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1.
Appl Opt ; 60(24): 7186-7199, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34613006

RESUMO

The Directional Polarimetric Camera (DPC) is the first Chinese multi-angle polarized Earth observation satellite sensor, which was successfully launched on 9 May 2018, onboard the GaoFen-5 satellite in the Chinese High-Resolution Earth Observation Program. The DPC's observation is one of the most important space-borne multi-spectral, multi-angular polarimetric measurements of the global Earth-atmosphere system at the present stage. Although rigorous radiometric calibration had been performed for the DPC before launch, its in-flight performance may change because of the process of launch, harsh environment of space, and aging of the sensor. Due to the absence of the onboard calibration system, vicarious calibration methods are necessary for the DPC's in-flight performance monitoring and calibration. In this paper, we adapted the Rayleigh absolute calibration method, the sun glint inter-band calibration method, and the sun glint polarization calibration method to the DPC sensor. First, the calibration errors of these three methods caused by ancillary data uncertainties (e.g., aerosol, chlorophyll concentration, absorption gases amount, and wind speed) were analyzed in detail. The error budgets show that the aerosol parameters (optical thickness and aerosol model) are some of the critical factors affecting both the radiometric and polarimetric calibration accuracies for the Rayleigh and sun glint methods. The DPC radiometric and polarimetric in-flight calibration during its commissioning phase was then implemented. The absolute coefficients of short spectral bands (443, 490, 565, and 670 nm) were calibrated by the well-characterized Rayleigh scattering signal over the ocean. Using the 565 nm band as a reference band, the Rayleigh absolute calibration was then transferred to other bands (443, 490, 670, and 865 nm) through inter-band calibration using the specular reflection of the sun over the ocean. The polarization measurements of the DPC at polarized bands (490, 670, and 865 nm) were calibrated with the polarized reflection of the sun glint over ocean. The preliminary results show that the radiometric sensitivity of the DPC changed very little after launch at the four visible bands. The absolute calibration coefficient differences from pre-flight calibration are smaller than 0.5% at the 443 and 670 nm bands, while they are within ±2% at the 490 and 565 nm bands. However, a large deviation at 865 nm band of about 9% from pre-flight calibration was indicated by the sun glint inter-band calibration. The degree of linear polarization measurement of the DPC is validated with high accuracy of about 0.02 at the 865 nm band, while the deviation at 490 and 670 nm bands are relatively larger, reaching 0.04. The DPC/GaoFen-5 shows a good in-flight performance of radiometric measurement and generally reliable polarimetric measurement after launch.

2.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(3): 609-17, 2016 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-27400492

RESUMO

Aerospace activity in near space (20-50 km) has become a research hotspot for aviation big countries worldwide. Solar radiation study, as the prerequisite to carry out aerospace activity, is facing the barrier of lacking of observation in near space layer. Ozone is the most important factor that affects radiation value in this layer. Based on ECMWF reanalysis data, this input key parameter and its horizontal, vertical and temporal characteristics are analyzedwith results showing obvious regional features in temporal-spatial distribution and varieties. With meteorological data and surface parameters, near space over China is divided into 5 parts. Key factors' value is confirmed over each division. With SBDART radiation transfer model, solar radiation and ultraviolet radiation simulation in near space are conducted separately. Results show that it is influenced by latitude, total ozone and its vertical distribution, radiation varies under complex rules. The average year and monthly solar radiation strengthens changes with latitude reduction, while annual range changes reversely. Air absorbing is related to latitude and land-sea contrast and shows different values and seasonal variations. The ultraviolet radiation over South China Sea reaches its maximum value and minimum annual range, as well as minimum monthly range with value strengthening in summer and weakening in winter. In other areas radiation increases in summer while weakens in winter, monthly range shows double peaks with higher value in spring and autumn, lower in summer and winter. Air absorption in ultraviolet radiation is influenced by multiple factors, vertical varieties over areas besides South China Sea enhance in summer time. The vertical changes of monthly ranges affected by air absorption show consistence in higher and lower layer in June and July, while in other months ranges are bigger in higher layer.

