topics

全部话题 - 话题: modulus
1 2 3 末页 (共3页)
a***n
发帖数: 3633
1
来自主题: Mathematics版 - Modulus of continuity的运算法则
如果知道了一个函数的Modulus of continuity或者其他信息,有没有
什么运算法则可以得到该函数的复杂组合的Modulus of continuity?
比如说如果知道了函数f(t,p)的一些情况,那么能否通过一些法则或者
关系直接知道函数J(p)=\int{Abs[f(t,p)]dt}的Modulus of continuity,
而不需计算那个绝对积分?谢谢!
b****g
发帖数: 54
2
来自主题: Macromolecules版 - 如何计算Young's Modulus ?
做了一个压缩试验,得到了一个curve
怎么用这个curve来计算Young's Modulus?
样品是一个Cubic 的polymer, 尺寸已纪录
多谢指点 :)
c*****y
发帖数: 6
3
为什么温度升高,elastic modulus 减小?
c*****y
发帖数: 6
4
如果软了,已经是plastic region了,没有elastic modulus 的概念了吧?
c*****y
发帖数: 6
5
如果软了,已经是plastic region了,没有elastic modulus 的概念了吧?
c*****y
发帖数: 6
6
Thanks!
I have two further questions to trouble you.
(1) Why young's modulus is proportional to d2E/dr2 at r=req?
(2) Why at T2, the binding potential should be like the red curve?
F****y
发帖数: 145
7
(1) Why young's modulus is proportional to d2E/dr2 at r=req?
Consider a spring,
F=kx;
The potential energy E=1/2Kx^2;
K=d^2E/dx^2
(2) Why at T2, the binding potential should be like the red curve?
Generally,
Total energy = potential energy + kinetical energy
Kinetical energy = KT
T increasing results in the increase of kinetical energy and the decrease of
potential energy if total energy is conservation.
m******h
发帖数: 5753
8
来自主题: Fishing版 - 谈谈鱼竿的选择
IM6, IM7 and IM8 是 Hexcel Corp. 用以比较他们公司的碳素产品标准,不是一个行
业标准,用他们生产的碳素做碳素竿自然标为IM6, IM7 and IM8 powered。 IM指越高
,碳素含量越高,竿子的弹性越强,硬度越大,也越脆。至于是否 IM 越高越好,同样
争论,而且碳素不只他一家, 其他方法同样生产出好竿子。IM 值和T值关系我没有注
意,后者这个概念在国内用的更多, 不过一般中高挡鱼竿采用 IM6-8的碳素,同样标
志是好竿的意思。
GLX - 65 million modulus
IMX - 55 million modulus
GL3 - 47 million modulus (IM8)
GL2 - 42 million modulus (IM7)
IM6 = 40 million
IM7 = 41 million
IM8 = 45 million
Standard Graphite - 33 million modulus
h**z
发帖数: 9751
9
牛鼻,猫猫说,假定young's modulus相同情况下,屈服强度低的先塑性形变,所以金
属形变和young's modulus无关。猫猫还说,因为你不知道大本和丰田的钢材的young's
modulus具体多少,所以他们的形变和young's modulus无关。
w********h
发帖数: 12367
10
来自主题: Macromolecules版 - question about mechanical properties.
(1) Compression modulus is different from tensile modulus for sure.
(2) You need to consider many parameters: modulus, strain and stress.
check your Experiments for Polymer Science edited by Ou Guorong.
There is one experiment for that, very detailed.
stiffness is judged by modulus;
toughness is judged by strain;
strength is judged by stress.


own
h********g
发帖数: 5
11
Guangfeng Zhao, Ming Liu and Fuqian Yang, The effect of an electric current
on the nanoindentation behavior of tin, Acta Materialia 60 (2012) 3773-3782
Abstract
Electrical–thermal–mechanical interactions determine the reliability and
performance of microelectromechanical devices and systems.
