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991.
Solar Energetic Particle Event of 2005 January 20: Release Times and Possible Sources 总被引:1,自引:0,他引:1
Gui-Ming Le Yu-Hua Tang Yan-Ben Han National Astronomical Observatories Chinese Academy of Sciences Beijing Key Laboratory of Radiometric Calibration Validation for Environmental Satellites China Meteorological Administration Beijing Department of Astronomy Nanjing University Nanjing National Center for Space Weather China Meteorological Administration Beijing 《中国天文和天体物理学报》2006,6(6):751-758
Based on cosmic ray data obtained by neutron monitors at the Earth's surface, and data on near-relativistic electrons measured by the WIND satellite, as well as on solar X-ray and radio burst data, the solar energetic particle (SEP) event of 2005 January 20 is studied. The results show that this event is a mixed event where the flare is dominant in the acceleration of the SEPs, the interplanetary shock accelerates mainly solar protons with energies below 130 MeV, while the relativistic protons are only accelerated by the solar flare. The interplanetary shock had an obvious acceleration effect on relativistic electrons with energies greater than 2 MeV. It was found that the solar release time for the relativistic protons was about 06:41 UT, while that for the near-relativistic electrons was about 06:39 UT. The latter turned out to be about 2 min later than the onset time of the interplanetary type III burst. 相似文献
992.
FanAiwu TangJiaxiang LiLi YangJun 《中国地质大学学报(英文版)》2005,16(1):79-83
The investigation of sliding isolation is mainlyfocused on the response of a structure subjected to asingle directional earthquake excitation. Fan andTang (2001) studied the slide limited friction (S LF)base isolation system, using a sequential exponentialfriction model. Zhang and Cheng (2001) studied theisolated effect of a sliding bearing as a friction damp er. Xiong and Yu (2002) studied the numerical meth od of sliding isolation system. But studying a singlecomponent of e… 相似文献
993.
我国快速城市化进程中普遍存在城市景观特色丧失、千城一面等城市建设规划与管理症结.随着经济发展,城市风貌与景观特色已广受关注.针对城市景观乱象,在总结国内外城市景观研究与应用的基础上,提出了开展城市景观调查、加强城市生态基础设施保护、重视乡土植物景观保护与利用以及加强环境经济与公共政策研究等思路,探讨了构建符合生态环境保护与可持续发展时代精神、结合城市自然环境特征、切合社会经济发展与居民文化生活状况的城市景观评价与控制体系,指出通过坚持城市景观特色的继承与发展进行有效地城市景观规划建设与管理的途径与方法. 相似文献
994.
本文利用EOF展开,对我国西部树轮指数和降水场进行了讨论,分别计算了降水和树轮的第一、第二主成份的周期。结果表明我国西部树轮和降水在空间与时间上都有着较好的对应关系。在此基础上,通过稳健回归方法对树轮和降水的传输函数进行了研究。 相似文献
995.
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????????YRY??2????????????????????о????????????????????????????????????????????????????????????????????????????2004??12??26???2005??3??28???????????????δ???????????????????????????0T11??0T18????????????ε????????仯??????????????ε???????0T11??0T18???????????????????????仯???С????????????????????????????????????????????2???????????????????????????????ù???????? 相似文献
996.
This study conducted four cruises during 2014–2017 to investigate relationships between macrobenthic communities and sediment contaminations in sea area around the Zhoushan Archipelago. Fourteen sites were categorized into three groups: high total heavy metal contamination content(HHMC), high total petroleum hydrocarbon content(HTPH), and low content ratio of heavy metal contamination content to total petroleum hydrocarbon content(HMC/TPH) areas. Four main taxa of macrofauna(polychaetes, bivalves, gastropods, and crustaceans) were determined to respond to environmental factors differently. While tolerant polychaetes being the minimal impact by environmental factors, bivalves were threated by heavy metal pollutions in sediment.Additionally, body size distribution frequency demonstrated that macrofauna in the low HMC/TPH areas were less disturbed by contamination than those in the HHMC and HTPH areas. The result represented the presentation of sensitive species while tolerant species are usually considered as small size organisms. Overall,this study confirmed the hypothesis that the contamination levels of small-scale patches is indicated by the condition of macrobenthic communities. 相似文献
997.
