Đề án về Sấm Sét

LI CAM OAN

Em xin cam oan y l cng trnh nghin cu ca ring em v c thc hin di s hng dn ca TS. Bi Th nh Vn. Cc s liu, kt qu nu trong bi tp ln l trung thc.

Em xin chu trch nhim v ti ca mnh!

Ngi thc hin ti

Th Minh

LI CM N

Em xin chn thnh cm n d hng dn tn tm ca c gio Bi Th nh Vn v cc thy c trong Khoa o to ti chc, trng i hc Ni V gip em hon thnh bi tp ln ny.

H Ni, thngnm 2015

Sinh vin

Th Minh

MC LC

PHN M U1

1.L do chn ti1

2.Mc ch nghin cu2

3.i tng nghin cu2

4.Phng php nghin cu2

5.Dn ni dung ti nghin cu2

PHN NI DUNG3

CHNG 1: C S L LUN V SM ST3

1.1 Sm st l g?3

1.2 Bn cht ca hin tng sm st3

1.2.1 Mt s khi nim3

1.2.2 Bn cht ca sm st4

1.3 c im ca st5

CHNG 2: ST HIM HA I VI I SNG7

2.1 i vi con ngi7

2.1.1 St c th gy thng tch bng nhng cch thc sau7

2.1.2 St nh gy thit hi ra sao8

2.2 i vi cc trang thit b in t v h thng thng tin lin lc8

CHNG 3: Cc bin php phng chng st10

3.1 Phng php dng lng Faraday10

3.1.1 Vt dn mang in10

3.1.2 Nguyn tc hot ng10

3.1.3 Lng Faraday11

3.2 Phng php chng st truyn thng (H Franklin)11

3.2.1 H Franklin gn thng12

3.2.2 H Franklin bao quanh hay nm trn (h mt xch hay li)12

3.3 Phng php chng st khng truyn thng13

3.3.1 H pht x sm13

3.3.2 H ngn chn st (H tiu tn nng lng st)13

3.3.3 Ht st bng tia Laser13

3.4 Phng php phng chng tch cc14

3.4.1 S dng cc trang thit b hin i14

3.4.2 Cc bin php bo v v chng st c khuyn khch14

3.4.2.1 Ln k hoch trc14

3.4.2.2 Thc hin quy tc nhn nghe15

3.4.2.3 Trnh st trong nh15

3.4.2.4 Trnh st nh ngoi tri16

3.2.4.5 Cp cu ngi b st nh16

CHNG 4: St - ngun nng lng qu gi17

4.1Bc u chinh phc st ca con ngi18

4.2 Gii thch cc hin tng lin quan n sm st

PHN KT LUN

TI LIU THAM KHO

PHN M U

1.L do chn ti

Xut pht t thc t cuc sng

- Theo nhng nghin cu ca Vin Vt L a Cu (Trung tm khoa hc t nhin & cng ngh quc gia), Vit Nam nm tm dng Chu , mt trong ba tm dng trn th gii.

+ Dng thng din ra t thng 4 10.

+ S ngy dng trung bnh khong 100 ngy/ nm v s gi dng trung bnh l 250 h/nm.

- Mi nm nc ta c ti hng chc ngi cht do st nh v thit hi do h hng thit b ln n hng trm triu ng. St cng l nguyn nhn chnh gy s c ct in ca li in cao p Vit NamV d:

T nm 1989 1994, c 286 c st nh xung ng dy 220kV t Ph Li H ng, H ng Ha Bnh v Ph Li Hi Phng.

Ti Na Hang (Tuyn Quang), st nh vo trm vi ba lin tc trong 4 nm t 1997 2000 gy hng thit b ca trm.

4/1998, mt tia st nh vo trm Ph Thy (Vin Vt L a Cu) gy hng hai i quan trc a l v a t, thit hi hng trm triu ng.

04/06/2001, st nh n mt my ct 220kV ca Nh my thy in Ha Bnh khin li in min Bc b r mch, nhiu nh my in b tch khi h thng khin mt in trn din rng.

- ng bo ng l a s cc cng trnh ln u khng p ng 6 yu cu phng chng st ca th gii.

V vy nn ti quyt nh chn ti lm vn nghin cu ca mnh: Sm st.

