a r X i v :a s t r o -p h /9804178v 1 17 A p r 1998
Mon.Not.R.Astron.Soc.000,Ln–Ln (1998)Printed 1February 2008
(MN plain T E X macros v1.6)
The terminal bulk Lorentz factor of relativistic electron-positron jets.
N.Renaud and G.Henri
Laboratoire d’Astrophysique,Observatoire de Grenoble,BP 53X F-38041Grenoble Cedex France Accepted —-.Received —-
ABSTRACT
We present numerical simulation of bulk Lorentz factor of relativistic electron-positron jet driven by Compton rocket e?ect from accretion disc radiation.The plasma is as-sumed to have a power-law distribution n e (γ)∝γ?s whith 1<γ<γmax and is con-tinuously reheated to compensate for radiation losses.We include full Klein-Nishina (hereafter KN)cross section,and study the role of energy upper cut-o?γmax ,spectral index s ,and source compactness.We determine terminal bulk Lorentz factor in the case of supermassive black holes relevant to AGN and stellar black holes relevant to galactic microquasars.In the latter case,Klein-Nishina cross section e?ect are more important,and induce terminal bulk Lorentz factor smaller than in the former case.Our result are in good agreement with bulk Lorentz factors observed in galactic sources (GRS1915+105,GROJ1655-40)and extragalactic ones.Di?erences in scattered radi-ation and acceleration mechanism e?ciency in AGN environment can be responsible for the variety of relativistic motion in those objects.We also take into account the in?uence of the size of the accretion disc;if the external radius is small enough,the bulk Lorentz factor can be as high as 60.
Key words:galaxies:active -galaxies:jets -radiation mechanism:miscellaneous -stars:individual:GRS1915+105,GROJ1655-40
1INTRODUCTION
Superluminal motion observed in Active Galactic Nuclei (AGN),especially in the blazars class,seems to be closely linked with high-energy emission.Such motion was recently observed in the Galaxy (Mirabel &Rodriguez 1994,Hjellm-ing &Rupen 1995,Tingay et al.1995)in the so-called mi-croquasars.Nevertheless di?erences are noticeable in those two cases.The latter systems were observed with small value of bulk Lorentz factor (around 2.5),while in the former ones values of about 10-20are frequent.It is well known that the radiation pressure acting on electron-positron plasma in the vicinity of a near Eddington accreting object is very e?-cient to accelerate the plasma outwards,since the gravita-tional force is around 1000times weaker than for an electron-proton plasma.However,Phinney (1987)has shown that for a realistic accretion disc emission,only moderate values of bulk Lorentz factors can be reached.Li &Liang (1996),have recently proposed that this mechanism could explain the rel-atively small γb ～2.5observed in galactic objects.They considered plasma composed with both e +e ?and e ?p and obtained the equation of motion using the Thomson cross section and including gravitation force.To explain higher values of γb ,O’Dell (1981)proposed the so-called ’Comp-ton rocket’e?ect,i.e.anisotropic Inverse Compton e?ect on a highly relativistic plasma.It was then argued (Phinney
1982)that because Compton cooling is always much more
rapid than bulk acceleration,only small value of γb ∞could be reached by this mechanism.However,taking into account that in the frame of the ’two-?ow’model (Sol,Pelletier &Ass′e o 1989),a pair plasma could be reheated by the tur-bulence triggered by a surrounding jet (Henri &Pelletier 1991),Marcowith,Henri &Pelletier (1995)showed that the Compton rocket becomes much more e?cient and acceler-ates pair plasma to Lorentz factor γb ～10.In another work Sikora et al.(1996)studied the radiation drag in AGN jets.They included relativistic electron-positron plasma acceler-ated in situ and relativistic protons which contribute to the inertia of the ?ow.They considered radiation emitted from an accretion disc,partially reprocessed by the outer part of the disc or by spherically distributed matter at a given distance from the central object.All Compton interactions were computed using Thomson cross section.They showed that in most cases jets should undergo radiation drag,and that the e?ciency of this mechanism becomes important for purely pair plasma dominating the jet luminosity.The aim of this paper is to study how Compton rocket e?ect can accelerate a pure pair plasma in the vicinity of accretion disc,taking into account the full KN cross section.Follow-ing Marcowith et al.(1995),we consider a blob of e +e ?pair plasma with an isotropic energy distribution in the comov-ing frame n ′e (γ′)∝γ
′?s
,where s is the spectral index.We c
1998RAS
2N.Renaud and G.Henri
assume that the acceleration process is e?cient enough in the jet to get a stationary energy distribution.We assume that the dynamics of the pair plasma is decoupled from the electron proton component and we do not include gravita-tion force.The radiation?eld is coming from an accretion disc.We include KN corrections in the description of the In-verse Compton interactions.We study the in?uence of both compactness of the radiation source,spectral index and up-per cut-o?γmax,and make then comparisons between AGN and galactic microquasars.We also consider the in?uence of scattered radiation by a Broad Line Region(BLR)and dusty torus around the central black hole.Finally we discuss the in?uence of accretion disc’s size that could be relevant to the high value of bulk Lorentz factors.
2COMPTON ROCKET EFFECT WITH
KLEIN-NISHINA CORRECTIONS
2.1Notations
All energies are measured in unit m e c2.We refer all quanti-ties expressed in the blob rest frame by a prime′,all quanti-ties in the particle rest frame by a star?and quantities in the disc frame are not labelled.Photon energies will be labelled byε,and the unit direction vector by k.We use the KN di?erential cross section(Rybicki&Lightman1979)given by:
dσ
16 ε?1ε?+ε?
1+ε?(1?cosφ?) .
σT=
8π
4πε0m e c2is the electron classical radius.This expression
applies to the scattering of a photon with energyε?and di-
rection k?in a photon with energyε?1and direction k?
