a r X i v :a s t r o -p h /0010238v 1 12 O c t 2000
K-Band Spectroscopy of Compact Star Clusters in NGC
4038/4039
Sabine Mengel,Matthew D.Lehnert,Niranjan Thatte,Lowell E.Tacconi-Garman and
Reinhard Genzel
Max-Planck-Institut f¨u r extraterrestrische Physik,Postfach 1312,D-85741,Garching,Germany
mengel,mlehnert,thatte,lowell,genzel@mpe.mpg.de
ABSTRACT
Integral ?eld spectroscopy in the K-band (1.9-2.4μm)was performed on four IR-bright star clusters and the two nuclei in NGC 4038/4039(“The Antennae”).Two of the clusters are located in the overlap region of the two galaxies,and together comprise ≈25%of the total 15μm and ≈10%of the total 4.8GHz emission from this pair of merging galaxies.The other two clusters,each of them spatially resolved into two components,are located in the northern galaxy,one in the western and one in the eastern loop of blue https://www.doczj.com/doc/0411668898.html,paring our analysis of Br γ,CO band-heads,He I λ2.058μm,H α(from archival HST data),and V ?K colors with stellar population synthesis models indicates that the clusters are extincted (A V ≈0.7?4.3mags)and young,displaying a signi?cant age spread (4-13Myrs).The starbursts in the nuclei are much older (65Myrs),with the nucleus of NGC 4038displaying a region of recent star formation northward of its K-band https://www.doczj.com/doc/0411668898.html,ing our derived age estimates and assuming the parameters of the IMF (Salpeter slope,upper mass cut-o?of 100M ⊙,Miller-Scalo between 1M ⊙and 0.1M ⊙),we ?nd that the clusters have masses between 0.5and 5×106M ⊙.
Subject headings:galaxies:individual:NGC 4038/4039,The Antennae —infrared:galaxies —galaxies:starburst —galaxies:interactions —stars:formation
1.Introduction
Arguably,one of the most fascinating recent as-trophysical discoveries is the rich population of young luminous blue “globular-like”clusters in strongly interacting and merging systems (Holtz-man et al.1992;Whitmore et al.1993,1997;Whitmore &Schweizer 1995,hereafter WS95).These clusters all appear much younger (<100Myrs)than both the old globular cluster sys-tem and underlying background population and have dynamical masses (M ～few ×105M ⊙–in a few cases –Ho &Filippenko 1996)and e?ec-tive radii very similar to the globulars (r e ～10pc –WS95).The formation of such clusters appears to be generic to the merger process and is likely the result of the high pressures that are induced dur-ing the merger process (e.g.,Elmegreen &Efremov 1997).
The star formation activity in NGC 4038/4039–the “Antennae”–has been known from stud-ies at various wavelengths,for example from H αspectroscopy (Rubin et al.1970)or the very blue colors observed in the HST images (WS95).Its relative proximity (19Mpc assuming H 0=75km s ?1Mpc ?1)makes it the ideal candidate for the study of merger induced star formation on scales of single star clusters and has allowed for the detection and investigation of a very large num-ber (≈800)of compact clusters (Whitmore et al.1999,WS95).The heavily extincted overlap re-gion was revealed to be the most active star forma-tion zone by radio observations (Hummel &Van der Hulst 1986)and imaging and spectroscopy performed with ISO (Mirabel et al.1998;Kunze et al.1996;Fischer et al.1996).The over-lap region is,however,relatively inconspicuous at optical wavelengths.The ISO results suggest
very young ages for these clusters and the pres-ence of high mass(50-60M⊙)stars.Interest-ingly,a signi?cant fraction of the total bolomet-ric?ux from the Antennae appears to originate in two clusters eastward of the NGC4039nu-cleus(numbers86/87/88/89/90in WS95),build-ing up an optically bright knot,and number80in WS95,which is optically extincted and declared a“very red object”.These two regions,which are the highest surface brightness features in the mid-infrared,contribute≈25%of the total?ux at15μm(Mirabel et al.1998)and≈20%of the total emission from discrete radio sources in NGC4038/4039(Hummel&Van der Hulst1986). These large fractions suggest that these two re-gions must constitute a signi?cant portion of the very recent or on-going star-formation within the Antennae.Understanding their properties within the perspective of the overall star formation his-tory of the Antennae is of prime importance to un-derstanding the bolometric output of these merg-ing galaxies.We discuss the properties of these re-gions as determined through IR integral?eld spec-troscopy in combination with data available from the literature.
2.Cluster Selection and Observations
Models of the merger of two spiral galaxies(like that currently being observed in NGC4038/4039) predict multiple bursts of star formation during the merger event(Mihos and Hernquist1996). Depending on the stage of the merger,these bursts can be in the region of overlap of the two galaxy disks,in the tidally shocked regions of the outer disks of each galaxy,or as signi?cant quantities of gas fall in towards the two nuclei,in the nu-clei of each galaxy.We observed the two most prominent clusters within the interaction zone, two other IR bright clusters in the outer arms of NGC4038/4039(likely to be tidally shocked re-gions),and the two nuclei.Such a selection would allow us(at a minimum)to probe the various regions of star-formation during the merger pro-cess within the inevitable constraint of only hav-ing a limited amount of observing time.While only observing six regions will not allow us to investigate the properties of the whole ensemble of compact clusters in the Antennae,our sam-ple allows us to crudely investigate the possi-ble range of ages across the Antennae.Figure 1shows the two clusters in the interaction zone ([WS95]86and[WS95]80),the two nuclei(NGC 4038and NGC4039)and two clusters in the outer loops([WS95]417/[WS95]428in the eastern and [WS95]405in the western),observed with the3D integral?eld spectrometer(Weitzel et al.1996; Krabbe et al.1995)in the K band.
For the observations,3D was combined with the tip-tilt-guider ROGUE(Thatte et al.1995)on the Anglo-Australian Telescope in February,1998 and April,1999.We used a K-band grism with a resolution ofλ/?λ=1000and a256x256NIC-MOS3array.256spectra are obtained simultane-ously,arranged in a16x16pixel?eld on the sky. The detector integration time per exposure was 100seconds.The on-source exposures were inter-leaved with o?-source(o?set60′′E of each cluster) exposures of identical integration time for the sky subtraction.To remove telluric features,the A2V star HD106819was observed roughly once every hour.In order to Nyquist sample the spectra,we dithered in the spectral direction by half a pixel using a piezo-driven mirror.The spatial pixel scale of0.′′4provided a?eld of view of6.′′4x6.′′4.
The conditions were generally not photomet-ric and?ux calibration achieved via aperture pho-tometry available from the literature(Bushouse &Stanford1992)in combination with Ks-band imaging(see also next section).The seeing dur-ing the observations of each individual region only showed moderate variation(<0.′′2)but was signif-icantly di?erent for di?erent objects.The values for each observation are discussed in section4. The total on-source integration time was6200s on the?rst?eld(hereafter abbreviated to[WS95]86), which is the optically bright star cluster,cor-responding to the numbers86/87/88/89/90in WS95;4200s on-source time for the second?eld (hereafter[WS95]80),which corresponds to the “very red object”number80in WS95;3120s on-source time for the?eld in the eastern loop(num-bers417and428in WS95);3840s for the targets in the western loop(WS95-number405and sev-eral fainter objects,hereafter[WS95]405).The nuclei of NGC4038and NGC4039were observed for3360s and2160s respectively.Due to a piezo failure,the spectrum of the nucleus of NGC4039 is not Nyquist sampled.
