期刊文献+
共找到15,275篇文章
< 1 2 250 >
每页显示 20 50 100
基于Gaussian、ECOSAR模型的紫外/次氯酸体系降解含卤阻燃剂的产物预测与毒性评估 被引量:1
1
作者 卢志磊 范勇杰 +3 位作者 陈洁洁 杨婧 吴春山 孙启元 《环境化学》 CAS CSCD 北大核心 2024年第1期82-91,共10页
含卤阻燃剂广泛应用于各类电子产品的生产,难降解且具有生物毒性.在生产和使用过程中,部分含卤阻燃剂会残留在水体并排放到水环境造成累积污染,威胁水环境安全,亟需探寻有效的降解去毒方法.本研究通过Gaussian与ECOSAR模型预测了四氯双... 含卤阻燃剂广泛应用于各类电子产品的生产,难降解且具有生物毒性.在生产和使用过程中,部分含卤阻燃剂会残留在水体并排放到水环境造成累积污染,威胁水环境安全,亟需探寻有效的降解去毒方法.本研究通过Gaussian与ECOSAR模型预测了四氯双酚A(TCBPA)、四溴双酚A(TBBPA)、十溴二苯乙烷(DBDPE)等3种典型含卤阻燃剂在紫外/次氯酸(UV/Cl)体系中的光催氧化降解路径与产物毒性.结果表明,UV/Cl体系中的含氯自由基(RCS)与羟基自由基(·OH)易攻击阻燃剂分子结构上键能较低、Fukui指数较高的位点,促使C—Cl键、C—Br键、C—C键等因为受到攻击而断裂,进而降解阻燃剂.同时,利用ECOSAR模型评估发现降解产物的急性毒性LC_(50)-96 h均低于100 mg·L^(-1),佐证了UV/Cl体系对含卤阻燃剂降解的有效性,并降低其环境危害.因此,采用Gaussian计算、ECOSAR模型相结合的分析方法,能够更加便捷地预测阻燃剂降解路径与产物毒性特征,为深入揭示UV/Cl体系光催氧化降解含卤阻燃剂机理提供新思路. 展开更多
关键词 gaussian Fukui指数 ECOSAR模型 含卤阻燃剂 紫外/次氯酸 生物毒性
原文传递
Bose–Einstein distribution temperature features of quasiparticles around magnetopolaron in Gaussian quantum wells of alkali halogen ions
2
作者 Xin Zhang Sarengaowa +7 位作者 Shuang Han Ran An Xin-Xue Zhang Xin-Ying Ji Hong-Xu Jiang Xin-Jun Ma Pei-Fang Li Yong Sun 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期521-526,共6页
We have applied strong coupling unitary transformation method combined with Bose–Einstein statistical law to investigate magnetopolaron energy level temperature effects in halogen ion crystal quantum wells.The obtain... We have applied strong coupling unitary transformation method combined with Bose–Einstein statistical law to investigate magnetopolaron energy level temperature effects in halogen ion crystal quantum wells.The obtained results showed that under magnetic field effect,magnetopolaron quasiparticle was formed through the interaction of electrons and surrounding phonons.At the same time,magnetopolaron was influenced by phonon temperature statistical law and important energy level shifts down and binding energy increases.This revealed that lattice temperature and magnetic field could easily affect magnetopolaron and the above results could play key roles in exploring thermoelectric conversion and conductivity of crystal materials. 展开更多
关键词 temperature effect quantum well asymmetric gaussian potential MAGNETOPOLARON
原文传递
Quantum correlations and entanglement in coupled optomechanical resonators with photon hopping via Gaussian interferometric power analysis
3
作者 Y.Lahlou B.Maroufi M.Daoud 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期204-211,共8页
Quantum correlations that surpass entanglement are of great importance in the realms of quantum information processing and quantum computation.Essentially,for quantum systems prepared in pure states,it is difficult to... Quantum correlations that surpass entanglement are of great importance in the realms of quantum information processing and quantum computation.Essentially,for quantum systems prepared in pure states,it is difficult to differentiate between quantum entanglement and quantum correlation.Nonetheless,this indistinguishability is no longer holds for mixed states.To contribute to a better understanding of this differentiation,we have explored a simple model for both generating and measuring these quantum correlations.Our study concerns two macroscopic mechanical resonators placed in separate Fabry–Pérot cavities,coupled through the photon hopping process.this system offers a comprehensively way to investigate and quantify quantum correlations beyond entanglement between these mechanical modes.The key ingredient in analyzing quantum correlation in this system is the global covariance matrix.It forms the basis for computing two essential metrics:the logarithmic negativity(E_(N)^(m))and the Gaussian interferometric power(P_(G)^(m)).These metrics provide the tools to measure the degree of quantum entanglement and quantum correlations,respectively.Our study reveals that the Gaussian interferometric power(P_(G)^(m))proves to be a more suitable metric for characterizing quantum correlations among the mechanical modes in an optomechanical quantum system,particularly in scenarios featuring resilient photon hopping. 展开更多
关键词 quantum correlations ENTANGLEMENT gaussian interferometric power logarithmic negativity optomechanics photon hopping
