位置业务技术研究及部署规划探讨

位置业务被誉为继短消息之后移动通信领域的又一杀手锏.为适应发展形势的需要,文中从多方面对不同类型的位置业务进行说明,然后给出位置业务平台实施方案,重点就现网部署及异地定位等关键问题进行探讨,最后给出了实际部署规划过程中的性能需求,所得结果具有理论意义及实用参考价值.     

暗孤子传输中双光子吸收效应的数值研究

用分步富里叶变换法求解了含双光子吸收效应的暗孤子NLS方程，得到了在此条件下暗孤子传输的数值图形。     

宽频段太赫兹辐射计高吸收率涂层的特性

为了对宽频段高吸收率太赫兹辐射计的特性进行表征,研究了吸收涂层材料的特性;对常见的吸波材料在太赫兹波段的吸收率进行仿真,探寻在太赫兹波段具有高吸收率的材料;将碳化硅与3M黑漆进行混合,以进一步提高涂层的吸收率,并通过仿真调整涂层内碳化硅颗粒的尺寸;根据仿真结果制备混合涂层,利用太赫兹时域光谱仪对混合涂层样品进行测量。结果表明:该混合涂层样品的光谱吸收率大于0.99,与仿真结果基本吻合。     

相位噪声对脉冲多普勒雷达性能的影响

讨论了频率源相位噪声对脉冲多普勒雷达杂波可见度、测速精度、速度分辨力性能的影响,给出了一种用频谱分析仪测量杂波可见度的方法,最后进行了实例分析     

机载有源相控阵预警雷达及应用

基于日益复杂的现代战场环境对预警机所带来的挑战,将有源相控阵雷达装备于预警机是一个提高预警机性能的有效途径。对相控阵雷达原理做了简要介绍,通过总结和分析有源相控阵雷达的特点,列举有源相控阵雷达在国外预警机上的应用实例和相关参数,指出机载有源相控阵预警雷达使预警机在时间能量管理、扫描跟踪速度、多目标处理能力、测量精度、抗干扰能力以及可靠性等方面都有了根本性的改善,可有效提高预警机现代战场上的生存能力和作战效能。     

高稳定大量程复合光纤干涉位移测量系统研究

为了使位移测量系统达到大量程、高分辨率,采用复合光纤干涉的方法,进行了理论分析和实验验证。利用光纤光栅作为反射镜,构成两个干涉光路几乎共路的光纤迈克尔逊干涉仪。其中一个光纤迈克尔逊干涉仪通过反馈控制补偿环境干扰对测量系统的影响,使测量系统适合在线测量;另一个干涉仪用于完成测量工作。两个不同波长的光同时作用于完成测量的干涉仪中,测量量程由两个波长的合成波干涉信号确定,使测量量程大于1mm;测量分辨率由其中一个单波长干涉信号确定,测量分辨率小于1nm。结果表明,这种基于复合光纤干涉仪的位移测量系统可以实现大量程、高稳定的位移在线测量。     

The Antioxidant and Hypolipidemic Effects of Mesona Chinensis Benth Extracts

In this study, the antioxidant and hypolipidemic effects of Mesona Chinensis Benth (MCB) extracts were evaluated. Seven fractions (F0, F10, F20, F30, F40, F50 and MTF) were obtained from the MCB ethanol extracts. Compared to the commercial antioxidants (vitamin C), MTF and F30 exhibited higher antioxidant activities in the antiradical activity test and the FRAP assay. The half-inhibition concentration (IC50) for MTF and F30 were 5.323 µg/mL and 5.278 µg/mL, respectively. MTF at 200 µg/mL significantly decreased the accumulation of TG in oleic acid (OA)-induced HepG2 cells and reversed the inhibitory effect of Compound C on AMPK (MTF and F30 significantly increased the glucose utilization of insulin-induced HepG2 cells). In addition, the components of MTF were identified by HPLC-MS, which were caffeic acid, quercetin 3-O-galactoside, isoquercetin, astragalin, rosmarinic acid, aromadendrin-3-O-rutinoside, rosmarinic acid-3-O-glucoside and kaempferol-7-O-glucoside. Through statistical correlations by Simca P software, it was found that the main antioxidant and hypolipidemic components of MCB might be caffeic acid, kaempferol-7-O-glucoside, rosmarinic acid-3-O-glucoside and aromadendrin-3-O-rutinoside, which may play important roles in the AMPK pathway. MTF and F30 in MCB could be potential health products for the treatment of hyperlipidemia.     

基于偏序关系的Rough集模型及其应用

在标准Rough集理论的指导下,利用偏序关系性质构造了不同分类,并以此为基础探讨了上、下近似集,从而构建了基于偏序关系的Rough集模型。新模型将Rough集理论的应用范围由等价关系扩展到偏序关系。为了更好地增强模型的实用性和灵括性,一方面从程度、精度、概率等角度出发分别对其进行了扩展,另一方面引入依赖度使其适用于研究各种非严格的偏序关系。给出了实例分析,并结合现实生活中的现象阐述了模型的应用价值。     

Synthesis and Anti-Neuroinflammatory Activity of 1,7-diphenyl-1,4-heptadien-3-ones in LPS-Stimulated BV2 Microglia Via Inhibiting NF-κB/MAPK Signaling Pathways

A series of 1,7-diphenyl-1,4-heptadien-3-ones with various substituents (HO-, CH₃O-, CH₃-, Cl-) on the phenyl rings were synthesized and evaluated for anti-neuroinflammatory effects in LPS-stimulated BV2 microglia. The pharmacological results showed that the target compounds bearing methoxy groups greatly inhibited LPS-induced NO release, and that the active compounds CU-19 and CU-21 reduced the level of NO, TNF-α, IL-6 and PGE-2, downregulated the expression of COX-2 and iNOS in LPS-stimulated BV2 cells. A study of the mechanism of action revealed that CU-19 and CU-21 inhibited the nuclear translocation of NF-κB and phosphorylation of MAPKs (ERK, JNK, and p38). A preliminary pharmacokinetic study in rats revealed that the pharmacokinetic properties of CU-19 and CU-21 were dramatically ameliorated in comparison with the pharmacokinetic properties of curcumin.     

High-performance potassium poly(heptazine imide) films for photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting is an appealing approach by which to convert solar energy into hydrogen fuel. Polymeric semiconductors have recently attracted intense interest of many scientists for PEC water splitting. The crystallinity of polymer films is regarded as the main factor that determines the conversion efficiency. Herein, potassium poly(heptazine) imide (K-PHI) films with improved crystallinity were in situ prepared on a conductive substrate as a photoanode for solar-driven water splitting. A remarkable photocurrent density of ca. 0.80 mA cm⁻² was achieved under air mass 1.5 global illumination without the use of any sacrificial agent, a performance that is ca. 20 times higher than that of the photoanode in an amorphous state, and higher than those of other related polymeric photoanodes. The boosted performance can be attributed to improved charge transfer, which has been investigated using steady state and operando approaches. This work elucidates the pivotal importance of the crystallinity of conjugated polymer semiconductors for PEC water splitting and other advanced photocatalytic applications.

Potassium poly(heptazine imide) photoanode is synthesized, and owing to the improved crystallinity, it has presented a remarkable performance for solar-driven water splitting.