基于Zigbee技术的井下人员定位系统的研究

首先对Zigbee技术进行了简介,并在整个传感器网络系统中使用CC2430芯片作为节点设计的核心处理器。之后给出了系统的硬件和软件设计流程,并利用Matlab工具对改进定位算法进行了仿真比较,最后对本项目工作进行了总结和展望。     

Nonempirical calculations of the one‐bond 29Si–13C spin–spin coupling constants taking into account relativistic and solvent corrections

The computational study of the one‐bond ²⁹Si–¹³C spin–spin coupling constants has been performed at the second‐order polarization propagator approximation (SOPPA) level in the series of 60 diverse silanes with a special focus on the main factors affecting the accuracy of the calculation including the level of theory, the quality of the basis set, and the contribution of solvent and relativistic effects. Among three SOPPA‐based methods, SOPPA(MP2), SOPPA(CC2), and SOPPA(CCSD), the best result was achieved with SOPPA(CCSD) when used in combination with Sauer's basis set aug‐cc‐pVTZ‐J characterized by the mean absolute error of calculated coupling constants against the experiment of ca 2 Hz in the range of ca 200 Hz. The SOPPA(CCSD)/aug‐cc‐pVTZ‐J method is recommended as the most accurate and effective computational scheme for the calculation of ¹J(Si,C). The slightly less accurate but essentially more economical SOPPA(MP2)/aug‐cc‐pVTZ‐J and/or SOPPA(CC2)/aug‐cc‐pVTZ‐J methods are recommended for larger molecular systems. It was shown that solvent and relativistic corrections do not play a major role in the computation of the total values of ¹J(Si,C); however, taking them into account noticeably improves agreement with the experiment. The rovibrational corrections are estimated to be of about 1 Hz or 1–1.5% of the total value of ¹J(Si,C). Copyright © 2014 John Wiley & Sons, Ltd.     

An appraisal of Luffa aegyptiaca extract and its isolated triterpenoidal saponins in Trichinella spiralis murine models

Trichinella spiralis is an intestinal and tissue parasitic nematode, emerging and re-emerging causative agent of a serious foodborne parasitic infection. This study aimed to evaluate the effect of Luffa aegyptiaca leaf extract and its triterpene glycosides on the intestinal and muscle stages of T. spiralis infection in vitro and in vivo. Phytochemical investigations of the extract led to the isolation of five compounds, namely (1) 3-O-β-d-glucopyranosyl-16-O-β-hydroxyolea12-en 23, 28-β-d-diglucopyranoside ester, (2) 3β-hydroxylolea12-en-28-oic acid (Oleanoic acid), (3) oleanolic acid 3-O-α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranoside, (4) 3-O-β-d-glucopyranosyl-28-β-d-glucopyranosyl oleanolate, and (5) stigmast-5, 22-dien-3-O-β-d-glucopyrano-side. Moreover, the in vitro study showed marked degeneration and destruction of adult worms and larval teguments with tested drugs. Also, in the in vivo study, mice were divided into six groups; group I: infected and untreated, group II: received leaf extract as prophylaxis, group III: infected and treated with leaf extract, group IV: treated with compound (4), group V: treated with compound (1), and group VI: treated with albendazole. Furthermore, the treatment efficacy was assessed by the adult and total larval counts, histopathological study of the small intestinal and muscle tissues, and immunohistochemical staining of CD34 in muscles. The results revealed a significant reduction of total adult and larval counts in prophylactic and treated groups compared to the positive control group, with a reduction of total adult count by 63.48% and 74.4% in compound (1) and compound (4) treated groups, respectively. Also, a reduction was detected in larval counts by 36.5%, and 93.6% in compound (1) and compound (4) treated groups during both the muscular and intestinal phases, respectively.Additionally, histopathological examination of the small intestine and muscles showed marked improvement with a reduction in the inflammatory infiltrates in treated groups. CD34 expressions were reduced in treated groups with more reduction in compound (4) treated group. In conclusion, this study implies that L. aegyptiaca leaf extract and its tested triterpene glycosides might be used for anti-trichinellosis treatments.     

