共查询到20条相似文献，搜索用时 296 毫秒
1.
-At present, it is still difficult to obtain an accurate maximum wind speed of typhoon with modern means,such as satellite survey , radar tracing and airplane reconnaissance. The performance of statistical equation established with observational maximum wind speed and the central pressure of typhoon is unstable ,and it is unreliable in operational use. Therefore a general pressure field model of typhoon is introduced in this paper based on atmospheric motion equations and formulas are derived for computing the maximum wind speed around typhoon center over sea surface . The theoretical curves derived from these formulas are in good agreement with those using the statistic empirical curves of typhoon pressure-wind relations over the western Pacific. Tests were conducted for typhoons which occurred in 1973 and in 1983 and the strongest typhoons selected each year during 1970 and 1978,the results were satisfactory. Meanwhile the analyses of computing results showed that the effect of Coriolis force could be 相似文献
2.
徐立论 《海洋学报(英文版)》1986,5(1):147-147
The development of the offshore industry on a world-wide basis has given rise to thegrowing demand for a good knowledge and understanding of the ocean wave environment.In addition to the accepted probabilistic and spectral methods of defining wave climate,attention has recently focussed on wave groups-a series of waves on enhanced amplitudeoccurring in close sequence. Such an occurrence is important in a range of offshore andcoastal engineering problems, particularly in the dynamic response of compliant offshore sys-tems and the stability of breakwaters. The paper presents a brief review of the previous work on wave groups, followed by 相似文献
3.
Chen Tieyun Zhang Huiyuan Proefessor Shanghai Jiao Tong University Shanghai
Engineer Shenzhen Shipbuilding Trading Co. LTD Shenzhen 《中国海洋工程》1993,(4)
- The formulation for the stress concentration matrix of multiplanar tubular joint with braces subjected to combined load is established in this paper. The formulations for SCF values of multiplanar tubular joints are compared with those by Wordsworth and Efthymiou. The stiffening effect and load-interaction effect are discussed. A spatial offshore jacket with braces subjected to combined load is computed as a numerical example. The maximum stress of each multiplanar tubular joint and its location are found through SCF matrix. Finally, the difference between the maximum stresses of multiplanar tubular joints and their corresponding uniplanar tubular joints are discussed. 相似文献
4.
Dai Yishan He Wuzhou Professor Harbin Shipbuilding Engineering Institute Harbin
Associate Professor Harbin Shipbuilding Engineering Institute Harbin 《中国海洋工程》1993,(3)
- Generated by an ideal sinusoidal motion of the vertical plate, the simplest linear solution in time domain for two-dimensional regular waves is derived. The solution describes the propagation process of the plane progressive wave with a front, and will approach the linear steady- state solution as the oscillation time of the plate approaches infinity. The solution presented in this paper can be used to provide an incident wave model with analytical expression for solving the problems of diffraction and response of floating bodies in time domain. 相似文献
5.
The algorithms of extracting chlorophyll-a(Chl-a) concentration have been established for Chinese moderate resolution imaging spectrometer(CMODIS) mounted on Shenzhou-3 spaceship launched on 25 March 2002.The CMODIS is an ocean color sensor with 30 visible channels and 4 infrared channels,much different from other ocean color satellites and needs new algorithms to process data.Three models of Chl-a concentration were established based on Chl-a data retrieved from sea-viewing wide field-of-view sensor(SeaWiFS),with the average relative errors of 26.6%,24%.0% and 33.5%,respectively.This practical and economic approach can be used for developing the algorithms of Chinese ocean color and temperature sensor(COCTS) on the satellite Haiyang-1 to derive the Chl-a concentration concentration distribution.The applicability of the algorithms was analyzed using some in situ measurements.Suspended sediment is the main factor influencing the accuracy of the spectral ratio algorithms of Chl-a concentration.The algorithms are suitable to using in the regions where suspended sediment concentrations(SSC) are less than 5 g/m3 under the condition of relative error of Chl-a concentration retrieval within 35%.High concentration of suspended sediment leads to the overestimate remote sensing retrieval of concentration of Chl-a,while low-middle SSCs lead to the low Chl-a concentration values using the spectral ratio algorithms.Since the accuracy of Chl-a concentration by the spectral ratio algorithms is limited to waters of Case 2,it is necessary to develop semi-analytical models to improve the performance of satellite ocean color remote sensing in turbid coastal waters. 相似文献
6.
