Characteristics of the surface mixed layer depths in the northern South China Sea in spring     

Chunhua Qiu  Yongsheng Cui  Jie Ren  Qiang Wang  Dan Huo  Jiaxue Wu  Huan Liu  Huabin Mao 《Journal of Oceanography》2016,72(4):567-576

The nature and characteristics of the mixed layer depth (MLD) remain uncertain in the northern South China Sea. Using in situ data, we examined the quality of different MLD definitions, investigated the spatial and diurnal variation in the MLD, and examined the mechanisms of mixed layer development during March 23–31, 2014. We made distinct calculations of the MLD; of which two are (a) the depths between two different temperatures (0.2, 0.6 °C) and (b) the depths between two density differences (0.125, 0.25 kg/m³); and the fifth calculation is a depth derived from the optimal linear fitness method. We found that the optimal linear fitness MLD was the best definition for our study region ,and that it deepened from the shelf to the slope. Twenty-four-hour diurnal variation in the MLDs and mixing layers was observed when the ship was moored. Mixing layers were characterized by turbulent dissipation rates. We found that the mixed layer underwent a ‘stable-decaying–developing’ process. During the stable period, the MLD was close to that of the mixing layer, but during the decay/development periods, the MLDs were larger/smaller than those of the mixing layers. We suggest that both velocity shear and buoyancy flux were important in mixed layer development. We quantitatively examined the mechanisms of mixing in the shelf region, with air–sea net heat flux determined to be the major factor, rather than wind speed or current velocity.  相似文献   

Bioactive compounds of sea cucumbers and their therapeutic effects   总被引：1，自引：0，他引：1  

时淑娟  冯文静  胡松  梁世秀  安妮娜  毛拥军 《中国海洋湖沼学报》2016,34(3):549-558

Sea cucumbers belong to the Class Holothuroidea of marine invertebrates. They are commercially valuable and prized as a food and folk medicine in Asia. Nutritionally, sea cucumbers have an impressive profile of valuable nutrients such as vitamins, minerals and amino acids. A number of unique biological and pharmacological activities/properties, including anticancer, anticoagulant/antithrombotic, antimicrobial, antioxidant, antihyperlipidemic, antihyperglycemic, anti-inflammatory, antihypertension and radioprotective, have been ascribed to various compounds isolated from sea cucumbers. The therapeutic properties and medicinal benefits of sea cucumbers can be linked to the presence of a wide array of bioactives, especially triterpene glycosides, acid mucopolysaccharide, sphingoid bases, glycolipids, fucosylated chondroitin sulfate, polysaccharides, phospholipids, cerebrosides, phosphatidylcholines, and other extracts and hydrolysates. This review highlights the valuable bioactive components as well as the multiple therapeutic properties of sea cucumbers with a view to exploring their potential uses as functional foods and a natural source of new multifunctional drugs.  相似文献   

北疆冰雪运动气候适宜性及其变化特征     

李淑娟  毛炜峄  陈静  姚俊强  李建刚  迪丽努尔&#x  托列吾别克 《气候变化研究进展》2021,17(5):537-547

基于北疆43站的降雪量、日平均气温、日最高气温以及日平均风速等资料,应用冰雪运动气候适宜性指数(ISCI),对1961—2017年冬春季北疆的冰雪运动适宜性及其变化特征进行评估,结果如下：(1)北疆大部分站点都适宜开展冰雪运动,阿勒泰等地最为适宜,但伊犁河谷大部分站点、阿拉山口与达坂城等地适宜程度相对较低。(2)冰雪运动气候适宜程度与降雪量并非线性关系,北疆冬春季区域平均降雪量越大,很适宜与不适宜开展冰雪运动的站点都越多。海拔在1200 m以上的站点均适宜开展冰雪运动。(3) ISCI指数的年际差异明显,区域平均ISCI指数随时间推进而减小,但不同站点的ISCI指数线性变化趋势有升有降。1998—2017年期间,北疆适宜冰雪运动的站点较之前大范围减少。(4)阿勒泰地区各站在所有时间阶段中均适宜开展冰雪运动,尤其是阿勒泰北部,冰雪运动气候适宜程度呈阶段性增大,而伊犁河谷大部分站点的冰雪运动适宜程度整体呈阶段性减小。  相似文献   

COUPLED PHYSICAL-ECOLOGICAL MODELLING IN THE CENTRAL PART OF JIAOZHOU BAY Ⅱ. COUPLED WITH AN ECOLOGICAL MODEL     

崔茂常  朱海 《中国海洋湖沼学报》2001,(1)

