... Formosulfite, BIII.— Les Nouvelles Plaques Extra-Rapides Marque Σ (Sigma), J.— Les Yeux Des Animaux Employés Comme ...
1904 - Gale Group | NCCO Photography
... system of π-electrons from that of the σ-electrons, when studying the energy levels of conjugated ... Hückel approximation, is that canonical structures involving π-σ or σ-σ resonance are negligible. It is then shown that n-σ and σ-σ exchange terms do not need to be taken ... uncertainties, particularly in the ionization energy of the σ-electrons. The exchange integral between the two n ... 2.73eV. That between a π and the σ orbital in the neighbouring carbon atom is +0. ...
Tópico(s): Spectroscopy and Quantum Chemical Studies
1952 - Royal Society | Proceedings of the Royal Society of London A Mathematical and Physical Sciences
... this case the ratio ab changes, e.g., σ-MoCr2Ni2 and σ-WCr8Ni5 as compared with σ-MoFe and σ-WFe. Le métal B de la phase AB2 ... cas, cependant, le rapport ab change, par exemple σ-MoCr2Ni2 et σ-WCr8Ni5 comparés à σ-MoFe et σ-WFe. Das B Metall der Laves Phase AB2 ... ändert sich jedoch das Verhältnis ab, d.h. σ-Mo Cr2Ni2 und σ-WCr8 Ni5 werden mit σ-MoFe und σ- ...
Tópico(s): Inorganic Chemistry and Materials
1953 - University of Toronto Press | Acta Metallurgica
E W Foster, Owen Willans Richardson,
... systems 3 p 3 Π → 2 s 3 Σ and 3 d 3 ΠΣΔ → 2 p 3 ... important lines of the system 3 s 3 Σ → 2 p 3 Π and 3 Y → 2 s 3 Σ , together with some lines of the triplet system 3 p 3 Σ → 2 s 3 Σ . The singlets are represented by about 20 lines coming from the states 3 d 1 Σ , 3 d 1 Πd , 3 s 1 Σ , 2 s 1 Σ , 3 1 K , 1 M , and 1 N and ending in 2 p 1 Σ or belonging to the system 3 p 1 Π → 2 s 1 Σ . There is also a small proportion of unclassified ...
Tópico(s): Atmospheric Ozone and Climate
1947 - Royal Society | Proceedings of the Royal Society of London A Mathematical and Physical Sciences
... of forbidden electronic transitions in heteronuclear molecules, 3 Σ + – 1 Σ + and 3 Σ − – 1 Σ + , are studied in the spectrum of the CO ... meter vacuum spectrograph. In most of the 3 Σ + – 1 Σ + bands all four predicted branches are observed. For ...
Tópico(s): Atmospheric Ozone and Climate
1955 - NRC Research Press | Canadian Journal of Physics
... the temperature. At absolute zero this spontaneous magnetization (σ 0 ) is equal to the saturation intensity (σ ∞ ) whilst at any other temperature (T) the value of σ 0 /σ ∞ is dependent only on the ratio T/θ ... the various domains. As the temperature rises, however, σ 0 becomes much less than σ ∞ , and the effect of an external field is ... density, J the mechanical equivalent of heat, and σ the intensity per unit volume. This equation was ... the equation d W = pdv + v H d σ, where v H d σ is the work done on the body by ... equation d T = H + H'/J ρcσ d σ, (2) where H' is the internal field, c ...
Tópico(s): Material Properties and Failure Mechanisms
1934 - Royal Society | Proceedings of the Royal Society of London Series A Containing Papers of a Mathematical and Physical Character
... a précédé le son à intervalles de 25 σ et de 50 σ, le réflexe au son a été augmenté d' ... normal à la lumière. A intervalles de 75 σ et plus, le réflexe au son a été ... l'inhibition arrivant à un maximum entre 100 σ et 200 σ, et continuant à plus petits degrés jusqu'à 450 σ, le plus long intervalle testé. On discute les ... Licht dem Laut mit einem Intervall von 25 σ und 50 σ vorausging, wurde die reflexive Reaktion auf einen auditiven ... reflexiven Reaktion auf Licht. Bei Intervallen von 75 σ oder mehr, war die reflexive Reaktion auf auditive ...
