To reduce the floor space of receiving antenna arrays, the Radio Ocean Remote SEnsing (RORSE) laboratory of Wuhan University developed a circular receiving array for a multi-frequency high frequency ...(MHF) radar system in 2014, consisting of seven uniformly spaced antenna elements positioned on a circle with a diameter of 5 m. The new system, which is abbreviated MHF-C radar, adopts frequency modulated interrupted continuous wave (FMICW) chirps and is capable of simultaneously operating at a maximum of four frequencies in the band of 7.5–25 MHz, and providing current, wave and wind maps every ten minutes. The phase direction-finding method is utilized to estimate the directions of the current signals, and array phase uncertainties are also taken into consideration in the signal model. This paper introduces the system in detail and investigates the performance of current measurements using MHF-C radars installed at Shengshan and Zhujiajian along the coast of the East China Sea. Radial current measurements derived from 8.27 MHz and 19.20 MHz at the same range are compared. Observations and comparisons between MHF-C radars and acoustic Doppler current profilers (ADCPs) are also presented in this paper. The results preliminarily demonstrate that the MHF-C radar system is capable of maintaining the same performance for current measurements whenever it steers to any other azimuth in the coverage and has a good ability to measure currents.
•The research contributes to digital, AI and smart manufacturing.•An automatic tool wear inspection method via a probability view was proposed.•The curved original tool boundary was reconstructed ...based on bayesian inference.•Probability functions were established according to the change law of edge grayscale.•The association principle between the change law and edge boundaries was discovered.
Accurate, rapid and automated tool wear inspection is critical to manufacturing quality, cost and efficiency in smart manufacturing systems. However, manual inspection of tool wear is still a common industrial practice which is inefficient, prone to human errors and not suitable for digitized manufacturing. Previously reported automatic tool wear inspection methods were inaccurate because they only used the remaining worn boundary (i.e., the partial-absence original tool boundary) to approximate tool wear. The authors discovered the association principle between the change law of the cutting edge grayscale and the relative position of the original and worn boundary, which was used to establish the probability functions to accurately reconstruct the curved original tool boundary via Bayesian Inference. The experiment results reported in this paper proved higher efficiency and accuracy than previous automatic tool wear inspection methods.
Cutting tool state recognition plays an important role in ensuring the quality and efficiency of NC machining of complex structural parts, and it is quite especial and challengeable for complex ...structural parts with single-piece or small-batch production. In order to address this issue, this paper presents a real-time recognition approach of cutting tool state based on machining features. The sensitive parameters of monitored cutting force signals for different machining features are automatically extracted, and are associated with machining features in real time. A K-Means clustering algorithm is used to automatically classify the cutting tool states based on machining features, where the sensitive parameters of the monitoring signals together with the geometric and process information of machining features are used to construct the input vector of the K-Means clustering model. The experiment results show that the accuracy of the approach is above 95% and the approach can solve the real-time recognition of cutting tool states for complex structural parts with single-piece and small-batch production.
Laser-driven white lighting is regarded as a next-generation high-power lighting because of the advantages of directional light emission, high brightness, and quasi-point source. In this work, we ...proposed a phosphor-aluminum composite (PAC) converter for laser-driven white lighting. The PAC was fabricated by sintering a phosphor glass film on an aluminum plate by using a lead-free tellurite glass. By adjusting the tellurite component, the tellurite glass achieves similar expansion coefficient with the aluminum, which can eliminate the crack and delamination of PAC. The yellow (Y) and yellow/red (Y/R) PACs were prepared by adding commercial Y3Al5O12:Ce3+ (YAG:Ce3+) and CaAlSiN3:Eu2+ (CASN:Eu2+) into the tellurite glass. These PACs were used as the reflective configuration of white laser diodes (LDs). As the layer number of phosphor glass film increases, the PAC-based white LDs with different optical performances were realized. Furthermore, the phosphor glass films of PACs display extremely low working temperature (<35 °C) under various laser powers due to the high thermal conductivity of aluminum plate. These results indicate that the prepared PAC is an efficient and stable color converter for high-brightness laser-driven white lighting.
•The tellurite glass achieves similar expansion coefficient with the aluminum.•The PACs display extremely low working temperature (<35 °C) under various laser powers.•The yellow and yellow/red PACs were prepared by screen-printing and sintering process.
•The synchronous association of geometry, process and monitoring information is established.•Time sequence and coordinate matching are combined for real-time synchronous association.•Variable ...geometry and process information is obtained with cloud points processing approach.•The real-time synchronous acquisition of various signals with different frequency is realized.•The synchronous association approach gets really valued data for intelligent manufacturing.
Data driven approach has been an effective means to realize intelligent manufacturing, and it is very important to get really valued data. It is difficult to realize real-time closed-loop control of complex machining conditions by only using monitoring signals without considering the geometry and process information of the workpiece which is being machined. Therefore, the synchronous association of geometry, process and monitoring information is the key to realize data-driven intelligent manufacturing. However, geometry, process and monitoring information is multi-source, multi-modal and heterogeneous data, and both static and dynamic information is involved, so the effectively synchronous association of the information is still a challenge. In order to address the issue mentioned above, the real-time synchronous association relationship among the three kinds of information is established by using the theoretical discrete cutter position points and the actual sampling cutter position point as linkages. In addition to that, time sequence matching and coordinate matching are combined for avoiding miss match of coordinate. Experimental results show that the proposed method can realize synchronous association of geometry, process and monitoring information in real time, and the average lag time for synchronous association at each cutter position point is far less than 0.1 ms, which is shorter than the minimum time period for signal acquisition.
