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171.
George Simopoulos Dimitris Konovessis Dracos Vassalos 《Journal of Marine Science and Technology》2008,13(2):164-177
In the light of the newly developed harmonised probabilistic damage stability regulations, set to come into force in 2009,
this article presents a systematic and thorough analysis of the sensitivity of the Attained Subdivision Index with reference
to a wide range of related design parameters. The sensitivity of the probabilistic regulations was investigated for a typical
large RoPax vessel, with variation of parameters, such as the number, positioning and local optimisation of transverse bulkheads;
the presence and position of longitudinal bulkheads below the main vehicle deck; the presence of side casings; and the height
of the main deck and double bottom. The effects of water on deck and of operational parameters (draught, centre of gravity
and trim) were also investigated. The results of the study, presented in graphical form, can provide valuable assistance to
the designer when determining subdivision characteristics at the very early stage of the design process, resulting in optimal,
efficient and safe ships. 相似文献
172.
An acoustic vector sensor (AVS) can capture more information than a conventional acoustic pressure sensor (APS). As a result, more output channels are required when multiple AVS are formed into arrays, making processing the data stream computationally intense. This paper proposes a new algorithm based on the propagator method for wideband coherent sources that eliminates eigen-decomposition in order to reduce the computational burden. Data from simulations and lake trials showed that the new algorithm is valid: it resolves coherent sources, breaks left/right ambiguity, and allows inter element spacing to exceed a half-wavelength. 相似文献
173.
To evaluate the clinical outcome, effectiveness and safety of the surgical management of traumatic lumbar spondylolisthesis
with transforaminal lumbar interbody fusion (TLIF) with short segmental instrumentation fixation. A retrospective review of
a consecutive series of 24 patients with traumatic lumbar spondylolisthesis treated with TLIF procedure was carried out. Intraoperative
spinal cord monitoring was used to confirm the peripheral neural function intact during the reduction of the spondylolisthesis.
Preoperative clinical and radiographic evaluation of all cases were originally collected prospectively. Data regarding blood
loss, operative time, duration of hospital stay, radiographic fusion, instrumentation failure and clinical result were collected
and observed at regular follow-up periods. All patients were engaged in high-energy accidents in the lower back and 16 patients
had concomitant injuries. The mean operative time was 124 min, mean blood loss was 350 mL, and mean hospital stay was 6.5
days. There were no complications such as incision infection, cerebrospinal fluide (CSF) leakage and nerve root injury and
so on. All patients demonstrated a solid lumbar interbody fusion within 4 months, and no evidence of spondylolisthesis correction
loss, instrumentation failure and loosing. They all were completely asymptomatic, with normal neurologic findings, and had
resumed their previous level of physical activities on the final follow-up. Meticulous clinical examination and careful imaging
assessment could assist an early diagonosis in cases of traumatic lumbar spondylolisthesis. Performing open reduction and
the TLIF procedure as soon as possible could restore segmental stability and painless function. The TLIF procedure was a safe,
effective technique to treat traumatic lumbar spondylolisthesis. 相似文献
174.
Face recognition via adaptive image combination 总被引:1,自引:0,他引:1
于威威 《上海交通大学学报(英文版)》2010,15(5):600-603
Dimension reduction and manifold learning are the two most popular feature extraction methods. The two methods focus on spatial
locality as a guiding principle to find a low-dimensional basis for describing high-dimensional data, but no bases or features
are more spatially localized than the original image pixels. So, adaptive image combination is presented to represent a class
by a combined sample. The combined sample is a linear combination of original samples in the same class. Adaptive image combination
(AIC) find the best combination coefficients by minimizing the intrapersonal distance and maximizing the interpersonal distance.
Experimental results show that AIC is effective. 相似文献
175.
