分类： 物理学 >> 核物理学 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： An experimental method was used to evaluate the primary isotope yields of semi-central collisions in the reaction system 64Zn+112Sn at 40A MeV. The characteristic nature of the hot nuclear matter at the time of the isotope formation was studied. The multiplicities of light particles (LPs) associated with intermediate mass fragments (IMFs) were determined experimentally by using a kinematical focusing technique. The primary isotope distributions, reconstructed by a Monte Carlo method, were compared with those of the AMD-Gemini simulations. ac/T=0.11 and asym/T=3.34 were extracted from the reconstructed primary fragments yield. These are consistent with those of the primary fragments of the AMD simulation.
分类： 物理学 >> 核物理学 提交时间： 2025-04-26
Li, Mr. Junfeng
Yang, Mr. Jiawei
Wang, Mr. Mou
Zhao, Dr. Pengcheng
Wang, Mr. Da
Yokoyama, Dr. Ryo
WANG, Dr. KAI
Zhang, Dr. Guangwei
Zhou, Dr. Wenzhong
Zhou, Mr. Lijun
摘要： In this paper, we propose an artificial intelligence (AI)-driven framework for predicting fission gas release (FGR) in liquid metal-cooled reactors. Three AI models are trained on a comprehensive FGR database comprising 10,065 data points generated from multi-physics simulations. The results reveal that Random Forest (RF) achieves superior prediction accuracy, with a mean error (ME) of 3.96% for the optimal parameter combination (p_lin0, a_grain0, po, and t). While RF excels in database predictions, the Transformer model demonstrates exceptional capability in capturing parameter-effect trends, such as the positive correlation between FGR and fuel linear power or time. This study underscores the potential of AI models, particularly RF and Transformer, in advancing FGR forecasting for reactor safety analysis. This work can provide a replicable methodological paradigm for the FGR prediction of nuclear reactors and reliable technical support for the safety margin assessment of liquid metal-cooled reactors.
分类： 物理学 >> 地球物理学、天文学和天体物理学 提交时间： 2024-09-25
摘要： Using a model-independent analysis method, we analyze $H(z)$ parameter data with some restrictive conditions. We find that: (a) the Universe might experience an accelerated expansion with a confidence level greater than 5 $\sigma$ at redshift $z_{101}\in (0, 0.36)$ and greater than 1.9 $\sigma$ at redshifts $z_{3835}\in (1.3, 1.53)$ and $z_{3836}\in (1.43, 1.53)$; (b) the Universe might experience a decelerated expansion with a confidence level greater than 1.5 $\sigma$ at redshift $z_{2012}\in (0.40, 0.52)$; (c) $w_{\rm{x}}\leq w_{\rm{t}}<-1$ with confidence level great than 1.6 $\sigma$ at redshift $z_{3836}\in (1.43, 1.53)$. These results indicate that the dark energy may be dynamic with equation of state crossing $-1$.
分类： 地球科学 >> 空间物理学 提交时间： 2017-01-04
摘要： A novel image registration scheme is devised in view of the weak affine transformation, which is a kind of similarity transformation with anisotropic scales or affine transformation without shearing. Two robust algorithms are proposed to retrieve the registration parameters from the error-prone initial correspondences based on the fast least trimmed squares (Fast-LTS) and the random sample consensus (RANSAC). In terms of several criteria, the algorithms are evaluated on three carefully selected datasets from different sensors and the experimental results demonstrate that the proposed scheme and algorithms perform robustly and accurately. Our findings also indicate that the Fast-LTS-based algorithm is more stable and appropriate for image registration than the RANSAC-based algorithm although the speed is slower. �2012 Elsevier B.V. All rights reserved.
