v**e
发帖数: 8422 | 1 40架生产中的波音787机翼出现裂纹
Wing cracks found on 787s in assembly
By: STEPHEN TRIMBLEWASHINGTON DCSource: Flightglobal.com11 hours ago
Roughly 40 Boeing 787s still in production may have cracks within shear ties
of a wing rib, the company says.
Boeing is inspecting aircraft that may have the condition on three assembly
lines in Everett, Washington, and North Charleston, South Carolina.
“We are addressing affected airplanes as required,” Boeing says in a
statement.
The issue is not expected to impact a pl... 阅读全帖 |
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g******o
发帖数: 4042 | 2 不可能成功降落
据纽约时报：
The investigators considered but dismissed the possibility that hijackers
landed the plane somewhere for later use in a terrorist attack, according to
a senior American official briefed on the investigation.
The data, the official said, “leads them to believe that it either ran out
of fuel or crashed right before it ran out of fuel.”
It would take a long runway to land a plane of that size, the official said.
Although the radius that the plane could have flown extends into South A... 阅读全帖 |
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m*****n
发帖数: 1513 | 3 MH370 Malaysia plane: How maths helped find an earlier crash
Statisticians helped locate an Air France plane in 2011 which was missing
for two years. Could mathematical techniques inspired by an 18th Century
Presbyterian minister be used to locate the mysterious disappearance of
Malaysia Airlines Flight MH370?
In June 2009, Air France flight 447 went missing flying from Rio de Janeiro
in Brazil to Paris, France.
Debris from the Airbus A330 was found floating on the surface of the
Atlantic five d... 阅读全帖 |
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x******g
发帖数: 33885 | 4 40万美刀可买一个town：
RAPID CITY, S.D. (AP) — A businessman looking to invest more time in his
traveling concession business is seeking a buyer for his rural, southwestern
South Dakota town — for the price of $400,000.
Lance Benson is the sole owner of Swett, an unincorporated hamlet in Bennett
County about two hours southeast of Rapid City. Benson — who bought the
town in 1998, gave it to his ex-wife in their divorce and reclaimed it in
2012 — put the town on the market last week, according he told th... 阅读全帖 |
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T**********e
发帖数: 29576 | 5 Johnson和MB一起到烙印便利店抢了一把，MB被射杀后作证他投降后被警察处决。
Key Witness In Michael Brown Shooting Has Warrant Out For Arrest
A key eyewitness in the shooting of unarmed teenager Michael Brown, whose
death set off violent protests in the St. Louis suburb of Ferguson,
reportedly has a warrant out for his arrest.
ABC17.com reported Wednesday that 22-year-old Dorian Johnson, who was with
Brown when he was shot, has a warrant out for his arrest for stealing in
Jefferson County, Missouri from 2011.
Johnson also was cha... 阅读全帖 |
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b********n
发帖数: 38600 | 6 http://www.theverge.com/2014/11/3/7149315/china-is-shooting-dow
Today, China revealed its first anti-drone laser weapon, on the heels of a
similar deployment by the US military earlier this year. According to state
media, the system can bring down a drone within five seconds of locating the
target, and is operable within a 1.2 mile radius of the installation. The
system is designed for drones flying at altitudes around 1600 feet and at
speeds of just over 100 miles per hour, putting most militar... 阅读全帖 |
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m********5
发帖数: 17667 | 7 50%的水源砷和铊超标
However, state officials tested 8 water supply wells within a one-mile
radius of some of those wells.
Four water samples came back with higher than allowable levels of nitrate,
arsenic, and thallium.
Those same chemicals are used by the oil and gas industry in the hydraulic
fracturing process and can be found in oil recovery waste-water.
http://www.nbcbayarea.com/investigations/Waste-Water-from-Oil-F |
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k*******r
发帖数: 16963 | 9 The search zone has now been extended to a 20km radius around Crepy-En-
Valois, in northern France |
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a*******g
发帖数: 1221 | 10 市长下令严禁所有city workers说坏话
http://www.nytimes.com/2015/01/22/sports/olympics/boston-releas
BOSTON — As part of the bid to host the 2024 Summer Olympics, Mayor Martin
J. Walsh has signed an agreement that prohibits employees of the city of
Boston from making negative comments about the Games or the process.
