【阅读】10/03起阅读寂静整理（10/14更新，47篇原始，41篇考古）

尽人事听天命

45一定是补牙那个，内应力

billyisfragile!

JOURNAL ARTICLE
Authenticating Ancient Marble Sculpture
Stanley V. Margolis
Scientific American
Vol. 260, No. 6 (JUNE 1989), pp. 104-111
Published by: Scientific American, a division of Nature America, Inc.
https://www.jstor.org/stable/24987292
Page Count: 8

Authenticating Ancient Marble Sculpture
Stone sculpture is notoriously difficult to prove genuine. As prices for such works skyrocket, geochemists are being called in to help settle questions that art history and a connoisseur's eye cannot resolve

By Stanley V. Margolis

第一段：博物馆的人怀疑一个叫Kursos (大概这样写)的艺术品（其实是一个statue, marble figure, 就是大理石雕像）不是真品，于是请Geochemical 的人来鉴定。Geochemists先identify从哪来的，什么quarry。但是不能确定，只能初步认为是怎样，但是还是不能确定具体可以追溯到什么年代。 （黑体字有题目）

In 1984 the J. Paul Getty Museum in Malibu, Calif., was offered a chance to buy an archaic Greek kouros: a larger-than-life marble figure of a youth. The two-meter-tall statue, said to be more than 2,500 years old, was superbly preserved but had been unknown to art historians; it was said to have resided in a private Swiss collection for many decades. Based on the putative importance of the piece, the owner was asking a higher price than had ever been paid for an ancient statue; several major newspapers reported that the sum was somewhere between eight and 12 million dollars.

Usually the first step in authenticating a work of sculpture is to identify  the quarry from which the stone came. This can often be done with great precision, because the isotopic makeup of marble varies significantly from one site to another. When isotope values overlap from one quarry to another, further chemical tests can tell the quarries apart. The kouros marble was  analyzed by our research group, which  included William S. Showers of North Carolina State University at Raleigh and Norman Herz of the University of Georgia, the latter an expert in the provenance of ancient marble. According to Herz, the kouros marble probably came from the ancient Cape Vathy quarries on the island of Thasos. These quarries were the oldest source  of dolomitic marble in the area, and  large kouroi were produced in Thasos  in the seventh and sixth centuries B.C.

第三段是把两个东西的C12 和C10的ratio作比较 得出一个结论（结论有考题）

第三段：Then, geochemist开始辨别crust里的carbon-18 dioxide-12和什么什么的carbon-14对比。发现ratio什么的不一样。

In the most crucial test we compared the ratio of oxygen 16 to oxygen 18 and that of carbon 12 to carbon 13 found in the calcite crust with the ratios found in the fresh dolomite from the interior. The ratios were similar and also resembled the ratios measured in dedolomitized dolomite found in nature. This finding ruled out the possibility that the calcite crust of the kouros had been artificially replicated or had precipitated out of  groundwater. In either case the oxygen and carbon isotope values of the crust would have been very different from those of fresh dolomite. The most reasonable explanation for the calcite on the kouros is that it developed through centuries of weathering.

有一题问the thickness of the layer of calcitic，可以用来determine下面什么？文章定位最后一段，有说根据thickness只能推断出no more than多少年，no less than多少年，然后有个选项是the maximum and minimum year什么的。
还有一题好像是关于最后一句，科学家最后认定那个什么CLAY是authentic，选项说虽然不能推断出actual age，但可以证明它是真品。

The thickness of the calcite crust by itself does not indicate an exact age for the sculpted surface, because the  rate of dedolomitization depends on  many unknown variables: the length of burial, the composition of the burial soil and the chemistry of groundwater and rainfall at the burial site. From  what is known about dedolomitization, the surface features of the Getty  kouros are consistent with an age of  no less than several centuries and no  more than several millennia.

billyisfragile!

https://forum.chasedream.com/thread-1152413-1-1.html

JOURNAL ARTICLE
Residual Stresses in Materials
I. C. Noyan and J. B. Cohen
American Scientist
Vol. 79, No. 2 (March-April 1991), pp. 142-153 (12 pages)
Published by: Sigma Xi, The Scientific Research Honor Society
https://www.jstor.org/stable/29774322

In a high-tech version of artisanship, engineers can manipulate an object’s internal stress fields to give it desired properties. The average person is likely to feel mildly alarmed on being told that dental fillings contain locked-in stresses. We all have a somewhat hazy understanding that stress leads to fracture and can vaguely recall dramatic instances of stress-related failures. Thus we are likely to feel that all material stresses are without redeeming value and should, if possible, be eliminated.

