检索结果-南通市图书馆

Continuity in weak topology:higher order linear systems of ODE

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2008年第6期51卷 1036-1058页

作者： ZHANG MeiRong Department of Mathematical Sciences,zhou pei-yuan center for applied mathematics,tsinghua university,beijing 100084.china Department of Mathematical Sciences Zhou Pei-Yuan Center for Applied Mathematics Tsinghua University Beijing 100084 China

We will introduce a type of Fredholm operators which are shown to have a certain con- tinuity in weak *** this,we will prove that the fundamental matrix solutions of k-th, k≥2,order linear systems of ordinary differential equations are continuous in coefficient matrixes with weak ***,Floquet multipliers and Lyapunov exponents for periodic systems are continuous in weak ***,for the scalar Hill’s equations,Sturm-Liouville eigenvalues, periodic and anti-periodic eigenvalues,and rotation numbers are all continuous in potentials with weak *** results will lead to many interesting variational problems.

关键词： continuity weak topology Fredholm operator linear system Hill’s equation eigenvalue rotation number Lyapunov exponent 34A30 34L40 37E45 34D08 58C07 46B50

An attempt to differential Galois theory of second order polynomial system and solvable subgroup of Mbius transformations

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2007年第5期50卷 748-760页

作者： Ke-ying GUAN & Jin-zhi LEI School of Science, beijing Jiaotong university, beijing 100044, china zhou pei-yuan center for applied mathematics, tsinghua university, beijing 100084, china School of Science Beijing Jiaotong University Beijing 100044 China zhou pei-yuan center for applied mathematics Tsinghua University Beijing 100084 China

By introducing the conception "relativistic differential Galois group" for the second order polynomial systems, we establish the relation between the conformal relativistic differential Galois group and the subgroup of Mobius transformations, and prove that the system is integrable in the sense of Liouville if its conformal relativistic differential Galois group is solvable with a derived length at most 2. Some omissions on the structures of solvable subgroups of Mobius transformations at the first author’s article published in this journal in 1996 are refreshed in this paper.

关键词： conformed differential Galois group Mobius transformations integrability in the sense of Liouville

Photonic neuromorphic architecture for tens-of-task lifelong learning

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第3期13卷 519-530页

作者： yuan Cheng Jianing Zhang Tiankuang zhou Yuyan Wang Zhihao Xu Xiaoyun yuan Lu Fang Sigma Laboratory Department of Electronic EngineeringTsinghua UniversityBeijing 100084China beijing National Research center for Information Science and Technology(BNRist) Beijing 100084China Institute for Brain and Cognitive Science Tsinghua University(THUIBCS)Beijing 100084China

Scalable,high-capacity,and low-power computing architecture is the primary assurance for increasingly manifold and large-scale machine learning *** electronic artificial agents by conventional power-hungry processors have faced the issues of energy and scaling walls,hindering them from the sustainable performance improvement and iterative multi-task *** to another modality of light,photonic computing has been progressively applied in high-efficient neuromorphic ***,we innovate a reconfigurable lifelong-learning optical neural network(L2 ONN),for highly-integrated tens-of-task machine intelligence with elaborated algorithm-hardware *** from the inherent sparsity and parallelism in massive photonic connections,L2 ONN learns each single task by adaptively activating sparse photonic neuron connections in the coherent light field,while incrementally acquiring expertise on various tasks by gradually enlarging the *** multi-task optical features are parallelly processed by multi-spectrum representations allocated with different *** evaluations on freespace and on-chip architectures confirm that for the first time,L2 ONN avoided the catastrophic forgetting issue of photonic computing,owning versatile skills on challenging tens-of-tasks(vision classification,voice recognition,medical diagnosis,etc.)with a single ***,L2 ONN achieves more than an order of magnitude higher efficiency than the representative electronic artificial neural networks,and 14×larger capacity than existing optical neural networks while maintaining competitive performance on each individual *** proposed photonic neuromorphic architecture points out a new form of lifelong learning scheme,permitting terminal/edge AI systems with light-speed efficiency and unprecedented scalability.

