检索结果-南通市图书馆

Irreversible rapid changes of magnetic field associated with the 2012 October 23 circular near-limb X1.8 Flare

Research in Astronomy and Astrophysics 2016年第6期16卷 99-104页

作者： dan-dan ye Chang Liu Haimin Wang Space Weather Research Laboratory and Big Bear Solar Observatory New Jersey Institute of TechnologyUniversity Heights

It has been found that photospheric magnetic fields can change in accordance with restructuring of the three-dimensional magnetic field following solar eruptions. Previous studies mainly use vector mag- netic field data taken for events near the disk center. In this paper, we analyze the magnetic field evolution associated with the 2012 October 23 X1.8 flare in NOAA AR 11598 that is close to the solar limb, using both the 45 s cadence line-of-sight and 12 min cadence vector magnetograms from the Helioseismic and Magnetic Imager on board Solar Dynamics Observatory. This flare is classified as a circular-ribbon flare with spine-fan type magnetic topology containing a null point. In the line-of-sight magnetograms, there are two apparent polarity inversion lines （PILs）. The PIL closer to the limb is affected more by the projection effect. Between these two PILs there lie positive polarity magnetic fields, which are surrounded by negative polarity fields outside the PILs. We find that after the flare, both the apparent limb-ward and disk-ward negative fluxes decrease, while the positive flux in-between increases. We also find that the horizontal mag- netic fields have a significant increase along the disk-ward PIL, but in the surrounding area, they decrease. Synthesizing the observed field changes, we conclude that the magnetic fields collapse toward the surface above the disk-ward PIL as depicted in the coronal implosion scenario, while the peripheral field turns to a more vertical configuration after the flare. We also suggest that this event is an asymmetric circular-ribbon flare： a flux rope is likely present above the disk-ward PIL. Its eruption causes instability of the entire fan-spine structure and the implosion near that PIL.

关键词： Sun flares -- Sun magnetic field

来源：

维普期刊数据库

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

服务器无感知计算系统性能优化技术研究综述

引用

软件学报 2025年第1期36卷 47-78页

作者：杨光刘杰曲慕子王帅叶丹钟华中国科学院大学中国科学院软件研究所软件工程技术研究开发中心计算机科学国家重点实验室(中国科学院软件研究所)

服务器无感知计算是新兴的云计算模式,它基于“函数即服务(FaaS)”的范式,以函数为部署和调度的基本单位,为用户提供大规模并行和自动伸缩的函数执行服务,且无需用户管理底层资源.对于用户,服务器无感知计算能够帮助他们摆脱集群底层基... 详细信息

服务器无感知计算是新兴的云计算模式,它基于“函数即服务(FaaS)”的范式,以函数为部署和调度的基本单位,为用户提供大规模并行和自动伸缩的函数执行服务,且无需用户管理底层资源.对于用户,服务器无感知计算能够帮助他们摆脱集群底层基础设施管理的负担,专注于业务层的开发和创新;对于服务提供商,服务器无感知计算将应用分解为细粒度的函数,极大地提高了调度效率和资源利用率.显著的优势让服务器无感知计算迅速吸引了业界的注意,然而,服务器无感知计算与传统云计算迥然不同的计算模式以及对任务各方面的严格限制给应用的迁移带来了诸多障碍,各种越来越复杂的任务也对服务器无感知计算的性能提出了越来越高的要求,服务器无感知计算的性能优化成为一个重要的研究课题.从4个方面对服务器无感知计算系统性能优化技术的相关研究工作进行梳理和综述,并介绍现有的系统实现.(1)介绍面向典型任务的优化技术,包括任务适配和针对特定任务的系统优化;(2)综述沙箱环境的优化工作,包括沙箱方案和冷启动优化技术,它们是决定函数运行速度的核心;(3)概括I/O和通信技术的优化,它们是服务器无感知计算应用程序的主要性能瓶颈;(4)简述相关的资源调度技术,包括面向平台和面向用户的调度策略,它们决定着系统的资源利用率和任务的执行效率.最后,总结当前服务器无感知计算性能优化技术所面临的问题和挑战,并展望未来可能的发展方向.

