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31.
The long-term CCD and photoelectric observations of YY Her covering the period of its post-outburst activity (JD 2 451 823 -- 2 452 996) are presented. We explain the periodic variations of the brightness of YY Her by the eclipses of the components in the system. The model with a deformed (non-homogeneous) envelope, surrounding the white dwarf is discussed. In addition, we observed a flare in about JD 2 452 440, during the primary minimum, that was later followed by an energetic outburst in JD 2 452 700. 相似文献
32.
重点介绍黑龙江省位置服务中心十年建设过程与研究成果,就中心硬件配备、平台建设进行阐述;对位置服务平台的逻辑组成、功能架构、终端产品接入及服务接口情况作详细说明;针对中心在北斗领域的研究应用、多年来探索的服务模式,以及位置服务标准化建设所做工作进行探讨。文末对黑龙江省位置服务中心下一步的新技术研究与产品化、市场化策略予以展望。 相似文献
33.
Uncertainty in the interpretation of geological data is an inherent element of geology. Datasets from different sources: remotely sensed seismic imagery, field data and borehole data, are often combined and interpreted to create a geological model of the sub-surface. The data have limited resolution and spatial distribution that results in uncertainty in the interpretation of the data and in the subsequent geological model(s) created. Methods to determine the extent of interpretational uncertainty of a dataset, how to capture and express that uncertainty, and consideration of uncertainties in terms of risk have been investigated. Here I review the work that has taken place and discuss best practice in accounting for uncertainties in structural interpretation workflows. Barriers to best practice are reflected on, including the use of software packages for interpretation. Experimental evidence suggests that minimising interpretation error through the use of geological reasoning and rules can help decrease interpretation uncertainty; through identification of inadmissible interpretations and in highlighting areas of uncertainty. Understanding expert thought processes and reasoning, including the use of visuospatial skills, during interpretation may aid in the identification of uncertainties, and in the education of new geoscientists. 相似文献
34.
Zsolt Kővári Katalin Oláh János Bartus Klaus G. Strassmeier Michael Weber Albert Washuettl John B. Rice Szilárd Csizmadia 《Astrophysics and Space Science》2006,304(1-4):375-377
Doppler images are presented for the RS CVn-type binary ζ And. Our upgraded Doppler imaging code TempMapε takes into account the distorted geometry of the primary giant component. On the maps several low latitude spots are restored with a temperature contrast of about 1000 K. Some weak polar features are also found. Cross-correlation of the consecutive Doppler-maps suggests solar-like differential surface rotation. 相似文献
35.
对马尼拉全海笋Barneamanilensis(Philippi)的生态环境、生活习性与分布等进行了观察。马尼拉全海笋在我国仅分布于南海,生活在潮间带高、中潮区风化岩石或胶粘的泥质中,生活海区的水温8~32℃,盐度20~33,海水pH8.2~8.4,穴深随壳长的增长而加深,洞穴与滩面呈45~90°。以底栖硅藻和有机碎屑为食。壳长平均第一年为45.1mm,第二年达57.2mm,第三年63.2mm。雌雄异体,繁殖期在夏季。肉可食用。 相似文献
36.
In this study complete BV light curves of the W Ursae Majoris binary V1073 Cygni obtained in 2005 are presented. We have used the spectroscopic data of V1073 Cyg obtained by Ahn et al. (1992) for analysis. The analysis of radial velocity and light curves was made with Wilson} program (1998) and the geometric and physical elements} of the system were derived. By searching the simultaneous} solutions of the system, we have determined the masses and radii of the components: 1.64M⊙, 2.275R⊙ for the primary component and 0.55M⊙, 1.397R⊙ for the secondary component respectively. The effective temperature of 6494 ± 53 K for the secondary component was also estimated. 相似文献
37.