关键词： life neural versatile

Spin Evolution of the Magnetar SGR J1935+2154

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第1期24卷 201-211页

作者： Ming-Yu Ge yuan-pei Yang Fang-Jun Lu Shi-Qi zhou Long Ji Shuang-Nan Zhang Bing Zhang Liang Zhang pei Wang Kejia Lee Weiwei Zhu Jian Li Xian Hou Qiao-Chu Li Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China South-Western Institute For Astronomy Research Yunnan UniversityKunming 650504China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China Key Laboratory of Stellar and Interstellar Physics and School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China School of Physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China university of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Nevada center for Astrophysics University of NevadaLas VegasNV 89154USA Department of Physics and Astronomy University of NevadaLas VegasNV 89154USA National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Department of Astronomy Peking UniversityBeijing 100871China CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Yunnan Observatories Chinese Academy of SciencesKunming 650216China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key laboratory of Modern Astronomy and Astrophysics Nanjing UniversityNanjing 210023China

Fast radio bursts(FRBs)are short pulses observed in radio frequencies usually originating from cosmological *** discovery of FRB 200428 and its X-ray counterpart from the Galactic magnetar SGR J1935+2154suggests that at least some FRBs can be generated by ***,the majority of X-ray bursts from magnetars are not associated with radio *** fact that only in rare cases can an FRB be generated raises the question regarding the special triggering mechanism of *** we report long time spin evolution of SGR J1935+2154 until the end of *** to v and v,the spin evolution of SGR J1935+2154 could be divided into two *** first stage evolves relatively steady evolution until 2020 April *** the burst activity in2020,the spin of SGR J1935+2154 shows strong variations,especially for *** the burst activity in 2022October,a new spin-down glitch with△v/v=(-7.2±0.6)×10^(-6)is detected around MJD 59876,which is the second event in SGR J1935+*** the end,spin frequency and pulse profile do not show variations around the time of FRB 200428 and radio bursts 221014 and 221021,which supply strong clues to constrain the trigger mechanism of FRBs or radio bursts.

关键词： (stars:)pulsars:general (stars:)pulsars:individual(SGR J1935+2154) X-rays:bursts

Quantifying the natural growth rate of hepatocellular carcinoma:A real-world retrospective study in southwestern china

在线全文

学校读者我要写书评

暂无评论

World Journal of Hepatology 2024年第5期16卷 800-808页

作者： Li Tu Hong Xie Qi Li Ping-Gui Lei pei-Ling Zhao Fan Yang Chi Gong yuan-Lin Yao Shi zhou Department of General Practice The Affiliated Hospital of Guizhou Medical UniversityGuiyang 550004Guizhou ProvinceChina Clinical Medicine Soochow UniversitySuzhou 215123Jiangsu ProvinceChina Department of Radiology The Affiliated Hospital of Guizhou Medical UniversityGuiyang 550004Guizhou ProvinceChina Department of Clinical Laboratory center The Affiliated Hospital of Guizhou Medical UniversityGuiyang 550004Guizhou ProvinceChina Key Laboratory of Biology and Medical Engineering Guizhou Medical UniversityGuiyang 550025Guizhou ProvinceChina Department of Radiology Yanhe Tujia Autonomous County People's HospitalTongren 565300Guizhou ProvinceChina Department of Radiology The Qiandongnan Miao and Dong Autonomous Prefecture People's HospitalKaili 556000Guizhou ProvinceChina Department of Interventional Radiology The Affiliated Hospital of Guizhou Medical UniversityGuiyang 550004Guizhou ProvinceChina

BACKGROUND In recent years,approximately half of the newly diagnosed cases and mortalities attributed to hepatocellular carcinoma(HCC)have been reported in *** the high incidence of HCC,there remains a paucity of data regarding the natural growth pattern and the determination of optimal surveillance intervals specific to the Chinese *** To quantify the natural tumor growth pattern of HCC in regional *** A retrospective analysis was performed on patients from a single institution in Southwest china who had undergone two or more serial dynamic computed tomography or magnetic resonance imaging scans between 2014 and 2020,without having received any anti-cancer *** growth was assessed using tumor volume doubling time(TVDT)and tumor growth rate(TGR),with volumes measured manually by experienced *** univariate linear regression and descriptive analysis were applied to explore associations between growth rates and clinical *** This study identifies the median TVDT for HCC as 163.4 d,interquartile range(IQR)72.1 to 302.3 d,with a daily TGR of 0.42%(IQR 0.206%-0.97%).HCC growth patterns reveal that about one-third of tumors grow indolently with TVDT exceeding 270 d,another one-third of tumors exhibit rapid growth with TVDT under 90 d,and the remaining tumors show intermediate growth rates,with TVDT ranging between 3 to 9 *** The identified TGRs support biannual surveillance and follow-up for HCC patients in certain regions of *** the observed heterogeneity in HCC growth,further investigation is warranted.

