Temporal Purity and Quantum Interference of Single Photons from Two Independent Cold Atomic Ensembles

The temporal purity of single photons is crucial to the indistinguishability of independent photon sources for the fundamental study of the quantum nature of light and the development of photonic technologies. Currently, the technique for single photons heralded from time-frequency entangled biphotons created in nonlinear crystals does not guarantee the temporal-quantum purity, except using spectral filtering. Nevertheless, an entirely different situation is anticipated for narrow-band biphotons with a coherence time far longer than the time resolution of a single-photon detector. Here we demonstrate temporally pure single photons with a coherence time of 100 ns, directly heralded from the time-frequency entangled biphotons generated by spontaneous four-wave mixing in cold atomic ensembles, without any supplemented filters or cavities. A near-perfect purity and indistinguishability are both verified through Hong-Ou-Mandel quantum interference using single photons from two independent cold atomic ensembles. The time-frequency entanglement provides a route to manipulate the pure temporal state of the single-photon source

AutoFP: a GUI for highly automated Rietveld refinement using an expert system algorithm based on FullProf

AutoFP, a highly automated software toolkit, has been developed to improve the extent of automation of the widely used Rietveld refinement program FullProf [Rodríguez-Carvajal (1993). Physica B, 192, 55-69]. An expert system algorithm is used as the control layer to simulate the manual process when FullProf is used to perform Rietveld refinement. This enables the program to complete the Rietveld refinement highly automatically. It is shown that the expert system algorithm is a good choice for automating Rietveld refinement. The programming interface is available for advanced users to implement their own acquired experience of refinement or add new Rietveld refinement engines to AutoFP. AutoFP can be also used as an automated Rietveld refinement engine by other programs. AutoFP is an open-source software package developed in Python, and it is user friendly, easy to learn and easy to use

Selenium‐doping induced two antiferromagnetic transitions in thiospinel compounds CuCo₂S_(4‐x)Se_x (0 ≤ x ≤ 0.8)

A series of copper thiospinels compounds, CuCo₂S_(4‐x)Se_x (x = 0, 0.2, 0.4, 0.6, 0.8), have been successfully synthesized by solid state reaction and their structure and magnetic properties have been studied. The Rietveld refinements of X‐Ray diffractions indicate that both the lattice constants and the nearest neighbor Cu‐Cu distances increase with increasing selenium doping. A weakly antiferromagnetic transition occurring at about 4 K is observed in CuCo₂S₄. Two antiferromagnetic transitions at about 3.5 K and 6 K are observed in selenium‐doped samples, which suggest that the exchange couplings associated with Cu‐S(Se)‐Cu and Cu‐Se(S)‐Cu, respectively, are responsible for the two antiferromagnetic transitions. Detailed analysis of the experimental results further indicate that the nearest‐neighbor molecular field coefficient is comparable to the next‐neighbor molecular field coefficient. We propose a reasonable model to explain this phenomenon

OphGLM: Training an Ophthalmology Large Language-and-Vision Assistant based on Instructions and Dialogue

Large multimodal language models (LMMs) have achieved significant success in general domains. However, due to the significant differences between medical images and text and general web content, the performance of LMMs in medical scenarios is limited. In ophthalmology, clinical diagnosis relies on multiple modalities of medical images, but unfortunately, multimodal ophthalmic large language models have not been explored to date. In this paper, we study and construct an ophthalmic large multimodal model. Firstly, we use fundus images as an entry point to build a disease assessment and diagnosis pipeline to achieve common ophthalmic disease diagnosis and lesion segmentation. Then, we establish a new ophthalmic multimodal instruction-following and dialogue fine-tuning dataset based on disease-related knowledge data and publicly available real-world medical dialogue. We introduce visual ability into the large language model to complete the ophthalmic large language and vision assistant (OphGLM). Our experimental results demonstrate that the OphGLM model performs exceptionally well, and it has the potential to revolutionize clinical applications in ophthalmology. The dataset, code, and models will be made publicly available at https://github.com/ML-AILab/OphGLM.Comment: OphGLM:The first ophthalmology large language-and-vision assistant based on instructions and dialogu

Prevalence of metabolic syndrome among middle-aged and elderly adults in China: current status and temporal trends

