%PDF-1.7 % 11 0 obj << /Type /Page /Parent 1 0 R /LastModified (D:20250725034037+08'00') /Resources 2 0 R /MediaBox [0.000000 0.000000 595.276000 841.890000] /CropBox [0.000000 0.000000 595.276000 841.890000] /BleedBox [0.000000 0.000000 595.276000 841.890000] /TrimBox [0.000000 0.000000 595.276000 841.890000] /ArtBox [0.000000 0.000000 595.276000 841.890000] /Contents 12 0 R /Rotate 0 /Group << /Type /Group /S /Transparency /CS /DeviceRGB >> /Annots [ 6 0 R ] /PZ 1 >> endobj 12 0 obj <> stream xUN0 ӝ 5>+ UP% !~$Zh {0#7Qx')*%U۴IOA@7C@Rvf}p_9~'H ;H& HakQJZ'źQ!N9V2Ifjku 7VZT*ǕAOeSkGÿ?'M~?;_*U'. ӛgQ#O! "LQ& IT8SLnEMRhz2۪#V ӡ,۽RV6JϬM^%R2~C hkI ߞ68 4O{Lbg.%cK(KCz F=O=*};TwԷ/ȍyqvkm{$ې?F6f>;d۬@ReWYYQEHZ%ց͝](HORl4ƾs{ endstream endobj 13 0 obj << /Type /Page /Parent 1 0 R /LastModified (D:20250725034037+08'00') /Resources 2 0 R /MediaBox [0.000000 0.000000 595.276000 841.890000] /CropBox [0.000000 0.000000 595.276000 841.890000] /BleedBox [0.000000 0.000000 595.276000 841.890000] /TrimBox [0.000000 0.000000 595.276000 841.890000] /ArtBox [0.000000 0.000000 595.276000 841.890000] /Contents 14 0 R /Rotate 0 /Group << /Type /Group /S /Transparency /CS /DeviceRGB >> /Annots [ 8 0 R ] /PZ 1 >> endobj 14 0 obj <> stream xY_lDthڲh08{' X׵e& ,Y–M4D҂V!Qi6m 1 ^=RBS1wvZeB?YU>/wwD-_p"؁P:Gq>Y  CpG)bb^BaQV3Xa}ch-Q{PbA8)R*ZQm_ q!"b&fń(HţP;cCh+@o?=dpUC/%[-4 yw]/?.ǮN-Kx5I5e`  (g#aѐM,A2^1xk\_*KIgbj 3+dK&'&4Wpy8 ]w%2Dx.No3CU"t—HGpjm'.;Q~LyLĹAqbF'<8qKWFɞx.s ]ԲY:k :P}.i FM1-qBu TH{`S=;7g"`>)3=6> /PZ 1 >> endobj 16 0 obj <> stream xY[lUMMZ؞A(YBKL@˥]K,Ȧ*m6AOMMx&4"QB41\HhYϙ3^ 1ʹgΙVf:3Zg-:C+Z,3r Ya:f\nm"{-3]qKkv7rV8l 4̒MEůvfL1?4fEilc4ݦ)ׂ{7fmVÅ!22/FǭѤ`$98Ius`rd|gfԕjJ#E[Xd͓"Pmq&8U;!$,վ2 N<,2 p;bGDsÃ|@ UC¡pUݕK+ K{vd+*tT(<K\Ԗ℅mt ܒ.EI%c1}D`xzW8DZ^@/xA`[>~)|m<1.X5_8uP):>j[[sJeV_ޝտܖd) Sl&7QfC5K,cw Guҡ8 P,V"eSuI u$,3hVPnJ٩/%i&<#a-NNzKG j|SJ񔭧%pB8l4y=M<ޮ,ZV'U/l_*Ί:cNO7G ӁPH_g+„5v9b'گ+9j"'^iy)紂iqߏiG*qC~\BN`h|7=(~jkT(R ;ɚn,LY:BLs# Ե$Yd&0SGr*7-\m<:oƑ~;_7?3m(;C~5m Kšth<fy P y8-n?ч:w&ݸ}M3+pF7@w 24ÅVgr[NwI\ TP%̮\_e s4xQBtsiu9AGy1~c9(z^8 u Hy$$< hA+ 櫹8*!> /PZ 1 >> endobj 18 0 obj <> stream x՚L}njvPi@@i:&lsY !gEN3!MHJ4Dm?B[lR5A]NUFԥL#6Ih8[{{><*d Ƚ痤$A%xFgſZHʢsM.dDjģ+}bjY~a+v@[j)qsUGʥ55P_uts""}Mdi }#E.B[\$w3I-[yf`FVXm6W%lY^?>Q8j`7?h;\g)V=<z~[ŗ-^,*#_>Լ)<'yt|^4?/|4"@;핀٬4Y|v6 3RA@}.L̺DH  _Ū`|qmHlI eP9M`66L`?6ϏL:@@;U ~+ ġ n3>aBld{9Yi' bgŸ2Nn(v98c@l =P8ە6[|;b0C8TC= 4Ԫ njB.