关键词： Hepatocellular carcinoma Natural tumor growth pattern Tumor volume doubling time Tumor growth rate Realworld retrospective study

Mechanism and control of nonuniform phase transformation of microalloyed dual-phase steel during cooling process after hot rolling

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 Iron and Steel Research International 2024年第2期31卷 428-441页

作者： Wen-quan Sun Sheng-yi Yong Tie-heng yuan Chao Liu San-bao zhou Rui-chun Guo Meng-xia Tang National Engineering Research center for Advanced Rolling and Intelligent Manufacturing University of Science and Technology BeijingBeijing100083China Strip Production Plant Xichang Steel and Vanadium Corporation of Pangang GroupXichang615000SichuanChina

After cooling in the hot rolling process,the metallographic structure of microalloyed dual-phase steel is nonuniform along the rolling direction,while the thickness fluctuation of microalloyed dual-phase steel with a nonuniform metallographic structure will occur during cold *** mechanism of nonuniform phase transformation of microalloyed dual-phase steels was studied during the cooling process after hot rolling,and the nonuniform phase transformation of microalloyed dual-phase steel was regulated during the cooling process after hot rolling through process ***,the empirical equation of phase transformation temperature was measured by a dilatometer considering thermal ***,the phase field and temperature field of laminar cooling process were calculated to provide initial boundary conditions for the finite element *** that,the coupling finite element model of the temperature phase transformation of the strip steel in coiling transportation process was *** simulation results show that the different thermal contact conditions of the microalloyed dual-phase steel during coil transportation lead to uneven cooling of the coil,which leads to nonuniform transformation of the coil along the rolling *** addition,by prolonging the time interval from coiling to unloading,the phenomenon of nonuniform phase transformation of microalloyed dual-phase steel can be effectively *** simulation results are applied to industrial *** application results show that prolonging the time interval from coiling to unloading can effectively improve the nonuniform phase transformation of microalloyed dual-phase steel in the cooling process after hot rolling.

关键词： Microalloyed dual-phase steel Thickness fluctuation Cooling Heat conduction Nonuniform phase transition Finite element method

DNA damage chemotherapeutic drugs suppress basal-like breast cancer growth by down-regulating the transcription of the FOXO1-KLF5 axis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Genes & Diseases 2024年第1期11卷 91-94页

作者： Qiuxia Cui Jian Sun Jingping yuan Juanjuan Li Chuanyu Yang Guangshi Du Chengang zhou Pu Qiu Jidong Gao yuanqi Zhang Dewei Jiang Ceshi Chen Affiliated Hospital of Guangdong Medical university Science&Technology of china ZhanjiangGuangdong 524000China Department of Breast Surgical Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital and Shenzhen HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeShenzhenGuangdong 518116China Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province Kunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650223China Department of Pathology Renmin Hospital of Wuhan UniversityWuhanHubei 430060China Department of Breast and Thyroid Surgery Renmin Hospital of Wuhan UniversityWuhanHubei 430060China Translational Medicine Research center of Guizhou Medical university GuiyangGuizhou 550025China Department of Breast Surgical Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Yunnan Cancer Hospital and the Third Affiliated Hospital of Kunming Medical university and Yunnan Cancer center KunmingYunnan 650500China Academy of Biomedical Engineering Kunming Medical UniversityKunmingYunnan 650500China

Most basal-like breast cancers(BLBCs)have a poor prognosis and high crossover with triple-negative breast cancers(TNBCs).However,approximately 50%of TNBC patients develop chemoresistance.^(1) Dexamethasone reportedly induces Krüppel-like factor 5(KLF5)and can cause docetaxel and cisplatin resistance in TNBC.A super-enhancer can maintain the transcription of KLF5.

