now available in english for the first time， physics andpartial differential equations， volumel bridges physics and appliedmathematics in a manner that is easily accessible to readers withan undergraduate-level background in these disciplines. readers who are more familiar with mathematics than physics willdiscover the connection between various physical and mechanicaldisciplines and their related mathematical models， which aredescribed by partial differential equations （pdes）. the authorsestablish the funda-mental equations for fields such as electrodynamics; fluid dynamics， magnetohydrodynamics， and reacting fluiddynamics; elastic， thermoelastic， and viscoelastic mechanics; the kinetic theory of gases; special relativity; and quantum mechanics. readers who are more familiar with physics than mathematics willbenefit from in-depth explanations of how pdes work as effectivemathematical tools to more clearly express and present the basicconcepts of physics. the book describes the mathematical structuresand features of these pdes， including the types and basic characteristics of the equations， the behavior of solutions， and some commonly used approaches to solving pdes. the first volume of the chinese edition of this book waspublished in july 1997， and the second volume was published in june2000. in july 2000， upon the readers' request， we corrected severaltypographical errors and republished the first volume. in this edition， minor typographical errors are corrected， and asmall paragraph has been added to section 5.5.4 in chapter 5， whilethe remaining text is unchanged. we would like to take this opportunity to express our sincerethanks to our teachers，friends， and readers for their encouragementand support.
