基于ADS1115的FPGA接口设计

随着电子技术的加速发展,更好地处理现实生活中的模拟信号和数字世界中的数字信号,是人们迫切的需求。核心器件FPGA实现对16位高精度模数转换芯片ADS1115的控制。VHDL硬件描述语言设计I2C总线运行模式。结合ADS1115工作时序特点,设计有限状态机,实现对控制电路的逻辑控制。根据FPGA结构特点和I2C总线的通信协议,设计相关驱动程序,实现采集单路模拟量。通过对相应电路的实际测量,证明所设计的方案有效、可靠,同时可应用于其它类似的模数转换装置。

View of thermodynamic phase transition of the charged Gauss-Bonnet AdS black hole via the shadow

We examine thermodynamic phase transition(PT)of the charged Gauss-Bonnet Ad S black hole(BH)by utilizing the shadow radius.In this system,we rescale the corresponding Gauss-Bonnet coefficientαby a factor of 1/(D-4),and ensure thatαis positive to avoid any singularity problems.The equation derived for the shadow radius indicates that it increases as the event horizon radius increases,making it an independent variable for determining BH temperature.By investigating the PT curve in relation to shadows,we can observe that the shadow radius can be used as an alternative to the event horizon radius in explaining the phenomenon of BH PT.Furthermore,the results indicate that an increase in the parameterαcorresponds to a decrease in the temperature of the BH.By utilizing the relationship between the temperature and the shadow radius,it is possible to obtain the thermal profile of the Gauss-Bonnet AdS BH.It is evident that there is an N-type variation in temperature for pressures P<P_(c).Additionally,as the parameterαincreases,the region covered by shadow expands while the temperature decreases.The utilization of BH shadows as a probe holds immense significance in gaining a deeper understanding of BH thermodynamic behavior.

基于ADS1256的地电阻率仪数据采集系统设计

地震地电阻率监测目的是观测特定区域的对地电阻率随时间的变化,对测量精度要求很高。文章介绍的基于24位模数转换器ADS1256设计的地电阻率仪数据采集系统,具有高精度、低噪声、大动态和抗干扰能力强的特点,实验室测试结果表明其电压分辨力达到10μV,峰峰噪声小于7μV,动态范围达到120 dB,数据采集系统主要技术性能指标满足地震地电阻率监测预测研究的需求,也可应用于其他需要高精度、低噪声直流电压测量的领域。

高维AdS黑洞的约化保真率/全息子区域复杂度对偶

为阐述约化保真率/全息子区域复杂度对偶在更高维情形下的推广,通过几何计算和场理论计算分析高维AdS黑洞热场双态的约化保真率(RFS)、全息子区域复杂度(HC)和热力学体积之间的相关性,推导出RFS/HC的对偶关系,进一步验证RFS/HC对偶猜想在高维时空中的黑洞系统和量子系统中的适用性和有效性,阐明任一局部区域的各子系统都与整个系统具有关联映射的全息关系。

Long-term trends in the abundance and breeding performance in Adélie penguins:the Argentine Ecosystem Monitoring Program

In this work,we report long-term trends in the abundance and breeding performance of Adélie penguins(Pygoscelis adeliae)nesting in three Antarctic colonies(i.e.,at Martin Point,South Orkneys Islands;Stranger Point/Cabo Funes,South Shetland Islands;and Esperanza/Hope Bay in the Antarctic Peninsula)from 1995/96 to 2022/23.Using yearly count data of breeding groups selected,we observed a decline in the number of breeding pairs and chicks in crèche at all colonies studied.However,the magnitude of change was higher at Stranger Point than that in the remaining colonies.Moreover,the index of breeding success,which was calculated as the ratio of chicks in crèche to breeding pairs,exhibited no apparent trend throughout the study period.However,it displayed greater variability at Martin Point compared to the other two colonies under investigation.Although the number of chicks in crèche of Adélie penguins showed a declining pattern,the average breeding performance was similar to that reported in gentoo penguin colonies,specifically,those undergoing a population increase(even in sympatric colonies facing similar local conditions).Consequently,it is plausible to assume a reduction of the over-winter survival as a likely cause of the declining trend observed,at least in the Stranger Point and Esperanza colonies.However,we cannot rule out local effects during the breeding season affecting the Adélie population of Martin Point.

