阅读专业书籍对提高阅读能力有帮助吗？
就当是泛读吧，有必要吗？或者推荐一下更有效率的东西。- ^0 a( b4 x2 ]8 t) Z$ w* |
这是一本《地球化学》中的一点，可以吗？6 m. | j7 |; N
Chapter 2: Energy, Entropy and Fundamental
5 ^1 K2 m0 \9 @+ FThermodynamic Concepts
/ S2 D: P/ u7 c- [2.1 The Thermodynamic Perspective3 A- k( d1 ~$ w- V. w c
We defined geochemistry as the application of chemical knowledge and techniques to solve9 {1 c6 l4 e& x: w: ]; A
geological problems. It is appropriate, then, to begin our study of geochemistry with a review0 W* l/ A( z0 T6 o
of physical chemistry. Our initial focus will be on thermodynamics. Strictly defined,
3 F5 }4 y9 Q+ F5 t) D! r2 Xthermodynamics is the study of energy and its transformations. Chemical reactions and changes of
$ s& C$ g0 l8 Q# `7 d( }2 f1 ?2 w) bstates of matter inevitably involve energy changes. By using thermodynamics to follow the energy,
$ T) h% v: Z! `5 D8 U/ ], l4 M8 rwe will find that we can predict the outcome of chemical reactions, and hence the state of matter in
' p; V/ H5 X+ W. |! Wthe Earth. In principle at least, we can use thermodynamics to predict at what temperature a rock
" F5 Q4 [. [& K3 B! m. Owill melt and the composition of that melt, and we can predict the sequence of minerals that will, h0 X( q& w) K2 e
crystallize to form an igneous rock from the melt. We can predict the new minerals that will form8 B9 n& X5 W. r% J# _; s% S5 q! y6 x5 f
when that igneous rock undergoes metamorphism, and we can predict the minerals and the composition5 P9 c+ o! g4 _, W
of the solution that forms when that metamorphic rocks weathers. Thus thermodynamics$ l. t( ^% \2 f$ K6 l5 \; L
allows us to understand (in the sense that we defined understanding in Chapter 1) a great variety of8 i, z- @" o! y- c0 g
geologic processes.
6 g# a# Q3 \# R* vThermodynamics embodies a macroscopic viewpoint, i.e., it concerns itself with the properties of a
8 S4 }2 e8 S$ O y# @8 vsystem, such as temperature, volume, heat capacity, and it does not concern itself with how these6 P: C# [4 p, h+ w$ d6 K
properties are reflected in the internal arrangement of atoms. The microscopic viewpoint, which is9 y; J6 G5 o) M6 }
concerned with transformations on the atomic and subatomic levels, is the realm of statistical mechanics
% p* k/ D9 |& o- m1 Uand quantum mechanics. In our treatment, we will focus mainly on the macroscopic (thermodynamic)3 _: ^+ k$ d( q7 S3 j8 V4 J
viewpoint, but we will occasionally consider the microscopic (statistical mechanical)
! E& c4 |: K) @/ Lviewpoint when our understanding can be enhanced by doing so.
+ @* x' F/ j* w4 ?In principle, thermodynamics is only usefully applied to systems at equilibrium. If an equilibrium system6 h5 V" O8 R Z( C+ {" t# v# Q2 g) D
is perturbed, thermodynamics can predict the new equilibrium state, but cannot predict how,2 q1 `$ v0 |- M
how fast, or indeed whether, the equilibrium state will be achieved. (The field of irreversible thermodynamics,
6 [$ k5 I1 |6 G' p' T8 e5 N+ Dwhich we will not treat in this book, attempts to apply thermodynamics to nonequilibrium- R$ \, h# t. O4 G8 d8 X/ w2 P0 {
states. However, we will see in Chapter 5 that thermodynamics, through the principle
' R3 x- t9 v" B3 d9 yof detailed balancing and transition state theory, can help us predict reaction rates.)
0 C9 h# |9 j& d# f0 C% r: N, F3 DKinetics is the study of rates and mechanisms of reaction. Whereas thermodynamics is concerned
( [1 p0 X5 X/ l5 Gwith the ultimate equilibrium state and not concerned with the pathway to equilibrium, kinetics( H9 T; V! f- V3 s$ n0 k+ }2 @
concerns itself with the pathway to equilibrium. Very often, equilibrium in the Earth is not$ k: Z- Y8 }3 P# ^. R' H. t
achieved, or achieved only very slowly, which naturally limits the usefulness of thermodynamics.
y. J3 O* p) u4 o; E) sKinetics helps us to understand how equilibrium is achieved and why it is occasionally not" T6 u6 s! `- s# \/ R
achieved. Thus these two fields are closely related, and together form the basis of much of geochemistry., F* p5 Q/ S9 K' W
We will treat kinetics in Chapter 5.
