a r X i v :a s t r o -p h /0503344v 1 16 M a r 2005
Abundance Analyses of Field R V Tauri Stars,VI:An Extended
Sample
Sunetra Giridhar
Indian Institute of Astrophysics;Bangalore,560034India
giridhar@iiap.res.in
David https://www.doczj.com/doc/f517987045.html,mbert
The W.J.McDonald Observatory;University of Texas;Austin,TX 78712-1083
dll@https://www.doczj.com/doc/f517987045.html,
Bacham E.Reddy 1
Indian Institute of Astrophysics;Bangalore,560034India
ereddy@iiap.res.in
Guillermo Gonzalez
Department of Physics and Astronomy;Iowa State University;Ames,IA 50011-3160
gonzog@https://www.doczj.com/doc/f517987045.html,
David Yong
Department of Astronomy;University of Texas;Austin,TX 78712-1083
tofu@https://www.doczj.com/doc/f517987045.html,
ABSTRACT
An abundance analysis is presented and discussed for a sample of 14RV Tauri stars.The present abundance data and those from our previous papers and by other workers are combined in an attempt to further understanding of the dust-gas separation process which a?icts many RV Tauri variables.We propose that a star’s intrinsic (i.e.,initial)metallicity is given by the photospheric zinc abundance.Variables warmer that about 5000K and with an initial metallicity [Fe/H]≥?1are a?ected by dust-gas separation.Variables of all metallicities and cooler than about T e??5000K are una?ected by dust-gas separation.The RV Tauri variables show a spread in their C abundances with the lower boundary of the points in the C versus Zn plane falling close to the predicted trend for giants after the ?rst dredge-up.The upper boundary is inhabited by a few stars that
are carbon-rich.The O abundances in the mean follow the predicted trend from
unevolved stars in line with the expectation that photospheric O abundance is
una?ected by the?rst dredge-up.An evolutionary scenario involving mass loss
by a?rst ascent or early-AGB red giant,the primary star of a binary,is sketched.
Subject headings:stars:abundances–stars:AGB and post-AGB–stars:vari-ables(RV Tauri)
1.Introduction
In this series of papers,we have been exploring the chemical compositions of RV Tauri variables in the Galactic?eld.This exploration concludes here with abundance analyses reported for fourteen variables.Of these,twelve are analysed for the?rst time,one(LR Sco)was previously analysed by us before its status as a RV Tauri variable was appreciated by Lloyd Evans(1999),and one(DY Ori)is analysed more thoroughly than in our earlier attempt.
Beginning with the analysis of the southern RV Tauri variable IW Car(Giridhar,Rao, &Lambert1994,Paper I),we have shown that the atmospheric composition of a RV Tauri star may be abnormal in the sense that the photospheric abundance anomalies are roughly correlated with the predicted condensation temperature for low pressure gas of solar com-position.In particular,elements(e.g.,Al,Ca,Ti,and Sc)with the highest condensation temperatures(～1600K)may be seriously underabundant relative to their abundance ex-pected from the abundances of elements(e.g.,S and Zn)of low condensation temperature (Gonzalez,Lambert&Giridhar1997a,Paper II;Gonzalez,Lambert&Giridhar1997b,Pa-per III;Giridhar,Lambert&Gonzalez1998,Paper IV;Giridhar,Lambert&Gonzalez2000, Paper V).Our?ndings were con?rmed by independent analyses of several RV Tauri stars by Van Winckel et al.(1998),Maas,Van Winckel,&Waelkens(2002),and Maas(2003).These abundance anomalies imply that the RV Tauri’s photosphere is de?cient in those elements which condense most readily into dust grains.We refer to the principal operation necessary to achieve the de?ciencies as dust-gas separation.
If such a separation is to a?ect the photospheric composition,three conditions must be met.First(condition A),a site for dust formation must exist near the star.Two proposed locations compete to meet this condition:the wind o?the star or a circumstellar or circumbinary disk.Second(condition B),a mechanism must be identi?ed to separate
dust from gas.It has been supposed that radiation pressure on the dust grains drives them through the gas and away from the star(s).Third(condition C),the dust-free gas accreted by the star must become the dominant constituent of the star’s photosphere.Here the principal issue is that the photosphere is a part of a convective envelope.In order for the photosphere to assume a composition dominated by dust-free gas,the mass of the envelope must be small relative to the mass of accreted gas.
Our earlier analyses have shown that the severity of the atmospheric abundance anoma-lies di?ers from one RV Tauri to another.These di?erences presumably are clues to the circumstances under which the above conditions are or are not met.Taking them in inverse order,the following may be noted.Relevant to condition C,the coolest RV Tauri variables independent of their metallicity are free of the abundance anomalies.One interpretation is that these stars have deep convective envelopes which dilute accreted gas and prevent the appearance of abundance anomalies even when gas but not dust is accreted(Paper V). Stars of intrinsically low metallicity such as the variables in globular clusters(Gonzalez and Lambert1997;Russell1998)and some high-velocity variables in the?eld appear immune to the e?ects of a dust-gas separation.This fact is relevant to condition B:it is likely a consequence of the inability of radiation pressure on dust grains to force a separation of dust from gas when the mass fraction of dust is very low,as it is in a metal-poor cool environment. Accretion under these circumstances will not change the surface composition of the star even if it has a shallow envelope.
With respect to condition A,the extremely metal-de?cient A-type post-AGB stars are evidence that dust-gas separation does not have to occur in a stellar wind(Van Winckel2003). The prototypical example is HR4049(T e?=7600K)with an extensive infrared excess from dust but its stellar wind,if it exists,is surely too hot to be the site of dust formation. Yet,dust-gas separation has provided a photospheric abundance of[Fe/H]??4.8for a star with an initial abundance[Fe/H]≈?0.4.Van Winckel,Waelkens,&Waters(1995) showed that HR4049and other similar metal-de?cient stars were spectroscopic binaries. The dust-gas separation is presumed to occur in a circumbinary dusty disk.Superposition of the pulsational velocity variation on an orbital variation complicates a demonstration that all RV Tauri stars a?ected by dust-gas separation are binaries.Certainly,several RV Tauri stars are known to be spectroscopic binaries.An assessment of the direct and indirect evidence(Van Winckel et al.1998)led Van Winckel(2003)to write that‘binarity may very well be a common phenomenon among RV Tauri stars’.The question of dust-gas separation occurring in a wind o?a cool star remains open.
An aim of this paper was to enlarge the sample of RV Tauri variables in order to test in more depth previous deductions about the dust-gas separation processes.We present
abundances for the fourteen variables listed in Table1.
This new sample particularly increases the representation of high-velocity RV Tauri stars.
2.Observations and Abundance Analyses
The program stars and dates of observation are listed in Table1along with the measured radial velocity,the pulsational period,the Preston spectroscopic type A,B,or C(Preston et al.1963),and the photometric type a or b.The photometric type b indicates that the light curve shows a long-term modulation.
A majority of the stars were observed with the McDonald Observatory’s2.7m Harlan J. Smith re?ector with the CCD-equipped‘2dcoud′e’spectrograph(Tull et al.1995).A spectral resolving power R=λ/?λ?60000was used and a broad spectral range was covered in a single exposure.A S/N ratio of80-100over much of the spectral range was achieved.Figure 1illustrates the quality of typical spectra.
The stars LR Sco and AZ Sgr were observed at CTIO,Chile with the4m Blanco telescope equipped with a cross-dispersed echelle Cassegrain spectrograph and a CCD of2048×2048 pixels.The spectrograph was set to record the wavelength interval4900?A to8250?A in 45orders.Spectral coverage was complete between these limits.The resolving power R?35,000was achieved,as measured from the Th lines in the Th-Ar comparison spectrum.
Spectra were rejected if they showed line doubling,markedly asymmetric lines,or strong emission at Hβ.(Emission was almost always present at Hα.)It is presumed that the spectra not showing these characteristics represent the atmosphere at a time when standard theoretical models may be applicable.This presumption should be tested by analysis of a series of spectra taken over the pulsational cycle.This remains to be done but in previous papers we have analysed several stars using spectra taken at di?erent phases and obtained consistent results.A striking example was given in Paper III where three observations of SS Gem gave widely di?erent e?ective temperatures(4750,5500,and6500K)but similar results for the composition.
The abundance analyses were performed as described in earlier papers of this series.The 2002version of the spectrum synthesis code MOOG(Sneden1973)was used with ATLAS model atmospheres(Kurucz1993).Molecule formation was taken into account in computing the line spectrum.Hyper?ne splitting was considered for the lines of relevant atoms and lines(e.g.Sc,Mn).Atmospheric parameters were determined in the usual way from the
Fe i and Fe ii lines by demanding excitation and ionization equilibrium,and that the iron abundance be independent of the equivalent width.Ionization equilibrium is also satis?ed for Si,Ti,and Cr:the mean abundance di?erence(in dex)between neutral and ionized lines is+0.08±0.16for Si from11stars,?0.02±0.16for Ti from7stars,and0.00±0.11for Cr from13stars.The adopted parameters listed in Table2were used for the full abundance analysis.Abundances are referred to the solar abundances given by Lodders(2003,her Table 1).Results are given in Table3for the stars obviously carrying the signatures of dust-gas separation and in Table4for the other stars.
3.The Chemical Compositions
The chemical composition of a RV Tauri variable may be a blend of several signatures.
(i)initial composition of the star,(ii)the e?ects of deep mixing during stellar evolution on the composition,and(iii)the e?ects of the dust-gas separation,and(iv)if the RV Tauri stars are the primary of a spectroscopic binary,a change of composition may have resulted from mass transferred from the companion.
The initial composition may be anticipated from abundances of elements thought to be essentially una?ected in the course of evolution as single or binary star and also by dust-gas separation.Here,S and Zn are deemed to qualify as such elements.Published abundance analyses of main sequence stars show that a star’s initial composition is generally predictable to within a small uncertainty from a determination of the abundance of one element–see Goswami&Prantzos(2000–their Figure7)for a graphical summary.We adopt S and Zn as the reference elements here,from which we predict initial abundances of other elements to high accuracy.
Although the prehistory of RV Tauri variables is unknown in detail,it may be assumed that they have experienced the?rst dredge-up which brings CN-cycled material into the atmosphere.This reduces the C abundance and increases the N abundance(Iben1967).If RV Tauri variables have evolved from the AGB on which they may have experienced thermal pulses and the third dredge-up,they are expected to be enriched in C and possibly also in the s-process elements(Busso,Gallino and Wasserburg1999).This last statement will require modi?cation if a star has accreted substantial amounts of gas from a companion directly or through transfer from a circumbinary disk.If the RV Tauri stars are the primary of a binary, a change of composition may have resulted from mass transferred from the companion.
When gas cools and dust grains form,the abundances of the elements in the gas phase are reduced below their initial abundances.Calculations of the equilibrium distribution of
an element between dust and gas have been reported by many authors and,most recently, by Lodders(2003;her Table1).Principal factors in?uencing the gas phase abundances are the temperature,pressure,and initial composition.
For elements providing major species of grains(e.g.,Al and corundum–Al2O3),one may de?ne a condensation temperature(here,T′C)at which the vapor pressure of the grain equals the partial pressure of the species in the gas.Below this condensation temperature, a species is highly underabundant in the gas.Other elements,particularly trace elements, are absorbed by major species of grains with a degree of absorption which may di?er from element to element for a given grain type.This has led to the concept of a‘50%condensation temperature’–the temperature at which50%of the trace element is in the gas and50%in grains.We adopt the50%condensation temperatures given by Lodders(2003)in her Table 8for gas of solar composition(Her Table1)at a total pressure of10?4bar.We denote the adopted temperatures by the symbol T C.For elements providing the major species of grains, the di?erence between T′C and the cooler T C is less than40K for all but two elements-Si and Ca-which we discuss below(Section4.1).