*,nrUԎTς9h9 EM˒lL6(7jyf@4U"vPNPJBY/s/(8?r(ycXM@HSQ >w=fhm ?bulc=v_H]L̅I~gW'/dyE쪊RKѤwb# ;KLq v/n m~[$!Y{@PJa߮(vVZNfUŰ*{n!#l|rUIˁM =L9>ӵusME@hGR3UO)IEIh Rԕ8 : 'ICnۀkLL-U1)mĥ[}8rűBPr _"t8 K e>&+L56k @D};"= (Pn,"aQ|^fΥZL|,AIFAEv9w\ѐsG@4T 2hЕ>E bayMMCىt*8ܓOAr"Ʉ})= TUhĈ=** W =ߪ)mR43I&F:+.5=`P$TL."?/KR`EX,U S*COad>G[)CݬUV#H84= &H7V”'I_ 7ͪ; TF˾ԃUe&o4wl2P%o \5tQ)7Ƕ)xLkl)eJwPR O@IfCuZVJ,Gr}p"fܺ,;rK{0n𫾏ywa`ߋccw[YDSMy$8 L*qK?k'&a?Һ2Mx]ԭ7:>ҡtjyѤ(V`󁤫WEuX2^R::6J8`GFkN|y 3^e{5dnٷ qK&oURBL,Qvc_op{O<O0N <#= eĢ,y{?W;vy iT{Md JnAG$X Ȓ+FegIP +jAǩ>yFqȫ<|ӑ-Q> /PZ 1 >> endobj 20 0 obj <> stream x}LeZ_e1C? }z+odOQ{upln"᭮H,%bt&-1df043$Dk2J{H5^|{U6;P"DU]@r ~Ѹ%,OLl~J"5cfg3Z7L.>ډFZm1nҼ qs}[ em!UՃ#ՄTCYGϣb.xpyG&Cta$Qc{Vv~n  dcb|ѓYhrUAtJ%MI @E'p3sbs}͟_:y/:X1Y,N -GjPj$Q n 4'84\A Sf\z}bujb( [F=EkK9?QL144єAQS(g#6OOVLNsyPڅ.I;P"!vqr2.gF(. sXQ:!!!d {FSJv!P=}"rAIΌ|U!m0FJ! e&֋bVDC$]kӥmĮ" ajj1mg W -*5끐|)Q^xMKw[|W(͒@F1ysҷ0@Xt~[SS ) fjw?q=HQ)4:gF̏.\ْJ?w")5jXuc!óeVMu*F`$kV ?]j*ã5 b9}NTW+*|գ( h i .`Vk, 2gM+*rA5ZEG!5Ĭa82T _&*rVYD.#S)8 *F:jn1G@v3Xʾ:5[UiPN-}♰B񒬧9l.l# ~+)URu\LlR4:`֞f[6J xxޖyRn#|] AHbw$+ş6ٱ^;(‹e;o  endstream endobj 21 0 obj << /Type /Page /Parent 1 0 R /LastModified (D:20250725034037+08'00') /Resources 2 0 R /MediaBox [0.000000 0.000000 595.276000 841.890000] /CropBox [0.000000 0.000000 595.276000 841.890000] /BleedBox [0.000000 0.000000 595.276000 841.890000] /TrimBox [0.000000 0.000000 595.276000 841.890000] /ArtBox [0.000000 0.000000 595.276000 841.890000] /Contents 22 0 R /Rotate 0 /Group << /Type /Group /S /Transparency /CS /DeviceRGB >> /PZ 1 >> endobj 22 0 obj <> stream x3357r/ RR) z`Tf`hISp 2mFC L,2L)sS3= S3c\.s|@ 4r}Kz t@kb@A@YY+cfdfdc'x,05,nfBH(Lgz{:~=MM ~a#S @M˹yd{-. qg8Lhf\Ay3=X[E3$ Ja[.V/eOD-k/ 9K A^hY@'bcPNf?8p+< 0G#0օLJPK11#`zt!HSI0Ky>ԽQx+vR9Yc)9gXE0 Fv4e&͜)X<ܐ?\i8xBxeQ~WGAIxxʼnQ]IţhSmd,.EoiMAh`ߵQ̖3f;ܴY,AOG qaB-y';|(n=I|%. "ɓd Qm\>Q. EۆAfc۪ͨ> `4y$Kя/*~[sC]%X\# @KW ճ YH38 oc;a:7- fQsO endstream endobj 23 0 obj << /Type /Page /Parent 1 0 R /LastModified (D:20250725034037+08'00') /Resources 2 0 R /MediaBox [0.000000 0.000000 595.276000 841.890000] /CropBox [0.000000 0.000000 595.276000 841.890000] /BleedBox [0.000000 0.000000 595.276000 841.890000] /TrimBox [0.000000 0.000000 595.276000 841.890000] /ArtBox [0.000000 0.000000 595.276000 841.890000] /Contents 24 0 R /Rotate 0 /Group << /Type /Group /S /Transparency /CS /DeviceRGB >> /PZ 1 >> endobj 24 0 obj <> stream xݙkAƷ$ 6$4nͺ$JDc4biGO^ԃRг ^<[Iif&lXlvw<3}~7 {D$nX8e|E1dKȨvޘ lHpF1iܼ3O~`"3ŒCß];.mAkKVd7-Y̭ A^)h ҧJ+tѳى{#+v"lڹq` g]" ă-ONr.Rv~mjFX%t^-ӛBu0 +aRBU+ڸzP,MgAmJ!uA6oA +D9");&s_{LPuv++~s_Gn}6X*U4†F3[&!V?