分类： 核科学技术 >> 裂变堆工程技术 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： In atmospheric dispersion models of nuclear accident, the dispersion coefficients were usually obtained by tracer experiment, which are constant in different atmospheric stability classifications. In fact, the atmospheric wind field is complex and unstable. The dispersion coefficients change even in the same atmospheric stability, hence the great errors brought in. According to the regulation, the air concentration of nuclides around nuclear power plant should be monitored during an accident. The monitoring data can be used to correct dispersion coefficients dynamically. The error can be minimized by correcting the coefficients. This reverse problem is nonlinear and sensitive to initial value. The property of searching the optimal solution of Genetic Algorithm (GA) is suitable for complex high-dimensional situation. In this paper, coupling with Lagrange dispersion model, GA is used to estimate the coefficients. The simulation results show that GA scheme performs well when the error is big. When the correcting process is used in the experiment data, the GA-estimated results are numerical instable. The success rate of estimation is 5% lower than the one without correction. Taking into account the continuity of the dispersion coefficient, Savitzky-Golay filter is used to smooth the estimated parameters. The success rate of estimation increases to 75.86%. This method can improve the accuracy of atmospheric dispersion simulation.
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2025-06-20
摘要： We analyze DESI DR2 data with a model-independent method and find that: (a) the expansion of the universe may speed up with a confidence level more than 2.3 $\sigma$ at redshift $z_{51}\in (0.51, 0.955)$; (b) the expansion of the universe may speed down with a confidence level greater than 1.7 $\sigma$ at redshift $z_{75}\in (0.955, 1.484)$; (c) $w_{\rm{x}}\leq w_{\rm{t}}<-1$ with confidence level exceeding 1.6 $\sigma$ at redshift $z_{53}\in (0.922, 0.955)$.
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2025-05-12
摘要： We argue that the existence of thermal phenomena, together with thephenomena of particle creation and annihilation, imposes fundamentalconstraints on the dynamics of physical systems. Specifically, thepresence of these phenomena jointly requires that a finite systemcan only have a finite number of microscopic physical states,which naturally leads to the necessity of a quantization frameworkand an inherently probabilistic dynamic structure.We show that deterministic hidden-parameter theories, suchas Bohmian mechanics, are incompatible with these requirements.Furthermore, we briefly explore why the gravitational wave fieldis more likely to be quantum in nature rather than classical.
分类： 物理学 >> 核物理学 提交时间： 2025-01-15
摘要： This paper presents a study of the application of the radial basis function augmented with finite difference method in solving the two-dimensional steady-state one-group isotropic neutron transport equation. Compared to traditional numerical algorithms, the proposed method has the advantage of generating data nodes rapidly and not relying on meshes. Therefore, it is particularly suitable for solving differential equations defined in complex geometric regions. In the proposed method, two forms of radial basis functions are used as interpolation basis functions, and the numerical solution to the equation is obtained by solving the corresponding weights on a stencil of a given size. Because the shape parameters significantly affect the stability of the numerical algorithm, selecting optimal shape parameters can minimize the errors. In this study, two methods, namely the fixed shape parameter method and the leave-one-out method, are used to determine optimal shape parameters values.
分类： 生物学 >> 植物学 >> 应用植物学 提交时间： 2020-05-31 合作期刊: 《干旱区科学》
摘要： The Penman-Monteith (PM) method is the most widely used technique to estimate potential worldwide evapotranspiration. However, current research shows that there may be significant errors in the application of this method in arid areas, although questions remain as to the degree of this estimation error and how different surface conditions may affect the estimation error. To address these issues, we evaluated the uncertainty of the PM method under different underlying conditions in an arid area of Northwest China by analyzing data from 84 meteorological stations and various Moderate Resolution Imaging Spectroradiometer (MODIS) products, including land surface temperature and surface albedo. First, we found that when the PM method used air temperature to calculate the slope of the saturation vapor pressure curve, it significantly overestimated the potential evapotranspiration; the mean annual and July–August overestimation was 83.9 and 36.7 mm, respectively. Second, the PM method usually set the surface albedo to a fixed value, which led to the potential evapotranspiration being underestimated; the mean annual underestimation was 27.5 mm, while the overestimation for July to August was 5.3 mm. Third, the PM method significantly overestimated the potential evapotranspiration in the arid area. This difference in estimation was closely related to the underlying surface conditions. For the entire arid zone, the PM method overestimated the potential evapotranspiration by 33.7 mm per year, with an overestimation of 29.0 mm from July to August. The most significant overestimation was evident in the mountainous and plain non-vegetation areas, in which the annual mean overestimation reached 5% and 10%, respectively; during July, there was an estimation of 10% and 20%, respectively. Although the annual evapotranspiration of the plains with better vegetation coverage was slightly underestimated, overestimation still occurred in July and August, with a mean overestimation of approximately 5%. In order to estimate potential evapotranspiration in the arid zone, it is important that we identify a reasonable parameter with which to calibrate the PM formula, such as the slope of the saturation vapor pressure curve, and the surface albedo. We recommend that some parameters must be corrected when using PM in order to estimate potential evapotranspiration in arid regions.
