更改

此词条暂由Henry 翻译。

此词条暂由Henry 翻译。柯里昂审校

{{more citations needed|date=September 2010}}

{{more citations needed|date=September 2010}}

A single [[chemical reaction]] is said to be '''autocatalytic''' if one of the reaction products is also a [[catalyst]] for the same or a coupled reaction.<ref name=Steinfeld>Steinfeld J.I., Francisco J.S. and Hase W.L. ''Chemical Kinetics and Dynamics'' (2nd ed., Prentice-Hall 1999) p.151-2  {{ISBN|0-13-737123-3}}</ref> Such a reaction is called an '''autocatalytic reaction'''.

A single [[chemical reaction]] is said to be '''autocatalytic''' if one of the reaction products is also a [[catalyst]] for the same or a coupled reaction.<ref name=Steinfeld>Steinfeld J.I., Francisco J.S. and Hase W.L. ''Chemical Kinetics and Dynamics'' (2nd ed., Prentice-Hall 1999) p.151-2  {{ISBN|0-13-737123-3}}</ref> Such a reaction is called an '''autocatalytic reaction'''.

一个单一的化学反应，如果其中一个反应产物也是同一反应或耦合反应的催化剂，则称为具有自催化性质。这种反应称为<font color="#ff8000"> 自催化反应autocatalytic reaction</font>。

一个单一的化学反应，如果其中一个反应产物也是同一反应或耦合反应的催化剂，则称为具有自催化性质。这种反应称为<font color="#ff8000"> 自催化反应autocatalytic reaction</font>。

A ''set'' of chemical reactions can be said to be "collectively autocatalytic" if a number of those reactions produce, as reaction products, catalysts for enough of the other reactions that the entire set of chemical reactions is self-sustaining given an input of energy and food molecules (see [[autocatalytic set]]).

A ''set'' of chemical reactions can be said to be "collectively autocatalytic" if a number of those reactions produce, as reaction products, catalysts for enough of the other reactions that the entire set of chemical reactions is self-sustaining given an input of energy and food molecules (see [[autocatalytic set]]).

如果一系列化学反应作为反应产物产生足够多的其他反应的催化剂，使整套化学反应在能量和食物分子输入的情况下能够自我维持，则可以说这些化学反应是”集体自催化”的。

如果一系列化学反应作为反应产物产生足够多的其他反应的催化剂，使整套化学反应在能量和食物分子输入的情况下能够自我维持，则可以说这些化学反应是”集体自催化”的。

==Chemical reactions化学反应==

==化学反应==

A chemical reaction of two reactants and two products can be written as

A chemical reaction of two reactants and two products can be written as

:<math> \alpha A + \beta B \rightleftharpoons \sigma S + \tau T</math>

:<math> \alpha A + \beta B \rightleftharpoons \sigma S + \tau T</math>

where the Greek letters are [[stoichiometric coefficients]] and the capital Latin letters represent chemical species. The chemical reaction proceeds in both the forward and reverse direction. This equation is easily generalized to any number of reactants, products, and reactions.

where the Greek letters are [[stoichiometric coefficients]] and the capital Latin letters represent chemical species. The chemical reaction proceeds in both the forward and reverse direction. This equation is easily generalized to any number of reactants, products, and reactions.

其中希腊字母是化学计量系数，大写拉丁字母代表化学物种。化学反应在正向和反向两个方向进行。这个方程可以很容易地推广到任意数量的反应物、产物和反应。

其中希腊字母是化学计量系数，大写拉丁字母代表化学物种。化学反应在正向和反向两个方向进行。这个方程可以很容易地推广到任意数量的反应物、产物和反应。

===Chemical equilibrium化学平衡===

===化学平衡===

In [[chemical equilibrium]] the forward and reverse [[reaction rate]]s are such that each chemical species is being created at the same rate it is being destroyed. In other words, the rate of the forward reaction is equal to the rate of the reverse reaction.

In [[chemical equilibrium]] the forward and reverse [[reaction rate]]s are such that each chemical species is being created at the same rate it is being destroyed. In other words, the rate of the forward reaction is equal to the rate of the reverse reaction.

在化学平衡状态，正向和反向的反应速率是这样的情况：每一种化学物质都以同样的速率生成和消失。换句话说，正向反应的速率等于反向反应的速率。

在化学平衡状态，正向和反向的反应速率是这样的情况：每一种化学物质都以同样的速率生成和消失。换句话说，正向反应的速率等于反向反应的速率。

:<math> k_+ [ A ]^\alpha [B ]^\beta  = k_{-} [S ]^\sigma[T ]^\tau \,</math>

:<math> k_+ [ A ]^\alpha [B ]^\beta  = k_{-} [S ]^\sigma[T ]^\tau \,</math>

K _ + [ a ] ^ alpha [ b ] ^ beta = k _ {-}[ s ] ^ sigma [ t ] ^ tau，</math >  

K _ + [ a ] ^ alpha [ b ] ^ beta = k _ {-}[ s ] ^ sigma [ t ] ^ tau，</math >  

Here, the brackets indicate the concentration of the chemical species, in [[mole (unit)|moles]] per liter, and k₊ and k₋ are [[rate constant]]s.

Here, the brackets indicate the concentration of the chemical species, in [[mole (unit)|moles]] per liter, and k₊ and k₋ are [[rate constant]]s.

这里，括号表示化学物质的浓度，以摩尔/升为单位，k+和 k-是速率常数。

这里，括号表示化学物质的浓度，以摩尔/升为单位，k+和 k-是速率常数。

===Far from equilibrium远离平衡态===

===远离平衡态===

Far from equilibrium, the forward and reverse reaction rates no longer balance and the concentration of reactants and products is no longer constant. For every forward reaction <math>\alpha  </math> molecules of A are destroyed. For every reverse reaction  <math>\alpha  </math> molecules of A are created. In the case of an [[elementary reaction]] step the [[reaction order]] in each direction equals the molecularity, so that the rate of change in the number of moles of A is then

Far from equilibrium, the forward and reverse reaction rates no longer balance and the concentration of reactants and products is no longer constant. For every forward reaction <math>\alpha  </math> molecules of A are destroyed. For every reverse reaction  <math>\alpha  </math> molecules of A are created. In the case of an [[elementary reaction]] step the [[reaction order]] in each direction equals the molecularity, so that the rate of change in the number of moles of A is then

