a r X i v :0809.5076v 1 [h e p -p h ] 29 S e p 2008
NUHEP-TH/08-05
Light Sterile Neutrino E?ects at θ13-Sensitive Reactor Neutrino Experiments
Andr′e de Gouv?e a and Thomas Wytock
Northwestern University,Department of Physics &Astronomy,2145Sheridan Road,Evanston,IL 60208,USA
We study the impact of very light sterile neutrinos (?m 2new ∈[1,10]×10
?2
eV 2,sin 22θnew <10?1)on upcoming θ13-driven reactor antineutrino experiments like Double-CHOOZ and Daya Bay.Oscillations driven by these vales of ?m 2new a?ect data in the near and far detectors di?erently and hence potentially modify the capability of these experimental setups to constrain and measure sin 22θ13.We ?nd that the hypothesis θnew =0negatively impacts one’s ability to either place an upper bound on sin 22θ13in the advent of no oscillation signal or measure sin 22θ13if a θ13-driven signal is observed.The impact of sterile neutrino e?ects,however,depends signi?cantly
on one’s ability to measure the recoil positron energy spectrum.If sin 22θnew >～10?2
,upcoming θ13-driven reactor antineutrino experiments should be able to measure sin 22θnew and ?m 2new ,along
with sin 2
2θ13,as long as one is sensitive to distortions in the recoil positron energy spectrum in the near (and far)detectors.
I.INTRODUCTION
Next-generation reactor antineutrino experiments are currently under construction (for details on concrete projects see [1,2]).Guided by the results of current neutrino oscillation experiments [3],these are aimed at observing electron antineutrino disappearance driven by the “atmospheric”mass-squared di?erence,?m 213,and hence measuring the still elusive θ13mixing angle (cf.Sec.II).
In order to signi?cantly improve on previous reactor antineutrino experiments,next-generation experiments will make use of a two-detector setup.A far detector is to be placed an optimal distance away from the reactor core so as to maximize θ13-driven electron antineutrino disappearance,while a near detector is placed close to the reactor core in order to measure the “unoscillated”electron antineutrino ?ux.Assuming di?erences between near and far detectors are understood at the few permille level and that enough statistics are accumulated,one ultimately aims at being sensitive to sin 22θ13values around 1%.
The setup summarized above relies on the assumption that all neutrino oscillation phenomena are properly described in terms of three massive neutrinos which interact under the well-known weak interactions.Current data reveal this to be an excellent assumption,but the possibility of other “subleading”e?ects remains.Here,we consider the possibility that light sterile neutrinos mix slightly with active neutrinos and hence modify the standard neutrino oscillation picture.
Sterile neutrinos —gauge singlet fermions —are among the simplest extensions of the standard model of particle physics.They may be an integral part of the physics responsible for neutrino masses [4,5],and may be a component of the dark matter in the Universe [6].Theoretically speaking,nothing is known about sterile neutrino masses,and very light sterile neutrinos (say m ν?1keV)are as natural (as de?ned by ’tHooft)as very heavy ones (say m ν?1010GeV).Experiments,therefore,provide almost all the unbiased information we have regarding sterile neutrino masses.We brie?y discuss experimental constraints in Sec.II.
We concentrate on sterile neutrinos that could qualitatively a?ect the interpretation of θ13-driven reactor neutrino experiments.We ?nd that this can happen for very light sterile neutrinos that introduce to the three-neutrino-oscillation picture a new mass-squared di?erence of order (1?10)×10?2eV 2.For example,the “hypothetical presence”of such sterile states hinders the ability of these experiments to rule out certain values of θ13if no evidence for oscillations is observed.On the other hand,small sterile neutrino e?ects,if present,may lead to very signi?cant oscillatory e?ects in the near detector even in the limit of vanishing θ13.Detailed results are presented in Sec.III,along with a study of how well θ13and sterile mixing parameters can be simultaneously measured with next-generation reactor neutrino data.
Before proceeding,we’d like to highlight our goals and the limitations of our analysis.We are interested in discussing the fact that sterile neutrinos can signi?cantly alter the interpretation of the comparison between near and far detector data in reactor antineutrino experiments.We would also like to point out that the near detector —because it is expected to collect hundreds of thousands of neutrino scattering events —may play an active role in revealing new,unexpected physics.With this in mind,our simulations,discussed in more detail in Sec.III,are not aimed at realistically describing experimental setups or quantitatively gauging their capabilities.Qualitatively,however,we believe that all of the e?ects discussed in this manuscript will manifest themselves once real experimental data is analyzed.Our main message,along with our results,is summarized in Sec.IV.
II.VERY LIGHT STERILE NEUTRINO EFFECTS AT REACTOR EXPERIMENTS
We are adding to the three active neutrinos a fourth sterile state and are hence faced with four neutrino mass eigenstates.The electron neutrinoνe can be expressed as a linear combination ofνi,i=1,2,3,4:νe= i U eiνi. We order the neutrino masses as follows(for a detailed discussion see[7]).ν4is the“mostly sterile”state(|U s4|2?|U s1,s2,s3|2)whileν1,2,3are mostly active.ν1,2,3are de?ned in the“usual way”:m21 The electron neutrino(or antineutrino)survival probability is P ee= i=1,2,3,4|U ei|2exp i?m2i1L 4Eν ,(II.2) where L is the antineutrino propagation distance(baseline),Eνis the neutrino energy and?m2ij≡m2j?m2i. Current data constrain|U e4|2 ?m212L 4Eν ?4(1?|U e4|2)|U e4|2sin2 ?m214L 4Eν ?sin2 ?m214L 4Eν ?8×10?3 L Eν 2.(II.6) This contribution is both very small for almost all baselines and energies of interest and also well-known from combined solar and KamLAND data.Given the intentions of this paper,its inclusion in the following discussion is of no practical consequence.?We have also not included matter e?ects,which can be safely neglected. In this limit,P ee is a function of two mass-squared di?erences(?m214and?m213)and two elements of the lepton mixing matrix.We will parameterize|U e3|and|U e4|in the“standard way”(see,for example,[7]): |U e3|2=cos2θ14sin2θ13,|U e4|2=sin2θ14,(II.7) so that P ee=1?cos4θ14sin22θ13sin2 ?m213L4Eν .