Zang Jiaye 《海洋学报(英文版)》1995,(4)
Ｔｈｅ ｄｉｓｔｒｉｂｕｔｉｏｎ ｏｆ ｍｅｔｈａｎｅ ｉｎ ｔｈｅ Ｔｏｋｙｏ－ｗａｎＺａｎｇＪｉａｙｅ（ＲｅｃｅｉｖｅｄＡｕｇｕｓｔ８，１９９５；ａｃｃｅｐｔｅｄＳｅｐｔｅｍｂｅｒ２，１９９５）Ａｂｓｔｒａｃｔ：Ｅｌｅｖｅｎｓｔａｔｉｏｎｓｗｅｒ... 相似文献
7.
An annual in situ corrosion experiment of carbon steel and low alloy steel is reported in this paper. The results show that the corrosion rate varies with the beginning month of immersion. The corrosion rates of 09CuWSn steel panels immersed at the end of April and May when larger fouling organisms grow heavily are 0.1180 and 0.1342 mm/y respectively, 相似文献
8.
Wu Lianyuan Hu Gangyi Professor Shanghai Jiaotong University Shanghai Engineer Wuhan Ship Development & Design Institute Wuhan 《中国海洋工程》1994,(2)
-This paper adopts approximate formulas for residual stresses caused by cold bending for plates with stress-strain curve form a = K n. A typical distribution of the longitudinal residual stress due to welding is also assumed. The effects of residual stress due to cold bending and welding on plastic buckling of axially compressed cylindrical shells are studied by the finite element method. 相似文献
9.
The Effect of Internal Fluid on the Response of Vortex-Induced Vibration of Marine Risers 总被引：5，自引：1，他引：5
Based on Iwan‘s wake oseillator model developed with the classical van der Pol equalion, the differential equation for the response of the vortex-induced vihration (VIV) of the riser considering the effect of the internal flowing fluid and the external marine environmental condition is derived. The effect of the intermal flowing fluid on the response of VIV of the riser is studied by means of the Finite Element Method. The results show that the effect of the internal fluid velocity on the VIV of the riser is strong when the natural frequency of the riser is close to the vortex shedding frequency. In addition, the increase of the top tension can decrease the sensitivity of the riser to the internal fluid velocity. 相似文献
10.
In this paper a refraction-diffraction model with friction is used to compute wave characteristics in a region near a certain port. Comparing with the results from refraction model, and with the data observed during a typhoon in 1985, it is found that the characteristics from the refraction-diffraction model with friction are reasonable, and that the results are in rather good agreement with observations. Thus it can be concluded that the model is effective for computing coastal wave characteristics over complicated bottom topography. 相似文献
11.
俞慕耕 《海洋学报(英文版)》1984,3(4):596-600
Based ourself mainly on the harmonic constant in the tide table (English-edition), we acquire data from 320 tidal observatories, calculate the different tidal ranges and cotidal hours of the South China Sea, and by the contour line method, draw the M_2, S_2. K_1, O_1 constituent charts, thus better showing the tide distribution in the South China Sea and presenting tide characteristics in the area more accurately. 相似文献
12.
The larvae of Styela canopus show the highest rates of settlement and metamorphosiswhen treated with 40 mM KCl-elevated seawater at 25 ℃ in temperature and 27.0 in salinity. Inducedby 40 mM KCl-elevated seawater, it took Styela canopus larvae approximately 3 h after hatching to de-velop competence to settle and metamorphose. The present experiment shows that Styela canopus larvaeis an ideal model organism for examining the efficiency of antifouling substance. 相似文献
13.
Ｔｈｅａｐｐｌｉｃａｔｉｏｎｏｆｔｈｅｆｒａｃｔａｌｇｅｏｍｅｔｒｙｉｎｔｈｅｓｔｕｄｙｏｆｓｅａ－ｆｌｏｏｒｖｏｌｃａｎｏＴａｏＣｈｕｎｈｕｉ，ＪｉｎＸｉａｎｇｌｏｎｇ，ＬｕＷｅｎｚｈｅｎｇａｎｄＨｕａＺｕｇｅｎ（ＲｅｃｅｉｖｅｄＯｃｔｏｂｅｒ４，... 相似文献
14.
Cai Bingji Lian fiuangshan Lin Yuhui Lin Mao Dai Yanyu Liu Jinghong Chen Ruixiang 《海洋学报(英文版)》1996,15(1):139-144
ＴｈｅｂａｓｉｃｆｅａｔｕｒｅｓｏｆｚｏｏｐｌａｎｋｔｏｎｉｎｔｈｅｗｅｓｔｅｒｎｗａｔｅｒｓｏｆＴａｉｗａｎＳｔｒａｉｔＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｅｓｓａｙｕｓｅｓｔｈｅｄａｔａｆｒｏｍａｃｏｍｐｒｅｈｅｎｓｉｖｅｓｕｒｖｅｙｃａｒｒｉｅｄｏｕ... 相似文献
15.