3.
Zhongguo Zhen Jiu ; 35(6): 591-3, 2015 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-26480562

RESUMO

Clinical literature of bronchial asthma treated with acupoints application from January 2000 to March 2014 in modern periodicals databases was retrieved through computer. With cluster analysis and frequency analysis methods of data mining, acupoints selecting and medication rules of bronchial asthma treated with acupoints application were analyzed. Total 38 articles were included eventually, including 25 acupoints and 42 medicines. The results indicate that on acupoints selecting, Feishu (BL 13) is used as the main acupoint and 3 groups of bladder meridian and conception vessel acupoints are applied alternately and on medicines, Baijiezi (Brassica alba Boiss), Xixin (Radix et Rhizoma Asari), Gansui (Radix Kansui), Yanhusuo (Corydalis) and Mahuang (Radix et Rhizonma Ephedrae) are primarily adopted, epispastic medicines being the main medicines; medicines mostly belong to lung meridian, main medicines being unchanged mostly with Shengjiang as guiding drug.


Assuntos
Pontos de Acupuntura , Terapia por Acupuntura , Antiasmáticos/uso terapêutico , Asma/terapia , Meridianos , Asma/tratamento farmacológico , Mineração de Dados , Bases de Dados Factuais , Humanos
4.
Zhongguo Zhen Jiu ; 35(11): 1177-80, 2015 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-26939343

RESUMO

To make a systematic study on acupoints selection and medication rules for allergic rhinitis treated with acupoint application, literature regarding clinical researches on acupoint application for allergic rhinitis since 2000 has been retrieved; medication and acupoints involved were preprocessed and cluster analysis technique was applied to classify the data. As a result, a total of 37 pieces of literature were included, involving 27 types of herbs and 33 acupoints. The results showed Baijiezi (Brassica alba Boiss), Xixin (Radix et Rhizoma Asari), Gansui (Radix Kansui), Yanhusuo (Corydalis), Jiangzhi (Ginger juice) and Baizhi (Radix angelicae) constituted the main herb prescription, and the layer was increased along with frequency of use. Feishu (BL 13), Dazhui (GV 14), Shenshu (BL 23), Pishu (BL 20), Gaohuang (BL 43), Fengmen (BL 12) constituted the main acupoint prescription, which were clustered into 4 classes; Feishu (BL 13) and Dazhui (GV 14) constituted the first class; Pishu (BL 20) and Shenshu (BL 23) constituted the second class; the first and second class merged into the third class, Including Feishu (BL 13), Dazhui (GV 14), Shenshu (BL 23) and Pishu (BL 20); Gaohuang (BL 43) and Fengmen (BL 12) constituted the fourth class; the fourth class and the third class constituted the whole acupoint prescription. It was showed that for the allergic rhinitis treated with acupoint application, the medication was mainly epispastic herbs with pungent nature that belonged to the lung, spleen and kidney meridian, which presented the principle of simultaneous treatment of principal and subordinate symptoms; also the medication can be selected from core layer to supporting layer based on clinical needs; for the selection of acupoints, acupoints in lung and bladder meridian were mainly selected to assist exterior and resist the pathogenic qi, which could treat allergic rhinitis fundamentally by joint use with acupoints in soleen and kidney meridian.


Assuntos
Pontos de Acupuntura , Medicamentos de Ervas Chinesas/administração & dosagem , Rinite Alérgica/tratamento farmacológico , Mineração de Dados , Bases de Dados Bibliográficas , Medicamentos de Ervas Chinesas/química , Humanos , Meridianos
5.
Artigo em Inglês | MEDLINE | ID: mdl-24761151

RESUMO

It had been indicated in the previous studies that acupuncture relieved the excessive excitation of hypothalamic-pituitary-adrenal cortex axis (HPAA) function induced by stress stimulation. But the changes in glucocorticoid receptor (GR) induced by acupuncture have not been detected clearly. The objective of the study was to observe the impacts of acupuncture on the protein expressions of corticotrophin releasing hormone (CRH), adrenocorticotropic hormone receptor (ACTHR), and GR under the physiological and stress states. The results showed that under the stress state, acupuncture upregulated the protein expression of GR in the hippocampus, hypothalamic paraventricular nucleus (PVN), and pituitary gland, downregulated the protein expression of GR in the adrenal cortex, and obviously reduced the protein expressions of CRH and ACTHR. Under the physiological state, acupuncture promoted GR protein expression in the hippocampus and CRH protein expression in the hippocampus and PVN. The results explained that acupuncture regulated the stress reaction via promoting the combination of glucocorticoids (GC) with GR, and GR protein expression. The increase of GR protein expression induced feedback inhibition on the overexpression of CRH and ACTHR, likely decreased GC level, and caused the reduction of GR protein expression in the adrenal cortex.

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