一种通过USB接口的可靠固件升级技术

本文提出一种可靠固件升级的技术。该技术采用外部主晶振,工作异常时自动切换到校准后的内部晶振,还使用了DFU检测序列、看门狗等方法。相对于传统的固件升级技术,该技术具有抗干扰能力强、可靠、易于使用等优点。     

STM32的双路信号源及其配置平台设计

针对目前测量分析、弱信号检测的需求,以STM32F107和AD9958为核心实现了一种高分辨率幅度、频率、相位的双路信号源。首先对直接数字合成(Direct Digital Synthesis,DDS)工作原理进行介绍,重点分析了杂散的主要来源,并设计LC椭圆低通滤波器对杂散进行抑制。设计输出电路使信号源满足低频需求,并可直接用于驱动负载。最后采用STM32F107和VC6.0搭建了配置平台,对信号源波形灵活控制。     

Temporal aggregation and spurious instantaneous causality in multiple time series models

Large aggregation interval asymptotics are used to investigate the relation between Granger causality in disaggregated vector autoregressions (VARs) and associated contemporaneous correlation among innovations of the aggregated system. One of our main contributions is that we outline various conditions under which the informational content of error covariance matrices yields insight into the causal structure of the VAR. Monte Carlo results suggest that our asymptotic findings are applicable even when the aggregation interval is small, as long as the time series are not characterized by high levels of persistence.     

Evaluation of the agronomic effectiveness of natural and partially acidulated phosphate rocks in several soils using32P isotopic dilution techniques

The agronomic effectiveness of two natural phosphate rocks (PRs) from North Carolina (USA) and Togo and their 50% partially acidulated products (PAPRs) was evaluated in two greenhouse experiments using³²P isotopic dilution techniques, namely L and A_L values.In the first experiment rye grass was grown in a soil from Ghana. While the proportion of P in the plant derived from the P fertilizer (Pdff) ranged on. the average from about 10% for the PRs up to 80% for the PAPRs, the P fertilizer recovery was less than 1% for a 60-day growth period. In the second experiment, average values of P in the maize plants derived from the PAPRs ranged from 35% to 75% in 3 different soils. Both PRs were ineffective with the exception of North Carolina PR in the Seibersdorf soil. The P fertilizer recovery was 0.25% for the North Carolina PR in this soil whereas the recovery values ranged from 1.2% to 1.6% for the PAPRs.Mean values of the relative fertilizer efficiency estimated from the L values of each soil were less than 1% for the PRs whereas the values for the PAPRs which were dependent on soil type ranged from 20% up to 45%. The coefficient of relative effect of partial acidulation, that was calculated from the ratio of A_L values for PR and PAPR in each soil indicated that partial acidulation increased the effectiveness of the natural PRs in all soils under study.This study showed that the use of³²P isotope dilution techniques allows an accurate measurement of the P availability from natural and modified PR products to crops. Another advantage is that quantitative comparison of the P sources under study, PRs and PAPRs in this case, can be made even in soils where there is no response to the applied P sources.     

基于STM32的轨道方向不平顺检测系统设计

轨道不平顺是影响列车乘坐舒适性和平稳性的主要激励源,对轨道不平顺信号进行准确检测和有效的分析处理,以尽可能提高铁路维修效率,保障高速列车行车安全。为了准确检测轨道方向不平顺信号,基于惯性基准法原理,研制了以STM32F103 Cortex-M3 ARM处理器为控制核心的自动化检测系统。系统调理采集包括伺服加速度计、陀螺仪、倾角仪等多路传感器转换而来的模拟信号,然后传输到车载服务器中分析处理。检测结果以实时波形图的形式显示,能够准确有效地判断不平顺状态。     

一种户外多功能定位与测量装置的设计实现

本设计是针对在户外登山、旅行、勘测过程中常常既需要定位系统,又需要温度、高度、气压、湿度等参数测量系统的情况下,设计的一种多功能便携式测量工具。本系统采用STM32作为控制器,移植了μC/OS实时操作系统,驱动GPS模块和各种传感器模块,实现了数据的实时采集显示。本系统采用了0.96’OLED作为显示单元,STM32引入了低功耗模式,锂电池供电,提升了系统的便携性和低功耗。     

