Accurate Shortwave Radiation Simulation with a Two-Layer Aerosol Model in Xinjiang Region

To harness the rich solar energy resources in Xinjiang Region of Northwest China,this study tries to address the issue of lack of downward surface shortwave radiation(DSSR)observations and the need to improve the accuracy of satellite retrieval and numerical simulation of DSSR under varied sky and meteorological conditions.(1)A two-layer aerosol model specific to Xinjiang was developed to capture the vertical distributions of aerosols based on multiple data sources including lidar,GPS sounding,ground meteorological observations,and profiles from the ECMWF reanalysis version 5(ERA5)data.The results show that the ERA5/PBLH(planetary boundary layer height)and ERA5/ALH(aerosol layer height)could be used to establish the two-layer aerosol model and characterize the vertical distribution of aerosols in Xinjiang Region.(2)Using the Santa Barbara Discrete Atmospheric Radiative Transfer(SBDART)model,a localized inverse model of clear-sky DSSR was established.After parameter adjustment and using the optimal combination of input parameters for DSSR simulation together with the two-layer aerosol model,the model-simulated DSSR(DSSRSBD)under clear-sky conditions improved significantly compared to the initial results,with all fitting indices greatly improved.(3)In addition,the study demonstrated that the impact of the two-layer aerosol model on DSSR was more pronounced under dust conditions than clear-sky conditions.(4)Using the localized clear-sky DSSR inversion model and its required parameters,simulations were also conducted to capture the spatiotemporal distribution of DSSR under clear-sky conditions in Xinjiang from 2017 to 2019.The annual average DSSR_(SBD)under clear-sky conditions in Xinjiang during 2017–2019 was 606.78 W m^(-2),while DSSR from CERES(DSSR_(CER))under the same conditions was generally higher(703.95 W m^(-2)).(5)It is found that satellite remote sensing products experienced data loss in high-altitude snow areas,where numerical simulation technology could serve as a valuable complement.

刺激响应聚合物微针在经皮给药中的应用

聚合物微针自身具有良好的机械性能和优异的生物相容性,能以微创的方式刺穿皮肤角质层,实现药物的高效经皮吸收,从而有效治疗各种疾病,如糖尿病、癌症、肥胖以及眼部疾病等。如何调控聚合物微针中负载药物的释放行为,是微针经皮给药需要关注的核心要素。刺激响应释放聚合物微针作为一种新兴的按需给药技术,能根据外界环境条件或自身生理环境变化实现药物的局部精确释放,是当前经皮给药领域的研究热点之一。目前,刺激响应聚合物微针的研究主要集中在光响应、pH响应、酶响应以及葡萄糖响应聚合物微针方面。本文将从微针在不同疾病中的应用,详细综述刺激响应聚合物微针的研究进展,并对这一领域的未来发展进行展望。

Seasonal variation in particle contribution and aerosol types in Shanghai based on satellite data from MODIS and CALIOP

Although the concentration of atmospheric particulate matter in Shanghai has declined in recent years,aerosols remain one of the major pollutants affecting air quality.Herein,spatio-seasonal variation in aerosol optical properties and aerosol types were studied overa 10-year period(2006-2015)in Shanghai,China,using satellite data from Moderate Resolution Imaging Spectroradiometer(MODIS)and CloudAerosol Lidar with Orthogonal Polarization(CALIOP).The average aerosol optical depth values for central urban and suburban areas of Shanghai were between 0.9 and 1.0.Clear seasonal variation in aerosol concentrations occurred,causing strongest attenuation in summer and weakest attenuation in autumn.Polluted dust,polluted continental(urban/industrial)and smoke aerosols were the main aerosol types.Desert dust aerosols occurred in the Shanghai area at higher altitudes(greater than 3 km)in spring,related to dusty weather in the north;while in winter,smoke aerosols occurred at high altitudes,related to haze pollution in the north.The aerosols detected in autumn were mainly from local sources,comprising polluted dust,polluted continental,and smoke aerosols.Aerosols in Shanghai clearly reflect both local and regional sources at different times.

Comparison of aerosol characteristics during haze periods over two urban agglomerations in China using CALIPSO observations

Using CALIPSO （cloud-aerosol lidar and infrared pathfinder satellite observation） vertical observation data during haze periods from January 2007 to December 2008, we analyzed differences in aerosol char- acteristics near the surface, as well as in the middle troposphere between the Beijing-Tianjin-Hebei metropolitan region （Area A） and the Yangtze River Delta region （Area B） in China. One significant dif- ference was that haze pollution in Area A was related to local and non-local aerosols, while in Area B it was related to local anthropogenic sources. In all seasons apart from autumn, aerosol pollution in Area A was more severe than in Area B, both near the surface and at higher altitudes, In Area A, non-spherical aerosols were dominant from 0 to 4 km in spring, summer, and winter; while in autumn, there were con- siderably high numbers of non-spherical aerosols below 0.5 km, and near-spherical aerosols from 0.5 to 4 km. In Area B, both near-spherical and non-spherical aerosols were common in all seasons. Moreover, aerosols with attenuated color ratios of 0-0.2 were more common in all seasons in Area A than in Area B, indicating that fine particle pollution in Area A was more serious than in Area B. Finally, relatively large aerosols linked to gravity settling appeared more frequently near the surface in Area A than in Area B.

Transport of black carbon aerosols from non-local sources:A case study in Shanghai

Black carbon （BC） aerosol mass carried by winds of varying directions from non-local sources was esti- mated based on hourly measured data of BC mass concentration （CBc） and meteorological parameters from January 2008 to December 2012 in Shanghai, and the relationship between annual average CBc and wind speed was analyzed. The results show that the annual average CBC decreased with wind speed for speeds exceeding 0.3 m/s. The relationship between the two was determined by a linear fit with corre- lation coefficient 0,88. Assuming BC aerosol mass of non-local sources transported by a southeast wind was zero, annual average BC concentrations （μg/m3） carried by winds of variable direction were 1.99 （southwest）, 1.95 （west）, 1.15 （northwest）, 0.54 （south）, 0.39 （north）, 0.01 （northeast）, and 0.01 （east）. BC aerosol mass of non-local sources transported by wind to Shanghai was about 6404.05 t per year, among which the total contribution of southwest, west, and northwest winds was nearly 84~;. The aerosol mass transported to Shanghai in winter accounted for 35% that of the entire year, and was greater than that of the other seasons.