在远离平衡态时，正向和反向反应速率不再是平衡的，反应物和产物的浓度不再是恒定的。对于每一个前向反应，a 的分子会消失。对于每一个逆反应，a 的分子都会被产生出来。在基本反应步骤中，每个方向的反应级数等于“反应分子数”（molecularity），因此 a 的摩尔数的变化率就是

在远离平衡态时，正向和反向反应速率不再是平衡的，反应物和产物的浓度不再是恒定的。对于每一个前向反应，a 的分子会消失。对于每一个逆反应，a 的分子都会被产生出来。在基本反应步骤中，每个方向的反应级数等于“反应分子数”（molecularity），因此 a 的摩尔数的变化率就是

:<math>{d \over dt}[ A ] =-\alpha  k_+ [ A ]^\alpha [B ]^\beta  +\alpha k_{-} [S ]^\sigma[T ]^\tau \,</math>

:<math>{d \over dt}[ A ] =-\alpha  k_+ [ A ]^\alpha [B ]^\beta  +\alpha k_{-} [S ]^\sigma[T ]^\tau \,</math>

:<math>{d \over dt}[ B ] =-\beta  k_+ [ A ]^\alpha [B ]^\beta  +\beta k_{-} [S ]^\sigma[T ]^\tau \,</math>

:<math>{d \over dt}[ B ] =-\beta  k_+ [ A ]^\alpha [B ]^\beta  +\beta k_{-} [S ]^\sigma[T ]^\tau \,</math>

:<math>{d \over dt}[ S ] =\sigma  k_+ [ A ]^\alpha [B ]^\beta  -\sigma k_{-} [S ]^\sigma[T ]^\tau \,</math>

:<math>{d \over dt}[ S ] =\sigma  k_+ [ A ]^\alpha [B ]^\beta  -\sigma k_{-} [S ]^\sigma[T ]^\tau \,</math>

:<math>{d \over dt}[ T ] =\tau  k_+ [ A ]^\alpha [B ]^\beta  -\tau k_{-} [S ]^\sigma[T ]^\tau \,</math>

:<math>{d \over dt}[ T ] =\tau  k_+ [ A ]^\alpha [B ]^\beta  -\tau k_{-} [S ]^\sigma[T ]^\tau \,</math>

This system of equations has a single stable  [[Fixed point (mathematics)|fixed point]] when the forward rates and the reverse rates are equal (when <math>{d \over dt}=0</math> for every species). This means that the system evolves to the equilibrium state, and this is the only state to which it evolves.<ref>{{cite journal |last1=Ross |first1=John |last2=Garcia-Colin |first2=Leopoldo S. |title=Thermodynamics of chemical systems far from equilibrium |journal=The Journal of Physical Chemistry |date=March 1989 |volume=93 |issue=5 |pages=2091–2092 |doi=10.1021/j100342a075}}</ref>

This system of equations has a single stable  [[Fixed point (mathematics)|fixed point]] when the forward rates and the reverse rates are equal (when <math>{d \over dt}=0</math> for every species). This means that the system evolves to the equilibrium state, and this is the only state to which it evolves.<ref>{{cite journal |last1=Ross |first1=John |last2=Garcia-Colin |first2=Leopoldo S. |title=Thermodynamics of chemical systems far from equilibrium |journal=The Journal of Physical Chemistry |date=March 1989 |volume=93 |issue=5 |pages=2091–2092 |doi=10.1021/j100342a075}}</ref>

这个系统的方程组有一个单一的稳定不动点解，这个解的情况就是每个物种的正向速率和反向速率相等。这意味着这个系统是往平衡状态演化，而且这个平衡状态这是系统演化到的唯一状态。

这个系统的方程组有一个单一的稳定不动点解，这个解的情况就是每个物种的正向速率和反向速率相等。这意味着这个系统是往平衡状态演化，而且这个平衡状态这是系统演化到的唯一状态。

===Autocatalytic reactions自催化反应===

===自催化反应===

[[Image:Sigmoid curve for an autocatalytical reaction.jpg|256px|right|thumb|Sigmoid variation of product concentration in autocatalytic reactions]]

[[Image:Sigmoid curve for an autocatalytical reaction.jpg|256px|right|thumb|Sigmoid variation of product concentration in autocatalytic reactions|链接=Special:FilePath/Sigmoid_curve_for_an_autocatalytical_reaction.jpg]]

Sigmoid variation of product concentration in autocatalytic reactions

Sigmoid variation of product concentration in autocatalytic reactions

自催化反应中产物浓度的 s 形变化

自催化反应中产物浓度的 s 形变化

Autocatalytic reactions are those in which at least one of the products is a reactant. Perhaps the simplest autocatalytic reaction can be written<ref name=Steinfeld/>  

Autocatalytic reactions are those in which at least one of the products is a reactant. Perhaps the simplest autocatalytic reaction can be written<ref name=Steinfeld/>

 

自催化反应是那些其中至少一个产物是反应物的反应。最简单的自催化反应可以是这样的形式

自催化反应是那些其中至少一个产物是反应物的反应。最简单的自催化反应可以是这样的形式

<math>[A]=\frac{[A]_0+[B]_0}{1+\frac{[B]_0}{[A]_0}e^{([A]_0+[B]_0)kt}}</math>

<math>[A]=\frac{[A]_0+[B]_0}{1+\frac{[B]_0}{[A]_0}e^{([A]_0+[B]_0)kt}}</math>

with the rate equations (for an elementary reaction)

with the rate equations (for an elementary reaction)

<math>[B]=\frac{[A]_0+[B]_0}{1+\frac{[A]_0}{[B]_0}e^{-([A]_0+[B]_0)kt}}</math>.

<math>[B]=\frac{[A]_0+[B]_0}{1+\frac{[A]_0}{[B]_0}e^{-([A]_0+[B]_0)kt}}</math>.

