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Wave decomposition phenomenon and spectrum evolution over submerged bars

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Acta Oceanologica Sinica 2009年第3期28卷 82-92页

作者： LI Benxia YU Xiping national Marine Environmental Forecasting center State Oceanic Administration Beijing 100081China Department of Hydraulic Engineering Tsinghua University Beijing 100084 China

Wave decomposition phenomenon and spectrum evolution over submerged bars are investigated by a previously developed numerical model. First, the computed free surface displacements of regular waves at various locations are compared with the available experimental data to confirm the validity of the numerical model, and satisfactory agreements are obtained. In addition, variations of decomposition characteristics with incident wave parameters and the change of energy spectrum for regular waves are also studied. Then the spectrum evolution of irregular waves over submerged bars, as well as the influence of incident peak wave period and the steepness of the front slope of the bar on spectrum evolution, is investigated. Wave decomposition and spectral shape are found to be significantly influenced by the incident wave conditions. When the upslope of the bar becomes 1：2. the length of the slope becomes shorter and will not benefit the generation of high frequency energy, so spectrum evolution is not significant.

关键词： wave decomposition spectrum evolution nonlinear waves irregular waves submerged bars

Distinguished Effects of Interannual Salinity Variability on the Development of the Central-Pacific El Ni o Events

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Atmospheric and Oceanic Science Letters 2012年第2期5卷 123-127页

作者： ZHENG Fei 1,WAN Li-Ying 2.and WANG Hui 3 1 International center for Climate and Environment Science (ICCES),Institute of Atmospheric Physics,Chinese Academy of Sciences,{2. 10002.,china 2.Key Laboratory of Research on Marine Hazards Forecasting,national Marine Environmental Forecasting center,{2. 100081,china 3 national meteorological center,{2. 100081,china [a] International center for Climate and Environment Science (ICCES) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China[b] Key Laboratory of Research on Marine Hazards Forecasting National Marine Environmental Forecasting Center Beijing 100081 China[c] National Meteorological Center Beijing 100081 China

El Nio events in the central equatorial Pacific (CP) are gaining increased attention,due to their increasing intensity within the global warming *** physical processes have been identified in the climate system that can be responsible for the modulation of El Nio,especially the effects of interannual salinity *** this work,a comprehensive data analysis is performed to illustrate the effects of interannual salinity variability using surface and subsurface salinity fields from the Met Office ENSEMBLES (EN3) quality controlled ocean *** is demonstrated that during the developing phase of an El Nio event,a negative sea surface salinity (SSS) anomaly in the western-central basin acts to freshen the mixed layer (ML),decrease oceanic density in the upper ocean,and stabilize the upper *** related oceanic processes tend to reduce the vertical mixing and entrainment of subsurface water at the base of the ML,which further enhances the warm sea surface temperature (SST) anomalies associated with the El Nio ***,the effects of interannually variable salinity are much more significant during the CP-El Nio than during the eastern Pacific (EP) El Nio,indicating that the salinity effect might be an important contributor to the development of CP-El Nio events.

关键词： salinity effect CP-E1 Nifio EN3 dataset

The relativistic consistent angular-momentum projected shell model study of the N=Z nucleus ^(52.Fe

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Science china(Physics,Mechanics & Astronomy) 2009年第10期52卷 1471-1476页

作者： LI YanSong1,2.& LONG GuiLu1,2.1 Department of Physics,Tsinghua University,beijing 100084,china 2.{2. of Nuclear Theory,national Laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 730000,china 1. Department of Physics Tsinghua University Beijing 100084 China 2. center of Nuclear Theory National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China

The relativistic consistent angular-momentum projected shell model(ReCAPS) is used in the study of the structure and electromagnetic transitions of the low-lying states in the N=Z nucleus *** model calculations show a reasonably good agreement with the *** backbending at 12. is reproduced and the energy level structure suggests that neutron-proton interactions play important roles.

关键词： ReCAPS relativistic mean field angular-momentum projection method 52.e neutron-proton interaction

umerical tests of efficiency of the retrospective time integration scheme in the self-memory model

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Progress in Natural Science:Materials International 2004年第9期 89-92页

作者： GU Xiangqian 1*, YOU Xingtian 2. ZHU He 2.and CAO Hongxing 1(1. Chinese Academy of meteorological Sciences, beijing 100081,{2. 2. Training center of{2. meteorological Administration, beijing 100081,{2.)

A set of numerical tests was carried out to compare the retrospective time integral scheme in a self memory model, whose dynamic kernel is the barotropical quasi geostrophic model, with the ordinary centered difference scheme in the barotropical quasi geostrophic model. The Rossby Haurwitz wave function was taken as the initial fields for both schemes. The results show that in comparison with the ordinary centered difference scheme, the retrospective time integral scheme reduces by 2.orders of magnitude the forecast error, and the forecast error increases very little with lengthening of the time step. Therefore, the retrospective time integral scheme has advantages of improving the forecast accuracy, extending the predictable duration and reducing the computation amount.