Our assumption is that the e?ects of dust-gas separation on a stellar composition will be revealed as a correlation between the underabundance of an element and that element’s condensation temperature.Obvious approximations may invalidate the assumption:grain formation around the RV Tauri stars may not occur under conditions of thermodynamic equi-librium;the pressures may di?er from one formation site to another;the initial composition may di?er,as must certainly be the case for the high velocity stars,from the assumed solar mix.Yet,the fact is that,in many cases,the underabundances are remarkably smoothly correlated with T C(and T′C).
In the following subsections,we present and discuss the compositions of the stars in Table1but leave comment on the C,N,and O abundances and heavy(Y to Eu)elements to subsequent sections.Six stars have a composition greatly a?ected by dust-gas separation (or another process):UY CMa,EQ Cas,HP Lyr,DY Ori,LR Sco,and BZ Sct.For the remainder of the sample,the signature of dust-gas separation is less distinct and may be absent.
3.1.UY Canis Majoris
Our abundance analysis(Table3)shows clearly that UY CMa is a victim of severe dust-gas separation.This is not unexpected because Preston et al.(1963)assigned it their spectroscopic class B,and our earlier analyses of Class B stars found them a?ected by dust-
gas separation.Elements of the highest T C(e.g.,Sc and Ti)are underabundant by a factor of about200.The de?ciencies[X/H]are very well correlated with condensation temperature T C(Figure2).2Judged by the abundances of Na,S,and Zn,elements of low condensation temperature,the initial metallicity corresponds to[Fe/H]??0.4.A possibly slightly higher metallicity is suggested by the O abundance with the implication that even Na,S,and Zn may be slightly depleted.The high radial velocity suggests that UY CMa belongs to the thick disk.We have not adjusted the[X/H]by the small amounts necessary to account for the fact that a thick disk star of[Fe/H]??0.4has a non-solar mix of elements,i.e.,[X/Y] =0(Reddy et al.2003).
3.2.RX Capricorni
Inspection of the abundances listed in Table4suggests that RX Cap is either a mod-erately metal-poor thick disk star or a rather metal-rich halo star,but possessing a normal composition una?ected by dust-gas separation.The inferred initial iron abundance is[Fe/H]?-0.7from consideration of S,Zn,Fe and Ni abundances.Within the possible errors and especially considering that some abundances are based on a single line,a majority of the relative abundances[X/Fe]are as expected.We note,for example,the positive[X/Fe]for theα-elements Mg,Si,S,and Ti,and the mild de?ciency of Mn.One detects a suggestion of dust-gas separation from the low Sc abundance:[Sc/Fe]=?0.4when[Sc/Fe]?0.0is expected,and just possibly,from Ca which is slightly underabundant relative to expectation for anα-element.
3.3.EQ Cassiopeiae
Three spectra of this variable were available.One was rejected because some lines showed distinct doubling and He i5875?A was in emission.The spectrum from1999,August 19was crowded with lines,but unblended lines found with the help of the Arcturus spectrum are symmetric.The atmosphere at this time was quite cool(T e?=4500K).A useful spectrum from2001,August19caught the star at a warmer phase(T e?=5300K).Although Hαwas in emission,unblended lines were symmetric and deemed suitable for an abundance analysis.
A radial velocity of?158±1km s?1was measured from the1999August and2001August spectra con?rming that the star is of high velocity.The two spectra provide similar results for the elemental abundances.Iron abundances from the two spectra are given in Table2.
In Table3,we list the abundances from the2001spectrum.Di?erences in[X/Fe]between the2001and1999spectra are in the range?0.20to+0.14with di?erences of less than±0.1 for nine of the15elements common to the two analyses.
There are what appear to be signatures of the dust-gas separation(Figure3)but the [X/H]versus T C relation is not as striking and simple as that for UY CMa.Preston et al.’s (1963)assignment of the class B?may re?ect a hint of the unusual composition di?erences between the star and RV B stars like UY CMa.The abundances[S/H]?[Zn/H]??0.4 point to an initial[Fe/H]of?0.5to?0.4.The gross underabundances of Ca and Sc([Ca/H] =?2.0and[Sc/H]=?3.1)point to dust-gas separation.Yet,among the RV Tauri variables analysed by us in this series of papers,EQ Cas is unique in showing additional anomalies. In particular,the Na abundance is remarkably low:[Na/Fe]=-0.9where all other RV Tauri variables,even those severely a?ected by dust-gas separation,show a positive[Na/Fe]. Furthermore,our estimate for[Na/Fe]may be an upper limit because the Na i lines are very weak.The other anomalies are the low values of[Cr/H],[Mn/H],and[Cu/H]and the high value of[Ti/H]relative to other elements of similar T C.These outstanding anomalies are shown by the two independent analyses of the star except that the Cu i lines were not observed in the1999spectrum.Rao&Reddy(2005)show that EQ Cas abundances are tightly correlated with an element’s?rst ionisation potential(FIP).This suggests that a mechanism other than dust-gas separation has a?ected the photospheric abundances.
3.4.DF Cygni
Two spectra were acquired but only one had symmetric unblended lines suitable for an abundance analysis(Table4).Line selection was made by reference to the spectrum of Arcturus,but given the crowded spectrum,some key elements(e.g.,Al and S)proved undetectable,and many others are represented by no more than one or two lines.The iron abundance is close to solar.Setting aside elements represented by just one line,the sole apparent anomaly is Sc([Sc/H]=[Sc/Fe]=-1.0not0.0).The Sc underabundance is suggestive of the onset of dust-gas separation but,as for other stars in Table4,Sc(and Ca, in some stars)is the only indicator of this e?ect.This isolation of Sc leads one to wonder about other possible explanations,e.g.,non-LTE e?ects.
3.5.HP Lyr
This star came to our attention through Graczyk et al.’s(2002)report of it as‘possibly the hottest RV Tau type object’.These authors estimated the e?ective temperature to be about7700K.Our spectrum corresponds to T e?=6300K.The radial velocity of-107km s?1indicates that HP Lyr is a high-velocity star.The intrinsic metallicity of the star as assessed from S,Zn,and Na is slightly sub-solar([Fe/H]??0.2).We suppose that HP Lyr may belong to the thick disk.The abundances(Table3and Figure4)show the signature of dust-gas separation.The correlation between[X/H]and T C is tight with almost no scatter in excess of that attributable to the observational errors in[X/H].
3.6.TX Ophiuchi
Most elements(Table4)have the abundance expected of a normal star with[Fe/H]=?1.2,the measured iron abundance.This metallicity and the high radial velocity suggest that the star belongs to the Galactic thick disk.One notes the normal[Na/Fe]and[Zn/Fe] but observes that Ca,Sc,and Ti,elements of high condensation temperature,are apparently underabundant with[Ca/Fe],[Sc/Fe],and[Ti/Fe]by about0.5,0.6,and0.3dex,respectively, below the expected initial value for a thick disk star of[Fe/H]=?1.2.Aluminum,also of high condensation temperature,however,has its expected initial abundance.
A comparison with RX Cap reveals that the abundances scale with the di?erence in [Fe/H]of0.4dex between the two stars.The mean di?erence in[X/H]in the sense TX Oph minus RX Cap is0.5dex from20elements with an element-to-element scatter consistent with the measurement errors.This consistency extends to Ca,Ti,and Sc.
3.7.UZ Ophiuchi
Two spectra are suitable for an abundance analysis.The spectrum from the2.7m telescope taken on2002,June30is our primary source.An earlier spectrum from2001, July13taken on the2.1m with the Sandiford Cassegrain echelle(McCarthy et al.1995) provided coverage of the interval4500?A to5200?A.Since most of the elements were covered in2002spectrum and abundances derived at two epochs are in good agreement,we chose to use only2002estimates.The radial velocities of?95.1±0.9km s?1in2001July and ?90.2±0.8km s?1in2002June suggest membership of the Galactic thick disk for UZ Oph. Abundances are given in Table4.
The composition resembles that of RX Cap,a star of similar metallicity and which we described as essentially possessing its initial composition.Relative to RX Cap,the mean abundance di?erence between UZ Oph and RX Cap is?[X/H]=?0.15from13elements from Na to Zn with no element having a?outside the errors of measurement.The six heavy elements Y,La,Ba,Ce,Nd,Sm and Eu do provide a signi?cantly di?erent result:?=?0.63:UZ Oph is relatively underabundant in Y to Sm but not in Eu relative to RX Cap and the expected initial composition.
3.8.DY Orionis
DY Orionis was analysed in Paper II.Our reanalysis uses a new spectrum providing greater wavelength coverage which enabled us to cover more elements relative to the earlier study.Our new results are in good agreement with the earlier results.The star,as noted in Paper II,is severely a?ected by dust-gas separation(Table3and Figure5).Particularly striking is the sharp onset of depletion for elements with T C above1100K:Na is barely depleted with[Na/Fe]of?0.3but Si,Mn and Cr have[X/H]??1.9.
3.9.AI Scorpii
The abundance analysis(Table4)implies that AI Sco’s composition is that expected of a star with the measured[Fe/H]=-0.7.The apparent anomalies are a mild overabundance of Na and S and an underabundance of Ca,Sc,and Ti.Relative to RX Cap,Na to Zn are slightly overabundant:?=+0.13from13elements.The heavy elements–Y to Nd –are underabundant:?=-0.13from?ve elements.Europium has a normal abundance. These small di?erences between AI Sco and RX Cap could be attributed to the inevitable observational errors.
3.10.LR Scorpii
This star was analysed previously(Giridhar,Rao,&Lambert1992)and discussed as a victim of dust-gas separation in Paper V.Our new analysis is summarized in Table3.Maas (2003)has presented an abundance analysis based on spectra obtained in2000and2001 when the spectroscopically estimated parameters(T e?,log g)were(6250,0.5)and(5250, 0.0),respectively.His abundances agree well with ours,especially for[X/Fe].
Elements with T C 1400K suggest an initial iron abundance[Fe/H]=?0.2which
with the low radial velocity indicates that LR Sco is a member of the Galactic thin disk. Our abundance analysis(Table3and Figure6)shows that elements with a condensation temperature higher than1600K are clearly underabundant for which[X/H]??0.2for all elements is expected.
Our abundances[X/H]are generally in good agreement with the1992results obtained from a1989spectrum but for Al,Sc,Ti,and Y our results di?er from the1992values by ?0.4,?0.4,?0.7,and?1.5dex,respectively.We note that the quartet are the elements with T C of about1600K.May one ascribe the di?erences between our present and previous results to a growth of the depletion of the highest T C elements abundance?According to Lodders&Fegley,the initial condensates of the?ve elements are Al2O3,CaAl12O19,Sc2O3, CaTiO3,and Y2O3.This mix precludes a substantial depletion of Ca.Calcium with T C= 1505K gave the same result([Ca/H]=?0.5)from the1989and2002spectra.Maas(2003) abundances may be consistent with the suspected lowering of the abundances of Al,Sc,Ti and Y between1989and2002,but a uniform analysis of all available spectra is desirable. Observations of LR Sco should be continued.
3.11.AR Sagittarii
The abundance analysis is summarized in Table4.This high-velocity star shows no convincing evidence for a dust-gas separation.The initial metallicity is identi?ed as[Fe/H]??1.2.Relative to TX Oph,a star of the same measured[Fe/H],the mean?is0.0from 14elements from Na to Zn,and?0.12from seven elements from Ba to Eu.In short,AR Sgr and TX Oph are of essentially identical normal composition.
3.12.AZ Sagittarii
The star was in a cool phase at the time of observation and the spectrum is crowded with lines.The abundance analysis(Table4)is based on few lines.The available spectrum did not go shortward of about4900?A and,therefore,the blue and useful Zn i lines were not recorded.Our spectrum gives the radial velocity as?110km s?1.This velocity identi?es AZ Sgr as a high-velocity star.