关键词： FOXO1 drugs damage

DVsc:An Automated Framework for Efficiently Detecting Viral Infection from Single-cell Transcriptomics Data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Genomics, Proteomics & Bioinformatics 2024年第2期22卷 189-200页

作者： Fei Leng Song Mei Xiaolin zhou Xuanshi Liu Yefeng yuan Wenjian Xu Chongyi Hao Ruolan Guo Chanjuan Hao Wei Li Peng Zhang beijing Key Laboratory for Genetics of Birth Defects Beijing Pediatric Research Institute/MOE Key Laboratory of Major Diseases in Children/Rare Disease CenterBeijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijing 100045China Institute of Biomedical Engineering University of TorontoTorontoM5S 3G9Canada

Single-cell RNA sequencing(scRNA-seq)has emerged as a valuable tool for studying cellular heterogeneity in various fields,particularly in virological *** studying the viral and cellular transcriptomes,the dynamics of viral infection can be investigated at a single-cell ***,limited studies have been conducted to investigate whether RNA transcripts from clinical samples contain substantial amounts of viral RNAs,and a specific computational framework for efficiently detecting viral reads based on scRNA-seq data has not been ***,we introduce DVsc,an open-source framework for precise quantitative analysis of viral infection from single-cell transcriptomics *** applied to approximately 200 diverse clinical samples that were infected by more than 10 different viruses,DVsc demonstrated high accuracy in systematically detecting viral infection across a wide array of cell *** innovative bioinformatics pipeline could be crucial for addressing the potential effects of surreptitiously invading viruses on certain illnesses,as well as for designing novel medicines to target viruses in specific host cell subsets and evaluating the efficacy of *** supports the FASTQ format as an input and is compatible with multiple single-cell sequencing ***,it could also be applied to sequences from bulk RNA sequencing *** is available at http://62.***.32.33:5000/DVsc.

关键词： Single-cell RNA sequencing Viral transcriptome Cellular transcriptome Viral infection Quantitative analysis Bulk RNA sequencing

Gas exchange optimization in aircraft engines using sustainable aviation fuel:A design of experiment and genetic algorithm approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and AI

Energy and AI 2024年第3期17卷 261-280页

作者： Zheng Xu Jinze pei Shuiting Ding Longfei Chen Shuai Zhao Xiaowei Shen Kun Zhu Longtao Shao Zhiming Zhong Huansong Yan Farong Du Xueyu Li Pengfei Yang Shenghui Zhong Yu zhou Hangzhou International Innovation Institute Beihang UniversityHangzhou311115China Research Institute of Aero-Engine Beihang UniversityBeijing102206China Civil Aviation university of china Tianjin300300China Aircraft/Engine Integrated System Safety beijing Key Laboratory Beijing100083China Aero Engine Academy of china Beijing101304China School of Energy and Power Engineering Beihang UniversityBeijing100083China AVIC Chengdu Aircraft Design and Research Institute Chengdu610091China AVIC Nanjing Engineering Institute of Aircraft Systems Nanjing211106China School of Transportation Science and Engineering Beihang UniversityBeijing100083China Faculty of Science and Engineering University of Nottingham Ningbo ChinaNingbo315100China

The poppet valves two-stroke(PV2S)aircraft engine fueled with sustainable aviation fuel is a promising option for general aviation and unmanned aerial vehicle propulsion due to its high power-to-weight ratio,uniform torque output,and flexible valve ***,its high-altitude gas exchange performance remains unexplored,presenting new opportunities for optimization through artificial intelligence(AI)*** study uses validated 1D+3D models to evaluate the high-altitude gas exchange performance of PV2S aircraft *** valve timings of the PV2S engine exhibit considerable flexibility,thus the Latin hypercube design of experiments(DoE)methodology is employed to fit a response surface model.A genetic algorithm(GA)is applied to iteratively optimize valve timings for varying *** optimization process reveals that increasing the intake duration while decreasing the exhaust duration and valve overlap angles can significantly enhance high-altitude gas exchange *** optimal valve overlap angle emerged as 93°CA at sea level and 82°CA at 4000 m *** effects of operating parameters,including engine speed,load,and exhaust back pressure,on the gas exchange process at varying altitudes are further *** higher engine speed increases trapping efficiency but decreases the delivery ratio and charging efficiency at various *** effect is especially pronounced at elevated *** increase in exhaust back pressure will significantly reduce the delivery ratio and increase the trapping *** study demonstrates that integrating DoE with AI algorithms can enhance the high-altitude performance of aircraft engines,serving as a valuable reference for further optimization efforts.

关键词： Poppet valves two-stroke Design of experiment Genetic algorithm optimization Heavy fuel aircraft engine High altitude gas exchange performance