分类： 环境科学技术及资源科学技术 >> 环境科学技术基础学科 提交时间： 2020-04-23 合作期刊: 《干旱区科学》
摘要： The Penman-Monteith (PM) method is the most widely used technique to estimate potential worldwide evapotranspiration. However, current research shows that there may be significant errors in the application of this method in arid areas, although questions remain as to the degree of this estimation error and how different surface conditions may affect the estimation error. To address these issues, we evaluated the uncertainty of the PM method under different underlying conditions in an arid area of Northwest China by analyzing data from 84 meteorological stations and various Moderate Resolution Imaging Spectroradiometer (MODIS) products, including land surface temperature and surface albedo. First, we found that when the PM method used air temperature to calculate the slope of the saturation vapor pressure curve, it significantly overestimated the potential evapotranspiration; the mean annual and July–August overestimation was 83.9 and 36.7 mm, respectively. Second, the PM method usually set the surface albedo to a fixed value, which led to the potential evapotranspiration being underestimated; the mean annual underestimation was 27.5 mm, while the overestimation for July to August was 5.3 mm. Third, the PM method significantly overestimated the potential evapotranspiration in the arid area. This difference in estimation was closely related to the underlying surface conditions. For the entire arid zone, the PM method overestimated the potential evapotranspiration by 33.7 mm per year, with an overestimation of 29.0 mm from July to August. The most significant overestimation was evident in the mountainous and plain non-vegetation areas, in which the annual mean overestimation reached 5% and 10%, respectively; during July, there was an estimation of 10% and 20%, respectively. Although the annual evapotranspiration of the plains with better vegetation coverage was slightly underestimated, overestimation still occurred in July and August, with a mean overestimation of approximately 5%. In order to estimate potential evapotranspiration in the arid zone, it is important that we identify a reasonable parameter with which to calibrate the PM formula, such as the slope of the saturation vapor pressure curve, and the surface albedo. We recommend that some parameters must be corrected when using PM in order to estimate potential evapotranspiration in arid regions.
分类： 地球科学 >> 水文学 提交时间： 2024-02-21 合作期刊: 《干旱区科学》
摘要： Groundwater quality assessment is important to assure safe and durable water use. In semi-arid areas of Algeria, groundwater represents the main water resource for drinking water supply of the rural population as well as for irrigation of agricultural lands. Groundwater samples from wells and springs were collected from the Gargaat Tarf and Annk Djemel sub-watersheds of the Oum El Bouaghi, Algeria, and were analyzed and compared with the World Health Organization (WHO) standards. Results showed that most of the measured physical and chemical parameters exceeded the quality limits according to the WHO standards. Groundwater had a slightly alkaline water pH (7.00–7.79), electrical conductivity>1500 µS/cm, chloride>500 mg/L, calcium>250 mg/L, and magnesium>155 mg/L. Water quality index (WQI) results showed that 68% of the area had excellent water quality, 24% of the samples fell into good category, and only 8% were of poor quality and unsuitable for human consumption. Six wells in the area showed bacterial contamination. Total coliforms (453.9 (±180.3) CFU (colony-forming units)/100 mL), fecal coliforms (243.2 (±99.2) CFU/100 mL), and fecal streptococci (77.9 (±32.0) CFU/100 mL) loads were above the standard limits set by the WHO. These results confirmed that water resources in the study area were strongly influenced by anthropogenic activities and were not recommended for consumption as drinking water.
