Eilenberg–Moore algebras for stochastic relations

We investigate the category of Eilenberg–Moore algebras for the Giry monad associated with stochastic relations over Polish spaces with continuous maps as morphisms. The algebras are identified as the positive convex structures on the base space. The forgetful functor assigning a positive convex structure the underlying Polish space has the stochastic powerdomain as its left adjoint.     

Mechanistic model and numerical analysis for corrosion damage of reinforced concrete structure

Through sampling, we have conducted systematically the analyses of changing characteristics of steel bar corrosion and crack width on reinforced concrete surfaces. Based on the analyses from the sampling, we have obtained the mathematical model for outer elliptical contour and the formulas to calculate thickness of corrosion layer at any associated point on steel bars. A stress model of discrete displacement on fictitious boundary for the corrosion layer and corresponding solutions for displacement and stress on the fictitious boundary have been advanced, which solve quantitatively the stress to the structure acted by corrosion layer. Finally, under the conditions of displacement on the fictitious boundary and by applying numerical manifold method, we had performed the simulation of track for crack propagation caused by corrosion and expansion of side steel bars as time elapses in existing reinforced concrete structures. The simulation results have conformed to those of the experiment.     

浅析人民币区域国际化的条件和利弊

认为随着中国经济的快速发展和外贸的大量增加,人民币国际化已不可避免.人民币国际化将给中国开辟一条利用国际资金的最佳途径.分析了人民币国际化进程顺利发展的条件.     

单调函数的C′保形插值方法

对于给定的单调数组,本文描述了一种保形三次插值样条函数,得到的样条函数是C′连续的,且计算简单,最后该文还估算了插值函数的误差。     

Buckling and postbuckling of cylindrical shells with one end pinned and the other end free

Using finite element analysis, this paper examines the linear bifurcation buckling loads, and nonlinear collapse loads, of cylindrical shells with one end pinned and the other end free, under a variety of axial and pressure load combinations. The pinned end is formulated so as to provide no axial restraint. For the bifurcation analysis, loads are related back to the classical solutions for cylinder buckling loads, to explain the very low values found for this set of boundary conditions.The nonlinear analysis includes both imperfections and material plasticity. In this analysis, it is found that cylindrical shells with pinned-free boundary conditions are notably imperfection insensitive, and for a range of geometries are able to reach collapse loads significantly greater than their bifurcation load. For other geometries, collapse loads very close to the bifurcation load are found. This unusual imperfection insensitivity for a cylindrical shell is explained in terms of the large flexibility engendered by the pinned-free boundary conditions and the oval buckling mode.     

面向降噪的蜗杆砂轮磨削齿面纹理改善方法

蜗杆砂轮磨是广泛应用于中小模数齿轮的批量精加工方法,但在实际加工过程中,蜗杆砂轮磨齿易在齿向形成规则的平行齿面纹理,从而增大了齿轮的啮合噪声。分析磨削过程中蜗杆砂轮与齿轮的接触特性,建立了啮合方程和接触点方程,阐述了接触迹构成整个齿面的机理;分析蜗杆砂轮磨齿的磨削特性,建立瞬时接触点的磨削速度和形状模型,计算磨粒在齿面上的磨削路径,分析磨削特性对齿面微观几何结构的影响,得到齿面的整体纹理模型;结合齿面纹理与噪声激励的关系,分析出齿面规则纹理对齿轮噪声的影响机理,提出按照正弦函数变化的冲程变速蜗杆砂轮磨齿加工方法;进行了蜗杆砂轮磨削常规加工与变冲程速度加工的对比试验,结果表明,该方法加工的齿面接触点位置具有一定的随机性,形成不规则的齿面纹理,不同转速下齿轮啮合噪声声压级总值减小约3.5 dB,已经达到改善齿面纹理的效果。     

Q235/304碳钢-不锈钢复合板界面结合的有限元模拟

应用MARC软件对304不锈钢(%:17～19Cr、8～11Ni)/Q235碳钢(%:0.14～0.22C)复合板前5道次往复热轧过程(变形率%:3.4、10.4、25.0、37.8、49.4)进行有限元模拟,得出Q235钢和304不锈钢在界面处的应力和应变分布。模拟结果表明,在两种材料都进入塑性变形状态时,界面处法向应力值达到或超过304不锈钢界面温度下的变形抗力,且两种材料应变平均值的差值≤0.01时即可复合,该模拟结果与生产试验结果一致;这说明使用小的单道次变形率,大的累积变形率可获得结合良好的碳钢/不锈钢复合板。     

赛汉塔拉凹陷储层评价与油气勘探有利地区

赛汉塔拉凹陷已经有约二十年的油气勘探历史,应用地质、地震和储层物性资料,结合沉积微相研究成果,对赛汉塔拉凹陷白垩系油气勘探目的层进行综合研究和储层评价,提出凹陷内油气勘探有利地区。     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

充放电方式对MH/Ni电池容量测试的影响

放电容量是MH/Ni电池的一个最重要的性能参数。充放电制度对放电容量的检测结果有很大的影响。本文研究了充电电流、充电容量、搁置时间、放电电流、放电终止电压对放电容量检测结果的影响 ,总结了可供电池生产厂家和用户参考的规律。