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标题: 请教 og-153 [打印本页]

作者: ecsniffer    时间: 2004-2-14 00:31
标题: 请教 og-153
153、Technological improvements and reduced equipment costs have made converting solar energy directly into electricity far more cost-efficient in the last decade.However, the threshold of economic viability for solar power(that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants) is unchanged at thirty-five dollars.
Which of the following,if true,does most to help explain why the increased cost-efficiency of solar power has not decreased its threshold of economic viability?
A) The cost of oil has fallen dramatically.
B)The reduction in the cost of solar-power equipment has occured despite increased raw material costs for that equipment.
C)Technological changes have increased the efficiency of oil-fired,power plants.
D)Most electricity is generated by coal-fired or nuclear,rather than oil-fired,power plants.
E)When the price of oil increases, reserves of oil not previously worth exploiting become economically viable.
The key:C. Why not A? Please!


作者: dorbear    时间: 2004-2-15 11:40
The cost of the oil does not always positively related to its price    about which the argument is talking.
作者: 盈盈绿茶    时间: 2004-2-21 10:50
(that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants)


请问,括号内的内容如何理解呢?


作者: boxxzzy    时间: 2004-2-21 11:28
以下是引用盈盈绿茶在2004-2-21 10:50:00的发言:
(that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants)



请问,括号内的内容如何理解呢?





一个太阳能发电提升的最高极限价格————仍然比new oil-fired power plants所发的电经济的价格。
作者: cranberry    时间: 2004-2-21 15:34
油价只是构成火电厂成本的一部分,A只说了油价,而C说了提高了效率,降低了成本
作者: dydingding    时间: 2004-3-5 14:37
153、Technological improvements and reduced equipment costs have made converting solar energy directly into electricity far more cost-efficient in the last decade.However, the threshold of economic viability for solar power(that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants) is unchanged at thirty-five dollars.


什么意思:技术的进步和设备成本的降低使得太阳能转化为电更加节约成本,然而,太阳能技术的经济性(为了使新太阳能工厂比新燃油工厂更加经济,每桶油价的价格必须上涨的价格)没有变化,还是35元。


题目问:为什么太能能源的成本下降没有使(要求油价上涨的)价格下降


是这个意思吗?


    


    


作者: 雪落无声    时间: 2004-3-5 18:47
economic viability for solar power(that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants)


economic viability用比例的话怎么表示?当时看得时候也晕菜了~小飞,你的解释我还是不太懂,我觉得这个economic viability是个比例,that is 是解释,但是我还是没弄明白是个怎么样的比例


作者: weiyu    时间: 2004-3-6 00:29
First of all, threshold in Chinese means 阈值,比如水的沸点为100, 100称为水沸的阈值。原文(that is 只有提高每桶原油一定的价格(OP)才能保证太阳能发电比原油发电更经济 )是对太阳能经济阈值的解释。想一想,太阳能发电都随科技的发展变得便宜了,为什么每桶原油还要涨35美元才能保证太阳能发电比原油发电更经济呢,只有一点,那就是原油发电效率也提高了。
作者: LES    时间: 2004-6-17 18:47

看了很对前辈的讨论,可是偶还是对that is引导的解释不得要领。大家的解释似乎都是一个增长量的概念,而偶的理解偏偏是增加到的一个值。下面是偶的翻译,请大家告诉我到底哪里出了问题。谢谢!

that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants.

对黑体部分的语法理解是
in order for new solar power plants to be more economical than new oil-fired power plants, oil would have to rise to the price per barrel.

对整句的翻译是
也就是说,为了使新的太阳能发电厂新的以石油为燃料的发电厂更经济,石油必须涨到的每桶价格。


作者: chwayne    时间: 2004-6-17 22:08

LES, 你的理解是对的.

如果对国际油价有概念的话,很多年了,国际油价正常情况下每桶基本都低于USD35,多在20-30之间徘徊,that is, 说的当然是oil要涨到solar power经济可行的threshold,the price per barrel USD35 。 但好像理解成要涨USD35,也不影响解题。


作者: LES    时间: 2004-6-17 22:22

谢谢你,chwayne。

你是否对the threshold of economic viability 这个经济名词有概念?可否解释一下。偶说的是经济学上的概念,而非题目中所说的。

就这题中的理解偶有点糊涂,不看that is引导的解释,觉得是一个相对值的概念;而根据that is引导的解释,如果上面偶的翻译是对的话,又是一个绝对值的概念。

谢谢!


作者: luoffice    时间: 2004-6-18 08:57
以下是引用LES在2004-6-17 18:47:00的发言:

看了很对前辈的讨论,可是偶还是对that is引导的解释不得要领。大家的解释似乎都是一个增长量的概念,而偶的理解偏偏是增加到的一个值。下面是偶的翻译,请大家告诉我到底哪里出了问题。谢谢!

that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants.


