基于多尺度自适应特征聚合网络的 ECT 图像重建

针对深层卷积神经网络在电容层析成像图像重建过程中存在电容特征提取尺度单一、中间层特征利用率不高等问题, 提出了一种多尺度自适应特征聚合网络模型。 首先,利用堆叠的增强型选择核卷积模块设计了一种特征增强模块(FEM),并 通过串联多个 FEM 自适应地提取电容向量多个尺度的特征信息,极大地减少了使用普通卷积所带来的伪影现象;其次,引入了 一种特征聚合机制,采用长短残差连接加强了远近特征信息的相关性,解决了网络中间层特征利用不充分的问题。 实验结果表 明,与传统算法及卷积神经网络算法相比,所提方法在主观视觉效果和客观评价指标上都具有更好的性能,图像相关系数最高 达到 0. 962 9,图像相对误差降低至 0. 053 0。     

SPR谱仪的研制及在磁光复合薄膜测试中的应用

针对SPR增强磁光效应研究中复合金属薄膜结构的SPR激发测试,研制了一套角度扫描型SPR谱仪。通过巧妙的结构设计和运动控制,使得角度扫描过程中样品测试点始终处于棱镜底面样品基片的中心,保证了测试过程的一致性。对50nm金膜的重复性测验表明SPR谱仪具有较高的重复性和稳定度。利用搭建的SPR谱仪对磁光复合薄膜的测试结果表明,在制备的样品中,Au(15nm)/Co(5/10nm)/Au(5nm)复合结构是磁光等离子体系研究的最佳平台。     

基于变动频率滤波的新型数字锁相环

提出了一种应用于单相并网系统中的基于变动频率滤波原理的优化型数字锁相环,并加入了频率控制以及初始相位角定位等模块.在保留了现有优化型锁相环结构简单,灵敏度高,动态响应快等优点的前提下、解决了其存在的抗谐波干扰能力差,频率超调大等问题.利用Matlab软件对电网电压幅值、频率和相位角的突变、谐波注入等参数变化的影响做了仿真研究.在此基础上,搭建了以TMS320F2812 DSP为控制核心的实验装置,仿真验证和试验结果证明了该方法的可行性.     

水平井裸眼砾石充填防砂完井工艺在胜利海上油田的应用

胜利海上水平井防砂主要以水平井裸眼挂滤防砂为主,但大泵提液后出砂严重。研究分析认为,水平井滤砂管挡砂能力弱和防砂后未进行酸洗清除滤饼,是导致井筒局部高强度产液造成大量出砂的原因。通过优化设计和配套技术攻关,在CB22G-P2井成功进行了水平井裸眼砾石充填防砂完井试验,并形成了以水平井裸眼砾石充填防砂、酸洗工艺和变频控制大泵生产为代表的水平井大泵提液综合配套技术。目前该井采用φ6mm油嘴生产,日产液104t,日产油91.5t,含水12%,提液增油效果显著。     

滚动转子式补气压缩机在热泵系统中的实验研究

介绍了滚动转子式补气压缩机的设计,并将其在热泵系统中进行了实验研究。分析了不同制热工况下滚动转子式补气压缩机的性能,对比了带闪发器与过冷器的经济器热泵系统、滚动转子式与涡旋式补气压缩机的性能。结果表明:随着室外环境温度的下降,滚动转子式补气压缩机补气后制热量提升比例逐步增大;滚动转子式补气压缩机制热实验中,带闪发器系统的制热量较高;在超低温制热工况下滚动转子式补气压缩机制热量提升18%左右,与涡旋式补气压缩机相比制热量相当,性能略高。     

Hydrogenated amorphous carbon films used for carbon-sealed double-coated optical fibers

