全文获取类型
收费全文 | 28299篇 |
免费 | 3366篇 |
国内免费 | 2308篇 |
专业分类
电工技术 | 3268篇 |
技术理论 | 3篇 |
综合类 | 3321篇 |
化学工业 | 3640篇 |
金属工艺 | 1234篇 |
机械仪表 | 1720篇 |
建筑科学 | 2465篇 |
矿业工程 | 1093篇 |
能源动力 | 1299篇 |
轻工业 | 1052篇 |
水利工程 | 867篇 |
石油天然气 | 1235篇 |
武器工业 | 547篇 |
无线电 | 2758篇 |
一般工业技术 | 3076篇 |
冶金工业 | 973篇 |
原子能技术 | 457篇 |
自动化技术 | 4965篇 |
出版年
2024年 | 167篇 |
2023年 | 444篇 |
2022年 | 718篇 |
2021年 | 837篇 |
2020年 | 977篇 |
2019年 | 960篇 |
2018年 | 861篇 |
2017年 | 1064篇 |
2016年 | 1118篇 |
2015年 | 1111篇 |
2014年 | 1640篇 |
2013年 | 1775篇 |
2012年 | 1767篇 |
2011年 | 1945篇 |
2010年 | 1443篇 |
2009年 | 1487篇 |
2008年 | 1533篇 |
2007年 | 1762篇 |
2006年 | 1730篇 |
2005年 | 1487篇 |
2004年 | 1287篇 |
2003年 | 1100篇 |
2002年 | 1033篇 |
2001年 | 894篇 |
2000年 | 764篇 |
1999年 | 706篇 |
1998年 | 496篇 |
1997年 | 474篇 |
1996年 | 411篇 |
1995年 | 371篇 |
1994年 | 328篇 |
1993年 | 291篇 |
1992年 | 215篇 |
1991年 | 146篇 |
1990年 | 135篇 |
1989年 | 96篇 |
1988年 | 80篇 |
1987年 | 54篇 |
1986年 | 42篇 |
1985年 | 23篇 |
1984年 | 35篇 |
1983年 | 27篇 |
1982年 | 25篇 |
1981年 | 13篇 |
1980年 | 13篇 |
1979年 | 18篇 |
1978年 | 9篇 |
1977年 | 7篇 |
1959年 | 9篇 |
1951年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
A. Kaklauskas E.K. ZavadskasM. Seniut G. DzemydaV. Stankevic C. Simkevi?iusT. Stankevic R. PaliskieneA. Matuliauskaite S. KildieneL. Bartkiene S. IvanikovasV. Gribniak 《Engineering Applications of Artificial Intelligence》2011,24(6):928-945
This article describes the analysis of emotional state and work productivity using a Web-based Biometric Computer Mouse Advisory System to Analyze a User's Emotions and Work Productivity (Advisory system hereafter) developed by this paper's authors. The Advisory system determines the level of emotional state and work productivity integrally by employing three main biometric techniques (physiological, psychological and behavioral). By using these three biometric techniques, the Advisory system can analyze a person's eleven states of being (stress, work productivity, mood, interest in work) and seven emotions (self-control, happiness, anger, fear, sadness, surprise and anxiety) during a realistic timeframe. Furthermore, to raise the reliability of the Advisory system even more, it also integrated the data supplied by the Biometric Finger (blood pressure and pulse rates). Worldwide research includes various scientists who conducted in-depth studies on the different and very important areas of biometric mouse systems. However, biometric mouse systems cannot generate recommendations. The Advisory system determines a user's physiological, psychological and behavioral/movement parameters based on that user's real-time needs and existing situation. It then generates thousands of alternative stress management recommendations based on the compiled Maslow's Pyramid Tables and selects out the most rational of these for the user's specific situation. The information compiled for Maslow's Pyramid Tables consists of a collection of respondent surveys and analyses of the best global practices. Maslow's Pyramid Tables were developed for an employee working with a computer in a typical organization. The Advisory system provides a user with a real-time assessment of his/her own productivity and emotional state. This article presents the Advisory system, a case study and a scenario used to test and validate the developed Advisory system and its composite parts to demonstrate its validity, efficiency and usefulness. 相似文献
162.
163.
164.