2.Mc ch nghin cu

- Vic nghin cu sm st gip chng ta hiu r hn v bn cht ca sm st. Thng qua bi hc, tuyn truyn gip cho mi ngi c ci nhn ng n v sm st, cch phng chng sm st, t bo v bn thn v ngi xung quanh.

- Nm c nhng thnh tu mi ca con ngi trong cng cuc chinh phc sm st.

3.i tng v phm vi nghin cu

Bn cht ca hin tng sm st.

Cch phng chng sm st.

St l ngun nng lng qu gi.

4.Phng php nghin cu

- c v nghin cu cc ti liu c lin quan n bn cht v cch phng chng sm st.

- Phng php phn tch v tng hp ti liu.

5.Cu trc ca ti

Ngoi phn m u, kt lun, danh mc ti liu tham kho, ti c chia lm 4 chng:

Chng 1: C s l lun v sm st

Chng 2: St him ha i vi i sng

Chng 3: Cc bin php phng chng st

Chng 4: St - ngun nng lng qu gi.

PHN NI DUNG

CHNG 1: C S L LUN V SM ST

1.1 Sm st l g?

St hay tia st l hin tng phng in trong kh quyn gia cc m my v t hay gia cc m my mang cc in tch khc du.

Sm l ting ng do chp t nng khng kh. Khi khng kh n ra rt nhanh, n gy ra ting ng. Ta c th nghe thy sm trong vng bn knh 20 25 km.

1.2 Bn cht ca hin tng sm st

1.2.1 Mt s khi nim

- S phng in t lc: thc nghim chng minh, trong cht kh, khi in trng mnh, hiu in th ln th d c ngng tc dng ca cc tc nhn ion ha, s phng in vn c duy tr.

- Tia la in l qu trnh phng in t lc xy ra trong cht kh khi c tc dng ca in trng mnh lm ion ha kh, bin phn t kh trung ha thnh ion dng v electron t do.

1.2.2 Bn cht ca sm st

- Nhng cn gi nh v hi m khng n nh lm gia tng nhng m my dy c trong mt cn gi cun ln pha trn hoc pha di. iu khin cc ht ma, bng v tuyt trong m my va chm, c xt. S va chm ny lm cc in tch tch ri. Ch yu do i lu nn in tch dng bn ln cao trong khi in tch m sa xung thp. Hai min in tch khc du ca m my dng ging nh hai bn ca mt t in khng l, khng kh gia chng l cht cch in, lc u ngn khng cho cc in tch chy li gp nhau v nng dn hiu in th gia hai cc ca hai bn t in. Gia phn chn m my dng v mt t tch in (do hng ng tnh in) cng l mt t in vi khng kh cch in nm gia hai bn t in. S mt cn bng in tch tng ln bn trong m my, gia m my v mt t. in trng ca khng kh lc ny c cng khong 3.106 V/m. Khi hiu in th gia hai bn t in ln nh thng cht in mi (khng kh) gia hai bn, th c tia la in phng qua. Ngi ta gi l tia chp hay tia st.

- Chp nung nng khng kh xung quanh n ti gn 27.760oC, nng hn c b mt mt tri. Sc nng khng khip ny lm cho khng kh gin n t ngt, to ra ting n ln, gi l ting sm (nu phng in gia 2 m my) hoc ting st (nu phng in gia m my v mt t).

- Khi s mt cn bng in tch gia my v mt t ln ti mc in tch m phn thp ca m my bt u di chuyn hng v mt t, in tch m ti gn mt t lm cho in tch dng dng ln cc vt th cao (chng hn nh cy, nh, ct in, con ngi). Khi in tch m t m my kt ni vi nhng in tch dng ang dng ln t mt t ny, mt tia chp chi sng xut hin.

Vy: bn cht ca hin tng st l s phng in trong cht kh p sut bnh thng, st pht sinh do s phng in gia cc m my tch in tri du hoc gia mt m my tch in vi mt t to thnh tia la in khng l.

1.3 c im ca st

St ta ra mt nhit lng rt ln

T hin tng thng thy trong t nhin nh st nh vo cy gy bc chy, st nh gy chy rng chng t: nhit lng do st nh ta ra ry ln. Nhit c th ln ti hng nghn C nn rt nguy him. St c th lm nng chy cc vt liu bng kim loi, vn cong nhng ct in, nh tan mt ngi nh,trong chp mt.

