樹莓一名覆盆子，又叫懸鉤子，【本草綱目】上記作『複盆子』，明朝名醫李時珍說︰

五月子熟，其色烏赤，故俗名烏 、大麥莓、插田 ，亦曰栽秧 。甄權《本草》一名馬 ，【集解】《別錄》曰︰五月採。蓬子以八、九月熟，故謂之割田 。複盆以四、五月熟，故謂之插田 ，正與《別錄》五月採相合。二 熟時色皆烏赤，故能補腎。其四、五月熟而色紅者 ，乃田也，不入。

【氣味】甘，平，無毒。

【主治】益氣輕身，令發不白（《別錄》）…。

覆盆子的果實是一種聚合果，成熟後有紅色、金色和黑色。初生時或有綠色，很少能見到白色的。在中國雖有大量分佈，卻鮮為人知 ，屬於野果 ── 少有種植與販售 ── 卻有著多種藥物價值。

古代『河圖』和『洛書』都是以『五為中央』，也就是以『大地』為主的意思，強調人與大自然的和諧。太陽系在古人的眼中，就像個大陽鐘，推動著『春生』『夏長』『秋收』『冬藏』的循環，而土為四季之主，扮演著『生化』── 五行生克制化 ── 的角色，實在可以說是大自然的生命醫生。而後又將『仁、義、禮、智』按照德性歸給了『春、秋、夏、冬』，把『信』這個字賦予了大地。這整個的寓意說的就是宇宙的『生生不息』！！

─── 《複盆子，熟了。》

 

影響

化學反應速率

反應速率即化學反應進行的快慢，單位為 mol/(L·s) 或 mol/(L·min)。用單位時間內反應物的濃度的減少或生成物濃度的增加量來表示。濃度單位一般用莫耳·升^-1，時間單位用秒、分或小時。化學反應並非均勻速率進行：反應速率分為平均速率（一定時間間隔裡平均反應速率）和瞬時速率（給定某時刻的反應速率），可通過實驗測定 。反應物本身的性質，外界因素：溫度，濃度，壓強，催化劑，光，雷射，反應物顆粒大小，反應物之間的接觸面積和反應物狀態 ，x射線，γ射線，固體物質的表面積，與反應物的接觸面積，反應物的濃度也會影響化學反應速率。

碰撞學說

碰撞理論，是由德國的 Max Trautz 及英國的 William Lewis 在1916年及 1918年分別提出的。

1. 碰撞學說：任何化學反應的發生，必需反應粒子互相接近碰撞，則反應速率與碰撞次數成正比。
2. 活化能：所謂活化能就是能使粒子發生反應的最低能量。
3. 有效碰撞：所謂有效碰撞是指碰撞的粒子其能量超過活化能,且碰撞方向(位向)要正確（發生化學反應所需的能量）。

影響反應速率的因素

除了反應物的性質以外，濃度、溫度和催化劑也是影響反應速率的重要因素。氣體反應的快慢還與壓力有關。增加反應物的濃度，即增加了單位體積內活化分子的數目，從而增加了單位時間內反應物分子的有效碰撞的次數，導致反應速率加快。提高反應溫度，即增加了活化分子的百分數，也增加了單位時間內反應物分子有效碰撞的次數，導致反應速率加快。使用正催化劑，改變了反應歷程，降低了反應所需的活化能，使反應速率加快。在化工生產中，常控制反應條件來加快反應速率，以增加產量。有時也要採取減慢反應速率的措施，以延長產品的使用時間。

 

的原因可多了！如是春生、夏長、秋收、冬藏之『四季循環』怎麼可能呢？

據知有一類遠離平衡態的化學反應叫做

化學鐘

化學鐘（英語：Chemical clock，又稱為化學振盪）是指遠離平衡態的化學反應體系，在開放條件下並不趨向穩定，而是圍繞穩態以時間為橫坐標，中間物濃度出現有節律的極大值或極小值，而且時間有序。