基于收发平衡判定的TCP流量回放方法 总被引:2,自引:1,他引:1
基于真实网络流量的互动式回放测试是当前针对防火墙、IPS等串接型安全设备进行测评的最新方法.文中在分析现有基于状态判定的TCP流量互动式回放方法基础之上,引入收发平衡机制,提出了一种基于收发平衡和状态判定相结合的新的TCP流量回放方法.通过在发送TCP数据包前优先进行收发平衡判定将数据包发送出去,提出的方法能够有效减少TCP流量在发送过程中的状态判定开销,提高回放性能.对引入收发平衡机制前后的TCP流量回放方法的差异进行了分析比较.从单个TCP会话特性、并发会话流量特性、网络传输延迟与丢包等角度分析验证了影响引入收发平衡机制后的算法有效性的因素.实际流量实验表明,文中所提方法在回放TCP流量时性能有显著提升,适用于在更大规模的流量环境下对防火墙、IPS等串接型网络安全设备进行测评. 相似文献
165.
Bae Jun Young 《Information Sciences》2009,179(24):4284-1770
The idea of (faithful) intuitionistic fuzzy transformation semigroup, intuitionistic admissible relation, and intuitionistic (strong) homomorphism are introduced and their basic properties are examined. 相似文献
166.
J. Cucurull Author Vitae R. Martí Author Vitae Author Vitae S. Robles Author Vitae Author Vitae 《Journal of Systems and Software》2009,82(12):1927-1940
The existence of heterogeneous mobile agent systems hinders the interoperability of mobile agents. Several solutions exist, but they are limited in some aspects. This article proposes a full interoperability solution, in the context of the IEEE-FIPA agent standards, composed of three parts. The first part is a simple language-independent agent interface that enables agents to visit locations with different types of middlewares. The second part is a set of design models for the middlewares to support agents developed for different programming languages and architectures. And the third part is a method based on agents with multiple codes and a common agent data encoding mechanism to enable interoperability between middlewares that do not support the same programming languages. Furthermore two agent interoperability implementations, and its corresponding performance comparison, carried out over the JADE and AgentScape agent middlewares are presented. 相似文献
167.
When an implementation under test (IUT) is state-based, and its expected abstract behavior is given in terms of a finite state machine (FSM), a checking sequence generated from a specification FSM and applied to an IUT for testing can provide us with high-level confidence in the correct functional behavior of our implementation. One of the issues here is to generate efficient checking sequences in terms of their lengths. As a major characteristics, a checking sequence must contain all β-sequences for transition verification. In this paper, we discuss the possibility of reducing the lengths of checking sequences by making use of the invertible transitions in the specification FSM to increase the choice of β-sequences to be considered for checking sequence generation. We present a sufficient condition for adopting alternative β-sequences and illustrate typical ways of incorporating these alternative β-sequences into existing methods for checking sequence generation to reduce the lengths. Compared to the direct use of three existing methods, our experiments show that most of the time the saving gained by adopting alternative β-sequences falls in the range of 10–40%. 相似文献
168.
Binary oxides of manganese and vanadium have been synthesized by solid state sintering, in which the mass ratio of the individual components Mn2O3 and VO2 have been varied from 90:10 to 5:95. The bulk ceramic samples were characterized by X-ray diffraction and scanning electron microscopy with energy dispersive X-ray analysis. The initial compositions either rich in Mn2O3 or in equi-proportion by mass with VO2 yield β-Mn2V2O7 or a new crystalline form of Mn2V2O7, with unit cell parameters: a = 7.73091 Å, b = 6.640788 Å, c = 6.70779 Å α = γ = 90° and β = 98.7086° which is designated as γ-Mn2V2O7. The compositions, richer in VO2 produce MnV2O6 co-existing with V2O5 the proportion of which increases with increase in VO2. The surface microanalysis shows a spherical-granular morphology in Mn2V2O7 structure and plate/rod-like structures co-existing with granular morphology in case of MnV2O6 together with V2O5. The electrical parameters of the negative temperature coefficient thermistors were determined. Depending on the constituent oxide composition, the NTC thermistors showed room temperature resistivity in the range of 6.52 × 102 to 6.1 × 106 Ω-cm. The thermistor constant and activation energy are in the range of 0.12–0.458 eV and 1393–4801 K, respectively. 相似文献
169.
磁盘的随机I/O延时制约了存储系统的性能提高,具备高性能随机I/O特性的固态盘(solid state disk,SSD)逐渐成为关注的热点.分析了磁盘、Flash型SSD以及DRAM型SSD三类设备不同的性能特点,讨论了SSD存储加速技术的研究现状,提出了一种面向Lustre文件系统的固态盘存储加速系统架构,介绍和分析了各模块的构成与原理,提出了对象迁移策略. 相似文献
170.