水体中TN/TP与藻类产生周期及产生量的关系

通过室内模拟的方法研究了用自来水作为试验水,当TN/TP在25∶1～4∶1的范围变化时,藻类的产生周期及产生量的变化情况.试验设置了25∶1,20∶1,15∶1,12∶1,10∶1,4∶1 6个比值.为了探讨温度对藻类产生的影响,分别在夏季和冬季做了对比试验.结果表明:当TN/TP在25∶1～12∶1的范围时,藻类的产生周期随TN/TP的减少而缩短,产生量随着TN/TP的减少而增加.在TN/TP为12∶1时藻类的产生周期最短,产生量最多.而TN/TP从12∶1～10∶1时,藻类的产生周期却随TN/TP的减少而增加,产生量随TN/TP的减少而减少.在TN/TP为4∶1时,没有产生藻类.季节对藻类的产生影响比较大.在夏季,藻类的产生周期较短,生产量较多;在冬季,藻类的产生周期较长,生产量相对较少.     

印度洋暖池热含量变化对低纬高原汛期降水的影响

 利用美国Scripps海洋研究所提供的1961—2003年的海洋热含量再分析资料、低纬高原148站降水资料和NCEP/NCAR环流再分资料,采用EOF分析、相关分析、合成分析等方法研究了印度洋暖池热含量变化,及其对低纬高原6—8月降水的影响及其可能原因.结果表明,印度洋暖池6—8月热含量变化E0F分析第1模态为全场一致型,解释方差为28%.印度洋暖池热含量与中国低纬高原6—8月降水的关系主要体现为与云南北部和东部等地区的显著正相关,这种相关关系源于前期2—4月,且随时间的推移其影响范围不断扩大,至同期时达到最好.在印度洋暖池热含量偏高年,暖池区持续的加热异常在东侧对流层低层激发出反气旋式环流异常,造成副高西伸,从而在副高外围形成一条自孟加拉湾向低纬高原区域的经向水汽输送带,为低纬高原区域输送大量的水汽,从而造成低纬高原区域降水增多.相反,在印度洋暖池热含量异常偏低时,西南风水汽输送带较弱,水汽输送无法穿越山脉输送到低纬高原区,造成低纬高原汛期降水偏少.
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亚洲季风区平均雨季起始期的时空分布特征

 利用1961~1990年平均的降水资料,计算了亚洲季风区内91个测站的相对降水指数.在定义相对降水指数大于147作为雨季开始的标志后发现,亚洲季风区中最早进入雨季的地区位于青藏高原东南侧的纵向岭谷北部地区.该地区在3月份进入雨季,即纵向岭谷北部地区著名的“桃花汛”.在此基础上初步讨论了“桃花汛”形成的原因是由于青藏高原大地形作用下,暖湿西南气流沿纵向岭谷向着低纬高原的爬坡抬升作用,结合来自青藏高原的偏北气流带下的冷平流沿纵向河谷的下楔作用最终导致了该地区雨季的开始.     

331例高温和寒冷季节急性脑血管病临床特点及防治分析

目的探讨高温和寒冷季节本地区急性脑血管病（ACVD）患者高危因素、临床特点,找出有效防治方法。方法回顾我院三个高温和寒冷季节在我院神经内外科住院的ACVD病人331例临床资料,进行统计学及流行病学分析。结果高温季节162例ACVD患者：缺血性脑卒中（CIS）99例;出血性脑卒中（CHS）57例;混合性脑卒中6例。寒冷季节169例ACVD患者：CHS85例;CIS71例;混合性脑卒中13例。两季节331例ACVD患者：高血压病242例;手术治疗43例;急性溶栓44例;高压氧治疗200例。结论本地区高温季节ACVD以CIS为主,CHS其次;寒冷季节以CHS为主,CIS其次;混合性脑卒中均少;高血压是两季节ACVD显著高危因素;积极有效的治疗可降低两季节ACVD发病率和致残程度,提高息者生活质量。     

Modeling impacts of East Asian Ocean-Land thermal contrast on spring southwesterly winds and rainfall in eastern China