-N #ГœJ,tȨo(.#1`Xֆ( kf̝ڎTV= kDxY厾c]SI%"1mQ^ (,Ʀ0Y$g釅 gه!9υץmRbO#pd,/<߫TTgqW{dޏEtfd [TW )Q -SN긼 J.^ Xېy*$YJutk:W̓)Kso BP endstream endobj 25 0 obj << /Type /Page /Parent 1 0 R /LastModified (D:20250725034037+08'00') /Resources 2 0 R /MediaBox [0.000000 0.000000 595.276000 841.890000] /CropBox [0.000000 0.000000 595.276000 841.890000] /BleedBox [0.000000 0.000000 595.276000 841.890000] /TrimBox [0.000000 0.000000 595.276000 841.890000] /ArtBox [0.000000 0.000000 595.276000 841.890000] /Contents 26 0 R /Rotate 0 /Group << /Type /Group /S /Transparency /CS /DeviceRGB >> /PZ 1 >> endobj 26 0 obj <> stream x3357r/ RR) z`Tf`hISp 2mFC L,2L)sS3= S3c\.s|@ 4r}Kz t@kb@A@YY+cfdfd`ǕgO*bLLhm !^ G#4? 3R= 9O%0l[a4s=="Տa~jfj?Φ&?ݰ bc R40=L{hϑ"雹BY&q%ifU:A7 YP>< [l-Yw6,5H=iy1?ݸe&R2x$ {P0mF(I#=kBL+ TfU7YdGX6WA^D.@y$Kqxpx1!3ȌdOf1F&ٙ= 2Mκ- yTT7%h6(s@كK؆г?7%ԭ{A[!Wׯux wnpp{1ŀ1㐃shL`cL[6Ľg^0*rM̡,Y`pa0024(^3? u/bŢDX@ Z{ gVRCg-)T fo endstream endobj 27 0 obj << /Type /Page /Parent 1 0 R /LastModified (D:20250725034037+08'00') /Resources 2 0 R /MediaBox [0.000000 0.000000 595.276000 841.890000] /CropBox [0.000000 0.000000 595.276000 841.890000] /BleedBox [0.000000 0.000000 595.276000 841.890000] /TrimBox [0.000000 0.000000 595.276000 841.890000] /ArtBox [0.000000 0.000000 595.276000 841.890000] /Contents 28 0 R /Rotate 0 /Group << /Type /Group /S /Transparency /CS /DeviceRGB >> /PZ 1 >> endobj 28 0 obj <> stream xAOAg=@cZبr5Bn_?g@0hfG .:r;䈊A\ERB8͎0hHnX4F»H."ia.J9{8Q36n[g2@{g_l;[ܢnK4&&n /SC]xSفyBӾ Ȣ\Sh2~ ~101*wt咰5z-4` }xS^txk/\D|"m" aGݢkv4֡nJ(.BϱC X\K4Fth*F(7o 6p^}kj lsoS* endstream endobj 29 0 obj << /Type /Page /Parent 1 0 R /LastModified (D:20250725034037+08'00') /Resources 2 0 R /MediaBox [0.000000 0.000000 595.276000 841.890000] /CropBox [0.000000 0.000000 595.276000 841.890000] /BleedBox [0.000000 0.000000 595.276000 841.890000] /TrimBox [0.000000 0.000000 595.276000 841.890000] /ArtBox [0.000000 0.000000 595.276000 841.890000] /Contents 30 0 R /Rotate 0 /Group << /Type /Group /S /Transparency /CS /DeviceRGB >> /PZ 1 >> endobj 30 0 obj <> stream xݙjPB1y-8sd.; T 53NETZP0Ba.