20,448 research outputs found
A good professional reputation is in the eye of the beholder
No full textReputation is audience-specific, write Gokhan Ertug, Tamar Yogev, Yonghoon Lee and Peter Hedströ
Spin-forbidden transitions in the vicinity of the 2 (1)Pi(u)<- X(1)Sigma(+)(g) band system of Rb(2)
No full textWe have investigated the Rb(2) 475 nm system by resonance enhanced two-photon ionization spectroscopy in a pulsed molecular beam. Strong extra bands accompanying the 2 (1)Pi(u) nu' = 5 - 8 <- X (1)Sigma(+)(g) nu '' = 0 bands were newly observed. Rotational analysis of the main and extra bands reveals that the 2 (1)Pi(u) nu' = 5 - 8 levels are significantly perturbed, mainly by the 3 (3)Sigma(+)(u)(1(u)) state and also by the 2 (3)Pi(u)(1(u)) state. For the major perturber, 3 (3)Sigma(+)(u)(1(u)), the intensity borrowing has been found to be facilitated by the 2 (3)Pi(+)(u)(1(u)) potential energy curve crossing near 21100 cm(-1). For the vibronic-band intensities of the 2 (3)Pi(u)(1(u)) nu' <- X (1)Sigma(+)(g) nu '' = 0 transitions observed in this spectral region, intensity borrowing was most effective when the 2 (3)Pi(u)(1(u)) levels were close to the 3 (3)Sigma(+)(u)(1(u)) levels. A deperturbation fit for the perturbing bands has provided the 2 (1)Pi(u)-3 (3)Sigma(+)(u)(1(u)) coupling constants
Visible-Light-Enabled Ortho-Selective Aminopyridylation of Alkenes with N-Aminopyridinium Ylides
No full text© 2020 American Chemical Society.By utilizing an underexplored reactivity mode of N-aminopyridinium ylides, we developed the visible-light-induced ortho-selective aminopyridylation of alkenes via radical-mediated 1,3-dipolar cycloaddition. The photocatalyzed single-electron oxidation of N-aminopyridinium ylides generates the corresponding radical cations that enable previously inaccessible 1,3-cycloaddition with a broader range of alkene substrates. The resulting cycloaddition adducts rapidly undergo subsequent homolytic cleavage of the N-N bond, conferring a substantial thermodynamic driving force to yield various β-aminoethylpyridines. Remarkably, amino and pyridyl groups can be installed into both activated and unactivated alkenes with modular control of ortho-selectivity and 1,2-syn-diastereoselectivity under metal-free and mild conditions. Combined experimental and computational studies are conducted to clarify the detailed reaction mechanism and the origins of site selectivity and diastereoselectivity11sci
Analysis of internet users' interests based on windows GUI messages
No full textIt is important to unobtrusively observe users' interactions on web browsers for the measurement of users' interest. Moreover, the observation should be performed on the client side in real time, because the contents of web pages are dynamically subject to change in the current Internet environment. In this paper, we suggest a simple method of inferring a user's interest for web contents by monitoring the amount of processed GUI messages while the user is reading a web page. We developed a software module that runs behind the Internet Explorer and monitors the number of processed GUI messages, the viewing time and the size of a web page. We found that the number of processed GUI messages, when properly normalized by the size of a web page, is close correlated with a user's interest for web contents
Photodissociation and Laser Spectroscopy of alkali metal dimers in a very cold molecular beam
No full textPerformance analysis of OBS networks using the effective bandwidth method
No full textThis article provides a new scheme for the blocking probability evaluation for optical burst switching networks. While several previous articles used mainly links as servers, we consider switches as servers. In order to evaluate the blocking probability at switches, we use the effective bandwidth method. The method shows more accurate results and the accuracy of the method is proven by simulation and numerical analyses
Conformational study of tyramine and its water clusters by laser spectroscopy
