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161.
绒螯蟹种质资源研究进展 总被引:1,自引:1,他引:1
本文综述了近年来有关绒螯蟹属在形态学、遗传学和育种学方面的研究进展 ,着重介绍了同工酶、RAPD和 mt DNA技术在绒螯蟹群体遗传学中的应用 ,提出遗传学分类标准的建立是绒螯蟹属分子分类的关键所在。 相似文献
162.
1993年分析了不同大小斑节对虾肌肉中游离氨基酸含量和肌肉蛋白质 的氨基酸组成。虾体肌肉中有各种游离氨基酸存在,但数量很少,而且比例与肌肉 中结合氨基酸不一致。不同大小斑节对虾,其肌肉中氨基酸组成基本一样,不同的 是小虾的半胱氨酸、蛋氨酸含量比中虾、成虾的低;成虾的缬氨酸、异亮氨酸含量比 小虾、中虾的低,而酪氨酸、苯丙氨酸、天门冬氨酸较高。随着虾体的长大,甘氨酸、 丙氨酸的含量逐渐下降,而脯氨酸的含量升高。雌雄虾的氨基酸组成基本一致,只 是雄虾的甘氨酸含量偏低,精氨酸含量偏高。 相似文献
163.
SubunitcompositionandchromophorecontentofR-phycocyaninandallophycocyaninfromPorphyrahaitanensis¥GaoHongfeng;CaoWendaandJiMing... 相似文献
164.
不同pH海水和不同时间处理紫菜、石莼对呼吸强度和致死酸度试验结果表明,紫菜比石莼耐酸力强。在海水温度为18℃条件下,分别用pH_2、pH_3、pH_4、pH_5、pH_6、pH_7、pH_8处理,处理时间20分钟,紫菜除pH_2处理对呼吸强度有抑制作用和培养5天后有20%死亡外,pH_3、pH_4、pH_5、pH_6、pH_7、pH_8各组处理对呼吸强度都有促进作用,培养5天后没有死亡现象,而石莼经pH_2、pH_3处理,对呼吸强度都有抑制作用,培养5天后,pH_2处理组全部死亡,pH_3处理有50%死亡。pH_3和pH_4在海水温度为18℃条件下,处理时间为40分钟时,对紫菜呼吸强度有促进作用,培养5天报,pH_3处理组仅有20%死亡。而pH_3对石莼呼吸强度有抑制作用,培养5天后,全部灭亡。在生产上是否可以考虑用pH_3的海水处理紫菜网帘以达到消除石莼(杂藻)的目的,将是一项具有生产意义的待试验课题。 相似文献
165.
166.
V. A. Bezverkhny 《Izvestiya Atmospheric and Oceanic Physics》2007,43(3):317-322
Characteristics of the Arctic Oscillation and El Niño-Southern Oscillation effects manifested on interannual scales in the equatorial stratosphere are determined. Wavelet analysis of local phase shifts, coherence, and correlation is used to obtain correlation portraits of the largest factors of climate variability against the background of coherent variations in the equatorial stratospheric wind speed at the 50- and 15-hPa pressure levels. It is shown that the Arctic Oscillation and El Niño-Southern Oscillation signals may reach the tropical stratosphere. The signals are easily identified in a wide range of scales, including quasi-biennial, 3-to 5-year, and 10-to 11-year periods. The results obtained reflect a coherent pattern of the manifestation of these signals at the selected stratospheric levels. It is found that the El Niño-Southern Oscillation effect at periods close to 10–11 years reaches the stratospheric level rather rapidly, in the same or next month, while the effects of the Arctic Oscillation index are delayed by nine months. The estimates obtained show that a phase shift of almost 180° in the Arctic Oscillation index relative to the equatorial stratospheric wind occurred in almost all of the range of interannual periods in 1978 and 1992. For the El Niño-Southern Oscillation, an increase in local correlations on a scale of 3-to 5-year variations was observed in 1980–1990, a 180° phase shift occurred in 1992, and the correlation with stratospheric wind increased in 1992–2004. The estimates obtained are indicative of a change in the atmospheric circulation pattern that took place in the Northern Hemisphere in 1978–1991. 相似文献
167.
