Large High Quality Research Articles

Energy Transfer for Constructing Circularly Polarized Luminescence Materials: Recent Progress and Future Prospects

AbstractCircularly polarized luminescence (CPL) materials hold significant promise in multidisciplinary fields such as circularly polarized organic light‐emitting diodes, biological probes, data storage, and information encryption. However, these cutting‐edge applications also put forward higher requirements for the design of CPL materials, requiring large dissymmetry factor and high emission quality. For this purpose, diverse approaches have been explored to generate and enhance CPL emission. Among them, energy transfer (ET) strategy stands out as it can be readily implemented in a wide range of CPL materials. The present work overviews latest advances in energy transfer for generating and modulating CPL, involving small organic molecules, polymers, metal complexes, liquid crystals, as well as new‐emerging chiral luminescent materials. It is anticipated that the review article will garner increased attention toward energy transfer systems and facilitate the advancement of CPL materials.

Parameters impact analysis on contact characteristics of intersected beveloid gear and involute cylindrical gear

According to gear geometry and tooth contact analysis (TCA) theory, the TCA model of intersected beveloid gear and involute cylindrical gear pair is built. The formulas for calculating curvature and contact ellipse at contact points are derived, and the shape and region of contact ellipse are determined. Then, the impacts of cone angle, helix angle and installation errors on contact characteristics are studied by numerical examples. The finite element model of gear pair is established to carry out the loaded tooth contact analysis (LTCA) and verify the accuracy of theoretical TCA model. The results show that gear pair with small cone angle or big helix angle has wide contact area, large carrying capacity and high transmission quality. The shaft angle error may cause the edge contact of gear pair, while the axial position error has limited effect. The research can provide input parameters for the study of tooth surface wear mechanism and dynamics in the future work.

MEMS fast steering mirror with a large optical aperture and high surface quality for free-space optical communication

This work presents a MEMS fast steering mirror fabricated by an 8-inch AlScN platform, with a large optical aperture of up to 10 mm and high surface quality (RMS < 20 nm, PV < 120 nm), intended for free-space optical communication. The device comprises a high reflective mirror plate, a pillar and four cantilever beams with AlScN thin films. This device is prepared by a wafer-level eutectic bonding process. A reinforcement structure is proposed to increase the resonant frequency and the resistance to deformation. The mechanical performance, including resonant frequency, step response, linearity, and long-term stability are characterized. The maximum tilting angle is 1.38 mrad at 68 V, the settling time is improved from 400 ms in the open-loop control mode to 0.5 ms with the double step algorithm. The relationship of the resonant frequency, surface figure, and the depth of reinforced ribs is studied through characterizing devices with different depths of reinforced ribs. The bonding quality and the mutual melting states of bonding layers interface are investigated.

Improved piezoelectric and photoluminescence properties in Ce-doped PSN-PMN-PT piezoelectric ceramics by multiscale coordination

The large piezoelectric coefficient (d33) and high mechanical quality factor (Qm) are essential for piezoelectric ceramics used in high-power devices. It is pity that the two parameters are usually opposite, with higher d33 corresponding to lower Qm. In order to well-balance the d33 and Qm, the rare-earth element Ce with multi-valence was introduced into the 0.06 Pb(Sc1/2Nb1/2)O3-0.61 Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 (xCe-PSN-PMN-PT) ceramics in this work. The structure, electrical properties and optical properties of ceramics were systematically analyzed. Optimal electrical performances (d33 = 719 pC/N, Qm = 256, and dielectric loss tanδ = 0.007) were obtained in 0.02Ce-PSN-PMN-PT ceramics. These excellent performances originate from the multiscale coordination effects among defect dipoles, local structural heterogeneity, domain structure, phase structure, and grain size. The xCe-PSN-PMN-PT ceramics exhibit excellent photoluminescence properties in the blue wavelength range. Our research provides a new paradigm for deep-sea electro-optical communication.

