支架式教学在初中数学教学中的应用研究

支架式教学由建构主义理论衍生出来,是近年来在我国教育中较为受欢迎的一种教学方式.在支架式教学模式下,教师将教学内容划分为多个小的环节,学生在教师的引导下,不断攀爬支架,最终完成教学任务.整个教学过程中,教师始终处于一个引导者的角色,而学生的主体地位能够得到很好的体现.将支架式教学应用到初中数学课堂教学,不仅能够提高学生数学课堂的参与度,还能够体现出新课程改革理念对学生主体地位的要求,是现阶段值得提倡的一种教学方式.     

Safety and waste considerations in donated blood screening

We study an important problem faced by Blood Centers, of selecting screening tests for donated blood to reduce the risk of “transfusion-transmitted infectious diseases” (TTIs), including the human immunodeficiency virus (HIV), hepatitis viruses, human T-cell lymphotropic virus, syphilis, West Nile Virus, and Chagas’ Disease. This decision has a significant impact on health care quality in both developed and developing countries. The budget-constrained decision-maker needs to construct a portfolio of screening tests, from a set of available tests, each with given efficacy (sensitivity and specificity) and cost, to administer to each unit of donated blood so as to minimize the “risk” of a TTI for blood classified as “infection-free.” While doing this, it is critical, for a viable blood system, that the decision-maker does not falsely (i.e., through screening error) discard too much of the infection-free blood (“waste”). We construct mathematical models of this decision problem, considering the various objective functions (minimization of the TTI risk or the weighted TTI risk) and various constraints (on budget and wasted blood) relevant in practice. Our work generates insights on the test selection problem. We show, for example, that a reduction in risk does not necessarily come at the expense of an increase in waste. This underscores the importance of considering these different metrics in decision-making through an optimization-based model. Our work also highlights the importance of generating region-specific testing schemes that explicitly take into account the regional prevalence and co-infection rates, along with the impacts of the infections on the society and individuals.     

Analytical evaluation of the characteristic curve of a blood bank and its usefulness in blood banking

In this paper the characteristic curve of a blood bank (BB) for a particular blood group (BG) (which expresses the probability of ultimate wastage of a unit of blood by outdating as a function of the age of blood entering the BB) is evaluated analytically and its usefulness is examined. The application of the model developed is examined in a major teaching hospital.     

Numerical simulation of solitary blood waves in an elastic tube subjected to a localised deformation

In order to well apprehend what really happens in a locally deformed elastic tube, a numerical analysis of the liquid flow in such a media has been undertaken. A cylindrical tube with constant rigidity subjected to a localised dilatation is first considered and results obtained help to understand the behaviour and the developing process of aneurysm. The analysis of the effects of stenoses on blood flow is also done.     

Traveling wave solutions in the mathematical model of blood coagulation

Under normal conditions, blood coagulation provides an effective protective mechanism preventing bleeding in case of vessel damage. Details of its functioning are of particular importance since any blood coagulation disorders lead to severe physiological aggravations. Multiple experimental and computational studies demonstrate the thrombin concentration distribution to determine the spatio-temporal dynamics of clot formation. Propagating from the injury site with constant speed, thrombin concentration profile can be modeled with a traveling wave solution of the system of partial differential equations describing main reactions of the coagulation cascade. In the current study, we derive conditions on the existence and stability of such solutions and provide an analytic approach of their wave speed estimation.     

血液动力学中血管流激波与驻波的相互作用

血液动力学问题是生物力学心血管系统中的重要研究课题.血管内斑块处,血管截面和血管壁的材质发生变化,对血液流动产生重要影响.血液流动中基本波及其相互作用对探究血液流动的规律、生理学意义及与疾病的关系有着重要的意义.本文研究血液动力学血液流动简化数学模型的基本波的相互作用.血管流模型是3×3非严格双曲型方程组.构造性地得到了初值为三段常状态时,血管流问题的解,即解决了激波与驻波的相互作用问题.特别地,给出四种后前激波与驻波的相互作用的结果.     

Energy decay result in a Timoshenko‐type system of thermoelasticity of type III with weak damping

We investigate in this paper a thermoelastic system where the oscillations are defined by the Timoshenko model and the heat conduction is given by Green and Naghdi theories. We introduce 2 new stability numbers κ₁ , κ₂, and we prove a general decay result, from which the exponential and polynomial decays are only special cases.     

Existence and uniqueness of maximal strong solution of a 1D blood flow in a network of vessels

We study the well-posedness of a system of one-dimensional partial differential equations modeling blood flows in a network of vessels with viscoelastic walls. We prove the existence and uniqueness of maximal strong solution for this type of hyperbolic/parabolic model. We also prove a stability estimate under suitable nonlinear Robin boundary conditions.     

系数在结合超代数的矩阵李超代数的2-上循环

设α是域F上的结合超代数满足[α,α]=α或α=F．证明了当m n>1时,H2(glm|n(α),F)(?)HC1(α,F)．定义了一大类广义微分算子李超代数,作为W-无穷代数W∞(glN)的推广．确定了这些李超代数的2-上循环．同时给出了矩阵量子微分算子李超代数的2-上同调群．