No full textTyramine and its monohydrated clusters have been investigated by several laser spectroscopic methods in a pulsed molecular beam. The conformational structures and their effects on hydration have been revealed by resonant two-photon ionization (R2PI), UV-UV ion-dip, and ab initio calculations. UV rotational band contour spectra of the S-1 <- S-0 origin bands enabled determination of ethylamine side chain conformations for all seven stable conformers of tyramine. When coexpanding tyramine with a mixture of Ar and water vapor, we have found two kinds of conformational effects on hydration. One is sensitive to conformation of the ethylamine chain and the other to the orientation of the OH group, particularly in the most stable pair of conformers. UV-UV ion-dip spectra detected seven stable conformers of the monohydrated clusters, of which hydrogen-bonding structures, spectral shifts, and origin band intensity distributions are well explained by considering tyramine as a hybrid of phenylethylamine (PEA) and phenol. Monohydration of the most stable gauche conformer pair (cis and trans) of tyramine leads to more detailed conformational assignments regarding the orientation of the phenolic OH group. Cyclic hydrogen-bonding linkage formed in the monohydrated cluster pair is found to be sensitive to the orientation of the phenolic OH group. One of the cluster pair, in which tyramine has the gauche-cis conformation, is more stabilized by the cyclic hydrogen bonding and its origin band intensity becomes stronger than that of the other
Supplemental Material - Feasibility of a Low-Power, Low-Resolution Laser-Induced Breakdown Spectroscopy Instrument for Analysis of Nickel Alloys: Quantification of the Major Alloying Elements and Classification
No full textSupplemental Material for Feasibility of a Low-Power, Low-Resolution Laser-Induced Breakdown Spectroscopy Instrument for Analysis of Nickel Alloys: Quantification of the Major Alloying Elements and Classification by Hanbum Choi, Hyang Kim, Song-Hee Han, Sunhye Kim, Sehoon Jung, Sang-Ho Nam and Yonghoon Lee in Applied Spectroscopy</p
Observation of ultraviolet rotational band contours of the DNA base adenine: Determination of the transition moment
No full textWe report the first observation and analysis of rotational band contours of the jet-cooled DNA base adenine for three vibronic bands at 36 062, 36 105, and 36 248 cm(-1). The lowest n pi* and pi pi* states have been labeled with their excited-state vibronic symmetry, and a strong pi pi*-n pi* vibronic coupling via an out-of-plane vibrational mode has been revealed. The rotational band contours have been recorded by resonant two-photon ionization (R2PI) and analyzed by a genetic algorithm (GA) based fit to obtain the optimum band parameters. The vibronic band at 36 062 cm(-1) shows dominant c-type character with transition dipole moment (TDM) components mu(2)(a):mu(2)(b):mu(2)(c)=0.09: 0.17:0.74 and those at 36 105 and 36 248 cm(-1) show abc-hybrid character with predominantly in-plane TDM components. The band at 36 062 cm-1 has been assigned as the n ->pi* transition, and the 36 105 cm(-1) band as the pi ->pi* transition by the symmetry analysis. The band at 36 248 cm(-1) provides evidence of the strong pi pi*-n pi* vibronic coupling via an out-of-plane vibrational mode
Changes in Space Usage Behaviours after the Implementation of Seouls Bus Rapid Transit Project in Jongno Street: A Social Data Analysis
No full text© SPSD Press from 2010, SPSD Press, KanazawaThis study analysed blog data to examine visitors behavioural changes following the introduction of a bus rapid transit (BRT) system in Seoul to vitalise public transport. Using blog texts, we assessed the appearance frequency of numerous keywords, including Jongno Street (the target location), public transportation,, and bus-only lane, to identify and categorise frequently visited places and examine the changes in user behaviours before and after project implementation. Based on this analysis, we categorised the significant places into nine types (public spaces, cultural and religious places, open spaces, major places, historic sites, streets, and structures) in accordance with Jongnos attributes. We found that the scope of visitors activities increased within a 1-km radius of the bus station and most people visited open spaces, streets, and major places and engaged in various activities before reaching their final destination. The visitors who used public transport often walked to their destinations within a 1-km radius. This showed that the BRT system implemented on Jongno Street contributed to the creation of a vigorous, walkable urban environmentN
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