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111.
112.
Mathematical Geosciences - The presence of outliers in geochemical data can impact the accuracy of grade models and influence the interpretation of mine assay data. Removal of outliers is therefore... 相似文献
113.
Leung CC Jefferson TA Hung SK Zheng GJ Yeung LW Richardson BJ Lam PK 《Marine pollution bulletin》2005,50(12):33-1719
114.
115.
K. C. Leung D. S. Zhai R. X. Zhang Q. Y. Liu J. T. Zhang Y. L. Yang 《Astrophysics and Space Science》1984,99(1-2):411-411
This is a preliminary report on the joint research project between 3 observatories: Beijing, Yunnan, and Behlen Observatories from China and the United States. The systems we have been dealing with are primary of late spectral types and with short periods. Most of the observations were secured from the observatories in China. The computational analysis is carried out in University of Nebraska, Lincoln. The photometric solutions are based on the Wilson and Devinney method. Out of 11 systems analyzed 6 of them: AO Cam, ER Ori. BX Peg, BB Peg, U Peg, and SW Lac are found to be contact systems. All of them are having their primary eclipses at occultation. Therefore they can be classified as W-type W U Ma systems. They also show other W-type characteristics.Three systems: ZZ Aur, RZ Dra, and AX Vir are found to be semi-detached systems, with low mass components filling their Roche surfaces. The massive components are having their radii fairly close to Roche surfaces and are larger than their contact companions.The last two systems: AT Cam and AZ Cam are found to be detached systems, but with their low mass components almost filling their Roche surfaces. This type of configuration is of great interest to our understanding of close binary evolution. We believe that these systems are at phase immediately after the normal Algol phase, where the mass lossing components detached from the Roche surfaces at the conclusion active mass lost phase.Paper presented at the Lembang-Bamberg IAU Colloquium No. 80 on Double Stars: Physical Properties and Generic Relations, held at Bandung, Indonesia, 3–7 June, 1983. 相似文献
116.
A search was made for periodic fluctuations in the thermal brightness temperatures recorded by the Pioneer Venus orbiter's infrared radiometer. Data were averaged in 10 × 10° latitude-longitude bins for each of the 72 days the instrument was in operation. This time series of thermal brightness temperatures was then analyzed to determine the amplitude of fluctuations at periods from 2 to 64 days at four levels in the atmosphere (at the cloud tops and at approximately 70, 80, and 90 km). The amplitude of such fluctuations is small at equatorial latitudes and increases to a maximum at 60–70° latitude at most altitudes. The period of the highest amplitude fluctuation is 5.3±0.4 days (at all altitudes) except at 70–80°, where a 2.9-day period which appears to correspond to the polar dipole dominates the cloud-top channel. The amplitude of the periodic fluctuations is a maximum at the cloud tops, decreasing to a minimum at the 80-km channel, and increasing again at the 90-km channel. 相似文献
117.
A series of centrifuge tests were performed to investigate the response of a free-head monopile due to cyclic lateral loading in normally consolidated clay. By linking the maximum reaction-force point of the final cycles in all tests with various amplitudes, a postcyclic reaction-force curve is obtained, which can be used to assess the postcyclic remolded lateral stiffness. To numerically analyze the tests, a strength degradation model of the clay is calibrated by the T-bar cyclic test. However, this model is T-bar-dependent, which is unable to capture the degrading behavior of the monopile stiffness. Thus, a modification approach is proposed based on the upper bound theory, and the modified model is further combined with finite element analysis to simulate the cyclic behavior of the model pile. The simulation results show similar degrading trend and consistent postcyclic remolded lateral stiffness with the model tests. This further demonstrates that the remolded lateral stiffness mainly depends on the soil remolded strength, which is one of the parameters calibrated by the T-bar tests. Based on this finding, a simplified numerical analysis is proposed, which can predict the postcyclic reaction-force curve by performing one monotonic loading instead of modeling the whole process of cyclic loading. 相似文献
118.
Donald G. York Pushpa Khare Daniel Vanden Berk Varsha P. Kulkarni Arlin P. S. Crotts James T. Lauroesch Gordon T. Richards Donald P. Schneider Daniel E. Welty Yusra Alsayyad Abhishek Kumar Britt Lundgren Natela Shanidze Tristan Smith Johnny Vanlandingham Britt Baugher Patrick B. Hall Edward B. Jenkins Brice Menard Sandhya Rao Jason Tumlinson David Turnshek Ching-Wa Yip Jon Brinkmann 《Monthly notices of the Royal Astronomical Society》2006,367(3):945-978
119.
We used the Behlen observatory 0.76 m telescope and the CCD photometer to secure 689 observation of the eclipsing binary star
KN Per. The observations were made on 8 nights during 1993 and 1994 with V and R bandpass filters. From 7 determinations of
eclipse timings of minimum (V&R together), we have determined a new epoch and an orbital period of 0.8664604 days. The published
spectral classification is A9.
The 1993 version of the Wilson-Devinney model gave the photometric solutions. The adopted solution indicates that KN Per is
a W UMa type contact binary. The mass ratio, q = (m2/m1, where star 1 eclipses at the primary minimum) = 0.23 suggests that KN Per is a W UMa system with A-type configuration. The
secondary minimum shows a total eclipse. The asymmetry in the light curve is fitted with a cold spot on the secondary component
of the system. The luminosity difference between the components is very large KN Per therefore, is most likely a single line
spectroscopic binary. We recommend spectroscopic study of this system. Generally contact systems of spectral type A9 have
periods ranging from 0.4 to 0.6 days. KN Per has considerably longer period and thus appears to be an evolved contact system
with case B mass transfer.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
120.
Knowledge of dispersal and establishment during the early stages of invasion is essential for allocating monitoring effort, detecting nascent populations and predicting spread. The scarcity of these data, however, provides little guidance for monitoring programs. Here we present data on the adult distribution and the subsequent pattern of larval recruitment from a nascent population of the invasive tunicate Ciona intestinalis in Prince Edward Island, Canada. Existing niche models indicate the entire study site is suitable for recruitment, suggesting an equal probability of detection throughout the site. In contrast, we found a heterogeneous pattern of larval recruitment, including areas of zero recruitment. By fitting a dispersal kernel, we show Ciona is not capable of naturally dispersing between bays, restricting further spread, and provide guidance for future monitoring. Our results also highlight how large-scale models, although important, lack the small-scale patterns essential for monitoring and early detection of invasive species. 相似文献