全文获取类型
收费全文 | 4280篇 |
免费 | 256篇 |
国内免费 | 3篇 |
学科分类
工业技术 | 4539篇 |
出版年
2024年 | 3篇 |
2023年 | 43篇 |
2022年 | 47篇 |
2021年 | 206篇 |
2020年 | 133篇 |
2019年 | 136篇 |
2018年 | 158篇 |
2017年 | 133篇 |
2016年 | 178篇 |
2015年 | 118篇 |
2014年 | 170篇 |
2013年 | 363篇 |
2012年 | 287篇 |
2011年 | 389篇 |
2010年 | 231篇 |
2009年 | 237篇 |
2008年 | 232篇 |
2007年 | 211篇 |
2006年 | 174篇 |
2005年 | 120篇 |
2004年 | 127篇 |
2003年 | 111篇 |
2002年 | 99篇 |
2001年 | 54篇 |
2000年 | 57篇 |
1999年 | 53篇 |
1998年 | 94篇 |
1997年 | 73篇 |
1996年 | 45篇 |
1995年 | 39篇 |
1994年 | 31篇 |
1993年 | 26篇 |
1992年 | 13篇 |
1991年 | 17篇 |
1990年 | 20篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 14篇 |
1986年 | 6篇 |
1985年 | 14篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 3篇 |
1980年 | 6篇 |
1978年 | 4篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1967年 | 3篇 |
1966年 | 2篇 |
排序方式: 共有4539条查询结果,搜索用时 40 毫秒
81.
E. Castillo D.P. Morales G. Botella A. García L. Parrilla A.J. Palma 《Digital Signal Processing》2013,23(6):1897-1909
This paper describes a novel model for fetal heart rate (FHR) monitoring from single-lead mother?s abdomen ECG (AECG) measurements. This novel method is divided in two stages: the first step consists on a one-step wavelet-based preprocessing for simultaneous baseline and high-frequency noise suppression, while the second stage efficiently detects fetal QRS complexes allowing FHR monitoring. The presented structure has been simplified as much as possible, in order to reduce computational cost and thus enable possible custom hardware implementations. Moreover, the proposed scheme and its fixed-point modeling have been tested using real abdominal ECG signals, which allow the validation of the presented approach and provide high accuracy. 相似文献
82.
Álvaro Rubio-Largo Miguel A. Vega-Rodríguez Juan A. Gómez-Pulido Juan M. Sánchez-Pérez 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2013,17(2):199-211
Nowadays, the most promising technology for designing optical networks is the wavelength division multiplexing. This technique divides the huge bandwidth of an optical fiber link into different wavelengths, providing different available channels per link. However, a problem comes up when it is necessary to interconnect a set of traffic demands. This problem is known as routing and wavelength assignment problem, and due to its complexity (NP-hard problem) it is very suitable for being solved using evolutionary computation. The selected heuristics is the artificial bee colony algorithm, an heuristics based on the behavior of honeybee foraging for nectar. Therefore, we have applied multiobjective optimization to solve the static routing and wavelength assignment problem, and adapted this algorithm to the multiobjective context. New results have been obtained that significantly improve those published in previous researches. 相似文献
83.
84.
Within the enterprise, information infrastructure as the mean to bring together different software applications is the key component to enable cooperation and information and knowledge exchange in an open-distributed environment. The paper addresses the issues of industrial application integration in business processes using agent-enabled service-oriented architectures (SOA). In this paper, we show that agent-enabled SOA can play an important role for service integration. Our framework combines Web services (WS) and intelligent agent technologies orchestrated by a business process management system. This framework looks for unification of agent and WS service models, is grounded in a semantic SOA of an agent platform and is supported by the Component Agent Platform Over .NET Framework agent platform tools. We describe the architecture and illustrate the approach by an industrial application scenario from petroleum wells’ drilling. 相似文献
85.
Dynamic memory allocation has been used for decades. However, it has seldom been used in real-time systems since the worst
case of spatial and temporal requirements for allocation and deallocation operations is either unbounded or bounded but with
a very large bound.
In this paper, a new allocator called TLSF (Two Level Segregated Fit) is presented. TLSF is designed and implemented to accommodate
real-time constraints. The proposed allocator exhibits time-bounded behaviour, O(1), and maintains a very good execution time. This paper describes in detail the data structures and functions provided by
TLSF. We also compare TLSF with a representative set of allocators regarding their temporal cost and fragmentation.
Although the paper is mainly focused on timing analysis, a brief study and comparative analysis of fragmentation incurred
by the allocators has been also included in order to provide a global view of the behaviour of the allocators.
The temporal and spatial results showed that TLSF is also a fast allocator and produces a fragmentation close to that caused
by the best existing allocators.
相似文献
Alfons Crespo (Corresponding author)Email: |
86.