\>|nD]wa(I=$23Lss̐]%b- 0/5XZU emﺸk]`ʒ}X$ǃTyƾE+~Ur&'ҳ*\yhvFgI{]Eb-QbxUp;uVQ9*,]p rMW=rMu.C0>6LN+#1‹D"!1$NoNloOx8 #MKd$Kgcܻsޣ_Ƨg cMáz7_f0@s_ MuNmϠvM>(z ju϶Hcj[$ۿII{WzQ)(6辩 St\GeYazQt܊zwj6eХ˼O "pM!R w)T WQ .p .pEVU܉UA*RM@5L^S> /PZ 1 >> endobj 32 0 obj <> stream xݙkAǷnNބa<-tvfw'Pel1Mc+Q  E<ڋo!t kvfSRo’e;3v NXIA-c 'J.dA.q>$FC6b-n/F)iىmQ_XqxF,jWOSvsi6(J|=6IkhLZ#}aΉ6b'=h8d n4g:>ޓUn/} VFF_W`u\5.R* .԰v+ HEd R3'5ԨqHiF @jL @jL"U5wJ )OjT54Xu|<@RCśc*#Oj`V5T.H.rGGyԐThD36ޓdsX8͠s臆|[]`3"_uEsW;v_C$+LfZYhfGPd(l5޺JZ>Gk-4ug 2͹^ tP&r)1=F0ʯd,񗍱yo' endstream endobj 33 0 obj << /Type /Page /Parent 1 0 R /LastModified (D:20250725034037+08'00') /Resources 2 0 R /MediaBox [0.000000 0.000000 595.276000 841.890000] /CropBox [0.000000 0.000000 595.276000 841.890000] /BleedBox [0.000000 0.000000 595.276000 841.890000] /TrimBox [0.000000 0.000000 595.276000 841.890000] /ArtBox [0.000000 0.000000 595.276000 841.890000] /Contents 34 0 R /Rotate 0 /Group << /Type /Group /S /Transparency /CS /DeviceRGB >> /PZ 1 >> endobj 34 0 obj <> stream x=K@ŚL. ]Kk7:m EŪXt.BA: ?"b~( BH} w<\PĴ+p܅\]"|r㬰%m2L>-Xr54s+XdGI#1QAE\  ;ƤS—*TKB0^!2n'qe|($nr6R2{ϩi֙(]&^ޘA9Y 3vph ۩gn|FcChM؉FȾvFT?5BjCIg2;8;=~,ۅvPHAͻg=|\ pRQ]t-=/ .7!Eمܜ)ƘƨƼw> /PZ 1 >> endobj 36 0 obj <> stream xMK0[z(lIڴC"NC;N.Og xӻċ!( 6I)-i7O oR ]( ('72oQ]H.݂EWC_ qc}>#ETӒk ͏C)'HQm!yF#zL42xLb4e(t'܍c"ۑ{&^7ffĨ+$ @n4g=~\9㕋Sޣ̷s@у<D49yҗyVjﭼ䦜[|9p֮ (}Gv<_a R=vW K1 ,Ӊk.h¢Hk> /PZ 1 >> endobj 38 0 obj <> stream x3357r/ RR) z`Tf`hISp 2mFC L,2L)sS3= S3c\.s|@ 4r}Kz t@kb@A@YY+cfdfdvۀ10'D !^ ]0=#TU651(0(3IuzϏ̦Ckfh^1`nQ[rp{ kZTXC+Ns0l;̞>\3ݯ3:Mۘ2x,j,`? endstream endobj 39 0 obj << /Type /Page /Parent 1 0 R /LastModified (D:20250725034037+08'00') /Resources 2 0 R /MediaBox [0.000000 0.000000 595.276000 841.890000] /CropBox [0.000000 0.000000 595.276000 841.890000] /BleedBox [0.000000 0.000000 595.276000 841.890000] /TrimBox [0.000000 0.000000 595.276000 841.890000] /ArtBox [0.000000 0.000000 595.276000 841.890000] /Contents 40 0 R /Rotate 0 /Group << /Type /Group /S /Transparency /CS /DeviceRGB >> /Annots [ 9 0 R 10 0 R ] /PZ 1 >> endobj 40 0 obj <> stream x3357r/ RR) z`Tf`hISp 2mFC L,2L)sS3= S3c\.s|@ 4r}K0%(ħ(]h%К"X9F(08,, ̍1323TIQ֨ v ]AO7ozjAr^THUY]^2x\:X=nq?&C"1~X AE=34@7ܴ#C{&ifQj CFɵ]{$%C{ɵX[SΤC{ cU}Z0#'(?"b"թ $?