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A Preliminary Study of "I" and "We" in Teachers' Talk in a Military Academy
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作者 ZHANG Jing GAO Li ZHENG Zhen 《Sino-US English Teaching》 2014年第10期783-790,共8页
This paper is a qualitative study of how and why English teachers in military academy use personal pronoun I and inclusive and exclusive we. Through analysis of teachers' use of/and we in the taped videos, some diffe... This paper is a qualitative study of how and why English teachers in military academy use personal pronoun I and inclusive and exclusive we. Through analysis of teachers' use of/and we in the taped videos, some differences in the frequency use of inclusive we and exclusive we have been found and a number of effects the inclusive pronouns create are illustrated. Specifically, the paper reveals how 1 and we help teachers create a sense of authority in the classroom, showing how teachers are aligning with the students. Inclusive pronouns can act as a positive politeness device by imparting knowledge, organizing the contents, and highlighting the important and difficult points. It is noticed that there is fuzziness between inclusive personal pronoun and exclusive pronoun, which can be manipulated by the teacher to create authority or closeness with students. 展开更多
关键词 classroom discourse inclusive and exclusive personal pronoun pragmatic function FUZZINESS
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Biases of the Arctic climate in a regional ocean-sea iceatmosphere coupled model: an annual validation 被引量:4
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作者 LIU Xiying 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第9期56-67,共12页
The Coupling of three model components, WRF/PCE (polar climate extension version of weather research and forecasting model (WRF)), ROMS (regional ocean modeling system), and CICE (community ice code), has been... The Coupling of three model components, WRF/PCE (polar climate extension version of weather research and forecasting model (WRF)), ROMS (regional ocean modeling system), and CICE (community ice code), has been implemented, and the regional atmosphere-ocean-sea ice coupled model named WRF/PCE- ROMS-CICE has been validated against ERA-interim reanalysis data sets for 1989. To better understand the reasons that generate model biases, the WRF/PCE-ROMS-CICE results were compared with those of its components, the WRF/PCE and the ROMS-CICE. There are cold biases in surface air temperature (SAT) over the Arctic Ocean, which contribute to the sea ice concentration (SIC) and sea surface temperature (SST) biases in the results of the WRF/PCE-ROMS-CICE. The cold SAT biases also appear in results of the atmo- spheric component with a mild temperature in winter and similar temperature in summer. Compared to results from the WRF/PCE, due to influences of different distributions of the SIC and the SST and inclusion of interactions of air-sea-sea ice in the WRF/PCE-ROMS-CICE, the simulated SAT has new features. These influences also lead to apparent differences at higher levels of the atmosphere, which can be thought as responses to biases in the SST and sea ice extent. There are similar atmospheric responses in feature of distribution to sea ice biases at 700 and 500 hPa, and the strength of responses weakens when the pressure decreases in January. The atmospheric responses in July reach up to 200 hPa. There are surplus sea ice ex- tents in the Greenland Sea, the Barents Sea, the Davis Strait and the Chukchi Sea in winter and in the Beau- fort Sea, the Chukchi Sea, the East Siberian Sea and the Laptev Sea in summer in the ROMS-CICE. These differences in the SIC distribution can all be explained by those in the SST distributions. These features in the simulated SST and SIC from ROMS-CICE also appear in the WRF/PCE-ROMS-CICE. It is shown that the performance of the WRF/PCE-ROMS-CICE is determined to a large extent by its components, the WRF/PCE and the ROMS-CICE. 展开更多
关键词 Arctic climate coupled model numerical simulation
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WindSat satellite comparisons with nearshore buoy wind data near the U.S. west and east coasts 被引量:2
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作者 ZHANG Lei SHI Hanqing +1 位作者 YU Hong YI Xin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第7期50-58,共9页
Nearshore wind speeds retrieved by WindSat are validated by a comparison with the moored buoy observations near the U.S. west and east coasts. A 30 min and 25 km collection window is used for the WindSat wind data and... Nearshore wind speeds retrieved by WindSat are validated by a comparison with the moored buoy observations near the U.S. west and east coasts. A 30 min and 25 km collection window is used for the WindSat wind data and buoy measurements from ]anuary 2004 to December 2014. Comparisons show that the overall root-mean-square error is better than 1.44 m/s near the U.S. coasts, and the result for the east coast is better than that for the west coast. The retrieval accuracy of the descending portions is slightly better than that of the ascending portions. Most buoy-to-buoy variations are not significantly correlated with the coastal topography, the longitude and the distance from the shore or satellite-buoy separation distance. In addition, comparisons between a polarimetric microwave radiometer and a microwave scatterometer are accomplished with the nearshore buoy observations from 2007 to 2008. The WindSat-derived winds tend to be lower than the buoy observations near the U.S. coasts. In contrast, the QuikSCAT-derived winds tend to be higher than the buoy observations. Overall, the retrieval accuracy of WindSat is slightly better than that of QuikSCAT, and these satellite-derived winds are sufficiently accurate for scientific studies. 展开更多
