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| 1 | Third generation of vortex identification methods:Omega and Liutex/Rortex based systems显示文摘A vortex is intuitively recognized as the rotational/swirling motion of fluids,but a rigorous and universally-accepted definition is still not available.Vorticity tube/filament has been regarded equivalent to a vortex since Helmholtz proposed the concepts of vorticity tube/filament in 1858 and the vorticity-based methods can be categorized as the first generation of vortex identification methods.During the last three decades,a lot of vortex identification methods,including 0,A,and Aci criteria,have been proposed to overcome the problems associated with the vorticity-based methods.Most of these criteria are based on the Cauchy-Stokes decomposition and/or eigenvalues of the velocity gradient tensor and can be considered as the second generation of vortex identification methods.Starting from 2014,the Vortex and Turbulence Research Team at the University of Texas at Arlington(the UTA team)focus on the development of a new generation of vortex identification methods.The first fruit of this effort,a new Omega(/2)vortex identification method,which defined a vortex as a connected region where the vorticity overtakes the deformation,was published in 2016.In 2017 and 2018,a Liutex(previously called Rortex)vector was proposed to provide a mathematical definition of the local rigid rotation part of the fluid motion,including both the local rotational axis and the rotational strength.Liutex/Rortex is a new physical quantity with scalar,vector and tensor forms exactly representing the local rigid rotation of fluids.Meanwhile,a decomposition of the vorticity to a rotational part namely Liutex/Rortex and an anti-symmetric shear part(RS decomposition)was introduced in 2018,and a universal decomposition of the velocity gradient tensor to a rotation part(7?)and a non-rotation part(NR、was also given in 2018 as a counterpart of the traditional Cauchy-Stokes decomposition.Later in early 2019,a Liutex/Rortex based Omega method called Omega-Liutex,which combines the respective advantages of both Liutex/Rortex and Omega methods,was developed.And a latest objective Omega method,which is still under development,is also briefly introduced.These advances are classified as the third generation of vortex identification methods in the current paper.To elaborate the advantages of the third-generation methods,six core issues for vortex definition and identification have been raised,including:(1)the absolute strength,(2)the relative strength,(3)the rotational axis,(4)the vortex core center location,(5)the vortex core size,(6)the vortex boundary.The new third generation of vortex identification methods can provide reasonable answers to these questions,while other vortex identification methods fail to answer all questions except for the approximation of vortex boundaries.The purpose of the current paper is to summarize the main ideas and methods of the third generation of vortex identification methods rather than to conduct a comprehensive review on the historical development of vortex identification methods. | Chaoqun Liu Yi-sheng Gao Xiang-rui Dong Yi-qian Wang Jian-ming Liu Yu-ning Zhang Xiao-shu Cai Nan Gui | 2019 | Journal of Hydrodynamics2019，31，2： | 82 |
| 2 | 徕卡三维激光扫描系统在文物保护领域的应用显示文摘 | 李滨 | 2008 | 测绘通报2008，，6： | 46 |
