Frame scaling function sets and frame wavelet sets in

In this paper, we classify frame wavelet sets and frame scaling function sets in higher dimensions. Firstly, we obtain a necessary condition for a set to be the frame wavelet sets. Then, we present a necessary and sufficient condition for a set to be a frame scaling function set. We give a property of frame scaling function sets, too. Some corresponding examples are given to prove our theory in each section.     

Graphite nanosheets doped with Fe, Ni, and N, synthesized in one step, and their unique magnetic performance

Graphite nanosheets (GNs) doped with N, Fe, or Ni were synthesized by pyrolysis of metal tetrapyridinoporphyrazine (MPTpz, M=Fe²⁺, and Ni²⁺) and a mixture of MPTpzs in a chemical vapor deposition furnace. The products obtained were characterized by scanning and transmission electron microscopy, and X-ray photoelectron spectroscopy. The magnetic properties of the GNs obtained were investigated at room temperature using a vibrating sample magnetometer with an applied field of −10 000-10 000 Gs. The results show the GNs obtained are terrace-like and ultra-thin, with very high aspect ratio. Fe, Ni and N atoms have been doped to the GNs successfully. There are two types of N atom that are introduced into pure carbon systems: pyrinidic and graphitic N atoms. The GNs obtained exhibit ferromagnetic behavior at room temperature. Sample S1, obtained by pyrolysis of a mixture of MPTpzs (M=Fe²⁺ and Ni²⁺), have the highest coercivity force. The saturation magnetization (M_s), remanent magnetization (M_r), and coercivity (H_c) values of sample S1 are 24.51 emu g⁻¹, 3.95 emu g⁻¹, and 207.34 Gs, respectively.     

Synthesis of propylene carbonate from carbon dioxide using trans‐dichlorotetrapyridineru‐ thenium(II) as catalyst

trans‐Dichlorotetrapyridineruthenium(II) [trans‐RuCl₂(py)₄] was synthesized and the structure was determined by single crystal X‐ray crystallography. Highly efficient formation of propylene carbonate (PC) from carbon dioxide and propylene oxide was achieved by using a catalyst system composed of trans‐RuCl₂(py)₄ and hexadecyl trimethyl ammonium bromide under mild conditions (4h, 80 °C, 3.0 MPa). PC was obtained in nearly 100% selectivity without the formation of a polymer. The catalyst could be recycled constantly many times without any significant loss of its catalytic activity. On the basis of the results, a mechanism for the reaction was proposed. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.     

DMSO作为新的合成子在有机合成中的应用研究进展

二甲亚砜(DMSO)不但可以作为有机溶剂,同时还可以作为反应试剂,在有机合成中得到了广泛的应用.由于其具有来源广、价格低廉、操作简单等优点,近年来将DMSO作为反应试剂应用于有机合成反应引起了广大化学家的关注.本文作者对近几年来DMSO作为合成子在有机合成中的应用按照引入官能团的种类进行了总结,详细阐述了其转化为甲磺酰基、甲酰基、氰基、甲硫基等官能团的方法学研究,以期为开发DMSO新的应用提供参考依据.     

Cu（OTf）2催化苄基卤代物与三丁基烯丙基锡的偶联反应

研究了苄基卤代物与三丁基烯丙基锡的偶联反应,当以10mol%Cu(OTf)2为催化剂,CH2Cl2为溶剂时,1-氯甲基-4-苯基萘与三丁基烯丙基锡于室温反应1h,交叉偶联反应产物1-(3-丁烯基)-4-苯基萘(3b)收率即达93%.结果表明,芳环含供电子基的底物反应活性较高,在室温反应几分钟即可完成,而芳环含吸电子基的底物反应活性低.反应产物3b,1-溴-4-(3-丁烯基)萘(3c)和1-(3-丁烯基)-4-硝基萘(3f)未见报道,且其结构经表征确认.     

三维涡流问题A,φ-Ω法分区变分原理*

本文给出了在涡流区、场源区采用矢量磁位A、标量电位φ,而在非导电区(气隙)采用标量磁位Ω,来求解三维涡流问题的分区变分原理.通过泛函变分能得到不同区域内的控制方程,自然边界条件,以及满足电磁连续性要求的区域界面连续条件.     

