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161.
<正>Representatives of the extinct psocid family Empheriidae are known from Eocene Baltic amber, Lowermost Eocene French amber(Oise),and Lower Cretaceous Spanish amber(Alava).We report herein the first discovery of an empheriid psocid from the Cretaceous amber of New Jersey as Jerseyempheria grimaldii gen.et sp. nov.The fossil is figured and described.The new species is distinguished from related taxa.A discussion and checklist of Empheriidae are provided.  相似文献   
162.
Scholars are rarely able to examine anti-dam movements that result in project suspensions or cancellations since these cases are rare empirically. Yet, they are central to understanding how anti-dam movements can succeed. This paper analyzes the movements against Myanmar’s Myitsone Dam and Thailand’s Kaeng Suea Ten Dam. Likely the most successful anti-dam movements in Southeast Asia in recent years, they achieved suspension over 6 and 37 years, respectively. The research is based on 60 semistructured interviews carried out over a period of 8 months. Leveraging thinking from both the constructionist and structural schools within the field of social movement studies, it is found that the framing of the Myitsone Dam as a project threatening the national cultural heritage of Myanmar (in combination with political change in the country in 2010/2011) largely explains the movement’s success. Meanwhile, the set of sophisticated tactics (including inter alia demonstrations, Thai Baan research, 24/7 monitoring of the dam site, and spiritual activities) was decisive for the efficacy of the movement against Thailand’s Kaeng Suea Ten Dam.  相似文献   
163.
Loss estimation from future earthquakes is of growing importance in planning earthquake protection strategies in high-risk areas. Loss models based on the spectral displacement approach are now widely used because of generally acknowledged deficiencies in earlier approaches using macroseismic intensity or peak ground-motion parameters. However, there has been to date rather little earthquake damage data by which the new generation of models can be assessed and which can be used to calibrate the parameters involved. The availability of several detailed damage surveys carried out following the 1999 Kocaeli earthquake in Turkey, provides a rare opportunity for such an assessment. In this paper the losses which would be predicted from two different approaches to loss assessment – one using predicted macroseismic intensity, the other using the spectral displacement method – are compared with actual observed losses in the Kocaeli event at two different locations where surveys were carried out. One of these sites was very close to the surface fault rupture (< 3 km distance), the other at a distance of about 4.5 km. It is shown that the predictive methods available generally overestimated the losses at these distances, and a number of possible reasons for these discrepancies are considered. The sensitivity of loss estimates to variations in the key parameters governing the estimation in each case are explored, in particular with respect to modifications in the parameters of the attenuation relationships and the vulnerability parameters. The implications of these results for estimating future losses are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
164.
The combination of multi-beam echo-sounder swath bathymetry and high-resolution deep-towed sidescan sonar provides a powerful database from which to examine mid-ocean ridge processes. We have used such a database, gathered from the Mid-Atlantic Ridge north of the Kane Fracture Zone (the MARNOK area), to examine the relationship between tectonic, volcanic, and bathymetric segmentation. We have identified structural domains, with different fault distributions, and neovolcanic segments that are distinct from the 2nd or 3rd order bathymetric segmentation.From their mutual relationships, a model is proposed for the magmatic accretion of oceanic crust at slow spreading ridges that relates the local melt supply to the tectonic style. We suggest that these are mutually interactive, and determine whether volcanic extrusion along the ridge is continuous and slow, or episodic and rapid.  相似文献   
165.
This article presents comparisons among the five ground-motion models described in other articles within this special issue, in terms of data selection criteria, characteristics of the models and predicted peak ground and response spectral accelerations. Comparisons are also made with predictions from the Next Generation Attenuation (NGA) models to which the models presented here have similarities (e.g. a common master database has been used) but also differences (e.g. some models in this issue are nonparametric). As a result of the differing data selection criteria and derivation techniques the predicted median ground motions show considerable differences (up to a factor of two for certain scenarios), particularly for magnitudes and distances close to or beyond the range of the available observations. The predicted influence of style-of-faulting shows much variation among models whereas site amplification factors are more similar, with peak amplification at around 1s. These differences are greater than those among predictions from the NGA models. The models for aleatory variability (sigma), however, are similar and suggest that ground-motion variability from this region is slightly higher than that predicted by the NGA models, based primarily on data from California and Taiwan.  相似文献   
166.