St l s phng in t cc m my dng xung t

Q = I2.R.t

Trong : Q: nhit lng ta ra (J)

I: cng dng in (A)

R: in tr ()

t: thi gian (s)

Nhit lng do st ta ra rt ln, m ta bit st nh trong mt thi gian rt ngn (khong 100ln/s) nn theo cng thc, I truyn qua cy phi rt ln (khong 10000 50000 A). Mt tia st thng thng c th thp sng bng n 100W trong 3 thng.

St khng bao gi nh theo ng thng

ng i ca st cong queo v n phi chn con ng no cn in t nht, ngha l i vo cc ni tp trung nhiu phn t dn in nht.

Nhng ni st thng nh vo

St thng nh nhiu nht vo nhng ni c sc cn in tng i t. V d: st hay nh vo nhng cy c nhiu r v r n su vo lng t nh cy a, cy si.

St cng nh vo nhng ni dn in tt.

+ St hay nh vo nhng cy cha nhiu nc.

+ Nhng ni m t (nhng khe ni, vc su, v y nhng khe, vc tp trung nhiu hi m hay nhng ngun nc)

+ Nhng vng t st thng dn in nhiu hn t ct, do vy st hay nh xung hn.

+ t c nhiu mch nc ngm v dng ct chy (lu sa) pha di cng l mi ngon ca st.

Tiu kt: St nh ra km theo mt ngun nng lng rt ln c kh nng ph hy, t chy cng trnh nh ca, cu ng. St thng nh vo nhng ni dn in tt, c sc cn in t v ng i ca st khng bao gi l ng thng.

CHNG 2: ST HIM HA I VI I SNG

2.1 i vi con ngi

- St k git ngi ng th 2 sau l (song ch git mt ngi mi ln), l st th lin quan ti thi tit, mi nm cp i nhiu sinh mng hn so vi bo v lc xoy.

- Hng nm, st lm khong 5000 ngi, ng thi lm hng trm ngi khc b thng. Mt tr, thiu tp trung, ri lon gic ng, t lit, chong vng v suy nhc l nhng chng bnh m ngi b st nh mc phi.

2.1.1 St c th gy thng tch bng nhng cch thc sau

St nh thng vo v tr nn nhn t trn m my xung

Khi nn nhn ng cnh vt b st nh. St c th phng qua khong cch khng kh gia ngi v vt. Trong trng hp ny gi l st nh tt ngang.

St nh khi nn nhn tip xc vi vt b st nh.

in p bc. Khi ngi tip xc vi mt t mt vi im, st lan truyn trn mt t.

St lan truyn qua ng dy cp ti cc vt nh in thoi, tivi, cm.

Theo thng k M, nn nhn b st nh:

2.1.2 St nh gy thit hi ra sao

- Tia st c dng in rt mnh v nhit ti vi chc ngn C. Do , nu b st nh thng, ngi v sc vt c th s b chy bng v cht nhanh chng.

- Khi st nh xung t, trong bn knh khong 20m u c in th. Nu ta ang trong bn knh , th gia hai chn ta s c mt in p c gi l in p bc. Cng ng gn ni st nh, in p bc cng ln v dng in qua hai chn vo ngi cng cao, c kh nng gy cht ngi.

- St hay nh vo cc cng trnh kin trc, nh ca cao v ng tr tri nh cc nh cao tng, gc chung nh th, ng khi, nh my in, trm bin p, ng-ten bu inlm h hi nh ca v thit b in.

2.2 i vi cc trang thit b in t v h thng thng tin lin lc

- V d:

+ Nm 1963, mt chic Boeing bay cao 1.500m b st nh khin ton b hnh khch v t li b thit mng.

+ Nm 1969, con tu Apollo 12 v nm 1987, con tu Atlas Centuor u b tc ng bi s phng in trong my dng khin chng chuyn ng lch qu o, b nh iu khin hot ng khng chnh xc.

- Trong thi i thng tin hin nay, mng my tnh, h thng iu hnh thng tin, ng-ten cng cng, tr thnh nhng tm im ph hoi ca mch xung in t st. T l cc h thng thng tin b st ph hoi vt xa t l y cc ta kin trc.

- Nhng thit b in, in t trong gia nh (nht l radio, tivi, my tnh) rt d b nhim in khi tia chp le sng km theo ting n d di. Dng in ny c th i qua v gy thit hi cho cc dn my in t, i khi cn gy thng tn cho c con ngi.

