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771.
772.
????????????????????????????Σ?????????????????????????????????趨???????????м???????е???????????????????ó?????????????????????????????????????????????????????????????????????????????淽??????????????????????????????????????????????????????????????????????????????淽???????????????????????????????????÷??????????Ч??? 相似文献
773.
???????6?????л?????????GNSS?????????????????????????????????????????GNSS??????????????о??е???á? 相似文献
774.
??VAV??ETERNA??????????????????????????????????????????????????????????????????????人???????????????з????????????, ??????VAV?????????????????ETERNAС,??????????????????????????????????????????????????????????VAV??ETERNA????????????? 相似文献
775.
776.
本试验利用一个室外露天水容量为187立方米的水泥池进行马氏珠母贝人工育苗,一次育出贝苗5065万只,平均每立方米水体收贝苗27.08万只。室外大池育苗具有耗饵量少,节约人力,培育的幼虫和贝苗生长快和产苗量大等优点,能够迅速提高贝苗总产量,解决目前存在的贝苗(?)足的困难,值得提倡推广。 相似文献
777.
Chen Hong-Fei Xu Wen-Yao Chen Geng-Xiong Hong Ming-Hua Peng Feng-Lin 《Solar physics》2001,204(1-2):339-349
In this paper geomagnetic disturbances at middle and low latitudes are discussed by using geomagnetic data of the magnetic
storm of 15–16 July 2000. This storm is a response to the solar Bastille Day flare on 14 July. Generally, the geomagnetic
disturbances at middle and low latitudes during a storm are mainly caused by three magnetospheric–ionospheric current systems,
such as the ring current system (RC), the partial ring current and its associated region II field-aligned currents (PR), and
the region I field-aligned currents (FA). Our results show that: (1) The northward turning of IMF-Bz started the sudden commencement of the storm, and its southward turning caused the main phase of the storm. (2) The PR- and
FA-currents varied violently in the main phase. In general, the field of the FA-current was stronger than that of the PR-current.
(3) In the first stage of the recovery phase, the RC-field gradually turned anti-parallel to the geomagnetic axis from a 15°
deviation, and the local time (Λ) pointed by the RC-field stayed at 16:00. After that, Λ rotated with the stations, and the
RC-field was not anti-parallel to the geomagnetic axis, but 5°–10° deviated. These facts suggest that the warped tailward
part of the ring current decays faster than the symmetric ring current. 相似文献
778.
Utilizing the occultation data observed by LEO (low earth orbit) satellites, we can invert the profiles of air pressure, water vapor, temperature of terrestrial atmosphere and so on, and they are the valuable data resources for studying the meteorology and atmospheric sciences. The assimilation techniques with the occultation data can effectively improve these profiles of meteorological parameters, thus they can improve the accuracy of current numerical weather forecasting. The greatest difficulty is the huge amount of calculation to enter into the meteorological operational processes for applying the parameter profiles observed by occultation with the method of variational assimilation. With the improvements of the function of one-dimensional variational assimilation and the new design for iterative process, the defects of repeated calculation of the large dimension matrix can be avoided, thereby improving the computational efficiency of variational assimilation. In the discussion of applicability, it is used as the true value of the vectors of the background field plus one white Gaussian noise to test the variational assimilation results on the occultation data of satellite CHAMP. 相似文献
779.
地震断层气监测的现状与展望 总被引:1,自引:0,他引:1
断层气测量是地震科学研究的重要方法之一,断层气测量具有实用、轻便、快便、价廉等优点,在地震监测预报和减灾活动中具有广阔的应用前景和巨大的潜力。本文对断层气测量在地震科学中的应用和现状作了简要的介绍,同时探讨了我国地震断层气监测系统中存在的一些主要问题,对今后的发展进行了展望。最后简单介绍了几种断层气监测新技术及新型气敏传感器。 相似文献
780.
Wan Mengfei Liu Zhongdong Chen Yongfu Lu Caiyuan Li Kechang Wang Fahe Wang Xiaomei Liu Boxiang 《中国海洋湖沼学报》2019,37(3):892-897
Octenylsuccinate starch ester, also called pure gum, is non-toxic and odourless modified starch which is widely used in many food fields. This study synthesized pure gum in a reaction kettle using the low molecular weight trehalose and octenyl succinic acid. An orthogonal test was carried out to find how the reaction factors affect the synthetization of octenylsuccinic acid polysaccharide ester and to optimize the reaction at single factor level. The optimal products were obtained using 1:2 of octenylsuccinic acid:alginic acid, catalysed by 0.1% p-toluenesulfonic acid catalyst for 1.5 h at 200℃ under vacuum conditions.The gained product contains up to 46% of seaweed gel monoesters. The degree of esterification of the polysaccharide is controlled by the use of the small-molecule trehalose. Compared with the traditional methods, our process can reduce raw material cost and improve emulsification stability of pure gum. These all can significantly improve the market competitiveness of pure gum products. 相似文献