Three-dimensional structure of a low salinity tongue in the southern Taiwan Strait observed in the summer of 2005

Cruise observations with CTD (conductivity-temperature-depth) profiler were carried out in the southern Taiwan Strait in the summer of 2005. Using the cruise data, two-dimensional maps of salinity and temperature distributions at depths of 5, 10, 15, 20, and 30 m were generated. The maps show a low salinity tongue sandwiched by low temperature and high salinity waters on the shallow water side and high temperature and high salinity waters on the deep water side. The further analysis indicates that the low salinity water has a nature of river-diluted water. A possible source of the diluted water is the Zhujiang (Pearl) Estuary. Meanwhile, the summer monsoon is judged as a possible driving force for this northeastward jet-like current. The coastal upwelling and the South China Sea Warm Current confine the low salinity water to flow along the central line of the strait. Previous investigations and a numerical model are used to verify that the upstream of the low salinity current is the Zhujiang Estuary. Thus, the low salinity tongue is produced by four major elements:Zhujinag Estuary diluted water, monsoon wind driving, coastal upwelling and South China Sea Warm Current modifications.     

源于克雷伯氏菌Klebsiella sp.AC-11的3株噬菌体的生物学特性

从国家海洋局第三海洋研究所海水养殖池中分离得到一株细菌AC-11,16SrDNA序列分析表明其与肺炎克雷伯氏菌肺炎亚种(Klebsiella pneumoniae subsp.pneumoniae)具有最高的序列同源性达99.78%.以此菌株为宿主菌,于2008年11月采用双层平板法分离得到3株裂解性噬菌体KP1,KP...     

Observations on shell growth and morphology of the bivalve Ruditapes philippinarum

The bivalve Ruditapes philippinarum is not only one of the main mollusc species in the west Pacific Ocean, but also one of the main species for aquaculture in China. Knowledge of growth of the R. philippinarum shell will improve our understanding of the shell as an environmental archive. It is also useful for the aquaculture of R. philippinarum. In this research, a hanging box culture method was introduced in the culture of R. philippinarum. The bivalves were cultured for 126 days, from March 31 to August 3, 2002. The average growth rates of shell width, height, and thickness were 0.069, 0.046, and 0.032 mm/d, respectively. The mean increase of average individual wet mass was 0.028 g/d. The largest growth rates of both shell and average individual wet mass occurred in June, indicating that water temperature and bivalve reproduction were 2 important factors. The shell morphology underwent significant changes with shell growth. The ratio of height to thickness (value of B/C) shifted 1.58 in the first 60 days to 1.54 in the last 30 days, which was resulted from the change in major shell growth direction. Periodic changes in the B/C ratio led to corrugated shell form, which could be used to determine the age of the shell.     

Microphysical Effects of Cloud Seeding in Supercooled Stratiform Clouds Observed from NOAA Satellite

Based on the satellite retrieval methodology, the spectral characteristics and cloud microphysical properties were analyzed that included brightness temperatures of Channels 4 and 5, and their brightness temperature difference (BTD), the particle effective radius of seeded cloud track caused by an operational cloud seeding and the microphysical effects of cloud seeding were revealed by the comparisons of their differences inside and outside the seeded track. The cloud track was actually a cloud channel reaching 1.5-km deep and 14-km wide lasting for more than 80 min. The effective radius of ambient clouds was 10-15μm, while that within the cloud track ranged from 15 to 26μm. The ambient clouds were composed of supercooled droplets, and the composition of the cloud within the seeding track was ice. With respect to the rather stable reflectance of two ambient sides around the track, the visible spectral reflectance in the cloud track varied at least 10%, and reached a maximum of 35%, the reflectance of 3.7μm in the seeded track relatively decreased at least 10%. As cloud seeding advanced, the width and depth were gradually increased. Simultaneously the cloud top temperature within the track became progressively warmer with respect to the ambient clouds, and the maximum temperature differences reached 4.2 and 3.9℃at the first seeding position for Channels 4 and 5. In addition, the BTD in the track also increased steadily to a maximum of 1.4℃, compared with 0.2-0.4℃of the ambient clouds. The evidence that the seeded cloud became thinner comes from the visible image showing a channel, the warming of the cloud tops, and the increase of BTD in the seeded track. The seeded cloud became thinner mainly because the cloud top descended and it lost water to precipitation throughout its depth. For this cloud seeding case, the glaciation became apparent at cloud tops about 22 min after seeding. The formation of a cloud track in the supercooled stratiform clouds was mainly because that the seeded cloud volume glaciated into ice hydrometeors that precipitated and so lowered cloud top height. A thin line of new water clouds formed in the middle of the seeded track between 38 and 63 min after seeding, probably as a result of rising motion induced by the released latent heat of freezing. These clouds disappeared in the earlier segments of the seeded track, which suggested that the maturation of the seeding track was associated with its narrowing and eventual dissipation due to expansion of the tops of the ambient clouds from the sides inward.     

