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71.
To test a recent suggestion that perceptual learning in visual search is non-specific, two groups of subjects were trained on visual search tasks and tested for transfer of learning to new tasks. One group was trained on parallel ("pop-out") tasks and transferred to serial, conjunction tasks and the other group trained on conjunction and transferred to pop-out. Some (not all) tasks which are initially serial, rapidly became parallel. Some transfer occurred between the different types of tasks. Under some conditions transfer was either absent or even negative. The specificities observed may reflect the roles of the brain regions involved in learning. 相似文献
72.
PJ Heins KA Karpinia JW Maruniak JE Moorhead CH Gibbs 《Canadian Metallurgical Quarterly》1998,69(7):812-818
Probing pain threshold (PPT) assessments were conducted in the facial and oral sulci of maxillary central incisors and first molars of 10 periodontally healthy adults. All subjects were systemically healthy, free of pain, and reported no current medication usage. A computer-linked electronic probe, modified to deliver steadily increasing forces up to 200 grams, was used to collect the data. The system contained a subject operated "off-switch" which, upon activation, signaled the computer to record the subject's PPT. Assessments of each subject's PPTs were conducted on 3 separate occasions at 7-day intervals. Results indicated that the facial sulci of the incisors were the most pain sensitive. They displayed a mean PPT of 50.9 +/- 26.6 grams. The oral sulci of the incisors exhibited a mean PPT of 76.5 +/- 45.2 grams. Facial and oral sulci of the molars evidenced mean PPT values of 102.6 +/- 52.1 grams and 113.5 +/- 51.3 grams, respectively. These data suggest that sulci associated with incisor teeth are nearly twice as pain sensitive as sulci associated with molar teeth. In addition, facial sulci are significantly more pain sensitive than oral sulci. Data did not indicate a visit effect nor a side-of-mouth effect on PPT values. 相似文献
73.
CH Park K Nishimura M Kitano K Matsuda Y Okamoto T Ban 《Canadian Metallurgical Quarterly》1996,111(5):1092-1102
This study investigated the mechanism of right ventricular failure during bypass of the left side of the heart by precisely assessing right ventricular function with use of a conductance catheter. Bypass of the left side of the heart was established with a centrifugal pump in 10 mongrel dogs weighing 11 to 19 kg. Right ventricular function during left heart bypass was evaluated by two parameters that were both derived from measurement of relative change in right ventricular volume by the conductance catheter technique. One parameter was the right ventricular end-systolic pressure-volume relationship as a load-independent index, and the other was the peak right ventricular pressure-right ventricular stroke volume relationship as a "force-velocity relationship." These parameters were measured in both normal and failing hearts while afterload was increased by bilateral intrapulmonary balloon inflation. Moreover, changes in these relationships were observed by varying assist ratios of left heart bypass from 0% to 100%. Failing heart models were induced by normothermic aortic clamping for 20 minutes. The right ventricular end-systolic pressure-volume relationship in normal hearts did not change, irrespective of the assist ratio of left heart bypass, whereas that in failing hearts decreased from 4.25 +/- 1.41 mm Hg/ml without bypass of the left side of the heart to 3.53 +/- 1.30 mm Hg/ml after 100% assist of left heart bypass (p < 0.05). In the peak right ventricular pressure-right ventricular stroke volume relationship, right ventricular stroke volume was almost constant in normal hearts when afterload was increased regardless of the assist ratio of left heart bypass. Moreover, right ventricular stroke volume was maintained at a higher level during bypass of the left side of the heart compared with that without left heart bypass. However, that slope of the relationship in failing hearts was inversely linear and became significantly steeper after 100% assist of bypass of the left side of the heart compared with that without left heart bypass (-0.131 +/- 0.042 versus -0.051 +/- 0.038, p < 0.005). Therefore ++these two slopes of the relationship intersected at a point that was considered the critical point of afterload during bypass of the left side of the heart. In other words, right ventricular stroke volume was decreased by 100% left heart bypass above the critical point of afterload. In conclusion, this study demonstrates not only that bypass of the left side of the heart results in an increase in right ventricular stroke volume in both normal and failing hearts at the physiologic range of afterload, but also that right ventricular function against higher afterload is impaired by 100% assist of bypass of the left side of the heart in failing hearts. 相似文献
74.