Using the nanoindentation technique the effect of an electric current
on the indentation deformation of Sn strips was studied for an
indentation load in the range 50–200 lN. During the indentation an e... 阅读全帖
B*******e
发帖数: 691
12
来自主题: Computation版 - Urgent question about ADINA!!! Thanks!!!
go to simwe.com , there is a board for ADINA, could you input Young's Modulus f
each element or area? What you mean rondom Young's Modulus? WHat kind
of problem has random Young's Modulus?
G*H
发帖数: 624
13
来自主题: Mathematics版 - TAO对张的另外一个结果泼了点冷水
例外零点 不是 指不在s=1/2线上的零点.
Every Dirichlet L-function is associated with a Dirichlet character and, in
particular, the Riemann zeta-function is the Dirichlet L-function of modulus
1. So the Riemann function is a special L-function, and the Riemann
Hypothesis (RH) is a special case of the Generalized Riemann Hypothesis (GRH
). While GRH claims all non-trivial zeros of a L-function lie on the line Re
(s)=1/2, what people can prove now is the existence of some very small
regions close to Re(s)=1 free o... 阅读全帖
s*x
发帖数: 8041
14
来自主题: Military版 - 很久很久以前那个古老的年代
前言
很久很久以前那个古老的年代,从罗光男的光南集团开始,台湾其实已经建立起碳纤维
复合材料王国的优势了。打不死的中小企业、天下无敌的模具设计能力、吓死人能够山
寨的机械装备和制造厂商、在再加上台塑还他妈的竟然可以生产碳纤维这种高级货,这
根本简直就是为碳纤维复合材料量身打造的基础啊。
所以后来光南集团倒闭后(倒闭八卦很多,三天三夜也说不完),培养出来的工程师四
散八方,就有如把整篮的种子洒向了肥沃的土壤,创业成功的例子比比皆是,更是造成
了台湾复合材料工业百花齐放的盛况。从碳纤球拍、碳纤钓竿、碳纤高尔夫球杆到今天
的高级碳纤维自行车。这些可都是货真价实的创造台湾经济奇迹的幕后无名英雄啊。当
然了,他们钱也没少赚。
从某方面讲,复合材料很适合台湾中小企业的发展。设备简单,进入门槛低,加上一开
始说的台湾整体产业环境相当优良,因此台湾的复合材料厂商实在是数不胜数啊。
说了这么多无聊的话是不是想被人炮轰?不过复合材料这种东西制备工艺千万种,碳纤
维跟树脂的搭配更是千奇百怪,这一领域绝对是易懂难精。台湾复合材料公司又这么多
,每家公司都还有自己的一套理论,想要自以为是的介绍复合材料领域,难免... 阅读全帖
C******d
发帖数: 20
15
看了各位在“高速遭遇重大车祸。。。”一文中的关于材料和结构的讨论,忍不住来说
几句。
大家的讨论中提到了这样几个术语:
Stiffness,材料的刚度,或材料弹性变形模量(Elastic Modulus)
Toughness,材料的韧性,材料对裂纹扩展抵抗能力
Yield strength,材料的强度,或材料开始发生塑性变形的强度
Buckling,失稳,这是一个结构的性能,是指一个结构(尤其是细长的状和柱状的结构
)在发生塑性变形(yielding)之前发生弹性大变形。
Buckling 又可分宏观失稳和局部失稳(也即ceecheck提到的local buckling)。
如ceecheck提到的“弹性模量(Elastic Modulus)对于一般的金属都是相同”--正确
,然而只是对钢材而言,铝合金的弹性模量大约只有钢的1/3(当然铝的质量也大约只
有钢的1/3)。
renxiaoyao贴中提到“同一结构,在受到同样大小力变形大小用stiffness来衡量。回
到你的问题,toughness高的材料是延展性好的塑性材料。在设计一样的情况下,强度
越高的材料stiffness越高,也
h******7
发帖数: 980
16
来自主题: Automobile版 - 大家看这个想法可行吗?
