第一篇： EARTH AGE
第一篇是讲的早期科学家们估计地球寿命。
首先说人们很早就在预估地球寿命了;之后一段讲的近代一位科学家采用生物一代代进化速度的方式预估了三叠纪的长度，但基于的假设是进化速率基本相同，其估计已经有一定准确度了。后来讲科学家利用这种方式预估地球寿命，其弱点是有部分化石找不到而且更基本的错误是地球在生物诞生之前那段时间无法估计。(这里有插空题)之后讲了科学家用其他方式预估，有种是采用测算地壳沉积岩石厚度的方法，但问题是没有考虑板块运动以及腐蚀。另一种是计算海水盐度发，理想地认为一开始地球海洋是淡水，不断地填充盐才有了现在这样子，但这也忽略了盐分与海底大陆架之间的复杂作用以及其他(这里会考题问科学家忽略了什么)。但作者对于科学家基于盐度推出的几千万年的寿命还是给予肯定的。因为这已经验证了地球寿命远比原先预计的几百万年要多得多。而且也有一批科学家从其他领域验证了这个结果。
The age of the Earth is 4.54 ± 0.05 billion years.This age is based on evidence from radiometric age dating of meteorite material and is consistent with the ages of the oldest-known terrestrial and lunarsamples. Following the scientific revolution and the development of radiometric age dating, measurements of lead in uranium-rich minerals showed that some were in excess of a billion years old.
Because the exact accretion time of Earth is not yet known, and the predictions from different accretion models range from a few millions up to about 100 million years, the exact age of Earth is difficult to determine. It is also difficult to determine the exact age of the oldest rocks on Earth, exposed at the surface, as they are aggregates of minerals of possibly different ages.
【岩层研究法】Studies of strata, the layering of rocks and earth, gave naturalists an appreciation that Earth may have been through many changes during its existence. These layers often contained fossilized remains of unknown creatures, leading some to interpret a progression of organisms from layer to layer.
In the 1790s, the British naturalist William Smith hypothesized that if two layers of rock at widely differing locations contained similar fossils, then it was very plausible that the layers were the same age. William Smith's nephew and student, John Phillips, later calculated by such means that Earth was about 96 million years old.
The naturalist Mikhail Lomonosov, regarded as the founder of Russian science, suggested in the mid-18th century that Earth had been created separately from the rest of the universe, several hundred thousand years before. Lomonosov's ideas were mostly speculative, but in 1779, the French naturalist the Comte du Buffon tried to obtain a value for the age of Earth using an experiment: He created a small globe that resembled Earth in composition and then measured its rate of cooling. This led him to estimate that Earth was about 75,000 years old
In 1862, the physicist William Thomson (who later became Lord Kelvin) of Glasgow published calculations that fixed the age of Earth at between 20 million and 400 million years. He assumed that Earth had formed as a completely molten object, and determined the amount of time it would take for the near-surface to cool to its present temperature. His calculations did not account for heat produced via radioactive decay (a process then unknown to science) or convection inside the Earth, which allows more heat to escape from the interior to warm rocks near the surface.
【生物进化方法】Geologists had trouble accepting such a short age for Earth. Biologists could accept that Earth might have a finite age, but even 100 million years seemed much too short to be plausible. Charles Darwin, who had studied Lyell's work, had proposed his theory of the evolution of organisms by natural selection, a process whose combination of random heritable variation and cumulative selection implies great expanses of time. (Geneticists have subsequently measured the rate of genetic divergence of species, using the molecular clock, to date the last universal ancestor of all living organisms no later than 3.5 to 3.8 billion years ago)。
In a lecture in 1869, Darwin's great advocate, Thomas H. Huxley, attacked Thomson's calculations, suggesting they appeared precise in themselves but were based on faulty assumptions. The German physicist Hermann von Helmholtz (in 1856) and the Canadian astronomer Simon Newcomb (in 1892) contributed their own calculations of 22 and 18 million years respectively to the debate: they independently calculated the amount of time it would take for the Sun to condense down to its current diameter and brightness from the nebula of gas and dust from which it was born. Their values were consistent with Thomson's calculations. However, they assumed that the Sun was only glowing from the heat of its gravitational contraction. The process of solar nuclear fusion was not yet known to science.
Other scientists backed up Thomson's figures as well. Charles Darwin's son, the astronomer George H. Darwin of the University of Cambridge, proposed that Earth and Moon had broken apart in their early days when they were both molten. He calculated the amount of time it would have taken for tidal friction to give Earth its current 24-hour day. His value of 56 million years added additional evidence that Thomson was on the right track.
