全文获取类型
收费全文 | 1320篇 |
免费 | 67篇 |
国内免费 | 147篇 |
学科分类
工业技术 | 1534篇 |
出版年
2024年 | 2篇 |
2023年 | 10篇 |
2022年 | 38篇 |
2021年 | 34篇 |
2020年 | 36篇 |
2019年 | 23篇 |
2018年 | 19篇 |
2017年 | 26篇 |
2016年 | 30篇 |
2015年 | 50篇 |
2014年 | 69篇 |
2013年 | 65篇 |
2012年 | 104篇 |
2011年 | 118篇 |
2010年 | 61篇 |
2009年 | 65篇 |
2008年 | 78篇 |
2007年 | 75篇 |
2006年 | 108篇 |
2005年 | 69篇 |
2004年 | 64篇 |
2003年 | 64篇 |
2002年 | 59篇 |
2001年 | 32篇 |
2000年 | 40篇 |
1999年 | 33篇 |
1998年 | 27篇 |
1997年 | 27篇 |
1996年 | 22篇 |
1995年 | 24篇 |
1994年 | 6篇 |
1993年 | 9篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1973年 | 1篇 |
排序方式: 共有1534条查询结果,搜索用时 15 毫秒
1.
为了探讨在安卓平台上构建医用图像采集系统的开发个案,分析通过以智能手机、平板电脑为核心安卓设备通过拍照获得化验单数据后进行文本识别并提交智慧医疗系统的解决方案。本文首先通过二值化算法形成低阈值图像数据,使用卷积神经元网络算法对文本进行逐一识别,使用K-means算法对识别后的单字文本进行字段记录值的整合并形成元数据库服务于其他智慧医疗系统模块。在使用9000组数据对神经元网络进行前期训练的前提下,该系统的识别准确率达到了99.5%以上。本系统具有一定的可行性,对未来智慧医疗的系统开发有实践意义。 相似文献
2.
3.
This paper introduces a novel approach for identity authentication system based on metacarpophalangeal joint patterns (MJPs). A discriminative common vector (DCV) based method is utilized for feature selection. In the literature, there is no study using whole MJP for identity authentication, exceptionally a work (Ferrer et al., 2005) using the hand knuckle pattern which is some part of the MJP draws the attention as a similar study. The originality of this approach is that: whole MJP is firstly used as a biometric identifier and DCV method is firstly applied for extracting the feature set of MJP. The developed system performs some basic tasks like image acquisition, image pre-processing, feature extraction, matching, and performance evaluation. The feasibility and effectiveness of this approach is rigorously evaluated using the k-fold cross validation technique on two different databases: a publicly available database and a specially established database. The experimental results indicate that the MJPs are very distinctive biometric identifiers and can be securely used in biometric identification and verification systems, DCV method is successfully employed for obtaining the feature set of MJPs and proposed MJP based authentication approach is very successful according to state of the art techniques with a recognition rate of between 95.33% and 100.00%. 相似文献
4.
This study conducted short-term assessments of perceived air quality (PAQ) for six different realistic concentrations of ozone and limonene, separately or together, in room air. The impact of filtration and the influence of the ozone generation method were also examined. The evaluations were made in four identical 40 m3 low-polluting test offices ventilated at 1.4 h(-1) or in two identical 30 m3 stainless-steel chambers ventilated at 1.9 h(-1). Concentrations of ozone, total volatile organic compounds and size-fractionated particles were continuously monitored in each experiment. The results indicate that, for each of the six conditions, the PAQ was poorer when ozone and limonene were present together compared with when only ozone or only limonene was present. In the test offices a correlation was observed between the number of secondary organic aerosols produced by a given ozone/limonene condition and the sensory pollution load for that condition. The particles themselves do not appear to be the primary causative agents, but instead are co-varying surrogates for sensory offending gas-phase species. PRACTICAL IMPLICATIONS: Although the health consequences of long-term exposures to the products of ozone-initiated indoor chemistry remain to be determined, we judge that the sensory offending nature of selected products provides an additional reason to limit indoor ozone levels. Devices that emit ozone at significant rates should not be used indoors. Ozone-filtration of make-up air should also be beneficial in mechanically ventilated buildings located in regions that repeatedly violate outdoor ozone standards. Additionally, the use of limonene containing products should be curtailed during periods when indoor ozone levels are elevated. 相似文献
5.
最近及未来的几年 ,上海市境内将建成多条高速公路 ,如何提高高速公路的服务质量 ,出入口的通行能力是一条比较重要的衡量标准。汽车牌照自动识别系统利用先进的摄像技术、图像识别技术和计算机技术 ,对抓拍图像进行正确分割和快速处理 ,自动识别出汽车的牌照号码 ,提升了高速公路的服务水平 相似文献
6.
文章重点从政策层面比较系统地回顾了中国建设行业注册建筑师执业管理制度从建立到发展演变的过程以及注册资格国际互认方面的情况。 相似文献
7.
8.
9.
Several prototype vision-based approaches have been developed to capture and recognize unsafe behavior in construction automatically. Vision-based approaches have been difficult to use due to their inability to identify individuals who commit unsafe acts when captured using digital images/video. To address this problem, we applied a novel deep learning approach that utilizes a Spatial and Temporal Attention Pooling Network to remove redundant information contained in a video to enable a person’s identity to be automatically determined. The deep learning approach we have adopted focuses on: (1) extracting spatial feature maps using the spatial attention network; (2) extracting temporal information using the temporal attention networks; and (3) recognizing a person’s identity by computing the distance between features. To validate the feasibility and effectiveness of the adopted deep learning approach, we created a database of videos that contained people performing their work on construction sites, conducted an experiment, and then performed k-fold cross-validation. The results demonstrated that the approach could accurately identify a person’s identity from videos captured from construction sites. We suggest that our computer-vision approach can potentially be used by site managers to automatically recognize those individuals that engage in unsafe behavior and therefore be used to provide instantaneous feedback about their actions and possible consequences. 相似文献
10.
A graph G is well-covered if every minimal vertex cover of G is minimum, and it is well-dominated if every minimal dominating set of G is minimum. Studies on well-covered graphs were initiated in [Plummer, JCT 1970], and well-dominated graphs were first introduced in [Finbow, Hartnell and Nowakow, AC 1988]. Well-dominated graphs are well-covered, and both classes have been widely studied in the literature. The recognition of well-covered graphs has been proved to be coNP-complete by [Chvátal and Slater, AODM 1993] and [Sankaranarayana and Stewart, Networks 1992], but the complexity of recognizing well-dominated graphs has been left open since their introduction. We close this complexity gap by proving that recognizing well-dominated graphs is coNP-complete. This solves a well-known open question (cf. [Levit and Tankus, DM 2017] and [Gözüpek, Hujdurovic and Milanič, DMTCS 2017]), which was first asked in [Caro, Sebő and Tarsi, JAlg 1996]. Although the problem has been open for a long time, our proof is surprisingly simple. Finally, we show that recognizing well-totally-dominated graphs is coNP-complete, answering a question of [Bahadır, Ekim, and Gözüpek, AMC 2021]. 相似文献