`Ggyt{Ad,E''&O@a="~8x Ґ;q$7 ADVRGflguǺwRP7cCb|lhd  %@XP`Š`ǐ dcHdH|t0 gCg0b0bS iY&@ ېːP@\clhghnrS i#x!$KԐX 0kYBX@~yjQjBRBsBFyy^IrAJ^~Qz&, R endstream endobj 1 0 obj << /Type /Pages /Kids [ 11 0 R 13 0 R 15 0 R 17 0 R 19 0 R 21 0 R 23 0 R 25 0 R 27 0 R 29 0 R 31 0 R 33 0 R 35 0 R 37 0 R 39 0 R ] /Count 15 >> endobj 3 0 obj <> endobj 4 0 obj <> endobj 41 0 obj <> /FontDescriptor 42 0 R /DW 1000 /W [ 1 [ 278 278 355 556 556 889 667 191 333 333 389 584 278 333 278 278 ] 17 26 556 27 28 278 29 31 584 32 [ 556 1015 667 667 722 722 ] 38 [ 667 611 778 722 278 500 667 556 833 722 778 667 778 722 667 611 722 667 944 667 667 ] 59 59 611 60 62 278 63 [ 469 500 333 556 556 500 556 556 278 556 556 222 222 500 222 833 ] 79 82 556 83 [ 333 500 278 556 500 722 ] 89 91 500 92 [ 334 260 334 584 ] 100 102 333 107 107 428 109 [ 222 222 333 333 ] 127 129 584 130 [ 422 561 561 713 823 561 561 549 561 600 549 418 584 800 800 506 506 ] 147 150 584 151 151 549 152 156 584 157 [ 549 561 561 740 740 667 222 372 1022 ] 171 [ 667 1073 823 816 ] 175 183 600 185 188 713 250 [ 278 555 832 933 667 ] ] >> endobj 42 0 obj <> endobj 5 0 obj <> endobj 43 0 obj <> /FontDescriptor 44 0 R /DW 1000 /W [ 1 [ 278 278 355 556 556 889 667 191 333 333 389 584 278 333 278 278 ] 17 26 556 27 28 278 29 31 584 32 [ 556 1015 667 667 722 722 ] 38 [ 667 611 778 722 278 500 667 556 833 722 778 667 778 722 667 611 722 667 944 667 667 ] 59 59 611 60 62 278 63 [ 469 500 333 556 556 500 556 556 278 556 556 222 222 500 222 833 ] 79 82 556 83 [ 333 500 278 556 500 722 ] 89 91 500 92 [ 334 260 334 584 ] 100 102 333 107 107 428 109 [ 222 222 333 333 ] 127 129 584 130 [ 422 561 561 713 823 561 561 549 561 600 549 418 584 800 800 506 506 ] 147 150 584 151 151 549 152 156 584 157 [ 549 561 561 740 740 667 222 372 1022 ] 171 [ 667 1073 823 816 ] 175 183 600 185 188 713 250 [ 278 555 832 933 667 ] ] >> endobj 44 0 obj <> endobj 7 0 obj << /Type /XObject /Subtype /Form /FormType 1 /Filter /FlateDecode /BBox [0.000000 0.000000 595.276000 85.039370] /Matrix [1 0 0 1 0 0] /Resources << /ProcSet [/PDF /Text /ImageB /ImageC /ImageI] /Font << /F3 5 0 R /F2 4 0 R >> >> /Length 214 >> stream xs Qw3V0434.=Ss0\@ cT q:H:  `Z0E @!