Tópico(s): Circadian rhythm and melatonin
1933 - Taylor & Francis | The Journal of General Psychology
A. McLachlan, H. H. Dearman, R. Lefèbvre,
... essential assumptions in the new theory: (a) that σ-π exchange interaction is small; (b) that an antisymmetrised product U (π) V (σ), which allows π-π and σ-σ, but not σ-π correlations, is a good first approximation to ... formed exclusively of π-orbital configurations, and V (σ) exclusively of σ ones. In the framework of our theory the ... density in the molecular plane arises entirely from σ-electron excitations. The general relation aN=tr(QNρ) ... a hyperfine coupling matrix, whose elements depend on σ-π exchange integrals and excited σ triplet states. ...
Tópico(s): Synthesis and Properties of Aromatic Compounds
1960 - American Institute of Physics | The Journal of Chemical Physics
Lester E. Dubins, David A. Freedman,
... all countably additive, finite, signed measures on a σ-field Σ of subsets of a set X.There is ... is an element of 2 1 *, the smallest σ-field of subsets of M such that: for ... interesting subsets of M, under the assumption that Σ is countably generated.Here are some results.If X is compact metric, and Σ is the <7-field of Borel subsets of ... a countable field of subsets of X, and Σ the smallest σ-field including 2.1.Let jy be a ... function from (Ω x X, J^f x Σ) to the Borel line, then ω -• I f( ... from indicators of measurable rectangles.2.3.The σ-field Σ* is countably generated.
Tópico(s): Stochastic processes and financial applications
1964 - Mathematical Sciences Publishers | Pacific Journal of Mathematics
... given the level of E w ( dU / d σ w < 0 ) . These assumptions imply that indifference curves ... U ) = a + bE R − cE R 2 − c σ R 2 into one of the form: E ( U ) = k 1 E R − k 2 σ R 2 . That such a transformation is not ... implies non-linear indifference curves in the ER, σ R 2 plane while the second implies a ... Rb + ( E R a − E R b ) α σ R c = α 2 σ R a 2 + ( 1 − α ) 2 σ Rb 2 + 2 r ab α ( 1 − α ) σ Ra σ Rb but r ab = 1 , therefore the expression under the square root sign can be factored: σ Rc = [ α σ Ra + ( 1 − α ) σ R ...
Tópico(s): Capital Investment and Risk Analysis
1964 - Wiley | The Journal of Finance
... wurden 256 Ionen explizite in der Energiefunktion U (σ 1 , σ 2 , …, σ 23 ) berücksichtigt, wobei σ λ eine Verschiebungskomponente bedeutet. Das verzerrte Gitter hat volle kubische Symmetrie. Die Energie U (σ 1 , σ 2 , …, σ 23 ) setzt sich aus den Beiträgen der Coulomb‐, ... eines Rechenautomaten wurden die Werte der Funktion U (σ 1 , σ 2 , …, σ 23 ) berechnet und U (σ 1 , σ 2 , …, ...
Tópico(s): Inorganic Fluorides and Related Compounds
1964 - Wiley | physica status solidi (b)
... and N 14 O 18 , and G 2 Σ − –X 2 Π bands were sorted out from ... the other known NO band systems G 2 Σ − –X 2 Π shows almost no perturbations. Vibrational ... gave the following constants for the G 2 Σ − state of N 14 O 16 : T e = ... The combination defect observed in the G 2 Σ − –X 2 Π bands agrees with the defect found in the A 2 Σ + –X 2 Π(γ) bands except in sign, ... of the G state is confirmed as 2 Σ − . The "pure precession" relation between G 2 Σ − and X 2 Π is found to hold ... assigned to ν = 10 indicates that G 2 Σ − is predissociated by a repulsive 2 Σ − state ...