3.Data Reduction and Analysis
Data reduction was performed using the3D data reduction routines developed at MPE within the GIPSY(van der Hulst et al.1992)data reduction environment.Single frames were dark subtracted,linearized and sky subtracted using the sky frame that was closest chronologically and had the right spectral dithering position.The wavelength calibration was accomplished by ex-posures of a neon discharge lamp.The re-binning of the spectrally interleaved data was performed onto a600pixel linear wavelength axis.Bad pixels and cosmic rays were removed from the 16x16x600data cube,either by interpolation or by masking out.After spatial re-binning onto a 64x64pixel grid,the single cubes were stacked by centering each on its K-band continuum peak or the Brγpeak for[WS95]86and[WS95]80,respec-tively.Telluric features were removed by division by the atmospheric transmission pro?le obtained from the observations of the A2V star.The Brγabsorption line in the calibrator spectrum was in-terpolated linearly between the adjacent contin-uum.In the resulting cluster spectra,only the NGC4038nucleus spectrum shows a little remain-ing Brγemission from the calibrator,which is not a worry,because it is at zero redshift and does not contaminate the Brγemission from the object.
Object spectra were extracted using a square aperture centered on the continuum peak and sized to maximize the SNR of the resulting spec-trum.The individual apertures and their sizes are shown in Figure2.For?elds which showed signi?-cant o?sets between continuum and Brγline emis-sion peaks([WS95]405and the nucleus of NGC 4038),the aperture sizes were chosen so as to min-imize contamination between the continuum and line emitting regions.The spectra were?ux cali-brated using the K s-magnitudes from our?ux cal-ibrated SOFI image,obtained in May99at the NTT.The extracted spectra were normalized by dividing by the continuum value,estimated using a linear?t.From this we estimated the equivalent widths Wλof the Brγ-and the He I-lines and the CO-band-heads.For the creation of linemaps,the linear?t was performed for each spatial pixel and subtracted.The spectra of all the regions(divided into subregions for some of the?elds)are shown in Fig.2,together with the K s-band images.Over-laid are the contours of Brγor the H2(1-0)S(1)-line (labelled in Fig.2).
4.Results
Results obtained from our data,incorporating results from publicly available HST data(Hαand V-band images–Whitmore et al.1999),are listed in Table1.[WS95]86was slightly resolved while [WS95]80was unresolved(both combined data sets had a?nal FWHM～1.′′0;Fig.2).The FWHM of the seeing was～0.′′8during[WS95]417&428ob-servations,and the two clusters are marginally re-solved into single components.During[WS95]405 observations,the seeing was poor(1.′′6),but to the NE of the bright cluster,a fainter second cluster is visible.The tabulated values for[WS95]405-A and B refer to the bright cluster(A)and to the location of the Brγpeak(B).
We used the measured equivalent width of Brγ, W Brγ,and CO2.29μm band-head,W CO(Table 1),to determine the ages of the starbursts using stellar synthesis models(Leitherer et al.1999; Kovo,Sternberg&Alexander1998).See plots in Leitherer et al.(1999)(their Figures89and 101),showing the evolution of these parameters with burst age.Assuming an upper mass cut-o?M upper=100M⊙,Salpeter IMF slope and an instantaneous burst at solar metallicity,we de-rive ages of 3.7+1.0
?0.4×10
6yr for[WS95]86and
5.5+0.7
?0.8×10
6yr for[WS95]80.Gilbert et al.(2000) derive a value of～4Myrs for[WS95]80,assum-ing the same starburst parameters,in reasonable agreement with our value.The ages of the two clusters in[WS95]417&428are not very well con-strained,due to the low S/N of the data and the ambiguous value of the W CO.However,the values of W CO are su?ciently large to exclude additional errors introduced by the non-inclusion of the ther-mally pulsing asymptotic giant branch phase in the Geneva stellar evolution tracks that were in-corporated in Leitherer et al.(1999)(Origlia& Oliva2000).Age estimates of[WS95]417&428lie between8.5and12.8Myrs old.For the[WS95]405 spectra,it is not possible to get a consistent model age with the presence of both strong CO-band-heads and Brγemission with an instanta-neous burst.But given the size of the cluster (R eff=12.3pc,Whitmore et al.1999)it is plau-sible to assume that the star-formation has a?-
nite duration of a few Myrs(Efremov&Elmegreen 1998).Other possibilities that might explain why these clusters have both CO absorption and Brγemission are shock heating of the gas due to super-nova explosions,the seeing broadened Brγemis-sion from the region to the S-E of[WS95]405-A which contaminates the cluster spectrum,superso-lar metallicity,and possible gaps in our knowledge of stellar evolution and model atmospheres.It is interesting to compare the3D image and spectra of a region outside both[WS95]405clusters with the multi-color HST image,since our data show a Brγpeak to the SE of the K-band continuum peak of cluster A.This coincides with a dust?la-ment obvious in the HST image,and it could be the site of more recent star formation or of shock excitation in a more dusty environment.
A detailed discussion of the nuclear spectra is beyond the scope of the current paper.Here we only wish to emphasize how the spectra of the two nuclei di?er from the young compact clusters.The W CO of the two nuclei suggest the same possi-ble age range for both,65±15Myrs,considerably older than the ages estimated for the prominent young clusters.The northern nucleus also shows evidence for a more recent starburst to the north of the K-band peak,but it is di?cult to estimate its age due to the underlying continuum contribu-tion by the older background nuclear stellar pop-ulation.But the presence of Brγemission(no evi-dence for AGN activity was seen in other observa-tions so far)requires the presence of O or
B stars or recent shock excitation,thus implying that it is younger than～10-20Myrs.Under the assumption that there is no intrinsic gradient in W CO across the NGC4038nucleus,meaning that the observed lower W CO at the location of the Brγpeak can be attributed to the additional continuum from the young stellar population,we estimate the young star light continuum to contribute about1/5of the total continuum,which increases the observed W Brγto58?A.This then implies an age of the star-burst of around6Myrs,consistent with the e?ec-tive temperature of33000K derived from the low ratio of He I/Brγof0.17.
The age uncertainties given in Table1only take into account uncertainties in the signal-to-noise of the data and do not take into account the system-atic e?ects of selecting di?erent IMF slopes,upper and lower mass cuto?s,abundances,or uncertain-ties in the models themselves.
The extinction was derived by comparing the theoretical ratio of Hα/Brγ(case B recombina-tion ratio assuming T e=10000K from Storey& Hummer1995)with the observed https://www.doczj.com/doc/0411668898.html,ing the extinction curve of Draine(1989)for a fore-ground screen model,we derived A V of1.4±0.2 and4.3±0.2for[WS95]86and[WS95]80,respec-tively.They agree within the errors with the val-ues we derived from the V-K color excess with the intrinsic color derived from the models for the re-spective cluster ages(A V=1.6+0.6
?1.0
and3.7+0.6
?1.0
). For[WS95]417&428and[WS95]405,we used the V-K colors not to con?rm the extinction,but rather to further constrain the age.
The ratio of He Iλ2.058μm/Brγis not an un-ambiguous tracer of the e?ective temperature of the highest mass stars present in a stellar popula-tion(Shields1993;F¨o rster-Schreiber1998),but it was determined to compare with the ISO results at higher spatial resolution.The e?ective temper-atures derived from the ratios of He I/Brγ=0.47 and0.5are36,000and38,000K([WS95]86and [WS95]80,respectively),which corresponds to masses of roughly28M⊙and is below the44,000K (50-60M⊙)derived from mid-infrared line ratios by Kunze et al.(1996).Given the sensitivity of the He Iλ2.058μm line to nebular parameters (Shields1993)and the large aperture(14”×27”) used for the ISO measurement,some disagreement between our estimate and that obtained using ISO data for the temperature of the hottest stars is not surprising.Moreover,the relationship between temperature of the hottest stars and He I/Brγis not monotonic and thus our estimates for the mass should be considered lower limits.These up-per mass limits are consistent with our estimated ages of the[WS95]80cluster,while the younger age of[WS95]86would allow for the detection of higher mass stars.A qualitative comparison of the derived e?ective temperatures/ages of all ?elds agrees with the gradient in the[Ne III]/[Ne II]observed by Vigroux et al.(1996).