| 3 | Advanced gastric cancer:what we know and what we stillhave to learn显示文摘Gastric cancer is a common neoplastic disease and, more precisely, is the third leading cause of cancer death in the world, with differences amongst geographic areas. The definition of advanced gastric cancer is still debated. Different stadiating systems lead to slightly different stadiation of the disease, thus leading to variations between the single countries in the treatment and outcomes. In the present review all the possibilities of treatment for advanced gastric cancer have been analyzed. Surgery, the cornerstone of treatment for advanced gastric cancer, is analyzed first, followed by an investigation of the different forms and drugs of chemotherapy and radiotherapy. New frontiers in treatment suggest the growing consideration for intraperitoneal administration of chemotherapeutics and combination of traditional drugs with new ones. Moreover, the necessity to prevent the relapse of the disease leads to the consideration of administering intraperitoneal chemotherapy earlier in the therapeutical algorithm. | Federico Coccolini Giulia Montori Marco Ceresoli Simona Cima Maria Carla Valli Gabriela E Nita Arianna Heyer Fausto Catena Luca Ansaloni | 2016 | World Journal of Gastroenterology2016，22，3： | 25 |
| 4 | A Liutex based definition and identification of vortex core center lines显示文摘Six core issues for vortex definition and identification concern with (1) the absolute strength,(2) the relative strength,(3) the rotational axis,(4) the vortex core center,(5) the vortex core size, and (6) the vortex boundary (Liu C. 2019). However, most of the currently popular vortex identification methods, including the Q criterion, the criterion and the Acj criterion etc., are Eulerian local region-type vortex identification criteria and can only approximately identify the vortex boundary by somewhat arbitrary threshold. On the other hand, the existing Eulerian local line-type methods, which seek to extract line-type features such as vortex core line, are not entirely satisfactory since most of these methods are based on vorticity or pressure minimum that will fail in many cases. The key issue is the lack of a reasonable mathematical definition for vortex core center. To address this issue, a Liutex (previously named Rortex) based definition of vortex core center is proposed in this paper. The vortex core center, also called vortex rotation axis line here, is defined as a line where the Liutex magnitude gradient vector is aligned with the Liutex vector, which mathematically implies that the cross product of the Liutex magnitude gradient vector and the Liutex vector on the line is equal to zero. Based on this definition, a novel three-step method for extracting vortex rotation axis lines is presented. Two test cases, namely the Burgers vortex and hairpin vortices, are examined to justify the proposed method. The results demonstrate that the proposed method can successfully identify vortex rotation axis lines without any user-specified threshold, so that the proposed method is very straightforward, robust and efficient. | Yi-sheng Gao Jian-ming Liu Yi-fei Yu Chaoqun Liu | 2019 | Journal of Hydrodynamics2019，31，3： | 19 |
| 5 | The International Study Group of Pancreatic Surgery definition of delayed gastric emptying and the effects of various surgical modifications on the occurrence of delayed gastric emptying after pancreatoduodenectomy显示文摘BACKGROUND:A number of definitions have been used for delayed gastric emptying(DGE) after pancreatoduodenectomy and the reported rates varied widely.The International Study Group of Pancreatic Surgery(ISGPS) definition is the current standard but it is not used universally.In this comprehensive review,we aimed to determine the acceptance rate of ISGPS definition of DGE,the incidence of DGE after pancreatoduodenectomy and the effect of various technical