全文获取类型
收费全文 | 11654篇 |
免费 | 1390篇 |
国内免费 | 986篇 |
专业分类
电工技术 | 503篇 |
综合类 | 802篇 |
化学工业 | 716篇 |
金属工艺 | 1062篇 |
机械仪表 | 442篇 |
建筑科学 | 353篇 |
矿业工程 | 112篇 |
能源动力 | 82篇 |
轻工业 | 182篇 |
水利工程 | 47篇 |
石油天然气 | 113篇 |
武器工业 | 86篇 |
无线电 | 1799篇 |
一般工业技术 | 1617篇 |
冶金工业 | 2411篇 |
原子能技术 | 71篇 |
自动化技术 | 3632篇 |
出版年
2024年 | 72篇 |
2023年 | 271篇 |
2022年 | 389篇 |
2021年 | 492篇 |
2020年 | 411篇 |
2019年 | 293篇 |
2018年 | 239篇 |
2017年 | 315篇 |
2016年 | 319篇 |
2015年 | 366篇 |
2014年 | 519篇 |
2013年 | 591篇 |
2012年 | 655篇 |
2011年 | 997篇 |
2010年 | 716篇 |
2009年 | 779篇 |
2008年 | 776篇 |
2007年 | 783篇 |
2006年 | 735篇 |
2005年 | 723篇 |
2004年 | 652篇 |
2003年 | 510篇 |
2002年 | 459篇 |
2001年 | 383篇 |
2000年 | 232篇 |
1999年 | 183篇 |
1998年 | 166篇 |
1997年 | 161篇 |
1996年 | 137篇 |
1995年 | 128篇 |
1994年 | 101篇 |
1993年 | 90篇 |
1992年 | 68篇 |
1991年 | 40篇 |
1990年 | 51篇 |
1989年 | 42篇 |
1988年 | 38篇 |
1987年 | 7篇 |
1986年 | 13篇 |
1985年 | 13篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1979年 | 6篇 |
1977年 | 11篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1973年 | 5篇 |
1963年 | 5篇 |
1961年 | 5篇 |
1955年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
In executing tasks involving intelligent information processing, the human brain performs better than the digital computer. The human brain derives its power from a large number [O(1011)] of neurons which are interconnected by a dense interconnection network [O(105) connections per neuron]. Artificial neural network (ANN) paradigms adopt the structure of the brain to try to emulate the intelligent information processing methods of the brain. ANN techniques are being employed to solve problems in areas such as pattern recognition, and robotic processing. Simulation of ANNs involves implementation of large number of neurons and a massive interconnection network. In this paper, we discuss various simulation models of ANNs and their implementation on distributed memory systems. Our investigations reveal that communication-efficient networks of distributed memory systems perform better than other topologies in implementing ANNs. 相似文献
54.
研究了离散Hopfield神经网络(DHNN)和联想记忆神经网络的开关电流技术实现,利用多权输入跨导,开关电流延迟器(SID)和可编程电流比较器(PCC)实现了离散Hopield神经网络,并提出了利用离散Hopfield神经网络实现自联想记忆时相应的开关电流电路,所提出了开关电流神经网络适宜于超大规模集成,能在低电压(如3.3V)下工作。 相似文献
55.
This experiment was designed to use the graded dose-related amnesia produced by the benzodiazepine lorazepam (1.0, 2.0 mg/70 kg, oral) and the anticholinergic scopolamine (0.3, 0.6 mg/70 kg, subcutaneous) as a tool to explore the cognitive and neurochemical mechanisms underlying metamemory in the judgment of learning paradigm, with a placebo-controlled independent groups design in healthy volunteers (n=12/group). Results provide evidence for a pharmacological dissociation between effects on memory versus metamemory (relative accuracy of item-by-item monitoring) across a range of levels of memory performance and suggest that the drugs selectively impair those aspects of metamnemonic monitoring that require participants' awareness of their overall current state of functioning (absolute accuracy of prospective item-by-item monitoring, prospective global monitoring) but not those that rely solely on assessment of individual item characteristics (relative accuracy of item-by-item monitoring). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
56.
Hao Yin Chuang Lin Berton Sebastien Bo Li Geyong Min 《International Journal of Communication Systems》2005,18(8):711-729
Fast and accurate methods for predicting traffic properties and trend are essential for dynamic network resource management and congestion control. With the aim of performing online and feasible prediction of network traffic, this paper proposes a novel time series model, named adaptive autoregressive (AAR). This model is built upon an adaptive memory‐shortening technique and an adaptive‐order selection method originally developed by this study. Compared to the conventional one‐step ahead prediction using traditional Box–Jenkins time series models (e.g. AR, MA, ARMA, ARIMA and ARFIMA), performance results obtained from actual Internet traffic traces have demonstrated that the proposed AAR model is able to support online prediction of dynamic network traffic with reasonable accuracy and relatively low computation complexity. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
57.
Pascal Bondon 《时间序列分析杂志》2005,26(4):519-525
Abstract. The influence of missing observations on the linear prediction of a stationary time series is investigated. Simple bounds for the prediction error variance and asymptotic behaviours for short and long‐memory processes respectively are presented. 相似文献
58.
Porous NiTi shape memory alloy (SMA) is a novel biomedical material used for human hard tissue implant .The influence of elemental titanium powder characteristics such as powder morphology, particle size and specific surface area( SSA) on the minimal ignition temperature ,combustion temperature and final product of porous Ni-Ti SMA fabricated by combustion synthesis method was investigated in this paper by scanning electron microscopy (SEM) and laser diffraction.The preliminary data indicated that the titanium powder characteristics had a strong effect on combustion synthesis of porous NiTi SMA. 相似文献
59.
Sven Beyer Christian Jacobi Daniel Kröning Dirk Leinenbach Wolfgang J. Paul 《International Journal on Software Tools for Technology Transfer (STTT)》2006,8(4-5):411-430
In the verified architecture microprocessor (VAMP) project we have designed, functionally verified, and synthesized a processor
with full DLX instruction set, delayed branch, Tomasulo scheduler, maskable nested precise interrupts, pipelined fully IEEE
compatible dual precision floating point unit with variable latency, and separate instruction and data caches. The verification
has been carried out in the theorem proving system PVS. The processor has been implemented on a Xilinx FPGA.
A shorter version of this article with the title “Instantiating uninterpreted functional units and memory system: functional
verification of the VAMP” appeared in [8]. The work reported here was done while all the authors were with Saarland University. 相似文献
60.
Eye movements during natural tasks suggest that observers do not use working memory to capacity but instead use eye movements to acquire relevant information immediately before needed. Results here however, show that this strategy is sensitive to memory load and to observers' expectations about what information will be relevant. Depending upon the predictability of what object features would be needed in a brick sorting task, subjects spontaneously modulated the order in which they sampled and stored visual information using working memory more when the task was predictable and reverting to a just-in-time strategy when the task was unpredictable and the memory load was higher. This self organization was evidenced by subjects' sequence of eye movements and also their sorting decisions following missed feature changes. These results reveal that attentional selection, fixations, and use of working memory reflect a dynamic optimization with respect to a set of constraints, such as task predictablity and memory load. They also reveal that change blindness depends critically on the local task context, by virtue of its influence on the information selected for storage in working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献