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101.
Many time-critical applications require predictable performance in the presence of failures. This paper considers a distributed system with independent periodic tasks which can checkpoint their state on some reliable medium in order to handle failures. The problem of preemptively scheduling a set of such tasks is discussed where every occurrence of a task has to be completely executed before the next occurrence of the same task can start. Efficient scheduling algorithms are proposed which yield sub-optimal schedules when there is provision for fault-tolerance. The performance of the solutions proposed is evaluated in terms of the number of processors and the cost of the checkpoints needed. Moreover, analytical studies are used to reveal interesting trade-offs associated with the scheduling algorithms.This work has been supported by grants from the Italian Ministero dell'Università e della Ricerca Scientifica e Tecnologica and the Consiglio Nazionale delle Ricerche-Progetto Finalizzato Sistemi Informatici e Calcolo Parallelo. 相似文献
102.
Given a sequenceA of lengthM and a regular expressionR of lengthP, an approximate regular expression pattern-matching algorithm computes the score of the optimal alignment betweenA and one of the sequencesB exactly matched byR. An alignment between sequencesA=a1a2 ... aM andB=b1b2... bN is a list of ordered pairs, (i1,j1), (i2j2), ..., (it,jtt) such that ik < ik+1 and jk < jk+1. In this case the alignmentaligns symbols aik and bjk, and leaves blocks of unaligned symbols, orgaps, between them. A scoring schemeS associates costs for each aligned symbol pair and each gap. The alignment's score is the sum of the associated costs, and an optimal alignment is one of minimal score. There are a variety of schemes for scoring alignments. In a concave gap penalty scoring schemeS={, w}, a function (a, b) gives the score of each aligned pair of symbolsa andb, and aconcave function w(k) gives the score of a gap of lengthk. A function w is concave if and only if it has the property that, for allk > 1, w(k + 1) –w(k) w(k) –w(k –1). In this paper we present an O(MP(logM + log2
P)) algorithm for approximate regular expression matching for an arbitrary and any concavew.
This work was supported in part by the National Institute of Health under Grant RO1 LM04960. 相似文献
103.
Qi Jiyang Gao Yan Hu Yao Wang Xinggang Liu Xiaoyu Bai Xiang Belongie Serge Yuille Alan Torr Philip H. S. Bai Song 《International Journal of Computer Vision》2022,130(8):2022-2039
International Journal of Computer Vision - Can our video understanding systems perceive objects when a heavy occlusion exists in a scene? To answer this question, we collect a large-scale dataset... 相似文献
104.
Joan C. Lo Gerald J. Beck George A. Kaysen Christopher T. Chan Alan S. Kliger Michael V. Rocco Glenn M. Chertow for the FHN Study 《Hemodialysis international. International Symposium on Home Hemodialysis》2017,21(2):190-196
Introduction: End‐stage renal disease is associated with elevations in circulating prolactin concentrations, but the association of prolactin concentrations with intermediate health outcomes and the effects of hemodialysis frequency on changes in serum prolactin have not been examined. Methods: The FHN Daily and Nocturnal Dialysis Trials compared the effects of conventional thrice weekly hemodialysis with in‐center daily hemodialysis (6 days/week) and nocturnal home hemodialysis (6 nights/week) over 12 months and obtained measures of health‐related quality of life, self‐reported physical function, mental health and cognition. Serum prolactin concentrations were measured at baseline and 12‐month follow‐up in 70% of the FHN Trial cohort to examine the associations among serum prolactin concentrations and physical, mental and cognitive function and the effects of hemodialysis frequency on serum prolactin. Findings: Among 177 Daily Trial and 60 Nocturnal Trial participants with baseline serum prolactin measurements, the median serum prolactin concentration was 65 ng/mL (25th–75th percentile 48–195 ng/mL) and 81% had serum prolactin concentrations >30 ng/mL. While serum prolactin was associated with sex (higher in women), we observed no association between baseline serum prolactin and age, dialysis vintage, and baseline measures of physical, mental and cognitive function. Furthermore, there was no significant effect of hemodialysis frequency on serum prolactin in either of the two trials. Discussion: Serum prolactin concentrations were elevated in the large majority of patients with ESRD, but were not associated with several measures of health status. Circulating prolactin levels also do not appear to decrease in response to more frequent hemodialysis over a one‐year period. 相似文献
105.
106.
Unraveling Unprecedented Charge Carrier Mobility through Structure Property Relationship of Four Isomers of Didodecyl[1]benzothieno[3,2‐b][1]benzothiophene 下载免费PDF全文
Yusuke Tsutsui Guillaume Schweicher Basab Chattopadhyay Tsuneaki Sakurai Jean‐Baptiste Arlin Christian Ruzié Almaz Aliev Artur Ciesielski Alan R. Kennedy Vincent Lemaur Yoann Olivier Rachid Hadji Lionel Sanguinet Frédéric Castet Silvio Osella Dmytro Dudenko David Beljonne Jérôme Cornil Paolo Samorì Shu Seki Yves H. Geerts 《Advanced materials (Deerfield Beach, Fla.)》2016,28(33):7106-7114
107.