Toby Walsh 《Annals of Mathematics and Artificial Intelligence》2011,62(1-2):7-26
When agents are acting together, they may need a simple mechanism to decide on joint actions. One possibility is to have the agents express their preferences in the form of a ballot and use a voting rule to decide the winning action(s). Unfortunately, agents may try to manipulate such an election by mis-reporting their preferences. Fortunately, it has been shown that it is NP-hard to compute how to manipulate a number of different voting rules. However, NP-hardness only bounds the worst-case complexity. In this survey article, we summarize the evidence for and against computational complexity being a barrier to manipulation. We look both at techniques identified to increase complexity (for example, hybridizing together two or more voting rules), as well as other features that may change the computational complexity of computing a manipulation (for example, if votes are restricted to be single peaked then some of the complexity barriers fall away). We discuss recent theoretical results that consider the average case, as well as simple greedy and approximate methods. We also describe how computational ??phase transitions??, which have been fruitful in identifying hard instances of propositional satisfiability and other NP-hard problems, have provided insight into the hardness of manipulating voting rules in practice. Finally, we consider manipulation of other related problems like stable marriage and tournament problems. 相似文献
75.
Stuart D.C. Walsh Martin O. Saar Peter Bailey David J. Lilja 《Computers & Geosciences》2009,35(12):2353-2364
Many complex natural systems studied in the geosciences are characterized by simple local-scale interactions that result in complex emergent behavior. Simulations of these systems, often implemented in parallel using standard central processing unit (CPU) clusters, may be better suited to parallel processing environments with large numbers of simple processors. Such an environment is found in graphics processing units (GPUs) on graphics cards.This paper discusses GPU implementations of three example applications from computational fluid dynamics, seismic wave propagation, and rock magnetism. These candidate applications involve important numerical modeling techniques, widely employed in physical system simulations, that are themselves examples of distinct computing classes identified as fundamental to scientific and engineering computing. The presented numerical methods (and respective computing classes they belong to) are: (1) a lattice-Boltzmann code for geofluid dynamics (structured grid class); (2) a spectral-finite-element code for seismic wave propagation simulations (sparse linear algebra class); and (3) a least-squares minimization code for interpreting magnetic force microscopy data (dense linear algebra class). Significant performance increases (between 10× and 30× in most cases) are seen in all three applications, demonstrating the power of GPU implementations for these types of simulations and, more generally, their associated computing classes. 相似文献
76.
Performing and composing for interactive audiovisual system presents many challenges to the performer. Working with visual, sonic and gestural components requires new skills and new ways of thinking about performance. However, there are few studies that focus on performer experience with interactive systems. We present the work Blue Space for oboe and interactive audiovisual system, highlighting the evolving process of the collaborative development of the work. We consider how musical and technical demands interact in this process, and outline the challenges of performing with interactive systems. Using the development of Blue Space as a self-reflective case study, we examine the role of gestures in interactive audiovisual works and identify new modes of performance. 相似文献
77.
The development of healthy schools to support and nature the well-being of students, teachers, and staff is proposed as a first step toward the goal of comprehensive health education. A focus on healthy schools incorporates elements of an expanded concept of comprehensive health education that demands careful consideration of the physical, psychological, and social environment of the nation's schools--worksite to 51 million (students, teachers, and staff). The active participation of all stakeholders in environmental assessments, health and safety audits, and restructuring of schools is an essential part of the school reform movement. A healthy worksite concept supports the transformation of the school environment to increase "productivity" by enhancing the ability of teachers, staff, and students to function well. 相似文献
78.
Residuals of facial paralysis consist of a great variety of cosmetic and functional anomalies which differ in quality and/or quantity. An internationally standardized evaluation of such defects is mandatory for the assessment of the results of different therapeutic procedures. In the present study, a system has been developed to record the results of facial paralysis following therapy. Such a system does not require specialized training, instrumentation or require significant time for completion. A clearly-defined "Yes-No" evaluation criteria is established which creates a high interscorer reliability. The usefulness of this scoring system was tested by three examiners on 42 patients following facial nerve surgery, with an obtained interscorer reliability of 93%. 相似文献
79.
Goodyear Rodney K.; Abadie Philip D.; Walsh W. Bruce 《Canadian Metallurgical Quarterly》1983,30(2):283
Examined the graduate school origins of authors of Journal of Counseling Psychology (JCP) articles in Volumes 15–28 to extend a previous analysis of Volumes 1–24 by the 3rd author et al (1969). Comparisons of the 2 14-yr periods reveal that some universities retained the same or similar ranks across both periods, some declined in importance as sources of authors, and others emerged as major sources of JCP authors. (6 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
80.