全文获取类型
收费全文 | 5389篇 |
免费 | 224篇 |
国内免费 | 266篇 |
专业分类
电工技术 | 211篇 |
综合类 | 192篇 |
化学工业 | 398篇 |
金属工艺 | 218篇 |
机械仪表 | 447篇 |
建筑科学 | 322篇 |
矿业工程 | 114篇 |
能源动力 | 314篇 |
轻工业 | 223篇 |
水利工程 | 72篇 |
石油天然气 | 89篇 |
武器工业 | 22篇 |
无线电 | 289篇 |
一般工业技术 | 406篇 |
冶金工业 | 83篇 |
原子能技术 | 51篇 |
自动化技术 | 2428篇 |
出版年
2024年 | 4篇 |
2023年 | 102篇 |
2022年 | 101篇 |
2021年 | 184篇 |
2020年 | 169篇 |
2019年 | 133篇 |
2018年 | 98篇 |
2017年 | 143篇 |
2016年 | 183篇 |
2015年 | 184篇 |
2014年 | 251篇 |
2013年 | 333篇 |
2012年 | 228篇 |
2011年 | 353篇 |
2010年 | 240篇 |
2009年 | 302篇 |
2008年 | 313篇 |
2007年 | 323篇 |
2006年 | 280篇 |
2005年 | 282篇 |
2004年 | 227篇 |
2003年 | 190篇 |
2002年 | 171篇 |
2001年 | 133篇 |
2000年 | 125篇 |
1999年 | 136篇 |
1998年 | 135篇 |
1997年 | 106篇 |
1996年 | 81篇 |
1995年 | 79篇 |
1994年 | 62篇 |
1993年 | 56篇 |
1992年 | 43篇 |
1991年 | 23篇 |
1990年 | 22篇 |
1989年 | 21篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 12篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 2篇 |
排序方式: 共有5879条查询结果,搜索用时 46 毫秒
91.
This paper aims to propose a novel design approach for on-line path planning of the multiple mobile robots system with free collision. Based on the artificial bee colony (ABC) algorithm, we propose an efficient artificial bee colony (EABC) algorithm for solving the on-line path planning of multiple mobile robots by choosing the proper objective function for target, obstacles, and robots collision avoidance. The proposed EABC algorithm enhances the performance by using elite individuals for preserving good evolution, the solution sharing provides a proper direction for searching, the instant update strategy provides the newest information of solution. By the proposed approach, the next positions of each robot are designed. Thus, the mobiles robots can travel to the designed targets without collision. Finally, simulation results of illustration examples are introduced to show the effectiveness and performance of the proposed approach. 相似文献
92.
基于人工免疫算法的增量式用户兴趣挖掘 总被引:1,自引:0,他引:1
了解用户兴趣是为用户提供个性化服务的关键.用户兴趣有短期兴趣和长期兴趣之分,且具有不稳定性.受人工免疫系统的启发,巧妙地将免疫应答过程应用于用户兴趣挖掘.首先将概率与时间相结合,提出“概念时序动态”的概念,以更好地刻画用户在一段时间内对同一兴趣的关注程度;然后基于人工免疫原理,建立抽取兴趣标签的分类器来提取用户兴趣标签;最后针对增量式学习,建立兴趣标签的“概念时序动态”,刻画出用户兴趣自首次出现以来受关注的程度,以此为依据来判断兴趣是否存在迁移及遗忘现象,并为每个兴趣标签附上权重.其主要贡献是创造性地将人工免疫原理应用于用户短期兴趣和长期兴趣的挖掘,并具有增量特性,可以很好地体现用户兴趣迁移特征,是一种自然完整的用户兴趣模型.实验结果表明,该学习模型能够很好地发现用户关注的领域,其平均精度和召回率分别达到79.5%和74.4%,是目前最贴近用户的兴趣挖掘模型. 相似文献
93.
94.
95.
针对人工蜂群算法存在早熟现象和搜索过程容易陷入局部最优的缺陷,提出一种引入佳点集和猴群翻过程的改进人工蜂群算法。首先利用佳点集方法构造均匀的初始种群,通过保持种群的多样性,在一定程度上避免早熟现象,加快算法的收敛速度。然后学习猴群算法的翻过程,在寻优过程中使种群的搜索区域进行转移,从而跳出局部最优,得到全局最优解。在经典测试函数和CEC05测试函数集上的实验结果表明,与标准人工蜂群算法以及其它改进算法相比,算法性能优越,具有很强的鲁棒性和快速收敛的能力,且有效避免陷入局部最优。 相似文献
96.
