基于单片机的数据采集监控系统设计

重点介绍了基于单片机的数据采集系统的硬件结构，并在此基础上进行了软件设计。此系统采用主从式结构，上位机采用国内亚控公司的组态软件组态王，对系统实现监控；下位机以8051单片机为核心，进行采集转换和数据传送。上位机与下位机采用串口方式进行通信。     

Close-contact melting in a spherical enclosure

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A low scattering slot antenna based on broadband polarization conversion metasurface

An ultrawide band polarization conversion metasurface (PCM) is proposed to reduce the reflection of a slot antenna. The proposed PCM can convert a linearly polarized incident wave to the reflected wave with a 90° rotation. By arranging the PCM around the antenna symmetrically, an ideal phase cancelation is achieved. To verify the design, a metasurface‐slot antenna is simulated and measured to confirm the proposed PCM for a significant reduction of the reflection. Results show that the normal reflection of the proposed antenna at boresight is reduced more than 10 dB over an ultrawide band. In addition, 2 dB enhancement of the gain is achieved compared with a reference antenna which has the same dimensions. Meanwhile, the small influence is observed for the antenna radiation by introducing the PCM.     

一种新型高储能密度定形相变材料

采用山梨醇和对甲基苯甲醛合成了1,3∶2,4-二(4-甲基苯甲醛)山梨醇(MDBS),并将其作为石蜡类定形复合相变材料(PCM)的凝胶因子,然后以利用凝胶因子形成的三维网络结构作为石蜡的支撑材料,制备了一系列高储能密度的定形复合相变材料。对其进行凝胶解缔温度测试和泄漏量测试发现,添加一定量MDBS制备定形复合相变材料,可使定形复合相变材料中主储能材料——石蜡的含量大幅提高到90%以上,同时也为复合定形相变材料的开发提供了一条新的研究思路。     

Optimization of photochemical machining process parameters for manufacturing microfluidic channel

In the present study, the investigation on photochemical machining (PCM) of stainless steel (SS-304) by ferric chloride as etchant is reported. SS-304 is machined by PCM process to obtain accurate dimensions and better geometrical features. Weighted grey relational analysis (WGRA) technique is used in optimization of PCM process parameters. DoE (L₂₇) orthogonal array is applied to evaluate machining parameters, such as concentration of etchant, etching time, and temperature of etchant. The multiobjective optimization technique is used to optimize material removal rate (MRR), surface roughness (R_a), undercut (U_c) and etch factor (EF). Weighted grey relational grade is calculated to minimize U_c and surface roughness and to maximize MRR and EF. The quality characteristics MRR, EF, U_c, and R_a are reporting the improvement after the confirmatory test. The optimum machining parameters are processed to manufacture the microfluidic channel used in biomedical applications. The microfluidic channels and its assembly with Y-type for mixing of fluid with a size of 100 µm, 200 µm, and 300 µm are developed and investigated.     

Discussion on the Integrated Communication System of Local Electric Power Network in China

l.CurrentSituationandRequirementSofLocalElecforPowerCommunicationNetWorkinChinaWiththerapiddevelopmentofeIectricpowerindustry,increaseofthescaleoflocalelectricpowernetwork,andincreasingimprovementofthegradeofoperationandmanagement,therearehigherandhigherrequirementsforthecommunicationofelectricpowersystem.Especially,withrecentwidedeploymentofelectricpowernetworksupervisionandcontrol,unmannedsubstationandintemetworkingofremotecomputers,itisrequiredtotransmitalargeamountofdata,voice,videoand…     

基于TFLite实现个性化灯光控制系统

本文主要实现语音输入"开"、"关"信号来完成开发板上LED灯的开启和关闭,通过分别采集100次"开"、"关"、"环境噪音"等声音信号,并将采集的声音以CSV格式的数据集进行训练,再将训练得到的模型转换为TFLite格式,同时将该模型运行到开发板进行声音的推理,进而控制开发板上LED灯的开启和关闭操作。     

一种高效的混合内存布局机制与编码技术

随着大数据和多核技术的发展,传统内存技术的发展已经远远不能满足大量数据密集型应用涌现所催生的内存计算需求。近年来,新型非易失性存储器(NVM)的兴起与发展为打破传统内存技术瓶颈提供了契机。相变存储器(PCM)作为一种典型的新型非易失性存储器(NVM),与传统内存DRAM各有优势,被认为是最有可能代替传统内存DRAM的存储器,在内存应用中具有很好的发展前景。基于DRAM和PCM的混合内存使得同时发挥DRAM与PCM各自的优势成为可能,故提出一种DRAM与PCM混合内存架构,设计针对混合内存布局的高效读写策略及数据迁移机制,并且在混合内存系统中应用纠删码来提高系统的可靠性。实验表明,此混合内存系统能够大大减少能耗,提高数据吞吐量,同时保证读写的可靠性。     

波纹管对纳米复合相变材料蓄放热性能影响的试验研究

以纳米复合材料作为相变蓄热材料,加工制作了相变蓄热装置,并搭建了蓄热器热性能实验台,对传热元件分别为光管和波纹管的蓄热容器进行了相变蓄热实验,测量了相变材料的温度并通过数据采集仪进行数据采集,整理绘制了在不同条件下的温度时间曲线并进行了分析讨论。结果表明波纹管能够加快热媒体在波纹管中的流动,缩短蓄热所需时间,并且提高放热速率。     

基于LABVIEW的PCM编译码系统仿

脉冲编码调制（pulse code modulation,PCM）是最基本和最常用的模拟信号数字化方法．由于抗干扰能力强,被广泛应用于数字通信领域．本文在介绍了PCM编码原理基础上,以LabVIEW软件为平台对PCM编译码的方法和过程仿真．仿真软件可实现多种信号类型的PCM编译码实现,为人们理解PCM编译码提供了简单、...