关键词 WindSat polarimetric microwave radiometer nearshore wind validation
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Trends in Significant Wave Height and Surface Wind Speed in the China Seas Between 1988 and 2011 被引量:1
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作者 ZHENG Chongwei ZHANG Ren +2 位作者 SHI Weilai LI Xin CHEN Xuan 《Journal of Ocean University of China》 SCIE CAS CSCD 2017年第5期717-726,共10页
Wind and waves are key components of the climate system as they drive air-sea interactions and influence weather systems and atmospheric circulation. In marine environments, understanding surface wind and wave fields ... Wind and waves are key components of the climate system as they drive air-sea interactions and influence weather systems and atmospheric circulation. In marine environments, understanding surface wind and wave fields and their evolution over time is important for conducting safe and efficient human activities, such as navigation and engineering. This study considers long-term trends in the sea surface wind speed(WS) and significant wave height(SWH) in the China Seas over the period 1988–2011 using the Cross-Calibrated Multi-Platform(CCMP) ocean surface wind product and a 24-year hindcast wave dataset obtained from the WAVEWATCH-III(WW3) wave model forced with CCMP winds. The long-term trends in WS and SWH in the China Seas are analyzed over the past 24 years to provide a reference point from which to assess future climate change and offshore wind and wave energy resource development in the region. Results demonstrate that over the period 1988–2011 in the China Seas: 1) WS and SWH showed a significant increasing trend of 3.38 cm s^(-1)yr^(-1) and 1.52 cm yr^(-1), respectively; 2) there were notable regional differences in the long-term trends of WS and SWH; 3) areas with strong increasing trends were located mainly in the middle of the Tsushima Strait, the northern and southern areas of the Taiwan Strait, and in nearshore regions of the northern South China Sea; and 4) the long-term trend in WS was closely associated with El Ni?o and a significant increase in the occurrence of gale force winds in the region. 展开更多
关键词 ocean winds offshore Taiwan notable weather navigation environments forced conducting
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Crack tip higher order stress fields for functionally graded materials with generalized form of gradation
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作者 燕秀发 钱七虎 +2 位作者 卢红标 王玮 孙翱 《Journal of Central South University》 SCIE EI CAS 2010年第6期1177-1184,共8页
A generalized form of material gradation applicable to a more broad range of functionally graded materials(FGMs) was presented.With the material model,analytical expressions of crack tip higher order stress fields in ... A generalized form of material gradation applicable to a more broad range of functionally graded materials(FGMs) was presented.With the material model,analytical expressions of crack tip higher order stress fields in a series form for opening mode and shear mode cracks under quasi-static loading were developed through the approach of asymptotic analysis.Then,a numerical experiment was conducted to verify the accuracy of the developed expressions for representing crack tip stress fields and their validity in full field data analysis by using them to extract the stress intensity factors from the results of a finite element analysis by local collocation and then comparing the estimations with the existing solution.The expressions show that nonhomogeneity parameters are embedded in the angular functions associated with higher terms in a recursive manner and at least the first three terms in the expansions must be considered to explicitly account for material nonhomogeneity effects on crack tip stress fields in the case of FGMs.The numerical experiment further confirms that the addition of the nonhomogeneity specific terms in the expressions not only improves estimates of stress intensity factor,but also gives consistent estimates as the distance away from the crack tip increases.Hence,the analytical expressions are suitable for the representation of crack tip stress fields and the analysis of full field data. 展开更多
关键词 functionally graded materials crack tip nonhomogeneity asymptotic analysis higher order stress field
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Derivation of the thermal characteristics of mesoscale eddies
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作者 CHEN Xuan PAN Jing +2 位作者 ZHENG Chongwei ZHANG Xi HE Ming 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第3期8-13,共6页
This study aims at explaining the relationship between thermodynamic characteristics and direction of rotation of mesoscale eddies(MEs). The geometric characteristics of the MEs are under the following assumptions:... This study aims at explaining the relationship between thermodynamic characteristics and direction of rotation of mesoscale eddies(MEs). The geometric characteristics of the MEs are under the following assumptions: the structure of the MEs is symmetrical, and changes of oceanic physical variables are close to linear features in the radial direction in the ME regions. Based on these assumptions, by using primitive equations without friction under a cylindrical coordinate system, the thermodynamic characteristics of the MEs are derived, showing that the conventional relationship of warm anticyclonic eddies with high sea surface height(SSH) and cold cyclonic eddies with low SSH is not consistent with the SSH and sea surface temperature(SST) observations of eddies. The results show that the symmetrical form is an ideal approximation for the geometric characteristics of MEs. In consideration of the above assumptions, there are advantages for derivation of the characteristics of the MEs under a cylindrical coordinate. 展开更多
