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A preliminary study on the response of marine primary production to monsoon variations in the South China Sea Basic characteristics

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Acta Oceanologica Sinica 2008年第5期27卷 21-35页

作者： wang hui jin qihua gao shan Chinese Academy of Meteorological Sciences Beijing 100081 China

Seasonal, interannual and interdecadal variations of monsoon over the South China Sea （SCS） directly influence the ocean circulation and the mass transport process, etc. , especially the changes of horizontal circulation pattern and upwelling area. These changes directly influence the nutrient transport and the photosynthesis of phytoplankton, which induce the change of the marine ecosystem in the SCS, including the change of marine primary production in this sea area. On the basis of climatic data for long-time series and primary production estimated by remote sensing, the multi-time scale variations of monsoon, seasonal and interannual variations of primary production, and the response of primary production to monsoon variations were analyzed. Furthermore, the spatio-temporal variations of primary production in different sea areas of the SCS and their relations to the monsoon variations were given. The results showed that the strong southwesterly prevailed over the SCS in summer whereas the vigorous northeasterly in winter. The seasonal primary production in the entire sea area of the SCS also produced a strong peak in winter and a suhpeak in summer. And the seasonal primary production distributions displayed different characteristics in every typical sea area. The variations of the annual and summer averaged primary production in the entire sea area of the SCS showed almost the same rising trend as the intensity of the summer monsoon. Especially for 1998, the summer monsoon reached almost the minimum in the past 54 a when the primary production was also found much lower than any other year （ 1999--2005 ）. The responses of annual primary production to monsoon variation were displayed to different extent in different sea areas of the SCS ; especially it was better in the deep sea basin. Such research activities could be very important for revealing the response of marine ecosystem to the monsoon variations in the SCS.

关键词： South China Sea monsoon primary production

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Seasonal and spatial distributions of phytoplankton biomass associated with monsoon and oceanic environments in the South China Sea

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Acta Oceanologica Sinica 2008年第6期27卷 17-32页

作者： gao shan wang hui Chinese Academy of Meteorological Sciences China Meteorological Administration Beijing 100081 China College of Environmental Science and Engineering Ocean University of China Qingdao 266100 China National Marine Environmental Forecasting Center State Oceanic Administration Beijing 100081 China

Seasonal variations of phytoplankton/chlorophyll-a （Chl-a） distribution, sea surface wind, sea height anomaly, sea surface temperature and other oceanic environments for long periods are analyzed in the South China Sea （SCS）, especially in the two typical regions off the east coast of Vietnam and off the northwest coast of Luzon, using remote sensing data and other oceanographic data. The results show that seasonal and spatial distributions of phytoplankton biomass in the SCS are primarily influenced by the monsoon winds and oceanic environments. Off the east coast of Vietnam, Chl-a concentration is a peak in August, a jet shape extending into the interior SCS, which is associated with strong southwesterly monsoon winds, the coastal upwetling induced by offshore Ekman transport and the strong offshore current in the western SCS. In December, high Chl-a concentration appears in the upwelling region off the northwest coast of Luzon and spreads southwestward. Strong mixing by the strong northeasterly monsoon winds, the cyclonic circulation, southwestward coastal currents and river discharge have impacts on distribution of phytoplankton, so that the high phytoplankton biomass extends from the coastal areas over the northern SCS to the entire SCS in winter. These research activities could be important for revealing spatial and temporal patterns of phytoplankton and their interactions with physical environments in the SCS.

关键词： phytoplankton biomass chlorophyll-a monsoon upwelling South China Sea

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Spatio-temporal variability of chlorophyll a and its responses to sea surface temperature, winds and height anomaly in the western South China Sea

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Acta Oceanologica Sinica 2013年第1期32卷 48-58页

作者： gao shan wang hui LIU Guimei LI Hai National Marine Environmental Forecasting Center State Oceanic Administration College of Environmental Science and Engineering Ocean University of China

To understand the response of marine ecosystem to environmental factors, the oceanographic （physical and biochemical） data are analyzed to examine the spatio-temporal distributions of chlorophyll a （Chl a） associated with surface temperature, winds and height anomaly for long periods （1997-2008） in the western South China Sea （SCS）. The results indicate that seasonal and spatial distributions of Chl a are primarily in- fluenced by monsoon winds and hydrography. A preliminary Empirical Orthogonal Function （EOF） analysis of remotely sensed data is used to assess basic characteristics of the response process of Chl a to physical changes, which reveals interannual variability of anomalous low Chl a values corresponding to strong E1 Nifio （1997-1998）, high values corresponding to strong La Nifia （1999-2000）, low Chl a corresponding to moderate E1 Nifio （2001-2003）, upward Chl a after warm event in 2005 off the east coast of Vietnam. The variability of Chl a in nearshore and the Mekong River Estuary （MER） waters also suggests its response to these warm or cold processes. Considering the evidence for covariabilities between Chl a and sea surface temperature, winds, height anomaly （upwelling or downwelling）, cold waters input and strong winds mix- ing may play important roles in the spatial and temporal variability of high Chl a. Such research activities could be very important to gain a mechanistic understanding of ecosystem responses to the climate change in the SCS.