Judged with respect to a normal star of the measured[Fe/H]=?1.6,AZ Sgr’s anomalies are a high S abundance and a low Cr abundance:[S/H]is too high by about0.8dex and [Cr/H]is too low by about0.8dex.The S abundance is based on weak lines and is sensitive to the adopted e?ective temperature.The Cr abundance appears to be securely based as it
is derived using?ve neutral Cr lines of moderate strengths.Relative to TX Oph and AR Sgr,stars with a slightly higher measured[Fe/H],the S overabundance is less marked,but the Cr underabundance remains distinctive.Pending acquisition and analysis of additional spectra of AZ Sqr,preferably at a warmer phase,we adopt the conclusion that this star is a metal-poor high-velocity star una?ected by dust-gas separation.The Cr underabundance is unexplained.
3.13.BZ Scuti
This star’s composition(Table3and Figure7)shows evidence of dust-gas separation. Sodium,S,and Zn abundances show that BZ Sct’s initial metallicity was close to solar. These abundances are based on unblended lines in the spectrum of this warm RV Tauri star.Elements with a condensation temperature higher than about1200K are depleted by a factor of about eight with an element-to-element scatter comparable to the errors of measurement.There is a hint that elements with T C greater than1600K are more severely depleted.The extreme depletion of La is based on a single line.
3.1
4.V Vulpeculae
This star is clearly C-rich.The carbon enrichment derived from C i lines is also signaled by the presence of C2Swan bands.Apart from carbon and possibly sulfur,the composition of V Vul resembles closely that of the other mildly Fe-poor stars in Table4.The mean?, for example,relative to RX Cap is+0.40for11elements from Na to Zn,and+0.27for4 elements from Y to Eu,where the[Fe/H]di?erence is+0.4also.
4.The compositions of RV Tauri stars
4.1.Abundance Anomalies and Condensation Temperatures
In recent papers on RV Tauri compositions,abundance versus condensation temperature plots have been constructed with values of T C taken from Lodders&Fegley(1998)which are also50%condensation temperatures.Here,we adopt T C from Lodders(2003)(see Section 3).The e?ect of a substitution of the2003for the1998estimates of T C is in most cases a reduction in the scatter of[X/H]about the mean trend with T C for those stars obviously a?ected by the dust-gas separation.In our present sample,this is certainly the case for UY
CMa,HP Lyr,DY Ori,and LR Sco.The elements for which replacement of the1998by the 2003T C estimates reduces their status as outliers in the[X/H]versus T C plot are notably Si,and Ba.In the case of Si,T C is lowered to1302K from1529K in1998.The T C for Ba is raised from1162K in1998to1447K in2003.For other elements measured by us the change in T C from the1998and2003estimates di?ers by less than about50K,except for Ca and Cu for which the2003values are lower by130–140K,too small of a change to a?ect the appearance of a[X/H]versus T C correlation.
It is useful to look behind the T C estimates at the highest temperature condensates expected in equilibrium for solar composition gas.For this exercise,Lodders(2003)provides the details.Our discussion considers the development of condensates as gas is cooled in equilibrium.As long as equilibrium is maintained,the discussion is readily reworded to consider the dissolution of condensates as the gas-dust mixture is heated.
Inspection of Figures2,4,6,and7show that the four most depleted elements are Al,Sc, Ti,and Y with very similar T C(?1640K).The initial condensates are Al2O3and CaTiO3 leading at a slightly lower temperature to the major condensates CaAl12O19(hibonite)and CaTi3O10,Ca3Ti2O7,and Ca4Ti3O10(three forms of calcium titanate).Calcium titanate may severely deplete gas of Ti but not Ca;the initial Ca/Ti ratio is about20.Similarly, if hibonite scours Al from the gas,little Ca is removed and the initial ratio Ca/Al?1is increased to Ca/Al?10.Sc and Y are depleted as Sc2O3and Y2O3dissolve in hibonite.
Calcium and Ba are lost to grains at a slightly lower T C.The minor loss of Ca from the gas to hibonite is enhanced by the condensation of Ca2Al2SiO7(gehlenite)leading to Ca/Al ～1in the gas with both Ca and Al depleted for T C?1500K.Barium is removed from the gas when BaTiO3dissolves in calcium titanate.In the1998calculations,Ba was identi?ed as dissolving in CaTiO3(perovskite),but in the2003calculations it was considered to dissolve into forms of calcium titanate.It is interesting that although the mode of transfer of Ca and Ba to condensates di?ers their depletion[X/H]in the gas is generally quite similar for stars severely a?ected by dust-gas separation.(Rare earths—La to Eu in our analyses–dissolve in hibonite and titanate.)
Descending the T C scale,we encounter Mg and Si.Magnesium is removed from the gas primarily through Mg2SiO4(forsterite)with MgAl2O4(spinel)also contributing.If this were the sole way to remove Mg and Si from the gas,the Si/Mg ratio in the gas would swing from Si/Mg?1to?2.The T C for Si listed by Lodders&Fegley(1998)is the temperature at which gehlenite(Ca2Al2SiO7)forms but,because Ca and Al are at least an order of magnitude less abundant than Si,this condensate removes very little silicon from the gas.At a slightly lower temperature,MgSiO3(enstatite)condenses and then one expects Si/Mg～1and similar depletions of Mg and Si.The T C taken from Lodders(2003)refers
to condensation of enstatite.
4.2.Depletion patterns
The stars in this and earlier papers of our series exhibiting dust-gas separation seem to form a family with a single outcast.The main characteristic of the family is an ordering of depletions[X/H]by the condensation temperature T C.In our present sample,the extremes are marked by LR Sco and the pair HP Lyr and DY Ori.LR Sco would be deemed to have a normal composition but for depletions([X/H]～?1)of Al,Sc,Ti,and Y,the elements of the highest T C.At the other extreme,all elements with T C≥1200K show a depletion increasing with T C and attaining a level[X/H]～?3at the highest T C.This is not a single parameter family:see,for example,the di?erences in[X/H]between the extremes HP Lyr and DY Ori.
BZ Sct appears not to show the family’s smooth run of[X/H]with T C,but the several outliers(Cu,K,Sm,and La)in Figure7are based on a single line.If this is deemed a possible reason for the scatter,one is left with just Mn as showing a slightly discrepant[X/H].R Scuti was considered quite anomalous by Luck(1981)but,in Paper V,we showed that the underabundant elements,including the heavy elements analysed by Luck,were among those with the highest T C.With due allowance for errors in the abundance determinations, di?erences in initial abundances as a function of metallicity and population class(i.e.,thick versus thin disk),and small familial di?erences,all analysed stars but one may be said to belong to the same family bounded by LR Sco and HP Lyr-DY Ori3.
The sole non-member of the family is EQ Cas where the upper envelope to the run of [X/H]with T C resembles the pattern shown by HP Lyr,but several elements fall well below this envelope:notably,Na,Mn,and Cr.Rao&Reddy(2005)show that the[X/H]for EQ Cas are well correlated an elements’s FIP(see below).
4.3.Interstellar Depletions
The abundances for stars a?ected by dust-gas separation correlate quite well with those for the cool interstellar gas towardsζOph(Savage&Sembach1996)(Figure8).Depletions
of elements in interstellar gas are attributed to incorporation of the depleted element into and onto grains.The grains may have formed primarily in denser regions of interstellar clouds, but,as the detection and analysis of grains in meteorites demonstrates,some grains were formed in out?ows of red giants,stellar ejecta:supernovae and novae shells for example. Grain formation and depletion of atoms in the gas in the interstellar medium cannot be expected to mimic very closely the convolution of grain formation,depletion of gas in the dusty reservoir,separation of gas from dust,accretion of the gas,and mixing of the gas with the stellar atmosphere.Despite these caveats,the close correspondence between the a?ected RV Tauri stars and the interstellar gas is suggestive of a similarity between the physical processes involved.The di?erences between the stellar and interstellar depletions may be clues to the physical processes at work.
4.4.The Initial Fe Abundances
On the assumption that S and Zn are una?ected by dust-gas depletion,their abundances may be taken to be a star’s initial abundances,and,hence,used to provide estimates of the initial abundance of Fe and other elements.Sulfur and Zn are the sampled elements with the lowest T C which are considered to be una?ected by internal nucleosynthesis and mixing. The run of S and Zn abundances with Fe/H is known for unevolved stars(Mishenina et al.2002;Nissen et al.2004;Prochaska et al.2000;Ryde&Lambert2004).We are here interested in the abundances of thin and thick disk stars for which di?erences in[S/Fe]and [Zn/Fe]at a given[Fe/H]are small,say,about0.1dex with the larger values found for the thick disk stars.In successive?gures we show[Zn/Fe]and[S/Fe]versus[Fe/H](Figure9& 10),and[S/Zn]versus[Zn/H](Figure11).Stars with a radial velocity of greater than100 km s?1are termed‘high velocity’and shown by?lled symbols in the?gures.
In Figure9,we show[Zn/Fe]versus[Fe/H]for all of the RV Tauri variables considered in this and previous papers in this series.Results for additional RV Tauri variables are taken from Maas et al.(2002)for RU Cen and SX Cen,and Maas(2003)for IRAS09538-7622,16230-3410,17038-4815,and17233-4330.We have added a point for QY Sge(Rao, Goswami,&Lambert2002)which,on circumstantial evidence,was described as a dust-obscured RV Tauri variable.We elected not to add other post-AGB stars discussed by Maas (2003).Although,these omissions are spectroscopic binaries and some show e?ects of dust-gas separation,available photometry does not show RV Tauri-like light variations.The run of[Zn/Fe]for unevolved stars corresponds to[Zn/Fe]?0for the range of[Fe/H]covered in Figure9.Thick disk stars may have[Zn/Fe]?+0.1.
The limit[Zn/Fe]?0.0represents the lower boundary to the distribution of the observed
points.(The star with a distinctly negative value of[Zn/Fe]is DF Cyg with a crowded spectrum and an uncertain Zn abundance.)Stars along the lower boundary are those with an abundance pattern indicating little or no dust-gas separation.Several but not all high-velocity stars are near the boundary.The upper boundary to the data points follows the dashed line.This corresponds to approximately[Zn/Fe]=?[Fe/H]i.e.,the trajectory of a star with an initial abundance[Fe/H]=0and then depleted in Fe to varying degrees but with Zn undepleted.On the assumptions that Fe but not Zn is depleted and that initially [Zn/Fe]=0,the observed Zn abundance provides the star’s initial Fe abundance[Fe/H]0. By inspection,we see from Figure9that the[Fe/H]0runs from about+0.1to?1.4.This is shown by horizontal dotted line corresponding to[Zn/Fe]～0.It is shown by the?gure that the dust-gas separation is not an either-or e?ect.
The run of[S/Fe]versus[Fe/H](Figure10)resembles that in Figure9but with di?er-ences concerning the upper and lower boundaries.The lower boundary to the distribution of points runs systematically about0.2dex above the run of[S/Fe]with[Fe/H]for unevolved stars taken from Nissen et al.(2004).This o?set is possibly attributable to systematic errors in one or both analyses.The dashed line corresponds to[S/Fe]=[Fe/H].Several stars fall above this line.On the assumption that the S abundance is una?ected by dust-gas separation,the upper boundary in Figure10implies that the initial iron abundance for some stars is about[Fe/H]0=+0.4,which seems implausible.A possible alternative explanation is that the S abundances for the RV Tauri stars are overestimated by about0.2to0.4dex. These di?erences between Figures9and10necessarily make an appearance in Figure11 which shows that the[S/Zn]of the RV Tauri stars fall generally above the expected trend for unevolved stars taken from Nissen et al.
In summary,we suggest that the initial[Fe/H]of the RV Tauri and related stars is obtainable from their measured Zn abundance and the assumption that[Zn/Fe]=0for normal stars.
