a r X i v :a s t r o -p h /0504669v 1 29 A p r 2005
Saturated-State Turbulence and Structure from Thermal and Magnetorotational Instability in the ISM:Three-Dimensional
Numerical Simulations
Robert A.Piontek and Eve C.Ostriker
Department of Astronomy
University of Maryland
College Park,MD 20742-2421
rpiontek@https://www.doczj.com/doc/2017059105.html,,ostriker@https://www.doczj.com/doc/2017059105.html,
ABSTRACT
This paper reports on three-dimensional numerical simulations of dynamics
and thermodynamics in the di?use interstellar medium (ISM).Our models are local,account for sheared galactic rotation,magnetic ?elds,and realistic cool-ing,and resolve scales ≈1?200pc.This combination permits the study of quasi-steady-state turbulence in a cloudy medium representing the warm/cold atomic ISM.Turbulence is driven by the magnetorotational instability (MRI);our models are the ?rst to study the saturated state of MRI under strongly inho-mogeneous conditions,with cloud/intercloud density and temperature contrasts ～100.For volume-averaged densities ˉn =0.25?4cm ?3,the mean saturated-state velocity dispersion ranges from 8?1km s ?1,with a scaling δv ∝ˉn ?0.77.The MRI is therefore likely quite important in driving turbulence in low-density regions of the ISM,both away from the midplane in the inner Galaxy (as ob-served at high latitudes),and throughout the far outer Galaxy (where the mean density drops and the disk ?ares).The MRI may even be key to suppressing star formation at large radii in spiral galaxies,where the pressure can be high enough that without MRI-driven turbulence,a gravitationally-unstable cold layer would form.As expected,we ?nd that turbulence a?ects the thermal structure of the ISM.In all our simulations,the fraction of thermally-unstable gas increases as the MRI develops,and in the saturated state is largest in high-δv models.The mass fractions of warm-stable and unstable gas are typically comparable,in agreement with observations.While inclusion of resistive dissipation of magnetic ?elds could enhance the amount of thermally-unstable gas compared to current models,our present results indicate that even high levels of turbulence cannot wipe out the signature of thermal instability,and that a shift to a “phase con-tinuum”description is probably unwarranted.Instead,we ?nd that temperature
and density PDFs are broadened(and include extreme departures from equilib-
rium),but retain the bimodal character of the classical two-phase description.
Our presentation also includes results on the distribution of clump masses(the
mass spectrum peaks at～100M⊙),comparisons of saturated-state MRI scal-
ings with single-phase simulation results(we?nd B2 is independent ofˉn),and
examples of synthetic HI line pro?le maps(showing that physical clumps are not
easily distinguished in velocity components,and vice versa).
Subject headings:galaxies:ISM—instabilities—ISM:kinematics and dynamics
—ISM:magnetic?elds—MHD
1.Introduction
Far from the energizing regions of star formation in the Milky Way and other galaxies, the interstellar medium(ISM)is still roiling with activity,and rife with structure.Both the microphysical properties and turbulent activity have been increasingly well characterized by Galactic and extragalactic radio observations.In particular,recent high-resolution Galactic emission surveys in the21cm hydrogen line(e.g.McClure-Gri?ths et al.(2001);Taylor et al.(2003)),combined with Galactic absorption surveys(e.g.Heiles&Troland(2003); Mohan,Dwarakanath,&Srinivasan(2004)),and mapping of face-on external galaxies(e.g. Dickey et al.(1990);van Zee&Bryant(1999)),have begun to provide a wealth of thermal and kinematic information about the atomic ISM component,which comprises the majority of the total ISM mass in most spiral galaxies.Analysis of this data promises to yield a detailed empirical description of the atomic gas,which is known to consist of both warm and cold components,and to be strongly turbulent(e.g.Dickey&Lockman(1990)).
As observations of the ISM advance,there is a need on the theoretical side for increas-ingly sophisticated ISM modeling.With modern computational tools,it is possible to pursue time-dependent hydrodynamic models which incorporate many physical processes.This nu-merical modeling can extend established“classical”results for simpli?ed systems into more realistic regimes,and test conceptual proposals for the behavior of complex systems in a rigorous fashion.The goal of detailed ISM modeling,of course,is not sophistication for its own sake,but to gain understanding about how di?erent“elemental”processes interact, to ascertain which among many contributing processes are most important,and to aid in interpreting and developing reliable physical diagnostics from observations.
