检索结果-南通市图书馆

Exact mobility edges and topological phase transition in two-dimensional non-Hermitian quasicrystals

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) 2022年第2期65卷 82-90页

作者： Zhi-Hao xu xu Xia shu Chen Institute of Theoretical Physics and State Key Laboratory of Quantum Optics and Quantum Optics Devices Shanxi UniversityTaiyuan 030006China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China Chern Institute of Mathematics and LPMC Nankai UniversityTianjin 300071China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Yangtze River Delta Physics Research Center Liyang 213300China

The emergence of the mobility edge(ME)has been recognized as an important characteristic of Anderson *** difficulty in understanding the physics of the MEs in three-dimensional(3 D)systems from a microscopic image encourages the development of models in lower-dimensional systems that have exact *** most of the previous studies are concerned with one-dimensional(1 D)quasiperiodic systems,the analytic results that allow for an accurate understanding of two-dimensional(2 D)cases are *** this work,we disclose an exactly solvable 2 D quasicrystal model with parity-time(PT)symmetry displaying exact *** the thermodynamic limit,we unveil that the extended-localized transition point,observed at the PT symmetry breaking point,is topologically characterized by a hidden winding number defined in the dual *** coupling waveguide platform can be used to realize the 2 D non-Hermitian quasicrystal model,and the excitation dynamics can be used to detect the localization features.

关键词： quasicrystals mobility edges non-Hermitian systems localization properties

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于纸基微芯片的样本前处理方法研究进展

分析测试学报 2025年第1期44卷 91-98页

作者：马亚星顾梦杰李旭东沈先涛华中科技大学同济医学院公共卫生学院湖北武汉430030

纸基微芯片(μPADs)是一种以纸质材料为基底的简易、便携式检测平台,在临床诊断、食品质量控制和环境监测等领域显示出极大的应用前景。作为快速检测平台,纸基微芯片除了需要对目标物进行快速定量,还要完成样本的前处理过程。科学家近... 详细信息

纸基微芯片(μPADs)是一种以纸质材料为基底的简易、便携式检测平台,在临床诊断、食品质量控制和环境监测等领域显示出极大的应用前景。作为快速检测平台,纸基微芯片除了需要对目标物进行快速定量,还要完成样本的前处理过程。科学家近年来开发了多种基于纸基微芯片的样本前处理方法,用于不同样本中目标物的分析。由于纸基具有强兼容性能,增强纸基芯片的样本前处理功能并将其与各种快速检测方法联用,能极大地扩展纸基微芯片的应用领域。该文对纸基微芯片的自驱动以及纸基微芯片自驱动与外驱动相结合的样本前处理方法进行了总结,概述了纸基微芯片在目标分析物提取、富集等前处理方面的研究进展,探讨了各种纸基微芯片前处理方法的优点和局限性。另外还展望了纸基微芯片的发展方向—除了不断提高样品前处理能力来扩展其在样本制备中的应用,还需要开发商业化的纸基微芯片来满足各类行业的检测需求。

关键词：快速分析纸基微芯片分离驱动前处理

Predicting Chaotic Time Series Using Recurrent Neural Network

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2000年第2期17卷 88-90页

作者： ZHANG Jia-shu XIAO xian-Ci Department of Electronic Engineering University of Electronic Science and Technology of ChinaChengdu610054

A new proposed method, i.e. the recurrent neural network (RNN), is introduced to predict chaotic time series. The effectiveness of using RNN for making one-step and multi-step predictions is tested based on remarkable few datum points by computer-generated chaotic time series. Numerical results show that the RNN proposed here is a very powerful tool for making prediction of chaotic time series.