4.5.Carbon and Oxygen Abundances
Main sequence stars in evolving to red giants develop a deep convective envelope which brings CN-cycled products to the surface and,thus,reduces the surface C abundance and increases the surface N abundance(Iben1967).Oxygen is expected to be very little a?ected. The reduction in the C abundance is0.2to0.3dex(Lambert&Ries1981).After completion of He-core burning,material from the He-burning shell is dredged to the surface to increase the surface C abundance and also the O abundance.A star at this stage is known as an asymptotic giant branch(AGB)star.The He-burning shell may experience ignition of a
neutron source and synthesis of heavy elements by the the neutron-capture s-process.By examining the C,N,O,and heavy element(e.g.,Y and Ba)abundances of the RV Tauri stars and taking due note of the initial abundances and the possible depletion of the surface abundances of these elements,one hopes to specify the evolutionary state of the RV Tauri variables.
In the following discussion,[Zn/H]replaces[Fe/H]as the representative of a star’s initial composition.The initial C and O abundances as a function of Zn abundance are taken from measurements of unevolved stars(Nissen et al.2004;Akerman et al.2004).We adopt the LTE abundances given by Akerman et al.(2004).Their tabulated NLTE abundances for oxygen are about0.1to0.2dex smaller than the LTE values.Non-LTE abundances were not given for carbon.We assume that the?rst dredge-up experienced by a red giant reduced the initial C abundance by0.25dex,but left the initial O abundance undisturbed.
The observed C abundances(Figure12)lie above the predictions for a red giant by about0.4dex with a real star-to-star scatter.Carbon enrichment is suggested.However a similar displacement of observed from initial abundances occurs for[S/Zn].Since both the C and the S abundances are based on high-excitation atomic lines,the displacements may arise from similar systematic errors.The observed O abundances(Figure12)follow quite closely the trend of the initial abundances with[Zn/H].The observed C/O abundance ratios versus[Zn/H]are shown in Figure12.The lower boundary to the observed ratios follows the predicted trend for?rst dredge-up red giants.These may be stars which su?ered a reduction of surface C in becoming a red giant but did not later experience replenishment of C.Stars with the highest C/O ratio at a?xed[Zn/H]fall about0.5dex above the predicted trend. This spread probably represents a real star-to-star spread in C/O.Very few stars are C-rich, i.e.,log C/O≥0.
In summary,the RV Tauri variables have su?ered di?ering degrees of surface enrichment of carbon.Some stars,especially stars of high-velocity,have the C/O ratio anticipated for fresh red giants,i.e.,no obvious C enrichment occurred following the?rst dredge-up.Other stars have a C/O ratio indicating up to a factor of10enrichment over the ratio of a fresh giant.Few stars are carbon rich.There is no clear distinction in Figure12between the stars greatly a?ected by dust-gas separation and those una?ected.
4.6.The s-process Abundances
Mature AGB stars are carbon-rich(C/O>1)with enrichments of s-process products. Cool carbon stars on the AGB are s-process enriched by up to one dex(Abia et al.2002).
Post-AGB carbon-rich stars are similarly enriched(Reddy et al.2002;Van Winckel2003).
In the case of the RV Tauri stars una?ected by dust-gas separation,s-process abundances are directly obtainable from the measured abundances with respect to the iron abundance. No obvious enrichments are detected.For stars a?ected by dust-gas separation,the degree of s-process enrichment must be judged relative to the abundances of other elements of a similarly high T C.Inspection of Figures2through7shows that there is no detectable overabundance of s-process elements.This is true for all other RV Tauri variables from our series of papers and those analysed by Maas and colleagues.Our earlier suggestion that Ba may be overabundant in AR Pup and DS Aqr deserves reexamination.Barium,the only s-process element examined in AR Pup,was represented by a single strong line(Paper II).A similar situation applies to DS Aqr from Paper IV.New spectra of broad wavelength coverage should be obtained and analysed before DS Aqr and AR Pup are tagged as‘s-process enriched’.
In summary,the RV Tauri variables are unlikely to be descendants of luminous AGB stars in which s-process products from the He-burning shell have been dredged to the stellar surface.
4.7.Boundary Conditions for Dust-gas Separation
Dust-gas separation is not ubiquitous among RV Tauri stars.Inspection of the stars una?ected by the separation shows that their temperature and metallicity domains are both well bounded.These bounds are surely clues to the site of the dust-gas separation and the process by which a star of anomalous surface composition is created.
Our sample of RV Tauri variables show a low and high temperature boundary to the stars of anomalous composition.Stars of all metallicities with T e?≈5000K and cooler are una?ected by dust-gas separation.4This is shown by Figure13.Our T e?estimates are spectroscopic determinations from spectra at phases showing well de?ned symmetric absorption lines.The spectroscopic T e?may di?er with phases(at which spectroscopic analysis is pursued)for a given star;for example our three spectra of SS Gem gave T e?estimates of4750K,5500K and6500K(Paper III).E?ects of dust-gas separation are seen to the high temperature end of the RV Tauri sample.This boundary is presumably set by the blue edge of the instability strip.Depletion is seen in hotter stars(Van Winckel2003),
notably the extremely metal-poor star HR4049with T e?=7600K and with an observed iron abundance[Fe/H]??4.8.The oxygen abundance suggests an initial[Fe/H]near-0.5 for HR4049.
In paper V,we suggested that the coolest stars were una?ected because the convec-tive envelope was of su?cient mass to dilute accreted gas even were it cleansed of dust. Frankowski(2003)discusses the mass of the convective envelope(M CE)of post-AGB stars by drawing on published numerical calculations.It is clear that M CE increases with decreas-ing e?ective temperature:for example,M CE at4000K,5000K,and6000K is0.016M⊙, 0.002M⊙,and0.001M⊙,respectively.The M CE at6000K is some1000times the mass of the observable photosphere.Abundance de?ciencies for the high T C elements for stars on the hot side of the boundary may approach a thousandfold,and,in such cases,the surface and convective envelope must be composed of almost undiluted accreted gas.Although the increase of M CE to lower temperatures may play a role in suppressing the abundance anoma-lies,it hardly seems to o?er the full explanation.Perhaps,cooler variables have stronger winds which impede accretion of gas from a circumbinary disk.
The dust-gas separation appears suppressed among stars of a low initial metallicity.Our sample of RV Tauri stars suggests that the limiting initial metallicity is[Fe/H]≈?1.More metal-rich stars are a?ected,but less metal-rich stars do not show the abundance anomalies resulting from dust-gas separation,even if they are hotter than the above T e?boundary.For stars with[Fe/H] ?1,there is no strong evidence that the dust-gas separation e?ciency is sensitive to the initial metallicity.
In several examples,an a?ected RV Tauri star currently has a metallicity well below the limit[Fe/H]of?1for occurrence of a dust-gas separation.This is especially true for hotter stars like HR4049.Our inference from these observations is that it is the initial and not the current metallicity that is the key factor in establishing dust-gas separation.Hence, the dust-gas reservoir is a region with a metallicity in excess of[Fe/H]of-1.In a reservoir of low metallicity separation of dust and gas is inhibited and then if material is accreted from the reservoir by the star,the surface composition is unchanged.
There is a third boundary condition that may exist:e?ective dust-gas separation and accretion of gas but not dust by a star occurs e?ciently only in a binary system.This is spectacularly the case for the small sample of hot post-AGB stars like HR4049for which radial velocity monitoring has shown them to be single-lined spectroscopic binaries(Van Winckel et al.1995).For the RV Tauri variables,detection of orbital variations in the face of pulsational variations is a complexity calling for long campaigns of radial velocity monitoring. Nonetheless,the number of RV Tauri variables known to be spectroscopic binaries is growing as can be seen from Mass(2003).Van Winckel et al.(1998)have adduced indirect evidence
in support of the idea that RV Tauri variables are binaries with a circumbinary disk.
Finally,there is the caution suggested by Rao&Reddy(2005)from their consideration of the compositions of EQ Cas and CE Vir that showed that dust-gas separation may not always be the dominant factor behind abundance anomalies.We have mentioned the special abundance anomalies of EQ Cas in Section3.3.We remarked upon the lack of the usual correlation between[X/H]and T C.Rao&Reddy?nd that our[X/H]for EQ Cas are anti-correlated with?rst ionisation potential,FIP of the elements.These authors suggest that the stellar wind preferentially picks up ions over neutral atoms.At the top of the stellar atmosphere,low FIP elements will be present as the ions X+but atoms of the high FIP elements will remain neutral.The FIP-e?ect is a minor contributor to the stars for which anomalies exhibit a strong T C correlation(Paper IV).
5.Concluding Remarks
Conversion of the boundary conditions into an understanding of how RV Tauri stars with and without abundance anomalies arise remains elusive.Two contrasting scenarios were sketched in Paper V:the stars with anomalous abundances are(1)single stars with dust-gas separation occurring in the stellar wind(the S hypothesis),and/or(2)binary stars with dust-gas separation occurring in a circumbinary disk(the B hypothesis).The boundary condition on T e?is met by both hypotheses,if the deeper convective envelope for cooler stars acts to dilute the accreted gas.The boundary condition on initial metallicity seems more readily met by the B hypothesis;the circumbinary disk is comprised of gas ejected by either the RV Tauri’s companion and/or the RV Tauri star before the onset of accretion and alteration of the photospheric abundances.Indeed,mass loss induced by a companion may provide not only the circumbinary gaseous disk but also shifts the primary star o?the giant branch and into the instability strip.This boundary condition is not easily satis?ed for all stars by the S hypothesis;some RV Tauri stars have metal abundances less than the boundary[Fe/H]??1.
The B hypothesis provides a natural link between the RV Tauri stars and the A-type extremely metal-de?cient stars like HR4049which are known to be spectroscopic binaries. Binary RV Tauri stars are known.A determined campaign of radial velocity measurements for RV Tauri stars,especially those displaying anomalous abundances,is needed to establish the frequency of binaries.It should be noted too that the sample of HR4049-like stars is presently very small.A search for additional examples and a demonstration that they are (or are not!)spectroscopic binaries would also be valuable.