关键词：服务器无感知计算函数即服务云函数云计算性能优化

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Medium optimization for enhanced production of cytosine-substituted mildiomycin analogue (MIL-C) by Streptoverticillium rimofaciens ZJU 5119

引用

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第1期9卷 77-84页

作者： dan ye Zhi-nan XU Pei-lin CEN Department of Chemical and Biochemical Engineering Zhejiang University Hangzhou 310027 China

Cytosine-substituted mildiomycin analogue （MIL-C） was produced effectively by supplementing cytosine into the culture of Streptoverticillium rimofaciens. In order to improve the yield of MIL-C, statistically-based experimental designs were applied to optimize the fermentation medium for S. rimofaciens ZJU 5119. Fifteen culture conditions were examined for their significances on MIL-C production using Plackett-Burman design. The Plackett-Burrnan design and one-variable-at-a-time design indicated that glucose and rice meal as the complex carbon sources, and peanut cake meal and NH4NO3 as the complex nitrogen sources were beneficial for MIL-C production in S. rimofaciens ZJU 5119. The results of further central composition design （CCD） showed that the optimal concentration of glucose, rice meal and peanut cake meal were 18.7 g/L, 64.8 g/L and 65.1 g/L, respectively. By using this optimal fermentation medium, the MIL-C concentration was increased up to 1336.5 mg/L, an approximate 3.8-fold improvement over the previous concentration （350.0 mg/L） with un-optimized medium. This work will be very helpful to the large-scale production of MIL-C in the future.

关键词： Cytosine-substituted mildiomycin analogue (MIL-C) Plackett-Burman design Response surface methodology Streptoverticillium rimofaciens Nucleoside antibiotic

来源：

维普期刊数据库

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

Magnetic resonance imaging findings of carcinoma arising from anal fistula: A retrospective study in a single institution

引用

World Journal of Clinical Cases 2020年第21期8卷 5159-5171页

作者： Xin Zhu Tian-Shu Zhu dan-dan ye Shao-Wei Liu Department of Radiology The Affiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina The First Clinical Medical College Xuzhou Medical UniversityXuzhou 221004Jiangsu ProvinceChina Department of Radiology Quanzhou Orthopedic-Traumatological HospitalQuanzhou 362000Fujian ProvinceChina Department of Radiology Affiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina

BACKGROUND Magnetic resonance imaging(MRI)is currently the standard investigation for suspected perianal *** arising from anal fistula is very rare,and early diagnosis is often *** To describe and summarize the MRI findings of carcinoma arising from anal *** In this retrospective study,records of ten patients diagnosed with carcinoma arising from anal fistula and confirmed by surgery(n=7)or biopsy(n=3)between June 2006 and August 2018 were *** patients underwent preoperative pelvic *** features,signal characteristics,fistula between the mass and the anus,contrast enhancement of mass,signal and enhancement of peritumoral areas,and regional lymphadenopathy were *** All ten tumors were solitary(8 mucinous adenocarcinomas and 2 adenocarcinomas).The maximum diameter of the tumors ranged from 3.4 cm to 12.4 cm(median:4.15 cm;mean:5.68 cm).Eight patients had a fistula between the mass and the *** enhancement of the peritumoral areas was noted in three(3/5)*** or inguinal lymphadenopathy was noted in seven *** lesions of mucinous adenocarcinoma were multiloculated and cauliflower-like,with a thin capsule and focally unclear *** were markedly hyperintense on fat-suppressed T2WI,slightly hyperintense with focal hyperintensity on diffusion-weighted imaging(DWI),and hyperintense with focal hypointensity on apparent diffusion coefficient(ADC)map,with progressive mesh-like contrast *** had an infiltrative margin without a capsule and appeared heterogeneously hyperintense or slightly hyperintense on fat-suppressed T2WI,hyperintense on DWI,and hypointense on ADC map,with persistent heterogeneous *** Our study highlighted several characteristic and potentially helpful MRI findings to diagnose carcinomas arising from anal fistula.

关键词： Anal fistula Carcinoma Magnetic resonance imaging Morphologic features Signal characteristics Differential diagnosis

来源：

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

Phosphine-catalyzed acyl-transfer of heteroaryl ketones for the construction of N-fused heterocycles

引用

Chinese Chemical Letters 2024年第3期35卷 252-256页

作者： Yu Zhang De-Rui Han dan ye Hong Lu Hao Wei Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemistry&Materials ScienceNorthwest UniversityXi'an 710069China

An inexpensive phosphine catalyst was used effectively for a transition-metal-free acyl-transfer of N-containing heteroaryl ketones for the rapid synthesis of N-fused *** key pre-aromatic spirocyclic intermediate initialized by the single electron transfer(SET)process of Togni's reagentⅡpromoted by the tertiary phosphine resulted in an intriguing and alternative tactic for the cleavage of C–C *** using inexpensive tertiary phosphine as the catalyst,this skeleton-reorganizing approach of N-containing heteroaryl ketones allows a streamlined assembly of complex N-fused heterocycles with broad functional group tolerance.