关键词： series computer neural

CONVERGENCE PROPERTIES OF MULTI-DIRECTIONAL PARALLEL ALGORITHMS FOR UNCONSTRAINED MINIMIZATION

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2005年第4期23卷 357-372页

作者： Cheng-xian xu Yue-ting Yang Faculty of Sciences Xi'an Jiaotong University Xi'an 710049 China

Convergence properties of a class of multi-directional parallel quasi-Newton algorithms for the solution of unconstrained minimization problems are studied in this paper. At each iteration these algorithms generate several different quasi-Newton directions, and then apply line searches to determine step lengths along each direction, simultaneously. The next iterate is obtained among these trail points by choosing the lowest point in the sense of function reductions. Different quasi-Newton updating formulas from the Broyden family are used to generate a main sequence of Hessian matrix approximations. Based on the BFGS and the modified BFGS updating formulas, the global and superlinear convergence results are proved. It is observed that all the quasi-Newton directions asymptotically approach the Newton direction in both direction and length when the iterate sequence converges to a local minimum of the objective function, and hence the result of superlinear convergence follows.

关键词： Unconstrained minimization Multi-directional parallel quasi-Newton method Global convergece Superlinear convergence

Predicting Hyper-Chaotic Time Series Using Adaptive Higher-Order Nonlinear Filter

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2001年第3期18卷 337-340页

作者： ZHANG Jia-shu XIAO xian-Ci Department of Electronic Engineering University of Electronic Science and Technology of ChinaChengdu 610054

A newly proposed method,*** adaptive higher-order nonlinear finite impulse response(HONFIR)filter based on higher-order sparse Volterra series expansions,is introduced to predict hyper-chaotic time *** effectiveness of using adaptive HONFIR filter for making one-step and multi-step predictions is tested based on very few data points by computer-generated hyper-chaotic time series including Mackey-Glass equation and 4-dimensional nonlinear dynamical system.A comparison is made with some neural networks for predicting the Mackey-Glass hyper-chaotic time *** simulation results show that the adaptive HONFIR filter proposed here is a very powerful tool for making prediction of hyper-chaotic time series.

关键词： chaotic nonlinear Nonlinear

Antiproliferation and apoptosis induction of paeonol in HepG_2 cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第2期13卷 250-256页

作者： shu-Ping xu Guo-Ping Sun Yu-xian Shen Wei Wei Wan-Ren Peng Hua Wang Institute of Clinical Pharmacology of Anhni Medical University Key Laboratory of Antiinflammatory and Immunological Pharmacology in Anhui Province Key Laboratory of Research and Development of Chinese Medicine of Anhui province Hefei 230032 Anhui Province. China Department of Oncology The First Affiliated Hospital of Anhui Medical University Hefei 230022 Anhui Province China Department of Oncology Provincial Hospital of Anhui Hefei 230001 Anhui Province China

AIM： To investigate the antiproliferative effect of paeonol （Pae） used alone or in combination with chemotherapeutic agents [cisplatin （CDDP）, doxorubicin （DOX） and 5-fluorouracil （5-FU）] on human hepatoma cell line HepG2 and the possible mechanisms. METHODS： The cytotoxic effect of drugs on HepG2 cells was measured by 3-（4, 5-dimethylthiazol-2- yl）-2, 5-diphenyltetra-zolium bromide （MTT） assay. Morphologic changes were observed by acridine orange （AO） fuorescence staining. Cell cycle and apoptosis rate were detected by flow cytometry （FCM）. Drug-drug interactions were analyzed by the coefficient of drug RESULTS： Pae （7.81-250 mg/L） had an inhibitory effect on the proliferation of HepG2 cells in a dose-dependent manner, with the IC50 value of （104.77±7.28） mg/L. AO fluorescence staining and FCM assays showed that Pae induced apoptosis and arrested cell cycle at S phase in HepG2 cells. Further, different extent synergisms were observed when Pae （15.63, 31.25, 62.5 rag/L） was combined with CDDP （0.31-2.5 mg/L）, DOX （0.16-1.25 mg/L）, or 5-FU （12.5-100 mg/L） at appropriate concentrations. The IC50 value of the three drugs decreased dramatically when combined with Pae （P 〈 0.01）. Of the three different combinations, the sensitivity of cells to drugs was considerably ***： Pae had a significant growth-inhibitory effect on the human hepatoma cell line HepG2, which may be related to apoptosis induction and cell cycle arrest. It also can enhance the cytotoxicity of chemotherapeutic agents on HepG2 cells, and the S phase arrest induced by Pae may be one of the mechanisms of these interactions.