Amongst the sources seen in very high gamma-rays several are associated with Pulsar Wind Nebulae (“TeV plerions”). The study
of hard X-ray/soft gamma-ray emission is providing an important insight into the energetic particle population present in
these objects. The unpulsed emission from pulsar/pulsar wind nebula systems in the energy range accessible to the INTEGRAL satellite is mainly synchrotron emission from energetic and fast cooling electrons close to their acceleration site. Our
analyses of public INTEGRAL data of known TeV plerions detected by ground based Cherenkov telescopes indicate a deeper link between these TeV plerions
and INTEGRAL detected pulsar wind nebulae. The newly discovered TeV plerion in the northern wing of the Kookaburra region (G313.3+0.6
powered by the middle aged PSR J1420-6048) is found to have a previously unknown INTEGRAL counterpart which is besides the Vela pulsar the only middle aged pulsar detected with INTEGRAL. We do not find an INTEGRAL counterpart of the TeV plerion associated with the X-ray PWN “Rabbit” G313.3+0.1 which is possibly powered by a young pulsar. 相似文献
38.
The output of 25 models used in the Coupled Model Intercomparison Project phase 3 (CMIP3) were evaluated, with a focus on summer precipitation in eastern China for the last 40 years of the 20th century. Most models failed to reproduce rainfall associated with the East Asian summer monsoon (EASM), and hence the seasonal cycle in eastern China, but provided reasonable results in Southwest (SW) and Northeast China (NE). The simulations produced reasonable results for the Yangtze-Huai (YH) Basin area, although the Meiyu phenomenon was underestimated in general. One typical regional phenomenon, a seasonal northward shift in the rain belt from early to late summer, was completely missed by most models. The long-term climate trends in rainfall over eastern China were largely underestimated, and the observed geographical pattern of rainfall changes was not reproduced by most models. Precipitation extremes were evaluated via parameters of fitted GEV (Generalized Ex- treme Values) distributions. The annual extremes were grossly underestimated in the monsoon-dominated YH and SW regions, but reasonable values were calculated for the North China (NC) and NE regions. These results suggest a general failure to capture the dynamics of the EASM in current coupled climate models. Nonetheless, models with higher resolution tend to reproduce larger decadal trends and annual extremes of precipitation in the regions studied. 相似文献
39.
We present photometric observations of two post-common-envelope stars, NY Vir (=PG 1336-018) and HS 0705 + 6700. The V band CCD observation of NY Vir was performed by a 40 cm telescope at Ege University Observatory and the R band observations of HS 0705 + 6700 were performed by 100 cm telescope at TÜB?TAK National Observatory. The new light curves were analyzed by the WD code and the physical parameters of stars were determined. We obtained new mid-eclipse timings for HS 0705 + 6700 and combined them with those previously published data. The analysis of the O-C residuals yields a period of about 8.06 ± 0.28 yr and an amplitude of 98.5 s for the system HS 0705 + 6700, which is attributed to the third star physically bounded to the evolved eclipsing pair. A mass function of 1.2 × 10−4 M⊙ for the third star is obtained. The existence of a third star is also confirmed by the light curve analysis, indicating light contribution of about 0.043 at phase 0.25 in R-bandpass of the eclipsing pair. Using mass-luminosity relationship of the low mass stars we estimate a mass of 0.12 M⊙ with an orbital inclination of about 20°. The O-C residuals obtained for the system NY Vir were represented by a downward parabola which indicates orbital period decrease in the system. Using the coefficient of quadratic term we calculate a rate of orbital period decrease of about dP/dt = −4.09 × 10−8days yr−1. The period decrease we have measured in NY Vir may be explained by angular momentum loss from the binary system. 相似文献
40.
Flexible management of fishing rights and a sustainable fisheries industry in Europe 总被引:3,自引:0,他引:3
Although overexploitation of commercial fish stocks in European waters has been in the public debate now for more than 20 years, the European Union has so far failed to implement sustainable fisheries management. Millions in subsidies paid to the fishing industry have led to significant excess capacity in the fishing fleet. Various feeble attempts to stop overexploitation of marine resources have failed. The cause is that fishing policy is highly dominated by short-term socioeconomic interests. There is an urgent need for a new fisheries management system in Europe that supports reductions in the fishing fleet, increases responsibility among fishers and guarantees long-term conservation of natural marine resources.Transferable rights to fish have proved a reliable and effective means of creating incentives to conserve marine resources. By strengthening individual fishing rights under flexible quota management systems, the EU Member States could, within the Common Fisheries Policy, make a significant contribution to conserving fish stocks, to reducing excess capacity and to raising the profitability of the fisheries industry. A closer look at existing reservations against a flexible management system shows most of the objections to be overstated or capable of resolution. 相似文献