一种改进的基于信息传播率的复杂网络影响力评估算法

评价网络中节点的信息传播影响力对于理解网络结构与网络功能具有重要意义.目前,许多基于最短路径的指标,如接近中心性、介数中心性以及半局部(SP)指标等相继用于评价节点传播影响力.最短路径表示节点间信息传播途径始终选择最优方式,然而实际上网络间的信息传播过程更类似于随机游走,信息的传播途径可以是节点间的任一可达路径,在集聚系数高的网络中,节点的局部高聚簇性有利于信息的有效扩散,若只考虑信息按最优传播方式即最短路径传播,则会低估节点信息传播的能力,从而降低节点影响力的排序精度.综合考虑节点与三步内邻居间的有效可达路径以及信息传播率,提出了一种SP指标的改进算法,即ASP算法.在多个经典的实际网络和人工网络上利用SIR模型对传播过程进行仿真,结果表明ASP指标与度指标、核数指标、接近中心性指标、介数中心性指标以及SP指标相比,可以更精确地对节点传播影响力进行排序.     

Rapid computation of intermolecular interactions in molecular and ionic clusters: self-consistent polarization plus symmetry-adapted perturbation theory

A method that we have recently introduced for rapid computation of intermolecular interaction energies is reformulated and subjected to further tests. The method employs monomer-based self-consistent field calculations with an electrostatic embedding designed to capture many-body polarization (the "XPol" procedure), augmented by pairwise symmetry-adapted perturbation theory (SAPT) to capture dispersion and exchange interactions along with any remaining induction effects. A rigorous derivation of the XPol+SAPT methodology is presented here, which demonstrates that the method is systematically improvable, and moreover introduces some additional intermolecular interactions as compared to the more heuristic derivation that was presented previously. Applications to various non-covalent complexes and clusters are presented, including geometry optimizations and one-dimensional potential energy scans. The performance of the XPol+SAPT methodology in its present form (based on second-order intermolecular perturbation theory and neglecting intramolecular electron correlation) is qualitatively acceptable across a wide variety of systems-and quantitatively quite good in certain cases-but the quality of the results is rather sensitive to the choice of one-particle basis set. Basis sets that work well for dispersion-bound systems offer less-than-optimal performance for clusters dominated by induction and electrostatic interactions, and vice versa. A compromise basis set is identified that affords good results for both induction and dispersion interactions, although this favorable performance ultimately relies on error cancellation, as in traditional low-order SAPT. Suggestions for future improvements to the methodology are discussed.     

(±)-5,3’-二羟基-7,8-(2,2-二甲基吡喃)-4’-甲氧基黄烷酮的首次全合成

以廉价的异香草醛和2,4,6-三羟基苯乙酮为起始原料,经过C-异戊烯基化、环化、选择性的保护酚羟基、羟醛缩合、催化环化等步骤,脱保护基,以6.7%的总收率首次完成了天然吡喃型黄烷酮(±)-5,3’-二羟基-7,8-(2,2-二甲基吡喃)-4’-甲氧基黄烷酮的全合成.所有新化合物的结构都经过IR,1H NMR,MS,HRMS确认.     

新的溶胶-凝胶法制备Ge/SiO2量子点玻璃

以3－三氯锗丙酸和正硅酸乙酯为原料,通过水解、缩聚凝胶热处理及氢气反应,在SiO2凝胶玻璃中析出立方相Ge纳米晶,当x=30时,凝胶玻璃中除了析出立方相Ge纳米晶处,还析出六方相GeO2,利用XRD测试了Ge纳米晶的大小,发现随着掺杂量的增加,纳米颗粒粒径从1nm增大到10nm,电子衍射表明镶嵌在SiO2凝交玻璃中的Ge纳米晶为多晶结构。     

Direct optical resolution of the enantiomers of axially chiral compounds by high-performance liquid chromatography on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase

Summary The enantiomeric separation of nineteen biphenyl dimethyl dicarboxylate derivatives has been examined by HPLC on a chiral statonary phase prepared by coating aminopropylated silica gel with cellulose tris-(3,5-dimethylphenylcarbamate). It was found that trifluoroacetic acid (TFA) has a dominant effect on chiral separation for acidic compounds. The percentage of 2-propanol in the mobile phase does not have a large effect on the anantioselectivity but the separation was dramatically influenced by the kind of alcohol in the mobile phase. The effect of temperature on the chiral separation is also discussed. Most of the enantiomers investigated could be resolved satisfactorily.     

Large-scale Ni-doped ZnO nanowire arrays and electrical and optical properties

Large-scale Ni-doped ZnO nanowire (NW) arrays are grown. The electrical conductivity of a single Ni-doped ZnO NW has been increased for 30 times. The photoluminescence (PL) spectrum of the doped ZnO NWs has a red shift, suggesting possible doping induced band edge bending. The doped NW arrays could be the basis for building integrated nanoscale transistors, sensors, and photodetectors.     

糖尿病人微量元素谱的多元分析

胜多元分析了糖尿病患者样品中微量元素，了解微量元素与糖尿病的关系，并提出了新见解。用ＩＣＰ－ＡＥＳ测定糖尿病患者血、发中１８种微量和宏量元素 ；结果经多元分析处理，找到血、发共有的相关链：Ｍｎ－Ｎｉ－Ｃｕ－ＳｒＴｉ，它与患者年龄、性别、样品无关，看来它提供了机体的特殊信息。     

2020 Roadmap on gas-involved photo-and electro-catalysis

In this roadmap, we address the development and perspectives of hydrogen evolution reaction, oxygen reduction reaction, oxygen evolution reaction, carbon dioxide reduction reaction and nitrogen reduction.     

Microwave-Assisted Rapid Preparation of Substituted Carbazole-9-acetic and Propionic Acids and their Absorption and Fluorescence Spectra

 A rapid one-pot synthesis of substituted carbazole-9-acetic and -propionic acids under microwave irradiation is described. N-Alkylation and hydrolysis was carried out in DMF without catalyst. The absorption and fluorescence spectroscopic characteristics of the title compounds are discussed.     

Exponential sums over primes formed with coefficients of primitive cusp forms

Let Af（n） be the coefficient of the logarithmic derivative for the Hecke L-function. In this paper we study the cancellation of the function Ay（n） twisted with an additive character e（α√n）, α 〉0, i.e. Ef（x） = Σx〈n〈2x Af（n）e（α√n）.