On-Chip Micro Temperature Controllers Based on Freestanding Thermoelectric Nano Films for Low-Power Electronics

Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern microelectronics.However,this inevitably exac-erbates the inhomogeneity of temperature distribution in microsystems,making precise temperature control for electronic components extremely challenging.Herein,we report an on-chip micro temperature controller including a pair of thermoelectric legs with a total area of 50×50μm^(2),which are fabricated from dense and flat freestanding Bi2Te3-based ther-moelectric nano films deposited on a newly developed nano graphene oxide membrane substrate.Its tunable equivalent thermal resistance is controlled by electrical currents to achieve energy-efficient temperature control for low-power electronics.A large cooling temperature difference of 44.5 K at 380 K is achieved with a power consumption of only 445μW,resulting in an ultrahigh temperature control capability over 100 K mW^(-1).Moreover,an ultra-fast cooling rate exceeding 2000 K s^(-1) and excellent reliability of up to 1 million cycles are observed.Our proposed on-chip temperature controller is expected to enable further miniaturization and multifunctional integration on a single chip for microelectronics.

基于Modbus通讯协议的PLC运动控制研究

在基于Modbus通讯协议的PLC运动控制系统中,PLC作为主站,通过Modbus协议与从站设备(如变频器、电机控制器等)进行通讯。探讨了如何在上位机工控软件中通过Modbus通讯协议与PLC运动控制器及PLC输入输出模块进行数据交换以及逻辑程控。

基于Modbus-RTU的皮带机数据采集系统开发及应用

针对传统皮带机数据采集系统存在的电缆敷设量大、改造过程复杂、占用可编程逻辑控制器(PLC)点位多、经济性不高,以及大量电缆导致设备电气控制回路复杂、故障点众多等问题,文章提出了一种基于Modbus-RTU协议的皮带机数据采集系统。该系统深度融合了电气自动化控制技术,实现了对皮带机关键安全与生产监控参数的全面采集,包括拉绳开关状态、跑偏开关状态、温度振动检测数据、速度监测值、堵料检测信号及撕裂检测装置信息等。实验与应用结果显示,该系统不仅结构设计紧凑,大幅减少了电缆敷设量,简化了施工流程与调试步骤,还具备友好的用户界面,便于日常监控与维护。

基于电力云边协同的非侵入式Modbus TCP协议安全增强方法

分布式电源(distributed resources,DR)中智能边缘设备数据传输的安全问题为电力系统带来了安全隐患。Modbus TCP(transmission control protocol)协议作为边缘设备采用的通信手段之一,其协议安全性的不足使得系统易遭到网络空间的攻击。为保障电力设备数据传输安全,对现有安全手段进行整理,分析现有安全手段在DR应用场景下的不足,提出一种非侵入式Modbus TCP协议安全增强方法。该方法采用云边协同的架构,利用电力控制中心云平台管理访问控制原则,将实际访问控制决策模块部署在边缘设备,并通过细粒度的访问控制组合限制恶意行为。依据Modbus协议参考指南,搭建DR应用场景进行渗透测试,验证该方法能有效防御重放攻击和中间人攻击,可将安全开销控制在百微秒以内,显著优于其他安全手段,满足DR对实时性的需求。

Modbus-RTU协议的浮点数传输设计

为解决Modbus-RTU通信协议中保持寄存器不能直接传递高精度浮点数的问题,设计了一种共用体数据结构,定义联合变量,将浮点数和对应的存储数组共享同一内存空间,发送端用浮点数二进制码的方式传输浮点数,接收端再用浮点数的格式读取这4个字节内的数值,实现Modbus-RTU协议的浮点数传输设计。该方法经多次数据传输测试,可同时发送多个不同精度的浮点数,数据传输简单、高效。该方法可应用于需要采用Modbus-RTU协议进行多个浮点数数据传输且精度不同的通信系统中。

