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Atrial fibrillation and dementia: not just a coincidence
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作者 Udit Choubey Vasu Bansal +5 位作者 Priyanshi Shah FNU Anamika Vasu Gupta Sweta Sahu Miran Rezhan Rohit Jain 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2023年第9期697-701,共5页
Atrial fibrillation(AF)is the most common form of cardiac arrhythmia,affecting 3 to 6 million people in the US,with an increased incidence in women and elderly,with its prevalence estimated to increase from 5.1 millio... Atrial fibrillation(AF)is the most common form of cardiac arrhythmia,affecting 3 to 6 million people in the US,with an increased incidence in women and elderly,with its prevalence estimated to increase from 5.1 million in 2000 to 15.9 million in 2050 in the US population.[1]Age,hypertension,heart failure,myocardial infarction(MI),genetic factors,and associated systemic inflammatory states are well-established risk factors for the development of AF.[2–6]Lifestyle factors including alcohol consumption,smoking,obesity,sedentary lifestyle,and vigorous physical activity have also been implicated to contribute to the development of AF.[2,7–9]Studies suggest that AF drives up medical expenditure.[10]The European Society of Cardiology,based on the duration,responsiveness to treatment,and therapeutic attitude of the patient and physician,classifies AF into 4 types;when AF occurs and terminates by itself or by intervention within 7 days of onset,it is called paroxysmal AF;if sustained for more than a week,with or without intervention. 展开更多
关键词 SUSTAINED FIBRILLATION coincidence
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Hypothyroidism and non-alcoholic fatty liver disease:A coincidence or a causal relationship?
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作者 Barbara Janota Elżbieta Szczepańska +1 位作者 Brygida Adamek Ewa Janczewska 《World Journal of Hepatology》 2023年第5期641-648,共8页
Non-alcoholic fatty liver disease(NAFLD)is a global problem.It may be caused by metabolic and hormonal disorders,including hypothyroidism.However,non-thyroid causes of NAFLD in people with hypothyroidism,including imp... Non-alcoholic fatty liver disease(NAFLD)is a global problem.It may be caused by metabolic and hormonal disorders,including hypothyroidism.However,non-thyroid causes of NAFLD in people with hypothyroidism,including improper eating behavior and low physical activity,should be acknowledged.This study aimed to present the current literature on whether the development of NAFLD is related to hypothyroidism or a typical consequence of an unhealthy lifestyle in people with hypothyroidism.The results of previous studies do not allow for an unequivocal determination of the pathogenetic relationship between hypothyroidism and NAFLD.Important non-thyroid-initiating factors include providing too many calories in relation to requirements,consuming excessive amounts of monosaccharides and saturated fats,being overweight,and maintaining low physical activity levels.The recommended nutritional model for both hypothyroidism and NAFLD may be the Mediterranean diet,which is rich in fruits and vegetables,polyunsaturated fatty acids,and vitamin E. 展开更多
关键词 VITAMIN coincidence consuming
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Impact of random and scattered coincidences from outside of field of view on positron emission tomography/computed tomography imaging with different reconstruction protocols
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作者 Mahak Osouli Alamdari Pardis Ghafarian +2 位作者 Arman Rahmim Mehrdad Bakhshayesh‑Karam Mohammad Reza Ay 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第12期40-52,共13页
Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outsi... Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outside the field of view(FOV)on PET image quality for different reconstruction protocols.Imaging was performed on the Discovery 690 PET/CT scanner,using experimental configurations including the NEMA phantom(a body phantom,with six spheres of different sizes)with a signal background ratio of 4:1.The NEMA phantom(phantom I)was scanned separately in a one-bed position.To simulate the effect of random and scatter coincidences from outside the FOV,six cylindrical phantoms with various diameters were added to the NEMA phantom(phantom II).The 18 emission datasets with mean intervals of 15 min were acquired(3 min/scan).The emission data were reconstructed using different techniques.The image quality parameters were evaluated by both phantoms.Variations in the signal-to-noise ratio(SNR)in a 28-mm(10-mm)sphere of phantom II were 37.9%(86.5%)for ordered-subset expectation maximization(OSEM-only),36.8%(81.5%)for point spread function(PSF),32.7%(80.7%)for time of flight(TOF),and 31.5%(77.8%)for OSEM+PSF+TOF,respectively,indicating that OSEM+PSF+TOF reconstruction had the lowest noise levels and lowest coefficient of variation(COV)values.Random and scatter coincidences from outside the FOV induced lower SNR,lower contrast,and higher COV values,indicating image deterioration and significantly impacting smaller sphere sizes.Amongst reconstruction protocols,OSEM+PSF+TOF and OSEM+PSF showed higher contrast values for sphere sizes of 22,28,and 37 mm and higher contrast recovery coefficient values for smaller sphere sizes of 10 and 13 mm. 展开更多