分类： 地球科学 >> 水文学 提交时间： 2024-02-07 合作期刊: 《干旱区科学》
摘要： Groundwater quality assessment is important to assure safe and durable water use. In semi-arid areas of Algeria, groundwater represents the main water resource for drinking water supply of the rural population as well as for irrigation of agricultural lands. Groundwater samples from wells and springs were collected from the Gargaat Tarf and Annk Djemel sub-watersheds of the Oum El Bouaghi, Algeria, and were analyzed and compared with the World Health Organization (WHO) standards. Results showed that most of the measured physical and chemical parameters exceeded the quality limits according to the WHO standards. Groundwater had a slightly alkaline water pH (7.007.79), electrical conductivity>1500 S/cm, chloride>500 mg/L, calcium>250 mg/L, and magnesium>155 mg/L. Water quality index (WQI) results showed that 68% of the area had excellent water quality, 24% of the samples fell into good category, and only 8% were of poor quality and unsuitable for human consumption. Six wells in the area showed bacterial contamination. Total coliforms (453.9 (180.3) CFU (colony-forming units)/100 mL), fecal coliforms (243.2 (99.2) CFU/100 mL), and fecal streptococci (77.9 (32.0) CFU/100 mL) loads were above the standard limits set by the WHO. These results confirmed that water resources in the study area were strongly influenced by anthropogenic activities and were not recommended for consumption as drinking water.
分类： 地球科学 >> 水文学 提交时间： 2024-02-07 合作期刊: 《干旱区科学》
摘要： Groundwater quality assessment is important to assure safe and durable water use. In semi-arid areas of Algeria, groundwater represents the main water resource for drinking water supply of the rural population as well as for irrigation of agricultural lands. Groundwater samples from wells and springs were collected from the Gargaat Tarf and Annk Djemel sub-watersheds of the Oum El Bouaghi, Algeria, and were analyzed and compared with the World Health Organization (WHO) standards. Results showed that most of the measured physical and chemical parameters exceeded the quality limits according to the WHO standards. Groundwater had a slightly alkaline water pH (7.007.79), electrical conductivity>1500 S/cm, chloride>500 mg/L, calcium>250 mg/L, and magnesium>155 mg/L. Water quality index (WQI) results showed that 68% of the area had excellent water quality, 24% of the samples fell into good category, and only 8% were of poor quality and unsuitable for human consumption. Six wells in the area showed bacterial contamination. Total coliforms (453.9 (180.3) CFU (colony-forming units)/100 mL), fecal coliforms (243.2 (99.2) CFU/100 mL), and fecal streptococci (77.9 (32.0) CFU/100 mL) loads were above the standard limits set by the WHO. These results confirmed that water resources in the study area were strongly influenced by anthropogenic activities and were not recommended for consumption as drinking water.
分类： 核科学技术 >> 核探测技术与核电子学 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： Based on the statistical characteristics of energy spectrum and the features of spectrum-shifting in spectrometry, the parameter adjustment method of Gaussian function space was applied in the simulation of spectrum-shifting. The transient characteristics of energy spectrum were described by the Gaussian function space, and then the Gaussian function space was transferred by parameter adjustment method. Furthermore, the spectrum-shifting in measurement of energy spectrum was simulated. The applied example shows that the parameters can be adjusted flexibly by this method to meet the various requirements in simulation of energy spectrum-shifting. This method was one parameterized simulation method with good performance for the practical application.
分类： 计算机科学 >> 计算机软件 提交时间： 2022-12-07
摘要： For real parameter single objective optimization, Differential Evolution (DE) and Covariance Matrix Adaptation Evolution Strategy (CMA-ES) both perform powerfully. Nevertheless, in the field of real parameter single objective optimization, it is impossible for a given algorithm to perform well in all fitness landscapes. Practice has proved that ensemble of different algorithms may lead to improvement in solution. In this paper, based on two famous population-based metaheuristics - LSHADE-EpSin and HS-ES, we propose ensemble with successively executed constituent algorithms - HS-ES-DE. In our algorithm, HS-ES is replaced by L-SHADE-EpSin after stagnation is detected. Beside our HS-ES-DE, 12 population-based metaheuristics are involved in our experiments in which three benchmark test suites are employed. Experimental results show that our algorithm is very competitive.