There is a growing literature that promotes the presence of a mix of compensatory and semi-compensatory processing strategies
in the way that individuals evaluate packages of attributes in real or hypothetical markets, and make choices. This paper
proposes a specification for the utility form in a choice model to test if, given a pair of attributes with a common-metric
(e.g., components of travel time or cost), the attribute with the dominating level defines the marginal (dis)utility that
is assigned to both attributes. We refer to this processing strategy as a parameter transfer rule. We use a stated choice
data set, in the context of car driving individuals choosing between tolled and non-tolled routes, to estimate a mixed logit
model which incorporates the presence of the parameter transfer rule and the conventional fully compensatory rule, both existing
up to a probability. We find that if this parameter transfer heuristic is part of the mix, the WTP is more than 30% higher,
on average, than when only a fully compensatory rule is imposed. We also contrast the parameter transfer rule with other semi-compensatory
heuristics which have been investigated in other papers, and show that the finding adds further support to the accumulating
evidence that a semi-compensatory attribute processing rules tend to result in higher mean WTP estimates compared to the fully
compensatory attribute processing rule. 相似文献
176.
Development of a low-noise cooling fan for an alternator using numerical and doe methods 总被引:1,自引:0,他引:1
W. Kim W. -H. Jeon N. Hur J. -J. Hyun C. -K. Lim S. -H. Lee 《International Journal of Automotive Technology》2011,12(2):307-314
An alternator, which converts mechanical rotational energy into electrical energy, is an important component of a vehicle.
Alternators operate over a broad range of rotational speeds, typically from 3,000 RPM to 18,000 RPM, which demands a cooling
fan producing sufficient airflow, ideally with a minimum of noise. In the current study, an optimized alternator-cooling fan
was developed through a linked DOE(Design OF Experiment) process and numerical analysis. The SC/Tetra and FlowNoise S/W programs were used to calculate flow rates and noise levels, respectively, for the newly developed fan. Compared with
original model, the numerical results predicted a 3 dBA noise reduction; the measured reduction was 4 dBA. 相似文献
177.
B. J. Yoon J. Y. Lee J. H. Kim C. S. Han 《International Journal of Automotive Technology》2011,12(1):111-118
A navigation algorithm is indispensable for Unmanned Ground Vehicles (UGVs). During driving, UGVs follow a global path. In
this study, we propose a navigation algorithm using Real Time Kinematic (RTK)-Differential Global Positioning System (DGPS)
units and encoders to complement global path planning. Sometimes GPS systems lose their signals and receive inaccurate position
data due to many factors, such as edifice and barrier obstructions. This paper shows that GPS deviations can be solved using
a Dead Reckoning (DR) navigation method with encoders and that position errors can be decreased through the use of RTK-DGPS
units. In addition to this method, we will introduce a new waypoint update algorithm and a steering algorithm using RTK-DGPS
units. 相似文献
178.
T. Y. Shin S. Y. Kim J. Y. Choi K. S. Yoon M. H. Lee 《International Journal of Automotive Technology》2011,12(1):103-110
This paper presents a modified lateral control method for an autonomous vehicle with both look-ahead and look-down sensing
systems. To cope with sensor noise and modeling uncertainty in the lateral control of the vehicle, a modified LMI-based H
lateral controller was proposed, which uses the look-ahead information of the lateral offset error measured at the front of
vehicle and the look-down information of the vehicle yaw angle error between the reference lane and the centerline of the
vehicle. To verify the safety and the performance of the lateral control, a scaled-down vehicle was developed, and the positioning
of the vehicle was estimated with USAT. The proposed controller, which uses both look-ahead and look-down information, was
tested for lane changing and reference lane tracking with both simulation and experiment. The simulation and experimental
results show that the proposed controller has better tracking and handling performance compared with a controller that uses
only the look-ahead information of the target heading angle error. 相似文献
179.
180.
H. H. Lee H. W. Bang S. K. Kauh S. I. Kim 《International Journal of Automotive Technology》2011,12(3):351-358
The development of an inner-piston-chamber temperature measurement system is a necessary step in engine development or when
solving other fundamental problems related to automotive engines. There are various pre-existing measurement methods available,
e.g., the linkage method, piston telemetry, templog, and the electromagnetic induction method. In this study, we first redesigned
the coil sensor used in the electromagnetic induction method using PEEK and then used Taguchi methods to reduce the number
of experiments in the development process and finally utilized piston telemetry via Bluetooth to verify the precision and
accuracy of the redesigned PEEK coil sensor and electromagnetic induction method. The results displayed a reproducibility
within 0.5 degrees and an accuracy within 2 degrees Celsius. 相似文献