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31.
Daniel Lindvai-Soos Martin Horn 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2018,56(7):1002-1027
In this article a novel vehicle dynamics control concept is designed for a vehicle equipped with wheel individual electric traction machines, electronically controlled brakes and semi-active suspensions. The suspension's cross-couplings between traction forces and vertical forces via anti-dive and anti-squat geometry is utilised in the control concept to improve driving comfort and driving stability. The control concept is divided into one main and two cascaded branches. The main controller consists of a multivariable vehicle dynamics controller and a control allocation scheme to improve the vehicle's driving comfort. The cascaded feedback loops maintain the vehicle's stability according to wheel slip and vehicle sideslip. The performance of the combined vehicle dynamics controller is compared to a standard approach in simulation. It can be stated that the controller piloting semi-active suspensions together with brake and traction devices enables a superior performance regarding comfort and stability. 相似文献
32.
Keon Hee Baek Su Bin Choi Hee Rok Hong Nak Tak Jeong Hyeong Uk Moon Eun Seong Lee Hyung Min Kim Sung Uk Choi Myung Won Suh 《International Journal of Automotive Technology》2018,19(5):859-868
Ever since vehicle noise, vibration, and harshness (NVH) reduction technology made dramatic improvements, vehicle interior noises represented by Squeak and Rattle (S/R) becomes an ever more important factor to improve the emotional quality of vehicles. Generally, people detect S/R noises on automotive interior parts, brake system, suspension, Body in White (BIW), etc. Among them, the rear-glass joint is a major source for vehicle interior noise, and can cause S/R noises under a variety of environmental and driving conditions. This study uses, two approaches, experimental and numerical approaches, to define the cause of S/R noise at the rear-glass section. Based on these two approaches, this study confirms that S/R noises generate through the contact between bottom side of molding and BIW. The sealant penetration length, panelmolding distance, and sealant width are the parameters affecting noise generation. In addition, this study created an optimal design with Design of Experiments (DOE) of the rear-glass joint. The design maximized the sealant penetration length, which is a parameter that majorly affects noise. The optimal design comprises of two steps: sealant injections shape optimization and rear-glass joint parameter optimization. Each step is carried out with FEA and validated by sealant penetration experiments. Through these optimizations, this study obtained an optimum combination of design parameters and fignificantly reduced the noise generated by rear-glass section. 相似文献
33.
Kalle Olli Annemarie Clarke sa Danielsson Juris Aigars Daniel J. Conley Timo Tamminen 《Journal of Marine Systems》2008,73(3-4):284
In many parts of the world coastal waters with anthropogenic eutrophication have experienced a gradual depletion of dissolved silica (DSi) stocks. This could put pressure on spring bloom diatom populations, e.g. by limiting the intensity of blooms or by causing shifts in species composition. In addition, eutrophication driven enhanced diatom growth is responsible for the redistribution of DSi from the water phase to the sediments, and changes in the growth conditions may be reflected in the sediment diatom stratigraphy.To test for changes in diatom communities we have analyzed four sediment cores from the Baltic Sea covering approximately the last 100 years. The sediment cores originate from the western Gulf of Finland, the Kattegat, the Baltic Proper and the Gulf of Riga. Three out of the four cores reveal only minor changes in composition of diatom assemblages, while the Gulf of Riga core contains major changes, occurring after the second World War. This area is set apart from the other Baltic Sea basins by a high frequency of low after spring bloom DSi concentrations (< 2 µmol L− 1) during a relatively well defined time period from 1991–1998. In 1991 to 1993 a rapid decline of DSi spring concentrations and winter stocks (down to 5 µmol L− 1) in the Gulf was preceded by exceptionally intense diatom spring blooms dominated by the heavily silicified species Thalassiosira baltica (1991–1992; up to 5.5 mg ww L− 1). T. baltica has been the principal spring bloom diatom in the Gulf of Riga since records began in 1975. DSi consumption and biomass yield experiments with cultured T. baltica suggest that intense blooms can potentially exhaust the DSi stock of the water column and exceed the annual Si dissolution in the Gulf of Riga. The phytoplankton time series reveals another exceptional T. baltica bloom period in 1981–1983 (up to 8 mg L− 1), which, however, took place before the regular DSi measurements. These periods may be reflected in the conspicuous accumulation of T. baltica frustules in the sediment core corresponding to ca. 1975–1985. 相似文献
34.
Abstract The increasing capacity of technological tools, as well as the advent of geographic information systems, has multiplied the ability to process large sets of microdata. At the same time, modeling concerns and the quest for a more in-depth understanding of individual behaviors is requiring more, and better, data. The gap between scientific modeling and informational tools for decision-making seems to be widening. In the Greater Montreal area, large sets of microdata have been available for more than 30 years. Along with the development of modeling and planning tools, particular attention has been given to the continuous enlightening of planners and decision-makers with respect to the outcomes of the various surveys. This has led to the development of particular interactive tools, specifically addressed at local planners, which present the most significant information regarding travel and demography, for geopolitically relevant areas. This paper presents the most recent interactive tool that has been developed for local planners in the Montreal area. It integrates information from both the most recent travel survey held in the region and the Canadian census. It offers both ease of use and relevant analytical means to assist in exploring the complex relations between spatial locations, demographic features, and activity-travel indicators. 相似文献
35.