关键词 mesoscale eddies thermodynamic characteristics symmetry
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Multi-group ant colony algorithm based on simulated annealing method 被引量:2
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作者 朱经纬 芮挺 +1 位作者 廖明 张金林 《Journal of Shanghai University(English Edition)》 CAS 2010年第6期464-468,共5页
To overcome the default of single search tendency, the ants in the colony are divided into several sub-groups. The ants in different subgroups have different trail information and expectation coefficients. The simulat... To overcome the default of single search tendency, the ants in the colony are divided into several sub-groups. The ants in different subgroups have different trail information and expectation coefficients. The simulated annealing method is introduced to the algorithm. Through setting the temperature changing with the iterations, after each turn of tours, the solution set obtained by the ants is taken as the candidate set. The update set is obtained by adding the solutions in the candidate set to the previous update set with the probability determined by the temperature. The solutions in the candidate set are used to update the trail information. In each turn of updating, the current best solution is also used to enhance the trail information on the current best route. The trail information is reset when the algorithm is in stagnation state. The computer experiments demonstrate that the proposed algorithm has higher stability and convergence speed. 展开更多
关键词 ant colony algorithm simulated annealing method MULTI-GROUP candidate set update set
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Spurious Dianeutral Mixing in a Global Ocean Model Using Spherical Centroidal Voronoi Tessellations
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作者 ZHAO Shimei LIU Yudi 《Journal of Ocean University of China》 SCIE CAS 2016年第6期923-935,共13页
In order to quantitatively evaluate the spurious dianeutral mixing in a global ocean model MPAS-Ocean (Model for Prediction Across Scales) using a spherical centroidal voronoi tessellations developed jointly by the ... In order to quantitatively evaluate the spurious dianeutral mixing in a global ocean model MPAS-Ocean (Model for Prediction Across Scales) using a spherical centroidal voronoi tessellations developed jointly by the National Center for Atmospheric Research and the Los Alamos National Laboratory in the United States, we choose z* vertical coordinate system in MPAS-Ocean, in which all physical mixing processes, such as convection adjustment and explicit diffusion parameter schemes, are omitted, using a linear equation of state. By calculating the Reference Potential Energy (RPE), front revolution position, time rate of RPE change, probability density function distribution and dimensionless parameter 2", from the perspectives of resolution, viscosity, Horizontal Grid Reynolds Number (HGRN), Rea, and momentum transmission scheme, using two ideal cases, overflow and baroclinic eddy channel, we qualitatively analyze the simulation results by comparison with the three non-isopycnal models in Ilicak et al. (2012), i.e., MITocM, MOM, and ROMS. The results show that the spurious dianeutral mixing in the MPAS-Ocean increases over time. The spurious dianeutral transport is proportional to the HGRN directly and is reduced by increasing the lateral viscosity or using a finer resolution to control HGRN. When the HGRN is less than 10, spurious transport is reduced significantly. When using the proper viscosity closure, MPAS-Ocean performs better than MIT6c and MOM, closely to ROMS, in the 2D case without rotation, and much better than the above-mentioned three ocean models under the condition of 3D space with rotation due to the cell area difference between the hexa- gon cell and the quadrilateral cell with the same resolution. Both the Zalesak (1979) flux corrected transport scheme and Leith closure in MPAS-Ocean play an excellent role in reducing spurious dianeutral mixing. The performance of Leith scheme is preferable to the condition of three-dimensional baroclinic eddy. 展开更多
关键词 MPAS-Ocean spurious dianeutral mixing Reference Potential Energy (RPE) Leith scheme Horizontal Grid Rey-nolds Number (HGRN)
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Entanglement Teleportation via a Two-Qubit System with Anisotropic Couplings under a Different Nonuniform Magnetic Field 被引量:3
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作者 秦猛 《Communications in Theoretical Physics》 SCIE CAS CSCD 2013年第3期279-284,共6页
We examine entanglement teleportation,characterized by average fidelity,of two-qubit XY Z spin chain under different nonuniform magnetic field.The entanglement teleportation and the fidelity of entanglement teleportat... We examine entanglement teleportation,characterized by average fidelity,of two-qubit XY Z spin chain under different nonuniform magnetic field.The entanglement teleportation and the fidelity of entanglement teleportation are investigated separately.We show explicitly that the fidelity of entanglement teleportation can be enhanced by changing the direction of the magnetic field.This means that we can always get optimal fidelity by choosing the directions of magnetic field in the process of quantum teleportation.Moreover,the results show that in some cases the ferromagnetic chain also is a qualified candidate in the process of teleportation protocol. 展开更多
关键词 quantum teleportation FIDELITY different magnetic field
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