全文获取类型
收费全文 | 1406篇 |
免费 | 78篇 |
国内免费 | 112篇 |
专业分类
电工技术 | 9篇 |
综合类 | 63篇 |
化学工业 | 8篇 |
金属工艺 | 1篇 |
机械仪表 | 23篇 |
建筑科学 | 72篇 |
矿业工程 | 3篇 |
能源动力 | 2篇 |
轻工业 | 71篇 |
水利工程 | 1篇 |
石油天然气 | 11篇 |
武器工业 | 5篇 |
无线电 | 260篇 |
一般工业技术 | 15篇 |
冶金工业 | 9篇 |
原子能技术 | 1篇 |
自动化技术 | 1042篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 21篇 |
2019年 | 15篇 |
2018年 | 23篇 |
2017年 | 34篇 |
2016年 | 42篇 |
2015年 | 33篇 |
2014年 | 67篇 |
2013年 | 80篇 |
2012年 | 85篇 |
2011年 | 135篇 |
2010年 | 90篇 |
2009年 | 86篇 |
2008年 | 93篇 |
2007年 | 127篇 |
2006年 | 109篇 |
2005年 | 123篇 |
2004年 | 97篇 |
2003年 | 89篇 |
2002年 | 57篇 |
2001年 | 43篇 |
2000年 | 27篇 |
1999年 | 30篇 |
1998年 | 16篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有1596条查询结果,搜索用时 31 毫秒
71.
This paper explores the Cyber-Psychological and Cyber-Geographic aspects of hacking and hacktivism. An examination of the literature related to hackers and hacking reveals a complex nexus of spatial (including cyber-spatial such as “Notopia”) and psychological aspects of hacking, from which emerges a central question of how humans perceive and manipulate their cyber-identities. Concealing (real and cyber) identities is typical in hacking. With our progressive acculturation with identity-less and place-less modes of existence, our cyber-identities through time may be studied from within John Locke’s criterion of “memory” and the spatial-geographical criterion of identity. 相似文献
72.
Improvement of the secure dynamic ID based remote user authentication scheme for multi-server environment 总被引:2,自引:0,他引:2
Recently, Liao and Wang proposed a secure dynamic ID based remote user authentication scheme for multi-server environment, and claimed that their scheme was intended to provide mutual authentication, two-factor security, replay attack, server spoofing attack, insider and stolen verifier attack, forward secrecy and user anonymity. In this paper, we show that Liao and Wang's scheme is still vulnerable to insider's attack, masquerade attack, server spoofing attack, registration center spoofing attack and is not reparable. Furthermore, it fails to provide mutual authentication. To remedy these flaws, this paper proposes an efficient improvement over Liao–Wang's scheme with more security. The computation cost, security, and efficiency of the improved scheme are well suited to the practical applications environment. 相似文献
73.
74.
近年来,基于簇的水声传感器网络得到广泛应用。由于水声传感器多用于军事行业,使得提高水声传感器网络的安全性变得十分重要。针对提高水声传感器网络安全性这一问题,提出了结合ECC Diffie-Hellman密钥交换、一元高阶多项式、双线性映射和哈希函数的安全认证协议。经过分析,该协议满足了认证、访问控制、数据保密性、数据完整性和不可否认性等安全需求。结合BAN逻辑进行形式化分析,证明该协议是安全的;同时,将协议的两个阶段分别与同类型认证协议进行对比,实验结果表明,所提协议的性能在时间或者空间上有所提升。 相似文献
75.
WIFI无线登录安全性研究 总被引:1,自引:0,他引:1
一直以来,无线网络的安全问题都备受关注,其中认证是保证信息安全的一个重要环节。目前无线认证有多种方式,比如Radius认证,Web认证,端口认证等,本文通过调研分析Radius认证与Web认证两种无线认证方式,来比较在家庭路由认证状态下,两者的性能差异,从而更好的解决目前普遍存在的弱密码问题。 相似文献
76.
77.
Identity based broadcast encryption allows a centralized transmitter to send encrypted messages to a set of identities S, so that only the users with identity in S can decrypt these ciphertexts using their respective private key. Recently [Information Processing Letters 109 (2009)], an identity-based broadcast encryption scheme was proposed (Ren and Gu, 2009) [1], and it was claimed to be fully chosen-ciphertext secure without random oracles. However, by giving a concrete attack, we indicate that this scheme is even not chosen-plaintext secure. 相似文献
78.
Mu’awya NaserPedro Peris-Lopez Rahmat BudiartoBenjamín Ramos Álvarez 《Computer Communications》2011,34(18):2248-2249
In this letter, we analyze the security of an RFID authentication protocol proposed by Liu and Bailey [1], called privacy and authentication protocol (PAP). We present two traceability attacks and an impersonation attack. 相似文献
79.
A more efficient and secure ID-based remote mutual authentication with key agreement scheme for mobile devices on elliptic curve cryptosystem 总被引:1,自引:0,他引:1
Recently, Yang and Chang proposed an identity-based remote login scheme using elliptic curve cryptography for the users of mobile devices. We have analyzed the security aspects of the Yang and Chang's scheme and identified some security flaws. Also two improvements of the Yang and Chang's scheme have been proposed recently, however, it has been found that the schemes have similar security flaws as in the Yang and Chang's scheme. In order to remove the security pitfalls of the Yang and Chang and the subsequent schemes, we proposed an enhanced remote user mutual authentication scheme that uses elliptic curve cryptography and identity-based cryptosystem with three-way challenge-response handshake technique. It supports flawless mutual authentication of participants, agreement of session key and the leaked key revocation capability. In addition, the proposed scheme possesses low power consumption, low computation cost and better security attributes. As a result, the proposed scheme seems to be more practical and suitable for mobile users for secure Internet banking, online shopping, online voting, etc. 相似文献
80.
公钥基础设施在网络安全中的研究与应用 总被引:6,自引:0,他引:6
文章提出了一种基于PKI的网络安全模型,旨在为网络服务提供有效认证、访问控制、授权、传输机密性、不可否认性等安全机制。该模型在 PKI的基础上,结合了 Kerberos的优势,并扩展了其机制中服务票据的思想,提出了由授权服务器签名的授权证书的概念,以保证自治式与集中式访问控制相结合的安全管理模式。 相似文献