对黑体部分的语法理解是
in order for new solar power plants to be more economical than new oil-fired power plants, oil would have to rise to the price per barrel.

对整句的翻译是
也就是说,为了使新的太阳能发电厂新的以石油为燃料的发电厂更经济,石油必须涨到的每桶价格。


you are right

" to which oil would have to rise "= oil would have to rise to (the price)


作者: luoffice    时间: 2004-6-18 08:59
以下是引用chwayne在2004-6-17 22:08:00的发言:

LES, 你的理解是对的.


如果对国际油价有概念的话,很多年了,国际油价正常情况下每桶基本都低于USD35,多在20-30之间徘徊,that is, 说的当然是oil要涨到solar power经济可行的threshold,the price per barrel USD35 。 但好像理解成要涨USD35,也不影响解题。


nnd, lost huge on my QM short contract


作者: chwayne    时间: 2004-6-18 19:28

哎哟,那您老哥可亏大了,六月初的油价可创了20年的最高,今年也是1990年海湾战争之后首个再次突破USD40 per barrel的年份。你该不会是在最高的时候买的吧,buyer的loss可是seller 大大的margin,唉!ETS在这道题中说:油价超过threshold USD35,太阳能发电就比油发电更有利可图了。what does ETS imply----我们大家都去做太阳能吧。


作者: chwayne    时间: 2004-6-18 21:43
以下是引用LES在2004-6-17 22:22:00的发言:

谢谢你,chwayne。

你是否对the threshold of economic viability 这个经济名词有概念?可否解释一下。偶说的是经济学上的概念,而非题目中所说的。

就这题中的理解偶有点糊涂,不看that is引导的解释,觉得是一个相对值的概念;而根据that is引导的解释,如果上面偶的翻译是对的话,又是一个绝对值的概念。


谢谢!


LES MM,你可难着我了,偶不是学经济学的,不知道经济学中是否有这个概念呀,但应该不紧要,ETS says: No specialized knowledge of any particular field is required for answering the questions, and no knowledge of the terminology and conventions of formal logic is presupposed.  Weiyu对threshold 的解释是对的,通俗的说就是一个临界值或界限,本题说的是solar power 相对于oil-fired 发电的经济可行的临界值,并且这个临界值是用油价来表征的,即低于USD35 per barrel,solar power 相对于 oil-fired power 就经济可行,反之,Solar对oil-fired power 就没有竞争力。



括号中that is 后面是个名词短语,相当于threshold 的一个长长的同位语,括号内外说的都是一个绝对值的概念,只是题目问:cost-efficiency的增加为什么没有decrease这个绝对值(临界值),还是USD35 没变。



我觉得这题可能是OG上最绕的一道CR题了,楼主esciniffer问答案为什么不是A,又是这题最绕的地方。因为题目是用油价Po来表征该threshold, 故只能选C,如果换成用效率eo来表征threshold, 答案就是A。解答如下:



将两种产能方式写成函数:


Oil-fired:     Eo=fo(Po, eo)  Eo是所产的电能,fo 是函数的常量, Po是油价,eo是efficiency


Solar:      Es=fs(Ps, es)  s 表示输入成本价(与上面油价起相当作用的一个量),其他相应



求临界值就是将上面两个等起来,得:fo(Po, eo)= fs(Ps, es),


按题,是用Po 来表征threshold即求Ps,Ps=(fo, fs)(eo,es)(Po),只与两个效率有关,选C


若用eo来表征threshold , 即求es,es=(fo, fs)(Po, Ps) (eo),只与两个价格有关,选A



作者: LES    时间: 2004-6-18 22:08

chwayne, 太。。。。。。厉害了!!!

非。。。。。。常谢谢你这么耐心的解释!!!

可是偶发现不仅是经济概念的白痴,那些数学公式对偶就像天书

不过真。。。。。。的很感谢,偶觉得应该是搞明白了偶想明白的问题。

题目实际上就是用油价来衡量这个经济生存的临界值,有点类似金本位制(google上搜来搬弄一下)。


作者: robertchu    时间: 2004-6-19 07:30
实际上这是solar-genarated electricity 和 oil-generated electricity 赛跑,看谁更划算 :-)

作者: dream1111    时间: 2004-7-28 12:40
以下是引用chwayne在2004-6-18 21:43:00的发言:


即低于USD35 per barrel,solar power 相对于 oil-fired power 就经济可行,反之,Solar对oil-fired power 就没有竞争力。






Just based on common sense, this statement above is wrong.  Although chwayne's conclusion is right, it failed to explain clearly.


On this question, simply, oil price is not a factor to determine the threshold, which is only determined by costs in solar power and costs other than cost of oil in oil-derived power.


