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991.
王丹 《广东海洋大学学报》2005,25(5):101-103
在中国十九世纪末二十世纪初的启蒙运动中,启蒙思想家们将启蒙国民性的重点放在了批判儒家思想中的家族制度和家族伦理上。家族制度和家族伦理作为封建父权的安身立命之所,对它们的质疑和瓦解必然导致父权在整体上被瓦解,从此,父权走上了衰微之路。 相似文献
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席临平 《地球科学与环境学报》2001,23(2):75-76
对EDTA容量法测定水中硫酸根时,对加入沉淀剂后样品静置时间对测定结果的影响进行了研究。结果表明,在本法规定的浓度范围内,样品静置时间对测定结果无影响。 相似文献
994.
18O is an ideal tracer for characterizing hydrological processes because it can be reliably measured in several watershed hydrological compartments. Here, we present multiyear isotopic data, i.e. 18O variations (δ18O), for precipitation inputs, surface water and groundwater in the Shingobee River Headwaters Area (SRHA), a well‐instrumented research catchment in north‐central Minnesota. SRHA surface waters exhibit δ18O seasonal variations similar to those of groundwaters, and seasonal δ18O variations plotted versus time fit seasonal sine functions. These seasonal δ18O variations were interpreted to estimate surface water and groundwater mean residence times (MRTs) at sampling locations near topographically closed‐basin lakes. MRT variations of about 1 to 16 years have been estimated over an area covering about 9 km2 from the basin boundary to the most downgradient well. Estimated MRT error (±0·3 to ±0·7 years) is small for short MRTs and is much larger (±10 years) for a well with an MRT (16 years) near the limit of the method. Groundwater transit time estimates based on Darcy's law, tritium content, and the seasonal δ18O amplitude approach appear to be consistent within the limits of each method. The results from this study suggest that use of the δ18O seasonal variation method to determine MRTs can help assess groundwater recharge areas in small headwaters catchments. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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在深入分析IEEE 802.11标准的有线等价私密(WEP)安全漏洞的基础上,提出了用高级加密算法AES代替RC4,AES提供了比RC4更高的加密性能和更加强大的安全保护,因此AES方案必将成为新一代的加密标准. 相似文献
998.
首先介绍了基4时域抽取FFT算法的快速高效的原理及实现方法, 然后用MATLAB对该算法进行了仿真,分析了对其优化的几个方向,并提出了一种利用单一倒序表进行多点数位倒序的新方法.最后给出了在ADSP-BF533 DSP 上采用C语言实现FFT 的软件设计方法,并在ADSP-BF533 KZ-KIT LiteTM评估板上成功实现,经过实验验证, 结果正确,各项指标均达到了设计要求.该实现方法具有可移植性好、速度快等优点,具有很好的参考价值和应用前景. 相似文献
999.
Acartia clausi 《Estuarine, Coastal and Shelf Science》2001,52(6):715
Diel changes in vertical distribution and gut pigment contents of Acartia clausi andPseudodiaptomus hessei were studied during several 24-h time series performed between 1993 and 1997 in four sites of the Ebrié Lagoon (Côte d'Ivoire). The sites differed by their morphology and their hydrological structure and by the vertical distribution of chlorophyll biomass. Both species showed classical diel vertical migrations (DVM). Copepodites and adult stages of P. hessei were almost benthic during the day and evenly distributed through the water column at night. The amplitude of DVM of A. clausi increased from copepodites I–III to adults. Copepodites and adults of A. clausi increased significantly their gut fluorescence at night, whereas those of P. hessei showed no clear diel feeding rhythm (DFR). These results suggest that A. clausi feed mostly at night on phytoplanktonic particles and P. hessei feed mostly on benthic algal particles during the day and on sestonic particles at night. No relationship was observed between DFR and DVM because both patterns occurred when food was either vertically homogeneous or vertically stratified. The daily average gut fluorescence of A. clausi increased with ambient chlorophyll concentration until around 12–15 μg l−1, whereas no relationship was found for P. hessei. The implication of these patterns on the adaptation capacities and the behaviour of the two species are discussed. The DVM of P. hessei should explain its rarity in the estuarine area. The comparison of our results with previous ones suggests an evolution of A. clausi DFR between 1981–1982 and 1996–1997, in relation to an intensification of eutrophication. 相似文献
1000.
K. A. Stoyanov R. K. Zamanov G. Y. Latev A. Y. Abedin N. A. Tomov 《Astronomische Nachrichten》2014,335(10):1060-1063
We present new radial velocities of the high‐mass X‐ray binary star 4U 2206+54 based on optical spectra obtained with the Coudé spectrograph at the 2 m RCC telescope of the Rozhen National Astronomical Observatory, Bulgaria in the period November 2011–July 2013. The radial velocity curve of the He I δ6678 Å line is modeled with an orbital period Porb = 9.568 d and an eccentricity of e = 0.3. These new measurements of the radial velocity resolve the disagreements of the orbital period discussions. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献