:<math>{d \over dt}[ A ] =-  k_+ [ A ] [B ]  + k_{-} [B ]^2 \,</math>

:<math>{d \over dt}[ A ] =-  k_+ [ A ] [B ]  + k_{-} [B ]^2 \,</math>

一些自催化反应也以牺牲周围环境为代价，在系统中产生有序。例如，(时钟反应)有其浓度在时间上振荡的中间体，对应于时间顺序。其他反应产生空间分离的化学物质对应的空间秩序。更复杂的反应涉及到生物系统中的代谢途径和代谢网络。

一些自催化反应也以牺牲周围环境为代价，在系统中产生有序。例如，(时钟反应)有其浓度在时间上振荡的中间体，对应于时间顺序。其他反应产生空间分离的化学物质对应的空间秩序。更复杂的反应涉及到生物系统中的代谢途径和代谢网络。

The concentrations of A and B vary in time according to<ref name=Steinfeld/><ref name=Moore>Moore J.W. and [[Ralph Pearson|Pearson R.G.]] ''Kinetics and Mechanism'' (John Wiley 1981) p.26  {{ISBN|0-471-03558-0}}</ref>   

The concentrations of A and B vary in time according to<ref name=Steinfeld/><ref name=Moore>Moore J.W. and [[Ralph Pearson|Pearson R.G.]] ''Kinetics and Mechanism'' (John Wiley 1981) p.26  {{ISBN|0-471-03558-0}}</ref>

 

A和B的浓度随时间变化  

:<math>[A]=\frac{[A]_0+[B]_0}{1+\frac{[B]_0}{[A]_0}e^{([A]_0+[B]_0)kt}}</math>

:<math>[A]=\frac{[A]_0+[B]_0}{1+\frac{[B]_0}{[A]_0}e^{([A]_0+[B]_0)kt}}</math>

方程[同构于捕食-食饵模型和双反应自催化模型。在这个例子中，狒狒和猎豹在自动催化反应中相当于两种不同的化学物种 x 和 y

方程[同构于捕食-食饵模型和双反应自催化模型。在这个例子中，狒狒和猎豹在自动催化反应中相当于两种不同的化学物种 x 和 y

==Creation of order秩序创立==

==秩序创立==

Consider a coupled set of two autocatalytic reactions in which the concentration of one of the reactants A is much larger than its equilibrium value. In this case, the forward reaction rate is so much larger than the reverse rates that we can neglect the reverse rates.

Consider a coupled set of two autocatalytic reactions in which the concentration of one of the reactants A is much larger than its equilibrium value. In this case, the forward reaction rate is so much larger than the reverse rates that we can neglect the reverse rates.

===Background背景===

===背景===

<math> A + X \rightarrow 2X</math>

<math> A + X \rightarrow 2X</math>

<math> X + Y \rightarrow 2Y</math>

<math> X + Y \rightarrow 2Y</math>

然而，在许多情况下，物理系统自发地变得新生或有序。例如，尽管飓风造成了破坏，但与封闭房间中空气分子的随机运动相比，[[飓风]]的运动非常有序。更引人注目的是化学系统创造的秩序；最引人注目的是与生命相关的秩序。

然而，在许多情况下，物理系统自发地变得新生或有序。例如，尽管飓风造成了破坏，但与封闭房间中空气分子的随机运动相比，[[飓风]]的运动非常有序。更引人注目的是化学系统创造的秩序；最引人注目的是与生命相关的秩序。

<math> Y \rightarrow E</math>

<math> Y \rightarrow E</math>

用速率方程式

用速率方程式

</ref> In the hurricane example, hurricanes are formed from unequal heating within the atmosphere. The Earth's atmosphere is then far from [[thermal equilibrium]]. The order of the Earth's atmosphere increases, but at the expense of the order of the sun. The sun is becoming more disorderly as it ages and throws off light and material to the rest of the universe. The total disorder of the sun and the earth increases despite the fact that orderly hurricanes are generated on earth.

</ref> In the hurricane example, hurricanes are formed from unequal heating within the atmosphere. The Earth's atmosphere is then far from [[thermal equilibrium]]. The order of the Earth's atmosphere increases, but at the expense of the order of the sun. The sun is becoming more disorderly as it ages and throws off light and material to the rest of the universe. The total disorder of the sun and the earth increases despite the fact that orderly hurricanes are generated on earth.

<math>{d \over dt}[ X ] =  k_1 [ A ] [X ]  - k_{2} [X ][Y ] \,</math>

<math>{d \over dt}[ X ] =  k_1 [ A ] [X ]  - k_{2} [X ][Y ] \,</math>

A similar example exists for living chemical systems. The sun provides energy to green plants. The green plants are food for other living chemical systems. The energy absorbed by plants and converted into chemical energy generates a system on earth that is orderly and far from [[chemical equilibrium]]. Here, the difference from chemical equilibrium is determined by an excess of reactants over the equilibrium amount. Once again, order on earth is generated at the expense of entropy increase of the sun. The total entropy of the earth and the rest of the universe increases, consistent with the Second Law.

A similar example exists for living chemical systems. The sun provides energy to green plants. The green plants are food for other living chemical systems. The energy absorbed by plants and converted into chemical energy generates a system on earth that is orderly and far from [[chemical equilibrium]]. Here, the difference from chemical equilibrium is determined by an excess of reactants over the equilibrium amount. Once again, order on earth is generated at the expense of entropy increase of the sun. The total entropy of the earth and the rest of the universe increases, consistent with the Second Law.

<math>{d \over dt}[ Y ] =  k_2 [ X ] [Y ]  - k_{3} [Y ] \,</math>.

<math>{d \over dt}[ Y ] =  k_2 [ X ] [Y ]  - k_{3} [Y ] \,</math>.

Some autocatalytic reactions also generate order in a system at the expense of its surroundings. For example, ([[clock reactions]]) have [[reaction intermediate|intermediates]] whose concentrations oscillate in time, corresponding to temporal order. Other reactions generate spatial separation of [[chemical species]] corresponding to spatial order. More complex reactions are involved in [[metabolic pathway]]s and [[metabolic network]]s in [[biological systems]].

Some autocatalytic reactions also generate order in a system at the expense of its surroundings. For example, ([[clock reactions]]) have [[reaction intermediate|intermediates]] whose concentrations oscillate in time, corresponding to temporal order. Other reactions generate spatial separation of [[chemical species]] corresponding to spatial order. More complex reactions are involved in [[metabolic pathway]]s and [[metabolic network]]s in [[biological systems]].

