基于模糊评判的中小微企业银行贷款风险控制

通过分析影响中小微企业银行贷款的诸多风险因素,建立层次分析模型,利用模糊评判和指数标度,构建中小微企业银行贷款风险控制指标体系。     

物面倾斜对激光三角法测量误差影响的分析研究

针对传统方法测量位移时出现的分辨率低、准确性差、操作不便捷等问题,提出采用激光三角法非接触测量物体位移,而物面倾斜是影响测量精度的主要因素。通过分析激光三角测量的基本原理,基于朗伯定律,利用光散射原理研究了物面倾斜角与光能质心之间的关系;由沙氏条件下的几何光路关系,推导得到测量误差与倾斜角之间的关系式;通过实验数据对激光扫描测量产生的误差进行分析,验证理论推导的结果,在测量中具有避免出现粗大误差的实际意义。     

Micro-motion feature analysis and parameter estimation methods for moving ship

Micro-motion parameter estimation is an important way to improve ability of radar to detect the ship target. Focusing on the difficulty and speed problems existing in the current parameter estimation method of a complex moving ship, based on the analytical result of the echo's time-frequency features, a novel method to estimate the micro-motion period by calculating the backward shift cross-correlation coefficients of the echo's sparse time-frequency matrix is proposed in this paper. Firstly, the backward shift cross-correlation coefficients of the echo's sparse time-frequency matrix are calculated using the FFT (fast Fourier transform) algorithm. The peaks positions of the cross-correlation coefficients matrix are then detected. Finally, the period can be figured out quickly. Compared with the general method, the proposed method can estimate the micro-motion period accurately and quickly. A computer simulation is given to illustrate the effectiveness of the proposed method.     

Optimization algorithm for dynamic spectrum access based on Q-learning in cognitive radio networks

Under the centralized cognitive radio network architecture, considering the network performance and users' demands. We propose an optimized dynamic spectrum access algorithm based on Q-learning. The proposed algorithm has two steps, which consist of user request according to Q-learning and the application process according to the overall system performance. Simulation results show that the proposed scheme can improve the overall system performance obviously, and that the user requirements could be satisfied at the same time.     

气流式微注射器萃取与气相色谱-质谱联用直接分析烟叶中菊酯类农药

将气流式微注射器萃取技术(GP-MSE)与气相色谱-质谱(GC-MS)联用,建立了一种快速、简单的检测烟叶中菊酯类农药的方法,并通过优化萃取条件和加标回收率实验评价了方法的准确性.结果表明,6种菊酯类农药的加标回收率在83.56%~95.87%之间,相对标准偏差在1.3%~7.6%之间,具有很好的回收率与重复性,说明本文方法可用于检测烟叶样品中的菊酯类农药.     

基于用户喜好的个性推荐系统优化

采用协同过滤方式的传统推荐系统具有一定实用性,但也存在未考虑用户个性喜好的问题。为提高推荐精度,特别针对用户个性化特点和需求,提出了采用改进相似度计算和回归分析方法对协同过滤推荐进行系统优化。实验结果表明,优化算法可明显改善系统的推荐效果,并加强基于协同过滤推荐的有效性。     

Numerical simulation and optimization of the cylinder head water jacket based on the two-phase flow boiling heat transfer

Boiling heat transfer and the controllability of the thermal load of the cylinder head were studied. The thermodynamic phase change characteristics of the cylinder head coolant were considered and the mass, momentum and energy transfers between two phases were calculated with the interface transfer sub-models by using the computational fluid dynamics software CFX. Results showed that compared with the single-phase flow without considering the boiling heat transfer, the sub-cooled boiling heat transfer of the cylinder head was greatly increased. According to the results of the numerical simulation, an optimized structure of the water jacket was proposed. Finally, temperature and velocity of coolant, diameter of flow passage and mean bubble diameter that influences sub-cooled boiling were studied using the orthogonal experiment method.     

MnO2/CNTs电催化剂及其对C—H键的选择性催化活化

通过化学沉淀法制备了MnO2/CNTs复合电催化剂,采用X-射线衍射(XRD)对其晶型进行了表征.采用循环伏安法(CV)、恒电位电解研究了MnO2/CNTs电催化活化对甲氧基甲苯(pMT)中C—H键的电化学氧化行为,实验结果表明:MnO2和CNTs之间具有良好的催化协同作用.恒电位电解主要氧化产物为对甲氧基苯甲醛(p-MBA).通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)和高分辨透射电子显微镜(HRTEM)对MnO2/CNTs复合材料的形貌和微观结构进行了表征,结果表明:MnO2具有细须状结构.     

曝氧量对聚驱污水稀释聚合物溶液性能的影响

针对大庆油田聚合物驱清水用量日益紧张、清水配制稀释聚合物带来的弊病日益突出的现状,提出有效利用含油污水配注聚合物技术的研究。通过污水配制聚合物室内实验,利用空压曝氧方式改善水质,分析曝氧量对聚驱污水及深度处理污水所配聚合物黏度的影响,优化最佳曝氧量,为油田污水的有效利用提供技术支持。结果表明,深度处理污水最佳曝氧量为5.6mg/L左右,降低的黏损率为4.69%;聚驱污水最佳曝氧量为7.2mg/L左右,降低的黏损率为11.45%,说明该技术可以很大程度上提高含油污水稀释聚合物溶液的黏度稳定性。