Tópico(s): Molecular Spectroscopy and Structure
1964 - NRC Research Press | Canadian Journal of Physics
... deviation of this portfolio return, i.e. r ‒ / σ r . This is true even though this ratio ... and the standard deviation of this return be σ r . Equation (3) tells us that the market ( ... income = y ‒ A o ) and over-all risk σ y (or σ y A o ) as he may wish along ... risk is given by the slope coefficient ( r ‒ / σ r ), which is the reciprocal of the coefficient ... and it reduces its slope to ( r ‒ − r ∗ ) / σ r (from r − / σ r ). (See Figure I.) Note also that the “ ... debt) in relation to his over-all risk σ y , regardless of the scale of his investment ... operating expenses, the expected return r ‒ , standard deviation σ r , and hence the θ ratio of each ...
Tópico(s): Insurance and Financial Risk Management
1965 - Wiley | The Journal of Finance
... stochastic differential equation: dxt = m[xt, t] dt+ σ[xt, t] dyt where yt is the Brownian ... dxt = m[xt, t] dt + 12σ[xt, t](∂σ[xt, t]/∂xt)dt+ σ[xt, t]dyt. L'auteur étudie le problème ... équation différentielle stochastique dxt = m(xt, t)dt + σ (xt, t)dyt où yt représente le mouvement ... dxt = m[xt, t]dt+12σ[xt, t](∂σ[xt, t]/∂xt)dt + σ[xt, t]dyt. Dieser Beitrag befasst sich mit ... der stochastischeri Differentialgleichung: dxt = m(xt, t) dt + σ(xt, t) dyt, wo yt der Brownsche Bewegungsprozess ... dxt = m[xt, t]dt+12σ[xt, t](∂σ[xt, t]/∂xt)dt+σ[xt, t]dyt. ...
Tópico(s): Stochastic processes and statistical mechanics
1965 - Elsevier BV | International Journal of Engineering Science
... between the lowest π, π* triplet state and σ, π* (or π, σ*) singlet states (this explains Subspectrum I). (3) Second- ... π, π* triplet state and π, π* (or σ, σ*) singlet states (this accounts for the appearance of ... The S.O. matrix elements for the A31(σ,σ* or π,π*)↔3B1(σ,π* or π,σ*) is found to vanish for 1,4- but ... result, together with the fact that the 1A1 (σ,σ*)←1A1 transition has zero moment for 1,4- ...
Tópico(s): Catalytic Cross-Coupling Reactions
1965 - American Institute of Physics | The Journal of Chemical Physics
... versus the temperature T at different hydrostatic pressure σ, and ϵ(σ) at different T , was measured. The highest σ achieved was 12 800 kg/cm 2 , between 22 °C and 180 °C. At σ < 3500 kg/cm 2 , the Curie point T ... 2 /kg which ceases to be constant for σ > 3500 kg/cm 2 . The Curie‐Weiss temperature falls with growing σ. At higher σ, the Curie constant rises with growing σ. The ϵ(σ) graphs at constant T below 120 °C exhibit ... transition. Above 120 °C, ϵ decreases with growing σ. „Memory of pressure”︁ is observed on removal ...
Tópico(s): Glass properties and applications
1962 - Wiley | physica status solidi (b)
... remoulded samples were slightly stronger when the peak (σ 1 – σ 3 ) was used to define failure but the ... were stronger when failure was defined at peak (σ 1 ,/σ 3 ). The effect of overconsolidation varied with the ... the samples were remoulded or sedimented. When peak (σ 1 /σ 3 ) was used to define failure the effective ... quand on a employé la valeur de pointe (σ 1 – σ 3 ) pour déterminer la rupture mais les échantillons ... la rupture étaient determinée á valeur de pointe ((σ 1 /σ 3 ) L'effet de surconsolidation variait avec le ...
