基于属性识别准则大学生思想品德量化的数学模型

依据一定的社会评价标准,建立大学生思想品德评价的指标体系,利用现代数学方法——属性识别理论和层次分析方法,建立定量研究模型.     

光学低通滤波器的光学传递函数分析

光电成像系统的抽样过程会引起图像频谱在频谱空间上的多次复制,如果抽样过程不满足系统的奈奎斯特条件,相邻的频谱项就会产生混叠.光学传递函数可以反映系统中光学成像,抽样和重建等各个过程对图像信号频谱的响应.通过对使用光学低通滤波器(OLPF)光电成像系统的光学传递函数的分析,表明光学低通滤波器可以有效地限制图像的频谱宽度,使抽样满足奈奎斯特条件,达到消除频谱混叠,改善重建图像质量的目的.     

带次线性中立项的二阶广义Emden-Fowler微分方程的Philos型振动准则

研究一类带次线性中立项的二阶非线性广义Emden-Fowler时滞微分方程的振动性.利用Riccati变换和不等式技巧,在非正则条件下建立了该类方程多个简便的Philos型和Kamenev型新振动准则.所得定理也适应于包括经典Euler方程等线性非中立型方程,推广和改进了已有文献中的相应结果.最后还给出应用实例展示了所...     

基于图像处理的光学谐振腔自准直研究方法

针对我国氧碘化学激光器输出能量不断提高的情况下,主要限制光束质量的因素之一是出光过程中的光腔失调,提出了一种基于图像处理的光学谐振腔自准直研究方法。该研究方法利用氦氖穿腔光通过凹腔镜中心孔,并在凸腔镜后方放置工业相机,在屏幕上方形成一个干涉同心圆环。通过借助OpenCV库中二值化、霍夫圆检测等图像处理的方法,获得干涉同心圆环的圆心坐标,再通过以圆心为中心将图像分成上下左右四个部分,通过判断这四部分亮点像素的数量差值来预估干涉同心圆环的偏移状态,进而获得空腔条件下光学谐振腔发生变化的理论判据。实验结果表明,该方法可以获得相当精准的光学谐振腔失调判据,其失调判据选取左右亮点像素差值30000,上下亮点像素差值45000,为今后失调判据与步进电机自动调腔的结合做好充足的准备。     

Warm tachyon inflation and swampland criteria

In this study, the scenario of a two-component warm tachyon inflation is considered, where the tachyon field plays the role of the inflaton by driving the inflation. During inflation, the tachyon scalar field interacts with the other component of the Universe, which is assumed to be photon gas, i.e., radiation. The interacting term contains a dissipation coefficient, and the study is modeled based on two different and familiar choices of the coefficient that were studied in the literature. By employing the latest observational data, the acceptable ranges for the free parameters of the model are obtained. For any choice within the estimated ranges, there is an acceptable concordance between the theoretical predictions and observations. Although the model is established based on several assumptions, it is crucial to verify their validity for the obtained values of the free parameters of the model. It is found that the model is not self-consistent for all values of the ranges, and for some cases, the assumptions are violated. Therefore, to achieve both self-consistency and agreement with the data, the parameters of the model must be constrained. Subsequently, we consider the recently proposed swampland conjecture, which imposes two conditions on the inflationary models. These criteria rule out some inflationary models; however, warm inflation is among those that successfully satisfy the swampland criteria. We conduct a precise investigation, which indicates that the proposed warm tachyon inflation cannot satisfy the swampland criteria for some cases. In fact, for the first case of the dissipation coefficient, in which, there is dependency only on the scalar field, the model agrees with observational data. However, it is in direct tension with the swampland criteria. Nevertheless, for the second case, wherein the dissipation coefficient has a dependency on both the scalar field and temperature, the model exhibits acceptable agreement with observational data, and suitably satisfies the swampland criteria.     

A New Criterion for Brittle-Ductile Transition of Polymer Blends

The T_c criterion was first used by S. Wu for characterizing the brittleductile (B-D) transition of N6/EPDM blends. But in this paper, a new criterion which is based on the stress analysis of blends is proposed to characterize the B-D transitions of blends, namely, A criterionV_(fc) and d_c are the critical volume fractions and particle size of dispersed particles in blends, respectively. For given blends, A is independent of the morphology of dispersed phase and is only the characteristic parameter of matrix. The B-D transitions of different blends, including polar N6/EPDM blends, nonpolar PP/EPDM blends and PE/CaCO_3 composites, were manipulated with A criterion and satisfactory results were obtained. In addition, a new master curve for the impact strength of PP/EPDM blends versus V_f~2/d was obtained. The results showed that A criterion is more suitable than T_c criterion for characterizing the B-D transition of blends.     

Analysis of dissolution profiles of iron,zinc, and manganese from complex dietary supplements by ion chromatography and chemometrics

Four commercially available formulations containing iron, zinc, and manganese were subjected to dissolution profile testing during 60 min and the dissolution was analyzed by ion chromatography. The obtained curves were analyzed directly by principal component analysis (PCA). The main trend (87.1% of variance) was connected with average dissolution percentage over the investigated time. The second component (11.2% of variance) is connected with shape of dissolution profile. All metals behave in the similar way and the differences were connected with excipients. An additional fit was completed on 12 kinetic models: first order kinetics (4 variants), Higuchi (2 variants), Hixson-Crowell (2 variants), Korsemeyer-Peppas, Logistic (2 variants), Peppas-Sahlin, Quadratic (2 variants), Weibull (3 variants), and Zero order kinetics (2 variants). The ranking of the fitting was performed by Akaike information criteria (AIC) values with additional PCA analysis on them, an approach presented in literature for the first time. The main trend (67.4% of variance) was connected with average fit. The second (14.8% of variance) is connected with differences of fitting ability to investigated dissolution curves. This methodology brought an overall look to trends and variances inside obtained data, both the profile shape and fitting ability to particular models.     

固定接触界面切向静弹性刚度问题研究

根据两球体单峰同时受法向、切向载荷时微滑切向应力的分布以及MB模型,给出了界面的总切向接触静弹性条件刚度、总条件法向载荷的解析解。将切向接触静弹性条件刚度的解析解嵌入到有限元软件中,获得了整机的理论模态。以一款八四七厂华中工学院XHK5140型自动换刀计算机数控立式镗铣床上的结合部为研究对象,通过实验对解析解进行了定量验证。研究结果表明：在理论振型与实验振型一致的条件下,界面模型的相对误差在-19．2％～16．8％之间。     

Safety margin criterion of nonlinear unbalance elastic axle system

IntroductionAtpresentanewanddevelopingsubject—chaoticdynamicsstartsabroadprospectforanalysisofnonlinearsystem[1～ 5 ].Largerotatingmachineryisatypicalnonlinearnon_autonomoussystem .Thesaferunofrotorsystemisofgreatsignificancetosociallifeandeconomicdevelopment.Thestabilityisthekeytosafeoperation .Thesafestabilityanalysisandcontrolforlargesystemisnotonlyamajorbasicresearchbutalsoisveryimportanttosolvethesafeproblemsinlifeandproduction[6 ,7].Soar,althoughmanymathematicians,mechanistsandengineer…     

直杆塑性动力屈曲的双特征参数解

在关于轴向弹塑性压缩波下直杆塑性动力屈曲的研究中,将临界应力和屈曲惯性项指数参数作为一对特征参数求解．由动力屈曲发生瞬间的能量转换和守恒准则,导出波阵面上的屈曲变形补充约束条件．失稳控制方程、边界条件、塑性波阵面上的连续条件和补充约束条件构成定量求解两个特征参数和动力屈曲模态的完备条件。