The hottest planet

Of the over 200 known extrasolar planets, just 14 pass in front of and behind their parent stars as seen from Earth. This fortuitous geometry allows direct determination of many planetary properties. Previous reports of planetary thermal emission give fluxes that are roughly consistent with predictions based on thermal equilibrium with the planets' received radiation, assuming a Bond albedo of approximately 0.3. Here we report direct detection of thermal emission from the smallest known transiting planet, HD 149026b, that indicates a brightness temperature (an expression of flux) of 2,300 +/- 200 K at 8 microm. The planet's predicted temperature for uniform, spherical, blackbody emission and zero albedo (unprecedented for planets) is 1,741 K. As models with non-zero albedo are cooler, this essentially eliminates uniform blackbody models, and may also require an albedo lower than any measured for a planet, very strong 8 microm emission, strong temporal variability, or a heat source other than stellar radiation. On the other hand, an instantaneous re-emission blackbody model, in which each patch of surface area instantly re-emits all received light, matches the data. This planet is known to be enriched in heavy elements, which may give rise to novel atmospheric properties yet to be investigated.     

四翅滨藜形态表现及其发展潜力分析

对引种到克拉玛依地区的四翅滨藜的生态适应性及其饲料价值进行了研究,结果显示,四翅滨藜不仅具有耐干旱、耐寒冷和耐盐碱等多种优良特性,而且是适合在新疆乃至西北荒漠、半荒漠地区栽培的营养价值高、适口性好的一种饲料灌木,将在改善生态环境和发展畜牧业等方面具有很好的发展潜力.     

化学类人才培养模式的实践与探索

分析了高等教育面临的挑战,论述了化学专业办学思想、专业特色与办学定位,以及师资队伍建设、课程体系建设、教学方法更新、大学生创新性研究实验和毕业论文等在化学类专业创新人才培养中的重要性,介绍其在上述诸方面的实践情况。     

Conserved noncoding sequences are selectively constrained and not mutation cold spots

Noncoding genetic variants are likely to influence human biology and disease, but recognizing functional noncoding variants is difficult. Approximately 3% of noncoding sequence is conserved among distantly related mammals, suggesting that these evolutionarily conserved noncoding regions (CNCs) are selectively constrained and contain functional variation. However, CNCs could also merely represent regions with lower local mutation rates. Here we address this issue and show that CNCs are selectively constrained in humans by analyzing HapMap genotype data. Specifically, new (derived) alleles of SNPs within CNCs are rarer than new alleles in nonconserved regions (P = 3 x 10(-18)), indicating that evolutionary pressure has suppressed CNC-derived allele frequencies. Intronic CNCs and CNCs near genes show greater allele frequency shifts, with magnitudes comparable to those for missense variants. Thus, conserved noncoding variants are more likely to be functional. Allele frequency distributions highlight selectively constrained genomic regions that should be intensively surveyed for functionally important variation.     

局域网环境下的Powerpoint-2003实验教学

从实验角度出发。根据适应学习法和任务驱动法，利用网络中的局域网环境，实践教学中实验教师在powerpoint-2003媒体演示软件的主导性教学和少数民族学生的主体性学习（以下简称ppt软件），这有利于养成良好的计算机操作思维模式，培养、提高信息素养，实现在扩大学生规模的情况下，改善ppt软件学习的实验效果，激发学生学习的积极性。提高实验操作效率。     

苯胺盐酸盐与瓜环主客体包结物的晶体结构

用X射线单晶衍射方法研究六元瓜环和八元瓜环与苯胺盐酸盐的相互作用及其结构特征。从主客体包结配合物的晶体结构,可以看出苯胺的苯环进入了六元瓜环空腔,形成1：1包结配合物,两分子苯胺以相反的方向平行地进入八元瓜环空腔,形成了2：1包结配合物;表明苯胺与两种瓜环有不同的作用模式。     

Determining the composition of the Earth

A long-standing question in the planetary sciences asks what the Earth is made of. For historical reasons, volatile-depleted primitive materials similar to current chondritic meteorites were long considered to provide the 'building blocks' of the terrestrial planets. But material from the Earth, Mars, comets and various meteorites have Mg/Si and Al/Si ratios, oxygen-isotope ratios, osmium-isotope ratios and D/H, Ar/H2O and Kr/Xe ratios such that no primitive material similar to the Earth's mantle is currently represented in our meteorite collections. The 'building blocks' of the Earth must instead be composed of unsampled 'Earth chondrite' or 'Earth achondrite'.