郡县制国家现代化：中央政府如何扩大公共事务治理职能

郡县制国家的传统职能是“管人”,但是在当代,为了适应现代世界,需要加强和完善“管事”的职能。然而,加强“管事”的职能遇到的一大障碍,是“管事”与“管人”通常难以分开,带来管事与管人的冲突。在全国性公共事务上,面对管事与管人的冲突,郡县制国家的一种改革方向,即建立中央统一管理与地方属地管理相结合的体制,既扩大中央政府的治理职能,同时又发挥纵向约束机制的作用,从而能改善全国性公共事务治理。此种中央统一管理与地方属地管理相结合的体制,通常不是中央政府事先设计出来的,而是在改革过程中,经由中央政府与地方政府的策略性互动过程,逐渐建立起来的。因此,郡县制国家蕴含着一种潜力,即在公共事务治理上,包括地方公共事务和全国性公共事务,可以引入和发挥“纵向约束机制”的作用,使得国家既保持“管人”的基本体制不变,又能提高治理能力。     

Synthesis,Crystal Structure,and Biological Activity of 4-Chlorobenzaldehyde (2-trifluoromethylTrifluoromethyl-5,6,7,8-tetrahydrobenzo[4 ,5]-thieno[2,3-d]pyrimidin-4-yl)hydrazone Monohydrate

The novel title compound 4-chlorobenzaldehyde (2-trifluoromethyl-5,6,7,8- tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4-yl)hydrazone monohydrate (C18H14ClF3N4SH2O, Mr = 428.86) has been synthesized by a condensation reaction of 4-chlorobenzaldehyde with (2-trifluoromethyl-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4-yl)hydrazine, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c with a = 7.4252(7), b = 26.344(2), c = 10.3095(9) , = 109.407(2)°, V = 1902.0(3) 3 , Z = 4, Dc = 1.498 g/cm3 , μ = 0.356 mm-1 , F(000) = 880, the final R = 0.0564 and wR = 0.1681 for 2343 observed reflections with I > 2 (I). X-ray diffraction analysis reveals that the title hydrazone molecule is nearly planar except for the cyclohexene and trifluoromethyl moieties. In the crystal packing, the molecules form stacks by a three-dimensional framework, which results from intermolecular N(3)-H(3)···O(1), O(1)-H(1B)···N(2), O(1)- H(1B)···N(4) and O(1)-H(1A)···F(1) hydrogen bonds via water molecules together with π-π stacking interactions. Molecular geometry of the title compound in the ground state optimized by B3LYP functional with 6-311G** basis sets indicates that the calculations are in agreement with the experimental data. The preliminary bioassay suggested that the title compound exhibits relatively good fungicidal activity against Fusarium oxysporium f.sp.vasinfectum and Dothiorella gregaria.     

固态光聚合反应研究进展

光引发的固态聚合反应一直是令人感兴趣的研究领域.本文综述了固态光聚合的研究进展.着重介绍了双炔类体系,二烯类体系以及(甲基)丙烯酸酯体系的固态光聚合的研究工作以及应用前景.     

共形空间${\mathbb Q}^{n+1}_1$中类空超曲面的拼挤问题

通过对第二共形基本形式的模长平方作拼挤,给出Clifford超柱面的一个共形特征.     

TinO2和TinO2-(n=1-10)团簇的几何结构、电子和磁性质

基于密度泛函理论(DFT)的B3LYP方法,研究了TinO2和TinO2-(n=1-10)团簇的几何结构、电子结构以及磁性.结果表明,两个氧以分离的原子状态吸附在金属团簇的表面,呈现出以一个钛原子为中心的O-Ti-O的相邻吸附形式.中性团簇和阴离子团簇的能量最低结构相似.稳定性分析表明TinO2具有很高的稳定性,特别是TiO2和Ti7O2.此外,详细讨论了团簇的电离势、电子亲和能、电子解离能和能隙.基于最低能量结构,讨论了团簇的磁性,发现电荷从Ti原子向O原子转移,并且电荷转移主要发生在TinO2的Ti-3d、Ti-4s和O-2p轨道.磁性团簇中反铁磁序占据主导,磁矩主要来源Ti-3d电子的贡献,而两个氧原子的贡献非常小.     

