基于变结构补偿网络的WPT恒流/恒压充电系统

针对电动汽车充电无线电能传输(WPT)系统的网络补偿技术,研究了一种LCC-LCC/S型变结构补偿网络.通过开关控制,能够将松耦合变压器的原/副边补偿网络由恒流源-恒流源特性,切换为恒流源-恒压源特性,从而实现变化负载工况下的恒流或恒压输出,用以满足动力电池的充电需求.针对变结构切换过程中硬开关能量冲击导致的高电压应力...     

电动汽车EPS系统阻尼工况Bang-Bang-PID控制

电动助力转向(EPS)系统是电动汽车设计装配过程中的关键部件之一,EPS的阻尼控制可提高汽车高速行驶时横摆角速度的收敛,改善转向稳定性.建立EPS系统动力学模型和汽车三自由度转向模型,分析电动机转速与输出转矩之间的制动转矩关系,设计阻尼系数随车速的变化规律.设计Bang - Bang - PID控制算法,进行了仿真分析...     

基于关系数据库的XQuery查询的实现

XML的应用日益广泛，XML数据库技术也得到迅速的发展，但是从安全性、索引结构、事务处理等方面考虑，关系数据库仍然是更加可靠的选择。本文提出了在关系数据库的基础上提供虚拟的XML数据库、并实现xQuery查询的一种中间件的设计，结合了两者的优点。     

基于幅度调制和视觉掩蔽特性的彩色图像水印

提出了一种基于幅度调制的盲检测彩色图像水印算法,为了改善可见性,根据人眼视觉特性（HVS）自适应选择其嵌入位置。水印嵌入是通过修改图像中像素蓝色通道信息来实现的,而水印提取是基于对嵌入水印位置的邻域像素值的线性组合的预测而完成的。在嵌入过程中通过高斯模板来均衡调整嵌入水印后对宿主图像影响的强度。仿真实验证明该文算法不仅具有非常好的透明性,而且对诸如叠加噪声、JPEG压缩、平滑滤波、几何变换、图像增强等攻击具有很好的鲁棒性。     

公共数据库检索在模拟机维护中的应用

公共数据库(Common Database,CDB)检索也称为公共数据库查询技术,在数据库中获得的变量和参数可以用于模拟机接口系统的状态跟踪.在过去的模拟机维护实践中,凭借电路图寻找对应故障设备的特征变量(label),并在软件上进行监控,一般能够发现故障的症结,同时,公共数据库检索的方法对于操作者的知识储备、维护经验以及实验手段都有较高的要求,因此这种方法并不常用.但使用航空无线电协议(Aeronautical Radio Inc,ARINC)的器件对应的图纸、软件中,label通常不被明确标注,同时由于ARINC信号对采样设备要求较高、测量难度较大,无法在短时间内找到故障的位置或成因.因此就模拟机运行的软硬件环境进行了分析,提出了变量赋值对应现象观察的实验手段,将这种方法引入到普遍的故障性维护流程中,以期减少人员、工时和备件带来的额外成本.     

Are the two polymorphic sites of anti-Marek’s disease in White Leghorn chickens also suitable for Partridge Shank chickens?

Background: The selection of Marek’s disease (MD)-resistant breeds in Partridge Shank chicken, a popular local chicken breed in Henan Province of China, has practical value. We hypothesized that the two polymorphic sites (rs14527240 located in SMOC1 and GGaluGA156129 located in PTPN3) related to MD resistance in White Leghorn chickens are also applicable to Partridge Shank chickens. Methods: In this experiment, we screened 10 live hens and 2 live roosters with the double GG genotype by genotyping the two sites from 6500 Partridge Shank chickens. Nineteen one-day-old chicks with the double GG genotype were obtained by artificial insemination. Seventy-two one-day-old chickens (19 from the population expansion test and 53 randomly selected from chicken farms) were injected with 2000 plaque-forming units of the Md5 virus strain. After 100 days of infection, all chickens were examined by pathological anatomical examination, histological sectioning, genotyping, and a quantitative polymerase chain reaction of SMOC1 and PTPN3. Results: There was only one site (rs14527240 located in SMOC1) associated with MD in Partridge Shank chickens (p < 0.05), but the GG genotype of SMOC1 in Partridge Shank chickens indicated susceptibility to MD. SMOC1 expression in MD-susceptible chickens was also significantly higher than that in MDresistant chickens (p < 0.05). Conclusion: Therefore, the MD resistance sites selected from White Leghorn chickens were not completely suitable for Partridge Shank chickens, but they can be used as a reference. This study indicated that SMOC1 plays an important role in screening for MD resistance in poultry.