In this work, the authors thermodynamic equilibrium calculations developed a computer program in MATLAB of vapor-liquid multicomponent phases below the language for aqueous speciation and critical temperature of wat...In this work, the authors thermodynamic equilibrium calculations developed a computer program in MATLAB of vapor-liquid multicomponent phases below the language for aqueous speciation and critical temperature of water （647 K） and pressures up to 2 kilobar with two computational routines. The first routine calculates the aqueous speciation from the equations of mass balance, charge balance and mass action, forming a system of N equations and N unknowns describing the aqueous phase with N unknown chemical species, which is solved with Newton-Raphson method using the Debye-Hiickel and Bdotactivity coefficients that solved simultaneously with Henry＇s Law, the Soave-Redlich-Kwong equation of state and a Poynting correction term, calculate chemical potentials and composition of the phases of the system, which are used at the Ratchford-Rice flash routine that iteratively recalculates the distribution of gases in liquid, until convergence. The chemical composition data of gas and brine phases of production wells at standard conditions for 1998 and 2007 of the Los Humeros geothermal field are modeled in the described manner, deducing that fluids inside the pipes of the reservoir are corrosive and cause the precipitation of newly formed minerals such as iron and calcium sulfates and silica, at reservoir conditions.展开更多
The selectivity of gillnets for Oreochromis niloticus in Amerti reservoir （9°63′ N, 37°23′ E） was determined from gillnets with four mesh sizes （60, 80, 100 and 120 mm）. Four selectivity models （a nor...The selectivity of gillnets for Oreochromis niloticus in Amerti reservoir （9°63′ N, 37°23′ E） was determined from gillnets with four mesh sizes （60, 80, 100 and 120 mm）. Four selectivity models （a normal model assuming fixed spread, a normal model assuming that spread is proportional to mesh size, a lognormal model and a gamma model） were fitted to the data by using the share each length＇s catch total （SELECT） method. A total of 657 specimens of Oreochromis niloticus were caught （12.0-35.5 cm total length, TD. The sizes at first sexual maturity were 21.5 cm TL and 18.9 cm TL, respectively, for male and female Oreochromis niloticus. The lognormal selectivity curve provided the best fit to the data according to model deviance estimates with optimum selectivity of 16.66, 22.26, 27.78 and 33.38 cm TL for the 60, 80, 100 and 120 mm mesh sizes, respectively.展开更多
A new model of a quantum heat engine （QHE） cycle is established, in which the working substance consists of an interacting electrons system. One of our purposes is to test the validity of the second law of thermodyn...A new model of a quantum heat engine （QHE） cycle is established, in which the working substance consists of an interacting electrons system. One of our purposes is to test the validity of the second law of thermodynamics by this model, which is more general than the spin-1/2 antiferromagnetic Heisenberg model since it would recover the spin model when the on-site Coulomb interaction U is strong enough. On the basis of quantum mechanics and the first law of thermodynamics, we show no violation of the second law of thermodynamics during the cycle. We further study the performance characteristics of the cycle by investigating in detail the optimal relations of efficiency and dimensionless power output. We find that the efficiency of our engine can be expressed as η = t22/t21 in the large-U limit, which is valid even for a four sites QHE.展开更多
文摘In this work, the authors thermodynamic equilibrium calculations developed a computer program in MATLAB of vapor-liquid multicomponent phases below the language for aqueous speciation and critical temperature of water （647 K） and pressures up to 2 kilobar with two computational routines. The first routine calculates the aqueous speciation from the equations of mass balance, charge balance and mass action, forming a system of N equations and N unknowns describing the aqueous phase with N unknown chemical species, which is solved with Newton-Raphson method using the Debye-Hiickel and Bdotactivity coefficients that solved simultaneously with Henry＇s Law, the Soave-Redlich-Kwong equation of state and a Poynting correction term, calculate chemical potentials and composition of the phases of the system, which are used at the Ratchford-Rice flash routine that iteratively recalculates the distribution of gases in liquid, until convergence. The chemical composition data of gas and brine phases of production wells at standard conditions for 1998 and 2007 of the Los Humeros geothermal field are modeled in the described manner, deducing that fluids inside the pipes of the reservoir are corrosive and cause the precipitation of newly formed minerals such as iron and calcium sulfates and silica, at reservoir conditions.
文摘The selectivity of gillnets for Oreochromis niloticus in Amerti reservoir （9°63′ N, 37°23′ E） was determined from gillnets with four mesh sizes （60, 80, 100 and 120 mm）. Four selectivity models （a normal model assuming fixed spread, a normal model assuming that spread is proportional to mesh size, a lognormal model and a gamma model） were fitted to the data by using the share each length＇s catch total （SELECT） method. A total of 657 specimens of Oreochromis niloticus were caught （12.0-35.5 cm total length, TD. The sizes at first sexual maturity were 21.5 cm TL and 18.9 cm TL, respectively, for male and female Oreochromis niloticus. The lognormal selectivity curve provided the best fit to the data according to model deviance estimates with optimum selectivity of 16.66, 22.26, 27.78 and 33.38 cm TL for the 60, 80, 100 and 120 mm mesh sizes, respectively.
基金supported by the National Natural Science Foundation of China (Grant Nos.50971011,11174022 and 10974011)the Beijing Natural Science Foundation (Grant No.1102025)+1 种基金the State Key Laboratory of Software Development Environment (Grant No.SKLSDE-2011ZX-19)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20091102110038)
文摘A new model of a quantum heat engine （QHE） cycle is established, in which the working substance consists of an interacting electrons system. One of our purposes is to test the validity of the second law of thermodynamics by this model, which is more general than the spin-1/2 antiferromagnetic Heisenberg model since it would recover the spin model when the on-site Coulomb interaction U is strong enough. On the basis of quantum mechanics and the first law of thermodynamics, we show no violation of the second law of thermodynamics during the cycle. We further study the performance characteristics of the cycle by investigating in detail the optimal relations of efficiency and dimensionless power output. We find that the efficiency of our engine can be expressed as η = t22/t21 in the large-U limit, which is valid even for a four sites QHE.