High-Risk HPV Cervical Lesion Potential Correlations Mining over Large-Scale Knowledge Graphs

Lesion prediction, a very important aspect of cancer disease prediction, is an important marker for patients before they become cancerous. Currently, traditional machine learning methods are gradually applied in disease prediction based on patient vital signs data. Accurate prediction requires a large amount and high quality of data, however, the difficulty in obtaining and incompleteness of electronic medical record (EMR) data leads to certain difficulties in disease prediction by traditional machine learning methods. Secondly, there are many factors that contribute to the development of cervical lesions, some risk factors are directly related to it while others are indirectly related to them. In addition, risk factors have an interactive effect on the development of cervical lesions; it does not occur in isolation, a large-scale knowledge graph is constructed base on the close relationships among risk factors in the literature, and new potential key risk factors are mined based on common risk factors through a subgraph mining method. Then lesion prediction algorithm is proposed to predict the likelihood of lesions in patients base on the set of key risk factors. Experimental results show that the circumvents the problems of large number of missing values in EMR data and discovered key risk factors that are easily ignored but have better prediction effect. Therefore, The method had better accuracy in predicting cervical lesions.

Development of axion haloscopes for high-mass search at CAPP

The axion offers a well-motivated solution to two fundamental questions in modern physics: the strong CP problem and the dark matter mystery. Cavity haloscopes, exploiting resonant enhancement of photon signals, provide the most sensitive searches for axion dark matter in the microwave region. However, current experimental sensitivities are limited to the O(100)μeV range, while recent theoretical predictions for the axion mass favor up to O(102)μeV, suggesting the need of new experimental approaches that are suitable for higher mass regions. CAPP has developed/proposed several haloscopes effective for high-mass axion searches based on new cavity concepts and practical tuning mechanisms. They are characterized by large detection volumes and/or high quality factors at high frequencies, achieved by partitioning a single cavity into multiple cells, exploiting higher-order resonant modes, and constructing dielectric photonic crystal structures. Improving on the dish antenna haloscope scheme, a horn antenna array has also been proposed for volume-efficient broadband search in the THz region. We review these haloscope designs for sensitive search in the high-mass regions and discuss their impacts on future experiments.

Solid‐Liquid Interfacial Engineered Large‐Area Two‐Dimensional Covalent Organic Framework Films

AbstractConstructing uniform covalent organic framework (COF) film on substrates for electronic devices is highly desirable. Here, a simple and mild strategy is developed to prepare them by polymerization on a solid‐liquid interface. The universality of the method is confirmed by the successful preparation of five COF films with different microstructures. These films have large lateral size, controllable thickness, and high crystalline quality. And COF patterns can also be directly achieved on substrates via hydrophilic and hydrophobic interface engineering, which is in favor of preparing device array. For application studies, the PyTTA‐TPA (PyTTA: 4,4′,4′′,4′′′‐(1,3,6,8‐Tetrakis(4‐aminophenyl)pyrene and TPA: terephthalaldehyde) COF film has a high photoresponsivity of 59.79 μA W−1 at 420 nm for photoelectrochemical (PEC) detection. When employed as an active material for optoelectronic synaptic devices for the first attempt, it shows excellent light‐stimulated synaptic plasticity properties such as short‐term plasticity (STP), long‐term plasticity (LTP), and the conversion of STP to LTP, which can be used to simulate biological synaptic functions.

Solid-Liquid Interfacial Engineered Large-Area Two-Dimensional Covalent Organic Framework Films.

Constructing uniform covalent organic framework (COF) film on substrates for electronic devices is highly desirable. Here, a simple and mild strategy is developed to prepare them by polymerization on a solid-liquid interface. The universality of the method is confirmed by the successful preparation of five COF films with different microstructures. These films have large lateral size, controllable thickness, and high crystalline quality. And COF patterns can also be directly achieved on substrates via hydrophilic and hydrophobic interface engineering, which is in favor of preparing device array. For application studies, the PyTTA-TPA (PyTTA: 4,4',4'',4'''-(1,3,6,8-Tetrakis(4-aminophenyl)pyrene and TPA: terephthalaldehyde) COF film has a high photoresponsivity of 59.79 μA W-1 at 420 nm for photoelectrochemical (PEC) detection. When employed as an active material for optoelectronic synaptic devices for the first attempt, it shows excellent light-stimulated synaptic plasticity properties such as short-term plasticity (STP), long-term plasticity (LTP), and the conversion of STP to LTP, which can be used to simulate biological synaptic functions.