Cs>Co  ( Cs  the cost in solar power, Co in oil power)


Co= Cno + PoQo       ( Cno the costs other than costs of oil  , Po price of oil, Qo Quantities of oil consumeed in oil-drived power)


Cs=Co=Cno + PtQo   ( Pt threshold)


So, Choice C.


Why threshold is nothing with present oil prices?  'cause the threshold is calculated on the basis of oil price, the threshold already includes the cost of oil .


作者: cuihua    时间: 2004-8-3 20:21

threshhold 是指价格,一种对比的价格,

不是绝对值,A指的是绝对值


作者: lingling2005    时间: 2005-5-24 02:55

I see a lot of explaination about this question. But I still can not convince myself why A is incorrect.


"The price per barrel to which oil would...." I think this means the "the cost of oil". Any NN? Help!!!!



作者: snowjing    时间: 2005-7-26 04:48
以下是引用chwayne在2004-6-18 21:43:00的发言:


LES MM,你可难着我了,偶不是学经济学的,不知道经济学中是否有这个概念呀,但应该不紧要,ETS says: No specialized knowledge of any particular field is required for answering the questions, and no knowledge of the terminology and conventions of formal logic is presupposed.  Weiyu对threshold 的解释是对的,通俗的说就是一个临界值或界限,本题说的是solar power 相对于oil-fired 发电的经济可行的临界值,并且这个临界值是用油价来表征的,即低于USD35 per barrel,solar power 相对于 oil-fired power 就经济可行,反之,Solar对oil-fired power 就没有竞争力。






括号中that is 后面是个名词短语,相当于threshold 的一个长长的同位语,括号内外说的都是一个绝对值的概念,只是题目问:cost-efficiency的增加为什么没有decrease这个绝对值(临界值),还是USD35 没变。






我觉得这题可能是OG上最绕的一道CR题了,楼主esciniffer问答案为什么不是A,又是这题最绕的地方。因为题目是用油价Po来表征该threshold, 故只能选C,如果换成用效率eo来表征threshold, 答案就是A。解答如下:






将两种产能方式写成函数:



Oil-fired:     Eo=fo(Po, eo)  Eo是所产的电能,fo 是函数的常量, Po是油价,eo是efficiency



Solar:      Es=fs(Ps, es)  s 表示输入成本价(与上面油价起相当作用的一个量),其他相应






求临界值就是将上面两个等起来,得:fo(Po, eo)= fs(Ps, es),



按题,是用Po 来表征threshold即求Ps,Ps=(fo, fs)(eo,es)(Po),只与两个效率有关,选C



若用eo来表征threshold , 即求es,es=(fo, fs)(Po, Ps) (eo),只与两个价格有关,选A






chwayne的解释太经典啦,是对153题中最完整的解释,第一个提出threshold是用油价表示的概念。

这题对于做项目可行性分析的人而言肯定不难。但chwayne似乎写错了“低于”,应该是高于吧。油价低对于oil-fired是有利的,只有当油价高于每桶USD35,solar power的方案才是可行的。


作者: swlfx    时间: 2005-8-3 18:54
以下是引用snowjing在2005-7-26 4:48:00的发言:


chwayne的解释太经典啦,是对153题中最完整的解释,第一个提出threshold是用油价表示的概念。

这题对于做项目可行性分析的人而言肯定不难。但chwayne似乎写错了“低于”,应该是高于吧。油价低对于oil-fired是有利的,只有当油价高于每桶USD35,solar power的方案才是可行的。


同意snowjing。


作者: drift_er    时间: 2005-10-3 15:17

我还是没看懂


作者: dancerme814    时间: 2005-12-13 21:16

chwayne似乎写错了“低于”,应该是高于吧。油价低对于oil-fired是有利的,只有当油价高于每桶USD35,solar power的方案才是可行的。


SNOWJING meimei仔细看题目 chwayne的分析是对的  


Which of the following,if true,does most to help explain why the increased cost-efficiency of solar power has not decreased its threshold of economic viability?


作者: littlebriton    时间: 2006-3-29 07:09

我们之所以会选A是因为我们主观的认为火力发电一定要石油。不一定,还可以用煤,理论上甚至可以烧木头(别砸我)。


我的意思是石油在题目中根本没有实际意义,它只是一个价格符号,完全可以用金价来代替而又不改变题目意思。如果换了PRICE OF GOLD,我想没有人会选A了吧


作者: maydaythekid    时间: 2006-8-6 10:12
以下是引用littlebriton在2006-3-29 7:09:00的发言:

