共查询到18条相似文献，搜索用时 93 毫秒
1.
SeaWiFS和MODIS叶绿素浓度数据及其融合数据的全球可利用率 总被引：2，自引：0，他引：2
对2001年Sea WiFS和MODIS叶绿素浓度数据的全球可利用率进行了定量分析，二者在全球范围的变化趋势一致，年平均可利用率分别为12．4％和13．6％，其中MODIS叶绿素浓度的可利用率略高于SeaWiFS。利用小波变换方法对二者进行数据融合，经分析：SeaWiFS／MODIS叶绿素浓度融合数据相对于单一传感器数据提高了全球可利用率，其年平均为20．50％；融合数据保持了较高空间分辨率MODIS数据的海洋特征；融合数据与实测值比较，差值的均值和标准偏差分别为0．16mg／m^3和1．07mg／m0（SeaWiFS：0．46mg／m^3和2．22mg／m^3，MODIS：0．13mg／m^3和0．82mg／m^3）。与MODIS和Sea WiFS相比。融合数据接近MODIS优于SeaWiFS。结果表明小波变换方法用于SeaWiFS和MODIS叶绿素浓度数据融合的有效性。 相似文献
2.
我国海区SeaWiFS资料大气校正 总被引：13，自引：1，他引：13
利用光谱辐射传输理论，结合海上同步实测资料，开发出我国海区SeaWiFS资料大气校正模型。经卫星资料处理结果比对，本模型在一类水体，基本消除了412nm和443nm波段离水辐射率小于0的现象；在二类水体，利用临近一类水体的大气条件进行了有效的大气校正；同时建立了670nm,765nm,865nm波段的大气校正模型，这三个面适用于高浓度悬浮泥沙的信息提取。本模型用于处理我国海区的SeaWiFS资料比美国NASA模型更适合我国海区特定的大气和海洋环境，为SeaWiFS资料海洋水色信息提取和我国海洋一号（HY－1）及风云一号（FY－1C）卫星资料的大气校正研究提供了技术基础。 相似文献
3.
目的：建立护心康片多波长HPLC指纹图谱，并研究复方与组方药物指纹图谱峰的相关性。方法：采用C18色谱柱（4.6mm×200mm，5μm）；柱温35℃；0.1%磷酸溶液（A）-乙腈（B）为流动相梯度洗脱；流速1.0ml/min；检测波长分别为203nm（检测三七和黄芪）、270nm（检测丹参酮类）、286nm（检测丹参酚酸类和黄芪）。结果：建立了23个特征峰的护心康片HPLC指纹图谱，并对其特征峰进行了组方药物归属分析。结论：该方法能揭示复方主要色谱峰在组方药物中的归属，有效控制护心康片的质量。 相似文献
4.
药用红树林植物黄槿的化学成分研究 总被引：1，自引：0，他引：1
利用正相硅胶柱色谱、反相硅胶柱色谱、凝胶Sephadex LH-20柱色谱、制备薄层色谱（PTLC）及重结晶等分离手段，从海洋红树林植物黄槿（Hibiscus tilisceus）中分离得到11个化合物，通过MS、1D和2D NMR等波谱技术鉴定了所有化合物的结构，分别为coniferaldehyde（1），3,4-二羟基苯甲酸甲酯（2），松脂醇（3），丁香脂素（4），格榄酮（5），黄芪苷（6），植醇（7），胆甾-5-烯-3β，7α-二醇（8），胆甾-5-烯-3β，7β-二醇（9），胆甾醇（10）和声-胡萝卜苷（11）。这些化合物均为首次从该植物中分离获得。 相似文献
5.
目的：建立炎可宁丸质量标准。方法：采用显微鉴别法鉴别黄连。采用薄层色谱法（TLC）鉴别黄柏、大黄、黄芩、板蓝根、黄连。采用高效液相色谱（HPLC）法测定大黄素与大黄酚的含量,使用Phenomenex Luna C18色谱柱（4.6 mm ×250 mm,5μm）,以甲醇-0.1%磷酸溶液（85∶15）为流动相,流速为1.0 ml/min,柱温为30℃,检测波长为254 nm。采用HPLC法测定黄芩苷的含量,使用CAPCELL PAK C18色谱柱（4.6 mm×250 mm,5μm）,以甲醇-0.1%磷酸溶液(45∶55)为流动相,流速为1.0 ml/min,柱温为30℃,检测波长为280 nm。结果:薄层色谱斑点清晰;大黄素和大黄素酚的线性范围分别为9.3～465.0 ng、11.6～580.0 ng,加样回收率分别为93.3%、98.0%,RSD分别为1.8%、2.7%;黄芩苷的线性范围为68～3400 ng,加样回收率为97.2%,RSD为1.2%。结论:本法简便可靠、结果准确,可用于该制剂的质量控制。 相似文献
6.
