全文获取类型
收费全文 | 3766篇 |
免费 | 264篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 44篇 |
综合类 | 5篇 |
化学工业 | 883篇 |
金属工艺 | 72篇 |
机械仪表 | 55篇 |
建筑科学 | 163篇 |
矿业工程 | 5篇 |
能源动力 | 142篇 |
轻工业 | 264篇 |
水利工程 | 33篇 |
石油天然气 | 15篇 |
无线电 | 295篇 |
一般工业技术 | 791篇 |
冶金工业 | 609篇 |
原子能技术 | 26篇 |
自动化技术 | 632篇 |
出版年
2023年 | 59篇 |
2022年 | 98篇 |
2021年 | 169篇 |
2020年 | 116篇 |
2019年 | 114篇 |
2018年 | 140篇 |
2017年 | 127篇 |
2016年 | 138篇 |
2015年 | 116篇 |
2014年 | 186篇 |
2013年 | 261篇 |
2012年 | 228篇 |
2011年 | 291篇 |
2010年 | 194篇 |
2009年 | 179篇 |
2008年 | 186篇 |
2007年 | 169篇 |
2006年 | 148篇 |
2005年 | 94篇 |
2004年 | 107篇 |
2003年 | 69篇 |
2002年 | 78篇 |
2001年 | 32篇 |
2000年 | 26篇 |
1999年 | 44篇 |
1998年 | 63篇 |
1997年 | 46篇 |
1996年 | 28篇 |
1995年 | 34篇 |
1994年 | 26篇 |
1993年 | 24篇 |
1992年 | 17篇 |
1990年 | 19篇 |
1989年 | 17篇 |
1988年 | 12篇 |
1987年 | 12篇 |
1985年 | 23篇 |
1984年 | 19篇 |
1983年 | 17篇 |
1982年 | 22篇 |
1981年 | 26篇 |
1980年 | 13篇 |
1979年 | 25篇 |
1978年 | 19篇 |
1977年 | 17篇 |
1976年 | 23篇 |
1975年 | 18篇 |
1974年 | 18篇 |
1972年 | 11篇 |
1971年 | 12篇 |
排序方式: 共有4034条查询结果,搜索用时 0 毫秒
31.
Garfield Benjamin 《Digital Creativity》2016,27(1):24-36
ABSTRACTThe radical limit of post-anthropocentric creativity is a mode of completely nonhuman creative endeavour. Yet, the anthropocentrism prevails and conceptions of radically different civilisations and cultures are defined by current human thought that shapes and limits the understanding of what a genuinely alternative cultural production might entail. This article uses the Kardashev scale of civilisations, classified according to energy consumption at the planetary, stellar and galactic scales to consider culture beyond the current limits of an inherently anthropocentric perspective. In considering microdimensional, informational and universal extensions of Kardashev's scale, critical reflections on the anthropocentric limits of cultural epistemology create an opportunity to posit a universal framework of creativity. 相似文献
32.
Benjamin Aziz 《Journal of Grid Computing》2016,14(3):477-493
This paper presents an abstract specification of an enforcement mechanism of usage control for Grids, and verifies formally that such mechanism enforces UCON policies. Our technique is based on KAOS, a goal-oriented requirements engineering methodology with a formal LTL-based language and semantics. KAOS is used in a bottom-up form. We abstract the specification of the enforcement mechanism from current implementations of usage control for Grids. The result of this process is agent and operation models that describe the main components and operations of the enforcement mechanism. KAOS is used in top-down form by applying goal-refinement in order to refine UCON policies. The result of this process is a goal-refinement tree, which shows how a goal (policy) can be decomposed into sub-goals. Verification that a policy can be enforced is then equivalent to prove that a goal can be implemented by the enforcement mechanism represented by the agent and operation models. 相似文献
33.
Norbert Koppenhagen Benjamin Mueller Alexander Maedche Ye Li Stephanie Hiller 《Information Systems and E-Business Management》2016,14(3):613-636
E-procurement and supplier-relationship management systems have helped to substantially advance process execution in supply management. However, current supply network systems still face challenges of high data integration efforts, as well as the decoupling of structured data and processes from the growing amount of digitalized unstructured interactions of supply management professionals. Inspired by the room for improvement posed by this challenges, our research proposes a design for a supply network artifact in supplier qualification that addresses these problems by enabling holistic integration of data, processes, and people. The artifact is developed following an action design research approach. Building on a set of meta-requirements derived from literature and practice explorations, we conceptualize two design principles and derive corresponding design decisions that have been implemented in an software artifact. Finally, we formulate testable hypotheses and evaluate the artifact and its design in the context of supplier qualification. Our results show that the proposed design reduces mental effort of supply management professionals and significantly increases efficiency when performing typical supply network tasks such as supplier qualification. 相似文献
34.
Confirmation Bias in Online Searches: Impacts of Selective Exposure Before an Election on Political Attitude Strength and Shifts 下载免费PDF全文
Silvia Knobloch‐Westerwick Benjamin K. Johnson Axel Westerwick 《Journal of Computer-Mediated Communication》2015,20(2):171-187
Impacts of Internet use on political information seeking and subsequent processes have been subject to much debate. A 2‐session online field study presented online search results on political topics to examine selective exposure and its attitudinal impacts. Session 1 captured attitudes, including their accessibility. Session 2 tracked what online search results participants selected and how long they read them; participants then reported attitudes again. The study represented a 4x8x2x2 within‐subjects design: 4 topics, 8 browsing intervals each, with articles presenting opposing stances, with low versus high source credibility. Attitude‐consistent messages and messages from high‐credibility sources were preferred. Exposure to attitude‐consistent search results increased attitude accessibility and reinforced attitudes, whereas exposure to attitude‐discrepant content had opposite effects, regardless of messages' source credibility. 相似文献
35.
Peter J. Patsula Benjamin H. Detenber Yin-Leng Theng 《International journal of human-computer interaction》2013,29(7):675-702
Grounded in cognitive load theory, levels of processing theory, modes of learning research, and the facets of working memory (WM) framework, the primary goal of this investigation was to seek empirical evidence for a structure processing mechanism in WM that facilitates the coordination of associations made into coherent structures and the role this mechanism might play in performance and retention. This goal was motivated by a gap in the understanding of mental model production and encoding processes in WM. To carry out this goal, two usability studies were conducted to investigate retention, error, and time performance of Web-based menus created with structured or unstructured design. Relationships between these measures and coordination ability in WM, as well as storage and supervision ability, were also assessed. In Study 1, which tested simple Web-based menus, correlations of .28, ?.56, and ?.54 were detected between coordination (CC) and retention scores, CC and errors, and CC and time; in Study 2, which tested commercial Web-based menus, correlations of .46, ?.45, and ?.25 were detected. For Studies 1 and 2, differences in favor of structured design for retention, error, and time performance were highly significant (p < .001). 相似文献
36.
We present an odometry‐free three‐dimensional (3D) point cloud registration strategy for outdoor environments based on area attributed planar patches. The approach is split into three steps. The first step is to segment each point cloud into planar segments, utilizing a cached‐octree region growing algorithm, which does not require the 2.5D image‐like structure of organized point clouds. The second step is to calculate the area of each segment based on small local faces inspired by the idea of surface integrals. The third step is to find segment correspondences between overlapping point clouds using a search algorithm, and compute the transformation from determined correspondences. The transformation is searched globally so as to maximize a spherical correlation‐like metric by enumerating solutions derived from potential segment correspondences. The novelty of this step is that only the area and plane parameters of each segment are employed, and no prior pose estimation from other sensors is required. Four datasets have been used to evaluate the proposed approach, three of which are publicly available and one that stems from our custom‐built platform. Based on these datasets, the following evaluations have been done: segmentation speed benchmarking, segment area calculation accuracy and speed benchmarking, processing data acquired by scanners with different fields of view, comparison with the iterative closest point algorithm, robustness with respect to occlusions and partial observations, and registration accuracy compared to ground truth. Experimental results confirm that the approach offers an alternative to state‐of‐the‐art algorithms in plane‐rich environments. 相似文献
37.
Michael Wand Alexander Berner Martin Bokeloh Philipp Jenke Arno Fleck Mark Hoffmann Benjamin Maier Dirk Staneker Andreas Schilling Hans-Peter Seidel 《Computers & Graphics》2008,32(2):204-220
This paper describes a new out-of-core multi-resolution data structure for real-time visualization, interactive editing and externally efficient processing of large point clouds. We describe an editing system that makes use of the novel data structure to provide interactive editing and preprocessing tools for large scanner data sets. Using the new data structure, we provide a complete tool chain for 3D scanner data processing, from data preprocessing and filtering to manual touch-up and real-time visualization. In particular, we describe an out-of-core outlier removal and bilateral geometry filtering algorithm, a toolset for interactive selection, painting, transformation, and filtering of huge out-of-core point-cloud data sets and a real-time rendering algorithm, which all use the same data structure as storage backend. The interactive tools work in real-time for small model modifications. For large scale editing operations, we employ a two-resolution approach where editing is planned in real-time and executed in an externally efficient offline computation afterwards. We evaluate our implementation on example data sets of sizes up to 63 GB, demonstrating that the proposed technique can be used effectively in real-world applications. 相似文献
38.
Thomas F. O'Dwyer Benjamin K. Hodnett 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1995,62(1):30-37
Adsorption isotherms for sodium and trivalent chromium uptake from aqueous solutions onto Amberlite resin were prepared at 18°C. Adsorption of each cation followed the Langmuir model. The rate of uptake of each cation was found to be film diffusion controlled with sodium showing the most rapid uptake. In aqueous solutions containing both chromium and sodium as the only cationic species, it was found that with increasing initial concentration of sodium, the trivalent chromium uptake on the resin decreased substantially. To overcome this difficulty a four step redox–adsorption system has been developed for the removal of Cr3+ from tannery effluents. The first step comprises the oxidation of trivalent chromium to the hexavalent form using selected common oxidising agents. The liquid effluent is then passed through an Amberlite cation-exchange resin in step 2 where the sodium in the waste stream is completely removed. The anionic hexavalent form of chromium (Cr2O) passes unaltered through the resin along with the waste stream. In the third stage the dichromate is reduced back to the trivalent cationic form which is subsequently removed from the waste stream by a second Amberlite ion-exchange bed in stage 4. Each step in this process is assessed in batch and flow mode using simulated and real tannery effluents. 相似文献
39.
Lin Pei-Chun Yankson Benjamin Chauhan Vishal Tsukada Manabu 《The Journal of supercomputing》2022,78(13):15060-15088
The Journal of Supercomputing - Currently, many smart speakers, even social robots, appear on the market to help people's lives become more convenient. Usually, people use smart speakers to... 相似文献
40.
Optimized Photoinitiator for Fast Two‐Photon Absorption Polymerization of Polyester‐Macromers for Tissue Engineering 下载免费PDF全文