中国科学院机构知识库网格系统: 检索

Chip design with machine learning: a survey from algorithm perspective 期刊论文 OAI收割
SCIENCE CHINA-INFORMATION SCIENCES, 2023, 卷号: 66, 期号: 11, 页码: 31
作者: He, Wenkai; Li, Xiaqing; Song, Xinkai; Hao, Yifan; Zhang, Rui

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收藏 | 浏览/下载：28/0 | 提交时间：2023/12/04

chip design machine learning chip design automation design result estimation design optimization and correction design construction

Improved box-counting methods to directly estimate the fractal dimension of a rough surface 期刊论文 OAI收割
MEASUREMENT, 2021, 卷号: 177, 页码: 12
作者: Wu, Mingyang; Wang, Wensong; Shi, Di; Song, Zhenlong; Li, Minghui

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收藏 | 浏览/下载：24/0 | 提交时间：2021/06/18

Rough surface Box-counting dimension Cubic covering Stable measurement result Thick film

Periodicity Search on X-Ray Bursts of SGR J1935+2154 Using 8.5 yr of Fermi/GBM Data 期刊论文 OAI收割
The Astrophysical Journal, 2021, 卷号: 923, 页码: L30
作者: HXMT

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收藏 | 浏览/下载：22/0 | 提交时间：2022/02/08

2008 1471 Astrophysics - High Energy Astrophysical Phenomena Abstract: We performed a systematic search for X-ray bursts of the SGR J1935+2154 using the Fermi Gamma-ray Burst Monitor continuous data dated from 2013 January to 2021 October. Eight bursting phases, which consist of a total of 353 individual bursts, are identified. We further analyze the periodic properties of our sample using the Lomb-Scargle periodogram. The result suggests that those bursts exhibit a period of ~238 days with a ~63.2% duty cycle. Based on our analysis, we further predict two upcoming active windows of the X-ray bursts. Since 2021 July, the beginning date of our first prediction has been confirmed by the ongoing X-ray activities of the SGR J1935+2154.

Can a dam type of an alpine lake be derived from lake geometry? A negative result 期刊论文 OAI收割
JOURNAL OF MOUNTAIN SCIENCE, 2021, 卷号: 18, 期号: 3, 页码: 614-621
作者: Emmer, Adam; Curin, Vojtech

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收藏 | 浏览/下载：11/0 | 提交时间：2023/04/23

Alpine lake High mountain lake GLOFs Glacial lake Moraine-dammed Bedrock-dammed Negative result Cordillera Blanca

Massive Data Management and Sharing Module for Connectome Reconstruction 期刊论文 OAI收割
BRAIN SCIENCES, 2020, 卷号: 10, 期号: 5, 页码: 15
作者: Yuan, Jingbin; Zhang, Jing; Shen, Lijun; Zhang, Dandan; Yu, Wenhuan

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收藏 | 浏览/下载：30/0 | 提交时间：2020/08/03

connectome massive data management distributed storage and retrieval electron microscope image segmentation result image cache

The braking index of PSR B0540-69 and the associated pulsar wind nebula emission after spin-down rate transition 期刊论文 OAI收割
Monthly Notices of the Royal Astronomical Society, 2020, 卷号: 494, 页码: 1865-1870
作者: HXMT

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收藏 | 浏览/下载：55/0 | 提交时间：2022/02/08

stars: magnetic field stars: neutron pulsars: general Astrophysics - High Energy Astrophysical Phenomena Abstract: In 2011 December, PSR B054-69 experienced a spin-down rate transition (SRT), after which the spin-down power of the pulsar increased by $\sim 36{{\ \rm per\ cent}}$. About 1000 d after the SRT, the X-ray luminosity of the associated pulsar wind nebula (PWN) was found to brighten by $32\pm 8{{\ \rm per\ cent}}$. After the SRT, the braking index n of PSR B0540-69 changes from n = 2.12 to 0.03 and then keeps this value for about five years before rising to n = 0.9 in the following years. We find that most of the current models have difficulties in explaining the measured braking index. One exceptive model of the braking index evolution is the increasing dipole magnetic field of PSR B0540-69. We suggest that the field increase may result from some instabilities within the pulsar core that enhance the poloidal component at the price of toroidal component of the magnetic field. The increasing dipole magnetic field will result in the X-ray brightening of the PWN. We fit the PWN X-ray light curve by two models: one assumes a constant magnetic field within the PWN during the brightening and the other assumes an enhanced magnetic field proportional to the energy density of the PWN. It appears that the two models fit the data well, though the later model seems to fit the data a bit better. This provides marginal observational evidence that magnetic field in the PWN is generated by the termination shock. Future high-quality and high-cadence data are required to draw a solid conclusion.

