Separation mixed semen of two individuals using magnetic beads coupled ABH blood group antibody

In sexual assault cases, one of the most common samples collected is a mixed semen stain, which is often found on the vagina, female underwear, or bed sheets. However, it is usually difficult to identify the perpetrator based on this sample alone. One technique that has been developed to address this issue is magnetic bead-based separation. This method involves using modified magnetic microspheres to capture and enrich specific target cells, in this case, sperm cells. In this study, we utilized magnetic beads coupled with ABH blood group antibody to isolate sperm cells from an individual of a single ABO blood type. Subsequently, polymerase chain reaction amplification and capillary electrophoresis were employed to perform the genotyping the short tandem repeat (STR) loci. This approach allows for the identification of different individuals in a mixed seminal stain sample from two individuals, by first separating sperm cells based on ABH antigen differences and subsequently utilizing autosomal STR typing on the enriched single blood group cells.     

Epidemic transmission on SEIR stochastic models with nonlinear incidence rate

Our interest is to quantify the spread of an infective process with latency period and generic incidence rate that takes place in a finite and homogeneous population. Within a stochastic framework, two random variables are defined to describe the variations of the number of secondary cases produced by an index case inside of a closed population. Computational algorithms are presented in order to characterize both random variables. Finally, theoretical and algorithmic results are illustrated by several numerical examples. Copyright © 2016 John Wiley & Sons, Ltd.     

气相色谱–火焰光度法测定进口天然气中4种形态硫

建立气相色谱–火焰光度法测定进口液化天然气中4种形态硫的方法。探讨了色谱柱、进样口温度、分流比、柱流速、升温程序和FPD检测器等对测定结果的影响。在优化的实验条件下,评价了方法的可靠性。4种形态硫化物的质量浓度在10.0~200.0μg/L范围内,其对数与峰面积对数呈良好的线性关系,线性相关系数r在0.983 3~0.999 2之间,检出限为1.7~7.7μg/L,测定结果的相对标准偏差为0.56%~0.68%(n=5)。用该法测定天然气形态硫标准气体,测定值与标准值相比,相对误差为–1.6%~–1.2%。该方法具有较高的准确度,可应用于进口天然气中4种形态硫的分析。     

IOTEST在某型模拟对抗终端嵌入式软件测试中的应用

由于嵌入式系统对功能和性能的高要求,对嵌入式软件进行测试存在一定难度。嵌入式系统通过各种不同类型的接口与外界实现交互,故而对嵌入式系统的接口进行测试,是保证嵌入式软件质量的重要途径。以某型模拟对抗终端嵌入式软件为例,根据该型终端的特点,对基于IOTEST实现嵌入式软件测试的自动化进行研究。依照测试需求分析、测试环境搭建、测试建模、变量配置、测试脚本编写、测试执行的测试步骤和方法,通过测试实现过程详细说明了IOTEST在嵌入式软件测试中的应用。测试结果表明,IOTEST能够对嵌入式系统接口的正确性、实时性和可靠性进行有效地测试,该工具在测试过程中具备良好的实用性和通用性。在嵌入式软件的测试过程中合理使用IOTEST,可以有效提高测试效率,保证软件质量。     

非线性再生散度模型的诊断

Abstract. This article discusses the problem of the detection of influential cases in nonlinear re-productive dispersion models (NRDM). A diagnostic based on case-deletion approach in esti-mating equations is proposed. The relationships between the generalized leverage defined byWei et al. in 1998, statistical curvature, and the local influence of the response vector perturba-tions are investigated in NRDM. Two numerical examples are given to illustrate the results.     

震级频度与古登堡-里克特关系式偏离的实验与震例分析

基于一定时期内区域地震事件的地震震级(M)和频次(N)之间服从古登堡-里克特(G-R)震级频度关系lgN=a-bM的基本原理,本文通过对室内岩石破裂实验及华北地区部分中强以上(M≥5.0)地震震例研究发现,随着在岩石失稳(强地震)的临近,声发射事件能量或地震震级与频度之间不能较好地遵从G-R关系.出现较大偏离.这种偏离可作为强地震发生的前兆指标,对利用区域中小地震活动事件探讨预测强地震具有重要作用.     

