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Differentiation of Positional Isomers of Propyl Alcohols Using Filament-Induced Fluorescence 被引量:4
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作者 魏祥野 涂志伟 +2 位作者 刘畅 李贺龙 徐淮良 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第5期35-38,共4页
We experimentally demonstrate the recognition of positional isomers of propyl alcohol vapor through nonlinear fluorescence induced by high-intensity femtosecond laser filaments in air. By measuring characteristic fluo... We experimentally demonstrate the recognition of positional isomers of propyl alcohol vapor through nonlinear fluorescence induced by high-intensity femtosecond laser filaments in air. By measuring characteristic fluorescence of n-propyl and isopropyl alcohol vapors produced by femtosecond filament excitation, it is found that they show identical spectra, that is, those from molecular bands of CH, C2, Nit, OH and CN, while the relative intensities are different. By comparing the ratios of the CH and C2 signals, the two propyl alcohol isomers are differentiated. The different signal intensities are ascribed to different ionization potentials of the two isomer molecules, leading to different production efficiencies of fluorescing fragments. 展开更多
关键词 of IT on in Differentiation of Positional Isomers of Propyl Alcohols Using Filament-Induced Fluorescence that from
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On Skew Triangular Matrix Rings 被引量:3
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作者 Wang Wei-liang Wang Yao Ren Yan-li 《Communications in Mathematical Research》 CSCD 2016年第3期259-271,共13页
In this paper, we prove the existence and uniqueness of positive solutions for a system of multi-order fractional differential equations. The system is used to represent constitutive relation for viscoelastic model of... In this paper, we prove the existence and uniqueness of positive solutions for a system of multi-order fractional differential equations. The system is used to represent constitutive relation for viscoelastic model of fractional differential equations. Our results are based on the fixed point theorems of increasing operator and the cone theory, some illustrative examples are also presented. 展开更多
关键词 fractional differential equation Caputo fractional derivative fixed point theorem positive solution
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Extended tanh-function Method for Solving Traveling Wave Solutions of Nonlinear Kundu Equation
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作者 Cai Hua Guo Ning +2 位作者 Chang Jing Liu Li-huan Wu Xian-na 《Communications in Mathematical Research》 CSCD 2016年第3期281-288,共8页
In this paper, we study the existence of multiple positive periodic solutions for the second order differential equation x′′(t) + p(t)x′(t) + q(t)x(t) = f(t, x(t)).By using Krasnoselskii fixed point... In this paper, we study the existence of multiple positive periodic solutions for the second order differential equation x′′(t) + p(t)x′(t) + q(t)x(t) = f(t, x(t)).By using Krasnoselskii fixed point theorem, we establish some criteria for the existence and multiple positive periodic solutions for this differential equation. 展开更多
关键词 positive periodic solution multiplicity differential equation Krasnoselskii fixed point theorem
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Carrier phase-based ionospheric observables using PPP models
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作者 Yan Xiang Yang Gao +1 位作者 Junbo Shi Chaoqian Xu 《Geodesy and Geodynamics》 2017年第1期17-23,共7页
The ionosphere is one of the major error sources in Global Navigation Satellite System (GNSS) posi- tioning, navigation and timing. Estimating the ionospheric delays precisely is of great interest in the GNSS commun... The ionosphere is one of the major error sources in Global Navigation Satellite System (GNSS) posi- tioning, navigation and timing. Estimating the ionospheric delays precisely is of great interest in the GNSS community. To date, GNSS observables for ionospheric estimation are most commonly based on carrier phase smoothed code measurements. However, leveling errors, which affect the performance of ionospheric modeling and differential code bias (DCB) estimation, exist in the carrier phase smoothed code observations. Such leveling errors are caused by the multipath and the short-term variation of DCB. To reduce these leveling errors, this paper investigates and estimates the ionospheric delays based on carrier phase measurements without the leveling errors. The line-of-sight ionospheric observables with high precision are calculated using precise point positioning (PPP) techniques, in which carrier phase measurements are the principal observables. Ionosphere-free and UofC PPP models are applied and compared for their effectiveness to minimize the leveling errors. To assess the leveling errors, single difference of ionospheric observables for a short baseline is examined. Results show that carrier phase- derived ionospheric observables from PPP techniques can effectively reduce the leveling errors. Furthermore, we compared the PPP ionosphere estimation model with the conventional carrier phase smoothed code method to assess the bias consistency and investigate the biases in the ionospheric observables. 展开更多
关键词 differential code bias(DCB)Bias consistencyIonospheric observablePrecise point positioning (PPP)Leveling errors
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MULTIPLE POSITIVE SOLUTIONS OF A SINGULAR (n-1,1) CONJUGATE BOUNDARY VALUE PROBLEM WITH DELAY 被引量:2
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作者 Weng Peixuan\ Tian YanlingDept. of Math.,South China Normal Univ.,Guangzhou 51 0 631 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2000年第2期128-136,共9页
This paper discusses the singular ( n\|1,1 ) conjugate boundary value problem as follows by using a fixed point index theorem in cones[HL(2:1,Z;2,Z]u (n) (t)+a(t)f(u(w(t)))=0,(0<t<1), u(t)=φ(t),(-τ≤t&l... This paper discusses the singular ( n\|1,1 ) conjugate boundary value problem as follows by using a fixed point index theorem in cones[HL(2:1,Z;2,Z]u (n) (t)+a(t)f(u(w(t)))=0,(0<t<1), u(t)=φ(t),(-τ≤t<0), u (j) (0)=u(1)=0,(1≤j≤n-2).Effort is devoted to give some sufficient conditions for which the equation has at least two positive solutions.An example to illustrate the application of this theorem is given. [FQ(6*2。39,X-W] 展开更多
关键词 Conjugate boundary value problem functional differential equation multiple positive solution.Keywords:Conjugateboundaryvalueproblem functionaldifferentialequation multiplepositivesolu-tion.
