- 标题
- 摘要
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- 实验方案
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Enhancement of weld strength of laser-welded joints of AA6061-T6 and TZM alloys via novel dual-laser warm laser shock peening
摘要： In this paper, an experimental study is presented on an investigation to improve the weld strength of laser-welded joints via post-processing by warm laser shock peening (wLSP). A dual-laser setup was utilized to simultaneously heat the sample to a prescribed temperature and to perform the wLSP process on the laser-welded joints of AA6061-T6 and TZM alloys. Joints in overlap and bead-on-plate configurations were created by laser welding by a high-power fiber laser and post-processed with wLSP. The tensile tests carried out on wLSP-processed AA6061-T6 samples demonstrate an enhancement in the strength by about 20% over as-welded samples and the ductility of samples processed by wLSP improved by 30% over as-welded samples. The bead-on-plate (BOP) welds of TZM alloy processed with wLSP demonstrated an enhancement in strength by about 30% and the lap welds processed with wLSP demonstrated an increase in the joint strength by 22%. Finite element analysis revealed that the depth and magnitude of compressive stresses imparted by wLSP were greater than room temperature laser shock peening (rtLSP), which contributed to the enhancement of the joint strength for processed samples.
关键词： Al6061,Warm laser shock peening,Strength improvement,Laser welding,TZM
更新于2025-11-28 14:24:20
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Measurement and Investigation of the Incident Radiation in Case of Using Transparent Pyramidal Covers for Improving the Solar Panel’s Power Output
摘要： A new approach is presented to enhance the solar radiation intensity incident over the solar panel by using a transparent cover of pyramidal shapes. The pyramidal cover shape is manufactured of Polymethylmethacrylate dielectric material. The normal height of each pyramid is considered as a ratio of the base length. This ratio is considered in the present study to be 0.5, 1, and 1.5. The effect of the pyramidal covers on the solar panel voltage has been studied at different conditions. The experimental results confirm that the pyramidal cover shape causes the improvement to the solar panel output voltage by 4.2% when covering all the panel with pyramids of R=1 with a light incidence angle of 90 when the light rays come parallel to the panel surface. This improvement is found to decreases with covering fewer areas of the solar panel and with fewer incidence angles. It is found also that the distance between the light source and the panel is proportional to the output voltage improvement ratio compared to the panels output voltage without pyramidal cover. A mathematical model has been presented to prove the concept of increasing the electric and magnetic field of the incident radiation from the sun in case of presence of the transverse transparent barrier. Moreover, a mathematical ray tracking model was presented and validated with the experimental results by a maximum relative error of 14.8%
关键词： solar panel improvement,Incident radiation,enhancement of light field radiation,polarization,enhancement of solar radiation,transverse of transparent barrier
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Machine Learning and Cybernetics (ICMLC) - Chengdu (2018.7.15-2018.7.18)] 2018 International Conference on Machine Learning and Cybernetics (ICMLC) - Solar Image Matching Based on Improved Freak Algorithm
摘要： FREAK algorithm has the defects of not having scale invariance and single feature point matching strategy, being prone to unsatisfactory results. Based on AKAZE and RANSAC algorithm, an improved FREAK algorithm is proposed, named AKAZE-FREAK. The image pyramid was constructed by using the nonlinear diffusion filter and the numerical solution was obtained by fast display diffusion (FED) to obtain the image point coordinates with sub-pixel precision. Then the feature points were described by the FREAK descriptors to distribute directions for the feature points. Finally, based on the initial matching of the hamming distance to the eigen vector, RANSAC is used to eliminate the error matching point. In this paper, this algorithm is applied to the recognition of repeated shooting solar images. After the improved algorithm is compared with the SIFT-FREAK, SURF-FREAK and FREAK algorithms, it shows an improvement in the image feature point matching accuracy with good robustness on the scale difference, illumination difference and rotation difference of the image. It also improves the accuracy of the judgement of the late repeat.
关键词： Feature point matching,Improvement,AKAZE,FREAK
更新于2025-09-23 15:23:52
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Self Optimization Beam-Forming Null Control Based SINR Improvement
摘要： In this paper, a self optimization beamforming null control (SOBNC) scheme is proposed. There is a need of maintaining signal to interference plus noise ratio (SINR) threshold to control modulation and coding schemes (MCS) in recent technologies like Wi-Fi, Long Term Evolution (LTE) and Long Term Evolution Advanced (LTE-A). Selection of MCS depends on the SINR threshold that allows maintaining key performance index (KPI) like block error rate (BLER), bit error rate (BER) and throughput at certain level. The SOBNC is used to control the antenna pattern for SINR estimation and improve the SINR performance of the wireless communication systems. The nulling comes with a price; if wider nulls are introduced, i.e. more number of nulls are used, the 3 dB beam-width and peak side lobe level (SLL) in antenna pattern changes critically. This paper proposes a method which automatically controls the number of nulls in the antenna pattern as per the changing environment based on adaptive-network based fuzzy interference system (ANFIS) to maintain output SINR level higher or equal to the required threshold. Finally, simulation results show a performance superiority of the proposed SOBNC compared with minimum mean square error (MMSE) based adaptive nulling control algorithm and conventional fixed null scheme.