这个速率方程组被称为 Lotka-Volterra 方程，在捕食者-食饵关系中与族群动态最密切相关。这个方程组可以产生反应中间体 x 和 y 的振荡浓度。振荡的振幅取决于 a 的浓度(a 的浓度下降而没有振荡)。这种振荡是一种涌现的时间顺序，在平衡中不存在。

这个速率方程组被称为 Lotka-Volterra 方程，在捕食者-食饵关系中与族群动态最密切相关。这个方程组可以产生反应中间体 x 和 y 的振荡浓度。振荡的振幅取决于 a 的浓度(a 的浓度下降而没有振荡)。这种振荡是一种涌现的时间顺序，在平衡中不存在。

===Temporal order时间顺序===

===时间顺序===

A chemical reaction cannot oscillate about a position of final [[chemical equilibrium|equilibrium]] because the second law of thermodynamics requires that a [[thermodynamic system]] approach equilibrium and not recede from it. For a closed system at constant temperature and pressure, the [[Gibbs free energy]] must decrease continuously and not oscillate. However it is possible that the concentrations of some [[reaction intermediate]]s oscillate, and also that the ''rate'' of formation of products oscillates.<ref>Espenson, J.H. ''Chemical Kinetics and Reaction Mechanisms'' (2nd ed., McGraw-Hill 2002) p.190 {{ISBN|0-07-288362-6}}</ref>

A chemical reaction cannot oscillate about a position of final [[chemical equilibrium|equilibrium]] because the second law of thermodynamics requires that a [[thermodynamic system]] approach equilibrium and not recede from it. For a closed system at constant temperature and pressure, the [[Gibbs free energy]] must decrease continuously and not oscillate. However it is possible that the concentrations of some [[reaction intermediate]]s oscillate, and also that the ''rate'' of formation of products oscillates.<ref>Espenson, J.H. ''Chemical Kinetics and Reaction Mechanisms'' (2nd ed., McGraw-Hill 2002) p.190 {{ISBN|0-07-288362-6}}</ref>

另一个演示时间顺序的系统例子是 Brusselator (见 Prigogine 参考文献)。人们的反应是拥有属性的

另一个演示时间顺序的系统例子是 Brusselator (见 Prigogine 参考文献)。人们的反应是拥有属性的

[[File:CentralTendencyLV.jpg|thumb|right|350px|The Lotka–Volterra equation is [[isomorphic]] with the predator–prey model and the two-reaction autocatalytic model. In this example baboons and cheetahs are equivalent to two different chemical species X and Y in autocatalytic reactions.]]

[[File:CentralTendencyLV.jpg|thumb|right|350px|The Lotka–Volterra equation is [[isomorphic]] with the predator–prey model and the two-reaction autocatalytic model. In this example baboons and cheetahs are equivalent to two different chemical species X and Y in autocatalytic reactions.|链接=Special:FilePath/CentralTendencyLV.jpg]]

Consider a coupled set of two autocatalytic reactions in which the concentration of one of the reactants A is much larger than its equilibrium value. In this case, the forward reaction rate is so much larger than the reverse rates that we can neglect the reverse rates.

Consider a coupled set of two autocatalytic reactions in which the concentration of one of the reactants A is much larger than its equilibrium value. In this case, the forward reaction rate is so much larger than the reverse rates that we can neglect the reverse rates.

考虑一组耦合的两个自催化反应，其中一个反应物a的浓度远远大于其平衡值。在这种情况下，正向反应速率比反向速率大得多，我们可以忽略反向速率。  

考虑一组耦合的两个自催化反应，其中一个反应物a的浓度远远大于其平衡值。在这种情况下，正向反应速率比反向速率大得多，我们可以忽略反向速率。  

<math> A \rightarrow X</math>

<math> A \rightarrow X</math>

<math> 2X + Y \rightarrow 3X</math>

<math> 2X + Y \rightarrow 3X</math>

<math> B + X \rightarrow Y + D</math>

<math> B + X \rightarrow Y + D</math>

<math>  X \rightarrow E</math>

<math>  X \rightarrow E</math>

with the rate equations

with the rate equations

<math>{d \over dt}[ X ] = [A ] + [ X ]^2 [Y ]  - [B ] [X ] - [X ]  \,</math>

<math>{d \over dt}[ X ] = [A ] + [ X ]^2 [Y ]  - [B ] [X ] - [X ]  \,</math>

<math>{d \over dt}[ Y ] =  [B ] [X ] - [ X ]^2 [Y ]    \,</math>

<math>{d \over dt}[ Y ] =  [B ] [X ] - [ X ]^2 [Y ]    \,</math>

Here, we have neglected the depletion of the reactant A, since its concentration is so large. The rate constants for the three reactions are <math>k_1</math>, <math>k_2</math>, and <math>k_3</math>, respectively.

Here, we have neglected the depletion of the reactant A, since its concentration is so large. The rate constants for the three reactions are

 

 

<math>k_1</math>, <math>k_2</math>, and <math>k_3</math>, respectively.

where, for convenience, the rate constants have been set to 1.

where, for convenience, the rate constants have been set to 1.

This system of rate equations is known as the [[Lotka–Volterra equation]] and is most closely associated with [[population dynamics]] in predator–prey relationships. This system of equations can yield oscillating concentrations of the reaction intermediates X and Y. The amplitude of the oscillations depends on the concentration of A (which decreases without oscillation). Such oscillations are a form of emergent temporal order that is not present in equilibrium.

This system of rate equations is known as the [[Lotka–Volterra equation]] and is most closely associated with [[population dynamics]] in predator–prey relationships. This system of equations can yield oscillating concentrations of the reaction intermediates X and Y. The amplitude of the oscillations depends on the concentration of A (which decreases without oscillation). Such oscillations are a form of emergent temporal order that is not present in equilibrium.

这个速率方程组被称为[[Lotka–Volterra equation]]，在捕食者-猎物关系中与[[种群动力学]]联系最为密切。这个方程组可以得到反应中间体X和Y的振荡浓度，振荡的幅度取决于A的浓度（A的浓度减少而不振荡）。这种振荡是一种在平衡状态下不存在的突发时序形式。

这个速率方程组被称为[[Lotka–Volterra equation]]，在捕食者-猎物关系中与[[种群动力学]]联系最为密切。这个方程组可以得到反应中间体X和Y的振荡浓度，振荡的幅度取决于A的浓度（A的浓度减少而不振荡）。这种振荡是一种在平衡状态下不存在的突发时序形式。

The Brusselator in the unstable regime. A=1. B=2.5. X(0)=1. Y(0)=0. The system approaches a [[limit cycle. For B<1+A the system is stable and approaches a fixed point.]]

The Brusselator in the unstable regime. A=1. B=2.5. X(0)=1. Y(0)=0. The system approaches a [[limit cycle. For B<1+A the system is stable and approaches a fixed point.]]

