Corrélation entre possibilité d'effet laser et force oscillatrice de la transition fluorescente : cas des sels de pyrylium

1985 ◽  
Vol 63 (2) ◽  
pp. 191-194 ◽  
Author(s):  
Claude Rullière ◽  
Alain Declemy ◽  
Alexandru T. Balaban
Keyword(s):  
Oscillator Strength ◽  
Theoretical Calculations ◽  
Laser Action ◽  
Experimental Results ◽  
Quantum Yields ◽  
Pyrylium Salts

Laser action is demonstrated to occur in seven pyrylium salts between 4100 and 5100 Å with quantum yields extending from 4% to 12%. Theoretical calculations of the energy and oscillator strength of S0 → Sn transitions confirm band assignments deduced from experimental results. These results allow detection of a weak hidden transition in the 2,6-dimethyl-4-phenyl-pyrylium cation where laser action is not observed. This shows how important the magnitude of the oscillator strength of the first transition S0 → S1 is in selecting candidates to laser action. [Traduit par le journal]

Research of stamping of unequal channel bars. Part 5. Methods for calculating the extrusion of channels. 2. Extrusion of non-strengthening material

2021 ◽  
pp. 46-52
Author(s):  
A.L. Vorontsov
Keyword(s):  
Plane Strain ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
High Accuracy ◽  
Experimental Results ◽  
Die Forging

The results of experimental studies on the extrusion of channels from non-strengthening material are presented. Comparison of theoretical calculations with experimental results showed the high accuracy of the derived formulas. Keywords: die forging, extrusion, punch, matrix, misalignment, plane strain. [email protected]

Young’s Experiment on Slits with an Angle Between Them

2014 ◽  
Vol 9 (2) ◽  
pp. 173-179
Author(s):  
Anton Bogomyagkov ◽  
Viktor Dorokhov ◽  
Oleg Meshkov ◽  
Aleksandr Polygalov ◽  
Alexey Shcheglov
Keyword(s):  
Experimental Data ◽  
Interference Pattern ◽  
Intensity Distribution ◽  
Mathematical Analysis ◽  
Theoretical Calculations ◽  
Experimental Results ◽  
Digital Data ◽  
Hyperbolic Function ◽  
Standard Laboratory ◽  
Arbitrary Angle

Here are proposed a modified version of Young’s experiment on slits with an arbitrary angle between them. Also here performed mathematical analysis of the proposed scheme, showing that the intensity distribution can be approximated by a hyperbolic function. Experimental data confirm theoretical calculations. Analysis of the experimental results has conducted using two different methods of processing the digital data of the interference pattern. Theoretical calculations and experimental results established a nontrivial fact, that the interference patterns for slits with different, but symmetrical respect to 90° angles have the same intensity distribution. This experiment may be used as a standard laboratory work in University on optics workshop

scholarly journals Wavelength dependent nonlinear optical response of tetraphenylethene aggregation-induced emission luminogens

2018 ◽  
Vol 2 (12) ◽  
pp. 2263-2271 ◽  
Author(s):  
Jianbo Xiong ◽  
Xinyue Li ◽  
Chunqing Yuan ◽  
Sergey Semin ◽  
Zhaoquan Yao ◽  
...  
Keyword(s):  
Optical Properties ◽  
Nonlinear Optical ◽  
Theoretical Calculations ◽  
Experimental Results ◽  
Nlo Properties ◽  
Aggregation Induced Emission ◽  
Non Linear ◽  
Potential Applications ◽  
Linear Optical Properties ◽  
Linear Optical

Studies of the non-linear optical properties of classical AIEgens are rare, despite their important potential applications in organic composite photonic circuits. Here, we present experimental results, supported by theoretical calculations, of the non-linear optical (NLO) properties of TPE and its halogenated derivates.

Photochemische 2+2-Cycloadditionen von Äthylen und Acetylen an 1.3-Cyclohexadien unter erhöhtem Druck / Photochemical 2+2-Cycloadditions of Ethylene and Acetylene to 1,3-Cyclohexadiene under High Pressure

1977 ◽  
Vol 32 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Marlis F. Mirbach ◽  
Manfred J. Mirbach ◽  
Alfons Saus
Keyword(s):  
High Pressure ◽  
Quantum Yield ◽  
Room Temperature ◽  
Kinetic Scheme ◽  
Solvent Mixture ◽  
Experimental Results ◽  
Quantum Yields ◽  
Ethylene Pressure ◽  
Formal Kinetic

The photochemical cycloaddition of 1,3-cyclohexadiene (CHD) to ethylene and acetylene at pressures above 10 bar is described. Upon sensitized irradiation (2-acetylnaphthaline) CHD adds to ethylene at room temperature in dichloromethane to give cis-bicyclo[4,2,0]-oct-2-ene (1) along with dimers of cyclohexadiene. The yield of cross adduct increases with ethylene pressure (10-50 bar) whereas dimerisation decreases. Quantum yields of cross addition and dimerisation at 12 M ethylene were determined to be 0.31 and 0.35 respectively. At a pressure of 15 bar acetylene CHD reacts with acetylene to give bicyclo-[4,2,0]octa-2,7-diene (2) and bicyclo[2,2,2]octa-2,5-diene (3) as the major and minor products respectively. In a solvent mixture containing 60 vol-% CH2Cl2 and 40 vol-% acetone (2) is formed with a quantum yield of φ = 0.2. The experimental results are explained by a formal kinetic scheme.

