V 0 , j H , .. j E , H E , FA .. F A .. : F.. = μ0 jH. (9.53) (.9.6) M V 0 dh F .. (9.52) t dK d K c (1.43) 1.0 " ", (9.53) : dK = F.. dh = μ0 jHdh. (9.54) dh t (9.48) dW , : dW = Ejdh, (9.55)
(9.48) Ej - , V 0 . (9.54), (9.55) K K c, V t , W , V t : dK/ dW = μ0 H/ E ↔ K/ W = μ0 H/ E. (9.56) (9.56) ε01/2 E = μ01/2 H (9.29), E, H
E H t y , (9.56) : K/ W = (ε0μ0)1/2 = 1/ c, (9.57) = 1/(ε0 μ0)1/2 - . (9.57) , t
W , K K c, V t , : K = W/ c. (9.58) V 0 , (9.58) (9.35) w K. .
|
|
K . . c, V 0 t , (9.58) : K..= w/ c. (9.59) (9.37) w , , S , .. S , : w = S/ c. (9.60) (9.60) (9.59) , S S , K.. K.. , V 0 t : K..= S/ c2. (9.61) K. K . , V 0 t , S , (9.39) S E H : K.. = S / c2 = [ E, H]/ c2 ↔ S = c2 K.. (9.62) (9.62) S K. , V 0 t , c2 .
Q ρ(x, , z, t) (.9.7), t
x, z , V R ,
r M , , .. R << r.
Q c ρ(x, , z, t) OZ u , u v = 1/(ε0εμ0μ)1/2 ε μ , .. u << v.
|
t OZ .
- - (7.6) 7.1 " . " BM M Q c ρ(x, , z, t) ε μ , : BM = (μμ0/4 π)∫([ j, r]/ r3) dV, (9.64)
|
|
V
r - -, x, , z, ࠠ V R Q , M x M, M, z M, t ; r = [(x M - x)2 + (yM - y)2 +(zM - z)2]1/2 - r - x, , z, V R Q , M x M, M, z M , t .
[ j, r] (9.64) t j X, j Y OX, OZ
j (x, , z, t) , .. j X = 0, j Y = 0, :
[j, r] = -j Z (yM - y) i + j Z (xM - x) j . (9.65)
(9.65) (9.64) ࠠ
BM (.9.7) M Q c
ρ(x, , z, t) ε μ : BM = (μμ0/4 π)∫{[- j Z (yM - y) i + j Z (xM - x) j ]/ r3} dV, (9.66) V
r = [(x M - x)2 + (yM - y)2 +(zM - z)2]1/2 - r - x, , z, V R Q , M x M, M, z M, t .
BM (.9.7) M Q c ρ(x, , z, t) ε μ : BM = (μμ0/4 π) rot ∫( j/ r) dV, (9.67) V
C , , (9.67) :
BM = (μμ0/4 π) rot ∫( j/ r) dV = (μμ0/4 π)∫ rot ( j/ r) dV, (9.68) V V
C (5.42) 5.1 " . . " (9.68)
t ∂ j X/ ∂ x, ∂ j X/ ∂ y, ∂ j X/ ∂ z ∂ j Y/ ∂ x, ∂ j Y/ ∂ y, ∂ j Y/ ∂ z j X, j Y OX, OY j (x, , z, t) , .. ∂ j X/ ∂ x = 0, ∂ j X/ ∂ y = 0, ∂ j X/ ∂ z = 0 ∂ j Y/ ∂ x = 0, ∂ j Y/ ∂ y = 0, ∂ j Y/ ∂ z = 0, :
|
|
rot ( j/ r) = i ∂ { j Z/[(xM - x)2 + (yM - y)2 +(zM - z)2]1/2}/ ∂ y - j ∂ { j Z/[(xM - x)2 + (yM - y)2 +(zM - z)2]1/2}/ ∂ x ↔
↔ rot ( j / r) = - i j Z(yM - y)/[(xM - x)2 + (yM - y)2 +(zM - z)2]3/2} + j { j Z(xM - x)/[(xM - x)2 + + (yM - y)2 +(zM - z)2]3/2} ↔ rot ( j / r) = [- j Z (yM - y) i + j Z(xM - x) j ]/ r3, (9.69)
, j Z OZ , .. j Z = const,
" " .
