时间:2018-12-24 作者:英语课 分类:2017年Scientific American(一)月


英语课

 


Last time you hit the beach—and yeah, probably seems like a distant memory in the currently chilly 1 parts of the world—did you pack sunscreen? A beach umbrella? Or both?


Researchers put the two sun-protecting products to the test. First contender: a beach umbrella, which they evaluated with a spectrophotometer to see if UV rays passed through. They didn't…good sign so far. The second contender was sunscreen: 100 SPF.


Then the scientists rallied 81 people to go sunbathing 2 at a lake outside Dallas, for three hours around mid-day. Half got beach umbrellas. The other half, all-you-can-apply sunscreen. And because this is science—not a day at the beach, eh, let me rephrase that, not a walk in the park—the participants were not allowed to take a dip.


Twenty four hours after the solar exposure—enough time for any sunburns to ripen—the researchers visually inspected the sunseekers' skin. And they found that three times as many umbrella-sitters had sunburns somewhere on their bodies, compared to their sunscreen-slathering neighbors. And since the umbrellas themselves block UV rays, the burns are likely due to UV light bouncing off the sand and other surfaces, then hitting unprotected skin. The study is in JAMA Dermatology. [Hao Ou-Yang et al., Sun Protection by Beach Umbrella vs Sunscreen With a High Sun Protection Factor A Randomized Clinical Trial]


The caveat 3? Even sunscreen users weren't completely burn-free. So the researchers—some of whom, full disclosure, work at Johnson & Johnson, which makes sunscreen—instead recommend hedging your bets. Wear a wide-brimmed hat. Sit in the shade. Use sunblock, too. To ensure you don't need that fourth strategy: aloe vera.


—Christopher Intagliata



1 chilly
adj.凉快的,寒冷的
  • I feel chilly without a coat.我由于没有穿大衣而感到凉飕飕的。
  • I grew chilly when the fire went out.炉火熄灭后,寒气逼人。
2 sunbathing
n.日光浴
  • tourists sunbathing on the beach 在海滩上沐浴着阳光的游客
  • We've been sunbathing on the beach. 我们一直在海滩上晒日光浴。
3 caveat
n.警告; 防止误解的说明
  • I would offer a caveat for those who want to join me in the dual calling.为防止发生误解,我想对那些想要步我后尘的人提出警告。
  • As I have written before,that's quite a caveat.正如我以前所写,那确实是个警告。
学英语单词
alethic logics
all-over oneself
amygdalic
arloes
aromatic heterocyclic polymer
arrogating
assembly line production
astern-turbine
auto shut off circuit
Baudot code.
bias-to-window ratio
blattered
bombo r.
bor.
break-wind
burgundy-colored
business analysis
Campobello
Cigdemli
Civatte's disease
class ab fier
co-accuseds
cold snare
combjelly
constant expense
Decaps
differentiability from the right
disturbance signal
Dutch Reformed
Edsbruk
electrical impedance tomography
emsley
endothelioangiitis
ensmallening
epibolite
explorator
febli
file-fish
fluidized-bed gasification
flying squirrels
focus electrode potential
frost circles
genus rhinonicteriss
ginkgophyte
greasing substance
Groede
heat sensimeter
high speed steel ingot
hoxes
hydroxyphascolin
importer's entry of goods
incrementaltuner
industrial engineering
infiller
jerash (jarash)
Kadéï
Kirghiz Soviet Socialist Republic
laid one on
land quarantine
larrying
life characteristics questionnaire
lifeblogging
liquid power
maximum current interrupting rating
metabolic acidosis
motor with separate excitation
moving-conductor electromagnetic seismograph
non-pored timber
non-sustained
norweb
olecranon processes
Panslavic
phenacite
pixmaps
plantspersons
postorder with degrees
prepare the ground for sth
Programming software
protection and indemnity risks
radio isotope technique
rhachidian
Sanwa Bank
savings account trusts
shitheap
short-term note
south-easterlies
spice islandss
subrings
synpolydactyly
system initiation
tandem capacitor
three-forms
Titus Maccius Plautus
tornly
tyuratam (baykonyr)
undunerine
unleueful
upsilon component
valve timing gear
Verulam
web development
zelenko