共查询到20条相似文献,搜索用时 421 毫秒
1.
ThemutationsequenceofearthresistivityandearthquakesXin-HengLIU(刘心恒)andYun-ShengZHOU(周郧生)(SeismologicalBureauofYunnanProvince,... 相似文献
2.
TheefectoffocaldeptheroronmomenttensorinversionLISHENGXU(许力生)YUNTAICHEN(陈运泰)InstituteofGeophysics,StateSeismologicalBureau... 相似文献
3.
Discussiononuncertainties,attenuationofground motionandaseismicdesigncriterionTian-ZhongZHANG(张天中);Yun-ShengMA(马云生)andXiSHU(舒... 相似文献
4.
ApplicationofPPclustermethodintheearthquakeswarmanalysisShi-YongZHOU;(周仕勇)Ling-RenZHU;(朱令人)andChuan-LingDENG(邓传玲)(Seismologic... 相似文献
5.
Synthesisofaccelerationsofthe1976Tangshanearthquake(MS7.8)innearandfarfieldbyusingsemiempiricalmethodQIFENGLUO1)(罗奇峰)YU?.. 相似文献
6.
《地震学报(英文版)》1998,(4)
AsourceextentanalysisoftheLancangearthquake(Ms=7.6)of1988SI-HUAZHENG(郑斯华)JIANYANG(杨健)CenterforAnalysisandprediction,ChinaSeis... 相似文献
7.
On unified analysis of uncertainty in seismic hazard assessment 总被引:2,自引:0,他引:2
(胡聿贤,陈汉尧)Onunifiedanalysisofuncertaintyinseismichazardassessment¥Yu-XianHUandHan-YaoCHEN(InstituteofGeophysics,StateSeismolog... 相似文献
8.
郁曙君 《地震学报(英文版)》1995,8(2):249-258
StudyoftheintensityattenuationlawintheEastChinaPlainandthenorthwestofChina郁曙君Shu-JunYU(InstituteofGeophysics,StateSeismologic... 相似文献
9.
段星北 《地震学报(英文版)》1997,10(6):731-741
GeographicaldistributionofhypocentraldepthsofChineseearthquakesXING-BEIDUAN(段星北)InstituteofGeophysical,StateSeismologicalBur... 相似文献
10.
郝纪川 《地震学报(英文版)》1996,(4)
TheSixthSymposiumoftheSeismologicalSo┐cietyofChinaheldatZhangjiajie,HunanProvince,ChinaJI-CHUANHAO(郝纪川)InstituteofGeophysics,... 相似文献
11.
12.
Transformation of phosphorus species in settling seston and during early sediment diagenesis 总被引:9,自引:0,他引:9
Sequential P extraction was combined with electron microscop and X-ray spectroscopy to characterise various P species and to study their transformation in settling seston and in recent sediment. During early diagenesis most of the particulate P formed in the water was redissolved. No net transformation into species that would resist dissolution was observed.It was shown that
相似文献
• | the phosphorus (P) content and the P flux of settling particles varied seasonally over one order of magnitude |
• | particles became enriched with reductant soluble P (BD-P) while settling through the hypolimnion |
• | changes in BD-P were highly significantly correlated with changes in reductant soluble iron (BD-Fe) |
• | bacteria oxidising Fe and Mn seemed to be mainly responsible for this increase in P concentration |
• | other fractions including organic P did not change during sedimentation |
• | most of the organic P and of the Fe bound P and 70% of TP was released from the sediment during early diagenesis |
• | the sediment surface did not act as a trap for P migrating upwards from deeper sediment layers |
• | CaCO3 sedimentation contributed little to P sedimentation but significantly to the permanent burial of P. |
13.
During a cruise on board RV Gauss in May/June 1988, joint investigations into organochlorine compounds, dissolved trace metals, petroleum hydrocarbons and basic hydrography were carried out at representative stations of the Baltic Monitoring Programme (BMP). The aim of the cruise was to study distribution patterns and — using previous data — to establish temporal trends if at all discernible.Each group of contaminants investigated showed specific characteristics, with differences even between compounds within the same group. The differences are due to:
相似文献
| - the partition of contaminants between dissolved and adsorbed form; |
| - the response to redox conditions; |
| - the influence of microbial decay, organic production or changes in speciation. |
14.