原文传递
Reliable calculations of nuclear binding energies by the Gaussian process of machine learning
4
作者 Zi-Yi Yuan Dong Bai +1 位作者 Zhen Wang Zhong-Zhou Ren 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第6期130-144,共15页
Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the ... Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the nuclear binding energies are modeled directly using a machine-learning method called the Gaussian process. First, the binding energies for 2238 nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ability of the Gaussian process in the studies of binding energies. Then, the predictive power of the Gaussian process is studied by calculating the binding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeably, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 834, 137484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding energies and α-decay properties. 展开更多
关键词 Nuclear binding energies DECAY Machine learning gaussian process
下载PDF
MULTIPLE INTERSECTIONS OF SPACE-TIME ANISOTROPIC GAUSSIAN FIELDS
5
作者 陈振龙 苑伟杰 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期275-294,共20页
Let X={X(t)∈R^(d),t∈R^(N)}be a centered space-time anisotropic Gaussian field with indices H=(H_(1),…,H_(N))∈(0,1)~N,where the components X_(i)(i=1,…,d)of X are independent,and the canonical metric√(E(X_(i)(t)-X... Let X={X(t)∈R^(d),t∈R^(N)}be a centered space-time anisotropic Gaussian field with indices H=(H_(1),…,H_(N))∈(0,1)~N,where the components X_(i)(i=1,…,d)of X are independent,and the canonical metric√(E(X_(i)(t)-X_(i)(s))^(2))^(1/2)(i=1,…,d)is commensurate with■for s=(s_(1),…,s_(N)),t=(t_(1),…,t_(N))∈R~N,α_(i)∈(0,1],and with the continuous functionγ(·)satisfying certain conditions.First,the upper and lower bounds of the hitting probabilities of X can be derived from the corresponding generalized Hausdorff measure and capacity,which are based on the kernel functions depending explicitly onγ(·).Furthermore,the multiple intersections of the sample paths of two independent centered space-time anisotropic Gaussian fields with different distributions are considered.Our results extend the corresponding results for anisotropic Gaussian fields to a large class of space-time anisotropic Gaussian fields. 展开更多
关键词 anisotropic gaussian field multiple intersections Hausdorff measure capacity
下载PDF
Application of Gaussian Beam Summation Migration in Reflected In-seam Wave Imaging
6
作者 HAN Jianguang LÜQingtian +2 位作者 ZHANG Zhiheng YANG Shun WANG Shuo 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第1期276-284,共9页
The geological conditions for coal mining in China are complex,with various structural issues such as faults and collapsed columns seriously compromising the safety of coal mine production.In-seam wave exploration is ... The geological conditions for coal mining in China are complex,with various structural issues such as faults and collapsed columns seriously compromising the safety of coal mine production.In-seam wave exploration is an effective technique for acquiring detailed information on geological structures in coal seam working faces.However,the existing reflected in-seam wave imaging technique can no longer meet the exploration precision requirements,making it imperative to develop a new reflected in-seam wave imaging technique.This study applies the Gaussian beam summation(GBS)migration method to imaging coal seams'reflected in-seam wave data.Firstly,with regard to the characteristics of the reflected in-seam wave data,methods such as wavefield removal and enveloped superposition are employed for the corresponding wavefield separation,wave train compression and other processing of reflected in-seam waves.Thereafter,imaging is performed using the GBS migration technique.The feasibility and effectiveness of the proposed method for reflected in-seam wave imaging are validated by conducting GBS migration tests on 3D coal-seam fault models with different dip angles and throws.By applying the method to reflected in-seam wave data for an actual coal seam working face,accurate imaging of a fault structure is obtained,thereby validating its practicality. 展开更多
关键词 reflected in-seam wave gaussian beam summation migration numerical tests fault
下载PDF
Bessel–Gaussian beam-based orbital angular momentum holography
7
作者 季佳滢 郑志刚 +3 位作者 朱家龙 王乐 王新光 赵生妹 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期407-413,共7页
Orbital angular momentum(OAM), as a new degree of freedom, has recently been applied in holography technology.Due to the infinite helical mode index of OAM mode, a large number of holographic images can be reconstruct... Orbital angular momentum(OAM), as a new degree of freedom, has recently been applied in holography technology.Due to the infinite helical mode index of OAM mode, a large number of holographic images can be reconstructed from an OAM-multiplexing hologram. However, the traditional design of an OAM hologram is constrained by the helical mode index of the selected OAM mode, for a larger helical mode index OAM mode has a bigger sampling distance, and the crosstalk is produced for different sampling distances for different OAM modes. In this paper, we present the design of the OAM hologram based on a Bessel–Gaussian beam, which is non-diffractive and has a self-healing property during its propagation. The Fourier transform of the Bessel–Gaussian beam is the perfect vortex mode that has the fixed ring radius for different OAM modes. The results of simulation and experiment have demonstrated the feasibility of the generation of the OAM hologram with the Bessel–Gaussian beam. The quality of the reconstructed holographic image is increased, and the security is enhanced. Additionally, the anti-interference property is improved owing to its self-healing property of the Bessel-OAM holography. 展开更多
关键词 orbital angular momentum HOLOGRAPHY Bessel–gaussian beam OAM-multiplexing hologram
原文传递
Persymmetric adaptive polarimetric detection of subspace range-spread targets in compound Gaussian sea clutter
8
作者 XU Shuwen HAO Yifan +1 位作者 WANG Zhuo XUE Jian 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2024年第1期31-42,共12页
This paper focuses on the adaptive detection of range and Doppler dual-spread targets in non-homogeneous and nonGaussian sea clutter.The sea clutter from two polarimetric channels is modeled as a compound-Gaussian mod... This paper focuses on the adaptive detection of range and Doppler dual-spread targets in non-homogeneous and nonGaussian sea clutter.The sea clutter from two polarimetric channels is modeled as a compound-Gaussian model with different parameters,and the target is modeled as a subspace rangespread target model.The persymmetric structure is used to model the clutter covariance matrix,in order to reduce the reliance on secondary data of the designed detectors.Three adaptive polarimetric persymmetric detectors are designed based on the generalized likelihood ratio test(GLRT),Rao test,and Wald test.All the proposed detectors have constant falsealarm rate property with respect to the clutter texture,the speckle covariance matrix.Experimental results on simulated and measured data show that three adaptive detectors outperform the competitors in different clutter environments,and the proposed GLRT detector has the best detection performance under different parameters. 展开更多
关键词 sea clutter adaptive polarimetric detection compound gaussian model subspace range-spread target persymmetric structure
下载PDF
MAXIMAL FUNCTION CHARACTERIZATIONS OF HARDY SPACES ASSOCIATED WITH BOTH NON-NEGATIVE SELF-ADJOINT OPERATORS SATISFYING GAUSSIAN ESTIMATES AND BALL QUASI-BANACH FUNCTION SPACES
9
作者 林孝盛 杨大春 +1 位作者 杨四辈 袁文 《Acta Mathematica Scientia》 SCIE CSCD 2024年第2期484-514,共31页
Assume that L is a non-negative self-adjoint operator on L^(2)(ℝ^(n))with its heat kernels satisfying the so-called Gaussian upper bound estimate and that X is a ball quasi-Banach function space onℝ^(n) satisfying som... Assume that L is a non-negative self-adjoint operator on L^(2)(ℝ^(n))with its heat kernels satisfying the so-called Gaussian upper bound estimate and that X is a ball quasi-Banach function space onℝ^(n) satisfying some mild assumptions.Let HX,L(ℝ^(n))be the Hardy space associated with both X and L,which is defined by the Lusin area function related to the semigroup generated by L.In this article,the authors establish various maximal function characterizations of the Hardy space HX,L(ℝ^(n))and then apply these characterizations to obtain the solvability of the related Cauchy problem.These results have a wide range of generality and,in particular,the specific spaces X to which these results can be applied include the weighted space,the variable space,the mixed-norm space,the Orlicz space,the Orlicz-slice space,and the Morrey space.Moreover,the obtained maximal function characterizations of the mixed-norm Hardy space,the Orlicz-slice Hardy space,and the Morrey-Hardy space associated with L are completely new. 展开更多
关键词 Hardy space ball quasi-Banach function space gaussian upper bound estimate non-negative self-adjoint operator maximal function
下载PDF
Operational optimization of copper flotation process based on the weighted Gaussian process regression and index-oriented adaptive differential evolution algorithm
10
作者 Zhiqiang Wang Dakuo He Haotian Nie 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期167-179,共13页
Concentrate copper grade(CCG)is one of the important production indicators of copper flotation processes,and keeping the CCG at the set value is of great significance to the economic benefit of copper flotation indust... Concentrate copper grade(CCG)is one of the important production indicators of copper flotation processes,and keeping the CCG at the set value is of great significance to the economic benefit of copper flotation industrial processes.This paper addresses the fluctuation problem of CCG through an operational optimization method.Firstly,a density-based affinity propagationalgorithm is proposed so that more ideal working condition categories can be obtained for the complex raw ore properties.Next,a Bayesian network(BN)is applied to explore the relationship between the operational variables and the CCG.Based on the analysis results of BN,a weighted Gaussian process regression model is constructed to predict the CCG that a higher prediction accuracy can be obtained.To ensure the predicted CCG is close to the set value with a smaller magnitude of the operation adjustments and a smaller uncertainty of the prediction results,an index-oriented adaptive differential evolution(IOADE)algorithm is proposed,and the convergence performance of IOADE is superior to the traditional differential evolution and adaptive differential evolution methods.Finally,the effectiveness and feasibility of the proposed methods are verified by the experiments on a copper flotation industrial process. 展开更多
关键词 Weighted gaussian process regression Index-oriented adaptive differential evolution Operational optimization Copper flotation process
下载PDF
A Gaussian Noise-Based Algorithm for Enhancing Backdoor Attacks
11
作者 Hong Huang Yunfei Wang +1 位作者 Guotao Yuan Xin Li 《Computers, Materials & Continua》 SCIE EI 2024年第7期361-387,共27页
Deep Neural Networks(DNNs)are integral to various aspects of modern life,enhancing work efficiency.Nonethe-less,their susceptibility to diverse attack methods,including backdoor attacks,raises security concerns.We aim... Deep Neural Networks(DNNs)are integral to various aspects of modern life,enhancing work efficiency.Nonethe-less,their susceptibility to diverse attack methods,including backdoor attacks,raises security concerns.We aim to investigate backdoor attack methods for image categorization tasks,to promote the development of DNN towards higher security.Research on backdoor attacks currently faces significant challenges due to the distinct and abnormal data patterns of malicious samples,and the meticulous data screening by developers,hindering practical attack implementation.To overcome these challenges,this study proposes a Gaussian Noise-Targeted Universal Adversarial Perturbation(GN-TUAP)algorithm.This approach restricts the direction of perturbations and normalizes abnormal pixel values,ensuring that perturbations progress as much as possible in a direction perpendicular to the decision hyperplane in linear problems.This limits anomalies within the perturbations improves their visual stealthiness,and makes them more challenging for defense methods to detect.To verify the effectiveness,stealthiness,and robustness of GN-TUAP,we proposed a comprehensive threat model.Based on this model,extensive experiments were conducted using the CIFAR-10,CIFAR-100,GTSRB,and MNIST datasets,comparing our method with existing state-of-the-art attack methods.We also tested our perturbation triggers using various defense methods and further experimented on the robustness of the triggers against noise filtering techniques.The experimental outcomes demonstrate that backdoor attacks leveraging perturbations generated via our algorithm exhibit cross-model attack effectiveness and superior stealthiness.Furthermore,they possess robust anti-detection capabilities and maintain commendable performance when subjected to noise-filtering methods. 展开更多
关键词 Image classification model backdoor attack gaussian distribution Artificial Intelligence(AI)security
下载PDF
Optimization of Generator Based on Gaussian Process Regression Model with Conditional Likelihood Lower Bound Search
12
作者 Xiao Liu Pingting Lin +2 位作者 Fan Bu Shaoling Zhuang Shoudao Huang 《CES Transactions on Electrical Machines and Systems》 EI CSCD 2024年第1期32-42,共11页
The noise that comes from finite element simulation often causes the model to fall into the local optimal solution and over fitting during optimization of generator.Thus,this paper proposes a Gaussian Process Regressi... The noise that comes from finite element simulation often causes the model to fall into the local optimal solution and over fitting during optimization of generator.Thus,this paper proposes a Gaussian Process Regression(GPR)model based on Conditional Likelihood Lower Bound Search(CLLBS)to optimize the design of the generator,which can filter the noise in the data and search for global optimization by combining the Conditional Likelihood Lower Bound Search method.Taking the efficiency optimization of 15 kW Permanent Magnet Synchronous Motor as an example.Firstly,this method uses the elementary effect analysis to choose the sensitive variables,combining the evolutionary algorithm to design the super Latin cube sampling plan;Then the generator-converter system is simulated by establishing a co-simulation platform to obtain data.A Gaussian process regression model combing the method of the conditional likelihood lower bound search is established,which combined the chi-square test to optimize the accuracy of the model globally.Secondly,after the model reaches the accuracy,the Pareto frontier is obtained through the NSGA-II algorithm by considering the maximum output torque as a constraint.Last,the constrained optimization is transformed into an unconstrained optimizing problem by introducing maximum constrained improvement expectation(CEI)optimization method based on the re-interpolation model,which cross-validated the optimization results of the Gaussian process regression model.The above method increase the efficiency of generator by 0.76%and 0.5%respectively;And this method can be used for rapid modeling and multi-objective optimization of generator systems. 展开更多
关键词 Generator optimization gaussian Process Regression(GPR) Conditional Likelihood Lower Bound Search(CLLBS) Constraint improvement expectation(CEI) Finite element calculation
下载PDF
State of health prediction for lithium-ion batteries based on ensemble Gaussian process regression
13
作者 HUI Zhouli WANG Ruijie +1 位作者 FENG Nana YANG Ming 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2024年第3期397-407,共11页
The performance of lithium-ion batteries(LIBs)gradually declines over time,making it critical to predict the battery’s state of health(SOH)in real-time.This paper presents a model that incorporates health indicators ... The performance of lithium-ion batteries(LIBs)gradually declines over time,making it critical to predict the battery’s state of health(SOH)in real-time.This paper presents a model that incorporates health indicators and ensemble Gaussian process regression(EGPR)to predict the SOH of LIBs.Firstly,the degradation process of an LIB is analyzed through indirect health indicators(HIs)derived from voltage and temperature during discharge.Next,the parameters in the EGPR model are optimized using the gannet optimization algorithm(GOA),and the EGPR is employed to estimate the SOH of LIBs.Finally,the proposed model is tested under various experimental scenarios and compared with other machine learning models.The effectiveness of EGPR model is demonstrated using the National Aeronautics and Space Administration(NASA)LIB.The root mean square error(RMSE)is maintained within 0.20%,and the mean absolute error(MAE)is below 0.16%,illustrating the proposed approach’s excellent predictive accuracy and wide applicability. 展开更多
关键词 lithium-ion batteryies(LIBs) ensemble gaussian process regression(EGPR) state of health(SOH) health indicators(HIs) gannet optimization algorithm(GOA)
下载PDF
基于深度学习的Hermite-Gaussian光束模式分析方法研究
14
作者 张杰辉 白振旭 +2 位作者 安嘉硕 王雨雷 吕志伟 《河北工业大学学报》 CAS 2024年第5期13-21,共9页
提出了一种基于深度学习的Hermite-Gaussian(HG)光束模式分解方案,利用仿真生成的具有多个模式的模拟样本训练卷积神经网络,并通过训练好的模式识别网络采用迁移学习技术加速模式分解网络的训练过程。通过单次发射的强度图像,训练后的... 提出了一种基于深度学习的Hermite-Gaussian(HG)光束模式分解方案,利用仿真生成的具有多个模式的模拟样本训练卷积神经网络,并通过训练好的模式识别网络采用迁移学习技术加速模式分解网络的训练过程。通过单次发射的强度图像,训练后的神经网络能够对四模以内所有模式的HG光束实现高效准确的模式分解,获取HG光束的模式振幅和相位信息。实验结果表明,该方法在不同模式数量的识别和分解任务中均表现出较高的精度和稳定性,有望在光通信、光学成像、激光加工等领域得到广泛应用。 展开更多
关键词 深度学习 Hermite-gaussian光束 模式分解 迁移学习 模式识别
下载PDF
Designing Pair of Nonlinear Components of a Block Cipher over Gaussian Integers 被引量:1
15
作者 Muhammad Sajjad Tariq Shah Robinson Julian Serna 《Computers, Materials & Continua》 SCIE EI 2023年第6期5287-5305,共19页
In block ciphers,the nonlinear components,also known as sub-stitution boxes(S-boxes),are used with the purpose of inducing confusion in cryptosystems.For the last decade,most of the work on designing S-boxes over the ... In block ciphers,the nonlinear components,also known as sub-stitution boxes(S-boxes),are used with the purpose of inducing confusion in cryptosystems.For the last decade,most of the work on designing S-boxes over the points of elliptic curves has been published.The main purpose of these studies is to hide data and improve the security levels of crypto algorithms.In this work,we design pair of nonlinear components of a block cipher over the residue class of Gaussian integers(GI).The fascinating features of this structure provide S-boxes pair at a time by fixing three parameters.But the prime field dependent on the Elliptic curve(EC)provides one S-box at a time by fixing three parameters a,b,and p.The newly designed pair of S-boxes are assessed by various tests like nonlinearity,bit independence criterion,strict avalanche criterion,linear approximation probability,and differential approximation probability. 展开更多
关键词 gaussian integers residue class of gaussian integers block cipher S-boxes analysis of S-boxes
下载PDF
基于格林函数法研究分数阶Bessel-Gaussian光束近场传输
16
作者 施继忠 任志君 董永胜 《浙江师范大学学报(自然科学版)》 CAS 2023年第2期139-145,共7页
为揭示FBG(fractional-order Bessel-Gaussian)光束在近场传输时的光强和相位演化情况,基于光传播的独立性和叠加性原理,通过引入虚光源点,并结合格林函数法,严格推导了FBG光束的非傍轴积分表达式,并进一步利用非傍轴下的各阶修正解,精... 为揭示FBG(fractional-order Bessel-Gaussian)光束在近场传输时的光强和相位演化情况,基于光传播的独立性和叠加性原理,通过引入虚光源点,并结合格林函数法,严格推导了FBG光束的非傍轴积分表达式,并进一步利用非傍轴下的各阶修正解,精确计算了FBG光束轴上的光强分布.计算结果表明:对于分数阶Bessel-Gaussian光束的远场传输,利用经典的傍轴近似理论可以得到准确的计算结果,但在近场传输时,傍轴近似理论的计算结果误差很大,只有利用非傍轴修正解才能精确研究FBG光束的近场光学传输.研究结果为将FBG光束更好地应用于近场光学奠定必要的理论基础. 展开更多
关键词 格林函数法 分数阶Bessel-gaussian(FBG)光束 虚点源 近场传输
下载PDF
Gaussian和Multiwfn软件在计算制冷剂介电常数中的应用
17
作者 马跃 吴学秋 +1 位作者 杨敏 宋卫余 《广州化工》 CAS 2023年第14期147-150,共4页
物理化学的主要研究内容之一是化学体系的微观结构和性质。介电常数是物质的重要物理量,与物质的电子结构紧密相关。结合物理化学分析方法,利用Gaussian和Multiwfn软件对制冷剂材料的介电常数进行了探究,并与相应的实验值进行了对比分... 物理化学的主要研究内容之一是化学体系的微观结构和性质。介电常数是物质的重要物理量,与物质的电子结构紧密相关。结合物理化学分析方法,利用Gaussian和Multiwfn软件对制冷剂材料的介电常数进行了探究,并与相应的实验值进行了对比分析。通过结合分子可视化和量子化学计算软件,提高了化学教学的生动性,将该研究方法用于课堂教学,激发学生的研究兴趣,有利于学生对相关知识的理解。 展开更多
关键词 物理化学 介电常数 gaussian 09软件 Multiwfn软件
下载PDF
The asymptotic relation between the first crossing point and the last exit time of Gaussian order statistics sequences
18
作者 NING Zi-jun TAN Zhong-quan 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第4期545-561,共17页