关键词： South China Sea Chlorophyll a temperature wind upwelling

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Parameter sensitivity study of the biogeochemical model in the China coastal seas

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Acta Oceanologica Sinica 2015年第12期34卷 51-60页

作者： JI Xuanliang LIU Guimei gao shan wang hui National Marine Environmental Forecasting Center Key Laboratory of Research on Marine Hazards Forecasting National Marine Environmental Forecasting Center

In order to develop a coupled basin scale model of ocean circulation and biogeochemical cycling,we present a biogeochemical model including 12 components to study the ecosystem in the China coastal seas（CCS）.The formulation of phytoplankton mortality and zooplankton growth are modified according to biological characteristics of *** four sensitivity biological parameters,zooplankton assimilation efficiency rate（ZooAE_N）,zooplankton basal metabolism rate（ZooBM）,maximum specific growth rate of zooplankton（μ_（20）） and maximum chlorophyll to carbon ratio（Chl2C_m） are obtained in sensitivity experiments for the phytoplankton,and experiments about the parameter μ_（20＇）,half-saturation for phytoplankton NO_3 uptake（K_（NO_3）） and remineralization rate of small detritusN（SDeRRN） are *** results demonstrate that the biogeochemical model is quite sensitive to the zooplankton grazing parameter when it ranges from 0.1 to 1.2 d^（-1）.The K_（NO_3） and SDeRRN also play an important role in determining the nitrogen cycle within certain *** sensitive interval of KNO_3 is from 0.1 to 1.5（mmol/m^3）^（-1）,and interval of SEdRRN is from 0.01 and 0.1 d^（-1）.The observational data from September 1998 to July 2000 obtained at SEATS station are used to validate the performance of biological model after parameters *** results show that the modified model has a good capacity to reveal the biological process features,and the sensitivity analysis can save computational resources greatly during the model simulation.

关键词： China coastal seas biogeochemical model parameter sensitivity

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Chlorophyll a increase induced by surface winds in the northern South China Sea

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Acta Oceanologica Sinica 2012年第4期31卷 76-88页

作者： gao shan wang hui LIU Guimei HUANG Liangmin SONG Xingyu College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China National Marine Environmental Forecasting Center State Oceanic AdministrationBeijing 100081China State Key Laboratory of Oceanography in the Tropics Guangzhou 510301China Key Laboratory of Marine Bio-resources Sustainable UtilizationChinese Academy of SciencesGuangzhou 510301China

The response of chlorophyll a （Chl a） concentration to wind stress is analyzed in the South China Sea （SCS）, using in-situ data of Chl a and remote sensing data （QuikScat-sea surface wind （SSW）, AVHRR-sea surface temperature （SST）, AVISO merged-sea level anomalies （SLA）, SeaWiFS- derived Chl a and MODIS Terra-derived Chl a） in August/September/October 2004, 2006 and 2009. The variability of SSW, SST and SLA 7 d before in-situ Chl a sampling （including the work day of in^situ Chl a sampling） with the same latitude and longitude of the study area are investigated, and the correlation coefficients are calculated between these hydrographic factors and in-situ Chl a concentration. The results show that the Chl a-SSW correlation coefficients at upper layers （such as 0 m and 25 m） are more significant than those at deeper layers （such as 50, 75 and 100 m） 1 3 d before, which indicates that there is a time lag of strong surface winds stimulating phytoplankton bloom. By analyzing the relationship among the daily remote sensing derived （RS- derived） SSW, SST, SLA and 3 d averaged SeaWiFS/MODIS-derived Chl a concentration in the northern SCS in September 2004 and 2009 respectively, it shows that the intensity and speed of surface winds could have great influence on extend of Chl a increase. If surface winds reach 4-5 m/s over, Chl a concentration would increase 1-3 d after the process of strong surface winds in open sea area of the northern SCS mainly during September.

