的鲸鱼从四面八方千里迢迢赶来。明媚阳光下,它们或黑或白或灰的身影穿梭在圣劳伦斯湾湛蓝清澈的河水间,时不时凌空显露优美身姿,而后一... 5月底,圣劳伦斯湾的冰雪在暖风吹拂中开始消融。随着夏季来临,水温逐渐上升到11℃。这时,成群结队的鲸鱼从四面八方千里迢迢赶来。明媚阳光下,它们或黑或白或灰的身影穿梭在圣劳伦斯湾湛蓝清澈的河水间,时不时凌空显露优美身姿,而后一个鱼跃激起千层白浪。每年6到11月,正是魁北克省赏鲸的黄金季节。 展开更多
关键词 圣劳伦斯湾 魁北克省 明媚阳光 圣劳伦斯河 海洋哺乳动物 声纳仪 船上 海岸警卫队 景观大道 行驶速
原文传递
Stability and a fast calculation method of travel speed of pulse peak in convergence zone 被引量:4
13
作者 REN Yun ZHANG RenHe +2 位作者 WANG Jun GUO YongGang Luo WenYu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第7期1274-1282,共9页
A long-range sound propagation experiment was conducted in the West Pacific Ocean in summer 2013.The signals received by a towed array indicate that the travel speed of pulse peak(TSPP)in the convergence zones is stab... A long-range sound propagation experiment was conducted in the West Pacific Ocean in summer 2013.The signals received by a towed array indicate that the travel speed of pulse peak(TSPP)in the convergence zones is stable.Therefore,an equivalent sound speed can be used at all ranges in the convergence zones.A fast calculation method based on the beam-displace-ment ray-mode(BDRM)theory and convergence zone theory is proposed to calculate this equivalent sound speed.The computation speed of this proposed method is over 1000 times faster than that of the conventional calculation method based on the normal mode theory,with the computation error less than 0.4%compared with the experimental result.Also,the effect of frequency and sound speed profile on the TSPP is studied with the conventional and fast calculation methods,showing that the TSPP is almost independent of the frequency and sound speed profile in the ocean surface layer. 展开更多
关键词 travel speed pulse peak pulse propagation BDRM theory turning point convergence zone
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部