政策势差:基层政策执行难的一个分析视角--基于A区学位分配争议的考察

对基层政策执行难的解释多关注单阶段因素或其叠加影响,而弱化了跨阶段融合性分析。以A区学位分配为研究案例,基于田野观察与深度访谈分析,可以发现基层政策执行难的背后,存在上层政策目标向基层“下沉”与“内嵌”两个阶段间的政策势差因素,具体呈现为刚性下沉—弹性嵌入的条块势差、整体下沉—分步嵌入的远近势差、普适下沉—区别嵌入的点面势差,三者分别加剧了基层政策执行中的权衡性、过渡性与局部性难题。政策势差是“高位制定、低位执行”政策结构与“决策删简、执行协商”政策过程共同塑造的结果,是自上而下官僚体制逻辑与由内而外社会情境逻辑衔接中的时空间隙。政策势差情境下的基层政策执行应警惕完美主义与系统性低效两个误区,采取最大限度缩减和渐进调适的积极因应策略。

教育公平视角下的香港学位分配系统研究

香港学位分配系统对香港基础教育公平化具有重要作用。看似复杂的学位分配系统为何经久不衰,甚至成为现行升学系统中必不可少的部分,是值得思考的问题。从教育公平的视角分析香港学位分配系统,发现它首先确保所有适龄儿童都有升学机会。对于成绩优异但家境受限的学生而言,他们可以凭借自身的优势争取与他人同等的入学机会。其次,学位分配按照学校网进行,且对于同一组别的学生是随机的,从而在一定程度上使处于相同水平的学生享有相对均等的教育资源。此外,中小学生升学时无需参加公开考试,教育评价侧重全面发展。

电脑派位就公平吗？

时下流行用电脑派位的方式解决中小学学位分配问题。咋一看，电脑派位就跟摇奖一样，很公平，中不中得了大奖，全由老天说了算。各位就各安天命吧，这事谁也怨不了谁，派不到好学校，谁叫你八字生得不好。

Development of Three Multiplex PCR Primer Sets for Ark Shell(Scapharca broughtonii)and Their Validation in Parentage Assignment

Scapharca broughtonii is a commercially important and over-exploited species.In order to investigate its genetic diversity and population structure,43 novel polymorphic microsatellites were isolated and characterized.The number of alleles per locus ranged from 3 to 22 with an average of 6.93,and the observed and expected heterozygosities varied between 0.233 and 1.000,and 0.250 and 0.953,with an average of 0.614 and 0.707,respectively.Three highly informative multiplex PCRs were developed from nine of those microsatellites for S.broughtonii.We evaluated and validated these multiplex PCRs in 8 full-sib families.The average polymorphism information content(PIC) was 0.539.The frequency of null alleles was estimated as 3.13% of all the alleles segregation based on a within-family analysis of Mendelian segregation patterns.Parentage analysis of real offspring demonstrated that 100% of all offspring were unambiguously allocated to a pair of parents based on 3 multiplex sets.Those 43 microsatellite loci with high variability will be helpful for the analysis of population genetics and conservation of wild stock of S.broughtonii.The 3 sets of multiplex PCRs could be an important tool of pedigree reconstruction,population genetic analysis and brood stock management.

Theoretical studies on the complexation of uranyl with typical carboxylate and amidoximate ligands

Understanding of the bonding nature of uranyl and various ligands is the key for designing robust sequestering agents for uranium extraction from seawater. In this paper thermodynamic properties related to the complexation reaction of uranyl（VI） in aqueous solution （i.e. existing in the form of UO2（H20）52＋） by several typical ligands （L） including acetate （CH3CO2）, bicar- bonate （HOCO2-）, carbonate （CO32-）, CH3（NH2）CNO- （acetamidoximate, AO-） and glutarimidedioximate （denoted as GDO2-） have been investigated by using relativistic density functional theory （DFT）. The geometries, vibrational frequencies, natural net charges, and bond orders of the formed uranyl-L complexes in aqueous solution are studied. Based on the DFT analysis we show that the binding interaction between uranyl and amidoximate ligand is the strongest among the selected complexes. The thermodynamics of the complexation reaction are examined, and the calculated results show that complexation of uranyl with amidoximate ligands is most preferred thermodynamically. Besides, reaction paths of the substitution complexation of solvated uranyl by acetate and AO have been studied, respectively. We have obtained two minima along the reaction path of solvated uranyl with acetate, the monodentate-acetate complex and the bidentate-acetate one, while only one minimum involving monodentate-AO complex has been located for AO- ligand. Comparing the energy barriers of the two reaction paths, we find that complexation of uranyl with AO is more difficult in kinetics, though it is more preferable in thermodynamics. These results show that theoretical studies can help to select efficient ligands with fine-tuned thermodynamic and kinetic properties for binding uranyl in seawater.

Closed-loop Supply Chain Systems Constructed by 4PL and Performance Evaluation by Using Exergoeconomics

This paper introduces a new concept of 4PL, which is a contractor of the closed-loop supply chain coordination based on the division of community and the outsourcing development. The concept enriches the connotation of 4PL and broadens the thought for 4PL development. Secondly, according to the characteristics of the closed-loop supply chain in the different duration of the collaborative relationship and the dynamic characteristics of the closed-loop supply chaini we apply the fractal theory to establish a fractal system of 4PL coordinating closed-loop supply chain and propose different strategies for 4PL coordinating with different types of closed-loop supply chains in the various links of the system. Moreover, some strategic and proactive thinking are provided for 4PL＇s practices. Then based on the exergoeconomics theory, the closed-loop supply chain is regarded as a huge energy system with the new view, and the sustainability of the closed-loop supply chain system is discussed under the circumstance of exergoeconomics, and then the metric about “system negative environment effect” is introduced to measure the closed-loop supply chain system performance in the point of energy, a case study illustrates our conclusions.

Structures and magnetic properties of several novel lanthanide coordination polymers based on thiophene-2,5-dicarboxylic acid

Eight novel lanthanide complexes： {Ln（TDA）I.5（H20）2 },, （Ln = Pr（la）, Nd（2a）） and { Ln（TDA）（Ac）（H2O）}n （Ln = Pr（1）, Nd（2） Eu（3）, Gd（4）, Tb（5）, Dy（6）; TDA = Thiophene-2,5-dicarboxylic acid anion） have been constructed by hydrothermal reaction. Structural analyses reveal that complexes Ia and 2a belong to the space group C2/c, exhibiting three-dimensional （3D） frame- works. Complexes 1-6 with P2t/c space group were prepared in the presence of excessive ammonium acetate, giving rise to interesting 3D frameworks different from those of la and 2a. Magnetic property studies of 4-6 reveal the weak antiferromag- netic interaction exists between adjacent Gd3＋ in 4. The complex 6 displays rather rare slow magnetization relaxation behavior in 3D frameworks.