基于nRF905的无线温湿度检测与传输系统设计

针对短距离无线通信在数据采集中的优势,设计了基于无线射频传输技术的智能温湿度检测、传输系统.该系统以nRF905无线射频传输模块和AT89S52单片机为核心,由上位机和下位机两部分构成.上位机和下位机之间通过nRF905无线收发模块和PL2303转换芯片完成数据的无线传输以及RS232串口与USB的转换.     

分布式数字无线测温系统

从低功耗、小体积、使用简单等方面考虑,基于射频SoC nRF905和数字温度传感器DS18B20设计了一个无线测温系统,该系统能够实现多个节点温度数据同时采集,通过计算机监控软件和LCD显示器,能够显示各个节点的实时温度,在实时性数据采集场合有着广泛的应用.     

基于无线技术的压电陶瓷传感器状态监测研究

压电陶瓷传感器被广泛应用于结构振动控制中,其状态的正常与否直接影响着系统的稳定性。为克服传统用有线来监测传感器状态中存在的可靠性差、传输距离短的缺点和神经网络识别技术存在的实时性问题,提出以LabVIEW为平台,集合nRF905无线模块、51系列单片机、串口通信技术来设计一种新型的压电陶瓷传感器状态监测方法,实验证明该方法能有效地实现远程监控,并具有良好的实时性。     

基于CAN总线设计实现的数据采集监控系统

介绍目前国内较为流行的CAN总线的技术特点,然后从通信模块的硬件连接、软件设计、数据库三方面对数据采集监控系统进行描述。系统采用Philips公司的PCA82C250、SJA1000作为接口器件,由于应用了无线收发芯片nRF9E5,使得系统中的节点模块方便地接入或撤出CAN总线。实际运行表明,该系统能够满足数据采集与监控的要求,具有良好的工程应用价值。     

基于单片机的电能计量插座设计

介绍了一种具有电参数计量功能的基于单片机的电能计量插座。系统以AT89S51单片机为核心,计量芯片CS5460A通过采样电路完成对电能的测量,并把数据传送给单片机进行计算显示。nRF24L01+无线模块实现主机无线数据的采集和远端监控。X5045存储各项校准值和电量值,实现系统的自动校准和断电后电能值保留的功能。系统由程序实现报警和继电控制。     

基于nRF24L01的机器鱼余氯检测系统设计

基于nRF24L01无线射频收发器件和AT89S52单片机,采用VisualBasic图像编程软件生成实时监控软件,设计一种实时检测海水余氯含量的机器鱼余氯检测系统。本文详细地阐述该系统硬件和软件设计要点,给出了基于AT89S52设计的nRF24L01硬件接口电路和程序代码;讨论了该系统在海水余氯测控中的应用。     

基于nRF903的无线倾角传感器设计

无线倾角传感器是利用无线方式传输工业现场中测量被测端面倾斜度数值的测量仪器。文中介绍了一种以nRF903无线数传芯片为核心，利用集成倾角传感器和温度传感器设计出带有温度补偿功能的倾角传感器硬件电路，并以S3C2410为核心设计出数据接收端，对前端采集的数据进行处理。该系统稳定性好，通信效率高，可广泛应用于工业现场测控领域。     

基于RTX51和nRF905的多点温度遥测系统

针对传统近距离温度采集系统中单点温度测量范围小、传输不便,以及长距离测温系统中信号传输线路复杂、信号噪声大等缺点,提出采用RF(Radio Frequency)无线通信技术对多点温度进行无线遥测的方法,并设计了基于RTX51和RF905的多点温度遥测系统。以STC12C5A60S2为控制器、NRF905无线数据收发模块为无线遥测载体、TFT彩屏为人机交互界面、DS18B20为温度传感器搭建系统硬件平台,使用C和C++语言编写了系统软件。系统经过调试,可以实现预定功能,多点温度的无线遥测距离可以达到200 m,通信效果稳定可靠。     

NRF905无线收发模块在风电叶片声发射检测中的应用

针对有线设备检测旋转叶片时的缠线问题,提出运用无线技术对旋转叶片进行状态监测。设计一种基于叶片声发射信号的无线检测系统。采用模块化的设计思想,声发射传感器选用北京声华SR150M检测叶片声发射信号,控制单元选用STC系列12C5A60S2单片机实现数据存储和控制收发,无线收发模块选用NRF905芯片,上位机使用VB设计,实现数据接收处理。测试结果表明,该系统数据检测和传输处理可靠,能够实现叶片的状态监测;且软件具有可移植性,可为旋转物件状态监测提供方法。     

选煤厂煤泥干燥系统的改造

针对铁煤集团大兴矿选煤厂煤泥干燥系统存在的问题,从压滤机系统、905煤泥转载皮带输送机、滚筒干燥机、干燥机出口刮刀、干燥机电机、925粉煤输送带6个方面对选煤厂进行技术改造。改造后,选煤厂工艺指标达到预计目标,生产环节畅通,降低了维护工作量,新增经济效益765.05万元。     

Microsphere synthesis by emulsion copolymerizations of styrene with poly(methacrylic acid) macromonomers