Saving lives in earthquakes: successes and failures in seismic protection since 1960 总被引:1,自引:1,他引:0
Robin Spence 《Bulletin of Earthquake Engineering》2007,5(2):139-251
This paper will look at what we have and have not achieved in reducing the risks to human life from earthquakes in the last
50 years. It will review how success has been achieved in a few parts of the world, and consider what needs to be done by
the scientific and engineering community globally to assist in the future task of bringing earthquake risks under control.
The first part of the talk will re-examine what we know about the casualties from earthquakes in the last 50 years. Almost
80% of about 1 million deaths turn out to have been caused by just ten great earthquakes, together affecting a tiny proportion
of the territory at risk from heavy ground shaking. The disparity between richer and poorer countries is also evident, not
only in fatality rates, but also in their rates of change. But the existing casualty database turns out to be a very poor
basis for observing such differences, not only because of the small number of lethal events, but also because of the very
limited data on causes of death, types and causes of injury. These have been examined in detail in only a few, recent events.
All that can be said with certainty is that a few wealthier earthquake-prone countries or regions have made impressive progress
in reducing the risk of death from earthquakes, while most of the rest of the world has achieved comparatively little, and
in some areas the problem has become much worse. The second part of the paper looks in more detail at what has been achieved
country-by-country. Based on a new expert-group survey of key individuals involved in earthquake risk mitigation, it will
examine what are perceived to be the successes and failures of risk mitigation in each country or group of countries. This
survey will be used to highlight the achievements of those countries which have successfully tackled their earthquake risk;
it will examine the processes of earthquake risk mitigation, from campaigning to retrofitting, and it will consider to what
extent the achievement is the result of affluence, scientific and technical activity, political advocacy, public awareness,
or the experience of destructive events. It will ask to what extent the approaches pioneered by the global leaders can be
adopted by the rest. The final section of the talk will argue that it can be useful to view earthquake protection activity
as a public health matter to be advanced in a manner similar to globally successful disease-control measures: it will be argued
that the key components of such programmes—building in protection; harnessing new technology and creating a safety culture—must
be the key components of earthquake protection strategies also. It will consider the contribution which the scientific and
engineering community can make to bringing down today’s unacceptably high global earthquake risk. It will be suggested that
this role is wider than commonly understood and needs to include:
Building-in protection
Harnessing new technologies
Creating a safety culture
Examples of some of these actions will be given. International collaboration is essential to ensure that the resources and
expertise available in the richer countries is shared with those most in need of help. And perhaps the most important single
task for the engineering community is work to counter the widespread fatalistic attitude that future earthquakes are bound
to be at least as destructive as those of the past. 相似文献
• | Improving and simplifying information available for designers and self-builders of homes and infrastructure. |
• | Devising and running “building for safety” programmes to support local builders. |
• | Developing and testing cost-effective techniques for new construction and retrofit. |
• | Involvement in raising public awareness. |
• | Political advocacy to support new legislation and other actions. |
• | Prioritising action on public buildings, especially schools and hospitals. |
15.
Jo Ann Joselyn 《Pure and Applied Geophysics》1989,131(3):333-341
Based on published literature and the response to a questionnaire sent to geomagnetic field, ionospheric and magnetospheric researchers, several methods of choosing periods of quiet conditions based on geomagnetic records, as well as other observed parameters, have been identified. Caveats with respect to using geomagnetic indices to select quiet periods include the following:
相似文献
1. | Geomagnetic disturbances are strongly local. Even if the data from all available observatories indicate quiet behavior, there is the distinct possibility that some other location, not sampled, may be disturbed. |
2. | Geomagnetic indices are convenient but imperfect indicators of geomagnetic activity. Indices based on a quiet-day reference level have uncertainties comparable to the threshold value for quiet conditions. Indices representing average conditions during a 24-hr UT day may not be appropriate. |
3. | Geomagnetic activity does not fully reflect the range of possible factors that influence the ionosphere or magnetosphere. |
16.