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Physics of ferroelectric differential capacitance based upon free energy, and implications for use in electronic devices
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作者 C.M.Krowne 《Journal of Advanced Dielectrics》 CAS 2019年第1期6-21,共16页
In this paper,it is shown that for stable,steady state operation of devices typical of microwave and millimeter wave electronics,no negative differential capacitance is possible with conventional thinking.However,it m... In this paper,it is shown that for stable,steady state operation of devices typical of microwave and millimeter wave electronics,no negative differential capacitance is possible with conventional thinking.However,it may be possible,with strain engineering of materials,to obtain some if not all elements of the differential capacitance tensor which are negative.Rigorous derivations are provided based upon analyzing the physics using thermodynamic phenomenological free energy.It should be emphasized that,even with strain engineering,and possible discovery of some negative capacitive elements,stable operation will not be obtained because the thermodynamics precludes it. 展开更多
关键词 Gibbs and Helmholtz thermodynamic free energies phenomenological physical model stresses and strains negative and positive differential capacitances polarization permittivity and inverse permittivity tensors
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Differential attack on nonlinear combined sequences
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作者 LI Chao WANG Wenling HU Pengsong 《Frontiers of Electrical and Electronic Engineering in China》 CSCD 2007年第4期435-439,共5页
By using the coding properties and statistic properties of the plaintext,the differential properties of the key stream sequences generated by a nonlinear combined generator were analyzed.Then a differential attack alg... By using the coding properties and statistic properties of the plaintext,the differential properties of the key stream sequences generated by a nonlinear combined generator were analyzed.Then a differential attack algorithm on the nonlinear combined sequences was proposed.At last,an attack example adopting the differential attack algorithm was presented. 展开更多
关键词 combined generator differential attack differential position set differential validity
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Epigenome-wide DNA methylation study of whole blood in patients with sporadic amyotrophic lateral sclerosis 被引量:1
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作者 Zhengyi Cai Xinmiao Jia +2 位作者 Mingsheng Liu Xunzhe Yang Liying Cui 《Chinese Medical Journal》 SCIE CAS CSCD 2022年第12期1466-1473,共8页
Background:Epigenetics,and especially DNA methylation,contributes to the pathogenesis of sporadic amyotrophic lateral sclerosis(SALS).This study aimed to investigate the role of DNA methylation in SALS using whole blo... Background:Epigenetics,and especially DNA methylation,contributes to the pathogenesis of sporadic amyotrophic lateral sclerosis(SALS).This study aimed to investigate the role of DNA methylation in SALS using whole blood of SALS patients.Methods::In total,32 SALS patients and 32 healthy controls were enrolled in this study.DNA was isolated from whole blood collected from the participants.DNA methylation profiles were generated using Infinium MethylationEPIC BeadChip.Results:We identified 34 significant differentially methylated positions(DMPs)in whole blood from SALS patients,compared with the healthy controls.Of these DMPs,five were hypermethylated and 29 were hypomethylated;they corresponded to 13 genes.For the DMPs,ATAD3B and BLK were hypermethylated,whereas DDO,IQCE,ABCB1,DNAH9,FIGN,NRP1,TMEM87B,CCSAP,ST6GALNAC5,MYOM2,and RUSC1-AS1 were hypomethylated.We also identified 12 differentially methylated regions(DMRs),related to 12 genes(NWD1,LDHD,CIS,IQCE,TNF,PDE1C,LGALS1,CSNK1E,LRRC23,ENO2,ELOVL2,and ELOVL2-AS1).According to data from the Kyoto Encyclopedia of Genes and Genomes database,DNAH9 and TNF are involved in the amyotrophic lateral sclerosis(ALS)pathway.Correlation analysis between clinical features and DNA methylation profiling indicated that the methylation level of ELOVL2 and ARID1B was positively associated with the age of onset(r=0.86,adjust P=0.001)and disease duration(r=0.83,adjust P=0.01),respectively.Conclusions:We found aberrant methylation in DMP-and DMR-related genes,implying that many epigenetic alterations,such as the hypomethylation of DNAH9 and TNF,play important roles in ALS etiology.These findings can be helpful for developing new therapeutic interventions. 展开更多
关键词 Amyotrophic lateral sclerosis DNA methylation differentially methylated positions differentially methylated regions Whole blood
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