The polymer microspheres were synthesized by emulsion copolymerizations of styrene with vinyl benzyl terminated poly(methacrylic acid) (PMA) macromonomers in an aqueous ethanol solution. In these copolymerization systems, the macromonomer acted not only as a comonomer but also as a stabilizer. The particle diameters obtained from the water‐soluble initiator system showed smaller values than those obtained from the water‐insoluble initiator system. These polymer microspheres had a very narrow particle‐size distribution. The particle diameters depended strongly on the feed amount and molecular weight of PMA macromonomers, water fraction in the mixed solvent, and pH in the medium. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 900–905, 2002     

Nanopaper: Thin Films Prepared from Polymeric Nanotubes

A novel mesoporous material (“nanopaper”) prepared from template‐synthesized, polyelectrolyte‐stabilized polymer nanotubes is reported. The stacked network of completely collapsed, flat nanotubes forms the porous structure, which has a water‐vapor permeability that can be tuned by the stabilizer. The transport mechanism is elucidated based on microscopy, thermal analysis, spectroscopy characterization, and mass‐transfer theory. The results suggest that the nanotube surface plays a key role in the through‐film transport process. This effect vanishes in the more open films formed from micro‐fibrillated cellulose having similar fibril diameters. Nanopaper mechanical properties are also reported. With a pore structure and functionality that can be varied, nanopaper is a promising functional membrane.

     

梭式窑高温空气燃烧系统高效换热器的换热性能计算

本文对梭式窑高温空气燃烧系统进行了设计,按照设计构建实物进行实验,利用实验数据计算了高效换热器的换热性能。在窑内温度分别为：871、895、905℃,换向时间分别为：30、50、70s时．系统的总换热系数分别为28．8、28．9、28．9w／（m^2·℃）,理论节能率分别为：27．7％、26．6％、26．2％;在窑内温度为1203℃、换向时间为30s时,系统的总换热系数为：30．5W／（m^2·℃）,理论节能率为23．7％。     

Natural,untreated diamonds showing the A,B and C infrared absorptions (“ABC diamonds”), and the H2 absorption

Unusual brown to yellow diamonds of mixed type Ib/IaAB were analyzed. The occurrence of nitrogen in a combination of A, B and C centers directly detectable by IR spectroscopy in natural diamonds is considered to be extremely rare. We propose to call such stones ABC diamonds for short. These diamonds are characterized by a color, luminescence, and anomalous double refraction distribution which results from mixed growth: a center core formed by cuboid growth, rich in nitrogen, covered by an outer rim of “normal” octahedral growth, with much less nitrogen. Nitrogen in the core is present in a more aggregated state than in the rim, which is practically pure type Ib.In the infrared spectra, besides A, B and C 1-phonon absorptions a large number of previously undescribed, tentatively H-related features were identified in some samples; these proposed H-related features were only present in the periphery of the core and the rim of the diamonds, in the core practically no hydrogen was detected. The low temperature Vis/NIR spectra were mainly characterized by two defect-induced centers: the H2 center, and the apparently new 905 nm vibronic absorption with phonon-side bands at 880, 867, 847 nm plus a feature at 806.5 nm. The 905 nm absorption can possibly be attributed to a hydrogen-related center. Although these diamonds present a combination of spectroscopic characteristics (A + B + C center absorptions, H2 absorptions) deemed characteristic of certain HPHT-treated type Ia diamonds, they cannot be confused for such treated diamonds on the basis of their color, color distribution and some spectral peculiarities.     

Anti-Cancer Effects and Tumor Marker Role of Glutathione S-Transferase Mu 5 in Human Bladder Cancer

Our previous study demonstrated that the glutathione S-transferase Mu 5 (GSTM5) gene is highly CpG-methylated in bladder cancer cells and that demethylation by 5-aza-dC activates GSTM5 gene expression. The aim of the present study was to investigate the role of GSTM5 in bladder cancer. The levels of GSTM5 gene expression and DNA methylation were analyzed in patients with bladder cancer, and functional studies of GSTM5 were conducted using GSTM5 overexpression in cultured bladder cancer cells. Clinical analysis revealed that the GSTM5 mRNA expression was lower in bladder cancer tissues than in normal tissues and that the level of GSTM5 DNA methylation was higher in bladder cancer tissues than in normal urine pellets. Overexpression of GSTM5 decreased cell proliferation, migration and colony formation capacity. Glutathione (GSH) assay results indicated that cellular GSH concentration was decreased by GSTM5 expression and that GSH supplementation reversed the decrease in proliferation and migration of cells overexpressing GSTM5. By contrast, a GSH synthesis inhibitor significantly decreased 5637 cell GSH levels, survival and migration. Furthermore, GSTM5 overexpression inhibited the adhesion of cells to the extracellular matrix protein fibronectin. To elucidate the effect of GSTM5 on anticancer drugs used to treat bladder cancer, cellular viability was compared between cells with or without GSTM5 overexpression. GSTM5-overexpressed cells showed no significant change in the cytotoxicity of cisplatin or mitomycin C in 5637, RT4 and BFTC 905 cells. Though a degree of resistance to doxorubicin was noted in 5637 cells overexpressing GSTM5, no such resistance was observed in RT4 and BFTC 905 cells. In summary, GSTM5 plays a tumor suppressor role in bladder cancer cells without significantly affecting chemoresistance to cisplatin and mitomycin C, and the cellular GSH levels highlight a key mechanism underlying the cancer inhibition effect of GSTM5. These findings suggest that low gene expression and high DNA methylation levels of GSTM5 may act as tumor markers for bladder cancer.