全文获取类型
收费全文 | 351602篇 |
免费 | 32849篇 |
国内免费 | 22187篇 |
专业分类
电工技术 | 30814篇 |
技术理论 | 59篇 |
综合类 | 46722篇 |
化学工业 | 31653篇 |
金属工艺 | 11500篇 |
机械仪表 | 18912篇 |
建筑科学 | 40991篇 |
矿业工程 | 17122篇 |
能源动力 | 9768篇 |
轻工业 | 15830篇 |
水利工程 | 15552篇 |
石油天然气 | 12941篇 |
武器工业 | 3404篇 |
无线电 | 36157篇 |
一般工业技术 | 21966篇 |
冶金工业 | 16812篇 |
原子能技术 | 2837篇 |
自动化技术 | 73598篇 |
出版年
2024年 | 1612篇 |
2023年 | 4522篇 |
2022年 | 8617篇 |
2021年 | 9889篇 |
2020年 | 10252篇 |
2019年 | 8086篇 |
2018年 | 7276篇 |
2017年 | 8732篇 |
2016年 | 9974篇 |
2015年 | 11272篇 |
2014年 | 20470篇 |
2013年 | 18404篇 |
2012年 | 24007篇 |
2011年 | 25342篇 |
2010年 | 20035篇 |
2009年 | 20996篇 |
2008年 | 20266篇 |
2007年 | 25487篇 |
2006年 | 23467篇 |
2005年 | 20678篇 |
2004年 | 17473篇 |
2003年 | 15693篇 |
2002年 | 12826篇 |
2001年 | 10882篇 |
2000年 | 9073篇 |
1999年 | 7425篇 |
1998年 | 5579篇 |
1997年 | 4791篇 |
1996年 | 4349篇 |
1995年 | 3588篇 |
1994年 | 3122篇 |
1993年 | 2310篇 |
1992年 | 1973篇 |
1991年 | 1472篇 |
1990年 | 1252篇 |
1989年 | 1115篇 |
1988年 | 879篇 |
1987年 | 595篇 |
1986年 | 450篇 |
1985年 | 381篇 |
1984年 | 346篇 |
1983年 | 263篇 |
1982年 | 242篇 |
1981年 | 172篇 |
1980年 | 134篇 |
1979年 | 115篇 |
1978年 | 64篇 |
1977年 | 73篇 |
1976年 | 55篇 |
1975年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Jean-Claude Malela-Majika Sandile Charles Shongwe Olatunde Adebayo Adeoti 《Quality and Reliability Engineering International》2021,37(8):3314-3322
The sensitivity of a monitoring scheme depends on many factors including the variance of the charting statistic which is very important in the computation of the control limits. This paper discusses the computation of the variance of the recently proposed hybrid homogeneously weighted moving average (HHWMA) scheme which was based on an incorrect assumption. The correct variance is used to evaluate the run-length characteristics of the HHWMA scheme. It is observed that the incorrect variance has a significant impact on the sensitivity (or performance) of the HHWMA scheme. 相似文献
2.
3.
陈彦名 《电信工程技术与标准化》2015,(5)
介绍了目前最炙手可热的REST架构风格,该风格顺应Web2.0的兴起,完美的匹配了云计算时代来临的可扩展要求,在各种应用场景中都得到了充分的表现。根据其技术特点,分析了该风格的API在移动通信网络管理中的应用,从网管系统内部、网管系统之间以及网管系统与上层APP应用之间等多方面对是否适用于REST风格以及如何在合适的位置使用REST API进行了分析。 相似文献
4.
本文以云杉八齿小蠹Ips typographus Linnaeus为例,经标本选取,观察虫体整体形态,绘制整体结构草图,电子显微镜观察局部、得到局部数字图像,分别建立虫体每一部分的高精度细节。把模型每部分拼装在一起组成整体模型,构建出了云杉八齿小蠹三维虚拟昆虫数字化模型。 相似文献
5.
