检索结果-南通市图书馆

DISCRETE ENERGY ANALYSIS OF THE THIRD-ORDER VARIABLE-STEP BDF TIME-STEPPING FOR DIFFUSION EQUATIONS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2023年第2期41卷 325-344页

作者： Hong-lin Liao tao Tang tao zhou Department of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles(NUAA) MIITNanjing 211106China Division of Science and Technology BNU-HKBU United International CollegeZhuhai 519087China Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing100190China

This is one of our series works on discrete energy analysis of the variable-step BDF *** this part,we present stability and convergence analysis of the third-order BDF(BDF3)schemes with variable steps for linear diffusion equations,see,e.g.,[SIAM ***.,58:2294-2314]and[***.,90:1207-1226]for our previous works on the BDF2 *** this aim,we first build up a discrete gradient structure of the variable-step BDF3 formula under the condition that the adjacent step ratios are less than 1.4877,by which we can establish a discrete energy dissipation ***-robust stability and convergence analysis in the L^(2) norm are then *** the mesh robustness means that the solution errors are well controlled by the maximum time-step size but independent of the adjacent time-step *** also present numerical tests to support our theoretical results.

关键词： Diffusion equations Variable-step third-order BDF scheme Discrete gradient structure Discrete orthogonal convolution kernels Stability and convergence

Optimal programmable unambiguous discriminator between two unknown latitudinal states

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2016年第10期59卷 19-24页

作者： XiaoBing Sunian YuWei Li tao zhou School of Physical Science and Technology Southwest Jiaotong University

Two unknown states can be unambiguously distinguished by a universal programmable discriminator, which has been widely discussed in previous works and the optimal solution has also been obtained. In this paper, we investigate the programmable unambiguous discriminator between two unknown "latitudinal" states, which lie in a subspace of the total state space. By equivalence of unknown pure states to known average mixed states, the optimal solution for this problem is systematically derived, and the analytical success probabilities for the optimal unambiguous discrimination are obtained. It is beyond one's expectation that the optimal setting for the programmable unambiguous discrimination between two unknown "latitudinal" states is the same as that for the universal ones. The results in this work can be used for the realization of the programmable discriminator in laboratory.

关键词： programmable state discrimination unambiguous discrimination latitudinal state

Jiawei Xiaoyao capsule treatment for mild to moderate major depression with anxiety symptoms: a randomized, double-blind, double-dummy, controlled, multicenter, parallel-treatment trial

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2019年第3期39卷 410-417页

作者： Su Rui Fan Jiping Li tao Cao Xindong zhou Jie han Zhenyun Ma Yan Department of Scientific Research Beijing Hospital of Traditional Chinese MedicineCapital Medical UniversityBeijing 100010 China China Press of Traditional Chinese Medicine Beijing 100013 China Department of Neurology Guang An Men HospitalChina Academy of Chinese Medical Sciences Beijing 100053China Department of Chinese Medicine Beijing Anding Hospital Capital Medical University Beijing 100088China Department of Neurology Wangjing Hospital China Academy of Chinese Medical Sciences Beijing 100102China Department of Neurology Dongfang Hospital of Beijing University of Chinese Medicine Beijing 100029China Department of Pathophysiology and Allergy Research Vienna General Hospital Vienna A-1090 Austria

OBJECTIVE:To assess the efficacy and safety of Jiawei Xiaoyao (JWXY) capsules on mild to moderate depression with anxiety symptoms,a randomized,double-blind,double-dummy controlled,multicenter,parallel-treatment trial was carried out among 210 outpatients with mild to moderate depression and anxiety symptoms from three hospitals in Beijing ***:Participants were randomized into the JWXY group or the sertraline *** group received JWXY treatment and sertraline placebo,or sertraline and JWXY placebo for 8 *** outcomes were measured using the Hamilton Depression Rating Scale (HAMD),Hamilton Anxiety Rating Scale (HAMA) and the Clinical Global Impression ***:JWXY and sertraline had the equivalent effect on HAMD at every interview *** was more effective at reducing the HAMA scores at the 2nd and 12th week,HAMD sleep disturbance subscale scores at the 8th and 12th week,and HAMA somatic anxiety subscale scores at the 12th *** rate of adverse events in the two groups was the ***:For mild to moderate depression with anxiety symptoms,JWXY could be as effective as sertraline in alleviating depressive *** anxiety symptoms,JWXY may be effective more quickly and with longer lasting effects than *** particular,it may also improve quality of sleep and somatic anxiety *** is safe and cheaper than conventional antidepressants,and may be the first alternative choice for depression with anxiety symptoms.