目的：建立高效液相色谱（HPLC）法测定疏肝健脾解毒方中毛蕊异黄酮葡萄糖苷的含量。方法：采用HPLC法,以依利特Supersil ODS-C18柱（4.6 mm×250 mm,5 μm）为色谱柱,以乙腈-0.2%甲酸溶液为流动相梯度洗脱（0～23 min,12%乙腈;23～65 min,12%～26%乙腈）,流速为1.0 ml/min,柱温为30℃,检测波长为260 nm。结果：经方法学验证,毛蕊异黄酮葡萄糖苷在7.2～43.2 μg（R2=0.9998）范围内线性关系良好,精密度、稳定性和重复性试验的RSD 均＜2.0%（n=6）,加样回收率为98.87%（RSD为1.79%）。结论：本研究建立的含量测定方法简便,结果准确可靠,适用于疏肝健脾解毒方中毛蕊异黄酮葡萄糖苷的测定,可为其质量标准的深入研究提供依据。 相似文献
7.
认识海洋在全球碳循环中的作用及其对环境变化的响应，需要高时空分辨率的观测数据。由于轨道宽度、云雨天气、太阳耀斑等的影响，单一的水色传感器的观测能力十分有限，将多源海洋水色卫星进行融合是提高水色数据时空覆盖的一种有效途径。SeaWiFS和MERIS分别于2010年12月11日和2012年5月9日停止运行，在很大程度上降低了水色融合产品时空覆盖的提升。我们在融合过程中加入了FY-3 MERSI数据，生成了全球海洋叶绿素浓度遥感融合产品数据集。数据源包括SeaWiFS、MERIS、MODIS-Aqua、VIIRS和MERSI。结果表明：加入MERSI后，融合产品的日平均有效空间覆盖提高了9%；采样频率（同一区域一年中获取有效数据的次数）由57天/年提高到109天/年。利用实测数据和国外同类融合产品（ESA GlobColour和NASA MEaSUREs）对新的数据集进行了质量评价。与实测数据相比，加入MERSI的融合产品精度与未加入MERSI的融合产品基本一致；与国外同类融合产品的偏差小于10%。新数据集的时间序列特性与未加入MERSI的融合产品以及单传感器的一致。 相似文献
8.
目的：建立三金排石颗粒的质量标准。方法：采用薄层色谱法（TLC）分别对三金排石颗粒中的海金沙、栀子、大黄和山楂共四味中药进行定性研究;采用高效液相色谱法（HPLC）分别对金钱草中的槲皮素和山柰素进行定量研究,色谱柱为C18柱,流动相为甲醇-0.35%磷酸溶液（50∶50）,流速为1.0 ml/min,检测波长为360 nm,柱温为30℃,进样量为10 μl。结果：所建立的TLC法中,海金沙、栀子、大黄和山楂斑点清晰,分离度好,专属性强。槲皮素和山柰素的检测质量浓度线性范围分别在0.010～0.100 mg/ml、0.010～0.101 mg/ml之间（r=0.9993、0.9998,n=6）,精密度、稳定性、重复性试验的RSD均≤2%（n=6）,平均加样回收率分别为101.86%、101.48%（n=6）。结论：本研究所建立的三金排石颗粒的质量标准,TLC法及HPLC法操作简便,准确快速,重现性好,可有效控制三金排石颗粒的质量。 相似文献
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10.