From the extinction corrected Brγ?ux we can estimate the number of Lyman continuum photons,N Lyc.For this calculation,we used the extinction corrected Brγ?ux,a distance of19.2Mpc for the Antennae,and recombina-tion coe?cients from Hummer&Storey(1987) and Storey&Hummer(1995).We?nd that
N Lyc=3.1±0.3×1052s?1and 1.9±0.4×1052s?1 for[WS95]86and[WS95]80respectively.This somewhat lower than the value derived from the thermal radio continuum?ux density estimated by Hummel&Van der Hulst(1986),which re-sults in N Lyc=1.3±0.7×1053s?1for the sum of[WS95]86and[WS95]80.Given that our aper-tures are smaller,the di?culty in estimating the thermal contribution to the total radio emission, and that there is some di?use radio emission,it is not surprising that there is a di?erence be-tween the two estimates.It is also signi?cantly less than the value of1.0×1053photons s?1de-rived by Gilbert et al.(2000).Both our observed ?ux and estimated extinction are lower by factors of～2and both of these di?erences account for the discrepancy between our respective estimates of the Lyman continuum?ux.However,Gilbert et al.(2000)caution that the extinction value they derived(A K=1.1mag)should be considered an upper limit.
Comparing our results(M K(0)and N Lyc) with the models of Leitherer et al.(1999,as-suming a Salpeter IMF slope,M upper=100M⊙, high mass stars have already evolved o?the main sequence and are therefore not observed,and M lower=1M⊙)for the age determined for each cluster in the previous section,the total mass of
each cluster would be 1.6+1.2
?0.2and 3.0+3.6
?0.7×10
6
M⊙for[WS95]86and[WS95]80respectively.A lower mass limit equal to0.1M⊙(using Miller-Scalo slope for the lower mass end of the IMF) would imply masses a factor of1.6higher.For [WS95]417&428and[WS95]405,we crudely esti-mated their masses using only their extinction-corrected K-magnitudes compared to the mag-nitudes expected from our derived ages.Their masses are lower than the masses of[WS95]86 and[WS95]80,and lie between0.3and1.1×106 M⊙.
This places each of the very massive[WS95]86 and[WS95]80clusters into the same mass regime as M82A,which produces roughly the same amount of N Lyc,and has the same burst age (F¨o rster-Schreiber1998).Their masses are more than a factor of ten higher than the average mass of a globular cluster(Mandushev et al.1991). Even if they are expected to lose60%of their mass over a Hubble time(Cherno?&Weinberg1990), they will still represent the top-end of the globular cluster mass function.The[WS95]417&428and [WS95]405clusters have masses which are more moderate and comparable to the average globu-lar cluster mass.This mass range in the observed clusters is not surprising given that those two?elds contribute a substantial amount of the bolometric luminosity of the Antennae.But a more accurate mass estimate of a larger fraction of the popula-tion of young star clusters is necessary to judge if the young clusters could evolve to form a part of the globular cluster population of an elliptical galaxy.
5.Summary and Conclusions
We performed integral?eld spectroscopy in the K-band(1.9-2.4μm)on four star clusters and the nuclei in NGC4038/4039in order to derive the starburst properties and their variations with the location in the merger.Our analysis of Brγ,CO band-heads,He Iλ2.058μm/Brγ,Hα,and V-K colors indicates that the clusters show a consider-able age spread from4-13Myrs.The two star clusters in the interaction zone have ages near the lower limit of that range,while those in the outer loops lie near the top of that age range. These clusters sample the overall age gradient vis-ible in the Antennae,the details of which we will discuss in a forthcoming paper.The equivalent widths of the CO band-heads indicate that the starbursts in the nuclei are considerably older(65 Myrs;with the nucleus of NGC4038having evi-dence for a signi?cant contribution from younger population with an age of～6Myrs northward of its K-band continuum peak).The extinction is highly variable and especially high in some parts of the overlap region(A V=0.2to4.3).Using these age estimates and assuming the parameters of the IMF(Salpeter slope,upper and lower mass cut-o?s,etc.),we?nd that the clusters have masses ranging between0.3to3×106M⊙,(larger if the IMF is extended below1M⊙).Our observations that the K-band continuum peak(with its strong CO absorption)and the highest surface bright-ness Brγemission are not coincident in some re-gions and possible variations in W CO for clusters in[WS95]405and the nucleus of NGC4038argues for sequential star formation on small scales.
We thank the sta?of the AAT for their excel-
lent assistance at the telescope and the editor S. Willner and the referee for helping improve the presentation of our paper.
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Fig. 1.—The HST V-band image(Whitmore et al.1999)displayed in a logarithmic grayscale with the 3D-?elds and their numbering(referring to Whitmore&Schweizer(1995))as used in this paper indicated. The overall morphology is that of two colliding gas-rich spiral galaxies(likely Sc type).Eastward of the line connecting the two nuclei lies the so-called“interaction zone”or“overlap region”,which is heavily extincted in the optical.The size scale is indicated in the image.
Fig. 2.—K-band images of the observed?elds with Brγor H2contours,K-band spectra and the corre-sponding regions in color composite images taken from W99(blue:U+B,green:V,red:Hα).The greyscale images in the left column(top)are created from the3D data cubes by summation of the corresponding channels of the data cubes,continuum subtracted in the case of the emission line maps.They show the Brγdistribution in[WS95]86,[WS95]80,[WS95]417&428,[WS95]405and nucleus of NGC4038,and the H2(1-0)S(1)distribution in the nucleus of NGC4039.The highest contours represent95%of the maximum?ux, then from90%continuing in steps of10%downward.Maximum?uxes are2.0([WS95]86),1.7([WS95]80), 0.47([WS95]405),0.59(NGC4039nucleus)and0.46(NGC4038nucleus)×10?16erg s?1cm?2.The K magnitudes of the?elds are given in Table1.The spectra were extracted from the regions indicated in the K-band images.The?uxes are given in units of10?16erg s?1cm?2versus the wavelength inμm.The noise level is indicated in the top right corner of each spectrum.The images in the left column(bottom)show the corresponding regions of the HST multi-color image(W99)with U+B in the blue,V in the red and Hαin the red display.The scale is given as1′′bars(the pixel size in all3D images is0.′′2x0.′′2).At the distance of the Antennae1′′corresponds to93pc.N is up,E to the left in each image.
Table1
Observed Properties of the Six Fields
Property Unit[WS95]86[WS95]80[WS95]417[WS95]405-A NGC4039NGC4038
[WS95]428[WS95]405-B nucleus A and B
(1)(2)(3)(4)(5)(6)(7)(8)
Note.—Col.(1)—Measured properties with1σuncertainties.Apert.size is the size of the apertures from which the values were derived.W Brγindicates the equivalent width of the Brγline,W CO is the equivalent width of the12CO (2-0)bandhead feature,determined in the wavelength range2.3060-2.3092μm,which corresponds to the wavelength range given by Oliva et al.(1995),redshifted to the radial velocity of the Antennae.Its uncertainty was estimated from the neighbouring continuum.For comparison,a few values of W CO for stars observed with3D:K4.5Ib:15.3?A, M3.5Iab:19.6?A,K3III:9.1?A,M1III:12.1?A(F¨o rster-Schreiber1998).Age is the model age(instantaneous burst, Salpeter IMF between1and100M⊙,solar metallicity)that most closely matches the equivalent widths of Brγand CO. Where the value for W CO covered a range that did not behave monotonically with age,we gave an age range rather than a value±σ.T eff of the most massive stars as indicated by the He I/Brγratio,He I/Brγmeasured from the3D spectroscopy,m K from our spectroscopy,m V from HST images(Whitmore et al.1999),A V from the?ux ratio of Brγ/Hα,F Brγas measured from our data,F Hαfrom HST images(Whitmore et al.1999).Col.(2)—Unit in which the measurements in Cols.(3)to(8)are tabulated.Col.(3)to(8)—The measured properties(given in Col.(1))of the six observed?elds.The values for the properties of NGC4038-B(Age,T eff and the value for W Brγin parentheses) make use of an assumption about the continuum level,see text for details.Moreover,the age determination of the nuclei may be in?uenced by the non-inclusion of the TP-AGB phase in the Starburst99models.