关键词： Depression Anxiety Safety Randomized controlled trial Jiawei Xiaoyao

Spin excitations in nickelate superconductors

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2020年第8期63卷 114-122页

作者： tao zhou Yi Gao ZiDan Wang Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials Guangdong Provincial Engineering Technology Research Center for Quantum Precision MeasurementSchool of Physics and Telecommunication Engineeringand Frontier Research Institute for PhysicsSouth China Normal UniversityGuangzhou 510006China Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China Department of Physics and HKU-UCAS Joint Institute for Theoretical and Computational Physics at Hong Kong The University of Hong KongHong Kong 999077China

Applying a three-band model and the random phase approximation,we theoretically study the spin excitations in nickelate superconductors,which have been newly *** spin excitations were found to be incommensurate in the low energy *** spin resonance phenomenon emerged as the excitation energy *** intensity can be maximized at the incommensurate or commensurate momentum,depending on the out-of-plane *** spin excitations reverted to incommensurate at higher *** also discuss the similarities and differences in the spin excitations of nickelate and cuprate *** predicted results can be later validated in inelastic neutron scattering experiments.

关键词： nickelates superconductivity d-wave pairing spin susceptibility

Traveling wavefronts for a reaction-diffusion-chemotaxis model with volume-filling effect

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2017年第1期32卷 108-116页

作者： MA Man-jun LI Hui GAO Mei-yan tao Ji-cheng han Ya-zhou Department of Mathematics School of SciencesZhejiang Sci-Tech University Teaching and Research Section of Mathematics Zhuji Ronghuai School Department of Mathematics College of ScienceChina Jiliang University

In this paper, we study the propagation of the pattern for a reaction-diffusionchemotaxis model. By using a weakly nonlinear analysis with multiple temporal and spatial scales, we establish the amplitude equations for the patterns, which show that a local perturbation at the constant steady state is spread over the whole domain in the form of a traveling wavefront. The simulations demonstrate that the amplitude equations capture the evolution of the exact patterns obtained by numerically solving the considered system.

关键词： wavefront perturbation filling numerically exact capture traveling stationary scales modulated

Investigation of electropolishing characteristics of tungsten in ecofriendly sodium hydroxide aqueous solution

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2020年第3期8卷 265-278页

作者： Wei han Feng-zhou Fang Centre of Micro/Nano manufacturing Technology(MNMTDublin) University College DublinDublin 4Ireland State Key Laboratory of Precision Measuring Technology and Instruments Centre of Micro/Nano Manufacturing Technology(MNMT)Tianjin UniversityTianjin 300072People’s Republic of China

In this study,an eco-friendly electrolyte for electropolishing tungsten and the minimum material removal depth on the electropolished tungsten surface are investigated using an electrochemical etching *** a concentrated acid electrolyte,the polarization curve and current density transient are *** a NaOH electrolyte,the effects of interelectrode gap and electrolyte concentration on electropolishing are *** differences in electropolishing characteristics are compared among different electrolyte *** are etched on the electropolished tungsten surface to determine the minimum material removal depth on the tungsten *** results indicate the color effect due to a change in the thickness of the oxide film on the tungsten surface after electropolishing with a concentrated acid *** surface roughness decreases with the interelectrode gap width owing to the increased current density when using the NaOH ***,the electropolishing effect is less prominent with a significantly smaller gap because the generated bubbles are unable to escape from the narrow working gap in time.A material removal depth of less than 10 nm is achieved on the tungsten surface in an area of diameter 300 lm,using the electrochemical etching method.

