全文获取类型
收费全文 | 2627篇 |
免费 | 82篇 |
国内免费 | 95篇 |
专业分类
电工技术 | 106篇 |
综合类 | 68篇 |
化学工业 | 334篇 |
金属工艺 | 50篇 |
机械仪表 | 77篇 |
建筑科学 | 21篇 |
矿业工程 | 16篇 |
能源动力 | 126篇 |
轻工业 | 21篇 |
水利工程 | 3篇 |
石油天然气 | 12篇 |
武器工业 | 8篇 |
无线电 | 678篇 |
一般工业技术 | 516篇 |
冶金工业 | 21篇 |
原子能技术 | 35篇 |
自动化技术 | 712篇 |
出版年
2024年 | 8篇 |
2023年 | 28篇 |
2022年 | 36篇 |
2021年 | 46篇 |
2020年 | 51篇 |
2019年 | 44篇 |
2018年 | 46篇 |
2017年 | 63篇 |
2016年 | 68篇 |
2015年 | 49篇 |
2014年 | 130篇 |
2013年 | 143篇 |
2012年 | 144篇 |
2011年 | 220篇 |
2010年 | 158篇 |
2009年 | 186篇 |
2008年 | 241篇 |
2007年 | 171篇 |
2006年 | 147篇 |
2005年 | 106篇 |
2004年 | 95篇 |
2003年 | 93篇 |
2002年 | 78篇 |
2001年 | 52篇 |
2000年 | 83篇 |
1999年 | 44篇 |
1998年 | 45篇 |
1997年 | 47篇 |
1996年 | 28篇 |
1995年 | 31篇 |
1994年 | 22篇 |
1993年 | 20篇 |
1992年 | 20篇 |
1991年 | 21篇 |
1990年 | 12篇 |
1989年 | 13篇 |
1988年 | 8篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有2804条查询结果,搜索用时 0 毫秒
81.
Bruno Juliá-Díaz Joseph M. Burdis Frank Tabakin 《Computer Physics Communications》2006,174(11):914-934
This Mathematica 5.2 package1 is a simulation of a Quantum Computer. The program provides a modular, instructive approach for generating the basic elements that make up a quantum circuit. The main emphasis is on using the density matrix, although an approach using state vectors is also implemented in the package. The package commands are defined in Qdensity.m which contains the tools needed in quantum circuits, e.g., multiqubit kets, projectors, gates, etc. Selected examples of the basic commands are presented here and a tutorial notebook, Tutorial.nb is provided with the package (available on our website) that serves as a full guide to the package. Finally, application is made to a variety of relevant cases, including Teleportation, Quantum Fourier transform, Grover's search and Shor's algorithm, in separate notebooks: QFT.nb, Teleportation.nb, Grover.nb and Shor.nb where each algorithm is explained in detail. Finally, two examples of the construction and manipulation of cluster states, which are part of “one way computing” ideas, are included as an additional tool in the notebook Cluster.nb. A Mathematica palette containing most commands in QDENSITY is also included: QDENSpalette.nb.
Program summary
Title of program: QDENSITYCatalogue identifier: ADXH_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADXH_v1_0Program available from: CPC Program Library, Queen's University of Belfast, N. IrelandOperating systems: Any which supports Mathematica; tested under Microsoft Windows XP, Macintosh OS X, and Linux FC4Programming language used: Mathematica 5.2No. of bytes in distributed program, including test data, etc.: 180 581No. of lines in distributed program, including test data, etc.: 19 382Distribution format: tar.gzMethod of solution: A Mathematica package is provided which contains commands to create and analyze quantum circuits. Several Mathematica notebooks containing relevant examples: Teleportation, Shor's Algorithm and Grover's search are explained in detail. A tutorial, Tutorial.nb is also enclosed. 相似文献82.
Quite often in database search, we only need to extract portion of the information about the satisfying item. We consider
this problem in the following form: the database of N items is separated into K blocks of size b = N / K elements each and
an algorithm has just to find the block containing the item of interest. The queries are exactly the same as in the standard
database search problem. We present a quantum algorithm for this problem of partial search that takes about 0.34 fewer iterations than the quantum search algorithm. 相似文献
83.
Gas adsorption has an important influence on gas flow in a coal body. Research on the characteristics of coal and gas adsorption is the theoretical basis for studying gas flow in coal. In this paper, the interaction between methane, carbon dioxide and surface molecules of anthracite was simulated using the quantum chemistry method. Adsorption energy and adsorption configurations of different quantities of gas molecules absorbed on the coal surface were calculated. The results show that adsorption between coal and the two kinds of gas molecules is a physical adsorption process and there is an optimal configuration. Gas molecules are more easily adsorbed in the hydroxyl-containing side chain, while it is difficult for them to be adsorbed at the position of the benzene ring. Besides, carbon dioxide molecules are more readily adsorbed on the coal surface than methane molecules. The findings have an important significance in revealing the nature of gas adsorption in coal. 相似文献
84.
