全文获取类型
收费全文 | 9198篇 |
免费 | 686篇 |
国内免费 | 745篇 |
专业分类
电工技术 | 306篇 |
综合类 | 1810篇 |
化学工业 | 89篇 |
金属工艺 | 87篇 |
机械仪表 | 392篇 |
建筑科学 | 272篇 |
矿业工程 | 67篇 |
能源动力 | 21篇 |
轻工业 | 93篇 |
水利工程 | 49篇 |
石油天然气 | 46篇 |
武器工业 | 42篇 |
无线电 | 711篇 |
一般工业技术 | 270篇 |
冶金工业 | 562篇 |
原子能技术 | 15篇 |
自动化技术 | 5797篇 |
出版年
2024年 | 30篇 |
2023年 | 104篇 |
2022年 | 202篇 |
2021年 | 228篇 |
2020年 | 167篇 |
2019年 | 116篇 |
2018年 | 100篇 |
2017年 | 142篇 |
2016年 | 155篇 |
2015年 | 183篇 |
2014年 | 429篇 |
2013年 | 369篇 |
2012年 | 518篇 |
2011年 | 573篇 |
2010年 | 514篇 |
2009年 | 535篇 |
2008年 | 652篇 |
2007年 | 698篇 |
2006年 | 675篇 |
2005年 | 667篇 |
2004年 | 528篇 |
2003年 | 511篇 |
2002年 | 350篇 |
2001年 | 344篇 |
2000年 | 268篇 |
1999年 | 205篇 |
1998年 | 167篇 |
1997年 | 161篇 |
1996年 | 125篇 |
1995年 | 138篇 |
1994年 | 127篇 |
1993年 | 98篇 |
1992年 | 78篇 |
1991年 | 68篇 |
1990年 | 41篇 |
1989年 | 44篇 |
1988年 | 34篇 |
1987年 | 24篇 |
1986年 | 21篇 |
1985年 | 33篇 |
1984年 | 31篇 |
1983年 | 18篇 |
1982年 | 10篇 |
1981年 | 14篇 |
1980年 | 12篇 |
1979年 | 10篇 |
1978年 | 11篇 |
1977年 | 10篇 |
1975年 | 15篇 |
1971年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
为实时提取三维实体表面,提出一种基于GPGPU并行计算的实体表面实时提取方法。在分析深度剥离算法原理和GPU图形绘制管线的基础上,给出在GPU上利用深度剥离算法实现实时提取三维实体表面的算法;通过OpenGL的高级着色语言GLSL控制GPU的图形绘制管线实现了该算法,给出其伪代码。以龙、叶轮和刀具扫描体的模型为应用实例验证了该算法效果良好,特别是对于刀具扫描体表面的提取,可满足实时性要求。 相似文献
92.
针对现有的Web服务质量模型主要考虑的都是通用的服务质量属性,没有考虑特定的Web服务属性在评价中的作用,提出了一个新的Web服务质量模型,它引入了一个特定领域的服务质量属性,该模型包括三个子模型。模型中建立了相关的服务质量树和目标对象树,通过量化指标子模型对目标对象进行量化,形成相应的服务权重树。该模型既可适应用于单个的Web服务请求,也可以用于多个服务组合而成的请求。通过一个应用实例验证了模型的正确性和可用性。 相似文献
93.
针对精确实验数据的曲线拟合方程化处理方法已不再适应高精度测试技术的问题,提出了用三次样条插值函数进行曲线方程化处理的新方法,并创建了用MATLAB语言编写遗传算法程序进行曲线斜率求解的方法,通过实例表明,采用遗传算法求解出的三次样条插值函数非常适合精确实验数据的曲线方程化处理。 相似文献
94.
预训练语言模型在情感文本的生成任务中取得了良好效果,但现有情感文本生成方法多使用软约束的方式控制文本整体的情感属性,缺乏单词和短语级别的硬性控制。为解决以上问题,提出硬约束限制下的情感文本生成方法。首先使用方面情感分析技术提取句子的方面词、情感词并判断情感极性;之后,选择目标情感的方面词和情感词作为预训练语言模型的硬约束输入来重建完整句子,其中,设计了一种新的单词权重计算方法,旨在使模型优先生成重要单词。实验结果表明,该方法生成的句子不仅具有方面级情感,在文本质量和多样性的评价指标上也有显著提高。 相似文献
95.