关键词 Positron emission tomography/computed tomography(PET/CT) Random coincidences Scatter coincidences·Time of flight(TOF) Point spread function(PSF) Field of view(FOV) Noise equivalent count rate(NECR) Signal-toNoise ratio(SNR)
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A novel multi-channel porous structure facilitating mass transport towards highly efficient alkaline water electrolysis
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作者 Xinge Jiang Vasileios Kyriakou +6 位作者 Chen Song Xianbin Wang Sophie Costil Chunming Deng Taikai Liu Tao Jiang Hanlin Liao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期511-518,I0013,共9页
An advantageous porous architecture of electrodes is pivotal in significantly enhancing alkaline water electrolysis(AWE)efficiency by optimizing the mass transport mechanisms.This effect becomes even more pronounced w... An advantageous porous architecture of electrodes is pivotal in significantly enhancing alkaline water electrolysis(AWE)efficiency by optimizing the mass transport mechanisms.This effect becomes even more pronounced when aiming to achieve elevated current densities.Herein,we employed a rapid and scalable laser texturing process to craft novel multi-channel porous electrodes.Particularly,the obtained electrodes exhibit the lowest Tafel slope of 79 mV dec^(-1)(HER)and 49 mV dec^(-1)(OER).As anticipated,the alkaline electrolyzer(AEL)cell incorporating multi-channel porous electrodes(NP-LT30)exhibited a remarkable improvement in cell efficiency,with voltage drops(from 2.28 to 1.97 V)exceeding 300 mV under 1 A cm^(-1),compared to conventional perforated Ni plate electrodes.This enhancement mainly stemmed from the employed multi-channel porous structure,facilitating mass transport and bubble dynamics through an innovative convection mode,surpassing the traditional convection mode.Furthermore,the NP-LT30-based AEL cell demonstrated exceptional durability for 300 h under 1.0 A cm^(-2).This study underscores the capability of the novel multi-channel porous electrodes to expedite mass transport in practical AWE applications. 展开更多
关键词 Alkaline water electrolysis Mass transport Bubble dynamics Innovative convection mode multi-channel porous structure
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Design of Cold-Junction Compensation and Disconnection Detection Circuits of Various Thermocouples and Implementation of Multi-Channel Interfaces Using Them-A Secondary Publication
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作者 Hyeong-Woo Cha 《Journal of Electronic Research and Application》 2024年第1期93-105,共13页
Cold-junction compensation(CJC)and disconnection detection circuit design of various thermocouples(TC)and multi-channel TC interface circuits were designed.The CJC and disconnection detection circuit consists of a CJC... Cold-junction compensation(CJC)and disconnection detection circuit design of various thermocouples(TC)and multi-channel TC interface circuits were designed.The CJC and disconnection detection circuit consists of a CJC semiconductor device,an instrumentation amplifier(IA),two resistors,and a diode for disconnection detection.Based on the basic circuit,a multi-channel interface circuit was also implemented.The CJC was implemented using compensation semiconductor and IA,and disconnection detection was detected by using two resistors and a diode so that IA input voltage became-0.42 V.As a result of the experiment using R-type TC,the error of the designed circuit was reduced from 0.14 mV to 3μV after CJC in the temperature range of 0°C to 1400°C.In addition,it was confirmed that the output voltage of IA was saturated from 88 mV to-14.2 V when TC was disconnected from normal.The output voltage of the designed circuit was 0 V to 10 V in the temperature range of 0°C to 1400°C.The results of the 4-channel interface experiment using R-type TC were almost identical to the CJC and disconnection detection results for each channel.The implemented multi-channel interface has a feature that can be applied equally to E,J,K,T,R,and S-type TCs by changing the terminals of CJC semiconductor devices and adjusting the IA gain. 展开更多
关键词 R-type thermocouple(TC) Cold-junction compensation(CJC) TC disconnection detection multi-channel interface circuit Sensor interface
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集值Coincidence度及其应用
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作者 王志华 杨国为 《烟台师范学院学报(自然科学版)》 1994年第1期28-32,共5页
基于集值映象的Coincidence度理论,研究了一类算子包含问题的可解性,得到了锥拉压不动点定理的一个推广形式。
关键词 coincidence 集值映象 拓扑度
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集值Coincidence度及其应用
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作者 谢胜利 《淮北煤师院学报(自然科学版)》 1995年第2期19-25,共7页
对于组合算子包含问题,在L是零指标的Fredholm算子的条件下,本文基于集值映射的广义度,建立了集值Coincidence拓扑度,并将所得结果应用于集值映射不动点的存在性,推广了已有的结果。
关键词 coincidence 不动点 拓扑度 集值映射
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Threshold Photoelectron-photoion Coincidence Imaging of Dissociation Dynamic of NO+ at c3∏(v′=0) State 被引量:1
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作者 孙金大 单晓斌 +6 位作者 刘付轶 盛六四 唐小锋 牛铭理 宋磊 周晓国 刘世林 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第5期509-512,621,共5页
The photodissociation of NO+ at c3∏(v′=0) state is studied by threshold photoelectron- photoion coincidence imaging method. By some assumptions, the relations between velocity in center of mass (CM) coordinates... The photodissociation of NO+ at c3∏(v′=0) state is studied by threshold photoelectron- photoion coincidence imaging method. By some assumptions, the relations between velocity in center of mass (CM) coordinates and most probable center of mass (MPCM) coordinates, time of flight and displacement in the velocity map image of fragment ions are derived using vector addition of velocity and displacement on the condition of perpendicular molecular beam. Using these relations the velocity in CM coordinates, the velocity and angular distri- bution of N+ fragment ions in MPCM coordinates are obtained and discussed, respectively. 展开更多
关键词 Threshold photoelectron-photoion coincidence imaging Velocity map imag-ing Nitric oxide Kinetic energy released distribution Angular distribution
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A super-high resolution frequency standard measuring approach based on phase coincidence characteristics between signals 被引量:13
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作者 李智奇 周渭 +1 位作者 陈发喜 刘晨光 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第9期287-290,共4页
A method for super high resolution comparison measurement is proposed in this paper with a comparison between the frequency standards of different nominal frequencies, which is based on phase coincidence detection of ... A method for super high resolution comparison measurement is proposed in this paper with a comparison between the frequency standards of different nominal frequencies, which is based on phase coincidence detection of the two compared signals. It utilizes the regular phase shift characteristics between the signals. The resolution of the measurement approach can reach 10^-13/s at 5 MHz, and the self-calibration resolution can achieve 10^-14/s in the comparison between 10 MHz and 100 MHz, or even can reach 10^-15/s in the comparison between 10 MHz and 190 MHz. This method implies significant progress in the development of the high precision frequency standard comparison technology. 展开更多
关键词 frequency measurement RESOLUTION phase coincidence equivalent phase comparison frequency
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KKM TYPE THEOREMS AND COINCIDENCE THEOREMS ON L-CONVEX SPACES 被引量:13
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作者 丁协平 《Acta Mathematica Scientia》 SCIE CSCD 2002年第3期419-426,共8页
Some KKM theorems and coincidence theorems involving admissible set-valued mappings and the set-valued mappings with compactly local intersection property are proved in L-convex: spaces. As applications, some new fixe... Some KKM theorems and coincidence theorems involving admissible set-valued mappings and the set-valued mappings with compactly local intersection property are proved in L-convex: spaces. As applications, some new fixed point theorems are obtained in L-convex spaces. These theorems improve and generalize many important known results in recent literature. 展开更多
关键词 KKM type theorem coincidence theorem L-convex space
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Geant4 analysis and optimization of a double crystal phoswich detector for beta–gamma coincidence detection 被引量:2
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作者 Xing Fan Xian-Peng Zhang +1 位作者 Geng Tian Chao-Wen Yang 《Nuclear Science and Techniques》 SCIE CAS CSCD 2018年第4期92-97,共6页
In this study, a novel phoswich detector for beta–gamma coincidence detection is designed. Unlike the triple crystal phoswich detector designed by researchers at the University of Missouri, Columbia, this phoswich de... In this study, a novel phoswich detector for beta–gamma coincidence detection is designed. Unlike the triple crystal phoswich detector designed by researchers at the University of Missouri, Columbia, this phoswich detector is of the semi-well type, so it has a higher detection efficiency. The detector consists of BC-400 and NaI:Tl with decay time constants of 2.4 and 230 ns, respectively.The BC-400 scintillator detects beta particles, and the Na I:Tl cell is used for gamma detection. Geant4 simulations of this phoswich detector find that a 2-mm-thick BC-400 scintillator can absorb nearly all of the beta particles whose energies are below 700 keV. Further, for a 2.00-cmthick NaI:Tl crystal, the gamma source peak efficiency for photons ranges from a maximum of nearly 90% at 30 keV to 10% at 1 MeV. The self-absorption effect is also discussed in this paper in order to determine the carrier gas' s influence. 展开更多
关键词 GEANT4 PHOSWICH detector Beta–gamma coincidence DETECTION DETECTION efficiency
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COINCIDENCE THEOREMS IN PRODUCT G-CONVEX SPACES 被引量:2
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作者 丁协平 《Acta Mathematica Scientia》 SCIE CSCD 2005年第3期401-407,共7页
By applying the technique of continuous partition of unity, some new coincidence theorems for a better admissible mapping and a family of set-valued mappings defined on the product G-convex spaces are proved. Theorems... By applying the technique of continuous partition of unity, some new coincidence theorems for a better admissible mapping and a family of set-valued mappings defined on the product G-convex spaces are proved. Theorems of this paper improve, unify and generalize many important coincidence theorems and collectively fixed point theorems in recent literature. 展开更多
关键词 better admissible mapping coincidence theorem collectively fixed point G-convex space
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Intrinsic background radiation of LaBr3(Ce)detector via coincidence measurements and simulations 被引量:11
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作者 Hao Cheng Bao-Hua Sun +5 位作者 Li-Hua Zhu Tian-Xiao Li Guang-Shuai Li Cong-Bo Li Xiao-Guang Wu Yun Zheng 《Nuclear Science and Techniques》 SCIE CAS CSCD 2020年第10期33-42,共10页
The LaBr3(Ce)detector has attracted much attention in recent years because of its superior characteristics compared with other scintillating materials in terms of resolution and efficiency.However,it has a relatively ... The LaBr3(Ce)detector has attracted much attention in recent years because of its superior characteristics compared with other scintillating materials in terms of resolution and efficiency.However,it has a relatively high intrinsic background radiation because of the naturally occurring radioisotopes in lanthanum,actinium,and their daughter nuclei.This limits its applications in low-counting rate experiments.In this study,we identified the radioactive isotopes in theφ3"x 3"Saint-Gobain B380 detector by a coincidence measurement using a Clover detector in a low-background shielding system.Moreover,we carried out a Geant4 simulation of the experimental spectra to evaluate the activities of the main internal radiation components.The total activity of the background radiation of B380 is determined to be 1.523(34)Bq/cm^3.The main sources include 138La at 1.428(34)Bq/cm^3,207Tl at 0.0135(13)Bq/cm^3,211Bi at 0.0136(15)Bq/cm^3,215Po at 0.0135(3)Bq/cm^3,219Rn at 0.0125(12)Bq/cm^3,223Fr at 0.0019(11)Bq/cm^3,223Ra at 0.0127(10)Bq/cm^3,227Th at 0.0158(22)Bq/cm^3,and 227Ac at 0.0135(13)Bq/cm^3.Of these,the activities of 207Tl,211Po,215Po,223Fr,and 227Ac are deduced for the first time from the secular equilibrium established in the decay chain of 227Ac. 展开更多
关键词 LaBr3 coincidence measurement technique Intrinsic radiation GEANT4 simulation
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COINCIDENCE THEOREMS INVOKING COMPOSITES OF ACYCLIC MAPPINGS AND APPLICATIONS 被引量:2
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作者 丁协平 《Acta Mathematica Scientia》 SCIE CSCD 1999年第1期53-61,共9页
Some new coincidence theorems involving a new class of set-valued mappingscontaining composites of acyclic mappings defined on a contractible space are proved.As applications, some existence theorems of maximal elemen... Some new coincidence theorems involving a new class of set-valued mappingscontaining composites of acyclic mappings defined on a contractible space are proved.As applications, some existence theorems of maximal elements and solutions of abstract variational inequalities, and best approximation theorems are proved. These theorems improve and generalize a number of known results in recent literature. 展开更多
关键词 coincidence theorem maximal element variational inequality best approximation contractible space composites of acyclic mappings
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Intraseasonal Oscillation: the Global Coincidence and Its Relationship with ENSO Cycle 被引量:1
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作者 陈兴跃 王会军 +1 位作者 薛峰 曾庆存 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2001年第3期445-453,共9页
Based on the atmospheric reanalysis data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR), the interannual variability of the atmospheric intraseasonal oscill... Based on the atmospheric reanalysis data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR), the interannual variability of the atmospheric intraseasonal oscillation (ISO) and its relationships with the El Ni?o/Southern Oscillation (ENSO) cycle have been investigated. This work reveals that there exists global coincidence in the interannual variation of ISO among different latitude bands and that relationships between the interannual variation of ISO and the global sea surface temperature (SST) or the outgoing longwave radiation (OLR) are very complicated. We also find that the correlation coefficient between ISO and Ni?o33 SST anomaly has apparent decadal scale variability, which means that the inter-relationship is stronger in some periods and weaker in other periods. Key words Intraseasonal oscillation - Global coincidence - ENSO cycle This work was supported jointly by the Chinese Academy of Sciences Key project under contract KZCX2-203, and the National Natural Science Foundation of China under the Grant Nos. 49735160 and 49805004. 展开更多
关键词 Intraseasonal oscillation Global coincidence ENSO cycle
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SYSTEM OF COINCIDENCE THEOREMS IN PRODUCT TOPOLOGICAL SPACES AND APPLICATIONS (Ⅰ) 被引量:1
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作者 丁协平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第12期1547-1555,共9页
A new notion of finite continuous topological space(in short, FC-space) with out convexity structure was introduced. A new continuous selection theorem was established in FC-spaces. By applying the continuous select... A new notion of finite continuous topological space(in short, FC-space) with out convexity structure was introduced. A new continuous selection theorem was established in FC-spaces. By applying the continuous selection theorem, some new coincidence theorems for two families of set-valued mappings defined on product space of noncompact FC-spaces are proved under much weak assumptions. These results generalize many known results in recent literature. Some applications will be given in a follow-up paper. 展开更多
关键词 system of coincidence theorems continuous selection transfer compact open value FC-SPACE
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A RECENT COINCIDENCE EXPERIMENT OF GRAVITATIONAL WAVES WITH LONG BASELINE 被引量:1
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作者 HU Enke GUAN Tongren +8 位作者 YU Bo TANG Mengxi CHEN Shusen ZHENG Qingzhang P.F.Michelson B.E.Moskowitz M.S.McAshan W.M.Fairbank M.Bassan 《Chinese Physics Letters》 SCIE CAS 1986年第12期529-532,共4页
The results of coincidence experiment which was carried out in the whole month of April,1985 by two gravitational wave detectors in stanford and in Guangzhou are presented.It is found that up to sensitivity of h 10^(-... The results of coincidence experiment which was carried out in the whole month of April,1985 by two gravitational wave detectors in stanford and in Guangzhou are presented.It is found that up to sensitivity of h 10^(-16)the number of coincident events did not excess the number expected statistically. 展开更多
关键词 coincidence EXCESS coincide
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Cheating or Coincidence? Statistical Method Employing the Principle of Maximum Entropy for Judging Whether a Student Has Committed Plagiarism 被引量:1
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作者 M. P. Silverman 《Open Journal of Statistics》 2015年第2期143-157,共15页
Elements of correspondence (“coincidences”) between a student’s solutions to an assigned set of quantitative problems and the solutions manual for the course textbook may suggest that the stu-dent copied the work f... Elements of correspondence (“coincidences”) between a student’s solutions to an assigned set of quantitative problems and the solutions manual for the course textbook may suggest that the stu-dent copied the work from an illicit source. Plagiarism of this kind, which occurs primarily in fields such as the natural sciences, engineering, and mathematics, is often difficult to establish. This paper derives an expression for the probability that alleged coincidences in a student’s paper could be attributable to pure chance. The analysis employs the Principle of Maximum Entropy (PME), which, mathematically, is a variational procedure requiring maximization of the Shannon-Jaynes entropy function augmented by the completeness relation for probabilities and known information in the form of expectation values. The virtue of the PME as a general method of inferential reasoning is that it generates the most objective (i.e. least biased) probability distribution consistent with the given information. Numerical examination of test cases for a range of plausible conditions can yield outcomes that tend to exonerate a student who otherwise might be wrongfully judged guilty of cheating by adjudicators unfamiliar with the surprising properties of random processes. 展开更多