Phng thc tc ng ca st i vi cc trang thit b in, in t:

St nh trc tip

St nh gy cm ng: st nh gy cm ng l st nh v tr gn cng trnh, gn ng dy ngun hoc ng dy tn hiu (dy in thoi, dy mng). Dng in trong khe st rt ln, in-t trng rt mnh sinh ra trn cc dy dn ni trn, in p cm ng ln lan truyn theo ng dy dn vo thit b, lm hng chng.

Tiu kt: St nh c th gy ra t vong, ph hoi hng lot cc cng trnh, thit b in, in t bng cch nh trc tip vo i tng hoc truyn qua ng cp.

CHNG 3: CC BIN PHP PHNG CHNG ST

Vic nghin cu dng st l tin hnh quan st, nghin cu hot ng dng trong khng gian v thi gian, xc nh mt st (s tia st/km2/nm), tin hnh o cc thng s st khc nh cng dng in st, dc stThc hin chng st l da trn cc s liu iu tra c bn, la chn mt cch sng to cc cng ngh chng st thch hp cho tng i tng cn bo v:3.1 Phng php dng lng Faraday

3.1.1 Vt dn mang in

- Vt dn l vt c cha cc ht mang in t do; cc ht mang in ny c th chuyn ng trong ton b vt dn. C nhiu loi vt dn (rn, lng, kh).

- Trong cc vt dn kim loi, cc ht mang in t do l cc electron dn, chng c th chuyn ng t do t nguyn t ny sang nguyn t khc trong cc mng tinh th kim loi.

- Tnh cht ca vt dn mang in

+ Vt dn cn bng tnh in l mt khi ng th. Mt vt dn l mt mt ng th.

+ Vt dn mang in trng thi cn bng tnh in th in trng trong lng vt dn lun lun bng 0. Hay in tch trong lng vt dn bng 0.

+ in tch phn b khng u trn b mt vt dn: ni no lm vo th phn b in tch t nht, in tch phn b nhiu nht mi nhn.

3.1.2 Nguyn tc hot ng

Da trn tnh cht ca vt dn mang in: in trng trong lng mt vt dn rng mang in tch bng 0 nn mt vt dn khc nm trong lng vt dn rng s khng b nh hng bi in trng bn ngoi. Nh vy vt dn rng c tc dng nh mt mn bo v, che ch cho cc vt dn khc t bn trong n khi b nh hng bi in trng bn ngoi. V th vt dn rng c gi l mn in. Thc t nhng li kim loi dy (mau) cng c th coi l mn in.

3.1.3 Lng Faraday

- L lng kim loi bao kn khu vc bo v. Theo l thuyt sng in t th y l phng php l tng phng chng st. Phng php chng st ny c s dng bo v mt s khu vc c bit nh ni cha thuc n, ht nhn. Tuy nhin phng php ny tn km v khng kh thi p dng vo thc t cho tt c cc cng trnh.

3.2 Phng php chng st truyn thng (h Franklin)

Phng php chng st truyn thng c 2 dng l:

H gn thng vi nh.

H bao quanh hay nm trn.

3.2.1 H Franklin gn thng

- Dng kim thu st bng kim loi t trn nh nc nh, ni vi mt dy kim loi dn xung t. Phng php chng st ny thc hin hai nhim v: lm chch hng tia st vo nh v dn nng lng xung t v phn tn nng lng in trn my.

Thu li chng st c Benjamin Franklin pht minh nm 1760.

3.2.2 H Franklin bao quanh hay nm trn (h mt xch hay li)

- N thng bao gm h dy dn trn nh treo trn cc ct v ni vi h thng t. Cc dy ny thng t cch nh khong 10 20m. H ny c u vit l mt khi n tip nhn tia st th tia st cch xa khu vc bo v xa hn h Franklin ni trc tip. Dng bo v ny thng t hn dng gn trc tip.

Thc nghim cho thy, h Franklin khng cho hiu qu chng st 100%. Tuy st nh vo kim thu st nhiu hn v hiu qu ca phng php chng st l kh tt, song nhiu kt qu thc nghim cho thy st c th b qua kim thu st m nh trc tip vo nh mc d c th lm kim thu st ln rt cao. Ngay c khi st nh vo kim thu st th dy ni t khng hiu qu cho vic dn cc thnh phn tn s cao ca tia st khi c cc vt kim loi gn. Cc nh c cha cc dng c nhy cm vi st nh cc thit b in t s b hng hc. i vi cc thit b nhy cm ny cn phi c nhng thit b chng st chuyn dng.

