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Brain decade     
《Science (New York, N.Y.)》1990,247(4939):157
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The results from the meteorology instruments on the Viking 1 lander are presented for the first 20 sols of operation. The daily patterns of temperature, wind, and pressure have been highly consistent during the period. Hence, these have been assembled into 20-sol composites and analyzed harmonically. Maximum temperature was 241.8 degrees K and minimum 187.2 degrees K. The composite wind vector has a mean diurnal magnitude of 2.4 meters per second with prevailing wind from the south and counterclockwise diurnal rotation. Pressure exhibits diurnal and semidiurnal oscillations. The diurnal is ascribed to a combination of effects, and the semidiurnal appears to be the solar semidiurnal tide. Similarities to Earth are discussed. A major finding is a continual secular decrease in diurnal mean pressure. This is ascribed to carbon dioxide deposition at the south polar cap.  相似文献   

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陕西宝鸡市近50年农业气候资源特征分析   总被引:4,自引:0,他引:4  
【目的】研究陕西宝鸡市近50年农业气候资源的变化规律。【方法】选用宝鸡市11个县(区)气象站的1961—2008年气温、降水量和日照等气象要素统计资料,对宝鸡市近50年光资源、热量资源和水资源的变化特征进行分析。【结果】1)年日照时数以38.95h/10年的倾向率波浪式减少,其中以夏季减少趋势最明显,线性倾向率为-28.8h/10年;年平均气温以0.238℃/10年倾向率上升,冬、春季平均气温上升最快,夏季平均气温升温幅度最小;年降水量以倾向率为31.187mm/10年波动性减少,这种减少主要是由于春季和秋季降水量减少而致。2)由于气温升高,各农业界限温度的初日明显提前,终日推迟,持续时间明显增多,积温显著增加,以平均气温≥0℃和平均气温≥10℃时各指标变化较明显,平均气温≥20℃时各指标变化较小。【结论】近50年,由于气候变化,宝鸡市农业气候资源发生了明显变化,使农业生产的不稳定性增加、产量波动加大。  相似文献   

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Our perception of the universe has been altered by recent discoveries in astronomy, discoveries of new objects and of new phenomena, coming from a wide range of observing techniques. By 1990 astronomers expect to know more about the distribution of mass in the universe, the physics of energetic sources, and the intricate interconnections of astrophysical processes on a variety of spatial and temporal scales.  相似文献   

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The progress of instrumentation and measurement science in the next decade will be marked by three major trends. First, as the average instrument achieves a rather considerable level of intelligence, "dumb" systems will become the exception, and we will eventually begin to become proficient in exploiting the resulting capabilities. Second, more sophisticated understanding of measurement science and of actual measurement needs will drive instrumentation design advances such as miniaturized sensors and yet more "hyphenated" instruments and "mapping" instruments. Third, the combination of sensor-based instrumentation and microminiaturization will make possible distributed measurement by allowing point-of-use measurements by nonexperts.  相似文献   

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从编排导向、内容定位和广告设置等3个侧面对《读者》近十年的期刊进行了分析,发现《读者》中间蕴含着深深的宗教性特质.这种特质依次可分为3个层面,即显性宗教层面、隐性宗教层面和拜物宗教层面.显性宗教层面折射了祖先崇拜的痕迹,隐性宗教层面偏好于人性的取舍,而广告的设置上则隐含着深深的拜物教的因素,这3个层面互相影响,制约着《读者》的进一步发展.  相似文献   

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Atmospheric turbidity values calculated each month from solar radiation observations at MaunaLoa Observatory, Hawaii, show an increase of aerosols from 1958 through the present. These data indicate that either the effects of the Mount Agung eruption are still being observed or a longer-term trend of increasing turbidity is in evidence.  相似文献   

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Abortion and public opinion: the 1960-1970 decade   总被引:3,自引:0,他引:3  
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近十年广东稻瘟病菌生理小种变化分析   总被引:1,自引:0,他引:1  
从2006-2015年近10年间收集的来自广东各地的7225份穗颈瘟样本中分离出稻瘟病菌(Magnaportheoryzae)单孢菌株3690个,经接种到中国水稻稻瘟病菌鉴别品种上共鉴定出8群51个生理小种,其中以ZB群、ZC群和ZG群为主要优势种群,而ZB群出现频率最高,为48.44%~75.35%;病菌生理小种以ZB13、ZB15、ZC15、ZC13和ZG1为主要优势小种,其中ZB13出现频率最高,为32.47%.  相似文献   

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