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1.
I.IN~crIOXLocatedinthecoddlepatofTallmBasin,withanareaof33.76X104klnZ,theTaldirnakan~isinthehinterlandofEurasia.Blockedbythehighmountainsaround,vapourofoceancanhardlyreachthedesert.APartfromthis,asthedeSertisinthesinkingcompensationareaoftheascensionalaircurrentaamstheQinghal-XIZangPlateau,itSprecipitationisrareandtheevaporationcapacityisintensealltheyearround.Allthesecontributetotheformationsofthetypifydrydesertclimate.Theacidityindexofthedesertandthearoundregionisashighasmorethan50,w… 相似文献
2.
Modal Wave Number Tomography for South China Sea Front 总被引:10,自引:0,他引:10
1 .IntroductionTheSouthChinaSealiestothesoutheastpartoftheChinesecontinent.TheKuroshioflowsbytheeastsideoftheLuzonStraitfromsouthtonorthinwinter ,spring ,andautumn .TheKuroshioaf fectsnearcurrentfieldsandtemperaturefields,changingtheoceanenvironmentparametersandsoundpropagation .Thus ,theoceanacoustictomographytechniqueisofpotentialtolong term ,largescalemonitoringoftheocean .Themodalwavenumbertomographymethod (Rajanetal.,1 987;Frisketal.,1 989)isusedtoobtainthesoundspeedprofileinwatercol… 相似文献
3.
You Yuming Hou Min Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing Assistant Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing 《中国海洋工程》1992,(3)
- The data of landsat TM of multi-temporal for Lingdingyang Estuary, Pearl River in China is firstly used with suspended sediment concentration of field measurement to establish a correlative model equation. After the ratio processing of TM data and atmospheric correction, the images of suspended sediment concentration of different temporals are exported from the image processing systems AREIS II and III. These images express the characteristics of suspended sediment distribution, the mode of sediment transport and the extent of dispersion under the actions of tidal current and wind condition of different seasons. 相似文献
4.
Chen Guoping Yu Kuang-ming Zhang Jiachang Assistant Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing
Prof. Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing
Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing 《中国海洋工程》1991,(4)
This paper discusses the effect of berm width and elevation of composite slope on irregular wave run-up. Based on the data obtained from model tests, the formula and distribution of irregular wave run-up on composite slope are derived. The changing of wind speed, width and elevation of the berm are considered comprehensively. The wave run-up with various exceedance probability can be es-timated utilizing the distribution curves of irregular wave run-up. 相似文献
5.
Li Dashan Shen Ying Ren Rushu Chen Yao
Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing Associate Professor Hohai University Nanjing Master Hohai University Nanjing 《中国海洋工程》1997,(1)
In this paper,the characteristics of density current under the action of waves are describedwith the help of flume experiment and theoretical analysis.The study shows that turbid water under the ac-tion of the waves can present three types of motion,i.e.significant stratification,fragile stratification andstrong mixing.The motion of turbid water presents significant stratification when(H/D)/△ρ/ρ~(1/2)≤4.5,generally this state is known as density current.The formulas of motionvelocity,thickness,and discharge of density current moving on horizontal bottom are derived by use of ba-sic equations such as momemtum equation,equation of energy conservation and continuity equation offluid.The time-average velocity and the thickness of density current under the action of waves have a rela-tionship with such parameters as relative density(△ρ/ρ),wave height(H),and water depth(D).Whenthese parameters are determined,the time-average thickness and motion velocity of density current are al-so determined.The relat 相似文献
6.
Liu Jiaju Zhang Jingchao Prof. Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing Senior Engineer River Harbour Department Nanjing Hydralulic Research Institute Nanjing 《中国海洋工程》1992,(2)
- This paper, after briefly reviewing the experimental research on sediment transport on muddy beach since the 1950s, improves and perfects the method for forecasting siltation in navigation channels and harbour basins which was first put forward in China by the authors. In consideration of silty sediment and sand, some factors in forecasting methods have been changed and modified. Consequently, the modified methods can be used either to compute siltation in navigation channels and harbour basins on muddy beach or to compute siltation and scouring in navigation channels and harbour basins on both silty beach and sandy beach. The verification of field data from eleven large, medium and small natural harbours shows a good agreement between the forecasting by the modified method and the natural conditions. Finally, the paper deals with the rational utilization of water area after the construction of the West Dyke in Lianyungang, the maintenance of water depth of the navigation channel at the entrance, siltation distribution, siltation in the navigation channel and harbour basin for ships of 100 thousand tonnnage. Results once again prove that the prospect of constructing Lianyungang Harbour into a deepwater harbour is bright. 相似文献
7.
