基于仓单质押融资的物流企业与银行的演化博弈分析

物流企业与银行之间的良好合作关系是物流金融业务继续发展的前提和基础。以仓单质押融资业务为例,运用演化博弈理论对物流企业与银行之间的监督包庇问题进行了分析,构建复制动态方程和运用动态相位图分析群体策略的演化过程及结果,为建立良好的合作关系提供理论依据。分析结果表明:该动态系统的演化方向受到博弈支付矩阵以及系统的初始状态的影响。银行监督成本、银行的收益损失、物流企业的包庇成本和物流企业的罚金是影响演化结果的关键性因素。通过外部力量的加入,可促使系统演化至(不包庇,不监督)这一期望演化稳定策略。     

Exact traveling wave solutions and bifurcations in a nonlinear elastic rod equation

The exact parametric representations of the traveling wave solutions for a nonlinear elastic rod equation are considered. By using the method of planar dynamical systems, in different parameter regions, the phase portraits of the corresponding traveling wave system are given. Exact explicit kink wave solutions, periodic wave solutions and some unbounded wave solutions are obtained.     

丽江玛咖的营养成分分析及多糖体外的抗氧化作用

对丽江种植区玛咖（Lepidium meyenii Walp）的营养成分进行分析,其含有丰富的蛋白质、碳水化合物、矿物质、维生素、脂肪酸和氨基酸等,并通过试验证明玛咖多糖体外具有一定的抗氧化保健作用,为丽江玛咖成功引种和进一步的研究开发提供依据.     

送粉角度对激光熔覆铁基复合涂层形状特征的影响

通过分析激光熔覆过程中光束、粉末和熔池间的作用机理,建立了送粉式激光熔覆材料有效利用率的数学模型,在此基础上推导了送粉角度与工艺参数之间的定量关系式,并计算了不同送粉角度下的熔覆材料有效利用率、熔高和横截面积。结果表明,在熔覆工艺参数不变的条件下,理论计算的熔覆材料有效利用率、熔覆层高度和横截面积均随送粉角度的增加而增大,且均高于实验检测值。激光熔覆过程中,由于粉末烧损和机械损失,使熔覆材料有效利用率、熔高和横截面积随送粉角度变化出现最大值,理想送粉角度为60。     

一种简便的溶胶-凝胶法制备的La0.67Ca0.33MnO3纳米晶粉末的结构与性能（英文）

采用一种比较简单的溶胶-凝胶法在相对较低的温度下制备了钙钛矿锰氧化物La0.67Ca0.33MnO3纳米粉末。XRD结果显示干凝胶直接在500℃下煅烧即可得到单一钙钛矿相,而无需任何其他中间步骤。当煅烧温度从500℃上升到900℃时,纳米晶的尺寸相应的从30纳米长大到80纳米左右。分别采用扫描电镜和传统的四探针法表征了多晶靶材的表面形貌和电输运性能,观察到了电阻率-温度(ρ-T)曲线上绝缘体-金属转变温度TIM附近(270 K左右)非常陡的电阻率变化。     

Symmetry reductions and exact solutions to the systems of carbon nanotubes conveying fluid

In this paper, the systems of carbon nanotubes (CNTs) conveying fluid are considered by the combination of Lie symmetry analysis and the dynamical system method. All of the geometric vector fields of the three systems are obtained, then the symmetry reductions and exact solutions to the systems are investigated by the dynamical system and the power series method. Especially, the convergence of the power series solution to the nonlinear system is shown under the condition which is easily satisfied generally.     

The recursion operator method for generalized symmetries and Bäcklund transformations of the Burgers’ equations

In this paper, the generalized symmetries of the second-order Burgers’ equation are obtained through the symmetry transformation method. The Bäcklund transformations (BTs) of the two equations are constructed by the recursion operator method. Then, the infinite number of exact solutions to these equations are investigated in terms of the generalized symmetries and Bäcklund transformations. Furthermore, the Bäcklund transformations and conservation law of the general Burgers’ equations are discussed.     

The mean first passage time of a three-level atomic optical bistable system subjected to noise

The transient properties of a three-level atomic optical bistable system in the presence of multiplicative and additive noises are investigated. The explicit expressions of the mean first-passage time (MFPT) of the transition from the high intracavity intensity state to the low one are obtained by numerical computations. The impacts of the intensities of the multiplicative noise D M and the additive noise D A , the intensity of correlation between two noises λ , and the intensity of the incident light y on the MFPT are discussed, respectively. Our results show: (i) for the case of no correlation between two noises (λ = 0.0), the increase in D M and D A can lead to an increase in the probability of the transition to the low intracavity intensity state, while the increase in y can lead to a retardation of the transition; and (ii) for the case of correlation between two noises (λ = 0.0), the increase in λ can cause an increase in the probability of the transition, and the increase in D A can cause a retardation of the transition firstly and then an increase in the probability of the transition, i.e., the noise-enhanced stability is observed for the case of correlation between two noises.     

Atom diffusion in furnaces — models and measurements

Experimental as well as the theoretical approach to estimate diffusion coefficients for several analyte elements with different behavior in graphite furnaces, lead, gold, indium and chromium, were investigated. ‘Close’ graphite furnaces of two designs differing in the size of end apertures and the diameter of the injection port were used. The furnaces were fast heated at rates of approximately 10 000 K s⁻¹. The peak absorbance of all studied analytes was independent of geometry, suggesting that the separation of atomization and removal was attained. Residence times of the analytes in the two different furnaces were determined from absorbance tail shapes. In the case of gold, the influence of temperature in the range between 1800 and 2200 K on the residence time in both furnaces was also found. The residence times measured in the two different furnaces under otherwise identical conditions, made possible to select the accurate model of diffusional removal from several possible models. The knowledge of the accurate model allowed the estimate of experimental diffusion coefficients. They were thus compared with those semiempirically calculated from kinetic theory of gases, extended to allow for the intermolecular forces. The accuracy of these calculations is limited since the input data (critical temperatures, boiling temperature or melting temperature, molal volumes at the critical, boiling and melting points, metallic crystallographic radii and dissociation constants of metal dimers) are not known with adequate accuracy. The comparison of ‘theoretical’ and ‘experimental’ values of diffusion coefficients makes possible to assess value of using individual sources of input data for the semiempirical calculations.     

Influence of processing conditions on the crystal structure and magnetic behavior of La0.7Ca0.3MnO3±δ samples

In this work we report crystallographic structure variations and the related modifications on the magnetic behavior of La_0.7Ca_0.3MnO_3±δ introduced by heat-treatments in different synthesis atmospheric conditions. We have prepared polycrystalline ceramic samples using a modified polymeric precursors method, which produces highly homogeneous specimens.The use of argon atmosphere enlarges the crystalline c-axis as detected by Rietveld refinements. As a consequence, an improvement in the magnetic transition temperature T_C of the samples was observed.Our results also indicate that different heat-treatment conditions change the magnetic interactions between the ferromagnetic (F) and antiferromagnetic (AF) structures of these systems. Our conclusions rely on the use of AC magnetic susceptibility measurements as the experimental tool for measuring these variations.