97.
Neural Network and Classification Approach in Identifying Customer Behavior in the Banking Sector: A Case Study of an International Bank 下载免费PDF全文
Francisca Nonyelum Ogwueleka Sanjay Misra Ricardo Colomo‐Palacios Luis Fernandez 《人机工程学与制造业中的人性因素》2015,25(1):28-42
The customer relationship focus for banks is in development of main competencies and strategies of building strong profitable customer relationships through considering and managing the customer impression, influence on the culture of the bank, satisfactory treatment, and assessment of valued relationship building. Artificial neural networks (ANNs) are used after data segmentation and classification, where the designed model register records into two class sets, that is, the training and testing sets. ANN predicts new customer behavior from previously observed customer behavior after executing the process of learning from existing data. This article proposes an ANN model, which is developed using a six‐step procedure. The back‐propagation algorithm is used to train the ANN by adjusting its weights to minimize the difference between the current ANN output and the desired output. An evaluation process is conducted to determine whether the ANN has learned how to perform. The training process is halted periodically, and its performance is tested until an acceptable result is obtained. The principles underlying detection software are grounded in classical statistical decision theory. 相似文献
98.
The success of an artificial neural network (ANN) strongly depends on the variety of the connection weights and the network structure. Among many methods used in the literature to accurately select the network weights or structure in isolate; a few researchers have attempted to select both the weights and structure of ANN automatically by using metaheuristic algorithms. This paper proposes modified bat algorithm with a new solution representation for both optimizing the weights and structure of ANNs. The algorithm, which is based on the echolocation behaviour of bats, combines the advantages of population-based and local search algorithms. In this work, ability of the basic bat algorithm and some modified versions which are based on the consideration of the personal best solution in the velocity adjustment, the mean of personal best and global best solutions through velocity adjustment and the employment of three chaotic maps are investigated. These modifications are aimed to improve the exploration and exploitation capability of bat algorithm. Different versions of the proposed bat algorithm are incorporated to handle the selection of the structure as well as weights and biases of the ANN during the training process. We then use the Taguchi method to tune the parameters of the algorithm that demonstrates the best ability compared to the other versions. Six classifications and two time series benchmark datasets are used to test the performance of the proposed approach in terms of classification and prediction accuracy. Statistical tests demonstrate that the proposed method generates some of the best results in comparison with the latest methods in the literature. Finally, our best method is applied to a real-world problem, namely to predict the future values of rainfall data and the results show satisfactory of the method. 相似文献
99.
Simon Penny 《Digital Creativity》2013,24(3):197-204
This essay begins with discussion of four relatively recent works which are representative of major themes and preoccupations in Artificial Life Art: ‘Propagaciones’ by Leo Nuñez; ‘Sniff’ by Karolina Sobecka and Jim George; ‘Universal Whistling Machine’ by Marc Boehlen; and ‘Performative Ecologies’ by Ruari Glynn. This essay is an attempt to contextualise these works by providing an overview of the history and forms of Artificial Life Art as it has developed over two decades, along with some background in the ideas of the Artificial Life movement of the late 1980s and 1990s.1 相似文献
100.
The sedimentation is a pervasive complex hydrological process subjected to each and every reservoir in world at different extent. Hydrographic surveys are considered as most accurate method to determine the total volume occupied by sediment and its distribution pattern in a reservoir. But, these surveys are very cumbersome, time consuming and expensive. This complex sedimentation process can also be simulated through the well calibrated numerical models. However, these models generally are data extensive and require large computational time. Generally, the availability of such data is very scarce. Due to large constraints of these methods and models, in the present study, data driven approaches such as artificial neural networks (ANN), model trees (MT) and genetic programming (GP) have been investigated for the estimation of volume of sediment deposition incorporating the parameters influenced it along with conventional multiple linear regression data driven model. The aforementioned data driven models for the estimation of reservoir sediment deposition were initially developed and applied on Gobindsagar Reservoir. In order to generalise the developed methodology, the developed data driven models were also validated for unseen data of Pong Reservoir. The study depicted that the highly nonlinear models ANN and GP captured the trend of sediment deposition better than piecewise linear MT model, even for smaller length datasets. 相似文献