A multinomial choice framework was used to analyze data from hypothetical storm forecast scenarios administered via mail survey to a random sample of U.S. Gulf Coast residents. Results indicate that the issuance of a mandatory evacuation notice and the presence of higher wind speeds had the largest influence on increasing the likelihood of evacuation. Age, race, disability, distance, and education were significant in explaining one's decision to wait relative to choosing to evacuate. Blacks and disabled individuals were strictly less likely to wait and more likely to make an immediate evacuation decision. Hurricane Katrina evacuees and those with an evacuation destination identified were also more likely to decide to evacuate, but were also more likely to wait before deciding. Results indicate that residents of mobile homes were more likely to either evacuate or wait before making a decision, but strictly less likely not to evacuate. Respondents very confident in being rescued were strictly more likely not to evacuate. Results indicate that not having an evacuation destination identified was the most influential factor regarding the likelihood of not knowing what choice to make. 相似文献
36.
Abstract In the early 1970s, Seattle Piers 90/91 were declared surplus federal property by the GSA. These obsolescent half‐mile‐long piers and their adjacent uplands were purchased by the Port of Seattle for redevelopment. This urban waterfront site of almost 200 acres presents the Port of Seattle with a number of severe planning problems. While it is the last large deep‐water site on Elliott Bay, it is also in a very sensitive location, since it is overlooked on two sides by vocal residential communities with a history of active intervention in development projects on visual and other environmental grounds. At Piers 90/91, public concerns over the visual effects of port redevelopment include: 1. nuisance effects of night‐operations lighting on adjacent hillside residences; 2. nighttime obstruction of distant views due to increased foreground illumination; 3. day and night view obstruction by tall structures such as container‐handling cranes; 4. alteration of the character of both day and nighttime views by new port facilities. As part of a program to study the effects of alternative redevelopment strategies for Piers 90/91, the Port has undertaken a through examination of the visual effects of different uses, their visual appropriateness, and the ways by which adverse visual effects can be mitigated. The results were incorporated into an environmental impact statement which documented compliance with the Seattle Shoreline Master Program and with view protection and glare provisions of the City's S.E.P.A. guidelines. A systematic Visual Resource Management (VRM) approach was successfully employed on this coastal zone project. Major elements included visibility mapping, key view selection, analysis of existing visual character, simulation of alternatives, assessment of relative visual compatibility, and determination of effective mitigation measures. Community involvement has also been a critical element in this approach to assessing and managing the visual effects of redevelopment in a major urban port. 相似文献
37.
S. H. Lee T. W. Park K. H. Chung K. H. Choi K. K. Kim K. H. Moon 《International Journal of Automotive Technology》2011,12(1):75-82
HILS (Hardware In the Loop Simulation) and RBT (Requirement-Based Testing) are widely used to evaluate the performance and
reliability of automotive ECUs (Electronic Control Units). The HILS method is used to predict the behavior of ECU-installed
vehicles and to evaluate the performance of ECU controllers. RBT evaluates whether the embedded system satisfies the pre-defined
requirements. In this study, the behavior of a vehicle is regarded as a system requirement, and an embedded system test procedure
that evaluates the system requirement is proposed. In particular, a new method is introduced, which integrates HILS with RBT.
Using the proposed method, the behavior of an articulated vehicle equipped with an AWS (All Wheel Steering) ECU is evaluated
with RBT software. 相似文献
38.
Daniel Ainalis Vincent Rouillard Michael Sek 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2016,54(6):765-783
This paper describes the application of a practical analytical technique based on the random decrement method to estimate the rigid sprung mass dynamic characteristics (frequency response function) of road vehicles using only vibration response data during constant-speed operation. A brief history and development of the random decrement technique is presented, along with a summary of work undertaken on optimal parameter selection to establish the random decrement signature. Two approaches to estimate the dynamic characteristics from the random decrement signature are described and evaluated. A custom, single-wheeled vehicle (physical quarter car) was commissioned to undertake a series of on-the-road experiments at various nominally constant operating speeds. The vehicle, also instrumented as an inertial profilometer, simultaneously measured the longitudinal pavement profile to establish the vehicle's actual dynamic characteristics during operation. The main outcome of the paper is that the random decrement technique can be used to provide accurate estimates of the sprung mass mode of the vehicle's dynamic characteristics for both linear and nonlinear suspension systems of an idealised vehicle. 相似文献
39.
Daniel Brand 《Transportation》1972,1(3):247-264
This paper develops recommendations for improving in an evolutionary manner the performance of our urban ground transportation systems. The strengths and limitations of present static control technology and current computer traffic signal and freeway surveillance and control systems in urban areas are described. A taxonomy of possible information and control configurations in urban traffic operations is developed. The alternatives in the taxonomy are analysed and used as the basis for recommending specific real time information and control functions for improving, in an evolutionary manner, the performance of urban ground transportation systems. The recommended improvements would allow for the first time a meaningful substitution of operational control for physical (static) capacity increases in urban transportation. 相似文献
40.
This paper is an attempt to illustrate the stance of the Soviet Union in the law of the sea debate in the light of Soviet ocean activities. The paper has two sections. First, it examines the range of Soviet ocean activities. The considerable extent of Soviet ocean use underscores the importance which the Soviet Union places on the law of the sea debate and its consequent active participation in the process of international negotiation. Second, the paper considers the published record of the Soviet Union in the United Nations seabed debate. In seven years of debate the United Nations General Assembly and the Ad Hoc and permanent Seabed Commities and sub-Commities have generated a considerable body of documantation reflecting the public policy of over one hundred States concerning the law of the sea. Soviet expressions of opinion alone cover more than five hundred pages of documentation. Specific Soviet positions can be considered within two ganeral preferences: the protection of traditional freedoms of the high seas and opposition to ocean control by either coastal States or by an independent international ocean authority. The paper shows how these preferences and the specific Soviet negotiating positions defend and promote the maritime interests of the Soviet Union. 相似文献