On the Chow groups of certain cubic fourfolds

This note is about the Chow groups of a certain family of smooth cubic fourfolds. This family is characterized by the property that each cubic fourfold X in the family has an involution such that the induced involution on the Fano variety F of lines in X is symplectic and has a K3 surface S in the fixed locus. The main result establishes a relation between X and S on the level of Chow motives. As a consequence, we can prove finite-dimensionality of the motive of certain members of the family.     

Some Remarks on Real and Algebraic Cobordism

We investigate connections between Real cobordism, algebraic cobordism, quadratic forms, the Rost Motive, Morava K(n)-theories and analogues of homotopy classes of Hopf invariant 1.     

Motives and Etale Motives with Finite Coefficients

We prove that for suitable base fields, inverting the Bott element in Voevodsky’s category of motives with finite coefficients yields the category of étale motives with finite coefficients. Mathematics Subject Classifications (2000): 19E15, 14F42, 14F20. The first author was partially supported by the Clay Mathematics Institute.     

具有遣赠动机的生命周期模型

本文研究遗赠动机对个人消费与储蓄的影响.利用解优化问题的一阶条件,得出在给定的条件下个人存在最优的消费流和遗产使得个人的终身效用达到最大化,当个人获得的收入或遗产增加时,个人将消费更多并留下更多的遗产.进一步,文中在四种具体的遗赠动机函数下研究了遗赠动机对个人消费与储蓄行为的影响,证明在后三种遗赠动机下,储蓄与遗产随遗赠动机的强度增加而赠加;在门槛动机下,随着门槛的提高,个人的消费上升,储蓄下降.     

射频放电CO2激光器放电区物理过程的研究

本文认为射频放电CO₂激光器的高增益区是类法拉第暗区,并利用有质动力计算了阴极区和类法拉第暗区电子的能量及类法拉第暗区的尺寸,最后给出了四极放电CO₂激光器的一些实验结果。     

Instability of solution for the fourth order linear differential equation with varied coefficient

In this paper,we give some sufficient conditions of the instability for the fourth order linear differential equation with varied coefficient,at least one of the characteristic roots of which has positive real part,by means of Liapunov’s second method.     

Knight不确定下考虑保险和退休的最优消费-投资和遗产问题研究

研究在Knight不确定环境下,考虑投资者遗产和保险,在三种不同借款约束下的最优消费与投资问题.借助于倒向随机微分方程（BsDE）理论求出了投资者最优消费和投资策略的显式表达式.最后结合数值分析,给出含糊与含糊态度对最优消费和投资决策的影响.     

Dynamic lot-sizing model with demand time windows and speculative cost structure

We consider a deterministic lot-sizing problem with demand time windows, where speculative motive is allowed. Utilizing an untraditional decomposition principle, we provide an optimal algorithm that runs in O(nT³) time, where n is the number of demands and T is the length of the planning horizon.     

Weighted Completion of Galois Groups and Galois Actions on the Fundamental Group of P1 - {0,1, ∞}

Fix a prime number . We prove a conjecture stated by Ihara, which he attributes to Deligne, about the action of the absolute Galois group on the pro- completion of the fundamental group of the thrice punctured projective line. Similar techniques are also used to prove part of a conjecture of Goncharov, also about the action of the absolute Galois group on the fundamental group of the thrice punctured projective line. The main technical tool is the weighted completion of a profinite group with respect to a reductive representation (and other appropriate data).     

黄土湿陷性的微结构不平衡吸力成因论

分析了黄土粒间吸力的基本特性及其湿陷的微观过程,探讨了黄土在应力状态作用下由于浸水增湿而产生的微结构单元体滑移动力和阻力随饱和度、上覆土压力的变化规律,提出了微结构与广义吸力综合效应的湿陷性控制机理---微结构不平衡吸力成因论及其定量模型,从理论上分析了湿陷性与增湿水量、压力及深度的关系,揭示了土湿陷效应的内在规律。文中认为,湿陷过程就是水的楔入导致小孔隙广义吸力的逐渐丧失和大孔隙湿吸力的逐渐增大引起的微结构重建动力与重建阻力间的动态对抗过程。最后,讨论了湿陷的基本条件及影响因素。