目的：建立中药舒心片中丹酚酸B含量的测定方法。方法：采用高效液相色谱法（HPLC）测定舒心片中丹酚酸B的含量,色谱柱为Agilent TC-C18（2）色谱柱（4.6 mm×250 mm,5 μm）,以乙腈-0.1%的磷酸溶液（25∶75）为流动相;检测波长为286 nm;柱温为25℃;流速为1.0 ml/min。结果：供试品和对照品溶液中丹酚酸B与他峰分离度良好;在0.050～1.642 μg之间丹酚酸B呈良好线性关系,R=0.9993,丹酚酸B平均加样回收率为97.58%,RSD=0.25%。结论：经方法学验证,本法可用于舒心片的质量控制。 相似文献
11.
１９９５年春，美国国家宇航局（ＮＡＳＡ）将发射一颗携带宽视场海洋观测传感器（ＳｅａＷｉＦＳ）的海洋卫星（Ｓｅａｓｔａｒ）．宽视场海洋观测传感器是继工作了七年多，于１９８５年停止发送资料的Ｎｉｍｂｕｓ－７海岸带水色扫描仪（ＣＺＺ）之后的第一个星载海洋水色传感器，不像作为概念验证性实验的海岸带水色扫描仪那样，宽视场海洋观测传感器被设计用来提供充分精确的光合色素浓度资料以进行海洋初级生产力和生物地球化学定量研究［４］。宽视场海洋观测传感器将常规地每二日一次提供全球复盖资料。美国国家宇航局空间科学应用署（ＡＳＳＡ）和哥达德空间飞行中心（ＧＳＦＣ）为了发展、管理海洋水色研究资料系统而制定了宽视场海洋观测传感器计划，这个系统能有效地收集、处理、校正、检验、存档以及发布由宽视场海洋观测传感器接收到的资料。本文主要介绍了宽视场海洋观测传感器计划的目的意义，研究内容以及其他概况［２，３］。 相似文献
12.
《Estuarine, Coastal and Shelf Science》2005,62(1-2):75-94
This paper presents three years (1998–2000) of chlorophyll a (chl a) data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) for Case 2 waters of Chesapeake Bay and the middle Atlantic bight (MAB) to describe phytoplankton dynamics on seasonal to interannual time scales. We used extensive data on inherent and apparent optical properties in conjunction with satellite retrievals to: (1) characterize the bio-optical properties of the study area relevant to processing and interpreting SeaWiFS data; (2) test the applicability of the SeaWiFS bio-optical algorithm (OC4v.4) for the estuarine and coastal waters; (3) evaluate the accuracy of the SeaWiFS remote sensing reflectance (RRS) and chl a products on regional and seasonal bases using in situ observations. The characteristically strong absorption by chromophoric dissolved organic matter (acdom) and non-pigmented particulate matter (ad) in estuarine and coastal waters contributed to overestimates of chl a using OC4v.4 applied to in situ radiances for the Bay (mean ratio 1.42±1.20) and the MAB (2.60±1.36). Values of RRS from SeaWiFS in the blue region of the spectrum were low compared to in situ RRS, suggesting that uncertainties remain in atmospheric correction. Direct comparisons of SeaWiFS retrievals of chl a with in situ chl a for the Bay showed larger biases and uncertainties (mean ratio 1.97±1.85) than for chl a estimated from OC4v.4 applied to in situ RRS. The larger biases were attributed to errors in SeaWiFS radiances and the larger uncertainties to time-space “aliasing” of satellite observations and in situ measurements. To reduce the time differences between SeaWiFS and in situ data, we compared chl a obtained from continuous underway fluorometric measurements on selected ship tracks to SeaWiFS chl a and showed that SeaWiFS captured phytoplankton dynamics in much of the Bay. The agreement of SeaWiFS chl a with in situ chl a was strongest in the mid- (regions 3, 4) to lower Bay (regions 1, 2), and deteriorated toward the upper Bay (regions 5, 6), in part due to a reduction of sensitivity and an increase of noise for SeaWiFS products in the highly absorbing, low RRS waters of the upper Bay. A three-year time-series of SeaWiFS and in situ data showed that SeaWiFS accurately and reliably captured seasonal and interannual variability of chl a associated with variations of freshwater flow. Significant short-term variability of chl a in summer that was unresolved with shipboard data was detected in the SeaWiFS time-series and the implications are discussed. The overall performance of SeaWiFS in the mid- to lower Bay and the MAB, combined with high spatial (∼1 km2) and temporal (∼100 clear scenes per year) resolution, indicate current SeaWiFS products are valuable for quantifying seasonal to interannual variability of chl a in estuarine and coastal waters. 相似文献
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14.