Yong Yu Zhao-Xiang Qi Yin-Dun Mao Zheng-Hong Tang Ming Zhao 《Chinese Astronomy and Astrophysics》2009,33(3):322-332
Because of the influence of atmospheric refraction the astronomical observations of the objects with the angles of elevation below 15° are generally avoided, but for the sake of the complete theoretical research the atmospheric refraction under the condition of lower angles of elevation is still worthy to be analyzed and explored. Especially for some engineering applications the objects with low angles of elevation must be observed sometimes. A new idea for determining atmospheric refraction by utilizing the differential method is proposed. A series of observations of the starry sky at different heights are carried out and by starting from the zenith with a telescope with larger field of view, the derivatives of various orders of atmospheric refraction function at different zenith distances are calculated and finally the actually observed values of atmospheric refraction can be found via numerical integration. The method does not depend upon the strict local parameters and complex precise observational instrumentation, and the observational principle is relatively simple. By the end of 2007 a simply constructed telescope with a larger field of view at Xinglong Observing Station was employed to carry out trial observations. The values of atmospheric refraction at the true zenith distances of 44.8° to 87.5° were obtained from the practical observations based on the differential method, and the feasibility of the method of differential measurement of atmospheric refraction was preliminarily justified. Being limited by the observational conditions, the accuracy of the observed result was limited, the maximal accidental error was about 6” and there existed certain systematic errors. The value of the difference between the result obtained at the zenith distance of 84° and that given in the Pulkovo atmospheric refraction table was about 15”. How to eliminate the cumulative error introduced due to the integration model error is the key problem which needs to be solved in future. 相似文献
998.
Jingfeng Wang Yuming Wang Qingjuan Tang Yi Wang Yaoguang Chang Qin Zhao Changhu Xue 《中国海洋大学学报(英文版)》2010,9(1):94-98
Gelatin extracted from the body wall of the sea cucumber (Stichopus japonicus) was hydrolyzed with flavourzyme. Low-molecular-weight gelatin hydrolysate (LMW-GH) of 700–1700 Da was produced using an
ultrafiltration membrane bioreactor system. Chemiluminescence analysis revealed that LMW-GH scavenges high free radicals in
a concentration-dependent manner; IC50 value for superoxide and hydroxyl radicals was 442 and 285 μg mL−1, respectively. LMW-GH exhibited excellent inhibitory characteristics against melanin synthesis and tyrosinase activity in
B16 cells. Furthermore, LMW-GH notably increased intracellular glutathione (GSH), which in turn suppressed melanogenesis.
LMW-GH performs antioxidation activity, holding the potential of being used as a valuable ingredient in function foods, cosmetics
and pharmaceuticals or nutriceuticals. 相似文献
999.
Catastrophic debris flows triggered by a 14 August 2010 rainfall at the epicenter of the Wenchuan earthquake 总被引:3,自引:1,他引:3
The Wenchuan earthquake of May 12, 2008 produced large amounts of loose material (landslide debris) that are still present
on the steep slopes and in the gullies. This loose material creates an important hazard as strong rainfall can cause the development
of devastating debris flows that will endanger the resettled population and destroy the result of reconstruction efforts.
On 14 August 2010, a total of 21 debris flows were triggered by heavy rainfall around the town of Yingxue, located near the
epicenter of the Wenchuan earthquake. One of these debris flows produced a debris dam, which then changed the course of the
river and resulted in the flooding of the newly reconstructed Yinxue town. Prior to this catastrophic event, debris flow hazard
had been recognized in the region, but its potential for such widespread and devastating impacts was not fully appreciated.
Our primary objective for this study was to analyze the characteristics of the triggering rainfall and the sediment supply
conditions leading to this event. Our field observations show that even small debris flow catchment areas have caused widespread
sediment deposition on the existing fans. It is concluded that the whole of the area shaken by the Wenchuan earthquake is
more susceptible to debris flows, initiated by localized heavy rainfall, than had been assumed earlier. The results of this
study contribute to a better understanding of the conditions leading to catastrophic debris flow events in the earthquake-hit
area. This is essential for the implementation of proper early warning, prevention, and mitigation measures as well as a better
land use planning in this area. 相似文献
1000.
Jilong Wang Wei Liu Peilun Li Fujiang Tang Wanqiao Lu Jian Yang Tao Jiang 《海洋学报(英文版)》2021,40(8):182-186
In order to assess the effect of enhancement release of chum salmon (Oncorhynchus keta), otolith strontium (Sr) marking method was used to tag chum salmon released in Tangwang River in 2016. The homing chum salmon were detected and the samples were collected in Tangwang River, Ussuri River and Suifen River in the autumn of 2018. The samples were analyzed by examining Sr and calcium (Ca) fingerprints in the otolith using electron probe microanalysis. The results suggested that two samples collected in Tangwang River had the marking ring near the core of otolith where the Sr concentration and Sr/Ca ratio were significantly higher than comparative samples. Proving that the two fish belonged to the released population in Tangwang River in 2016. This article indicated the success of the enhancement release of chum salmon from the Tangwang River for the first time and also confirmed the validity of Sr marking in enhancement release of fishes. 相似文献