基于小波降噪预处理的组合导航系统研究

根据离散小波变换可降噪的特点,对捷联惯性导航系统（SINS）中惯性测量元件（IMU）的输出精度进行了研究,再与卫星定位系统（GPS）的输出进行卡尔曼滤波组合,进而达到降噪的目的,最后分别由静态时的实际量测数据以及动态时的理论仿真试验给予结果验证。试验结果表明,采用小波降噪预处理后的组合导航系统各项导航参数的精度都有了明显提高,从而提高了组合导航系统的可靠性。     

关于继承与发展羌族刺绣的几点思考

羌绣的历史非常悠久,它种类繁多,工艺精美绝伦,是羌族地区最具代表性和普遍性的手工艺品。然而历史发展到今天,羌绣在现代文明的大环境中面临前所未有的巨大冲击,在这样一个社会背景下,羌绣将如何生存、如何发展,如何焕发新的生机是我们面临的巨大挑战。文章即是从民族民间传统手工艺产业化的角度出发,为羌绣的发展提供几点新的思路。     

一种虚拟路由冗余协议负载均衡技术实现机制

标准VRRP（虚拟路由器冗余协议）解决在配置默认网关环境下消除网络单点故障问题,其协议自身不够灵活,即虚拟路由器中只有主设备进行流量转发,其他备用设备均作为备份不进行流量转发,无法负载分担,不能最大程度提高带宽和设备利用率。针对该局限,在此基于与某公司的合作项目,论述了一种虚拟路由冗余协议负载均衡实现机制,在标准VRRP协议分析研究基础上引入虚拟转发器和转发状态机,实现一个虚拟IP对应多个虚拟MAC的机制,无需配置多个备份组就能同时实现路由冗余备份和流量负载均衡,使局域网内用户能够通过每台虚拟转发器与外界通信,极大地提高资源利用率,最后以实验验证了设计可行性。     

A Novel Transfer Hydrogenation with High Hydrogen Utilization for the Hydrogenation of Halogenated Nitrobenzene without Hydrodehalogenation

In the novel catalytic transfer hydrogenation, 12 active hydrogen (H^*) can be transferred from water/ethanol system as the efficient hydrogen donor and used directly for the hydrogenation of halogenated nitrobenzene over Ru–Fe/C catalyst, obtaining o-chloroaniline (o-CAN) with 98.0% selectivity at 99.8% conversion without hydrodehalogenation. Most other halogenated nitrobenzenes were reduced with selectivity >98%, and conversion >99.0%. Moreover, the Ru–Fe/C catalyst was still active after reaction for 480 h.     

真空系统的设计

随着我国国民经济的快速发展和低温技术应用的普及,液氢、液氦等低温液化气体的应用日益广泛,低温冷箱(液化器)的需求量不断增长.抽真空工艺是其关键的工艺之一,同时液氢易燃易爆,必须进行防爆设计.以液氢冷箱为例,进行真空系统的工艺设计和防爆设计及选型.     

Effect of the molecular weight on the plasticization properties of poly(hexane succinate) in poly(vinyl chloride) blends

Blends of poly(vinyl chloride) (PVC) and poly(hexane succinate) (PHS) with various molecular weights were analyzed with respect to their mechanical properties, durability, and thermal stability. We found that the molecular weight of PHS played an important role in the plasticizing process, and the single glass-transition temperature (T _g) of the PVC blends measured by dynamic mechanical analysis supported the complete miscibility between PHS and PVC. The plasticizing efficiency of PHS increased as the molecular weight increased; this reflected the gradually increasing elongation at break and the decreased T _g of the PVC blend. Meanwhile, the higher molecular weight of PHS also improved the resistance of migration and thermal stability but decreased the biodegradability of the PVC blends; this was due to the strong intermolecular interactions between PHS and PVC. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47081.     

聚甲基丁二酸丁二醇酯的共聚改性

在1,4 丁二醇（BD）和甲基丁二酸（MSA）合成聚甲基丁二酸丁二醇酯（PBMS）的基础上,加入对苯二甲酸二甲酯（DMT）,采用熔融缩聚法对其共聚改性,得到一种新型的共聚物聚甲基丁二酸丁二醇酯 co 对苯二甲酸丁二醇酯（PBMT）。采用GPC、乌式黏度计等测定PBMT的特性黏度、酸值、羟值及相对分子质量,通过FT IR、1H NMR、DSC、TGA研究其化学结构和热性能。结果表明,在n(DMT+MSA)/n(BD)=1.00∶1.08,n(DMT)/n(MSA)=1∶1的条件下,PBMT的特性黏度及相对分子质量最大,酸值和羟值最小;催化剂选择钛酸四丁酯（TBOT）与氧化锌,二者协同效果最佳。通过FT IR与1H NMR测试表明,所需的目标产物PBMT被成功合成。DSC和TGA结果表明,PBMT的热性能比PBMS的热性能有大幅度提高。     

视频图像液位测量领域的专利检索策略分析

液位测量技术被广泛应用到多个领域中,尤其在涉及易爆、易挥发、强腐蚀及有毒性液体的液位测量时,给传统的液位检测带来一定难度.随着利用高分辨率视频图像传感器进行测量液位的微小变化成为可能,为液位测量提供了新的手段.本文通过对不同特点的申请文件进行分析,使用合适的检索策略以及适当的检索数据库进行检索,使得申请人和审查员寻找现有技术的过程变得更为高效、准确.     

Nrf2通路在氟他胺诱导的肝细胞线粒体生物合成中的作用

目的：探讨氟他胺对人肝细胞线粒体生物合成的影响以及抗氧化通路Nrf2的调节作用。方法：采用人源肝细胞HepG2,氟他胺（0~50 μmol/L）给药24 h,通过RT-PCR和Western blot方法,检测mtDNA拷贝数和线粒体生物合成关键蛋白的表达,再通过应用基因敲降和特异性激活剂或抑制剂等技术方法进一步观察ERK1/2对氟他胺诱导的线粒体生物合成的影响以及Nrf2通路的调控作用。结果：氟他胺可诱导线粒体生物合成,mtDNA拷贝数和ERK1/2、PGC-1α蛋白均呈现剂量依赖性上升;ERK1/2抑制和激活能改变氟他胺诱导的mtDNA拷贝数和PGC-1α的表达;Nrf2通路抑制可影响氟他胺诱导的mtDNA拷贝数和ERK1/2、PGC-1α的表达。 结论：氟他胺可影响线粒体生物合成,其机制与Nrf2介导的ERK1/2改变密切相关。     

Microstructure and wear property of hardfacing alloy with nitrogen strengthening

The nitrogen-alloying hardfacing alloy of the martensitic stainless steel was deposited on a low carbon steel substrate using hardfacing flux-cored wire. Microstructure and surface hardness of hardfacing alloy were investigated and measured by optical microscope and microhardness tester. Carbonitrides of the hardfacing alloy were observed by electron probe. The wear behaviour of the hardfacing alloy was studied using the belt abrasion test apparatus and the worn surface was analyzed by scanning electron microscopy. The results showed that carbonitride particles in the hardfacing alloy are complex MX (M:alloy elements; X:C, N) precipitate with fine size. These carbonitride particles distributed homogeneously in the hardfacing alloy and had a good strengthening effect on the wear property. The wear property of the hardfacing alloy with nitrogen was better than the one without nitrogen.