A truer picture of the behavior of materials is both more complicated and more interesting. It turns out that it is difficult to work a rigid material without introducing permanent internal stresses. Most common manufacturing operations, such as turning, grinding, and heat treatment, surface hardening, and welding, can set up internal stresses, and many familiar objects are subject to them, including dental fillings, computer chips, and pipelines. But these residual stresses can be beneficial as well as harmful. Indeed, manufacturers sometimes go to great lengths to introduce them. Many stress-related effects and recipes for obtaining them have long been known to artisans. What is new is the ability to measure the stress fields directly rather than inferring their nature from war page and breakage. Several trends in engineering design make this analytical competence important.

One of the trends is the proliferation of nontraditional materials. The best way to work a sword or to coil a spring may be known, but no comparable body of lore exists for ceramic transducers or semiconductor wafers or composite air foils. A second trend is the trimming of safety margins. Bridges and other load-bearing structures have traditionally been built with large safety factors, but the lavish use of materials required by this practice is increasingly uneconomic (原文在这里有改动，给了一些比较具体的数字); in the case of objects that must be lofted into space, a large safety factor is totally impractical. A third trend is the reduction in scale of many engineered systems. Residual stresses play a much more important role in the microscopic metal interconnects on the surface of a chip than they do in a thick electrical cable.


题目
1, What does the “analytical competence” refer to?
A) The ability to measure the stress field.
B) The ability to infer from warpage and breakage.

2, Which of the follow is a benefit of the improved measurement?
A) Allow structures to be built more economically.
B) 忘了

3, Which of the following about residual stress is supported by the argument?
A) Dental filling is beneficial
B) 忘了

calvinemp_ck

calvinemp_ck

billyisfragile!

JOURNAL ARTICLE
How Climate Evolved on the Terrestrial Planets
James F. Kasting, Owen B. Toon and James B. Pollack
Scientific American
Vol. 258, No. 2 (FEBRUARY 1988), pp. 90-97
Published by: Scientific American, a division of Nature America, Inc.

How Climate Evolved on the Terrestrial Planets
Planets with temperate, earthlike climates were once thought to be rare in our galaxy. Mathematical models now suggest that if planets do exist outside the solar system, many of them might be habitable
By James F. Kasting, Owen B. Toon and James B. Pollack

The Faint-Young-Sun Paradox
Our interest in the role of carbon dioxide in the evolution of the earth, Mars and Venus had its roots in another cosmological puzzle relating to the origin of the earth: the faint- young-sun paradox. Virtually every  model of stellar evolution indicates  that the sun was between 25 and 30 percent dimmer when the solar system formed some 4.6 billion years ago than it is today. Since then the  solar luminosity, or intensity, has  apparently increased approximately linearly with time.

第一段第一句话说，3.8billion年前，太阳比现在dimmer（暗示太阳温度低），但是当时地球表面有液态水了。科学家觉得不可思议，因为按计算地球应该是冰封状态，所以提出了一个假设，就是greenhouse吸收了太阳的热量。如何证明是不是greenhouse，就说海洋中氢会分解成较轻和较重的两种同位素，较轻的氢同位素会挥发到space中，较重的会沉淀在海里。然后有一段啰嗦的逻辑过程，反正就是说测较轻的氢同位素含量就能知道当时是不是greenhouse，然后就说证明不是这样的。第二段就是第二个假设，就是说云少，反射太阳光少，所以吸收太阳热量多。为什么云少呢？因为当时陆地少，而陆地是提供云形成必须的颗粒物的，因此云少。有一题问文章第一句（就是太阳dimmer那句）和文章最后一句（云少所以吸热多）的关系，我选第一句提出现象，最后一句提出可能解释。还有题问3.8billion年前哪件事是must be true，好像5个选项都是与now对比的。

The paradox arises, as Carl Sagan  and George H. Mullen of Cornell University pointed out about 15 years  ago, when one realizes that if the  earth's early atmosphere was the  same as it is now, a weak sun would  have resulted in an ice-covered earth  until about two billion years ago. Yet  the planet did not freeze. In fact, evidence from sedimentary rocks indicates that the earth has had liquid  oceans since at least 3.8 billion years  ago, when the geological record begins. Moreover, life has been present  for at least the past 3.5 billion years,  demonstrating that the earth's surface has never been entirely frozen  during that time. (Water can remain  fluid as long as the temperature is between zero and 374 degrees c.; it  boils and evaporates at 100 degrees C. at sea level today but will stay liquid at higher temperatures if the at­mospheric pressure is increased.)

