Capillary Encapsulation of Metallic Potassium in Aligned Carbon Nanotubes for Use as Stable Potassium Metal Anodes

Metallic potassium (K) is a desirable anode for potassium secondary batteries due to its low electrode potential in nonaqueous electrolytes and high theoretical capacity. Nevertheless, instability caused by dendritic growth, large volume changes, and parasitic side reactions hamper its practical application. Here, an anode containing metallic K is fabricated by infiltrating an aligned carbon nanotube membrane (ACM) with molten K because of its good wettability to molten K due to the strong capillary forces. The K metal is spatially distributed on the 3D ACM framework, which offers sufficient electrode/electrolyte contact for charge transfer. The robust ACM host provides a large number of K nucleation sites and physically confines the K deposited there, thus mitigating dimensional changes during cycling. The pathways for electrons and ions in the anode are associated to form a mixed conducting network, which is beneficial for the electrochemical redox. Consequently, the anode shows stable plating/stripping profiles with low polarization in symmetric cells using conventional carbonate‐based electrolytes. In addition, dendrite growth is suppressed, and the anode demonstrates excellent suitability when paired with a Prussian blue cathode in a full cell. This design strategy is expected to provide a way to address the problems with using metallic K anodes.     

浓核病毒分子生物学特性研究进展

浓核病毒是只感染无脊椎动物的细小病毒.该病毒颗粒直径为19～24 nm,无囊膜包裹,呈二十面体对称.病毒基因组为4～6 kb的单链线性DNA,基因组末端是与DNA复制相关的反向重复序列.浓核病毒的基因组包含编码非结构蛋白和衣壳蛋白的基因.对近年来关于浓核病毒分子生物学方面的研究取得的新进展进行了综述,介绍了浓核病毒基因组结构的分类和单双义浓核病毒的表达策略,以及浓核病毒在作为表达载体和生物防治方面的潜在应用能力.     

p16基因的原核表达及抗P16抗血清的制备

采用基因重租技术,将野生型p16 cDNA通过中间载体pVL1392最后载入表达载体pGEX-5T,IPTG诱导重组质粒转化的大肠杆菌,蛋白质印迹证实42×10~3的融合蛋白GST-P16的表达。表达了GST-P16的重组菌经加热破菌后行SDS-PAGE,将GST-P16蛋白条带切下后经反复冻融于皮内多点注射免疫家兔。所收获的兔血清经蛋白质印迹法检测到抗P16抗体滴度为1:625。结果表明通过pGEX-5T融合蛋白表达系统能方便地提供制备抗P16抗血清的免疫原,该免疫原未经纯化并未影响抗P16抗血清的产生。     

秦岭羚牛高度重复序列DNA片段的分子克隆和序列分析

羚牛（Budorcas taxicolor)属偶蹄目（Artiodactyla)、牛科（Bovidae),为我国一类大型珍贵保护动物。我们从其基因组中克隆得到若干约800bp的BamHI高度重复序列并对部分克隆进行了序列测定,发现它们显示了很高的同源性。利用其中一个单元为探针,对限制酶消化后的羚牛基因组DNA作杂交分析,发现其杂交谱带不具有个体及亚种间特异性,说明该重复序列在羚牛基因组中具有保守的分布和排列。在牛科动物中,羚牛BamHI片段与绵羊属和山羊属的相关序列具有高度同源性,而与水牛和家牛序列差异较大。这些结果为羚牛与羊亚科物种亲源关系较近的分类学观点提供了分子生物学证据。有证据表明,这些片段可能代表羚牛染色体着丝点的卫星DNA单体。     

Cell-based biosensors based on light-addressable potentiometric sensors for single cell monitoring

Cell-based biosensors incorporate cells as sensing elements that convert changes in immediate environment to signals for processing. This paper reports an investigation on light-addressable potentiometric sensor (LAPS) to be used as a possible cell-base biosensor that will enable us to monitor extracellular action potential of single living cell under stimulant. In order to modify chip surface and immobilize cells, we coat a layer of poly-L-ornithine and laminin on surface of LAPS chip on which rat cortical cells are grown well. When 10 microg/ml acetylcholine solution is administrated, the light pointer is focused on a single neuronal cell and the extracellular action potential of the targeted cell is recorded with cell-based biosensor based on LAPS. The results demonstrate that this kind of biosensor has potential to monitor electrophysiology of living cell non-invasive for a long term, and to evaluate drugs primarily.     

The identity of Ligularia yui (Asteraceae: Senecioneae) from China

Examination of both macro‐ and micro‐morphological characters have shown that Ligularia yui S. W. Liu is conspecific with Senecio spathiphyllus Franch., and is here reduced to a synonym of the latter species.     

气候变化背景下华北地区冬小麦生育期的变化特征

以21世纪初近10年的冬小麦(Triticum aestivum)生育期调研数据和气象站点数据为基础, 利用“多元逐步回归分析+残差插值”方法, 绘制了2000年后华北地区冬小麦生育期等值线图, 通过研究两个时期(1971-1980年和21世纪初近10年)华北地区气候资源及冬小麦生育期的变化, 探讨了气候变化对华北地区冬小麦生育期的影响。结果表明: (1)华北地区北部年均气温及≥10 ℃积温增加显著, 但降水减少, 暖干趋势明显, 中部和南部年平均气温和≥10 ℃积温也呈现增加趋势, 但降水增多, 日照下降, 出现暖湿趋势; (2)除南部江苏、安徽两省冬小麦播种期无明显变化外, 华北地区冬小麦播种期普遍推迟, 一般在7-10天; 冬小麦返青期变化较为复杂, 西部地区的冬小麦返青期推迟2-10天, 而东南部的山东、安徽及江苏地区冬小麦返青期明显提前, 一般在5-7天; 华北地区冬小麦的拔节期提前, 北部地区幅度较大, 为5-10天; 冬小麦抽穗期推迟明显, 以华北中部和北部最为明显, 为10-15天; 除华北南部胶东半岛外, 华北大部分地区冬小麦成熟期推迟, 一般在5-10天; (3)气候要素的波动是引起华北地区冬小麦生育期变化的主要原因: 日照时数与冬小麦返青期和拔节期呈显著相关, 日照时数减少, 冬小麦返青期和拔节期提前, 而受年平均气温升高的影响, 冬小麦抽穗期有所推迟, 积温的增加对冬小麦成熟期有推迟作用, 同时降水对冬小麦生长的拔节和抽穗有促进作用。