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171.
The 2011 magnitude 9.0 Tohoku-Oki earthquake: mosaicking the megathrust from seconds to centuries 总被引:5,自引:0,他引:5
Simons M Minson SE Sladen A Ortega F Jiang J Owen SE Meng L Ampuero JP Wei S Chu R Helmberger DV Kanamori H Hetland E Moore AW Webb FH 《Science (New York, N.Y.)》2011,332(6036):1421-1425
Geophysical observations from the 2011 moment magnitude (M(w)) 9.0 Tohoku-Oki, Japan earthquake allow exploration of a rare large event along a subduction megathrust. Models for this event indicate that the distribution of coseismic fault slip exceeded 50 meters in places. Sources of high-frequency seismic waves delineate the edges of the deepest portions of coseismic slip and do not simply correlate with the locations of peak slip. Relative to the M(w) 8.8 2010 Maule, Chile earthquake, the Tohoku-Oki earthquake was deficient in high-frequency seismic radiation--a difference that we attribute to its relatively shallow depth. Estimates of total fault slip and surface secular strain accumulation on millennial time scales suggest the need to consider the potential for a future large earthquake just south of this event. 相似文献
172.
Barry D Townsend M 《Science (New York, N.Y.)》2010,330(6001):174; author reply 177-174; author reply 178
173.
Transsphenoidal surgery: accuracy of an image‐guided neuronavigation system to approach the pituitary fossa (sella turcica) 下载免费PDF全文
174.
175.
Smith BA Soderblom L Beebe R Boyce J Briggs G Bunker A Collins SA Hansen CJ Johnson TV Mitchell JL Terrile RJ Carr M Cook AF Cuzzi J Pollack JB Danielson GE Ingersoll A Davies ME Hunt GE Masursky H Shoemaker E Morrison D Owen T Sagan C Veverka J Strom R Suomi VE 《Science (New York, N.Y.)》1981,212(4491):163-191
As Voyager 1 flew through the Saturn system it returned photographs revealing many new and surprising characteristics of this complicated community of bodies. Saturn's atmosphere has numerous, low-contrast, discrete cloud features and a pattern of circulation significantly different from that of Jupiter. Titan is shrouded in a haze layer that varies in thickness and appearance. Among the icy satellites there is considerable variety in density, albedo, and surface morphology and substantial evidence for endogenic surface modification. Trends in density and crater characteristics are quite unlike those of the Galilean satellites. Small inner satellites, three of which were discovered in Voyager images, interact gravitationally with one another and with the ring particles in ways not observed elsewhere in the solar system. Saturn's broad A, B, and C rings contain hundreds of "ringlets," and in the densest portion of the B ring there are numerous nonaxisymmetric features. The narrow F ring has three components which, in at least one instance, are kinked and crisscrossed. Two rings are observed beyond the F ring, and material is seen between the C ring and the planet. 相似文献
176.
The chemical analysis of the caffeine salt of a phosphomolybdic-tungstic acid compound (PTMC) is described. Twenty-seven dogs with advanced malignant tumours have been treated with PTMC by intramuscular or intravenous injection. Five dogs - one case of metastatic osteosarcoma, two cases of metastatic mammary carcinoma, one case of metastatic squamous cell carcinoma and one case of primary fibrosarcoma showed objective tumour regression for periods varying from four weeks to 20 months. Only two of the 27 dogs treated showed toxic effects. 相似文献
177.
Lipsitch M Cohen T Cooper B Robins JM Ma S James L Gopalakrishna G Chew SK Tan CC Samore MH Fisman D Murray M 《Science (New York, N.Y.)》2003,300(5627):1966-1970
Severe acute respiratory syndrome (SARS) is a recently described illness of humans that has spread widely over the past 6 months. With the use of detailed epidemiologic data from Singapore and epidemic curves from other settings, we estimated the reproductive number for SARS in the absence of interventions and in the presence of control efforts. We estimate that a single infectious case of SARS will infect about three secondary cases in a population that has not yet instituted control measures. Public-health efforts to reduce transmission are expected to have a substantial impact on reducing the size of the epidemic. 相似文献
178.
Estimating the mass of asteroid 253 mathilde from tracking data during the NEAR flyby 总被引:1,自引:0,他引:1
DK Yeomans J Barriot DW Dunham RW Farquhar JD Giorgini CE Helfrich AS Konopliv JV McAdams JK Miller WM Owen DJ Scheeres SP Synnott BG Williams 《Science (New York, N.Y.)》1997,278(5346):2106-2109
The terminal navigation of the Near Earth Asteroid Rendezvous (NEAR) spacecraft during its close flyby of asteroid 253 Mathilde involved coordinated efforts to determine the heliocentric orbits of the spacecraft and Mathilde and then to determine the relative trajectory of the spacecraft with respect to Mathilde. The gravitational perturbation of Mathilde on the passing spacecraft was apparent in the spacecraft tracking data. As a result of the accurate targeting achieved, these data could be used to determine Mathilde's mass as 1.033 (+/- 0.044) x 10(20) grams. Coupled with a volume estimate provided by the NEAR imaging team, this mass suggests a low bulk density for Mathilde of 1.3 grams per cubic centimeter. 相似文献
179.
180.
Megan Carney 《Agriculture and Human Values》2012,29(2):185-201
Santa Barbara County exhibits some of the highest rates of food insecurity in California, as well as in the United States. Through ethnographic research of three low-income, predominantly Latino communities in Santa Barbara County, this study examined the degree to which households had been experiencing heightened levels of food insecurity since the economic recession and ensuing coping strategies, including gender-specific repercussions and coping strategies. Methods included administering a survey with 150 households and conducting observation and unstructured interviews at various local food-centered venues. Results indicated that households from the three communities were experiencing heightened levels of food insecurity and that all three communities were employing diversification of procurement, adjustments to a reduced or limited food budget, reliance on food assistance, and revitalization of the home as a site of domestic food production and preparation as coping strategies. The results also suggested that women suffered disproportionately higher psychological and physical costs associated with compounding crises. In conclusion, the experiences narrated by low-income households reflect a form of citizenship that appears compromised by a host of variables perceived to exist outside the realm of local control. Shifting toward an operational framework of food sovereignty may allow these communities to become more resilient in the face of future political, environmental, social, and economic stressors. 相似文献