共查询到20条相似文献，搜索用时 93 毫秒
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In this paper, we have proposed an alternative seismic hazard modeling by using distributed seismicites. The distributed seismicity model does not need delineation of seismic source zones, and simplify the methodology of probabilistic seismic hazard analysis. Based on the devastating earthquake catalogue, we established three seismi- city model, derived the distribution of a-value in northern China by using Gaussian smoothing function, and cal-culated peak ground acceleration distributions for this area with 2%, 5% and 10% probability of exceedance in a 50-year period by using three attenuation models, respectively. In general, the peak ground motion distribution patterns are consistent with current seismic hazard map of China, but in some specific seismic zones which in-clude Shanxi Province and Shijiazhuang areas, our results indicated a little bit higher peak ground motions and zonation characters which are in agreement with seismicity distribution patterns in these areas. The hazard curves have been developed for Beijing, Tianjin, Taiyuan, Tangshan, and Ji’nan, the metropolitan cities in the northern China. The results showed that Tangshan, Taiyuan, Beijing has a higher seismic hazard than that of other cities mentioned above. 相似文献
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Yuanbo LIU Guoyu QIU Hongsheng ZHANG Yonghui YANG Yinsheng ZHANG Quan WANG Wenzhi ZHAO Li JIA Xibin JI Yujiu XIONG Chunhua YAN Ning MA Shumin HAN Yifan CUI 《中国科学:地球科学(英文版)》2022,65(2):197-214
Terrestrial evapotranspiration(ET)is a crucial link between Earth’s water cycle and the surface energy budget.Accurate measurement and estimation remain a major challenge in geophysical,biological,and environmental studies.Pioneering work,represented by Dalton and Penman,and the development of theories and experiments on turbulent exchange in the atmospheric boundary layer(ABL),laid the foundation for mainstream methodologies in ET estimation.Since the 1990s,eddy covariance(EC)systems and satellite remote sensing have been widely applied from cold to tropical and from arid to humid regions.They cover water surfaces,wetlands,forests,croplands,grasslands,barelands,and urban areas,offering an exceptional number of reports on diverse ET processes.Surface nocturnal ET,hysteresis between ET and environmental forces,turbulence intermittency,island effects on heterogeneous surfaces,and phase transition between underlying surfaces are examples of reported new phenomena,posing theoretical and practical challenges to mainstream ET methodologies.Additionally,based on non-conventional theories,new methods have emerged,such as maximum entropy production and nonparametric approaches.Furthermore,high-frequency on-site observation and aerospace remote sensing technology in combination form multi-scale observations across plant stomata,leaves,plants,canopies,landscapes,and basins.This promotes an insightful understanding of diverse ET processes and synthesizes the common mechanisms of the processes between and across spatial and temporal scales.All the recent achievements in conception,model,and technology serve as the basis for breaking through the known difficulties in ET estimation.We expect that they will provide a rigorous,reliable scientific basis and experimental support to address theoretical arguments of global significance,such as the water-heat-carbon cycle,and solve practical needs of national importance,including agricultural irrigation and food security,precise management of water resources and eco-environmental protection,and regulation of the urban thermal environment and climate change adaptation. 相似文献