P. Jian D. G. Ivey R. Bruce G. Knight 《Journal of Materials Science: Materials in Electronics》1996,7(2):77-83
A detailed microstructural study has been done on Au-Pd-Zn ohmic contacts to p-type InGaAsP epitaxially grown on InP. The doping level in the InGaAsP was 1.0 × 1019 to 1.5 × 1019 cm–3 near the surface with the Zn concentration graded to a value of 7 × 1018 cm–3 at the InGaAsP-InP interface. Metal layers (10 nm Pd,3 nmZn, 25 nm Pd and 50 nm Au) were deposited sequentially by electron beam evaporation. Contact resistances less than 10–4 cm2 were achieved for all annealing temperatures studied (380–440 C) and a minimum contact resistance of 2 × 10–6 cm2 was obtained for an anneal at 400 C for 20 s. Comparisons were made to similar metallizations on p-type InP. Lower contact resistances were achieved for the quaternary material compared with the binary material, however, contact stability and uniformity were worse. 相似文献
108.
We demonstrate a microfluidic continuous-flow protein separation process in which silica-coated superparamagnetic nanoparticles
interact preferentially with hemoglobin in a mixture with bovine serum albumin, and the resulting hemoglobin-nanoparticle
aggregates are recovered online using magnetophoresis. We present detailed modeling and analysis of this process yielding
quantitative estimates of the recovery of both proteins, validated by experiments. While several previous studies utilize
an average particle size in modeling magnetophoretic particle trajectories or process design, in this study we emphasize the
importance of accounting for particle size distributions in calculating particle recovery, and therefore in estimating separation
efficiency. We combine experimentally measured size distributions of protein-nanoparticle aggregates with simulations of particle
trajectories and provide a simple analytical method to calculate the efficiency of separation at various flow speeds, which
fully accounts for heterogeneity in particle sizes. Our method can potentially be used for affinity based biomolecular separations
at both analytical and preparative scales by exploiting well-established techniques to functionalize nanoparticle surfaces
with selective ligands. Further, the modeling methodology presented here may be applied to provide better estimates of particle
recovery in a broad range of magnetophoretic separation processes involving heterogeneity in particle sizes. 相似文献
109.
Anush?Krishna?MoorthyEmail author Alan?Conrad?Bovik 《Multimedia Tools and Applications》2011,51(2):675-696
Creating algorithms capable of predicting the perceived quality of a visual stimulus defines the field of objective visual
quality assessment (QA). The field of objective QA has received tremendous attention in the recent past, with many successful
algorithms being proposed for this purpose. Our concern here is not with the past however; in this paper we discuss our vision
for the future of visual quality assessment research. We first introduce the area of quality assessment and state its relevance.
We describe current standards for gauging algorithmic performance and define terms that we will use through this paper. We
then journey through 2D image and video quality assessment. We summarize recent approaches to these problems and discuss in
detail our vision for future research on the problems of full-reference and no-reference 2D image and video quality assessment.
From there, we move on to the currently popular area of 3D QA. We discuss recent databases, algorithms and 3D quality of experience.
This yet-nascent technology provides for tremendous scope in terms of research activities and we summarize each of them. We
then move on to more esoteric topics such as algorithmic assessment of aesthetics in natural images and in art. We discuss
current research and hypothesize about possible paths to tread. Towards the end of this article, we discuss some other areas
of interest including high-definition (HD) quality assessment, immersive environments and so on before summarizing interesting
avenues for future work in multimedia (i.e., audio-visual) quality assessment. 相似文献
110.
The authors’ previous work discussed a scalable abstract knowledge representation and reasoning scheme for Pervasive Computing Systems, where both low-level and abstract knowledge is maintained in the form of temporal first-order logic (TFOL) predicates. Furthermore, we introduced a novel concept of a generalised event, an abstract event, which we define as a change in the truth value of an abstract TFOL predicate. Abstract events represent real-time knowledge about the system and they are defined with the help of well-formed TFOL expressions whose leaf nodes are concrete, low-level events using our AESL language.In this paper, we propose to simulate pervasive systems by providing estimated knowledge about its entities and situations that involve them. To achieve this goal, we enhance AESL with higher-order function predicates that denote approximate knowledge about the likelihood of a predicate instance having the value True with respect to a time reference. We define a mapping function between a TFOL predicate and a Bayesian network that calculates likelihood estimates for that predicate as well as a confidence level, i.e., a metric of how reliable the likelihood estimation is for that predicate.Higher-order likelihood predicates are implemented by a novel middleware component, the Likelihood Estimation Service (LES). LES implements the above mapping; first, for each abstract predicate, it learns a Bayesian network that corresponds to that predicate from the knowledge stored in the sensor-driven system. Once trained and validated, the Bayesian networks generate a likelihood estimate and a confidence level. This new knowledge is maintained in the middleware as approximate knowledge therefore providing a simulation of the pervasive system, in the absence of real-time data. Last but not least, we describe an experimental evaluation of our system using the Active BAT location system. 相似文献