The carbon-sealed double-coated optical fiber is constructed from double-coated optical fiber sealed with a hydrogenated amorphous carbon film fabricated by plasma enhanced chemical vapor deposition. The pure methane (CH₄) and hydrogen (H₂) were selected as the precursor gases, and eight kinds of carbon film thicknesses by different deposited times were prepared with fixed CH₄/H₂ ratio. The radio-frequency power, substrate temperature, and working pressure were 200 W, 298 K, and 17 Pa, respectively. Characteristics of the carbon-sealed double-coated optical fibers prepared with different carbon film thicknesses were investigated. Experimental results indicated that when the carbon-film thickness was 113 nm, the carbon-sealed double-coated optical fibers had the highest mechanical strength, high resistance to moisture penetration, and good ability to withstand thermal loading. Additionally, external mechanical damage protection, abrasion resistance, bending flexibility, adhesion, stripping force, and bending insensitivity meet the fiber coating requirements. The carbon-sealed double-coated optical fiber is an optical fiber for optical transmission, and their properties are better than or equal to those of conventional double-coated optical fiber. Moreover, the carbon-sealed double-coated optical fiber is superior to nickel-sealed double-coated optical fiber in terms of water repellency and bending flexibility.     

Topotaxial fabrication of vertical Aux Ag1-x nanowire arrays: plasmon-active in the blue region and corrosion resistant

Topotaxial growth of Au(x) Ag(1-x) alloy nanowires (NWs) by postepitaxial deposition of Ag vapor on Au NWs and investigation of their plasmonic properties are reported. Ag vapor is supplied onto the epitaxially grown Au NWs, topotaxially turning them into Au(x) Ag(1-x) alloy NWs. The original geometries and alignments of the Au nanostructures are well preserved, while the composition of the alloy NWs is controlled by varying the Ag vapor supply time. The Au(0.5) Ag(0.5) NWs show high surface-enhanced Raman scattering (SERS) activity comparable to that of Ag NWs as well as highly increased oxidation resistance. The plasmon-active wavelength range of the Au(0.5) Ag(0.5) NW is significantly extended to the blue region compared to Au NWs. The Au(x) Ag(1-x) alloy NWs that have plasmonic activity in the blue region in addition to high corrosion resistance will make a superb material for practical plasmonic devices including SERS sensors and optical nanoantennas.     

Plasmonic nanogap-enhanced Raman scattering using a resonant nanodome array

The optical properties and surface-enhanced Raman scattering (SERS) of plasmonic nanodome array (PNA) substrates in air and aqueous solution are investigated. PNA substrates are inexpensively and uniformly fabricated with a hot spot density of 6.25 × 10(6) mm(-2) using a large-area nanoreplica moulding technique on a flexible plastic substrate. Both experimental measurement and numerical simulation results show that PNAs exhibit a radiative localized surface plasmon resonance (LSPR) due to dipolar coupling between neighboring nanodomes and a non-radiative surface plasmon resonance (SPR) resulting from the periodic array structure. The high spatial localization of electromagnetic field within the ～10 nm nanogap together with the spectral alignment between the LSPR and excited and scattered light results in a reliable and reproducible spatially averaged SERS enhancement factor (EF) of 8.51 × 10(7) for Au-coated PNAs. The SERS enhancement is sufficient for a wide variety of biological and chemical sensing applications, including detection of common metabolites at physiologically relevant concentrations.     

Hydrogen amplification from coke oven gas using a CO2 adsorption enhanced hydrogen amplification reactor

To improve coke oven gas (COG) energy conversion, alternative configurations for amplifying hydrogen from COG are proposed in this paper. In these new configurations, a CO₂ adsorption enhanced hydrogen amplification reactor is combined with a pressure swing adsorption separation unit (PSA) to produce pure hydrogen. Hydrogen production was integrated with desorption gas utilization, in situ CO₂ capture and waste heat recovery to improve COG energy conversion efficiency and decrease CO₂ emissions. To analyze the advantages of the flowsheet modifications, technical and economic performance indicators were used to evaluate and compare the performances of the various system configurations. Simulation results show that the alternative configurations proposed in this paper have higher energy conversion efficiencies, higher hydrogen yields and shorter dynamic payback periods. The variation of technical performance with reaction temperature, pressure, sorbent to carbon ratio and steam to carbon ratio were also analyzed using a sensitivity study. Optimal operating conditions for the CO₂ adsorption enhanced hydrogen amplification reactor were obtained based on the simulation results.