贵州水城硝灰洞的铀系年龄

本文报道了古人类遗址贵州水城硝灰洞钟乳石样的铀系年龄。溶洞表层钙板为11(范围10～13)万年,位于笫3堆积层下都的一小石笋为23(?)万年,含化石及文化遗物的堆积层应在13～23万年间形成,因此应属中更新世的晚期,水域人应属早期智人,“锐棱砸击文化”应起源于旧石器时代早期。硝灰洞岩溶发育期与深海钻孔δ(?)O曲线良好吻合,说明了全球性气候变迁对该地的影响。      

海洋琼胶降解细菌的筛选及HQM9琼胶酶研究

对红藻门江蓠和石花菜的共附生的琼胶降解细菌进行了系统的分离,共筛选得到琼肢降解细菌25株,选择其中有代表性的15株进行了分子鉴定,鉴定结果表明这些细菌主要分布在Agarivorans,Cellulophaga,Alteromonas,Saccharophagus,Glaciecola,Vibrio六个属中,另外初步判定...     

区域性地震安全性评价目标区地震构造特征研究——以三江口港产城新区为例

目标区地震构造调查是区域性地震安全性评价的基础工作.以广西来宾市三江口港产城新区为例,在收集、整理、分析已有的地层、地质资料的基础上,采用遥感解译、地形地貌分析、地震地质调查等手段,开展了目标区地震构造调查研究.调查结果显示:目标区发育早第四纪断陷盆地和3条早第四纪断裂,前者是区域间歇性升降运动和断块差异性抬升运动等新...     

中国东部夏季不同雨带类型的海洋和环流特征差异

利用1951-2009年NCEP/NCAR再分析资料、UKMO HADISST1全球月海表温度及中国东部地区120站的月降水量资料,首先定义出能够客观表征中国东部夏季3种雨带类型的指数,然后分析了3种雨带分布类型海洋和大气环流特征的主要差异,并进一步分析了前期海洋背景的差异特征对夏季东亚环流关键系统的预测蕴示.结果表明:(1)3种雨带类型对应的前期冬季海洋信号比当年夏季强,其差异主要表现在:多雨带出现在北方地区的Ⅰ型对应的是北太平洋海温呈显著的正距平、暖池及东澳暖流为负距平、南太平洋西风漂流区为正距平;多雨带出现在黄淮地区的Ⅱ型对应的海温分布则与Ⅰ型完全相反;多雨带出现在长江及其以南地区的Ⅲ型对应的海温分布在北太平洋海域与Ⅰ型基本一致;(2)3种雨带类型对应的环流及水汽输送特征的差异主要表现在:Ⅲ型与Ⅰ型具有几乎完全相反的环流及水汽输送特征,当出现Ⅲ型时,东亚中高纬度有强盛的阻塞形势发展和维持,中高纬度的经向环流异常加强,同时西太平洋副热带高压偏强,位置偏西、偏南,该地区呈反气旋性距平环流,西太平洋副热带纬向水汽输送加强,而出现Ⅰ型时则相反;Ⅱ型与Ⅰ型的环流及水汽输送特征更接近,两者的主要差异是:当出现Ⅱ型时,西太平洋副热带地区呈反气旋性距平环流,而出现Ⅰ型时该地区呈气旋性距平环流;(3)前期冬季赤道中东太平洋海温和南太平洋西风漂流区的海温异常变化可以作为夏季西太平洋副热带高压预报的重要前兆信号.     

Recover vigorous cells of Magnetospirillum magneticum AMB-1 by capillary magnetic separation

Cultivable magnetotactic bacteria (MTB) in laboratory can provide sufficient samples for molecular microbiological and magnetic studies. However, a cold-stored MTB strain, such as Magnetospirillum magneticum AMB-1, often loses its ability to synthesize magnetosomes and consequently fails to sense the external magnetic field. It is therefore important to quickly recover vigorous bacteria cells that highly capable of magnetosome producing. In this study, a modified capillary magnetic separation system was designed to recover a deteriorating strain of Magnetospirillum magneticum AMB-1 that long-term cold-stored in a refrigerator. The results show that all cells obtained after a 3-cycle treatment were vigorous and had the ability to produce magnetosomes. Moreover, the 3^rd-cycle recovered cells were able to form more magnetosome crystals. Compared with the colony formation method, this new method is time-saving, easily operated, and more efficient for recovering vigorous MTB cells.     