关键词： numerical tests self-memory model retrospective time integral scheme.

Improvement of the electrochemical performance of LiNi_(0.33)Mn_(0.33)Co_(0.33)O_2.cathode material by chromium doping

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Science china(Technological Sciences) 2010年第12期53卷 3214-3220页

作者： WANG Meng1, CHEN YunBo1, WU Feng2. SU YueFeng2.& CHEN Lin1 1 Advanced Manufacture Technology center, china Academy of Machinery Sicence and Technology, {2. 100083, china 2.School of Chemical Engineering and Environment, {2. Institute of Technology, beijing 100081, china 1. Advanced Manufacture Technology center China Academy of Machinery Sicence and Technology Beijing 100083 China2. School of Chemical Engineering and Environment Beijing Institute of Technology Beijing 100081 China

LiNi0.33Mn0.33-xCo0.33CrxO2.(x=0, 0.01, 0.02., 0.05) materials were synthesized by Cr3+ substitute of Mn4+ to enhance their electrochemical properties. The structure and electrochemical properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and charge/dis charge tests. The materials maintained the α-NaFeO2.type layered structure and the discharge capacities were also increase by doping appropriate amount of Cr3+. The sample with x= 0.02. exhibited the highest discharge capability of 181.6 mAh g?1 and the best cycle performance. EIS measurement showed that the Cr-doped electrode had the lower resistance impedance increase during cycling. The chemical diffusion coefficient of Li+ ion (DLi) was measured by potentiostatic intermittent titration technique (PITT). The result showed that DLi in Cr-doped electrode was faster than that of the un-doped one.

关键词： cathode material Cr-doped Li-ion battery electrochemical properties

Three-year changes of surface albedo of degraded grassland and cropland surfaces in a semiarid area

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Chinese Science Bulletin 2008年第8期53卷 1246-1254页

作者： LIU HuiZhi1↑, TU Gang2.3 & DONG WenJie4 1 State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chi- nese Academy of Sciences, beijing 10002., china 2.Laboratory of Research for Middle-High Latitude Circulation System and East Asia Monsoon, china meteorological Administration, Changchun 130062. china 3 Institute of meteorological Science of Jilin Province, Changchun 130062. china 4 national Climate center, beijing 100081, china State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Laboratory of Research for Middle-High Latitude Circulation System and East Asia Monsoon China Meteorological Administration Changchun China Institute of meteorological Science of Jilin Province Changchun China national Climate center Beijing China

Diurnal, seasonal and interannual variations of surface albedo of degraded grassland and cropland surfaces at a semiarid area of Tognyu have been investigated based on the continuous three years observational data from 2.03 to 2.05. The changes of surface albedo with solar elevation angle and soil moisture have been discussed also. It has been found that surface albedo has almost the same diurnal and seasonal variations on degraded grassland and cropland surfaces in the semiarid area, while sur- face albedo is large in winter and small in summer. The diurnal variation of the surface albedo has re- lationship with the weather condition. The diurnal cycle of the surface albedo likes the "U" shape curve in sunny day, while it is low-high after the rain, and high-low after the snow. The surface albedo has large variation in cloudy day, while it has no any variation in overcast day. The large difference of the surface albedo can be 0.04 in winter between two land surfaces, because the snow has large effects on the surface albedo in winter. The rainfall is an important factor in summer on the surface albedo, while the difference of the surface albedo is 0.01 only between two land surfaces. The differences of the surface albedo can also be 0.04 in autumn due to vegetation growing. The seasonal-average surface albeo from 2.03―2.05 is 0.2., 0.2., 0.2., 0.32.respectively in spring, summer, autumn and winter on the degraded grassland surface,while it is 0.2., 0.2., 0.2., 0.33 respectively in spring, summer, autumn and winter on the cropland surface. The surface albedo becomes smaller with the increase of solar elevation angle. When the solar elevation angle is greater than 40°, the surface albedo changes very little and tends to be a constant. The surface albedo has negative exponent functions with soil moisture in the growing season.

关键词：半干旱地区表面反照率土壤湿度草地退化

Some characteristics of the atmosphere during an adiabatic process

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Progress in Natural Science:Materials International 2006年第6期16卷 644-648页

作者： GAO Li, LI Jianping and REN Hongli (LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., china Graduate School of Chinese Academy of Sciences, beijing 100049, china national Climate center, Laboratory of Climate Studies, china meteorological Administration, beijing 100081, china) [a]LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China [b]Graduate School of Chinese Academy of Sciences Beijing China [c]national Climate center Laboratory of Climatic Studies China Meterological Administration Beijing China

Some important characteristics of the atmosphere during an adiabatic process are investigated, which include the invariability of atmospheric entropy range and local surface potential temperature, the conservation of the atmospheric mass intervened between any isentropic surface and the ground, and the isentropic surface intersecting with the ground. The analysis shows that the atmospheric reference state (ARS) for investigation on available potential energy (APE) should be defined objectively as the state which could be approached from the existing atmosphere by adiabatic adjustment, and be related to initial atmospheric state before adjustment. For the initial atmosphere state at any time, its corresponding ARS is different from the one at another time. Based on the above-mentioned conclusions, the reference state proposed by Lorenz cannot be obtained physically, so a new conception, the conditional minimum total potential energy, is put forward in order to objectively investigate atmospheric APE.