阿尔金山依协克帕提湖畔黑颈鹤观察初报

一、概况依协克帕提湖位于我国最大的自然保护区——阿尔金山保护区的东部,即东昆仑山的北支祁曼塔格山脚下的凹陷盆地东缘,其范围为:37°15′—37°23′N,90°11′～90°20′E。该区域属藏北羌塘高原的延伸部分,在景观上具有中亚荒漠向青藏高原过渡的特征。依协克帕提湖为淡水湖泊(阿尔金山保护区中90％的湖泊为咸水湖泊),海拔3900m。湖泊面积约15km~2,平均水深1～3m。湖泊南端宽圆,北部细长,整个形状象一只向南游动的蝌蚪。湖东为砾     

从两堂地理课的现场观察地理教师的教学行为——以黄赤交角的教学为例

教师的教学行为是指教师在课堂上所发生的行为。它会受到教学内容、学生因素、教师个人等多种因素的影响。教师的教学行为不仅直接影响到学生听课的效率,而且会对学生的未来产生重要的影响。以黄赤交角的教学为例,选取了两位地理教师在教学过程中的两个片段,分析教师的教学行为对学生可能产生的重要影响,旨在让一线教师懂得为了学生的未来,转变其教学行为的重要性。     

Histological Observation of Germ Cell Development and Discovery of Spermatophores in Ovoviviparous Black Rockfish（Sebastes schlegeli Hilgendorf） in Reproductive Season

Black rockfish（Sebastes schlegeli） is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process of germ cells in this ovoviviparous rockfish in reproductive season（October 2011–November 2012） with histological methods. We found that the gonad of mature fish showed notable seasonal changes in developmental characteristics and morphological structure. The sperm cells matured during a period lasting from October to December, significantly earlier than the oocytes did. A large number of spermatozoa and other cells occurred in testis at different developmental stages. Vitellogenesis in oocytes began in October, and gestation appeared in April next year. Spermatophores were discovered for the first time in Sebastes, which assembled in testis, main sperm duct, oviduct and genital tract, as well as ovarian cavity in October and April. These organs may serve either as production or hiding places for spermatophores and spermatozoa which were stored and transported in form of spermatophores. Testicular degeneration started from the distal part of testis in April, with spermatophores assembled in degenerating testis and waiting for transportation. The copulation probably lasted for a long period, during which the spermatozoa were discharged in batches as spermatophores. These spermatophores were coated with sticky materials secreted from the interstitial areas of testis and the main sperm duct, then transported into ovary.     

骆驼刺

正时至7月,艳阳高照。刺眼的太阳几乎焦灼着尕林格戈壁上的每一寸沙土,雨水是那么的稀缺,绿色更是罕见。放眼望去,一望无际的黄沙弥漫在干旱的空气中,让人觉得窒息。突然眼前一亮,那是一朵盛开在沙土里黄色的小花,如同满天星,一小朵挨着一小朵,俯身观察,周围一簇绿色的短小尖锐的叶子几乎与地面平行,但仔细观察,其实每枝每叶都坚挺的刺向天空,不媚、不娇、