比较级与最高级 1.as...as 与(not) as(so)...as as...as...句型中，as的词性 第一个as是副词，用在形容词和副词的原级前，常译为“同样地”。第二个as是连词，连接与前面句子结构相同的一个句子(相同部分常省略)，可译为“同..... He is as tall as his brother is (tall) . (后面的as 为连词) 只有在否定句中，第一个as才可换为so 改错: He is so tall as his brother.（X） 2.在比较状语从句中，主句和从句的句式结构一般是相同的 与as...as 句式中第二个as一样，than 也是连词。as和than这两个连词后面的从句的结构与前面的句子大部分情况下结构是相同的，相同部分可以省略。 He picked more apples than she did. 完整的表达为: He picked more apples than she picked apples. 后而的picked apples和前面相同，用did 替代。 He walked as slowly as she did.完整表达为: He walked as slowly as she walked slowly. she后面walked slowly与前面相同，用did替代。
3.谓语的替代 在as和than 引导的比较状语从句中，由于句式同前面 主句相同，为避免重复，常把主句中出现而从句中又出现的动词用do的适当形式来代替。 John speaks German as fluently as Mary does. 4.前后的比较对象应一致 不管后面连词是than 还是as,前后的比较对象应一致。The weather of Beijing is colder than Guangzhou. x than前面比较对象是“天气”，than 后面比较对象是“广州”，不能相比较。应改为: The weather of Bejing is colder than that of Guangzhou. 再如: His handwriting is as good as me. 应改为: His handwriting is as good as mine. 5.可以修饰比较级的词 常用来修饰比较级的词或短语有: Much,even,far,a little,a lot,a bit,by far,rather,any,still,a great deal等。 by far的用法: 用于强调，意为“...得多”“最最...”“显然”等，可修饰形容词或副词的比较级和最高级，通常置于其后，但是若比较级或最高级前有冠词，则可置于其前或其后。
常用兽药原粉汇总 原粉名称 适应症 安乃近临床上常用于猪附红细胞体、链球菌、弓形体、圆环病毒、 蓝耳病、猪瘟、猪丹毒等病引起的体温升高，有明显的解 热镇痛作用。鸡的禽流行性感冒、新城疫、法氏囊等引起 的体温升高，能迅速解除症状。 地美硝唑主要用于禽弧菌性肝炎、坏死性组织、火鸡组织滴虫病、 禽的毛滴虫病等，对牛的毛滴虫病也有很好的疗效。 氟苯尼考主要用于治疗： 1：猪：猪传染性萎缩性鼻炎、猪呼吸疲乏综合症（PRDC）、 传染性胸膜肺炎、气喘病、肺疫、仔猪黄白痢、副伤寒； 猪瘟、蓝耳病、乙型脑炎等引起的继发感染； 2：禽：慢性呼吸道病、气囊炎、鸭传染性浆膜炎、霍乱、 大肠杆菌病、沙门氏菌病；鸡新城疫、禽流感等引起的 继发； 3：水产类：由弧菌，链球菌，假单胞菌，爱德华氏菌， 产气单胞菌引起的虾的红腿病，幼体菌血症，甲壳溃疡病， 黑鳃和烂鳃病，丝状细菌病，河蟹的烂肢病，水霉病，颤 抖病，鱼的弧菌病，出血病、肠炎、赤皮、烂尾、腐皮等 细菌性爆发病。 黄芪多糖主要用于抗病毒，提高机体免疫力，如新城疫、法氏囊、 喉气管炎等疾病；对猪圆环病毒、蓝耳病、传染性胃肠炎、 肝炎等疾病有防治作用 磺胺间甲氧嘧啶钠主要用于治疗和预防各种敏感菌引起的呼吸道、消化道、 泌尿道感染及球虫病、猪弓形虫病、猪水肿病、鸡住白细 胞虫病、猪萎缩性鼻炎。局部灌注可治疗乳腺炎和子宫内 膜炎；水产类敏感菌所致的肺炎，出血性败血症。 磺胺氯吡嗪钠本品属磺胺类药物，具有性质稳定，抗菌谱较广，水溶性 好等优点。口服有效，并能很快分布至其它器官。主要用 于抗球虫病。 甲磺酸左旋氧氟沙 星本品主要用于治疗由敏感菌引起的畜禽呼吸系统、泌尿生殖系统、皮肤软组织、消化系统疾病。如禽的大肠杆菌病、沙门氏菌病、传染性鼻炎、鸡奇异变形杆菌病、葡萄球菌病、鸭疫巴氏杆菌病、禽霍乱、慢性呼吸道病、仔猪的喘气病、仔猪黄、白痢、仔猪副伤寒、牛传染性胸膜肺炎、牛出败、牛弧菌性疾病、牛流行性腹泻、羔羊疾病、传染 性胃肠炎等 甲硝唑主要用于禽弧菌性肝炎、坏死性肠炎、火鸡组织滴虫病、禽的毛滴虫病等，对牛的毛滴虫病也有很好的疗效。
二年级语文的、地、得用法教案 一、“的、地、得”的用法 “白勺的、提土地、双人得”是我们在语文学习中经常 使用的三个词，它们都起着连接作用；它们在普通话中都各 自有着不同的读音，但当他们附在词，短语，句子的前面或 后面，表示结构关系或某些附加意义的时候都读轻声“de”，没有语音上的区别。但在书面语中有必要写成三个不同的字，这样可以区分他们在书面语用法上的不同。这样做的好处， 就是可使书面语言精确化。 （一）首先我们来看白勺“的”的用法。通常白勺“的”的后面往往跟名词，我们用算式表示就是“的+名词”。名 词包括哪些呢？人物，如：妈妈、老师、校长。动植物，如：小鸟、小草、苹果。景物，如风景、西湖、运河。事物，衣服、头发、球赛，等等。它们都属于名词。 现在我们来举一些例子，比如：亲切的妈妈、大大的窗户、红红的花朵、优美的风景、精彩的球赛、机灵的小鸟、 漂亮的衣服、黑黑的头发、雄伟的长城……。 通过这些短语，我们不难发现白勺“的”前面的词语一 般用来说明白勺“的”后面事物怎么样。 白勺“的”除了可以用在名词前外，句子的末尾也用白 勺“的”。比如：我们是知道的。我们是一起来的。你是数 不清的。
（二）其次，我们来看提土“地”的用法。通常提土“地”的后面往往跟的是表示动作的词，也就是动词，我们 用算式表示就是“地+动词”。 比如：仔细地看，大声地说，慢慢地走。看，提土地后 面的看、说、走都是表示动作的词。 现在我们再来举几个例子：快速地跑，用力地抓，认真 地读，快活地游着，积极地参加，早早地离开，自由自在地 飞翔，一次又一次地握手、迅速地包围、沙沙地直响、斩钉 截铁地说、用力地踢、仔细地看……。也就是说，提土“地”前面的词语一般用来说明提土“地”后面的动作怎么样。 （三）最后，我们来看双人“得”的用法。双人“得” 前面多数是表示动作的词或词语，少数是形容词，我们用算 式表示就是“动词（形容词）+得”。比如：玩得开心，红得发紫，吃得好，大得很，跳得高，急得满头大汗，“玩、吃、跳”这些是动词，“大、红、急”这些是形容词，后面都得 用双人“得”。 现在我们再来举几个例子：玩得刺激，看得仔细，唱得 好听，写得端正，举得高高的，说得真精彩，气得双脚直跳、理解得十分深刻、乐得合不拢嘴、惊讶得目瞪口呆……。也 就是说，双人“得”后面的词语一般用来补充说明双人“得”前面的动作怎么样。 二、“的、地、得”用法补充说明：
感官动词和使役动词 默认分类2010-05-28 23:14:26 阅读46 评论0 字号：大中小订阅 使役动词，比如let make have就是3个比较重要的 have sb to do 没有这个用法的 只有have sb doing.听凭某人做某事 have sb do 让某人做某事 have sth done 让某事被完成（就是让别人做） 另外： 使役动词 1.使役动词是表示使、令、让、帮、叫等意义的不完全及物动词,主要有make(使,令), let(让), help(帮助), have(叫)等。 2.使役动词后接受词,再接原形不定词作受词补语。 He made me laugh. 他使我发笑。 I let him go. 我让他走开。 I helped him repair the car. 我帮他修理汽车。 Please have him come here. 请叫他到这里来。 3.使役动词还可以接过去分词作受词补语。 I have my hair cut every month. 我每个月理发。 4.使役动词的被动语态的受词补语用不定词,不用原形不定词。 (主)He made me laugh. 他使我笑了。 (被)I was made to laugh by him. 我被他逗笑了。 使役动词有以下用法： a. have somebody do sth让某人去做某事 ??i had him arrange for a car. b. have somebody doing sth.让某人持续做某事。 ??he had us laughing all through lunch. 注意：用于否定名时，表示“允许” i won't have you running around in the house. 我不允许你在家里到处乱跑。 ******** 小议“使役动词”的用法 1. have sb do 让某人干某事 e.g:What would you have me do? have sb/sth doing 让某人或某事处于某种状态，听任 e.g: I won't have women working in our company. The two cheats had the light burning all night long. have sth done 让别人干某事，遭受到 e.g:you 'd better have your teeth pulled out. He had his pocket picked. notes: "done"这个动作不是主语发出来的。 2.make sb do sth 让某人干某事 e.g:They made me repeat the story. What makes the grass grow?