Using the National Centers for Environmental Prediction–National Center for Atmospheric Research （NCEP–NCAR） reanalysis dataset, the NOAA’s Climate Prediction Center’s merged analysis of precipitation, and the MM5v3 Meso-scale Model, the impacts of surface temperature differences between the East Asian land and its adjacent oceans on spring southwesterly winds and rainfall over eastern China are studied. The modeling results show that the temperature differences exert strong influence on the occurrence of the southwesterly winds and rainfall over southern China and their northward advances. When surface temperature increases over the land and decreases over the oceans, the temperature gradient with a winter feature earlier changes toward the gradient with a summer feature. Both the low-pressure system east of the Tibetan Plateau and the subtropical high-pressure system over the western Pacific strengthen, accompanying with the strengthening of the lower-tropospheric southwesterly winds over eastern China. Accordingly, the upward motion increases over the Yangtze-Huaihe River （YHR） valleys and decreases over southern China, leading to an increase of spring rainfall over the YHR valleys and a decrease over southern China. Thus, the rain belt over eastern China appears over the YHR valleys but not over southern China. Under a weaker condition of the spring thermal contrast, the rain belt does not occur over eastern China. When the spring thermal contrast pronouncedly strengthens, the rain belt over southern China may advance northward into the YHR valleys during spring, though there is no onset of the tropical monsoon over the South China Sea. This forms a rain belt similar to that of the YHR valleys during the summer Meiyu period.     

长白落叶松净光合速率和呼吸速率的日变化及时空影响

不同季节测定了长白落叶松树冠３个层次,４个方向１２个部位的净光合速率和呼吸速率的日变化,得到双峰曲线型、单峰曲线型和平坦型３种日变化模式。结果受测定日的气象条件、测定叶在树冠中的位置和测定季节及它们的相互作用的综合影响。长白落叶松净光合速率和呼吸速率的平坦型日变化是由内因决定的,单峰及双锋曲线型日变化是由外因和内因共同决定的。净光合速率与呼吸速率呈正相关,二者的低谷与峰值同时出现。呈双峰曲线型日变化时,两个峰值的大小不同,下午峰值明显高于上午峰值,这与前人结果不同,午休现象与高温对有关酶系统的抑制及水分亏缺有关。     

干旱对云南易门县云南松生长的影响

通过干季（３～５月）对云南易门县三个样地（谷地、山腰和山脊）云南松的调查和实验分析,了解干旱条件下,不同的土壤水分和物理状况对云南松生长的影响．发现土壤是制约云南松生长的主要限制因子．云南松针叶脯氨酸的含量可作为云南松抗旱的一个生理指标．     

Population structure and reproductive biology of the fiddler crab Uca urvillei (Brachyura: Ocypodidae) in Maputo Bay (south Mozambique)

Although fiddler crabs are among the main faunal components in mangrove habitats, few studies have described the population structure and reproduction of tropical species. Such information is important for understanding their life cycle and ecology. In this study, the population structure and reproduction of Uca urvillei were studied at Costa do Sol, a tropical mangrove forest in Maputo Bay, southern Mozambique. Ten 1.0‐m² squares were sampled during low tide periods, between January and December 2003. The population is characterized by normal size distributions, which are slightly skewed to the left. Males on average are larger than females. Males were more abundant than females and the monthly sex ratios were male‐biased. Juveniles were found year‐round but were less common in June and December. Both gonadosomatic index and frequency of ovigerous females showed that Uca urvillei breeds continuously with peaks in summer and a strong decrease in winter. Egg number was proportional to female size.     

An observational study of snow aging and the seasonal variation of snow albedo by using data from Col de Porte,France

An 18-year long （1993-2011） comprehensive dataset of snow and meteorological variables from Col de Porte, France is used to analyze the variation of shortwave broadband albedo with elapsed time after snowfalls （snow aging） during each snow season. The effects of air temperature, snow surface temperature and snow depth on snow albedo are investigated. An index based on the accumulation of air temperature over several consecutive days with daily mean higher than 2.5 ℃ is proposed to divide each snow-covered period into a dry and the following wet snow season when this index reaches 18 ℃. The results indicate that snow surface albedo decreases exponentially with time in both dry and wet snow seasons. Snow albedo reduction with snow aging is small at low surface temperature and the reduction rate increases with the rise of surface temperature. However, the reduction rate is widely scattered within the observed range of temperature, implying a loose relationship between snow albedo and snow surface temperature. Snow albedo in wet snow season is generally smaller and decreases faster than in dry snow season. For Col de Porte site, snow depths to effectively mask the underlying surface are 21 and 33 cm in dry and wet snow season respectively.     

电子商务中客房销售预测模型研究

针对酒店客房销售量的市场规律,在电子商务系统中建立了一套客房销售预测模型,经过实践验证,效果较好。