Study on growth technology and optical properties of large size and high quality methylamine lead bromide single crystals

As a new generation of photoelectric materials, organic–inorganic halide perovskites have been widely used in photodetectors, solar cells and other fields, but most of the current mainstream applications are thin film materials.

Crystal Growth of the R2SiO5 Compounds (R = Dy, Ho, and Er) by the Floating Zone Method Using a Laser-Diode-Heated Furnace

In recent years, rare earth silicate compounds have attracted the extensive attention of researchers owing to their potential for applications in scintillation crystals in gamma ray or X-ray detectors, as well as in thermal or environmental barrier coatings. Large high quality crystals of three members of the rare earth monosilicates family of compounds, R2SiO5 (with R = Dy, Ho, and Er), have been grown by the floating zone method, using a laser-diode-heated floating zone furnace. Crystal growths attempts were carried out using different parameters in order to determine the optimum conditions for the growth of these materials. The phase purity and the crystalline quality of the crystal boules were analysed using powder and Laue X-ray diffraction. Single crystal X-ray diffraction experiments were carried out to determine the crystal structures of the boules. The optimum conditions used for the crystal growth of R2SiO5 materials are reported. The phase purity and high crystalline quality of the crystals produced makes them ideal for detailed investigations of the intrinsic physical and chemical properties of these materials.

BlockMatch: A Fine-Grained Binary Code Similarity Detection Approach Using Contrastive Learning for Basic Block Matching

Binary code similarity detection (BCSD) plays a vital role in computer security and software engineering. Traditional BCSD methods heavily rely on specific features and necessitate rich expert knowledge, which are sensitive to code alterations. To improve the robustness against minor code alterations, recent research has shifted towards machine learning-based approaches. However, existing BCSD approaches mainly focus on function-level matching and face challenges related to large batch optimization and high quality sample selection at the basic block level. To overcome these challenges, we propose BlockMatch, a novel fine-grained BCSD approach that leverages natural language processing (NLP) techniques and contrastive learning for basic block matching. We treat instructions of basic blocks as a language and utilize a DeBERTa model to capture relative position relations and contextual semantics for encoding instruction sequences. For various operands in binary code, we propose a root operand model pre-training task to mitigate semantic missing of unseen operands. We then employ a mean pooling layer to generate basic block embeddings for detecting binary code similarity. Additionally, we propose a contrastive training framework, including a block augmentation model to generate high-quality training samples, improving the effectiveness of model training. Inspired by contrastive learning, we adopt the NT-Xent loss as our objective function, which allows larger sample sizes for model training and mitigates the convergence issues caused by limited local positive/negative samples. By conducting extensive experiments, we evaluate BlockMatch and compare it against state-of-the-art approaches such as PalmTree and SAFE. The results demonstrate that BlockMatch achieves a recall@1 of 0.912 at the basic block level under the cross-compiler scenario (pool size = 10), which outperforms PalmTree (0.810) and SAFE (0.798). Furthermore, our ablation study shows that the proposed contrastive training framework and root operand model pre-training task help our model achieve superior performance.

Effects of Wuzhi Capsule on Whole-Blood Tacrolimus Concentration Levels: A Systematic Review and Meta-Analysis.

