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1.
中药在改善模拟失重兔主要脏器形态学变化中的作用   总被引:1,自引:0,他引:1  
通过实验探讨中药作为一种新的防护措施的可能性。实验动物为53只白兔, 用头低位悬吊方法模拟失重, 时间7天。实验前将兔分为四组:对照组, 悬吊组, 川芎组, 丹黄组, 实验中分别喂水或喂中药。实验后取脑、心、肺、肾、腹主动脉、比目鱼肌等6个脏器制片, 进行组织学观察。结果是两种中药均有改善模拟失重兔主要脏器血循环和组织结构的作用, 丹黄合剂的作用优于川芎。这说明中药作为一种新的防护措施是有希望的。   相似文献   

2.
航天“血淤症”及其防护措施   总被引:3,自引:0,他引:3  
根据实验结果及国外有关资料证明,失重或模拟失重时人和动物血循环系统的紊乱和中医“血淤症”时的变化十分相似,提出我国“活血化淤”中药有可能成为防止失重血循环紊乱的一种有效药物的看法。  相似文献   

3.
模拟失重时家兔耳廓微循环的变化   总被引:2,自引:0,他引:2  
为了解失重时体液头向分布这一因素对微循环的影响,比较了两组兔(平卧组和头低位20°悬吊组)在实验7天中耳廓微循环和血液流变学指标的变化。结果证明体液头向分布可引起一定的微循环障碍,表现为毛细血管和细静脉管径变粗、流速减慢、血液在静脉中潴留、红细胞聚集、耳廓出血及立位时微血管调节功能发生改变,血液流变学指标也出现相应变化。本文分析了其中一些变化的起因,提出一些新的看法。   相似文献   

4.
Gynura bicolor DC is not only an edible plant but also a kind of traditional Chinese herbal medicine. G. bicolor DC grown in controlled environmental chambers under 3 CO2 concentrations [450 (ambient), 1500 (elevated), 8000 (super-elevated) μmol mol−1] and 3 LED lighting conditions [white (WL), 85% red + 15% blue (RB15), 70% red + 30% blue (RB30) ] were investigated to reveal plausible antioxidant anabolic responses to CO2 enrichment and LED light quality. Under ambient and elevated CO2 levels, blue light increasing from 15% to 30% was conducive to the accumulation of anthocyanins and total flavonoids, and the antioxidant activity of extract was also increased, but plant biomass was decreased. These results demonstrated that the reinforcement of blue light could induce more antioxidant of secondary metabolites, but depress the effective growth of G. bicolor DC under ambient and elevated CO2 levels. In addition, compared with the ambient and elevated CO2 levels, the increased anthocyanins, total flavonoids contents and antioxidant enzyme activities of G. bicolor DC under super-elevated CO2 level could serve as important components of antioxidative defense mechanism against CO2 stress. Hence, G. bicolor DC might have higher tolerance to CO2 stress.  相似文献   

5.
China has great progress in the technology and application of ocean color remote sensing during 2004-2006. In this report, firstly, four major technical advances are displaying, including (1) the vector radiative transfer numerical model of coupled ocean-atmosphere system; (2) the atmospheric correction algorithm specialized on Chinese high turbid water; (3) systematical research of hyper-spectrum ocean color remote sensing; (4) local algorithms of oceanic parameters, like ocean color components, ocean primary productivity, water transparency, water quality parameters, etc. On the foundation of technical advances, ocean color remote sensing takes effect on ocean environment monitoring, with four major kinds of application systems, namely, (1) the automatic multi-satellites data receiving, processing and application system; (2) the shipboard satellite data receiving and processing system for fishery ground information; (3) Coastal water quality monitoring system, integrating satellite and airborne remote sensing technology and ship measurement; (4) the preliminary system of airborne ocean color remote sensing application system. Finally, the prospective development of Chinese ocean color remote sensing is brought forward. With Chinese second ocean color satellite (HY-1B) orbiting, great strides will take place in Chinese ocean color information accumulation and application.  相似文献   

6.
A REPORT OF GROUND EXPERIMENTS FOR BRAIN FUNCTION IN SPACE   总被引:1,自引:0,他引:1  
Mei Lei 《空间科学学报》1991,11(2):118-123
The brain function is of crucial importance in space adaptation and astronaut performance. According to the theory of nonequiliblium fluctuations a new technology, ET (Elec-troencephalofluctuography [EEFG] Technology), has been developed in our laboratory for space application. Information of different attracters, especially the dominant supra-slow (S) oscillations of the brain can be abstracted from the fluctuating brain waves. Specific Sspectral lines related to neurophysiological and neuro-chemical activities have been identified and charcteristic spatial patterns have been figured out. ETanalysis has been carried out in a series of ground experiments: (1) 20 degrees head lowered suspension experiments in rabbits; (2) 2Gz hypergravity experiments in rabbits; (3) effects of antimotionsickness drugs on rabbits during suspension; (4) clincal observations on patients with brain circulation diseases. Valuable information has been collected in all these experiments, which can hardly be obtained by means of other existing techniques. The potentiality of ETapplication in space research was discussed.   相似文献   

