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751.
J. Wu 《International Journal of Automotive Technology》2012,13(3):409-422
This paper presents a robust optimization method to decrease the variations in the performance of the designed system caused
by the unavoidable manufacturing, installation or measurement errors of the design variables. Generally, it is difficult and
costly to determine statistical information with sufficient precision for uncertain design variables; in this study, interval
numbers are used to describe the uncertain design variables, and only the bounds of these variables are required. An improved
interval truncation method is presented for estimating the variation ranges of the system performances. The robustness estimations
of the system performances are incorporated into the optimization formulation to obtain the nominal design variables, which
could make the system performances relatively robust; therefore, the design robustness is estimated and improved in the optimization
iteration process. The robust optimization method is applied to a general powertrain mounting system (PMS) to improve the
design robustness of the PMS decoupling layout and frequency allocation. The optimization results show that the robust optimization
method could effectively increase the decoupling ratios in the interested vertical and pitch directions, and the frequency
allocation is more robust than that obtained using the traditional deterministic optimization. 相似文献
752.
Uwe K. Jenisch 《WMU Journal of Maritime Affairs》2012,11(2):169-185
Maritime security in a broad sense means more than piracy and terrorism. This paper concentrates on the risk potential of current and future resource-related activities on the seabed. The seabed mining of hard mineral resources??in addition to hydrocarbons??leads to new controversial maritime boundary claims of states in their effort to expand national access rights to raw materials. Outer continental shelf claims in the Arctic Ocean are today's test bench for law of the sea conflicts. Fiber-optic cables running through regional seas, straits, and land bridges may become another risky issue, while the pattern of maritime transport routes is moving from Northern to Southern waters. Under a medium-term perspective, the sea level rise will endanger ports and coasts. Borderlines of maritime zones will move and thus generate more injustice and conflicts among states. The tools to solve borderline conflicts and options for dispute settlement are available in UNCLOS. Some other legal gaps are covered by the 2005 SUA Convention and by bilateral agreements, while resolutions by the UN Security Council begin to broaden rights of intervention and interdiction. The need for new laws remains. 相似文献
753.
A fuzzy model was presented to predict the weldment shape profile of submerged arc welds(SAW) including the shape of heat affected zone(HAZ).The SAW bead-on-plates were welded by following a full factorial design matrix.The design matrix consisted of three levels of input welding process parameters.The welds were cross-sectioned and etched,and the zones were measured.A mapping technique was used to measure the various segments of the weld zones.These mapped zones were used to build a fuzzy logic model.The membership functions of the fuzzy model were chosen for the accurate prediction of the weld zone.The fuzzy model was further tested for a set of test case data.The weld zone predicted by the fuzzy logic model was compared with the experimentally obtained shape profiles and close agreement between the two was noted.The mapping technique developed for the weld zones and the fuzzy logic model can be used for on-line control of the SAW process.From the SAW fuzzy logic model an estimation of the fusion and HAZ can also be developed. 相似文献
754.
We investigated the effects of the fuel injection timing — both for early and late injection — in conjunction with the throttle
opening ratio on the fuel-air mixing characteristics, engine power, combustion stability and emission characteristics of a
DI CNG spark engine and control system that had been modified and designed according to the author’s original idea. We verified
that the combustion characteristics were affected by the fuel injection timing and that the engine conditions were affected
by the throttle opening ratios and the rpm. The combustion characteristics were greatly improved for a complete open throttle
ratio with an early injection timing and for a partial throttle ratio with a late injection timing. The combustion duration
was governed by the duration of flame propagation in late injection timing scenarios and by the duration of early flame development
in cases of early injection timing. As the result, the combustion duration is shortened, the lean limit is improved, the air-fuel
mixing conditions are controlled, and the emissions are reduced through control of the fuel injection timing and vary according
to ratio of the throttle opening. 相似文献
755.
Compensation factor method for modeling springback of auto parts constructed with high-strength steel 总被引:1,自引:0,他引:1
X. -K. Zhang G. J. Zheng J. -N. Hu C. G. Li P. Hu 《International Journal of Automotive Technology》2010,11(5):721-727
To more accurately manufacture an auto-body workpiece, a predictive compensation factor method was used to predict the workpiece’s
springback, and the factors influencing springback are introduced. Based on this method, a numerical simulation was produced
to simulate the springback compensation after distortion of the workpiece. After analyzing the simulation results, a compensation
method was introduced to reduce the springback influence on an actual workpiece. Here, we used a fortified B-pillar, which
is a kind of longitudinal stand-frame workpiece, made with a high-strength steel material (TRIP700). The simulation results
indicated that the proposed method is feasible and can be efficiently used for predicting the distortion of springback compensation
of an auto-body workpiece. 相似文献
756.
The overall driving environment consists of the Traffic environment, vehicle and driver states (TVD). advanced driver assistance
Systems (ADAS) must consider not only information on each of the TVD states but also their context. Recent research has focused
on making more efficient and effective assistance systems by fusing all the information from the TVD states. Based on this
research trend, this paper focuses on decision-level fusion to estimate the level of danger of a warning by using visual information
of the traffic environment and the driver state. The driver state consists of the gazing region and the facial feature points
that are obtained using the active appearance model (AAM). The traffic environment state consists of time to collision (TTC),
time to lane Crossing (TLC), and lane color information, which are obtained from the environment in front of the vehicle,
i.e., position of lanes and other vehicles. Warnings against lane-off, collision, and driver inattention are generated by
fusing this vision-based information from inside and outside the vehicle. The experimental results prove that our vision-based
interactive driver assistance system reduces most useless warnings. 相似文献
757.
A. Badea A. Furones F. J. Páez C. González 《International Journal of Automotive Technology》2010,11(5):711-720
Pedestrians are the most vulnerable users of public roads and represent one of the largest groups of road casualties; their
death rate around the world due to vehicle-pedestrian collisions is high and tending to rise. In Spain, as in other countries
of the European Union, steps have been taken to reduce the number and consequences of such accidents, with encouraging results
in recent years. A key to countering this concern is the accident research activity that has obtained remarkable achievements
in different fields, especially when multidisciplinary approaches are taken. This paper describes the development of a multivariate
model that is able to detect the most influential parameters on the consequences of vehicle-pedestrian collision and to quantify
their impact on pedestrian fatality risk. First, an accident database containing detailed information and parameters of vehicle-pedestrian
collisions in Madrid has been developed. The accidents were investigated on the spot by INSIA accident investigation teams
and analyzed using advanced reconstruction techniques. The model was then developed with two components: (1) a classification
tree that characterizes and selects the explanatory variables, identifying their interactions, and (2) a binary logistic regression
to quantify the influence of each variable and interaction resulting from the classification tree. The whole model represents
an important tool for identifying, quantifying and predicting the potential impact of measures aimed at reducing injuries
in vehicle-pedestrian collisions. 相似文献
758.
This work presents the modeling and simulation of a novel free piston linear alternator. The modeling consists of two parts,
a thermodynamic model and dynamic model, and these are combined and solved by matlab/simulink. The effects of various intake
pressures, moving masses, ignition positions, and resistance loads are studied. The simulation results show that the free
piston motion is different from that of the traditional internal combustion engine (ICE). The free piston accelerates and
decelerates more quickly at the end of the stroke and additionally, the top dead center is free and changes accordingly with
the studied parameters. Thus, a high compression ratio can be easily achieved. 相似文献
759.
Electro-hydraulic braking system for autonomous vehicles 总被引:4,自引:0,他引:4
V. Milanés C. González J. E. Naranjo E. Onieva T. De Pedro 《International Journal of Automotive Technology》2010,11(1):89-95
Reducing the number of traffic accidents is a declared target of most governments. Since dependence on driver reaction is the main cause of road accidents, it would be advisable to replace the human factor in some driving-related tasks with automated solutions. To automate a vehicle, it is necessary to control the actuators of a car, i.e., the steering wheel, accelerator, and brake. This paper presents the design and implementation of an electro-hydraulic braking system consisting of a pump and various valves, allowing the control computer to stop the car. It is assembled in conjunction with the original circuit for the sake of robustness and to permit the two systems to halt the car independently. This system was developed for installation in a commercial Citroën C3 Pluriel of the AUTOPIA program. Various tests were carried out to verify its correct operation, and an experiment showing the integration of the system into the longitudinal control of the car is described. 相似文献
760.
B. Suh A. Frank Y. J. Chung E. Y. Lee Y. H. Chang S. B. Han 《International Journal of Automotive Technology》2010,11(4):555-563
This research is the first to develop a design for a powertain system of a plug-in parallel diesel hybrid electric bus equipped
with a continuously variable transmission (CVT) and presents a new design paradigm of the plug-in hybrid electric bus (HEB).
The criteria and method for selecting and sizing powertrain components equipped in the plug-in HEB are presented. The plug-in
HEB is designed to overcome the vulnerable limitations of driving range and performance of a purely electric vehicle (EV)
and to improve fuel economy and exhaust emissions of conventional bus and conventional HEBs. The control strategy of the complicated
connected propulsion system in the plug-in parallel HEB is one of the most significant factors in achieving higher fuel economy
and lower exhaust emissions of the HEV. In this research, a new optimal control strategy concept is proposed against existing
rule-based control strategies. The optimal powertrain control strategy is obtained through two steps of optimizations: tradeoff
optimization for emission control and energy flow optimization based on the instantaneous optimization technique. The proposed
powertrain control strategy has the flexibility to adapt to battery SOC, exhaust emission amount, classified driving pattern,
driving condition, and engine temperature. The objective of the optimal control strategy is to optimize the fuel consumption,
electricity use, and exhaust emissions proper to the performance targets. The proposed control strategy was simulated to prove
its validity by using analysis simulation tool ADVISOR (advanced vehicle simulator). 相似文献