N皇后问题的启发式算法探讨

搜索策略的选择与设计是人工智能领域问题求解的核心问题之一,直接影响到问题求解过程中存储空间的占用和计算的复杂性,影响到问题求解的效率。在给出N皇后问题形式化描述和现有搜索算法的基础上,设计了3种解决N皇后问题的启发式算法,并将其与深度优先和宽度优先等搜索策略进行了分析和比较,得出了几点关于设计启发式算法的启示。     

炸药乳化器安全监测方法及其发展

文章回顾了几种现行的乳化器安全运行检测方法,分析了各自的优缺点,介绍了一种使用现代振动监测诊断技术对乳化炸药生产线的关键设备乳化器进行在线安全监测的基本原理和功能,讨论了乳化器安全监测系统的发展方向.     

Fluorescence recovery assay for the detection of protein-DNA binding

We report a novel and straightforward fluorescence recovery assay which enables the detection of protein-DNA interactions and simultaneously determines relative binding affinities of sequence-specific DNA-binding proteins for a variety of DNA sequences in a multiplexed format. The detection of protein-DNA binding is accomplished by monitoring fluorescence recovery during exonuclease digestion of DNA sequences that are modified with fluorophore-quencher pairs. Retardation of fluorescence recovery occurs with binding of the protein to the putative DNA binding element, which arrests exonuclease digestion. The assay detects protein-DNA binding in a homogeneous solution simply, quickly, and reliably without using radioisotopes. Multiplexing is possible by labeling different DNA sequences with spectrally distinct dyes, allowing simultaneous analysis of experimental and control binding reactions in the same mixture.     

Structure factors of modified liquid Al–Si alloys

The structure factor and the coordination numbers of liquid Al–Si alloys with different Si content have been measured by a high temperature X-ray diffractometer. Radial distribution functions (RDFs), the nearest atomic distance and the coordination numbers of eutectic Al–Si alloys before and after being modified with Sr and Sb were studied. The RDFs of the liquid alloy were decomposed by five Gaussian peaks. The results show that a Si–Si covalent bond exists in the liquid of eutectic and hyper-eutectic alloys. Sr in the liquid Al–Si has a capability to weaken the covalent bonds of Si–Si, suppressing the nucleation of the eutectic silicon phase. On the other hand, Sb in the liquid Al–Si increases the order degree of Si atoms, decreasing the supercooling degree of the nucleation and promoting the nucleation of eutectic silicon.     

Orbitrap高分辨质谱法快速筛查上海市流通环节蔬菜的农药残留

摘 要：目的 建立蔬菜农药多残留的筛查方法。方法 使用国家标准方法规定的QuEChERS法净化蔬菜样品,结合静电场轨道阱高分辨质谱法(orbitrap high resolution mass spectrometry)开展809种农药的快速非靶向筛查。结果 62种阳性农药的筛查限(screening detection limit, SDL)为0.005~0.010 mg/kg,定量限(limits of quantitation, LOQ)为0.01 mg/kg,线性范围为0.01~0.20 mg/kg,线性相关系数(r2)为0.9917~0.9997,日内精密度为2.77%~6.98% (n=5),日间精密度为4.82%~10.8% (n=5)。200批次样品共检出62种农药,不合格样品28批次,不合格率为14.0%。豇豆的不合格情况比较突出,不合格样品22批次,主要的不合格项是灭蝇胺和噻虫胺。结论 方法快速、准确、分析通量高,在无标准品的情况下实现了蔬菜中809种农药的非靶向快速筛查,可为蔬菜农药残留风险监测和质量控制提供支撑。     

基于小波分解和RBF网络的三极管电路故障诊断

在分析现有三极管放大电路故障诊断算法不足的基础上,提出了一种基于模型的小波-RBF网络故障诊断算法。在PSPICE环境下建立三极管常见的故障模型,利用多层小波分解优异的时频特性提取故障特征参数,利用RBF强大的非线性分类能力和快速的收敛特性进行了典型共基极放大电路中三极管的软、硬故障诊断仿真。计算及仿真结果显示,这种故障诊断算法具有诊断速度快、诊断正确率高的特点。     

快速随机Hough变换多圆检测算法

随机Hough变换是检测圆的一种有效方法,但在处理多圆复杂图像时随机采样带来的大量无效累积会导致计算量过大。文中提出一种基于随机Hough变换的快速多圆检测算法,除去三类噪声点,通过随机采样到的一点按照一定规则搜索另外两点来确定候选圆,用原始图像对候选圆进行证据积累以判断是否为真圆。理论分析和实验结果表明：该算法较其他算法能更快地检测出图像中的多个圆,具有较好的应用价值。     

面向学生的高校智能管理系统的设计与实现

随着网络技术的快速发展,高校对学生信息化的建设和管理愈加重视。高校智能管理系统是高校信息化建设的重要展现。本文针对学生日常的生活轨迹和生活信息,进行相关的数据分析和挖掘,采用Python语言和MySQL数据库技术,在Flask框架上进行改进,实现了以学习管理、健康管理和生活管理三大功能模块的轻量级Web和安卓应用,将面向学生的高校智能管理系统打造成一个集成化的平台,以提升校园管理的工作效率和提供健康安全保障。     

GFAAS法测定LiMn2O4中的Pb和Cd

采用石墨炉原子吸收光谱法(GFAAs)测定锂离子电池正极材料LiMn2O4中杂质Pb和Cd的含量.探讨了HNO2浓度、Pb和Cd的灰化温度和原子化温度、基体改进剂对测定结果的影响.该方法的操作简单,准确度高,Pb的回收率为91.22%～93.75%,Cd的回收率为96.5%～108.6%;精密度好,两种元素测定的相对标准偏差RSD(n=lO)<5%.