关键词 PLAGIARISM CHEATING coincidence Information Entropy
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Dissociation Dynamics of Energy-Selected Ions using Threshold Photoelectron-Photoion Coincidence Velocity Imaging 被引量:1
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作者 Xiang-kun Wu Xiao-feng Tang +1 位作者 Xiao-guo Zhou Shi-lin Liu 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2019年第1期11-22,I0001,共13页
Threshold photoelectron-photoion coincidence (TPEPICO) is a powerful method to prepare and analyze internal energy- or state-selected ions. Here, we review the state-of-the-art TPEPICO imaging technique combining with... Threshold photoelectron-photoion coincidence (TPEPICO) is a powerful method to prepare and analyze internal energy- or state-selected ions. Here, we review the state-of-the-art TPEPICO imaging technique combining with tunable vacuum ultraviolet (VUV) synchrotron radiation and its recent applications at Hefei Light Source (HLS), especially on the fundamental data measurement and the dissociation dynamics of ions. By applying the double velocity map imaging for both electrons and ions in coincidence, the collection efficiency of the charged particles, the electron energy resolution and the resolving power of the released kinetic energy in dissociation have been greatly improved. The kinetic energy and the angular distributions of fragment ions dissociated from parent ions with definitive internal energy or state have been acquired directly from TPEPICO images. Some dissociation mechanisms involving non-adiabatic quantum effects, like conical intersection and internal conversion, have been revealed. Moreover, the mass-selected threshold photoelectron spectroscopy (MS-TPES) shows tremendous advantages in isomer-specific analysis of complex systems. 展开更多
关键词 PHOTODISSOCIATION Photoionizaiton coincidence Velocity imaging
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Improved image resolution on thoracic carcinomas by quantitative 18F-FDG coincidence SPECT/CT in comparison to 18F-FDG PET/CT 被引量:2
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作者 Yuming Zheng Chaoling Jin +4 位作者 Huijuan Cui Haojie Dai Jue Yan Pingping Han Bailing Hsu 《The Journal of Biomedical Research》 CAS CSCD 2020年第4期309-317,共9页
Currently,18F-FDG coincidence SPECT(Co-SPECT)/CT scan still serves as an important tool for diagnosis,staging,and evaluation of cancer treatment in developing countries.We implemented full physical corrections(FPC) to... Currently,18F-FDG coincidence SPECT(Co-SPECT)/CT scan still serves as an important tool for diagnosis,staging,and evaluation of cancer treatment in developing countries.We implemented full physical corrections(FPC) to Co-SPECT(quantitative Co-SPECT) to improve the image resolution and contrast along with the capability for image quantitation.FPC included attenuation,scatter,resolution recovery,and noise reduction.A standard NEMA phantom filled with 10:1 F-18 activity concentration ratio in spheres and background was utilized to evaluate image performance.Subsequently,15 patients with histologically confirmed thoracic carcinomas were included to undergo a 18 F-FDG Co-SPECT/CT scan followed by a 18 F-FDG PET/CT scan.Functional parameters as SUVmax,SUVmean,SULpeak,and MTV from both quantitative Co-SPECT and PET were analyzed.Image resolution of Co-SPECT for NEMA phantom was improved to reveal the smallest sphere from a diameter of 28 mm to 22 mm(17 mm for PET).The image contrast was enhanced from 1.7 to 6.32(6.69 for PET) with slightly degraded uniformity in background(3.1% vs.6.7%)(5.6% for PET).Patients’ SUVmax,SUVmean,SULpeak,and MTV measured from quantitative Co-SPECT were overall highly correlated with those from PET(r=0.82-0.88).Adjustment of the threshold of SUVmax and SUV to determine SUVmean and MTV did not further change the correlations with PET(r=0.81-0.88).Adding full physical corrections to Co-SPECT images can significantly improve image resolution and contrast to reveal smaller tumor lesions along with the capability to quantify functional parameters like PET/CT. 展开更多
关键词 18F-FDG coincidence SPECT/CT full physical corrections thoracic carcinomas image quantitation
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