Ｔｈｅｓｅｃｏｎｄｏｒｄｅｒｓｐｅｃｔｒｕｍｏｆｔｗｏ－ｄｉｍｅｎｓｉｏｎａｌｒａｎｄｏｍｗａｖｅｓ￥ＤｉｎｇＰｉｎｇｘｉｎｇ；ＳｕｎＦｕａｎｄＹｕＺｈｏｕｗｅｎ（ＲｅｃｅｉｖｅｄＪａｎｕａｒｙ１５，１９９３；ａｃｃｅｐｔｅｄＭａｙ３１，１９９３）Ａ... 相似文献
16.
The application of Hartley transform to ocean engineering 总被引：1，自引：0，他引：1
The Hartley transform is a real integral transform based on harmonic functions and hassome characteristics similar to the Fourier transform. Most applications in ocean engineering requiring the Fourier transform can also be performed by the Hartley transform. The fast Hartley transform is twice faster and more convenient to handle than the corresponding fast Fourier transform, so it is a real valued alternative to the complex Fourier transform in many applications. The use of the Hartley transform in ocean engineering is presented in detail in this paper, including wave spectral analysis, separation of waves, cross-correlation in PIV technique and expression of equation in the Hartley domain. The examples in the paper show deeply the advantage and efficiency of the Hartley transform over the Fourier transform. 相似文献
17.
The equilibrium range of wind wave frequency spectrum 总被引：2，自引：0，他引：2
Wen Shengchang 《海洋学报(英文版)》1990,9(1):1-11
-Theoretical form of equilibrium range is given on the basis of the wind wave frequency spectra proposed by Wenel al. (1988a,b,c, 1989a,b). The effects of peakness factor and water depth are discussed. In the case of deep water the e-quilibrium range is reduced to the form first proposed by Toba (1973) and the coefficient of the formula is shown to be the function of nondimensional fetch or peak frequency. Results of the present paper have been verified through field data. 相似文献
18.
Little was studied on oceanography and ecology on the eastern sea waters off the Philippines,Bashi Channel and Balintang Channel in the past.In this paper are presented the results of an ecological study on Ostracoda in the above-stated sea waters in which the samples of Ostracoda were collected in the North Pacific nets from 90 stations by Surveyer I(May-July,1968) in accordance with CSK Program.The study took into consideration the in situ temperature-salinity data.In addition,a comparative dissection has been carried out on the samples of Ostracoda obtained in the normal nettings trawled from bottom to surface during an annual survey(see May,1984-May,1985)in the west from the central line of the Taiwan Strait(see Fig.1) by the Third Institute of Oceanography,State Oceanic Administration.The interaction of different current systems,especially the Kuroshio on Ostracoda,is described from the distribution of different ecological attributions. 相似文献
19.
A comprehensive numerical study on the three-dimensional structure of a turbulent jet in crossflow is performed. The jet-to-crossflow velocity ratio (R) varies in the range of 2 - 16; both vertical jets and inclined jets without excess streamwise momentum are considered. The numerical results of the Standard two-equation k-ε model show that the turbulent structure can be broadly categorised according to the jet-to-crossflow velocity ratio. For strong to moderate jet discharges, i.e. R> 4, the jet is characterized by a longitudinal transition through a bent-over phase during which the jet becomes almost parallel with the main freestream, to a sectional vortex-pair flow with double concentration maxima; the computed flow details and scalar mixing characteristics can be described by self-similar relations beyond a dimensionless distance of around 20-60. The similarity coefficients are only weakly dependent on R. The cross-section scalar field is kidney-shaped and bifurcated, vvith distinct double concentr 相似文献
20.
《Marine Policy》2014
Fisheries managers have long relied on non-native fish to improve, sustain, or create recreational fishing opportunities, often without adequate consideration of potentially negative ecological consequences. There is growing advocacy for using the precautionary approach to avoid potentially serious or irreversible harm to the environment in the face of scientific uncertainty. This paper uses striped bass (Morone saxitilis) in Texas to examine possible effects that might have resulted had the precautionary approach been applied before stocking began in the 1960s when the species was considered non-native to Texas. The current range of reproducing striped bass populations extends from the North Atlantic Ocean to the U.S.–Mexico border. However, the western extent of the species current range beyond Louisiana is probably the result of stocking begun in 1965 that continues today. The historic range is yet unresolved. The best available information suggests that striped bass are not native to Texas, fish stocking has resulted in beneficial economic impacts, and any negative effects (i.e., harm) are currently unknown. It seems unlikely that application of the precautionary approach would have led to different outcomes in Texas than currently exist. However, the complete striped bass story has yet to be written. 相似文献