Lian Gan Ni Kan Hu Kai Guo Dawei . Professor Senior Engineer Marine Design & Research Institute of China Shanghai
. Senior Engineer Marine Design & REsearch Institute of China Shanghai
. Engineer Marine Design & Research Institute of China Shanghai 《中国海洋工程》1992,(4)
This paper describes the study of a single-column structure used as well-head platform. In order to check the reliability of computation theory and programme, model tests have been carried out. The paper introduces the conclusion of tests and the dynamic properties of single-column platform are obtained. 相似文献
8.
Yu Kuang-ming Zhang Jiachang Zhou Jiabao Professor Senior Engineer The River Harbour Department Nanjing Hydraulic Research Institute Nanjing Senior Engineer The River Harbour Department Nanjing Hydraulic Research Institute Nanjing 《中国海洋工程》1991,(4)
An empirical formula for estimating the overtopping discharge of wind-waves on a smooth-impermeable-simple slope dyke is derived through model tests in this paper, it can be adopted by related design departments in the determination of the crest elevation of the dyke. 相似文献
9.
Zuo Qihua Yang Zhengji .
Senior Engieer River Harbour Department Nanjing Hydraulic Research Institute Nanjing 《中国海洋工程》1996,(3)
- The variation of the amplitude of waves with varying incident angles when waves propagate through a typical approach channel is discussed by a numerical calculation method, the result of which shows that the influence of the channel on wave propagation is obvious. When the wave propagation direction is in coincidence with the channel axis, the wave amplitude ratio will decrease with the increase of propagation distance. When the incident angle is 15 - 30 , there appears an area of larger wave amplitude ratio on the side slope facing the waves, but at the another side, the wave amplitude ratio is generally small, indicating that the channel has a shielding effect. When waves propagate across the channel perpendicularly, the wave amplitude ratio can be calculated with the shallow water coefficient. 相似文献
10.
中国科学院海洋研究所海洋鱼类繁殖研究组 《海洋科学集刊》1978,(14):29-68
梭鱼(Mugil so-iuy Basilewsky)为我国北方咸淡水鱼类人工养殖的主要对象,南方也有养殖,属鲻科鱼类,广泛分布于热带和亚热带水域。其中尤以鲻鱼(Mugil cephalus B.)为甚。由于它们中的大多数种类适盐性广、食物链低、生长快和肉味美,因而成为海水,咸淡水,乃至淡水鱼类养殖的很好对象。主要养于印度-太平洋区域、地中海和黑海沿岸。1969年,在保加利亚瓦尔纳召开的国际生物学计划海洋生产力组(IBP/PM)的会议上,与联合国粮农组织(PAO)一道,把鲻科鱼类列为国际性生物研究课题之一,受到有关国家的普遍重视。近十多年,对于鲻科鱼类的人工繁殖研究,在某些种类上已取得较大进展。鲻梭鱼,可期在几年内,进入种苗的生产阶段。
我国劳动人民对鲻科鱼类养殖至少已有四个世纪的悠久历史,积累了极为丰富的生产经验。但自古以来,都是利用天然种苗进行养殖。近年来,由于大量兴修水利,淡水入海的运流量不断减少,天然种苗场受到某些影响,能捕到的天然苗也不如以往丰盛,加之种苗资源本身因受气象的影响各年也有所变动。为了使生产能按计划进行,人工繁殖种苗已成为当务之急。
1967年,我所和原天津淡水渔业公司工农养殖场合作,对咸淡水养殖梭鱼的人工繁殖开始进行研究。并在人工诱导排卵方面取得成功,所获卵子得到受精和孵化。1968年,中国科学院实验生物研究所的部分同志也参加了这项试验。当年共获得一千万卵子,其中有二百万卵子获得受精。孵苗十四万多尾。因受寒潮影响,大量胚卵在即将孵出前,或在孵出仔鱼之后不久死去。最后仅培育九百余尾达2公分以上的梭鱼苗。这一年的试验,为咸淡水养殖梭鱼的全人工繁殖打开了"通途"。1969年,养殖场由地方移交给部队,我所继而与中国人民解放军某部队进行合作,一直到1972年截止。1969年,室外池塘育苗成活率达30%,育成6厘米以上的梭鱼苗二千尾左右。这些苗经过越冬,到第二年春天,体长达20厘米以上。1972年,经过人工诱导排卵的亲鱼,在池塘中自行产卵和受精,并孵出仔鱼。这对咸淡水养殖梭鱼的人工繁殖来说,又迈开了新的一步。
本文总结了六年来(1967-1972)咸淡水养殖梭鱼人工繁殖试验所取得的初步成果。对咸淡水养殖梭鱼的生物学特性以及自然繁殖也作了初步观察。现将这一材料发表,供有关单位参考。 相似文献