第二种是关于cloud的理论，此段短——和水大概是正相关的变化。。。失忆了

Sagan and Mullen realized that the  paradox disappears if one assumes the earth's atmosphere has changed  in the course of time. For instance, if  the young planet had fewer clouds  than it has today, less of the sunlight  that impinged on the earth would  have been reflected back into space, and the planet would have been correspondingly warmer. Some 30 percent of the sunlight that currently  reaches the top of the atmosphere is  returned to space, most of it by  clouds. A chillier earth might well  have had fewer clouds but the geological record suggests the early  earth was actually warmer than today's. Parts of the planet are covered  with glaciers now, but there is no evidence of similar glaciation before  
about 2.7 billion years ago.

A more probable explanation is  that the greenhouse effect was more  pronounced in the distant past. Sagan and Mullen suggested that ammonia (NH3), an efficient absorber of  infrared, could have warmed the climate if the gas represented just 100 out of every million molecules of the air. Subsequent studies have shown,  however, that the sun would have  rapidly converted ammonia into the non greenhouse gases nitrogen and  hydrogen unless it was continually resupplied to the atmosphere from the planet's surface.

Other investigations have focused  on carbon dioxide, which sunlight  does not readily decompose. Carbon  dioxide is certainly abundant here;  the amount now stored in the planet  in carbonate rocks would exert a  pressure of about 60 bars if it were released into the atmosphere. (One bar  is equal to 14.5 pounds per square  inch, the pressure at sea level. Today  the earth's atmosphere contains  about .0003 bar of carbon dioxide.) If  just a few tenths of a bar of the stored  carbon dioxide was originally present as a gas, its additional greenhouse warming would have compensated for the reduced sunlight.

第三段开始说一个叫Michael的学者说我算了算二氧化碳的含量得出了一个数据，比它多地球太热比它少地球太冷，我算的很精确；其他学者反驳说他的因果不对，实际是温度和二氧化碳互相制衡达到稳定
有个问题问Michael没有考虑到什么？我选的好像是没考虑到互相调节还是啥的

第三段就说一个人做实验 证明了 二氧化碳浓度的什么rate确实是互相抵消的 然后再出来recent investigator说这个人错了，其实地球的二氧化碳浓度不是自己升高的，而是地球怎么样以后他被动升高的

The notion that higher carbon dioxide levels could have protected  the early earth from freezing soon  gave rise to a related idea: if the carbon dioxide level declined at a rate  that precisely counteracted the increase in solar luminosity with time, the decline might account for the fact that the earth's temperature has  always remained within reasonable  limits. One investigator, Michael H. Hart of NASA, undertook to calculate  such a compensatory rate.

Hart managed to work out a solution in which the levels of the gas declined approximately logarithmically with time, but his most interesting  finding was that very few of his calculations succeeded. In other words,  if the composition of the atmosphere  had at any time changed at a rate different from his precise solution, the  planet would have become unable to  support life. If the carbon dioxide level had declined too slowly, the earth  would have become a hothouse; if it  had declined too quickly, the oceans  would have frozen.

Hart did similar calculations for  cases in which the distance between  the earth and the sun was varied by  small amounts. He found that if the  earth had formed 5 percent closer to  the sun, the atmosphere would have  become so hot that the oceans would  have evaporated, a condition known  as a runaway greenhouse. Conversely, the planet would have encountered runaway glaciation if it had  formed as little as 1 percent farther  from the sun. Only in the relatively  narrow range of orbits between .95  astronomical unit and 1.01 A. U. could  one or the other of these climatic catastrophes be avoided. (One A.U. is  the distance between the sun and the earth, or 149.6 million kilometers.)  Hart termed this narrow band of orbital distances the continuously habitable zone (CHZ).

Hart's conclusions were unsettling  because they suggested that the  earth must have beaten extraordinary odds in avoiding the fate of Mars  or Venus. Only within the past few  years have investigators discovered  the flaw in his hypothesis. A mathematical model developed by James C. G. Walker and Paul B. Hays of the University of Michigan and by one of us  (Kasting) suggests that the changes  in carbon dioxide concentration did  not arise by sheer luck. Rather, carbon dioxide levels have probably  fluctuated in response to changes in  surface temperature. When the temperature goes up, atmospheric carbon dioxide levels decline, cooling  the surface; when the surface cools,  the abundance of atmospheric carbon dioxide increases and warms the  surface. The existence of such a negative-feedback loop means that the  earth probably has never been in  danger of undergoing either the runaway greenhouse or the runaway  glaciation postulated by Hart.

echo-LUO

明天考，祈祷不好换库

我的芋头呢

想问一下阅读jj什么时候看比较合适，看当月的还是换库后到考试前的。

cxxxxxy

mark