Comparison of simulated backgrounds with in-orbit observations for HE, ME, and LE onboard Insight-HXMT 期刊论文 OAI收割
Astrophysics and Space Science, 2020, 卷号: 365, 页码: 158
作者: HXMT

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收藏 | 浏览/下载：49/0 | 提交时间：2022/02/08

Insight-HXMT Geant4 simulation Background observation Astrophysics - Instrumentation and Methods for Astrophysics Abstract: Insight-HXMT, the first X-ray astronomical satellite in China, aims to reveal new sources in the Galaxy and to study fundamental physics of X-ray binaries from 1 to 250 keV. It has three collimated telescopes, the High Energy X-ray telescope (HE), the Medium Energy X-ray telescope (ME), and the Low Energy X-ray telescope (LE). Before the launch, in-orbit backgrounds of these three telescopes had been estimated through Geant4 simulation, in order to investigate the instrument performance and the achievement of scientific goals. In this work, these simulated backgrounds are compared with in-orbit observations. Good agreements are shown for all three telescopes. For HE, (1) the deviation of the simulated background rate after two years of operation in space is 5 % from the observation (2) the total background spectrum and the relative abundance of the 67 keV line show long-term increases both in simulations and observations. For ME, (1) the deviation of simulated background rate is within 15 % from the observation, and (2) there are no obvious long-term increase features in the background spectra of simulations and observations. For LE, the background level given by simulations is also consistent with observations. The consistencies of these comparisons validate that the Insight-HXMT mass model, i.e., space environment components and models adopted, physics processes selected, and detector constructions built, is reasonable. However, the line features at 7.5 and 8.0 keV, which are obvious in the observed spectra of LE, are not evident in simulations. This might result from uncertainties in the LE constructions.

碳氮稳定同位素比值在潮间带大型底栖动物组织间差异性研究 期刊论文 OAI收割
海洋学报, 2019, 卷号: 41, 期号: 4, 页码: 74-82
作者: 李宝泉

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潮间带大型底栖动物碳氮稳定同位素食源和营养级分析采样部位选取 intertidal zone macrobenthos carbon and nitrogen stable isotopes food sources and trophic levels study,sampling parts The technique of stable isotope analysis has been widely applied for the field of food web studies in recent years.However,few researches concerned about the impacts of different tissues used for analysis on the food web building.With the purpose of accuracy and comparability in the food web studies,the sampling tissues should be standardized.In this study,10macrobenthic species from the intertidal zone of the Yellow River Delta and Yantai were chosen as the target object to test the isotopic characteristic variations ofdelta~(13)C anddelta15 N at different body parts (whole bodies,muscles and gills).Our results show thatdelta~(13)C anddelta15 N values vary in different sampling tissues for most species,which indicates the different tissues used for analysis impact the food web building.To achieve a more accuracy and comparability result,suitable tissue should be primarily chosen for their food sources and trophic levels analysis.Namely,when the organism as predator,their muscles should first be chosen,for examples,adductor and foot muscles of mollusks,leg muscles of crabs and back muscles of fishes when the organism as prey, most of their tissues,except for indigestible part(for polychaetes,the digestive tract contents should be removed) should be chosen for analysis on food sources and trophic levels of the secondary consumer,for example,whole soft parts of mollusks,the mixture of muscles and gills of crabs.

A New Set of Parameters of High-Mass X-ray Binaries Found with their Cyclotron Lines 期刊论文 OAI收割
arXiv e-prints, 2018
作者: Zhang, Chengmin; Taani, Ali; Chaty, Sylvain; Karino, Shigeyuki; Song, Liming

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收藏 | 浏览/下载：75/0 | 提交时间：2019/07/12

Astrophysics - High Energy Astrophysical Phenomena Abstract: We have derived new physical quantities for several High-Mass X-ray Binaries (HMXBs) with supergiant (SG) companions through their cyclotron lines. The parameters are: the terminal velocity of the wind, the mass loss rate of the donor, the effective temperature and the magnetic fields. These parameters influence significantly the improvement of the model of accretion. In spite of the variety of their observational properties, the corresponding magnetic field is around B ~ 10^12 G. This result can be constrained by the effects on stellar evolution. In addition, we have performed a segmentation in the parameter space of donors intended for several SG-HMXB listed in our sample set. The parameter space can be categorized into five regimes depending on the possibility of disk formation associated with accretion from the stellar wind. This can give a quantitative clarification of the observed variability and the properties of these objects. We show that, when these systems come into the direct accretion region, systems with corresponding parameters can emit X-rays.

CLAP: Component-Level Approximate Processing for Low Tail Latency and High Result Accuracy in Cloud Online Services 期刊论文 OAI收割
IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS, 2017, 卷号: 28, 期号: 8, 页码: 2190-2203
作者: Han, Rui; Huang, Siguang; Wang, Zhentao; Zhan, Jianfeng

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收藏 | 浏览/下载：16/0 | 提交时间：2019/12/12

Cloud online services tail latency result accuracy component-level approximate processing aggregated data points