Comparative Analysis of Chlorophyll-a Distribution from SeaWiFS,MODIS-Aqua,MODIS-Terra and MERIS in the Arabian Sea 总被引：1，自引：0，他引：1
The variability of Chlorophyll-a (Chl-a) distribution derived from MODIS (on Aqua and Terra platforms) and MERIS sensors have been compared with SeaWiFS data in the Arabian Sea. MODIS Aqua has overestimated the SeaWiFS Chl-a within 25–32% in the coastal turbid (eutrophic) waters and underestimated in open ocean waters with error within 20%. However, there is no significant bias (?0.1 on log-scale) observed as the slope is well within 0.97-1.1 (log transformed). MODIS-Terra has underestimated the Chl-a concentration in open ocean waters by about 29–31%, which is higher than MODIS-Aqua. MODIS-Terra is observed to be more accurate than MODIS-Aqua in the coastal waters. MERIS is overestimating the SeaWiFS Chl-a with log RMS error of ～0.15 and log bias of ～0.13–0.2. The differences in the Chl-a estimates between each sensor are possibly due to differences in the sensor design, bio-optical algorithms and also due to the time differences between the satellites over passes. We have examined that the MERIS is performing similar to SeaWiFS and the MODIS-Aqua (Terra) data are reliable in open ocean (coastal) waters. However, Chl-a retrieval algorithms need to be improved especially for coastal turbid waters to continue with SeaWiFS data for long-term studies. 相似文献
15.
Are trends in SeaWiFS chlorophyll time-series unusual relative to historic variability 总被引：1，自引：0，他引：1
For selected locations in the Atlantic and Pacific Ocean, we compared surface ocean chlorophyll time series extracted from SeaWiFS imagery from 1997–2004 with the results of an ocean coupled circulation and biogeochemical model covering the period 1958–2004. During the 1997–2004 time period, linear trends in model and satellite time series were significantly correlated at most of the 44 sites we studied. Eleven sites were selected for further study, and we used the longer time series of the model to assess whether trends observed during the SeaWiFS period at these 11 sites were unusual in relation to those observed over the longer historical period covered by the model. The results show that the trends observed during the SeaWiFS period were not unusual and fell well within the range in magnitude of linear trends observed in other 8-year periods of model output. This result implies that the SeaWiFS satellite ocean color time series is not yet sufficiently long, on its own, to directly observe any long term changes in phytoplankton chlorophyll that may be occurring in the surface waters of the open ocean as a result of increased ocean stratification linked to global climate changed. 相似文献
16.
Atmospheric correction for China''s coastal water color remote sensing 总被引：14，自引：0，他引：14
INTRODUcrIONMeasurements from satellite have demonstrated that space sensor can be applied to measurethe sPectra of water-leaving radiance and proven that ocean color remote sensing is a powerfultcol for understanding oceanic, biological and physical processes. One sPecial ocean color satel-lite heaStar was successfully launched in August l997. It has brought to oceanOgraphers a wel-comed and improvd renewal of the ocean color of CZCS, VHRSR and arS. ffeaWiFS con-tributes much bette… 相似文献
17.
Joji Ishizaka Yasuhisa Kitaura Yasuharu Touke Hiroaki Sasaki Akihiko Tanaka Hiroshi Murakami Toshikazu Suzuki Kazumi Matsuoka Hideaki Nakata 《Journal of Oceanography》2006,62(1):37-45
High resolution SeaWiFS data was used to detect red tide events that occurred in the Ariake Sound, Japan, a small embayment
known as one of the most productive areas in Japan. SeaWiFS chlorophyll data clearly showed that a large red tide event, which
damaged seaweed (Nori) cultures, started early in December 2000 in Isahaya Bay, expanded to the whole sound and persisted
to the end of February 2001. The monthly average of SeaWiFS data from May 1998 to December 2001 indicated that the chlorophyll
peaks appeared twice a year, in early summer and in fall, after the peaks of rain and river discharge. The SeaWiFS data showed
that the red tide event during 2000–2001 winter was part of the fall bloom; however, it started later and continued significantly
longer than other years. Satellite ocean color data is useful to detect the red tide; however the algorithms require improvement
to accurately estimate chlorophyll in highly turbid water and in red tide areas. 相似文献