1,and
cosφ?=k?.k?
1
.
2.2The general picture
Figure1shows the general con?guration of the model.
The pair plasma is assumed to be described in the bulk rest frame by an energy distribution n′e(z,γ′)∝γ′?s for γmin<γ′<γmax,with s,γmin andγmax independent of z (see paragraph3.2.1for a further discussion of this assump-tion).The radiation force is due to soft photons coming from a standard accretion disc(Shakura&Sunyaev1973)around a Schwarzschild black hole.The inner radius of the accretion disc is r i=3r g(where r g is the Schwarzschild radius of the black hole).The outer radius r e is a free parameter.We use the black-body approximation for the disc emission so that the speci?c intensity at a radius r is:
Iν(r)=Bν(T ef f(r)),(1) where Bνis the Planck function and the e?ective tempera-ture T ef f is given by:
T ef f(r)= 3GM˙M
x 1+x+16x3+1
3M⊙
1017g.s?1
4π2 r2r1r1?αd r g(ν?νLyα),(5) The radiation is re-emitted by a ring for r1 c 1998RAS,MNRAS000,Ln–Ln The terminal bulk Lorentz factor of relativistic electron-positron jets.3 at a distance z on the jet axis is: Iν(z,θ)= χL d 1+ z z2+r20and for z>r0, 4πσ r4r3T4(r)r d r Bν((T(r)),(7) T is the dust temperature,σis the Stefan-Boltzmann con- stant,andχ′is the fraction of the disc luminosity that is reprocessed. 2.3Computation of the radiative force Let d p′ 1?1/γ′2c its velocity.The force exerced upon the pair plasma is then in the blob rest frame: F′z= d?′e dγ′n′e(γ′,?′e)d p′ F grav ～ m p c 4πH′ (1+2 d t? =? d n?dσ d t? =?c d n?dσ d t′ = d p?x c d E? d t′ =?σT d n?(f p(ε?)+β′f E(ε?)).(14) The two functions f p and f E are given by: f p(ε?)=(1+ε?)f(ε?), f E(ε?)=?ε?f(ε?), where the function f(ε?)corresponds to the ultrarelativistic case(β′=1)and is given by: f(ε?)= 1 ε?3(1+2ε?)3 +ln(1+2ε?)× 1 ε?3(1+2ε?)3 . We then use these expressions in equation(8). We can estimate the errors in the two extreme regimes described above.In the head-on approximation the?rst cor- rections are roughly 1 γ2crit ～γcrit ε ～ ε 2/3.For AGN ε ～10?4and we ?ndγcrit～20?30with a maximum error～0.2%while for a microquasar ε ～10?2andγcrit～5with a maximum error～5%. 2.4Equation of motion Following Phinney(1982)we determine the acceleration of pair plasma by considering the conservation of stress-energy c 1998RAS,MNRAS000,Ln–Ln 4N.Renaud and G.Henri tensor leading to Phinney’s(7)and(8)equations in the bulk rest frame: ? ?t′ [(ρ′+p′)γbβb]=F′z+βb F′0.(16) Combining these two equations and for a reheated relativis-tic plasma(with p′=ρ′/3)one?nds the equation of motion (with dz′=βb dt′and z=z′): dγb ρ′ 1 3γ2 b +1 .(17) To compute the radiative force by equation(14)we need the di?erential photon distribution in each electron rest frame. For this we use the Lorentz invariant d n γ′ 1/7,while for z crit>r e,γb∞∝ r i γ′ 1/4(see Appendix A).l= σT L The terminal bulk Lorentz factor of relativistic electron-positron jets. 5 Figure3.Equilibrium Lorentz factorγbeq as a function of z in the Thomson limit.γbeq is given for r e=10r g,r e=102r g, r e=103r g and r e=3.103r g.We also represent the two asymp- totic regimesγbeq∝z1/4for z r e=3.103r g . Figure4.The Equilibrium Lorentz factor calculated including KN corrections compared to Thomson solution.The?gure cor- responds to a stellar black hole M=5M⊙withγmax=107 for spectral index s=1.5and s= 5.The external radius is r e=3103r g and L=L Edd. in this paragraph still holds even including KN corrections. The critical point z crit is reached rather close to the central engine(before104Schwarzchild radii).For z>z crit the mo- tion is nearly balistic and so independent of the radiation force which has become too weak.It is so independent of any variation of the pair distribution unless these variations strengthen the radiation force.This scenario would require a more e?cient acceleration mechanism when moving away from the central source,which is very unlikely.Therefore our assumption of a stationary pair energy distribution on a large range of z does not in?uence strongly the terminal value ofγb,or in other words this value is essentially deter- mined by the local parameters at the critical distance. 3.2.2In?uence of the energy upper cut-o?and spectral index Figure6illustrates the in?uence of the spectral index(for 1.5≤s≤5)and the energy cut-o?(for103≤γmax≤ 107)on the terminal Lorentz factor.We chose M=5M⊙ representative for stellar black holes and M=109M⊙for supermassive black holes.The calculations were carried out for L=L Edd and L=0.1L Edd,where L is the luminosity of the accretion disc. Results are very sensitive to the spectral index value. There are3di?erent behaviours according to the value of s. (i)for s<2there exists a maximum terminal Lorentz factor as a function ofγmax and the curve intercepts the other ones. (ii)for2 less pronounced.The variation as a function ofγmax are smoother. (iii)for s>3no variation withγmax. We?nd that for low value ofγmax,our solutions agree with the Thomson regime solutions.Nevertheless KN corrections reduce the e?ciency of the Compton rocket e?ect.As a matter of fact,in the Thomson regime,an increase ofγmax leads to an increase of γ′2 (for s<3)and so ofγb∞.This mechanism is valid until KN corrections begin to dominate, roughly whenγmax ε ～1.So whenγmax is greater than ε ?1the radiation force does not increase anymore whereas the plasma inertiaρ′is much more important.This leads to a less e?cient acceleration mechanism.This e?ect is larger for small indexes explaining the inversion of the curve for highγmax.Indeed we?nd that acceleration is much more e?cient for s=2andγmax=107than for s=1.5and the same value ofγmax,in the case of stellar black hole.When steepening the pair distribution,the radiation force is dom- inated by the low energy part of the distribution.This fact explains why no variation is apparent withγmax for s>3. The plasma behaves dynamically as a cold one,and we?nd small value of terminal Lorentz factor.Finally including KN corrections in the calculations gives rise to an absolute upper limit to maximal Lorentz factor for a given luminosity. 3.2.3In?uence of the black hole mass As discussed above the in?uence of the mass of the central black hole is predominant.Stellar black holes with soft X-ray emission( ε ～10?2)are less e?cient in accelerating blob of pair plasma than supermassive black hole with softer ra- diated emission( ε ～10?4),because KN saturation e?ects occur at much lower energy.A more realistic description of the accretion disc around stellar black holes reinforces this discrepency.As shown in?gure7the radiation emitted from a two-temperature disc(Shapiro et al.1976)leads to smaller γb∞than in the case of standard accretion disc radiation. Because it is well established that accretion disc around stel- lar black holes should radiate up to a few keV(as in a two- temperatures disc),KN corrections play an important role in this case. c 1998RAS,MNRAS000,Ln–Ln 6N.Renaud and G. Henri Figure5.Solutions of the equation of motion in the case of a stellar black hole(M=5M⊙).We chose two di?erent initial con- ditionsγb init=2andγb init=5.r e=3103r g and L=L Edd. 3.2.4In?uence of the luminosity As ε ∝˙M1/4M?1/2,the luminosity of the disc also directly in?uences the maximum of the functionγb∞as a function ofγmax.As shown in?gure6,the maximum takes place at higherγmax when the luminosity decreases.Besides less luminous systems contribute to a lower radiation force and so to a less e?cient acceleration.In the Thomson regime one has a dependanceγb∞∝L1/7. 3.2.5E?ect of scattered radiation All the results described above are obtained when studying the disc radiation alone.We also include in our calculation BLR radiation?elds corresponding to two cases: a)re-emission from a ring located between r1and r2and with an emissivity given by equation(5) b)re-emission from spherically distributed matter at a distance r0from the central black hole with an emissivity given by equation(6). Figure8displays the equilibrium Lorentz factor in the pres- ence of a BLR located between r1=104r g and r2=105r g (case a),?gure8)in the Thomson regime.We also plotted the equlibrium Lorentz factor including KN corrections as well as the solution of the equation of motion for a plasma with s=2andγmax=105.As one can see,the e?ect of BLR onγbeq is very weakened by KN corrections.This can be understood because the photons coming from the BLR are blueshifted by the relativistic motion in the blob rest frame whereas the photons coming from the disc are red- shifted.So the dragging force from the BLR is much more reduced by KN corrections than the accelerating one due to disc photons.Due to the weakness of the radiation?eld, the dynamical solutionγb(z)is still less a?ected than the equilibrium value.The case of a spherical shell located at r0=104r g(case b))is illustrated in?gure9.One can see that the di?used radiation?eld strongly a?ects the motion that is almost stopped at the crossing of the shell,where ra- diation density is dominated by the isotropically scattered photons.However,the plasma is quickly reaccelerated after the crossing,and high Lorentz factor can be reached again. Sikora et al.(1996)argued that scattered radiation should lead to e?cient radiation drag.However,the in?u- ence of scattered radiation is strongly governed by the posi- tion of scattering clouds with respect to the critical distance z crit:if they lie below this critical distance,the plasma will be temporarily braked during the crossing of scatter- ing region,but will be quickly reaccelerated after it.If the clouds lie above z crit,the terminal Lorentz factor can indeed be strongly a?ected.Figure10and11display the terminal Lorentz factor as a function ofγmax for di?erent distances of the BLR.It can be seen that if it is close enough,the BLR can give still higher Lorentz factor than for the disc alone for the highest value ofγmax.This is because the solid angle substended by it at z crit is so small that its radiation?eld has an accelerating rather than decelerating e?ect.But even for a BLR between104and105r g,terminal Lorentz factor around10are clearly reachable.We conclude that the pres- ence of broad lines can a?ectγb∞,but does not prevent in general highly relativistic motions. We also discuss the e?ect of a possible emission from a hot dusty torus surrounding the central black hole outside the BLR region.The e?ect of such a scattered radiation ?eld is much more important because KN corrections are here almost negligible.Figure12shows the terminal Lorentz factor in the presence of an IR emitting ring heated at T= 1500K,located between r3and r4.It is obvious that the terminal Lorentz factor is strongly reduced to values around 3for the less favourable case(r3=104r g,r4=105r g).The situation is a little less dramatic for more distant sources (r3=105r g,r4=106r g)because the isotropic radiation density is lowered,andγb∞of5can be reached. 3.2.6In?uence of the accretion disc size For small value of r e the radiation is more anisotropic and so more e?cient to accelerate the pair plasma(see?gure 13).In this?gure r e=10r g and we show the solutions for which we obtain the largestγb∞in extragalactic and galac- tic cases.In this con?guration the radiation force is more e?cient andγb∞can be as high as60in the extragalac- tic case.The dependance on s andγmax is shown in?gure 14,where we extend the previous calculation to the case r e=10r g.We?nd the same global behaviour ofγb∞with spectral index andγmax. 4COMPARISONS WITH OBSER V ATIONS Our model gives good agreement with observations of rela- tivistic blob ejection in AGN and microquasars for the’disc alone’solution.Figure6shows that in the most favourable con?guration(s=1.5,γmax～106and L=L Edd)Compton rocket e?ect is able to accelerate pair plasma up to Lorentz factorγb∞≥20.This value is only gradually reached,the jet being much slower at small distances.One can obtain higher c 1998RAS,MNRAS000,Ln–Ln The terminal bulk Lorentz factor of relativistic electron-positron jets. 7 Figure 6.Terminal Lorentz factor γb ∞as a function of γmax for di?erent value of spectral index s .The two top pannels correspond to M =109M ⊙black hole with r e =3.103r g ,L =L Edd (left)and L =0.1L Edd (right).The two bottom pannels correspond to M =5M ⊙black hole with r e =3.103r g ,L =L Edd (left)and L =0.1L Edd (right). Figure https://www.doczj.com/doc/5214242785.html,parisons of terminal Lorentz factor for a standard accretion disc (right)and a two-temperature disc (Shapiro et al.1976)extended up to 15r g (left).In both case r e =3103r g ,M =5M ⊙and the accretion rate is the Eddington one. value for super-Eddington systems.One can notice that ob-servations of the faster extragalactic superluminal motion correspond to such value of bulk Lorentz factor (Vermeulen &Cohen 1994). This value is however strongly dependent on the spec-tal index s and the high energy particle distribution cut-o? c 1998RAS,MNRAS 000,Ln–Ln 8N.Renaud and G. Henri Figure8.Equilibrium Lorentz factor as a function of z for radia- tion coming from an accretion disc and BLR radiation from a ring located between r1=104r g and r2=105r g.The emissivity is de- scribed by equation(5)withχ=0.1andα=2.We also show the solution of the equation of motion for this case.The solid curve showsγbeq in Thomson regime.The plasma parameters are s=2andγmax=105.The black hole mass is M=109M⊙and L=L Edd . Figure9.Same as?gure8for a BLR radiation from a shell located at r0=104r g.The emissivity is described by equation (6)withχ=0.1. γmax.The precise value of s is not obvious to derive from observations.High energy spectra show typical X-ray spec- tral indexes around0.5,which correspond to s?2.There is very often a spectral break in the MeV range:this could be attributed to a break in the particle distribution,that would correspond toγmax=102.However,Marcowith et al.(1995) have shown that this break could be very well reproduced Figure10.Terminal Lorentz factorγb∞as a function ofγmax for the spectral index s=2.The solid line shows the solution obtained including KN corrections for a standard accretion disc. The scattered radiation is described by equation(5)withχ=0.1, α=2and di?erent locations of the BLR ring. Figure11.Same as?gure10for scattered radiation described by equation(6)withχ=0.1and di?erent locations of the BLR shell. byγ?γabsorption with an actual particle distribution giv- ing the primary photon spectrum that can extend to much higher energy.So high energy spectra may not be good indi- cators of the upper cut-o?γmax.Moreover,the high energy emission probably takes place at relatively small distances (around102r g)from the center,well below z crit:the?nal bulk Lorentz factor is not yet reached at this distance.On the other hand,the detection of photons with at least30 GeV,and even above TeV for some BL Lacs,implies an upper cut-o?γmax≥105. c 1998RAS,MNRAS000,Ln–Ln The terminal bulk Lorentz factor of relativistic electron-positron jets. 9 Figure12.The in?uence of a dusty ring combined with a BLR on the terminal Lorentz factorγb∞as a function ofγmax,for the spectral index s=2.The solid line shows the solution obtained including KN corrections for a standard accretion disc.The BLR ring emissivity is described by equation(5)withχ=0.1,α=2. The dusty ring emissivity is given by equation(7)withχ′=0.1or χ′=0.05.We chose di?erent locations for these two components. Figure13.Solutions of the equation of motion for a supermassive black hole(M=109M⊙)and a stellar black hole(M=5M⊙) with a compact accretion disc.r e=10r g and L=L Edd.γb init is the initial condition of the solution.We also represent the equi- librium Lorentz factor in Thomson regime. Radio spectral indexes are also di?cult to assess be- cause of synchrotron self-absorption,especially for radio- ?at quasars where the observed spectrum results probably from the superposition of many self-absorbed spectra.The optically thin index ranges mostly from0.5to1,which corresponds to2≤s≤ 3.With reasonable parameters (2≤s≤3andγmax≤105),our model predicts typical values4≤γb∞≤10which are the most frequently ob- served(Vermeulen&Cohen1994).Moreover,as shown in Sect.3.2.5,KN e?ects prevents from strong Compton drag induced by BLR radiation in the vicinity of the central black hole.The fastest superluminal motions may be attributed to those objects for which the BLR is weak and/or closest to the central object. On the other hand,the slowest motions(γb∞≤4)can be obtained in the presence of a rich and extended environ- ment of scattering material,such as BLR clouds and dusty torus.The presence of dust is inferred from an enhance- ment in the near infrared in some quasars spectra(Bairvai- nis1987).Nevertheless a nonthermal infrared component, attributed to synchrotron radiation from the relativistic jet, is also usually observed in radio-loud AGN.This compo- nent is generally predominant in?at spectrum radio quasars (Neugebauer et al.1986)and is necessary to explain rapid variations observed in infrared?aring objects.We can specu- late that these objects with the largest superluminal motion are those where the scattered thermal component is par- ticularly weak.Such’nonthermal’objects should not su?er strong radiation drag,while’thermal’ones should have the lowest terminal Lorentz factors.In conclusion the diversity among observed superluminal motions can be reproduced by our model by considering both in?uence of the plasma acceleration mechanism and AGN environment. The observed value of Lorentz factor of about2.5for the two microquasars(GRS1915+105,Mirabel&Rodriguez 1994and GROJ1655-40,Hjemlling&Rupen1995)with large spectral indexes(respectively s～4,Finoguenov et al.1994and s～4.6,Harmon et al.1995)are consistent with our results.We show?gure15the dependance ofγb∞ on compactness of the source for s=4and s=5.We ?nd that observations require L～0.2?0.3L Edd,which is very close to the result by Li&Liang(1996).This result is not strongly a?ected by the mass of the central black hole if the compactness of the source remains the same.The steep spectrums observed in these two objects ensure us that the terminal Lorentz factor is just dependant on the low energy cut-o?of the electron distribution.In this case a more realistic description of the accretion disc emission does not change our results for such spectral indexes(?gure7).Yet the maximal value ofγb∞is model dependant.The part of high energy emission contributes to decrease this value from the one obtained for a standard accretion disc.We?nd that value of about6can be reached in the most favourable case. Finally,γb∞is much higher for a small sized accretion disc.We?nd value of about60in the case of an external radius of10r g in the case of supermassive black hole. 5CONCLUSION We have considered the bulk acceleration of an electron- positron pair plasma in the vicinity of a central black hole. The acceleration is due to Compton rocket e?ect on the plasma and the radiation force originates from a standard accretion disc emission.The pair plasma is continuously re- heated by an e?cient turbulent mechanism wich takes place in the frame of the’two-?ow’model.Thus we assumed in our calculations a stationary power-law energy distribution for the pair.We included KN corrections in the computation c 1998RAS,MNRAS000,Ln–Ln 10N.Renaud and G. Henri Figure 14.Terminal Lorentz factor γb ∞as a function of γmax for di?erent value of spectral index s .The two pannels correspond to r e =10r g ,L =L Edd ,M =109M ⊙(left)and M =5M ⊙ (right). Figure 15.The terminal Lorentz factor as a function of L/L Edd and for two spectral indexes (s =4and s =5).M =5M ⊙,γmax =103. of the radiation force,and solved numerically the equation of motion.We studied con?gurations relevant to relativistic motion in AGN and galactic microquasars.The main results of our calculations can be summarized as follows: (i)For a given luminosity,the terminal Lorentz factor γb ∞admits an absolute maximum due to KN corrections.Val-ues of about 20can be reached in the extragalactic case,for su?ciently ?at spectrum (s ～1.5)and accretion at the Ed-dington rate which may correspond to the highest observed relativistic motion.For more reasonable plasma parameters (s ≤2and γmax ≤106)the Compton rocket e?ect can ac-count for the typical value of terminal Lorentz factor inferred from observations (γb ∞). (ii)Scattered radiation from extended BLR or dusty torus can brake e?ciently relativistic motion,even for a high en-ergy plasma.This Compton drag and a weak plasma heat-ing can be responsible for the lowest terminal Lorentz fac-tor observed.The highest superluminal motion could be at-tributed to objects with particularly weak di?use component and very e?cient heating. (iii)For stellar black holes KN corrections are important leading to smaller values than for a supermassive black hole.Recent observations of relativistic ejection in galactic micro-quasar are consistent with our results.ACKNOWLEDGMENTS We would like to thank the anonymous referee for his helpful remarks,especially for the description of scattered radiation.REFERENCES Barvainis,R.,1987,ApJ,320,537 Blumenthal,G.R.,Gould,R.J.,1970,Rev.of mod.physics,42, 2237,Bremsstrahlung,Synchrotron radiation,and Compton scattering of high-energy electrons traversing dilute gases Finoguenov,A.et al.,1994,ApJ,424,940Harmon,B.A.et al.,1995,Nature,374,703 Henri,G.,Pelletier,G.,1991,ApJ Letters,383,L7 Henri,G.,Pelletier,G.,Roland,J.,1993,ApJ Letters,404,L41Hjellming,R.M.,Rupen,M.P.,1995,Nature,375,464Li,H.,Liang,E.P.,1996,ApJ,458,514 Marcowith,A.,Henri,G.,Pelletier,G.,1995,MNRAS,277,681Mirabel,I.F.,Rodriguez,L.F.,1994,Nature,371,46Neugebauer,G.et al.,1986,ApJ,308,815O’Dell,S.L.,1981,ApJ Letters,243,L147Phinney,E.S.,1982,MNRAS,198,1109 Phinney,E.S.,1987,in Superluminal Radio Sources,ed.Zensus, J.A.&Pearson,T.J.,301(Cambridge,UK) Rybicki,G.B.,Lightman,A.P.,1979,Radiative Processes in Astrophysics (New York:John Wiley) Shakura,N.I.,Sunyaev,R.A.,1973,A&A,24,337 Shapiro,S.L.,Lightman,A.L.,Eardley,D.M.,1976,ApJ,204, 187 c 1998RAS,MNRAS 000,Ln–Ln The terminal bulk Lorentz factor of relativistic electron-positron jets.11 Sikora,M.,Sol,H.,Begelman M.C.,Madejski,G.M.,1996,MN- RAS,280,781 Sol,H.,Pelletier,G.,Ass′e o,E.,1989,MNRAS,327,411 Sunyaev,R.A.,Titarchuk,L.G.,1980,A&A,86,121 Tingay,S.J.et al.,1995,Nature,374,141 Vermeulen,R.C.,Cohen,M.H.,1994,ApJ,430,467 APPENDIX A:EQUILIBRIUM LORENTZ F ACTOR AND TERMINAL LORENTZ F ACTOR IN THOMSON REGIME Eddington parameters are de?ned as follows: J= 1 4π μIν(?)d?dν,(A1) K= 1 r1/4 i (A4) In the case z>r e we haveεu=r/z<1for1 we can expand the term(1+ε2u2)?βinto series: (1+ε2u2)?β= k(?1)kβ(β+1)...(β+k?1) k! × u2k?1e?12k?3/2 .(A6) The?rst coe?cients inεare then: I(2,β,1)=A0?βA1ε2+ β(β+1) 3?u?1e+ 2 3 , A1=u e?2u1/2 e +1～u e,(A8) A2=u3e 5 + 1 3 . The equivalents are given for u e?1.This gives for the Eddington parameters: J=(L/8π2r2i)(1?2b/3)?1ε2(A0?3/2A1ε2+15/8A2ε4), H=(L/8π2r2i)(1?2b/3)?1ε2(A0?2A1ε2+3A2ε4),(A9) K=(L/8π2r2i)(1?2b/3)?1ε2(A0?5/2A1ε2+35/8A2ε4). The equilibrium Lorentz factor isγbeq=(1?β2beq)?1/2where βbeq=x?(x2?1)1/2,(A10) with x= J+K 8 u3eε4,(A12) βbeq=1? u3/2 e r3/4 e r1/4 i .(A14) The asymptotic solution of equation(17)is approxima- tivelyγb∞=γbeq(z crit),where z crit is the location where the radiative force becomes to weak to maintainγb(z)= γbeq(z).This occurs when the evolution ofγbeq,i.e.?z0= γbeq/(dγbeq/d z)=dlog(z)/(z dlog(γbeq)),is larger than the evolution ofγb towardsγbeq,i.e.?z1=(dγb/d z)/(γb?γbeq). Using equation(17)one?nds: z crit～ 1dγb γbeq ?1.(A15) In the Thomson regime we can use equation(9)and(10) which give in the relativistic case: d F′z c 8π dγb = 2H m e c3 γ′2 r e 3/4 γ′2 m e c3r i γ′2 γ′ 1/7.(A20) This paper has been produced using the Royal Astronomical Society/Blackwell Science T E X macros. c 1998RAS,MNRAS000,Ln–Ln 关于欣赏的名人名言 本文是关于名人名言的，仅供参考，如果觉得很不错，欢迎点评和分享。 关于欣赏的名人名言 1、美貌常常比酒更坏，因为它能使持有者和欣赏者双方沉醉。——齐默尔曼 2、而你欣赏我因我本性不会改，别太认真，认真怎可放开自在。——林夕 3、人生犹如一本书，愚蠢者草草翻过，聪明人细细阅读。为何如此。因为他们只能读它一次。人生无益于人类，便是无价值的。 4、路是脚踏出来的，历史是人写出来的。人的每一步行动都在书写自己的历史。——吉鸿昌 5、一个不欣赏自己的人，是难以快乐的。——三毛 6、人生的价值，即以其人对于当代所做的工作为尺度。——徐玮 7、你要欣赏自己的价值，就得给世界增添价值。——歌德 8、人生天地之间，若白驹过隙，忽然而已。人生是最伟大的宝藏，我晓得从这个宝藏中选取最珍贵的珠宝。 9、春蚕到死丝方尽，人至期颐亦不休。一息尚存须努力，留作青年好范畴。——吴玉章 10、人生应该如蜡烛一样，从顶燃到底，一直都是光明的。—— 萧楚女 11、人的一生可能燃烧也可能腐朽，我不能腐朽，我愿意燃烧起来！——奥斯特洛夫斯基 12、风前有恨梅千点，沙上无人月一痕。——谭知柔《晚醉口占》 13、我给我母亲添了不少乱，但是我认为她对此颇为享受。——马克·吐温 14、恨芳菲世界，游人未赏，都付与，莺和燕。——陈亮 15、在孩子们的口头心里，母亲就是上帝的名字。——萨克雷 16、欣赏，这就是为着一件事物本身而爱好它，不为旁的理由。——达·芬奇 17、你若要喜爱你自己的价值，你就得给世界创造价值。——歌德 18、我们往往只欣赏自然，很少考虑与自然共生存。——王尔德 19、人生就象弈棋，一步失误，全盘皆输，这是令人悲哀之事；而且人生还不如弈棋，不可能再来一局，也不能悔棋。人生就是跋涉，人生就是开拓，人生就是与苦难争斗角逐；假如因我们承受苦难，能使后代免于受苦，那就是我们无上的幸福。 20、世界上的一切光荣和骄傲，都来自母亲。——高尔基 21、我之所有，我之所能，都归功于我天使般的母亲。——林肯 英美文学专业开题报告 引导语：各民族的文学中都有许多惊险、恐怖的故事,但似乎没有哪一种文学像英美文学那样不仅创作出数量众多、质量优秀的恐怖文学作品,而且还形成了一个持续发展、影响广泛的哥特传统。以下 是的为大家找到的英美文学专业开题报告。希望能够帮助到大家! 论文题目theApplicationandInnovation 一、选题的意义和研究现状 1.选题的目的、理论意义和现实意义长时期以来,人们视艾米莉?勃朗特为英国文学中的“斯芬克斯”。关于她本人和她的作品都有很多难解之谜,许多评论家从不同的角度、采用不同的方法去研究,得出了不同的结论,因而往往是旧谜刚解,新谜又出,解谜热潮似永无休止。 本文立足于欧美文学中的哥特传统研究《呼啸山庄》的创作源泉,指出艾米莉?勃朗特在主题、人物形象、环境刻画、意象及情节构造等方面都借鉴了哥特传统,同时凭借其超乎寻常的想象力,将现实 与超现实融为一体,给陈旧的形式注入了激烈情感、心理深度和新鲜 活力,达到了哥特形式与激情内容的完美统一,使《呼啸山庄》既超越了哥特体裁的“黑色浪漫主义”,又超越了维多利亚时代的“现实主义”,从而展现出独具一格、经久不衰的艺术魅力。 2.与选题相关的国内外研究和发展概况 各民族的文学中都有许多惊险、恐怖的故事,但似乎没有哪一种文学像英美文学那样不仅创作出数量众多、质量优秀的恐怖文学作品,而且还形成了一个持续发展、影响广泛的哥特传统 (Gothictradition)。哥特文学现在已经成为英美文学研究中的一个重要领域。对哥特文学的认真研究开始于20世纪二三十年代,到70年代以后,由于新的学术思潮和文学批评观念的影响,该研究出现了前所未有而且日趋高涨的热潮。 根据在国际互联网上的搜索,到2000年9月为止,英美等国的学者除发表了大量关于哥特文学的论文外,还至少出版专著达184部,其中1970年以后为126部,仅90年代就达59部,几乎占总数的三分之一。当然,近年来哥特文学研究的状况不仅在于研究成果迅速增加,更重要的是它在深度和广度方面都大为拓展,并且把哥特传统同英美乃至欧洲的历史、社会、文化和文学的总体发展结合起来。 二、研究方案 1.研究的基本内容及预期的结果(大纲)研究的基本内容:本文立足于欧美文学中的哥特传统研究《呼啸山庄》的创作源泉,指出艾米莉?勃朗特在主题、人物形象、环境刻画、意象及情节构造等方面都借鉴了哥特传统,同时凭借其超乎寻常的想象力,将现实与超现实融为一体,给陈旧的形式注入了激烈情感、心理深度和新鲜活力,达到了哥特形式与激情内容的完美统一,使《呼啸山庄》既超越了哥特体裁的“黑色浪漫主义”,又超越了维多利亚时代的“现实主义”,从而展现出独具一格、经久不衰的艺术魅力。 预期的结果(大纲): 1.ASurveyofGothic1.1DefinitionofGothic 1.2theOriginofGothicNovels 教育资料 《短歌行》 《短歌行》赏析(林庚) 曹操这一首《短歌行》是建安时代杰出的名作，它代表着人生的两面，一方面是人生的忧患，一方面是人生的欢乐。而所谓两面也就是人生的全面。整个的人生中自然含有一个生活的态度，这就具体地表现在成为《楚辞》与《诗经》传统的产儿。它一方面不失为《楚辞》中永恒的追求，一方面不失为一个平实的生活表现，因而也就为建安诗坛铺平了道路。 这首诗从“对酒当歌，人生几何”到“但为君故，沉吟至今”，充分表现着《楚辞》里的哀怨。一方面是人生的无常，一方面是永恒的渴望。而“呦呦鹿鸣”以下四句却是尽情的欢乐。你不晓得何以由哀怨这一端忽然会走到欢乐那一端去，转折得天衣无缝，仿佛本来就该是这么一回事似的。这才是真正的人生的感受。这一段如是，下一段也如是。“明明如月，何时可掇?忧从中来，不可断绝。越陌度阡，枉用相存。契阔谈宴，心念旧恩。月明星稀，乌鹊南飞。绕树三匝，何枝可依。”缠绵的情调，把你又带回更深的哀怨中去。但“山不厌高，海不厌深”，终于走入“周公吐哺，天下归心”的结论。上下两段是一个章法，但是你并不觉得重复，你只觉得卷在悲哀与欢乐的旋涡中，不知道什么时候悲哀没有了，变成欢乐，也不知道什么时候欢乐没有了，又变成悲哀，这岂不是一个整个的人生吗?把整个的人生表现在一个刹那的感觉上，又都归于一个最实在的生活上。“我有嘉宾，鼓瑟吹笙”，不正是当时的情景吗?“周公吐哺，天下归心”，不正是当时的信心吗? “青青子衿”到“鼓瑟吹笙”两段连贯之妙，古今无二。《诗经》中现成的句法一变而有了《楚辞》的精神，全在“沉吟至今”的点窜，那是“青青子衿”的更深的解释，《诗经》与《楚辞》因此才有了更深的默契，从《楚辞》又回到《诗经》，这样与《鹿鸣》之诗乃打成一片，这是一个完满的行程，也便是人生旅程的意义。“月明星稀”何以会变成“山不厌高，海不厌深”?几乎更不可解。莫非由于“明月出天山”，“海上生明月”吗?古辞说：“枯桑知天风，海水知天寒”，枯桑何以知天风，因为它高；海水何以知天寒，因为它深。唐人诗“一叶落知天下秋”，我们对于宇宙万有正应该有一个“知”字。然则既然是山，岂可不高?既然是海，岂可不深呢?“并刀如水，吴盐胜雪”，既是刀，就应该雪亮；既是盐，就应该雪白，那么就不必问山与海了。 山海之情，成为漫漫旅程的归宿，这不但是乌鹊南飞，且成为人生的思慕。山既尽其高，海既尽其深。人在其中乃有一颗赤子的心。孟子主尽性，因此养成他浩然之气。天下所以归心，我们乃不觉得是一个夸张。 . 目录 1、工程概况 (1) 2、编制依据 (1) 3、静置设备安装工序流程 (1) 4、施工准备 (2) 5、设备验收、清点及检查 (2) 6、基础的检查及验收 (3) 7、基础的处理 (4) 8、垫铁的选用及布置 (4) 9、设备安装施工 (6) 9.1、设备安装准备 (6) 9.2、设备安装 (7) 9.3、找正与找平 (7) 9.4、地脚螺栓与垫铁 (10) 9.5、二次灌浆 (10) 9.6、内件及填料安装 (11) 9.7、安全附件安装 (12) 9.8、梯子、平台安装 (12) 10、进度计划 (13) 11、HSE保证措施 (13) 11.1高处作业 (13) 11.2脚手架搭设 (14) 11.3起重吊装 (16) 12、主要劳动力安排 (16) 13、主要施工机具 (17) 1、工程概况 江苏威名石化有限公司年产15万吨环己酮项目位于江苏洋口港工业园区，该项目设备分别安装于单层钢结构厂房、两层钢结构厂房（楼面标高分别为8.2米和15.2米）、厂房外设备框架和露天设备基础。其中单层厂房内安装3台压缩机，为2台循环气压缩机K-5101A/B和1台废氢气压缩机K-5301，室外基础主要安装有3台塔设备和储罐，其余设备安装于两层主结构框架内。静止设备按功能分类明细如下： 序号类型数量单位备注 1 塔 3 台其中C-5203环己酮塔重88吨 2 换热器26 台 3 喷射器 1 台 4 反应器 3 台 5 储罐 5 台其中T-5103现场制作 6 容器15 台 7 分离器&洗涤器 6 台 8 电加热器 1 台 9 除油器 1 台环境专业 10 合计61 台 2、编制依据 《石油化工静设备安装工程施工质量验收规范》（GB50461-2008） 《现场设备、工业管道焊接工程施工规范》（GB50236-2011） 《现场设备、工业管道焊接工程施工质量验收规范》（GB50683-2011） 《石油化工静设备安装工程施工技术规程》（SH/T3542-2007） 《工业安装工程施工质量验收统一标准》（GB50252-2010） 3、静置设备安装工序流程 名人名言摘抄及赏析 名人名言以其深邃的哲理、丰富的内涵为人们广泛传诵，所以，值得我们摘抄并赏析。今天为你分享的是名人名言摘抄及赏析的内容，希望你会喜欢! 1) 形成天才的决定因素应该是勤奋.;;郭沫若 2) 学到很多东西的诀窍,就是一下子不要学很多.;;洛克 3) 自己的鞋子,自己知道紧在哪里.;;西班牙 4) 不要等待运气降临，应该去努力掌握知识。;;弗兰明 5) 人不能象走兽那样活着，应该追求知识和美德。;;但丁 6) 荣誉和财富，若没有聪明才智，是很不牢靠的财产。;;德谟克里特 7) 有教养的人的遗产，比那些无知的人的财富更有价值。;;德谟克里特 8) 知识是珍贵宝石的结晶，文化是宝石放出来的光泽。;;泰戈尔 9) 知识有如人体血液一样的宝贵。人缺少了血液，身体就要衰弱，人缺少了知识，头脑就要枯竭。;;高士其 10) 与其夸大胡说，不如宣布那个聪明的、智巧的、谦逊的警句：“我不知道”。;;伽利略 11) 人的理想志向往往和他的能力成正比。;;约翰逊 12) 人所缺乏的不是才干而是志向，不是成功的能力而是勤劳的 意志。;;部尔卫 13) 勇敢坚毅真正之才智乃刚毅之志向。;;拿破仑 14) 书卷多情似故人，晨昏忧乐每相亲。;;于谦 15) 读万卷书，行万里路。;;刘彝 16) 三人行，必有我师也。择其善者而从之，其不善者而改之。;;孔子 17) 知之者不如好之者，好之者不如乐之者。;;孔子 18) 敏而好学，不耻下问。;;孔子 19) 学而不思则罔，思而不学则殆。;;孔子 20) 外韧之味，久则可厌;读书之味，愈久愈深。;;程颐 名人名言摘抄及赏析（经典篇）1) 劳于读书，逸于作文。;;元代;程端礼 2) 读书如行路，历险毋惶恐。;;《清诗铎;读书》 3) 书读百遍，其义自见。;;晋;陈寿 4) 三日不读，口生荆棘;三日不弹，手生荆棘。;;清;朱舜水 5) 业精于勤，荒于嬉;行成于思，毁于随。;;韩愈 6) 鸟欲高飞先振翅，人求上进先读书。;;李苦禅 7) 艺术是一种使我们达到真实的假想。;;毕加索 8) 思考的意思是：亲近自己。;;乌纳木诺 9) 我们破灭的希望，流产的才能，失败的事业，受了挫折的雄心，往往积聚起来叫做嫉妒。;;巴尔扎克 10) 夜空挂满了星星，月亮像一只钓鱼的小船，仿佛航行在宽阔 2014 Final Exam Study Guide for American Literature Class Plan of Final Exam 1.Best Choice Question 10% 2.True or False Question 10% 3.Definition 10% 4.Give Brief Answers to Questions 30% 5.Critical Comments 40% American Literature Review Poe’s Poetic Ideas; Major Ideas in Emerson’s “Nature”; Whitman’s Style; Formal Features of Dickinson’s Poetry; Analysis of “Miniver Cheevy” by Edwin Arlington Robinson; Comment on “Stopping by Woods on a Snowy Evening” by Robert Frost; Naturalistic reading of Sister Carrie by Theodore Dreiser; The Theme and Techniques in Eliot’s “The Waste Land”; Theme and Technique in The Great Gatsby by Fitzgerald; Comment on Hemingway’s style and theme in A Farewell to Arms; Analysis of “Dry September” by William Faulkner; Literary terms: Transcendentalism American Naturalism The Lost Generation The Jazz Age Free Verse The Iceberg Analogy 曹操《短歌行【对酒当歌】》原文、翻译、赏析译文 原文 面对美酒应该高歌，人生短促日月如梭。对酒当歌，人生几何？ 好比晨露转瞬即逝，失去的时日实在太多！譬如朝露，去日苦多。 席上歌声激昂慷慨，忧郁长久填满心窝。慨当以慷，忧思难忘。 靠什么来排解忧闷？唯有狂饮方可解脱。何以解忧？唯有杜康。 那穿着青领（周代学士的服装）的学子哟，你们令我朝夕思慕。青青子衿，悠悠我心。 正是因为你们的缘故，我一直低唱着《子衿》歌。但为君故，沉吟至今。 阳光下鹿群呦呦欢鸣，悠然自得啃食在绿坡。呦呦鹿鸣，食野之苹。 一旦四方贤才光临舍下，我将奏瑟吹笙宴请宾客。我有嘉宾，鼓瑟吹笙。 当空悬挂的皓月哟，你运转着，永不停止；明明如月，何时可掇？ 我久蓄于怀的忧愤哟，突然喷涌而出汇成长河。忧从中来，不可断绝。 远方宾客踏着田间小路，一个个屈驾前来探望我。越陌度阡，枉用相存。 彼此久别重逢谈心宴饮，争着将往日的情谊诉说。契阔谈讌，心念旧恩。 明月升起，星星闪烁，一群寻巢乌鹊向南飞去。月明星稀，乌鹊南飞。 绕树飞了三周却没敛绕树三匝，何枝 翅，哪里才有它们栖身之 所？ 可依？ 高山不辞土石才见巍 峨，大海不弃涓流才见壮阔。（比喻用人要“唯才是举”，多多益善。）山不厌高，水不厌深。 只有像周公那样礼待贤 才（周公见到贤才，吐出口 中正在咀嚼的食物，马上接 待。《史记》载周公自谓： “一沐三握发，一饭三吐哺， 犹恐失天下之贤。”），才 能使天下人心都归向我。 周公吐哺，天 赏析 曹操是汉末杰出的政治家、军事家和文学家，他雅好诗章，好作乐府歌辞，今存诗22首，全是乐府诗。曹操的乐府诗多描写他本人的政治主张和统一天下的雄心壮志。如他的《短歌行》，充分表达了诗人求贤若渴以及统一天下的壮志。 《短歌行》是政治性很强的诗作，主要是为曹操当时所实行的政治路线和政策策略服务的，但是作者将政治内容和意义完全熔铸在浓郁的抒情意境之中，全诗充分发挥了诗歌创作的特长，准确而巧妙地运用了比兴手法，寓理于情，以情感人。诗歌无论在思想内容还是在艺术上都取得了极高的成就，语言质朴，立意深远，气势充沛。这首带有建安时代"志深比长""梗概多气"的时代特色的《短歌行》，读后不觉思接千载，荡气回肠，受到强烈的感染。 对酒当歌，人生几何？ 譬如朝露，去日苦多。 慨当以慷，幽思难忘。 何以解忧，唯有杜康。 青青子衿，悠悠我心。 但为君故，沈吟至今。 呦呦鹿鸣，食野之苹。 我有嘉宾，鼓瑟吹笙。 明明如月，何时可掇？ 忧从中来，不可断绝。 越陌度阡，枉用相存。 契阔谈，心念旧恩。 月明星稀，乌鹊南飞， 绕树三匝，何枝可依？ 山不厌高，海不厌深， 周公吐哺，天下归心。 《短歌行》是汉乐府的旧题，属于《相和歌?平调曲》。这就是说它本来是一个乐曲的名称，这种乐曲怎么唱法，现在当然是不知道了。但乐府《相和歌?平调曲》中除了《短歌行》还有《长歌行》，唐代吴兢《乐府古题要解》引证古诗“长歌正激烈”，魏文帝曹丕《燕歌行》“短歌微吟不能长”和晋代傅玄《艳歌行》“咄来长歌续短歌”等句，认为“长歌”、“短 名言警句赏析 本文是关于名人名言的，仅供参考，如果觉得很不错，欢迎点评和分享。 名言警句赏析 1、高岸为谷，深谷为陵。--《诗经·十月之交》 赏析： 高地变成山谷，深谷变成山陵。据科学推测，喜马拉雅山这个地方在七千万年以前还是一片汪洋大海，沧海变桑田，比喻世事多变。也比喻事物在一定的条件下总是向它相反的方面转化。 2、工欲善其事，必先利其器。一一《论语·卫灵公》 赏析： 工匠要想做好自己的工作，必须事先磨快工具。由此可知，一个人要胜任工作，必须首先学好本领。今日读好书，来日才能大展鸿图。 3、躬自厚而薄责于人。一一《论语·卫灵公》 赏析： 多责备自己，而少责备别人。这句话说的是要严以律己，宽以待人。严格要求自己，进步就快；宽容别人，就会远离怨恨。躬自：自己。“厚”后省略了一个“责”字。责：责备，要求。 4、爱人者，人恒爱之；敬人者，人恒敬之。--《孟子。离娄下》 赏析： 爱人的人别人总是爱他，尊敬别的人别人总是尊敬他。你怎样对待别 人，别人也往往会用同样的态度对待你。要想受人敬爱，必须敬爱他人。恒：常常。 2、躬自厚而薄责于人。--《论语。卫灵公》 赏析： 多责备自己，而少责备别人。这句话说的是要严以律己，宽以待人。严格要求自己，进步就快；宽容别人，就会远离怨恨。躬自：自己。“厚”后省略了一个“责”字。责：责备，要求。 3、好而知其恶，恶而知其美。--《礼记。大学》 赏析： 对你所喜欢的人，要知道他的缺点，不可偏袒；对你所厌恶的人，要知道他的优点，不可抹杀。我们评价一个人要客观公正，不要感情用事，不要因为自己的好、恶而产生偏见。好hào：喜爱。前“恶”è：缺陷和丑恶。后“恶”wù：讨厌，憎恨。 4、人一能之，己百能之；人十能之，己千能之。--《礼记。中庸》 赏析： 别人花一分力气就能学好的，自己就花百分的力气学好它；人家花十分的力气能学好的，自己就花千分的力气学好它。这句话说明人要自强，不甘落后。有了自强的心态，必然会勤奋，“勤能补拙”，原本不够聪明的人也会聪明起来了。 5、为者常成，行者常至。--《晏子春秋内篇。杂下》 赏析： Chapter III WEE QUESTION OF FORTUNE--FOUR-FIFTY A WEEK Once across the river and into the wholesale district, she glanced about her for some likely door at which to apply. As she contemplated the wide windows and imposing signs, she became conscious of being gazed upon and understood for what she was--a wage-seeker. She had never done this thing before, and lacked courage. To avoid a certain indefinable shame she felt at being caught spying about for a position, she quickened her steps and assumed an air of indifference supposedly common to one upon an errand. In this way she passed many manufacturing and wholesale houses without once glancing in. At last, after several blocks of walking, she felt that this would not do, and began to look about again, though without relaxing her pace. A little way on she saw a great door which, for some reason, attracted her attention. It was ornamented by a small brass sign, and seemed to be the entrance to a vast hive of six or seven floors. "Perhaps," she thought, "They may want some one," and crossed over to enter. When she came within a score of feet of the desired goal, she saw through the window a young man in a grey checked suit. That he had anything to do with the concern, she could not tell, but because he happened to be looking in her direction her weakening heart misgave her and she hurried by, too overcome with shame to enter. Over the way stood a great six- story structure, labelled Storm and King, which she viewed with rising hope. It was a wholesale dry goods concern and employed women. She could see them moving about now and then upon the upper floors. This place she decided to enter, no matter what. She crossed over and walked directly toward the entrance. As she did so, two men came out and paused in the door. A telegraph messenger in blue dashed past her and up the few steps that led to the entrance and disappeared. Several pedestrians out of the hurrying throng which filled the sidewalks passed about her as she paused, hesitating. She looked helplessly around, and then, seeing herself observed, retreated. It was too difficult a task. She could not go past them. So severe a defeat told sadly upon her nerves. Her feet carried her mechanically forward, every foot of her progress being a satisfactory portion of a flight which she gladly made. Block after block passed by. Upon streetlamps at the various corners she read names such as Madison, Monroe, La Salle, Clark, Dearborn, State, and still she went, her feet beginning to tire upon the broad stone flagging. She was pleased in part that the streets were bright and clean. The morning sun, shining down with steadily increasing warmth, made the shady side of the streets pleasantly cool. She looked at the blue sky overhead with more realisation of its charm than had ever come to her before. Her cowardice began to trouble her in a way. She turned back, resolving to hunt up Storm and King and enter. On the way, she encountered a great wholesale shoe company, through the broad plate windows of which she saw an enclosed executive 曹操《短歌行》其二翻译及赏析 引导语：曹操(155—220)，字孟德，小名阿瞒，《短歌行 二首》 是曹操以乐府古题创作的两首诗， 第一首诗表达了作者求贤若渴的心 态，第二首诗主要是曹操向内外臣僚及天下表明心迹。 短歌行 其二 曹操 周西伯昌，怀此圣德。 三分天下，而有其二。 修奉贡献，臣节不隆。 崇侯谗之，是以拘系。 后见赦原，赐之斧钺，得使征伐。 为仲尼所称，达及德行， 犹奉事殷，论叙其美。 齐桓之功，为霸之首。 九合诸侯，一匡天下。 一匡天下，不以兵车。 正而不谲，其德传称。 孔子所叹，并称夷吾，民受其恩。 赐与庙胙，命无下拜。 小白不敢尔，天威在颜咫尺。 晋文亦霸，躬奉天王。 受赐圭瓒，钜鬯彤弓， 卢弓矢千，虎贲三百人。 威服诸侯，师之所尊。 八方闻之，名亚齐桓。 翻译 姬昌受封为西伯，具有神智和美德。殷朝土地为三份，他有其中两分。 整治贡品来进奉，不失臣子的职责。只因为崇侯进谗言，而受冤拘禁。 后因为送礼而赦免， 受赐斧钺征伐的权利。 他被孔丘称赞， 品德高尚地位显。 始终臣服殷朝帝王，美名后世流传遍。齐桓公拥周建立功业，存亡继绝为霸 首。 聚合诸侯捍卫中原，匡正天下功业千秋。号令诸侯以匡周室，主要靠的不是 武力。 行为磊落不欺诈，美德流传于身后。孔子赞美齐桓公，也称赞管仲。 百姓深受恩惠，天子赐肉与桓公，命其无拜来接受。桓公称小白不敢，天子 威严就在咫尺前。 晋文公继承来称霸，亲身尊奉周天王。周天子赏赐丰厚，仪式隆重。 接受玉器和美酒，弓矢武士三百名。晋文公声望镇诸侯，从其风者受尊重。 威名八方全传遍，名声仅次于齐桓公。佯称周王巡狩，招其天子到河阳，因 此大众议论纷纷。 赏析 《短歌行》 (“周西伯昌”)主要是曹操向内外臣僚及天下表明心 迹，当他翦灭群凶之际，功高震主之时，正所谓“君子终日乾乾，夕惕若 厉”者，但东吴孙权却瞅准时机竟上表大说天命而称臣，意在促曹操代汉 而使其失去“挟天子以令诸侯”之号召， 故曹操机敏地认识到“ 是儿欲据吾著炉上郁!”故曹操运筹谋略而赋此《短歌行 ·周西伯 昌》。 西伯姬昌在纣朝三分天下有其二的大好形势下， 犹能奉事殷纣， 故孔子盛称 “周之德， 其可谓至德也已矣。 ”但纣王亲信崇侯虎仍不免在纣王前 还要谗毁文王，并拘系于羑里。曹操举此史实，意在表明自己正在克心效法先圣 西伯姬昌，并肯定他的所作所为，谨慎惕惧，向来无愧于献帝之所赏。 并大谈西伯姬昌、齐桓公、晋文公皆曾受命“专使征伐”。而当 今天下时势与当年的西伯、齐桓、晋文之际颇相类似，天子如命他“专使 征伐”以讨不臣，乃英明之举。但他亦效西伯之德，重齐桓之功，戒晋文 之诈。然故作谦恭之辞耳，又谁知岂无更讨封赏之意乎 ?不然建安十八年(公元 213 年)五月献帝下诏曰《册魏公九锡文》，其文曰“朕闻先王并建明德， 胙之以土，分之以民，崇其宠章，备其礼物，所以藩卫王室、左右厥世也。其在 周成，管、蔡不静，惩难念功，乃使邵康公赐齐太公履，东至于海，西至于河， 南至于穆陵，北至于无棣，五侯九伯，实得征之。 世祚太师，以表东海。爰及襄王，亦有楚人不供王职，又命晋文登为侯伯， 锡以二辂、虎贲、斧钺、禾巨 鬯、弓矢，大启南阳，世作盟主。故周室之不坏， 系二国是赖。”又“今以冀州之河东、河内、魏郡、赵国、中山、常 山，巨鹿、安平、甘陵、平原凡十郡，封君为魏公。锡君玄土，苴以白茅，爰契 尔龟。”又“加君九锡，其敬听朕命。” 观汉献帝下诏《册魏公九锡文》全篇，尽叙其功，以为其功高于伊、周，而 其奖却低于齐、晋，故赐爵赐土，又加九锡，奖励空前。但曹操被奖愈高，心内 愈忧。故曹操在曾早在五十六岁写的《让县自明本志令》中谓“或者人见 孤强盛， 又性不信天命之事， 恐私心相评， 言有不逊之志， 妄相忖度， 每用耿耿。 1、锲而不舍，金石可镂。 2、立志、工作、，是人类活动的三大要素。——巴斯德 3、有很多人是用青春的幸福作成功代价的。——莫扎特 4、我们手里的金钱是保持自由的一种工具。——卢梭 5、世上有很多好东西，是“带不走”的。 6、建筑在别人痛苦上的幸福不是真正的幸福。——阿·巴巴耶娃 7、一切幸福都并非没有烦恼，而一切逆境也绝非没有希望。——培根 8、灵感不过是“顽强的劳动而获得的奖赏”。——列宾 9、除了无法达成心愿之外，就数心愿达成了最伤感。 10、成功不是将来才有的，而是从决定去做的那一刻起，持续累积而成。 11、无论何时，不管怎样，我也绝不允许自己有一点点心丧气。——爱迪生 12、古往今来，凡成就事业，对人类有所作为的，无不是脚踏实地，艰苦登攀的结果。——钱三强 13、生活真象这杯浓酒，不经三番五次的提炼呵，就不会这样可口！——郭小川 14、失败是块磨刀石。 15、每一种或不利的突变，是带着同样或较大的有利的种子。——爱默生 16、我死国生，我死犹荣，身虽死精神长生，成功成仁，实现大同。——赵博生 17、一个人的价值，应该看他贡献什么，而不应当看他取得什么。——爱因斯坦 18、平凡的脚步也可以走完伟大的行程。 19、伟人之所以伟大，是因为他与别人共处逆境时，别人失去了信心，他却下决心实现自己的目标。 20、智慧源于勤奋，伟大出自平凡。——民谚 21、冬天已经到来，春天还会远吗？——雪莱 22、百败而其志不折。 23、如烟往事俱忘却，心底无私天地宽。——陶铸 24、沉沉的黑夜都是白天的前奏。——郭小川 25、世上最精明的糊涂便是“忘记”。 26、你明白，人的一生，既不是人们想象的那么好，也不是那么坏。——莫泊桑 27、爱，如呼吸。深爱，就是深呼吸。 28、莫找借口失败，只找理由成功。（不为失败找理由，要为成功找方法） 29、要做的事情总找得出时间和机会；不愿意做的事情也总能找得出借口。 30、壮志与毅力是事业的双翼--歌德大自然既然在人间造成不同程度的强弱，也常用破釜沉舟的斗争，使弱者不亚于强者。——孟德斯鸠 31、卓越的人一大优点是：在不利与艰难的遭遇里百折不饶。——贝多芬 32、天才就是这样，终身劳动，便成天才。——门捷列夫 33、天才就是无止境刻苦勤奋的能力。——卡莱尔 34、我以为挫折、磨难是锻炼意志、增强能力的好机会。——邹韬奋 35、首先是最崇高的思想，其次才是金钱；光有金钱而没有最崇高的思想的社会是会崩溃的。——陀思妥耶夫斯基 36、耐心之树，结黄金之果。 37、如果我们想要更多的玫瑰花，就必须种植更多的玫瑰树。 38、忍耐和是痛苦的，但它会逐给你好处。 39、骆驼走得慢，但终能走到目的地。 40、勤能补拙是良训，一分辛劳一分才。——华罗庚 41、严肃的人的幸福，并不在于风流、娱乐与欢笑这种种轻佻的伴侣，而在于坚忍与刚毅。——西塞罗 42、伟大的作品，不是靠力量而是靠坚持才完成的。 目的。笔者曾进行了这方面的一个实验；对乐理、视唱程度相当的Ａ、Ｂ两个班，在讲小调式时，Ａ班此时视唱只唱小调式作品，边唱边分析；Ｂ班只在乐理课上选一些典型作品作简单分析，而视唱课对小调作品概不介绍，结果发现Ａ班大部分同学对小调式的特点掌握清晰、分析作品透彻，而Ｂ班多数同学对小调式作品的分析仍感糊涂。 （二）乐理和视唱由同一老师任教，选用乐理与视唱进度相当、联系密切的教材。 两门课由同一老师任教，这样就使老师对两门课的进度有更好的把握，从而做到在教学内容上的衔接，使乐理教学与视唱教学融为一体。现在有些院校已开始了这方面的尝试，如河南的黄河科技学院，商丘师院等。据笔者了解，由同一个老师任教班级学生的乐理视唱学习效果明显好于非同一教师任教的班级。 教材的选择对教学影响极大，原来的视唱教材极少有乐理内容，而乐理教材中的谱例也不多。目前新的教材已改变了这种状况，现在视唱教材中有了很好的理论知识讲授，如许敬行、孙虹编著，高教出版社出版的《视唱练习》。乐理教材有了更多的谱例，如贾方爵编著、 西南师大出版社出版的《基本乐理》。选用此种联系密切的教材， 教师在教学的过程中更易做到理论联系实际，学生在自学时也更易理解。 （三）加强乐理、视唱教学与其他科目的横向联系 音乐中的许多课程，如欣赏、民族民间音乐、合唱、音乐史等的学习对学生综合专业素质的提高有很大帮助，对它们的学习与对乐理和视唱的学习又能达到互相促进的目的。在乐理学教学中，学生最易迷惑的就是调式调性的判断，而进行调式判断时首先要靠听觉分辨作品的五声性和西方性。但如何能够分辨其是五声性作品还是西方调式体系作品，靠的是学生对音乐的基本鉴赏力。这就要求学生平时在欣赏课上要认真去听、去辨别，而欣赏老师也应该对不同体裁的音乐作品进行详细的讲解，并引导学生去辨别。经过这样长期的训练，学生对于不同地域、不同风格的音乐作品都有了了解和掌握，辨别调式的问题自然迎刃而解。同样，民族民间课程的学习对于学生了解和掌握各民族的音乐风格、特点起重要作用。经过同学们对民歌、戏曲等曲型片断的实际训练，在视唱这些有特点的作品时，其音乐风格的把握就会更好一些，因律制原因产生的音准问题也会大大减少，学生对民族风格的视唱会唱得更有味，把握得更准确。在这方面，如果乐理和视唱课需要，可会同其他科目的教师对教学进度、教学内容作一些适当的调整，使之与乐理、视唱教学相适应。如有必要，也可请这方面的专家，就某一问题进行一次讲座，以加深同学们对某些问题的理解。教师亦可有目的地向学生介绍一些此方面的书籍，让学生去阅读；介绍一些音响资料，让学生有目的地听，从而拓宽学生的知识面，进而更好地学习和掌握乐理和视唱。 总之，视唱与乐理相结合并密切联系相关科目的教学方法，不仅可以使学生增加对音乐理论的感性认识，加强视唱时的理论指导，更增加了视唱课的趣味性，使乐理不再枯燥，视唱课不再单调。 当然，加强乐理、视唱与其他科目教学的联系并不是说这些课程什么地方都可以互融。有些乐理知识如音律很难让学生唱出来。但这并不能否认加强视唱、乐理与其他学科教学联系的必要性。 作者简介：刘建坤，商丘师范学院音乐系教师。 一、美国自然主义的产生 内战之后，美国处于一段相对和平的时期，资本主义经济蓬勃发展。然而，在经济发展的背后，人们却普遍产生了一种悲观情绪，传统的理想主义被抛弃，宇宙的在规律性和机械性中蕴涵的漠然性使其变成了人类的敌人，至少已经不是人类慈祥的朋友。斯蒂芬?克莱恩（Ｓｔｅｐｈｅｎ Ｃｒａｎｅ（１８７１－１９００））的一首小诗Ｇｏｄ ｉｓ ｃｏｌｄ［１］ 便生动地反映了这种状况： 一个人对宇宙说：／“阁下，我存在的！”／“不过，”传来宇宙的回答，／“你的存在虽是事实，却／并没有使我产生义务感。” 对这一思潮起决定性作用的是达尔文的进化论（Ｔｈｅｏｒｙ ｏｆ Ｅｖｏｌｕｔｉｏｎ）。达尔文认为：影响生物进化的因素有三种，即：自然选择、性的选择及个体有生之期获得特性的遗传。进化论的诞生，是对传统神学及理想主义神学的全盘否定，它取消了上帝设计师和创造者的地位，进而强调人类产生过程的机械性，以及人类进化过程的因果循环性。受其影响，悲观、忧郁的新自然哲学应运而生。新自然哲学指出，自然是一座对人类遭遇无动于衷的庞大机器，人类在自然中必然要为生存而相互竞争，而且，部分人的毁灭是人类进步中不可避免的现象。 悲观的新自然哲学在文学中的反映就是产生悲观宿命的自然主义文学。英国哲学家赫伯特?斯宾塞（ＨｅｒｂｅｒｔＳｐｅｎｃｅｒ）的“社会达尔文主义” （Ｓｏｃｉａｌ Ｄａｒｗｉｎｉｓｍ）以及美国内战后的社会状况，对自然主义在美国的产生和发展起了极大的作用。当时的主要作家往往把人置于庞大的自然和社会背景中，从而显示其渺小、脆弱以及无可奈何。 ＂生存＂是人类活动的最高目标，道德规范对于实际生活已经毫无意义。 在美国自然主义文学中，最为突出的代表是西奥多?德莱塞。 二、德莱塞在美国文学史上的地位 西奥多?德莱塞 ［Ｔｈｅｏｄｏｒｅ Ｄｒｅｉｓｅｒ （１８７１－１９４５）］是美国现代小说的先驱和代表作家，被认为是同海明威、福《嘉莉妹妹》是美国自然主义文学大师西奥多?德莱塞的处女作和成名作。自然主义在书中 主要表现为作者对失败者的深刻同情。 《嘉莉妹妹》中 自然主义赏析 文／姚晓鸣 编辑：冯彬彬 69 美与时代 ２００３．１１下 疏水阀的正确安装指南 疏水阀安装是否合适，对疏水阀的正常工作和设备的生产效率都有直接影响。安装疏水阀必须按正规安装要求、才能使疏水阀和设备达到最佳工作效率。 1. 在安装疏水阀之前一定要用带压蒸汽吹扫管道，清除管道中的杂物。 2. 疏水阀前应安装过滤器，确保疏水阀不受管道杂物的堵塞，定期清理过滤器。 3. 疏水阀前后要安装阀门，方便疏水阀随时检修。 4. 凝结水流向要与疏水阀安装箭头标志一致。 5. 疏水阀应安装在设备出口的最低处，及时排出凝结水，避免管道产生汽阻。 6. 如果设备的最低处没有位置安装疏水阀，应在出水口最低位置加个反水弯头（凝结水提升接头），把凝结水位提升后再装疏水阀，以免产生汽阻。 7. 疏水阀的出水管不应浸在水里。（如果浸在水里，应在弯曲处钻个孔，破坏真空，防止沙土回吸。） 8. 机械型疏水阀要水平安装。 9. 蒸汽疏水阀不要串联安装。 10. 每台设备应该各自安装疏水阀。 11. 热静力型疏水阀前需要有一米以上不保温的过冷管，其它形式疏水阀应尽量靠近设备。 12. 滚筒式烘干（带虹吸管型）设备选用疏水阀时请注明：选用带防汽阻装置的疏水阀，避免设备产生汽锁。 13. 疏水阀后如有凝结水回收，疏水阀出水管应从回收总管的上面接入总管，减少背压，防止回流。 14. 疏水阀后如有凝结水回收，不同压力等级的管线要分开回收。 15. 疏水阀后凝结水回收总管不能爬坡，会增加疏水阀的背压。 16. 疏水阀后凝结水进入回收总管前要安装止回阀，防止凝结水回流。 17. 在蒸汽管道上装疏水阀，主管道要设一个接近主管道半径的凝结水集水井，再用小管引至疏水阀。 18. 机械型疏水阀长期不用，要卸下排污螺丝把里面的水放掉，以防冰冻。 19. 发现疏水阀跑汽，要及时排污和清理过滤网，根据实际使用情况勤检查，遇有故障随时修理。每年至少要检修一次，清除里面的杂质。 疏水阀在整个蒸汽系统中被认为是个小配件，但对系统工作和经济运行影响很大，所以疏水阀的维护和检修也是至关重要的，只有充分重视疏水阀在生产上的重要作用。勤检修，使疏水阀经常处在良好的工作状态下，才能保证达到最佳节能效果和提高经济效益。 疏水阀的正确选型条件 1. 疏水阀的疏水量： 选用疏水阀时，必须按设备每小时的耗汽量乘以选用倍率2-3倍为最大凝结水量，来选择疏水阀的排水量。才能保证疏水阀在开车时能尽快排出凝结水，迅速提高加热设备的温度。疏水阀排放能量不够，会造成凝结水不能及时排出，降低加热设备的热效率。（当蒸汽加热设备刚开始送汽时，设备是冷的，内部充满空气，需要疏水阀把空气迅速排出，再排大量低温凝结水，使设备逐渐热起来，然后设备进入正常工作状态。由于开车时，大量空气和低温凝结水，较低的入口压力，使疏水阀超负荷运行，此时疏水阀要求比正常工作时的排水量大， 我要各种名人名言加名人名言的解析快急求 1、天才是百分之一的灵感加百分之九十九的汗水。 ——爱迪生 2、一个人几乎可以在任何他怀有无限热忱的事情上成功。 ——查尔斯·史考伯 3、深窥自己的心，而后发觉一切的奇迹在你自己。 ——培根 4、坚强的信念能赢得强者的心，并使他们变得更坚强。 ——白哲特 5、流水在碰到底处时才会释放活力。 ——歌德 6、那脑袋里的智慧，就像打火石里的火花一样，不去打它是不肯出来的。 ——莎士比亚 7、多数人都拥有自己不了解的能力和机会，都有可能做到未曾梦想的事情。 ——戴尔·卡耐基 8、勿问成功的秘诀为何，且尽全力做你应该做的事吧。 ——美华纳 9、苦难有如乌云，远望去但见墨黑一片，然而身临其下时不过是灰色而已。 ——里希特 10、幸运并非没有恐惧和烦恼；厄运也决非没有安慰和希望。 ——培根 11、不幸可能成为通向幸福的桥梁。 ——日本谚语 12、苦难磨炼一些人，也毁灭另一些人。 ——富勒 13、烈火试真金，逆境试强者。 ——塞内加 14、人生犹如一本书，愚蠢者草草翻过，聪明人细细阅读。 为何如此 . 因为他们只能读它一次。 ——保罗 15、过去属于死神，未来属于你自己。 ——雪莱 16、不要慨叹生活的痛苦！慨叹是弱者。 ——高尔基 17、不应当急于求成，应当去熟悉自己的研究对象，锲而不舍，时间会成全一切。 凡事开始最难，然而更难的是何以善终。 ——莎士比亚 18、如烟往事俱忘却，心底无私天地宽。 ——陶铸 19、生活真象这杯浓酒，不经三番五次的提炼呵，就不会这样可口！——郭小川 20、人生的价值，即以其人对于当代所做的工作为尺度。 ——徐玮关于欣赏的名人名言
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初中语文古文赏析曹操《短歌行》赏析(林庚)
静设备安装施工方案
名人名言摘抄及赏析
完善版美国文学期末重点
高中语文文言文曹操《短歌行(对酒当歌)》原文、翻译、赏析
名言警句赏析
高中英语选修课：英语文学欣赏 Sister Carrie 学生版讲义资料
曹操《短歌行》其二翻译及赏析
名人名言赏析
_嘉莉妹妹_中自然主义赏析
疏水阀的正确安装指南
我要各种名人名言加名人名言的解析快急求
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