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821.
In the Xiangshan Bay at the east coast of China, coastal marine pollution is conspicuous and severe in recent years. As transport of the pollutants is closely related to the coastal circulation, there is a great practical significance to investigate the circulation in this area. In this work, the surface pattern and vertical profiles of Lagrangian residual velocity (LRV) were studied based on field observation data from the inner Xiangshan Bay. By tracking GPS-GPRS drifters’ trajectories, the surface LRV pattern is going out in the central deep trough and flowing inwards near the shoreside. Combined with data from two mooring stations, vertical profiles of LRV is flowing out at surface and flowing in at the bottom, consistent with the gravitational circulation induced by baroclinic effects at the estuary. However, according to the diagnostic analysis, the main mechanism driving the residual current is barotropic rather than baroclinic. The LRV equation is controlled by the tidally-averaged barotropic pressure gradient force, tidal body force and tidally-averaged turbulent stress, while the tidally-averaged baroclinic pressure gradient force is one order of magnitude less than other forces. Additionally, the tidally mean eddy viscosity coefficient which is used in the expression of tidally-averaged turbulent stress might be not adequate and requires further studies. 相似文献
822.
It is apparent that there is a difference between mud coasts and sand coasts in such aspects as sediment components, hydrodynamics
of nearshore waters, and the formative process in configuration, and profile. The intensity distribution of waves affecting
the mud flats in Lianyungang, and the conditions determining tidal water levels, are discussed in this paper. A mathematical
model which describes the erosion process of mud flats has been derived on the basis of the results of tests for the mud process
in seawater. The model is satisfactory for the actual mud flat profile change in Lianyungang with artificial mud discharges. 相似文献
823.
于品清 《大地测量与地球动力学》1994,(1)
对《地球演化》一书中的某些重要论点提出质疑。认为运用角动量守恒原理应考虑其适用条件,这一定律不适用于地球核幔体;核幔体与岩石圈之间能否作相对运动尚有待证实;地壳运动的总趋势是逐渐减弱而不是逐步增强。 相似文献
824.
825.
After nearly 20 years of construction,we have successfully solved a series of hydrologic sedimentaryand environment problems encountered during the construction of the big deep water harbour inLianyungang which can now accommodate ships of 50000 tonnage.With the economic development,the channel of 50000 tonnage will be built soon, and of 100000 tonnage is under planning. Theconstruction of the international container shipping hub at the harbour is being accelerated in anticipationof the opening of the second Eurasian land bridge.The future development of the harbour will givegreat impetus to the local economy of Lianyungang City and make it an international city. 相似文献
826.
APPLICATION OF CLAYS TO REMOVAL OF RED TIDE ORGANISMS Ⅰ.COAGULATION OF RED TIDE ORGANISMS WITH CLAYS 总被引:26,自引:1,他引:26
Coagulation of red tide organism cells with clays is discussed in theory and the effects of some fac-tors on it are studied.A quantitative model is presented which describes how the coagulation varies withpH in solution.According to the model,within the pH-range between pH_(zpc_a)and pH_(zpc_b),V_R is negativeand the coagulation is strong and strongest at pH=(pH_(zpc_a)+pH_(zpc_b))/2.It is also demonstrated that whenthe diameter of clay particles is close to that of cells,the collision probability is low,resulting in weakercoagulation.The model results have been corroborated by experiments and so are scientific and theoreticalbases for application. 相似文献
827.
Study on the coagulation of four species of red tide organisms(Nitzschia pungens,Skeletonema costatum,Prorocentrum minimum and Noctiluca scintillans)with montmorillonite,and the effect ofmontmorillonite pretreatment on the coagulation shows that the capability for montmorillonite to coagu-late with them is in the order:N.pungens>S.costatum>P.minimum>N.scintillans.Thecoagulation is discussed from the aspects of the structure,shape,size,movement,habit,etc.of differ-ent species and the results are explained theoretically.The experimental results also indicate that the treat-ment of montmorillonite with acid can enhance its coagulating capability.This is due to the fact that Al(OH_2)_6~(+3),exchanged from the clay lattice by hydrogen ion H~+,forms hydroxy-aluminum polymers on thesurface of the montmorillonite.The hydroxy-aluminum polymers positively charge and increase the positivecharacteristic of the clay surface,and also serves as a bridge between adjacent surfaces of particles.Thesetwo functions enhance 相似文献
828.
829.
830.
Shen Wang Wei-Wei Zhu Di Li Zhi-Chen Pan Pei Wang James M.Cordes Shami Chatterjee Ju-Mei Yao Lei Qian You-Ling Yue Lei Zhang Ru-Shuang Zhao Shuang-Qiang Wang Jia-Rui Niu Mao Yuan Chen-Chen Miao Xiao-Yao Xie Zhi-Jie Liu Xu-Hong Yu Shan-Ping You Ling-Qi Meng FAST Collaboration 《天文和天体物理学研究(英文版)》2021,(10):97-107
We present Arecibo 327 MHz confirmation and follow-up studies of seven new pulsars discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST).These pulsars are discovered in a pilot program of the Commensal Radio Astronomy FAST Survey (CRAFTS) with the ultra-widebandwidth commissioning receiver.Five of them are normal pulsars and two are extreme nulling slow pulsars.PSR J2111+2132’s dispersion measure (DM:78.5 pc cm~(-3)) is above the upper limits of the two Galactic free electron density models,NE2001 and YMW16,and PSR J2057+2133’s position is out of the Scutum-Crux Arm,making them uniquely useful for improving the Galactic free electron density model in their directions.We present a detailed single pulse analysis for the slow nulling pulsars.We show evidence that PSR J2323+1214’s main pulse component follows a non-Poisson distribution and marginal evidence for a sub-pulse-drift or recurrent period of 32.3±0.4 rotations from PSR J0539+0013.We discuss the implication of our finding to the pulsar radiation mechanism. 相似文献