关键词： South China Sea phytoplankton bloom chlorophyll a surface wind vertical ,nixingand upwelling

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Temporal and spatial variability of the carbon cycle in the east of China's seas:a three-dimensional physical-biogeochemical modeling study

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Acta Oceanologica Sinica 2017年第3期36卷 60-71页

作者： JI Xuanliang LIU Guimei gao shan wang hui ZHANG Miaoyin National Marine Environmental Forecasting Center State Oceanic AdministrationBeijing 100081China Key Laboratory of Research on Marine Hazards Forecasting National Marine Environmental Forecasting CenterState Oceanic AdministrationBeijing 100081China

In the east of China＇s seas, there is a wide range of the continental shelf. The nutrient cycle and the carbon cycle in the east of China＇s seas exhibit a strong variability on seasonal to decadal time scales. On the basis of a regional ocean modeling system（ROMS）, a three dimensional physical-biogeochemical model including the carbon cycle with the resolution（1/12）°×（1/12）° is established to investigate the physical variations, ecosystem responses and carbon cycle consequences in the east of China＇s seas. The ROMS-Nutrient Phytoplankton Zooplankton Detritus（NPZD） model is driven by daily air-sea fluxes（wind stress, long wave radiation, short wave radiation, sensible heat and latent heat, freshwater fluxes） that derived from the National Centers for Environmental Prediction（NCEP） reanalysis2 from 1982 to 2005. The coupled model is capable of reproducing the observed seasonal variation characteristics over the same period in the East China Sea. The integrated air-sea CO_2 flux over the entire east of China＇s seas reveals a strong seasonal cycle, functioning as a source of CO_2 to the atmosphere from June to October, while serving as a sink of CO_2 to the atmosphere in the other months. The 24 a mean value of airsea CO_2 flux over the entire east of China＇s seas is about 1.06 mol/（m^2·a）, which is equivalent to a regional total of3.22 Mt/a, indicating that in the east of China＇s seas there is a sink of CO_2 to the atmosphere. The partial pressure of carbon dioxide in sea water in the east of China＇s seas has an increasing rate of 1.15 μatm/a（1μtm/a=0.101 325Pa）, but p H in sea water has an opposite tendency, which decreases with a rate of 0.001 3 a^（–1） from 1982 to *** activity is a dominant factor that controls the pCO_2 air in the east of China＇s seas, and followed by a temperature. The inverse relationship between the interannual variability of air-sea CO_2 flux averaged from the domain area and Ni？o3 SST Index indicates that the carbon cycle in the ea

关键词： the east of China's seas physical-biogeochemical model partial pressure of carbon dioxide in sea water air-sea CO2 flux

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Comparison of air-sea CO2 flux and biological productivity in the South China Sea,East China Sea,and Yellow Sea:a three-dimensional physical-biogeochemical modeling study

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Acta Oceanologica Sinica 2017年第12期36卷 1-10页

作者： JI Xuanliang LIU Guimei gao shan wang hui ZHANG Miaoyin National Marine Environmental Forecasting Center Beijing 100081China Key Laboratory of Research on Marine Hazards Forecasting National Marine Environmental Forecasting CenterState Oceanic AdministrationBeijing 100081China

Marginal seas play important roles in regulating the global carbon budget, but there are great uncertainties in estimating carbon sources and sinks in the continental margins. A Pacific basin-wide physical-biogeochemical model is used to estimate primary productivity and air-sea CO_2 flux in the South China Sea（SCS）, the East China Sea（ECS）, and the Yellow Sea（YS）. The model is forced with daily air-sea fluxes which are derived from the NCEP2 reanalysis from 1982 to 2005. During the period of time, the modeled monthly-mean air-sea CO_2 fluxes in these three marginal seas altered from an atmospheric carbon sink in winter to a source in summer. On annualmean basis, the SCS acts as a source of carbon to the atmosphere（16 Tg/a, calculated by carbon, released to the atmosphere）, and the ECS and the YS are sinks for atmospheric carbon（–6.73 Tg/a and –5.23 Tg/a, respectively,absorbed by the ocean）. The model results suggest that the sea surface temperature（SST） controls the spatial and temporal variations of the oceanic pCO_2 in the SCS and ECS, and biological removal of carbon plays a compensating role in modulating the variability of the oceanic pCO_2 and determining its strength in each sea,especially in the ECS and the SCS. However, the biological activity is the dominating factor for controlling the oceanic pCO_2 in the YS. The modeled depth-integrated primary production（IPP） over the euphotic zone shows seasonal variation features with annual-mean values of 293, 297, and 315 mg/（m^2·d） in the SCS, the ECS, and the YS, respectively. The model-integrated annual-mean new production（uptake of nitrate） values, as in carbon units, are 103, 109, and 139 mg/（m^2·d）, which yield the f-ratios of 0.35, 0.37, and 0.45 for the SCS, the ECS, and the YS, respectively. Compared to the productivity in the ECS and the YS, the seasonal variation of biological productivity in the SCS is rather weak. The atmospheric pCO_2 increases from 1982 to 2005, which is consistent with the anthropo

关键词： physical-biogeochemical model air to sea CO_2 flux South China Sea East China Sea Yellow Sea