Tópico(s): Grouting, Rheology, and Soil Mechanics
1962 - ICE Publishing | Géotechnique
... steel subjected to the general tensile loading cycle σ m ± σ a , where σ m ≥ σ a , have been studied using plate specimens containing ... were defined by the value of the parameter σ a 3 l; if σ a 3 l ≥ C m a crack would grow, whereas if σ a 3 l < C m it would remain ... m depended on the value of the ratio σ m /σ a . Its value at σ m /σ a = 1 corresponded to that derived ...
Tópico(s): Microstructure and Mechanical Properties of Steels
1967 - Pergamon Press | Journal of Mechanical Engineering Science
D. Clotman, Th. Zeegers‐Huyskens,
... sum of the polar substituent constants of Taft, Σ σ*, give approximately a straight line, but no linear ... account, the sum of the Taft steric factor, Σ Es, the following equations were found: for system I: log K = −1·07 Σ σ* + 0·13 Σ Es + 2·56 for system II: log K = −0·80 Σ σ* + 0·25 Σ Es + 1·97 for system III: log K = −0·38 Σ σ* + 0·44 Σ Es + 1·84. As ...
Tópico(s): Electrochemical Analysis and Applications
1967 - Pergamon Press | Spectrochimica Acta Part A Molecular Spectroscopy
... molecule and to transfer an equivalent amount of σ electrons to the chlorine atom. This π-electron ... by nitrogen and finally donated by nitrogen as σ charge goes to the Cl atom. The hydrogen atom of HCl donates parts of its σ electronic charge to the Cl atom. Thus, the chlorine atom accepts σ electrons from the hydrogen of HCl and σ electrons from the nitrogen. Therefore, in addition to ... HCl reaction, the nitrogen atom is a π→σ transformer with nearly unit efficiency. The reaction NH3+ ... NH3) is π donor, the N atom is σ→π transformer (σ donor and π acceptor), the ...
Tópico(s): Gas Sensing Nanomaterials and Sensors
1967 - American Institute of Physics | The Journal of Chemical Physics
K. M. S. Saxena, P. T. Narasimhan,
The nuclear magnetic shielding constants ( σ ) and diamagnetic susceptibilities ( χ ) of some atoms and ions have been calculated using Hartree‐Fock‐Slater ( hfs ) wave functions. With the ... a fourth‐order polynomial has been fitted for σ hfs ( Z ) of neutral atoms. The calculated shielding ... and ions by the general formula ( Z ± n ) = σ hfs ( Z ) ± n δ ± ( Z ), where n is ... to 100 have been obtained. Our results on σ hfs and χ hfs compare favourably with other ... a calculé les constantes d'écran magnétique nucléaire ( σ ) et les susceptibilités diamagnétiques ( χ ) de quelques atomes ...
Tópico(s): Quantum Mechanics and Non-Hermitian Physics
1967 - Wiley | International Journal of Quantum Chemistry
Let ψ(Σ) denote the frontier of the square Σ (see § 3.1). A major part of the proof of the ... fulfilled then the corresponding curve γnecessarily intersects ψ(Σ)in such a way that, from a certain ... on γ may move on the frontier ψ(Σ) itself for brief periods or that γ may intersect ψ(Σ) in a set of points with limit-points on ψ(Σ), and in either case the special enumeration, referred ... the points of intersection of γ with ψ(Σ) would be impossible. With the additional condition (2) | ... of §4.1, though with a somewhat different Σ; so that the boundedness theorem in the paper ...