(II.8) In the limitθ14→0we recover the well-known expression for P ee atθ13-driven reactor neutrino experiments:P ee= 1?sin22θ13sin2(?m213L/4Eν).Note that,in spite of the fact that we have three neutrino?avors,P ee is insensitive to the“sterile mass hierarchy”,i.e.,it cannot tell whether m4>m3,2,1or m4 While we have information regarding?m213,nothing is known about?m214.Here we concentrate on the region ?m214∈[1?10]×10?2eV2,for di?erent reasons.Phenomenologically,we are interested in sterile neutrino e?ects that qualitatively modify the observed oscillation pattern.?m214values smaller than10?2eV2start to mimick?m213 e?ects and are not considered,while?m214values much larger than10?1eV2lead to averaged out e?ects at both the near and far detectors and are hence less prominent.A detailed study of the e?ect of LSND/Mini-BooNE-inspired sterile neutrinos(?m214>～1eV2)was recently presented in[9].Theoretically,we have in mind a simple“seesaw”Lagrangian for the sterile neutrinos,where mostly active neutrino masses,mostly sterile neutrino masses and active–sterile mixing angles are naively related viaθ214～U2(m3/m4),where U stands for some weighted linear combination of the“active”mixing angles.Thereforeθ214values around10?1or10?2are naively related to m4values which are not more than one or two orders of magnitude larger than m3,2,1<0.05eV.Experimentally,the Bugey experiment disfavors sin22θ14values smaller than4×10?2for?m214>～10?1eV2while cosmological considerations constrain sin2θ14<10?2for?m214>10?1eV2[8].Both constraints are signi?cantly alleviated for smaller values of?m214. For?m214=10?2eV2,sin22θ14values as large as10?1are allowed by all neutrino and cosmological/astrophysical data[8]. To qualitatively understand the e?ect of sterile neutrinos in reactor neutrino setups we look at ?m214L 10?2eV2 L Eν .(II.9) For reactor antineutrinos,the oscillation length associated to?m214is of order the near detector distance for?m214 values in the range of interest.This means that sterile neutrinos can a?ect P ee in the near and far detectors in distinct ways.Given that the sensitivity to very small values ofθ13relies on a“near versus far”comparison,the presence of such sterile neutrinos can impact the reach of these experimental setups.Before proceeding with more quantitative results,we present a concrete qualitative example of what we mean. Imagine that in order to rule out a particularθ13value we relied solely on whether the near/far ratio deviated from expectations.It is useful to de?ne the observable near/far≡(N near/N0near)/(N far/N0far),where N is the observed number of events and N0the expected number of events(in the absence of oscillations)in the near or far detectors. near P ee(near) P ee(far) ,(II.10) where far～ 1?sin22θ14a14(near) cos4θ14 a14(near)?0.5 Nonzero values ofθ14,on the other hand,may lead to potentially very unexpected results.For example,it is easy to see that near/far ratio may exceed one(not possible whenθ14=0).In the case ofθ13=0,near/far is proportional to near 1?0.5sin22θ14 .(II.14) In this case,a near/far result di?erent from one leads to a measurement of both sin22θ14and?m214. III.NUMERICAL RESULTS In order to study the impact of very light sterile neutrinos onθ13-driven reactor antineutrino experiments,we simulate data for di?erent values of the mixing parameters?m213,14andθ13,14and proceed to analyze these data under distinct hypotheses.The expected number of events N i at a detector located a distance L from the source (assumed to be point-like)which are associated to incoming neutrino energies between E i and E i+?E is N i(L)=N0(L) E i+?E E iφ(Eν)σ(Eν)P ee(Eν)d Eν,(III.1) whereφ(Eν)is the energy dependent antineutrino?ux whileσ(Eν)is the total cross-section forˉνe+p→e++n. For concreteness,we use the expression for the time-averagedφ(Eν)adopted in[10](see also[11])while we use the expression forσ(Eν)computed in[12].N0(L)is a normalization factor that depends on the size of the detector,the intensity of the source,the running time and the source–detector distance(N0(L)∝L?2). We analyze our di?erent simulated data sets by performing a simpleχ2test,where χ2(?m214,θ14,?m213,θ13,α)=n bins i=1(N i?(1+α)T i)2(δN i)2 far+α2 N i.The sums are performed over all n bins energy bins in the near and far detectors.αis a nuisance parameter that governs how well the expected number of reactor antineutrino induced events at zero baseline can be predicted.δαcontains all uncertainties that are common to the expected number of events at both the near and far detectors,including uncertainties on the overall reactor antineutrino?ux,uncertainties on the energy dependence of the?ux,uncertainties on the antineutrino–target cross-sections,etc.No other systematic e?ects are considered,and, for the purposes of this analysis,we assume thatαdoes not depend on the energy bin.The role of theαparameter is simple.Roughly speaking,when T i/N i?1is smaller thanδα,most of the statistical power in the analysis comes from a comparison of near detector versus far detector expectations since in the limit where either detector is“turned o?”one can chooseαsuch that(N i?(1+α)T i)2is small whileα2/(δα)2is order one. We consider two di?erent simulated setups.In the Double-CHOOZ-like setup[1],we choose L near=400m, L far=1050m and N0(L)such that one would accumulate40,000events in the far detector in the absence of oscillations.For the near detector,we set the number of unoscillated events equal to that in the far detector times L2far/L2near.?In the Daya-Bay-like setup[2],we choose L near=400m,L far=1800m and N0(L)such that one would accumulate75,000events in the far detector in the absence of oscillations.As in the Double-CHOOZ-like setup,we set the unoscillated number of events in the near detector equal to that in the far detector times L2far/L2near.We?x δα=3%,which is of order the overall systematic uncertainty estimated in the CHOOZ experiment[13].Both the Double-CHOOZ and Daya Bay collaborations are aiming at understanding their experimental setups at a level that translates into,roughly,δα～1%.In what follows,we brie?y comment on the impact of allowing for smallerδαvalues. Two sample“data sets”for the Daya-Bay-like setup can be found in Fig.1.It depicts the number of events normalized to the expected number of events in the absence of oscillations in twenty equal-width recoil positron kinetic energy bins (E e =E ν?1.293MeV)between 1and 8MeV.In both panels,sin 22θ13=0.042,?m 213=2.2×10 ?3 eV 2,?m 214=1.0×10 ?2 eV 2.In the left-hand side,θ14=0so that,as far as this observable (P ee at the baselines and energies of interest here)is concerned,there are no sterile neutrinos.In the right-hand side,sin 22θ14=0.069.In the case sin 22θ14=0.069two features are noteworthy.One is that the ?m 214e?ects lead to visible distortions in the recoil electron energy spectrum both in the neat and far detectors,assuming the energy resolution is such that one can “see”the binning depicted in the ?gure.The other is that,on average,the near and far detectors point to a similar suppression of the expected number of events,as discussed in Sec.II. E e (MeV) O b s e r v e d /E x p e c t e d Daya Bay E e (MeV) O b s e r v e d /E x p e c t e d FIG.1:Number of events per energy bin in the Daya-Bay-like setup,normalized to the expected number of events in the absence of oscillations.Error bars are statistical only.The “data”correspond to sin 22θ13=0.042,?m 213=2.2×10 ?3 eV 2,?m 214=1.0×10 ?2 eV 2and sin 22θ14=0(left-hand side)or sin 22θ14=0.069(right-hand side).The grey [red]open circles (black closed circles)with smaller (larger)error bars correspond to “data”in the near (far)detector.The dotted [blue]line indicates the no-oscillation case. A.No Evidence for Oscillations In the absence of an oscillation signal,next-generation θ13-driven experiments rule out regions of the sin 22θ13×?m 213plane that are currently allowed by all neutrino data.Such a result would severely impact planning for next and next-next generation neutrino experiments.It would,for example,reveal that the NO νA experiment [14]cannot determine the neutrino mass hierarchy and strengthen the case for building a muon storage ring (neutrino factory)[15]. In order to study the impact of sterile neutrinos,we simulate data (as described above)consistent with no oscillations (θ13=θ14=0)and analyze it under two distinct hypotheses:(i)there are no light sterile neutrinos (as far as the setups in question are concerned,this is equivalent to θ14=0)and (ii)there is a fourth neutrino mass state with ?m 214∈[1,10]×10?2eV 2and sin 22θ14<0.1.In either case,we restrict ?m 213∈[2,3]×10?3 eV 2,as dictated by current neutrino data.? Figure 2depicts the region of parameter space ruled out at the 2σcon?dence level in the Double-CHOOZ-like (left-hand side)and Daya-Bay-like (right-hand side)setup.The darker continuous boundaries are obtained under the hypothesis that θ14=0.Note that,in spite of the simpli?ed nature of our analyses,our results agree qualitatively with those in [1,2].The lighter [red]dashed boundaries are obtained once χ2is marginalized over the “allowed”sin 22θ14×?m 214parameter space. Throughout,we perform two di?erent “types”of data analysis.In one case we consider a simple counting experiment (n bins =1),i.e.,one counts how many electron antineutrino candidate events appear in the near and far detectors and compares these numbers against expectations.In this case,the ability of sterile neutrinos to “mask”θ13e?ects is 2 2.12.22.32.42.52.62.72.82.9310-2 10-1 sin 22θ13 (?m 2)13 (10-3 e V 2 ) D-CHOOZ, 1 bin 2 2.12.22.32.42.52.62.72.82.9310-2 10-1 sin 22θ13 (?m 2)13 (10-3e V 2) Daya Bay, 1 bin 2 2.12.22.32.42.52.62.72.82.9310 -2 10-1sin 22θ13 (?m 2)13 (10-3e V 2 ) D-CHOOZ, 20 bins 2 2.12.22.32.42.52.62.72.82.9310 -2 10-1 sin 22θ13 (?m 2)13 (10-3e V 2) Daya Bay, 20 bins FIG.2:Region of the sin 22θ13×?m 213parameter ruled out,at the 2σcon?dence level in the Double-CHOOZ-like setup (left-hand side)and the Daya-Bay like setup (right-hand side).In the top panels we depict the result of a “total rate”experiment (n bins =1)while in the bottom the “data”is subdivided into 20recoil positron energy bins (n bins =20).The region to the right of the black,continuous line is ruled out under the hypothesis that there are no sterile neutrinos (θ14=0).The region to the right of the gray (red)dashed curve is ruled out under the hypothesis that ?m 214∈[1,10]×10 ?2 eV 2and sin 22θ14<0.1.optimal.The reason is simple.For a given value of sin 22θ13,?m 213one can “always”?nd a value of sin 22θ14,?m 214in the allowed region such that the number of events in the near detector di?ers from expectations as much as the number of events in the far detector.In this case,one cannot rely on the near/far comparison to “measure”the expected number of neutrino events and the sensitivity is governed by external uncertainties (δαparameter in Eq.(III.2)).The other case under consideration is n bins =20,i.e.,we take into account not only the overall suppression of the electron antineutrino ?ux but also potential distortions of the recoil positron energy spectrum.20recoil positron energy bins between 1and 8MeV corresponds to ?E =350keV.This is slightly wider than the expected energy resolution at both Double-CHOOZ [1]and Daya Bay [2].In this case,Fig.2reveals that the ability to exclude sin 22θ13values is not severely compromised by the light sterile neutrino hypothesis.The n bins =20case is,perhaps,a more faithful estimate of the results one would obtain with a realistic detector simulation.Detector and energy dependent systematic e?ects (not included in our analyses),however,tend to reduce the power of the binned analysis compared to overall ?ux one. Figure 3depicts the allowed region of parameter space in the sin 22θ13×sin 22θ14plane assuming the data in the Double-CHOOZ-like setup (left-hand side)and in the Daya-Bay-like setup (right-hand side)are consistent with no oscillations and after χ2is marginalized over the allowed values of ?m 213and ?m 2 14.In the counting experiment case (horizontal-vertical grey [red]hatching)one sees that when larger sin 22θ14values are considered,larger θ13values are consistent with no oscillations.This is in agreement with the estimate made in Eq.(II.13),which can be roughly translated as follows.By allowing di?erent values of ?m 214,the near/far ratio,on average,can be set to one for all θ14values satisfying sin 22θ14≤2sin 2 2θ13,assuming a 13(far)～1.Note that if θ13were set to zero,the analysis of a counting experiment consistent with no oscillations cannot rule out sin 22θ14=0.1.This is due to the fact that for n bins =1and large enough ?m 214θ14-driven oscillations average out at both the near and the far detectors.In this case the sensitivity to sin 22θ14is dominated by δα.Since that was set to 3%,in qualitative agreement with the original CHOOZ experiment,the sensitivity to sin 22θis similar to the sensitivity of the CHOOZ experiment to averaged out oscillations,sin 22θ<～0.1.For smaller values of δα,values of sin 2 2θ14larger than several percent are ruled out even in the n bins =1case. 10 -3 10 -2 10 -1 10 -2 10-1 sin 2 2θ13 s i n 22θ14 D-CHOOZ 10-3 10 -2 10 -1 10 -2 10 -1 sin 2 2θ13 s i n 22θ14 Daya Bay FIG.3:Allowed region of parameter space (2σcon?dence level)in the sin 22θ13×sin 22θ14plane assuming the data in the Double-CHOOZ-like setup (left-hand side)and in the Daya-Bay-like setup (right-hand side)are consistent with no oscillations.The (red)horizontal-vertical hatching indicates the result of a “total rate”experiment (n bins =1)while the black criss-crossed hatching corresponds to the “data”subdivided into 20recoil positron energy bins (n bins =20). In the case of the more ?nely binned data (20bins,criss-crossed black hatching)the absence of distortions in the energy spectrum at both detectors prevent large θ13or θ14values.Since θ14-driven oscillations lead,in the near detector,to potentially visible distortions of the antineutrino energy spectrum even for the largest considered value of ?m 214,the upper bound on sin 22θ14is stronger than that on sin 2 2θ13.For smaller values of δαthe results associated to n bins =20do not change qualitatively,while those associated to n bins =1start to approach the n bins =20case when δα～1%. B. Evidence for Oscillations (θ13-Driven) If θ13is large (sin 22θ13=few ×10?2),one expects a statistically signi?cant disappearance of electron antineutrinos in the far detector of θ13-driven reactor antineutrino experiments.In this case,one expects to not only reject the θ13=0hypothesis but also measure θ13(and,to a much lesser extend,?m 213).The result of such a measurement is also a?ected by whether one hypothesizes the presence of light sterile neutrinos. As in the previous subsection,we consider both the n bins =1and n bins =20case in order to highlight the e?ect of the light sterile neutrino hypothesis.Fig.4depicts the allowed region of parameter space extracted in the Daya-Bay-like setup assuming ?m 213=2.2×10 ?3 eV 2,sin 22θ13=0.042and θ14=0(the “data”depicted in Fig.1(left)).The case n bins =1(n bins =20)is depicted in the left (right)panel.Very similar results apply for the Double-CHOOZ-like setup.