The agreement prohibits city workers from making written or verbal
statements that “reflect unfavorably upon, denigrate or disparage, or are
detrimental to the reputation” of the International Ol... 阅读全帖 |
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d***o
发帖数: 7006 | 11 不是日本
Tsunami warning in Pacific as 7.5 quake strikes near Solomon Islands
The Pacific Tsunami Warning Center issued a 300-kilometer radius tsunami
warning after a shallow 7.5-magnitude earthquake was registered some 80
kilometers off Lata, in the Solomon Islands.
The quake’s epicenter centered at the depth of 12 km, northwest of the
provincial capital of Lata, according to US Geological Survey. While there
are some 550 people living in the town near the epicenter, the preliminary
warning issued ... 阅读全帖 |
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b********n
发帖数: 38600 | 12 More troubling results from the new F-35 Lightning
http://hotair.com/archives/2015/08/15/more-troubling-results-fr
The NSS study compared all three F-35 variants to foreign fighters — Russia
’s MiG-29 and Su-27 — and found it came up short in a variety of key areas
, including acceleration, combat radius and payload. Such deficiencies would
seriously hamper the U.S. jet in a dogfight. |
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r********1
发帖数: 7345 | 13 CONROE, Texas -- A series of explosions rocked an oil field chemical supply
company north of Houston on Friday, setting off a three-alarm fire that sent
a broad, dense column of thick, black smoke towering into the otherwise
blue skies.
Authorities knew of no injuries from the explosions and blaze that erupted
about 4:30 p.m., said Conroe Fire Marshal Mike Legoudes.
Firefighters took about two hours to bring the fire under control at the
DrillChem plant on the eastern fringe of Conroe, about 40 ... 阅读全帖 |
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k**1
发帖数: 1955 | 14 Index is difficult to measure. However, if you know radius on both sides of
the lens and center thickness, you can use ZEMAX to simulate the edge
thickness of the certain size of glasses and its index of refraction. That
will be very accurate
If you have astigmatism, it will be more difficult.
A senior optical engineer.
“ high index的主要目的是看的更清楚，而不是更薄。” this is a wrong
statement, this person cannot work in that shop. |
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f*******y
发帖数: 470 | 15 看看美帝的F22，作战半径也才852公里
Maximum speed:
At altitude: Mach 2.25 (1,500 mph, 2,410 km/h) [estimated][115]
Supercruise: Mach 1.82 (1,220 mph, 1,960 km/h)[115]
Range: >1,600 nmi (1,840 mi, 2,960 km) with 2 external fuel tanks
Combat radius: 460 nmi (with 100 nmi in supercruise clean)[266][N 6] (529 mi
, 852 km)
Ferry range: 1,740 nmi (2,000 mi, 3,220 km)
Service ceiling: >65,000 ft (20,000 m)
Wing loading: 77.2 lb/ft2 (377 kg/m2)
Thrust/weight: 1.08
Maximum design g-load: +9.0/−3.0 g[115]
。 |
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n****o
发帖数: 950 | 16 不需要记得什么拉梅系数，把球分成一层层的layers, then integrate with respect
to radius r就行了。在r处layer体积4*pi*r^2*dr,乘上密度rho_0*e^(-k*r)，然后从1
到无穷积分就是了。
胱大妈应该是把e^(-k*sqrt(x^2+y^2+z^2))抄成e^(-k）*sqrt(x^2+y^2+z^2)了。傻逼
也不想想，已经有一个常数rho_0在那儿了，再乘一个e^(-k)有个毛意思。再说积分也
不收敛啊。胱大妈抄这么道本科二年级的题来考弃婴，真尼玛笑死人了。 |
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m**c
发帖数: 7349 | 18 But over the last 13.8 billion years, the Universe has been continually
expanding – and at first it did so very rapidly. Taking that into account,
astronomers have worked out that the galaxies right on the edge of the
observable Universe, whose light has taken 13.8 billion years to reach us,
must now be 46.5 billion light years away
One possibility is that, somewhere, a few of our calculations are not quite
right
That is our best measurement for the radius of the observable Universe.
