x*****o
发帖数: 2505 | 1 去沙滩要先放气，这是常识嘛。
贴一片Foreser 车主的文章：
http://www.naturephotographers.net/articles0000/je0607-1.html
On the Beach in a Forester
Text and photography copyright © Jim Erhardt. All rights reserved.
Note - the thumbnails below are links to larger images.
No doubt, Subaru vehicles offer tremendous versatility and their AWD systems
remain among the best available today. It should therefore come as no
surprise that when properly equipped and driven, many Subaru models handle
deep, soft sand quite compe... 阅读全帖 |
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f****l
发帖数: 5514 | 2 不适合的，原因有二：1）kids板对成年男性来说会太软的 2)97mm也已经属于mid-fat
和fat之间了，这种宽度的板买超短的有一种脱裤子放屁的意思, 宽板牺牲了灵活性，
增加了表面积, 提高了floatation, 但是太短的话floatation反而降低了 |
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s*****c
发帖数: 753 | 3
That is totally wrong.
During acceleration, when the 相对静止 condition are reached. The air pressure
at the rear of the car would be greater than the front. That is why the air in
the car is acceleration with the car. The floatation force is due to the
pressure difference. Therefore, the ballon will float forward, just like it
want to flow upward. This floatation force will be greater than the mass of
the air the ballon replaces times the acceleration. But you only need the mass
of the H2 the ball |
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q****5
发帖数: 1660 | 4 2016年4月底中国进行了第七次高超音速飞行器试验（美国一开始给起名叫WU14后来改
称DF-ZF），获得成功，中国的第六次高超音速飞行器试验是在2015年11月，两次试验
间隔只有5个月，这样频密的试验在近十年的世界军事航天史上都是罕见的。
比较有意思的是，美国的类似试验在2014年就戛然而止，美国最近的一次高超音速飞行
器试验是美国陆军在2014年8月25日进行的AHW项目发射试验，结果发动机只燃烧了4秒
就炸毁在发射架上，这是AHW的第二次发射，第一次成功了，第二次失败，而且失败的
很惨，可以说惨不忍睹。更有趣的是，全世界没有谁为此公开讥讽美国，大家都心情复
杂的看着美国的失败。笔者个人感觉，这就像一个老杂技演员在舞台上偶然失手一样，
喝倒彩显然不合适，美国是谁？哪里跌倒了就在哪里站起来，谁也不怀疑他有这个本事
。问题是，整整过了2年，美国至今还没有站起来抖落一身的灰尘。
美国类似的失败还有雄心勃勃的HTV-2试验，HTV-2是技术上远比AHW先进得多的高超音
速飞行器，这个试验要是成功，还真会将中国和俄罗斯甩几条街。因为HTV-2试验要是
成功了，美国就会直接上HTV-3，也就... 阅读全帖 |
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r*f
发帖数: 39119 | 6 perfect age, but make sure if the gym allows u to use any floatation device.
.. |
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r*f
发帖数: 39119 | 7 u型绕起来，架在腋下，可以看看youtube的录像，挺好的，小孩活动起来很自如。
我们这里游泳池只允许小孩用这个，不让用别的floatation device。 |
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r*f
发帖数: 39119 | 8
怎么不能，泡沫塑料随便弯啊，成u型架在小孩胳膊下 就非常好用呀。
你要是担心,可以在后面稍微牵着点两端. 这个给小孩很大的自由性, 我们游泳池只允许
用这个,不许用一般那些floatation device。 |
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r*f
发帖数: 39119 | 9 我家老大是两岁的时候开始用noodle的。5岁以下的小孩下水，泳池规定
大人必须得贴近随时看着的，还不让用任何充气的floatation device。 |
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r*f
发帖数: 39119 | 10 我们这里社区泳池不让floatation device，可惜了我买的神气还带遮阳篷的泳圈。。。 |
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p***e
发帖数: 1318 | 11 personal floatation device. |
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i****r
发帖数: 1797 | 12 又回头看了一下第一张demo图，这张图里面表明frong deck, floor底下和transom旁边
都是有floatation的。这个过程没显示出来。 |
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c*******r
发帖数: 13580 | 13 I haven't heard about this brand, and judging from its retail price, I am
not very confident about its quality and performance.