§ Figure 4reveals that,in the case of a simple counting experiment,whether or not one allows for a light sterile state signi?cantly a?ects the precision with which θ13can be measured.In the n bins =20case,on the other hand,allowing for the existence of a light sterile neutrino does not signi?cantly impact the precision with which θ13(and ?m 213)is measured.The reason for this is simple.In the case of 1bin,a larger or smaller value of sin 2 2θ13can be made consistent with the data if it is accompanied by a large enough hypothetical sin 22θ14value.In the case n bins =20,large values of sin 22θ14are ruled out by the lack of distortion in the near (and far)detector recoil positron energy spectrum.This phenomenon is clearly seen in Fig.5(right),which depicts the allowed region of the sin 22θ14×sin 22θ13 2 2.12.22.32.42.52.62.72.82.930.050.1sin 2 2θ13 (?m 2)13 (10-3e V 2) Daya Bay, 1 bin 2 2.12.22.32.42.52.62.72.82.930.050.1sin 2 2θ13 (?m 2 )13 (10-3e V 2 ) Daya Bay, 20 bins FIG.4:Allowed region of parameter space (2σcon?dence level)in the ?m 213×sin 2 2θ13plane assuming the data in the Daya-Bay-like setup are consistent with ?m 213=2.2×10 ?3 eV 2,sin 22θ13=0.042and θ14=0.The light [green]solid densely shaded region corresponds to analyzing the data assuming θ14≡0,while the dark hatched region is obtaned if one allows for a fourth light neutrino.On the left panel a “total rate”experiment is performed (n bins =1)while in the right panel the data was subdivided into 20recoil positron energy bins (n bins =20). parameter space (once one marginalizes over the allowed ?m 213and ?m 2 14values).It is interesting to note that in the n bins =1case sin 22θ14values as large as 0.1are allowed at the two-sigma con?dence level.The reason for this is that, for large enough ?m 214and n bins =1,the sensitivity to sin 2 2θ14is dominated by δα,as discussed in the previous subsection.For smaller values of δαwe ?nd that “large”values of sin 22θ14are ruled out even in the n bins =1case. 10 -2 10 -1 10-3 10 -2 10-1 sin 2 2θ14 (?m 2)14 (e V 2) 10 -3 10 -2 10 -1 10 -2 10-1 sin 2 2θ13 s i n 22θ14 Daya Bay FIG.5:Allowed region of parameter space in the ?m 214×sin 22θ14plane (left)and the sin 22θ14×sin 2 2θ13plane (right) assuming the data in the Daya-Bay-like setup are consistent with ?m 213=2.2×10 ?3 eV 2,sin 22θ13=0.042and θ14=0at the 2σcon?dence level.On the right panel the (red)horizontal-vertical hatching indicates the result of a “total rate”experiment (n bins =1)while the black criss-crossed hatching corresponds to the “data”subdivided into 20recoil positron energy bins (n bins =20).On the left panel n bins =20. In the case n bins =20,the absence of a distorted positron energy spectrum in the near detector rules out sin 22θ14 values larger than 10?2or so.Fig.5(left)depicts the region of the ?m 214×sin 2 2θ14plane ruled out at the two sigma level assuming the data in the Daya-Bay-like setup are consistent with ?m 213=2.2×10 ?3 eV 2,sin 22θ13=0.042and θ14=0.Such a result would improve the current constraints on θ14by about an order of magnitude for the values of ?m 214highlighted here. C. Evidence for Oscillations (θ13and θ14-Driven) If θ14is nonzero (and large enough)and ?m 214～few ×10 ?2 eV 2,θ14-e?ects will produce non-trivial,distinct e?ects in the near and far detectors,as depicted in Fig.1(right).In this case,allowing for the presence of a light sterile neutrino during the data analysis would prove to be more than a choice —it would be necessary in order to obtain a proper ?t to the data of the reactor neutrino experiments under investigation here. Figure 6depicts two two-parameter 2σallowed regions of parameter space if the data in the Daya-Bay-like setup were consistent with ?m 213=2.2×10?3eV 2,sin 22θ13=0.042,?m 214=0.01eV 2 ,and sin 22θ14=0.03.Figure 6(left)depicts how well sin 22θ13(and ?m 213)can be measured in the case n bins =1and n bins =20after one marginalizes over sin 22θ14and ?m 2 14.These should be compared to Fig.4.It is clear that in the n bins =1case the fact that sin 22θ14is nonzero renders a “rates-only”measurement of sin 22θ13harder.In the n bins =20case,on the other hand,the impact of a non-zero sin 22θ14when it comes to measuring sin 22θ13is small.The reason for this is that in the n bins =20case distortions in the near (and,to a lesser extent,in the far)detector determine ?m 214and sin 2 2θ14,allowing the near/far comparison to “fully contribute”to the measurement of θ13. 22.12.22.32.42.52.62.72.82.930.050.1sin 2 2θ13 (?m 2)13 (10-3e V 2) 10 -3 10 -2 10 -1 10 -2 10-1 sin 2 2θ13 s i n 22θ14 Daya Bay FIG.6:Allowed region of parameter space in the ?m 213×sin 22θ13plane (left)and the sin 22θ14×sin 2 2θ13plane (right) assuming the data in the Daya-Bay-like setup are consistent with ?m 213=2.2×10?3eV 2,sin 22θ13=0.042,?m 214=0.01eV 2 ,and sin 22θ14=0.03at the 2σcon?dence level.On the left panel,the light [green]solid densely shaded region corresponds to n bins =20,while the dark hatched region corresponds to n bins =1.On the right panel,the (red)horizontal-vertical hatching indicates the result of a “total rate”experiment (n bins =1)while the black criss-crossed hatching corresponds to the “data”subdivided into 20recoil positron energy bins (n bins =20). Figure 6(right)depicts how well sin 22θ13and sin 22θ14can be measured in the case n bins =1and n bins =20after one marginalizes over both mass-squared di?erences.In the case n bins =1,virtually no constraint can be set on sin 22θ13.Curiously enough,if sterile e?ects were not included (θ14≡0),one would be able to establish that sin 22θ13=0.In this case,however,the wrong hypothesis in the data analysis would point to an allowed range for sin 22θ13that is slightly less than its real value (this is true at around the 1σlevel).For larger “true”values of θ14this e?ect is more pronounced.As discussed earlier,in the case n bins =20one is able to obtain a precise measurement of both mixing angles. For smaller values of true sin 22θ14,the impact of sterile neutrinos is,of course,less pronounced.Figure 7depicts two two-parameter 2σallowed regions of parameter space if the data in the Daya-Bay-like setup were consistent with ?m 213=2.2×10?3eV 2,sin 22θ13=0.042,?m 214=0.1eV 2 ,and sin 22θ14=0.0091.In this case,even in the n bins =1case one can establish that sin 22θ13=0(at the 2σlevel).In the n bins =20case,a reasonable measurement of both sin 22θ13and sin 22θ14can be performed —at the 2σlevel,sin 22θ14∈[0.002,0.015]and sin 22θ13∈[0.03,0.055],and correlations are small. We conclude this section with a short comment on the case θ13=0and θ14=0large.As far as measuring sin 22θ14is concerned,the situation here is qualitatively similar to the previous two cases displayed above.Due to the cancellation e?ects discussed earlier,an n bins =1analysis fails to severely constrain either θ13(similar to the situation depicted in Fig.2(top))and θ14.An n bins =20analysis,on the other hand,allows one to not only measure sin 22θ14and ?m 214with good precision but also constrain sin 2 2θ13signi?cantly,as in Fig.2(bottom). 