10.3北美放狗

谢妮黑

阅读
1. online store 和 physical store jj里面很详细了 但题目有难度，第一题问主旨，第二道题问P3的作用
2. 好像在jj里没看到，三段简单，讲了一种T物质被用来当清洁材料，第一段讲这种物质是被用在牙膏里的，后来发现可用来当清洁材料清除pollutant。第二段举例讲T具体的application。第三段提了这种物质的limitation。
3. 地震seismic map。两段一屏，我觉得蛮难的，得集中注意力好好读，考的全是长句子的细节题！！
4. 工业革命和women的地位，家庭。有道题考以下那个观点是第一段出现的两个学者提出的continued thesis 的underlying false assumption（大概是这个意思）。我感觉是问thesis中提到的哪个观点是被原文作者反驳的。还有道题考点定位在原文最后一句话，可直接找同义句的那个答案。

数学
1. 最后一题是抛硬币6次，相同结果不连续出现的几率，就是1/32(2/2^6化简得到）
2. 奖金题，第一名奖励125，第二名40，第三名15，总奖金1735，问最少发几个奖金。17个（化简之后125的14个，40的2个，15的2个）
3. Is x^2+4x-5>0? 条件一：x<1，条件二：x>5。选C
4. 一个多边形的内角和？条件一：每个内角140度，条件二：多边形周长72cm。选A
5. 五个数9，9，10，10，x，好像是问平均数？条件一：range=2 （不能确定是8还是11），平均数大于9（不能确定），加起来还是不能确定是8还是11所以选E
6. 半圆柱形帐篷的题，无门无地板，求表面积。选190
7. 坐标轴上有个直角三角形，三点分别为（-2，4）（-2，-3）（x, 4)，这个三角形的斜边长为根号下65，问x=？我算出x=2
8. a b是integers，a能否被7整除？条件一：a+b能整除7 条件二：a*b能整除7。我选的C
9. What amount, if invested for a year in a stock that has a 2% interest rate and is compounded semiannually, 会产生一样的总额跟你invest 10000到一个4%interest rate compounded quaterly的股票里。我算出来是10201(=10000(1+1%)^2)
10. a+b=10, 一下哪个一定对？1. if a>6, b<4 (对）2，if a is positive, then b is positive （不一定对，不选）3，if a is negative, then b is positive (对）
11. X=1/(1^2+3^2+5^2...) Y=1/(2^2+4^2+6^2...), Z=X+Y, 在一些情况下，Z=KY(不记得具体，但这个条件是迷惑条件可以很直接忽略），求X/Z?
X/Z=X/(X+Y), 上下同时除以X，得到1/(1+Y/X), 因为Y小于X, Y/X小于1大于0，所以范围是1/2<X/Z<1，选3/4。

IR
连续遇到两篇连问三题的文字图表题，一个是关于国家公园棕熊的，一个是关于老奶奶margo为grandchildren存钱上大学的。文字和题目有点绕的，要求太复杂计算的题我直接放弃。。时间不够

作文
一个卖accounting软件的公司发现它的personal（nonprofessional） accounting software的销量比起professional software的不好。问卷调查显示该公司的professional user说该公司professional software有advanced features所以很好，然后就conclusion说the most efficient way of increasing the sale of personal accounting software is to add advanced features.

danhuang745

Thanks for sharing! I thought the answer to question 7 is 6?

echodan

danhuang745 发表于 2019-10-4 07:38
Thanks for sharing! I thought the answer to question 7 is 6?

同意！               

billyisfragile!

好像在jj里没看到，三段简单，讲了一种T物质被用来当清洁材料，第一段讲这种物质是被用在牙膏里的，后来发现可用来当清洁材料清除pollutant。第二段举例讲T具体的application。第三段提了这种物质的limitation。

T物质 = titanium dioxide?

JOURNAL ARTICLE

Paving Out Pollution

LINDA WANG

Scientific American

Vol. 286, No. 2 (FEBRUARY 2002), p. 20

Published by: Scientific American, adivision of Nature America, Inc.

https://www.jstor.org/stable/26059543

Page Count: 1

A COMMON WHITENER HELPS TO CLEAN THE AIR

Buildings, roads and sidewalkshave developed an appetite for air pollution. Researchers in Japan and HongKong are testing construction materials coatedwith titanium dioxide—thestuff of white paint and toothpaste—tosee how well they can fight pollution.

Better known as a pigment for whiteness, titanium dioxide can clear the air because itis an efficient photocatalyst: it speeds the breakdown of water vapor by ultravioletlight. The results of this reaction are hydroxyl radicals, which attack bothinorganic and organic compounds, and turn them into molecules that can beharmlessly washed away with the next rainfall. But it wouldn’t work to smear toothpaste on the sidewalk—the titanium dioxidecrystals in such applications are too large (about 20 to 250 nanometers wide).The width of the pollution-fighting form is about seven nanometers, offeringmuch more surface area for photocatalysis.

In the early 1970s researchers from the Universityof Tokyo described titanium dioxide’s photocatalytic abilities. Since then, scientistshave exploited the compound to kill bacteria on hospital surfaces and to treatcontaminated water. Fighting nitrogen oxide on the streets is the latest twist.In Hong Kong, concrete slabs coated with titanium dioxide removedup to 90 percent of nitrogen oxides, most commonly spewed from older cars anddiesel trucks and a contributor to smog, acid rain and other environmental headaches.In taking care of the contaminants, a coating of titanium dioxide did in minutes what theenvironment does in months, says Jimmy Chai-Mei Yu, a chemist at the ChineseUniversity of Hong Kong. Moreover, he adds, because titanium dioxide is acatalyst, it could last forever.

Despite its promise, the compound is no magical cure. “The bigproblem with titanium dioxideis that it doesn’t absorb sunlight very well,” says Carl Koval, achemist at the University of Colorado at Boulder. Only 3 percent of sunlightfalls into the range needed for the titanium dioxide to work, points out Adam Heller, a chemicalengineer at the University of Texas at Austin. A recent advance by Ryoji Asahi of Toyota Central R&D Laboratoriesin Nagakute, Japan, boosted the efficiency to 10 percent, but, Heller notes,“it’s still a small fraction of the sunlight.”

And although titanium dioxide is relatively inexpensive,paving roads and coating buildings with this substance could add up. “Thecountries with the most air pollution will benefit the most from thistechnology,” Yu observes, “but unfortunately those are the countries that won’tbe able to afford it.”

谢妮黑

bzy! 发表于 2019-10-4 16:26
T物质 = titanium dioxide?
JOURNAL ARTICLEPaving Out PollutionLINDA WANGScientific AmericanVol. 286, ...

就是这个

谢妮黑

danhuang745 发表于 2019-10-4 07:38
Thanks for sharing! I thought the answer to question 7 is 6?

抱歉题目写错 已经改了

danhuang745

bzy! 发表于 2019-10-4 16:26
T物质 = titanium dioxide?
JOURNAL ARTICLEPaving Out PollutionLINDA WANGScientific AmericanVol. 286, ...

这样都可以找到！太牛了

killuacx

数学第九题我看到过原题：John deposited $10,000 to open a new savings account that earned 4 percent annual interest, compounded quarterly. If there were no other transactions in the account, what was the amount of money in John's account 6 months after the account was opened?

killuacx

killuacx 发表于 2019-10-5 10:48
数学第九题我看到过原题：John deposited $10,000 to open a new savings account that earned 4 percent a ...

额好像不是一个，答案一样

Warzdgesord

数学第三题按照楼主给的条件应该是B选项吧