基于Modbus/TCP协议的ATS与FSK系统间通信接口设计

根据墨西哥某城市地铁指挥控制系统的设计需求,列车自动监控(ATS)系统与频移键控(FSK)系统之间数据交互采用网络接口,基于Modbus/TCP协议实现相应的以太网通信。为此提出基于Modbus/TCP协议的ATS与FSK系统间通信接口设计方案:利用Modbus/TCP协议的扩展灵活性,在传统Modbus/TCP协议的基础上进行扩展,实现ATS与FSK系统间的模拟列控信息、列车检测信息、FSK传输配置信息、网络配置信息的安全可靠传输;为了高效便捷地将从网口接收的信息解析后传输给FSK系统,选择在ARM/Linux+FPGA平台上实现通信接口。测试验证结果表明:该通信接口设计方案结构清晰且方便移植,能够正确有效地实现ATS与FSK系统间通信。

Temperature-Based Fan Speed Optimization Strategy

As energy efficiency and indoor comfort increasingly become key standards in modern residential and office environments,research on intelligent fan speed control systems has become particularly important.This study aims to develop a temperature-feedback-based fan speed optimization strategy to achieve higher energy efficiency and user comfort.Firstly,by analyzing existing fan speed control technologies,their main limitations are identified,such as the inability to achieve smooth speed transitions.To address this issue,a BP-PID speed control algorithm is designed,which dynamically adjusts fan speed based on indoor temperature changes.Experimental validation demonstrates that the designed system can achieve smooth speed transitions compared to traditional fan systems while maintaining stable indoor temperatures.Furthermore,the real-time responsiveness of the system is crucial for enhancing user comfort.Our research not only demonstrates the feasibility of temperature-based fan speed optimization strategies in both theory and practice but also provides valuable insights for energy management in future smart home environments.Ultimately,this research outcome will facilitate the development of smart home systems and have a positive impact on environmental sustainability.

Reinforced temperature control of a reactive double dividing-wall distillation column

The mass and thermal coupling makes the control of the reactive double dividing-wall distillation column(R-DDWDC) an especially challenging issue with a highly interactive nature. With reference to the separation of an ideal endothermic quaternary reversible reaction with the most unfavorable ranking of relative volatilities(A + B ■ C + D with α_(A)>α_(C)>α_(D)>α_(B)), the operation rationality of the R-DDWDC is studied in this contribution. The four-point single temperature control system leads to great steady-state discrepancies in the compositions of products C and D and the reason stems essentially from the failure in keeping strictly the stoichiometric ratio between reactants A and B. A temperature plus temperature cascade control scheme is then employed to reinforce the stoichiometric ratio control and helps to secure a substantial abatement in the steady-state discrepancies. A temperature difference plus temperature cascade control scheme is finally synthesized and leads even to better performance than the most effective double temperature difference control scheme. These outcomes reveal not only the operation feasibility of the R-DDWDC but also the general significance of the proposed temperature difference plus temperature cascade control scheme to the inferential control of any other complicated distillation columns.

工控网络Modbus TCP协议异常报文检测方法

工业控制网络系统包含Modbus报文传输数据、TCP/IP主机通信行为数据、工控协议数据等大量复杂数据,容易造成数据冗余,降低异常报文检测精度,增加检测时间,从而增加工控网络被攻击几率。为此,提出一种基于支持向量机(SVM)的工控网络Modbus TCP协议异常报文检测方法。利用SVM建立工控网络分层数据模型,在应用层中定义Modbus协议报文,使用核函数对非平稳的随机Modbus协议报文进行离散处理,减少工控网络数据冗余。结合m阶马尔科夫序列,在TCP/IP数据链路层中对离散Modbus协议报文进行异常特征提取,完成Modbus报文异常检测。仿真测试结果表明:所提方法可以有效降低数据冗余,工控网络重复数据存储率为0.39%;Modbus TCP协议异常报文检测精度为95.73%;Modbus TCP协议异常报文检测时间为0.5 ms,以期为工控网络安全提供技术支持。

Experimental study on temperature stress calculation and temperature control optimization of concrete based on early age parameters