So far, most of the applications of robotic technology to education have mainly focused on supporting the teaching of subjects
that are closely related to the Robotics field, such as robot programming, robot construction, or mechatronics. Moreover,
most of the applications have used the robot as an end or a passive tool of the learning activity, where the robot has been
constructed or programmed. In this paper, we present a novel application of robotic technologies to education, where we use
the real world situatedness of a robot to teach non-robotic related subjects, such as math and physics. Furthermore, we also
provide the robot with a suitable degree of autonomy to actively guide and mediate in the development of the educational activity.
We present our approach as an educational framework based on a collaborative and constructivist learning environment, where
the robot is able to act as an interaction mediator capable of managing the interactions occurring among the working students.
We illustrate the use of this framework by a 4-step methodology that is used to implement two educational activities. These
activities were tested at local schools with encouraging results. Accordingly, the main contributions of this work are: i) A
novel use of a mobile robot to illustrate and teach relevant concepts and properties of the real world; ii) A novel use of
robots as mediators that autonomously guide an educational activity using a collaborative and constructivist learning approach;
iii) The implementation and testing of these ideas in a real scenario, working with students at local schools.
相似文献
Alvaro Soto (Corresponding author)Email: |
87.
Andrew Grayland Chris Jefferson Ian Miguel Colva M. Roney-Dougal 《Annals of Mathematics and Artificial Intelligence》2009,57(1):75-102
Variable symmetries in a constraint satisfaction problem can be broken by adding lexicographic ordering constraints. Existing general methods of generating such sets of ordering constraints can require a huge number of constraints. This adds an unacceptable overhead to the solving process. Methods exist by which this large set of ordering constraints can be reduced to a much smaller set automatically, but their application is also prohibitively costly. In contrast, this paper takes a bottom-up approach. It examines some commonly-occurring families of groups and derives a minimal set of ordering constraints sufficient to break the symmetry each group describes. These minimal sets are then used as building blocks to generate minimal sets of ordering constraints for groups constructed via direct and imprimitive wreath products. Experimental results confirm the value of minimal sets of ordering constraints, which can now be generated much more cheaply than with previous methods. 相似文献
88.
J García Marco A Miguel Sosa J García Conde A Miguel García C Arbona V Escrig I Benet I Navarro A Ruiz F Carbonell 《Canadian Metallurgical Quarterly》1994,39(4):241-244
PURPOSE: To assess the "in vivo" effect of 13-cis-retinoic acid and low dose Ara-C in MDS as well as to establish "in vitro" advantage of retinoid dose-related growth pattern on bone marrow cultures as defined by culture timing and CFU-GM proliferative response. PATIENTS AND METHODS: We evaluated 28 patients diagnosed of MDS according to FAB classification, of whom 4 cases had RA, 8 cases SRA, 14 cases RAEB and 2 cases RAEB-T. Patients who had RA and SRA were treated with oral 13-cis-retinoic acid at doses of 20-40 mg daily for 4 months and those cases with RAEB and RAEB-T had subcutaneous Ara-C at doses of 3 mg/m2 twice a day for 21 days. The "in vivo" and "in vitro" effect of retinoic acid on the haemopoietic differentiation was evaluated by the growth CFU-GM in semisolid cell culture methods. RESULTS: Increasing in vitro concentrations of 13-cis retinoic acid did not enhance the growth of myelodysplastic progenitors. Nevertheless, our study did not find any beneficial therapeutic effect of retinoic compounds in MDS patients. In this study, low-dose Ara-C (3 mg/m2) showed similar effects when compared with higher doses reported by others. Furthermore, in terms of CFU-GM proliferation the concentration of colonies before and after treatment were fairly similar in all but two patients. CONCLUSIONS: The results drawn from our study demonstrated that there is no beneficial advantage of 13-cis-retinoic acid as a differentiation inducing agent on myelodysplastic patients. In contrast, lower doses of Ara-C showed similar effects on haemopoiesis of MDS patients than standard doses of 10-20 mg/m2 but with less side effects. 相似文献
89.
Fouto Ana R. Nunes Rita G. Pinto Joana Alves Luísa Calado Sofia Gonçalves Carina Rebolo Margarida Viana-Baptista Miguel Vilela Pedro Figueiredo Patrícia 《Magma (New York, N.Y.)》2022,35(5):779-790
Magnetic Resonance Materials in Physics, Biology and Medicine - Histogram-based metrics extracted from diffusion-tensor imaging (DTI) have been suggested as potential biomarkers for cerebral small... 相似文献
90.
Ortega-Cabezas Pedro Miguel Colmenar-Santos Antonio Borge-Diez David Blanes-Peiró Jorge Juan Higuera-Pérez Jorge Alcaide Eric 《Software Quality Journal》2022,30(3):687-728
Software Quality Journal - The number of electronic control units (ECU) installed in vehicles is increasingly high. Manufacturers must improve the software quality and reduce cost by proposing... 相似文献