modifications on its incidence.DATA SOURCE:We searched PubM ed for studies regarding DGE after pancreatoduodenectomy that were published from 1 January 1980 to 1 July 2015 and extracted data on DGE definition,DGE rates and comparison of DGE rates among different technical modifications from all of the relevant articles.RESULTS:Out of 435 search results,178 were selected for data extraction.The ISGPS definition was used in 80% of the studies published since 2010 and the average rates of DGE and clinically relevant DGE were 27.7%(range:0-100%;median:18.7%) and 14.3%(range:1.8%-58.2%;median:13.6%),respectively.Pylorus preservation or retrocolic reconstruction were not associated with increased DGE rates.Although pyloric dilatation,Braun's entero-enterostomy and Billroth Ⅱ reconstruction were associated with significantly lower DGE rates,pyloric ring resection appears to be most promising with favorable results in 7 out of 10 studies.CONCLUSIONS:ISGPS definition of DGE has been used in majority of studies published after 2010.Clinically relevant DGE rates remain high at 14.3% despite a number of proposed surgical modifications.Pyloric ring resection seems to offer the most promising solution to reduce the occurrence of DGE. | Rajesh Panwar Sujoy Pal | 2017 | Hepatobiliary & Pancreatic Diseases International2017，16，4： | 13 |
| 6 | 2019 Chinese guideline for the management of hypertension in the elderly显示文摘Table of contents Preamble 1 Introduction 1.1 Class of recommendations and level of evidences 1.2 Definition and categories of hypertension in the elderly 1.3 Current status of epidemiology of hypertension in the elderly 1.4 The characteristics of hypertension in the elderly. | 无 Qi HUA Li FAN Jun CAI Lu-Yuan CHEN Wei-Wei CHEN Ping-Jin GAO Yi-Fang GUO Qing HE Jing LI Nan-Fang LI Wei-Min LI Yue LI Mei-Lin LIU Ning-Ling SUN Wen WANG Liang-Di XIE Jin-Gang YANG Hong YUAN | 2019 | Journal of Geriatric Cardiology2019，16，2： | 11 |
| 7 | 英语广告标题的修辞特色显示文摘“平均来说,读标题的人数是读正文人数的五倍。”资深广告学家大卫·奥格尔维(DavidOgilvy)总结多年广告创作的经验指出,“因此,可以说标题一经写成,就等于一美元的广告费中花去了80美分。如果你的标题起不到推销的作用,那就等于浪费了80%的广告费... | 邓嵘 | 1998 | 中国科技翻译1998，11，4： | 10 |
| 8 | 基于PDDL的成像卫星任务规划建模显示文摘基于对成像卫星任务规划问题的特点的深入分析,提出一种基于状态-动作模型的任务规划建模的方法:采用PDDL语言对成像卫星的领域知识进行描述,解决动作的持续时间约束、复杂的资源约束和一类特殊的外部事件约束的表达问题,最终建立成像卫星任务规划模型。通过对该建模方法的模型描述能力分析,表明该建模方法较传统规划建模方法具有较好的描述能力,能满足描述成像卫星任务规划问题的要求。 | 陈克伟 安蓓 王炎娟 张辉 | 2008 | 兵工自动化2008，27，12： | 9 |
| 9 | 面向飞机全生命周期的MBD数据管理解决方案探讨显示文摘基于模型的定义(Model Based Definition,MBD)技术的应用将工程技术人员从百年来的二维文化中解放出来,给飞机的研制手段和研制过程带来了革命性的变化。通过在三维模型上定义完整的产品定义信息,替换过去依靠二维图样飞机定义方式,使得设计、工艺、工装等参与飞机研制的人员能够在直观、语义信息丰富的三维可视化环境下进行并行研制和沟通交流,有助于促进飞机研制周期的缩短和产品质量的提高。 | 余定方 | 2010 | 航空制造技术2010，53，23： | 9 |
| 10 | 西门子64排SOMATOM Definition Flash双源CT机典型故障分析与处理显示文摘0引言
西门子64排SOMATOM Definition Flash双源CT机(简称"炫速双源CT机")是第二代双源CT,也是目前全球最尖端、最先进的大型医疗设备,它具有不受心率限制的心血管成像,可实现超越探测器宽度的大范围灌注,具备以"炫速扫描、锐影技术"为代表的超低剂量成像,负荷条件下的心肌灌注检查等特点。设备平时运行稳定,但由于各种客观因素的存在,各种故障的出现也难以避免。 | 韦国文 | 2017 | 医疗卫生装备2017，38，9： | 7 |
| 11 | Considerations on the concept, definition, and diagnosis of amyotrophic lateral sclerosis显示文摘The concept, definition, and diagnosis of amyotrophic lateral sclerosis(ALS) currently present some problems. This article systematically reviews the literature on the history, current concepts, definition, and diagnosis of ALS, and discloses the present problems based on the retrieved literature and the authors' clinical experience. The current concepts and definitions of ALS have not yet been unified or standardized in clinical practice, and are sometimes vague or inaccurate, which can cause difficulties for neurologists in the clinical treatment of ALS. The concept and definition of