全文获取类型
收费全文 | 389篇 |
免费 | 9篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 399篇 |
出版年
2023年 | 2篇 |
2022年 | 13篇 |
2021年 | 8篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 6篇 |
2014年 | 11篇 |
2013年 | 24篇 |
2012年 | 17篇 |
2011年 | 17篇 |
2010年 | 19篇 |
2009年 | 26篇 |
2008年 | 29篇 |
2007年 | 16篇 |
2006年 | 10篇 |
2005年 | 12篇 |
2004年 | 11篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 25篇 |
1997年 | 12篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 2篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 6篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有399条查询结果,搜索用时 0 毫秒
1.
Moritoshi Yasunaga Noriyuki Aibe Yoshiki Yamaguchi Yorihisa Yamamoto Takaaki Awano Ikuo Yoshihara 《Artificial Life and Robotics》2008,12(1-2):219-222
Watching and tracking an object while seeing a much wider view is one of advantages of the eye system. We proposed and developed
a tracking camera system that mimics the eyes by using double-lens modules. In the system, a wide view is captured through
the wide-lens module, while the target in it is tracked and magnified through the telescopic lens module. Electronic circuits
for tracking control are implemented onto the reconfigurable VLSI or FPGA in order to embed the parallelism in the tracking
algorithm into the hardware. A successfully developed FPGA-based prototype performs high-speed tracking at the video-rate.
This work was present in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27,
2007 相似文献
2.
3.
MQ Fujita N Hashida M Shin H Nakanishi W Yoshihara K Aozasa 《Canadian Metallurgical Quarterly》1998,55(6):600-606
Poly(A)+ mRNA was isolated from leaves of potato plants (Solanum tuberosum L. cv. Desiree) according to standard protocols. This poly(A)+ mRNA was injected via glass microcapillaries into oocytes that were surgically removed from the African clawed toad Xenopus laevis. As a control, oocytes were either injected with H2O or remained untreated. Three days after injection the oocytes were analyzed by two electrode voltage clamping. Current voltage analysis revealed that a K+ channel from potato was functionally expressed in injected oocytes. The identity of this K+ channel was confirmed by its substrate specificity and a shift in the reversal potential. In particular, when the outside K+ concentration was increased the reversal potential of poly(A)+ injected oocytes shifted to more positive values. Furthermore, K+ outward currents declined when the outside K+ concentration was raised from 0.1 to 100 mM. Inward currents increased with an elevation of the K+ concentration. Several pharmaceuticals were tested for their potential to block this K+ channel. As a result, the channel was completely blocked by BaCl2. A three state reaction kinetic model was used to simulate the currents through the K+ transport protein as function of the extracellular K+ concentration. In particular, the simulation revealed current voltage relations that exactly matched the measured ones. Saturation of current voltage curves emerged from the simulation as a consequence of high extracellular potassium concentration. 相似文献
4.
Reconstructing the World’s Museums 总被引:2,自引:0,他引:2
Virtual exploration tools for large indoor environments (e.g. museums) have so far been limited to either blueprint-style 2D maps that lack photo-realistic views of scenes, or ground-level image-to-image transitions, which are immersive but ill-suited for navigation. On the other hand, photorealistic aerial maps would be a useful navigational guide for large indoor environments, but it is impossible to directly acquire photographs covering a large indoor environment from aerial viewpoints. This paper presents a 3D reconstruction and visualization system for automatically producing clean and well-regularized texture-mapped 3D models for large indoor scenes, from ground-level photographs and 3D laser points. The key component is a new algorithm called “inverse constructive solid geometry (CSG)” for reconstructing a scene with a CSG representation consisting of volumetric primitives, which imposes powerful regularization constraints. We also propose several novel techniques to adjust the 3D model to make it suitable for rendering the 3D maps from aerial viewpoints. The visualization system enables users to easily browse a large-scale indoor environment from a bird’s-eye view, locate specific room interiors, fly into a place of interest, view immersive ground-level panorama views, and zoom out again, all with seamless 3D transitions. We demonstrate our system on various museums, including the Metropolitan Museum of Art in New York City—one of the largest art galleries in the world. 相似文献
5.
Emad Shihab Akinori Ihara Yasutaka Kamei Walid M. Ibrahim Masao Ohira Bram Adams Ahmed E. Hassan Ken-ichi Matsumoto 《Empirical Software Engineering》2013,18(5):1005-1042
Bug fixing accounts for a large amount of the software maintenance resources. Generally, bugs are reported, fixed, verified and closed. However, in some cases bugs have to be re-opened. Re-opened bugs increase maintenance costs, degrade the overall user-perceived quality of the software and lead to unnecessary rework by busy practitioners. In this paper, we study and predict re-opened bugs through a case study on three large open source projects—namely Eclipse, Apache and OpenOffice. We structure our study along four dimensions: (1) the work habits dimension (e.g., the weekday on which the bug was initially closed), (2) the bug report dimension (e.g., the component in which the bug was found) (3) the bug fix dimension (e.g., the amount of time it took to perform the initial fix) and (4) the team dimension (e.g., the experience of the bug fixer). We build decision trees using the aforementioned factors that aim to predict re-opened bugs. We perform top node analysis to determine which factors are the most important indicators of whether or not a bug will be re-opened. Our study shows that the comment text and last status of the bug when it is initially closed are the most important factors related to whether or not a bug will be re-opened. Using a combination of these dimensions, we can build explainable prediction models that can achieve a precision between 52.1–78.6 % and a recall in the range of 70.5–94.1 % when predicting whether a bug will be re-opened. We find that the factors that best indicate which bugs might be re-opened vary based on the project. The comment text is the most important factor for the Eclipse and OpenOffice projects, while the last status is the most important one for Apache. These factors should be closely examined in order to reduce maintenance cost due to re-opened bugs. 相似文献
6.
7.
Since the control methods of a transport system between processing machines are specialized for each layout of the system,
it is difficult to design prompt schedules and control logic for new complicated systems, especially in cases of machine faults
or restructuring the system to modify the layout. In this article, we describe a multiagent transport control system which
utilizes pheromone information. Each element of the system acts as an agent and estimates the appropriate path and time to
drive out the products using information obtained by communication with other elements as well as pheromone information deposited
on the tracks of the products. 相似文献
8.
9.
Yasutaka Takahashi Kenji Mutoh Seiji Motojima Kohzo Sugiyama 《Journal of Materials Science》1981,16(5):1217-1222
Both dimethylamino- (I) and diethylamino-alane dimers (II), [(R2N)2AlH]2 (I, R=Me; II, R=Et) decompose above 800° C under a few hundred Pa of hydrogen to dark greyish, hard (Vickers hardness larger than 2000), oxidation-resistive and oxidation-protective deposits which are tentatively identified as Al5C3N. The deposits are stable to moisture and diluted hydrochloric acid in contrast to those obtained below 800° C, but they easily dissolve in sodium hydroxide solution at room temperature evolving a gas. The deposits on a stainless steel substrate adhere strongly to the substrate and remain so on rapid heating and cooling. The electrical resistivity of the deposits is in the range 102 to 104 cm. 相似文献
10.
Nanocube Superlattices of Cesium Lead Bromide Perovskites and Pressure‐Induced Phase Transformations at Atomic and Mesoscale Levels 下载免费PDF全文
Yasutaka Nagaoka Katie Hills‐Kimball Rui Tan Ruipeng Li Zhongwu Wang Ou Chen 《Advanced materials (Deerfield Beach, Fla.)》2017,29(18)
Lead halide perovskites are promising materials for a range of applications owing to their unique crystal structure and optoelectronic properties. Understanding the relationship between the atomic/mesostructures and the associated properties of perovskite materials is crucial to their application performances. Herein, the detailed pressure processing of CsPbBr3 perovskite nanocube superlattices (NC‐SLs) is reported for the first time. By using in situ synchrotron‐based small/wide angle X‐ray scattering and photoluminescence (PL) probes, the NC‐SL structural transformations are correlated at both atomic and mesoscale levels with the band‐gap evolution through a pressure cycle of 0 ? 17.5 GPa. After the pressurization, the individual CsPbBr3 NCs fuse into 2D nanoplatelets (NPLs) with a uniform thickness. The pressure‐synthesized perovskite NPLs exhibit a single cubic crystal structure, a 1.6‐fold enhanced photoluminescence quantum yield, and a longer emission lifetime than the starting NCs. This study demonstrates that pressure processing can serve as a novel approach for the rapid conversion of lead halide perovskites into structures with enhanced properties. 相似文献