关键词： Electropolishing NaOH solution Surface roughness Tungsten Etching

Oxidation behavior of artificial magnetite pellets

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2017年第6期24卷 603-610页

作者： han-quan Zhang Jin-tao Fu School of Resource and Civil Engineering Wuhan Institute of Technology Wuhan 430205 China Western Mining Company Xi’ning 810001 China

The oxidation behavior of artificial magnetite pellets was investigated through measurements of the oxidation degree and mineralogical analysis. The results show that artificial magnetite pellets are much easier to oxidize than natural magnetite. The oxidation is controlled through two different reaction mechanisms. The oxidation of artificial magnetite is dominated by internal diffusion, with an activation energy of 8.40 kJ/mol, at temperatures less than 800°C, whereas it is controlled by chemical reaction, with a reaction activation energy of 67.79 kJ/mol, at temperatures greater than 800°C. In addition, factors such as the oxygen volume fraction and the pellet diameter strongly influence the oxidation of artificial magnetite: a larger oxygen volume fraction and a smaller pellet diameter result in a much faster oxidation process.

关键词： artificial magnetite pellets oxidation reaction mechanisms

Mobile-robotic machining for large complex components:A review study

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2019年第8期62卷 1388-1400页

作者： tao Bo ZHAO XingWei DING han State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and Technology

Even though the robotic machining has achieved great success in machining of small components, it lacks the competence to machine large complex components, such as wind turbine blade, train carriage, and aircraft wing. In order to cope with this issue,the mobile machining robot system, which consists of a robot arm integrated with a mobile platform, is proposed to achieve the large workspace and high dexterity, and thus has the potential to machine the large complex components. However, due to the limitation of motion accuracy and structural stiffness, the current mobile-robots are hard to satisfy the high precision requirement of machining tasks. In this paper, some historical mobile-robotic machining systems are reviewed firstly, followed by some key techniques related to structure optimization, dynamics of the machining process, localization, and control techniques, which are fundamental for the structural stiffness and motion accuracy of mobile-robots. Finally, the prospect of mobile-robotic machining and the open questions are addressed.

关键词： robotic machining industrial robot mobile-robot accuracy stiffness

MCIF-Transformer Mask RCNN:Multi-Branch Cross-Scale Interactive Feature Fusion Transformer Model for PET/CT Lung Tumor Instance Segmentation

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第6期79卷 4371-4393页

作者： Huiling Lu tao zhou School of Medical Information&Engineering Ningxia Medical UniversityYinchuan750004China School of Computer Science and Engineering North Minzu UniversityYinchuan750021China Key Laboratory of Image and Graphics Intelligent Processing of State Ethnic Affairs Commission NorthMinzu UniversityYinchuan750021China

The precise detection and segmentation of tumor lesions are very important for lung cancer computer-aided ***,in PET/CT(Positron Emission Tomography/Computed Tomography)lung images,the lesion shapes are complex,the edges are blurred,and the sample numbers are *** solve these problems,this paper proposes a Multi-branch Cross-scale Interactive Feature fusion Transformer model(MCIF-Transformer Mask RCNN)for PET/CT lung tumor instance segmentation,The main innovative works of this paper are as follows:Firstly,the ResNet-Transformer backbone network is used to extract global feature and local feature in lung *** pixel dependence relationship is established in local and non-local fields to improve the model perception ***,the Cross-scale Interactive Feature Enhancement auxiliary network is designed to provide the shallow features to the deep features,and the cross-scale interactive feature enhancement module(CIFEM)is used to enhance the attention ability of the fine-grained ***,the Cross-scale Interactive Feature fusion FPN network(CIF-FPN)is constructed to realize bidirectional interactive fusion between deep features and shallow features,and the low-level features are enhanced in deep semantic ***,4 ablation experiments,3 comparison experiments of detection,3 comparison experiments of segmentation and 6 comparison experiments with two-stage and single-stage instance segmentation networks are done on PET/CT lung medical image *** results showed that APdet,APseg,ARdet and ARseg indexes are improved by 5.5%,5.15%,3.11%and 6.79%compared with Mask RCNN(resnet50).Based on the above research,the precise detection and segmentation of the lesion region are realized in this *** method has positive significance for the detection of lung tumors.

关键词： PET/CT images instance segmentation mask RCNN interactive fusion transformer