如何写先进个人事迹 篇一：如何写先进事迹材料 如何写先进事迹材料 一般有两种情况：一是先进个人，如先进工作者、优秀党员、劳动模范等；一是先进集体或先进单位，如先进党支部、先进车间或科室，抗洪抢险先进集体等。无论是先进个人还是先进集体，他们的先进事迹，内容各不相同，因此要整理材料，不可能固定一个模式。一般来说，可大体从以下方面进行整理。 (1)要拟定恰当的标题。先进事迹材料的标题，有两部分内容必不可少，一是要写明先进个人姓名和先进集体的名称，使人一眼便看出是哪个人或哪个集体、哪个单位的先进事迹。二是要概括标明先进事迹的主要内容或材料的用途。例如《王鬃同志端正党风的先进事迹》、《关于评选张鬃同志为全国新长征突击手的材料》、《关于评选鬃处党支部为省直机关先进党支部的材料》等。 (2)正文。正文的开头，要写明先进个人的简要情况，包括：姓名、性别、年龄、工作单位、职务、是否党团员等。此外，还要写明有关单位准备授予他(她)什么荣誉称号，或给予哪种形式的奖励。对先进集体、先进单位，要根据其先进事迹的主要内容，寥寥数语即应写明，不须用更多的文字。 然后，要写先进人物或先进集体的主要事迹。这部分内容是全篇材料
的主体，要下功夫写好，关键是要写得既具体，又不繁琐；既概括，又不抽象；既生动形象，又很实在。总之，就是要写得很有说服力，让人一看便可得出够得上先进的结论。比如，写一位端正党风先进人物的事迹材料，就应当着重写这位同志在发扬党的优良传统和作风方面都有哪些突出的先进事迹，在同不正之风作斗争中有哪些突出的表现。又如，写一位搞改革的先进人物的事迹材料，就应当着力写这位同志是从哪些方面进行改革的，已经取得了哪些突出的成果，特别是改革前后的．经济效益或社会效益都有了哪些明显的变化。在写这些先进事迹时，无论是先进个人还是先进集体的，都应选取那些具有代表性的具体事实来说明。必要时还可运用一些数字，以增强先进事迹材料的说服力。 为了使先进事迹的内容眉目清晰、更加条理化，在文字表述上还可分成若干自然段来写，特别是对那些涉及较多方面的先进事迹材料，采取这种写法尤为必要。如果将各方面内容材料都混在一起，是不易写明的。在分段写时，最好在每段之前根据内容标出小标题，或以明确的观点加以概括，使标题或观点与内容浑然一体。 最后，是先进事迹材料的署名。一般说，整理先进个人和先进集体的材料，都是以本级组织或上级组织的名义；是代表组织意见的。因此，材料整理完后，应经有关领导同志审定，以相应一级组织正式署名上报。这类材料不宜以个人名义署名。 写作典型经验材料-般包括以下几部分： (1)标题。有多种写法，通常是把典型经验高度集中地概括出来，一
小学生个人读书事迹简介怎么写800字 书,是人类进步的阶梯,苏联作家高尔基的一句话道出了书的重要。书可谓是众多名人的“宠儿”。历来,名人说出关于书的名言数不胜数。今天小编在这给大家整理了小学生个人读书事迹,接下来随着小编一起来看看吧! 小学生个人读书事迹1 “万般皆下品,惟有读书高”、“书中自有颜如玉,书中自有黄金屋”,古往今来,读书的好处为人们所重视,有人“学而优则仕”,有人“满腹经纶”走上“传道授业解惑也”的道路……但是,从长远的角度看,笔者认为读书的好处在于增加了我们做事的成功率,改善了生活的质量。 三国时期的大将吕蒙,行伍出身,不重视文化的学习,行文时,常常要他人捉刀。经过主君孙权的劝导,吕蒙懂得了读书的重要性,从此手不释卷,成为了一代儒将,连东吴的智囊鲁肃都对他“刮目相待”。后来的事实证明,荆州之战的胜利,擒获“武圣”关羽,离不开吕蒙的“运筹帷幄,决胜千里”,而他的韬略离不开平时的读书。由此可见,一个人行事的成功率高低,与他的对读书,对知识的重视程度是密切相关的。 的物理学家牛顿曾近说过,“如果我比别人看得更远,那是因为我站在巨人的肩上”,鲜花和掌声面前,一代伟人没有迷失方向,自始至终对读书保持着热枕。牛顿的话语告诉我们,渊博的知识能让我们站在更高、更理性的角度来看问题,从而少犯错误,少走弯路。
读书的好处是显而易见的,但是,在社会发展日新月异的今天,依然不乏对读书,对知识缺乏认知的人,《今日说法》中我们反复看到农民工没有和用人单位签订劳动合同,最终讨薪无果;屠户不知道往牛肉里掺“巴西疯牛肉”是犯法的;某父母坚持“棍棒底下出孝子”,结果伤害了孩子的身心,也将自己送进了班房……对书本,对知识的零解读让他们付出了惨痛的代价,当他们奔波在讨薪的路上,当他们面对高墙电网时,幸福,从何谈起?高质量的生活,从何谈起? 读书,让我们体会到“锄禾日当午,汗滴禾下土”的艰辛;读书,让我们感知到“四海无闲田,农夫犹饿死”的无奈;读书,让我们感悟到“为报倾城随太守,西北望射天狼”的豪情壮志。 读书的好处在于提高了生活的质量,它填补了我们人生中的空白,让我们不至于在大好的年华里无所事事,从书本中,我们学会提炼出有用的信息,汲取成长所需的营养。所以,我们要认真读书,充分认识到读书对改善生活的重要意义,只有这样,才是一种负责任的生活态度。 小学生个人读书事迹2 所谓读一本好书就是交一个良师益友,但我认为读一本好书就是一次大冒险,大探究。一次体会书的过程,真的很有意思,咯咯的笑声,总是从书香里散发;沉思的目光也总是从书本里透露。是书给了我启示,是书填补了我无聊的夜空,也是书带我遨游整个古今中外。所以人活着就不能没有书,只要爱书你就是一个爱生活的人,只要爱书你就是一个大写的人,只要爱书你就是一个懂得珍惜与否的人。可真所谓
个人先进事迹简介 01 在思想政治方面,xxxx同学积极向上,热爱祖国、热爱中国共产党,拥护中国共产党的领导.利用课余时间和党课机会认真学习政治理论,积极向党组织靠拢. 在学习上,xxxx同学认为只有把学习成绩确实提高才能为将来的实践打下扎实的基础,成为社会有用人才.学习努力、成绩优良. 在生活中,善于与人沟通,乐观向上,乐于助人.有健全的人格意识和良好的心理素质和从容、坦诚、乐观、快乐的生活态度,乐于帮助身边的同学,受到师生的好评. 02 xxx同学认真学习政治理论,积极上进,在校期间获得原院级三好生,和校级三好生,优秀团员称号,并获得三等奖学金. 在学习上遇到不理解的地方也常常向老师请教,还勇于向老师提出质疑.在完成自己学业的同时,能主动帮助其他同学解决学习上的难题,和其他同学共同探讨,共同进步. 在社会实践方面,xxxx同学参与了中国儿童文学精品“悦”读书系,插画绘制工作,xxxx同学在班中担任宣传委员,工作积极主动,认真负责,有较强的组织能力.能够在老师、班主任的指导下独立完成学院、班级布置的各项工作. 03 xxx同学在政治思想方面积极进取,严格要求自己.在学习方面刻苦努力,不断钻研,学习成绩优异,连续两年荣获国家励志奖学金；作
为一名学生干部,她总是充满激情的迎接并完成各项工作,荣获优秀团干部称号.在社会实践和志愿者活动中起到模范带头作用. 04 xxxx同学在思想方面,积极要求进步,为人诚实,尊敬师长.严格 要求自己.在大一期间就积极参加了党课初、高级班的学习,拥护中国共产党的领导,并积极向党组织靠拢. 在工作上,作为班中的学习委员,对待工作兢兢业业、尽职尽责 的完成班集体的各项工作任务.并在班级和系里能够起骨干带头作用.热心为同学服务,工作责任心强. 在学习上,学习目的明确、态度端正、刻苦努力,连续两学年在 班级的综合测评排名中获得第1.并荣获院级二等奖学金、三好生、优秀班干部、优秀团员等奖项. 在社会实践方面,积极参加学校和班级组织的各项政治活动,并 在志愿者活动中起到模范带头作用.积极锻炼身体.能够处理好学习与工作的关系,乐于助人,团结班中每一位同学,谦虚好学,受到师生的好评. 05 在思想方面,xxxx同学积极向上,热爱祖国、热爱中国共产党,拥护中国共产党的领导.作为一名共产党员时刻起到积极的带头作用,利用课余时间和党课机会认真学习政治理论. 在工作上,作为班中的团支部书记,xxxx同学积极策划组织各类 团活动,具有良好的组织能力. 在学习上,xxxx同学学习努力、成绩优良、并热心帮助在学习上有困难的同学,连续两年获得二等奖学金. 在生活中,善于与人沟通,乐观向上,乐于助人.有健全的人格意 识和良好的心理素质.
优秀党务工作者事迹简介范文 优秀党务工作者事迹简介范文 ***，男，198*年**月出生，200*年加入党组织，现为***支部书记。从事党务工作以来，兢兢业业、恪尽职守、辛勤工作，出色地完成了各项任务，在思想上、政治上同党中央保持高度一致，在业务上不断进取，团结同事，在工作岗位上取得了一定成绩。 一、严于律己，勤于学习 作为一名党务工作者，平时十分注重知识的更新，不断加强党的理论知识的学习，坚持把学习摆在重要位置，学习领会和及时掌握党和国家的路线、方针、政策，特别是党的十九大精神，注重政治理论水平的提高，具有坚定的理论信念;坚持党的基本路线，坚决执行党的各项方针政策，自觉履行党员义务，正确行使党员权利。平时注重加强业务和管理知识的学习，并运用到工作中去，不断提升自身工作能力，具有开拓创新精神，在思想上、政治上和行动上时刻同党中央保持高度一致。 二、求真务实，开拓进取 在工作中任劳任怨，踏实肯干，坚持原则，认真做好学院的党务工作，按照党章的要求，严格发展党员的每一个步骤，认真细致的对待每一份材料。配合党总支书记做好学院的党建工作，完善党总支建设方面的文件、材料和工作制度、管理制度等。
三、生活朴素，乐于助人 平时重视与同事间的关系，主动与同事打成一片，善于发现他人的难处，及时妥善地给予帮助。在其它同志遇到困难时，积极主动伸出援助之手，尽自己最大努力帮助有需要的人。养成了批评与自我批评的优良作风，时常反省自己的工作，学习和生活。不但能够真诚的指出同事的缺点，也能够正确的对待他人的批评和意见。面对误解，总是一笑而过，不会因为误解和批评而耿耿于怀，而是诚恳的接受，从而不断的提高自己。在生活上勤俭节朴，不铺张浪费。 身为一名老党员，我感到责任重大，应该做出表率，挤出更多的时间来投入到**党总支的工作中，不找借口，不讲条件，不畏困难，将总支建设摆在更重要的位置，解开工作中的思想疙瘩，为攻坚克难铺平道路，以支部为纽带，像战友一样团结，像家庭一样维系，像亲人一样关怀，践行入党誓言。把握机遇，迎接挑战，不负初心。
