天津七里海湿地鸟类区系及类群多样性研究

2002年2月至2003年2月,对天津七里海湿地鸟类资源进行了调查,共记录到鸟类12目、23科、78种,其中古北界40种(51．28％),广布种31(39．74％),东洋界7种(8．97％)。古北界成分处于绝对优势,与七里海地区处在古北界动物地理区划上是一致的。旅鸟43种,夏候鸟23种,冬候鸟4种,留鸟8种,以旅鸟为主,占总数的55．13％,该地区处于南北迁徙的路线上。其次夏候鸟占29．49％,冬候鸟和留鸟各占5．13％和10．26％。优势种为灰椋鸟、麻雀、红嘴鸥和家燕;天鹅、红隼、黄爪隼、白尾鹞等为国家重点保护鸟类。从类群(科种)多样性分析,陆地鸟对该地区鸟类多样性贡献大。由于栖息地破坏及人为干扰等原因,湿地鸟类明显少于天津其它湿地的鸟类。研究表明,在一定时空条件下,地域景观的复杂性决定这一地区的鸟种数量。     

Time, Energy, and Territoriality of the Anna Hummingbird (Calypte anna)

The male Anna Hummingbird accommodates seasonal changes in energy demands by varying its allocation of time and energy among different activities; total energy expenditures change relatively little. Augmented terrritorial defense during the breeding season is made possible by increased feeding efficiency due to the availability at this time of very nectar-rich flowers.     

Jupiter's Atmosphere: Its Structure and Composition

Recent laboratory and observational data support the hypothesis that the composition of Jupiter's atmosphere is consistent with the relative abundances of the elements found in the sun. A model based on this assumption provides a reasonable interpretation of abundances of hydrogen and other gases obtained from studies of various regions of the planet's spectrum. Two presently unidentified absorptions may be caused by organic molecules in the Jovian atmosphere.     

Plasma Composition in Jupiter's Magnetosphere: Initial Results from the Solar Wind Ion Composition Spectrometer

The ion composition in the Jovian environment was investigated with the Solar Wind Ion Composition Spectrometer on board Ulysses. A hot tenuous plasma was observed throughout the outer and middle magnetosphere. In some regions two thermally different components were identified. Oxygen and sulfur ions with several different charge states, from the volcanic satellite lo, make the largest contribution to the mass density of the hot plasma, even at high latitude. Solar wind particles were observed in all regions investigated. Ions from Jupiter's ionosphere were abundant in the middle magnetosphere, particularly in the highlatitude region on the dusk side, which was traversed for the first time.     

不同氮磷钾配施比例对烤烟化学成分和中性致香物质的影响

为研究不同氮磷钾配施对烤烟内在质量的影响,2014年于四川省会理县,以K326为材料,研究了氮磷钾配施对烤烟化学成分和中性致香物质含量的影响.结果表明,各处理的总糖和还原糖含量、糖碱比仍较高,烟碱、总氮含量较适宜,氯含量差异较大,氮磷钾比例为1∶1.6∶2.0(T2)处理钾含量最高,氮碱比均在1以内,T2处理上部和下部叶钾氯比最高,氮磷钾比例1∶0.5∶2.5(T3)处理中部叶钾氯比最高.不同氮磷钾配施可有效提高烤烟各类致香物质的含量,上部和中部叶中性致香物质含量均以氮磷钾比例1∶1.6∶2.0的处理最高,因此,该处理是提高烟叶质量的有效措施.     

林分类型对土壤节肢动物群落组成和分布的影响

在不同林分类型中,节肢动物在个体数和类群组成上存在较大差异,而类群数差异不显著;节肢动物具有垂直分层现象,并具有明显的袁聚性;在不同层次的土壤中,土壤理化性质的不同因素对土壤节肢动物群落的个体数和类群数的产生不同影响。     

Asteroid 1986 DA: Radar Evidence for a Metallic Composition

Echoes from the near-Earth object 1986 DA show it to be significantly more reflective than other radar-detected asteroids. This result supports the hypothesis that 1986 DA is a piece of NiFe metal derived from the interior of a much larger object that melted, differentiated, cooled, and subsequently was disrupted in a catastrophic collision. This 2-kilometer asteroid, which appears smooth at centimeter to meter scales but extremely irregular at 10- to 100-meter scales, might be (or have been a part of the parent body of some iron meteorites.     

