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Retrievals of aerosol optical depth and total column ozone from Ultraviolet Multifilter Rotating Shadowband Radiometer measurements based on an optimal estimation technique

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Frontiers of Earth Science 2014年第4期8卷 610-624页

作者： Chaoshun LIU maosi chen Runhe SHI Wei GAO Key Laboratory of Geographic Information Science Ministry of Education East China Normal University Shanghai 200062 China USDA UV-B Monitoring and Research Program Natural Resource Ecology Laboratory Colorado State University Fort Collins CO 80523 USA

A Bayesian optimal estimation （OE） retrieval technique was used to retreive aerosol optical depth （AOD）, aerosol single scattering albedo （SSA）, and an asymmetry factor （g） at seven ultraviolet wavelengths, along with total column ozone （TOC）, from the measurements of the UltraViolet Multifilter Rotating Shadowband Radiometer （UV-MFRSR） deployed at the Southern Great Plains （SGP） site during March through November in 2009. The OE technique specifies appropriate error covariance matrices and optimizes a forward model （Tropospheric ultraviolet radiative transfer model, TUV）, and thus provides a supplemental method for use across the network of the Department of Agriculture UV-B Monitoring and Research Program （USDA UVMRP） for the retrieval of aerosol properties and TOC with reasonable accuracy in the UV spectral range under various atmo- spheric conditions. In order to assess the accuracy of the OE technique, we compared the AOD retreivals from this method with those from Beer＇s Law and the AErosol RObotic Network （AERONET） AOD product. We also examine the OE retrieved TOC in comparison with the TOC from the U.S. Department of Agriculture UV-B Monitoring and Research Program （USDA UVMRP） and the Ozone Monitoring Instrument （OMI） satellite data. The scatterplots of the estimated AOD from the OE method agree well with those derived from Beer＇s law and the collocated AERONET AOD product, showing high values of correlation coefficients, generally 0.98 and 0.99, and large slopes, ranging from 0.95 to 1.0, as well as small offsets, less than 0.02 especially at 368 nm. The comparison of TOC retrievals also indicates the promising accuracy of the OE method in that the standard deviations of the difference between the OE derived TOC and other TOC products are about 5 to 6 Dobson Units （DU）. Validation of the OE retrievals on these selected dates suggested that the OE technique has its merits and can serve as a supplemental tool in further analyzing UVMRP data.

关键词： optimal estimation aerosol optical depth totalcolumn ozone Ultraviolet Multifilter Rotating ShadowbandRadiometer (UV-MFRSR) Aerosol Robotic Network(AERONET) Tropospheric ultraviolet radiative transfermodel (TUV)

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Comparison of aerosol optical depth of UV-B Monitoring and Research Program （UVMRP）, AERONET and MODIS over continental United States

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Frontiers of Earth Science 2013年第2期7卷 129-140页

作者： Hongzhao TANG maosi chen John DAVIS Wei GAO USDA UV-B Monitoring and Research Program Natural Resource Ecology Laboratory Colorado State University Fort Collins CO 80521 USA Department of Ecosystem Science and Sustainability Colorado State University Fort Collins C-O 80521 USA

The concern about the role of aerosols as to their effect in the Earth-Atmosphere system requires observation at multiple temporal and spatial scales. The Moderate Resolution Imaging Spectroradiameters （MODIS） is the main aerosol optical depth （AOD） monitoring satellite instrument, and its accuracy and uncertainty need to be validated against ground based measurements routinely. The comparison between two ground AOD measurement programs, the United States Department of Agriculture （USDA） Ultmviolet-B Monitoring and Research Program （UVMRP） and the Aerosol Robotic Network （AERONET） program, confirms the consistency between them. The intercomparison between the MODIS AOD, the AERONET AOD, and the UVMRP AOD suggests that the UVMRP AOD measurements are suited to be an alternative ground-based validation source for satellite AOD products. The experiments show that the spatial-temporal dependency between the MODIS AOD and the UVMRP AOD is positive in the sense that the MODIS AOD compare more favorably with the UVMRP AOD as the spatial and temporal intervals are increased. However, the analysis shows that the optimal spatial interval for all time windows is defined by an angular subtense of around 1° to 1.25°, while the optimal time window is around 423 to 483 minutes at most spatial intervals. The spatial-temporal approach around 1.25° ＆ 423 minutes shows better agreement than the prevalent strategy of 0.25° ＆ 60 minutes found in other similar investigations.

