Calculation of circulation in the South China Sea during summer of 2000 by the modified inverse method

On the basis of hydrographic data obtained in August 2000 cruise, the circulation in the South China Sea (SCS) is computed by the modified inverse method in combination with SSH data from TOPEX/ERS-2 analysis. For study of the dynamical mechanism, which causes the pattern of summer circulation in the SCS, the diagnostic model (Yuan et al. 1982. Acta Oceanologica Sinica,4(1):1-11; Yuan and Su. 1992. Numerical Computation of Physical Oceanography.474-542) is used to simulate numerically the summer circulation in the SCS. The following results have been obtained. (1) The central and southwestern SCSs are dominated mainly by anticy-clonic circulation systems. They are mainly as follows. 1) There is strong anticyclonic eddy southeast of Vietnam (W1). Its horizontal scale is about 300 km, and it extends vertically from the surface to the about 1 000 m level. 2) There are a warm eddy W2 southeast of Zhongsha Islands and the anticyclonic circulation system W3 west off the Luzon Island. 3) There is a stronger cyclonic eddy C1 between the anticyclonic eddies W1 and W2.4) A strong northward coastal jet is present near the coast of Vietnam, and separates from the coast of Vietnam at about 12° N to the northeast.(2)The northern SCS is dominated mainly by a cyclonic circulation system. There is a cyclonic circulation system near and north of Section N2. (3) The southeastern SCS is dominated mainly by the cyclonic circulation system. (4) Comparing the results of circulation in the SCS during the summer of 2000 with those during the summer of 1998, it is found that they agree qualitatively, but there is the some difference between them in quantity.This shows that the circulation in the SCS has obviously seasonal feature. (5) The dynamical mechanism which products the basic pattern of summer circulation is because the following two reasons: 1) the joint effect of the baroclinity and relief (JEBAR) is essential dynamical cause; and 2) it is next important dynamical cause that the interaction between the wind stress and bottom topography under the southerly monsoon. (6) Comparing the hydrographic structure and distribution of stream functions with the SSH data from TOPEX/ERS-2 analysis in the SCS during August of 2000, they agree qualitatively.

Analysis of the Lost Circulation Problem

The well-known“lost circulation”problem refers to the uncontrolled flow of whole mud into a formation.In order to address the problem related to the paucity of available data,in the present study,a model is introduced for the lost-circulation risk sample profile of a drilled well.The model is built taking into account effective data(the Block L).Then,using a three-dimensional geological modeling software,relying on the variation function and sequential Gaussian simulation method,a three-dimensional block lost-circulation risk model is introduced able to provide relevant information for regional analyses.

Evaluation of gases'molecular abundance ratio by fiber-optic laser-induced breakdown spectroscopy with a metal-assisted method

A metal-assisted method is proposed for the evaluation of gases’molecular abundance ratio in fiber-optic laser-induced breakdown spectroscopy(FO-LIBS).This method can reduce the laser ablation energy and make gas composition identification possible.The principle comes from the collision between the detected gases and the plasma produced by the laser ablation of the metal substrate.The interparticle collision in the plasma plume leads to gas molecules dissociating and sparking,which can be used to determine the gas composition.The quantitative relationship between spectral line intensity and molecular abundance ratio was developed over a large molecular abundance ratio range.The influence of laser ablation energy and substrate material on gas quantitative calibration measurement is also analyzed.The proposed metal-assisted method makes the measurement of gases’molecular abundance ratios possible with an FO-LIBS system.

A Method for Diagnosing the Secondary Circulation with Saturated Moist Entropy Structure in a Mature Tropical Cyclone

Under the adiabatic, axisymmetric and steady assumption, a relationship between the saturated moist entropy structure and the secondary circulation in a tropical cyclone(TC) is derived from the continuity equation. It is found that the isentropic surfaces coincide with the streamlines, and the streamfunction can be expressed with saturated moist entropy. The secondary circulation and the saturated moist entropy structure depend on each other. Thus, a method for diagnosing the secondary circulation with the structure of saturated moist entropy is proposed. The method is verified with a simulated intense idealized TC with a highly axisymmetric structure. The diagnosed secondary circulation reproduces well the moist inflow in the boundary layer and the moist updraft in the eyewall. This method facilitates secondary circulation diagnosis in theoretical or mature TCs that satisfy the adiabatic, axisymmetric and steady approximations.