布鲁塞尔振子有一个固定点

布鲁塞尔振子有一个固定点

====Another idealized example: Brusselator另一个理想化模型：布鲁塞尔振子====

====另一个理想化模型：布鲁塞尔振子====

<math>[ X ] =  A    \,</math>

<math>[ X ] =  A    \,</math>

Another example of a system that demonstrates temporal order is the [[Brusselator]] (see Prigogine reference). It is characterized by the reactions

Another example of a system that demonstrates temporal order is the [[Brusselator]] (see Prigogine reference). It is characterized by the reactions

 

<math>[ Y ] =  {B \over A}    \,</math>.

<math>[ Y ] =  {B \over A}    \,</math>.

:<math> A \rightarrow X</math>

:<math> A \rightarrow X</math>

<math> B>1+A^2  \,</math>

<math> B>1+A^2  \,</math>

:<math> B + X \rightarrow Y + D</math>

:<math> B + X \rightarrow Y + D</math>

with the rate equations

with the rate equations

An idealized example of spatial spontaneous symmetry breaking is the case in which we have two boxes of material separated by a permeable membrane so that material can diffuse between the two boxes. It is assumed that identical Brusselators are in each box with nearly identical initial conditions. (see Prigogine reference)

An idealized example of spatial spontaneous symmetry breaking is the case in which we have two boxes of material separated by a permeable membrane so that material can diffuse between the two boxes. It is assumed that identical Brusselators are in each box with nearly identical initial conditions. (see Prigogine reference)

<math>{d \over dt}[ X_1 ] = [A ] + [ X _1]^2 [Y_1 ]  - [B ] [X_1 ] - [X_1 ]  + D_x\left( X_2 - X_1 \right)\,</math>

<math>{d \over dt}[ X_1 ] = [A ] + [ X _1]^2 [Y_1 ]  - [B ] [X_1 ] - [X_1 ]  + D_x\left( X_2 - X_1 \right)\,</math>

<math>{d \over dt}[ Y_1 ] =  [B ] [X_1 ] - [ X_1 ]^2 [Y_1 ]  + D_y\left( Y_2 - Y_1\right)  \,</math>

<math>{d \over dt}[ Y_1 ] =  [B ] [X_1 ] - [ X_1 ]^2 [Y_1 ]  + D_y\left( Y_2 - Y_1\right)  \,</math>

where, for convenience, the rate constants have been set to 1.

where, for convenience, the rate constants have been set to 1.

其中，为了方便起见，速率常数被设置为1。  

其中，为了方便起见，速率常数被设置为1。  

<math>{d \over dt}[ X_2 ] = [A ] + [ X _2]^2 [Y_2 ]  - [B ] [X_2 ] - [X_2 ]  + D_x\left( X_1 - X_2 \right)\,</math>

<math>{d \over dt}[ X_2 ] = [A ] + [ X _2]^2 [Y_2 ]  - [B ] [X_2 ] - [X_2 ]  + D_x\left( X_1 - X_2 \right)\,</math>

[[File:080205 Brusselator picture.jpg|thumb|right|350px|The Brusselator in the unstable regime. A=1. B=2.5. X(0)=1. Y(0)=0. The system approaches a [[limit cycle]]. For B<1+A the system is stable and approaches a [[Fixed point (mathematics)|fixed point]].]]

[[File:080205 Brusselator picture.jpg|thumb|right|350px|The Brusselator in the unstable regime. A=1. B=2.5. X(0)=1. Y(0)=0. The system approaches a [[limit cycle]]. For B<1+A the system is stable and approaches a [[Fixed point (mathematics)|fixed point]].|链接=Special:FilePath/080205_Brusselator_picture.jpg]]

<math>{d \over dt}[ Y_2 ] =  [B ] [X_2 ] - [ X_2 ]^2 [Y_2 ]  + D_y\left( Y_1 - Y_2\right)  \,</math>

<math>{d \over dt}[ Y_2 ] =  [B ] [X_2 ] - [ X_2 ]^2 [Y_2 ]  + D_y\left( Y_1 - Y_2\right)  \,</math>

布鲁塞尔振子有一个固定点在

布鲁塞尔振子有一个固定点在

<chem>glucose{} + 2ADP{} + 2P_\mathit{i}{} + 2NAD -> 2(pyruvate){} + 2ATP{} + 2NADH</chem>.

<chem>glucose{} + 2ADP{} + 2P_\mathit{i}{} + 2NAD -> 2(pyruvate){} + 2ATP{} + 2NADH</chem>.

===Spatial order空间秩序===

===空间秩序===

The details of the process are quite involved, however, a section of the process is autocatalyzed by phosphofructokinase (PFK). This portion of the process is responsible for oscillations in the pathway that lead to the process oscillating between an active and an inactive form. Thus, the autocatalytic reaction can modulate the process.

The details of the process are quite involved, however, a section of the process is autocatalyzed by phosphofructokinase (PFK). This portion of the process is responsible for oscillations in the pathway that lead to the process oscillating between an active and an inactive form. Thus, the autocatalytic reaction can modulate the process.

An idealized example of spatial [[spontaneous symmetry breaking]] is the case in which we have two boxes of material separated by a permeable membrane so that material can [[diffusion|diffuse]] between the two boxes. It is assumed that identical Brusselators are in each box with nearly identical initial conditions. (see Prigogine reference)

An idealized example of spatial [[spontaneous symmetry breaking]] is the case in which we have two boxes of material separated by a permeable membrane so that material can [[diffusion|diffuse]] between the two boxes. It is assumed that identical Brusselators are in each box with nearly identical initial conditions. (see Prigogine reference)

 

:<math>{d \over dt}[ X_1 ] = [A ] + [ X _1]^2 [Y_1 ]  - [B ] [X_1 ] - [X_1 ]  + D_x\left( X_2 - X_1 \right)\,</math>

:<math>{d \over dt}[ X_1 ] = [A ] + [ X _1]^2 [Y_1 ]  - [B ] [X_1 ] - [X_1 ]  + D_x\left( X_2 - X_1 \right)\,</math>

==Real examples实例==

==实例==

Real examples of [[clock reaction]]s are the [[Belousov–Zhabotinsky reaction]] (BZ reaction), the [[Briggs–Rauscher reaction]], the [[Bray–Liebhafsky reaction]] and the [[iodine clock reaction]]. These are oscillatory reactions, and the concentration of products and reactants can be approximated in terms of [[damping|damped]] [[oscillation]]s.