关键词： aerosol optical depth (AOD) United States Department of Agriculture (USDA) UV-B Monitoring andResearch Program (UVMRP) Aerosol Robotic Network (AERONET) Moderate Resolution Imaging Spectmradiameters (MODIS) validation spatial-temporal approach

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Algae （Microcystis and Scenedesmus） absorption spectra and its application on Chlorophyll a retrieval

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Frontiers of Earth Science 2013年第4期7卷 522-530页

作者： Di WU maosi chen Qiao WANG Wei GAO Satellite Environment Center Ministry of Environmental Protection Beijing 100094 China USDA UV-B Monitoring and Research Program Natural Resource Ecology Laboratory Colorado State University Fort Collins CO 80521 USA Department of Ecosystem Science and Sustainability Colorado State University Fort Collins CO 80521 USA

Blue algae and green algae are the dominant phytoplankton groups that contribute to the eutrophication and the water bloom in inland water of China. The absorption coefficients （spectra） of the algae, which do not change with its intrinsic optical characteristics and the observation geometry, are strictly additive quantities. The characteristics of the absorption spectra of the two algae are presented. The pure blue algae and the pure green algae cultured in the laboratory environment are diluted and mixed at ten volume ratios. The Quantitative Filter Technique was applied to measure their absorption spectra. The ＂hot-ethanol extraction＂ method was chosen to calculate their concentration of Chlorophyll a. The retrieval algorithm developed in this study extracts the mapping information between each individual alga and their Chlorophyll a concentration via Continuous Wavelet Transform, and retrieves the Chlorophyll a concentration of each alga in their mixture using a trust region optimizer. The results show that the retrieved and the measured Chlorophyll a concentrations of the blue algae and the green algae components in the ten mixture match well with the average relative error of 5.55%.

关键词： algae absorption coefficient spectra Chlorophyll a trust region Continuous Wavelet Transform

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The calibration methods for Multi-Filter Rotating Shadowband Radiometer： a review

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Frontiers of Earth Science 2013年第3期7卷 257-270页

作者： maosi chen John DAVIS Hongzhao TANG Carolyn OWNBY Wei GAO USDA UV-B Monitoring and Research Program Natural Resource Ecology Laboratory Colorado State University Fort Collins CO 80521 USA Department of Ecosystem Science and Sustainability Colorado State University Fort Collins CO 80521 USA

The continuous, over two-decade data record from the Multi-Filter Rotating Shadowband Radiometer （MFRSR） is ideal for climate research which requires timely and accurate information of important atmospheric components such as gases, aerosols, and clouds. Except for parameters derived from MFRSR measurement ratios, which are not impacted by calibration error, most applications require accurate calibration factor（s）, angular correction, and spectral response function（s） from calibration. Although a laboratory lamp （or reference） calibration can provide all the information needed to convert the instrument readings to actual radiation, in situ calibration methods are implemented routinely （daily） to fill the gaps between lamp calibrations. In this paper, the basic structure and the data collection and pretreatment of the MFRSR are described. The laboratory lamp calibration and its limita- tions are summarized. The cloud screening algorithms for MFRSR data are presented. The in situ calibration methods, the standard Langley method and its variants, the ratio-Langley method, the general method, Alexandrov＇s comprehensive method, and chen＇s multi-channel method, are outlined. The reason that all these methods do not fit for all situations is that they assume some properties, such as aerosol optical depth （AOD）, total optical depth （TOD）, precipitable water vapor （PWV）, effective size of aerosol particles, or angstrom coefficient, are invariant over time. These properties are not universal and some of them rarely happen. In practice, daily calibration factors derived from these methods should be smoothed to restrain elTor.