3，5-二硝基苯甲酸镉配合物的合成、晶体结构、热稳定性和荧光性质

以3,5-二硝基苯甲酸,咪唑为配体,合成了新化合物[Cd(H₂O)₂(DNBA)(Im)₂](DNBA)·H₂O,(DNBA=3,5-二硝基苯甲酸阴离子)。该配合物属正交晶系,空间群为Ccc2,晶胞参数：a=1.324 99(4) nm,b=1.516 01(5) nm,c=2.789 22(8) nm;V=5.602 7(3) nm³,D_c=1.719 g·cm^-3,Z=8,μ=0.866 mm^-1,F(000)=2 912,最终偏离因子R₁=0.058 3,wR₂=0.146 4。该配合物中包含两个单核镉(Ⅱ)配合物,且配合物中还包含未配位的3,5-二硝基苯甲酸,金属中心均是六配位变形八面体结构。并测定和研究了标题化合物的热重和荧光性能。     

Extraction of coal-tar pitch using NMP/ILs mixed solvents

Coal-tar pitch(CP)is a promising carbon raw material for producing needle coke,carbon fiber etc.During processing,the H/C ratio,ash content,and quinoline insoluble(QI)in the CP are the key factors that influence the material preparation.In this study,NMP was selected to extract CP first;then[BMIM]Cl/NMP mixed solvent was used;and finally a series of ionic liquids(ILs)mixtures with NMP were developed for the extraction of CP to obtain the refined pitch.The extracts were analyzed via elemental analysis,TGA,FT-IR,and 13C-NMR.Results indicate that different NMP/IL mass ratios or different kinds of ILs have impact on the extraction yield.The relationship of the hydrogen to carbon(H/C)ratio changed with different solvents and QI extracts were obtained.Results showed that the H/C ratios changed little between NMP extracts and could be adjusted by changing the NMP/ILs mass ratio or using different ILs.The extracts are suitable for preparation mesophase pitch because of no ash content,low QI,and appropriate H/C ratios.As a result,NMP can be used to refine pitch.In addition,[BMIM]Cl is good mixed with NMP for CP extraction,because it can obtain a relatively high yield under the same extraction conditions.     

Ru掺杂对Fe催化剂上酚类化合物加氢脱氧影响的密度泛函理论研究北大核心CSCD

采用密度泛函理论(DFT)计算研究了苯酚、邻甲酚、愈创木酚在不同结构Ru-Fe(211)表面上吸附活化性能和加氢脱氧反应路径.结果表明,Ru掺杂能促进H2分子在Fe(211)表面上解离,提高加氢脱氧反应速率.酚类在1Ru_(ads)-Fe(211)表面上吸附比在1Ru_(sub)-Fe(211)表面上更稳定,苯酚和邻甲酚脱羟基步骤能垒分别降低0.13和0.28 eV,有利于生成芳烃.愈创木酚在1Ru_(sub)-Fe(211)表面上加氢脱氧优势路径是先脱甲氧基生成苯酚,苯酚再加氢脱氧生成产物苯(速控步骤能垒1.16 eV);而在1Ru_(ads)-Fe(211)表面上愈创木酚先脱羟基再脱甲基生成苯酚的路径更具有动力学优势(速控步骤能垒1.21 eV).计算结果表明Ru掺杂方式影响Fe催化剂对酚反应分子的吸附稳定性以及加氢脱氧反应路径和性能.与1Ru掺杂Fe(211)催化剂相比,增加Ru原子数形成4Ru_(ads)-Fe(211),能够进一步提高酚类反应物的吸附强度,但导致加氢脱氧反应能垒升高.因此,在Fe催化剂上以表面吸附的形式掺杂少量贵金属Ru更利于酚类加氢脱氧生成芳烃.     

超高效液相色谱法测定餐饮油烟中的十五种醛酮

采用在流动相中添加四氢呋喃的方法来改善丙烯醛-2,4-二硝基苯肼(DNPH)和丙酮-DNPH的分离,然后优化流动相比例和梯度,确定了UPLC分析醛酮-DNPH的色谱条件。有机溶剂消耗量和分析时间分别是传统方法的1/20~1/10和12%~30%;工作曲线线性相关系数、方法检出限和测定下限均满足HJ683-2014的规定;UPLC法测定醛酮的2,4-二硝基苯肼衍生物的平均回收率为91.5%~101%。基于常规的超高效反向C18色谱柱,在40℃条件下建立了高效分离醛酮混标的UPLC方法,方法已用于测定餐饮油烟中醛酮类化合物。     

CRISPR-Cas System for RNA Detection and Imaging

The system of clustered regularly interspaced short palindromic repeats(CRISPR)and CRISPR-associated endonucleases(Cas)have been widely used in gene editing,disease treatment,molecular diagnosis and chromosome imaging.On account of the programmable target recognition of CRISPR-Cas system and the specific targeting function toward RNA of type Ⅵ class Ⅱ Cas proteins,CRISPR-Cas system has been deployed as RNA recognition and detection tools,exhibiting promising application potentials in the field of RNA detection and imaging.In this review,we summarize the latest research progresses as well as development prospects of CRISPR-Cas system in RNA diagnosis and live cell RNA imaging.