各向异性

Multi tool use
WMAP所測得宇宙微波背景辐射下之(极小的)非均向性
非均向性(anisotropy),或作各向異性,與各向同性相反,指物体的全部或部分物理、化学等性质随方向的不同而有所变化的特性,例如石墨单晶的电导率在不同方向的差異可达数千倍,又如天文學上,宇宙微波背景輻射亦擁有些微的非均向性。許多的物理量都具有非均向性,如弹性模量、电导率、在酸中的溶解速度等。
不同領域的運用
物理學
各向异性可分为
地質學
在地球物理的研究領域常常使用的是地震波的非均向性,意指地震波在不同方向傳遞的波速不同。造成此現象的原因是岩石的組成礦物本身就是不具有均向性的(實際上,唯一具有均向性的晶系為等軸晶系),而且大部分的造岩礦物都具有此現象,例如石英、長石、橄欖石。當地震波傳遞經過此種晶體時,會造成垂直方向振動的波與水平方向振動的波波速不同,當地震波抵達測站後,測站會量到兩個不同方向振動的波抵達之時間差。藉由量測時間差(Splitting Time),就可以推知地球內部礦物的分佈情況。
另外在礦藏探勘中,也常用到利用每個岩層之間,電阻率的非均向性(例如平行岩層走向與垂直岩層走向所量到的電阻率不一樣)來建構地底的結構,進而探知礦藏或油氣的分佈。
材料科學
木材、竹子等都具有各向异性的特点。
晶体的各向异性:同一晶体的不同方向上具有不同的性能
參考文獻
规范控制 | - AAT: 300221183
- GND: 4002073-3
|
---|
|
AL5Y2vo7rZiSja4Qhwc9L0kZN GQaesqUWw yWTwPhF2oR4NjaM,Vq3tf,pbqICi7zyVx27Swc,UvwZtcSZU8v1AM
Popular posts from this blog
Ramiro Burr's New Blog - to go back: www.ramiroburr.com From Latin rock to reggaeton, boleros to blues,Tex-Mex to Tejano, conjunto to corridos and beyond, Ramiro Burr has it covered. If you have a new CD release, a trivia question or are looking for tour info, post a message here or e-mail Ramiro directly at: musicreporter@gmail.com Top Tejano songwriter Luis Silva dead of heart attack at 64 By Ramiro Burr on October 23, 2008 8:40 AM | Permalink | Comments (12) | TrackBacks (0) UPDATE: Luis Silva Funeral Service details released Visitation 4-9 p.m. Saturday, Rosary service 6 p.m. Saturday at Porter Loring, 1101 McCullough Ave Funeral Service 10:30 a.m. Monday St. Anthony De Padua Catholic Church, Burial Service at Chapel Hills, 7735 Gibbs Sprawl Road. Porter Loring (210) 227-8221 Related New Flash: Irma Laura Lopez: long time record promoter killed in accident NewsFlash: 9:02 a.m. (New comments below) Luis Silva , one of the most well-known ...
1 I having trouble getting my ResourceDictionary.MergedDictionaries to load from app.xaml. My WPF app has a static class with a Main defined and startup object set to it. Within Main I created an instance of App and run it. The override OnStartup fires and the mainwindow.cs InitializeComponent gives the error "Message "Cannot find resource named 'MaterialDesignFloatingActionMiniAccentButton'. If I put the resources in the mainwindow.xaml everything is fine, but I wanted them to load at the app level so I they are not in each page. Any help appreciated. public partial class App protected override void OnStartup(StartupEventArgs e) base.OnStartup(e); var app = new MainWindow(); var context = new MainWindowViewModel(); app.DataContext = context; app.Show(); from the Main.. var app = new App(); app.Run(); app.xaml.. <Application x:Class="GS.Server.App" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:...
up vote 2 down vote favorite There is a clear pattern that show for two separate subsets (set of columns); If one value is missing in a column, values of other columns in the same subset are missing for any row. Here is a visualization of missing data My tries up until now, I used ycimpute library to learn from other values, and applied Iterforest. I noted, score of Logistic regression is so weak (0.6) and thought Iterforest might not learn enough or anyway, except from outer subset which might not be enough? for example the subset with 11 columns might learn from the other columns but not from within it's members, and the same goes for the subset with four columns. This bar plot show better quantity of missings So of course, dealing with missings is better than dropping rows because It would affect my prediction which does contain the same missings quantity relatively. Any better way to deal with these ? [EDIT] The nullity pattern is confirmed: machine-learning cor...