124,266 research outputs found
Increase in soil organic carbon by agricultural intensification in northern China
Acknowledgements. This research was supported by National Natural Science Foundation of China (no. 31370527 and 31261140367) and the National Science and Technology Support Program of China (no. 2012BAD14B01-2). The authors gratefully thank the Huantai Agricultural Station for providing of the Soil Fertility Survey data. We also thank Zheng Liang from China Agricultural University for the soil sampling and analysis in 2011. Thanks are extended to Jessica Bellarby for helpful discussion and suggestions.Peer reviewedPublisher PD
Dynamics of tilt-based browsing on mobile devices
A tilt-controlled photo browsing method for small mobile devices is presented. The implementation uses continuous inputs from an accelerometer, and a multimodal (visual, audio and vibrotactile) display coupled with the states of this model. The model is based on a simple physical model, with its characteristics shaped to enhance usability. We show how the dynamics of the physical model can be shaped to make the handling qualities of the mobile device fit the browsing task. We implemented the proposed algorithm on Samsung MITs PDA with tri-axis accelerometer and a vibrotactile motor. The experiment used seven novice users browsing from 100 photos. We compare a tilt-based interaction method with a button-based browser and an iPod wheel. We discuss the usability performance and contrast this with subjective experience from the users. The iPod wheel has significantly poorer performance than button pushing or tilt interaction, despite its commercial popularity
The Multi-Phase Medium in the Interstellar Complex N44
We have obtained high-resolution HI observations of N44, one of the largest
HII complexes in the Large Magellanic Cloud. The distribution and internal
motions of the HI gas show dynamic effects of fast stellar winds and supernova
blasts. Numerous HI holes are detected, with the most prominent two
corresponding to the optically identified superbubbles Shell 1 and Shell 2. The
HI gas associated with Shell 1 shows an expansion pattern similar to that of
the ionized gas shell, but the mass and kinetic energy of the HI shell are 3--7
times those of the ionized gas shell. The total kinetic energy of the neutral
and ionized gas of Shell 1 is still more than a factor of 5 lower than expected
in a pressure-driven superbubble. It is possible that the central OB
association was formed in a molecular cloud and a visible superbubble was not
fully developed until the ambient molecular gas had been dissociated and
cleared away. This hypothesis is supported by the existence of a molecular
cloud toward N44 and the fact that the apparent dynamic age of the superbubble
Shell 1 is much shorter than the age of its OB association LH47. Accelerated HI
gas is detected at the supernova remnant 0523-679. The mass and kinetic energy
in the associated HI gas are also much higher than those in the ionized gas of
0523-679. Studies of interstellar gas dynamics using ionized gas alone are
clearly inadequate; neutral gas components must be included.Comment: 18 pages,5 figures; for "figures", see at
"http://www.astro.uiuc.edu/~sek/N44.html" (4.9 MB postscript.gz) ; Appear to
ApJ, 503, 729 (Aug 20
Protons associated with centers of solar activity and their propagation in interplanetary magnetic field regions co-rotating with the sun
Protons associated with centers of solar activity and propagation in interplanetary magnetic field regions co-rotating with su
Development of a new machine system for the forming of micro-sheet-products
Most of the developed micro-forming machines were based on standalone concepts which do not support efficient integration to make them fully automated and integrated. At present, material feeding in micro-forming is not of sufficient precision and reliability for high throughput manufacturing applications. Precise feeding is necessary to ensure that micro-parts can be produced with sufficient accuracy, especially in multi-stage forming, while high-speed feeding is a must to meet the production-rate requirements. Therefore, design of a new high-precision and high-speed feeder for micro-forming is proposed. Several possible approaches are examined with a view to establishing feasible concepts. Based on the investigation, several concepts for thin sheet-metal feeding for micro-forming are generated, they being argued and assessed with applicable loads and forces analysis. These form a basis of designing a new feeder
NASA Workshop on future directions in surface modeling and grid generation
Given here is a summary of the paper sessions and panel discussions of the NASA Workshop on Future Directions in Surface Modeling and Grid Generation held a NASA Ames Research Center, Moffett Field, California, December 5-7, 1989. The purpose was to assess U.S. capabilities in surface modeling and grid generation and take steps to improve the focus and pace of these disciplines within NASA. The organization of the workshop centered around overviews from NASA centers and expert presentations from U.S. corporations and universities. Small discussion groups were held and summarized by group leaders. Brief overviews and a panel discussion by representatives from the DoD were held, and a NASA-only session concluded the meeting. In the NASA Program Planning Session summary there are five recommended steps for NASA to take to improve the development and application of surface modeling and grid generation
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