主要事迹简介怎么写 概括?简要地反映?个单位(集体)或个?事迹的材料。简要事迹不?定很短，如果情况 多的话，也有?千字的。简要事迹虽然“简要”，但切忌语?空洞，写得像?学?期末鉴定。 ?应当以事实来说话。简要事迹是对某单位或个?情况概括?简要地反映情况，?如有三个??很突出，就写三个??，只是写某???时，要把主要事迹突出出来。 简要事迹?般来说，?少要包括两个??的内容。?是基本情况。简要事迹开头，往往要??段?字来表述?些基本情况。如写?个单位的简要事迹，应包括这个单位的?员、 承担的任务以及?段时间以来取得的主要成绩。如写个?的简要事迹，应包括该同志的性 别、出?年?、参加?作时间、籍贯、民族、?化程度以及何时起任现职和主要成绩。这 样上级组织在看了材料的开头，就会对这个单位或个?有?个基本印象。?是主要特点。 这是简要事迹的主体部分，最突出的事例有?个??就写成?块，并按照?定的逻辑关系进 ?排列，把同类的事例排在?起，?个??通常由?个?然段或?个?然段组成。 写作时，特别要注意以下四点： 1.?第三?称。就是把所要写的对象，是集体的?“他们”来表述，是个?的称之为“他(她)”。 (她)”，单位可直接写名称，个?可写其姓名。 为了避免连续出现?个“他们”或“他 2.掌握好时限。?论是单位或个?的简要事迹，都有?个时间跨度，既不要扯得太远，也不 要故意混淆时间概念，把过去的事当成现在的事写。这个时间跨度多长，要根据实际情况 ?定。如上级要某个同志担任乡长以来的情况就写他任乡长以来的事迹;上级要该同志两年 来的情况，就写两年来的事迹。当然，有时为了需要，也可适当地写?点超过这个时间的 背景情况。 3.?点他?的语?。就是在写简要事迹时，可?些群众的语?或有关?员的语?，这样会给??种?动、真切的感觉，衬托出写作对象?较?的思想境界。在?他?语?时，可适当加?，但不能造假。 4.?事实说话。简要事迹的每?个??可分为多个层次，?个层次先??句话作为观点，再???两个突出的事例来说明。?事实说话时，要尽量把?个事例说完整，以给?留下深 刻印象。
树立榜样的个人事迹简介怎么写800字 榜样是阳光,温暖着我们的心;榜样如马鞭,鞭策着我们努力奋斗;榜样似路灯,照亮着我们前进的方向。今天小编在这给大家整理了树立榜样传递正能量事迹作文,接下来随着小编一起来看看吧! 树立榜样传递正能量事迹1 “一心向着党”,是他向着社会主义的坚定政治立场;“人的生命是有限的,可是,为人民服务是无限的,我要把有限的生命投入到无限的为人民服务中去”,是他的至理名言;“甘学革命的“螺丝钉”,是他干一行爱一行、钻一行的爱岗敬业态度。他——雷锋,是我们每一个人的“偶像”…… 雷锋的事迹传遍大江南北,他,曾被人们称为可敬的“傻子”。一九六零年八月,驻地抚顺发洪水,运输连接到了抗洪抢险命令。他强忍着刚刚参加救火工作被烧伤的手的疼痛,又和战友们在上寺水库大坝连续奋战了七天七夜,被记了一次二等功。望花区召开了大生产号召动员大会,声势很大,他上街办事,正好看到这个场面,他取出存折上在工厂和部队攒的200元钱,那时,他的存折上只剩下了203元,就跑到望花区党委办公室要为之捐献出来,为建设祖国做点贡献,接侍他的同志实在无法拒绝他的这份情谊,只好收下一半。另100元在辽阳遭受百年不遇洪水的时候,他捐献给了正处于水深火热之中的辽阳人民。在我国受到严重的自然灾害的情况下,他为国家建设,为灾区捐献出自已的全部积蓄,却舍不得喝一瓶汽水。就这样,他毫不犹豫的捐出了自己的所有积蓄,不求功名,不求名利,只求自己心安理得,只求为
革命献出自己的微薄之力,甘愿做革命的“螺丝钉”——在一次施工任务中,他整天驾驶汽车东奔西跑,很难抽出时间学习,他就把书装在挎包里,随身带在身边,只要车一停,没有其他工作时,就坐在驾驶室里看书。他曾经在自己的日记中写下这样一段话：”有些人说工作忙,没时间学习,我认为问题不在工作忙,而在于你愿不愿意学习,会不会挤时间来学习。要学习的时间是总是有的,问题是我们善不善于挤,愿不愿意钻。一块好好的木板,上面一个眼也没有,但钉子为什么能钉进去呢?这就是靠压力硬挤进去的。由此看来,钉子有两个长处：一个是挤劲,一个是钻劲。我们在学习上也要提倡这种”钉子“精神,善于挤和钻。”这就是他,用自己的实际行动来证明自己,用自己的亲生经历来感化世人,用自己的所作所为来传颂古今……人们都拼命地学习他的精神,他的精神被不同肤色的人所敬仰。现在,一切都在变,但是,那些决定人类向前发展的基本要素没有变,那些美好的事物没有变,那些所谓的“螺丝钉”精神没有变——而这正是他的功劳,是他开启了无私奉献精神的大门,为后人树立了做人的榜样…… 这就是他,一位中国家喻户晓的全心全意为人民服务的楷模,一位共产主义战士!他作为一名普通的中国人民解放军战士,在他短暂的一生中却助人无数。而且,伟大领袖毛泽东主席于1963年3月5日亲笔为他题词：“向雷锋同志学习”。 正是因为如此,全国刮起了学习雷锋的热潮。雷锋已经离开我们很长时间了。但是雷锋的精神却深深地在所有中国人心中扎下了根,现在它已经长成一株小树。正以其顽强的生命力,茁壮成长。我坚信,
大学生先进事迹简介怎么写 苑xx，男，汉族，1990年07月22日出生，中国共青团团员，入党积极分子，现任xx学院电气优创0902班班长，担任xx学院09级总负责人、xx学院团委学生会科创部干事、xx学院文艺团主持部部长。 步入大学生活一年以来，他思想积极，表现优秀，努力向党组织靠拢，学习刻苦，品学兼优，工作认真负责，脚踏实地，生活勤俭节约，乐于助人。一直坚持多方面发展，全面锻炼自我，注重综合能力、素质拓展能力的培养。再不懈的努力下获得了多项荣誉： ●获得09-10学年xx大学“百佳千优”(文化体育)一等奖学金和“百佳千优”(班级建设)二等奖学金; ●获得09-10学年xx大学“优秀学生干部”荣誉称号; ●2010年xx大学普通话知识竞赛中获得一等奖; ●2010年xx大学主持人大赛中获得一等奖，被评为金话筒; ●xx学院首届“大学生文明修身”活动周——再生比赛中获得一等奖; ●xx学院首届“大学生文明修身”活动周——演讲比赛中获得一等奖。 一、刻苦钻研树学风 作为班长，他在学习方面，将班级同学分成各个学习小组，布置每日学习任务，分组竞争，通过开展各项趣味学习活动，全面调动班级同学的积极性，如：排演英语戏剧、文学常识竞答、数学辅导小组等。他带领全班同学努力学习、勤奋刻苦，全班同学奖学金获得率达91%，四级通过率达66%。 二、勤劳负责建班风
在日常班级工作中，他尽心尽力，通过网络组织建立班级博客，把班级的日常情况，班级比赛，特色主题班会等活动，及时上传到 班级博客，以方便更多同学了解自己的班级，也把班级的魅力、特色，更全面、更具体的展现出来。 在班级建设中，他带领全班同学参加学院组织的各项文体活动中也收获颇多： ●在xx学院首届“大学生文明修身”活动周中荣获第二名， ●xx学院首届乒乓球比赛中荣获第一名、精神文明奖， ●在xx学院“迎新杯”男子篮球赛中荣获第四名、最佳组织奖。 除了参加学院组织的各项活动外，为了进一步丰富班级同学们的课余生活，他在班级内积极开展各式各样的课余活动： ●普通话知识趣味比赛，感受中华语言的魅力，复习语文文学常识，为南方同学打牢普通话基础，推广普通话知识。 ●“我的团队我的班”主题班会活动中，创办特色活动“情暖你我心”天使行动，亲切问候、照顾其他同学的生活、学习方面细节 小事，即使在寒冷的冬天，也要让外省的同学感受到家一样的温暖。 ●“预览科技知识”科技宫之行，作为现代大学生，不能只顾书本知识，也要跟上时代，了解时代前沿最新科技。 ●感恩节“感谢我们身边的人”主题班会活动，在这个特殊的节日里，他带领同学们通过寄贺卡、送礼物等方式，来感谢老师辛勤 的付出;每人写一封家书，寄给父母，感谢父母劳苦的抚育，把他们 的感激之情，转化为实际行动来感化周围的人;印发感恩宣传单，发 给行人，唤醒人们的感恩的心。 三、热情关怀暖人心 生活中，他更能发挥榜样力量，团结同学，增强班级凝聚力。时刻观察每一位同学的情绪状态，在心理上帮助同学。他待人热情诚恳，积极帮助生活中有困难的同学：得知班级同学生病高烧，病情 严重，马上放下午饭，赶到同学寝室，背起重病同学到校医院进行
个人事迹简介 我是来自计算机与与软件学院的学生，现在为青年志愿者协会的干事，在班级担任生活委员。在过去的一年里，我注重个人能力的培养积极向上，热心公益，服务群众，奉献社会，热忱的投身于青年支援者的行动中！一年时间虽短，但在这一年的时间里，作为一名志愿者，我确信我成长了很多，成熟了很多。“奉献、友爱、互助、进步”这是我们志愿者的精神，在献出爱心的同时，得到的是帮助他人的满足和幸福，得到的是无限的快乐与感动。路虽漫漫，吾将上下而求索！在以后的日子里，我会在志愿者事业上做的更好。 在思想上，我积极进取,关心国家大事，并多次与同学们一起学习志愿者精神,希望我们会在新的世纪里继续努力,发扬我国青年的光传统,不懈奋斗,不断创造,奋勇前进,为实现中华民族的伟大复兴做出了更大的贡献。 在学习上刻苦认真，抓紧时间，不仅学习好学科基础知识，更加学好专业课知识，在课堂上积极配合老师的教学，乐意帮助其它同学，有什么好的学习资料，学习心得也与他们交流，希望大家能共同进步。在上一个年度总成绩在班级排名第四，综合考评在班级排名第二。在工作中，我认真负责，出色的完成老师、同学交给的各项任务，所以班级人际关系良好。
此外参加了学院组织的活动，并踊跃地参加，发挥自己的特长，为班级争得荣誉。例如：参加校举办的大合唱比赛并获得良好成绩；参加了计算机与软件学院党校学习并顺利结业；此外,参加了计算机与软件进行的“计算机机房义务打扫与系统维护”的活动。在这些活动中体验到了大学生生活的乐趣。 现将多次参与各项志愿活动汇报如下：2013年10月26日，参加计算机与软件学院团总支实践部、计算机与软件学院青年志愿者协会组织“志愿者在五福家园的健身公园开展义务家教招新活动”；2013年11月7日，参加组成计算机与软件学院运动员方阵在田径场参加学院举办的学校运动会；2013年12月5日，参与学校学院组织的”一二．五“大合唱比赛；2014年3月12日，参加由宿舍站长组织义务植树并参与植树活动；2014年3月23日，在计算机与软件学院团总支书记茅老师的带领下，民俗文化传承协会、计算机与软件学院青年志愿者协会以及学生会的同学们参观了“计算机软件学院的文化素质教育共建基地--南京市民俗博物馆”的活动；2014年3月26日，参加有宿舍站长组织的“清扫宿舍公寓周围死角垃圾”的活动；2014年4月5日，参加由校青年志愿者协会、校实践部组织的“南京市雨花台扫墓”活动，2014年4月9日，作为班级代表参加计算机软件学院组织部组织的“计算机应用office操作大赛”的活动。 在参与各项志愿活动的同时，我的学习、工作、生活能力得到了提高和认可，丰富生活体验，提供学习的机会，提供学习的机会。
《个人事迹简介》 个人事迹简介（一）： 李维波，男，中共党员，自2003年应聘农电工以来，他就把自己的一切奉献给了他热爱的电力事业。在多年的工作中爱岗敬业，勤勤恳恳，任劳任怨。2003年至2007年先后担任过xx供电所线损管理员、用电检查管理员、两率管理员、线路工作负责人;2007年调到xx供电所任用电检查管理员、客户经理;2009年5月调到xx供电所任营销员兼用电检查管理员。 刚踏入电力工作的时候，他还是个电力行业的门外汉，可他深深的明白：知识改变思想!思想改变行动!行动决定命运这句话，明白在当今学习的社会里，对于电力更就应不断的吸取新的知识，更新新的观念，以满足时代对于电力的更高的要求。正是这样他透过自己的努力学习，一步步的从门外汉变成了此刻的技术骨干。 一、加强政治学习，提高理论思想水平 多年以来，他在工作中始终坚持学习邓小平理论和三个代表重要思想。他深知：一个人只有有了与时俱进的思想做指导，人的认识才会提高，思想才能净化，行为也才能与时代同步，与社会同步，与发展同步，也才能成为社会发展的推动者、有作为者，正因为如此，他严格要求自己，认真学习思想理论方面的知识，抓紧一切时间学习，认真听，做好笔记，写好心得，并且用三个代表思想来约束自己，不断提高自身的修养，从而真正实践党的全心全意为人民服务的宗旨。 二、加强专业知识的学习，提高专业技术 在当今信息化的时代，科学技术飞速发展，尤其在电力行业这个技术密集型企业中，学习显得尤为重要。从踏进电力企业的大门开始，他就自觉学习专业知识，以书本为老师，阅读各方面的相关书籍，不断丰富自己的理论基础;以老同志为师傅，细心观察他们的实际操作，不断丰富自己的实践经验;以实践为老师，从中加深对知识的理解和领会。从2003年开始，学会了计算机普通操作，掌握了电力安全方面相关知识、电工基础知识、供电营业规则，参加局每年安规考试多次得到全局前十名，2005年农电体制改革考试应知和应会总分全局第5名。 三、发扬三千精神，做好优质服务 2007年，xx所因滩坑移民影响，电费回收率难以上升，应对电费回收的复杂严峻形势，