大多数形容词有三种形式,原级,比较级和最高级, 以表示形容词说明的性质在程度上的不同。 形容词的原级: 形容词的原级形式就是词典中出现的形容词的原形。例如: poor tall great glad bad 形容词的比较级和最高级: 形容词的比较级和最高级形式是在形容词的原级形式的基础上变化的。分为规则变化和不规则变化。 规则变化如下: 1) 单音节形容词的比较级和最高级形式是在词尾加 -er 和 -est 构成。 great (原级) (比较级) (最高级) 2) 以 -e 结尾的单音节形容词的比较级和最高级是在词尾加 -r 和 -st 构成。wide (原级) (比较级) (最高级) 3)少数以-y, -er, -ow, -ble结尾的双音节形容词的比较级和最高级是在词尾加 -er 和 -est 构成。 clever(原级) (比较级) (最高级) 4) 以 -y 结尾,但 -y 前是辅音字母的形容词的比较级和最高级是把 -y 去掉,加上 -ier 和-est 构成. happy (原形) (比较级) (最高级) 5) 以一个辅音字母结尾其前面的元音字母发短元音的形容词的比较级和最高级是双写该辅音字母然后再加 -er和-est。 big (原级) (比较级) (最高级) 6) 双音节和多音节形容词的比较级和最高级需用more 和 most 加在形容词前面来构成。 beautiful (原级) (比较级) (比较级) difficult (原级) (最高级) (最高级) 常用的不规则变化的形容词的比较级和最高级: 原级------比较级------最高级 good------better------best many------more------most much------more------most bad------worse------worst far------farther, further------farthest, furthest 形容词前如加 less 和 least 则表示"较不"和"最不 形容词比较级的用法: 形容词的比较级用于两个人或事物的比较,其结构形式如下: 主语+谓语(系动词)+ 形容词比较级+than+ 对比成分。也就是, 含有形容词比较级的主句+than+从句。注意从句常常省去意义上和主句相同的部分, 而只剩下对比的成分。
常用兽药原粉药使用说明 抗生素类药物的选用 1、由革兰氏阳性菌引起的疾病，如猪丹毒、破伤风、炭疽、马腺疫、气肿疽、牛放线菌病、葡萄球菌性和链球菌性炎症、败血症等，可选用青霉素类、头孢菌素类、四环素类和大环内酯类、林可霉素等。 2、由革兰氏阴性菌引起疾病，如巴氏杆菌病、大肠杆菌病、沙门氏菌病、肠炎、泌尿道炎症，选用氨基糖苷类、氟喹诺酮类等。 3、由耐青霉素G 金黄色葡萄球菌所致呼吸道感染、败血症等，可选用耐青霉素酶的半合成青霉素，如苯唑西林、氯唑西林，也可选用大环内酯类和头孢菌素类抗生素。 4、由绿脓杆菌引起的创面及尿路感染、败血症、肺炎等，选用庆大霉素、多黏菌素等。 5、由支原体引起的猪喘气病和鸡慢性呼吸道病，则应首选氟喹诺酮类药，如恩诺沙星、红霉素、泰乐菌素、泰妙菌素等。 一.喹诺酮类： 1、氧氟沙星（纯粉）： （作用与用途）本品对多数革兰氏阴性、阳性菌、霉形体和某些厌氧菌有较强杀灭作用，主要用于治疗大肠杆菌病，霍乱、沙门氏菌病、慢性呼吸道病、鸭巴氏杆菌病等；（用法与用量）预防10g兑水200kg,冶疗100kg 1日2次，连用3-5天。 2、盐酸环丙沙星（纯粉） （作用与用途）本品是一种新型喹喏酮类、广谱、高效抗菌药。对各种细菌和霉形体均有强大的杀灭作用，尤其适用于细菌混合感染，主要用于鸡慢性呼吸道病、大肠杆菌、沙门氏菌、葡萄球菌、绿脓杆菌、霉形体及嗜血杆菌等细菌感染引起的消化道、呼吸道、肺部及全身炎症，临床上常作为消化道疾病用药。 （用法与用量）预防10克兑水100公斤，治疗50公斤，混料加倍，连用3-5天
3、乳酸环丙沙星（纯粉） 作用与用途）作用与用途同盐酸环丙沙星，其不同之处在于乳酸环丙沙星水溶性大大增强，吸收率高且吸收迅速，血药浓度高，因而治疗效果大大增强。 （用法与用量）同盐酸环丙沙星 4、氟哌酸（盐酸诺氟沙星）（纯粉） （作用与用途）本品属第三代喹诺酮类广谱抗菌药，高效，安全。主要用于大肠 杆菌、沙门氏菌、葡萄球菌、绿脓杆菌、霉形体及嗜血杆菌等细菌感染引起的消化道、呼吸道、肺部及全身炎症，临床上常作为消化道疾病用药。 （用法与用量）预防10克兑水100公斤，治疗50 公斤，混料加倍，连用3-5天 5、盐酸蒽诺沙星（纯粉） （作用与用途）本品为最新开发出的喹诺酮类药物之一，对各种细菌和霉形体有特效，本品的特点是广谱、高效、见效极快、杀菌彻底，有克菌王之称，是目前防治各种细菌病及霉形体病的特效药物。 （用法与用量）预防10克兑水100公斤，治疗50 公斤，混料加倍，连用3-5天 6、盐酸洛美沙星（纯粉） （作用与用途）本品是第三代喹诺酮类最新抗菌药，对各种细菌和霉形体有特效，口服吸收完全，用药后一小时就可达到有效杀菌浓度，见效极快，作用时间长达8小时，是目前治疗各种细菌病及鸡慢性呼吸道病的特效药物。 （用法与用量）预防10 克兑水200公斤，治疗兑水100公斤，连用3-5 天。 二、大环内脂类： 1、替米考星（纯品） 编辑版word
《“的、地、得”的用法》语文微课教案 《“的、地、得”的用法》语文微课教案 一、教学背景 在语言文字规范化大背景下，帮助学生解决应用“的地得”的疑惑与困难。 二、设计思路 针对学生对于“的地得”的误用与忽视展开教学，规范结构助词“的地得”的使用。按照“问题的提出、问题的分析、问题的解决”的思路展开教学，总结归纳优化的方式方法。 三、教学目标 1、知道“怎么样的什么、怎么样地干什么、干得怎么样”三种固定搭配。 2、掌握“的、地、得”的区别与联系。 3、运用小儿歌“动前土、名前白、行动后面双人来”的口诀帮助正确使用“的、地、得”。 四、教学重难点 1、知道“的、地、得”的区别。 2、在实际情境中正确运用“的、地、得”。 五、教学时间 8分钟微课堂 六、教学适用对象 义务教育九年制内的学生 七、教学准备 多媒体课件、录屏软件 八、教学设计与过程 开场白： 同学们好！今天我们一起来学习“的、地、得”的正确用法。首先我们来了解一下它们的区别。 1、相同之处：原来它们都是念轻声“de”，都是结构助词，起连接作用。 2、不同之处：在书面语中要写成三个不同的字，而且它们的搭配及用法也各不相同。（1）怎么样的什么 （2）怎样样地干什么 （3）干得怎么样 下面我们就来学习一下它们的正确用法。 白勺“的”的结构是用“形容词或名词或代词+的+名词”来表示，而我们最常见，用得最多的还是“形容词+的+名词”的结构。 而土也“地”的用法可以用“形容词+地+动词”的结构来表示。 双人“得”是用“动词+得+形容词”的结构来表示 3、练习巩固 （1）形近区分 静静（的）河面静静（地）写字欢乐（的）山谷 欢乐（地）歌唱满意（地）点头满意（的）作品 （2）类别区分
感官动词 1.see, hear, listen to, watch, notice等词，后接宾语，再接省略to的动词不定式或ing形式。前者表全过程，后者表正在进行。句中有频率词时，以上的词也常跟动词原形。 注释:省略to的动词不定式--to do是动词不定式，省略了to,剩下do，其形式和动词原形是一样的，但说法不同。 see sb do sth 看到某人做了某事 see sb doing sth 看到某人在做某事 hear sb do sth 听到某人做了某事 hear sb doing sth 听到某人在做某事 以此类推... I heard someone knocking at the door when I fell asleep. (我入睡时有人正敲门,强调当时正在敲门) I heard someone knock at the door three times. (听到有人敲门的全过程) I often watch my classmates play volleyball after school. (此处有频率词often) （了解）若以上词用于被动语态，须将省略的to还原： see sb do sth----sb be seen to do sth hear sb do sth----sb be seen to do sth 以此类推... We saw him go into the restaurant. → He was seen to go into the restaurant. I hear the boy cry every day. → The boy is heard to cry every day. 2.感官动词look, sound, smell, taste, feel可当系动词，后接形容词。 He looks angry. His explanation sounds reasonable. The cakes smell nice.