园林设计与现代构成之间的关系

构成就是组合、结构、构造的意思,即将一些基本的视觉元素,如点、线、面等按照形式美的法则进行重新的结构,然后将抽象美转化成形式美。园林设计是使用一些艺术的手段对园林进行合理的布局,使之符合人们的需求,与周围的环境能达到和谐统一的活动。主要对现代构成与园林设计之间的关系做了简单的探讨。     

Deprotection of Acetyl Group on Amino Group with Thionyl Chloride and Pyridine

[Objective] This study aimed to analyze the deprotection of acetyl group on amino group.[Method] A simple,convenient one-pot amino protection group of amide removed by thionyl chloride and pyridine via efficient chlorination and hydrolysis with 1,2-dichloroethane as solvent at ambient temperature has been developed.[Result] Pyridine is crucial to the reaction;the best solvent is 1,2-dichloroethane,and the most suitable reaction temperature is the ambient temperature;in addition,the yield is the highest as the molar ratio of pyridine to N-(4-bromophenyl) acetamide is 1:1.[Conclusion] The significant features of this protocol include short reaction time,cleaner reaction profiles,under mild reaction conditions and easy purification,and simple workup that precludes the use of toxic solvents.     

语篇的特征和英语基础写作

根据语篇的连贯和衔接特征，讨论了英语写作的原则和方法。实例分析表明：零乱的语句可以通过衔接和连贯原则组合成语篇，但语篇的要旨因衔接和连贯的方式不同而迥异。     

Composition and physical properties of Enceladus' surface

Observations of Saturn's satellite Enceladus using Cassini's Visual and Infrared Mapping Spectrometer instrument were obtained during three flybys of Enceladus in 2005. Enceladus' surface is composed mostly of nearly pure water ice except near its south pole, where there are light organics, CO2, and amorphous and crystalline water ice, particularly in the region dubbed the "tiger stripes." An upper limit of 5 precipitable nanometers is derived for CO in the atmospheric column above Enceladus, and 2% for NH3 in global surface deposits. Upper limits of 140 kelvin (for a filled pixel) are derived for the temperatures in the tiger stripes.     

Composition and structure of the martian upper atmosphere: analysis of results from viking

Densities for carbon dioxide measured by the upper atmospheric mass spectrometers on Viking 1 and Viking 2 are analyzed to yield height profiles for the temperature of the martian atmosphere between 120 and 200 kilometers. Densities for nitrogen and argon are used to derive vertical profiles for the eddy diffusion coefficient over the same height range. The upper atmosphere of Mars is surprisingly cold with average temperatures for both Viking 1 and Viking 2 of less than 200 degrees K, and there is significant vertical structure. Model calculations are presented and shown to be in good agreement with measured concentrations of carbon monoxide, oxygen, and nitric oxide.     

今日恒兴——打造国际化农业产业化集团

打造国际化农业产业化集团是恒兴集团的历史使命 "打造国际化农业产业化集团,是恒兴集团的历史使命.我们在宏观上的想法是:完成集团的产业价值链,加强科学技术,大力发展种苗、饲料、养殖、水产品加工,提倡绿色环保营养安全食品."     

Composition and dynamics of plasma in Saturn's magnetosphere

During Cassini's initial orbit, we observed a dynamic magnetosphere composed primarily of a complex mixture of water-derived atomic and molecular ions. We have identified four distinct regions characterized by differences in both bulk plasma properties and ion composition. Protons are the dominant species outside about 9 RS (where RS is the radial distance from the center of Saturn), whereas inside, the plasma consists primarily of a corotating comet-like mix of water-derived ions with approximately 3% N+. Over the A and B rings, we found an ionosphere in which O2+ and O+ are dominant, which suggests the possible existence of a layer of O2 gas similar to the atmospheres of Europa and Ganymede.     

野生三角鲂幼鱼鱼体的化学组成及能量密度

为探讨野生三角鲂(Magalohrama tarminalis)鱼体化学组成随生长的变化规律,在韩江下游潮州江段采集三角鲂39尾,按体长分为6个组,分别测定鱼体化学组成,推算其能量密度.结果表明:野生三角鲂含水量、蛋白质含量、脂肪含量、灰分含量分别占鲜重的72.94 %～ 76.70 %,13.28%～17.66%、2.42%～7.53%和4.10%～5.69%,能量密度为4.13～7.14 kJ/g;三角鲂鱼体体长与蛋白质含量、脂肪含量、能量密度呈极显著(P<0.01)正线性关系,而与灰分含量(P<0.05)、含水量(P<0.01)分别呈正、负线性相关关系;含水量与蛋白质含量、脂肪含量、能量密度呈极显著(P<0.01)负线性关系,而与灰分含量呈显著(P<0.05)负线性相关关系.表明,野生三角鲂的含水量和体长均可用来预测其鱼体生化组成和能量密度.