基于链式存储结构的ADS-B信号解码系统设计与实现

针对传统ADS-B信号解码系统的问题,如解码准确率低、数据传输速率小和解码实时性差,本文基于AD9361和Xilinx的Zynq-7000通用软件无线电平台提出了解决方案。该方案通过提高ADS-B信号采样率来提高解码准确率,并进行原理阐述和验证。此外,为了应对采样率增加导致的数据量增加问题,引入了链式存储结构作为DMA的缓存区域。实验结果表明,与传统解码系统相比,本文提出的系统识别并解码ADS-B信号的准确率提高了10%。链式存储结构的引入提高了数据处理速度,满足飞机航迹实时显示需求。此外,该系统的数据传输速率最高可达到682 Mb/s,满足高速数据传输的需求。

ADS软件在“高频电子线路”实践教学中的应用

在高频电子线路的教学中引入工程实践辅助教学,设计仿真及实物演示,从而大大提升学生学习的积极性和主动性,提高学生的工程实践技能和创新能力。通过创新教学手段和教学方法,在使学生扎实掌握基本理论的基础上,提高课堂教学效果。文章论述了低噪声放大器的主要技术指标,对电路设计中的诸多要点进行了分析,通过在高频电子线路课程教学中引入ADS射频电路仿真软件进行低噪放的模拟和优化,最终实现了三级低噪声放大器的研制。通过电路调试,达到了预定的技术指标,成功实现了高性能、小尺寸、低噪声放大器的建设目标。

ADS Injector-I 2 K superfluid helium cryogenic system

The Accelerator Driven Sub-critical(ADS)system is a strategic plan to solve the nuclear waste problem for nuclear power plants in China.High-energy particle accelerators and colliders contain long strings of superconducting devices,superconducting radio frequency cavities,and magnets,which may require cooling by 2 K superfluid helium(HeliumⅡ).2 K superfluid helium cryogenic system has become a research hot spot in the field of superconducting accelerators.In this study,the ADS Injector-I 2 K cryogenic system is examined in detail.The cryogenic system scheme design,key equipment,and technology design,such as the 2 K Joule–Thomson(J–T)heat exchanger and cryomodules CM1+CM2 design,are examined,in addition to the commissioning and operation of the cryogenic system.The ADS Injector-I 2 K cryogenic system is the first 100 W superfluid helium system designed and built independently in China.The ADS proton beam reached 10 Me V at 10 m A in July 2016 and 10 Me V at 2 m A in continuous mode in January 2017 and has been operated reliably for over 15,000 h,proving that the design of ADS Injector-I 2 K cryogenic system,the key equipment,and technology research are reasonable,reliable,and meet the requirements.The research into key technologies provides valuable engineering experience that can be helpful for future projects such as CI-ADS(China Initiative Accelerator-Driven System),SHINE(Shanghai High Repetition Rate XFEL and Extreme Light Facility),PAPS(Platform of Advanced Photon Source Technology),and CEPC(Circular Electron-Positron Collider),thereby developing national expertise in the field of superfluid helium cryogenic systems.

基于CC3200和ADS1299表面肌电无线采集系统

该文设计了一种多通道表面肌电无线采集系统,该系统硬件主要由TI公司的ADS1299集成模拟前端芯片和CC3200无线MCU构成。按照行业标准测量硬件关键性指标,测量结果均优于行业标准,能够满足多场景任务下连续使用。该系统具有性能高、功耗低、体积小等优点,已应用在运动手势识别的表面肌电信号检测中,具有很好的应用价值。

基于误差修正方法的改进SINS/ADS

针对捷联惯导系统(SINS)导航误差累积、定位精度低的问题,利用大气数据系统(ADS)修正SINS的状态量,包括失准角、速度误差与位置误差,提出一种SINS/ADS误差修正方法,分别对SINS、基于文献的SINS/ADS与本文基于误差修正方法的SINS/ADS进行导航仿真与对比,仿真结果验证了该方法能有效抑制误差发散,降低导航误差,提高定位精度。

基于ZYNQ-7000与ADS125H02的高精度模数转换设计

在数据采集与实时控制等系统中,对模数转换(ADC)的同步性、准确度与精度要求越来越高。基于目前对微控制器低功耗、小型化以及高速处理速度的应用需求,设计采用XILINX公司的ZYNQ-7000系列微控制器,在PL端利用SPI串行接口与模数转换芯片ADS125H02进行通信,编写嵌入式代码,进行仿真测试,并通过串口将双通道电压幅值实时同步发送至上位机,实现24位、±5 V的低噪声、高精度的双极性双通道模拟数据的采集转换。结果测试表明,基于ZYNQ-7000与ADS125H02的模数转换具有同步性好、精度高、移植性强、适用面广等优点。

