检索结果-南通市图书馆

Analysis of atmospheric turbulence in the upper layers of sea fog

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Oceanology and Limnology 2015年第3期33卷 809-818页

作者：李永平郑运霞 shanghai typhoon institute China Meteorological Administration

Atmospheric turbulence plays a vital role in the formation and dissipation of fog. However,studies of such turbulence are typically limited to observations with ultrasonic anemometers less than 100 m above ground. Thus,the turbulence characteristics of upper fog layers are poorly known. In this paper,we present 4-layers of data,measured by ultrasonic anemometers on a wind tower about 400 m above the sea surface; we use these data to characterize atmospheric turbulence atop a heavy sea fog. Large differences in turbulence during the sea fog episode were recorded. Results showed that the kinetic energy,momentum flux,and sensible heat flux of turbulence increased rapidly during the onset of fog. After onset,high turbulence was observed within the uppermost fog layer. As long as this turbulence did not exceed a critical threshold,it was crucial to enhancing the cooling rate,and maintaining the fog. Vertical momentum flux and sensible heat flux generated by this turbulence weakened wind speed and decreased air temperature during the fog. Towards the end of the fog episode,the vertical distribution of sensible heat flux reversed,contributing to a downward momentum flux in all upper layers. Spatial and temporal scales of the turbulence eddy were greater before and after the fog,than during the fog episode. Turbulence energy was greatest in upper levels,around 43. m and 450 m above mean sea level(AMSL),than in lower levels of the fog(3.0 m and 410 m AMSL); turbulence energy peaked along the mean wind direction. Our results show that the status of turbulence was complicated within the fog; turbulence caused fluxes of momentum and sensible heat atop the fog layer,affecting the underlying fog by decreasing or increasing average wind speed,as well as promoting or demoting air temperature stratification.

关键词： ultrasonic anemometers turbulence characteristics momentum flux sensible heat flux variation in sea fog

Climatic variation of tropical cyclones affecting china during the past 50 years

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2011年第8期54卷 1226-1237页

作者： YING Ming YANG YuHua CHEN BaoDe ZHANG Wei Laboratory of typhoon Forecast Technique Shanghai Typhoon Institute China Meteorological Administration Shanghai 200030 China

Trends of the tropical cyclones (TCs) influence on china and its four subregions,namely the South china (SC),East china (EC),Northeast china (NEC),and china's inland area (CI),are detected by applying quantile regression to the CMA-STI tropical cyclone best track and related severe wind and precipitation observation *** results indicate that in the past 50 years,the number of TCs affecting china and its four subregions has remained steady,except that the frequency in extremely active years has decreased not only in china as a whole,but also in *** addition,TC activity is found to have weakened over the northwest South china Sea,Guangdong,and Shandong ***,the most important changes in seasonality are found in the first quartiles of the number of days of TCs affecting *** the extreme values of sustained winds all have decreasing trends,the extreme values of wind gusts are completely different not only among different orders of extreme values,but also among different ***,the trends of extreme TC rainfall,namely the maximum storm precipitation and the maximum 1-h precipitation,are not significant.

关键词： tropical cyclone wind and precipitation climatic variation china

An ocean-land-atmosphere coupled model for tropical cyclone landfall processes: The multi-layer ocean model and its verification

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2006年第2期25卷 33-48页

作者： DUAN Yihong YU Runling LI Yongping shanghai typhoon institute of {3. Meteorological administration Shanghai 200030China

POM (Princeton ocean model) tentatively taken as the ocean part of an ocean-land atmosphere coupled modcl is verified for the ultimate purpose of studying the landfall process of tropical cyclone (TC) in the western North Pacific. The POM is tested with monthly mean wind stress in the summer and given lateral boundary conditions. The results indicate that the equilibrium state of the ocean is in accordance with the climate mean, with the error in sea surface temperature (salinity) less than 0.5 ℃ (0.5). The simulated occan currents are reasonable as *** numerical experiments are designed to verify the oceanic response to a stationary or moving TC. It is found that the results agree fairly well with the previous work, including both the drop magnitude and the distribution ofsca temperature. Compared with the simple two-layer ocean model used by some other studies, the response of the ocean to a TC is more logical here. The model is also verified in a real case with a TC passing the neighborhood of a buoy station. It is shown that the established ocean model can basically reproduce the sea surface temperature change as observed.

