全文获取类型
收费全文 | 91803篇 |
免费 | 9063篇 |
国内免费 | 5223篇 |
专业分类
电工技术 | 6464篇 |
技术理论 | 3篇 |
综合类 | 8314篇 |
化学工业 | 14887篇 |
金属工艺 | 4658篇 |
机械仪表 | 5106篇 |
建筑科学 | 7515篇 |
矿业工程 | 2493篇 |
能源动力 | 2193篇 |
轻工业 | 11007篇 |
水利工程 | 1945篇 |
石油天然气 | 3738篇 |
武器工业 | 898篇 |
无线电 | 10207篇 |
一般工业技术 | 9590篇 |
冶金工业 | 3394篇 |
原子能技术 | 1013篇 |
自动化技术 | 12664篇 |
出版年
2024年 | 525篇 |
2023年 | 1711篇 |
2022年 | 3337篇 |
2021年 | 4171篇 |
2020年 | 3314篇 |
2019年 | 2595篇 |
2018年 | 2786篇 |
2017年 | 3092篇 |
2016年 | 2837篇 |
2015年 | 3973篇 |
2014年 | 5187篇 |
2013年 | 5923篇 |
2012年 | 6806篇 |
2011年 | 7336篇 |
2010年 | 6497篇 |
2009年 | 6111篇 |
2008年 | 6156篇 |
2007年 | 5634篇 |
2006年 | 5306篇 |
2005年 | 4283篇 |
2004年 | 3006篇 |
2003年 | 2429篇 |
2002年 | 2407篇 |
2001年 | 2067篇 |
2000年 | 1810篇 |
1999年 | 1420篇 |
1998年 | 1016篇 |
1997年 | 804篇 |
1996年 | 778篇 |
1995年 | 620篇 |
1994年 | 483篇 |
1993年 | 346篇 |
1992年 | 293篇 |
1991年 | 232篇 |
1990年 | 168篇 |
1989年 | 160篇 |
1988年 | 111篇 |
1987年 | 73篇 |
1986年 | 62篇 |
1985年 | 44篇 |
1984年 | 29篇 |
1983年 | 24篇 |
1982年 | 29篇 |
1981年 | 11篇 |
1980年 | 32篇 |
1979年 | 13篇 |
1976年 | 4篇 |
1974年 | 2篇 |
1959年 | 13篇 |
1951年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
基于MSTP以太网专线进行远程视音频传输,是一种结构简单、线路便宜、容易搭建的传输系统.由于MSTP以太网专线的独特设计,点到点的透传方式,容易实现对用户MAC帧点到点的透传,在线路上能独享带宽,业务延迟小,且和其它业务完全隔离,安全性高,这种业务适合广播级视音频信号远程传输的应用. 相似文献
2.
3.
4.
刘潜 《江汉石油职工大学学报》2015,28(1):102-103
本文介绍了江汉油田员工考勤管理工作的基本情况,梳理和分析了当前员工考勤管理中存在的问题及原因,提出了要进一步细化和完善管理制度,强化过程监督和责任落实,逐步推进考勤公示制度化等措施。 相似文献
5.
6.
7.
BDI模型能够很好地解决在特定环境下的Agent的推理和决策问题,但在动态和不确定环境下缺少决策和学习的能力。强化学习解决了Agent在未知环境下的决策问题,却缺少BDI模型中的规则描述和逻辑推理。针对BDI在未知和动态环境下的策略规划问题,提出基于强化学习Q-learning算法来实现BDI Agent学习和规划的方法,并针对BDI的实现模型ASL的决策机制做出了改进,最后在ASL的仿真平台Jason上建立了迷宫的仿真,仿真实验表明,在加入Q-learning学习机制后的新的ASL系统中,Agent在不确定环境下依然可以完成任务。 相似文献
8.
Introduction
The IEC central office informed in 7/543/AC that the secretariat of TC 7 would be taken over by the Chinese National Committee on January 10, 2003 and affirmed subsequently in 7/544/AC that the secretariat of TC 7 has been taken over by the Chinese National Committee which appointing secretary in Shanghai Electric Cable Research Institute as no objection has been raised by the Standardization Management Board members. It's the first IEC secretariat that assumed by China, with great significance, just as commented by the media that the commitment indicate undoubtedly China is to play a much more active and important role in the world especially after its entry into world trade organization as well as the trend of global economic integration. 相似文献
9.
易前 《水利水电工程设计》2006,25(4):12-13
镜面混凝土是水电工程建设中新兴的一门施工技术,在乌江索风营水电站地下厂房岩锚梁混凝土施工中采用了镜面混凝土,这在技术上是一次大胆的尝试和创新,既满足了功能上的要求,同时也达到了美观和装饰地下厂房的效果,为今后水电工程施工中广泛采用镜面混凝土技术提供了样本和宝贵经验。 相似文献
10.
Uplink scheduling in wireless systems is gaining importance due to arising uplink intensive data services (ftp, image uploads
etc.), which could be hampered by the currently in-built asymmetry in favor of the downlink. In this work, we propose and
study algorithms for efficient uplink packet-data scheduling in a CDMA cell. The algorithms attempt to maximize system throughput
under transmit power limitations on the mobiles assuming instantaneous knowledge of user queues and channels. However no channel
statistics or traffic characterization is necessary. Apart from increasing throughput, the algorithms also improve fairness
of service among users, hence reducing chances of buffer overflows for poorly located users.
The major observation arising from our analysis is that it is advantageous on the uplink to schedule “strong” users one-at-a-time,
and “weak” users in larger groups. This contrasts with the downlink where one-at-a-time transmission for all users has shown
to be the preferred mode in much previous work. Based on the optimal schedules, we propose less complex and more practical
approximate methods, both of which offer significant performance improvement compared to one-at-a-time transmission, and the
widely acclaimed Proportional Fair (PF) algorithm, in simulations. When queue content cannot be fed back, we propose a simple modification of PF, Uplink PF (UPF), that offers similar improvement.
Hereafter, we refer to users with low recieved power at the base even when transmitting at peak transmit power as “weak” users,
and the strongly recieved users at the base as “strong” users.
Krishnan Kumaran is currently a member of the Complex Systems Modeling section in the Corporate Strategic Research of ExxonMobil Corp., Clinton,
NJ. Formerly, he was a Member of Technical Staff in the Mathematics of Networks and Systems Research Department at Bell Labs
in Murray Hill, NJ, where his research interests were in modeling, analysis and simulation of design, resource management
and scheduling issues in telecommunication networks.
Lijun Qian is an assistant professor in the Department of Electrical Engineering at Prairie View A&M University. He received his B.S.
from Tsinghua University in Beijing, M.S. from Technion-Israel Institute of Technology, and Ph.D. from WINLAB, Rutgers University,
all in electrical engineering. Before joining PVAMU, he was a researcher at Networks and Systems Research Department of Bell
Labs in Murray Hill, NJ. His major research interests are in wireless communications and networking technologies, especially
in radio resource management, protocol design, TCP/RLP optimization and MPLS traffic engineering. 相似文献