中国科学院机构知识库网格系统: 检索

Construction of the Primorsky No. 1 and No. 2 International Transport Corridors: Risk Evaluation and Mitigation Policies 期刊论文 OAI收割
SUSTAINABILITY, 2021, 卷号: 13, 期号: 4, 页码: 24
作者: Yang, Yang; Dong, Suocheng; Boldanov, Tamir; Li, Fujia; Cheng, Hao

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收藏 | 浏览/下载：20/0 | 提交时间：2021/04/25

Primorsky No 1 and No 2 international transport corridors risk evaluation spatial distribution mitigation policies entropy method

Construction of the Primorsky No. 1 and No. 2 International Transport Corridors: Risk Evaluation and Mitigation Policies 期刊论文 OAI收割
SUSTAINABILITY, 2021, 卷号: 13, 期号: 4, 页码: 24
作者: Yang, Yang; Dong, Suocheng; Boldanov, Tamir; Li, Fujia; Cheng, Hao

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收藏 | 浏览/下载：26/0 | 提交时间：2021/04/25

Primorsky No 1 and No 2 international transport corridors risk evaluation spatial distribution mitigation policies entropy method

No pulsed radio emission during a bursting phase of a Galactic magnetar 期刊论文 OAI收割
Nature, 2020, 卷号: 587, 页码: 63-65
作者: HXMT

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Astrophysics - High Energy Astrophysical Phenomena Abstract: Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown physical origin observed at extragalactic distances^1-3. It has long been speculated that magnetars are the engine powering repeating bursts from FRB sources^4-13, but no convincing evidence has been collected so far¹⁴. Recently, the Galactic magnetar SRG 1935+2154 entered an active phase by emitting intense soft íray bursts¹⁵. One FRB-like event with two peaks (FRB 200428) and a luminosity slightly lower than the faintest extragalactic FRBs was detected from the source, in association with a soft íray/hard-X-ray flare^18-21. Here we report an eight-hour targeted radio observational campaign comprising four sessions and assisted by multi-wavelength (optical and hard-X-ray) data. During the third session, 29 soft-íray repeater (SGR) bursts were detected in íray energies. Throughout the observing period, we detected no single dispersed pulsed emission coincident with the arrivals of SGR bursts, but unfortunately we were not observing when the FRB was detected. The non-detection places a fluence upper limit that is eight orders of magnitude lower than the fluence of FRB 200428. Our results suggest that FRB-SGR burst associations are rare. FRBs may be highly relativistic and geometrically beamed, or FRB-like events associated with SGR bursts may have narrow spectra and characteristic frequencies outside the observed band. It is also possible that the physical conditions required to achieve coherent radiation in SGR bursts are difficult to satisfy, and that only under extreme conditions could an FRB be associated with an SGR burst.

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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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.

Synthesis, characterization, and ethylene polymerization behaviors of late-transition metal complexes coordinated with chlorinated bis(arylimino)pyridine ligand 期刊论文 OAI收割
polymer, 2014, 卷号: 55, 期号: 18, 页码: 4611-4618
Liu, Heng; Wang, Feng; Liu, Li; Jai,Xiang-Yu; Zheng,Wenjie; Guo,Jun; Zhang,Chun-Yu; Bai,Chen-Xi; Hu,Yan-Ming; Zhang,Xue-Quan

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A series of late-transition metal complexes supported with chlorinated bis(arylimino)pyridine ligands [2 Ar = 2 Ar = 2 Ar = 2 Ar = 4-Cl-2 Ar = 4-Br-2 6-(ArN=CCl)(2)C5H3N]MtCl(2) (Ar = 2 6-(Pr2C6H3)-Pr-i 6-Et2C6H3 6-Me2C6H3 6-Me2C6H2 6-Me2C6H2 4 Mt = Fe (1b) Mt = Co (1c) Mt = Fe (1d) Mt = Fe (1e) Mt = Fe (1f) 6-Me3C6H2 Co (2b) Ni (3c) Co (2d) Co (2e) Co (2f)) were synthesized. At the presence of methylaluminoxane (MAO) Mt = Fe (1a) Fe(II)- and Co(II)- based complexes were highly active towards ethylene polymerization Co (2a) affording polymers with bimodal and unimodal molar. mass distributions Ni (3a) respectively while the Ni(II)-based complexes gave no polymer products. Moreover the obtained polyethylenes were predominately saturated and vinyl-terminated for Fe(II)- and Co(II)-based complexes respectively. Changing the ligand environment polymerization parameters also posed a great influence on the catalytic activities and the properties of the resulting polymers. (C) 2014 Elsevier Ltd. All rights reserved.