(9.69) (9.68) ࠠ
BM (.9.7) M Q c ρ(x, , z, t) ε μ , (9.66): BM = (μμ0/4 π)∫{[ - j Z (yM - y) i + j Z (xM - x) j ]/ r3} dV, (9.70) V
(9.70), (9.67), (9.66), (9.64), (9.64) (9.67), BM (.9.7) M Q c ρ(x, , z, t) ε μ : BM = (μμ0/4 π)∫([ j, r]/ r3) dV= (μμ0/4 π) rot ∫( j/ r) dV, (9.71) V V
B , j (x, , z, t) , (. 9.7) M ε μ , (9.71) : BM ≈ (μμ0/4π) rot {(1/ r)∫ u ρ[t - (r/ v )] dV, (9.72) V
[t - (r/ v )] - (2.69) 2.0 " ", 頠 ρ V R , τ = r/ v , B M , r V ρ(t) V t , ρ[t - (r/ v )]
V , t τ = r/ v , v = 1/(ε0εμ0μ)1/2 V M ; 1/ r - r V M , B , , r R , .. r >> R, V , r M (.5.2), (.5.3) 5.1 " . . " Q ; j (x, , z, t) = u ρ[t - (r/ v )] - , (9.72) Q OZ u , t τ = r/ v , v = 1/(ε0εμ0μ)1/2 V M .
|
|
Q ρ (. 9.7) , ..
Q , (9.72) u , : BM ≈ (μμ0/4π) rot ( u / r)∫ρ[t - (r/ v )] dV = {μμ0 Q[t - (r/ v )]/4π} rot ( u / r), (9.73) V
Q[t - (r/ v )] = ∫ρ[t - (r/ v )] dV - ρ V ,
V
t τ = r/ v , v = 1/(ε0εμ0μ)1/2 V M , BM .
(.9.7) p Q (5.61) 5.1 " . . " Q , z , : p Q = Qz k, (9.74)
k - (1.1) 1.0 " " OZ .
p Q ′ t (9.74) p Q : p Q ′ = Q(dz/ dt) k = u Q ↔ u = p Q ′ / Q, (9.75)
u = j (dz/ dt) - u Q c ρ(x, , z, t) , t OZ .
(9.75) (9.73) BM M , (.9.7) r ࠠ V , Q , ε μ p Q ′ t (10.74) p Q , : BM ≈ (μμ0/4π) rot { p Q ′ [t - (r/ v )]/ r}, (9.76)
p Q ′ [t - (r/ v )] - t (9.74) p Q , Q[t - (r/ v )] V , t τ = r/ v , v = 1/(ε0εμ0μ)1/2 V M , B .
Q c ρ (.9.8) OZ u , .. j OZ , (.7.3) 7.1 " . " B Q , OXY . (5.42) 5.1 B M X, B M Y OX, OY (9.76) BM (.9.8) M
|
|
|
B M Y = (μμ0/4π)(x/ r2){(1/ r) pZQ ′ [ t - (r/ v )] + (1/ v ) pZQ ′′ [ t - (r/ v )]} ≈ (μμ0/4π)(x/ r2){1/ v ) pZQ ′′ [ t - (r/ v )]}, (9.78)
pZQ ′′ [t - (r/ v )] - t (10.74) p Q Q ; r = (x2 + 2 + z2)1/2 - (. 09.0.8) r - V R Q , M x, , z, t ; r >> R - V M , BM , r M (.5.2), (.5.3) 5.1 "" Q ; " ≈" , r M ,
BM , Q , .. r → ∞, (1/ r) pZ Q ′ [t - (r/ v )] (9.77), (9.78) (1/ v ) pZQ ′′ [t - (r/ v )] .
BZ OZ BM (.9.8) M , .. BM OZ Q , OXY .
BM B M φ, ,
(.9.8) eφ , BM M : BM = (μμ0/4π r){(1/ v ) pZQ ′′ [t - (r/ v )]} sinθ eφ, (9.79)
θ - , .
HM M , Q (.9.8) OZ
B H (7.127) 7.2 " " B = μ0 μ H, :
HM = (1/4π r v )pZQ ′′ [t - (r/ v )]sin θ eφ . (9.80)
|
E : E = H (μ0μ/ ε0ε)1/2
v = 1/(ε ε0μμ0)1/2↔ (μ0μ)1/2 = 1/ v (ε0ε)1/2 ↔ E = H / v ε0ε ↔ E = (1/4πε ε0 r v 2) pZQ ′′ [t - (r/ v )] sinθ e θ. (9.81)
(. 9.9) e θ - , M , , θ ; H eφ φ ; S er r -, E , H, S, e θ θ .
