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关键词： 信息与通信系统   无线传感器网络   能量空洞   动态分簇路由   多组分混合物扩散  

摘要： 为抑制无线传感器网络（WSN）能量空洞的形成和发展，均衡能量消耗和空洞分布，系统分析了空洞边缘存活区内节点密度、节点剩余能量和数据传输量，以及多能量空洞距离等参数对能量空洞产生和发展的影响；为客观描述能量空洞特性，提出了能量空洞、融合能量空洞、空洞边缘域、空洞距离等一系列定义，借鉴多组分液体混合物扩散理论，通过计算能量空洞的扩散角度和扩散速度，构建了能量空洞演化模型。在此基础上，从基于能量空洞扩散系数的WSN分簇方法、抑制能量空洞的WSN数据传输优化方法和能量空洞边缘域内节点休眠调度策略三方面进行了研究。仿真结果表明，与LEACH、UCDTS和EHSRA等算法相比，所提算法在网络寿命、数据传输量、能耗均衡和空洞分布等方面均有显著提升。

摘要： 随着电动车的普及与发展,充电桩的需求也逐渐增加. 为了实现充电桩的高效安全运行,充电桩智能检测系统应运而生. 充电桩智能检测系统通过对充电桩的各项参数进行实时监测,可以提供远程监控、故障预警、数据分析等功能.

标准号: GB/T 44051-2024

摘要： 本文件规定了基于ISO5817确立的焊缝质量等级，对壁厚在3.2mm~8.0mm之间的低合金钢和／或铁素体钢全熔透焊接接头进行相控阵超声检测(PAUT）的验收等级。本文件适用于根据ISO20601给出的指示分类的验收等级。

关键词： Multiobjective optimization  

摘要： The engineering parameters of enhanced geothermal system (EGS) will directly affect the heat recovery performance and economic benefits. Optimizing the parameters to achieve the best scheme is crucial for promoting the field application of EGS projects. In this paper, a multi-objective simulation-optimization (MOSO) framework for EGS is proposed. Effective electrical power, flow impedance, and levelized cost of electricity (LCOE) are considered as optimization objectives. A numerical model of heterogeneous hot dry rock (HDR) is developed based on spatial frequency to determine the response values of the three objective functions. The Plackett-Burman (PB) method is used to compare the influence of different parameters on the objective function. Five significant engineering parameters are selected as decision variables to establish the objective function. The proxy model of the objective function is obtained through central composite design (CCD) fitting. Finally, the Pareto optimal solution set is obtained by comparing six multi-objective optimization algorithms, and the optimal solution of the nondominated sorting genetic algorithm II with adaptive rotation based simulated binary crossover (NSGA-II-ARSBX) algorithm is selected as the global optimal engineering design through comprehensive evaluation combined with the entropy weight method. The results show that the comprehensive score of the optimal solution is 0.88208. Compared with the original scheme, the effective power generation has increased by 3.7239 MW, and the LCOE has decreased by 0.007257 $/kWh. The research results are helpful in guiding the optimization of the heat recovery process. © 2024, The Authors. All rights reserved.

关键词： 无线传感器网络   节点部署   地形粗糙度   网络生命周期  

摘要： 针对起伏地形下无线传感器网络节点部署数目多的问题，首先，采用数字高程模型与Delaunay三角剖分对起伏地形表面建模，确定节点部署问题解空间；然后，建立节点部署算法搜索维度与网络覆盖率之间的函数关系，并基于改进的海洋捕食者算法形成候选个体集；而后，以收益函数遗憾最小化为准则，使用候选个体衍生新个体；最后，通过以网络覆盖率、网络密度为指标构建的筛选函数，选出最佳个体并将其纳入部署节点集合.仿真结果表明：与同类算法相比，在不同目标覆盖率和地形粗糙度下，所提算法在保证网络连通性的基础上，能有效地降低节点部署数目；且在全覆盖情况下，所提算法部署的网络具有较长的生命周期.

关键词： 偏振不敏感   布拉格光栅   切趾   光波导  

摘要： 【目的】针对集成光子滤波器在密波分复用系统的应用，【方法】文章提出了一种基于绝缘衬底硅(SOI)上的偏振不敏感窄带切趾布拉格光栅滤波器。采用外脊布拉格光栅结构实现横电场基模(TE0)和横磁场基模(TM0)的相互耦合与转换，使光栅滤波器在分别输入TE0和TM0模式时，输出的滤波谱线能达到一致。同时，引入高斯分布的互补光栅错位调制结构来抑制滤波谱线中的旁瓣。此外，设计了两种不同宽度的光栅波纹，并实现了窄带滤波。【结果】仿真结果表明，滤波器实现了偏振不敏感，旁瓣抑制比大于22.12 dB，3 dB带宽为1.16 nm，具有良好的偏振一致性。【结论】文章所提工作为硅基光子回路与系统提供了一种偏振不敏感窄带滤波方案。

关键词： long-term carbon cycle   bathymetry   planetary feedbacks  

摘要： The shape of the ocean floor (bathymetry) and the overlaying sediments provide the largest carbon sink throughout Earth's history, supporting similar to one to two orders of magnitude more carbon storage than the oceans and atmosphere combined. While accumulation and erosion of these sediments are bathymetry dependent (e.g., due to pressure, temperature, salinity, ion concentration, and available productivity), no systemic study has quantified how global and basin scale bathymetry, controlled by the evolution of tectonics and mantle convection, affects the long-term carbon cycle. We reconstruct bathymetry spanning the last 80 Myr to describe steady-state changes in ocean chemistry within the Earth system model LOSCAR. We find that both bathymetry reconstructions and representative synthetic tests show that ocean alkalinity, calcite saturation state, and the carbonate compensation depth (CCD) are strongly dependent on changes in shallow bathymetry (ocean floor <= 600 m) and on the distribution of the deep marine regions (>1,000 m). Limiting Cenozoic evolution to bathymetry alone leads to predicted CCD variations spanning 500 m, 33 to 50% of the total observed variations in the paleoproxy records. Our results suggest that neglecting bathymetric changes leads to significant misattribution to uncertain carbon cycle parameters (e.g., atmospheric CO2 and water column temperature) and processes (e.g., biological pump efficiency and silicate-carbonate riverine flux). To illustrate this point, we use our updated bathymetry for an Early Paleogene C cycle case study. We obtain carbonate riverine flux estimates that suggest a reversal of the weathering trend with respect to present-day, contrasting with previous studies, but consistent with proxy records and tectonic reconstructions.

关键词： Statistical methods  

摘要： Coal is the primary energy resource in South Africa and is produced for various markets, such as thermal, metallurgical, export, and local. The coal market is increasingly demanding high quality. For this reason, low-quality coal must be upgraded to high-quality products using flotation processes. The crushed raw coal used in this study was obtained from one of the South African coal mines. In the current study, optimization, and modeling of the flotation process of coal fines have been carried out using CCD statistical methods. Through XRD analysis, coal's fine composition is mainly characterized by a high amount of silicate minerals. Results indicate the goodness of fit between the coal ash content fits and the experimental flotation data with R2 and adjusted R2 correlation coefficients respectively equivalent to 0.9944 and 0.9938. All the parameters (collector concentration, frother dosage, solids%, and impeller speed were found statistically significant. Based on the CCD statistical method, the current study's optimal conditions are 8.9min, 1988.59 g/t, 150 g/t, and 1789 rpm with a satisfactory calculated desirability above 0.9. At optimal conditions, coal yield and ash content have been reported as 49% and 16%. CCD can be thus considered a useful statistical tool for the modelling and optimization of the coal flotation process. © 2024, The Authors. All rights reserved.

关键词： 光纤光学   光纤传感   法布里-珀罗干涉   并联游标增敏   应变  

摘要： 提出并制备了一种游标增敏型光纤法珀应变传感器，实现高灵敏度应变测量。该传感器由两个单模光纤（SMF）-空芯光纤（HCF）-单模光纤（SMF）结构的法布里-珀罗干涉仪（FPI）并联组成，分别作为传感腔和参考腔。保持传感腔不变，选择不同的参考腔，利用游标效应解调，追踪并联后反射谱包络的漂移，可实现不同的放大倍数。实验结果表明：在0～900με的应变范围内，单个传感腔的应变灵敏度为1.31 pm/με，并联之后传感器的应变灵敏度分别达到-11.5 pm/με和-12.76 pm/με，放大了8.7倍和9.74倍，传感器的应变灵敏度显著提升，同时，传感器具备制作简单、高灵敏度、易操作和低成本等特点，具有广阔的应用前景。