关键词： Phosphine catalysis Acyl-transfer N-Fused heterocycles C–C bond activation Aromatization

来源：

维普期刊数据库

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

An adaptive sliding mode controller for accommodating actuator failures

An adaptive sliding mode controller for accommodating actuat...

引用

第25届中国控制与决策会议

作者： Li-Ying Hao dan ye Guang-Hong Yang School of Information Science and Engineering Northeastern University State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences

ISBN: (纸本)9781467355339

This paper deals with the robust adaptive fault-tolerant compensation control problem for linear systems with actuator faults. By incorporating the matrix full-rank factorization technique with sliding surface design successfully, the total failure of certain actuators can be coped with, under the assumption that redundancy is available in the system. Without the need for a fault detection and isolation (FDI) mechanism, an adaptive sliding mode controller based on a new lemma is designed to maintain the sliding mode, where the gain of the nonlinear unit vector term is updated automatically to compensate the effects of actuator faults, and exogenous disturbances. The effectiveness of the proposed design method is illustrated via an example.

关键词： Fault-tolerant control (FTC) adaptive method sliding mode control (SMC) matrix full-rank factorization

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Diagnostic performance of texture analysis in the differential diagnosis of perianal fistulising Crohn’s disease and glandular anal fistula

引用

World Journal of Gastrointestinal Surgery 2023年第5期15卷 882-891页

作者： Xin Zhu dan-dan ye Jian-Hua Wang Jing Li Shao-Wei Liu Department of Radiology Affiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina Department of Radiology Quanzhou Orthopedic-Traumatological HospitalQuanzhou 362000Fujian ProvinceChina

BACKGROUND Perianal fistulising Crohn's disease(PFCD)and glandular anal fistula have many similarities on conventional magnetic resonance ***,many patients with PFCD show concomitant active proctitis,but only few patients with glandular anal fistula have active *** To explore the value of differential diagnosis of PFCD and glandular anal fistula by comparing the textural feature parameters of the rectum and anal canal in fat suppression T2-weighted imaging(FS-T2WI).METHODS Patients with rectal water sac implantation were screened from the first part of this study(48 patients with PFCD and 22 patients with glandular anal fistula).Open-source software ITK-SNAP(Version 3.6.0,http://***/)was used to delineate the region of interest(ROI)of the entire rectum and anal canal wall on every axial section,and then the ROIs were input in the Analysis Kit software(version V3.0.0.R,GE Healthcare)to calculate the textural feature *** feature parameter differences of the rectum and anal canal wall between the PFCD group vs the glandular anal fistula group were analyzed using Mann-Whitney U *** redundant textural parameters were screened by bivariate Spearman correlation analysis,and binary logistic regression analysis was used to establish the model of textural feature ***,diagnostic accuracy was assessed by receiver operating characteristic-area under the curve(AUC)*** In all,385 textural parameters were obtained,including 37 parameters with statistically significant differences between the PFCD and glandular anal fistula ***,16 texture feature parameters remained after bivariate Spearman correlation analysis,including one histogram parameter(Histogram energy);four grey level co-occurrence matrix(GLCM)parameters(GLCM energy_all direction_offset1_SD,GLCM entropy_all direction_offset4_SD,GLCM entropy_all direction_offset7_SD,and Haralick correlation_all direction_offset7_SD);four texture param

关键词： Anal fistula Crohn’s diseases Magnetic resonance imaging Texture analysis Differential diagnosis

来源：

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

Microstructures and mechanical properties of SiBCNAl ceramics produced by mechanical alloying and subsequent hot pressing

引用

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第10期11卷 761-765页

作者： dan ye De-chang JIA Zhi-hua YANG Zhen-lin SUN Peng-fei ZHANG Institute for Advanced Ceramics Harbin Institute of Technology Harbin 150001 China

Amorphous SiBCNAl powders were prepared via a mechanical alloying (MA) technique using crystalline silicon (Si), hexagonal boron nitride (h-BN), graphite (C), and aluminum (Al) as starting materials. SiBCNAl powders were consolidated by a hot pressing (HP) technique at 1800 °C under a pressure of 30 MPa in argon and nitrogen. The sintering atmosphere had a great influence on the microstructures and mechanical properties of the ceramics. The two ceramics had different phase compositions and fracture surface morphologies. For the ceramics sintered in argon, flexural strength, fracture toughness, elastic modulus and Vickers hardness were 421.90 MPa, 3.40 MPa·m1/2, 174.10 GPa, and 12.74 GPa, respectively. For the ceramics sintered in nitrogen, the mechanical properties increased, except for the Vickers hardness, and the values of the above properties were 526.80 MPa, 5.25 MPa·m1/2, 222.10 GPa, and 11.63 GPa, respectively.

