Файл:Halflife-sim.gif

Page contents not supported in other languages.

Halflife-sim.gif(100 × 188 пиксел, файлын хэмжээ: 17 КБ, MIME төрөл: image/gif, эргэлдсэн, 80 фрэйм, 8.5 s)

Энэ файл нь Wikimedia Commons-нх бөгөөд бусад төслүүд үүнийг хэрэглэх боломжтой. Доор файлын тайлбарын хуудсан дээрх тайлбарыг оруулсан байгаа:

Товч агуулга

Тайлбар
English: Simulation of many identical atoms undergoing radioactive decay, starting with either four atoms (left) or 400 atoms (right). The number at the top indicates how many half-lives have elapsed. Note the law of large numbers: With more atoms, the overall decay is less random. Image made with Mathematica, I am happy to send the source code if you would like to make this image more beautiful, or for any other reason.
Огноо
Эх үүсвэр Энэ миний бүтээл
Зохиогч Sbyrnes321

Лиценз

Public domain I, the copyright holder of this work, release this work into the public domain. This applies worldwide.
In some countries this may not be legally possible; if so:
I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.
(* Source code written in Mathematica 6.0, by Steve Byrnes, 2010. I release this code into the public domain. *)

SeedRandom[2]

(*Build list of point coordinates and radii*)

BuildCoordList[SqCenterX_, SqCenterY_, SqSide_, PtsPerRow_] := 
  Flatten[Table[{i, j}, {i, SqCenterX - SqSide/2, SqCenterX + SqSide/2, SqSide/(PtsPerRow - 1)},
     {j, SqCenterY - SqSide/2, SqCenterY + SqSide/2, SqSide/(PtsPerRow - 1)}], 1];

coordslist = Join[
   BuildCoordList[3.5, 1, 1.8, 20],
   BuildCoordList[3.5, 3, 1.8, 20],
   BuildCoordList[3.5, 5, 1.8, 20],
   BuildCoordList[3.5, 7, 1.8, 20],
   BuildCoordList[1, 1, .7, 2],
   BuildCoordList[1, 3, .7, 2],
   BuildCoordList[1, 5, .7, 2],
   BuildCoordList[1, 7, .7, 2]];
NumPts = Length[coordslist];
radiuslist = Join[Table[.03, {i, 1, 4*400}], Table[.1, {i, 1, 4*4}]];

(*Draw borders*)

xlist = {0, 2};
leftx = 0;
rightx = 2;
numx = Length[xlist];
ylist = {0, 2, 4, 6, 8};
topy = 0;
boty = 8;
numy = Length[ylist];
lines = {};
For[i = 1, i <= numy, i++, 
  lines = Append[lines, Line[{{leftx, ylist[[i]]}, {rightx, ylist[[i]]}}]]];
For[i = 1, i <= numx, i++, 
  lines = Append[lines, Line[{{xlist[[i]], topy}, {xlist[[i]], boty}}]]];

xlist = {2.5, 4.5};
leftx = 2.5;
rightx = 4.5;
numx = Length[xlist];
ylist = {0, 2, 4, 6, 8};
topy = 0;
boty = 8;
numy = Length[ylist];
For[i = 1, i <= numy, i++, 
  lines = Append[lines, Line[{{leftx, ylist[[i]]}, {rightx, ylist[[i]]}}]]];
For[i = 1, i <= numx, i++, 
  lines = Append[lines, Line[{{xlist[[i]], topy}, {xlist[[i]], boty}}]]];

(*Write numbers:
I want to be able to write a number with one decimal place,
including padding with ".0" when it's an integer.*)

WriteNum[num_] := Block[{rounded}, rounded = N[Floor[num, 0.1]];
    If[FractionalPart[rounded] == 0, ToString[rounded] <> "0", ToString[rounded]]];

(*Randomly choose decay times:
To get an expontial-decay-distributed random number, we pick a number uniformly between 0 and 1.
Take its negative log to get the time that it blows up, which is between 0 and infinity.
But divide by log 2 so that when the time = 1, there's 50% chance of decaying. *)

BlowTime = Table[-Log[RandomReal[]]/Log[2], {i, 1, NumPts}];

(*Draw graphics*)

GraphicsList = {};
NumFrames = 80;
TimePerFrame = .05;

Video = {};
For[frame = 1, frame <= NumFrames, frame++,
  CurrentTime = (frame - 1)*TimePerFrame;
  ImageGraphicsList = lines;
  ImageGraphicsList = 
   Append[ImageGraphicsList, Text[WriteNum[CurrentTime], {.8, 8.5}, {-1, 0}]];
  ImageGraphicsList = 
   Append[ImageGraphicsList, Text[WriteNum[CurrentTime], {3.3, 8.5}, {-1, 0}]];
  For[pt = 1, pt <= NumPts, pt++,
   If[CurrentTime < BlowTime[[pt]], 
    ImageGraphicsList =   Append[ImageGraphicsList, {Blue, Disk[coordslist[[pt]], radiuslist[[pt]]]}]]];
  Video = Append[Video, Graphics[ImageGraphicsList, ImageSize -> 100]];];

(*Pause at start*)
Video = Join[Table[Video[[1]], {i, 1, 5}], Video];

(*Export*)
Export["test.gif", Video, "DisplayDurations" -> {10}, "AnimationRepititions" -> Infinity ]

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts англи

creator англи

28 Нэгдүгээр сар 2010

Файлын түүх

Огноо/цаг дээр дарж тухайн үеийнх нь файлын байдлыг харна уу.

Огноо/ЦагЖижиг зурагХэмжээХэрэглэгчТайлбар
одоогийн19:41, 25 Гуравдугаар сар 201019:41, 25 Гуравдугаар сар 2010-н байдлаарх хувилбарын жижиг хувилбар100 × 188 (17 КБ)AiyizoOptimized animation, converted to 16 color mode
06:35, 5 Хоёрдугаар сар 201006:35, 5 Хоёрдугаар сар 2010-н байдлаарх хувилбарын жижиг хувилбар100 × 188 (156 КБ)Sbyrnes321Changed top-bottom split to left-right split, with space between; pause at start; 400 atoms in each crowded box instead of 296. (Thanks to Bdb484 for suggestions.)
00:26, 29 Нэгдүгээр сар 201000:26, 29 Нэгдүгээр сар 2010-н байдлаарх хувилбарын жижиг хувилбар61 × 131 (75 КБ)Sbyrnes321{{Information |Description={{en|1=Simulation of many identical atoms undergoing radioactive decay. The number at the top indicates how many half-lives have elapsed. Note that after one half-life there are not ''exactly'' one-half of the atoms remaining, o

Дараахь хуудсууд уг файлтай холбогдсон байна:

Файлын хэрэглээ (бүх төсөл)

Дараах бусад вики энэ файлыг ашигладаг: