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Journal of Computational Mathematics 2022年第5期40卷 814-834页

作者： huan Liu Xiangcheng zheng Hongfei Fu School of Mathematical Sciences Fudan UniversityShanghai 200433China School of Mathematical Sciences Peking UniversityBeijing 100871China School of Mathematical Sciences Ocean University of ChinaQingdao 266100China

In this paper,we study the well-posedness and solution regularity of a multi-term variable-order time-fractional diffusion equation,and then develop an optimal Galerkin finite element scheme without any regularity assumption on its true *** show that the solution regularity of the considered problem can be affected by the maximum value of variable-order at initial time t=*** precisely,we prove that the solution to the multi-term variable-order time-fractional diffusion equation belongs to C 2([0,T])in time provided that the maximum value has an integer limit near the initial time and the data has sufficient smoothness,otherwise the solution exhibits the same singular behavior like its constant-order *** on these regularity results,we prove optimalorder convergence rate of the Galerkin finite element ***,we develop an efficient parallel-in-time algorithm to reduce the computational costs of the evaluation of multi-term variable-order fractional *** experiments are put forward to verify the theoretical findings and to demonstrate the efficiency of the proposed scheme.

关键词： Variable-order Multi-term time-fractional diffusion equation Solution regularity Galerkin finite element Parareal method.

Rapid and robust initialization for monocular visual inertial navigation within multi-state Kalman filter

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Chinese Journal of Aeronautics 2018年第1期31卷 148-160页

作者： Wei fang Lianyu zheng School of Mechanical Engineering and Automation Beihang University

Sensor-fusion based navigation attracts significant attentions for its robustness and accuracy in various applications. To achieve a versatile and efficient state estimation both indoor and outdoor, this paper presents an improved monocular visual inertial navigation architecture within the Multi-State Constraint Kalman Filter （MSCKF）. In addition, to alleviate the initialization demands by appending enough stable poses in MSCKF, a rapid and robust Initialization MSCKF （I-MSCKF） navigation method is proposed in the paper. Based on the trifocal tensor and sigmapoint filter, the initialization of the integrated navigation can be accomplished within three consecutive visual frames. Thus, the proposed I-MSCKF method can improve the navigation performance when suffered from shocks at the initial stage. Moreover, the sigma-point filter is applied at initial stage to improve the accuracy for state estimation. The state vector generated at initial stage from the proposed method is consistent with MSCKF, and thus a seamless transition can be achieved between the initialization and the subsequent navigation in I-MSCKF. Finally, the experimental results show that the proposed I-MSCKF method can improve the robustness and accuracy for monocular visual inertial navigations.

关键词： Estimator initialization Navigation Kalman filter Pose estimation Visual inertial fusion

A TWO-STAGE ALGORITHM OF NUMERICAL EVALUATIONOF INTEGRALS IN NUMBER-THEORETIC METHODS

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Journal of Computational Mathematics 1999年第3期17卷 285-292页

作者： fang, KT zheng, ZK Hong Kong Baptist Univ Dept Math Hong Kong Hong Kong Chinese Acad Sci Inst Appl Math Beijing 100080 Peoples R China Fudan Univ Dept Stat & Operat Res Shanghai 200433 Peoples R China

To improve the numerical evaluation of integrals in Number-Theoretic Methods, we give a two-stage algorithm. The main idea is that we distribute the points according to the variations of the quadrature on the subdomai... 详细信息

关键词： numerical integration Monte Carlo method number-theoretic method

Characterization of eating quality and starch properties of two Wx alleles japonica rice cultivars under different nitrogen treatments

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Journal of Integrative Agriculture 2020年第4期19卷 988-998页

作者： huanG Shuang-jie ZHAO Chun-fang ZHU Zhen ZHOU Li-hui zheng Qing-huan WANG Cai-lin Institute of Food Crops Jiangsu Academy of Agricultural Sciences/Jiangsu High Quality Rice R&D Center/Nanjing Branch of China National Center for Rice ImprovementNanjing 210014P.R.China College of Tea Science Xinyang Agriculture and Forestry UniversityXinyang 464000P.R.China Agri-Tech Extension Center of Wancheng District Nanyang 473000P.R.China

To understand the effect of nitrogen(N) fertilizer on rice(Oryza sativa L.) eating and cooking quality(ECQ). Here, we investigated the ECQ attributes, physicochemical foundation of ECQ, and amylopectin fine structure of two Waxy(Wx) alleles japonica rice cultivars Nanjing 9108(NJ9108) and Huaidao 5(HD5) under four N rates(0, 150, 300, and 450 kg ha^-1). Sensory and pasting properties of the two cultivars varied depending on N rates. Compared with the control(0 kg ha^-1), the overall eating quality and sensory value were significantly decreased under the N rates of 300 and 450 kg ha^-1. Further, conventional descriptive analysis showed that the stickiness and retrogradation of cooked rice were significantly decreased. These results indicated that application of N fertilizer seems to affect the texture of cooked rice, causing it to be less sticky, lowering its retrogradation, and consequently reducing its palatability. Results from rapid visco analyzer(RVA) revealed that the peak and breakdown viscosities significantly decreased, while the setback viscosity and peak time increased under the N rates of 300 and 450 kg ha^-1. However, no significant difference was observed when the N rate was 150 kg ha^-1, indicating that less N fertilization can maintain rice ECQ. As the N rate increasing, protein content increased, whereas apparent amylose content, starch content, and gel consistency almost unchanged. Interestingly, compared with the control, under N treatments, the percentage of short amylopectin branches in NJ9108 was decreased, but increased in HD5, as controlled by amylopectin synthesis-related genes. Notably, SSI and BEIIb were down-regulated in NJ9108, whereas BEIIb was up-regulated in HD5. Thus, the palatability of both rice cultivars was significantly decreased under excessive N fertilization as a consequence of reduced stickiness and retrogradation of the cooked rice, which might have resulted from an elevated protein content and altered amylopectin fine struc

关键词： rice(Oryza sativa L.) nitrogen fertilizer eating and cooking quality amylopectin fine structure

语言模型辅助的英语科技论文摘要语步语料库构建研究

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外语学刊 2025年第1期 29-38页

作者：李洪政王若锦刘芳冯冲北京理工大学外国语学院北京102488 语言工程与认知计算工信部重点实验室北京102488 北京理工大学计算机学院北京100081

语步结构是学术论文中的文本语篇单位,在学术用途英语等方面具有重要价值。尽管关于学术论文的语步研究非常丰富,但语步标注数据资源仍然相对较少。本研究借助自然语言处理领域的语言模型构建了涵盖多个学科领域的英语科技论文摘要语步... 详细信息

语步结构是学术论文中的文本语篇单位,在学术用途英语等方面具有重要价值。尽管关于学术论文的语步研究非常丰富,但语步标注数据资源仍然相对较少。本研究借助自然语言处理领域的语言模型构建了涵盖多个学科领域的英语科技论文摘要语步标注语料库,包括近3.4万个语步结构。语料库构建的第一阶段依靠专家标注形成高质量语料,在第二阶段也是主要阶段,采用基于BERT架构的自动标注模型,在保证标注质量的同时能够快速提升标注速度、扩大标注规模。本研究随后开展了摘要语步自动标注识别实验,对比自动标注模型与大语言模型ChatGPT和Claude3识别不同学科领域的语步结构的效果,验证了模型和语料库的价值。该研究能为科技论文写作智能批改等自然语言处理任务以及学术用途英语等外语教学与研究等提供必要的数据资源,也验证了大语言模型辅助构建语言资源的可能性,体现了语言智能驱动的智慧外语教育的重要性,能有效推动外语教育数字化转型。

关键词：语步结构语料库摘要文本大语言模型

Uniqueness and Radial Symmetry of Least Energy Solution for a Semilinear Neumann Problem

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Acta Mathematicae Applicatae Sinica 2008年第3期24卷 473-482页

作者： zheng-ping Wang huan-song Zhou Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences P.O.Box 71010 Wuhan 430071 China

Consider the following Neumann problem d△u- u ＋ k（x）u^p = 0 and u 〉 0 in B1, δu/δv =0 on OB1,where d 〉 0, B1 is the unit ball in R^N, k（x） = k（｜x｜） ≠ 0 is nonnegative and in C（-↑B1）, 1 〈 p 〈 N＋2/N-2 with N≥ 3. It was shown in [2] that, for any d 〉 0, problem （＊） has no nonconstant radially symmetric least energy solution if k（x） ≡ 1. By an implicit function theorem we prove that there is d0 〉 0 such that （＊） has a unique radially symmetric least energy solution if d 〉 d0, this solution is constant if k（x） ≡ 1 and nonconstant if k（x） ≠ 1. In particular, for k（x） ≡ 1, do can be expressed explicitly.

关键词： Implicit function theorem least energy solution radial symmetry Neumann problem elliptic

Modeling of mechanical behaviors for natural fiber reinforced composites under hygrothermal ageing

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Science China(Physics,Mechanics & Astronomy) 2017年第12期60卷 80-82页

作者： zheng Zhong fang Tian School of Science Harbin Institute of Technology School of Aerospace Engineering and Applied Mechanics Tongji University

In recent years,natural fiber reinforced composites have been widely applied to various industrial products for their excellent environmental-friendly *** is essential to understand the mechanical properties of natural fiber reinforced composites under their in-service *** with synthetic fibers,the hydrophilicity of natural fibers could result in a much larger quantity of water absorption from the moisture atmosphere,which would have adverse consequences for the durability of natural fiber reinforced composites[1].The environmental temperature would affect the

关键词： reinforced durability moisture consequences friendly ageing constitutive have hydrolysis deterioration

Treatment of Pneumocystis jirovecii pneumonia in non-human immunodeficiency virus-infected patients using a combination of trimethoprim-sulfamethoxazole and caspofungin

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World Journal of Clinical Cases 2022年第9期10卷 2743-2750页

作者： huan-huan Wu Shuang-Yan fang Yan-Xiao Chen Lan-fang Feng Department of Respiratory Medicine Dongyang Hospital Affiliated to Wenzhou Medical UniversityDongyang 322100Zhejiang ProvinceChina

BACKGROUND Pneumocystis jirovecii pneumonia(PJP)is an infectious disease common in immunocompromised ***,the currently,the clinical characteristics of non-HIV patients with PJP infection have not been fully *** To explore efficacy of trimethoprim–sulfamethoxazole(TMP-SMX)and caspofungin for treatment of non-human immunodeficiency virus(HIV)-infected PJP *** A retrospective study enrolled 22 patients with non-HIV-infected PJP treated with TMP-SMX and caspofungin from 2019 to *** manifestations,treatment and prognosis of the patients were *** Five patients presented with comorbidity of autoimmune diseases,seven with lung cancer,four with lymphoma,two with organ transplantation and four with membranous nephropathy associated with use of immunosuppressive *** main clinical manifestations of patients were fever,dry cough,and progressive *** patients presented with acute onset and respiratory *** most common imaging manifestation was ground glass opacity around the hilar,mainly in the upper *** patients were diagnosed using next-generation sequencing,and were treated with a combination of TMP-SMX and *** them,17 patients received short-term adjuvant glucocorticoid *** patients recovered well and were discharged from *** Non-HIV-infected PJP have rapid disease progression,high risk of respiratory failure,and high *** of TMP-SMX and caspofungin can effectively treat severe non-HIVinfected PJP patients with respiratory failure.

关键词： Acquired immunodeficiency syndrome Non-human immunodeficiency virus-infected patients Immunosuppression caspofungin Mortality Pneumocystis jirovecii pneumonia

Uniform and Semi-uniform Convergence for Discontinuous Skew-product Transformation and Observation

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Acta Mathematica Sinica,English Series 2021年第2期37卷 333-344页

作者： Xia PAN Zuo huan zheng Zhe ZHOU College of Liberal Arts and Sciences National University of Defense TechnologyChangsha 410073P.R.China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190P.R.China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049P.R.China ollege of Mathematics and Statistics Hainan Normal UniversityHaikou 571158P.R.China

In this paper, for a discontinuous skew-product transformation with the integrable observation function, we obtain uniform ergodic theorem and semi-uniform ergodic theorem. The main assumptions are that discontinuity sets of transformation and observation function are ignorable in some measure-theoretical sense. The theorems extend the classical results which have been established for continuous transformations and continuous observation functions.

关键词： Skew-product transformation uniform ergodicity semi-uniform ergodicity

Water pumping analysis and experimental validation of beach well infiltration intake system in a seawater source heat pump system

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Frontiers in Energy 2015年第3期9卷 335-342页

作者： huan ZHANG Shu LIU Xuejing zheng Gaofeng CHEN School of Environmental Science and Engineering Tianjin University Tianjin 300072 China China Architecture Design and Research Group Beijing 100044 China

Based on energy conservation equation and Darcy＇s law, a model of beach well infiltration intake system applied in a seawater source heat pump system was established. The model consists of the seawater seepage and the heat transfer process. A porous medium model in a software named FLUENT was applied to simulate the seepage and the heat transfer process. This model was also validated by field experiment conducted on the seashore in Tianjin, China. The maximum relative error between simulation results and experimental results was 2.1% （less than 5%）, which was acceptable in engineering applica- tion. The porosity and coefficient of thermal conductivity of the aquifer soil were determined to be 0.49 W/（m. K） and 1.46W/（m.K）, respectively in the simulation. In addition, the influencing factors of pumping water of beach well were also analyzed. The pumping water was found to increase when the distance between the beach well and the impervious boundary becomes longer, when the distance between the beach well and the supplying water source shortens, when the diameter of the beach well enlarges, and the drawdown enlarges.

关键词： water pumping analysis experimental valida-tion infiltration intake system seawater source heat pump