Real examples of [[clock reaction]]s are the [[Belousov–Zhabotinsky reaction]] (BZ reaction), the [[Briggs–Rauscher reaction]], the [[Bray–Liebhafsky reaction]] and the [[iodine clock reaction]]. These are oscillatory reactions, and the concentration of products and reactants can be approximated in terms of [[damping|damped]] [[oscillation]]s.

时钟反应]]的真正例子是[[Belousov–Zhabotinsky reaction]]（BZ反应）、[[Briggs–Rauscher 反应]]、[[Bray–Liebhafsky 反应]]和[[碘钟反应]]。这些都是振荡反应，产物和反应物的浓度可以用阻尼，振荡来近似。  

时钟反应]]的真正例子是[[Belousov–Zhabotinsky reaction]]（BZ反应）、[[Briggs–Rauscher 反应]]、[[Bray–Liebhafsky 反应]]和[[碘钟反应]]。这些都是振荡反应，产物和反应物的浓度可以用阻尼，振荡来近似。  

In 1995 Stuart Kauffman proposed that life initially arose as autocatalytic chemical networks.

In 1995 Stuart Kauffman proposed that life initially arose as autocatalytic chemical networks.

== Optics example光学实例 ==

== 光学实例 ==

Autocatalysis plays a major role in the processes of life.  Two researchers who have emphasized its role in the origins of life are Robert Ulanowicz  and Stuart Kauffman.

Autocatalysis plays a major role in the processes of life.  Two researchers who have emphasized its role in the origins of life are Robert Ulanowicz  and Stuart Kauffman.

Another autocatalytic system is one driven by light coupled to photo-polymerization reactions. In a process termed optical autocatalysis, positive feedback is created between light intensity and photo-polymerization rate, via polymerization-induced increases in the refractive index. Light's preference to occupy regions of higher refractive index results in leakage of light into regions of higher molecular weight, thereby amplifying the photo-chemical reaction. The positive feedback may be expressed as:<ref name=":0">{{Cite journal|last=Biria|first=Saeid|last2=Malley|first2=Phillip P. A.|last3=Kahan|first3=Tara F.|last4=Hosein|first4=Ian D.|date=2016-11-15|title=Optical Autocatalysis Establishes Novel Spatial Dynamics in Phase Separation of Polymer Blends during Photocuring|journal=ACS Macro Letters|volume=5|issue=11|pages=1237–1241|doi=10.1021/acsmacrolett.6b00659}}</ref>

Another autocatalytic system is one driven by light coupled to photo-polymerization reactions. In a process termed optical autocatalysis, positive feedback is created between light intensity and photo-polymerization rate, via polymerization-induced increases in the refractive index. Light's preference to occupy regions of higher refractive index results in leakage of light into regions of higher molecular weight, thereby amplifying the photo-chemical reaction. The positive feedback may be expressed as:<ref name=":0">{{Cite journal|last=Biria|first=Saeid|last2=Malley|first2=Phillip P. A.|last3=Kahan|first3=Tara F.|last4=Hosein|first4=Ian D.|date=2016-11-15|title=Optical Autocatalysis Establishes Novel Spatial Dynamics in Phase Separation of Polymer Blends during Photocuring|journal=ACS Macro Letters|volume=5|issue=11|pages=1237–1241|doi=10.1021/acsmacrolett.6b00659}}</ref>

 

Autocatalysis occurs in the initial transcripts of rRNA. The introns are capable of excising themselves by the process of two nucleophilic transesterification reactions. The RNA able to do this is sometimes referred to as a ribozyme.  Additionally, the citric acid cycle is an autocatalytic cycle run in reverse.

Autocatalysis occurs in the initial transcripts of rRNA. The introns are capable of excising themselves by the process of two nucleophilic transesterification reactions. The RNA able to do this is sometimes referred to as a ribozyme.  Additionally, the citric acid cycle is an autocatalytic cycle run in reverse.

Noting that photo-polymerization rate is proportional to intensity<ref>{{Cite journal|last=Decker|first=Christian|date=1998-02-01|title=The use of UV irradiation in polymerization|url=|journal=Polymer International|language=en|volume=45|issue=2|pages=133–141 |doi=10.1002/(SICI)1097-0126(199802)45:2<133::AID-PI969>3.0.CO;2-F}}</ref> and that refractive index is proportional to molecular weight,<ref>{{Cite journal|last=Askadskii|first=A. A.|year=1990|title=Influence of crosslinking density on the properties of polymer networks|journal=Polymer Science U.S.S.R.|volume=32|issue=10|pages=2061–2069|doi=10.1016/0032-3950(90)90361-9}}</ref> the positive feedback between intensity and photo-polymerization establishes the auto-catalytic behavior. Optical auto-catalysis has been shown to result on spontaneous [[pattern formation]] in photopolymers.<ref>{{Cite journal|last=Burgess|first=Ian B.|last2=Shimmell|first2=Whitney E.|last3=Saravanamuttu|first3=Kalaichelvi|date=2007-04-01|title=Spontaneous Pattern Formation Due to Modulation Instability of Incoherent White Light in a Photopolymerizable Medium|journal=Journal of the American Chemical Society|volume=129|issue=15|pages=4738–4746|doi=10.1021/ja068967b|pmid=17378567|issn=0002-7863}}</ref><ref>{{Cite journal|last=Basker|first=Dinesh K.|last2=Brook|first2=Michael A.|last3=Saravanamuttu|first3=Kalaichelvi|title=Spontaneous Emergence of Nonlinear Light Waves and Self-Inscribed Waveguide Microstructure during the Cationic Polymerization of Epoxides|journal=The Journal of Physical Chemistry C|language=en|volume=119|issue=35|pages=20606–20617|doi=10.1021/acs.jpcc.5b07117|year=2015}}</ref><ref>{{Cite journal|last=Biria|first=Saeid|last2=Malley|first2=Philip P. A.|last3=Kahan|first3=Tara F.|last4=Hosein|first4=Ian D.|date=2016-03-03|title=Tunable Nonlinear Optical Pattern Formation and Microstructure in Cross-Linking Acrylate Systems during Free-Radical Polymerization|journal=The Journal of Physical Chemistry C|volume=120|issue=8|pages=4517–4528|doi=10.1021/acs.jpcc.5b11377|issn=1932-7447}}</ref> Hosein and co-workers discovered that optical autocatalysis can also occur in photoreactive polymer blends, and that the process can induce binary phase morphologies with the same pattern as the light profile.<ref name=":0" /> The light undergoes optical [[Modulational instability|modulation instability]], spontaneous dividing into a multitude of optical filaments, and the polymer system thereby forms filaments within the blend structure.<ref name=":0" /> The result is a new system that couples optical autocatalytic behavior to [[spinodal decomposition]].