Time series measurements from light vessel and coastal stations in the transition area of the Kattegat and the Baltic Sea are analyzed for the period August 1975 to March 1976. The data consist of daily sampled salinities from different depth levels and daily means of sea levels, surface current, and wind, respectively. The purpose of this paper is to examine the dynamics of the mass- and salt-transport during a major salt water inflow.The principal conclusions of this paper are that
相似文献
1) | the dynamics of the barotropic water exchange between the Kattegat and the Baltic Sea resembles that of a Helmholtz-resonator with a geostrophically controlled flow in the connecting channel; |
2) | the water exchange is forced by both the east component of the windstress over the North Sea and the windstress component in 30o true over the Baltic Sea; |
3) | the salinity in the upper layer of the Kattegat is governed by a permanent weak salt flux directed from the bottom to the surface layer and the outflow of less saline Baltic water into the upper layer of the Kattegat whereas the salinity of the Belt Sea is advected by the local currents along the main channel; |
4) | the most favorable conditions for a major salt inflow are initially a mean sea level of the Baltic lowered by about 30 cm followed by west winds steadily increasing over the following several ten days. Moreover, the hitherto used definition of a major salt water inflow is discussed and an improved definition is proposed. |
17.
The spontaneous and evoked activity of electroreceptors were electrophysiologically studied. The results are:
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 380–386, 1991. 相似文献
1. | The spontaneous discharge rate ranged from 15 to 85 imp/s with a mode of 50 imp/s for 126 organs of 18 animals. |
2. | By analysis of periodic histograms and interspike interval histograms of responses to sinusoidal electric stimulations, the frequency response characteristic was determined. The frequency response curve shows a band pass type, the band width ranged from 5 Hz to 30 Hz and the best frequency is around 15 Hz. |
3. | The thresholds of responses for 47 organs were measured by injection of sinusoidal current into the organs. The threshold values were less than 0.1nA (61μV/cm) for 35 organs (74%), and less than 0.01nA (6.1 μV/cm) for the rest of 9 organs (19%). |
18.
Akira Takada 《Bulletin of Volcanology》1988,50(2):106-118
The Subvolcanic structure of the central dike swarm associated with the Miocene Otoge ring complex and the Shitara igneous complex, central Japan, has been reconstructed. The central dike swarm was supplied from several aligned magma reservoirs. Flow lineations observed at the margin of the dikes converge towards a region that is regarded as a magma reservoir about 1–2 km below present sea level. The minimum diameter of the magma reservoir corresponds to the width of the central dike swarm, estimated to be about 3–4 km. The inferred magma reservoir of the Otoge ring complex, may have a zoned structure, as suggested by the flow lineations of dikes and the arrangement of cone sheets. Felsic magma occupied the upper part, about 1–2 km below present sea level, and basic magma the lower part, deeper than 2 km. The centre of the Shitara igneous complex is interpreted to be composed of several other shallow magma reservoirs. The distribution pattern in plan view of the central dike swarm is summarized from the frequency of dikes (defined by the number of dikes per kilometre in the direction normal to the trend of the dike swarm) and the variations of the different properties of individual dikes along the dike swarm. It has a plane of symmetry normal to the dike swarm above the magma reservoir. The patterns critical to a general understanding of the dike formation are:
相似文献
1. | A region of low dike frequency is present above the magma reservoir and a radial dike pattern occurs around the magma reservoir. |
2. | From both sides of the magma reservoir, the axes of high dike frequency extend symmetrically along the central zone of the dike swarm. |
3. | The number as well as the individual and total thickness of felsic dikes increases towards the magma reservoir. |
4. | The number of basic dikes increases towards both sides of the magma reservoir, while the individual thicknesses of basic dikes increase with distance from the magma reservoir. |
19.
Experimental study on the mechanism of non-synchronism of seismo-electromagnetic radiation precursors 总被引:1,自引:0,他引:1
IntroductionThrough20-oddyears’observationandstudyafterthe1976Tangshangreatearthquake,theseismo-electromagneticradiationprec... 相似文献
20.
The problem of fitting a probability distribution, here log-Pearson Type III distribution, to extreme floods is considered from the point of view of two numerical and three non-numerical criteria. The six techniques of fitting considered include classical techniques (maximum likelihood, moments of logarithms of flows) and new methods such as mixed moments and the generalized method of moments developed by two of the co-authors. The latter method consists of fitting the distribution using moments of different order, in particular the SAM method (Sundry Averages Method) uses the moments of order 0 (geometric mean), 1 (arithmetic mean), –1 (harmonic mean) and leads to a smaller variance of the parameters. The criteria used to select the method of parameter estimation are:
These criteria are transformed into value functions or fuzzy set membership functions and then three Multiple Criteria Decision Modelling (MCDM) techniques, namely, composite programming, ELECTRE, and MCQA, are applied to rank the estimation techniques. 相似文献
| - the two statistical criteria of mean square error and bias; |
| - the two computational criteria of program availability and ease of use; |
| - the user-related criterion of acceptability. |