The aim of the research is evaluating the classification performances of eight different machine-learning methods on the antepartum cardiotocography (CTG) data. The classification is necessary to predict newborn health, especially for the critical cases. Cardiotocography is used for assisting the obstetricians’ to obtain detailed information during the pregnancy as a technique of measuring fetal well-being, essentially in pregnant women having potential complications. The obstetricians describe CTG shortly as a continuous electronic record of the baby's heart rate took from the mother's abdomen. The acquired information is necessary to visualize unhealthiness of the embryo and gives an opportunity for early intervention prior to happening a permanent impairment to the embryo. The aim of the machine learning methods is by using attributes of data obtained from the uterine contraction (UC) and fetal heart rate (FHR) signals to classify as pathological or normal. The dataset contains 1831 instances with 21 attributes, examined by applying the methods. In the paper, the highest accuracy displayed as 99.2%. 相似文献
6.
7.
In this paper, novel computing approach using three different models of feed-forward artificial neural networks (ANNs) are presented for the solution of initial value problem (IVP) based on first Painlevé equation. These mathematical models of ANNs are developed in an unsupervised manner with capability to satisfy the initial conditions exactly using log-sigmoid, radial basis and tan-sigmoid transfer functions in hidden layers to approximate the solution of the problem. The training of design parameters in each model is performed with sequential quadratic programming technique. The accuracy, convergence and effectiveness of the proposed schemes are evaluated on the basis of the results of statistical analyses through sufficient large number of independent runs with different number of neurons in each model as well. The comparisons of these results of proposed schemes with standard numerical and analytical solutions validate the correctness of the design models. 相似文献
8.
9.
Although greedy algorithms possess high efficiency, they often receive suboptimal solutions of the ensemble pruning problem, since their exploration areas are limited in large extent. And another marked defect of almost all the currently existing ensemble pruning algorithms, including greedy ones, consists in: they simply abandon all of the classifiers which fail in the competition of ensemble selection, causing a considerable waste of useful resources and information. Inspired by these observations, an interesting greedy Reverse Reduce-Error (RRE) pruning algorithm incorporated with the operation of subtraction is proposed in this work. The RRE algorithm makes the best of the defeated candidate networks in a way that, the Worst Single Model (WSM) is chosen, and then, its votes are subtracted from the votes made by those selected components within the pruned ensemble. The reason is because, for most cases, the WSM might make mistakes in its estimation for the test samples. And, different from the classical RE, the near-optimal solution is produced based on the pruned error of all the available sequential subensembles. Besides, the backfitting step of RE algorithm is replaced with the selection step of a WSM in RRE. Moreover, the problem of ties might be solved more naturally with RRE. Finally, soft voting approach is employed in the testing to RRE algorithm. The performances of RE and RRE algorithms, and two baseline methods, i.e., the method which selects the Best Single Model (BSM) in the initial ensemble, and the method which retains all member networks of the initial ensemble (ALL), are evaluated on seven benchmark classification tasks under different initial ensemble setups. The results of the empirical investigation show the superiority of RRE over the other three ensemble pruning algorithms. 相似文献
10.
A small handful of recent studies have addressed a phenomenon known as “phantom vibration syndrome”. This refers to when phone users perceive their device to vibrate, indicating that a call or text is incoming, when in fact the phone did not vibrate at all. Though these studies show that most users do not find phantom vibration hallucinations to be very bothersome, they also find that a large majority of users experience this phenomenon. This paper explores what the striking prevalence of phantom vibration syndrome means for our contemporary relationships with technology. I begin with a review of the theories purporting to explain these data, which largely rely on particular understandings of the brain. Next I develop an alternative theory of phantom vibration syndrome based on insights from the philosophical tradition of phenomenology. This account considers the ways users develop bodily and perceptual habits regarding how the phone is understood and used. By critically contrasting these different theories, we can refine our questions about what the high prevalence of phantom vibration syndrome implies about our contemporary technological situation. 相似文献