Doubling it... 阅读全帖 |
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w*********g
发帖数: 30882 | 19
If your scope is limited within the top 1% group, I have to say your
sampling radius is too small. And your conclusion is meaningless to most
people |
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b***y
发帖数: 14281 | 20 Chemicals Catch Fire at Plant Flooded by Harvey
Arkema facility was flooded with six feet of water due to Tropical Storm
Harvey
Footage Shows Aftermath of Houston Chemical Plant Explosion
Aerial footage shows a Houston-area Arkema chemical plant after two
explosions were reported early Thursday following widespread flooding in the
region caused by Harvey. Photo: Associated Press
By Russell Gold, Erin Ailworth and Dan Molinski
Updated Aug. 31, 2017 11:54 a.m. ET
149 COMMENTS
CROSBY, Texas—Conta... 阅读全帖 |
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f****t
发帖数: 15913 | 21 F16低空最大速度是1。2马赫，和歼十一样，楼主是真SB
*********************************
Specifications (F-16C Block 50)[edit]
GENERAL DYNAMICS F-16 FIGHTING FALCON.svg
View of underside of F-16 during a vertical climb
Testing of the F-35 diverterless supersonic inlet on an F-16 testbed. The
original intake with Splitter plate is shown in the top image
Weapons Storage and Security System vault in raised position holding a B61
nuclear bomb, adjacent to an F-16. The vault is within a Protective Aircraft
Shelter.
Data from ... 阅读全帖 |
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l*******1
发帖数: 16217 | 22 Performance
Maximum speed: 590 km/h (319 knots, 367 mph)
Cruise speed: 520 km/h (281 knots, 323 mph)
Stall speed: 148 km/h (80 knots, 92 mph)
这飞机标准二战水平
g-limit: +7/-3.5 g)
Range: 720 nmi (827 mi, 1,330 km)
Combat radius: 550 km (300 nmi, 342 mi) (hi-lo-hi profile, 1,500 kg (3,300
lb) of external stores)[202]
Ferry range: 1,541 nmi (1,774 mi, 2,855 km) [203]
Endurance: 8hrs 24mins[203]
Service ceiling: 10,668 m (35,000 ft)
Rate of climb: 16.4 m/s (3,242 ft/min) |
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发帖数: 1 | 23 That's a 35 kg projectile, which leaves the muzzle with 115 megajoules and
arrives with 50 megajoules. I expect it'll punch through about 2 kg/cm^2 of
material when it arrives, which is about 8 meters of concrete.
https://www.quora.com/How-does-the-US-Navy-rail-gun-work-That-must-need-an-
insane-instantaneous-current-How-do-they-get-that-How-do-they-keep-it-from-
melting
貌似能量不少。
但是好像只对hard target有用。
For example, a rail gun projectile hitting a hard target like a tank or
concrete bunker will und... 阅读全帖 |
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发帖数: 1 | 24 F35B Combat radius
早期数据869千米 469 nautical miles |
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T*******x
发帖数: 8565 | 25 好。那我给你个机会，证明你自己的资格。黎曼Zeta函数在z=1.5+100i，的解析函数展
开，的radius of convergence是多少？
我看你怎么自取其辱。 |
|
发帖数: 1 | 26 你想让他免费教你？算盘打得不错
盹盹盹
[在 TheMatrix (TheMatrix) 的大作中提到：]
:好。那我给你个机会，证明你自己的资格。黎曼Zeta函数在z=1.5+100i，的解析函数
展开，的radius of convergence是多少？
:我看你怎么自取其辱。
:☆ 发自 iPhone 买买提 1.24.07 |
|
d**********i
发帖数: 524 | 27 polyester有很多种，你自己先去研究一下服装面料吧。CK做内衣的polyester肯定不是
普通的你认为的那种polyester好吧。你们土了吧唧什么都不懂就瞎喷。我实在是看不
下去，人家产品设计的人不比你懂服装材料？你实在不懂就去搜。不要纯棉纯棉的叫唤
The micro-fibre polyester (inner layer) and modal (outer
layer) bi-layer knitted fabrics have better moisture management property
because of better wetting time, high wetting radius, good absorption rate
and good spreading speed of sweat, and hence provide high level of comfort
and can be preferred for active ...