ＩＮＴＲＯＤＵＣＴＩＯＮＭｕｃｈｅｆｆｏｒｔｈａｓｂｅｅｎｍａｄｅｔｏｗａｒｄｓｉｍｕｌａｔｉｏｎｏｆｔｈｅｅｃｏｓｙｓｔｅｍｅｖｏｌｕｔｉｏｎｉｎｃｏａｓｔａｌｚｏｎｅ.Ｔｈｅｆｉｒｓｔｍａｔｈｅｍａｔｉｃａｌｄｅｓｃｒｉｐｔｉｏｎｏｆｔｈｅｓｅａｓｏｎａｌｐｌａｎｋｔｏｎｄｙｎａｍｉｃｓ(Ｒｉｌｅｙｅｔａｌ.,1949)ｗａｓａｄｖａｎｃｅｄｂｙｔｈｅｅｃｏｌｏｇｉｃａｌｔｈｅｏｒｙｏｎｔｈｅｒｅｇｕｌａｔｉｏｎｏｆｐｏｐｕｌａｔｉｏｎｓｂｙｃｏｍｐｅｔｉｔｉｏｎａｎｄｐｒｅｄａｔｏｒｐｒｅｙｉｎｔ…  相似文献   

The JVAS/CLASS search for 6-arcsec to 15-arcsec image separation lensing     

P.M. Phillips  I.W.A. Browne  N.J. Jackson  P.N. Wilkinson  S. Mao  D. Rusin  D.R. Marlow  I. Snellen  M. Neeser 《Monthly notices of the Royal Astronomical Society》2001,328(4):1001-1015

The Jodrell Bank–VLA Astrometric Survey (JVAS) and the Cosmic Lens All Sky Survey (CLASS) have been systematically searched for multiple gravitational imaging of sources with image separations between 6 arcsec and 15 arcsec, associated with galaxy group and cluster lensing masses. The radio and optical follow-up observations of all candidates are presented. From a total of ∼15 000 sources only one weak candidate remains and this is not contained in the statistically complete sample of flat-spectrum JVAS/CLASS sources of 11 670 sources. A simple Press–Schechter analysis is performed. For singular isothermal sphere lenses the lack of multiple image systems is inconsistent with the currently favoured cosmologies with     at the 4.2 σ level. Cored isothermal lenses reduce the expected number of lens systems and we suggest that the most probable interpretation of our results is that the surface mass density of groups and clusters of galaxies is not high enough to cause multiple imaging and the presence of the mass concentrations associated with individual galaxies is required to produce image separations such as those in B0957+561.  相似文献   

射电脉冲星搜寻工作的进展     

潘炼德  Mao Wei  Huang Yong  Pan Liande 《天文学进展》2001,19(1):55-67

评述了射电脉冲星搜寻及观测研究的巨大贡献和重要意义，分析了影响脉冲星搜寻工作的几个关键因素（如灵敏度，色散，观测频率及设备等），着重介绍和分析了自发现脉冲星（特别是发现第一颗秒脉冲星）以来所进行的卓有成效的脉冲星搜寻工作（包括脉冲星的早期寻，毫秒脉冲星的初期搜寻，高银续脉冲星搜寻，定向搜寻以及进一步的广域深空搜寻等）的情况，结果，意义和进展。  相似文献   

开展我国云量分布的卫星资料统计研究的建议     

毛节泰 《天文研究与技术》1996,(Z1)

收集连续三年每小时的静止卫星红外云图，用温度阈值法判断有云或晴空，从而统计出我国全国范围中２０×２０ｋｍ２网格上晴天和云量分布概率，以供天文台选址参考。  相似文献   

低纬子午环光轴变化的内涵和测定方法   总被引：2，自引：2，他引：0  

陈林飞  彭青玉  冒蔚 《天文研究与技术》1997,(Z1)

叙述了子午环观测中测定和修正光轴变化或镜筒弯曲的必要性，简述了传统子午环的测定和修正方法，论述了低纬子午环引起光轴变化的因素和实时测定光轴变化的方法，讨论了在光轴变化测定值中的误差来源。  相似文献   

低纬子午环配备科学CCD的初步方案     

彭青玉  王晓彬  冒蔚 《天文研究与技术》1997,(Z1)

根据低纬子午环配备科学ＣＣＤ后仍然能对天体位置作绝对测定的要求，提出了该仪器配备科学ＣＣＤ的初步方案，包括在子午方向和卯酉方向观测时，ＣＣＤ芯片如何跟踪星像，如何将芯片致冷，提高信噪比，既能保持镜筒的平衡，又不破坏观测室内空气的稳定性，如何更准确地测定光轴指向的变化。文中还对一次观测的天区面积作了估计。  相似文献   

中国出口双折射滤光器   总被引：1，自引：0，他引：1  

李挺  毛伟军  陆海天  朱勇 《天文学进展》2001,19(3):331-335

中国科学院南京天文仪器研制中心在20世纪80年代研制35cm太阳磁场望远镜滤光器取得巨大的成功，其在双折射滤光器领域内的水平，已被国际太阳物理界公认。1989年以来，已向日本和韩国出口了11台复杂而昂贵的Lyot滤光器，并已在有关国立天文台和天文馆投入常规观测。最近，还为国外客户修复3台Lyot滤光器，它们都是德国和法国在30年前生产的。  相似文献