Nh vy, phng php chng st truyn thng trong nhiu nm qua chng t kh nng bo v ca n, tuy nhin i vi yu cu cao nh hin nay (cc thit b in t, nh my ht nhn, n dc) th nhng nhc im nu trn s c th gy thit hi khn lng.

3.3 Phng php chng st khng truyn thng

3.3.1 H pht x sm

- Mt vi dng c c s dng gy pht x sm nh ngun phng x v kch thch in ca kim.

3.3.2 H ngn chn st (h tiu tn nng lng ca st)

- H ngn chn st vi mc ch l phn tn in tch ca my dng trc khi n phng in. Hay ni khc i l to m my in dng ti khu vc lm chch tia st khi khu vc bo v. Nhiu dng dng c phn tn c s dng. Ch yu cu to bi rt nhiu kim mi nhn ni t. Nhng im ny c th nh nhng dng li kim loi, bn chi Cc dng c ny c tc dng chuyn in tch dng t t vo kh quyn.

3.3.3 Ht st bng tia Laser

- Ngy nay chng ta cn chng st cho cc cng trnh hin i i hi phng php chng st c hiu qu cao v d nh kho cht n n dc, ht nhn, cc trung tm my tnh quan trng (iu khin bay, trung tm iu khin mng). Nhm tm kim gii php chng st 100%, cc cng ty hng nm u t hng triu dollar cho cng vic nghin cu ht st bng laser. Cc nhm nghin cu mnh v vn ny l gio s Bazelyan (Nga), gio s Zen Kawazaki (Nht). c nhng kt qu bc u. Ti Nht, nm 1997, sau rt nhiu ln th nghim ngi ta 2 ln thu c tia st bng cch ny. Theo kin cc chuyn gia, v k thut c th thc hin c. Kh khn ch ng b ha v chi ph cho mt c chng st bng phng php ny c th ni l t hn vng. Hng nghin cu ny ang c tip tc.

3.4 Phng php phng chng tch cc

3.4.1 S dng cc trang thit b hin i

- Mt dng phng php c s dng c hiu qu trong nhng nm gn y l d bo dng st sm. Nh vo cc thit b hin i nh raa, v tinh, cc h thng nh v phng in, ngi ta c th d bo c kh nng c dng st xy ra ti khu vc trong khong thi gian t vi gi n 30 pht. Cc phng php ny c ng dng rng ri trong hng khng, in lc, an ton cho con ngi Thit b EFM v ESID t ti trm Ph Thy (Gia Lm) cng c kh nng ny.

3.4.2 Cc bin php bo v v chng st c khuyn khch

- V st l hin tng ngu nhin cho nn khng c v tr an ton tuyt i. Tuy nhin vic ch ng phng, trnh st tm ni an ton hn c th lm gim ng k kh nng b st nh. Cn phi hng dn gio dc phng chng st an ton cho con ngi.

3.4.2.1 Ln k hoch trc

- Nghe d bo thi tit. Khi nghe bn tin d bo thi tit, ln k hoch lm vic phng. Khi lm khu vc no , trc cc ni c th tr ma v trnh st an ton. Phi tnh c thi gian t ch lm vic n ni an ton. Thng th cn dng ko n rt nhanh trong vng 15 pht v di chuyn vi vn tc 40km/h. Ni chung khi ang ni khng an ton th cn phi n cc du hiu ca dng nh my en, khng kh lnh, gi.

3.4.2.2 Thc hin quy tc nhn nghe

- Khi st xy ra, thot tin ta thy tia chp le ln v sau c ting sm km theo. Nu bn tnh khong thi gian t lc tia chp le ln v lc nghe thy ting sm th c th xc nh c khong cch ti ni st xy ra. Chia s giy cho 3 ta c khong cch n tia st. V d m c 3 giy th st cch v tr ng l 3/3 = 1km.

- Nu nh khong thi gian bn m c t khi thy tia chp v nghe ting sm nh hn 30 giy th bn nm trong tm ngm ca tia st ri, phi cn thn.