英语比较级和最高级的用法归纳 在学习英语过程中，会遇到很多的语法问题，比如比较级和最高级的用法，对于 这些语法你能够掌握吗？下面是小编整理的英语比较级和最高级的用法，欢迎阅读！ 英语比较级和最高级的用法 一、形容词、副词的比较级和最高级的构成规则 1.一般单音节词和少数以-er，-ow结尾的双音节词，比较级在后面加-er，最高级 在后面加-est; (1)单音节词 如：small→smaller→smallest short→shorter→shortest tall→taller→tallest great→greater→greatest (2)双音节词 如：clever→cleverer→cleverest narrow→narrower→narrowest 2.以不发音e结尾的单音节词，比较在原级后加-r，最高级在原级后加-st; 如：large→larger→largest nice→nicer→nicest able→abler→ablest 3.在重读闭音节(即：辅音+元音+辅音)中，先双写末尾的辅音字母，比较级加-er，最高级加-est; 如：big→bigger→biggest hot→hotter→hottest fat→fatter→fattest 4.以“辅音字母+y”结尾的双音节词，把y改为i，比较级加-er，最高级加-est; 如：easy→easier→easiest heavy→heavier→heaviest busy→busier→busiest happy→happier→happiest 5.其他双音节词和多音节词，比较级在前面加more，最高级在前面加most; 如：bea utiful→more beautiful→most beautiful different→more different→most different easily→more easily→most easily 注意：(1)形容词最高级前通常必须用定冠词 the，副词最高级前可不用。 例句： The Sahara is the biggest desert in the world. (2) 形容词most前面没有the，不表示最高级的含义，只表示"非常"。 It is a most important problem. =It is a very important problem.
《“的、地、得”的用法》语文微课教案 一、教学背景 在语言文字规范化大背景下，帮助学生解决应用“的地得”的疑惑与困难。 二、设计思路 针对学生对于“的地得”的误用与忽视展开教学，规范结构助词“的地得”的使用。按照“问题的提出、问题的分析、问题的解决”的思路展开教学，总结归纳优化的方式方法。 三、教学目标 1、知道“怎么样的什么、怎么样地干什么、干得怎么样”三种固定搭配。 2、掌握“的、地、得”的区别与联系。 3、运用小儿歌“动前土、名前白、行动后面双人来”的口诀帮助正确使用“的、地、得”。 四、教学重难点 1、知道“的、地、得”的区别。 2、在实际情境中正确运用“的、地、得”。 五、教学时间 8分钟微课堂 六、教学适用对象 义务教育九年制内的学生 七、教学准备
多媒体课件、录屏软件 八、教学设计与过程 开场白： 同学们好！今天我们一起来学习“的、地、得”的正确用法。首先我们来了解一下它们的区别。 1、相同之处：原来它们都是念轻声“de”，都是结构助词，起连接作用。 2、不同之处：在书面语中要写成三个不同的字，而且它们的搭配及用法也各不相同。 （1）怎么样的什么 （2）怎样样地干什么 （3）干得怎么样 下面我们就来学习一下它们的正确用法。 白勺“的”的结构是用“形容词或名词或代词+的+名词”来表示，而我们最常见，用得最多的还是“形容词+的+名词”的结构。 而土也“地”的用法可以用“形容词+地+动词”的结构来表示。 双人“得”是用“动词+得+形容词”的结构来表示 3、练习巩固 （1）形近区分 静静（的）河面静静（地）写字欢乐（的）山谷
欢乐（地）歌唱满意（地）点头满意（的）作品 （2）类别区分 1）跑（得）飞快飞快（地）跑 2）愉快（的）旅行旅行（得）愉快 3）强烈（的）渴望强烈（地）渴望 （3）综合杂糅 小雏鹰飞到大树的上方，高兴地喊起来：“我真的会飞啦！而且飞（得）很高呢！” 小结：能填对这个句子的你肯定就已经学会它们的用法了！ 4、特殊情况 质疑：假如遇到特殊情况怎么办呢？ 我从书包里拿出书交给她们，她们高兴得．围着我跳起舞来。（出自二年级上册《日记两则》） （1）质疑：为什么这里要使用“得”呢？ （2）释疑：原来这里强调的是心情，动词在后，形容词在前，相当于后置，“得”修饰“跳舞”而非“围”。现在你明白了吧？ 5、小结归纳： 怎么样，你们学会了吗？为了让同学们能够更快的记住它们的用法，老师送给大家一首口诀来帮助你们熟记三个“的”的正确使用方法：动前土、名前白、行动后面双人来。
英语中感官动词的用法 一、感官动词 1、感官动词(及物动词)有：see/notice/look at/watch/observe/listen to/hear/feel(Vt)/taste(Vt)/smell(Vt) 2、连缀动词(含感官不及物动词) be/get/become/feel/look/sound/smell/taste/keep/stay/seem/ appear/grow/turn/prove/remain/go/run 二、具体用法： 1、see, hear, smell, taste, feel,这五个动词均可作连系动词，后面接形容词作表语，说明主语所处的状态。其意思分别为"看/听/闻/尝/摸起来……"。除look之外，其它几个动词的主语往往是物，而不是人。 例如：These flowers smell very sweet.这些花闻起来很香。 The tomatoes feel very soft.这些西红柿摸起来很软。 2、这些动词后面也可接介词like短语，like后面常用名词。 例如：Her idea sounds like fun.她的主意听起来很有趣。 3、这五个感官动词也可作实义动词,除look(当"看起来……"讲时)只能作不及物动词外,其余四个既可作及物动词也可作不及物动词,此时作为实义动词讲时其主语一般为人。 例如:She smelt the meat.她闻了闻那块肉。 I felt in my pocket for cigarettes.我用手在口袋里摸香烟。 4、taste, smell作不及物动词时,可用于"t aste / smell + of +名词"结构,意为"有……味道/气味"。 例如:The air in the room smells of earth.房间里的空气有股泥土味。 5、它们(sound除外)可以直接作名词,与have或take构成短语。 例如：May I have a taste of the mooncakes?我可以尝一口这月饼吗？taste有品位、味道的意思。 例如：I don’t like the taste of the garlic.我不喜欢大蒜的味道。 She dresses in poor taste.她穿着没有品位。 look有外观，特色的意思，例：The place has a European look.此地具有欧洲特色。 feel有感觉，感受的意思，watch有手表，观察的意思。例：My watch is expensive.我的手表很贵。 6、其中look, sound, feel还能构成"look / sound / feel + as if +从句"结构，意为"看起来/听起来/感觉好像……"。 例如：It looks as if our class is going to win.看来我们班好像要获胜了。 7、感官动词+do与+doing的区别： see, watch, observe, notice, look at, hear, listen to, smell, taste, feel + do表示动作的完整性，真实性；+doing 表示动作的连续性，进行性。 I saw him work in the garden yesterday.昨天我看见他在花园里干活了。(强调"我看见了"