A revision is presently under way to upgrade the status of the `Designrecommendations for earthquake resistance of structures', commonlyreferred to as Eurocode 8 (or EC8). In order to improve the definition ofthe design elastic response spectra (ERS) as defined in the Eurocode 8 –Part 1 (Draft May 2001), the values of the soil amplification factors havebeen calculated for sites on sedimentary soils, both stiff (category B) andsoft (category C), with respect to rock sites (category A), such ascontemplated in EC8. The work was performed by a systematic study ofresponse spectra as a function of magnitude and site conditions, usingrecords from the European Strong-Motion Database.The results confirm the occurrence of systematic spectral amplification onsedimentary soils with respect to reference rock in a large set of Europeanstrong motion data. Such amplification has been quantified through ameasure derived from the Housner Spectrum Intensity definition.The values of the soil coefficients recommended in the current version ofEC 8 are shown to be realistic for category C, in the case of a moderateseismicity context. However the values for subsoil class B need to besignificantly increased both for the moderate and high seismicity context.  相似文献   
167.
The current study was carried out from May 2014 to April 2015 to estimate the stock status of P. viridis in Marudu Bay. The gonad development was monitored by histological examination, while the population parameters including asymptotic length (L), growth coefficient (K), mortality rate (Z, F and M), exploitation level (E) and recruitment of P. viridis were estimated using the lengthfrequency data. Results of the current study demonstrated that P. viridis in Marudu Bay spawned throughout the year with two major peaks, one in April to May and another one in October to December. The recruitment pattern was continuous with the peak in May to June 2014, which corresponded to the first spawning peak in April. However, no significant recruitment was observed from the second spawning peak due to the difference in spawning timing between male and female populations. The estimated asymptotic length (L), growth coefficient (K), total mortality (Z), natural mortality (M), fishing mortality (F) and growth performance (ф) of P. viridis in Marudu Bay were estimate to be 117 mm, 0.97 yr-1, 4.39 yr-1, 1.23 yr-1, 3.16 yr-1 and 4.123, respectively. The exponent b of the lengthweight relationship was 2.4 and exploitation level (E) was 0.72. The high mortality, low condition indices and negative allometric of P. viridis in Marudu Bay is caused by a lack of suitable food in the surrounding water.  相似文献   
168.
169.
Mammoth Mountain is a seismically active volcano 200 000 to 50 000 years old, situated on the southwestern rim of Long Valley caldera, California. Since 1989 it has shown evidence of unrest in the form of earthquake swarms (Hill et al. 1990), volcanic 'long-period' earthquakes (Pitt & Hill 1994), increased output of magmatic 3He (Sorey et al. 1993) and the emission of about 500 tonnes day −1 of CO2 (Farrar et al. 1995; Hill 1996; M. Sorey, personal communication, 1997), which has killed trees and poses a threat to human safety. Local-earthquake tomography shows that in mid-1989 areas of subsequent tree-kill were underlain by extensive regions where the ratio of the compressional and shear elastic-wave speeds VP/VS was about 9 per cent lower than in the surrounding rocks. Theory (Mavko & Mukerji 1995), experiment (Ito, DeVilbiss & Nur 1979), and experience at other geothermal/volcanic areas (Julian et al. 1996) and at petroleum reservoirs (Harris et al. 1996) indicate that VP/VS is sensitive to pore-fluid compressibility, through its effect on VP . The observed VP/VS anomaly is probably caused directly by CO2, and seismic VP/VS tomography is thus a promising tool for monitoring gas concentration and movement in volcanoes, which may in turn be related to volcanic activity.  相似文献   
170.
The number of equivalence classes of central configurations of $n \le 4$ bodies of positive mass is known to be finite, but it remains to be shown if this is true for $n \ge 5$ . By allowing one mass to be negative, Gareth Roberts constructed a continuum of inequivalent planar central configurations of $n = 5$ bodies. We reinterpret Roberts’ example and generalize the construction of his continuum to produce a family of continua of central configurations, each with a single negative mass. These new continua exist in even dimensional spaces $\mathbb R ^k$ for $k \ge 4$ .  相似文献   
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