：你知道我说什么再来喷好吧？
：夏老三说给她老公买的内裤面料大部分... 阅读全帖 |
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f**********u
发帖数: 348 | 28 愚公我跟你说你真不懂一点儿化学，就别出来丢人了。
[在 dayuguanshui (大禹灌水) 的大作中提到：]
:polyester有很多种，你自己先去研究一下服装面料吧。CK做内衣的polyester肯定不
是普通的你认为的那种polyester好吧。你们土了吧唧什么都不懂就瞎喷。我实在是看不
:下去，人家产品设计的人不比你懂服装材料？你实在不懂就去搜。不要纯棉纯棉的叫唤
:The micro-fibre polyester (inner layer) and modal (
outer layer) bi-layer knitted fabrics have better moisture management
property
:because of better wetting time, high wetting radius, good absorption rate
:and good spreading speed of sweat, and hence provide high level of comfort
:and c... 阅读全帖 |
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发帖数: 1 | 29 送外卖要小费的
而且要在一定radius范围内
多数居民区都没戏 |
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发帖数: 1 | 30 radius 5 miles以内
也可以微信下单drive through
堂吃是没什么人去了
应该能活下来 |
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v**e
发帖数: 8422 | 31 华尔街时报：中国无人机技术迅速赶上世界先进水平，将争夺市场（英）
NEW YORK (MarketWatch) — China’s pilotless technology for the military is
catching up with designs from the U.S. and Israel and may soon pose a
challenge in the international marketplace, The Wall Street Journal reported
Friday.
The U.S. and Israel are currently the world’s leaders in drone technology
and unmanned aerial vehicles, or UAVs. But austerity measures in the U.S.
and among its European allies have contractors such as Northrop Grumman Corp
. (NOC 63.22,... 阅读全帖 |
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v**e
发帖数: 8422 | 33 全文照翻：澳大利亚航空专业人士对丝带图片的评论，感觉是目前为止最实在最客观的
送交者: stdlxz13 2010年12月29日
Australia Air Power on J-20
Dr Carlo Kopp
Over the last few days imagery of what is claimed to be China's new stealth
fighter has appeared on a range
of Chinese Internet sites. There have been no official disclosures as yet,
so many of the claims appearing in
the media may only be speculation presented as fact.
在过去几天里被称为是中国的新型隐身战机的图片在大批中国军事网站上出现。现在还
没有官泄，所以很多细节大家其
实都是在YY。（不过作者基本默认不是PS)
The aircraft may be a technology demonstrator ... 阅读全帖 |
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h*l
发帖数: 807 | 34 read between the lines,you can figure out what it means.
Assertion: F-22 production uses a shim line and national spreading of
suppliers has cut quality, thus the F-22 lacks interchangeable parts.
Fact: The F-22 does not have a shim line. During the earliest stages of
production while tooling was undergoing development, there were a few
aircraft with slight differences which were subsequently modified. The F-22
supplier base is the best in the industry, as demonstrated by the aircraft’
s high qu... 阅读全帖 |
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g**1
发帖数: 10330 | 35 http://www.theregister.co.uk/2011/01/20/unavailabe_gps_warning/
FAA to pilots: Expect 'unreliable or unavailable' GPS signals
Unspecified Pentagon 'tests' cited
Posted in Government, 20th January 2011 21:15 GMT
The US Federal Aviation Administration is warning pilots to expect
“unreliable or unavailable” signals from their global positioning gear
as a result unspecified tests being carried out by the Department of
Defense.