Temperature control curve is the key to achieving temperature control and crack prevention of high concrete dam during construction,and its rationality depends on the accurate measurement of temperature stress.With the simulation testing machine for the temperature stress,in the present study,we carried out the deformation process tests of concrete under three temperature curves:convex,straight and concave.Besides,we not only measured the early-age elastic modulus,creep parameters and stress process,but also proposed the preferred type.The results show that at early age,higher temperature always leads to greater elastic modulus and smaller creep.However,the traditional indoor experiments have underestimated the elastic modulus and creep development at early age,which makes the calculated value of temperature stress too small,thus increasing the cracking risk.In this study,the stress values of the three curves calculated based on the strain and early-age parameters are in good agreement with the temperature stress measured by the temperature stress testing machine,which verifies the method accuracy.When the temperature changes along the concave curve,the law of stress development is in consistent with that of strength.Under this condition,the stress fluctuation is small and the crack prevention safety of the concave type is higher,so the concave type is better.The test results provide a reliable basis and support for temperature control curve design and optimization of concrete dams.

Optimization of the Plugging Agent Dosage for High Temperature Salt Profile Control in Heavy Oil Reservoirs

After steam discharge in heavy oil reservoirs,the distribution of temperature,pressure,and permeability in different wells becomes irregular.Flow channels can easily be produced,which affect the sweep efficiency of the oil displacement.Previous studies have shown that the salting-out plugging method can effectively block these channels in high-temperature reservoirs,improve the suction profile,and increase oil production.In the present study,the optimal dosage of the plugging agent is determined taking into account connection transmissibility and inter-well volumes.Together with the connectivity model,a water flooding simulation model is introduced.Moreover,a non-gradient stochastic disturbance algorithm is used to obtain the optimal plugging agent dosage,which provides the basis for the high-temperature salting-out plugging agent adjustment in the field.

基于LwIP和Modbus TCP协议的网络控制器设计

为了实现对终端设备的网络远程控制和监测,该文设计了一款基于LwIP和Modbus TCP协议的网络控制器。该控制器以STM32F107RCT6和LAN9303芯片为核心,设计出了网络通信电路、网口电路、A/D采样电路、光耦隔离电路和IO口电路。软件设计主要完成了LwIP协议栈的移植、Modbus TCP协议程序和其他控制程序的编写。经过测试,所设计的网络控制器在对设备进行远程控制和监测时具有数据传输可靠、通讯稳定和实时性好的优点,能满足工厂使用。

Single-Stage Wide-Range CMOS VGA with Temperature Compensation and Linear-in-dB Gain Control

A novel wide-range CMOS variable gain amplifier （VGA） topology is presented. The proposed VGA is composed of a variable transconductor and a novel variable output resistor and can offer a high gain variation range of 80dB while using a single variable-gain stage. Temperature-compensation and decibel-linear gain characteristic are achieved by using a control circuit that provides a gain error lower than ±1.5dB over the full temperature and gain ranges. Realized in 0.25μm CMOS technology, a prototype of the proposed VGA provides a total gain range of 64.5dB with 55.6dB-linear range,a P-1dB varying from - 17.5 to 11.5dBm,and a 3dB-bandwith varying from 65 to 860MHz while dissipating 16.5mW from a 2.5V supply voltage.

Response of Over-summer Hydroponic Lettuce to Nutrient Solution Temperature Control

Temperature, as an important feature of hydroponic nutrient solution, is closely related to dissolved oxygen content of nutrient solution and growth status of plant roots. How to precisely adjust the temperature of nutrient solution is the key to obtain high quality and high yield of hydroponic vegetables over summer. With Lactuca sativa vat. crispa ＇Luosheng No.3＇ as the test material, the effect of chiller cooling technology on the temperature of nutrient solution, as well as on the yield and quality of Luosheng No.3, in over-summer hydroponic cultivation was studied. The results showed that the chiller cooling technology controlled the nutrient solution temperature in a reasonable range （（20 ± 1）℃） and promoted the growth and dry matter accumulation of Luosheng No.3, instead of affecting the quality. In short, the chiller cooling technology is applicable to the temperature regulation of nutrient solu- tion in hydroponics over summer.

Studies on the Economical and Practical Temperature Control Facility of Deep-Litter Systems for Swine Production

Deep-Litter System is a high yield approach to raise swine with pollution free in a lower cost. In the research, based on the heat stress in summer caused by fermentation, three temperature-control systems were designed, including natural ventilation through transoms, forced ventilation via fans, and cooling by hyperbaric spray system. Specifically, the latter intermittent auto-pressurized spray system developed in our lab, which could spray successively via pressure from storage tubes without wetting the fermentation bed, is suitable for the promotion with the deep-litter technology in rural regions , since the power consumption is only 1 kwh per day.