- Nu thi gian ny nh hn 20 giy th phi di chuyn n ni an ton hn. Khi nghe thy ting sm u tin bt k l g cng cn phi thy nguy him n. St c th nh cch xa ni c ma ti 15 20km.

3.4.2.3 Trnh st trong nh

- Khi tri sp xy ra cn dng, th bin php trnh st tt nht l nn v nh. Ch an ton trnh st l ta nh, hay cng s c lp t h thng chng st (n gin nht l ct thu li Franklin)

- Khi trong nh th nn ng xa ca s, ca ra vo, cc dng in, trnh cc ch m t nh bung tm, b nc, vi nc, khng nn dng in thoi tr trng hp rt cn thit. Nn rt phch cm cc thit b in trc lc c dng gn xy ra.

- Vi cc ng dy in thoi hay dy in v ni vi li bn ngoi nn rt c th b nh hng st nh lan truyn. Nn trnh xa cc dy ny v cc vt dng in vi khong cch t nht l 1m. Tivi ni vi dy ng-ten ngoi tri cng rt cn rt ra khi c dng.

3.4.2.4 Trnh st nh ngoi tri

- Trong trng hp khng kp chy tm ni n nu an ton, tuyt i khng tr ma di cy ci, trnh cc khu vc cao hn xung quanh, trnh xa cc vt dng kim loi nh xe p, xe my, hng ro st.

- Tm ch kh ro, nu xung quanh c cy cao hn th nn tm ch thp, tm v tr thp.

- Ngi v tr cng thp cng tt, tay m c. Phn tip xc ca ngi vi mt t l t nht. Nhn chn, khng c nm xung t. ng xa cc vt cao, ra ngay khi nhng ni cha nc nh bi bin, ao, h, mng. Cc vng nh ni hay sn ni nh cao cng rt nguy him. Nu trong rng th tm nhng ni cy thp hn v tha trnh.

- Khng ng thnh nhm ngi gn nhau. Nu nh bn cm thy tc b dng ln (nh cm gic in khi s tay vo trc mn hnh tivi) th iu c ngha l c th b st nh bt c lc no. Lp tc ci ngi xung v ly tay che tai, khng nm xung t hay t tay ln t.

- i vi cc vt c b mt kim loi nh xe but, tu ha, t, nu khng th ngi ra ngoi v khng chm n thn xe, v bc kim loi th nhng ch ny l an ton. Ngc li, i vi cc t, tu thy h hay khng c v bc kim loi th li nguy him. Sau khi nghe thy ting st 30 pht th c th tr li lm vic bnh thng.

3.4.2.5 Cp cu ngi b st nh

Ngoi lm chy, bng, st cn gy tc hi ti h thn kinh, gy xng, mt thnh gic, th gic hay tr nh. Ngi b st nh cn c cu tr ngay tc khc.

Nu ngi b st nh b ngt (tim ngng p, tt th) phi thc hin khn cp cc ng tc h hp, tr tim nhn to. Tm nhng ni b gy, c bit cn thn khng di di nhng nn nhn nu nghi ng b gy ct sng. nhng ni b bng kh v tm cch nhanh nht nhn vin y t n.

Trong cn dng, nu cm thy iu g bt thng nh trong ngi nhng nhc, tc git git, lng tay lng gy dng ln d l cc bn ang trong khu vc sp b st nh. Phi phn ng tht nhanh, ri khi ni ang ng bng cch nhy c c hay nhy chm hai chn nh chim s (tuyt i khng nn chy, v nu bc di hai chn, in p s ln v to ra dng in i t chn ny qua ngi sang chn kia, ngi s b in git cht, cng khng nn nm di ra t). Nu khng th ri xa ni c th lp tc ngi ngay xung, thu mnh nh li (hoc ng chm 2 chn hay co mt chn ln). Nu c vt cch in nh vn, nha th nn ngi ln , ci u thp xung, hai tay che u.

Kt lun: Hin nay c nhiu phng php phng chng st, tuy nhin c nhiu phng php i hi yu cu cao, tn km v khng kh thi khi p dng cho tt c cc cng trnh. V vy cn xem xt cc iu kin thc t a ra phng php chng st ti u, hp l nht v phi tun th theo phng php mt cch nghim tc.

CHNG 4: ST NGUN NNG LNG QU GI

Vo mt thi im bt k trn tri t c khong 2.000 cn dng ang hot ng. Mt cn dng bnh thng ko di 4 ting c th c 10.000 c phng in trong c 1000 2000 c phng xung t.