Extraction Process of Green Pigment from Leaves of Arctium lappa L. by Ultrasound Assisted Method and Its Stability Study

[Objectives] The research aimed to extract green pigment from leaves of Arctium lappa L. and inspect its stability. [Methods] Ultrasound assisted method was used. [Results] Water bath temperature had little impact on green pigment, and Al^(3+), Cu^(2+), Mg^(2+) and Zn^(2+) in metal ions greatly affected green pigment, while Fe^(3+) had very little impact on the stability of green pigment. pH did not basically affect green pigment of A. lappa L. [Conclusions] The extraction rate and stability of green pigment from leaves of A. lappa L. were higher, and it was one of materials suitable for extracting green pigment.

FINITE ELEMENT ANALYSIS FOR THE UNSTEADY NEARSHORE CIRCULATION DUE TO WAVE－CURRENT INTERACTION（II）──TWO－STEP EXPLICIT FINITE ELEMENT METHOD

In this paper, the two-step explicit finite element analysis for the numerical modelof the unsteady nearshore circulation proposed in Ref [ 1]and its realization of Fortranprogram are presented.A circulation has been clearly shown in the calculated wave-current velocity field,and it is in good agreement with observations

A New Behavior-Assisted Semantic Recognition Method for Smart Home

In the recent Smart Home(SH)research work,intelligent service recommendation technique based on behavior recognition,it has been extensively preferred by researchers.However,most current research uses the Semantic recognition to construct the user’s basic behavior model.This method is usually restricted by environmental factors,the way these models are built makes it impossible for them to dynamically match the services that might be provided in the user environment.To solve this problem,this paper proposes a Semantic behavior assistance(Semantic behavior assistance,SBA).By joining the semantic model on the intelligent gateway,building an SA model,in this way,a logical Internet networks for smart home is established.At the same time,a behavior assistant method based on SBA model is proposed,among them,the user environment-related entities,sensors,devices,and user-related knowledge models exist in the logical interconnection network of the SH system through the semantic model.In this paper,the data simulation experiment is carried out on the method.The experimental results show that the SBA model is better than the knowledge-based pre-defined model.

Photoluminescence and Structural Properties of ZnO Nanorods Growth by Assisted-Hydrothermal Method

Semiconducting zinc oxide (ZnO) nanorods were obtained in bulk quantity by an hexamethylenetetramine (HMTA)-assisted hydrothermal method at low temperature (90°C) with methenamine ((CH3)6N4 as surfactant and catalyst and zinc nitrate Zn(NO3)2·6H2O as Zn source. The structure and phase of ZnO nanorods were studied using x-ray diffraction (XRD) and high resolution transmission electron microscopy techniques (HRTEM). The morphology of the nanostructures was studied by scanning electron microscope (SEM) method. The photoluminescence (PL) properties were investigated founding two emission bands under UV excitation.

Advantages and Main Problems of Multimedia-Assisted Teaching Method in College English Teaching

As the information age commenced in the late 20th century.English is using rapidly as a universal language all over the world.However,Chinese English teacher faces many troubles in original teaching method.Multimedia-aided teaching method,based on multimedia and network technologies,comes into being.With its rich content and vivid forms,teachers can change the boring learning condition and atmosphere by means of pictures,sounds,images and so on.The advantages and disadvantages of it are analyzed in this paper.And then concluded that only by use it rationally,can the advantages outweigh the disadvantages.

孔助光纤(Hole-assisted lightguide fiber)色散和双折射特性的研究

通过改变包层中空气孔的参数,孔助光纤(holeassistedlightguidefiber)具有比传统光纤更容易调节的色散和双折射特性.采用有限差分法研究了包层空气孔数目、大小和位置等参数对孔助光纤色散和双折射特性的影响.数值计算结果表明增加空气孔的数目和尺寸以及减小空气孔到纤芯的距离都能够使得零色散向短波长方向移动,减小空气孔与纤芯的距离有助于获得更大的双折射.