【Radiometric dating同位素年龄测定法】Rockminerals naturally contain certain elements and not others. By the process of radioactive decay of radioactive isotopes occurring in a rock, exotic elements can be introduced over time. By measuring the concentration of the stable end product of the decay, coupled with knowledge of the half life and initial concentration of the decaying element, the age of the rock can be calculated. Typical radioactive end products are argon from potassium-40 and lead from uranium and thorium decay. If the rock becomes molten, as happens in Earth's mantle, such nonradioactive end products typically escape or are redistributed.Thus the age of the oldest terrestrial rock gives a minimum for the age of Earth assuming that a rock cannot have been in existence for longer than Earth itself.Modern radiometric dating
Radiometric dating continues to be the predominant way scientists date geologic timescales. Techniques for radioactive dating have been tested and fine-tuned for the past 50+ years. Forty or so different dating techniques have been utilized to date, working on a wide variety of materials. Dates for the same sample using these different techniques are in very close agreement on the age of the material.
Possible contamination problems do exist, but they have been studied and dealt with by careful investigation, leading to sample preparation procedures being minimized to limit the chance of contamination. Hundreds to thousands of measurements are done daily with excellent precision and accurate results. Even so, research continues to refine and improve radiometric dating to this day
Source://en.wikipedia.org/wiki/Age_of_the_Earth#p#副标题#e#
第二篇： GERMAN RAILWAY
第二篇讲的是近代德国基于铁路工业的发展。
这篇结构为很简洁的三段。第一段总起说了下德国发展铁路后带动了一系列的发展进步。第二段细说了下铁路引领了什么进步，主要是铁、煤以及其他诸如化工产业之类的发展。然后作者列举了一个现象，通过铁路带动化工产业这个例子来阐述。(这里考作者的阐述方法)之后还强调了下铁路带动了一个P城市的兴旺，这个城市通过兴建各种配套设施啥的，体现了铁路给城市带来的翻天覆地的变化。第三段主要还是围绕P展开说了下，说由于铁路使得市场扩大了之类的。之后说了铁路还帮助人们能够在更大范围找工作以及周边产业给了更多的人就业机会。(这里有双选题)最后还说铁路打通了德国东西的连接，(运河是南北的)标志着德国工业的振兴blabla。
German Railways.
As far as railway development is concerned, no corner of the world is making more rapid progress than Germany. A recent survey issued by the German railway authorities states that, during 1927, the German railways handled 1,909,000,000 passengers and 489,000,000 tons of merchandise. Steam locomotives number 24,575 and electric locomotives 316. The German railways operate some 62,940 passenger carriages, and the stock of goods wagons totals 674,318. As a result of a consistent effort at standardization, the number of types of locomotives in service on the German lines has been reduced from 250 in 1920 to 40 at the present time. Despite this standardization, the door is being left open to experiment, and, at the moment, attention is being devoted to the development of high pressure locomotives, some of these experimental machines having steam pressures as high as 880lbs. per square inch.
German Railway history began with the opening of the steam-hauled Bavarian Ludwig Railway between Nuremberg and Fürth on 7 December 1835. This had been preceded by the opening of the horse-hauled Prince William Railway on 20 September 1831. The first long distance railway was the Leipzig-Dresden railway, completed on 7 April 1839.
German unification in 1871 stimulated consolidation, nationalization into state-owned companies, and further rapid growth. Unlike the situation in France, the goal was support of industrialization, and so heavy lines crisscrossed the Ruhr and other industrial districts, and provided good connections to the major ports of Hamburg and Bremen. By 1880, Germany had 9,400 locomotives pulling 43,000 passengers and 30,000 tons of freight, and forged ahead of France
Source：//nzetc.victoria.ac.nz/tm/scholarly/tei-Gov03_11Rail-t1-body-d7-d2-d6.html
Social and economic benefits
【P的兴旺】Prussia nationalized its railways in an effort both to lower rates on freight service and to equalize those rates among shippers. Instead of lowering rates as far as possible, the government ran the railways as a profitmaking endeavor, and the railway profits became a major source of revenue for the state. The nationalization of the railways slowed the economic development of Prussia because the state favoured the relatively backward agricultural areas in its railway building. Moreover, the railway surpluses substituted for the development of an adequate tax system.
In order to enable the free exchange of goods wagons between the different state railway administrations, the German State Railway Wagon Association (DeutscherStaatsbahnwagenverband or DSV) was formed in 1909. The standard wagons that resulted are often referred to as 'DSV wagons'.