员工主要事迹写法： ｘｘ，一个普通的名字。一个平凡的身影，经常出现在酒店的各个区域巡视。他是保安部副主管。 ｘｘ，自20ｘｘ年x月份进入酒店工作以来，一直表现出色，爱岗敬业，努力学习业务知识，也因此由一名普通保安员逐步成长为酒店一名管理人员，在20ｘｘ年x月正式接手保安部副主管一职。同年6月，参加宁波消防安全管理员的培训，并拿到了相应的资格证书。 作为酒店一名基层管理者，他处处起到了模范带头的作用，他的工作态度会影响整个团队，正所谓：火车跑得快，全靠车头带。在日常工作中他不怕困难，勇于承担责任，用在工作上，就是那份执着、坚定、信念。每当这时，他总是憨厚的笑笑：“还是领导有方，我只是一个执行者罢了”！ 20ｘｘ年x月份，根据国家气象局预报的台风预测消息，第9号强台风“梅花”正向本地移动，可能在6日夜间在浙江省中北部沿海登陆，或紧擦宁波市沿海北上，但不管哪种路线都将对宁波造成严重影响。我酒店在林总经理的号召下，立即由工程部张经理带领工程保安部及各部门相关人员迅速成立临时抗台小组。ｘｘ也同时参加了前期各项准备工作，并同相关人员一同在酒店蹲守两个日夜，直至“梅花”绕道离开。他还开玩笑说：“这个日子很特别，七夕情人节碰上了梅超风”。
20ｘｘ年，对于酒店保安部来说，是较为艰辛的一年，由于市场原因，使得保安部人力处于紧张状态，即使如此，他还是较为圆满的完成了部门的各项培训及其它各项工作，并在ｘｘ月份对酒店全员进行了为期三天的消防知识培训，用自己所学到的知识来跟大家一起分享。同月底，在酒店各层领导的组织与鼓励下圆满的完成了消防模拟演习，事后他说：“大家都比我做的好，我还要努力加强学习啊”。 20ｘｘ年底，酒店餐饮客情非常好，餐饮部自身人员不能满足服务需求，需要其他部门帮工跑菜，这个问题也就落在了工程保安部的肩上。每天在厨房都能看到那一身保安制服的跑菜员，不用问，那肯定是ｘｘ。仅x月份，他在做好自己本职工作的同时，利用非当班时间帮工累计56小时。当然也有其他部门的帮工人员，他们都是优秀的，正是有这些非常优秀的员工，使得酒店营业部门顺利完成了各项任务。每当这时，他又会说：“我虽然是过来帮忙的，但我要把它当成自己的本职工作来做”。 20ｘｘ年底，临近春节，好多员工都想回家过年，保安部员工也不例外，但人员紧张怎么办呢，他又给大家做思想工作，同时分开安排人员回家的假期，以保证春节期间的正常排班，保障酒店的正常运行。但谁能知道他在酒店工作三年多了，每年的春节都是在酒店过的，每年的中秋节也都是在酒店过的，难道他不想在佳节时与家人团聚吗?每当这时，他又说：“人员紧张，名额有限，让给他们。呵呵，再说，我是以店为家”，也许这时，他的笑容里带有一丝让人难以察觉的苦涩！
个人工作事迹简介 在每一个岗位上都有积极分子，在评选时我们叫他们先进个人。那么个人工作事迹简介怎么写呢?下面由为你提供的个人工作事迹简介，希望能帮到你。 个人工作事迹简介(一)我想自己并不比别人聪明，但我可以更加努力，所谓勤能补拙、笨鸟先飞”。这就是同志的信条。从92年参加银行工作至今，正是这股“事事处先”的精神一直激励他、支持他，培养了他良好的思想品质和积极的工作态度。现将一年来该同志先进事迹总结如下： 一、认真做好本职工作。 xx年度16月份，该同志主要在分行稽核部工作，另外兼分行会计出纳部会计检查辅导员。主要工作包括：完成了对各支行财务专项稽核、理财业务专项稽核、对分行机关各部室进行了专项稽核、协同分行办公室实施了劳动工资专项稽核、表外业务专项稽核、分行信贷业务专项稽核、参与总行组织的对深圳地区支行的会计专项稽核、配合人行杭州中支对我分行进行真实性专项检查、实施了内控制度评价稽核、分类分层次监管稽核、分行(管理部)专项现场稽核、支行行长离任稽核、做好计算机xx年问题监管工作，做好贷款到期回收的监控工作和重要业务交接工作、参与分行“营业窗口酒店式”服务组织考评工作、对业务工作中出现的问题及时介入实时监督。作为分行会
计检查辅导员，还负责做好了对支行会计业务的检查辅导工作和季度会计规范化检查工作。 下半年，该同志调分行营业部负责营业厅工作。能够从营业厅实际出发，狠抓基础性工作： 1、优化服务环境，规范服务行为。从服务仪表、服务态度、服务语言、服务规范等方面严格要求员工，推出“每周一星”“服务明星”活动，在分行规范化服务评比中取得第一名; 2、抓岗位培训，强员工素质。推出岗位练兵活动，对员工技能进行强化训练，配合分行快捷工程做好限时服务，在分行技能测试中获总分第一; 3、加强内部管理，建立监督机制，员工自我监督、领导日常监督、社会公开监督紧密结合。同时，建立例会制度总结不足，表扬先进，直接调动员工服务意识和主动意识。 4、把解决认识问题和思想教育贯彻始终，开展形式多样的谈心教育，及时澄清员工的模糊认识，做到上下思想统一，员工步调一致。 5、做好业务培训和规范操作工作，在分行会计规范化检查中成绩居前。 经过半年努力，员工的服务意识和服务质量明显提高，营业环境有效改善，内部管理、规范操作、风险控制得到加强，有效地促进了服务工作的全面提高。同时，在不断改善营业环境、服务设施和推行“微笑服务、两站三声、一双手”为基本内容的柜台服务规范基础上，把抓单纯服务态度转变到以客户为中心、以客户满意为准绳的服务要
简历个人先进事迹范文 在简历上拟写一些先进优秀事迹，对自己的有很大的帮助，今天我们就一起来看看简历个人先进事迹吧! xx，男，1992年2月出生，是×××学校××班学生，现任×××学校轮滑协会会长，入校以来，他严格遵守学院的各项规章制度，他认真踏实，学习勤奋，自觉性强，各科成绩优秀，积极参加各项活动，在思想、学习、生活、个人等方面都取得了较大的进展!受到老师和领导的好评! 他自觉努力学习马列主义、毛泽东思想、邓小平理论和 ___等重要思想，坚持科学发展观，认真贯彻党的十八大精神，不断地扩充自己的思想政治知识，学习党的先进理论知识、坚决拥护共产党的领导，自觉践行社会主义荣辱观。并在各方面起到模范带头作用。通过参加党校培训，认真的学习了各种政治理论知识，在政治思想方面，在思想和行动上严格要求自己，在不断加强自身素养的同时，做好各项工作，全心全意为同学服务。 在学习上，他能做到认真踏实，勤学苦练，刻苦钻研专业知识，努力在学习上取得优良的成绩，积极配合老师的的各项工作的展开，配合校学生会、社团联、团委的工作展开，同时还积极参与院学生会、
分团委、新闻资讯台的各项工作。还曾被评为“军训标兵”，并获得荣誉证书! 在班级里，他是一名优秀学生，和同学相处的十分融洽，互相关心，共同努力，同学们都很喜欢他，信任他。平时，他养成了批评与自我批评的优良作风。他不但能够真诚的指出同学的错误缺点，也能够正确的对待同学的批评和意见。面对同学的误解，他总是一笑而过，不会因为同学的误解和批评而耿耿于怀，而是诚恳的接受，从而不断的提高自己。在生活上他也十分俭朴，从不铺张浪费，也从不乱花一分钱。有时候在学习空闲时间找一些兼职工作，增加一些生活费，为家庭减少一些负担。但是，只要哪个同学在生活上遇到了困难，他都能力尽所能的帮助解决，只要听说有什么捐块活动，他都会竭劲所能的献出自己的一份力量，曾为贫困地方捐出过衣服和英语磁带，他具有良好的道德品质，吃苦耐劳的精神，他是值得学习的好榜样! 20xx年入学天津工业大学，加入了天津工业大学分团委实践部，在一年的工作中，刻苦学习，坚持完成部长分配放入各项任务，多次拉到赞助，为分团委的各项工作提供的资金上的保障，获得“优秀个人奖”，20xx年第一学期参加了大学生创业教育课程，担任班长一职，由于每星期只上一节课，而且学生于不同的学院，不同的班级，在这种情况下，老师分配的工作及任务坚持送到每位同学的耳朵中，得到了同学的信赖和好评。期末完成了创业教育课程，并荣获了奖章，
[中学]个人事迹简介范文 事迹简介 **～男～1991年8月15日出生～现担任****大学09金融一班团支部的组织委员。入校以来严格遵守学校的各项规章制度～做好模范带头作用。平日我妥善处理好班级工作以及和同学之间的关系～在各个方面取得了较大的进展。 1..认真学习～努力工作～。 在学习上我还算是比较系统的学习并掌握了较为扎实的专业知识～虽然在刚刚入校的时候由于没有形成较好的文科思维遇到了很多困难～但是在我坚忍不拔的毅力的驱使下～在第一学期获得了全班第四名的好成绩。在大一下学期获得了全班第二名。在大二第一学期更是获得全班第一名的好成绩～在工作方面～可以用尽心尽力来形容～只从当上了的班上的组织委员～才知道这个职位不是那么的容易～不过总的来说还算做的不错～其中我觉得最好的几次也是最有成就感的事就是春游。一次是上学期去落雁岛春游～作为组织委员我是是身先士卒去考察了下当地的情况～历经千辛万苦终于找到了地方～弄到了说明书和优惠方案。第二次春游是去华农～记得那次是两个班联谊～为了这次联谊的顺利进行～我已经做了一个星期的活动策划了～当时去了之后我发现大家都是各玩各的～甚至有些人直接出去逛了～全然不顾春游的目的～后来我鼓起勇气把家里集结在一起～做了一个非常好远的游戏～在场的人无不不亦乐乎。可以说这次联谊是非常成功的～获得了一致好评: 平时在班上我充当的活动组织者～包括团委和班委方面的工作～ 其中我充当的是班上的联络员～帮忙解决同学的困难。反馈同学的消息～同时让他们能及时知道对自己有用的信息:
我还从事过党组织组织的青年志愿者活动～每次都会全身性地投入于工作～可能是太投的缘故～有一次一不小心把手机弄丢了～对我来说可谓是当头棒喝～但是我还是坚持完成了湖北社区的志愿者工作。 在过去的一个暑假里～我进行了暑期社会实践～可谓是真正的的体会到了生活的艰苦～我打工一个月～每天工作15个小时～在里面由于我是新工～虽然我是大学生～但毕竟人家干的事技术活～还是遭到别人的白眼～在我努力的工作下和不断地摸索中～最终获得了500块钱的工资和大家的不舍。实践过后的我更加坚信我学习的信念～对于来自农村的我～唯有读书这座桥梁～能让我通向成功的彼岸: 2..思想积极上进～不断提到思想素养。 在入校以前～我对什么政治～历史～马克思主义～毛泽东思想～邓小平理论～以及三个代表重要思想可谓是没有一点概念。更重要的是我是完全一点兴趣都没有～但是在深刻的学习了以后～我发现我的观念有了很大的改变～觉得原来学习这些提到素养的知识并不是我想象中的那么无聊～对于马克思的剩余价值理论以及辩证观可谓是佩服的五体投地～现在我还是孜孜不倦的学习着～现在的我较以前的水平有了质的飞跃 3.体育方面 入校以来～总共参加了两次新生杯篮球大赛～从刚开始的青涩到 后来的老练～经历了不少起伏～每次比赛过后我都会发生抽搐现象～可能是我体质的原因～一场比赛过后～小腿都会疼几天～但是我没有被困难吓倒～两次篮球比赛我们分别以09级第一名和全员第三名完美的结束比赛。这些肯定是给我大学生活添上了丰富多彩的一笔～同时也增进了我和同学之间的感情: 4.所在寝室卫生以及评比情况 虽然在寝室文化节里～没有获奖。但我还是尖刺吧寝室收拾到最干净～和同寝室的同学关系搞到最好～在我们的努力下～我们寝室已经多次被评为?优秀寝室?。