Wuzhi Capsule (WZC) is a traditional Chinese medicinal herb widely used to treat drug-induced hepatitis or liver dysfunction and is usually prescribed in China to increase tacrolimus concentration. Several studies with small sample sizes have shown that WZC can increase tacrolimus concentration levels in clinical practice. This study aimed to evaluate the effect of WZC on whole-blood tacrolimus concentration levels and safety. We searched 7 databases for randomized clinical trials (RCTs) and observational studies (OSs) comparing whole-blood tacrolimus concentration levels between WZC and non-WZC treatments. Data analysis was performed using Review Manager version 5.3. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines. Eleven studies involving 6 RCTs and 5 OSs were included. The meta-analysis indicated that whole-blood tacrolimus concentration levels in the WZC group was significantly higher than that of the non-WZC group [weighted mean difference = 1.38, 95% CI (confidence interval), 1.21-1.56, P < 0.001], and similar results were shown in all the subgroups of follow-up time, different primary disease, and different WZC doses. In the self-control OSs, the whole-blood tacrolimus concentration levels in the WZC group was significantly higher than the non-WZC group (weighted mean difference = 1.17, 95% CI, 0.71-1.64, P < 0.001). WZC was generally well tolerated and there was no significant difference in the incidence of adverse reactions between the 2 groups. WZC can increase whole-blood tacrolimus concentration levels. This may be an economical and practical treatment choice for patients, especially those with poor oral tacrolimus absorption capabilities. Nevertheless, RCTs and OSs with large sample sizes and high quality are needed in the future to confirm these positive results.

Study of electrode structures for 5.89 GHz A1 mode Lamb wave resonators to achieve fs×kt2×Q > 247×109 Hz

This work demonstrates a laterally excited shear bulk acoustic wave resonator (XBAR) based on a 300-nm-thick ZY-cut Lithium Niobate thin film, which takes advantages of high frequency, large electromechanical coupling coefficient (kt2) and high quality factor (Q). A bi-electrode structure was proposed to weaken the effects of mechanical and electrical loading introduced by the metal electrodes, while enhancing the coupling between the electric field and stress. In addition, the electrode configurations including interdigitated electrodes (IDEs) number, metal coverage and effective electrode length were studied to eliminate spurious modes and improve resonators’ performance. The fabricated devices can achieve the resonant frequency of 5.89 GHz using the first-asymmetric (A1) mode Lamb wave in suspended LiNbO3 thin film. Combined with the high operating frequency and high kt2 characteristics of the A1 mode Lamb wave, the measured results show that the designed bi-electrode structure XBAR achieves a kt2 value of 14 % and a high Q value of 300.

An Image Unmixing and Stitching Deep Learning Algorithm for In-Screen Fingerprint Recognition Application

The market share of organic light-emitting diode (OLED) screens in consumer electronics has grown rapidly in recent years. In order to increase the screen-to-body ratio of OLED phones, under-screen or in-screen fingerprint recognition is a must-have option. Current commercial hardware schemes include adhesive, ultrasonic, and under-screen optical ones. No mature in-screen solution has been proposed. In this work, we designed and manufactured an OLED panel with an in-screen fingerprint recognition system for the first time, by integrating an active sensor array into the OLED panel. The sensor and display module share the same set of fabrication processes when manufactured. Compared with the current widely commercially available under-screen schemes, the proposed in-screen solution can achieve a much larger functional area, better flexibility, and smaller thickness, while significantly reducing module cost. A point light source scheme, implemented by lighting up a single or several adjacent OLED pixels, instead of a conventional area source scheme as in the CMOS image sensor, or a CIS-based solution, has to be adopted since the optical distance is not long enough due to the integration. We designed a pattern for the point light sources and developed an optical unmixing network model to realize the unmixing and stitching of images obtained by each point light source at the same exposure time. After training, data verification of this network model shows that this deep learning algorithm outputs a stitched image of large area and high quality, where FRR = 0.7% given FAR = 1:50 k. In despite of a poorer quality of raw images and a much more complex algorithm compared with current commercial solutions, the proposed algorithm still obtains results comparable to peer studies, proving the effectiveness of our algorithm. Thus, the time required for fingerprint capture in our in-screen scheme is greatly reduced, by which one of the main obstacles for commercial application is overcome.