22.12.22.32.42.52.62.72.82.930.050.1sin 22θ13 (?m 2)13 (10-3e V 2) 10 -3 10 -2 10 -1 10 -2 10-1 sin 2 2θ13 s i n 22θ14 Daya Bay FIG.7:Allowed region of parameter space in the ?m 213×sin 22θ13plane (left)and the sin 22θ14×sin 2 2θ13plane (right) assuming the data in the Daya-Bay-like setup are consistent with ?m 213=2.2×10 ?3 eV 2,sin 22θ13=0.042,?m 214=0.1eV 2,and sin 22θ14=0.0091at the 2σcon?dence level.On the left panel,the light [green]solid densely shaded region corresponds to n bins =20,while the dark hatched region corresponds to n bins =1.On the right panel,the (red)horizontal-vertical hatching indicates the result of a “total rate”experiment (n bins =1)while the black criss-crossed hatching corresponds to the “data”subdivided into 20recoil positron energy bins (n bins =20). IV.DISCUSSION AND CONCLUSIONS We have discussed the impact of very light sterile neutrinos on the interpretation of next-generation θ13-driven reactor antineutrino experiments.For ?m 214values between 1and 10×10 ?2 eV 2,θ14-driven oscillations a?ect data in the far and near detectors di?erently,leading to several potentially interesting e?ects.In the absence of a positive oscillation signal,the hypothesis θ14=0negatively impacts one’s ability to rule out very small θ13values as would-be θ14-driven e?ects in the near and far detectors can mask θ13-driven e?ects in the far detector.Similarly,if a positive θ13-driven signal is observed,would-be θ14-driven e?ects negatively impact ones ability to measure the value of sin 22θ13.The above results are more or less pronounced depending on one’s ability to “see”distortions of the recoil positron energy spectrum.A simple counting experiment is very susceptible to hidden θ14-driven e?ects while a binned data analysis (at both the near and far detectors)seems able to disentangle θ13from θ14-driven e?ects. If there is indeed a light sterile neutrino associated to ?m 214∈[1,10]×10 ?2 eV 2,θ13-driven reactor antineutrino experiments should be able to see large spectral distortions in the near detector,in which case one can determine not only θ14but also ?m 214.It is curious to note that,for ?m 214values close to 0.1eV 2 ,the roles of the near and far detectors as far as studying θ14-driven e?ects are reversed compared to those associated to studying θ13-driven e?ects.For these mass-squared di?erences,oscillation e?ects average out in the far detector (even in a ?nely-binned analysis).This allows one to determine the “averaged-out”neutrino ?ux and hence helps extract the value of θ14from the depths of the oscillation minima.In the absence of θ14-driven e?ects,we estimate that values of sin 22θ14as small as 1percent can be ruled out with a binned analysis (Fig.5(left)). Sterile neutrino e?ects at θ13-driven reactor experiments have been considered in the past,but in a di?erent mass-squared di?erence regime.The authors of [9]recently discussed the e?ect of sterile neutrinos related to a potential 3+2solution to the LSND anomaly.?There,the new mixing angles and mass-squared di?erences lead to averaged out e?ects at both the near and far detectors.Here,on the other hand,we concentrate on a lower mass-squared di?erence regime where this is not the case. If there are indeed such light sterile neutrinos,it is likely that the most sensitive terrestrial probes of their existence are the setups discussed here.This is not a coincidence:we are concentrating on values of ?m 214where oscillation e?ects in the near detector are optimal.Other near-future probes include long-baseline accelerator-based neutrino oscillation experiments.However,?m 214-driven e?ects at next-generation θ13-driven appearance long-baseline exper- iments are proportional to the product of the squares of two potentially small mixing angles(Pμe∝θ214θ224,using the notation of[7]).Furthermore,next-generation studies of muon neutrino disappearance at similar setups are also unlikely to achieve sensitivity competitive with the one discussed here.Note that?m214is large enough that it leads to averaged-out e?ects at the far detector but too small to mediate observable e?ects in the near detectors of next-generation long-baseline experiments.??Detailed recent analyses of next-generation oscillation probes of light sterile neutrinos,concentrating on?m214values above0.1eV2,can be found in[19,20,21,22]. It is important to appreciate that this range of sterile neutrino parameters is not motivated by any existing data,nor does it help address any existing outstanding issue in fundamental physics.On the other hand,as already emphasized, little is known about sterile neutrinos.Evidence for sterile neutrinos at any mass range would qualitatively change our understanding of particle physics(and probably shed light on the mechanism behind light neutrino masses). Finally,light sterile neutrinos qualify as an example of non-standard physics that may appear in next-generation reactor neutrino experiments.They can not only lead to nontrivial oscillation patterns in the data,but also modify the interpretation of reactor antineutrino data when it comes to measuring or constrainingθ13.Our results also highlight the fact that new and interesting results may come out of the data in the near detector[23],which may provide more information than the measurement of the“L=0”reactor antineutrino?ux.We conclude by re-emphasizing that our simulations and analyses are not aimed at realistically describing experimental setups or quantitatively gauging their reach.Qualitatively,however,our results capture the nontrivial impact of light sterile neutrinos atθ13-driven reactor antineutrino experiments.We hope that our?ndings will prompt the collaborations to pursue quantitative estimates of the impact of the very light sterile neutrinos introduced here. Acknowledgments A preliminary version of the results discussed here was presented as TW’s senior undergraduate thesis at North-western University.We are happy to thank Heidi Schellman for feedback on TW’s undergraduate senior thesis and for encouragement.This work is sponsored in part by DOE grant#DE-FG02-91ER40684. [1]F.Ardellier et al.[Double Chooz Collaboration],arXiv:hep-ex/0606025. [2]X.Guo et al.