Phylogenetic relationship and phenotypic comparison of Psychrobacter species isolated from polar oceans

To investigate the phylogenetic relationship and biogeography of bacterioplankton in polar oceans, four Psychrobacter strains, BSw10170, BSw20352, BSw20370, and BSw20461, isolated from seawater of the Bering Sea, the Chukchi Sea, and the Prydz Bay, were characterized by 16S rDNA sequencing and physiological and biochemical testing. Results demonstrated that close relationships existed between the Arctic and Antarctic strains with sequence similarities higher than 97%. These four Psychrobacter strains not only showed almost identical phenotypic characteristics among them, but also shared a lot of similarities with those related Psychrobacter species, indicating that psychrotolerance and halotolerance of Psychrobacter strains may be among the reasons for their bipolar, even global distribution in marine environments at the genus level.     

No oceans on Titan from the absence of a near-infrared specular reflection

With its substantial atmosphere of nitrogen, hydrocarbons and nitriles, Saturn's moon Titan is a unique planetary satellite. Photochemical processing of the gaseous constituents produces an extended haze that obscures the surface. Soon after the Voyager fly-bys in 1980 and 1981 photochemical models led to the conclusion that there should be enough liquid methane/ethane/nitrogen to cover the surface to a depth of several hundred metres. Recent Earth-based radar echoes imply that surface liquid may be present at a significant fraction of the locations sampled. Here we present ground-based observations (at near-infrared wavelengths) and calculations showing that there is no evidence thus far for surface liquid. Combined with the specular signatures from radar observations, we infer mechanisms that produce very flat solid surfaces, involving a substance that was liquid in the past but is not in liquid form at the locations we studied.     

寒冷地区窗在围护结构中的节能研究

从建筑节能的角度，分析寒冷地区窗在围护结构中的能耗问题，阐述其节能途径和技术措施。     

Phylogenetic relationship and phenotypic comparison of Psychrobacter species isolated from polar oceans

To investigate the phylogenetic relationship and biogeography of bacterioplankton in polar oceans, four Psychrobacter strains, BSw10170, BSw20352, BSw20370, and BSw20461, isolated from seawater of the Beijing Sea, the Chukchi Sea, and the Prydz Bay, were characterized by 16S rDNA sequencing and physiological and biochemical testing. Results demonstrated that close relationships existed between the Arctic and Antarctic strains with sequence similarities higher than 97 %. These four Psychrobacter strains not only showed almost identical phenotypic characteristics among them, but also shared a lot of similarities with those related Psychrobacter species, indicating that psychrotolerance and halotolerance of Psychrobacter strains may be among the reasons for their bipolar, even global distribution in marine environments at the genus level.     

气候变暖吞噬珊瑚礁?

珊瑚礁作为非常珍贵的海洋资源,可以给人类和经济带来多种利益,比如提供食物、维持生计、支撑旅游业、保护海岸,甚至有助于抵御疾病等等,但一份最新的综合分析报告显示,目前世界上75%的珊瑚礁正遭受来自伞球如气候变化因素以及区域范嗣内的符种威胁.     

梅花香自苦寒来——参加机械创新大赛有感

介绍了指导参加全国机械创新设计竞赛的整个过程。从学员创新思想的偶然产生,到实物制作的种种难题,本着简单实用的参赛原则,更新和论证了四套方案,历尽艰辛,终获成功。