文章尝试在企业全要素生产率(TFP)的估计中考虑技术采用异质性,利用基于固定效应的有限混合模型,解决企业TFP估计中的内生性和异质性问题.该方法从条件极大似然视角出发,将固定效应与有限混合模型有机结合,应用机器学习中的EM算法,在完成对企业TFP估计的同时,实现对企业技术采用类型的识别.将该方法应用于1998-2014 年中国工业企业数据,发现行业内存在 2-5种技术采用类型,技术采用对企业TFP影响幅度在20%左右,样本期内各行业中高技术采用企业所占比例逐步上升.分行业看,高技术采用企业TFP水平较低,但增长率较高,低技术采用企业TFP较高,但增长率较低;分所有制看,国有企业并不一定是相对低效的,其效率的改进更多来源于低技术企业的技术升级;分区域看,样本期末东部发展相对较慢,主要是其他地区低技术采用企业技术升级造成的.由此看出,基于技术采用异质性对TFP进行测算,有助于高质量发展主题下更有针对性地制定相关政策提升企业全要素生产率.

针对重大疫情防控中地方政府与社会公众的行为策略选择和博弈过程,本文通过建立博弈模型进行仿真分析.研究结果表明:当地方政府采取严格防控的收益大于成本时,其策略选择会趋向于严格防控;而社会公众则关注选择主动隔离或自由流动策略造成的成本与产生的收益.因而,地方政府应完善重大疫情研判、评估、决策和协同防控机制,树立风险治理底线思维和兜底思维,以成本—收益原则为杠杆,积极引导公众科学、理性地应对疫情,并促进公众主动配合疫情防控措施的落实.

本文对高等学校非数学专业公共基础课高等数学的课堂教学结构、教学方法和教学模式进行了梳理,针对目前公共数学课时少、强度大、任务重,课堂教学效果不理想的问题.结合作者30年的课堂教学实践和研究,提出了适当地运用以问题引领的数学课堂教学模式,并将数学建模思想融入基础课教学是解决上述问题和实现以学生为中心的现代教育理念的一个有效途径.

We develop a theory of universal central extensions for Hom-Lie antialgebra. It is proved that a Hom-Lie antialgebra admits a universal central extension if and only if it is perfect. Moreover, we show that the kernel of the universal central extension is equal to the second homology group with trivial coefficients.

We study the total quantum correlation, semiquantum correlation and joint quantum correlation induced by local von Neumann measurement in bipartite system. We analyze the properties of these quantum correlations and obtain analytical formula for pure states. The experimental witness for these quantum correlations is further provided and the significance of these quantum correlations is discussed in the context of local distinguishability of quantum states.

In this paper,we study the orbit of the function of groupoids.By using the related properties of the function of groupoids,we have a natural diffeomorphism under three different function of groupoids.This theory develops the related properties of the function of groupoids and provides us the necessary foundation for the study of the function of groupoids.

Let g be a Lie algebra over a field K. Endow the polynomial ring K[t] with a g-action by derivations and consider the resulting crossed product K[t]⊙θg in the category of (K,K[t])-Lie algebras. We explore Lie-Rinehart bialgebra structures on (K[t],K[t]⊙θg) that arise via compatible pairs and ε-dynamical r-matrices. We give a complete classification for g=sl(2,K).

In the paper,we have defined equivariant vector field on Riemann symmetric space and Studied its basic properties.We give a formula to obtain covariant contact along geodesic curves.In the end,we use these results to study the section curvature of Riemann symmetric space and give a method to deduce section curvature.

We show that every source connected Lie groupoid always has global bisections through any given point. This bisection can be chosen to be the multiplication of some exponentials as close as possible to a prescribed curve. The existence of bisections through more than one prescribed point is also discussed. We give some interesting applications of these results.

在我国医药价格虚高、医院的垄断地位导致了患者"有病不医"问题的产生,并成为社会问题,该文通过博弈论的方法,对各方利益进行博弈分析和研究,结论是进行医药分离等医疗体制改革是解决这一问题的关键方法.

中国已经成为世界第二大石油消费国,石油价格的波动对我国的影响不容忽视。从博弈论的角度分析油价波动的原因,石油民族主义情绪是一个不容忽视的因素;应用ARCH类模型对我国国内油价的波动率进行研究的结果表明,我国国内原油价格收益率序列呈现明显的GARCH效应,国内油价波动受国际油价的冲击性较高并呈现较长的持续性。我国应加大技术创新投入,改革石油定价机制,加强石油战略储备等,尽量减少高油价带来的负面影响。

In this paper, in accordance with the knowledge of Groupoid, we proved that the nature life of Lie Group on a Fundamental Groupoid has a coadjoint equivariant momentum mapping. The geometric properties of Symplectic Groupoid were described.

In this paper, we study Lie Rinehart bialgebras over a commutative algebra, the algebraic generalization of Lie algebroids. More precisely, we analyze the structure of action Lie Rinehart bialgebras over the polynomial ring K[t] induced by actions of Lie algebras on K[t].

We study polynomial representations of finite dimensional (R or C) Lie algebras. As a total classification, we show that there are altogether three types of such nontrivial representations and give their subtle structures.

令(Γ==>P,α,β)是辛群胚.本文首先证明了K是Γ的拉格朗日双截面的充要条件,其次证明了一个关于中拉格朗日双截面的存在性定理.利用以上结果进而可以得到若K是Γ的拉格朗日双截面,则(Γ=K,(),ψ)也是辛群胚,且与Γ辛群胚同构,最后给出拉格朗日双截面的具体例子.

本文通过对李群胚和李群胚作用的相关概念的理解,分析了李群胚作用的矩映射的性质并讨论了李群胚上与矩映射有关的问题,从而得到了一些重要结论.

In this paper, some properties of reduction for symplectic Γ-spaces are discussed. The properties of stable subgroups are discussed. We find that the symplectic action of a symplectic groupoid on a symplectic manifold can induce a symplectic map between reduced symplectic manifolds. This symplectic action can be characterized by the action of its induced symplectic groupoid on a symplectic manifold. Lastly, we shall discuss Poisson reduction and give a Poisson reduction theorem.

本文在已有研究成果的基础上,更加全面、系统地总结了(李)群胚,特别是辛群胚的有关性质,得到了一些重要的结论.

In this paper, we use the notion of morphisms of Lie bialgebroids to discuss thePoisson groupoids action, we obtain some properties of the Poisson action of a Poisson groupoid on aPoisson manifold in the sense of the morphisms of Lie bialgebroids.