ALS need to be further ascertained, and the current diagnostic criteria for ALS require further development. The identification of effective and objective biomarkers may be a feasible method for the early and accurate diagnosis of ALS. Therefore, future research should focus on the identification of reliable biomarkers—especially neuroimaging biomarkers—through autopsy. Standardizing the concept and definition of ALS and formulating clear diagnostic criteria will largely avoid many uncertainties in the future clinical research and treatment of ALS, which will greatly benefit patients. | Ren-Shi Xu Min Yuan | 2021 | Neural Regeneration Research2021，16，9： | 5 |
| 12 | Gait Definition and Successive Gait-transition Method Based on Energy Consumption for a Quadruped显示文摘In nature,to realize the smooth motion for different speeds,the continuous gait transition is usually required for the quadrupeds.Thus,the gait simulation of quadrupeds is a requisite step to obtain the stable and energy-efficient gait for the walking machines.In this paper,the definitions of the two gait parameters,phasic difference and duty factor are presented,which can determine the gait of the quadrupeds.Then,several typical gaits of the quadrupeds are analyzed such that the seven standard gaits and corresponding parameters are summarized.Additionally,the variance law of the two parameters,which determine the relationship of gait transition,is analyzed.Furthermore,the quadruped gait derivative spectrum (QGDS) is proposed and the gait definition of the quadrupeds is presented.To minimize the power consumption,the choice criterion of gait,the optimal gait in terms of the motion speed,duty factory,and power consumption for the walking machines,is developed.Last,the continuous variance of the gait is implemented by the simulation of the gait transition from walk to trot,which evaluate the choice criterion and transition of gait. | ZHAO Danpu XU Jing WU Dan CHEN Ken LI Chengrong | 2012 | Chinese Journal of Mechanical Engineering2012，25，1： | 5 |
| 13 | Verticality Detection Algorithm Based on Local Image Sharpness Criterion显示文摘In the high precision image measurement system,the verticality error between the axis of the shooting system and the measured object can bring error of the measurement result.The high demand of the system’s vertical degree is raised by measure system due to the demands of high precision and disposable full field imaging in the micro-parts imaging measurement.The existing method of optical axis verticality detection cannot meet the demand all.In order to achieve the high-precision adjustment of the system optical axis,the algorithm of detecting verticality based on regional image definition is proposed.First,the objected standard image is divided into fixed area.Then,the object plane is moved from the downside to the upside of the focus plane,meanwhile,recording the definition function values of each standard image region at each step,and fitting out the clearest positions of the regions.Finally,according to the inter-regional relations between the locations and the height difference of the each regional clearest position,the small angle between the optical axis and the measured surface can be calculated.The experiment is based on the given image of lithography template with the scale of 10 μm as move unit,and the results show that this method effective reduced the small angle between the system optical axis and the measured body in high-precision image measuring system,the evaluation accuracy is less than 0.1°,meeting the requirements in high-precision measurement.The proposed method of detecting verticality based on regional image definition can evaluate the verticality error between the axis of the shooting system and the measured object accurately,effectively and conveniently. | ZHANG Jin WANG Zhong YE Shenghua YANG Chun LI Lin | 2012 | Chinese Journal of Mechanical Engineering2012，25，1： | 5 |
