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51.
Gonzalo Gurrea Vicente Blanca-Giménez Vicente Pérez María-Antonia Serrano Juan-Carlos Moreno Solar Radiation Group of the Universitat Politècnica de València 《Asia-Pacific Journal of Atmospheric Sciences》2018,54(4):599-610
The goal of this study was to statistically analyse the variability of global irradiance and ultraviolet erythemal (UVER) irradiance and their interrelationships with global and UVER irradiance, global clearness indices and ozone. A prediction of short-term UVER solar irradiance values was also obtained. Extreme values of UVER irradiance were included in the data set, as well as a time series of ultraviolet irradiance variability (UIV). The study period was from 2005 to 2014 and approximately 250,000 readings were taken at 5-min intervals. The effect of the clearness indices on global irradiance variability (GIV) and UIV was also recorded and bi-dimensional distributions were used to gather information on the two measured variables. With regard to daily GIV and UIV, it is also shown that for global clearness index (kt) values lower than 0.6 both global and UVER irradiance had greater variability and that UIV on cloud-free days (kt higher than 0.65) exceeds GIV. To study the dependence between UIV and GIV the χ2 statistical method was used. It can be concluded that there is a 95% probability of a clear dependency between the variabilities. A connection between high kt (corresponding to cloudless days) and low variabilities was found in the analysis of bi-dimensional distributions. Extreme values of UVER irradiance were also analyzed and it was possible to calculate the probable future values of UVER irradiance by extrapolating the values of the adjustment curve obtained from the Gumbel distribution. 相似文献
52.
D. Kesten M. Weber Ch. Haberland Ch. Janssen A. Agnon Y. Bartov I. Rabba The DESERT Group 《International Journal of Earth Sciences》2008,97(1):153-169
The left-lateral Dead Sea Transform (DST) in the Middle East is one of the largest continental strike-slip faults of the world.
The southern segment of the DST in the Arava/Araba Valley between the Dead Sea and the Red Sea, called Arava/Araba Fault (AF),
has been studied in detail in the multidisciplinary DESERT (DEad SEa Rift Transect) project. Based on these results, here,
the interpretations of multi-spectral (ASTER) satellite images and seismic reflection studies have been combined to analyse
geologic structures. Whereas satellite images reveal neotectonic activity in shallow young sediments, reflection seismic image
deep faults that are possibly inactive at present. The combination of the two methods allows putting some age constraint on
the activity of individual fault strands. Although the AF is clearly the main active fault segment of the southern DST, we
propose that it has accommodated only a limited (up to 60 km) part of the overall 105 km of sinistral plate motion since Miocene
times. There is evidence for sinistral displacement along other faults, based on geological studies, including satellite image
interpretation. Furthermore, a subsurface fault is revealed ≈4 km west of the AF on two ≈E–W running seismic reflection profiles.
Whereas these seismic data show a flower structure typical for strike-slip faults, on the satellite image this fault is not
expressed in the post-Miocene sediments, implying that it has been inactive for the last few million years. About 1 km to
the east of the AF another, now buried fault, was detected in seismic, magnetotelluric and gravity studies of DESERT. Taking
together various evidences, we suggest that at the beginning of transform motion deformation occurred in a rather wide belt,
possibly with the reactivation of older ≈N–S striking structures. Later, deformation became concentrated in the region of
today’s Arava Valley. Till ≈5 Ma ago there might have been other, now inactive fault traces in the vicinity of the present
day AF that took up lateral motion. Together with a rearrangement of plates ≈5 Ma ago, the main fault trace shifted then to
the position of today’s AF. 相似文献
53.
将电阻率层析技术应用于地震监测,由视电阻率值重建出介质的真电阻率图像,取得了较好效果.在宝坻台和昌黎台设立的两个试验点上于1998年4月14日ML5.0和ML4.4唐山两次地震前的6天左右层析图像出现了明显的异常变化:宝坻台的电阻率图像一改通常的在平稳背景上叠加小量随机变化的特点,出现了一种有序性特征的新图样;昌黎台也出现了反差加大、高低阻区集中分布的有序性特征.上述异常图样均在震后消失.层析图像在震前出现的熵值降低可能是这次地震活动的前兆.地层导电结构和孔隙度的变化,是引起电阻率异常的直接原因.研究表明,常规的单一极距的视电阻率测量之所以对真电阻率的变化不敏感且丧失空间分辨能力,是由于该物理量同时具有积分值和位函数这两个固有特征所决定的.在地震监测中,改造现行观测系统,引入层析成像,是发展技术的方向. 相似文献
54.
中国地震局地震监测台网技术人员培训团 《国际地震动态》2001,(4):12-15
中国地震局地震监测台网技术人员培训团一行15人于2000年9月2-20日赴德国地球科学研究中心(GFZ)和联邦地球科学及自然资源研究院(BGR)进行了培训,在德国的周密安排和中德以方的共同努力下,培训团圆满地完成了预期的培训任务,文章就这次的培训及培训团所了解到的情况作了介绍。 相似文献
55.