Noting that photo-polymerization rate is proportional to intensity<ref>{{Cite journal|last=Decker|first=Christian|date=1998-02-01|title=The use of UV irradiation in polymerization|url=|journal=Polymer International|language=en|volume=45|issue=2|pages=133–141 |doi=10.1002/(SICI)1097-0126(199802)45:2<133::AID-PI969>3.0.CO;2-F}}</ref> and that refractive index is proportional to molecular weight,<ref>{{Cite journal|last=Askadskii|first=A. A.|year=1990|title=Influence of crosslinking density on the properties of polymer networks|journal=Polymer Science U.S.S.R.|volume=32|issue=10|pages=2061–2069|doi=10.1016/0032-3950(90)90361-9}}</ref> the positive feedback between intensity and photo-polymerization establishes the auto-catalytic behavior. Optical auto-catalysis has been shown to result on spontaneous [[pattern formation]] in photopolymers.<ref>{{Cite journal|last=Burgess|first=Ian B.|last2=Shimmell|first2=Whitney E.|last3=Saravanamuttu|first3=Kalaichelvi|date=2007-04-01|title=Spontaneous Pattern Formation Due to Modulation Instability of Incoherent White Light in a Photopolymerizable Medium|journal=Journal of the American Chemical Society|volume=129|issue=15|pages=4738–4746|doi=10.1021/ja068967b|pmid=17378567|issn=0002-7863}}</ref><ref>{{Cite journal|last=Basker|first=Dinesh K.|last2=Brook|first2=Michael A.|last3=Saravanamuttu|first3=Kalaichelvi|title=Spontaneous Emergence of Nonlinear Light Waves and Self-Inscribed Waveguide Microstructure during the Cationic Polymerization of Epoxides|journal=The Journal of Physical Chemistry C|language=en|volume=119|issue=35|pages=20606–20617|doi=10.1021/acs.jpcc.5b07117|year=2015}}</ref><ref>{{Cite journal|last=Biria|first=Saeid|last2=Malley|first2=Philip P. A.|last3=Kahan|first3=Tara F.|last4=Hosein|first4=Ian D.|date=2016-03-03|title=Tunable Nonlinear Optical Pattern Formation and Microstructure in Cross-Linking Acrylate Systems during Free-Radical Polymerization|journal=The Journal of Physical Chemistry C|volume=120|issue=8|pages=4517–4528|doi=10.1021/acs.jpcc.5b11377|issn=1932-7447}}</ref> Hosein and co-workers discovered that optical autocatalysis can also occur in photoreactive polymer blends, and that the process can induce binary phase morphologies with the same pattern as the light profile.<ref name=":0" /> The light undergoes optical [[Modulational instability|modulation instability]], spontaneous dividing into a multitude of optical filaments, and the polymer system thereby forms filaments within the blend structure.<ref name=":0" /> The result is a new system that couples optical autocatalytic behavior to [[spinodal decomposition]].

注意到光聚合速率与强度成正比，折射率与分子量成正比，强度和光聚合之间的正反馈建立了自催化行为。光自催化已经被证明可以导致光聚合物中自发图案的形成。Hosein和他的同事发现，光自催化也可以发生在光活性聚合物混合物中，并且该过程可以诱导具有与光轮廓相同图案的二元相形态。光经历了光调制不稳定性，自发地分裂成许多光学细丝，因此，聚合物系统在共混结构中形成细丝。结果是一个将光学自催化行为与旋节分解相耦合的新系统。

注意到光聚合速率与强度成正比，折射率与分子量成正比，强度和光聚合之间的正反馈建立了自催化行为。光自催化已经被证明可以导致光聚合物中自发图案的形成。Hosein和他的同事发现，光自催化也可以发生在光活性聚合物混合物中，并且该过程可以诱导具有与光轮廓相同图案的二元相形态。光经历了光调制不稳定性，自发地分裂成许多光学细丝，因此，聚合物系统在共混结构中形成细丝。结果是一个将光学自催化行为与旋节分解相耦合的新系统。

==Biological example生物实例==

 

==生物实例==

</ref> Glycolysis consists of the degradation of one molecule of glucose and the overall production of two molecules of [[Adenosine triphosphate|ATP]]. The process is therefore of great importance to the energetics of living cells. The global glycolysis reaction involves [[glucose]], [[Adenosine diphosphate|ADP]], [[Nicotinamide adenine dinucleotide|NAD]], [[Pyruvic acid|pyruvate]], [[Adenosine triphosphate|ATP]], and NADH.

</ref> Glycolysis consists of the degradation of one molecule of glucose and the overall production of two molecules of [[Adenosine triphosphate|ATP]]. The process is therefore of great importance to the energetics of living cells. The global glycolysis reaction involves [[glucose]], [[Adenosine diphosphate|ADP]], [[Nicotinamide adenine dinucleotide|NAD]], [[Pyruvic acid|pyruvate]], [[Adenosine triphosphate|ATP]], and NADH.

糖酵解包括一个葡萄糖分子的降解和两个分子[[三磷酸腺苷| ATP]]的合成。因此，这个过程对活细胞的能量学非常重要。全局糖酵解反应涉及[[葡萄糖]]、[[二磷酸腺苷| ADP]]、[[烟酰胺腺嘌呤二核苷酸| NAD]]  

 

糖酵解包括一个葡萄糖分子的降解和两个分子[[三磷酸腺苷| ATP]]的合成。因此，这个过程对活细胞的能量学非常重要。全局糖酵解反应涉及[[葡萄糖]]、[[二磷酸腺苷| ADP]]、[[烟酰胺腺嘌呤二核苷酸| NAD]]

过程的细节是相当复杂的，然而，过程的一部分是由[[磷酸果糖激酶]]（PFK）自动催化的。这个过程的这一部分负责路径中的振荡，导致过程在一个活跃的和一个不活跃的形式之间振荡。因此，自催化反应可以调节这一过程。

过程的细节是相当复杂的，然而，过程的一部分是由[[磷酸果糖激酶]]（PFK）自动催化的。这个过程的这一部分负责路径中的振荡，导致过程在一个活跃的和一个不活跃的形式之间振荡。因此，自催化反应可以调节这一过程。

