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61.
Neonatal swimming behavior was studied after a single subcutaneous injection of L-dopa methyl ester (50 mg/kg; 200 mg/kg) apomorphine (0.1 mg/kg; 1.0 mg/kg), DL-amphetamine (0.5 mg/kg; 10 mg/kg), haloperidol (0.5 mg/kg; 1.0 mg/kg), L-tryptophan (50 mg/kg; 100 mg/kg), methysergide (1.0 mg/kg; 5.0 mg/kg) as well as intraventricular injection of 100 microgram 6-OHDA. 1-, 3-, 5- and 7-day-old rats were placed into a temperature-controlled aquarium (37 degrees C) and the pattern of motor coordination, latency time to swimming (LTS) and the number of foreleg strokes for 10 s (FS) were measured. When compared to the physiological saline-injected controls, rats that received L-dopa showed a striking increase of FS at all ages but the most striking improvement of motor coordination was found in newborn rats. On day 1 both doses of DL-amphetamine induced increases in FS and improvement of motor coordination, whereas apomorphine failed to show any effect at this age. On days 3, 5 and 7 low doses of DL-amphetamine and apomorphine increased the FS. However, high doses resulted in a decrement in swimming performance. Haloperidol impaired swimming on day 1 but produced a significant increase of FS on days 5 and 7. Neonatal injection of 6-OHDA delayed development of motor coordination, reduced FS and increased LTS. On days 3, 5 and 7 high doses of L-tryptophan elicited an increase of FS, while high doses of methysergide caused significant impairment of performance. It is suggested that the brain rapidly converts the administered L-dopa to dopamine during the first week of life and there appears to be a strong dependent relationship between the pattern of motor coordination and the amount of available dopamine in the developing brain.  相似文献   
62.
PACS, a computer program to simulate very slow settling of rigid equal spheres into a randomly packed bed, is described. Simulated packings of 6,000, 10,000, and 15,000 spheres are anisotropic. Mean void fraction is 0.42 and mean number of nearest neighbours 6.0. There are numerous cases of four spheres arranged in a tetrahedron, but no larger ordered regions. These findings, plus local voidage, distribution of circles in a section, angular distribution, and radial distribution are compared to theoretical and experimental results.  相似文献   
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An array of electrode tips with 6-microm center-to-center spacing, fabricated through chemical etching of an optical fiber bundle, and coated with gold, was used for initiating electrochemiluminescence (ECL) in an aqueous solution of Ru(bpy)3(2+) and tri-n-propylamine (TPrA). ECL generated at the tips of the electrodes in the array was detected with a CCD camera and exhibited both high sensitivity and high resolution. In the case in which the ECL signal could not be distinguished from the background, ECL signals could be obtained by pulsing the array and summing multiple CCD images. The behavior of this array was compared to a second array that consisted of individual electrodes insulated with an electrophoretic paint.  相似文献   
66.
The cerebellar model articulation controller (CMAC) has some attractive features, namely fast learning capability and the possibility of efficient digital hardware implementation. Although CMAC was proposed many years ago, several open questions have been left even for today. The most important ones are about its modeling and generalization capabilities. The limits of its modeling capability were addressed in the literature, and recently, certain questions of its generalization property were also investigated. This paper deals with both the modeling and the generalization properties of CMAC. First, a new interpolation model is introduced. Then, a detailed analysis of the generalization error is given, and an analytical expression of this error for some special cases is presented. It is shown that this generalization error can be rather significant, and a simple regularized training algorithm to reduce this error is proposed. The results related to the modeling capability show that there are differences between the one-dimensional (1-D) and the multidimensional versions of CMAC. This paper discusses the reasons of this difference and suggests a new kernel-based interpretation of CMAC. The kernel interpretation gives a unified framework. Applying this approach, both the 1-D and the multidimensional CMACs can be constructed with similar modeling capability. Finally, this paper shows that the regularized training algorithm can be applied for the kernel interpretations too, which results in a network with significantly improved approximation capabilities.  相似文献   
67.
We propose a novel approach to cross-lingual language model and translation lexicon adaptation for statistical machine translation (SMT) based on bilingual latent semantic analysis. Bilingual LSA enables latent topic distributions to be efficiently transferred across languages by enforcing a one-to-one topic correspondence during training. Using the proposed bilingual LSA framework, model adaptation can be performed by, first, inferring the topic posterior distribution of the source text and then applying the inferred distribution to an n-gram language model of the target language and translation lexicon via marginal adaptation. The background phrase table is enhanced with the additional phrase scores computed using the adapted translation lexicon. The proposed framework also features rapid bootstrapping of LSA models for new languages based on a source LSA model of another language. Our approach is evaluated on the Chinese–English MT06 test set using the medium-scale SMT system and the GALE SMT system measured in BLEU and NIST scores. Improvement in both scores is observed on both systems when the adapted language model and the adapted translation lexicon are applied individually. When the adapted language model and the adapted translation lexicon are applied simultaneously, the gain is additive. At the 95% confidence interval of the unadapted baseline system, the gain in both scores is statistically significant using the medium-scale SMT system, while the gain in the NIST score is statistically significant using the GALE SMT system.  相似文献   
68.
Cross-cultural psychologists assume that core cultural values define to a large extent what a culture is. Typically, core values are identified through an actual self-importance approach, in which core values are those that members of the culture as a group strongly endorse. In this article, the authors propose a perceived cultural importance approach to identifying core values, in which core values are values that members of the culture as a group generally believe to be important in the culture. In 5 studies, the authors examine the utility of the perceived cultural importance approach. Results consistently showed that, compared with values of high actual self-importance, values of high perceived cultural importance play a more important role in cultural identification. These findings have important implications for conceptualizing and measuring cultures. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
69.
电信运营商和电视运营商在为消费者提供视频内容服务上不断展开竞争。然而,与电视运营商相比,大部分电信运营商的基础设施还不具备传输高质量视频所需的带宽。因此,在内容分配上,电信运营商没有使用正交振幅调制(QAM)和MPEG2视频编码等数字调制技术,而是采用了互联网协议(IP)网络,利用MPEG4-Part10(也称为H.264-AVC)等新的编码方案来为消费者提供视频内容。  相似文献   
70.
This paper describes a dual-core 64-b Xeon MP processor implemented in a 65-nm eight-metal process. The 435-mm2 die has 1.328-B transistors. Each core has two threads and a unified 1-MB L2 cache. The 16-MB shared, 16-way set-associative L3 cache implements both sleep and shut-off leakage reduction modes. Long channel transistors are used to reduce subthreshold leakage in cores and uncore (all portions of the die that are outside the cores) control logic. Multiple voltage and clock domains are employed to reduce power  相似文献   
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