Lng in nng tch cha trong mt ln st xut hin c th ko mt on tu 14 toa chy c 200km.

Ch mt tia sng thng thng c th thp sng bng n 100W trong ba thng, l mt ngun nng lng khng l.

Cng sut ca lung in st rt ln. Nu in p hai u lung in l 10.000.000V, dng in l 20.000A th trong khonh khc chp st y, cng sut ca n c th t 200 triu KW. ng tic l thi gian phng in qu ngn, ch khong 50 100 s. V vy, tng nng lng m mt ln st phng ra khng thp sng cho mt thnh ph ln trong mt gi, hn na, in chp rt kh khng ch, mun trc tip li dng nng lng ca n v cng kh. y vn l bi ton hc ba t ra cho cc nh khoa hc.

St cn c th thc hin vai tr ca i thm d a cht, gip con ngi tm ra ngun khong sn. St vn thch nh vo nhng vt th d dn in, m nhng ni c kim loi v du kh th tnh dn in cao hn nhng vng khc. Cn c vo thng k s ln xy ra st, nhng khu vc thng c st th kh nng cha khong sn v du kh cao hn.

Cc nh khoa hc cn nu ra tng to bo dng st chng ma . Dn st vo trong nhng tng my c kh nng sinh ma , nng lng cc ln v nhit rt cao s ph hy cc tng nc , bin chng thnh nc trnh gy thin tai.

4.1 Bc u chinh phc st ca con ngi

Tuy st l k git ngi th hai sau l, l st th thi tit. Nhng n cng l mt trong nhng ngun nng lng qu gi. Cc nh khoa hc sm nhn ra iu nn ang bt tay vo nghin cu v chinh phc st, bt n phc v tt cho con ngi. Vic lm y bc u mang li kt qu kh quan.

+ D on lng ma bng sm st

+ Mng trm ra a thi tit v sn bay

Trm ra a thi tit c kh nng ghi nhn nhng c im cu trc my qua gi tr phn hi v tuyn t cc ht nc v cc ht tinh th bng trong my. Cc nh kh tng s phn tch v pht hin ra sm nhng r my c kh nng pht trin mnh trong vng bn knh quan trc ca ra a, theo di s pht trin ca chng v nh gi kh nng xut hin dng, st nh cc ch tiu nhn bit hin tng.

Mng trm m st Vit Nam: trong nm 2001, phng Vt l kh quyn c trang b hai thit b: thit b m s ln phng in trong my, my my v my t (ESID) vi cc bn knh hot ng khc nhau, chnh xc kh ln v thit b o cng in trng (EFM). Kt hp cc thit b ny vi ra a thi tit, c th tin hnh d bo st ti khu vc t my trc thi gian khong na ting. ng thi vi vic s dng cc thit b mua sn, phng Vt l kh quyn (Vin Vt l a cu) ang th nghim t ch thit b nh v phng in, thit b o cng in trng, thit b do bin v dc dng st v d kin a vo hot ng nm 2002 2003. Mng trm d kin gm 8 trm trn phm vi c nc.

+ Tu v tr hot ng bng sm st

+ To ra phn nitrogen c li cho cy trng

iu kin nhit v p sut cao khi st sinh ra chnh l iu kin sn xut m nit. Nh tc dng ca st m mi nm to ra hn 2 t tn phn m nit trn ton cu.

Cc nh khoa hc tin hnh ch to phn bn ha hc bng st nhn to trong phng th nghim, nhng ting sm rn ng tri t cng c ch i vi vic lm ti xp t v s sinh trng ca thc vt.

+ St phng in lm cc phn t oxy O2 trong khng kh kt hp to thnh kh ozon O3 hp thu cc tia t ngoi bo v s sng trn tri t.

+ S dng nng lng st cung cp in cho thnh ph

+ S dng tia X nm bt s di chuyn ca st

Khi st di chuyn t m my n mt t trong on ng t 30 160 pht, c gi l bc trong quy trnh bc dn u, tia X xut hin ngay bn di mi bc, khong 1/1.000.000 giy sau khi mt bc kt thc. Tia X do st to ra, n lc ny mt ngy no c th gip d on v tr st nh.