Broadly,the presence of structure in the atomic ISM can be easily understood as a consequence of the bistable thermal equilibrium curve over a range of pressures,including
those typical of the ISM.Since the temperatures of the two stable thermal equilibria di?er by a factor of～100(at?xed pressure),the“classical”expectation based on the principle of pressure equilibrium is a system of cold,dense clouds embedded in a much more di?use warm intercloud medium(Field,Goldsmith,&Habing1969).Thermal instability(TI)tends to move gas parcels at intermediate temperatures into one of the stable phases(Field1965). Clouds are initially expected to condense at preferred scales where conduction limits local thermal gradients.While these basic processes are certainly involved in establishing the ISM’s structure,the end result is a complex product of evolution and interactions with other physical processes,leaving many open questions.For example,how do the agglomerations and disruptions of cold clouds depend on the turbulence properties,and how does this a?ect the mass function of condensations that results?
Many processes have been proposed that can produce turbulence in the ISM(see e.g. Mac Low et al.(2004);Elmegreen&Scalo(2004)for recent reviews).Traditionally,tur-bulence is thought to be driven primarily by supernovae(McKee&Ostriker1977)(and, to a lesser extent,expanding HII regions),because the total kinetic energy they are able to supply could be su?cient to o?set the turbulent dissipation in the Milky Way’s di?use ISM(Spitzer1978,Ch.11).Supernovae are certainly the primary source of turbulence near regions of high-mass star formation.However,it is not clear how e?ectively this energy can in fact be shared with the bulk of the ISM,so other sources may be(or combine to be)of comparable importance.Indeed,observations indicate that the levels of turbulence are not strongly correlated with spiral arms(where star formation is enhanced),and are just as large in outer galaxies(where overall star formation rates are low)as in inner regions(van Zee& Bryant1999;Petric&Rupen2001).Moreover,recent3D simulations(Korpi et al.1999;de Avillez&Breitschwerdt2005)in which turbulence is driven solely by supernovae?nd that velocity dispersions are signi?cantly lower in cold gas than in warm gas,inconsistent with observations(Heiles&Troland2003).
An obvious non-stellar energy source for the ISM is galactic rotation.Wherever the angular velocity decreases outward and magnetic?elds are present,the powerful magnetoro-tational instability(MRI)is expected to tap this rotation and drive large-amplitude ISM turbulence(Sellwood&Balbus1999;Kim,Ostriker,&Stone2003;Dziourkevitch,Elstner, &R¨u diger2004).Detailed development of MRI has primarily been studied in adiabatic or isothermal gas,where turbulent velocities and Alfv′e n speeds grow into rough equipartition at slightly subsonic levels(e.g.Hawley,Gammie,&Balbus(1995,1996)hereafter HGB1, HGB2)).Adiabatic and isothermal models,however,are essentially single phase,with only small variations in density and temperature.How do turbulent saturation levels di?er in a medium where there are huge variations in conditions,such that subsonic speeds with respect to the di?use gas are highly supersonic with respect to the dense gas?
In the real ISM,dynamics must a?ect thermodynamics,and vice versa.The turbulent power input is signi?cant,and both(irreversible)dissipative heating and(reversible)PdV heating and cooling can alter distributions of temperatures compared to the narrow spikes at warm and cold equilibria that would otherwise occur.In turn,thermodynamics potentially can a?ect loss rates of turbulence:supersonic compressions are dissipative while subsonic compressions are not,and dissipation of magnetic energy by reconnection depends on local conditions of density and temperature.Cloudy structure also changes e?ective?ow“colli-sion”times,as well as?eld line geometry.Indeed,recent observational evidence has shown that the fraction of unstable gas in the ISM may be signi?cant;Heiles&Troland(2003) found that at high latitudes,about half the warm neutral medium(WNM)lies at thermally unstable temperatures between500-5000K.Numerical models which include e?ects of star formation(Rosen&Bregman1995;Korpi et al.1999;de Avillez2000;Wada,Spaans,& Kim2000;Gazol et al.2001;Wada&Norman2001;Wada2001;Mac Low et al.2004;Slyz et al.2004)?nd both turbulence and signi?cant fractions of unstable gas,although it is not clear how much the temperature distributions are a?ected by the direct heat inputs in the star formation feedback algorithms of these models.