Preference-based multiobjective artificial bee colony algorithm for optimization of superheated steam temperature control

In order to incorporate the decision maker＇s preference into multiobjective optimization a preference-based multiobjective artificial bee colony algorithm PMABCA is proposed.In the proposed algorithm a novel reference point based preference expression method is addressed.The fitness assignment function is defined based on the nondominated rank and the newly defined preference distance.An archive set is introduced for saving the nondominated solutions and an improved crowding-distance operator is addressed to remove the extra solutions in the archive.The experimental results of two benchmark test functions show that a preferred set of solutions and some other non-preference solutions are achieved simultaneously.The simulation results of the proportional-integral-derivative PID parameter optimization for superheated steam temperature verify that the PMABCA is efficient in aiding to making a reasonable decision.

基于Modbus协议的通信设计及调试方法研究

Modbus作为一种典型的现场总线协议,具有开放、简洁、无需缴纳许可证费用等突出特征,在反应堆仪控系统及各类工业控制系统中具有广泛的应用。首先,对Modbus协议标准中的主要内容进行了概述。然后,从系统设计层面介绍了Modbus协议通信接口在网络架构、应用层、数据链路层及物理层上的设计要素。从设备层面阐述了存储空间分配、地址映射等设计要素。最后,对如何确定Modbus通信接口的正确性和健壮性进行总结和阐述。按照自底向上的思路,从调试和测试目标、调试和测试步骤、常用工具选用和注意事项等方面分别阐述了各层次的调试和测试方法及要点。所总结的设计要素和调试测试方法可为支持Modbus协议通信接口的控制系统/设备设计、调试和测试提供良好的参考。

基于LSTM的Modbus TCP协议模糊测试优化方法

针对工控系统传输协议模糊测试的路径爆炸和约束求解问题,提出一种基于长短时记忆(LSTM)网络的Modbus TCP协议模糊测试优化方法,挖掘出两种工控协议漏洞,分别为非法写入漏洞和数据值边界漏洞。抓取模糊测试数据包形成数据集,并根据状态码将其分为正常用例、异常用例和无效用例三种,通过LSTM识别出无效用例并剔除,提高漏洞挖掘效率。实验结果表明,LSTM识别模糊测试数据集的准确率达到93.87%,经过LSTM优化后的测试用例通过率从30.75%提升至33.99%。

Temperature distribution and dynamic control of secondary cooling in slab continuous casting

To predict and optimize the temperature distribution of slab continuous casting in steady operational state, a three-dimensional model （named ＂offline model＂） based on the heat transfer and solidification theories was developed. Both heat transfer and flux distribution characteristics of the nozzle sprays on the slab were considered, and the complicated boundary conditions, such as spray cooling, natural convection, thermal radiation as well as contact cooling of individual rolls were involved in the model. By using the calibrated caster dependent model factors, the calculated temperature and shell thickness accorded well with the measured. Furthermore, a dynamic secondary water cooling control system was also developed on the basis of a two-dimensional transient heat transfer model （named ＂online model＂） and incremental PID control algorithm to reduce slab surface temperature fluctuation in unsteady state. Compared with the traditional spray table control method, the present online model and dynamic PID control demonstrate a higher capability and flexibility to adjust cooling water flowrate and reduce slab surface temperature fluctuation when the casting speed is changed.

Fuzzy self-tuning PID control of the operation temperatures in a two-staged membrane separation process

A two-staged membrane separation process for hydrogen recovery from refinery gases is introduced. The principle of the gas membrane separation process and the influence of the operation temperatures are analyzed. As the conventional PID controller is difficult to make the operation temperatures steady, a fuzzy self-tuning PID control algorithm is proposed. The application shows that the algorithm is effective, the operation temperatures of both stages can be controlled steadily, and the operation flexibility and adaptability of the hydrogen recovery unit are enhanced with safety. This study lays a foundation to optimize the control of the membrane separation process and thus ensure the membrane performance.