安全工程流体力学创新实践教学模式探究

流体力学是安全工程类本科专业的基础必修课。通过创新安全工程流体力学理论教学模式、融合学科专业知识及改革实践教学方法,提出了教学改革总体思路和方案,梳理了安全工程流体力学中的核心知识脉络体系;将看似孤立的基础理论三大方程穿插融合在一起,并延伸至安全工程专业中的流体力学知识点,使学生明确安全工程流体力学学什么、怎么学、如何用;丰富安全工程流体力学实践教学环节,鼓励学生自主组队开展探索性自做实验,拓宽实践教学形式及方法,引导学生开展针对性虚拟仿真模拟实验,提升学生创新能力。     

无机元素化学的智慧“教与学”*

依托校内无机化学在线课程,将基于“超星”学习通平台的混合式教学模式引入元素化学知识的学习,设计了“MOOC+案例精讲+QQ群辅助”的教学策略。实践过程中,借助MOOC自主学习低阶的知识点,采用专题直播、分组活动、PBL教学法开展高阶知识点的学习,QQ群辅助进行实时答疑。学习通平台串联起了教室端、移动端和管理端,师生线上线下的交流互动,有助于实现愉快、高效的智慧“教与学”。调查显示,基于“一平三端”的混合教学形式得到大部分学生的认可。     

应力约束全局化策略下的连续体结构拓扑优化

利用Mises强度理论，提出了应力约束全局化策略，将局 部的应力约束问题转化为结构整体的应变能约束问题. 基于ICM(独立、连续、映射)方法， 引入了独立、连续的拓扑变量，对单元重量、单元刚度和单元许用应力的过滤函数进行了选 择，建立了以重量为目标，以结构应变能代替应力约束的多工况下连续体结构拓扑优化模型， 寻找到了多工况下的最佳传力路径. 运用对偶二次规划方法对上述优化模型进行了求解. 另 外，利用PCL语言，在MSC/PATRAN的开发平台上，实现了应用应力约束全局化策略进行连 续体结构拓扑优化的模块化处理. 数值算例表明了该方法的可行性和有效性.     

Analysis of time-periodic nonlinear dynamical systems undergoing bifurcations

In this study a new procedure for analysis of nonlinear dynamical systems with periodically varying parameters under critical conditions is presented through an application of the Liapunov-Floquet (L-F) transformation. The L-F transformation is obtained by computing the state transition matrix associated with the linear part of the problem. The elements of the state transition matrix are expressed in terms of Chebyshev polynomials in timet which is suitable for algebraic manipulations. Application of Floquet theory and the eigen-analysis of the state transition matrix at the end of one principal period provides the L-F transformation matrix in terms of the Chebyshev polynomials. Since this is a periodic matrix, the L-F transformation matrix has a Fourier representation. It is well known that such a transformation converts a linear periodic system into a linear time-invariant one. When applied to quasi-linear equations with periodic coefficients, a dynamically similar system is obtained whose linear part is time-invariant and the nonlinear part consists of coefficients which are periodic. Due to this property of the L-F transformation, a periodic orbit in original coordinates will have a fixed point representation in the transformed coordinates. In this study, the bifurcation analysis of the transformed equations, obtained after the application of the L-F transformation, is conducted by employingtime-dependent center manifold reduction andtime-dependent normal form theory. The above procedures are analogous to existing methods that are employed in the study of bifurcations of autonomous systems. For the two physical examples considered, the three generic codimension one bifurcations namely, Hopf, flip and fold bifurcations are analyzed. In the first example, the primary bifurcations of a parametrically excited single degree of freedom pendulum is studied. As a second example, a double inverted pendulum subjected to a periodic loading which undergoes Hopf or flip bifurcation is analyzed. The methodology is semi-analytic in nature and provides quantitative measure of stability when compared to point mappings method. Furthermore, the technique is applicable also to those systems where the periodic term of the linear part does not contain a small parameter which is certainly not the case with perturbation or averaging methods. The conclusions of the study are substantiated by numerical simulations. It is believed that analysis of this nature has been reported for the first time for this class of systems.