3000kg的车,在45°的斜坡上,如果用不锈钢做小细轴,shear modulus=79.3Gpa(参考
wiki,
shear modulus中的表格),如果截面是正方形,细轴长20cm,正方形的边长只要6cm就
可以保证不会
断掉,边长8.5cm就可以在其余条件相同的情况下支撑6000kg的车,所以在上下坡上应
该没有问题。
进出curb的速度不会太快,所以动力就可以很大,一般的curb方向的倾斜应该也还好。
下雪是个大问题,要好好考虑考虑。
h**z
发帖数: 9751
17
牛鼻,非力猫说假定Young's modulus一样的情况下,谁屈服强度低谁先塑性形变,所
以继续肯定前面说的Young's modulus和形变没有关系。你就别死撑了,都joke了。
x*******6
发帖数: 994
18
来自主题: Faculty版 - 审稿转让
I have an article about the electric modulus and mechanism analysis on an
electric ceramic. You should be an expert in the area of AC conductivity,
electric modulus analysis, and electrical conduction mechanism of electrical
ceramic. You should have deep knowledge in XRD, Impedance analysis in
electrical conductivity, dielectric properties and relaxation behavior of
electric materials, AC conduction experience model like barrier hopping
model (CBH). I prefer to recommend you if you have the rela... 阅读全帖
C********7
发帖数: 1035
19
来自主题: Immigration版 - 审稿机会(高分子化学)
关键词:Stimuli-responsive, Thixotropic Hydrogel of Melamine, Zn(II)
orotate complex, Gel-Nano Composite,Multiwalled Carbon Nanotube, FTIR,
TEM, AFM, WAXS,storage modulus (G'), loss modulus (G'')
RSC的新刊物,还没有IF
Send me your name, email, list of publications。
你最好有高分子和化学的背景,有PhD的优先考虑。
M**c
发帖数: 19
20
来自主题: Cycling版 - 高手帮忙看看这款FUJI怎么样?
Thanks! I have copied the spec below.
Is this a price worth to buy?
Bottom Bracket:Press-fit BB86 sealed bearing
Brakes: Shimano 105
Cassette: Shimano Tiagra, 12-30T, 10-speed
Chain: KMC X10, 10-speed
Crankset: Oval 730 forged alloy, 50/34T
Fork: FC-440 carbon monocoque w/ tapered carbon steerer & carbon dropout
Frame: C5 high-modulus carbon, integrated head tube w/ 1 1/2" lower,
internal cable routing, oversized PIIS BB86 shell, double water bottle
mounts, C5 high-modulus carbon thin seatstays... 阅读全帖
f*****x
发帖数: 137
21
ATOLL a high-modulus graphite blend = L-tech salt blank;
Theorum = high-modulus graphite blank = LSI。。。
O*******d
发帖数: 20343
22
铜和阳极铝根本不在考虑之列。
Despite the great numbers of metals and alloys known to man, remarkably few
warrant even preliminary consideration for uses as implant materials. The
relatively corrosive environment combined with the poor tolerance of the
body to even minute concentrations of most metallic corrosion products
eliminates from discussion most metallic materials. Of the possible metallic
candidates, tantalum and the noble metals do not have suitable mechanical
properties for the construction of most ... 阅读全帖
l**********1
发帖数: 5204
23
来自主题: Biology版 - 不再发送摘要,请多包涵!
Btw, after CNS resubmit then Move On
have you try to submit your draft to PHYSICAL REVIEW E
likes him: Eric Cytrynbaum of UBC
//www.math.ubc.ca/~cytryn/index.shtml
his paper:
Estimating the bending modulus of a FtsZ bacterial-division protein filament. (2012)
//www.math.ubc.ca/~cytryn/research/publications.shtml
pdf file link is here:
//www.pubup.org/story.php?title=estimating-the-bending-modulus-of-a-ftsz-
bacterial-division-protein-
filament
ps:
FAQ
why You removed your original post at 0 f... 阅读全帖
A******n
发帖数: 34
24
来自主题: Computation版 - Abaqus material question?
Hi, there. I am simulating a soil layer and its modulus is changing linearly
with its depth. The deeper the soil, the higher the modulus.