Tailoring MoS2 Ultrathin Sheets Anchored on Graphene Flexible Supports for Superstable Lithium‐Ion Battery Anodes

2D MoS₂ has a significant capacity decay due to the stack of layers during the charge/discharge process, which has seriously restricted its practical application in lithium‐ion batteries. Herein, a simple preform‐in situ process to fabricate vertically grown MoS₂ nanosheets with 8–12 layers anchored on reduced graphene oxide (rGO) flexible supports is presented. As an anode in MoS₂/rGO//Li half‐cell, the MoS₂/rGO electrode shows a high initial coulomb efficiency (84.1%) and excellent capacity retention (84.7% after 100 cycles) at a current density of 100 mA g^?1. Moreover, the MoS₂/rGO electrode keeps capacity as high as 786 mAh g^?1 after 1000 cycles with minimum degradation of 54 µAh g^?1 cycle^?1 after being further tested at a high current density of 1000 mA g^?1. When evaluated in a MoS₂/rGO//LiCoO₂ full‐cell, it delivers an initial charge capacity of 153 mAh g^?1 at a current density of 100 mA g^?1 and achieves an energy density of 208 Wh kg^?1 under the power density of 220 W kg^?1.     

环形嵌段共聚物的胶束化行为模拟

利用Monte Carlo模拟, 对比了相同组成下环形二嵌段共聚物AB和线形三嵌段共聚物ABA在选择性溶剂中的胶束化行为. 结果发现, 相同链组成的环形和线形嵌段共聚物的临界胶束浓度(cmc)的差别与A嵌段的比例(f_A)及B嵌段间的吸引强度(ε)密切相关. 在f_A较小、 ε较大的情况下, 相应环形嵌段共聚物的cmc值更小; 而在f_A较大、 ε较小的情况下, 线形嵌段共聚物的cmc值更小. 为了进一步理解胶束化行为同f_A及ε的关系, 计算了胶束化过程中熵和势能部分对自由能的贡献. 结果表明, 在所研究的f_A和ε范围内, 环形嵌段共聚物形成胶束时的熵损失更小, 因而从熵贡献角度来看, 环形嵌段共聚物更易发生胶束化. 而从势能贡献角度来看, 当f_A较小、 ε较大时, 环形嵌段共聚物形成胶束时势能有较大程度的降低, 对自由能的贡献更大, 因而此时环形嵌段共聚物更易发生胶束化. 而当f_A较大、 ε较小时, 线形嵌段共聚物形成胶束时势能有较大程度的降低, 对自由能的贡献更大, 因而此时线形嵌段共聚物更易发生胶束化. 由此可见, 对体系的胶束化自由能进行系统分析, 有助于更好地理解环形和线形嵌段共聚物的胶束化行为.     

Synthesis and structure of the β-carboline derivatives and their binding intensity with cyclin-dependent kinase 2

Series of 3-substituted of 6-aminosulfonyl-β-carbolines were designed and synthesized. In addition, the binding mode of these β-carboline derivatives with cyclin-dependent kinase 2 (CDK2) was studied by means of fluorescence measurements and molecular docking calculation. The results showed that replacement of 3-cyclohexylmethoxy group will increase the hydrophobic binding interaction with the deep hydrophobic pocket of CDK2 correlate to the higher binding intensity.     

软三嵌段两面神胶体粒子自组装行为的模拟研究

采用软补丁粒子模型及相应的介观动力学模拟方法, 研究了软三嵌段两面神胶体粒子在稀溶液条件下的自组装行为. 通过合理调节补丁大小和补丁之间的吸引强度, 软三嵌段两面神胶体粒子能够自组装形成非常丰富的聚集结构, 包括线状结构、 六方柱状结构、 体心四方束状结构以及三维网络状结构. 此外, 分析了与纤维结构类似的体心四方束状结构形成的动力学机理. 模拟结果为实验上设计并制备新颖的超胶体纳米结构提供一定的理论支持.