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人类是万物之灵长,拥有着地球上的最高智慧,但这却丝毫不能改变生命的脆弱。本刊以特写方式还原洪水肆虐的瞬间,是为了铭记这段历史,让逝者安息,让生者坚强。母亲最后一刻水于下托起幼女小曹今年30岁,在房山区青龙湖镇许海涛的家具厂里工作,她是3个女孩的母亲。7月21日当晚,小曹和她的妹妹,被洪水困在了同一间屋子里。情急之下,他们拨通了身在外地的徐海涛的电话求救,但洪水却仍在不停地向小屋子里冲过来,水位越来越高……眼看再不走就是等死,小曹决定 相似文献
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The stream sediments of Wadi El Reddah(North Eastern Desert,Egypt)are geochemically and mineralogically investigated.Their content of radioactive and other heavy minerals is mainly represented by thorite,uranothorite,zircon,monazite,xenotime,columbite,fergusonite,and unknown rare earth elements(REEs)bearing minerals as well as cassiterite.Special emphasis on REE content of thorite,uranothorite,zircon and xenotime has been done to correlate them with the increase of uranium contents in these sediments.The key evidence for the presence lowtemperature alteration processes includes the presence of some zircon crystals as remnants after complete dissolution of the overgrowth zircon in severe acidic environment,the sulphur content,biogenic minerals,occurrence of unusual minerals as cassiterite pore filling in zircon,variation in the REEs content from the surrounding granites to the stream sediments and the abundance of monazite in the surrounding granites.Most minerals are partially and/or completely altered,which indicated by the pseudomorphism of zircon by xenotime,thorite,and uranothorite. 相似文献
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正十年前,慕名找李早先生治印。刚过知天命之年的他已是满头银发,格外引人注目。其儒雅的仪表,清癯的脸庞,眉宇间流露着儒家的学者风范,言行中展现出深厚的国学素养,"精、气、神"俱佳,给我留下了深刻的印象。知道李早先生的书法篆刻作品比认识他本人要早,因其在书法篆刻领域的成就如雷贯耳,圈内圈外很有知名度,其父李伏雨更是一代大家。刘江老师曾评价李早:"李早君家学渊源,克绍箕裘。尚处壮年,成绩斐然,为中国当代 相似文献
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这里树木高大密集,平均30多米高,有的甚至80多米。视野里到处是勾连的藤蔓,树丛间更有众多不知名的植物堆叠在一起,让人无处落脚。虽然茂密的树叶遮蔽了灼人的阳光,但并不阴凉,反而像一个密不透风的蒸笼,闷热,潮湿,不一会就让人浑身黏腻。这还不算,当你披荆斩棘地往前行走的时候,说不定会踩到巨蟒、毒蛇,或者一不小心碰到有毒植物。 相似文献
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金色五月,总给人带来好心情,3天的小长假。给了我探访东山岛的机会。4月28日,我抱着探秘的心情踏上了这个神奇的海岛。
东山岛古称铜山,距漳州市区158公里,离厦门200公里左右,是东山县所在地,简称陵岛。主岛形似蝴蝶亦称蝶岛,是福建省第二大岛。它介于厦门市和汕头之间,隶属于福建省漳州市。 相似文献
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美丽的青海湖,就像一个绝代佳人,静静地躺在圣洁的雪域高原。在湛蓝的天空下,巍峨的群山中,这里仿佛是人间仙境。古往今来,她凭借独有的美丽,不知吸引了多少游客,不远千里,跨过万水千山,为的只是一睹她的风采。慢慢地,这里游人如织。也正因于此,虽然青海湖的魅力依然不减当年,但垃圾之困让青海湖备受折磨。 相似文献
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泰宁,这片古老而文明的红土地,地质历史悠久,人文气息浓厚,她离凡尘比较远,离人类的心灵则比较近。其实,我们每个人的心中都有个泰宁,都有一份令人遐思的和谐泰宁;所以有人说：不在泰宁,就在去泰宁的路上…… 相似文献
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观石是一种修养,赏石是一种文化;石头若有千奇百怪种,心灵就有五彩缤纷画;一块石头,一种语言。石头种类繁多,举不胜举,钻石、翡翠、玛瑙、美玉皆是人间佳话,也有形容美人如玉一说,以石喻人,以人喻石,分量着实不轻。 相似文献
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修济刚 《地震地磁观测与研究》2014,(Z3)
2014年即将过去,主编修济刚先生在2015年到来之际,为本刊撰写了新年寄语,让我们拥着改革开放的大潮,踏实工作,严谨科研,精心观测,使地震研究更好地为社会及民众服务。 相似文献
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关于菊花石,盛传着这么一个故事。古代浏阳河畔有一位秀才,酷爱菊花,经常赏菊吟诗,并把最喜爱的女儿取名为"菊花"。"菊花"与书童"菊石"相爱,却遭到封建思想严重的秀才百般阻挠。菊花与菊石宁死不屈,在重阳节的夜晚,手挽手投入碧波潭中,从此,潭中的岩石上绽开着一朵朵洁白晶莹的菊花。这当然只是一个传说而已,是过去的人不清楚 相似文献