全文获取类型
收费全文 | 16322篇 |
免费 | 2213篇 |
国内免费 | 1106篇 |
专业分类
电工技术 | 3139篇 |
综合类 | 1066篇 |
化学工业 | 807篇 |
金属工艺 | 284篇 |
机械仪表 | 818篇 |
建筑科学 | 126篇 |
矿业工程 | 298篇 |
能源动力 | 685篇 |
轻工业 | 141篇 |
水利工程 | 20篇 |
石油天然气 | 29篇 |
武器工业 | 36篇 |
无线电 | 3590篇 |
一般工业技术 | 845篇 |
冶金工业 | 79篇 |
原子能技术 | 52篇 |
自动化技术 | 7626篇 |
出版年
2024年 | 104篇 |
2023年 | 581篇 |
2022年 | 753篇 |
2021年 | 887篇 |
2020年 | 1020篇 |
2019年 | 728篇 |
2018年 | 833篇 |
2017年 | 1483篇 |
2016年 | 1515篇 |
2015年 | 1297篇 |
2014年 | 1602篇 |
2013年 | 1296篇 |
2012年 | 1650篇 |
2011年 | 1295篇 |
2010年 | 786篇 |
2009年 | 994篇 |
2008年 | 365篇 |
2007年 | 606篇 |
2006年 | 474篇 |
2005年 | 229篇 |
2004年 | 127篇 |
2003年 | 137篇 |
2002年 | 137篇 |
2001年 | 133篇 |
2000年 | 105篇 |
1999年 | 120篇 |
1998年 | 34篇 |
1997年 | 31篇 |
1996年 | 32篇 |
1995年 | 35篇 |
1994年 | 21篇 |
1993年 | 20篇 |
1992年 | 19篇 |
1991年 | 20篇 |
1990年 | 17篇 |
1989年 | 13篇 |
1988年 | 37篇 |
1987年 | 86篇 |
1986年 | 11篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1978年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
91.
92.
93.
94.
95.
无人机辅助物联网技术被广泛应用于灾害应急通信中,但物联网设备的通信中存在多种不确定因素。针对位置参数区间存在不确定性的问题,提出了无人机辅助物联网通信的鲁棒优化方法。使用椭球不确定集对地面物联网设备位置参数区间不确定性进行描述,建立了包含不确定性的物联网设备通信鲁棒优化模型,并对模型进行了求解。为提高模型求解的准确性,提出一个有关位置参数区间不确定和椭球误差域之间的相关分析方法,分析了两类不确定因素对物联网设备通信模型的影响程度。以地面物联网设备最优部署和通信最小功率为目的,设计了仿真实验。结果表明,在不确定因素存在时,所提优化模型能有效实现地面物联网设备间的最优部署和通信功率最小化。 相似文献
96.
The integrated data collection system hasn't changed much over the years. Their growth is dominated by digital filtering, and they get a new avionics bus. Time division multiplexing is still used to communicate with the system's data collector. These schemes make use of commands and data buses. While this method works, it has many drawbacks. These shortcomings are overwhelming the strict system architecture, system bandwidth limits, and expertise to only obtain an avionics bus, otherwise system bandwidth and one-way flow of data and control. This lead for high-end video recorders. To quietly monitor our actions and valuable information provides important warnings. However, it is usually completed by a device with this small processing power, which tracks the device, stores the data of the user's data, and is limited in processing. Therefore, it is important to store and process user data in the cloud to track 5 G network activity. This article proposes a simple 5G network gateway solution for custom user monitoring equipment. Collects charge data on Network 5G and Charging-aware multi-mode based routing protocol (CMRP). The CMRP routing mechanism is not yet stable, but the changes depend on the state of the energy charge sensor. This cannot be complemented by energy-efficient sensors and routing protocols that consume less energy. 相似文献
97.
Managing sports performance is very important in the sports industry. Performance, the executives, centers on boosting competitor execution and decreasing the danger of injury. Several factors contribute to these goals, including player health, emotional status, exercise load and physical intensity requirements. Generally speaking, injury prediction is an essential component of injury prevention, and successful identification of injury prediction is a primary indicator for effective prevention. The proposed Artificial Neural Network (ANN) objective is to develop and use early-doing ability and exercise load data to validate a hierarchical machine learning prediction system with accurate detection of player injuries. The physical and workload that requires detection of this early personalized damage can be avoided with specific help. The framework is used to test 21 soccer players’ sports information from various sources, including gathered and inside burden information, outside burden information, and review information. The entirety of this information is fused into the proposed framework to improve the exactness of harm expectation. This calculation distinguishes competitors in danger of injury, with their early intervention available. 相似文献
98.
The paper suggests a new methodology for secure cyber–physical systems design. The proposed methodology consists of two main cycles. The main goal of the first cycle is in design of the system model, while the second one is about development of the system prototype. The key idea of the methodology is in providing of the most rational solutions that are improving the security of cyber–physical systems. Such solutions are called alternatives and built according to functional requirements and non-functional limitations to the system. Each cycle of the methodology consists of the verification process and seven stages that are associated with the used cyber–physical system model. The objective of the verification process is in checking of constructed models and prototypes in terms of their correctness and compatibility. The model represents cyber–physical systems as sets of building blocks with network between them, takes elements internal structure into account and allows direct and reverse transformations. The novelty of the suggested methodology is in the combination of design, development and verification techniques within a single approach. To provide an example of the design methodology application, in this paper it is used to improve the semi-natural model of the railway infrastructure. 相似文献
99.
FrequentItemsetMining (FIM) is one of the most important data mining tasks and is the foundation of many data mining tasks. In Big Data era, centralized FIM algorithms cannot meet the needs of FIM for big data in terms of time and space, so Distributed Frequent Itemset Mining (DFIM) algorithms have been designed to meet the above challenges. In this paper, LocalGlobal and RedistributionMining which are two main paradigms of DFIM algorithm are discussed; Two algorithms of these paradigms on MapReduce named LG and RM are proposed while MapReduce is a popular distributed computing model, and also the related work is discussed. The experimental results show that the RM algorithm has better performance in terms of computation and scalability of sites, and can be used as the basis for designing the DFIM algorithm based on MapReduce. This paper also discusses the main ideas of improving the DFIM algorithms based on MapReduce. 相似文献
100.
《Displays》2021
Semantic segmentation based on the complementary information from RGB and depth images has recently gained great popularity, but due to the difference between RGB and depth maps, how to effectively use RGB-D information is still a problem. In this paper, we propose a novel RGB-D semantic segmentation network named RAFNet, which can selectively gather features from the RGB and depth information. Specifically, we construct an architecture with three parallel branches and propose several complementary attention modules. This structure enables a fusion branch and we add the Bi-directional Multi-step Propagation (BMP) strategy to it, which can not only retain the feature streams of the original RGB and depth branches but also fully utilize the feature flow of the fusion branch. There are three kinds of complementary attention modules that we have constructed. The RGB-D fusion module can effectively extract important features from the RGB and depth branch streams. The refinement module can reduce the loss of semantic information and the context aggregation module can help propagate and integrate information better. We train and evaluate our model on NYUDv2 and SUN-RGBD datasets, and prove that our model achieves state-of-the-art performances. 相似文献