THE RESONANCE ESCAPE FACTOR AND DENSITY SPATIAL DISTRIBUTION OF Li 670.970 nm RESONANCE LINES

2009 ◽  
Vol 23 (09) ◽  
pp. 1189-1197 ◽  
Author(s):  
JIAN HE ◽  
QINGGUO ZHANG ◽  
QINGDONG CHEN
Keyword(s):  
Spatial Distribution ◽  
Oscillator Strength ◽  
Optical Depth ◽  
Ground State ◽  
Resonance Absorption ◽  
Experimental Results ◽  
Line Center ◽  
Number Density ◽  
Escape Factor ◽  
Good Agreement

In this letter, the resonance escape factors and spatial distribution of three resonance absorption lines that making up the Li 670.970 nm line are discussed theoretically, for both Lorentzian and Voigt profiles. The oscillator strength, the number density of the absorbing atoms in the ground state, and the optical depth in the line center are discussed also in the calculation. The results we calculated are in good agreement with the experimental results. This calculation will be significant in the research of plasma Li atom.

Ring opening copolymerization of ε-caprolactone and diselenic macrolide carbonate for well-defined poly(ester-co-carbonate): kinetic evaluation and ROS/GSH responsiveness

2020 ◽  
Vol 11 (9) ◽  
pp. 1597-1605 ◽  
Author(s):  
Jiahao Wang ◽  
Chuanhao Sun ◽  
Jieni Hu ◽  
Yanling Huang ◽  
Yunxiang Lu ◽  
...  
Keyword(s):  
Ring Opening ◽  
Theoretical Calculations ◽  
Experimental Results ◽  
Kinetic Evaluation ◽  
Composition And Structure ◽  
Competitive Mechanism

Theoretical calculations agreed well with the experimental results. The competitive mechanism was proposed to clarify the composition and structure of the copolymers.

scholarly journals Subsurface imaging of flexible circuits via contact resonance atomic force microscopy

2019 ◽  
Vol 10 ◽  
pp. 1636-1647 ◽  
Author(s):  
Wenting Wang ◽  
Chengfu Ma ◽  
Yuhang Chen ◽  
Lei Zheng ◽  
Huarong Liu ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Theoretical Calculations ◽  
Contact Stiffness ◽  
Metal Layer ◽  
Experimental Results ◽  
Subsurface Imaging ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cover Thickness ◽  
Contact Resonance

Subsurface imaging of Au circuit structures embedded in poly(methyl methacrylate) (PMMA) thin films with a cover thickness ranging from 52 to 653 nm was carried out by using contact resonance atomic force microscopy (CR-AFM). The mechanical difference of the embedded metal layer leads to an obvious CR-AFM frequency shift and therefore its unambiguous differentiation from the polymer matrix. The contact stiffness contrast, determined from the tracked frequency images, was employed for quantitative evaluation. The influence of various parameter settings and sample properties was systematically investigated by combining experimental results with theoretical analysis from finite element simulations. The results show that imaging with a softer cantilever and a lower eigenmode will improve the subsurface contrast. The experimental results and theoretical calculations provide a guide to optimizing parameter settings for the nondestructive diagnosis of flexible circuits. Defect detection of the embedded circuit pattern was also carried out, which indicates the capability of imaging tiny subsurface structures smaller than 100 nm by using CR-AFM.

scholarly journals Experimental Study on the Local Drag of Completion String with Packers in Horizontal Wells

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 657 ◽  
Author(s):  
Qimin Liang ◽  
Bairu Xia ◽  
Baolin Liu ◽  
Zhen Nie ◽  
Baokui Gao
Keyword(s):  
Experimental Study ◽  
Oil And Gas ◽  
Theoretical Calculations ◽  
Horizontal Wells ◽  
Experimental Results ◽  
Economic Losses ◽  
Horizontal Section ◽  
Friction Coefficients ◽  
Oil And Gas Fields ◽  
Gas Fields

The multistage stimulation technology of horizontal wells has brought huge benefits to the development of oil and gas fields. However, the completion string with packers often encounters stuck due to the large drag in the horizontal section, causing huge economic losses. The local drag of the completion string with packers in the horizontal section is very complicated, and it has not been fully understood by theoretical calculations. A local drag experiment is designed to simulate the influence of microsteps and cuttings on the local drag of the completion string with packers in the inclined and horizontal sections. An obvious increase of the local drag of the packer is found at microsteps of the horizontal section, and the local drag is greatly affected by the amount of sand. In addition, the string with packers will vibrate during the tripping process in the deviated section, and the local drag is different when different amounts of sand are in the hole, but the change law is similar. The experimental results show that the friction coefficients of the packers with different materials in the horizontal section vary greatly, resulting in different local drags. It indicates that the local drag of the completion string not only depends on the microsteps and sand quantity in the wellbore, but also on the material difference of the packers. Only if microsteps and cuttings are removed can the completion string be tripped into horizontal wells smoothly.

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