D M , Q (.9.9) OZ (5.87) 5.2 " . . ", D E D = ε0ε E, (9.81) : D = (1/4π r v 2) pZQ ′′ [t - (r/ v )] sinθ e θ. (9.82)
(9.80) H
M , Q (.9.9) OZ , H φ eφ :
H φ = (1/4π r v ) pZQ ′′ [ t - (r/ v )] sinθ, (9.83)
pZQ ′′ [ t - (r/ v )] - OZ t p Q Q , OZ , Q[t - (r/ v )] V , t τ = r/ v , v = 1/(ε0εμ0μ)1/2 V M ,
B .
H r er , .. S er . E, H (9.39) S = [ E H] S , .. E, H er , , S .
H θ eθ H M , Q
(.9.9) OZ , , .. H eθ .
H θ, H r eθ, er H M , Q (.9.9) OZ , : H θ = 0; H r = 0. (9.84) (.9.9) E, H (9.39) S = [ E H] S , E eφ , H , .. E eθ Eθ , : Eθ = (1/4πε ε0 r v 2) pZQ ′′ [t - (r/ v )] sinθ, (9.85)
Eθ E (9.28) Em/ Hm = (μ0μ/ ε0ε)1/2 Em, Hm E H , (9.10) v = 1/(ε ε0μμ0)1/2 ε μ .
E φ, E r eθ, er E M , Q (.9.9) OZ , : E φ = 0; E r = 0. (9.86)
(9.85), (9.83) E, H (.9.9)
E, H r M , . Q OZ , .. θ , E, H E, H .
.
, , . (.9.10) q+ ω (1.19) 1.0 q- . p t : p = pm cosω t, (9.87)
pm = - qlm k - (5.61) 5.1 " . . " lm q+ q- t0 = 0 OZ p ; k . pZQ ′′ OZ p ′′ (t) t (9.87) p , (9.83), (9.85) Eθ, H φ, eφ, eθ (. 09.0.9)
E, H
M , : pZQ ′′ (t) = - ω2 pZmcosω t, (9.88)
|
|
M t , ω (.9.10) OZ : Eθ = - (ω2 pZmsinθ /4πε ε0 r v 2) cos[ω t - (2π r/ λ)], (9.89)
H φ = -(ω2 pZm sinθ /4π r v ) cos[ω t - (2π r/ λ)], (9.90)
(2π r/ λ) - (2.69) 2.0 " " λ ε μ r M , , ω t t .
(9.89) Eθm = ω2 pZmsinθ /4πε ε0 r v 2,(9.90) H φ m = ω2 pZmsinθ /4π r v
E H r (.9.9) θ , .. θ
r - , OZ , : Eθm, H φ m ~ (1/ r) sinθ. (9.91)
|
Δ t < S> = ∫{[ Eθm H φ m cos2[ω t - (2π r/ λ)]/Δ t} dt ~ Eθm H φ m ~ (1/ r2) sin2θ, (9.92) 0
< S> . < S (θ) > θ
r - (.9.11) , OZ ,
. , , OZ , .. θ = π/2. , (.9.11) , OZ , .. θ = 0 π, .
,
(9.39) S , S , .. , , t t (.9.12) OZ Q , (9.83), (9.85) E, H M eθ, eφ :
S = [ E, H] =[ Eθ eθ, H φ eφ] = [ eθ (1/4πε ε0 r v 2) pQ ′′ [ t - (r/ v )] sinθ, eφ (1/4π r v ) pQ ′′ [ t - (r/ v )] sinθ ] = = (pQ ′′ sinθ/4π r)2(1/ε ε0 v 3) er, (9.93)
pQ ′′ = | pZQ ′′| - t (9.74) p Q Q , | pZQ ′′| OZ t p Q Q , Q OZ ; er - , r -, M , , S .
(.9.12) er eθ, eφ , : er = [ eθ, eφ]. (9.94) (.9.12) P , .. , t F , S (9.93) er S dF , (9.47) S F : P = = ∫ S d F = ∫ er (pQ ′′ sinθ dF/4π r)2(1/ε ε0 v 3) er r2 sinθ dF dθ dφ =
F F
π 2π π 2π
= [(pQ ′′ )2/16π2ε ε0 v 3] ∫ sin3θ dF dθ ∫ dφ = - [(pQ ′′ )2/16π2ε ε0 v 3] ∫(1 - cos2θ dF) dcosθ dF ∫ dφ =
0 0 0 0
π π
= - [(pQ ′′ )2/16π2ε ε0 v 3][(cosθ dF)| - (cos3θ dF/3)|]2π = - [(pQ ′′ )2/16π2ε ε0 v 3][-2 - (-2/3)]2π = 0 0
= - [(pQ ′′ )2/8πε ε0 v 3](- 4/3) = (pQ ′′ )2/6πε ε0 v 3, (9.95)
: 0.173 . |