关键词： Paeonol Hepatocellular carcinoma Apoptosis Cell cycle Cisplatin Doxorubicin 5-fluorouracil Synergistic effect

A Survey of Image Synthesis and Editing with Generative Adversarial Networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2017年第6期22卷 660-674页

作者： xian Wu Kun xu Peter Hall TNList and the Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China the Department of Computer Science University of BathBathUK

This paper presents a survey of image synthesis and editing with Generative Adversarial Networks（GANs）. GANs consist of two deep networks, a generator and a discriminator, which are trained in a competitive way. Due to the power of deep networks and the competitive training manner, GANs are capable of producing reasonable and realistic images, and have shown great capability in many image synthesis and editing *** paper surveys recent GAN papers regarding topics including, but not limited to, texture synthesis, image inpainting, image-to-image translation, and image editing.

关键词： image synthesis image editing constrained image synthesis generative adversarial networks imageto-image translation

Improved quality of life in patients with gastric cancer after esophagogastrostomy reconstruction

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2009年第25期15卷 3183-3190页

作者： Hao Zhang Zhe Sun Hui-Mian xu Ji-xian Shan shu-Bao Wang Jun-Qing Chen State Key Department of General Surgery Department of Surgical Oncology First Affiliated Hospital of China Medical University Shenyang 110001 Liaoning Province China

AIM:To compare postoperative quality of life (QOL) in patients with gastric cancer treated by esophagogastrostomy reconstruction after proximal ***: QOL assessments that included functional outcomes (a 24-item survey about treatment-specific symptoms) and health perception (Spitzer QOL Index) were performed in 149 patients with gastric cancer in the upper third of the stomach, who had received proximal gastrectomy with additional ***: Fifty-four patients underwent reconstruction by esophagogastric anterior wall end-to-side anastomosis combined with pyloroplasty (EA group); 45 patients had reconstruction by esophagogastric posterior wall end-to-side anastomosis (EP group); and 50 patients had reconstruction by esophagogastric end-to-end anastomosis (EE group). The EA group showed the best postoperative QOL, such as recovery of body weight, less discomfort after meals, and less heart burn or belching at 6 and 24 mo postoperatively. However, the survival rates, surgical results and Spitzer QOL index were similar among the three ***: Postoperative QOL was better in the EA than EP or EE group. To improve QOL after proximal gastrectomy for upper third gastric cancer, the EA procedure using a stapler is safe and feasible for esophagogastrostomy.

关键词： Gastric cancer Proximal gastrectomy Esophagogastrostomy Quality of life

Promotion effect of Au single-atom support graphene for CO oxidation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2022年第11期33卷 4822-4827页

作者： Ping Yan Song shu xian Shi Jianjun Li College of Architecture and Environment Sichuan UniversityChengdu 610065China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 611731China

CO oxidation is a vital catalytic reaction for environmental purification,facing challenges due to the catalysts applied to oxidize CO are mainly rare and expensive noble *** the high atomic availability,catalytic efficiency,and selectivity of single-atom catalysis,it has been widely studied and proven to be brilliant in CO *** single-atom catalysts are regarded as excellent single-atom catalysts in oxidizing CO,whose progress is limited by the indistinct understanding of the reaction mechanism and role of the active ***,DFT calculation was used to investigate CO oxidation processes,active mechanisms,and the role of Au *** involving prominent physical and chemical properties was selected as a model *** single-atom support graphene materials exhibit better CO oxidation activities than pristine graphene,among which CO oxidation property on Au/GP is the highest with a0.38 eV rate-determining barrier following ER *** outstanding performances including excellent electronic structures,adsorption properties,and strong activation of intermediate products contribute to the high CO oxidation activity of Au/GP,and the Au single-atom is the active *** work provides a novel guide for single-atom catalytic CO oxidation,accelerating the development of single-atom catalysis.

关键词： Single-atom Graphene CO oxidation ER mechanism DFT