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81.
3-(1-吲哚基)丙酸及其衍生物的合成 总被引：1，自引：0，他引：1
介绍了3-(1-吲哚基)丙酸(3a)及其衍生物3-(5-溴-1-吲哚基)丙酸(3b)和3-(5,6-二氯.1-吲哚基)丙酸(3c)的合成方法.首先以3,3'-二硫代二丙酸二甲酯为原料与吲哚、5-溴-1-氢吲哚、5,6-二氯-1-氢吲哚的阴离子进行迈克尔加成反应.再对其碱性条件下进行水解、酸化,得到目标产物3a～3c,收率分别为49.5%,50.8%和35.1%.通过IR,1HNMR对所有化合物的结构进行了表征. 相似文献
82.
Chuanxin Qin Shuanglin Dong Fuyi Tan Xiangli Tian Fang Wang Yunwei Dong Qinfeng Gao 《中国海洋大学学报(英文版)》2009,8(3):296-302
Optimal stocking densities were investigated for the sea cucumber Apostichopus japonicus Selenka under feed-supplement and non-feed-supplement regimes in net enclosures for 333 d. Substantial weight loss occurred
during the aestivation phase (AE). Decreased growth rates were also observed during the winter phase (WT). In contrast, sea
cucumbers showed rapid growth during the spring (SP) and autumn (AU) phases. Feeding regimes considerably influenced the growth
performance, i.e., sea cucumbers grew faster under feed-supplement regime than under non-feed-supplement regime (P < 0.05). The average survival rates of sea cucumbers under feed-supplement regime were higher than those under non-feed-supplement
regime for both the autumn phase and spring phase, but the differences were only significant for the latter phase (P < 0.05). The fitted B-N curves showed that the optimal stocking densities, in terms of net production, were 22.3 ind. m-2
for feed-supplement regime and 14.1 ind. m-2 for non-feed-supplement regime. 相似文献
83.
东海黑潮温盐与中国东部气温和降水的相互关系 总被引：1，自引：0，他引：1
采用东海黑湖主流段长时间序列的实测温盐资料，研究了东海黑潮上层温度、上层盐度的变化及其与中国东部降水和地面气温的关系。结果表明，在过去50年内，东海黑潮上层海温呈上升趋势，而上层盐度略呈下降趋势。东海黑潮上层海温和我国东部地面气温的关系在冬季十分密切，呈现出大面积显著的正相关，这与冬季南下冷空气的整体降温作用有关。夏季，长江中下游江水的增多致使大量长江冲淡水入海，导致黑潮上层水盐度下降，此时东海黑潮上层盐度与我国大陆东部降水呈负相关。 相似文献
84.
85.
《Marine Policy》2005,29(2):163-174
This paper reviews differences and overlaps between hydrographic surveying and marine scientific research in the exclusive economic zone (EEZ), including the concept of military surveying. It concludes that recent trends with technology, the utility of hydrographic data and State practice suggest that hydrographic surveying in the EEZ should be under the jurisdiction of the coastal State. Paradoxically arguments for military surveys in the EEZ being outside coastal State jurisdiction appear stronger than those for hydrographic surveying. The paper offers some guidelines related to the conduct of hydrographic surveying in the EEZ. 相似文献
86.
1Introduction Heat flux yielded by modern seafloor hydrother-mal activity could be next only to heat radiation fromthe sun to the earth, and be similar to energy pro-duced by volcanism. And mass flux of hydrothermalactivity could be close to that of river… 相似文献
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88.
Introduction The accurate gradual change style seismic phases identification is an older new question for discussion. Wavelet transform has good localization properties in time-frequency domain, and is a effective tool to analyze seismic signal which has been applied to detection of many kinds of signal, picture processing and other fields. When a kind of new signal stack up another kind of signal, more high frequency signal components will happen at onset time of new signal. Based on the wave… 相似文献
89.
In April and September of 2005, two sediment cores were collected from Lake Aha, which is polluted by the acid mine drainage
of the mining industries. Sulfate-reducing bacteria (SRB) groups and their quantity were analyzed by using PCR and FISH (fluorescence
in situ hybridization), respectively. The results showed that four SRB groups (Desulfotomaculum, Desulfobulbus, Desulfococcus–Desulfonema–Desulfosarcina and Desulfovibrio–Desulfomicrobium) were detected in September, while only three SRB groups (Desulfotomaculum, Desulfobulbus and Desulfococcus–Desulfonema–Desulfosarcina) were detected in April. Desulfovibrio–Desulfomicrobium was not detected and was expected to exist inactively, in April. Meanwhile, the distribution of every SRB group was wider
in September than in April. The results indicated that different SRB groups had different vertical and temporal distribution.
The vertical and temporal distribution of SRB was mainly in the upper sediments, and the number of SRB groups and quantity
were larger in September than in April. It suggested that the environmental conditions of sediments in September were more
suitable for SRB.
An erratum to this article can be found at 相似文献
90.
为考虑中间主应力对岩石极限破坏强度作用,在广义Hoek-Brown强度准则幂率项中添加定量表征中间主应力项,构建新的三维Hoek-Brown强度准则。该准则在主应力空间是通过3个角点外接Hoek-Brown准则包络面的曲六面体,在 空间包络线是幂律型曲线。通过与Hoek-Brown准则、Drucker-Prager准则和Mogi准则分别对4组真三轴压缩强度试验数据的拟合对比分析,探讨其反映中间主应力效应的适用性。结果表明,修正的Hoek-Brown强度准则拟合试验数据效果总体最好,Mogi准则次之,Hoek-Brown准则和Drucker-Prager准则较差。从而修正的Hoek-Brown强度准则最适用于粗面岩、大理岩和花岗岩等硬脆性岩石的真三轴强度预测及中间主应力影响规律描述。 相似文献