To study the alternating current （AC） impedance properties of Ag/AgC1 electrocardiograph （ECG） electrodes, the electrode pair was gel-to-gel connected, and then the electrical potential was recorded after a safe s...To study the alternating current （AC） impedance properties of Ag/AgC1 electrocardiograph （ECG） electrodes, the electrode pair was gel-to-gel connected, and then the electrical potential was recorded after a safe stimulating current passes through the electrode pair, so the AC impedance data of ECG electrodes were obtained. Varying the frequency and value of stimulating current, the detailed comparison and analysis of AC impedance properties of the electrodes were performed, and the stability was further characterized by using the continuous measurement within 24 h. The experimental results show that the AC impedance values of electrodes decreased, and then slightly increased with the increase of frequency of stimulating current. The minimum AC impedance value was obtained when the frequency was changed to 10 kHz. When the stimulating current increased, the AC impedance values of electrodes showed a slight decrease, but did not change significantly. Besides, the continuous measurement results show that the impedance value presented a significant increase in the initial 30 min, and then was stabilized in the following measuring process.展开更多
By connecting tercarbazole(3 Cz)and triphenyltriazine(TRz)units with a diphenyl ether group,we designed and synthesized a new donor-spacer-acceptor structure molecule9’-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenoxy)...By connecting tercarbazole(3 Cz)and triphenyltriazine(TRz)units with a diphenyl ether group,we designed and synthesized a new donor-spacer-acceptor structure molecule9’-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenoxy)phenyl)-9’H-9,3’:6’,9"-tercarbazole(3 Cz-o-TRz)as the multifunctional component of exciplex emitters.As expected,the intermolecular charge-transfer transition is dominant for3 Cz-o-TRz because of the space-enough and conjugation-forbidden linkage of the diphenyl ether group,increasing the intrinsic characteristics of the 3 Cz and TRz moieties in its single-molecule state.Accordingly,three common electron acceptors(4,6-bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine(B3 PyMPm),4,6-bis(3,5-di(pyridin-4-yl)phenyl)-2-methylpyrimidine(B4 PyMPm),and(1,3,5-triazine-2,4,6-triyl)tris(benzene-3,1-diyl)tris(diphenylphosphineoxide)(POT2 T))and three common electron donors(4,4’-(cyclohexane-1,1-diyl)bis(N,N-di-p-tolylaniline)(TAPC),tris(4-(10 H-phenoxazin-10-yl)phenyl)amine(TPA-PXZ),and N1-phenyl-N4,N4-bis(4-(phenyl(m-tolyl)amino)phenyl)-N1-(m-tolyl)benzene-1,4-diamine(m-MTDATA))were chosen to construct six exciplex emitters with 3 Cz-o-TRz.In the organic light-emitting diodes(OLEDs),the emission spectra of these exciplex emitters could be gradually modulated from 510 to 590 nm.In addition,TAPC:3 Cz-o-TRz-and 3 Cz-o-TRz:PO-T2 T-based OLEDs achieved desirable performance with maximum external quantum efficiencies(EQEs)around 12%.Moreover,a simple tandem OLED containing TAPC:3 Cz-o-TRz and 3 Czo-TRz:PO-T2 T emitters realized optimal performance with an ultralow turn-on voltage of 2.4 V and a maximum EQE of14.1%.These results indicate the great potential of the donorspacer-acceptor structure compounds in developing exciplex emitters.展开更多
In this paper, the authors prove the existence of solutions for degenerate elliptic equations of the form-div(a(x)▽_p u(x)) = g(λ, x, |u|^(p-2)u) in R^N, where ▽_pu =|▽u|^(p-2)▽u and a(x) is a degenerate nonnegat...In this paper, the authors prove the existence of solutions for degenerate elliptic equations of the form-div(a(x)▽_p u(x)) = g(λ, x, |u|^(p-2)u) in R^N, where ▽_pu =|▽u|^(p-2)▽u and a(x) is a degenerate nonnegative weight. The authors also investigate a related nonlinear eigenvalue problem obtaining an existence result which contains information about the location and multiplicity of eigensolutions. The proofs of the main results are obtained by using the critical point theory in Sobolev weighted spaces combined with a Caffarelli-Kohn-Nirenberg-type inequality and by using a specific minimax method, but without making use of the Palais-Smale condition.展开更多
The relation between strong mixing and conditionally strong mixing is answered by examples,that is,the strong mixing property of random variables does not imply the conditionally strong mixing property,and the opposit...The relation between strong mixing and conditionally strong mixing is answered by examples,that is,the strong mixing property of random variables does not imply the conditionally strong mixing property,and the opposite implication is also not true.Some equivalent definitions and basic properties of conditional strong mixing random variables are derived,and several conditional covariance inequalities are obtained.By means of these properties and conditional covariance inequalities,a conditional central limit theorem stated in terms of conditional characteristic functions is established,which is a conditional version of the earlier result under non-conditional case.展开更多
基金Project(111gpy06) supported by Fundamental Research Funds for the Central Universities,ChinaProject(101055807) supported by the Innovative Experiment Plan for College Students of Sun Yat-sen University,ChinaProject(KF201115) supported by the Opening Fund of Laboratory Sun Yat-sen University,China
文摘To study the alternating current （AC） impedance properties of Ag/AgC1 electrocardiograph （ECG） electrodes, the electrode pair was gel-to-gel connected, and then the electrical potential was recorded after a safe stimulating current passes through the electrode pair, so the AC impedance data of ECG electrodes were obtained. Varying the frequency and value of stimulating current, the detailed comparison and analysis of AC impedance properties of the electrodes were performed, and the stability was further characterized by using the continuous measurement within 24 h. The experimental results show that the AC impedance values of electrodes decreased, and then slightly increased with the increase of frequency of stimulating current. The minimum AC impedance value was obtained when the frequency was changed to 10 kHz. When the stimulating current increased, the AC impedance values of electrodes showed a slight decrease, but did not change significantly. Besides, the continuous measurement results show that the impedance value presented a significant increase in the initial 30 min, and then was stabilized in the following measuring process.
