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881.
层结切变流中的Rossby波的稳定度 总被引:1,自引:0,他引:1
Rossby波的稳定度问题是大气动力学的中心问题之一,这方面的研究工作已有很多。早期,文献[1-4,9]采用标准波型法对此问题作了开创性的研究,得到了许多重要结论。如,有关不稳定的判据,稳定波和不稳定波的结构,以及它们对维持大气环流所起的作用等。 相似文献
882.
An experiment was performed to determine the dietary phosphorus requirement of the young abalone,Haliotis discus hannai. Five semi-purified diets were formulated to provide a series of graded levels of dietary total phosphorus (0.23%–1.98) from
monobasic potassium phosphate (KH2P04). The brown alga,Laminaria japonica, was used as a control diet. Similar size abalone were distributed in a single-pass, flow-through system using a completely
randomized design with six treatments and three replicates each treatment. The abalone were hand-fed to satiation with appropriate
diets in excess, once daily at 17:00. The feeding trial was run for 120-d. Survival rate and soft-body to shell ratio (SB/S)
were constantly maintained regardless of dietary treatment. However, the weight gain rate (WGR), daily increment in shell
length (DISL), muscle RNA to DNA ratio (RNA/DNA), carcass levels of lipid and protein, soft-body alkaline phosphatase (SBAKP),
and phosphorus concentrations of whole body (WB) and soft body (SB) were significantly (ANOVA, P<0.05) affected by the dietary
phosphorus level. The dietary phosphorus requirements of the abalone were evaluated from the WGR, DISL, and RNA/DNA ratio
respectively, by using second-order polynomial regression analysis. Based on these criteria, about 1.0%–1.2% total dietary
phosphorus, i.e. 0.9%–1.1% dietary available phosphorus is recommended for the maximum growth of the abalone.
Project 39670572 supported by the NSFC. 相似文献
883.
我国土壤中结合态硒的含量和分布规律 总被引:18,自引:3,他引:15
本文提出并建立了Jackson法系统分离土壤中不同形态硒的实验程序,研究了我国几种土壤表层(0—20cm)中硒的结合形态及其地理分布规律,并对植物可利用性作了评价。 相似文献
884.
UBV photoelectric observations of the W UMa-type binary V471 Cas were made from September to November 1984. Its colour indices were found to be(B-V)=0
.
m
771±0
.
m
02 and(U-B)=0
.
m
196±0
.
m
02. TheU, B, andV light curves of V471 Cas show some photometric fluctuations. We found that its orbital period is not 0.335998 days which was given by GCVS (1986), but 0.405356 days.Photometric orbital elements of V471 Cas were found using the Wilson-Devinney method. V471 Cas is a contact system, in which the overcontact factor is 0.19, its mass ratio of two components is 0.5947, and orbital minclination is in 83.29 degrees. 相似文献
885.
本文计算和讨论了强磁场下由冷的催化物质组成的中子星外壳的组份和状态方程。文中考虑了晶格能和强磁场下均匀电子气体的交换能的贡献.得出结论:(1)强磁场使低密度区的状态方程变软;(2)强磁场对高密度区的状态方程几乎没有影响;(3)核质量公式对外壳的组份影响较明显. 相似文献
886.
我国流动SLR首次取得观测成果 总被引:7,自引:7,他引:0
介绍了流动SLR系统TROS建成后在北京,乌鲁木齐,拉萨3个站的观测情况。这是流动卫星光测距系统在我国首次正式运行,开创了SLR流动观测的先例,实现了我国SLR领域多年来的愿望。对乌鲁木齐和世界屋脊城市拉萨观测的实现有其重要意义,引起国内外广泛关注。对TROS的建站和观测等问题进行了讨论,给出了观测结果。 相似文献
887.
888.
Lu Tan 《Chinese Astronomy and Astrophysics》1981,5(4):377-380
Neutrinos with non-zero mass could gather to form a new kind of astronomical bodies: the Neutrino Astronomical Objects (NAO). We have investigated the mechanism of their formation and the relation of this formation to that of the galaxies, ascertained their e, p, He4 content, whose presence should produce a series of observable effects. NAOs are a peculiar kind of heavenly bodies with many new properties. They have a linear size of the order of 100 pc, a total neutrino content of the order of 1014M and an e, p, He4 content of the order of 109M. 相似文献
889.
The stalagmite chronological table is established based on the definition of annual character of microlayers of a stalagmite
by comparing the laminated rhythm to natural cyclic processes. Climatic anomalies lasting over ten years and rapid climatic
changes such as abrupt changes of mean value, of variability, of trend and of cycles are discovered from the stalagmite chronological
table. Stalagmites which record interannual to century scale climatic changes are excellent
This work is a part of PANASH/PEP-II Project, and supported by the National Natural Science Foundation of China (Grant Nos.49672134,
49894170), Chinese Academy of Sciences (Grant No.KZ951-A1-402-06-02), and State Science & Technology Commission of China. 相似文献
890.
Grey characteristics of microbanding of stalagmite in Shihua Cave, Beijing and its climatic signification(I) 总被引:2,自引:0,他引:2
Xiaoguang Qin Dongsheng Liu Ming Tan Tieying Li Jinpo Lü Zhaoyan Gu Houyuan Lü Zhongli Ding Zhengtang Guo Jiaqi Liu Gaozhong Nie 《中国科学D辑(英文版)》1998,41(2):151-157
Grey microstructure of microbanding in thin sections of stalagmite T9501 from Shihua Cave, Beijing was studied. The types
of grey and the morphologic features of organic material were classified. The signification of microbanding and annual layer
was discussed. The standard distinguishing the false annual layer and the multi-year layer is set up, which provides the theoretic
fundaments for paleoclimatic study.
Project supported by the National Natural Science Foundation of China (Grant No. 49672134). 相似文献