Tópico(s): Advanced Mathematical Modeling in Engineering
1967 - Wiley | Proceedings of the London Mathematical Society
Abstract The values of Δε and σ 0 in the expression σ = σ 0 exp {−Δε/ 2kT } for the dark conductivity σ, tend to increase together over the whole range ... confined roughly between two lines given by log σ 0 = αΔε + β, the compensation rule, with log σ 0 varying from 5 ± 4 for Δε equal ... for Δε = 4.0 e.v. The parameter σ 0 is related to the mobility of charge ... carriers in order of increasing Δε and log σ 0 : ( a ) intrinsic bulk thermal generation, transport by ... only account for a restricted range of log σ 0 , from 4 to 1.0, except perhaps ...
Tópico(s): Electrochemical Analysis and Applications
1967 - Wiley | Journal of Polymer Science Part C Polymer Symposia
... satisfying an, in general, anisotropic dispersion relation P (σ, k ) = 0 between frequency σ and wave-number vector k . If the forcing ... velocity U , then oscillatory forcing terms of frequency σ 0 (which would be replaced by 0 in ... to about 10/ T ) produce waves of frequency σ 0 + U. k (the Doppler effect). For any ... the wave-number k satisfies the equation P (σ 0 + U.k,k ) = 0, representing a surface in wave-number space here called S (σ 0 ), and their position relative to that of ... with a particular value of k on S (σ 0 ) are found in a direction, stretching out ...
Tópico(s): Fluid Dynamics and Turbulent Flows
1967 - Cambridge University Press | Journal of Fluid Mechanics
G. Herzberg, J. D. Simmons, Arnold M. Bass, S. G. Tilford,
The forbidden I 1 Σ − –X 1 Σ + transition of CO has been observed in absorption at high resolution in the vacuum ultraviolet region. As expected for a 1 Σ − – 1 Σ + transition, the bands consist of single Q branches, ... or very weak. Although the selection rule prohibiting Σ − –Σ + transitions is rigorous for dipole radiation at zero rotation, the I 1 Σ − –X 1 Σ + transition can occur for higher rotational levels because ...
Tópico(s): Spectroscopy and Laser Applications
1966 - NRC Research Press | Canadian Journal of Physics
... quantatively in terms of a molar conductivity coefficient σ M → (1/αM)(σ p - σ 0)/σ 0 where σ p is the measured peak conductance, and σ 0 the linearly interpolated background conductance at the ... α is the dissociation constant of the complex. σ M values are listed for 11 complexes, together ... Preliminary experiments indicate that some correlation exists between σ M values and esr results. La méthode décrite ... quantitativement en fonction d'un coeflicient de conductivitémolaire σ M = (1/αM) · (σ p - σ 0)/σ 0 oúσ p est ...
Tópico(s): Ionic liquids properties and applications
1966 - Elsevier BV | Electrochimica Acta
Mitiko Gō, Nobuhiro Gō, Harold A. Scheraga,
The Zimm–Bragg parameters s and σ for the helix-coil transition in polyglycine and poly-l-alanine are calculated in terms of molecular quantities, based on our earlier ... residues at each end, reduces the values of σ by a factor of 100.0−100.8. ... this source of entropy cancels when s and σ are obtained (as is shown numerically). The computations ... a comparison of calculated and experimental values of σ is possible because this quantity is not affected ... CO groups. For poly-l-alanine, s and σ are computed for both right- and left-handed ...
Tópico(s): Chemical Synthesis and Analysis
1970 - American Institute of Physics | The Journal of Chemical Physics
... They represent transitions from the ground state to [σ g 2 π u 4 Π g 3 2 Π 3/2g ]np σ u Π 1u , [σ g 2 π u 4 π g 3 2 Π 3/2g ]np π u Σ + (0 u + ), [σ g 2 π u 4 π g 3 2 Π 3/2g ]nf σ u Π 1u , [σ g 2 π u 4 π g 3 2 Π 3/2g ]nf π u , Σ + (0 u + ), and [σ g 2 π u 4 π g 3 ... to transitions to different states involving the common [σ g 2 π u 4 π g 3 ...
Tópico(s): Atmospheric Ozone and Climate
1970 - NRC Research Press | Canadian Journal of Physics