关键词： tropical cyclone ocean coupled model

Analysis and prognosis of tropical cyclone genesis over the western North Pacific on the background of global warming

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2007年第1期26卷 23-34页

作者： LI Yongping WANG Xiaofeng YU Runling QIN Zenghao Open Laboratory for typhoon Research Shanghai Typhoon Institute China Meteorological Administration Shanghai 200030

As revealed by the observational study, there are more tropical cyclones generated over the western North Pacific from the early 1950s to the early 1970s in the 20th century and less tropical cyclones from the mid-1970s to the present. The decadal change of ＂tropical cyclones activities are closely related to the decadal changes of atmospheric general circulation in the troposphere, which provide favorable or unfavorable conditions for the formation of tropical cyclone. Furthermore, based on the simulation of corresponding atmospheric general circulation from a coupled climate model under the schemes of Intergovemmental Panel on Climate Change （IPCC）,special report on emission scenarios （SRES） A2 and B2 emissions scenarios an outlook on the tropical cyclone frequency generated over the western North Pacific in the coming half century is presented. It is indicated that in response to the global climate change the general circulation of atmosphere would become unfavorable for the formation of tropical cyclone as a whole and the frequency of tropical cyclones formation would likely decrease by 5% within the next half century, although more tropical cyclones would appear during a short period in it.

关键词： IPCC SRES A2 and B2 general circulation anomaly frequency of tropical cyclone

Graphene enhances artemisinin production in the traditional medicinal plant Artemisia annua via dynamic physiological processes and miRNA regulation

在线全文

学校读者我要写书评

暂无评论

Plant Communications 2024年第3期5卷 31-46页

作者： Junfeng Cao Zhiwen Chen Luyao Wang Ning Yan Jialing Lin Lipan Hou Yongyan Zhao Chaochen Huang Tingting Wen Chenyi Li Saeed ur Rahman Zehui Liu Jun Qiao Jianguo Zhao Jie Wang Yannan Shi Wei Qin Tong Si Yuliang Wang Kexuan Tang Frontiers Science Center for Transformative Molecules Joint International Research Laboratory of Metabolic and Developmental SciencesPlant Biotechnology Research CenterFudan-SJTU Nottingham Plant Biotechnology R&D CenterSchool of Agriculture and BiologyShanghai Jiao Tong UniversityShanghai 200240China Engineering Research Center of Coal-based Ecological Carbon Sequestration Technology of the Ministry of Education Key Laboratory of Graphene Forestry Application of National Forest and Grass AdministrationShanxi Datong UniversityDatong 037009China National Key Laboratory of Plant Molecular Genetics Institute of Plant Physiology and Ecology/CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai 200032China Hainan institute Zhejiang UniversityYongyou Industry ParkYazhou Bay Sci-Tech CitySanya 572000China College of Agriculture and Biotechnology Zhejiang UniversityHangzhou 310058China Shandong Provincial Key Laboratory of Dryland Farming Technology College of AgronomyQingdao Agricultural UniversityQingdao 266109China institute of Millet Crops Hebei Academy of Agriculture&Forestry Sciences/Hebei Branch of China National Sorghum Improvement CenterShijiazhuang 050035China