[Daya Bay Collaboration],arXiv:hep-ex/0701029. [3]For a pedagogical discussion and many references see,for example,A.de Gouv?e a,arXiv:hep-ph/0411274.For recent comprehensive reviews see,for example,M.C.Gonzalez-Garcia and M.Maltoni,Phys.Rept.460,1(2008);A.Strumia and F.Vissani,arXiv:hep-ph/0606054.See also[16]. [4]P.Minkowiski,Phys.Lett.B67,421(1977);M.Gell-Mann,P.Ramond and R.Slansky in Supergravity,eds.D.Freedman and P.Van Niuenhuizen(North Holland,Amsterdam,1979),p.315;T.Yanagida in Proceedings of the Workshop on Uni?ed Theory and Baryon Number in the Universe,eds.O.Sawada and A.Sugamoto(KEK,Tsukuba,Japan,1979); S.L.Glashow,1979Carg`e se Lectures in Physics—Quarks and Leptons,eds.M.L′e vy et al.(Plenum,New York,1980), p.707.See also R.N.Mohapatra and G.Senjanovi′c,Phys.Rev.Lett.44,912(1980)and J.Schechter and J.W.F.Valle, Phys.Rev.D22,2227(1980). [5]A very low-energy seesaw was proposed in A.de Gouv?e a,Phys.Rev.D72,033005(2005).See also A.de Gouv?e a,J.Jenkins and N.Vasudevan,Phys.Rev.D75,013003(2007);F.L.Bezrukov and M.Shaposhnikov,Phys.Rev.D75,053005(2007); A.de Gouv?e a,arXiv:0706.1732[hep-ph]for recent discussions of the phenomenology of low-energy versions of the seesaw mechanism. [6]For a connection between dark matter and the seesaw mechanism see T.Asaka,S.Blanchet and M.Shaposhnikov,Phys. Lett.B631,151(2005);T.Asaka and M.Shaposhnikov,Phys.Lett.B620,17(2005); [7]A.de Gouv?e a and J.Jenkins,Phys.Rev.D78,053003(2008). [8]M.Cirelli,G.Marandella,A.Strumia and F.Vissani,Nucl.Phys.B708,215(2005). [9]A.Bandyopadhyay and S.Choubey,arXiv:0707.2481[hep-ph]. [10]P.Huber and T.Schwetz,Phys.Rev.D70,053011(2004). [11]H.Murayama and A.Pierce,Phys.Rev.D65,013012(2002). [12]P.Vogel and J.F.Beacom,Phys.Rev.D60,053003(1999). [13]M.Apollonio et al.[CHOOZ Collaboration],Eur.Phys.J.C27,331(2003). [14]D.S.Ayres et al.[NOνA Collaboration],arXiv:hep-ex/0503053. [15]See,for example,A.Bandyopadhyay et al.[ISS Physics Working Group],arXiv:0710.4947[hep-ph]. [16]C.Amsler et al.[Particle Data Group],Phys.Lett.B667(2008)1. [17]P.Adamson et al.[MINOS Collaboration],arXiv:0806.2237[hep-ex]. [18]M.Maltoni and T.Schwetz,Phys.Rev.D76,093005(2007). [19]A.Donini,M.Maltoni,D.Meloni,P.Migliozzi and F.Terranova,JHEP0712,013(2007). [20]A.Dighe and S.Ray,Phys.Rev.D76,113001(2007). [21]S.Goswami and T.Ota,Phys.Rev.D78,033012(2008). [22]S.Choubey,JHEP0712,014(2007). [23]The large data samples which will be collected at near detectors could also allow for a new precision measurement of sin2θW viaˉν+e elastic scattering,as discussed in J.M.Conrad,J.M.Link and M.H.Shaevitz,Phys.Rev.D71,073013 (2005). 民歌篇教案范文 1、喜欢聆听、演唱民歌及具有民族风格的通俗歌曲，愿意探索有关民歌的音乐文化知识。 2、掌握有关民歌的基本知识。 3、通过欣赏，初步感知南北民歌的风格特点，感受民族音乐与民俗风情的丰富多彩。 重点：着重欣赏广东民歌《对花》，同时听辨《槐花几时开》《拨根芦柴花》《上去高山望平川》《猜花》等民歌。 难点：本篇以“花”为立足点，使学生借此了解东南西北民歌的不同风格，感受民歌的绚丽风采。 一、导入： 1、欣赏流行音乐视频片段：《茉莉花》——梁静茹 师提问：大家熟悉这首流行歌吗？喜欢吗？ 这首流行歌曲是中国江南民歌《茉莉花》改编而成，一曲茉莉花，芬芳香四方，这首脍炙人口的江苏民歌几乎是我们国家在重要事件和相关国际重要场合下的必奏之歌。在北京奥运会上，《茉莉花》作为主旋律背景音乐向世界展示了中国文化，让世界了解了中国。可见，民族音乐之于民族的重要性。 2、民歌是什么？ 民歌是人民的歌、民族的歌，是真实反映劳动人民情感、生活的歌曲作品。民歌以口头传播，一传十十传百，一代传一代的传下去至今，每个民族都有自己的生活方式，并在代代积淀与传承中形成了自己独特的文化。不同的文化又赋予了音乐不同的形式和内涵，形成了风格迥异的民族音乐。它们是音乐文化的基础和源泉。 3、民歌的分类：山歌、号子、小调。 二、新授： 在中国的民歌中，“花”是一个最普遍的主题，其用法有三种：一是以花喻人，借花表法情爱；二是歌颂大自然，传授自然知识；三是借花起兴，以花为歌唱媒介，而花本身没有特定含义。 我们今天这堂课正是从“花”出发，了解东南西北民歌的不同风格，感受民歌的绚丽风采。（点出本课围绕的中心话题，引发学生的关注。） 1、以“花”为题材的各地民歌 ①、四川民歌《槐花几时开》 （介绍“晨歌”，聆听歌曲，体验歌曲中富有地方特色的“啥子”的唱段） ②、江苏民歌《拔根芦柴花》 （介绍“秧田歌”，聆听歌曲，了解歌词中出现的众多花名的意义） ③、青海民歌《上去高三望平川》 （介绍“河湟花儿”，聆听歌曲，谈谈自己所感受到的演唱风格） ④、辽宁民歌《猜花》 1、SDN是什么？ SDN(Software Defined Network)即软件定义网络，是一种网络设计理念。网络硬件可以集中式软件管理，可编程化，控制转发层面分开，则可以认为这个网络是一个SDN网络。SDN 不是一种具体的技术，不是一个具体的协议，而是一个思想，一个框架，只要符合控制和转发分离的思路就可以认为是SDN. 2、传统网络面临的问题？ 1）传统网络部署和管理非常麻烦，网络厂商杂，设备类型多，设备数量多，命令行不一致2）流量全局可视化难 3）分布式架构中，当网络发生震荡时，网络收敛过程中，有可能出现冗余的路径通告信息4）网络流量的剧增，导致底层网络的体积膨胀、压力增大；网络体积越大的话，需要收敛的时间就越长 5）想自定义设备的转发策略，而不是网络设备里面的固定好的转发策略 -------->sdn网络可以解决的问题 3、SDN的框架是什么 SDN框架主要由，应用层，控制层，转发层组成。其中应用层提供应用和服务（网管、安全、流控等服务），控制层提供统一的控制和管理（协议计算、策略下发、链路信息收集），转发层提供硬件设备（交换机、路由器、防火墙等）进行数据转发、 4、控制器 1）控制器概述 在整个SDN实现中，控制器在整个技术框架中最核心的地方控制层，作用是上接应用，下接设备。在SDN的商业战争中，谁掌握了控制器，或者制定了控制器的标准，谁在产业链条中就最有发言权 2）控制器功能 南向功能支撑：通过openflow等南向接口技术，对网络设备进行管控，拓扑发现，表项下 发，策略指定等 北向功能：目前SDN技术中只有南向技术有标准文案和规范，而北向支持没有标准。即便如此，控制器也需要对北向接口功能进行支持，REST API,SOAP,OSGI,这样才能够被上层的应用调用 东西向功能支持：分布式的控制器架构，多控制器之间如何进行选举、协同、主备切换等3）控制器的种类 目前市场上主要的控制器类型是：opendaylight （开发语言Java），Ryu(开发语言python), FloodLihgt(开发语言Java)等等 5、opendaylight（ODL）控制器介绍 ODL拥有一套模块化、可插拔灵活地控制平台作为核心，这个控制平台基于Java开发，理论上可以运行在任何支持Java的平台上，从Helium版本开始其官方文档推荐的最佳运行环境是最新的Linux（Ubuntu 12.04+）及JVM1.7+。 ODL控制器采用OSGi框架，OSGi框架是面向Java的动态模型系统，它实现了一个优雅、完整和动态的组件模型，应用程序（Bundle）无需重新引导可以被远程安装、启动、升级和卸载，通过OSGi捆绑可以灵活地加载代码与功能，实现功能隔离，解决了功能模块可扩展问题，同时方便功能模块的加载与协同工作。自Helium版本开始使用Karaf架构，作为轻量级的OSGi架构，相较于早前版本的OSGi提升了交互体验和效率，当然其特性远不仅仅于此。 ODL控制平台引入了SAL（服务抽象层），SAL北向连接功能模块，以插件的形式为之提供底层设备服务，南向连接多种协议，屏蔽不同协议的差异性，为上层功能模块提供一致性服务，使得上层模块与下层模块之间的调用相互隔离。SAL可自动适配底层不同设备，使开发者专注于业务应用的开发。 此外，ODL从Helium开始也逐渐完成了从AD-SAL（Application Driven Service Abstraction Layer）向MD-SAL（Model Driven Service Abstraction Layer）的演进工作，早前的AD-SAL，ODL控制平台采用了Infinispan技术，In?nispan是一个高扩展性、高可靠性、键值存储的分布式数据网格平台，选用Infinispan来实现数据的存储、查找及监听，用开源网格平台实现controller的集群。MD-SAL架构中采用Akka实现分布式messageing。 6、ODL的总体框架 ODL控制器主要包括开放的北向API，控制器平面，以及南向接口和协议插件。北向API 有OSGI和REST两类，同一地址空间应用使用OSGI类，而不同地址空间的应用则使用REST 类。OSGI是有状态的连接，有注册机制，而rest是无状态链接。上层应用程序利用这些北 上海汉雷汽车氙气灯常用车型对照表 part1：常用车型对照表汽车氙气灯常用的汽车类型主要如以下表格所示： Part2：汽车氙气灯常见故障及解决方案 改装氙气灯的九种常故障和十种解决方案各类汽车安装HID氙气灯常见问题故障及解决方案：问题一）安装后灯能正常亮，但是仪表台故障报警灯亮（通常所说的故障灯亮问题）。 如：奥迪A4 1.8T、06款宝马、速腾近光、迈腾、明锐、福克斯、沃尔沃近光、标致206等。 引起故障原因：原车是50W-60W,氙气灯是35W,一部分高档欧美车都经过电脑检测，会检测出“功率不匹配”，所以亮红灯。安定器电流不回路或者安定器启动电流过大(大于7A)也会引起。 解决方案： 方案一：用带2OW假负载的线组可以解决问题，20W+35W，刚好55W，与原车一样，所以电脑检测便正常了。 方案二：更换55W的灯泡及55W安定器，也可解决问题。 方案三：回路电流不回路.可能是原车的功率检测电路检测的是地线的回路电流，安定器地线一定要和原灯泡地线接在一起,在加上一个20W假负载可以解决.(安定器外壳与安定器地线一定是绝缘的才可以) 方案四：改用启动电流小的安定器或加装抗干扰*。以上几种方案，均可解决仪表故障灯显示问题，安装店或消费者可自行选择改装方案。问题二）安装后灯泡出现爆闪或经常出现熄灭或左右灯不同时亮等现象。 如：06款宝马X5、3251、5201、奔驰S350、S500、路虎、华晨宝马3系等。 解决方案： 步骤一：查看大灯线路工作电流是否正常，如果线路正常，则按以下方案继续解决问题； 步骤二：查看大灯线路是否有经过行车电脑，如有经过，需加专用*方能恢复正常；步骤三：加装专用的爆闪及不足*。目前已成功解决的车型案例： A.福特冀虎 B.斯柯达 C.大众领驭 D.速腾 E.迈腾 （以上问题的主要原因是安定器启动电路太大引起的，我们公司新款奔驰、宝马专安定器启动电流在4.5A左右,能够有效降低以上问题出现的机率。）问题三）安装后会由于电磁干扰汽车电路出现烧电脑版现象，常见故障车型如：别克君越、别克陆尊、现代御翔高级版、酷派、大切诺基。 引起故障原因及现象：由于原车配特殊电子电路板（也称电脑板），很容易受干扰，会烧坏电路板或灯光闪烁或自动熄灭。 解决方案： 方案一：用专用配置电路结构的专用安定器可解决； 方案二：加装高级抗干扰器也可解决以上现象； 方案三：选择启动电流小的安定器,并适当加大滤波电容容量可以解决，所以质量好的安定器相当重要，消费者在选择购买时多进行了解，以确保消费的权益。问题四）部分车型安装了HID氙气灯之后，在打开灯的瞬间收音机有咔嚓声或无声，无法正常收听电台或有干扰声。 引起故障的原因：咔嚓声或无声是因为安定器启动电路大造成的，干扰声的主要原因是：安定器内部升压电路频率与收音机内部频率信号重叠而产生干扰；同时也有方向性的原因。 解决方案：可将安定器移位或调转方向安装便可，基本上可以解决问题，如果彻底解决信号问题则要将安定器屏蔽隔离即可；咔嚓声或瞬间无声，如不影响正常收听收音机，不建议改动，（更换冲击电流小的或无冲击的安定器可以解决，也可以通过电瓶直接供电给安定器（那加装HID氙气灯加强线组），但改装麻烦，需懂技术的人员操作。）问题五）为什么有的车型在安装氙气灯后，开灯时发现一边灯亮，一边不亮，这是什么原因？ 引起故障的原因：是由于启动电流不足而造成的，多数安定器的启动电流需要7~8A左右，（在一到两分钟之后稳定到3.5A 左右）,而一般原车大灯线路的电流设计为5.5A-6A,所以会产生启动电流不足，因此导致只有一组HID灯能够得到足够的启动电流，所以产生一亮一灭的情况，这种情况很常见。 解决方案： 方案一：加装一套带继电器的线组，直接从电瓶供电（那HID氙气灯加强线）。 方案二：检查安定器的12V输入端跟插座的接触是否松动。这种情况会导致车辆在行车过程中，因震动而使HID供电不足而产生故障。 方案三：HID氙气灯是属于高压气体放电灯，安定器里面增加了高压保护线路，在遇到异常情况下，安定器会自动切断电源，保障使用以及车辆的安全，在排除异常情况之后，重新打开电源，安定器将能正常工作。如果还未能解决问题，可将安定器邮寄回我司重新调整、检查原因，我司将会在最短时间内处理问题。问题六）部分车型安装HID灯已用了一段时间，现在变光不了，经检查远光的保险丝烧断了，但换了保险丝，一开灯又烧断是什么原因？ 引起故障的原因：短路。 解决方案：造成该问题的最大可能是安定器损坏（内部升压MOS被击穿）占该类故障的95%，也有可能是安定器在安装的过程中，电源线破皮没有做好绝缘措施，与地线搭在一起造成的，带线组控制器的也有可能是线组控制器内部短路造成的，需要逐一排查，方可解决问题。问题七）现代酷派安装了HID氙气灯之后，启动发动机引擎打开后会出现一闪一闪的，但引擎不启动能正常工作，这是什么原因？ 引起故障的原因：安装完氙气大灯后，在汽车引擎不发动的情况下，氙气大灯都能正常亮或是变光，但一发动汽车引擎，氙气大灯就会产生闪灯或熄灭的情况，而车辆仪表台的故障灯也会亮起，原因就是大灯控制线路经过行车电脑检测，也就是我们平常所说的CANBUS问题，而氙气大灯的工作原理以及工作功率跟卤素灯的不同，使得行车电脑检测不到氙气大灯的反馈信号所致。 