我们之所以会选A是因为我们主观的认为火力发电一定要石油。不一定,还可以用煤,理论上甚至可以烧木头(别砸我)。

我的意思是石油在题目中根本没有实际意义,它只是一个价格符号,完全可以用金价来代替而又不改变题目意思。如果换了PRICE OF GOLD,我想没有人会选A了吧

严重同意!仔细看括号部分:Oil-fired plant VS Solar power plants

oil 确实是且只是其中一个因素,C选项直接提到“Oil-fired plant ”, 靠谱多了!(VS单纯提到 oil price的A)

回过头来想,有时候还真的是审题不够谨慎,汗


[此贴子已经被作者于2006-8-6 10:16:02编辑过]

作者: ashura    时间: 2006-11-5 07:45
以下是引用littlebriton在2006-3-29 7:09:00的发言:

我们之所以会选A是因为我们主观的认为火力发电一定要石油。不一定,还可以用煤,理论上甚至可以烧木头(别砸我)。

我的意思是石油在题目中根本没有实际意义,它只是一个价格符号,完全可以用金价来代替而又不改变题目意思。如果换了PRICE OF GOLD,我想没有人会选A了吧

可不是!其实选项D还专门提醒了一下:Most electricity is generated by coal-fired or nuclear, rather than oil-fired, power plants.


作者: huangyh03    时间: 2007-9-10 04:38
以下是引用LES在2004-6-17 18:47:00的发言:

看了很对前辈的讨论,可是偶还是对that is引导的解释不得要领。大家的解释似乎都是一个增长量的概念,而偶的理解偏偏是增加到的一个值。下面是偶的翻译,请大家告诉我到底哪里出了问题。谢谢!

that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants.

对黑体部分的语法理解是
in order for new solar power plants to be more economical than new oil-fired power plants, oil would have to rise to the price per barrel.

对整句的翻译是
也就是说,为了使新的太阳能发电厂新的以石油为燃料的发电厂更经济,石油必须涨到的每桶价格。

斑竹就是斑竹,一语中第,我认为这才是这句话的正确理解,og解释也符合此意思
作者: hollygrail    时间: 2007-11-6 01:42
对economic viability不同的理解会得出不同的答案:
1.如果economic viablity(EV)跟现实的油价相关,那么A当然是可能的解释.
2.但这里EV是和现实的油价无关的.直白的说economic viability $35相当于用$35/barrel的oil发电 .
假如技术进步前每barrel oil发1000度电
技术进步前:
Solar   1000 degree              Oil 1000 degree
    cost $35                   $35
技术进步后,S的cost-effectiveness增加,假如能发2000度电,而economic viablity保持不变,则相应的oil power plan每$35也要发2000度电,所以oil power plan的cost-effctiveness要增加:
S   2000 degree              O 2000 degree
    cost $35                   $35
或者按下面的式子:
C(S) 每度电solar power plan的成本
Economic viability  = C(S)/每度电oil pwer plan需要的石油barrel数
S的cost-effectiveness增加,分子减少,分母也要同步减少以保持EV不变,故oil power plan的cost-effcitveness增加.
注:EV是一个shreshold,如果现实的油价大于EV,则用solar划算,反之则不划算.
(OG: Actual oil prices control how far, given the viability threshold, solar
power is from economic viability but do not figure in the determination of the
threshold.)
economic viability for solar power (that is, the price
per barrel to which oil would have to rise in order for new solar power plants
to be more economical than new oil-fired power plants)


作者: benja    时间: 2009-4-6 16:01
2 楼的解释  nice!!!
[此贴子已经被作者于2009-4-6 16:02:28编辑过]

作者: ksay    时间: 2011-11-30 17:33
刚看到ron大神上周在manhattan更新了这道题的解释。。。如果这道题的题眼确在ron大神指出的地方 怕是上面得各位大神们都想多了。。。

read the passage carefully: the conclusion is about "the price per barrel to which oil would have to rise (theoretically) in order for new solar power plants to be more economical".
therefore, we are thinking about a potential threshold price for oil at which something would happen. the current price of oil -- or, indeed, the current state of absolutely anything regarding oil -- is irrelevant, so you can strike choices a/c very quickly.

here's an analogy, if you don't understand:
let's say i'm looking at a pair of pants with a 32-inch waist.
if the passage discusses “the waist size i would have to reach to wear these pants”, then that is 32 inches, regardless of my current waist size (which is completely irrelevant).
作者: shirryzhan    时间: 2012-6-2 21:26
The threshold of economic viability for solar power (that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants)--- means:The oil-fired power should have been more economical than solar power, but only if the oil rises to $35, the solar power could be more economical than oil power.


So we can tell, if the cost of solar power reduces, which means solar power is more economically viable, the threshold of economic viability should be lower, maybe to $30, because oil price doesn’t need to make so much sacrifice for solar power’s success. However, the threshold is still $35, it means that the oil power at the same time also gets more efficient. In a conclusion, oil price still need to make such a big sacrifice - % 35, to help keep solar power's economic viability.






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