优秀员工事迹材料简介 篇一：先进个人事迹简介 先进个人事迹简介 XXX，男，XX年XX月出生，XX年毕业于XXX大学，现任XXX 农机管理员。多年来，他兢兢业业，尽心尽责，工作中勇挑重担，思路开阔、善于学习、勤于思考，虚心向老同志学习业务，默默无闻地奋战在农机工作的第一线。 “在岗就要爱岗，爱岗就要敬业”是他的职业理念。工作中，他一心扑在事业上，兢兢业业，埋头苦于。在工作期间他从不擅自离岗和请假。不管大小事情，他都认认真真地去做，而且做得非常出色。他这种敬业精神受到了单位干部职工的广泛赞誉。办公室是个综合部门，日常事务多，人手少，工作繁忙。他主动承担了文明单位创建、职工教育培训、宣传思想工作等工作。同时，在审核文稿、起草有关材料、处理来信来访、接待来人来客、配合纪检监察等工作方面，他也积极主动，任劳任怨。在他的带动和影响下，办公室的各项工作取得了长足进步。 他常年深入农村和农业生产第一线，每到一处，亲自向农民宣传农机技术和机具，把自己所学的知识毫不保留传授给农民。他经常说，要提高农机科技水平，引导农民使用先进适用的农机新技术、新机具，关键是提高农民的科技意识，这就要靠我们农机工作者广泛宣传，不
断加大科普宣传力度。他经常组织科技人员利用现场会等时机，对农民进行培训。每年组织的送科技下乡活动都在5次以上，技术讲座2以上，发放资料100余份。受教育人数近200人次。 多年来，他为了铸造自己的事业，摸爬滚打，苦干实干、无私奉献，他凭着对工作高度负责的态度和执着敬业的精神，深深的感染和激励着身边的每一位同志，起到了模范带头作用。他只是一名普通的农机管理员，他的事迹也并非惊天动地，但平凡孕育高尚、细小昭示博大，他把对农机事业的一片赤诚融于他的行动，在平凡的工作岗位上，做出了卓越的成绩，在他的身后，留下的是一串串坚实而闪光的足迹。篇二：20XX年前台优秀员工先进事迹简介 优秀员工XXX先进事迹简介 XXX，前厅部前台接待。20XX年8月15日入职至今，努力工作，把每一步都走的踏踏实实，并收获了辛勤耕耘的硕果累累。并始终坚持“在其位，谋其政，尽其职，胜其任”的生活，学习和工作方式。20XX年7、8月份，酒店举行的星级服务师考试，考试前努力复习酒店各部门材料必知，熟练前台操作系统，模拟练习客人接待等。在考试中取得了“五星级服务员”头衔。20XX年10月份，由于工作表现与工作努力，在同事与领导投票下，被选为本月“服务明星”。20XX年1月份凌晨，在跟客人办理入住时，通过交谈她细心的发现客人得了感冒，此时也是凌晨 了，她和西餐值班的厨师处借来了姜丝和红糖，从服务中心借了热水壶，为客人熬制了一壶姜汤水送到了房间，客人很是感动，连连表示
主要事迹简介怎么写 主要事迹怎么写?主要事迹范文个人主要事迹范文 个人主要事迹怎么写? 概括而简要地反映一个单位(集体)或个人事迹的材料。简要事迹不一定很短，如果情况多的话，也有几千字的。简要事迹虽然“简要”，但切忌语言空洞，写得像小学生期末鉴定。而应当以事实来说话。简要事迹是对某单位或个人情况概括而简要地反映情况，比如有三个方面很突出，就写三个方面，只是写某一方面时，要把主要事迹突出出来。 简要事迹一般来说，至少要包括两个方面的内容。一是基本情况。简要事迹开头，往往要用一段文字来表述一些基本情况。如写一个单位的简要事迹，应包括这个单位的人员、承担的任务以及一段时间以来取得的主要成绩。如写个人的简要事迹，应包括该同志的性别、出生年月、参加工作时间、籍贯、民族、文化程度以及何时起任现职和主要成绩。这样上级组织在看了材料的开头，就会对这个单位或个人有一个基本印象。二是主要特点。这是简要事
迹的主体部分，最突出的事例有几个方面就写成几块，并按照一定的逻辑关系进行排列，把同类的事例排在一起，一个方面通常由一个自然段或几个自然段组成。 写作时，特别要注意以下四点: 1.用第三人称。就是把所要写的对象，是集体的用“他们”来表述，是个人的称之为“他(她)”。为了避免连续出现几个“他们”或“他(她)”，单位可直接写名称，个人可写其姓名。 2.掌握好时限。无论是单位或个人的简要事迹，都有一个时间跨度，既不要扯得太远，也不要故意混淆时间概念，把过去的事当成现在的事写。这个时间跨度多长，要根据实际情况而定。如上级要某个同志担任乡长以来的情况就写他任乡长以来的事迹;上级要该同志两年来的情况，就写两年来的事迹。当然，有时为了需要，也可适当地写一点超过这个时间的背景情况。 3.用点他人的语言。就是在写简要事迹时，可用些群众的语言或有关人员的语言，这样会给人一种生动、真切的感觉，衬托出写作对象比较高的思想境界。在用他人语言时，可适当加工，但不能造假。
事迹简介 **，男，1991年8月15日出生，现担任****大学09金融一班团支部的组织委员。入校以来严格遵守学校的各项规章制度，做好模范带头作用。平日我妥善处理好班级工作以及和同学之间的关系，在各个方面取得了较大的进展。 1..认真学习，努力工作，。 在学习上我还算是比较系统的学习并掌握了较为扎实的专业知识，虽然在刚刚入校的时候由于没有形成较好的文科思维遇到了很多困难，但是在我坚忍不拔的毅力的驱使下，在第一学期获得了全班第四名的好成绩。在大一下学期获得了全班第二名。在大二第一学期更是获得全班第一名的好成绩，在工作方面，可以用尽心尽力来形容，只从当上了的班上的组织委员，才知道这个职位不是那么的容易，不过总的来说还算做的不错，其中我觉得最好的几次也是最有成就感的事就是春游。一次是上学期去落雁岛春游，作为组织委员我是是身先士卒去考察了下当地的情况，历经千辛万苦终于找到了地方，弄到了说明书和优惠方案。第二次春游是去华农，记得那次是两个班联谊，为了这次联谊的顺利进行，我已经做了一个星期的活动策划了，当时去了之后我发现大家都是各玩各的，甚至有些人直接出去逛了，全然不顾春游的目的，后来我鼓起勇气把家里集结在一起，做了一个非常好远的游戏，在场的人无不不亦乐乎。可以说这次联谊是非常成功的，获得了一致好评！ 平时在班上我充当的活动组织者，包括团委和班委方面的工作，
其中我充当的是班上的联络员，帮忙解决同学的困难。反馈同学的消息，同时让他们能及时知道对自己有用的信息！ 我还从事过党组织组织的青年志愿者活动，每次都会全身性地投入于工作，可能是太投的缘故，有一次一不小心把手机弄丢了，对我来说可谓是当头棒喝，但是我还是坚持完成了湖北社区的志愿者工作。 在过去的一个暑假里，我进行了暑期社会实践，可谓是真正的的体会到了生活的艰苦，我打工一个月，每天工作15个小时，在里面由于我是新工，虽然我是大学生，但毕竟人家干的事技术活，还是遭到别人的白眼，在我努力的工作下和不断地摸索中，最终获得了500块钱的工资和大家的不舍。实践过后的我更加坚信我学习的信念，对于来自农村的我，唯有读书这座桥梁，能让我通向成功的彼岸！2..思想积极上进，不断提到思想素养。 在入校以前，我对什么政治，历史，马克思主义，毛泽东思想，邓小平理论，以及三个代表重要思想可谓是没有一点概念。更重要的是我是完全一点兴趣都没有，但是在深刻的学习了以后，我发现我的观念有了很大的改变，觉得原来学习这些提到素养的知识并不是我想象中的那么无聊，对于马克思的剩余价值理论以及辩证观可谓是佩服的五体投地，现在我还是孜孜不倦的学习着，现在的我较以前的水平有了质的飞跃 3.体育方面 入校以来，总共参加了两次新生杯篮球大赛，从刚开始的青涩到
---------------------------------------------------------------范文最新推荐------------------------------------------------------ 先进事迹简介怎么写 要拟定恰当的标题。 先进事迹材料的标题，有两部分内容必不可少，一是要写明先进个人姓名和先进集体的名称，使人一眼便看出是哪个人或哪个集体、哪个单位的先进事迹。二是要概括标明先进事迹的主要内容或材料的用途。例如《王鬃同志端正党风的先进事迹》、《关于评选张鬃同志为全国新长征突击手的材料》、《关于评选鬃处党支部为省直机关先进党支部的材料》等。 然后，要写先进人物或先进集体的主要事迹。 这部分内容是全篇材料的主体，要下功夫写好，关键是要写得既具体，又不繁琐；既概括，又不抽象；既生动形象，又很实在。总之，就是要写得很有说服力，让人一看便可得出够得上先进的结论。比如，写一位端正党风先进人物的事迹材料，就应当着重写这位同志在发扬党的优良传统和作风方面都有哪些突出的先进事迹，在同不正之风作斗争中有哪些突出的表现。又如，写一位搞改革的先进人物的事迹材料，就应当着力写这位同志是从哪些方面进行改革的，已经取得了哪些突出的成果，特别是改革前后的。经济效益或社会效益都有了哪些明显的变化。在写这些先进事迹时，无论是先进个人还是先进集体的，都应选取那些具有代表性的具体事实来说明。必要时还可运用一些数字，以增强先进事迹材料的说服力。 1 / 15
最后，是先进事迹材料的署名。 一般说，整理先进个人和先进集体的材料，都是以本级组织或上级组织的名义；是代表组织意见的。因此，材料整理完后，应经有关领导同志审定，以相应一级组织正式署名上报。这类材料不宜以个人名义署名。 先进事迹范文（一） 中国共产党的优秀党员、党的优秀民族干部，内蒙古自治区党委常委、呼和浩特市委书记牛玉儒同志，因病医治无效，于2004年8月14日4时30分在北京不幸逝世，享年51岁。 牛玉儒同志1952年11月出生于内蒙古自治区通辽市一个革命干部家庭。1970年5月在通辽县农村插队锻炼。 1971年12月在哲里木盟盟委办公室工作。1975年11月加入中国共产党。1977年3月担任通辽县莫力庙公社党委书记。1978年2月在中央民族学院干部培训班政治专业学习。1979年7月在内蒙古自治区哲里木盟委员会组织部工作。1980年5月调内蒙古自治区政府办公厅工作。 1983年3月在内蒙古自治区纪律检查委员会先后任秘书、秘书长、常委，其间于1987年9月至1989年11月在内蒙古管理干部学院行政管理专业学习。1989年11月开始，先后任内蒙古自治区政府副秘书长兼办公厅主任、政府党组成员，秘书长兼办公厅党组书记。1996年11月任内蒙古自治区包头市委副书记、市长。2001年2月任内蒙古自治区副主席、政府党组成员。2003年4月任内蒙古自治区党委常委、呼和浩特市委书记。牛玉儒同志是第九届全国人民代表大会代表。