In this paper,we study the asymptotic relation between the first crossing point and the last exit time for Gaussian order statistics which are generated by stationary weakly and strongly dependent Gaussian sequences.I... In this paper,we study the asymptotic relation between the first crossing point and the last exit time for Gaussian order statistics which are generated by stationary weakly and strongly dependent Gaussian sequences.It is shown that the first crossing point and the last exit time are asymptotically independent and dependent for weakly and strongly dependent cases,respectively.The asymptotic relations between the first crossing point and the last exit time for stationary weakly and strongly dependent Gaussian sequences are also obtained. 展开更多
关键词 rst crossing point last exit time stationary gaussian sequences gaussian order statistic se-quences
下载PDF
A Robust Indoor Localization Algorithm Based on Polynomial Fitting and Gaussian Mixed Model 被引量:2
19
作者 Long Cheng Peng Zhao +1 位作者 Dacheng Wei Yan Wang 《China Communications》 SCIE CSCD 2023年第2期179-197,共19页
Wireless sensor network(WSN)positioning has a good effect on indoor positioning,so it has received extensive attention in the field of positioning.Non-line-of sight(NLOS)is a primary challenge in indoor complex enviro... Wireless sensor network(WSN)positioning has a good effect on indoor positioning,so it has received extensive attention in the field of positioning.Non-line-of sight(NLOS)is a primary challenge in indoor complex environment.In this paper,a robust localization algorithm based on Gaussian mixture model and fitting polynomial is proposed to solve the problem of NLOS error.Firstly,fitting polynomials are used to predict the measured values.The residuals of predicted and measured values are clustered by Gaussian mixture model(GMM).The LOS probability and NLOS probability are calculated according to the clustering centers.The measured values are filtered by Kalman filter(KF),variable parameter unscented Kalman filter(VPUKF)and variable parameter particle filter(VPPF)in turn.The distance value processed by KF and VPUKF and the distance value processed by KF,VPUKF and VPPF are combined according to probability.Finally,the maximum likelihood method is used to calculate the position coordinate estimation.Through simulation comparison,the proposed algorithm has better positioning accuracy than several comparison algorithms in this paper.And it shows strong robustness in strong NLOS environment. 展开更多
关键词 wireless sensor network indoor localization NLOS environment gaussian mixture model(GMM) fitting polynomial
下载PDF
2D Q-compensated multi-component elastic Gaussian beam migration 被引量:1
20
作者 Chao Chen Ji-Dong Yang +2 位作者 Xin-Ru Mu Zhen-Chun Li Jian-Ping Huang 《Petroleum Science》 SCIE EI CAS CSCD 2023年第1期230-240,共11页
Elastic waves are affected by viscoelasticity during the propagation through the Earth,resulting in energy attenuation and phase distortion,in turn resulting in low seismic imaging accuracy.Therefore,viscoelasticity s... Elastic waves are affected by viscoelasticity during the propagation through the Earth,resulting in energy attenuation and phase distortion,in turn resulting in low seismic imaging accuracy.Therefore,viscoelasticity should be considered in seismic migration imaging.We propose a Q compensated multicomponent elastic Gaussian beam migration(Q-EGBM)method to(1)separate the elastic-wave data into longitudinal(P)and transverse(S)waves to perform PP-wave and PS-wave imaging;(2)recover the amplitude loss caused by attenuation;(3)correct phase distortions caused by dispersion;(4)improve the resolution of migration imaging.In this paper,to accomplish(2),(3),and(4),we derive complex-valued traveltimes in viscoelastic media.The results of numerical experiments using a simple five-layer model and a sophisticated BP gas model show that the method presented here has significant advantages in recovering energy decay and correcting phase distortion,as well as significantly improving imaging resolution. 展开更多
关键词 Q-compensated VISCOELASTIC gaussian beam migration MULTI-COMPONENT Absorption attenuation
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部