Background: Metabolic syndrome (MetS) is a cluster of major risk factors for cardiovascular diseases. We aimed to estimate prevalence and distribution of MetS among middle-aged and elderly adults in China. Methods: The present analysis used data from a national study in 2014–2015. We defined MetS by different definitions, and compared results of the present study and previous nationally representative studies to illustrate possible temporal changes in MetS prevalence. Results: The estimated prevalence of MetS was 18.4% by the ATP III criteria, 34.0% by the revised ATP III criteria, and 26.9% by IDF criteria. The prevalence was higher in women, older adults, those with lower education level, and in economically developed regions. Contrasting with previous national studies, adults in urban areas had a lower rate of MetS than those in rural areas (odds ratio 0.94; 95% CI 0.92−0.97). Rural adults had worse deterioration or less improvement in abdominal obesity, overweight, hypertension, and high fasting plasma glucose, than urban adults, which was particularly striking for women. Conclusion: While measures to prevent and control cardiovascular diseases need to be strengthened in China, rapid increasing risk factors among rural residents and women should be prioritized in making public health policy decisions

Pressure-induced superconductivity in topological type II Dirac semimetal NiTe₂

Very recently, NiTe₂ has been reported to be a type II Dirac semimetal with Dirac nodes near the Fermi surface. Furthermore, it is unveiled that NiTe₂ presents the Hall Effect, which is ascribed to orbital magnetoresistance. The physical properties behavior of NiTe₂ under high pressure attracts us. In this paper, we investigate the electrical properties of polycrystalline NiTe₂ by application of pressure ranging from 3.4GPa to 54.45Gpa. Superconductivity emerges at critical pressure 12GPa with a transition temperature of 3.7K, and Tc reaches its maximum, 6.4 K, at the pressure of 52.8GPa. Comparing with the superconductivity in MoP, we purposed the possibility of topological superconductivity in NiTe₂. Two superconductivity transitions are observed with pressure increasing in single crystal

Compatibility research of laser additive repairing (LAR) TA15 forgings with Ti6Al4V-xTA15 alloy

The application of mixed powders with different mass fraction on laser additive repairing (LAR) can be an effective way to guarantee the performance and functionality of repaired part in time. A convenient and feasible approach is presented to repair TA15 forgings by employing Ti6Al4V-xTA15 mixed powders in this paper. The performance compatibility of Ti6Al4V-xTA15 powders from the aspects of microhardness, tensile property, heat capacity, thermal expansion coefficient and corrosion resistance with the TA15 forgings was fully investigated. The primary α laths were refined and the volume fraction of the secondary α phase was increased by increasing the mass fraction of TA15 in the mixed Ti6Al4V-xTA15 powders, leading to varied performances. In conclusion, the mixed Ti6Al4V-70%TA15 (x=70%) powders is the most suitable candidate and is recommended as the raw material for LAR of TA15 forgings based on overall consideration of the compatibility calculations of the laser repaired zone with the wrought substrate zone

Research progress on and molecular mechanism of vacuum sealing drainage in the treatment of diabetic foot ulcers

Diabetic foot ulcers (DFUs) are common chronic wounds and a common complication of diabetes. The foot is the main site of diabetic ulcers, which involve small and medium-sized arteries, peripheral nerves, and microcirculation, among others. DFUs are prone to coinfections and affect many diabetic patients. In recent years, interdisciplinary research combining medicine and material science has been increasing and has achieved significant clinical therapeutic effects, and the application of vacuum sealing drainage (VSD) in the treatment of DFUs is a typical representative of this progress, but the mechanism of action remains unclear. In this review, we integrated bioinformatics and literature and found that ferroptosis is an important signaling pathway through which VSD promotes the healing of DFUs and that System Xc-GSH-GPX4 and NAD(P)H-CoQ10-FSP1 are important axes in this signaling pathway, and we speculate that VSD is most likely to inhibit ferroptosis to promote DFU healing through the above axes. In addition, we found that some classical pathways, such as the TNF, NF-κB, and Wnt/β-catenin pathways, are also involved in the VSD-mediated promotion of DFU healing. We also compiled and reviewed the progress from clinical studies on VSD, and this information provides a reference for the study of VSD in the treatment of DFUs