The origin and evolution history of the Curonian Spit in the Baltic Sea are discussed based on geological and geomorphologic data. Evidence of the correlation between the spit formation stages and the Holocene sea level oscillations is presented. The ledges of moraine basement and marine accumulative features formed a single barrier. Its subsequent transformation occurred under the influence of the wave-related lithodynamic and eolian processes. 相似文献
168.
The main stages in the development of the Pechora Sea are discussed. It is established that, during the high sea level stand corresponding to the warmest epoch of the Mikulino Interglacial, the Pechora Sea represented a more spacious, as compared with its present-day size, basin owing to the flooded valleys of river lower reaches. No sea in its present-day configuration existed during the last (Valdai) glaciation. At that time, the sea could have occupied only a narrow area along the southern coast of Novaya Zemlya, where marine sedimentation was in progress during the Late Pleistocene and Holocene. During the glaciation and postglacial time, the dried bottom of the former Pechora Sea accumulated large volumes of sand that are now concentrated largely in the accretion structures along its southern coast. In the current century, changes will occur mainly in the coastal zone of the Russkii Zavorot Peninsula, Pesyakov Island, the Varandei Settlement area, and the Medynskii Zavorot Peninsula, where a shoreline retreat for a distance of 0.5 km is expected. 相似文献
169.
V. Yu. Rusakov 《Oceanology》2007,47(2):245-260
This publication considers the probing data on aquatic anomalies (hydrothermal plumes) in the areas of 26° and 29° N of the Mid-Atlantic Ridge (MAR). The mass of the hydrothermal iron supply and the intensity of the iron sedimentation onto the bottom were estimated by means of sediment traps. It was found that the plume of the TAG hydrothermal vent 6 km3 in volume contained about 67 t of suspended Fe; the plume of the Broken Spur field (up to 8.24 km3 in volume) contained 23.5 t or less because of the lower concentration. The data on the sedimentary matter fluxes showed that 0.3–0.5% of the hydrothermal iron was precipitated immediately from a plume of neutral buoyancy onto the bottom; the bulk of the iron was dissipated into the environment. From the dimensions of the plumes, the flow dynamics, the iron concentrations in the plumes, and the amounts of iron supplied by hydrothermal vents, it was found that the resident time of the plumes considered was from 5 to 10 days. 相似文献
170.
I. I. Mokhov M. G. Akperov V. E. Lagun E. I. Lutsenko 《Izvestiya Atmospheric and Oceanic Physics》2007,43(3):259-265
Characteristics of polar mesoscale cyclones (PMCs) over the North European Basin are analyzed using cloud cover distribution data for 1981–1995. Special features of the annual cycle and interannual variations in characteristics of Arctic mesocyclones with a spiral and comma-shaped cloud structure are discussed. Against the background of large interannual variations, no statistically significant trends were found in the characteristics of Arctic mesocyclones over the North European Basin in the late 20th century. It is shown that the cumulative frequency distribution of PMCs is well approximated by an exponential function in a size range for Arctic mesocyclones from 50 to 400 km. The applicability of the Weibull distribution as an approximation of the PMC size distribution of the number of cyclone days is analyzed. It is shown that the correspondence between the real distribution and the Weibull distribution became worse in the 1990s than in the 1980s, especially the first half of the 1980s. Much of this was due to an increased local maximum in the 1990s in the distribution of polar mesocyclones with diameters about 400 km. This local maximum was found for all types of mesoscale vortices and for all analyzed five-year subperiods during 1981–1995. A large discrepancy between the frequency distribution functions for PMCs depending on their diameters was shown to exist for different types of Arctic mesocyclones. 相似文献