More than的用法 A. “More than+名词”表示“不仅仅是” 1)Modern science is more than a large amount of information. 2)Jason is more than a lecturer; he is a writer, too. 3) We need more than material wealth to build our country.建设我们国家，不仅仅需要物质财富. B. “More than+数词”含“以上”或“不止”之意，如： 4)I have known David for more than 20 years. 5)Let's carry out the test with more than the sample copy. 6) More than one person has made this suggestion. 不止一人提过这个建议. C. “More than+形容词”等于“很”或“非常”的意思，如： 7)In doing scientific experiments, one must be more than careful with the instruments. 8)I assure you I am more than glad to help you. D. more than + (that)从句，其基本意义是“超过（=over）”，但可译成“简直不”“远非”.难以，完全不能（其后通常连用情态动词can） 9) That is more than I can understand . 那非我所能懂的. 10) That is more than I can tell. 那事我实在不明白。 11) The heat there was more than he could stand. 那儿的炎热程度是他所不能忍受的 此外，“more than”也在一些惯用语中出现，如： more...than 的用法 1. 比……多，比……更 He has more books than me. 他的书比我多。 He is more careful than the others. 他比其他人更仔细。 2. 与其……不如 He is more lucky than clever. 与其说他聪明，不如说他幸运。 He is more （a）scholar than （a）teacher. 与其说他是位教师，不如说他是位学者。 注：该句型主要用于同一个人或物在两个不同性质或特征等方面的比较，其中的比较级必须用加more 的形式，不能用加词尾-er 的形式。 No more than/not more than 1. no more than 的意思是“仅仅”“只有”“最多不超过”，强调少。如： --This test takes no more than thirty minutes. 这个测验只要30分钟。 --The pub was no more than half full. 该酒吧的上座率最多不超过五成。-For thirty years，he had done no more than he （had）needed to. 30年来，他只干了他需要干的工作。 2. not more than 为more than （多于）的否定式，其意为“不多于”“不超过”。如：Not more than 10 guests came to her birthday party. 来参加她的生日宴会的客人不超过十人。 比较： She has no more than three hats. 她只有3顶帽子。（太少了） She has not more than three hats. 她至多有3顶帽子。（也许不到3顶帽子） I have no more than five yuan in my pocket. 我口袋里的钱最多不过5元。（言其少） I have not more than five yuan in my pocket. 我口袋里的钱不多于5元。（也许不到5元） more than, less than 的用法 1. （指数量）不到，不足 It’s less than half an hour’s drive from here. 开车到那里不到半个钟头。 In less than an hour he finished the work. 没要上一个小时，他就完成了工作。 2. 比……（小）少 She eats less than she should. 她吃得比她应该吃的少。 Half the group felt they spent less than average. 半数人觉得他们的花费低于平均水平。 more…than,/no more than/not more than (1)Mr．Li is ________ a professor; he is also a famous scientist． (2)As I had ________ five dollars with me, I couldn’t afford the new jacket then． (3)He had to work at the age of ________ twelve． (4)There were ________ ten chairs in the room．However, the number of the children is twelve． (5)If you tel l your father what you’ve done, he’ll be ________ angry． (6)－What did you think of this novel? －I was disappointed to find it ________ interesting ________ that one． 倍数表达法 1. “倍数+形容词（或副词）的比较级+than+从句”表示“A比B大（长、高、宽等）多少倍” This rope is twice longer than that one.这根绳是那根绳的三倍（比那根绳长两倍）。The car runs twice faster than that truck.这辆小车的速度比那辆卡车快两倍（是那辆卡车的三倍）。 2. “倍数+as+形容词或副词的原级+as+从句”表示“A正好是B的多少倍”。
