考虑溯源系统应用的优质农产品双渠道供应链决策研究

优质农产品溯源系统的引入,既能提升有效供给、缩短流通时间,又能降低流通中的数量损耗和价值损失,由此带来了双渠道供应链系统在投资、销售、定价等方面的系列决策问题。考虑制造商开辟电子渠道、从溯源系统降低流通损耗和提高质量出发,分别构建制造商主导型的双渠道供应链决策模型。通过对比分析应用前后各成员在投资、定价及销售方面的最优策略,得到相关的核心边界值。数值仿真结果表明:核心边界值主要与双重损耗的改善程度及其他参数相关,各成员及系统接受溯源系统的应用成本不同,应用成本对各渠道销量的影响程度亦不相同,但各成员调整定价的应用成本边界值是一致的。     

促进学科核心素养发展的不同实施模式的主题教学研究——以“氮循环”主题为例

主题教学因其整合性和问题解决的情境能够实现促进学科核心素养的发展,促进学科核心素养发展的主题教学呈现出3种不同开放度的实施模式:常态教学中开放度小、常态教学中开放度大、翻转课堂的主题教学实施模式。为了探索3种实施模式的教学效果,挖掘教学中的关键问题与对策,以“氮循环”主题教学为例,在3个实验班开展实证研究。研究结果表明,3种实施模式均实现了促进学生学科核心素养的发展,但对促进学科核心素养的不同维度效果不同。3种实施模式都存在实现学科核心素养的发展进阶、学生的情感发展过程、建立评价体系、教师有效干预等方面的关键问题,此外每种实施模式也有其特有的关键问题,本研究依据教学实践给出了积极建议和对策。     

How computational methods and relativistic effects influence the study of chemical reactions involving Ru‐NO complexes?

Two treatments of relativistic effects, namely effective core potentials (ECP) and all‐electron scalar relativistic effects (DKH2), are used to obtain geometries and chemical reaction energies for a series of ruthenium complexes in B3LYP/def2‐TZVP calculations. Specifically, the reaction energies of reduction ( A ‐ F ), isomerization ( G‐I ), and Cl⁻ negative trans influence in relation to NH₃ ( J ‐ L ) are considered. The ECP and DKH2 approaches provided geometric parameters close to experimental data and the same ordering for energy changes of reactions A ‐ L . From geometries optimized with ECP, the electronic energies are also determined by means of the same ECP and basis set combined with the computational methods: MP2, M06, BP86, and its derivatives, so as B2PLYP, LC‐wPBE, and CCSD(T) (reference method). For reactions A ‐ I , B2PLYP provides the best agreement with CCSD(T) results. Additionally, B3LYP gave the smallest error for the energies of reactions J ‐ L . © 2017 Wiley Periodicals, Inc.     

Experimental investigation of the effect of temperature on the strength of polyimide contact structures

A new photogrammetry based measurement technique for contact areas in line contact structures is developed. From the data collected by this technique, a method for measuring the contact strength of contact structures in high temperature applications is proposed. The contact strength of a line contact structure of polyimide at different temperatures is measured; the results show that the increase in temperature decreases the contact strength of the structure. The effect of temperature on the contact strength is studied by investigating the occurrence and evolution of yielding core within the structure at different temperatures. The decrease in the yield strength and elastic modulus of the polyimide material at high temperature induces core yielding at lower loads and eases the propagation of core yielding to the surface.     

Calculations on polarization properties of alkali metal atoms using Dirac–Fock plus core polarization method

A semi-empirical atomic structure model method is developed in the framework of a relativistic case. This method starts from Dirac-Fock calculations using B-spline basis set. The core-valence electron correction is then treated in a semiempirical core polarization potential. As an application, the polarization properties of alkali metal atoms, including the static polarizabilities and long-range two-body dispersion coefficients, have been calculated. Our results are in good agreement with the results obtained from ab initio relativistic many-body perturbation method and the available experimental measurements.     

核心力量训练在排球运动员力量训练中的作用探析

近年来,核心力量训练在体育运动中的运用已成为很多人关注的焦点,特别是运动员核心力量训练的研究。本文通过对核心力量定义的界定,论述了排球运动员核心力量训练意义和作用,指出排球运动员核心力量训练的内容及方法,旨在为广大同仁提供参考。     

从文献利用统计分析看数字资源学科保障情况——以重庆交通大学为例

以问卷调查的方式,统计了数字资源在重庆交通大学的利用情况,探讨了9种主要的中外文数据库与高校学科专业的设置是否相适应,与目标用户的专业知识结构是否相符合,以此来衡量数字资源对高校主干学科的保障度。     

基于核心元数据的海量影像编目数据查询

影像数据的查询是影像数据的发布与共享的前提，该文在对比研究围内外元数据制定与管理特点之后，针埘影像数据海量性特点，结合影像编目数据查询特点，提出基于核心元数据的海量影像编目数据查询方法，经过实验能够高效的实现海量影像编目数据的查询。     

高校图书馆权利政策的探讨

阐述了图书馆权利政策的内涵与意义,分析了图书馆权利和道德的内在关联以及高校图书馆权利和道德的主要特点及其特殊性,提出了高校图书馆权利政策的发展方向。     

论延安精神与社会主义核心价值体系建设

延安精神是中国共产党在革命和战争年代形成的重要精神信仰和价值追求,是指导中国革命和建设走向伟大胜利的重要法宝。在改革开放和平发展的新阶段,建设社会主义和谐社会,开创中国特色社会主义建设的新局面,需要继续发扬延安精神,延安精神是改革和建设的动力来源和精神支持。延安精神在社会主义核心价值体系上是其重要的组成部分,社会主义核心价值体系是延安精神在改革开放新时代的创新和新发展。弘扬延安精神,有利于社会主义核心价值体系的建设和发展。延安精神和社会主义核心价值体系,在本质上是一致的。