We investigated the effects of graphene on the model herb Artemisia annua,which is renowned for produc-ing artemisinin,a widely used pharmacological *** growth and biomass were promoted when *** was cultivated with low concentrations of graphene,an effect which was attributed to a 1.4-fold increase in nitrogen uptake,a 15%–22%increase in chlorophyllfluorescence,and greater abun-dance of carbon cycling–related *** to 10 or 20 mg/L graphene resulted in a�60%increase in H2O2,and graphene could act as a catalyst accelerator,leading to a 9-fold increase in catalase(CAT)ac-tivity in vitro and thereby maintaining reactive oxygen species(ROS)***,graphene exposure led to an 80%increase in the density of glandular secreting trichomes(GSTs),in which artemisinin is biosynthesized and *** contributed to a 5%increase in artemisinin content inmature ***-estingly,expression of miR828 was reduced by both graphene and H2O2 treatments,resulting in induction of its target gene AaMYB17,a positive regulator of GST *** molecular and genetic assays showed that graphene-induced H2O2 inhibits micro-RNA(miRNA)biogenesis through Dicers and regulates the miR828–AaMYB17 module,thus affecting GST *** results suggest that graphene may contribute to yield improvement in *** via dynamic physiological processes together with miRNA regulation,and it may thus represent a new cultivation strategy for increasing yield capacity through nanobiotechnology.

关键词： Artemisia annua artemisinin glandular secreting trichomes GSTs miRNA graphene

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

游泳短纤维鼻滴剂用于鼻脑药物传递

Science Bulletin 2024年第14期69卷 2153-2155页

作者：徐臆茹丁涛陈信良 The International Peace Maternity and Child Health Hospital School of MedicineShanghai Jiao Tong UniversityShanghai 200030China shanghai Key Laboratory of Embryo Original Diseases Shanghai 200030China Department of Orthopaedics Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint DiseasesShanghai Institute of Traumatology and OrthopaedicsRuijin HospitalShanghai Jiao Tong University School of MedicineShanghai 200025China

The brain,the most vital and intricate organ in the human body,governs neural *** within the brain is protected by the blood–brain barrier(BBB),a unique and highly regulated semi-permeable membrane[1].Due to the BBB obstruction,traditional drug delivery methods,such as oral administration or intravenous injection,often fail to efficiently deliver drugs to the brain[2].

关键词：药物传递 drugs injection

西藏羊卓雍错湖面水热通量变化及其与气象因子的关联

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 2024年第2期34卷 397-414页

作者：张雪芹靳铮沈鹏珂郑度 Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Department of Atmospheric and Oceanic Sciences Fudan UniversityShanghai 200438China National Climate Center China Meteorological AdministrationBeijing 100081China

Lake surface water-heat exchange and its climatic attribution critically influence alpine lakes’evaporation mechanism and water storage balance with climate ***,this paper first explored the hourly,daily,and monthly water-heat flux variations of the lake surface and their correlations with meteorological factors based on the eddy covariance turbulent flux observation over the Yamzhog Yumco,an alpine lake in south Tibet in the non-freezing period(April-December)in 2016 and *** found that the average latent heat flux was much higher than the sensible heat flux on the lake surface from April to ***,the water-heat flux exhibited remarkable seasonal variation,with a prominent role of higher air temperature and humidity in summer jointly controlling the lake-air energy ***,the main controlling meteorological factors for the water-heat flux variation of the lake surface differed with diversified ***,the lake-air temperature difference was the most significant meteorological factor related to sensible heat flux on the half-hourly,daily,and monthly ***,the latent heat flux was strongly positively correlated with wind speed and the synergies of wind speed and water vapor pressure deficit on the daily and half-hourly ***,the lake surface heat flux was significantly negatively correlated with net radiation flux on the daily and monthly *** negative correlation can be attributed to the seasonal variation of the water surface net radiation,and the phase difference in heat flux intensity caused by the lake-air temperature difference and heat capacity *** findings will hopefully improve the understanding of energy exchange and evaporation mechanisms for alpine lakes in a warming climate.