The Application of the Computer Assisted Instruction(CAI) in English Teaching in High Schools

On the basis of the brief introduction to CAI and some its distinctive features,this paper minutely arrives at the principles of the application of CAI in high schools and analyses the implication brought about by its application.This research is to provide a further help for English teachers in high shools,so that the students can effectively improve the level of English language learning.

HYBRID FINITE ANALYTIC SOLUTIONS OF SHALLOW WATER CIRCULATION

The hybrid finite analytic(HFA) method is a kind of numerical scheme in rectangular element. In order to simulate the shallow circulation in irregular bathymetry by HFA scheme, the model in sigma coordinate system was obtained. The model has been tested against three cases: 1) Wind induced circulation; 2) Density driven circulation and 3) Seiche oscillation. The results obtained in the present study compare well with those obtained from the corresponding analytical solutions under idealized for the above three cases. The hybrid finite analytic method and the circulation model in sigma coordinate system can be used calculate the flow and water quality in estuaries and coastal waters.

Advances in Studying Oceanic Circulation from Hydrographic Data with Applications in the South China Sea

Methods for studying oceanic circulation from hydrographic data are reviewed in the context of their applications in the South China Sea. These methods can be classified into three types according to their different dynamics as follows: (1) descriptive methods, (2) diagnostic methods without surface and bottom forcing, and (3) diagnostic methods with the above boundary forcing. The paper discusses the progress made in the above methods together with the advancement of study in the South China Sea circulation.

A two-time-level split-explicit ocean circulation model (MASNUM) and its validation

A two-time-level, three-dimensional numerical ocean circulation model（named MASNUM） was established with a two-level, single-step Eulerian forward-backward time-differencing scheme. A mathematical model of large-scale oceanic motions was based on the terrain-following coordinated, Boussinesq, Reynolds-averaged primitive equations of ocean dynamics. A simple but very practical Eulerian forward-backward method was adopted to replace the most preferred leapfrog scheme as the time-differencing method for both barotropic and baroclinic modes. The forward-backward method is of second-order of accuracy, computationally efficient by requiring only one function evaluation per time step, and free of the computational mode inherent in the three-level schemes. This method is superior to the leapfrog scheme in that the maximum time step of stability is twice as large as that of the leapfrog scheme in staggered meshes thus the computational efficiency could be doubled. A spatial smoothing method was introduced to control the nonlinear instability in the numerical integration. An ideal numerical experiment simulating the propagation of the equatorial Rossby soliton was performed to test the amplitude and phase error of this new model. The performance of this circulation model was further verified with a regional（northwest Pacific） and a quasi-global（global ocean simulation with the Arctic Ocean excluded） simulation experiments. These two numerical experiments show fairly good agreement with the observations. The maximum time step of stability in these two experiments were also investigated and compared between this model and that model which adopts the leapfrog scheme.

Fluid structure interaction for circulation valve of hydraulic shock absorber

Based on the working principle and the damping characteristic of hydraulic shock absorber,a fluid structure interaction method was presented,which was used to analyze the microcosmic and high-frequency processing mechanism of fluid structure interaction between circulation valve and liquid of hydraulic shock absorber.The fluid mesh distortion was controlled by the CEL language,and the fluid structure interaction mathematical model was established.The finite element model was established by ANSYS CFX software and was analyzed by dynamic mesh technique.The local sensitive computational area was meshed by prismatic grid,which could reduce the negative volume problem during the simulation.The circulation valve and liquid of hydraulic shock absorber were simulated and analyzed under the condition of sinusoidal inlet velocity loads.Flow characteristic and dynamics characteristic were obtained.The pressure distribution and the displacement of circulation value were obtained,and the acceleration curve of circulation valve was simulated and analyzed.The conformity of the final simulation results with the experimental datum indicates that this method is accurate and reliable to analyze the dynamics characteristic between circulation valve and liquid of hydraulic shock absorber,which can provide a theoretical foundation for optimizing hydraulic shock absorber in the future.

