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排序方式: 共有3921条查询结果,搜索用时 31 毫秒
61.
Samuel Aupetit Virginie Gallier Jacques Riff Stéphane Espié Flavien Delgehier 《Ergonomics》2016,59(8):1109-1120
This article sets out to identify the typical risky situations experienced by novice motorcyclists in the real world just after licensing. The procedure consists of a follow-up of six novices during their first two months of riding with their own motorbike instrumented with cameras. The novices completed logbooks on a daily basis in order to identify the risky situations they encountered, and were given face-to-face interviews to identify the context and their shortcomings during the reported events. Data show a large number of road configurations considered as risky by the riders (248 occurrences), especially during the first two weeks. The results revealed that a lack of hazard perception skills contributed to the majority of these incidents. These situations were grouped together to form clusters of typical incident scenarios on the basis of their similarities. The most frequent scenario corresponds to a lane change in dense traffic (15% of all incidents). The discussion shows how this has enhanced our understanding of novice riders’ behaviour and how the findings can improve training and licensing. Lastly, the main methodological limitations of the study and some guidelines for improving future naturalistic riding studies are presented.
Practitioner Summary:
This article aims to identify the risky situations of novice motorcyclists in real roads. Two hundred forty-eight events were recorded and 13 incident scenarios identified. Results revealed that a lack of hazard perception contributed to the majority of these events. The most frequent scenario corresponds to a lane change in dense traffic. 相似文献
62.
The importance of traceability in software development has long been recognized, not only for reasons of legality and certification, but also to enable the development itself. At the same time, organizations are known to struggle to live up to traceability requirements, and there is an identified lack of studies on traceability practices in the industry, not least in the area of tooling and infrastructure. This paper presents, investigates and discusses Eiffel, an industry developed solution designed to provide real time traceability in continuous integration and delivery. The traceability needs of industry professionals are also investigated through interviews, providing context to that solution. It is then validated through further interviews, a comparison with previous traceability methods and a review of literature. It is found to address the identified traceability needs and found in some cases to reduce traceability data acquisition times from days to minutes, while at the same time alternatives offering comparable functionality are lacking. In this work, traceability is shown not only to be an important concern to engineers, but also regarded as a prerequisite to successful large scale continuous integration and delivery. At the same time, promising developments in technical infrastructure are documented and clear differences in traceability mindset between separate industry projects is revealed. 相似文献
63.
Road‐Centered Map‐Aided Localization for Driverless Cars Using Single‐Frequency GNSS Receivers 下载免费PDF全文
Zui Tao Philippe Bonnifait Vincent Frémont Javier Ibanez‐Guzman Stéphane Bonnet 《野外机器人技术杂志》2017,34(5):1010-1033
Accurate localization with high availability is a key requirement for autonomous vehicles. It remains a major challenge when using automotive sensors such as single‐frequency Global Navigation Satellite System (GNSS) receivers, a lane detection camera, and proprioceptive sensors. This paper describes a method that enables the estimation of stand‐alone single‐frequency GNSS errors by integrating the measurements from a forward‐looking camera matched with lane markings stored in a digital map. It includes a parameter identification method for a shaping model, which is evaluated using experimental data. An algebraic observability study is then conducted to prove that the proposed state vector is fully observable in a road‐oriented frame. This observability property is the basis to develop a road‐centered Extended Kalman filter (EKF) that can maintain the observability of every component of the state vector on any road, whatever its orientation. To accomplish this, the filter needs to handle road changes, which it does using bijective transformations. The filter was implemented and tested intensely on an experimental vehicle for driverless valet parking services. Field results have shown that the performance of the estimation process is better than solutions based on EKF implemented in a fixed working frame. The proposed filter guarantees that the drift along the road direction remains bounded. This is very important when the vehicle navigates autonomously. Furthermore, the road‐centered modeling improves the accuracy, consistency, and robustness of the localization solver. 相似文献
64.
Joseph A. Cazier Benjamin B. M. Shao Robert D. St. Louis 《Information Systems Frontiers》2007,9(5):515-529
This study explores how value congruence contributes to the formation of trust in e-businesses, and how trust and value congruence
influence consumers to share personal information. It is hypothesized that the perceived values of organizations regarding
moral, social, environmental and political causes can have an effect on the trusting beliefs of e-commerce consumers and their
willingness to disclose private personal information. A total of 775 subjects rated their perceived value congruence with
organizations, their trusting beliefs, and the types of information they would be willing to disclose. This study finds that
value congruence not only plays a role in mediating the trust of consumers for the organizations, but it also has a strong
effect on determining their willingness to disclose personal information. In some cases, the influence of value congruence
is greater than that of trust, even though trust has been touted in the literature as one of the most important factors in
e-commerce. This research expands prior work by using structural equation modeling to test the relative strength of the effect
of value congruence on each dimension of trust and the overall trust level, as well as its direct effect on behavioral intentions
in terms of information sharing for non-profit and for-profit organizations.
相似文献
Robert D. St. LouisEmail: |
65.
66.
Directionally solidified samples of an Al-2 wt% Ti alloy were annealed at temperatures between 435° C and 660° C to investigate the thermal stability of phases formed during an incomplete peritectic transformation. The proportion of Al3Ti present in the assolidified alloy is less than equilibrium up to about 480° C, and more than equilibrium at higher temperatures. Hence, Al3Ti particles will be stable up to about 500° C and will tend to dissolve at higher temperatures. Diffusion due to non-equilibrium composition of the phase continues at all temperatures but is sluggish up to about 600° C. The diffusion coefficient of Ti in Al at 635° C is estimated to be 2×10–11 cm2 sec–1. 相似文献
67.
P. Ståhle 《International Journal of Fracture》1983,22(3):203-216
The limit of validity of linear fracture mechanics is specified by the minimum allowable crack length through an ASTM convention. Extension into the non-linear region ought to imply an extension towards smaller allowable cracks. In order to elucidate the question “How short is the smallest crack that fits the methods of fracture mechanics, and how do shorter cracks than that behave?” a pilot investigation is carried out. The process region is modelled as a Barenblatt line region and plastic flow off-side the process region is neglected. Results show that instability occurs before the process region is fully developed (as at large cracks) if the crack is short. This implies large deviations from the large crack fracture mechanics if the crack is very small. Even cracks of infinitesimal length are included in the study. 相似文献
68.
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70.
This paper presents an overview of the image analysis techniques in the domain of histopathology, specifically, for the objective of automated carcinoma detection and classification. As in other biomedical imaging areas such as radiology, many computer assisted diagnosis (CAD) systems have been implemented to aid histopathologists and clinicians in cancer diagnosis and research, which have been attempted to significantly reduce the labor and subjectivity of traditional manual intervention with histology images. The task of automated histology image analysis is usually not simple due to the unique characteristics of histology imaging, including the variability in image preparation techniques, clinical interpretation protocols, and the complex structures and very large size of the images themselves. In this paper we discuss those characteristics, provide relevant background information about slide preparation and interpretation, and review the application of digital image processing techniques to the field of histology image analysis. In particular, emphasis is given to state-of-the-art image segmentation methods for feature extraction and disease classification. Four major carcinomas of cervix, prostate, breast, and lung are selected to illustrate the functions and capabilities of existing CAD systems. 相似文献