From the Manual, I found I can use
*MATERIAL
*ELASTIC, DEPENDENCIES=1
E1, V1, 1.
E2, v2, 2.
The problem is that how can I relate the E1 to the top layer and E2 to the
bottom layer.
Thanks!
c*******d
发帖数: 1197
25
【 以下文字转载自 NanoST 讨论区 】
发信人: colinliud (hed), 信区: NanoST
标 题: 有没有做nanoindentation实验,测杨氏模量的
发信站: BBS 未名空间站 (Thu Jan 28 18:27:20 2010, 美东)
用的是MTS nano xp,测得的杨氏模量我直接用作sample的模量值;
但是看到paper中(oliver and pharr方法衍生的一系列方法),都是讲从unloading
curve来获取数据,计算模量,里面用的是reduced modulus,
想问一下这个reduced modulus就是indentation测得的值吗?(如果忽略indenter的影
响)。
简单点说,就是通过indentation测出数据就可以当初sample的杨氏模量吗? 还是要把
从unloading curve中获取的数据再通过 oliver and pharr提出的方程 计算后再获得?
可能说的有点语无伦次,但是我想做过indentation的高手应该能看清楚吧,呵呵!
x*******6
发帖数: 994
26
来自主题: Engineering版 - 审稿转让
I have an article about the electric modulus and mechanism analysis on an
electric ceramic. You should be an expert in the area of AC conductivity,
electric modulus analysis, and electrical conduction mechanism of electrical
ceramic. You should have deep knowledge in XRD, Impedance analysis in
electrical conductivity, dielectric properties and relaxation behavior of
electric materials, AC conduction experience model like barrier hopping
model (CBH). I prefer to recommend you if you have the rela... 阅读全帖
x*******6
发帖数: 994
27
来自主题: Engineering版 - 审稿转让
I have an article about the electric modulus and mechanism analysis on an
electric ceramic. You should be an expert in the area of AC conductivity,
electric modulus analysis, and electrical conduction mechanism of electrical
ceramic. You should have deep knowledge in XRD, Impedance analysis in
electrical conductivity, dielectric properties and relaxation behavior of
electric materials, AC conduction experience model like barrier hopping
model (CBH). I prefer to recommend you if you have the rela... 阅读全帖

发帖数: 1
28
来自主题: Engineering版 - 审稿转让
你好。我可以接这个文章。

:I have an article about the electric modulus and mechanism analysis on an
:electric ceramic. You should be an expert in the area of AC conductivity,
:electric modulus analysis, and electrical conduction mechanism of
electrical ceramic. You should have deep knowledge in XRD, Impedance
analysis in
:electrical conductivity, dielectric properties and relaxation behavior of
:electric materials, AC conduction experience model like barrier hopping
:model (CBH). I prefer to recommend you ... 阅读全帖
x*******6
发帖数: 994
29
来自主题: Engineering版 - 审稿转让
I have an article about the electric modulus and mechanism analysis on an
electric ceramic. You should be an expert in the area of AC conductivity,
electric modulus analysis, and electrical conduction mechanism of electrical
ceramic. You should have deep knowledge in XRD, Impedance analysis in
electrical conductivity, dielectric properties and relaxation behavior of
electric materials, AC conduction experience model like barrier hopping
model (CBH). I prefer to recommend you if you have the rela... 阅读全帖
s****e
发帖数: 2934
30
来自主题: Macromolecules版 - 请教一个关于制polymer film的问题
如果测大的样品就用模子压那种两头宽中间细的样条,直接用杨氏模量的仪器拉断样条。如果是小的样品就用spincoating。总之膜的厚度要均匀。可以用SAWS和nanoindentation的方法来测。SAWS
可以测薄的样品,薄到150nm,要测膜的厚度和密度。nanoindentation测厚一点的样品,可以到1um。还有一个叫fracture energy的Gc,这个参数加上stress modulus和young's modulus就
可以表征薄膜的机械性能了。
hardness有好几种,其中一种是用diamond在材料上划一道口子,看口子的深浅,还有一种是Indentation hardness,顾名思义就是压一个口子。这2种都是对于bulk的样品来说的。
所以那种随便用溶剂浇一个膜的俺木有听说过,不是很清楚。
c******h
发帖数: 4573
31
来自主题: Macromolecules版 - 请教一个关于制polymer film的问题
我知道那种dogbone样条
我们做杨氏都是普通cast film然后再用模子把膜切成dogbone形状
所以我看你说做杨氏模量不能用在玻璃板上cast的film想问问应该怎么制备膜

条。如果是小的样品就用spincoating。总之膜的厚度要均匀。可以用SAWS和
nanoindentation的方法来测。SAWS
品,可以到1um。还有一个叫fracture energy的Gc,这个参数加上stress modulus和
young's modulus就
有一种是Indentation hardness,顾名思义就是压一个口子。这2种都是对于bulk的样
品来说的。
w********h
发帖数: 12367
32
固含量 or gel fraction is not crosslinking density.