Water conservancy projects in China: Achievements, challenges and way forward SCI/SSCI论文 OAI收割
2013
作者: Zhang M.; Yang H.

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Ecological and environmental impacts Water conservancy projects Central Document No. 1 of 2011 Stringent control Water resources management three-gorges dam past 50 years climate-change yangtze-river xinjiang uygur lower reaches tarim river management biodiversity groundwater

Hydrochemical Characteristics and Solute Dynamics of Meltwater Runoff of Urumqi Glacier No.1, Eastern Tianshan, Northwest China 期刊论文 OAI收割
Journal of Mountain Science, 2012, 卷号: 9, 期号: 4, 页码: 472-482
FENG Fang; LI Zhongqin; JIN Shuang; DONG Zhiwen; WANG Feiteng

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Ionic concentration EC and TDS Rock weathering Solute fluxes Urumqi Glacier No.1

High beam quality all-solid-state 1053nm nd: Glass amplifier shaping by LCSLM at repetition frequency (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Optical, Electronic Materials and Applications 2012, OEMA 2012, May 25, 2012 - May 26, 2012, Chongqing, China
作者: Zhang X.; Qiu J.; Zhang X.; Zhang X.

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A laser amplifier of LD pumping Nd: glass with a high beam quality and stability the modulation degree near field is less than 1.23:1. (2012) Trans Tech Publications which amplifies nanosecond laser pulse Switzerland. has been developed in this paper. Under 1Hz repetition frequency when the flat top pulse of 3 ns width and 1 nJ energy is injected as the seed pulse the average output energy of the laser amplifier is 115.3 mJ with a net gain of 109 the energy dispersion degree of the outputting laser is no more than 2%

Impacts of climate warming on alpine glacier tourism and adaptive measures: a case study of baishui glacier no. 1 in yulong snow mountain, southwestern china 期刊论文 iSwitch采集
Journal of earth science, 2010, 卷号: 21, 期号: 2, 页码: 166-178
作者: Wang Shijin; He Yuanqing; Song Xiaodong

收藏 | 浏览/下载：38/0 | 提交时间：2019/05/10

Alpine glacier Global warming Baishui glacier no. 1 Impact and adaptation

A design on a control method of a new type of focal plane shutter (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
Xue L.; Ming L.; Zheng L.-N.; Zhou J.-F.; Zhang H.-W.; Zhang J.-C.

收藏 | 浏览/下载：43/0 | 提交时间：2013/03/25

In order to ensure appropriate exposure time and no exposure while electric charge is transferring after taking a photograph it is necessary to have the shutter mechanism cooperate with CCD for area CCD aerial cameras. The ground object illumination has a wide range which is from 4000Lx to 100000Lx so a shutter which is high efficient and a continuous stepless adjustment are also required. This paper introduces the fundamental principle structural design and control procedure about this new focal plane shutter. Under the control of DSP the velocity of shutter curtain governed by the shutter motor can be not only precisely controlled but also the durability and the reliability are increased. The experiment results have shown that this new shutter has the higher stability of movement long life span with more than 105 operating times a wide range of exposure time from1/ 50s to 1/ 320s(depending on the slit width)and the exposure error is less than 10%. With the CCD gain adjustment the performance of this shutter is fully satisfied with the requirements of area CCD aerial cameras. 2010 IEEE.