关键词： self optimization beamforming null control,adaptive neural fuzzy inference system (ANFIS),SINR improvement,digital beam-forming (DBF)
更新于2025-09-23 15:22:29
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Improvement of Thin Film Adhesion Due to Bombardment by Fast Argon Atoms
摘要： A new hollow cathode sputtering system is used for beam-assisted deposition of thin films on dielectric substrates. A copper target placed at the hollow cathode bottom is uniformly sputtered by argon ions from the glow discharge plasma filling the cathode. Through an emissive grid, sputtered copper atoms leave the cathode together with accelerated argon ions. On their way to the substrate, the ions—due to charge exchange collisions—turn into fast argon atoms bombarding the growing film. With increasing argon ion energy, continuous bombardment results in the film adhesion improvement and reduction of the deposition rate down to zero, at an energy of about 2 keV. The pulsed bombardment does not influence the film deposition rate, and results in a monotonic growth of the film adhesion up to 20 MPa when increasing the fast atom energy up to 10 keV.
关键词： neutral beam assisted deposition,adhesion improvement,thin films,dielectric substrates
更新于2025-09-23 15:22:29
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Enhancing the performance of photo-bioelectrochemical fuel cell using graphene oxide/cobalt/polypyrrole composite modified photo-biocathode in the presence of antibiotic
摘要： Photo-bioelectrochemical fuel cell (PBFC) holds a great potential to harvest sustainable electrical energy from wastewater, but low power output limits its applications due to poor electrochemical performance of photo-biocathode. Additionally, antibiotics are ubiquitous in wastewater streams, but little is known regarding their effects on photo-biocathode performance of the PBFC. This study attempted to increase power output of PBFC through improvement of the photo-biocathode performance by modifying the biocathode with graphene oxide/cobalt/polypyrrole (GO/Co/PPy) composite in the presence of oxytetracycline. The GO/Co/PPy composite modified electrode fabricated by one-step electropolymerization method exhibited more excellent catalytic activity toward oxygen reduction compared to Co-alone and Co/PPy modified electrode. The PBFC with GO/Co/PPy composite modified biocathode produced a maximum power density of 19 mW/m2, which was almost 4-fold higher than that produced with the bare biocathode (4.9 mW/m2) due to improved bio-electrocatalytic performance of the bicathode by the GO/Co/PPy composite. The maximum power density of the PBFC was further increased 4.6 (105.5 mW/m2), 3.7 (88.7 mW/m2), 2.9 (74.6 mW/m2) and 1.9 (56 mW/m2) fold by exposure to 5, 10, 20, and 50 mg/L OTC, respectively. The further increases in power was due to reduced cathode's charge transfer resistance using degradation products of OTC as mediators and OTC-stimulated growth of species with extracellular electron transfer ability. However, the photosynthesis and growth of alga was negatively affected by OTC concentration higher than 10 mg/L, resulting performance deterioration of bicathode.
关键词： Photo-bioelectrochemical fuel cell,Electrode modification,Oxytetracycline,Performance improvement,Power generation
更新于2025-09-23 15:22:29
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[IEEE 2018 7th International Conference on Computer and Communication Engineering (ICCCE) - Kuala Lumpur, Malaysia (2018.9.19-2018.9.20)] 2018 7th International Conference on Computer and Communication Engineering (ICCCE) - CPW-Fed Patch Antenna with Reflecting Metasurface Covering for WLAN and WiMAX Applications
摘要： A coplanar waveguide (CPW)-fed multiband patch antenna with the integration reflecting metasurface covering has been designed and performance characteristics are critically analyzed. The proposed low profile antenna can offers the wireless communications services for WLAN and WiMAX applications. The rectangular shaped patch antenna consists of pair of C-, L- and splitted-T shape slotted radiator, and 2D reflective metasurface covering at the back of patch which is separated by dielectric layer of substrate. The details of the antenna design structure and performance criteria are discussed through numerical simulation using full-wave electromagnetic simulator. The simulation results shows that by employing the reflecting metasurface covering, the -10dB impedance bandwidth has considerably increased than the typical CPW-fed patch antenna: from 440 MHz to 570 MHz (29%), 390 MHz to 480 MHz (23%) and 900 MHz to 1060 MHz (18%) for three different operating bands centered at 2.5, 3.5 and 5.5 GHz respectively. The simulated result shows the antenna with RMC integration achieves peak gain of 6.56 dBi, 6.43 dBi and 6.97 dBi with average gain of 6.45 dBi, 6.27 dBi and 6.82 dBi at three operating bands respectively which are higher than the typical patch antenna.