normally people use shear modulus (G) or tensile modulus to deduce Mc
between two neighboring crosslinks via Mc=rouRT/G.
B********e
发帖数: 10014
33

I might say, Zhang could call his paper "A new bound for an
incomplete Kloosterman sum to composite moduli, and bounded prime gaps".
Kowalski noted (and was kinda surprised) the "higher" Kloostermania such as
Kuznetsov trace formula and sums of Kloosterman sums did not appear (as in
BFI). To state the "philosophy" of Zhang's new element in one (long)
sentence: When you Weyl shift a suitable incomplete Kloosterman sum to a
composite modulus by multiples of a (small) factor of said... 阅读全帖
k*****a
发帖数: 1518
34
the reason is:
these modulus are not independent from one another.
you dont have to input so many modulus. you input caused the confilction
of different material properties, so comes the problem.
g****n
发帖数: 1786
35
来自主题: ME版 - 外行问问题
测试材料的机械性质,用3-point bending test,测出来bending modulus和transverse
rupture strength,这两个和flexural modulus, flexural strength有什么关系?谢谢
c*******d
发帖数: 1197
36
用的是MTS nano xp,测得的杨氏模量我直接用作sample的模量值;
但是看到paper中(oliver and pharr方法衍生的一系列方法),都是讲从unloading
curve来获取数据,计算模量,里面用的是reduced modulus,
想问一下这个reduced modulus就是indentation测得的值吗?(如果忽略indenter的影
响)。
简单点说,就是通过indentation测出数据就可以当初sample的杨氏模量吗? 还是要把
从unloading curve中获取的数据再通过 oliver and pharr提出的方程 计算后再获得?
可能说的有点语无伦次,但是我想做过indentation的高手应该能看清楚吧,呵呵!
a********0
发帖数: 34
37
Conceptually, viscosity and internal friction is the same thing. But you can
measure it by different means, resulting in different quantities and units.
Viscosity is a measure of stress at a certain strain rate. Glass's viscosity
may be very high but because it can still flow its viscosity is still
finite. You can directly measure viscosity based on its definition.
I don't know much about "phonon lifetime" but I guess you are talking about
some mechanical relaxation test, probably using acoustic... 阅读全帖
s*****c
发帖数: 753
38
来自主题: Science版 - 让我头痛死了的问题
You don't know the variable, you don't know the relationship. Only input and
output. Sounds like impossible.
Suppose the actual relation is y=ax+bx+cx+dx, where x is the input, and
a,b,c,d are your unknown parameter.
Then you can only get (a+b+c+d), the sum of the parameters. There is no way
you can get each parameter.
Suppose the relation is y=a+bx+cx^2+dx^3, you could solve a, b, c, d from
fitting. Now how do you know which is which. Is a the young's modulus or b
the young's modulus?