The kinetics of hydrogen transport through amorphous Pd82−yNiySi18 alloys (y=0-32) by analysis of anodic current transient

Hydrogen transport through amorphous Pd_82−yNi_ySi₁₈ alloys (y=0-32) was investigated in 0.1 M NaOH solution by analysis of the anodic current transient. It was found that the anodic current transient shows the non-Cottrell behaviour, but its shape and value remain nearly constant regardless of the hydrogen discharging potential. From the coincidence of the anodic current transient theoretically calculated with that experimentally measured, it is suggested that the change in surface concentration of hydrogen with time is uniquely given by the rate of hydrogen transfer from absorbed state at the electrode sub-surface to adsorbed state on the electrode surface. This means that neither the ‘constraint of constant concentration’ nor the ‘constraint by Butler-Volmer behaviour’ is effective at the electrode surface during hydrogen extraction. On the basis of the theoretical current-time relation under the ‘constraint by hydrogen transfer of absorbed state to adsorbed state’, the hydrogen diffusivity was determined to have an almost constant value of (1.3±0.4)×10⁻⁸ cm² s⁻¹, irrespective of the Ni content and in the absence of Ni. On the other hand, it is inferred that the rate constant of hydrogen transfer decreases markedly with increasing Ni content due to the Ni(OH)₂ layer formed on the electrode surface.     

基于STM32的航天器电气负载监控系统设计

针对传统电气负载监控系统通信纠错率较低,造成航天器电气负载监控准确率较差的问题,基于STM32设计一种新的航天器电气负载监控系统;分别设计电气负载监控系统的硬件和软件;系统硬件主要设计了嵌入式数据接口以及外接设备、驱动芯片以及监控继电器控制模块,WLAN驱动芯片能够有效降低成本和功耗,提高通信速率;通过电气负载监控执行实现软件功能,建立电力负载管理中心软件,提高监控系统的通信能力,提升负载监控的准确性;实验结果表明,基于STM32的航天器电气负载监控系统通信纠错率平均值为92%,航天器电气负载监控过程误差较小,具有一定的实际应用性。     

基于STM32的植物补光调控系统设计

光照是植物生长和发育的重要环境因子之一,在植物组织培养过程中,为了更好地利用LED光源对组培室内植物进行补光,节约能源和提高补光效率,设计了一种基于STM32的植物补光调控系统;系统采用STM32作为微控制器,设计植物补光总控中心和补光调控节点电路,补光总控中心通过RS485通信模块与安装在组培室内的多个补光调控节点进行指令和数据的通信,补光调控节点根据补光总控中心的任务指令和补光参数,协调补光调控节点的各个电路模块之间相互工作,实现按时、按量对组培室内的植物进行补光;经过实验测试结果表明,该系统环保、易操作且性能稳定可靠,能够实现补光的同时节约能源,进而减少了组培室的育苗成本,为在植物组培室内实现植物的补光提供参考。     

一种高压开关综合数据采集与监测系统设计

高压开关是电力系统中实现电路分合控制的重要电力装备,对高压开关进行在线监测可以实时监测其运行状态,进而为故障诊断、预测、电寿命、绝缘等分析提供数据来源,可以提高高压开关整体运行可靠性和减少故障时间;数据采集与监测装置是实现这种在线监测功能的核心装置,基于FPGA+STM32双处理器架构的高速数据采集系统,利用FPGA灵活的可编程特性实现高速并行数据采集,利用STM32微控制器强大的处理能力和丰富的外围接口实现数据处理、控制和传输,FPGA和STM32之间通过FSMC接口实现快速数据交换;装置采集了高压开关设备多个传感器数据,通过工业串口液晶屏作为本地人机交互界面,同时以太网接口通过TCP协议上传数据给远端,实现了高压开关运行状态的在线监测。