Recent simulations have addressed nonlinear evolution,in2D and3D,of TI in the ISM without“stellar”energy inputs(Hennebelle&P′e rault1999;Burkert&Lin2000;V′a zquez-Semadeni,Gazol,&Scalo2000;S′a nchez-Salcedo,V′a zquez-Semadeni,&Gazol2002;Kritsuk &Norman2002;V′a zquez-Semadeni et al.2003;Audit&Hennebelle2004;Kritsuk&Norman 2004),and there have also been many numerical studies,in2D and3D,of the MRI in single-phase gas.In previous work,we performed2D studies of TI and MRI in combination (Piontek&Ostriker(2004),hereafter Paper I).Paper I showed that MRI growth rates in a two-phase medium are comparable to those in a single-phase medium with the sameˉρand ˉB,provided that the cloud separation along?eld lines does not exceed half of the fastest-
growing MRI wavelength(typically～100pc).Although there have been suggestions that TI itself could be a signi?cant source of turbulence,“pure TI”models we performed show that for pressures comparable to mean galactic values(i.e.away from HII regions or recent supernovae),velocity dispersions are only a few tenths of a km s?1.In our2D simulations, the MRI leads to large-amplitude velocities and magnetic?elds,but as for single-phase2D models,late time behavior is dominated by the“channel?ow;”quasi-steady turbulence is possible only for3D?ows.The present work constitutes the extension of Paper I to3D,in order to study the saturated state of MRI in the presence of a two-phase medium.As we shall describe,we have performed a variety of simulations,with parameters covering a range of conditions characteristic of the atomic ISM.
The plan of this paper is as follows:In§2we brie?y describe the numerical method,and the initializations for the various models we have performed.In§3we present the results
of our simulations in terms of the models’physical structure,thermodynamic distributions, and turbulent states(in velocities and magnetic?elds),as well as exhibiting sample syn-thetic observations based on our simulated data.We summarize,discuss the astronomical implications of our results,and compare to previous work in§4.
2.Numerical Methods and Model Parameters
The numerical methods utilized for the present study are essentially the same as those of Paper I,but extended from2D to3D.For a complete description of the numerical method and tests,please see that work.Here,we brie?y summarize the salient points.
We integrate the time-dependent equations of magnetohydrodynamics with a version of the ZEUS code(Stone&Norman1992a,b).ZEUS uses a time-explicit,operator-split,?nite di?erence method for solving the MHD equations on a staggered mesh,capturing shocks via an arti?cial viscosity.Velocities and magnetic?eld vectors are face-centered,while energy and mass density are volume-centered.ZEUS employs the CT and MOC algorithms(Evans &Hawley1988;Hawley&Stone1995)to maintain?·B=0and ensure accurate propagation of Alfv′e n waves.
We have implemented volumetric heating and cooling terms,and a thermal conduction term.The update due to net cooling is solved implicitly using Newton-Raphson iteration. For a given hydrodynamical time step,the change in temperature in each zone is limited to be less than25%.This is a somewhat larger fraction than the10%limit used in Paper I,which allows us to run with larger time steps needed to make3D calculations practical. Tests have shown that relaxing this constraint does not a?ect cloud structure;?T exceeds 10%only in a very small fraction of zones.The conduction term is solved explicitly using a seven point stencil for the second derivative of temperature.We also model the di?erential rotation of the background?ow and the variation of the stellar/dark matter gravitational potential in the local limit with x≡R?R0?R0,where R0is the galactocentric radius of the center of our computational domain.The equations we solve are therefore:
?ρ
?t +v·?v=?