==Shape tailoring of thin layers薄层剪裁==

==薄层剪裁==

It is possible to use the results from an autocatalytic reaction coupled with [[reaction–diffusion system]] theory to tailor the design of a thin layer. The autocatalytic process allows controlling the nonlinear behavior of the oxidation [[Front (physics)|front]], which is used to establish the initial geometry needed to generate the arbitrary final geometry.<ref>{{cite journal |last1=Alfaro-Bittner |first1=K. |last2=Rojas |first2=R.G. |last3=Lafleur |first3=G. |last4=Calvez |first4=S. |last5=Almuneau |first5=G. |last6=Clerc |first6=M.G. |last7=Barbay |first7=S. |title=Modeling the Lateral Wet Oxidation of into Arbitrary Mesa Geometries |journal=Physical Review Applied|date=22 April 2019|volume=11 |issue=4|page=044067|doi=10.1103/PhysRevApplied.11.044067|url=https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.11.044067}}</ref> It has been successfully done in the wet oxidation of <math>Al_xGa_{1-x}As</math> to obtain arbitrary shaped layers of <math>AlO_x</math>.

It is possible to use the results from an autocatalytic reaction coupled with [[reaction–diffusion system]] theory to tailor the design of a thin layer. The autocatalytic process allows controlling the nonlinear behavior of the oxidation [[Front (physics)|front]], which is used to establish the initial geometry needed to generate the arbitrary final geometry.<ref>{{cite journal |last1=Alfaro-Bittner |first1=K. |last2=Rojas |first2=R.G. |last3=Lafleur |first3=G. |last4=Calvez |first4=S. |last5=Almuneau |first5=G. |last6=Clerc |first6=M.G. |last7=Barbay |first7=S. |title=Modeling the Lateral Wet Oxidation of into Arbitrary Mesa Geometries |journal=Physical Review Applied|date=22 April 2019|volume=11 |issue=4|page=044067|doi=10.1103/PhysRevApplied.11.044067|url=https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.11.044067}}</ref> It has been successfully done in the wet oxidation of <math>Al_xGa_{1-x}As</math> to obtain arbitrary shaped layers of <math>AlO_x</math>.

利用自催化反应与[[反应-扩散系统]]理论相结合的结果，可以定制薄层的设计。自动催化过程允许控制氧化的非线性行为，用于建立生成任意最终几何体所需的初始几何体

利用自催化反应与[[反应-扩散系统]]理论相结合的结果，可以定制薄层的设计。自动催化过程允许控制氧化的非线性行为，用于建立生成任意最终几何体所需的初始几何体

==Phase transitions相变==

 

==相变==

反应物的初始量决定了与体系化学平衡的距离。初始浓度越大，系统离平衡越远。随着初始浓度的增加，[[熵|阶]]发生突变。这种突变被称为[[相变]]。在相变阶段，宏观量的波动，如化学浓度，随着系统在更有序的状态（低熵，如冰）和更无序的状态（更高的熵，如液态水）之间振荡而增加。同样，在相变过程中，宏观方程，如速率方程，会失效。速率方程可以从微观角度推导出来。推导通常依赖于对微观动力学方程的[[平均场理论]]近似。平均场理论在大波动的情况下会崩溃（见[[平均场理论]]文章进行讨论）。因此，由于大的波动发生在相变附近，宏观方程，如速率方程，失败了。随着初始浓度的进一步增加，系统进入有序状态，在这种状态下波动又很小。（见Prigogine参考文献）

反应物的初始量决定了与体系化学平衡的距离。初始浓度越大，系统离平衡越远。随着初始浓度的增加，[[熵|阶]]发生突变。这种突变被称为[[相变]]。在相变阶段，宏观量的波动，如化学浓度，随着系统在更有序的状态（低熵，如冰）和更无序的状态（更高的熵，如液态水）之间振荡而增加。同样，在相变过程中，宏观方程，如速率方程，会失效。速率方程可以从微观角度推导出来。推导通常依赖于对微观动力学方程的[[平均场理论]]近似。平均场理论在大波动的情况下会崩溃（见[[平均场理论]]文章进行讨论）。因此，由于大的波动发生在相变附近，宏观方程，如速率方程，失败了。随着初始浓度的进一步增加，系统进入有序状态，在这种状态下波动又很小。（见Prigogine参考文献）

==Asymmetric autocatalysis不对称自催化 ==

==不对称自催化 ==

Asymmetric autocatalysis occurs when the reaction product is [[chiral]] and thus acts as a chiral catalyst for its own production. Reactions of this type, such as the [[Soai reaction]], have the property that they can amplify a very small [[enantiomeric excess]] into a large one. This has been proposed as an important step in the origin of biological [[homochirality]].<ref name="Soai2001">{{cite journal|vauthors=Soai K, Sato I, Shibata T | title=Asymmetric autocatalysis and the origin of chiral homogeneity in organic compounds. | journal=The Chemical Record | year= 2001 | volume= 1 | issue= 4 | pages= 321–32 | pmid=11893072 | doi= 10.1002/tcr.1017| pmc= }}</ref>

Asymmetric autocatalysis occurs when the reaction product is [[chiral]] and thus acts as a chiral catalyst for its own production. Reactions of this type, such as the [[Soai reaction]], have the property that they can amplify a very small [[enantiomeric excess]] into a large one. This has been proposed as an important step in the origin of biological [[homochirality]].<ref name="Soai2001">{{cite journal|vauthors=Soai K, Sato I, Shibata T | title=Asymmetric autocatalysis and the origin of chiral homogeneity in organic compounds. | journal=The Chemical Record | year= 2001 | volume= 1 | issue= 4 | pages= 321–32 | pmid=11893072 | doi= 10.1002/tcr.1017| pmc= }}</ref>  

 

非对称自催化发生在反应产物为[[手性]]时，因此作为手性催化剂进行自身生产。这种类型的反应，如[[Soai反应]]，具有将很小的[[对映体过量]]放大为大反应的性质。在这一点上，手性被认为是生物起源的一个重要步骤  

非对称自催化发生在反应产物为[[手性]]时，因此作为手性催化剂进行自身生产。这种类型的反应，如[[Soai反应]]，具有将很小的[[对映体过量]]放大为大反应的性质。在这一点上，手性被认为是生物起源的一个重要步骤  

== Role in origin of life生命起源中的角色 ==

 

== 生命起源中的角色 ==