关键词： Multi-Filter Rotating Shadowband Radiometer (MFRSR) calibration review

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Assimilation of atmospheric infrared sounder radiances with WRF-GSI for improving typhoon forecast

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Frontiers of Earth Science 2018年第3期12卷 457-467页

作者： Yan-An LIU Zhibin SUN maosi chen Hung-Lung Allen HUANG Wei GAO Key Laboratory of Geographic Information Science (Ministry of Education) East China Normal University Shanghai 200241 China School of Geographic Sciences East China Normal University Shanghai 200241 China ECNU-CSU Joint Research Institute for New Energy and the Environment East China Normal University Shanghai 200062 China Joint Laboratory for Environmental Remote Sensing and Data Assimilation East China Normal University Shanghai 200241 China Natural Resource Ecology Laboratory Colorado State University Fort Collins CO 80523 United States Cooperative Institute for Meteorological Satellite Studies University of Wisconsin-Madison Madison WI 53706 United States

The Atmospheric Infrared Sounder （AIRS） can provide the profile information on atmospheric temperature and humidity in high vertical resolution. The assimilation of its radiances has been proven to improve the Numerical Weather Prediction （NWP） in global models. In this study, regional assimilation of AIRS radiances was carried out in a community assimilation system, using Gridpoint Statistical Interpolation （GSI） coupled with the Weather Research and Forecasting （WRY） model. The AIRS channel selection, quality control, and radiances bias correction were examined and illustrated for optimized assimilation. The bias correction scheme in the regional model showed that corrections on most of the channels produce satisfactory results except for several land surface channels. The assimilation and forecast experiments were carried out for three typhoon cases （Saola, Damrey, and Haikui in 2012） with and without including AIRS radiances. Results show that the assimilation of AIRS radiances into the WRF/GSI model improves both the typhoon track and intensity in a 72-hour forecast.

关键词： AIRS WRF/GSI model radiance assimilation typhoon forecast

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Development of the DayCent-Photo model and integration of variable photosynthetic capacity

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Frontiers of Earth Science 2018年第4期12卷 765-778页

作者： Jonathan R.STRAUBE maosi chen William J.PARTON Shinichi ASSO Yan-An LIU Dennis S.OJIMA Wei GAO USDA UV-B Monitoring and Research Program Natural Resource Ecology LaboratoryColorado State UniversityFort CollinsCO 80521USA Natural Resource Ecology Laboratory.Colorado State University Fort CollinsCO 80523USA Key Laboratory of Geographic Information Science (Ministry of Education) East China Normal UniversityShanghai 200241China School of Geographic Sciences East China Normal UniversityShanghai 200241China ECNU-CSU Joint Research Institute for New Energy and the Environment Shanghai 200062China Department of Ecosystem Science and Sustainability Colorado State UniversityFort CollinsCO 80523USA

We integrated a photosynthetic sub-model into the daily Century model (DayCent) to improve the estimations of seasonal changes in carbon fluxes at the Niwot Ridge LTER site and the Harvard forest LTER site (DayCent-Photo). The photosynthetic sub-model, adapted from the SIPNET/PnET family of models, includes solar radiation and vapor pressure deficit controls on production, as well as temperature and water stress terms. A key feature we added to the base photosynthetic equations is the addition of a variable maximum net photosynthetic rate (Amax). We optimized the parameters controlling photosynthesis using a variation of the Metropolis-Hastings algorithm along with data-assimilation techniques. The model was optimized and validated against observed net ecosystem exchange (NEE) and estimated gross primary production (GPP) and ecosystem respiration (RESP) values for AmeriFlux sites at Niwot Ridge and Harvard forest. The inclusion of a variable Amax rate greatly improved model performance (NEE RMSE = 0.63 gC·m–2, AIC = 2099) versus a version with a single Amax parameter (NEE RMSE = 0.74 gC·m–2, AIC = 3724). DayCent-Photo was able to capture the inter-annual and seasonal flux patterns for NEE, GPP, ecosystem respiration (RESP), and daily actual evapotranspiration (AET), but tended to overestimate yearly NEE uptake. The DayCent-Photo model has been successfully set up to simulate daily NEE, GPP, RESP, and AET for deciduous forest, conifer forests, and grassland systems in the US using AmeriFlux data sets and has recently been improved to include the impact of UV radiation surface litter decay (DayCent-UV). The simulated influence of a variable Amax rate suggests a need for further studies on the process controls affecting the seasonal photosynthetic rates. The results for all of the forest and grassland sites show that maximum Amax values occurs early during the growing period and taper off toward the end of the growing season.