Flexible array of high performance and stable formamidinium-based low-n 2D halide perovskite photodetectors for optical imaging

Metal halide perovskites are attracting increasing attention as photodetectors (PDs) materials due to their excellent photoelectric properties. However, integrating perovskite to realize high-resolution perovskite pixel arrays remains critical to enable practical devices. Herein, we demonstrate a high-responsivity and stable 10 × 10 flexible PDs array based on formamidinium-based quasi-2D Ruddlesden-Popper (BA)2FAPb2I7 (n = 2) (BA= butylammonium, C4H9NH3+) perovskite elements for image sensing. The high-performance (BA)2FAPb2I7 arrays are synthesized on a polyethylene terephthalate (PET) flexible substrate, on a large scale, high quality, and controllable manner by introducing Au nanoparticles to enhance film quality upon the annealing process and recrystallization by applying formamidinium chloride (FACl) post-treatment to reduce perovskite film defects, combined with an innovative SiO2-assisted hydrophilic and hydrophobic surface treatment strategy. The prepared flexible PDs arrays show excellent optoelectronic properties with high responsivity (5.9 A W−1), a detectivity of 8.2 × 1012 Jones, large on/off current ratio (up to 3 × 104), ultimate response speed (12.8 μs/10.1 μs), and wide spectral response range. In addition, the device shows outstanding mechanical stability under severe bending (θ = 120°) and excellent folding durability after thousands of bending cycles. It also exhibits excellent environmental stability with only a slight degradation of photoresponse after 100 days of storage under the ambient environment. Finally, the integrated flexible PDs arrays can be used as an effective visible light image sensor with good spatial resolution, paving a multifunctional and competitive way for future wearable sensors and artificial vision systems. One-sentence summaryLow-dimensional halide perovskite layers pixelized on a polyethylene terephthalate (PET) flexible substrate provide high performance photodetectors.

High-cooperativity cavity magnon-polariton using a high-Qdielectric resonator

The hybrid system consisting of microwave photons and ferromagnetic magnons has been studied in the context of quantum sensing and quantum manipulation of magnons. We demonstrate a strong coupling between magnons and photons in a dielectric resonator with a large dielectric constant and high quality factor. The coupling rate between magnons and photons amounts to g/2π=126 MHz, and the corresponding cooperativity reaches C=1.09×106 at cryogenic temperature. The high cooperativity is mainly due to the small internal decay rate of the resonator, which is advantageous for various quantum magnonics experiments.

Porous Lead Iodide Layer Promotes Organic Amine Salt Diffusion to Achieve High Performance p‐i‐n Flexible Perovskite Solar Cells

AbstractFlexible perovskite solar cells (FPSCs) are attracting widespread research and attention for their benefits as the next‐generation wearable electronic products. However, there are still many challenges in the quest to achieve dense, pinhole‐free, high crystal quality, low defect, and stable perovskite films, which limit further improvement in the efficiency and stability of FPSCs. Herein, a novel technique for the incorporation of quaternary ammonium halide (QAH) additives to prepare fluffy porous lead iodide layers by using a two‐step sequential deposition method, is reported. Benefiting from the good diffusion of organic amine salts on porous PbI2 layers, flat and dense perovskite films are produced with large particle sizes, few defects, and high crystal quality. Finally, the champion rigid and flexible p‐i‐n PSCs with the 2‐(acetyloxy)‐N,N,N‐trimethylethanium chloride (AtaCl) additive achieves exciting power conversion efficiencies (PCE) of 23.40% and 21.10%, respectively. The device with the AtaCl additive retains over 90% of its original PCE under ambient conditions (40 ± 5% relative humidity (RH)) over 1000 h of aging without encapsulation. In addition, the flexible device with the AtaCl additive shows excellent stability under mechanical bending conditions, retaining ≈85% of its original PCE after 10 000 cycles (bending radius = 5 mm).