解决方案：加装*或用带解码功能的专用安定器即可。（注：奥迪A4，福特冀虎，宝马X5车有同样问题出现）问题八）各种车型安装所遇到的问题故障及解决方案：1）帕萨特在安装HID氙气灯后在变光时会产生CD音响停顿的现象，这是什么原因？ 引起故障的原因：是HID氙气大灯启动电流大，造成电源不稳定，从而使音响停顿，此种情况普遍存在。 headlight 汽车雾灯，按所安装在汽车的位置来分，分为：1、汽车前雾灯；2、汽车后雾灯。 按使用材料来分，分为：1、气体汽车雾灯；2、LED汽车雾灯。 编辑本段汽车前雾灯型号 H1 H1底座的汽车前雾灯，功率是55W，灯泡直径是8.5mm，总长是62.5mm，灯头表示为P14.5s。使用H1汽车前雾灯的车型如毕加索。 H3 H3底座的汽车前雾灯，功率是55W，灯泡直径是11.5mm，总长是42.0mm，灯头表示为PK 22s。使用H3汽车前雾灯的车型如比亚迪F3、吉普jeep-2500等。 H4 H4底座的汽车前雾灯，功率是60/55W，灯泡直径是17.0mm，总长是92.0mm，灯头表示为P43t-38。使用H4汽车前雾灯的车型如一汽威乐。 H7 H7底座的汽车前雾灯，功率是55W，灯泡直径是11.0mm，总长是57.0mm±2.0，灯头表示为PX 26d。使用H7汽车前雾灯的车型如奔驰S系列、奥迪Q5等。 H8 H8底座的汽车前雾灯，功率是35W，灯头表示为PGJ 19-1。使用H8汽车前雾灯的车型如福特福克斯。 H11 H11底座的汽车前雾灯，功率是55W，灯头表示为PGJ 19-2，使用H11汽车前雾灯的车型如东风雪铁龙C2。 9004 9004底座的汽车前雾灯，功率是65/45W，灯头表示为P29t，也可称为HB1。 9005 9005底座的汽车前雾灯，功率是60W，灯头表示为P20d，也可称为HB3。 9006 9006底座的汽车前雾灯，功率是51W，灯头表示为P22d，也可称为HB4。使用9006汽车前雾灯的车型如丰田威驰、马自达3等。 编辑本段汽车后雾灯型号 P21W P21W，功率是21W，灯泡直径是26.5mm，总长为52.5mm，也可称为BA15S或1156。使用P21W汽车后雾灯的车型如赛纳、新雅途等。 W21W W21W，功率是21W，也可称为7440。使用W21W汽车后雾灯的车型如马自达3等日系汽车。 P27W P27W，功率是27W，可也称为3156。 W16W W16W，功率是16W，灯泡直径是15.2mm，总长是35.6mm，灯头表示为W2.1×9.5d。使用W16W汽车后雾灯的车型如奥迪Q5。 编辑本段汽车雾灯的位置 汽车前雾灯，一般位于汽车大灯下面，左右各一个；汽车后雾灯，一般位于汽车尾灯，和汽车倒车灯成对称放置，且左边的是雾灯，右边的是倒车灯，即单后雾灯单倒车灯。 编辑本段冬季雾灯养护 冬季易起雾起霜，能见度低，所以一定要及时观察雾灯、高位刹车灯工作是否正常，发现变黑的灯泡一定要尽早换掉。普通卤素大灯一般使用两年后光线就会减弱，最好及时更换或维修。 民歌篇教案 《xx四方》——民歌篇教学设计 【教学年级】：高一年级 【教学课时】：一课时 【设计思路】：通过聆听，了解民歌的风格特征，感受民歌的艺术魅力，培养学生对中国民歌的喜爱和兴趣，体现以音乐审美为核心的理念。通过民歌的学习让学生认识到：民族音乐是中华民族数千年来劳动人民智慧的结晶，是劳动人民创造的宝贵文化遗产，是中华民族传统文化的组成部分；同时帮助学生树立“音乐作为文化”和“文化中的音乐”的观念，培养学生“弘扬民族音乐文化”、理解多元文化的理念，从而达到理解和尊重多元的世界文化的目的。 【教学目标】： 、喜欢聆听、演唱民歌及具有民族风格的通俗歌曲，愿意探索有关民歌的音乐文化知识。 2、掌握有关民歌的基本知识。 3、通过欣赏，初步感知南北民歌的风格特点，感受民族音乐与民俗风情的丰富多彩。 【教学重点，难点】： 重点：着重欣赏广东民歌《对花》，同时听辨《槐花几时开》《拨根芦柴花》《上去高山望平川》《猜花》等民歌。 难点：本篇以“花”为立足点，使学生借此了解东南西 xx民歌的不同风格，感受民歌的绚丽风采。 【教学准备】：多媒体、视频、音频等 【教学过程】： 一、导入： 、欣赏流行音乐视频片段：《茉莉花》——梁静茹师提问：大家熟悉这首流行歌吗？喜欢吗？ 这首流行歌曲是中国江南民歌《茉莉花》改编而成，一曲茉莉花，芬芳香四方，这首脍炙人口的江苏民歌几乎是我们国家在重要事件和相关国际重要场合下的必奏之歌。在北京奥运会上，《茉莉花》作为主旋律背景音乐向世界展示了中国文化，让世界了解了中国。可见，民族音乐之于民族的重要性。 2、民歌是什么？ 民歌是人民的歌、民族的歌，是真实反映劳动人民情感、生活的歌曲作品。民歌以口头传播，一传十十传百，一代传一代的传下去至今，每个民族都有自己的生活方式，并在代代积淀与传承中形成了自己独特的文化。不同的文化又赋予了音乐不同的形式和内涵，形成了风格迥异的民族音乐。它们是音乐文化的基础和源泉。 3、民歌的分类：山歌、号子、小调。 二、新授： 在中国的民歌中，“花”是一个最普遍的主题，其用法 有三种：一是以花喻人，借花表法情爱；二是歌颂大自然，传授自然知识；三是借花起兴，以花为歌唱媒介，而花本身没有特定含义。 我们今天这堂课正是从“花”出发，了解东南西北民歌的不同风格，感受民歌的绚丽风采。（点出本课围绕的中心话题，引发学生的关注。） 、以“花”为题材的各地民歌 ①、xx民歌《槐花几时开》 （介绍“晨歌”，聆听歌曲，体验歌曲中富有地方特色的“啥子”的唱段） ②、xx民歌《拔根芦柴花》 本文作为码农学ODL系列的SDN基础入门篇，分为两部分。第一部分，主要讲述SDN是什么，改变了什么，架构是什么样的，第二部分，简要介绍如何去学习SDN。 1.什么是SDN SDN(Software Define Network) ，即为软件定义网络，可以看成网络界的操作系统。从SDN的提出至今，其内涵和外延也不断地发生变化，越来越多的人认为“可以集中控制、开放可编程和转控分离的网络”就是SDN网络，并且还延伸出软件定义计算、软件定义存储以及软件定义安全等。SDN加快了新业务引入的速度，提升了网络自动化运维能力，同时，也降低了运营成本。SDN的基础 知识如下图所示，下面各小节内容将根据该图内容进行展开论述： 1.1.SDN基础 1.1.1.SDN本质及核心 我们知道，传统网络中的路由器也存在控制平面和转发平面，在高端的路由器或交换机还采用物理分离，主控板上的CPU不负责报文转发，专注于系统的控制；而业务板则专注于数据报文转发。所以路由器或交换机内的控制平面与转发平面相对独立又协同工作，如图所示： 但这种分离是封闭在被称为“盒子”的交换机或路由器上，不可编程；另一方面，从IP网络的维度来考虑，采用的是分布式控制的方式：在控制面，每台路由器彼此学习路由信息，建立各自的路由转发表；在数据面，每台路由器收到一个IP 包后，根据自己的路由转发表做IP转发； IP网络的这种工作方式带来了运维成本高、业务上线慢等问题，并越来越难以满足新业务的需求，传统上通过添加新协议、新设备等手段来缓解问题的方式，收益越来越少。穷则思变，许多人产生了革命的想法，现有的网络架构既然无法继续演进发展，为何不推倒重来，重新定义网络呢？真可谓“时势造英雄”，2006年斯坦福大学Nick McKeown教授为首的研究团队提出了OpenFlow的概念用于校园网络的试验创新，后续基于OpenFlow给网络带来可编程的特性，SDN （Software Defined Network）的概念应运而生。 SDN将原来封闭在“盒子”的控制平面抽取出来形成一个网络部件，称之为SDN 控制器，这个控制器完全由软件来实现，控制网络中的所有设备，如同网络的大脑，而原来的“盒子”只需要听从SDN控制器的命令进行转发就可以了。在SDN 的理念下，所有我们常见的路由器、交换机等设备都变成了统一的转发器，而所有的转发器都直接接受SDN控制器的指挥，控制器和转发设备间的接口就是OpenFlow协议。其简单模型如图所示： 《花飘四方》——民歌篇教学设计 【教学年级】：高一年级 【教学课时】：一课时 【设计思路】：通过聆听，了解民歌的风格特征，感受民歌的艺术魅力，培养学生对中国民歌的喜爱和兴趣，体现以音乐审美为核心的理念。通过民歌的学习让学生认识到：民族音乐是中华民族数千年来劳动人民智慧的结晶，是劳动人民创造的宝贵文化遗产，是中华民族传统文化的组成部分；同时帮助学生树立“音乐作为文化”和“文化中的音乐”的观念，培养学生“弘扬民族音乐文化”、理解多元文化的理念，从而达到理解和尊重多元的世界文化的目的。 【教学目标】： 1、喜欢聆听、演唱民歌及具有民族风格的通俗歌曲，愿意探索有关民歌的音乐文化知识。 2、掌握有关民歌的基本知识。 3、通过欣赏，初步感知南北民歌的风格特点，感受民族音乐与民俗风情的丰富多彩。 【教学重点，难点】： 重点：着重欣赏广东民歌《对花》，同时听辨《槐花几时开》《拨根芦柴花》《上去高山望平川》《猜花》等民歌。 难点：本篇以“花”为立足点，使学生借此了解东南西北民歌的不同风格，感受民歌的绚丽风采。 【教学准备】：多媒体、视频、音频等 【教学过程】： 一、导入： 1、欣赏流行音乐视频片段：《茉莉花》——梁静茹 师提问：大家熟悉这首流行歌吗？喜欢吗？ 这首流行歌曲是中国江南民歌《茉莉花》改编而成，一曲茉莉花，芬芳香四方，这首脍炙人口的江苏民歌几乎是我们国家在重要事件和相关国际重要场合下的必奏之歌。在北京奥运会上，《茉莉花》作为主旋律背景音乐向世界展示了中国文化，让世界了解了中国。可见，民族音乐之于民族的重要性。 2、民歌是什么？ 民歌是人民的歌、民族的歌，是真实反映劳动人民情感、生活的歌曲作品。民歌以口头传播，一传十十传百，一代传一代的传下去至今，每个民族都有自己的生活方式，并在代代积淀与传承中形成了自己独特的文化。不同的文化又赋予了音乐不同的形式和内涵，形成了风格迥异的民族音乐。它们是音乐文化的基础和源泉。 3、民歌的分类：山歌、号子、小调。 二、新授： 在中国的民歌中，“花”是一个最普遍的主题，其用法有三种：一是以花喻人，借花表法情爱；二是歌颂大自然，传授自然知识；三是借花起兴，以花为歌唱媒介，而花本身没有特定含义。 我们今天这堂课正是从“花”出发，了解东南西北民歌的不同风格，感 Hey Jude, don't make it bad. 嘿！Jude，不要这样沮丧 Take a sad song and make it better 唱首悲伤的歌曲让事情好转Remember to let her into your heart 将她牢记在心底 Then you can start to make it better. 然后开始让事情好转 Hey Jude, don't be afraid 嘿Jude，不要害怕 You were made to go out and get her. 你生来就是要得到她 The minute you let her under your skin, 在你将她放在心上的时候 Then you begin to make it better. 你就开始做的更好 And anytime you feel the pain, 无论何时，当你感到痛苦 hey Jude, refrain, 嘿Jude 停下来 Don't carry the world upon your shoulders. 不要把全世界都扛在你肩膀上 For well you know that it's a fool who plays it cool 你应该很清楚谁耍酷谁就是笨蛋 By making his world a little colder. 这会使他世界更加冰冷 Hey Jude don't let me down 嘿Jude 不要让我失望 You have found her, now go and get her. 你已遇见她现在去赢的她芳心 Remember to let her into your heart, 记住将她牢记在你心中 Then you can start to make it better. 然后你就可以开始做的更好 So let it out and let it in, hey Jude, begin, 所以遇事要拿得起放得下嘿！jude ，振作起来 You're waiting for someone to perform with. 你一直期待的那个和你一起表演的人 And don't you know that it's just you, hey Jude, you''ll do 你不知道那个人就是你自己吗？嘿jude 你办得到的The movement you need is on your shoulder 下一步该怎么做就全看你自己 Hey Jude, don't make it bad. 嘿Jude 不要这样消沉 Take a sad song and make it better 唱首伤感的歌曲会使你振作一些 Remember to let her under your skin 记得心中常怀有她 Then you'll begin to make it better 然后你就会使它变得更好 Better better better better better better, Oh. 更好、更好、更好、更好、更好 Na na na, na na na na, na na na Hey Jude The Beatles ?这首歌就是英国的难忘今宵！！！伦敦奥运会的压轴歌曲，我觉得很适合大合唱由麦卡特尼创作的，鼓励列农的儿子朱利安勇敢面对现实，在约翰列侬离婚后希望朱利安不要消沉其实这首歌的原名是Hey Julian，后来改为Hey Jules, 最终变成Hey Jude ?《Hey Jude》是Paul McCartney（保罗·麦卡特尼，The Beatles（披头士乐队，又称甲壳虫乐队）成员之一）为一个五岁的孩子写下的一首歌。这个男孩叫Julian，是John Lennon（约翰·列侬）与前妻Cynthia 的儿子。1968年夏天，John Lennon开始和Yoko Ono（小野洋子）同居了，他与前妻Cynthia的婚姻也到了崩溃的边缘 ?Paul一直非常喜爱John Lennon的儿子Julian，他担心大人之间的婚姻变故会对一个小孩子带来心理上的阴影。（不过，当时Paul也正和相恋5年的未婚妻Jane Asher分手，开始与Linda Eastman 的感情）他曾说：“我总是为父母离异的孩子感到难过。大人们也许没什么，但是孩子……”同时，他也想要安慰一下Cynthia。于是有一天，他去了Cynthia的家里，还给她带了一枝红玫瑰，开玩笑的对她说：“Cyn，你说咱俩结婚怎么样？”说完两人同时大笑起来，Cynthia从他的玩笑中感受到了温暖和关心。 ?Paul在车里为Julian写下了这首Hey Jude （Hey，Julian），可当时的Julian并不知道。直到二十年后，Julian才明白这首歌是写给自己的。他一直很喜爱爸爸的这个朋友，像一个叔叔一样的Paul。John Lennon也非常喜爱这一首歌。自从第一次 听到，他就觉得，“噢，这首歌是写给我 的！”Paul 说“Hey，John！去吧，离开我们和Yoko在一起吧。”他似乎又在说：“Hey，John！不要离开！来 自：”https://www.doczj.com/doc/e74883041.html,/view/965993.htm OpenDaylight与Mininet应用实战之复杂网络验证（五） 1多交换机的测试 Mininet中本身就支持多交换机网络拓扑的模拟创建，可通过Python API自定义拓扑创建满足使用者在仿真过程中的多方位需求。 下面举出具体示例验证多交换机支持： 执行此条命令后，查看ODL的Web界面显示的网络拓扑。界面拓扑显示如下： 对所有的虚拟host之间进行互ping操作，通过pingall命令，验证主机间的连通性，继而可验证支持多交换机的功能。 由pingall显示的结果可看出，主机间能够互相通信，且将数据包的流转发给交换机，并由交换机上报给ODL控制器来下发流表使主机通信。 主机通信过程中可查看交换机的流表信息及本身信息。 由交换机流表信息显示可知，控制器通过策略将流表下发到交换机中，使主机发出的数据包转发到下一目的地址。每个交换机查看信息的端口都不同，从第一个交换机端口号为6634开始，以后每一个交换机依次在之前交换机端口号的基础上加1，如第二个交换机的端口为6635。其他交换机的流表信息及自身设备信息可根据此说明进行查看。 2多控制器的测试 多控制器验证支持测试包括两种情况： ■OpenFlow网络中多个同一类型的控制器； ■OpenFlow网络中多个不同类型的控制器； 2.1多个同一类型的控制器验证 测试OpenFlow网络中多个同一类型的controller，比如OpenDaylight，多个ODL之间通过 OpenFlow1.0协议标准交互。 通过Mininet验证，在Mininet中模拟创建的OvS交换机不能指定连接多个控制器，且在同一个Mininet中创建的多个交换机不能指定不同的控制器。所以在验证交换机被多个同一类型的控制器管控时，不能通过用Mininet来验证，但是可通过真实交换机来验证。 如，在真实交换机中设置连接此文中的ODL控制器及另一个ODL控制器，命令为： 连接两个相同类型的ODL控制器，其中192.168.5.203为上述实验使用的控制器，192.168.5.111为另外安装使用的ODL控制器。通过执行如下命令查看交换机连接的控制器信息。 is_connected:true表示交换机都成功连接上控制器。交换机连接到这两个控制器后，控制器通过设备拓扑管理也可以发现此交换机，同时控制器管控存在主备关系，但控制器都可对交换机进行管控、下发流表等操作。 通过真实OpenFlow交换机连接多个控制器，可以实施，且已经验证，控制器和控制器之间存在主备关系，多控制器都可以对连接的交换机进行管控。 2.2多个不同类型的控制器验证 在OpenFlow网络中多个不同类型的controller，比如同时存在NOX和ODL，它们之间如果遵循OpenFlow协议标准的话，也是能够协作工作的。多个不同类型的控制器管控交换机与2.1小节是同样的道理。 如，在真实交换机中设置连接此文中的ODL控制器及其他另一个不同类型的控制器，如POX，命令为： 连接两个不同控制器，其中192.168.5.203为上述实验使用的控制器，192.168.5.111为另外安装使用的POX控制器。经试验验证，ODL与POX都遵循OF1.0版本的协议标准，所以在复杂网络多控制器情况下，只要控制器遵循相同的标准规范，控制器之间可进行对网络的通信管理等。此处实验结果与2.1节一致。交换机连接这两个控制器后，控制器管控存在主备关系，但控制器都可对交换机进行管控、下发流表等操作。 3总结 本文主要对复杂网络多交换机及多控制器的支持验证。因Mininet现在无法模拟多控制器管控一个交换机的情况，所以本专题还是侧重对多交换机的管控实验。至此，OpenDaylight 与Mininet应用实战专题将结束，有介绍不到位或者有疑问的地方请多多指教，互相交流。谢谢！ 《Hey Jude》歌词中英文... Hey jude, don't make it bad 嗨，jude，不要如此消沉 Take a sad song and make it better 唱一首感伤的歌，振作一些 Remember to let her into your heart 记得要真心爱她 Then you can start to make it better 生活会开始好起来 Hey jude, don't be afraid 嗨，jude，不要害怕 You were made to go out and get her 去追她，留住他 The minute you let her under your skin 当你深爱上她的那一刻 Then you begin to make it better 生活变得美好起来 And anytime you feel the pain, hey jude, refrain 嗨，jude，不管何时你感到痛苦，要忍耐 Don't carry the world upon your shoulders 别把整个世界压在心头 For well you know that it's a fool who plays it cool 你知道愚蠢的人总是装做什么都不在乎 By making his world a little colder 把他的世界伪装得有些冷酷 Hey jude, don't let me down 嗨，jude，不要让我失望 You have found her, now go and get her 既然找到所爱的人，就要勇敢追求 Remember to let her into your heart 记住要真心爱她 Then you can start to make it better 汽车灯光标志图解 相信大家都记得考驾照时，灯光的使用就是必考项目，可见其在驾驶中的重要性。车灯除了具备照明的作用外，还有提示与警示的作用，说白了，懂得车灯的使用方法，也就懂得了保命的技巧一一防止被其他车误撞。下面我们来教大家认识灯光标志。 通常，德系和美系车型的汽车灯光控制调节都设置在方向盘的左下方，标识也较好理解，上图是以奥迪车型为例。没有大灯自动调节的车型就会设有手动调节旋钮，而打开近光灯后配合转向灯拨杆前推就可以变换为远光灯，往后拉则远光灯闪一下，也就是俗称的闪灯，许多车主在会车时常常用到。了解更多：远光灯和近光灯的区别远光灯正确使用方法 转向灯大家应该都知道，向下为左，向上为右。左边的按钮则是行车电脑调节，可以选择显示油耗或续航里程等。有些高配车型的转向灯拨杆上还设有车道辅助系统，可以监控前方道路，当车辆偏离航道时通过方向盘震动提示驾驶者。 与德系美系不同，日韩车型和我们的自主车，都习惯于将灯光控制集中在方向盘后的转向灯拨杆上，但功能和标识都大同小异，没有多少区别，在此就不重复介绍了。 车顶灯的标识和操作都较为简单，其中车内照明灯按键处于中间位置时，打开车门车内就会自动亮起，也可以通过左右两 边的按键手动操作。了解更多：汽车内部按钮图解 灯光部分：灯光是平时最常用到的功能之一， 因此先拿出来说说。大灯控制主要有两个位置，欧系主要占据方向盘面板左侧，日韩系则以方向盘左侧拨杆为“阵地” 这两种方式其实各有优劣，只要适应都没有任何问题。而且各种按钮的指示都是统一的，所以不会有识别难度。随着灯光技术发展，诸如自动大灯、全天候灯、停车指示灯甚至夜视系统也越来越普及，好在这些灯光标志一般都非常形象，比如夜视系统就是车道上方一轮月牙，一目了然。 ★汽车车灯怎么用 每次晚上走斑马线过马路，我都要往来车方向多看几眼，以确定是否有车。我之所以要多看几眼，是因为我必须提防那些晚上不开车灯的“奇葩司机” ！实际上，这些“奇葩司机”有不少是新手，他们对车灯的使用方法一窍不通，甚至连怎么开车灯都不懂……“路上都有路灯了，我能看清楚，没必要开灯了吧？”这可能是新手们晚上不开灯的常用理由。 车灯除了具备照明的作用外，还有提示与警示的作用，说白了，懂得车灯的使用方法，也就懂得了保命的技巧防止被其他车误撞。本期《新手看过来》，我们就来说说车灯应该怎么用。 ? 车灯开关在哪里？都长啥样？ 新手在学习如何使用车灯之前，首先要弄明白车灯的开关 菜鸟水平初步设置OpenDaylight OVSDB + Openstack测试环境 Hannibal （SDNAP首发） 刚接触SDN和OpenDaylight两个多月时间，还处于人云亦云照葫芦画瓢的水平，在很多大牛的指导文章帮助下，初步搭建一个很简单的OpenDaylight OVSDB + Openstack调试环境。第一次写技术文章，请多包涵。 一、准备 硬件： 双核Core i7，内存4GB，一个以太网卡的Thinkpad X201t，普通个人用笔记本 Host环境： 64位Ubuntu 13.10，OVS 2.0.90 VM环境： 2个Virtualbox VM，Fedora 19 + OVS 2.0.0 + Devstack 。导入Virtualbox都是缺省配置。两个VM的下载地址： https://https://www.doczj.com/doc/e74883041.html,:443/v1/96991703573236/imgs/Fedora19--2node-Devstack.tar.bz2 Size: 4983728003 bytes MD5sum: dfd791a989603a88a0fa37950696608c 二、原理 OpenDaylight（ODL）是一个由Linux基金会支持，多个网络厂商参与的开源SDN控制器项目。Openstack是开源的IaaS项目。如何让两个平台整合以便更好的发挥作用是本环境搭建的目的。 现有的解决方案之一，就是利用Openstack Neutron的ML2 Plugin，将网络复杂性丢到ODL。也就是说，Openstack通过ML2 Plugin，与OpenDaylight的NB API进行会话，具体网络部署的实现交由OpenDaylight Controller来实现。 中英双语歌词 Hey Jude, don't make it bad. 嘿 Jude 不要这样消沉 Take a sad song and make it better. 唱首伤感的歌曲会使你振作一些Remember to let her into your heart, 记住要永远爱她 Then you can start to make it better. 开始新的生活 Hey Jude, don't be afraid. 嘿 Jude 不要担心 You were made to go out and get her. 去追她，留下她 The minute you let her under your skin, 拥抱她的时候 Then you begin to make it better. 将开始新的生活 And anytime you feel the pain, 无论何时，当你感到痛苦的时候 hey Jude, refrain, 嘿 Jude 放松一下自己 Don't carry the world upon your shoulders. 不要去担负太多自己能力以外的事 For well you know that it's a fool who plays it cool 要知道扮酷是很愚蠢的 Hey Jude, don't make it bad. 嘿 Jude 不要这样消沉 Take a sad song and make it better. 唱首伤感的歌曲会使你振作一些Remember to let her into your heart, 记住要永远爱她 Then you can start to make it better. 开始新的生活 Hey Jude, don't be afraid. 嘿 Jude 不要担心 You were made to go out and get her. 去追她，留下她 The minute you let her under your skin, 拥抱她的时候 Then you begin to make it better. 将开始新的生活 And anytime you feel the pain, 各种车灯操作使用说明和仪表标识大全(新手,考驾照必备) 第1章车灯术语汇总 (1) 第2章车灯的“傻瓜”操作手册(组图) (2) 第3章车灯拨杆使用扫盲指南 (6) 第4章汽车灯光必备常识和误区解读 (7) 第5章车辆灯光控制杆操作图解说明 (11) 01大灯开关每控制杆上每一个标示的意义及使用 (11) 02汽车灯光使用有讲究 (15) 03车辆灯光的使用 (15) 第1章车灯术语汇总 双闪灯【俗名：故障灯，危险报警闪光灯，双跳灯】 小灯 前后位灯 后位灯 示廓灯 近光灯 远光灯 前雾灯 后雾灯 后位灯：前位灯与后位灯，俗称小灯，也有人叫做示宽灯。它的作用，主要是用以表示汽车的存在及大体的宽度，便于其他车辆在会车和超车时判断。 制动信号灯，简称制动灯，俗称刹车灯，是用来提醒后面的车辆本车已经采取制动措施的警告灯。它安装在汽车的尾部，红色，当汽车制动时，线路接通，自动发出红光。由于制动灯对汽车的安全关系重大，因此，它的亮度明显大于后位灯，一般是后位灯亮度的五倍以上。白天距离100m以上就可看清。 非规范用语：刹车灯 第2章车灯的“傻瓜”操作手册(组图) 如果一位驾驶员被问到：“您知道汽车那些信号灯都是怎么回事吗，该如何正确使用？”，也许这位被问到的朋友会一脸惊诧还略带些茫然的看着提问者。但这的确并不是个可笑的问题，现如今大街上跑的车越来越多，而并不能正确使用汽车信号等的朋友也随之增多，这里面不光有新手，而且还有不少驾龄颇长的老司机。 适时开启示廓灯、大灯和伤不起的远光灯 先来说说我们平时经常用到的这几组灯吧。每当天近傍晚、华灯初上的时候，我们一般会习惯性的打开示廓灯。光从字面上看，“示”是警示的意思；“廓”有轮廓之意，所以示廓灯是一种警示标志的车灯，用来提醒其它车辆注意的示意灯，既能表示汽车高度又能表示宽度。但如今有很多车的仪表盘都带有自发光功能，因此在天刚刚擦黑时未将示廓灯开启的情况比比皆是，这里要奉劝各位车主们，为了大家的安全，还是多动一下手指为好。 后示廓灯在向路人及其它追随者显示自己的身材，以免发生不必要的亲密接触 Openstack的Ocata版本与opendaylight 的Carbon版本集成详解 作者：胡章丰，zfhu2001@https://www.doczj.com/doc/e74883041.html, 前提条件 ===================================================================== 1.已搭建好的可用openstack ocata环境一套 2.已下载的opendaylight carbon-sr1发布版本 3.本文档所述环境地址：控制节点：192.168.137.101，网络节点192.168.137.101，计算节点：192.168.137.101,192.168.137.102，ODL控制器节点：192.168.137.100 4.建议ODL控制器节点与Openstack控制节点采用独立节点安装，否则会有端口冲突，需要修改若干配置文件来避免冲突 ===================================================================== 部署opendaylight控制器 ===================================================================== ODL控制器节点执行： 解压缩软件包 tar xzvf distribution-karaf-0.6.1-Carbon.tar.gz cd distribution-karaf-0.6.1-Carbon/ 开启iptables规则（建议将下列规则写入脚本文件，配置开机自动执行，否则每次重启后需要手动添加这些规则） iptables -I INPUT -p tcp --dport 8181 -j ACCEPT iptables -I INPUT -p tcp --dport 8080 -j ACCEPT iptables -I INPUT -p tcp --dport 6640 -j ACCEPT iptables -I INPUT -p tcp --dport 6653 -j ACCEPT 启动odl控制器 ./bin/karaf 安装odl组件（只能装这几个） feature:install odl-netvirt-openstack odl-dlux-core odl-mdsal-apidocs 验证是否安装成功（打开如果是黑板一块，则说明安装成功） 看看能否打开http://ODL控制器节点ip地址:8181/index.html =====================================================================民歌篇教案范文
SDN及ODL概括性总结
上海汉雷汽车氙气灯常用车型对照表
汽车灯型号对照表
民歌篇教案
ODL之SDN入门篇
花飘四方
Hey Jude 歌词流程图及英文歌词与翻译
hey,jude含义解析
OpenDaylight与Mininet应用实战之复杂网络验证(五)
HI jude
汽车灯光标志图解
菜鸟水平初步设置OpenDaylight-OVSDB-+-Openstack测试环境
中英双语歌词
各种车灯操作使用说明和仪表标识大全(新手,考驾照必备)
Openstack的Ocata版本与opendaylight 的Carbon版本集成详解
相关主题
文本预览