分类： 天文学 >> 天文仪器与技术 提交时间： 2025-04-24 合作期刊: 《Astronomical Techniques and Instruments》
Ting Zhang
Hailong Zhang
Yazhou Zhang
Xu Du
Wenna Cai
Han Wu
Yuyue Jiao
Wanqiong Wang
Jie Wang
Xinchen Ye
Jia Li
摘要： Astronomical spectroscopy is crucial for exploring the physical properties, chemical composition, and kinematic behavior of celestial objects. With continuous advancements in observational technology, astronomical spectroscopy faces the dual challenges of rapidly expanding data volumes and relatively lagging data processing capabilities. In this context, the rise of artificial intelligence technologies offers an innovative solution to address these challenges. This paper analyzes the latest developments in the application of machine learning for astronomical spectral data mining and discusses future research directions in AI-based spectral studies. However, the application of machine learning technologies presents several challenges. The high complexity of models often comes with insufficient interpretability, complicating scientific understanding. Moreover, the large-scale computational demands place higher requirements on hardware resources, leading to a significant increase in computational costs. AI-based astronomical spectroscopy research should advance in the following key directions. First, develop efficient data augmentation techniques to enhance model generalization capabilities. Second, explore more interpretable model designs to ensure the reliability and transparency of scientific conclusions. Third, optimize computational efficiency and reduce the threshold for deep-learning applications through collaborative innovations in algorithms and hardware. Furthermore, promoting the integration of cross-band data processing is essential to achieve seamless integration and comprehensive analysis of multi-source data, providing richer, multidimensional information to uncover the mysteries of the universe.
分类： 核科学技术 >> 辐射物理与技术 提交时间： 2025-04-07
Xiang-Fei Wang
Kai-Jie Chen
Hang-Hua Xu
Gong-Tao Fan
Zi-Rui Hao
Zhen-Wei Wang
Long-Xiang Liu
Yue Zhang
Sheng Jin
Qian-kun Sun
Zhi-Cai Li
Pu Jiao
Meng-Die Zhou
Yu-Long Shen
Meng-Ke Xu
Hong-Wei Wang
摘要： A Monte Carlo simulation code and an analytical calculation code for polarization study were developed at Shanghai Laser Gamma Source (SLEGS), employing the unique laser Compton slant scattering (LCSS) mode. The intensity of spatial distributions and its Stokes parameters are simulated for LCSS of linearly/circularly polarized laser photons and unpolarized relativistic electrons. The polarization degree of the incident photon is almost completely transferred to the scattered gamma rays for any incident angle. For a linearly polarized laser incident in a fixed direction, the direction of polarization of the scattered gamma-ray changes with the scattering angle. The measured polarization direction and size of the scattered gamma spatial distribution are in general agreement with the simulation in the linearly polarized laser case.
分类： 物理学 >> 核物理学 提交时间： 2016-09-13
摘要： In this paper we showed a systematic method of appropriate parameter choice for a circular pp collider by using analytical expression of beam-beam tune shift limit started from given design goal and technical limitations. A parameter space has been explored. Based on parameters scan and considerations from RF systems, a set of appropriate parameter designed for a 50Km and a 100Km circular proton-proton collider was proposed.
分类： 核科学技术 >> 核探测技术与核电子学 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： On the basis of preliminary studies, a novel duo-parameter model consisting of amplitude filter factor and frequency filter factor for low-pass S-K filter is presented in this paper. The model is established by applying numerical differentiation method. Some simulation experiments and real data tests are carried out to verify the feasibility and superiority of the new algorithm. The results show that this duo-parameter model of low-pass S-K filter can be used to achieve high performance in signal processing and nuclear spectrum smoothing.
分类： 物理学 分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-12-28
摘要： We examine the parameter space of the constrained MSSM by considering various experimental constraints. For the dark matter sector, we require the neutralino dark matter to account for the relic density measured by the WMAP and satisfy the XENON limits on
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