基于CC2420模块无线温湿度监测系统设计

针对现有的温湿度测量系统布设线缆的复杂,提出了一种新的基于ZigBee技术的解决方案,利用CC2420模块与单片机构成的对温湿度的实时监测。本文依据传感器节点功耗低、成本低、体积小等硬件限制条件,设计了一种基于射频芯片CC2420和单片机ATmega128为核心的无线传感器网络的温湿度监控系统。     

基于ZigBee的监测系统的设计

根据zigBee的堆栈协议,建立了一个小型星状网络系统,设计了一种基于zigBee的温湿度监测系统。系统终端节点以ATMEGA16L为内核,以一体化的温湿度传感器SHT111为采集设备,使用专用的zigBee传输模块CC2420。主节点以ATMEGA16和CC2420分别作为主控部分和传输芯片。采用液晶12864,计算出终端节点测量的温度、湿度值并显示在液晶屏上。通过适当的软、硬件抗干扰处理,设计出的多点无线温湿度采集系统具有实用性、小型化等特点。     

基于Zigbee的分布式温度采集系统的设计

无线数据采集是Zigbee的重要应用领域,但对节点的地址管理和重组,以及电源管理一直比较敏感.设计了一种基于芯片CC2430和Z-Stack协议栈的多点温度采集系统,可对节点进行动态管理,新设计的电源管理方案延长了电池的使用寿命.本方案的特点在于组网方便,重组能力强,节点电池寿命长.     

基于CC2430的无线传感器网络系统节点设计

无线传感器网络是由一组传感器节点以自组织的方式构成的无线网络.以CC2430为主控单元,设计了以无线传感器的主节点、信标节点和移动机器人为基本结构无线传感器网络系统,着重设计了主节点与PC机的串行通信及各节点间的无线通信方法.实验结果证明了所述方法的正确性和有效性.     

基于CC3200的设备电源远程控制系统设计

针对工业设备电源接入无线网络实现远程监测与控制的要求,设计了一款基于CC3200的数据实时监测和远程控制系统,并给出了硬件和软件设计方案。系统采用CC3200内嵌的应用MCU对电源进行信息采集和控制,采集的数据通过内嵌的Wi-Fi网络处理器无线传递到本地服务器并存入SQL数据库中,而来自终端的控制命令通过Wi-Fi处理器接收并送给应用MCU处理。实验结果表明系统运行稳定可靠,灵活高效,具有良好的应用前景。     

基于太阳能光伏的无线户外环境监测系统设计

设计了一种采用太阳能供电模式的无线户外环境监测系统;该系统由终端节点,ZigBee-GSM网关和上位机数据存储中心组成,集成ZigBee和GSM无线通信,根据用户发送的短信指令控制终端节点数据采集的通断,同时用户发送短信指令远程查询户外环境的重要信息;针对户外环境因子的特点,选用工业级、灵敏度高的传感器,对户外不同位置的PM2.5浓度和紫外线指数进行测量,测量结果既可在上位机实时显示和存储,也可以由ZigBee-GSM网关通过SIM900A模块发送至移动终端;户外测试结果表明,该系统运行稳定,数据传输可靠,能快速地实现远程遥测功能,为户外环境远程监测提供了一种技术手段。     

Pollen indication to source plants in the eastern desert of China

Pollen analysis is one of the important resources for the reconstruction of palaeoclimate and palaeovegetation. The relationship between modern pollen and vegetation is the foundation of pollen analysis. Owing to its complexity and importance, many polynologists and plant-ecologists have been studying on it[1―17]. In 1963, M. B. Davis gave the definition of R-values[2] that have carried forward the quantitative relationship between pollen and vegetation. However, R-value is changeable for d…