WCDMA直放站的应用分析

对WCDMA直放站的原理、主要技术指标、覆盖半径计算及其对系统的干扰进行分析和阐述，并就如何最大限度发挥直放站作用进行了必要的工程和理论探讨，同时结合工程实际情况提出了相应的解决方案。     

The period variation of DY Hercules

In this paper the researchers collected 28 times of maximum light including 4 times of those observed at the Xinglong station, the National Astronomical Observation of China between May 27, 2004 and June 1, 2004 and 1 time of maximum light from a 60 cm telescope on May 4, 1984. It found that the O-C point distribution was more completely compared than in any papers published before. The period is decreasing at the rate of about (1.4±0.1)×10⁻⁸ per year, which should not be caused by stellar evolution. It might be only part of a binary orbital light-time variation or other unknown reason. The time scale is longer than Pocs and Szeidl’s suggestion; the star needs more observations before we can be certain of the exact light-time variation.     

黄淮海平原的利用和改造

黄淮海平原在我国占有重要的地位。但长期以来,这里存在着干旱、洪涝、盐碱和风沙等自然灾害,一亿亩以上的低产农田,农业产量不稳不高,人民生活水平提高不快。不过,只要趋利避害、发挥优势,就可挖掘巨大的生产潜力,把它逐步建设成为我国重要的商品粮、棉、油、大豆和水果生产基地与综合性的农业区。作出这一决策的有利条件是:该区土地、光、温等资源存在着一定的优势;劳动力资源充足,城市、工业、交通发达,有利于农业的发展;农业历史发展悠久,具备一定的生产基础;国家对这一地区的开发、利用和治理已经取得了一定的效果和经验。治理、改造黄淮海平原的战略思想应该是:统一领导,全面规划,综合治理,先易后难,点面结合,长期坚持,讲究实效。在克服自然灾害方面,应按照排涝——除盐——抗旱——培肥的顺序来解决问题,逐步改善自然生态环境;同时建立与之相适应的农业生产结构系统。为了从根本上保障除灾增产目标的实现,从长远来说,南水北调,黄、淮、海三大河流的整治及中、上游的土壤保持,都是与发展黄淮海平原农业生产有关的重大问题。     

A VLBI study of 20 southern extragalactic radio sources

This paper describes a 5 GHz VLBI survey in the southern hemisphere. The first observation of 23 extragalactic radio sources was conducted in November 1992. Twenty VLBI images were obtained, of which 15 sources show core-jet structure, one has a two-sided jet, and three sources are unresolved. No compact double source was found. Eleven of the 16 sources with core-jet (including a two-aided jet) show evidence of jet bending. In addition, four sources appear to be superluminal, of which three sources are new.     

Features of clay minerals in the YSDP102 core on the continental shelf of the southeast Yellow Sea

Ninety-eight clay mineral samples from the YSDP102 core were analyzed by x-ray diffractometer to study the four clay minerals: illite, chlorite, kaolinite and smectite. Twenty-eight samples had been analyzed on the laser particle-siz eanalyzer to reveal the particle features of the sediments. Distribution of the clay minerals and the particle characteristics in the YSDP102 core show that the core experienced three different depositional periods and formed three different sedimentary intervals due to different sediment sources and different depositional environments. Features of the clay minerals and the heavy minerals in the YSDP102 core indicate that coarse-grained sediments and fine-grained sediments result from different sources. The Yellow Sea Warm Current has greatly influenced the sedimentary framework of this region since the current‘s formation.     

青狮潭暴雨气候特征统计分析

对1981～2006年3～8月份青狮潭水库各水文雨量站点重大降雨的时空分布,重大暴雨过程的主要影响系统的特征做了统计分析.结果表明:青狮潭暴雨、大暴雨的年际、月际分布很不均,90年代是暴雨高峰期,是80年代和21世纪以来的1.6倍左右.5～6月是暴雨过程集中期.从各月各站点的暴雨过程分布看,北部站点明显多于南部站点.暴雨雨带与湘桂走廊相近.低层系统以锋面最多,低空急流次之,第三为西南涡.通过分析,揭示了青狮潭降水基本气候特征和基本影响系统,对提高局地暴雨预报准确率、促进重大暴雨的预报服务工作和提高桂林城乡供水、农业灌溉、防洪、漓江旅游补水工程都有着重要意义.     

Studies on the Equatorial Spot of G-type Contact Binary UV Lyn

New CCD photometric observations of G-type contact binary UV Lyn were obtained in 2006 and 2020,when the light curves(LCs)showed positive O'Connell effect and n...     

Old stellar population synthesis： new age and mass estimates for Mayall Ⅱ = G1

Mayall Ⅱ = G1 is one of the most luminous globular clusters （GCs） in M31. Here, we determine its age and mass by comparing multicolor photometry with theoretical stellar population synthesis models. Based on far- and near-ultraviolet GALEX photometry, broad-band UBVRI, and infrared JHKs 2MASS data, we construct the most extensive spectral energy distribution of G 1 to date, spanning the wavelength range from 1538 to 20 000A. A quantitative comparison with a variety of simple stellar population （SSP） models yields a mean age which is consistent with G1 being among the oldest building blocks of M31 and having formed within ～1.7 Gyr after the Big Bang. Irrespective of the SSP model or stellar initial mass function adopted, the resulting mass estimates （of order 10^7M⊙） indicate that GI is one of the most massive GCs in the Local Group. However, we speculate that the cluster＇s exceptionally high mass suggests that it may not be a genuine GC. Our results also suggest that G1 may contain, on average, （1.65±0.63） × 10^2L⊙ far-ultraviolet-bright, hot, extreme horizontal-branch stars, depending on the adopted SSP model. In addition, we demonstrate that extensive multi-passband photometry coupled with SSP analysis enables one to obtain age estimates for old SSPs that have similar accuracies as those from integrated spectroscopy or resolved stellar photometry, provided that some of the free parameters can be constrained independently.     

On the Systematic Errors in the Astrometric Catalogues ACR and CMC13 Based on CCD Drift Scanning Observations

Error analyses are made of ACR (Astrometric Calibration Regions along the celestial equator) and CMC13 (Carlsberg Meridian Catalogue 13), two astrometric catalogues compiled on the basis of CCD drift scanning observations and published respectively before and after 2000. Through a comparison with the UCAC2 (the second U.S. Naval Observatory CCD Astrograph Catalogue), the form and size of the errors are analyzed numerically. The main and possible sources of the errors are analyzed from the standpoint of observing mode and data reduction. It is found that there is evident magnitude difference between the ACR and CMC13 in the equatorial direction, and that there exists periodic variation close to the CCD field of view along the right ascension and also a systematic variation close to the size of reduction zone along the declination.     

Variability Study of the SX Phoenicis Star BL Camelopardalis

New time-series photometric observations of BL Cam in the V band and white light were made during 2005 to 2007 at the Xinglong Station of China. The frequency analysis confirms two closely separated frequencies, 25.181 d-1 and 25.571 d-1, but the frequency of 31-32 d-1 reported in the literature was not detected in the new data. New times of maximum light were determined from both our light curves and those available on Internet, allowing a more comprehensive study of the O - C diagram, together with the times of maximum light in the literature. A new interpretation, including the period increasing before 1988 and decreasing since 1992 of BL Cam and the light-time effect in a binary system, looks plausible.