The standardisation of goods wagons under the German State Railway Wagon Association, that had produced the Verbandsbauart ('Association design') wagons, continued as new designs using interchangeable components were introduced from about 1927. These were the Austauschbauart ('interchangeable design') wagons. The 1930s saw the introduction of welded construction and solid wheels replacing spoked wheels on new goods wagons. As the Second World War loomed, production was geared towards the war effort. The focus was on fewer types but greater numbers of so-called Kriegsbauart or wartime designs for the transportation of large quantities of tanks, vehicles, troops and supplies.
【德国铁路对工业影响】During the Second World War, austere versions of the standard locomotives were produced to speed up construction times and minimise the use of imported materials. These were the so-called war locomotives (Kriegslokomotiven and ?bergangskriegslokomotiven)。 Absent a good highway network and trucks, the Germans relied heavily on the railways, supplemented by slower river and canal transport for bulk goods. The rail yards were the main targets of the "transportation strategy" of the British and American strategic bombing campaign of 1944-45, and resulted in massive destruction of the system.
【东德和西德的铁路】After World War II, Germany (and the DRG) was divided into 4 zones: US, British, French and Soviet. The first three eventually combined to form the Federal Republic of Germany (the West) and the Russian zone became the German Democratic Republic (the East)。 German territories beyond the Oder were ceded to Poland except for the northern part of East Prussia, which was ceded to the Soviet Union in 1945.From 1949, the new governments assumed authority for railway operations. The DRG's (or DR's) successors were named Deutsche Bundesbahn (DB, German Federal Railways) in West Germany, and Deutsche Reichsbahn (DR, German State Railways) in East Germany kept the old name to hold tracking rights in western Berlin.
Unlike the DRG, which was a corporation, both the DB and the DR were federal state institutions, directly controlled by their respective transportation ministries. Railway service between East and West was restricted; there were around five well-controlled and secure checkpoints between West and East Germany, and about the same number between East Germany and West Berlin. Four transit routes existed between West Germany and West Berlin; citizens of West Berlin and West Germany were able to use these without too much harassment by the East German authorities.#p#副标题#e#
第三篇：WEATHERING OF ROCK
第三篇讲岩石风化。
段落很多所以就一起讲了好了。首先总起是列举了两种风化方式：化学上的和生物上的。文章主讲了化学上的，化学上的有三种，水侵蚀、二氧化碳侵蚀、氧气侵蚀(翻译很不专业就表嘲笑啦)。水侵蚀主要说的是水与岩石中物质接合使得其膨胀等等;二氧化碳侵蚀就是列举了类似钟乳石那种因潮湿环境融入二氧化碳而慢慢风化侵蚀的现象(化学的涉及到碳酸盐遇碳酸根生成可溶的碳酸氢盐，然后流失)，干燥环境下不是很明显;氧气侵蚀主要发生在阳光照射强烈的地方，氧化后呈红色，多发生于热带。(这里有题大概是考推测热带的土多为红色的啥的)最后作者也说了些生物侵蚀的例子，强调的是它可能没有想象中的作用那么大，因为其中也包含着化学侵蚀部分。而且生物侵蚀有利于土壤的生成，本身是对植物好的。文章末尾讲了一个真菌，通过从岩石中提取矿物质，使岩石最终崩碎呈小块状以及另外一种方式(忘了)来进行生物侵蚀。(生物影响涉及到植物的根，不过这一点作用被过分关注了;讲了lichen，这种生物对石头的侵蚀既有生物作用又有化学作用)
Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters. Weathering occurs in situ, or "with no movement", and thus should not be confused with erosion, which involves the movement of rocks and minerals by agents such as water, ice, snow, wind and gravity.
Two important classifications of weathering processes exist – physical and chemical weathering. Mechanical or physical weathering involves the breakdown of rocks and soils through direct contact with atmospheric conditions, such as heat, water, ice and pressure. The second classification, chemical weathering, involves the direct effect of atmospheric chemicals or biologically produced chemicals (also known as biological weathering) in the breakdown of rocks, soils and minerals.
The materials left over after the rock breaks down combined with organic material creates soil. The mineral content of the soil is determined by the parent material, thus a soil derived from a single rock type can often be deficient in one or more minerals for good fertility, while a soil weathered from a mix of rock types (as in glacial, aeolian or alluvial sediments) often makes more fertile soil. In addition many of Earth's landforms and landscapes are the result of weathering processes combined with erosion and re-deposition.
【Chemical weathering】Chemical weathering changes the composition of rocks, often transforming them when water interacts with minerals to create various chemical reactions. Chemical weathering is a gradual and ongoing process as the mineralogy of the rock adjusts to the near surface environment. New or secondary minerals develop from the original minerals of the rock. In this the processes of oxidation and hydrolysis are most important.