The Notice to Airmen, or NOTAM (PDF) said the GPS tests will be carried
o... 阅读全帖 |
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T****r
发帖数: 22092 | 36 U.S. Flights Over Plant Gather Crucial Data
By DAVID E. SANGER and WILLIAM J. BROAD
Published: March 17, 2011
http://www.nytimes.com/2011/03/18/world/asia/18intel.html?_r=1&
WASHINGTON — The first readings from American data-collection flights o
ver the stricken Fukushima nuclear plant in Japan show that the worst of
the contamination has not spewed beyond the 18-mile range of highest co
ncern established by Japanese authorities, but there is also no indicati
on that another day of frantic effor... 阅读全帖 |
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d********g
发帖数: 455 | 37 哈哈， 楼上都别high了。醒醒。
咒是咒不死f22的。
人家471mi （410nm）作战半径是指 310nm的亚音速巡航，加100nm的超音速巡航。 另
外流出14%的余量作战
Combat Radius (NM) Mission 1 (Sub+Super) 310+100nm 14%
梦球给的连接说的很仔细，没看明白就出来high，太露怯了。 |
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S***a
发帖数: 3956 | 38 查了一下发现枭龙居然都有1352 km的combat radius,3480 km的ferry range.真不知道
F35怎么会搞得这么短腿. |
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t*n
发帖数: 14458 | 39 发财那个八成是带了副油箱高高高神马的
查了一下发现枭龙居然都有1352 km的combat radius,3480 km的ferry range.真不知道
F35怎么会搞得这么短腿. |
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g**1
发帖数: 10330 | 40 http://indiatoday.intoday.in/story/mig-27-aircraft-crashes-in-r
MiG-27 aircraft crashes in Rajasthan's Barmer district, pilot ejects safely
A MiG-27 aircraft of the Indian Air Force crashed in Rajasthan's Barmer
district on Tuesday. Pilot Wing Commander Nishikant Singh ejected on time
and was rushed to the Jodhpur's Military Hospital where his condition was
said to be stable and out of danger.
The aircraft was on a routine sortie when it crashed near a hamlet, Allawani
- Ki- Dhani, 30 km from Ba... 阅读全帖 |
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e*c
发帖数: 395 | 41 我用的是图上的数据。wiki上F-16C combat radius只有295nm，估计是没挂副油箱。作
战半径计算弹性太大，不可能精确就是了。不管怎样，F-35“短腿”是myth同学们没有
疑问了吧。
而且，转进一下的话，要考虑到未来的增长空间哦。搞个保型油箱。或者换上崭新的第
五代发动机，立刻省油1/4，大大增程。 |
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w********r
发帖数: 14958 | 42 combat radius都是估算。 按人家作战标准估算。 各个国家标准不同，结果没有比较
意义。
只有最大航程更有意义。 |
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d**********0
发帖数: 13081 | 43 简单的查了下。。
Su-25 (Su-28) Frogfoot Close-Support Aircraft, Russia
http://www.airforce-technology.com/projects/su25/
The Su-25 can climb at the rate of 58m/s. The maximum speed of the aircraft
is 950km/h. The combat radius and ferry range of the aircraft are 375km and
7,500km respectively. The normal range of the Su-25 is 750km. The service
ceiling is 7,000m. |
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a***e
发帖数: 27968 | 44 at 1000m/s, 30sec will cover a 30km range.
the radar at most need to work for 1min.
at 30KW, that is about 500WH power needed.
the battery of your UPS running typical 8AH and 12V or near 100WH.
a typical car batter give you about 50AH and 12V, that is 600WH.
doesn't sound very difficult at all.
when air plane lost power, it use a
wind turbine to generate power needed for control.
not a really big deal.
finding a target like Carrier is not a big deal.
if Sat update the position at 200km away,
onl... 阅读全帖 |
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w***n
发帖数: 2474 | 45 Here's What Would Happen If a Nuclear Bomb Landed Near You
We all know a nuclear war would be bad, but it's kind of abstract.
Personally, I always just assumed I'd be vaporized if a nuclear bomb fell
near me. Apparently not, according to this video, which provides a
terrifying, in-depth look at just what would happen if you were close to a
nuclear ground zero. The real problem, we discover, is that "close" is a
relative term.
