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401.
402.
In an attempt to reduce CO2 emissions from motorized transport, the Taiwanese government introduced an idling stop policy for vehicles in early 2007.
This paper seeks to quantify the environmental benefits of the policy based on a stated preference analysis. Motorcyclists
were surveyed at urban intersections in Taiwan, to identify the amount of time they would be willing to turn off their engines
while waiting at traffic lights (the WTO). A contingent valuation framework based on stated preference questions was designed
to determine the WTO. Results obtained from the Spike model showed that the average motorcyclist’s WTO is 82 s. In another
analysis, in which other variables were taken into consideration, such as the possibility that the policy will be enacted
as legislation, the expected WTO increased to 101 s. In both cases, an idling stop policy would have positive environmental
effects, reducing gasoline usage by 1021 L per hour and reducing CO2 emissions by 0.56 metric tons per hour at the intersection studied during peak periods. 相似文献
403.
This paper seeks to improve our understanding of passengers’ behavioral intention by proposing an integrated framework from
the attitudinal perspective. According to the literature in marketing research, we establish a causal relationship model that
considers “service quality-satisfaction-behavioral intentions” paradigm, perceived value theory, and switching barrier theory.
Exploring passengers’ behavioral intention from satisfaction and perceived value help to understand how passengers are attracted
by the company, while switching barriers assist in realizing how passengers are “locked” into a relationship with the current
company. Furthermore, in order to capture the nature of service quality, we adopt a hierarchical factor structure which serves
service quality as the higher-order factor. In this study, coach industry is selected as our research subject. The empirical
results, as hypothesized, show that all causal relationships are statistically significant, and perceived value us the most
important predictor of satisfaction and passengers’ behavioral intention. In conclusion, the managerial implications and suggestions
for future research are discussed. 相似文献
404.
Statistical and dynamical analyses of propagation mechanisms of solitary internal waves in a two-layer stratification 总被引:2,自引:0,他引:2
Chen-Yuan Chen 《Journal of Marine Science and Technology》2011,16(1):100-114
The blocking effect of submarine ridges on the propagation of internal solitary waves (ISWs) over the topography of the seabed
results in the fission of the solitary waves that accompany the generation of reflected and transmitted waves. In this study,
multivariate analysis of variance (MANOVA) is used to investigate the inseparable relationship between the transmission and
reflection. An examination of the error sums of squares and cross-products (SSCP) matrix and the correction matrix shows that
the correlation between the transmission (at/ai) and reflection coefficients (ar/ai) is quite low (0.284). Moreover, from
multivariate testing, including Pillai’s trace, Wilks’ lambda, Hotelling’s trace and Roy’s largest root, we conclude that
the ridge height has a large effect (η = 0.456) on both the amplitude of the transmitted and reflected waves, as well as large (η = 0.411) and very large (η = 0.469) effects on the amplitudes of the transmitted and reflected waves, respectively. In conclusion, the results in the
present study highlight the importance of the role played by ridge height in coherent ISW transmission and reflection during
oceanic wave–ridge interactions. 相似文献
405.
Hirotada Hashimoto Naoya Umeda Akihiko Matsuda 《Journal of Marine Science and Technology》2011,16(4):448-461
The new intact stability criteria which are under development at the International Maritime Organization (IMO) are required
to cover a broaching phenomenon, well known as a great threat to high-speed vessels which can lead to capsizing. Some reports
exist which demonstrate that their numerical models can predict a highly nonlinear phenomenon of broaching. However, additional
validation studies are needed for unconventional vessels, in addition to conventional ones, to develop direct stability assessment
methods for the new intact stability criteria. In this research, we selected as the subject ship a wave-piercing tumblehome
vessel with twin screws and twin rudders, a design expected to be one of a new generation of high-speed monohull ships. Firstly,
a series of captive model tests were conducted to measure the resistance, the manoeuvring forces, the wave-exciting forces,
the heel-induced hydrodynamic forces, and the roll restoring variation for the unconventional tumblehome vessel. Secondly,
the existing mathematical model which had been developed for broaching prediction of conventional vessels with a single propeller
and a single rudder was extended to unconventional vessels with twin propellers and twin rudders. Finally, comparisons between
numerical simulations and the existing free running model experiments were conducted. As a result, it was demonstrated that
fair quantitative prediction of broaching is realised when the rudder force variation, the roll restoring variation and the
heel-induced hydrodynamic force for large heel angles are taken into account. 相似文献
406.
Interfacial heat transfer is a key issue in many solidification processes. In the paper, a novel experimental apparatus has
been designed and on this basis, the instantaneous interfacial heat transfer between molten steel or solidified shell and
copper substrate during the first 0.2 s has been studied. The investigated parameters include melt superheat, substrate temperature
and surface roughness. The results show that the peak value of the interfacial heat flux in the first stage of liquid/solid
contact increases with melt superheat and changes slightly with substrate temperature and surface roughness. The interfacial
heat flux in the stage of solid/solid contact has a similar trend of slow decrease in most conditions. 相似文献
407.
This paper presents a full-scale solution to the detection of the traffic data using laser device. Range images, gathered
by a particular laser camera, are used in the multi-threshold segmentation. The multi-threshold segmentation is based on the
height of the moving objects. In order to get the precise height of the moving objects, mapping of the original terrain is
performed on the first step. On each layer, the clustering algorithm called iteration-self organizing data analysis techniques
algorithm (ISODATA) is conducted afterwards. Kalman filtering technique is applied to recognize and track the moving objects.
Extensive experiments show that these algorithms are effective in object recognition and tracking, as well as robust in the
applications. 相似文献
408.
The development of an innovative H
∞ controller for looper and tension control in hot strip finishing mills is traced based on approximately linearized model.
This solution has been considered thanks to its well-known robustness and simplicity characteristics concerning disturbances’
attenuation. The controller is designed based on an optimal problem with linear matrix inequality (LMI) constraints, and the
problem is solved by the mincx function of Matlab LMI Toolbox. Simulation results show the effectiveness of the proposed controller
compared with conventional ones. 相似文献
409.
Numerical simulation of macrosegregation during steel ingot solidification using continuum model 总被引:1,自引:0,他引:1
A continuum model is adopted to study the macrosegregation phenomena during solidification of large steel ingots. Evolution
of temperature, melt velocity, and compositional concentration field during a 22 t steel ingot solidification are illustrated
by using the finite volume method. Numerical results of temperature distribution are validated by experiments. The influence
of local permeability relates to the friction that the melt experienced in mushy region is investigated. It is shown that
the continuum model is able to predict the temperature field, and the variation of permeability obviously affects the melt
flowing behavior and the final compositional distribution. 相似文献
410.
An optimization scheme for choosing the optimum number of secondary users in cooperative spectrum sensing based on the cyclostationary
feature detection with Neyman-Pearson criterion is proposed in this paper. The optimal soft combination test statistic for
the cooperative spectrum sensing based on cyclostationary feature detection is derived according to the generalized likelihood
ratio test and its corresponding detection performance is deduced. A target function, considering two important parameters
as the resource use efficiency and the number of samples employed by each cooperative secondary user in the system design,
is constructed to obtain the optimum number of cooperative secondary users. It can be found that the selection scheme is to
make a tradeoff between the system complexity of the cognitive radio network and the global sensing performance of the cooperative
spectrum sensing. 相似文献