要發生持續的化學振盪，除了遠離平衡態和開放體系兩個條件外，在體系中必存在自催化或反饋型的反應。此外體系還必須具有雙穩態性，即可在兩個穩態之間來回震盪。

化學振盪屬非平衡態熱力學，必然是耗散結構，在動力學上屬非線性動力學，是化學混沌的一種現象。

研究化學振盪對於解釋自組織及混沌科學的規律具有十分重要的作用。

 

可能與此有關？

所以好奇什麼是『化學振子』哩！

Chemical oscillator

A chemical oscillator is a complex mixture of reacting chemical compounds in which the concentration of one or more components exhibits periodic changes, They are a class of reactions that serve as an example of non-equilibrium thermodynamics with far-from-equilibrium behavior. The reactions are theoretically important in that they show that chemical reactions do not have to be dominated by equilibrium thermodynamic behavior.

In cases where one of the reagents has a visible color, periodic color changes can be observed. Examples of oscillating reactions are the Belousov-Zhabotinsky reaction (BZ), the Briggs-Rauscher reaction, the Bray-Liebhafsky reaction and the chlorine dioxide – iodine – malonic acid reaction.

History

The earliest scientific evidence that such reactions can oscillate was met with extreme scepticism. In 1828, G.T. Fechner published a report of oscillations in a chemical system. He described an electrochemical cell that produced an oscillating current. In 1899, W. Ostwald observed that the rate of chromium dissolution in acid periodically increased and decreased. Both of these systems were heterogeneous and it was believed then, and through much of the last century, that homogeneous oscillating systems were nonexistent. While theoretical discussions date back to around 1910, the systematic study of oscillating chemical reactions and of the broader field of non-linear chemical dynamics did not become well established until the mid-1970s.^[1]

Theory

Chemical systems cannot oscillate about a position of final equilibrium because such an oscillation would violate the second law of thermodynamics. For a thermodynamic system which is not at equilibrium, this law requires that the system approach equilibrium and not recede from it. For a closed system at constant temperature and pressure, the thermodynamic requirement is that the Gibbs free energy must decrease continuously and not oscillate. However it is possible that the concentrations of some reaction intermediates oscillate, and also that the rate of formation of products oscillates.^[2]

Theoretical models of oscillating reactions have been studied by chemists, physicists, and mathematicians. In an oscillating system the energy-releasing reaction can follow at least two different pathways, and the reaction periodically switches from one pathway to another. One of these pathways produces a specific intermediate, while another pathway consumes it. The concentration of this intermediate triggers the switching of pathways. When the concentration of the intermediate is low, the reaction follows the producing pathway, leading then to a relatively high concentration of intermediate. When the concentration of the intermediate is high, the reaction switches to the consuming pathway.

Different theoretical models for this type of reaction have been created, including the Lotka-Volterra model, the Brusselator and the Oregonator. The latter was designed to simulate the Belousov-Zhabotinsky reaction.^[3]

 

只見簡短文字，不如順著鏈接先看圖呦☺

Belousov–Zhabotinsky reaction

A Belousov–Zhabotinsky reaction, or BZ reaction, is one of a class of reactions that serve as a classical example of non-equilibrium thermodynamics, resulting in the establishment of a nonlinear chemical oscillator. The only common element in these oscillators is the inclusion of bromine and an acid. The reactions are important to theoretical chemistry in that they show that chemical reactions do not have to be dominated by equilibrium thermodynamic behavior. These reactions are far from equilibrium and remain so for a significant length of time and evolve chaotically. In this sense, they provide an interesting chemical model of nonequilibrium biological phenomena, and the mathematical models of the BZ reactions themselves are of theoretical interest and simulations.^[1]

Plot of the electrode potential of a BZ reaction, using silver electrodes against an Ag/AgNO₃ half-cell

 

An essential aspect of the BZ reaction is its so called “excitability”; under the influence of stimuli, patterns develop in what would otherwise be a perfectly quiescent medium. Some clock reactions such as Briggs–Rauscherand BZ using the tris(bipyridine)ruthenium(II) chloride as catalyst can be excited into self-organising activity through the influence of light.