双向土钉锚喷技术在重力式挡墙设计中的应用研究

将土钉锚喷技术应用到重力式挡墙的结构施工中,形成双向土钉锚喷重力挡土墙。以北京某奥运室外地下雨水收集池基坑支护工程为例,对它的设计原理、稳定性计算以及使用范围进行了详细说明,特别是对该方法在挡土墙加固方面的设计及施工方法进行了全面阐述。工程实践证明,该方法具有安全性大,施工效牢高,费用低的特点。     

西安未央湖趋磁细菌多样性与磁学研究

对西安郊区未央湖趋磁细菌的生物多样性和磁学性质进行了系统研究.光学和透射电子显微镜分析发现,未央湖趋磁细菌主要为杆菌,它们的磁小体多为子弹头形状并呈链状排列;磁学分析表明这些磁小体颗粒以单畴磁铁矿为主;并发现一类同时含有磁铁矿和胶黄铁矿磁小体的趋磁杆菌.基于16S rRNA基因的系统发育分析发现,未央湖趋磁细菌主要分布在变形菌门的δ-变形菌纲(75％)和α-变形菌纲(25％).本研究结果还有助于为利用趋磁细菌群落指示环境变化提供依据.     

Isolation and diversity analysis of heterotrophic bacteria associated with sea anemones

A study was undertaken to investigate the heterotrophic bacterial flora associated with the sea anemones. Samples of the sea anemones Anthopleura midori were collected from the coast of Weihai and bacteria were isolated from these samples. Additionally, high numbers of viable bacteria were obtained from the celom wall and surface of anemone, the community of cultivable bacteria was very diverse. As a result of this isolation, 60 strains were obtained, 56 of them were selected for identification and characterization by 16S rRNA gene sequence analysis and limited phenotypic testing. Among these isolates, 16 strains were phylogenetically related to members of the genus Pseudoalteromonas and neighboring taxa. Other isolates included members of the genera Colwellia, Vibrio, Acinetobacter, Pseudomonas, Endozoicomonas, Roseovarius, Paracoccus, Loktanella, Leisingera, Sulfitobacter, Bacillus, Staphylococcus, Plantibacter, Microbacterium, Micrococcus, Joostella, Psychroserpens, Cellulophaga, Krokinobacter, Polaribacter and Psychrobacter. Seven potential novel species were found. Among 60 strains, 17 of them can produce proteolytic exoenzyme, 20 can produce lipolytic exoenzyme. Strain NQ8 has strong antagonistic effects on some Vibrio strains. This study demonstrates that the culturable fraction of bacteria from the sea anemones Anthopleura midori is diverse and appears to possess much potential as a source for the discovery of novel bioactive materials.     

基于低频振荡信号的中国南方冬半年持续性低温指数延伸期预报试验

利用1961-2009年36°N以南、108°E以东中国大陆191个站点逐日最低气温和NCEP/NCAR再分析日平均格点,研究与区域持续性低温事件有关的大气低频振荡信号,寻找可以在一定程度上表征不同类型区域持续性低温事件的指数,并尝试结合DERF2.0系统的预报产品进行持续性低温指数的延伸期预报试验。结果表明:（1）在研究范围内的区域持续性低温事件可以归纳为江北型、江南型和全区域型3类,其中江北型和江南型事件的环流背景差异体现在异常环流中心的纬度位置上,而全区域型事件属于增强型的江北型事件;（2）江北型和江南型区域平均最低气温时间序列的10-30 d低频分量的位相和强度变化与区域持续性低温事件的发生有显著关系,可以作为表征区域持续性低温事件指数和预报量;（3）100°-120°E范围内850 hPa温度场距平的经验正交函数分解前两个主模态具有显著的10-30 d变化周期,并且其空间结构分别与江北型和江南型事件的典型环流特征一致,前两个主模态时间系数能够作为持续性低温指数的预报因子;（4）检验结果表明,DERF2.0系统对上述预报因子有一定的预报能力。在延伸期预报时效内,利用统计学和动力学相结合的方法制作的持续性低温指数的预报效果好于模式直接预报的2 m气温,该预报方法有助于提升区域持续性低温事件的延伸预报能力。