关键词： SiBCNAl ceramics Hot pressing (HP) Mechanical properties Microstructure Mechanical alloying (MA)

来源：

维普期刊数据库

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

Comparison of two thioxopeptide bond photoswitches in insect kinin

引用

Chinese Chemical Letters 2010年第4期21卷 476-479页

作者： Cong, Zhi Yuan Yang, Long Fei Jiang, Ling ye, dan Dong, Shou Liang Lanzhou Univ Inst Biochem & Mol Biol Sch Life Sci Lanzhou 730000 Peoples R China

The photoisomerization abilities of secondary thioxopeptide bond(CS-NH) and thioxo prolyl bond(CS-N) incorporated into the C-terminal pentapeptide of insect kinin were compared.H-Phe-Phe-Ψ[CS-NH]-D-Ala-Trp-Gly-NH_2 and H-Phe-Tyr-Ψ[CS-N]- Pro-Trp-Gly-NH_2 were studied by UV-vis *** isomerization energy barriers of the two segments,Ac-Phe-Ψ[CS-NH]- D-Ala-NH_2 and Ac-Tyr-Ψ[CS-N]-Pro-NH_2 picked from the two peptides,were calculated using ab initio *** cis isomer of CS-N is more stable than th...

关键词： Photoswitch Thioxopeptide bond Energy barrier

来源：

维普期刊数据库

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

Comprehensive Analysis of Expressed Sequence Tags from the Pulp of the Red Mutant ‘Cara Cara’ Navel Orange (Citrus sinensis Osbeck)

引用

Journal of Integrative Plant Biology 2010年第10期52卷 856-867页

作者： Jun-Li ye An-dan Zhu Neng-Guo Tao Qiang Xu Juan Xu Xiu-Xin Deng National Key Laboratory of Crop Genetic Improvement National Center of Citrus Breeding Huazhong Agricultural University Wuhan430070 China

Expressed sequence tag （EST） analysis of the pulp of the red-fleshed mutant ＇Cara Cara＇ navel orange provided a starting point for gene discovery and transcriptome survey during citrus fruit maturation. interpretation of the EST datasets revealed that the mutant pulp transcriptome held a high section of stress responses related genes, such as the type III metallothionein-like gene （6.0%）, heat shock protein （2.8%）, Cu/Zn superoxide dismutase （0.8%）, late embryogenesis abundant protein 5 （0.8%）, etc. 133 transcripts were detected to be differentially expressed between the red mutant and its orange-color wild genotype ＇Washington＇ via digital expression analysis. Among them, genes involved in metabolism, defense/stress and signal transduction were statistical overrepresented. Fifteen transcription factors, composed of NAM, ATAF, and CUC transcription factor （NAC）; myeloblastosis （MYB）; myelocytomatosis （MYC）; basic helix-loop-helix （bHLH）; basic leucine zipper （bZIP） domain members, were also included. The data reflected the distinct expression profile and the unique regulatory module associated with these two genotypes. Eight differently expressed genes analyzed in digital were validated by quantitative real- time polymerase chain reaction. For structural polymorphism, both simple sequence repeats and single nucleotide polymorphisms （SNP） loci were surveyed; dinucleotide presentation revealed a bias toward AG/GA/TC/CT repeats （52.5%）, against GC/CG repeats （0%）. SNPs analysis found that transitions （73%） outnumbered transversions （27%）. Seventeen potential cultivar-specific and 387 heterozygous SNP loci were detected from ＇Cara Cara＇ and ＇Washington＇ EST pool.

关键词： PLANT genetics ORANGE (Fruit) -- Varieties GENETIC polymorphisms NUCLEOTIDE sequence TRANSCRIPTION factors HEAT shock proteins EFFECT of stress on plants PLANT gene expression POLYMERASE chain reaction

来源：

维普期刊数据库

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：