Hehe,
f********m
发帖数: 8397
39
【 以下文字转载自 Automobile 讨论区 】
发信人: Claypond (Claypond), 信区: Automobile
标 题: “高速遭遇重大车祸。。。”讨论:倒第什么才是安全的车
发信站: BBS 未名空间站 (Sat Nov 18 23:47:49 2006)
看了各位在“高速遭遇重大车祸。。。”一文中的关于材料和结构的讨论,忍不住来说
几句。
大家的讨论中提到了这样几个术语:
Stiffness,材料的刚度,或材料弹性变形模量(Elastic Modulus)
Toughness,材料的韧性,材料对裂纹扩展抵抗能力
Yield strength,材料的强度,或材料开始发生塑性变形的强度
Buckling,失稳,这是一个结构的性能,是指一个结构(尤其是细长的状和柱状的结构
)在发生塑性变形(yielding)之前发生弹性大变形。
Buckling 又可分宏观失稳和局部失稳(也即ceecheck提到的local buckling)。
如ceecheck提到的“弹性模量(Elastic Modulus)对于一般的金属都是相同”--正确
,然而只是对钢材而言,铝合金的
p*********e
发帖数: 32207
40
☆─────────────────────────────────────☆
weatherx (贫农--砖头党,金牌小密探) 于 (Wed Jul 15 13:36:00 2009, 美东) 提到:
我日。
http://www.autoblog.com/2009/07/15/video-tata-nano-gets-its-cra
☆─────────────────────────────────────☆
fatboyslim (fatboyslim) 于 (Wed Jul 15 13:41:11 2009, 美东) 提到:
我没根据,胡猜的。
nano是自己设计的,整体上考虑了安全性。
landwind的原型isuzu的那个能在美国卖,安全性应该也不差,但是江铃拿掉了很多东
西,或者材料上以次充好,结果车身强度大为降低。
是不是因为nano车本身轻crash test也很站便宜。
帝国主义亡我之心不死,crash test作弊!哈哈
☆─────────────────────────────────────☆
weatherx (贫农--砖头党,... 阅读全帖
T*******x
发帖数: 8565
41
来自主题: Military版 - 向黎曼猜想发起总攻
研究了一下Gamma函数的integrand,x^n/e^x,
如图橙黄色曲线是n=6。能看出一些性质。
首先最高点在x=6。这个时候被积函数是n^n/e^n,这是Stirling formula,结果~n!。
其次,积分的主要部分就是曲线下面积,尾部到无穷远基本可以忽略。
如果把曲线近似看作一个三角形的话,高和底都和Stirling formula给出的值有关,是
三角形的面积近似等于n!。
再考虑z=n+bi也就是z有虚部的情况,
x^(bi)=e^(ib ln(x)),也就是只提供相位,对modulus无贡献。b ln(x)随x不均匀变化
,所以考虑一个x=e^y的变换。蓝色曲线就是变换后的函数。横坐标方向压缩了。
考虑b越来越大的情况,也就是相位变化,一圈一圈的越来越快。形象的看就是x方向拧
螺旋,拧的圈数越来越多,螺旋越来越密。对于任意固定的n,b越大积分越小,因为相
位的变化,都相互抵消了。所以不管实部是多少,沿着虚部向无穷远处走,Gamma函数
都趋于0。
Alpha函数,也就是把被积函数分母替换为e^x-1。这个被积函数画个图可以看出和
Gamma函数的被积函数基本重合... 阅读全帖

发帖数: 1
42
来自主题: Military版 - 向黎曼猜想发起总攻
高点在x=7处严格发散
盹盹盹
[在 TheMatrix (TheMatrix) 的大作中提到:]
:研究了一下Gamma函数的integrand,x^n/e^x,
:如图橙黄色曲线是n=6。能看出一些性质。
:首先最高点在x=6。这个时候被积函数是n^n/e^n,这是Stirling formula,结果~n!。
:其次,积分的主要部分就是曲线下面积,尾部到无穷远基本可以忽略。
:如果把曲线近似看作一个三角形的话,高和底都和Stirling formula给出的值有关,
是三角形的面积近似等于n!。
:再考虑z=n+bi也就是z有虚部的情况,
:x^(bi)=e^(ib ln(x)),也就是只提供相位,对modulus无贡献。b ln(x)随x不均匀变
化,所以考虑一个x=e^y的变换。蓝色曲线就是变换后的函数。横坐标方向压缩了。
:考虑b越来越大的情况,也就是相位变化,一圈一圈的越来越快。形象的看就是x方向
拧螺旋,拧的圈数越来越多,螺旋越来越密。对于任意固定的n,b越大积分越小,因为