香港正大生物制药 一.喹诺酮类： 氧氟沙星（纯粉）： （作用与用途）本品对多数革兰氏阴性、阳性菌、霉形体和某些厌氧菌有较强杀灭作用，主要用于治疗大肠杆菌病，霍乱、沙门氏菌病、慢性呼吸道病、鸭巴氏杆菌病等； （用法与用量）预防10g兑水200kg，冶疗100kg，1日2次，连用3-5天。 盐酸环丙沙星（纯粉） （作用与用途）本品是一种新型喹喏酮类、广谱、高效抗菌药。对各种细菌和霉形体均有强大的杀灭作用，尤其适用于细菌混合感染，主要用于鸡慢性呼吸道病、大肠杆菌、沙门氏菌、葡萄球菌、绿脓杆菌、霉形体及嗜血杆菌等细菌感染引起的消化道、呼吸道、肺部及全身炎症，临床上常作为消化道疾病用药。 （用法与用量）预防10克兑水100公斤，治疗50公斤，混料加倍，连用3-5天。 乳酸环丙沙星（纯粉） （作用与用途）作用与用途同盐酸环丙沙星，其不同之处在于乳酸环丙沙星水溶性大大增强，吸收率高且吸收迅速，血药浓度高，因而治疗效果大大增强。（用法与用量）同盐酸环丙沙星 氟哌酸（盐酸诺氟沙星）（纯粉） （作用与用途）本品属第三代喹诺酮类广谱抗菌药，高效，安全。主要用于大肠杆菌、沙门氏菌、葡萄球菌、绿脓杆菌、霉形体及嗜血杆菌等细菌感染引起的消化道、呼吸道、肺部及全身炎症，临床上常作为消化道疾病用药。 （用法与用量）预防10克兑水100公斤，治疗50公斤，混料加倍，连用3-5天。 盐酸蒽诺沙星（纯粉） （作用与用途）本品为最新开发出的喹诺酮类药物之一，对各种细菌和霉形体有特效，本品的特点是广谱、高效、见效极快、杀菌彻底，有克菌王之称，是目前防治各种细菌病及霉形体病的特效药物。 （用法与用量）预防10克兑水100公斤，治疗50公斤，混料加倍，连用3-5天。 盐酸洛美沙星（纯粉） （作用与用途）本品是第三代喹诺酮类最新抗菌药，对各种细菌和霉形体有特效，口服吸收完全，用药后一小时就可达到有效杀菌浓度，见效极快，作用时间长达8小时，是目前治疗各种细菌病及鸡慢性呼吸道病的特效药物。 （用法与用量）预防10克兑水200公斤，治疗兑水100公斤，连用3-5天。二、大环内脂类： 替米考星（纯品） （作用与用途）本品为泰乐菌素的高科技替代产品，对革兰氏阳性菌和支原体有很强的抗菌活性，临床主要用于畜禽呼吸道及猪的支原体肺炎（尤其是对鸡的败
二年级语文的、地、得用法教案一、“的、地、得”的用法 “白勺的、提土地、双人得”是我们在语文学习中经常 使用的三个词，它们都起着连接作用；它们在普通话中都各 自有着不同的读音，但当他们附在词，短语，句子的前面或 后面，表示结构关系或某些附加意义的时候都读轻声“de”，没有语音上的区别。但在书面语中有必要写成三个不同的字，这样可以区分他们在书面语用法上的不同。这样做的好处， 就是可使书面语言精确化。 （一）首先我们来看白勺“的”的用法。通常白勺“的”的后面往往跟名词，我们用算式表示就是“的+名词”。名 词包括哪些呢？人物，如：妈妈、老师、校长。动植物，如：小鸟、小草、苹果。景物，如风景、西湖、运河。事物，衣服、头发、球赛，等等。它们都属于名词。 现在我们来举一些例子，比如：亲切的妈妈、大大的窗户、红红的花朵、优美的风景、精彩的球赛、机灵的小鸟、 漂亮的衣服、黑黑的头发、雄伟的长城……。 通过这些短语，我们不难发现白勺“的”前面的词语一 般用来说明白勺“的”后面事物怎么样。 白勺“的”除了可以用在名词前外，句子的末尾也用白 勺“的”。比如：我们是知道的。我们是一起来的。你是数 不清的。
（二）其次，我们来看提土“地”的用法。通常提土“地”的后面往往跟的是表示动作的词，也就是动词，我们 用算式表示就是“地+动词”。 比如：仔细地看，大声地说，慢慢地走。看，提土地后 面的看、说、走都是表示动作的词。 现在我们再来举几个例子：快速地跑，用力地抓，认真 地读，快活地游着，积极地参加，早早地离开，自由自在地 飞翔，一次又一次地握手、迅速地包围、沙沙地直响、斩钉 截铁地说、用力地踢、仔细地看……。也就是说，提土“地”前面的词语一般用来说明提土“地”后面的动作怎么样。 （三）最后，我们来看双人“得”的用法。双人“得” 前面多数是表示动作的词或词语，少数是形容词，我们用算 式表示就是“动词（形容词）+得”。比如：玩得开心，红得发紫，吃得好，大得很，跳得高，急得满头大汗，“玩、吃、跳”这些是动词，“大、红、急”这些是形容词，后面都得 用双人“得”。 现在我们再来举几个例子：玩得刺激，看得仔细，唱得 好听，写得端正，举得高高的，说得真精彩，气得双脚直跳、理解得十分深刻、乐得合不拢嘴、惊讶得目瞪口呆……。也 就是说，双人“得”后面的词语一般用来补充说明双人“得”前面的动作怎么样。 二、“的、地、得”用法补充说明：
1.感官动词用法之一：see, hear, listen to, watch, notice等词，后接宾语，再接动词原形或ing形式。前者表全过程，后者表正在进行。句中有频率词时，以上的词也常跟动词原形。 I heard someone knocking at the door when I fell asleep. (我入睡时有人正敲门) I heard someone knock at the door three times. (听的是全过程) I often watch my classmates play volleyball after school.(此处有频率词often) 若以上词用于被动语态，后面原有动词原形改为带to不定式： We saw him go into the restaurant. →He was seen to go into the restaurant. I hear the boy cry every day. →The boy is heard to cry every day. 2.感官动词用法之二：look, sound, smell, taste, feel可当系动词，后接形容词： He looks angry. It sounds good. The flowers smell beautiful. The sweets taste sweet. The silk feels soft. I felt tired. They all looked tired. 这些动词都不用于被动语态。如：The sweets are tasted sweet.是个病句。注意：如果加介词like,则后不可接形容词，而接名词或代词：
常用兽药原粉药使用说明
常用兽药原粉药使用说明 抗生素类药物的选用 1、由革兰氏阳性菌引起的疾病，如猪丹毒、破伤风、炭疽、马腺疫、气肿疽、牛放线菌病、葡萄球菌性和链球菌性炎症、败血症等，可选用青霉素类、头孢菌素类、四环素类和大环内酯类、林可霉素等。 2、由革兰氏阴性菌引起疾病，如巴氏杆菌病、大肠杆菌病、沙门氏菌病、肠炎、泌尿道炎症，选用氨基糖苷类、氟喹诺酮类等。 3、由耐青霉素G金黄色葡萄球菌所致呼吸道感染、败血症等，可选用耐青霉素酶的半合成青霉素，如苯唑西林、氯唑西林，也可选用大环内酯类和头孢菌素类抗生素。 4、由绿脓杆菌引起的创面及尿路感染、败血症、肺炎等，选用庆大霉素、多黏菌素等。 5、由支原体引起的猪喘气病和鸡慢性呼吸道病，则应首选氟喹诺酮类药，如恩诺沙星、红霉素、泰乐菌素、泰妙菌素等。
一.喹诺酮类： 1、氧氟沙星（纯粉）： （作用与用途）本品对多数革兰氏阴性、阳性菌、霉形体和某些厌氧菌有较强杀灭作用，主要用于治疗大肠杆菌病，霍乱、沙门氏菌病、慢性呼吸道病、鸭巴氏杆菌病等； （用法与用量）预防10g兑水200kg，冶疗100kg，1日2次，连用3-5天。2、盐酸环丙沙星（纯粉） （作用与用途）本品是一种新型喹喏酮类、广谱、高效抗菌药。对各种细菌和霉形体均有强大的杀灭作用，尤其适用于细菌混合感染，主要用于鸡慢性呼吸道病、大肠杆菌、沙门氏菌、葡萄球菌、绿脓杆菌、霉形体及嗜血杆菌等细菌感染引起的消化道、呼吸道、肺部及全身炎症，临床上常作为消化道疾病用药。（用法与用量）预防10克兑水100公斤，治疗50公斤，混料加倍，连用3-5天。 3、乳酸环丙沙星（纯粉） （作用与用途）作用与用途同盐酸环丙沙星，其不同之处在于乳酸环丙沙星水溶性大大增强，吸收率高且吸收迅速，血药浓度高，因而治疗效果大大增强。（用法与用量）同盐酸环丙沙星 4、氟哌酸（盐酸诺氟沙星）（纯粉） （作用与用途）本品属第三代喹诺酮类广谱抗菌药，高效，安全。主要用于大肠杆菌、沙门氏菌、葡萄球菌、绿脓杆菌、霉形体及嗜血杆菌等细菌感染引起的消化道、呼吸道、肺部及全身炎症，临床上常作为消化道疾病用药。 （用法与用量）预防10克兑水100公斤，治疗50公斤，混料加倍，连用3-5天。 5、盐酸蒽诺沙星（纯粉） （作用与用途）本品为最新开发出的喹诺酮类药物之一，对各种细菌和霉形体有特效，本品的特点是广谱、高效、见效极快、杀菌彻底，有克菌王之称，是目前防治各种细菌病及霉形体病的特效药物。 （用法与用量）预防10克兑水100公斤，治疗50公斤，混料加倍，连用3-5天。