6,739 research outputs found

    Net charge fluctuation and string fragmentation

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    We present simulation results of net charge fluctuation in Au+AuAu+Au collisions at snn\sqrt{s_{nn}}=130 GeV from a dynamic model, JPCIAE. The calculations are done for the quark-gluon phase before hadronization, the pion gas, the resonance pion gas from ρ\rho and ω\omega decays and so on. The simulations of the charge fluctuation show that the discrepancy exists between the dynamic model and the thermal model for a pion gas and a resonance pion gas from ρ\rho and ω\omega decays while the simulated charge fluctuation of the quark-gluon phase is close to the thermal model prediction. JPCIAE results of net charge fluctuation in the hardonic phase are nearly 4-5 times larger than one for the quark-gluon phase, which implies that the charge fluctuation in the quark-gluon phase may not survive the hadronization (string fragmentation) as implemented in JPCIAE.Comment: 9 pages, 3 figure

    Exact Numerical Solution of the BCS Pairing Problem

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    We propose a new simulation computational method to solve the reduced BCS Hamiltonian based on spin analogy and submatrix diagonalization. Then we further apply this method to solve superconducting energy gap and the results are well consistent with those obtained by Bogoliubov transformation method. The exponential problem of 2^{N}-dimension matrix is reduced to the polynomial problem of N-dimension matrix. It is essential to validate this method on a real quantumComment: 7 pages, 3 figure

    keqing: knowledge-based question answering is a nature chain-of-thought mentor of LLM

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    Large language models (LLMs) have exhibited remarkable performance on various natural language processing (NLP) tasks, especially for question answering. However, in the face of problems beyond the scope of knowledge, these LLMs tend to talk nonsense with a straight face, where the potential solution could be incorporating an Information Retrieval (IR) module and generating response based on these retrieved knowledge. In this paper, we present a novel framework to assist LLMs, such as ChatGPT, to retrieve question-related structured information on the knowledge graph, and demonstrate that Knowledge-based question answering (Keqing) could be a nature Chain-of-Thought (CoT) mentor to guide the LLM to sequentially find the answer entities of a complex question through interpretable logical chains. Specifically, the workflow of Keqing will execute decomposing a complex question according to predefined templates, retrieving candidate entities on knowledge graph, reasoning answers of sub-questions, and finally generating response with reasoning paths, which greatly improves the reliability of LLM's response. The experimental results on KBQA datasets show that Keqing can achieve competitive performance and illustrate the logic of answering each question.Comment: 12 pages, 6 figure

    Measurement to radius of Newton’s ring fringes using polar coordinate transform

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    Background: Newton’s ring method is often used to measure many physical parameters. And some measured physical quantity can be extracted by calculating the radius parameter of circular fringes from Newton's ring configuration. Methods: The paper presents a new measuring method for radius of circular fringes, which includes three main steps, i.e., determination of center coordinates of circular fringes, polar coordinates transformation of circular fringes, and gray projection of the transformed result which along the horizontal direction. Then the radius values of each order ring are calculated. Results: The simulated results indicate that the measuring accuracy of the radius under the effect of random noise can keep the degree of less than 0.5 pixels. Conclusions: The proposed method can obtain the radius data of each order closed circular fringes. Also, it has several other advantages, including ability of good anti-noise, sub-pixel accuracy and high reliability, and easy to in-situ use

    Quantitative and dark field ghost imaging with ultraviolet light

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    Ultraviolet (UV) imaging enables a diverse array of applications, such as material composition analysis, biological fluorescence imaging, and detecting defects in semiconductor manufacturing. However, scientific-grade UV cameras with high quantum efficiency are expensive and include a complex thermoelectric cooling system. Here, we demonstrate a UV computational ghost imaging (UV-CGI) method to provide a cost-effective UV imaging and detection strategy. By applying spatial-temporal illumination patterns and using a 325 nm laser source, a single-pixel detector is enough to reconstruct the images of objects. To demonstrate its capability for quantitative detection, we use UV-CGI to distinguish four UV-sensitive sunscreen areas with different densities on a sample. Furthermore, we demonstrate dark field UV-CGI in both transmission and reflection schemes. By only collecting the scattered light from objects, we can detect the edges of pure phase objects and small scratches on a compact disc. Our results showcase a feasible low-cost solution for non-destructive UV imaging and detection. By combining it with other imaging techniques, such as hyperspectral imaging or time-resolved imaging, a compact and versatile UV computational imaging platform may be realized for future applications.Comment: 9 pages, 5 figure

    Diversity of sperm cells of different size in photoperiod-sensitive genic male-sterile rice

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    Sperm cells of photoperiod-sensitive genic male-sterile rice (PGMR) were isolated from pollen tubes using two step osmotic shock with BSA and sucrose solution, which were separated and purified using a micromanipulator. The highest ratio of viable sperm cells was obtained when pollen grains cultured in a medium containing 1.5 mM BSA and 10% sucrose solution. Fluorescein diacetate (FDA) stain was used to determine the viable sperm cells. The size of two sperm cells of PGMR nongken 58S were different but the dimorphism of sperm cells in 58S needs to be confirmed by further work

    An efficient process for wastewater treatment to mitigate free nitrous acid generation and its inhibition on biological phosphorus removal

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    Free nitrous acid (FNA), which is the protonated form of nitrite and inevitably produced during biological nitrogen removal, has been demonstrated to strongly inhibit the activity of polyphosphate accumulating organisms (PAOs). Herein we reported an efficient process for wastewater treatment, i.e., the oxic/anoxic/oxic/extended-idle process to mitigate the generation of FNA and its inhibition on PAOs. The results showed that this new process enriched more PAOs which thereby achieved higher phosphorus removal efficiency than the conventional four-step (i.e., anaerobic/oxic/anoxic/oxic) biological nutrient removal process (41 ± 7% versus 30 ± 5% in abundance of PAOs and 97 ± 0.73% versus 82 ± 1.2% in efficiency of phosphorus removal). It was found that this new process increased pH value but decreased nitrite accumulation, resulting in the decreased FNA generation. Further experiments showed that the new process could alleviate the inhibition of FNA on the metabolisms of PAOs even under the same FNA concentration
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