7.
The quality and availability of Uncalibrated Phase Delay (UPD) solutions are crucial to the Precise Point Positioning (PPP) service, and the long-term temporal variability and its contributing factors should be better understood. In this paper, we comprehensively investigate the long-term time-varying characteristics of each UPD product respectively generated by a global and regional network and their interoperable application in PPP-AR (ambiguity resolution), the sampling of the WL and NL UPDs are daily and 30 s, respectively. Firstly, in terms of our 30 day Wide-Lane (WL) UPD products of 31 satellites, the Standard Deviation (STD) of each satellite WL UPDs ranges from 0.04 to 0.06 cycles, indicating that the long-term prediction accuracy of satellite WL UPD is sufficient for fixing Wide-Lane ambiguities. Secondly, when a satellite in eclipsing the discontinulity may corrupt the determination of Narrow-Lane (NL) UPD in form of offset, as a result of lacking or poor satellite attitude dynamic modeling. When the influence of discontinuity is removed, the STD of our estimated satellite NL UPDs is less than 0.05 cycles. Thirdly, the STD of our estimated receiver WL UPDs is mainly below 0.2 cycles, which implies that its stability is one order poorer that of the satellite. In addition, if they are used for stations in and around the network covered region, the stability of the UPD products from the CMONOC (Crustal Movement Observation Network of China) is better than that from a global network, benefit from the fact that all the CMONOC stations are equipped with the same receiver type. Finally, the PPP-AR results show that a rate of 82.9% for stations with a WL-ambiguity-fixed rate of over 90% while 69.5% for stations with an NL-ambiguity-fixed rate of over 80% can be achieved when using UPD from the global network, which is worse than that of using UPD from the CMONOC (85.7% for stations with a WL-ambiguity-fixed rate of over 90% while 75% for stations with an NL-ambiguity-fixed rate of over 80%). The results of the experiment on the UPD interoperable application in PPP show that the global network UPD products can provide a fast AR at any single station, and the convergence time is well below 25 min. Particularly, when the location of a station is in and around the regional network, our results show that the PPP results obtained using regional UPDs enable the consistent use of global UPDs. When the location of a station is far away from the regional network, using the regional UPDs can not achieve PPP-AR. Finally, the WL UPDs of the previous day is used for forecasting to estimate the NL UPDs, the stability analysis results of NL UPDs solution and positioning results are demonstrate the validity of forecasted UPD products.  相似文献   

8.
Parameterization of dynamical and thermal effects of stationary orographic gravity waves (OGWs) generated by the Earth’s surface topography is incorporated into a numerical model of general circulation of the middle and upper atmosphere. Responses of atmospheric general circulation and characteristics of planetary waves at altitudes from the troposphere up to the thermosphere to the effects of OGWs propagating from the earth surface are studied. Changes in atmospheric circulation and amplitudes of planetary waves due to variations of OGW generation and propagation in different seasons are considered. It is shown that during solstices the main OGW dynamical and heat effects occur in the middle atmosphere of winter hemispheres, where changes in planetary wave amplitudes due to OGWs may reach up to 50%. During equinoxes OGW effects are distributed more homogeneously between northern and southern hemispheres.  相似文献   

9.
In this paper, the response of the equatorial and low latitude ionosphere to three intense geomagnetic storms occurred in 2002 and 2003 is reported. For that, critical frequency of F2-layer foF2 and the peak height hmF2 hmF2 for the stations Jicamarca (11.9°S), Ascension Is (7.92°S) and Tucuman (26.9°S) are used. The results show a “smoothing” of the Equatorial Anomaly structure during the development of the storms. Noticeable features are the increases in foF2 before the storm sudden commencement (SC) at equatorial latitudes and the southern crest of the Equatorial Anomaly. In some cases nearly simultaneous increases in foF2 are observed in response to the storm, which are attributed to the prompt electric field. Also, positive effects observed at equatorial and low latitudes during the development of the storm seem to be caused by the disturbance dynamo electric field due to the storm-time circulation. Increases in foF2 above the equator and simultaneous decreases in foF2 at the south crest near to the end of a long-duration main phase are attributed to equatorward-directed meridional winds. Decreases in foF2 observed during the recovery phase of storms are believed to be caused by composition changes. The results indicate that the prompt penetration electric field on the EA is important but their effect is of short lived. More significant ionospheric effects are the produced by the disturbance dynamo electric field. The role of storm-time winds is important because they modify the “fountain effect” and transport the composition changes toward low latitudes.  相似文献   

10.
随着概率安全评定技术(PSA,Probabilistic Safety Assessment)的发展,该技术已经开始逐步向工程应用领域渗透,但其在应用方面还存在若干的问题,失效评定曲线的概率化就是其主要问题之一.对多个厂家、多种炉号、多种板厚4种国产钢种5种裂纹形式的大量失效评定曲线进行了概率分析,采用三段分析法和逼近法得到了不同可靠度下的4种国产钢的概率失效评定曲线及其表达式,以及一般长屈服平台国产钢在不同可靠度下的一般失效评定曲线及其表达式.运用这些表达式可实现适合我国国产钢种含缺陷构件的工程概率安全评定分析.   相似文献   

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