关键词： available potential energy adiabatic isentropic surface atmospheric reference state conditional minimum total potential energy.

Summer Arctic sea fog

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Acta Oceanologica Sinica 2001年第2期20卷 183-196页

作者： Xie Simei, Xue Zhenhe, Jiang Dezhong, Zou Bin, Qu Shaohou (1. national Research center for Marine Environment Forecasts,{2., china 2. Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., china) Natl. Res. Ctr. for Marine Envrn. Fo Beijing 100081 China

Synchronous or quasi-synchronous sea-land-air observations were conducted using advanced sea ice, atmospheric and marine instruments during china's First Arctic Expedition. *** on the Precious data from the expedition, it was found that in the Arctic Ocean, most part of which is covered with ice or is mixed with ice, various kinds of sea fog formed such as advection fog, radiation fog and vapor fog. Each kind he its own characteristic and mechanics of creation. In the southern part of the Arctic Ocean, due to the sufficient warm and wet flow there, it is favorable for advection fog to form, which is dense and lasts a long time. On ice cap or vast floating ice, due to the strong radiation cooling effect, stable radiating fog is likely to form. In floating ice area there forms vapor fog with the appearance of masses of vapor from a boiling pot, which is different from short-lasting land fog. The study indicates that the reason why there are many kinds of sea fog form in the Arctic Ocean is because of the complicated cushion and the consequent sea-air interaction caused by the sea ice distribution and its unique physical characteristics. Sea fog is the atmospheric phenomenon of sea-air heat exchange. Especially, due to the high albedo of ice and snow surface, it is diffcult to absorb great amount of solar radiation during the polar days. Besides, ice is a poor conductor of heat; it blocks the sea-air heat exchange. The sea-air exchange is active in floating ice area where the ice is broken. The sea sends heat to the atmosphere in form of latent heat; vapor fog is a way of sea-air heat exchange influencing the climate and an indicator of the extent of the exchange. The study also indicates that the sea also transports heat to the atmosophere in form of sensible heat when vapor fog occurs.

关键词： Arctic sea fog vapor fog radiation fog advection fog mechanism of the creation of sea fog

Photogeneration of the free radicals and singlet oxygen by chrysophanol from rheum

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Science china Chemistry 2004年第5期47卷 381-387页

作者： RAO Jing1,2. XIE Jie1, ZHAO Jingquan1 & ZHU Teng2.1. Key Laboratory of Photochemistry, center for Molecular Science, Institute of Chemistry, The Chinese Academy of Sciences, beijing 100080,{2. 2. University of Science and Technology beijing, beijing 10083,{2. 1. Key Laboratory of Photochemistry Center for Molecular Science Institute of Chemistry The Chinese Academy of Sciences 100080 Beijing China 2. University of Science and Technology beijing 10083 Beijing China

In the current work, chryosphanol (MHAQ) was isolated and purified from rheum, and the photosensitization activities were studied. In nitrogen-saturated DMSO solution, irradia- tion of chryosphanol (MHAQ) with visible light (>430 nm) produced the semiquinone radical anions (MHAQ??), which was intensified significantly by an electron donor NADH, suggesting electron transfer between the excited and ground state photosensitizer molecules. In an air-saturated DMSO solution, superoxide radical anions (O2.), trapped by DMPO, were detected. ?? It was proved that O2.was not originated from the singlet oxygen (1O2. but dependent on DMPO, ?? chrysophanol, oxygen and the irradiation time. The singlet oxygen and OH could also be pro- ? duced by the photosensitization of the photosensitizer. These suggest that chrysophanol pos- sesses the photosensitization activity via Type I mechanism and Type II mechanism. To evaluate the photosensitization activities of MHAQ, emodin and mixed anthraquinone derivatives ex- tracted from rheum, the relative productivities of O2.were estimated to be 1.8, 1.1 and 1.0 re- ?? spectively and the quantum yields for singlet oxygen to be 0.36, 0.53 and 0.14 respectively. Therefore, these low-cost pigments may be potentially used as phototherapeutic medicine for some kind of vascular diseases or photo-activated pesticides.

关键词： chrysophanol, ESR, semiquinone radical anions, superoxide radical anions, hydroxyl radical, singlet oxygen.