For instance, if the bomb dropped on a clear night, people up to 53 mi... 阅读全帖 |
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b****r
发帖数: 1395 | 46 注：本文仅适用于hockey skates和figure skates。
我极力推荐初学者使用hockey skates作为入门，不但是我个人的体会，而且是有理论
依据支持的。
几个术语：
ROH: Radius of Hollow从冰刀的截面观察，两个edge和中间的hollow实际上是一段弧
线，这段弧线所在的圆的半径就是这里所说的ROH。对于相同宽度的刀刃如果ROH越大，
那么hollow就越浅。但事实上不同的刀的宽度也是不一样的，同样的ROH越薄的刀磨出
来的hollow越浅。所以这里引出下面一个术语。
bite angle: 还是从冰刀的截面观察，以edge为切点作hollow所在的圆的切线，这条切
线与两个edge所在的直线所够成的角就要bite angle。bite angle越大hollow就越深而
ROH也就越小。
rocker: 从侧面观察冰刀，刀的两端实际上是圆弧，这里冰球刀明显而花样刀不那么明
显。这个圆弧就称为rocker。这个圆弧所在的圆的半径越小rocker就越大，就更利于转
弯。
toe picks: 就是花样刀前面的齿，在跳跃中常用。 |
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l******t
发帖数: 843 | 47 看见很多人在冰球版和奥运版问过速滑刀的问题。发现冰球大牛Baylor已经把球刀讲得
很清楚了，而速滑大牛hengmei2（在自行车版外号“很美”）又不常来冒泡。我以前滑
过十几年大道速滑，最近又玩儿了3年短道速滑，还在教我4岁的儿子，就来说说速滑刀
吧。
1、长度（length）：一般速滑刀的长度是鞋长的130%-150%，理论上越长越有利于蹬冰
，而且单位压强越小也就是越快。但是越长也就越不容易在弯道倒脚（crossover）。
近年来，专业速滑运动员的冰刀有越来越长的趋势。尤其是短道速滑，对比10年前的选
手，同一鞋号选手使用的冰刀普遍长了1-1.5英寸。比如，现在一般8号的鞋配16.5英寸
刀，我自己10.5号的鞋配17.5寸或18寸刀。
2、宽度(width)：有几张速滑运动员拿冰刀切面包的图片，其实很误导，让很多人以为
速滑刀跟菜刀一样。标准比赛用短道速滑刀是1.1mm，比如最常见的Maple系列的Gold、
Duro、MadDog，和Bont系列的Platinum K190刀。有些体重较轻的女运动员（比如我国
和韩国的很多女选手）常定做1.05毫米的刀，而一些体重较大的加拿... 阅读全帖 |
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l****z
发帖数: 29846 | 48 【 以下文字转载自 GunsAndGears 讨论区 】
发信人: happyfrog (happyfrog), 信区: GunsAndGears
标 题: 我与刀枪----那个男银不爱枪
发信站: BBS 未名空间站 (Sun Oct 13 12:25:16 2013, 美东)
我的经历估计跟大多数版上的兄弟差不多，对枪的迷恋从男孩时代就开始了。
那个男银不爱枪。 小学三年级时，同班同学拿了一把逼真的古铜色的左轮玩具枪，那
真叫大伙眼馋死了。我家里条件不好，自己一向很节省，高中前平时没有划过零用钱的
。可那次，第一次动了心。我偷偷的把春节一位 亲戚给的压岁钱留了10元，去地摊买
了那把一样的枪。可真正拿到手以后，心里感到不都是快乐，更多的是自责。当然家里
马上就发现了，后来找去那小贩想退未果，肉痛啊，那时候可是八十年代，10元钱钢钢
的。小孩子不懂事啊。
来美国以后，比较轻松的博士生前两年，让我有机会第一次enojy my life. 喜欢上了
玩counter strike。
经常做完实验回来，会沉浸于其中一两个小时。先是和自己几个哥们相互厮杀，后来到
网上试试。虽然自己技术很次... 阅读全帖 |
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T*********I
发帖数: 10729 | 49 An 84-year-old man was thrown to the ground and cuffed by cops Sunday after
allegedly jaywalking on the Upper West Side, a witness said.
Kang Chun Wong, 84, needed to be hospitalized for a head wound after police
knocked him to the ground when he tried to walk away as they ticketed him,
witnesses and the man’s son said.
“Beating up an 84-year-old man for jaywalking?” said the outraged son, who
did not give his name. “It’s just unbelievable.
An eyewitness said cops tried to give Wong a summons at... 阅读全帖 |
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l****z
发帖数: 29846 | 50 World's First Robot-Run Lettuce Farm to Produce 30,000 Heads Daily; Tipping
Point for Workerless Agriculture
updated on Fri Jan 29, 2016 07:20
Future of Farming
The future of farming has arrived. It's vertical, soilless, and run by
robots.
Tech Insider reports World's First Robot-run farm will harvest 30,000 heads
of lettuce daily.
The Japanese lettuce production company Spread believes the farmers of
the future will be robots.
So much so that Spread is creating the world's first farm m... 阅读全帖 |
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