ADS 100影像数据制作DOM技术探讨

本文通过对ADS 100影像数据在河流调查制作DOM生产过程中各个技术环节的总结,着重说明了在XPro软件下处理ADS 100影像数据时各工序的作业方法和注意事项,为今后ADS影像在航测生产项目中更好、更广泛地应用提供参考。

基于ADS和HFSS的矿井UWB射频前端电磁联合仿真方法

射频前端是矿井超宽带(UWB)定位系统的重要组成部分,其电磁性能影响定位精度。目前UWB定位系统射频前端设计一般针对单独器件或芯片使用ADS或HFSS进行仿真设计,随着射频前端设计的频段越来越高,分立元件、传输线等三维结构之间引起的寄生效应对射频前端电路性能的影响越来越大,需要研究板级射频前端电磁联合仿真方法。针对上述问题,提出了一种基于ADS和HFSS的矿井UWB射频前端电磁联合仿真方法。首先,采用HFSS软件对无源器件进行建模,并用HFSS软件直接进行仿真得到对应的snp文件。然后,使用ADS软件建立有源器件原理图,将参数读取控件和原理图连接,并将snp文件导入控件中。最后,在ADS中对原理图进行仿真,ADS和HFSS之间通过S参数作为媒介来进行联合操作,实现UWB射频前端电磁特性的联合仿真。综合运用ADS和HFSS对UWB射频前端有源器件、无源器件及整体板级电路进行联合仿真,并根据仿真原理制作测试样品,实验结果表明,联合仿真结果与样品实测结果匹配,可用于UWB射频前端设计和电磁性能综合测试。将以电磁联合仿真方法设计的射频前端制作成PCB样品并用于UWB定位系统进行定位极限距离测试,测试结果表明,以电磁联合仿真方法设计的射频前端完全可以满足实际产品性能需求,在设计阶段对实际产品效果预测准确,提高了设计效率,降低了设计成本。

Fabrication of adsorbents with enhanced CuⅠ stability: Creating a superhydrophobic microenvironment through grafting octadecylamine

In atmospheric conditions, CuⅠis easily oxidized to CuⅡdue to the coexistence of moisture and oxygen.The poor oxidation inhibition of CuⅠrestricts the practical application of CuⅠ-containing materials.Herein we introduce an approach to construct a superhydrophobic microenvironment in CuⅠfunctionalized metal–organic frameworks by coordinatedly grafting organic amine compounds onto open metal sites(OMSs), which can hinder the accessibility of moisture to pores thereby enhancing the stability of CuⅠ. As a proof of concept, MIL-101(Cr) with abundant OMSs and octadecylamine(OA)with long hydrophobic alkyl groups are used as carrier and surface coating. As superhydrophobic porous materials, the resultant CuⅠM-OA exhibits improved CuⅠstability in addition to retaining high crystallinity and intact porosity while almost all CuⅠis oxidized in hydrophilic CuⅠM upon exposure in a humid atmosphere for 30 h. CuⅠM-OA owns excellent adsorption desulfurization performance(ADS) with regard to thiophene, benzothiophene, and 4,6-dimethyl dibenzothiophene. Even from hydrated fuel, the adsorption performance of CuⅠM-OA maintains well while the adsorption capacity of CuⅠM decreases to 7% after4 cycles. The remarkable moisture resistance, CuⅠstability, and high porosity make the current adsorbent CuⅠM-OA highly promising for the practical ADS process.

Shadow thermodynamics of AdS black hole with the nonlinear electrodynamics term

We creatively employ the shadow radius to study the thermodynamics of a charged Ad S black hole with a nonlinear electrodynamics(NLED)term.First,the connection between the shadow radius and event horizon is constructed with the aid of the geodesic analysis.It turns out that the black hole shadow radius shows a positive correlation as a function of the event horizon radius.Then in the shadow context,we find that the black hole temperature and heat capacity can be presented by the shadow radius.Further analysis shows that the shadow radius can work similarly to the event horizon in revealing black hole phase transition process.In this sense,we construct the thermal profile of the charged Ad S black hole with inclusion of the NLED effect.In the P<Pc case,it is found that the N-type trend of the temperature given by the shadow radius is always consistent with that obtained by using the event horizon.Thus,we can conclude for the charged Ad S black hole that the phase transition process can be intuitively presented as the thermal profile in the shadow context.Finally,the effects of NLED are carefully analyzed.