Adenilton J. da SilvaAuthor Vitae Wilson R. de OliveiraAuthor VitaeTeresa B. LudermirAuthor Vitae 《Neurocomputing》2012,75(1):52-60
A supervised learning algorithm for quantum neural networks (QNN) based on a novel quantum neuron node implemented as a very simple quantum circuit is proposed and investigated. In contrast to the QNN published in the literature, the proposed model can perform both quantum learning and simulate the classical models. This is partly due to the neural model used elsewhere which has weights and non-linear activations functions. Here a quantum weightless neural network model is proposed as a quantisation of the classical weightless neural networks (WNN). The theoretical and practical results on WNN can be inherited by these quantum weightless neural networks (qWNN). In the quantum learning algorithm proposed here patterns of the training set are presented concurrently in superposition. This superposition-based learning algorithm (SLA) has computational cost polynomial on the number of patterns in the training set. 相似文献
85.
基于QPSO-LSSVM的数据库相似重复记录检测算法 总被引:1,自引:0,他引:1
针对大规模数据库的相似重复记录的检测问题,提出了一种量子群优化算法(QPSO)与最小二乘支持向量
机(LSSVM)相结合的相似重复记录检测方法(QPSC}LSSVM)。首先计算记录字段的相似度值;然后利用QPSO对
LSSVM参数进行优化,构建相似重复记录检测模型;最后通过具体数据集进行仿真测试实验。仿真结果表明,QPSCL
LSSVM不仅提高了重复记录检测准确率,而且提高了检测效率,是一种有效的相似重复记录检测算法。 相似文献
86.
从两个方面对量子演化算法进行改进:(1)因量子染色体的量子位处于叠加态和纠缠态,无法使用传统的交叉方式对量子位进行操作,设计了针对测量后的经典染色体进行全干扰交叉,这样既不会破坏量子染色体的固有的并行性,又可以增加测量后染色体的多样性,继而影响量子染色体进化方向,加快算法的收敛速度,有效地防止"早熟";(2)设计了概率触发器启动量子非门进行量子变异。实验表明,改进的量子演化算法比起先前的算法具有更好的寻优能力,更稳定的收敛度。 相似文献
87.
The development, operation, and applications of two configurations of an integrated plasma-aided nanofabrication facility (IPANF) comprising low-frequency inductively coupled plasma-assisted, low-pressure, multiple-target RF magnetron sputtering plasma source, are reported. The two configurations of the plasma source have different arrangements of the RF inductive coil: a conventional external flat spiral “pancake” coil and an in-house developed internal antenna comprising two orthogonal RF current sheets. The internal antenna configuration generates a “unidirectional” RF current that deeply penetrates into the plasma bulk and results in an excellent uniformity of the plasma over large areas and volumes. The IPANF has been employed for various applications, including low-temperature plasma-enhanced chemical vapor deposition of vertically aligned single-crystalline carbon nanotips, growth of ultra-high aspect ratio semiconductor nanowires, assembly of optoelectronically important Si, SiC, and Al1-xInxN quantum dots, and plasma-based synthesis of bioactive hydroxyapatite for orthopedic implants. 相似文献
88.
针对故障模式之间存在交叉数据的诊断不确定问题,将多层激励函数的量子神经网络引入多传感器信息融合之中,提出一种基于量子神经网络的多传感器信息融合故障诊断算法。并将其应用到旋转机械故障诊断中,通过测试被诊断设备的振动速度和加速度信号,求出两传感器对各故障模式的故障隶属度,利用多层激励函数的量子神经网络进行信息融合,得到融合的各故障模式隶属度值,确定真正的故障模式,提高了故障诊断的准确率。 相似文献
89.
本文主要介绍水电厂现地控制单元的改造方案,详细介绍了Quantum系列PLC在功能实现和程序的编制上的应用技巧,现场实践证明该方案设计合理、运行稳定。 相似文献
90.
We investigate a quantum-correction method for Monte Carlo device simulation. The method consists of reproducing quantum mechanical
density-gradient simulation by classical drift-diffusion simulation with modified effective oxide thickness and work function
and using these modifications subsequently in Monte Carlo simulation. This approach is found to be highly accurate and can
be used fully automatically in a technology computer-aided design (TCAD) workbench project. As an example, the methodology
is applied to the Monte Carlo simulation of the on-current scaling in p- and n-type MOSFETs corresponding to a 65 nm node technology. In particular, it turns out that considering only the total threshold
voltage shift still involves a significant difference to a Monte Carlo simulation based on the combined correction of oxide
thickness and work function. Ultimately, this quantum correction permits to consider surface scattering as a combination of
specular and diffusive scattering where the conservation of energy and parallel wave vector in the specular part takes stress-induced
band structure modifications and hence the corresponding surface mobility changes on a physical basis into account. 相似文献