关键词： patch antenna,low-profile,reflecting metasurface covering,CPW-fed,WiMAX/WLAN Applications,radiation pattern improvement
更新于2025-09-23 15:21:21
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[IEEE 2019 IEEE PES Innovative Smart Grid Technologies Conference - Latin America (ISGT Latin America) - Gramado, Brazil (2019.9.15-2019.9.18)] 2019 IEEE PES Innovative Smart Grid Technologies Conference - Latin America (ISGT Latin America) - Financial Impact of the Binomial Tariff in the Investment in Residential Photovoltaic Systems
摘要： The design of a sensitivity improved dual diaphragm based vibrating wire transducer for sensing pneumatic pressure is proposed. The improvement achieved in sensitivity of a dual diaphragm structure over the single diaphragm category is veri?ed through experiments. An experimental setup for ef?ciently assessing the dynamic performances of the pressure transducers is presented. Eventually, the improved sensitivity concedes improvement in precision and resolution of the instrument. While the vibrating wire transducer based pressure sensors always show better dynamic performances over others, the present dual diaphragm structure offers improved sensitivity, which adds to their dynamic performances and overall performance characteristics.
关键词： sensitivity improvement,time constant measurement,Diaphragm structure,dynamic pressure sensor
更新于2025-09-23 15:21:01
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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - Regional band-gap tailoring of 1550nm-band InAs quantum dot Intermixing by controlling ion implantation depth
摘要： This paper studies the electric vehicle (EV) charging scheduling problem to match the stochastic wind power. Besides considering the optimality of the expected charging cost, the proposed model innovatively incorporates the matching degree between wind power and EV charging load into the objective function. Fully taking into account the uncertainty and dynamics in wind energy supply and EV charging demand, this stochastic and multistage matching is formulated as a Markov decision process. In order to enhance the computational efficiency, the effort is made in two aspects. Firstly, the problem size is reduced by aggregating EVs according to their remaining parking time. The charging scheduling is carried out on the level of aggregators and the optimality of the original problem is proved to be preserved. Secondly, the simulation-based policy improvement method is developed to obtain an improved charging policy from the base policy. The validation of the proposed model, scalability, and computational efficiency of the proposed methods are systematically investigated via numerical experiments.
关键词： smart grid,simulation-based policy improvement (SBPI),renewable energy,Electric vehicle (EV)
更新于2025-09-23 15:21:01
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Study on the improvement of p-type multi-crystalline silicon material for solar cells by the hydrogenation with electron injection
摘要： In this paper, we have found that the ef?ciency of p-type mono-crystalline silicon (mono-Si) passivated emitter and rear contact (PERC) solar cells can be increased by 0.12%abs. with the process of hydrogenation with electron injection (HEI). However, the same scheme was not suitable for p-type multi-crystalline silicon (mc-Si) solar cells. To promote power conversion ef?ciency (PCE) for the mc-Si solar cells, we have explored a developed HEI process for the mc-Si solar cells to improve the device performance. Meanwhile, we also analysed the mechanization inside the solar cells after applying the HEI process. Through the design of experiment (DOE), the correlation among injection current, temperature, injection time and ef?ciency improvement was analysed in detail. It was proved that mc-Si solar cells require higher current injection and temperature to passivate the complex impurities in the bulk, when compared to mono-Si solar cells. With the optimal scheme explored by this paper, the open circuit voltage (Uoc), short circuit current density (Jsc) and ?ll factor (FF) of p-type mc-Si solar cells, respectively, increased by 1.2 mV, 0.11 mA cm?2 and 0.05%abs., respectively. The ef?ciency was improved about 0.11 ± 0.005%abs.. These results will provide a certain method and basis for further improving the ef?ciency of mc-Si PERC cells and overcoming the light-elevated temperature-induced degradation by HEI process.
关键词： Hydrogenation,ef?ciency improvement,p-type mc-Si material,solar cells
更新于2025-09-23 15:21:01