4,882 research outputs found

    Meromorphic exact solutions of the generalized Bretherton equation

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    The generalized Bretherton equation is studied. The classification of the meromorphic traveling wave solutions for this equation is presented. All possible exact solutions of the generalized Brethenton equation are given

    Threshold photoelectron photoion coincidence spectroscopy and selected ion flow tube reactions of CHF3: comparison of product branching ratios

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    The threshold photoelectron and threshold photoelectron photoion coincidence spectra of CHF3_3 in the range 13.5 – 24.5 eV have been recorded. Ion yields and branching ratios have been determined for the three fragments CF3+_3^+, CHF2+^+ and CF+^+. The mean kinetic energy releases into fragment ions involving either C-H or C-F bond cleavage have been measured, and compared with statistical and impulsive models. CHF3+_3^+ behaves in a non-statistical manner characteristic of the small-molecule limit, with the ground electronic state and low-lying excited states of CHF3+_3^+ being largely repulsive along the C-H and C-F coordinates, respectively. The rate coefficients and product ion branching ratios have been measured at 298 K in a selected ion flow tube for the reactions of CHF3_3 with a large number of gas-phase cations whose recombination energies span the range 6.3 through 21.6 eV. A comparison between the branching ratios from the two experiments, together with an analysis of the threshold photoelectron spectrum of CHF3_3, shows that long-range charge transfer probably occurs for the Ar+^+ and F+^+ atomic ions whose recombination energies lie above ca. 15 eV. Below this energy, the mechanism involves a combination of short-range charge transfer and chemical reactions involving a transition state intermediate

    The Humane Society of the United States 1954-1979: Twenty-Five Years of Growth and Achievement

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    The HSUS came into being because, for several years previously. a great many people throughout the United States were aware of the tremendous need for a strong humane group that would actively endorse and work towards eliminating, on a national scale, some of the more obvious cruelties and injustices imposed on animals in slaughterhouses and by uncontrolled breeding of domestic pets. They also realized the necessity for a humane organization that would act in a missionary role. to encourage and assist in the formation of humane societies in the thousands of towns and areas where none existed.https://www.wellbeingintlstudiesrepository.org/ebooks/1027/thumbnail.jp

    Twenty-Five Years of Growth & Achievement: The Humane Society of the United States (1954-1979)

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    The HSUS came into being because, for several years previously, a great many people throughout the United States were aware of the tremendous need for a strong humane group that would actively endorse and work towards eliminating, on a national scale, some of the more obvious cruelties and injustices imposed on animals in slaughterhouses and by uncontrolled breeding of domestic pets. They also realized the necessity for a humane organization that would act in a missionary role, to encourage and assist in the formation of humane societies in the thousands of towns and areas where none existed

    Credible Decentralized Exchange Design via Verifiable Sequencing Rules

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    Trading on decentralized exchanges has been one of the primary use cases for permissionless blockchains with daily trading volume exceeding billions of U.S.~dollars. In the status quo, users broadcast transactions and miners are responsible for composing a block of transactions and picking an execution ordering -- the order in which transactions execute in the exchange. Due to the lack of a regulatory framework, it is common to observe miners exploiting their privileged position by front-running transactions and obtaining risk-fee profits. In this work, we propose to modify the interaction between miners and users and initiate the study of {\em verifiable sequencing rules}. As in the status quo, miners can determine the content of a block; however, they commit to respecting a sequencing rule that constrains the execution ordering and is verifiable (there is a polynomial time algorithm that can verify if the execution ordering satisfies such constraints). Thus in the event a miner deviates from the sequencing rule, anyone can generate a proof of non-compliance. We ask if there are sequencing rules that limit price manipulation from miners in a two-token liquidity pool exchange. Our first result is an impossibility theorem: for any sequencing rule, there is an instance of user transactions where the miner can obtain non-zero risk-free profits. In light of this impossibility result, our main result is a verifiable sequencing rule that provides execution price guarantees for users. In particular, for any user transaction AA, it ensures that either (1) the execution price of AA is at least as good as if AA was the only transaction in the block, or (2) the execution price of AA is worse than this ``standalone'' price and the miner does not gain (or lose) when including AA in the block.Comment: 32 Page

    Monoid presentations of groups by finite special string-rewriting systems

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    We show that the class of groups which have monoid presentations by means of finite special [λ]-confluent string-rewriting systems strictly contains the class of plain groups (the groups which are free products of a finitely generated free group and finitely many finite groups), and that any group which has an infinite cyclic central subgroup can be presented by such a string-rewriting system if and only if it is the direct product of an infinite cyclic group and a finite cyclic group

    “can” you really make a battery out of that?

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    Explicit expressions for meromorphic solution of autonomous nonlinear ordinary differential equations

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    Meromorphic solutions of autonomous nonlinear ordinary differential equations are studied. An algorithm for constructing meromorphic solutions in explicit form is presented. General expressions for meromorphic solutions (including rational, periodic, elliptic) are found for a wide class of autonomous nonlinear ordinary differential equations

    Exact Results on the Space of Vacua of Four Dimensional SUSY Gauge Theories

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    We consider four dimensional quantum field theories which have a continuous manifold of inequivalent exact ground states -- a moduli space of vacua. Classically, the singular points on the moduli space are associated with extra massless particles. Quantum mechanically these singularities can be smoothed out. Alternatively, new massless states appear there. These may be the elementary massless particles or new massless bound states.Comment: 19 pages, RU-94-1

    Mixed (open/closed) N=(2,2) string theory as an integrable deformation of self-duality

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    The exact effective field equations of motion, corresponding to the perturbative mixed theory of open and closed (2,2) world-sheet supersymmetric strings, are investigated. It is shown that they are only integrable in the case of an abelian gauge group. The gravitational equations are then stationary with respect to the Born-Infeld-type effective action.Comment: 9 pages, LaTe
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