The process of mountain block uplift is important in exposing new rock strata to the atmosphere and moisture, enabling important chemical weathering to occur; significant release occurs of Ca++ and other minerals into surface waters.[6]
Rainfall is acidic because atmospheric carbon dioxide dissolves in the rainwater producing weak carbonic acid. In unpolluted environments, the rainfall pH is around 5.6. Acid rain occurs when gases such as sulfur dioxide and nitrogen oxides are present in the atmosphere. These oxides react in the rain water to produce stronger acids and can lower the pH to 4.5 or even 3.0. Sulfur dioxide, SO2, comes from volcanic eruptions or from fossil fuels, can become sulfuric acid within rainwater, which can cause solution weathering to the rocks on which it falls.
Some minerals, due to their natural solubility (e.g. evaporites)， oxidation potential (iron-rich minerals, such as pyrite)， or instability relative to surficial conditions (see Goldich dissolution series) will weather through dissolution naturally, even without acidic water.
One of the most well-known solution weathering processes is carbonation, the process in which atmospheric carbon dioxide leads to solution weathering. Carbonation occurs on rocks which contain calcium carbonate, such as limestone and chalk. This takes place when rain combines with carbon dioxide or an organic acid to form a weakcarbonic acid which reacts with calcium carbonate (the limestone) and forms calcium bicarbonate. This process speeds up with a decrease in temperature, not because low temperatures generally drive reactions faster, but because colder water holds more dissolved carbon dioxide gas.[citation needed] Carbonation is therefore a large feature of glacial weathering.
The reactions as follows:
CO2 + H2O => H2CO3
carbon dioxide + water => carbonic acid
H2CO3 + CaCO3 =>Ca(HCO3)2
carbonic acid + calcium carbonate => calcium bicarbonate
Carbonation on the surface of well-jointed limestone produces a dissected limestone pavement. This process is most effective along the joints, widening and deepening them.
【水合作用】Hydration
Mineral hydration is a form of chemical weathering that involves the rigid attachment of H+ and OH- ions to the atoms and molecules of a mineral.When rock minerals take up water, the increased volume creates physical stresses within the rock. For example iron oxides are converted to iron hydroxides and the hydration of anhydrite forms gypsum.
Hydrolysis on silicates and carbonates：Hydrolysis is a chemical weathering process affecting silicate and carbonate minerals. In such reactions, pure water ionizes slightly and reacts with silicate minerals.
【氧化】Oxidation
Within the weathering environment chemical oxidation of a variety of metals occurs. The most commonly observed is the oxidation of Fe2+ (iron) and combination with oxygen and water to form Fe3+ hydroxides and oxides such as goethite, limonite, and hematite. This gives the affected rocks a reddish-brown coloration on the surface which crumbles easily and weakens the rock. This process is better known as 'rusting', though it is distinct from the rusting of metallic iron. Many other metallic ores and minerals oxidize and hydrate to produce colored deposits, such as chalcopyrites or CuFeS2 oxidizing to copper hydroxide and iron oxides.
【生物风化】Biological weathering
A number of plants and animals may create chemical weathering through release of acidic compounds, i.e. moss on roofs is classed as weathering. Mineral weathering can also be initiated and/or accelerated by soil microorganisms.
【lichen例子】Lichens on rocks are thought to increase chemical weathering rates. For example, an experimental study on hornblende granite in New Jersey, USA, demonstrated a 3x - 4x increase in weathering rate under lichen covered surfaces compared to recently exposed bare rock surfaces.
The most common forms of biological weathering are the release of chelating compounds (i.e. organic acids, siderophores) and of acidifying molecules (i.e. protons, organic acids) by plants so as to break down aluminium and iron containing compounds in the soils beneath them. Decaying remains of dead plants in soil may form organic acids which, when dissolved in water, cause chemical weathering. Extreme release of chelating compounds can easily affect surrounding rocks and soils, and may lead to podsolisation of soils.
The symbiotic mycorrhizal fungi associated with tree root systems can release inorganic nutrients from minerals such as apatite or biotite and transfer these nutrients to the trees, thus contributing to tree nutrition.[8] It was also recently evidenced that bacterial communities can impact mineral stability leading to the release of inorganic nutrients.[9] To date a large range of bacterial strains or communities from diverse genera have been reported to be able to colonize mineral surfaces and/or to weather minerals, and for some of them a plant growth promoting effect was demonstrated.[10] The demonstrated or hypothesised mechanisms used by bacteria to weather minerals include several oxidoreduction and dissolution reactions as well as the production of weathering agents, such as protons, organic acids and chelating molecules.