In this letter, high-quality white light-emitting diodes (WLEDs) were fabricated by combining a YAG:Ce 3+ phosphor-in-glass (PiG) with a red liquid-type quantum dot (LQD). The PiG_LQD-based WLEDs ...achieve a warm white light with an excellent color rendering index (CRI; Ra = 93.9, R9 = 97.7, and R13 = 98.1) at the current of 100 mA. The corresponding correlated color temperature and luminous efficacy (LE) are 3764 K and 62 lm/W, respectively. In comparison with the PiG integrated with solid-type QD, the PiG_LQD exhibits high LE, excellent CRI, and low surface temperature due to the prevention of self-aggregation and surface defects of QDs in the solid state and the efficient heat dissipation of PiG_LQD. The results indicate that the fabricated WLEDs are promising lighting devices for high-quality lighting applications.
Manufacturing of aircraft structural parts has the characteristics of multiple varieties, complex structures and small batches, which make the manufacturing resource allocation highly difficult. This ...paper proposes a manufacturing resource allocation method with knowledge-based fuzzy comprehensive evaluation, considering multiple manufacturing resources including process planners, machine tools and cutting tools, as well as manufacturing process schemes of aircraft structural parts. Knowledge in terms of experts' experience and historical data is used for fuzzy comprehensive evaluation. A manufacturing resource allocation model is proposed based on the analysis of manufacturing processes of aircraft structural parts. The capability of planners, the complexity of structural parts, the reliability of machine tools, the reliability of cutting tools and the correlations between manufacturing resources and structural parts are evaluated using the fuzzy comprehensive evaluation method. Multiple manufacturing resources are allocated based on the fuzzy comprehensive evaluation results. A prototype system has been implemented and a case study is used to validate the proposed approach.
Currently, white light-emitting diodes (WLEDs) have been widely applied in lighting, display, and medical fields. However, there still exists the problem of low color rendering index (CRI, Ra). In ...this work, phosphor-converted WLEDs (pc-WLEDs) with ultrahigh Ra were fabricated using Y 3 Al 3 Ga 2 O 12 :Ce 3+ green phosphor and CaAlSiN 3 :Eu 2+ red phosphor configuration structure. The broad emission spectrum of the green phosphor compensates for the gap of the cyan-emitting region that realizes full-spectrum white-light emission. The weight ratio of green/red phosphors was controlled to optimize the optical performances of pc-WLEDs. At the ratio of 0.15/0.012, the fabricated pc-WLED exhibits a natural white light with an ultrahigh R a of 95.2 and an incredibly small International Commission on Illumination (CIE) chromaticity coordinates deviation (D uv = -0.0034) at 350 mA. The corresponding correlated color temperature (CCT) and luminous efficiency (LE) are 4526 K and 62.34 lm/W, respectively. Furthermore, two separated phosphor configuration structures were constructed for pc-WLEDs. The R up/G down structure achieves the highest LE of 64.93 lm/W, and the corresponding CCT and R a are 5714 K and 95.8, respectively, chiefly due to the compensation for reabsorption effect caused by the large difference in the luminous efficacy of radiation (LER) between dichromatic phosphors. The results demonstrate that by adjusting the phosphor configuration structure, the pc-WLEDs with high color rendering can be obtained, which have great applications in high-quality lighting.
Metastasis is the major cause of cancer deaths, and cancer cells evolve to adapt to various tumor microenvironments, which hinders the treatment of tumor metastasis. Platelets play critical roles in ...tumor development, especially during metastasis. Here, we elucidate the role of platelet mitochondria in tumor metastasis. Cancer cells are reprogrammed to a metastatic state through the acquisition of platelet mitochondria via the PINK1/Parkin-Mfn2 pathway. Furthermore, platelet mitochondria regulate the GSH/GSSG ratio and reactive oxygen species (ROS) in cancer cells to promote lung metastasis of osteosarcoma. Impairing platelet mitochondrial function has proven to be an efficient approach to impair metastasis, providing a direction for osteosarcoma therapy. Our findings demonstrate mitochondrial transfer between platelets and cancer cells and suggest a role for platelet mitochondria in tumor metastasis.
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•Cancer cells acquire mitochondria from platelets to enhance metastasis tendency•Mitochondria transfer is dependent on PINK1/Parkin-Mfn2 pathway•Platelet mitochondria alter cancer cell metabolic status and modulate oxidative stress
Zhang et al. report that cancer cells are reprogrammed to a metastatic state through the acquisition of platelet mitochondria via the PINK1/Parkin-Mfn2 pathway. They discover that transferred platelet mitochondria drive metabolic shift and ROS reduction in cancer cells. Targeting platelet mitochondria is a potential treatment for cancer metastases.
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