Computer simulation of the Belousov–Zhabotinsky reaction occurring in a Petri dish

Patterns shown in the Petri dish

History

A stirred BZ reaction mixture showing changes in color over time

The discovery of the phenomenon is credited to Boris Belousov. In 1951, while trying to find the non-organic analog to the Krebs cycle, he noted that in a mix of potassium bromate, cerium(IV) sulfate, malonic acid, and citric acid in dilute sulfuric acid, the ratio of concentration of the cerium(IV) and cerium(III) ions oscillated, causing the colour of the solution to oscillate between a yellow solution and a colorless solution. This is due to the cerium(IV) ions being reduced by malonic acid to cerium(III) ions, which are then oxidized back to cerium(IV) ions by bromate(V) ions.

Belousov made two attempts to publish his finding, but was rejected on the grounds that he could not explain his results to the satisfaction of the editors of the journals to which he submitted his results.^[2] Soviet biochemist Simon El’evich Shnoll encouraged Belousov to continue his efforts to publish his results. In 1959 his work was finally published in a less respectable, nonreviewed journal.^[3]

After Belousov’s publication, Schnoll gave the project in 1961 to a graduate student, Anatol Zhabotinsky, who investigated the reaction sequence in detail;^[4] however, the results of these men’s work were still not widely disseminated, and were not known in the West until a conference in Prague in 1968.

A number of BZ cocktails are available in the chemical literature and on the web. Ferroin, a complex of phenanthroline and iron, is a common indicator. These reactions, if carried out in petri dishes, result in the formation first of colored spots. These spots grow into a series of expanding concentric rings or perhaps expanding spirals similar to the patterns generated by a cyclic cellular automaton. The colors disappear if the dishes are shaken, and then reappear. The waves continue until the reagents are consumed. The reaction can also be performed in a beaker using a magnetic stirrer.

Andrew Adamatzky,^[5] a computer scientist in the University of the West of England, reported on liquid logic gates using the BZ reaction.^[6]

Strikingly similar oscillatory spiral patterns appear elsewhere in nature, at very different spatial and temporal scales, for example the growth pattern of Dictyostelium discoideum, a soil-dwelling amoeba colony.^[7] In the BZ reaction, the size of the interacting elements is molecular and the time scale of the reaction is minutes. In the case of the soil amoeba, the size of the elements is typical of single-celled organisms and the times involved are on the order of days to years.

Investigators are also exploring the creation of a “wet computer”, using self-creating “cells” and other techniques to mimic certain properties of neurons.^[8]

Chemical mechanism

The mechanism for this reaction is very complex and is thought to involve around 18 different steps which have been the subject of a number of research papers.^[9][10]

In a way similar to the Briggs–Rauscher reaction, two key processes (both of which are auto-catalytic) occur; process A generates molecular bromine, giving the red colour, and process B consumes the bromine to give bromide ions.^[11]

One of the most common variations on this reaction uses malonic acid (CH₂(CO₂H)₂) as the acid and potassium bromate (KBrO₃) as the source of bromine. The overall equation is:^[11]

3CH₂(CO₂H)₂ + 4BrO⁻₃ → 4Br⁻ + 9CO₂ + 6H₂O

Variants

Many variants of the reaction exist. The only key chemical is the bromate oxidizer. The catalyst ion is most often cerium, but it can be also manganese, or complexes of iron, ruthenium, cobalt, copper, chromium, silver, nickel and osmium. Many different reductants can be used. (Zhabotinsky, 1964b; Field and Burger, 1985)^[12]

Many different patterns can be observed when the reaction is run in a microemulsion.

 

Briggs–Rauscher reaction

The Briggs–Rauscher oscillating reaction is one of a small number of known oscillating chemical reactions. It is especially well suited for demonstration purposes because of its visually striking colour changes: the freshly prepared colourless solution slowly turns an amber colour, suddenly changing to a very dark blue. This slowly fades to colourless and the process repeats, about ten times in the most popular formulation, before ending as a dark blue liquid smelling strongly of iodine.