I own my snowshoes, but I use them only once or twice a year. I am not a
huge fan of snowshoeing. So take my advice with a grain of salt.
In general, what you need depends on what terrains you are in and what the
purpose they will serve. Tubular frames are only good for flat terrains. We
have no flat terrains that would be covered by snow in PNW so basically
tubulars ar... 阅读全帖 |
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O****e
发帖数: 3290 | 14 Rated #1 in mixed snow by Ski Magazine.
The 2012 Blizzard Bonafide is a super versatile ski. Tip & Tail Rocker,
Slight Camber Underfoot. The all new Flipcore is a revolutionary new rocker
technology. Natural spring, lightweight floatation in powder, while yet
retaining excellent stability are the immediate advantages of Blizzard's new
construction. All of this is made possible through the flipped wood core (
the ski is actually made upside down in the mold), whose downward-facing
convex side for... 阅读全帖 |
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f****l
发帖数: 5514 | 15 On a groomed trail, a good skier put MOST of his weight on either his inner
left edge or inner right edge in MOST of the time.
You can still ski by distributing your weight on both feet, but you cannot
ski very smoothly and stable in this way.
Powder ski is a little different, because you need better floatation.
Mogul ski may be also have some exeptions, but I do not know. |
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a*i
发帖数: 1652 | 16 no, the reason is that you don't have floatation |
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g*******e
发帖数: 1706 | 18 到了海里反正我们要在她身边，觉得没有这些东西反而好handle她。 当然她大一点了
要自己玩了，也许搞个floatation device. |
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s***n
发帖数: 1114 | 19 youtube上面对第二个视频的评论都很淫荡。。。
比如：
In case of an emergency,
your nuts can be used as a floatation devise. |
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s*****c
发帖数: 753 | 20
if you consider 浮力影响 can not be neglected, the light ball will land
later if you make them the same size.
You can make the heaver ball the same size as a ballon, it will still
land
first.
Actually, you have to use the same material for both ball to eliminate
the effect of the floatation force.
The force a ball experience is F=m*g-rho_medium*V*g
where medium is air or water...
If your ball is 实行, V=m/rho_ball. therefore
F=m*g-m*rho_medium/rho_ball*g
the 加速度 will be g*(1-rho_medium/rho_ball).
Of... 阅读全帖 |
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g****t
发帖数: 31659 | 21 这种情况下考虑浮力,跟考虑相对论同时性差不多吧.我看都是扯淡.
if you consider 浮力影响 can not be neglected, the light ball will land
later if you make them the same size.
You can make the heaver ball the same size as a ballon, it will still
land
first.
Actually, you have to use the same material for both ball to eliminate
the effect of the floatation force.
The force a ball experience is F=m*g-rho_medium*V*g
where medium is air or water...
If your ball is 实行, V=m/rho_ball. therefore
F=m*g-m*rho_medium/rho_ball*g
the 加速度 will ... 阅读全帖 |
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A********6
发帖数: 1 | 22 如题。在读冶金的PhD，准备下半年毕业，非常想去休斯顿工作。不知道做我们这个方
向容易在休斯顿找到工作不？在网上查了一下休斯顿地区的工作，有关Mineral
processing很多是钢铁冶金，感觉我们现在做的有色金属方向的工作岗位很少。有朋友
或者前辈了解这个方向休斯顿的就业状况吗？或者知道有公司在休斯顿从事这方面的工
作？有其他朋友告诉我也可以申请一下半导体相关的行业，因为这行业也牵涉到表面化
学处理。请问是不是可行呀？休斯顿这行业如何？希望不吝解答。在这里先谢谢大家了
。 |
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c*******e
发帖数: 814 | 23 This is not an entry level job but I thought somebody might be
interested.
It is also posted on their website:
WWW.Ecolab.com
Title: Scientist Job Description
Ecolab is a leading provider of value-driven, sustainable water and
wastewater management solutions. Ecolab delivers comprehensive
solutions to meet the unique needs of our clients. Our systems use
cutting edge technology to provide the most effective and efficient
treatment available. Make your expertise work for you at Ecolab, the
soluti... 阅读全帖 |
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