| 14 | 三维模型定义(MBD)发展动态显示文摘一、为什么应该对三维模型定义感兴趣?首先做一个简单的比较.如图1和图2两种零件表达方式,哪种更加直观清晰?很显然图2 更加直观清晰,这就是三维模型定义的优势。三维模型定义(Model Based Definition,MBD)就是一项把三维标注和属性直接关联定义到三维模型的工程实践。 | 吴军 胡其登 | 2015 | CAD/CAM与制造业信息化2015，，2： | 4 |
| 15 | 心脏冠状动脉CTA在心脏血管性疾病中的临床应用显示文摘目的探索冠状动脉CTA在临床心脏血管性疾病中的应用价值。方法使用SOMATOM Definition AS螺旋CT扫描仪对81例临床考虑冠心病或者冠状动脉狭窄的病例进行冠状动脉CTA检查,将冠状动脉CTA检查结果与DSA检查结果进行对比以判定冠状动脉CTA检查的敏感性及特异性。结果 81例患者中,有1例检查失败不能分析,3例检查不满意评估困难,77例检查结果满意。结论冠状动脉CTA具有评价血管敏感性高的特点,在临床中有重要的应用价值具有逐步取代DSA的趋势。 | 南松芹 时玉芝 李玉莲 阚兴亮 | 2013 | 中国医药指南2013，11，11： | 4 |
| 16 | 基于模型定义技术的发展及应用——智能制造的关键技术显示文摘产品数字化定义(Product Digital Definition,PDD)是工程技术人员对所设计产品的形状、尺寸、技术参数及其制造信息等的一种数字化描述,它经历了漫长的发展过程。目前,基于模型定义(Model Based Definition, M B D)是产品数字化定义技术的最新发展,也是智能制造的关键技术。 | 范玉青 | 2015 | 金属加工(冷加工)2015，，17： | 4 |
| 17 | Definition of colorectal anastomotic leakage: A consensus survey among Dutch and Chinese colorectal surgeons显示文摘AIM To determine the level of consensus on the definition of colorectal anastomotic leakage(CAL) among Dutch and Chinese colorectal surgeons.METHODS Dutch and Chinese colorectal surgeons were asked to partake in an online questionnaire. Consensus in the online questionnaire was defined as > 80% agreement between respondents on various statements regarding a general definition of CAL,and regarding clinical and radiological diagnosis of the complication.RESULTS Fifty-nine Dutch and 202 Chinese dedicated colorectal surgeons participated in the online survey. Consensus was found on only one of the proposed elements of a general definition of CAL in both countries: ‘extravasation of contrast medium after rectal enema on a CT scan'. Another two were found relevant according to Dutch surgeons: ‘necrosis of the anastomosis found during reoperation',and ‘a radiological collection treated with percutaneous drainage'. No consensus was found for all other proposed elements that may be included in a general definition.CONCLUSION There is no universally accepted definition of CAL in the Netherlands and China. Diagnosis of CAL based on clinical manifestations remains a point of discussion in both countries. Dutch surgeons are more likely to report ‘subclinical' leaks as CAL,which partly explains the higher reported Dutch CAL rates. | Stefanus J van Rooijen Audrey CHM Jongen Zhou-qiao Wu Jia-fu Ji Gerrit D Slooter Rudi MH Roumen Nicole D Bouvy | 2017 | World Journal of Gastroenterology2017，23，33： | 4 |
| 18 | 一种基于内容模型图的XML Schema Definition的提取方法显示文摘使用XML Schema能够对XML文档进行有效性验证以及对查询、转换等操作进行优化,但是实际应用中大量XML文档缺失关联的Schema。提出了一种根据XML文档自动提取对应的XML Schema Definition(XSD)的方法XSDInfer,先根据合并规则将XML解析过程中分析得到的模式信息记录在内容模型图中,再根据生成规则将其转化为内容模型表达式,进而得到XSD。XSDInfer能够在内存消耗比较少的情况下快速地处理超大规模、深度嵌套的XML文档,同时支持XSD的上下文相关的内容模型,提取出的XSD也具有更好的可读性。实验表明,与同类方法相比,XSDInfer具有更好的可扩展性和表达能力。 | 宁静 刘杰 叶丹 | 2010 | 计算机科学2010，37，6： | 3 |
| 19 | 中国高清晰度电视(HDTV)发展的有关问题显示文摘一、世界各国 DTV&HDTV的发展概况DTV(digital television)HDTV(high definition television) | 余兆明 | 1999 | 现代电视技术1999，，4： | 3 |
| 20 | 眼视光师在眼健康保健事业中的角色——谈WCO“眼视光师执业范畴的基本模式”显示文摘世界眼视光学会(The World Council of Optometry下简称WCO)是一家代表全球20余万眼视光师的国际组织,曾于1992年召集该专业的顶尖专家学者汇聚巴黎,讨论眼视光学在21世纪的未来发展,提出被公认的21世纪。眼视光学的定义”(21st century Definition of Optometry)。2005年,WCO在加纳举行的全体会员大会上通过了全球适用的眼视光师执业范畴的基本模式,以协助世界各地眼视光师执业范围趋于一致。今秉承WCO文件精神,遵其意,将有关理念介绍给国内同道,相信对我国视光学及其教育的规范化,具有重要的指导和借鉴意义。 | 宋慧琴 | 2008 | 中国眼镜科技杂志2008，，2： | 3 |
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