ʁDM,, , L, MBR5:U$- dP`(C=d L> /XObject << /XT7 7 0 R >> >> endobj 6 0 obj <> /H /I>> endobj 8 0 obj <> /H /I>> endobj 9 0 obj <> /H /I>> endobj 10 0 obj <> /H /I>> endobj 45 0 obj << /Title (N-VY'epcnLNsrm^RgNS\\URMfoxzvbTJ2025-2032^t ) /Producer (TCPDF 6.2.26 \(http://www.tcpdf.org\)) /CreationDate (D:20250725034037+08'00') /ModDate (D:20250725034037+08'00') /Trapped /False >> endobj 46 0 obj << /Type /Metadata /Subtype /XML /Length 4308 >> stream application/pdf 中国大数据行业现状深度分析与发展前景研究报告(2025-2032年) 2025-07-25T03:40:37+08:00 2025-07-25T03:40:37+08:00 2025-07-25T03:40:37+08:00 TCPDF 6.2.26 (http://www.tcpdf.org) uuid:27d07756-3224-8920-1288-845102644299 uuid:27d07756-3224-8920-1288-845102644299 http://ns.adobe.com/pdf/1.3/ pdf Adobe PDF Schema http://ns.adobe.com/xap/1.0/mm/ xmpMM XMP Media Management Schema internal UUID based identifier for specific incarnation of a document InstanceID URI http://www.aiim.org/pdfa/ns/id/ pdfaid PDF/A ID Schema internal Part of PDF/A standard part Integer internal Amendment of PDF/A standard amd Text internal Conformance level of PDF/A standard conformance Text endstream endobj 47 0 obj << /Type /Catalog /Version /1.7 /Pages 1 0 R /Names << >> /ViewerPreferences << /Direction /L2R >> /PageLayout /SinglePage /PageMode /UseNone /OpenAction [11 0 R /FitH null] /Metadata 46 0 R >> endobj xref 0 48 0000000000 65535 f 0000021623 00000 n 0000024912 00000 n 0000021782 00000 n 0000021888 00000 n 0000023143 00000 n 0000025047 00000 n 0000024420 00000 n 0000025262 00000 n 0000025472 00000 n 0000025682 00000 n 0000000015 00000 n 0000000485 00000 n 0000001049 00000 n 0000001519 00000 n 0000002784 00000 n 0000003236 00000 n 0000005151 00000 n 0000005603 00000 n 0000007823 00000 n 0000008275 00000 n 0000009583 00000 n 0000010035 00000 n 0000010868 00000 n 0000011320 00000 n 0000012180 00000 n 0000012632 00000 n 0000013452 00000 n 0000013904 00000 n 0000014768 00000 n 0000015220 00000 n 0000015952 00000 n 0000016404 00000 n 0000017180 00000 n 0000017632 00000 n 0000018184 00000 n 0000018636 00000 n 0000019182 00000 n 0000019634 00000 n 0000020386 00000 n 0000020863 00000 n 0000022029 00000 n 0000022891 00000 n 0000023289 00000 n 0000024156 00000 n 0000025900 00000 n 0000026181 00000 n 0000030572 00000 n trailer << /Size 48 /Root 47 0 R /Info 45 0 R /ID [ <27d07756322489201288845102644299> <27d07756322489201288845102644299> ] >> startxref 30782 %%EOF