全文获取类型
收费全文 | 348篇 |
免费 | 16篇 |
国内免费 | 16篇 |
专业分类
电工技术 | 10篇 |
综合类 | 19篇 |
化学工业 | 11篇 |
金属工艺 | 14篇 |
机械仪表 | 17篇 |
建筑科学 | 12篇 |
矿业工程 | 6篇 |
能源动力 | 3篇 |
轻工业 | 14篇 |
水利工程 | 6篇 |
石油天然气 | 7篇 |
武器工业 | 1篇 |
无线电 | 152篇 |
一般工业技术 | 28篇 |
冶金工业 | 3篇 |
原子能技术 | 3篇 |
自动化技术 | 74篇 |
出版年
2023年 | 3篇 |
2022年 | 1篇 |
2021年 | 6篇 |
2020年 | 11篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 11篇 |
2015年 | 23篇 |
2014年 | 45篇 |
2013年 | 19篇 |
2012年 | 44篇 |
2011年 | 35篇 |
2010年 | 17篇 |
2009年 | 21篇 |
2008年 | 15篇 |
2007年 | 18篇 |
2006年 | 16篇 |
2005年 | 17篇 |
2004年 | 18篇 |
2003年 | 15篇 |
2002年 | 14篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有380条查询结果,搜索用时 15 毫秒
1.
浅谈新一代光盘存储技术HD DVD和Blu-ray Disc 总被引:1,自引:0,他引:1
本文对DVD的替代者HDDVD和Blu—ray Disc作一技术介绍,并对它们的优劣进行了分析。 相似文献
2.
The behavior of hydrogen absorption and release in hydrogen decrepitation (HD) process of Nd-Fe-B alloys were investigated. The results reveal that the reactivity and the amount of hydrogen absorption in HD process are related to the surface activity of the alloy so that the fresh and active surface has a higher efficiency. The presence of Nd-rich phase at the grain boundary is an essential factor of the HD activity of the alloy at room temperature. On degassing, hydrogen is released from the HD powder continuously with increasing temperature. And the residual hydrogen is as low as 0.0015% at 1073K, which shows that the hydrogen is almost exhaused. It is feasible to remove the hydrogen from the HD powder by heating treatment at the temperature of 523-723K for 1h prior to the magnetic field forming in order to decrease the harmful effect of hydrogen on the easy axis alignment of HD magnet. 相似文献
3.
通过XDCAM、P2HD在大洋D^3-edit、D^3-edit HD、苹果非编上的测试,分析各自的特点,总结出相应的工作流程,为下一步的设备选型和应用打下基础。 相似文献
4.
5.
DSI箱体和STD箱体是HD seis VSP测井仪器的核心部件,维持其正常运转是保障井下设备安全工作的前提。针对DSI箱体出现的故障,应结合DSI控制电路图,锁定故障元器件,分别在配件充足和不足两种情况下进行处理。STD箱体的硬盘故障和电池故障有别于常规计算机,解决其故障的方法是遵循特点,做硬盘更换和系统安装,并重新设置引导系统,使系统进入正常运转。 相似文献
6.
对NdFeB铸块在HD工艺中温度和压力对吸氢行为的影响进行了研究。研究发现,NdFeB铸块在氢爆过程中明显存在孕育期,其吸氢过程分为四个阶段:孕育期阶段、慢速吸氢阶段、快速吸氢阶段和缓慢吸氢阶段;随着氢气压力(1~4atm)的升高,孕育时间缩短,吸氢越快;随着温度的升高,NdFeB铸块吸氢越迅速,当温度升至一定程度时,孕育期消失。扫描电镜观察发现,NdFeB合金氢爆破碎中的断裂方式包括沿晶和穿晶断裂,氢爆粉末尺寸小于50μm,取得了较好的氢爆效果。 相似文献
7.
以桃林口水库为试点,应用高清视频处理技术对水库水位进行远程自动监测,介绍了系统的工作原理与总体设计方案,选取最优的视频采集技术及合理的无线数据传输方式,利用视频图像处理的算法去掉图片冗余信息,推断得出计算水位精确的数据,并将结果存放于数据库中。实现了无人值守水库水位数据的远程查看、及时保存、绘制折线图与自动监测报警的功能。 相似文献
8.