This paper presents a segment-based probabilistic approach to robustly recognize continuous sign language sentences. The recognition strategy is based on a two-layer conditional random field (CRF) model, where the lower layer processes the component channels and provides outputs to the upper layer for sign recognition. The continuously signed sentences are first segmented, and the sub-segments are labeled SIGN or ME (movement epenthesis) by a Bayesian network (BN) which fuses the outputs of independent CRF and support vector machine (SVM) classifiers. The sub-segments labeled as ME are discarded and the remaining SIGN sub-segments are merged and recognized by the two-layer CRF classifier; for this we have proposed a new algorithm based on the semi-Markov CRF decoding scheme. With eight signers, we obtained a recall rate of 95.7% and a precision of 96.6% for unseen samples from seen signers, and a recall rate of 86.6% and a precision of 89.9% for unseen signers. 相似文献
96.
The usefulness of Software Architecture (SA) documentation depends on how well its Architectural Knowledge (AK) can be retrieved by the stakeholders in a software project. Recent findings show that the use of ontology-based SA documentation is promising. However, different roles in software development have different needs for AK, and building an ontology to suit these needs is challenging. In this paper we describe an approach to build an ontology for SA documentation. This approach involves the use of typical questions for eliciting and constructing an ontology. We outline eight contextual factors, which influence the successful construction of an ontology, especially in complex software projects with diverse AK users. We tested our ‘typical question’ approach in a case study and report how it can be used for acquiring and modeling AK needs. 相似文献
97.
This paper discusses the adoption of a pluralist theoretical framework – one that is also multiparadigmatic – for conducting and publishing information system (IS) research. The discussion is illustrated by a single case study involving the Australian cotton industry. The theoretical framework is informed by three sociological theories, each with its particular paradigmatic assumptions: structuration theory as a meta‐theory, and diffusion of innovations and gender relations as lower‐level theories from notionally opposing paradigms. Theoretical pluralism helped to produce rich findings, illuminating both the social nature of women farmers' roles, the materiality of the cotton farming context, the characteristics of the decision support systems in use and the recursive way in which human agency and institutional pressures shape each other. Because users of so‐called divergent paradigms often face criticism based on the incommensurability issue, one of the main contributions of this paper is to discuss the value of a pluralist and multiparadigmatic theoretical framework in dealing with complex IS social phenomena. 相似文献
98.
《Advanced Engineering Informatics》2014,28(4):272-286
Building Information Models (BIM) are comprehensive digital representations of buildings, which provide a large set of information originating from the different disciplines involved in the design, construction and operation processes. Moreover, accessing the data needed for a specific downstream application scenario is a challenging task in large-scale BIM projects. Several researchers recently proposed using formal query languages for specifying the desired information in a concise, well-defined manner. One of the main limitations of the languages introduced so far, however, is the inadequate treatment of geometric information. This is a significant drawback, as buildings are inherently spatial objects and qualitative spatial relationships accordingly play an important role in the analysis and verification of building models. In addition, the filters needed in specific data exchange scenarios for selecting the information required can be built by spatial objects and their relations. The lack of spatial functionality in BIM query languages is filled by the Query Language for Building Information Models (QL4BIM) which provides metric, directional and topological operators for defining filter expressions with qualitative spatial semantics. This paper focuses on the topological operators provided by the language. In particular, it presents a new implementation method based on the boundary representation of the operands which outperforms the previously presented octree-based approaches. The paper discusses the developed algorithms in detail and presents extensive performance tests. 相似文献
99.
循环结构是C语言程序设计中的重难点,其掌握情况对于后续章节的学习效果尤为关键。本文以什么是循环、何时需要使用循环以及如何使用循环三个问题为主线,通过精心选择的教学案例和灵活有效的教学方法来进行解答,以激发学生兴趣,培养编程思想。 相似文献
100.
本文利用R语言对关注度不高、转发量不太大的机器人教育微博进行了可视化研究。在分析技术实现过程的同时,我们得出结论是:机器人教育的舆情由教育官方媒体和企业培训机构主导;经济力量决定着参与讨论的程度;微博不是学习内容交流的主阵地。 相似文献