Preparation of Hierarchically Trimodal-Porous ZSM-5 Composites through Steam-assisted Conversion of Macroporous Aluminosilica Gel with Two Different Quaternary Ammonium Hydroxides

This article presents a detailed structural study of a new spherical Mg Cl2-supported Ti Cl4 Ziegler-Natta catalyst for isotactic propylene polymerization, and researches on the relationship between catalyst structure and polymer properties. The spherical support with the chemical composition of CH3CH2 OMg OCH(CH2Cl)2 has been synthesized from a new dispersion system and is used as the supporting material to prepare Ziegler-Natta catalyst. The XRD analysis indicates that the catalyst is fully activated with δ-Mg Cl2 in the active catalyst. The far-IR spectrometric results confirm again the presence of δ-Mg Cl2 in the active catalyst. Textural property of the active catalyst exhibits high surface area coupled with high porosity. The high activity in propylene polymerization is mainly ascribed to the full activation and the porous structure of the catalyst. Scanning electron microscopy/energy dispersive spectrometer mapping results indicate a uniform titanium distribution throughout the catalyst particles. Particle size analysis shows that the catalyst has a narrow particle size distribution. The perfect spherical shape, uniform titanium distribution and narrow particle size distribution of the catalyst confirm the advantage of polymer particles production with less fines. The solid state 13 C NMR and mid-IR spectroscopic analyses indicate that there exists strong complexation between diisobutyl phthalate and Mg Cl2, which leads to the high isotacticity of polypropylene.

Relation between viscoplastic flow, periodic feature and Joule heat validity for electrically assisted friction stir welding

Electrically assisted friction stir welding is a promising way to improve liquidity of viscoplastic metal. However, this local heat source only can take into effect in a certain contact interface status. Semi-analytical model and FEM are adopted to analyze materials flow in electrically assisted FSW. Semi-analysis results show that Joule heating is validity with rotation speed 1 400 r/min and travel speed 400 mm/min. The maximum flow velocity is 0.033 m/s when travel speed is 400 mm/min, and it increases to 0.043 m/s with current assistant. Visco-plasticizing efficiency is a key factor to decide whether Joule heat is significant, and viscoplastic flow can periodically make circuit short. Periodic torque, axial force and onion rings surface show dynamic flow process, which can be used to illustrate the dynamic contact resistance feature and correct the calculation equation of Joule heat. This paper is aim to point out the potential relation between viscoplastic flow, periodic torque and Joule heating validity.

Electric-Field-Assisted Growth of Ga-Doped ZnO Nanorods Arrays for Dye-Sensitized Solar Cells

A photoanode with Ga-doped ZnO nanorods has been prepared on F-doped SnO2 (FTO) coated glass substrate and its application in dye-sensitized solar cells (DSSCs) has been investigated. Ga-doped ZnO nanorods have been synthesized by an electric-field-assisted wet chemical approach at 80?C. Under a direct current electric field, the nanorods predominantly grow on cathodes. The results of the X-ray photoelectron spectroscopy and photoluminescence verify that Ga dopant is successfully incorporated into the ZnO wurtzite lattice structure. Finally, employing Ga-doped ZnO nanorods with the length of ~5 μm as the photoanode of DSSCs, an overall energy conversion efficiency of 2.56% is achieved. The dramatically improved performance of Ga-doped ZnO based DSSCs compared with that of pure ZnO is due to the higher electron conductivity.

Simulating the Upper Ocean Circulation on the Belize Shelf: An Application of a Triply Nested-Grid Ocean Circulation Model

We present a three-level nested-grid ocean circulation modeling system for the Belize shelf of the western Caribbean Sea. The nested-grid system has three subcomponents: a coarse-resolution outer model of the western Caribbean Sea; an intermediate-resolution middle model of the southern Meso-American Barrier Reef System; and a fine-resolution inner model of the Belize shelf. The two-way nesting technique based on the semi-prognostic method is used to exchange information between the three subcomponents. We discuss two applications of the nested-grid system in this study. In the first application we simulate the seasonal mean circulation in the region, with the nested system forced by monthly mean surface fluxes and boundary forcing. The model results reproduce the general circulation features on the western Caribbean Sea and meso-scale circulation features on the Belize shelf. In the second application, we simulate the storm-induced circulation during Hurricane Mitch in 1998, with the nested-grid system forced by the combination of monthly mean forcing and idealized wind stress associated with the storm. The model results demonstrate that the storm-induced currents transport a large amount of estuarinc waters from coastal regions of Honduras and Guatemala to offshore reef atolls.