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71.
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O. V. Kopelevich S. V. Sheberstov O. Yunev O. Basturk Z. Z. Finenko S. Nikonov V. I. Vedernikov 《Journal of Marine Systems》2002,36(3-4)
Absolute values of chlorophyll a concentration and its spatial and seasonal variations in the Black Sea were assessed by using satellite CZCS and in situ data. Since the satellite CZCS had operated for the 1978–1986 period, CZCS data was used for assessing the past state of the Black Sea just before the onset of drastic changes observed in late 1980s. The approach used for the calculation of the absolute values of chlorophyll a concentration from CZCS data was based on the direct comparison of in situ chlorophyll a data and those of CZCS and by applying the algorithm developed for the transformation of CZCS data into chlorophyll a values. CZCS Level 2 data related with pigment concentration having a spatial resolution of 1 km at nadir were used. The daily Level 3 files were derived by binning Level 2 values into 4-km grid cells and the monthly and seasonal Level 3 files were created by averaging the daily Level 3 files over the corresponding period. In situ chlorophyll a data were obtained by spectrophotometric and fluorometric methods in 15 scientific cruises over the 1978–1986 period. Total number of ship-measured data used for the comparison with those CZCS values was 590.Chlorophyll a concentration (Chl) was derived from CZCS values (C) with regression equations Chl=kC; the coefficient of transformation k was calculated from six different data sets by taking into account distinctions between subregions and seasons. The reasons for difference in the k values have been analyzed.Statistical comparison of the chlorophyll a values measured in situ and those derived from CZCS data was based on log-transformed data and gave the following results: regression SLOPE=0.842, regression INTERCEPT=−0.081, coefficient of determination (R2)=0.806, root–mean–square ERROR=0.195. The mean monthly chlorophyll a distributions derived from CZCS data over 1978–1986 have been constructed and the mean seasonal chlorophyll a values in different regions have been calculated and analyzed. The significant difference in chlorophyll concentration between the western shelf regions and the open part of the Black Sea has been demonstrated, especially in warm season. At almost all seasons, the highest chlorophyll concentration is observed in the western interior shelf region which is under strong influence of Danube. The summer mean chlorophyll concentration in this region is 18 times higher than that in the open parts and about nine times higher than in the eastern shelf region. The greatest seasonal variations are observed in the open part of the Black Sea: chlorophyll concentration in cold season is four to six times higher than in summer and three to five times higher than in April and October. To the contrary, in the western interior shelf regions, the concentration is higher in May–October (about twice than that in November–March). Seasonal variations in the western outer shelf regions are smoothed out as compared with both the western interior shelf and the open regions. 相似文献
73.
EFFECTOFCO-SUPPLEMENTATIONOFVITAMINEANDSELENIUMONNORMALANDMALIGNANTCELLPROLIFERATIONHuWenliang;LiuLihua;AnthonyTDiplock.(Depa... 相似文献
74.
介绍了用于200km/h速度等级电力机车轮盘制动装置的结构、工作原理、技术参数。型式试验及装车考核运用表明,该制动装置能满足200km/h机车对基础制动系统较高的安全可靠性要求。 相似文献
75.
维生素E对糖尿病大鼠高级糖基化终末产物及其受体和肾功的影响 总被引:2,自引:0,他引:2
目的观察维生素E对糖尿病大鼠高级糖基化终末产物(AGEs)及其受体(RAGE)和肾功能的影响。方法利用链脲佐菌素腹腔注射法诱导建立糖尿病大鼠模型。将实验用SD大鼠随机分为正常对照组(NC组)、糖尿病组(DM组)和维生素E治疗组(VE组),治疗8周。观察大鼠的一般状况,监测血糖(BGL)、糖化血红蛋白(HbA1C)、尿素氮(BUN)、血肌酐(Scr)、内生肌酐清除率(Ccr)、尿白蛋白排泄率(UAER)、肾重/体重比值;应用荧光显微镜观察肾脏组织AGEs,免疫组化方法检测RAGE含量。结果①与NC组比较,DM组大鼠体重、血糖、HbA1C、BUN、UAER、肾重/体重比值均明显增高(P<0.01),Ccr明显下降(P<0.01),肾脏AGEs及RAGE含量均明显增高(P<0.01);②与DM组相比,VE组UAER、肾重/体重比值明显降低(P<0.05),Ccr明显升高(P<0.01),肾脏AGEs及RAGE含量均明显降低(P<0.05)。结论维生素E无降糖作用,但可能通过减轻糖尿病大鼠肾组织的非酶糖基化过程,从而减轻AGEs与受体结合后导致的对肾脏组织的损伤,对糖尿病大鼠肾脏具有保护作用。 相似文献
76.
从电子商务中商品信息及其评价获取的实际应用出发,在分析了搜索技术在电子商务中的作用和应用现状的基础上,设计了一个用于搜索商品信息和商品评价的Internet信息搜索系统;并从实现技术上,提出了开发这个系统的体系结构,分析了各组成模块的功能和特点,着重研究了Internet信息搜索系统中的网络蜘蛛相关技术。 相似文献
77.
随着世界经济的发展,世界海运货物周转量随之增加,国际海运业的碳排放量持续增长,航运业减排的任务十分艰巨。本文结合航运业碳排放的特点,研究分析了国际海事组织(IMO)、欧盟及航运企业采取的一系列减排措施和采取的行动,为我国航运业减少碳排放提供了借鉴和参考依据。 相似文献
78.
格式塔理论强调认知的整体观与完形观,对译学研究有一定的启示.科技文章思维缜密,逻辑严谨,文体上表现出一定的格式塔特质.文章以科技英语(EST)为语料,格式塔理论宏观阐述与科技翻译具体实例相结合,探讨格式塔理论及其相关原则(接近、相似、闭合、简约)对科技英语汉译实践的观照. 相似文献
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