相位的变化,都相互抵消了。所以不管实部是多少,沿着虚部向无穷远处走,Gamma函数
:都趋于0... 阅读全帖
A***n
发帖数: 8859
43
来自主题: Automobile版 - TDI召回:High Pressure Fuel Line leak
我跟您说,自以为是的人太多了。压强和Young's Modulus, yielding strength都分不
清就可以发表高见。笑话见得太多了,这么好笑真的很少。
h**z
发帖数: 9751
44
felixcat这回子牛逼起来俄,忘了半个月前被打脸打得不能自理还苦苦死撑。young's
modulus搞明白了么?哥这边搞有限元的,轻劝你卖弄前小心点哦/
h**z
发帖数: 9751
45
来自主题: Automobile版 - 现款奔驰C class太不人性化了
young's modulus是猫猫心中永远的痛
c*********5
发帖数: 5813
46
来自主题: ebiz版 - 问一个很弱的comsol问题
直接有modulus你定义一下磁场就行了
A********e
发帖数: 354
47
【 以下文字转载自 Biology 讨论区 】
发信人: albertsmwk (.)(.), 信区: Biology
标 题: 第一批“青年千人计划”生物类@publication列表@
发信站: BBS 未名空间站 (Thu Aug 18 15:04:16 2011, 美东)
花了一个小时,深深的鄙视一下自己的无聊行径!!
125 蔡亮 男 1980年11月 复旦大学 生命
科学 2007年12月毕业于[美国]北卡大学 [美国]加州大学旧金山分校 博士后
Cai L, Mostov K. Polarity is destiny. Cell. 2009 Nov 13;139(4):660-2. PubMed
PMID: 19914162; PubMed Central PMCID: PMC2900917.
Cai L, Makhov AM, Schafer DA, Bear JE. Coronin 1B antagonizes cortactin and
remodels Arp2/3-containing actin branche... 阅读全帖
a**********k
发帖数: 1953
48
来自主题: JobHunting版 - an algorithm question
A pseudorandom number generator is a way of generating a large quantity of
random-looking numbers, if
all we have is a little bit of randomness (known as the seed). One simple
scheme is the linear congruential
generator, where we pick some modulus m, some constants a, b, and a seed x0
, and then generate the
sequence of outputs x0 , x1 , x2 , x3 , . . . according to the following
equation:
xt+1 = mod (axt + b, m)
(Notice that 0 ≤ xt < m holds for every t.)
You’ve discovered that a popular web si
i**********e
发帖数: 1145
49
来自主题: JobHunting版 - 去某刚上市公司面试被赶出来了。
你那题分行打印是 text justification(我猜的,错了请纠正). 用一个 vector of
tokens 暂时储存,然后尽量塞尽可能多的字进 vector. 过后就是计算字与字之间的空
格多少个。就是用 division 算字之间的空格最少多少个。然后 modulus 计算 extra
space 多少个。
也就是说处理了一行,再打印出来一行。
还有要注意一些 edge cases,包括一行只能填下一个字怎么办?这时候只能 left/
right justify。
这题思路不难,但是写起程序要考虑周全还是挺有难度的,主要考你基本功。
尽快 move on 吧,还有很多好的公司等着你。

on, in respectful of your time and our time”
直接问,我们问你technical的问题。
这个在对方提示下写的差不多了。
b***r
发帖数: 4186
50
来自主题: JobHunting版 - 去某刚上市公司面试被赶出来了。
为什么用modulus算?
直接减一下不行么?
天哪,我这么菜鸟啊

of
extra
1 2 3 末页 (共3页)