Test of Linear Part in Tuner System of ADS 25 MeV Linac

The tuner system of ADS 25 MeV Linac(Fig.1)built in CM1,CM2 and CM3 consists of 17 tuners and every tuner consists of two parts-linear drive unit and tuning implement unit.Linear drive unit is mainly composed of step motor,reduction box,screw-nut and coupler(Fig.2).To learn about the working conditions and structure characteristics,17 tuners were tested and the CM1-2,CM2-3 and CM3-1 were chosen as representatives to give a brief introduction of test procedure and results.

基于ADS仿真的最佳干扰信号分析

为了研究不同类型干扰信号对特定通信链路的干扰效果,应用ADS软件,通过调用多种DSP电路功能模块,在成功搭建PM调制通信链路的基础上,通过注入多种类型干扰信号,研究了基于特定通信链路误码率随不同类型干扰信号的信干比变化情况,以及当干扰信号采用不同码速率时,对通信链路误码率的影响,并针对仿真结果进行了理论分析。通过统计计算,结合通信链路各个关键节点处信号频谱的分布变化,得出信号解调过程中的频谱搬移与杂散信号的伴随出现,低通滤波器对带外信号的强抑制作用,以及采用较高码速率的通信干扰信号,其频谱扩展导致干扰效果不佳等结论。该研究可以进一步丰富ADS软件的应用场景,仿真结论可以指导通信干扰策略的制定。

同步辐射装置主信号源的扩展方法研究

主信号源是同步辐射装置的关键组成部分之一,它不仅用于产生同步辐射光源各子系统所需的稳定度极高的参考信号,还用于生成整个装置的控制系统所需的高精度工作时钟。一般使用射频信号源作为主信号源,而商业射频信号源一般只配备单输出通道,远远不能满足同步辐射装置的需要,使用传统功分器对主信号通道进行扩展又存在幅度衰减、精度下降且相位不一致的问题。为解决上述问题,利用射频芯片AD9361,研究了对主信号源的单路输出进行扩展的方法。该方法可根据用户需求完成相应数量的信号通道扩展,设计了AD9361芯片和FPGA主控模块相结合的硬件架构。搭建实验平台,开展了射频信号源在C波段扩展的实验研究,对所提出的扩展方法进行实验验证。实验结果表明,该方法能保证扩展信号的幅度、频率与相位与主信号保持高度一致。

A Health Monitoring System Using IoT-Based Android Mobile Application

Numerous types of research on healthcare monitoring systems have been conducted for calculating heart rate,ECG,nasal/oral airflow,temperature,light sensor,and fall detection sensor.Different researchers have done different work in the field of health monitoring with sensor networks.Different researchers used built-in apps,such as some used a small number of parameters,while some other studies used more than one microcontroller and used senders and receivers among the microcontrollers to communicate,and outdated tools for study development.While no efficient,cheap,and updated work is proposed in the field of sensor-based health monitoring systems.Therefore,this study developed an android-based mobile system that can remotely monitor electrocardiograms(ECGs),pulse oximetry,heart rate,and body temperature.The microcontroller’s Wi-Fi device is used to manage wireless data transport.The findings of the patient are saved on the Firebase server for further usage in the mobile app.The performance of the proposed device is tested on ten numbers of different patients age-wise in terms of beats per minute(BPM),ECG,Temperature,and SpO2.This system uses temperature,pulse,ECG,blood pressure,and eye blink sensors.This device makes the usage of a tiny pulse sensor that has been designed to provide an accurate and optimal readout of the pulse rate and a temperature sensor is also included.With the help of an MCU,our system measures the pulse rate in beats per minute(bpm),blood oxygen level temperature measurements,and ECG readings and communicates this information to the Firebase server.To check the performance of the proposed system first,the BPM parameter was checked on the cardiac monitor.Then,the proposed model is tested on different patients age-wise.The simulation result shows that the BPM reading is not much different than the BPM of the cardiac monitor.According to the simulation findings,the proposed model achieved the best performance as compared to commercially available devices.