A unified framework of medical information annotation and extraction for Chinese clinical text

Medical information extraction consists of a group of natural language processing (NLP) tasks, which collaboratively convert clinical text to pre-defined structured formats. This is a critical step to exploit electronic medical records (EMRs). Given the recent thriving NLP technologies, model implementation and performance seem no longer an obstacle, whereas the bottleneck locates on a high-quality annotated corpus and the whole engineering workflow. This study presents an engineering framework consisting of three tasks, i.e., medical entity recognition, relation extraction and attribute extraction. Within this framework, the whole workflow is demonstrated from EMR data collection through model performance evaluation. Our annotation scheme is designed to be comprehensive and compatible between the multiple tasks. With the EMRs from a general hospital in Ningbo, China, and the manual annotation by experienced physicians, our corpus is of large scale and high quality. Built upon this Chinese clinical corpus, the medical information extraction system show performance that approaches human annotation. The annotation scheme, (a subset of) the annotated corpus, and the code are all publicly released, to facilitate further research.

Effects of Exergaming on Musculoskeletal Pain in Older Adults: Systematic Review and Meta-analysis

Exercise is effective for musculoskeletal pain. However, physical, social, and environmental factors make it difficult for older adults to persist in exercising. Exergaming is a new pathway that combines exercise with gameplay and may be helpful for older adults to overcome these difficulties and engage in regular exercise. This systematic review aimed to determine the efficacy of exergaming to improve musculoskeletal pain in older adults. The search was performed in 5 databases (PubMed, Embase, CINAHL, Web of Science, and Cochrane Library). The risk of bias for randomized controlled studies was assessed using the revised Cochrane Risk of Bias tool in randomized trials (RoB 2), and the methodological quality was assessed using the Physiotherapy Evidence-Based Database scale. Standardized mean difference and 95% CI were calculated using fixed-effects model meta-analyses in the Review Manager version 5.3 (RevMan 5.3). Seven randomized controlled studies were included, which contained 264 older adults. Three of the 7 studies reported significant improvements in pain after the exergaming intervention, but only 1 reported a significant difference between groups after adjustment for baseline (P<.05), and another reported a significant improvement in thermal pain between the 2 groups (P<.001). The results of the meta-analysis of the 7 studies showed no statistically significant improvement in pain compared to the control group (standardized mean difference -0.22; 95% CI -0.47 to 0.02; P=.07). Although the effects of exergames on musculoskeletal pain in older adults are unknown, exergame training is generally safe, fun, and appealing to older adults. Unsupervised exercise at home is feasible and cost-effective. However, most of the current studies have used commercial exergames, and it is recommended that there should be more cooperation between industries in the future to develop professional rehabilitation exergames that are more suitable for older adults. The sample sizes of the studies included are small, the risk of bias is high, and the results should be interpreted with caution. Further randomized controlled studies with large sample sizes, high quality, and rigor are needed in the future. PROSPERO International Prospective Register of Systematic Reviews CRD42022342325; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=342325.

Hydrogen-rich syngas production by catalytic cracking of polypropylene over activated carbon based monometallic and bimetallic Fe/Ni catalysts

The aim of this study is to efficiently produce hydrogen-rich syngas. The thermal conversion experiment of polypropylene was carried out in a two-stage pyrolytic-catalytic device. Activated carbon based catalyst was developed, the catalytic performance of monomial and bimetallic catalysts was explored, and the influence of metal addition ratio in bimetallic catalysts on hydrogen production performance was analyzed. The microscopic morphology and structural characterization of the unreacted and spent catalyst were analyzed, and the effect of active substance in catalyst on the reaction performance was described. Under optimized reaction conditions, bimetallic catalyst 5Fe–10Ni had excellent catalytic activity, large hydrogen yield (136.32 mmol/gPP) and high carbon deposition quality. For this high performance catalyst, the catalyst stability was verified by 10 cycles of recycling experiments. The method of hydrogen production from waste plastic cracking in this paper will provide new ideas for high value utilization of plastic and hydrogen production.