类球形正交LiMnO2的制备、微结构和电化学性能

以共沉淀法得到的类球形MnCO₃为前驱物，制备了类球形正交LiMnO₂(So-LiMnO₂)，采用XRD、SEM和N₂吸附技术对样品进行表征；与非球形正交LiMnO₂(No-LiMnO₂)进行了对比研究。结果表明：o-LiMnO₂的堆垛层错度、结晶状况、颗粒形貌和大小与前驱物的微结构密切相关；在80次电化学循环测试过程中，So-LiMnO₂经15次循环可达最大的放电容量152 mAh·g^-1，其容量衰减平均每次循环0.58 mAh·g^-1；而No-LiMnO₂要经过38次循环才能达到最大放电容量128 mAh·g^-1，容量衰减平均每次循环高达1.24 mAh·g^-1。TEM和EDS分析证明：由一次粒子团聚的类球形So-LiMnO₂能有效地抑制电解液对材料的腐蚀、减少Mn的溶解，从而提高了电化学循环能力。     

有关键能的几个问题

本文讨论了与键能有关的几个问题：即键能和键焓，键离解能和平均键能，原子轨道的成键能力和键的强弱等。     

Ab Initio Study on the Anti-HIV Activities of Hydroxyflavones

1 INTRODUCTION AIDS, in other words, Acquired Immunodefici-encysyndrome, is a viral contagious disease withhigh death rate. However, effective treatment againstit has not appeared so far. At present, about 100kinds of natural compounds that could be extractedfrom natural products or artificially synthesized havebeen found to have anti-HIV activities to some ex-tent. They belong to flavonoid, terpenoid, steroid, cou-marin, peptide, alkaloid etc., respectively. Previousstudies show that…     

三(2-氨基乙基)胺-镉(Ⅱ)-2-甲基咪唑三元配合物的合成、结构与抗微生物活性

The complex [Cd(tren)(meim)](ClO₄)₂ was synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. The compound crystallizes in monoclinic system, space group P2₁/m with a=0.786 8(2) nm, b=0.834 2(2) nm, c=1.496 2(4) nm, M_r=538.64, Z=2, F(000)=542, D_c=1.822 g·cm^-3, T=298(2) K, μ=1.435 mm^-1 and λ=0.071 073 nm. The structure was refined to R=0.045 8 and wR=0.123 1 for 1 489 observed reflections with I>2σ(I). The complex was valued for its antimicrobial activity against bacterial strands using the agar diffusion method. It was found to be active against the four test bacterial organisms. CCDC: 600198.     

2-甲基-6-对甲苯基-1,6-庚二烯的合成

以对甲苯乙酮(1)为原料,经烯醇硅醚化,Lewis酸催化Michael加成反应和Wittig反应,合成了新倍半萜烯化合物2-甲基-6-对甲苯基-1,6-庚二烯。     

天花粉蛋白溶液构象与稳定性及生物活性的关系

用圆二色性研究了天花粉蛋白在不同PH,不同温度和不同的时间条件下的溶液构象变化.阐明了天花粉蛋白溶液的外部环境,并研究了天花粉蛋白的溶液构象与抗生育活性的关系,结果表明随着溶液中a-helix含量的增加,抗生育活性也相应增加,当a-helix含量减少到15%以下,其抗生育活性也就丧失.     

尖吻蝮蛇毒抗凝血因子(ACF)含量和钙离子含量的定量测定及钙离子结合位点的初步研究

由紫外光谱法测定蛋白质浓度,用ICP测定Ca含量,从而确定一个ACF分子中含一个钙离子.ACF中分子中除一个高亲和性钙结合位点外,至少还有一个低亲和性钙结合位点,只有当过量钙离子存在时,才可能在低亲和性钙结合位点上进一步结合钙离子.Tb~(3+)具有比Ca~(2+)离子更强的键合ACF能力,能定量结合在ACF中的两个位点上,且能全部取代ACF中Ca~(2+).文中提及的金属离子对ACF的抗凝血活性没有显著的影响.     

凝胶型苯乙烯系离子交换树脂的强度及抗渗透性的影响因素研究 (I)

本文就单体组成中不同引发剂，链转移剂，环二烯，烯丙基类化合物和氧气等对凝胶型苯乙烯系阳离子交换树脂的强度和抗渗透性的影响进行了系统研究。结果显示，采用0．30％的过氧化2－乙基己酸叔丁酯（OT）和0．01％的过氧化苯甲酸特丁酯（CP）代替过氧化二苯甲酰（BPO作引发剂，或者加入0．02％的链转移剂十二烷基硫醇，均能够在一定程度上改善共聚物珠粒的结构均匀性，提高其合成的离子交换树脂的磨后圆球率和抗渗透性能。     

Molecular Simulation on Transport Properties of Confined Water

The diffusivity and viscosity of water confined in micropores were studied by molecular dynamics simulations. The effects of pore width and density were analyzed at pore widths from 0.9 to 2.6nm. The diffusivity in micropores is lower than that of the bulk, and it decreases as pore width decreases and as density increases. But the viscosity in micropores is much larger than that of the bulk, and it increases as pore width decreases and as density increases. The diffusivity in channel parallel direction is obviously larger than that in channel perpendicular directions.     

烟草可替代青蒿批量生产抗疟药

正德国马克斯普朗克分子植物生理学研究所专家发明了从烟草中提取青蒿素的方法,从而可以满足大批量廉价生产抗疟疾药物的需要。这项研究成果刊登在科学杂志《eL ife》上。全球对抗疟疾药物需求很高,但大批量廉价生产始终做不到,因为药物的主要成分青蒿素需要从天然植物青蒿中提取,而青蒿生长的地域和数量受限。德国马普分子植物生理学研究所专家发明了一种特殊的方法,从烟草中提取青蒿素,从而可以大批量廉价生产抗疟疾药物。