4.2 Gii thch cc hin tng lin quan n sm st

4.2.1 St hn

- St hn l hin tng t nhin cha c li gii thch tha ng, d ch l nguyn l. thng l mt qu cu pht sng di ng trong cn ma sm st, kch thc c qu cam hay qu nho, thi gian ko di t vi giy n vi pht. St hn xut hin hu nh ng thi vi mt tia st nh t trn my xung t. N thng bay cao vi mt, km theo m thanh nh vo c trc khi bin mt. Cng c khi n bay kh cao v sng n mc c th nhn thy vo ban ngy.

4.2.2 V sao st hay nh vo vt th cao cht vt ng n c?

Nhng vt th cao cht vt mang in tch cm ng nhiu hn mt t, c kh nng ht sng in mnh hn, v th n ht tia in mt cch d dng.

4.2.3 V sao lun thy chp trc ri mi nghe thy ting sm?

V tc truyn ca nh sng nhanh hn nhiu so vi tc truyn ca m thanh. Trong khng kh, mi giy nh sng i c 30 vn km, tng ng chy 7,5 vng quanh xch o trn tri t. Tc ca m thanh trong khng kh ch i c 340m/s, bng 1/900.000 ln so vi tc ca nh sng. Thi gian tia sng pht sinh t chp truyn n mt t khng n mt phn vi chc vn giy; th nhng m thanh cng chy vi c ly nh vy cn phi c thi gian di hn.

i khi chng ta ch nhn thy chp m khng nghe thy ting sm, chnh l v tng my phng in cch chng ta qu xa, hoc do m thanh pht ra khng vang. Chnh v khi m thanh truyn trong khng kh th nng lng ca n gim i nhiu, n cui cng khng cn nghe thy ting sm na.

4.2.4 V sao xut hin chp dng hnh cy v hnh cu?

Vo lc chng vng ti ca ma h, m my hng i qua lm nng mt t, thm tc dng tim nhit ca hi nc ng bng lan rng rt cao v dy, my un nh cy c th gi mun hnh mun v xut hin nhiu nhng b phn li ca vt th.

khu vc m nh sng mt tri chiu n th c mu hng sm, nhng bng rm m mt tri khng chiu n c th cnh sc mu m u v xm xt. Trn bin cc m my, c nhng vt ma ni tip chn tri. Trn nh nhng m my c khi my nh mu vng tri ra trn bu tri. Trong m my c tia chp xut hin r rt, tia chp xuyn qua m my nh l con rn bc, khi nh sng tia chp pht quang, m my en t nhin hng ln nh l thanh st va mi ly ra khi l luyn.

Kt lun: St mang theo mt lung nng lng v hn, dn dn con ngi tm ra c phng php n tn dng ngun nng lng s dng vo cuc sng. Vic hiu v c ch ca st nh s gip con ngi c th d on trc c nhng ni st s nh vo, d on c lng ma, phc v pht trin kinh t, k thut v trnh khi nguy him n tnh mng.

KT LUN

Sm st l k st th th hai ca thi tit, khi st n st gy ra cho con ngi bit bao thit hi v vt cht, thm ch cp i sinh mng ca con ngi.

Nhn thy nhng hu qu do st gy ra, con ngi i vo nghin cu khc phc n, trong thi gian tm hiu, cc nh khoa hc khm ph ra c rng: bn cnh nhng tc hi, st cng l mt ngun nng lng qu gi vn cha c con ngi khm ph.

Vi nhng thnh tu khoa hc k thut hin i ngy nay, con ngi ang tng bc chinh phc sm st, bt n phc v con ngi.

Chng ta cn c ci nhn mi v hiu bit su sc v bn cht cng nh cc cch phng chng sm st, sm st tr thnh mt ngi bn hu ch ca con ngi.

TI LIU THAM KHO

1. David Halliday, Robert Resnick, Jeal Walker, C s vt l (tp 4), NXB Gio dc, 2007 trang 132 134.

2. Lng Duyn Bnh, D Tr Cng, Nguyn Hu H - Vt l i cng (tp 2), NXB Gio dc, 2003 trang 61 65.

3. Sch gio khoa vt l 11 nng cao, NXB Gio dc, 2008 trang 106 113.

4. Cc trang web vi t kha tra cu dng in trong cht kh, sm st, cch phng chng st, lng Faraday, h Franklin, ngun nng lng trong st,

+ http://vnexpress.net

+ http://thuvienvatly.com.vn

+ Wikipedia.

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