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401.
The hybridization of the conventional thermal vehicles nowadays constitutes a paramount importance for car manufacturers,
facing the challenge of minimizing the consumption of the road transport. Although hybrid power train technologies did not
converge towards a single solution, series/parallel power trains with power-split electromechanical transmissions prove to
be the most promising hybrid technology. In fact, these power trains show maximum power train overall efficiency and maximum
fuel reduction in almost all driving conditions compared to the conventional and other hybrid power trains. This paper addresses
the model and design of the electro-mechanical configuration of one of the most effective HEV power trains: case study of
the 2nd generation Prius. It presents the simulation work of the overall operation of the Toyota Hybrid System (THS-II) of
the Prius, and explores not only its power-split eCVT innovative transmission system but also its overall supervision controller
for energy management. The kinematic and dynamic behaviors of the THS-II power train are explained based on the power-split
aspect of its transmission through a planetary gear train. Then, the possible regular driving functionalities that result
from its eCVT operation and the energy flow within its power train are outlined. A feed-forward dynamic model of the studied
power train is next proposed, supervised by a rule-based engineering intuition controller. The energy consumption of the THS-II
proposed model has been validated by comparing simulation results to published results on European, American and Japanese
regulatory driving cycles. 相似文献
402.
T. X. Wu D. J. Thompson 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2002,37(3):157-174
The wheel/rail contact forces are calculated in the frequency domain using a track model with multiple wheels on the rail. The effects of the wave reflections between the wheels on the contact force are studied. Different pad stiffnesses are used in the calculations to investigate the influence on the contact force. It is shown that the contact force can have up to four main peaks in the frequency region 550-1200?Hz due to the wave reflections between the wheels, so that the wavelengths of short pitch corrugation can be expected to be associated with multiple frequencies. As a conclusion, it is recommended that in a model for predicting short pitch corrugation the effects of multiple wheel/rail interactions need to be included. 相似文献
403.
404.
Atmospheric molar fraction of CO2 (xCO2atm) measurements obtained on board of ships of opportunity are used to parameterize the seasonal cycle of atmospheric xCO2 (xCO2atm) in three regions of the eastern North Atlantic (Galician and French offshore and Bay of Biscay). Three selection criteria are established to eliminate spurious values and identify xCO2atm data representative of atmospheric background values. The filtered data set is fitted to seasonal curve, consisting of an annual trend plus a seasonal cycle. Although the fitted curves are consistent with the seasonal evolution of xCO2atm data series from land meteorological stations, only ship-board measurements can report the presence of winter xCO2atm minimum on Bay of Biscay. Weekly air–sea CO2 flux differences (mmol C·m− 2 day− 1) produced by the several options of xCO2atm usually used (ship-board measurements, data from land meteorological stations and annually averaged values) were calculated in Bay of Biscay throughout 2003. Flux error using fitted seasonal curve relative to on board measurements was minimal, whereas land stations and annual means yielded random (− 0.2 ± 0.3 mmol C·m− 2·day− 1) and systematic (− 0.1 ± 0.4 mmol C·m− 2 day− 1), respectively. The effect of different available sources of sea level pressure, wind speed and transfer velocity were also evaluated. Wind speed and transfer velocity parameters are found as the most critical choice in the estimate of CO2 fluxes reaching a flux uncertainty of 7 mmol C·m− 2·day− 1 during springtime. The atmospheric pressure shows a notable relative effect during summertime although its influence is quantitatively slight on annual scale (0.3 ± 0.2 mmol C·m− 2·day− 1). All results confirms the role of the Bay of Biscay as CO2 sink for the 2003 with an annual mean CO2 flux around − 5 ± 5 mmol C m− 2 day− 1. 相似文献
405.
Francisco Pérez José A. Suárez Juan A. Clemente Antonio Souto 《Journal of Marine Science and Technology》2007,12(2):83-94
Nowadays, bulbous bow forms have become a common design feature in most conventional ship designs. The design of a bulbous
bow is usually attempted with the use of certain form parameters that are imposed using the designer's experience or regression
values that provide the optimum parameters based on experimental tests or computational fluid dynamics (CFD) calculations.
In this article, the geometric modelling of a bulbous bow form that complies with a series of parameters is presented. First,
a wire model was constructed with cubic B-spline curves that hold certain form parameters that the designer wants to impose.
Second, a B-spline surface that fits these splines was mathematically constructed. A review of the influence of the design
parameters used on the bulbous bow properties was made. This method could be used prior to numerical optimization of a bulbous
bow because different variations of the design can be easily generated. These variations can be tested numerically using CFD
software. A practical application example of the method is shown. 相似文献
406.
陈玉社 《西安交通大学学报(英文版)》1995,(2)
CHARACTERISTICSOFACTIONPOTENTIALANDTHEIRUNDERLYINGOUTWARDCURRENTSINMAMMALIANTASTERECEPTORCELLSChenYushe;X.Sun,M.S.Herness(Ind... 相似文献
407.
408.
W.X. Wu B.V. Brickle J.H. Smith R.K. Luo 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1998,30(3):229-236
A model for the numerical simulation of vehicle/track interaction and stick-slip vibration is presented. A finite element model is developed to calculate vertical contact forces. These forces are then coupled through the contact patch into a non-linear time-domain model by which the stick-slip vibration behaviour of a wheel-rail system is analysed. The investigation suggests that stick-slip vibration may occur if a vehicle which has a maligned or an initial 'wind-up' wheeiset meets a vertical irregularity or contaminants on the track. 相似文献
409.
410.