中国地震局地震监测技术考察团访问美国 总被引:2,自引:0,他引:2
中国地震局地震监测技术考察团 《国际地震动态》2001,(11):29-34
为了解和借鉴美国地震研究和地震监测的成果、先进技术和经验,中国地震局地震监测技术考察团于2001年7月12-25日赴美进行了学术考察和交流活动。文章介绍了这次考察活动的概况及美国地质调查局、美国国家地震信息中心、帕克菲尔德地震实验场和美国地震学合作研究会等科研单位近期的研究工作和计划,重点介绍了即将在帕克菲尔德进行的深部钻孔计划、美国地震学合作研究会的地球透镜计划及美国地质调查局即将建设的先进的国家地震系统。 相似文献
56.
ThefocalmechanismsolutionoftheMs6.5WudingearthquakeinYunnanProvinceofOctober24,1995SHUTIANMA1)(马淑田)WEIZHAO2)(赵薇)1)Institute... 相似文献
57.
The methods PARAFAC and three-way PLS are compared with respect to their ability to predictreversed-phase retention values.Special attention is paid to simple validatory tools,the meaning and useof which are explained.The simple validatory tools consist of percentages of explained variation in the training set and thosethat can be calculated with the use of markers.These markers are special(reference)solutes,the retentionvalues of which are used to gain information about a new object for which predictions are wanted.Different validatory tools can be calculated with the use of these marker retention values:percentagesof used variation and mean sum of squared residuals after applying the model to these marker retentionvalues.The validatory tools are evaluated on their power to estimate their test set counterparts:thepercentages of explained variation in the test set and mean sum of squared prediction errors in the test set.Two different data sets from reversed-phase chromatography are used to evaluate the validatory tools.The first data set has a high signal-to-noise ratio and is measured under the same measurementconditions.The second data set has a low signal-to-noise ratio and is measured under differentmeasurement conditions.Some of the simple validatory tools seem to have relevance to their test setcounterparts,even in the case of the second data set. 相似文献
58.
重庆市江北5.2,5.4级地震的地质构造背景 总被引:2,自引:0,他引:2
1989年11月20日的重庆市江北5.2级、5.4级地震。被认为是处于四川东部台拗的一系列线状、弧形状构造在现代近东西向应力作用下,这一发育极为完整的构造再次活动的结果。其具体背景构造有华蓥山构造带、七曜山—金佛山构造带和长寿—南桐构造带。它们是该区中强地震的直接控震构造。这些构造带控制了该区的岩性、构造和应力的积累、释放。故认为地震的发生正是上述构造带相继多次活动,从而导致江北地区地腹构造发生粘滑性活动的结果。 相似文献
59.
中国科学院海洋研究所剖面仪研制组 《海洋科学集刊》1974,(9):17-26
近十年来,探测海底几十米至几百米松散沉积层分层结构的“海底浅地层剖面仪”已逐步发展定型,并广泛用于海底工程施工和海洋地质研究方面。这种浅地层剖面仪主要采用以下几种声源装置:电致伸缩器件、磁致伸缩器件、电磁脉冲声源、电火花放电器以及气枪。
浅层剖面仪实际上是一种以地层为探测目标的主动声纳,本文给出了有关的声纳方程式,它将有助于这类仪器的工程设计和性能预报。
从探层声纳方程式出发,采用电磁脉冲声源研制了浅层剖面仪,获得了穿透地层几十米的较高分辨率的记录。对此,本文也作了简单的介绍。 相似文献
60.
Decentring poverty studies: Middle class alliances and the social construction of poverty 总被引:1,自引:0,他引:1
Victoria Lawson with Middle Class Poverty Politics Research Group 《Singapore journal of tropical geography》2012,33(1):1-19
Editors' Note: The following is the tenth in the Singapore Journal of Tropical Geography Lecture Series. It is based on the plenary presentation of 13 April at the AAG held in Seattle in 2011. In this essay I explore relational poverty analysis to take seriously the spatially varied intersections of political‐economic, social ordering and cultural‐political processes in shaping understandings of poverty. My work as part of the Middle Class Poverty Politics Research Group employs a relational comparative methodology to theorize where, when and under what circumstances those framed as ‘middle class’ act in opposition to or in solidarity with those named as ‘poor’. Our approach focuses on the exploitative effects of capital accumulation, processes of unequal sociospatial categorization and political and discursive systems that limit or exclude the poor. Our research focuses on places experiencing capitalist crisis because intense periods of restructuring highlight material and discursive struggles over poverty. We conclude by identifying a research agenda focused on the ways in which poverty politics are constituted by the nonpoor through place and in the articulation of places with processes of political economy, governance and cultural politics. 相似文献