Oscillogram made in July 1972 by Briggs and Rauscher.

History

The first known homogeneous oscillating chemical reaction, reported by W. C. Bray in 1921,^[1] was between hydrogen peroxide (H₂O₂) and iodate (IO₃⁻) in acidic solution. Because of experimental difficulty, it attracted little attention and was unsuitable as a demonstration. In 1958 B. P. Belousov in the Soviet Union discovered the Belousov–Zhabotinsky reaction (BZ reaction),^[2] which is suitable as a demonstration, but it too met with skepticism (largely because such oscillatory behaviour was unheard of up to that time) until A. M. Zhabotinsky, also in the USSR, learned of it and in 1964 published his research.^[3] In May 1972 a pair of articles in the Journal of Chemical Education^[4][5] brought it to the attention of two science instructors at Galileo High School in San Francisco. They discovered the Briggs–Rauscher oscillating reaction^[6] by replacing bromate (BrO₃⁻) in the BZ reaction with iodate and adding hydrogen peroxide. They produced the striking visual demonstration by adding starch indicator. Since then, many other investigators have added to the knowledge and uses of this very unusual reaction.

Description

Initial conditions

The initial aqueous solution contains hydrogen peroxide, an iodate, divalent manganese (Mn²⁺) as catalyst, a strong chemically unreactive acid (sulphuric acid (H₂SO₄) or perchloric acid (HClO₄) are good), and an organic compound with an active (“enolic“) hydrogen atom attached to carbon which will slowly reduce free iodine (I₂) to iodide (I⁻). (Malonic acid (CH₂(COOH)₂) is excellent for that purpose.) Starch is optionally added as an indicator to show the abrupt increase in iodide ion concentration as a sudden change from amber (free iodine) to dark blue (the “iodine-starch complex“, which requires both iodine and iodide.)^[7]

Recently it has been shown, however, that the starch is not only an indicator for iodine in the reaction.^[8] In the presence of starch the number of oscillations are higher and the period times are longer compared to the starch-free mixtures. It was also found that the iodine consumption segment within one period of oscillation is also significantly longer in the starch containing mixtures. This suggests that the starch probably acts as a reservoir for the iodine and iodide because of the starch-triiodide equilibrium, thereby modifying the kinetics of the steps in which iodine and iodide are involved.

The reaction is “poisoned” by chloride (Cl⁻) ion, which must therefore be avoided, and will oscillate under a fairly wide range of initial concentrations. For recipes suitable for demonstration purposes, see Shakhashiri^[9] or Preparations in the external links.

Terminal conditions

The residual mixture contains iodinated malonic acid, inorganic acid, manganous catalysts, unreacted iodate and hydrogen peroxide. After the oscillations cease, the iodomalonic acid decomposes and iodine is produced. The rate of decomposition depends on the conditions. All of the components present in the residual mixture are of environmental concern: Iodate, iodine and hydrogen peroxide are strong oxidants, the acid is corrosive and manganese has been suggested to cause neurological disorders^[10]. A simple method has been developed employing thiosulfate and carbonate – two inexpensive salts – to remove all oxidants, neutralize the acidity and recover the manganous ion in the form of manganese dioxide^[8].

Behaviour in time

The reaction shows recurring periodic changes, both gradual and sudden, which are visible: slow changes in the intensity of colour, interrupted by abrupt changes in hue. This demonstrates that a complex combination of slow and fast reactions are taking place simultaneously. For example, following the iodide ion concentration with a silver/silver iodide electrode^[6] (see Videos) shows sudden dramatic swings of several orders of magnitude separated by slower variations. This is shown by the oscillogram above. Oscillations persist over a wide range of temperatures. Higher temperatures make everything happen faster, with some qualitative change observable (see Effect of temperature). Stirring the solution throughout the reaction is helpful for sharp colour changes, otherwise spatial variations may develop (see Videos). Bubbles of free oxygen are evolved throughout, and in most cases, the final state is rich in free iodine