全文获取类型
收费全文 | 26240篇 |
免费 | 2319篇 |
国内免费 | 1558篇 |
专业分类
电工技术 | 463篇 |
技术理论 | 1篇 |
综合类 | 1065篇 |
化学工业 | 968篇 |
金属工艺 | 434篇 |
机械仪表 | 519篇 |
建筑科学 | 223篇 |
矿业工程 | 101篇 |
能源动力 | 958篇 |
轻工业 | 177篇 |
水利工程 | 39篇 |
石油天然气 | 56篇 |
武器工业 | 32篇 |
无线电 | 4818篇 |
一般工业技术 | 1931篇 |
冶金工业 | 128篇 |
原子能技术 | 146篇 |
自动化技术 | 18058篇 |
出版年
2024年 | 97篇 |
2023年 | 587篇 |
2022年 | 919篇 |
2021年 | 1225篇 |
2020年 | 1178篇 |
2019年 | 960篇 |
2018年 | 985篇 |
2017年 | 1965篇 |
2016年 | 2268篇 |
2015年 | 1664篇 |
2014年 | 2523篇 |
2013年 | 1719篇 |
2012年 | 1747篇 |
2011年 | 1717篇 |
2010年 | 1433篇 |
2009年 | 1637篇 |
2008年 | 892篇 |
2007年 | 1382篇 |
2006年 | 1239篇 |
2005年 | 714篇 |
2004年 | 327篇 |
2003年 | 366篇 |
2002年 | 428篇 |
2001年 | 414篇 |
2000年 | 264篇 |
1999年 | 299篇 |
1998年 | 158篇 |
1997年 | 123篇 |
1996年 | 120篇 |
1995年 | 92篇 |
1994年 | 122篇 |
1993年 | 74篇 |
1992年 | 74篇 |
1991年 | 73篇 |
1990年 | 63篇 |
1989年 | 62篇 |
1988年 | 82篇 |
1987年 | 6篇 |
1986年 | 16篇 |
1985年 | 18篇 |
1984年 | 14篇 |
1983年 | 8篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 11篇 |
1976年 | 7篇 |
1975年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
91.
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
92.
Microsystem Technologies - This paper represents low power and high speed design issues of Hamming code generation and error detection circuit using complementary metal oxide semiconductor (CMOS)... 相似文献
93.
94.
We compare the current density–voltage (J–V) and magnetoconductance (MC) response of a poly(3-hexyl-thiophene) (P3HT) device (Au/P3HT(350 nm)/Al) before and after annealing above the glass transition temperature of 150 °C under vacuum. There is a decrease of more than 3 orders of magnitude in current density due to an increase of the charge injection barriers after de-doping through annealing. An increase, approaching 1 order of magnitude, in the negative MC response after annealing can be explained by a shift in the Fermi level due to de-doping, according to the bipolaron mechanism. We successfully tune the charge injection barrier through re-doping by photo-oxidation. This leads to the charge injection and transport transitioning from unipolar to ambipolar, as the bias increases, and we model the MC response using a combination of bipolaron and triplet-polaron interaction mechanisms. 相似文献
95.
96.
97.
The effects of physical embodiment and physical presence were explored through a survey of 33 experimental works comparing how people interacted with physical robots and virtual agents. A qualitative assessment of the direction of quantitative effects demonstrated that robots were more persuasive and perceived more positively when physically present in a user׳s environment than when digitally-displayed on a screen either as a video feed of the same robot or as a virtual character analog; robots also led to better user performance when they were collocated as opposed to shown via video on a screen. However, participants did not respond differently to physical robots and virtual agents when both were displayed digitally on a screen – suggesting that physical presence, rather than physical embodiment, characterizes people׳s responses to social robots. Implications for understanding psychological response to physical and virtual agents and for methodological design are discussed. 相似文献
98.
1-read/1-write (1R1W) register file (RF) is a popular memory configuration in modern feature rich SoCs requiring significant amount of embedded memory. A memory compiler is constructed using the 8T RF bitcell spanning a range of instances from 32 b to 72 Kb. An 8T low-leakage bitcell of 0.106 μm2 is used in a 14 nm FinFET technology with a 70 nm contacted gate pitch for high-density (HD) two-port (TP) RF memory compiler which achieves 5.66 Mb/mm2 array density for a 72 Kb array which is the highest reported density in 14 nm FinFET technology. The density improvement is achieved by using techniques such as leaf-cell optimization (eliminating transistors), better architectural planning, top level connectivity through leaf-cell abutment and minimizing the number of unique leaf-cells. These techniques are fully compatible with memory compiler usage over the required span. Leakage power is minimized by using power-switches without degrading the density mentioned above. Self-induced supply voltage collapse technique is applied for write and a four stack static keeper is used for read Vmin improvement. Fabricated test chips using 14 nm process have demonstrated 2.33 GHz performance at 1.1 V/25 °C operation. Overall Vmin of 550 mV is achieved with this design at 25 °C. The inbuilt power-switch improves leakage power by 12x in simulation. Approximately 8% die area of a leading 14 nm SoC in commercialization is occupied by these compiled RF instances. 相似文献
99.
《Engineering Applications of Artificial Intelligence》2006,19(3):235-245
This research is motivated by a scheduling problem found in the diffusion and oxidation areas of semiconductor wafer fabrication facilities, where the machines can be modeled as parallel batch processors. Total weighted tardiness on parallel batch machines with incompatible job families and unequal ready times of the jobs is attempt to minimize. Given that the problem is NP hard, a simple heuristic based on the Apparent Tardiness Cost (ATC) Dispatching Rule is suggested. Using this rule, a look-ahead parameter has to be chosen. Because of the appearance of unequal ready times and batch machines it is hard to develop a closed formula to estimate this parameter. The use of inductive decision trees and neural networks from machine learning is suggested to tackle the problem of parameter estimation. The results of computational experiments based on stochastically generated test data are presented. The results indicate that a successful choice of the look-ahead parameter is possible by using the machine learning techniques. 相似文献
100.
《Optical Fiber Technology》2006,12(3):238-242
We measure the system impacts due to the amplitude of group-delay (GD) ripple in single and cascaded chirped fiber Bragg gratings (CFBGs). Signals with smaller pulse width result in smaller performance variation at the same data rate. A 65-ps peak-to-peak GD ripple induces 0.9, 1.7, and 2.7 dB maximum penalties for 10, 20, and 40-Gb/s, respectively. We also find that cascading gratings with random ripple causes much less degradation than cascading gratings with the same ripple profile. 相似文献