基金supported by the National Natural Science Foundation of China(51773029,52073040,51533005 and 51821002)the Fundamental Research Funds for the Central Universities(ZYGX2016Z010)the International Cooperation and Exchange Project of Science and Technology Department of Sichuan Province(2019YFH0057 and 2019YFH0059)。
文摘By connecting tercarbazole(3 Cz)and triphenyltriazine(TRz)units with a diphenyl ether group,we designed and synthesized a new donor-spacer-acceptor structure molecule9’-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenoxy)phenyl)-9’H-9,3’:6’,9"-tercarbazole(3 Cz-o-TRz)as the multifunctional component of exciplex emitters.As expected,the intermolecular charge-transfer transition is dominant for3 Cz-o-TRz because of the space-enough and conjugation-forbidden linkage of the diphenyl ether group,increasing the intrinsic characteristics of the 3 Cz and TRz moieties in its single-molecule state.Accordingly,three common electron acceptors(4,6-bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine(B3 PyMPm),4,6-bis(3,5-di(pyridin-4-yl)phenyl)-2-methylpyrimidine(B4 PyMPm),and(1,3,5-triazine-2,4,6-triyl)tris(benzene-3,1-diyl)tris(diphenylphosphineoxide)(POT2 T))and three common electron donors(4,4’-(cyclohexane-1,1-diyl)bis(N,N-di-p-tolylaniline)(TAPC),tris(4-(10 H-phenoxazin-10-yl)phenyl)amine(TPA-PXZ),and N1-phenyl-N4,N4-bis(4-(phenyl(m-tolyl)amino)phenyl)-N1-(m-tolyl)benzene-1,4-diamine(m-MTDATA))were chosen to construct six exciplex emitters with 3 Cz-o-TRz.In the organic light-emitting diodes(OLEDs),the emission spectra of these exciplex emitters could be gradually modulated from 510 to 590 nm.In addition,TAPC:3 Cz-o-TRz-and 3 Cz-o-TRz:PO-T2 T-based OLEDs achieved desirable performance with maximum external quantum efficiencies(EQEs)around 12%.Moreover,a simple tandem OLED containing TAPC:3 Cz-o-TRz and 3 Czo-TRz:PO-T2 T emitters realized optimal performance with an ultralow turn-on voltage of 2.4 V and a maximum EQE of14.1%.These results indicate the great potential of the donorspacer-acceptor structure compounds in developing exciplex emitters.
文摘In this paper, the authors prove the existence of solutions for degenerate elliptic equations of the form-div(a(x)▽_p u(x)) = g(λ, x, |u|^(p-2)u) in R^N, where ▽_pu =|▽u|^(p-2)▽u and a(x) is a degenerate nonnegative weight. The authors also investigate a related nonlinear eigenvalue problem obtaining an existence result which contains information about the location and multiplicity of eigensolutions. The proofs of the main results are obtained by using the critical point theory in Sobolev weighted spaces combined with a Caffarelli-Kohn-Nirenberg-type inequality and by using a specific minimax method, but without making use of the Palais-Smale condition.
基金supported by National Natural Science Foundation of China (GrantNo. 11126333)the Natural Science Foundation Project of Chongqing (Grant No. 2009BB2370)the SCRof Chongqing Municipal Education Commission (Grant Nos. KJ120731 and KJ100726)
文摘The relation between strong mixing and conditionally strong mixing is answered by examples,that is,the strong mixing property of random variables does not imply the conditionally strong mixing property,and the opposite implication is also not true.Some equivalent definitions and basic properties of conditional strong mixing random variables are derived,and several conditional covariance inequalities are obtained.By means of these properties and conditional covariance inequalities,a conditional central limit theorem stated in terms of conditional characteristic functions is established,which is a conditional version of the earlier result under non-conditional case.