关键词： lake surface water-heat flux meteorological factor eddy covariance alpine lakes Yamzhog

A Localization Method of High Energy Transients for All-sky Gamma-ray Monitor

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第10期24卷 25-35页

作者： Yi Zhao Wangchen Xue Shaolin Xiong Qi Luo Yuanhao Wang Jiacong Liu Heng Yu Xiaoyun Zhao Yue Huang Jinyuan Liao Jianchao Sun Xiaobo Li Qibin Yi Ce Cai Shuo Xiao Shenglun Xie Chao Zheng Yanqiu Zhang Chenwei Wang Wenjun Tan Zhiwei Guo Chaoyang Li Zhenghua An Gang Chen Yanqi Du Min Gao Ke Gong Dongya Guo Jiang He Jianjian He Bing Li Gang Li Xinqiao Li Jing Liang Xiaohua Liang Yaqing Liu Xiang Ma Rui Qiao Liming Song Xinying Song Xilei Sun Jin Wang Ping Wang Xiangyang Wen Hong Wu Yanbing Xu Sheng Yang Dali Zhang Fan Zhang Hongmei Zhang Peng Zhang Shu Zhang Zhen Zhang Shijie Zheng Keke Zhang Xingbo Han Haiyan Wu Hu Tai Hao Geng Gaopeng Lu Wei Xu Fanchao Lyu Hongbo Zhang Fangjun Lu Shuangnan Zhang Department of Astronomy Beijing Normal UniversityBeijing 100875China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China College of Physics Hebei Normal UniversityShijiazhuang 050024China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guizhou Normal UniversityGuiyang 550001China School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China institute of Astrophysics Central China Normal UniversityWuhan 430079China College of physics Sciences Technology Hebei UniversityBaoding 071002China Physics and Space Science College China West Normal UniversityNanchong 637002China School of Computing and Artificial Intelligence Southwest Jiaotong UniversityChengdu 611756China College of Electronic and information Engineering Tongji UniversityShanghai 201804China Innovation Academy for Microsatellites of Chinese Academy of Sciences Shanghai 201304China National Space Science Center Chinese Academy of SciencesBeijing 100190China School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Electronic Information School Wuhan UniversityWuhan 430072China Key Laboratory of Transportation Meteorology of china Meteorological administration Nanjing Joint Institute for Atmospheric SciencesNanjing 210000China Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up *** based on the relative counts of different detectors has been widely used for all-sky gamma-ray *** are two major methods for this count distribution localization:χ^(2)minimization method and the Bayesian *** we propose a modified Bayesian method that could take advantage of both the accuracy of the Bayesian method and the simplicity of the χ^(2)*** comprehensive simulations,we find that our Bayesian method with Poisson likelihood is generally more applicable for various bursts than the χ^(2)method,especially for weak *** further proposed a location-spectrum iteration approach based on the Bayesian inference,which could alleviate the problems caused by the spectral difference between the burst and location *** method is very suitable for scenarios with limited computation resources or timesensitive applications,such as in-flight localization software,and low-latency localization for rapidly follow-up observations.

关键词： methods:data analysis methods:analytical (stars:)gamma-ray burst:general

Design and assembly of a nested imaging X-ray telescope for the Hot Universe Baryon Surveyor mission

在线全文

学校读者我要写书评

暂无评论

Astronomical Techniques and Instruments 2024年第3期1卷 157-165页

作者： Jun Yu Ruohui Xian Xiaoqiang Wang Yifan Wang Zhanshan Wang Wei Zhang Yibo Cai Jing Yang Xi Lu Wei Wang Wei Cui institute of Precision Optical Engineering Tongji UniversityShanghai 200092China shanghai institute of Satellite Engineering Shanghai 201109China Department of Astronomy Tsinghua UniversityBeijing 100084China

The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progress in the design and construction of nested X-ray telescopes which were designed to use a three-stage conic-approximation type assembly to simplify the manufacturing process. The mirror substrate is made using the thermal glass slumping method, with mirrors characterized by a root-mean-square roughness of 0.3.nm, with expected high reflectivity and good thermal stability. We also discuss methods of telescope construction and conduct a deformation analysis of the manufactured mirror. The in situ measurement system program is developed to guide the telescope assembly process.

关键词： Nested X-ray telescope Thermal glass slumping Telescope assembly In situ measurement