Kayo Suzuki Author Vitae Author Vitae Hiroaki Ikeda Author Vitae Author Vitae Fumio Adachi Author Vitae 《Computers & Electrical Engineering》2008,34(1):21-37
This paper focuses on a practical design for an efficient scalable image database and retrieval system over broadband networks. It describes a concrete solution for the implementation of HD/SHD (high-definition/super-high-definition) still image retrieval services which can be used in different applications. The structure of the complete system, consisting of a directory server, an image server, and MMI (man-machine interface) devices, has been presented, detailing each element and their corresponding functions. The desired HD/SHD image is displayed on the HD-PDP (plasma display panel) with the aid of image matching. The proposed system generates image index automatically, eliminating special skills in preparing index images and crucially reducing the processing time (from 35 min to 110 s), and does not use keywords. It has been also shown that these indices can be used for quite accurate image retrieval, i.e., the system provides high precision rates (currently up to 98%) to the user, eliminating troubles encountered in the image retrieval operations due to limitation on the user’s age, culture, knowledge, and languages.The broadband IP networks currently have a number of issues from the viewpoint of practical system operations, and so the requirements and issues needed for the networks are discussed from the viewpoint of in-service performance, differentiation among different types of services, secure connections, and so on, focusing on handling of HD/SHD still images. 相似文献
9.
杨其 《数字社区&智能家居》2009,5(5):3565-3567
在传统矩阵信号采集和传输系统中,主要是对单个矩阵信号的采集和传输,但随着科技的发展,多路矩阵开关在工业和军事中的应用越来越广泛,对多路矩阵信号的有效采集和传输成为亟待解决的问题。本系统就是针对这个问题.在单个矩阵开关信号采集和传输的基础上,利用信号采集和传输的有关原理,采用串行通信技术和单片机控制技术实现了对多路矩阵信号的有效采集和传输。 相似文献
10.
Extranasal Staphylococcus aureus colonization predisposes to bloodstream infections in patients on hemodialysis with noncuffed internal jugular vein catheters
下载免费PDF全文
![点击此处可从《Hemodialysis international. International Symposium on Home Hemodialysis》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Anand Devraj Venkata Siva Tez Pinnamaneni Manisha Biswal Raja Ramachandran Vivekanand Jha 《Hemodialysis international. International Symposium on Home Hemodialysis》2017,21(1):35-40
Introduction: Staphylococcal infection of endogenous origin is an important cause of morbidity and mortality in patients who receive hemodialysis (HD). The risk of such infections in nasal carriers of the organism is well defined. Extranasal carriage of the organism at extranasal sites may pose similar risks. Methods: A total of 70 patients about to undergo internal jugular vein catheterization for HD were enrolled in this prospective observational study. Swab cultures were obtained from anterior nares, posterior pharynx, axillae, toe web spaces, and vascular access sites at baseline and 1 week later. A patient was defined as a persistent carrier when the same organism was grown in both samples. Staphylococcus aureus bloodstream infections were assessed by blood and catheter tip cultures over a 90‐day period. Findings: The mean age of the patients was 43.71 ± 16.2 years. Persistent S. aureus carriage at anterior nares, throat, axilla, toe web spaces, vascular access site, and all sites was documented in 27.9%, 11.4%, 40%, 32.9%, 4.3%, and 64.2% of patients, respectively. Fifteen patients developed S. aureus infections. Catheter related S. aureus infections (CRI) were more likely in persistent carriers than nonpersistent carriers with odds ratios (95% CI) of 10.2 (2.8–37.1), 8.6 (1.7–42.2), 17.3 (3.4–86.0), 3.0 (0.9–9.8), and 1.9 (0.2–22.4) for anterior nares, throat, axilla, toe web spaces, and vascular access site carriers, respectively. The probability of developing CRI in persistent S. aureus carriers was 55% compared to none in noncarriers at 90 days (P = 0.04). Discussion: Extranasal S. aureus carriage is as significant a risk factor as nasal carriage for staphylococcal infections in patients on HD through catheters. The study is limited by lack of molecular phenotyping. 相似文献