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Treatment effects and periodontal status of chronic periodontitis after routine Er:YAG laser-assisted therapy

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World Journal of Clinical Cases 2021年第32期9卷 9762-9769页

作者： Yong-Zhi gao Yan Li shan-shan Chen Bo Feng hui wang Qiao wang Department of Stomatology The First Affiliated Hospital of Qiqihar Medical UniversityQiqihar 161041Heilongjiang ProvinceChina Department of Anatomy Basic Medical CollegeZunyi Medical UniversityZunyi 563006Guizhou ProvinceChina The Ward of Department of Ophthalmology and Torhinolaryngology The First Affiliated Hospital of Qiqihar Medical UniversityQiqihar 161041Heilongjiang ProvinceChina Department of Stomatology Qiqihar ENT HospitalQiqihar 161006Heilongjiang ProvinceChina Department of Stomatology The Second Affiliated Hospital of Qiqihar Medical UniversityQiqihar 161005Heilongjiang ProvinceChina

BACKGROUND Routine preclinical interventions for patients with chronic periodontitis such as supragingival cleaning and subgingival curettage,establishing a balanced occlusal relationship,and irrigation with 3%hydrogen peroxide can relieve the symptoms to some ***,there is room for improvement in the overall *** example,Er:YAG lasers can quickly increase the temperature of the irradiated tissue,effectively eliminate dental plaque and calculus,reduce periodontal pockets,adjust periodontal microecology,and reduce the gingival *** content of factors in the liquid,and then achieve the purpose of *** The aim was evaluate the effect of Er:YAG laser-assisted routine therapy on the periodontal status in chronic *** Between October 2018 and January 2020,106 patients with chronic periodontitis in our hospital were randomly assigned to either the study or control group,with 53 patients in each *** control group underwent routine therapy,and the study group underwent Er:YAG laser therapy in addition to routine *** evaluated the treatment outcome in both *** status was determined by clinical attachment loss(CAL),gingival index(GI),periodontal probing depth(PD),dental plaque index(PLI),and sulcular bleeding index(SBI),inflammatory factors in the gingival crevicular fluid,tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),IL-8],and colony forming units(CFUs).RESULTS Total effectiveness in the study group(94.34%)was higher than that in the control group(79.25%,P0.05).However,after treatment,the parameters in the study group(PD,2.97±0.38 mm;CAL,2.71±0.64 mm;SBI,2.07±0.32;GI,0.51±0.11;PLI,1.29±0.34)were lower than those in the

关键词： Er:YAG laser therapy Chronic periodontitis Periodontal status Oral inflammatory factors

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Genetic optimization of ladle scheduling in empty-ladle operation stage based on temperature drop control

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Journal of Iron and Steel Research International 2022年第4期29卷 563-574页

作者： Yu-jie Hong Qing Liu Jian-ping Yang Jian wang shan gao Hong-hui Li State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Laiwu Iron and Steel Group Yinshan Section Steel Co.Ltd.Laiwu 271100ShandongChina

To optimize ladle scheduling in the empty-ladle operation stage of steel plants,a mathematical scheduling model was established for the empty-ladle operation stage,taking the minimum total waiting time in the empty-ladle operation stage as the optimization goal and setting the equipment assignment uniqueness as the key *** improved genetic algorithm was designed to calculate the mathematical scheduling *** the operation of the genetic algorithm,the strategy of"ladle temperature drop control"was adopted to solve the problem of equipment conflicts and reduce unreasonable ladle temperature drops to enhance"red-ladle"*** main production modes operating at 95%capacity in a Chinese steel plant were simulated using the genetic optimization *** results showed that the genetic optimization model could improve the efficiency of ladle operation and reduce the total waiting time in the empty-ladle operation stage by 868–1147 min.

关键词： Ladle scheduling Empty-ladle operation Waiting time Genetic algorithm Temperature drop

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Simulation of particle flow in a bell-less type charging system of a blast furnace using the discrete element method

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Particuology 2014年第5期12卷 167-177页

作者： Jianliang Zhang Jiayong Qiu Hongwei Guo shan Ren hui Sun Guangwei wang Zhengkai gao School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

A three-dimensional model was established by the discrete element method （DEM） to analyze the flow and segregation of particles in a charging process in detail. The simulation results of the burden falling trajectory obtained by the model were compared with the industrial charging measurements to validate the applicability of the model. The flow behavior of particles from the weighing hopper to the top layer of a blast furnace and the heaping behavior were analyzed using this model. A radial segregation index （RSI） was used to evaluate the extent of the size segregation in the charging process. In addition, the influence of the chute inclination angle on the size segregation and burden profile during the charging process was investigated.

关键词： Discrete element method Blast furnace Bell-less charging system Granular flow Size segregation

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