关键词： DayCent-Photo model seasonal maximum net photosynthetic rate net ecosystem exchange gross primary production UV radiation

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基于异构多智能体自注意力网络的路网信号协调顺序优化方法

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交通运输系统工程与信息 2024年第3期24卷 114-126页

作者：陈喜群朱奕璋谢宁珂耿茂思吕朝锋浙江大学建筑工程学院智能交通研究所杭州310058 浙江大学工程师学院智能交通研究所杭州310058 浙江大学建筑工程学院杭州310058

针对路网交通信号控制的复杂性,本文提出基于异构多智能体自注意力网络的路网信号协调顺序优化方法,提升路网范围内多交叉口信号控制策略性能。首先,模型考虑多交叉口交通流的空间相关性,采用基于自注意力机制的价值编码器学习交通观测... 详细信息

针对路网交通信号控制的复杂性,本文提出基于异构多智能体自注意力网络的路网信号协调顺序优化方法,提升路网范围内多交叉口信号控制策略性能。首先,模型考虑多交叉口交通流的空间相关性,采用基于自注意力机制的价值编码器学习交通观测表征,实现路网级通信;其次,面向多智能体策略更新的非稳态环境,模型在前序智能体的联合动作基础上,基于多智能体优势分解的策略解码器,顺序决策最优反应动作;最后,设计基于有效行驶车辆的动作掩码机制,在时效完备区间自适应调节决策频率,并提出考虑等待公平性的时空压力奖励函数,进一步提高策略性能与实用性。在杭州路网数据集上验证模型有效性,结果表明:所提模型在2个数据集和5个性能指标上均优于基准模型;相比最优基准模型,所提模型平均行程时间降低10.89%,平均排队长度降低18.84%,平均等待时间降低22.21%。此外,所提模型的泛化能力更强,且显著减少车辆等待时间过长的情形。

关键词：智能交通深度强化学习路网信号控制异构多智能体时空压力奖励

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Norlichexanthone purified from plant endophyte prevents postmenopausal osteoporosis by targeting ERa to inhibit RANKL signaling

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Acta Pharmaceutica Sinica B 2021年第2期11卷 442-455页

作者： Keqi Wang Yongyan chen Shuo Gao maosi Wang Mengmeng Ge Qian Yang Mingkai Liao Lin Xu Junjie chen Zhiping Zeng Haifeng chen Xiao-kun Zhang Ting Lin Hu Zhou School of Pharmaceutical Sciences Fujian Provincial Key Laboratory of Innovative Drug Target ResearchXiamen UniversityXiamen 361102China High Throughput Drug Screening Platform Xiamen UniversityXiamen 361102China

Although different types of drugs are available for postmenopausal osteoporosis,the limitations of the current therapies including drug resistances and adverse effects require identification of novel anti-osteoporosis ***,we defined that norlichexanthone(NOR),a natural product,is a ligand of estrogen receptor-alpha(ERα)and revealed its therapeutic potential for postmenopausal *** used mammalian-one hybrid assay to screen for ERαmodulators from crude extracts of several plant *** a result,NOR purified from the extract of endophyte ARL-13 was identified as a selective ERα*** directly bound to ERαwith an affinity in nanomolar range,revealing that it is a natural ligand of ERα.NOR induced osteoblast formation in MC3T3-E1 precursor ***,NOR inhibited receptor activator of nuclear factor-kappa B ligand(RANKL)-induced osteoclast formation in both RAW264.7 macrophages and mouse primary ***,NOR inhibited RANKL-induced association of ERαand TRAF6 to prevent ERα-mediated TRAF6 activation via Lys63-linked ***,NOR exhibited potent anti-osteoporosis efficacy in an ovariectomized mouse *** to estrogen,NOR was of much less capability in stimulating endometrial hyperplasia and promoting mammalian cancer cell *** together,our study identified NOR as a natural and high affinity ligand of ERαwith substantial anti-osteoporosis but less estrogenic activity.

关键词： Norlichexanthone Osteoporosis Osteoclast RANKL signaling TRAF6 ERa

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“貌似”的盾言功能及其语义机制考探

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湖南工业大学学报（社会科学版） 2015年第6期20卷 101-106页

作者：陈荔华侨大学外国语学院福建厦门361021

"貌似"作盾言结构的功能语言学分析,认为"貌似"属于新用法,其聚合义体的层级空间化的形成是以构词元素结构相对松散化为代价的,其去模糊化功能蜕变成了模糊化功能。

关键词： “貌似” 盾言经验元功能分析意义实现机制

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