?P
4πρ
(?×B)×B+2q?2x?x?2?×v(2)?E
?B
sities of n=0.25,0.67,1.5and4.0cm?3,as well as one with lower magnetic?eld strength,β=P gas/P mag=1000.We also performed an isothermal simulation with c s=2.8km s?1 and n=1.0cm?3.This value of c s was chosen so that the initial thermal pressure matches the mean late-time pressure in our cooling models.Finally,we also performed a simulation with heating and cooling turned on that was initialized from the saturated-state,turbulent isothermal model.For all our models we adopt the galactic orbital period at the solar radius, 2.5×108yr,to normalize the shear rate.
Since increasing or decreasing the mean density by a large factor relative to n=1cm?3 would initialize the gas in a thermally stable state,some of our simulations are initialized with a medium already in a two-phase state,rather than with a uniform density.For these models,spherical clouds of cold dense gas are inserted into a warm ambient medium at random locations.The number of clouds is adjusted so that the average density of the cloudy medium is at the desired level.A similar simulation was performed in Paper I, which allowed us to study the growth rates of the MRI in an initially quiescent cloudy medium.Since the2D simulations of Paper I were axisymmetric there was no evolution of the model until MRI modes began to grow.This allowed us to compare directly the MRI growth rates of an adiabatic run with a two-phase run,illustrating the e?ect of cloud size and distribution on the growth rates.In the present3D simulations,however,the evolution is rapid because the symmetry in the azimuthal direction is broken.Individual clouds are sheared out relatively quickly,and also begin to merge with nearby clouds.Nevertheless, because MRI-driven turbulence eventually dominates both the initially-thermally-unstable and initially-two-phase models,at late times the two are indistinguishable.
On top of the initial conditions given above,we add pressure perturbations with a white noise spectrum at the0.1%level to seed the TI and MRI.In the next section,we describe results from our standard run in detail,and comment on di?erences with the other runs as is appropriate.
3.Results
3.1.Overall Evolution
Figures1and2are volume renderings of the3D density data cube,from our run with ?ducial parameters,and resolution2563,at t=1.0and9.0orbits.The early development of both TI and MRI in the present set of3D simulations is quite similar to the development previously described for2D simulations in Paper I.Initially the gas is thermally unstable. The cooling time scale is much shorter than the orbital time scale,and the gas quickly
separates into many small,cold clouds embedded in a warm ambient medium.This phase of the evolution lasts about20Myr,which is comparable to the2D simulations of Paper I. The typical size scale of the clouds is about5pc,consistent with expectations for the fastest growing modes at the adopted level of conductivity.The size scale of the clouds is still fairly close to its initial distribution in Figure1at t=1.0orbits.
After the initial condensation phase of TI is complete,large scale galactic shear begins to drive the evolution.Already at t=2.0orbits,the clouds have become elongated in the?y direction.During the?rst few orbits interactions take place between nearby clouds,which typically lead to mergers,increasing the typical size scale signi?cantly.At about t=4.0 orbits(=109yrs)the modes of the MRI have grown signi?cantly and now begin to dominate the evolution of the model.The simulation becomes fully turbulent,drastically altering the dynamics compared to the axisymmetric model of Paper I.Shear from the MRI with velocities in all directions,combined with galactic shear with velocities in the azimuthal direction,leads to repeated disruptive interactions and collisions between clouds.Clouds merge into an interconnected network,with individual entities existing for only short periods of time.It is di?cult to convey the dynamical nature of the simulations to the reader using only snapshots in time;the animation associated with Figures1-2shows this much more clearly.
While the structure remains highly dynamic,a quasi-equilibrium saturated state is established by t～5orbits,and the statistical properties of the gas remain relatively constant throughout the latter half of the simulation(up to t=10orbits).The approach to a quasi-steady turbulent state in these models is generally similar to the results for isothermal or adiabatic single phase models(e.g.HGB1,HGB2).In the remainder of§3,we discuss details of evolution and quasi-steady properties,similarities and di?erences from single-phase models,and dependencies on model parameters.
3.2.Density Structure
The density probability distribution functions(PDFs)from our standard run(at1283) are shown in Figure3at t=1,2.5,5.0,and9orbits.We show both mass-weighted and volume-weighted density PDFs in Panels A-D,and compare the PDFs of the1283and2563 runs in Panel D.Similar to our results in Paper I,we?nd that by mass,most of the gas is in the cold phase,while the warm phase occupies most of the volume.After the initial development of TI has completed,at t=1.0orbits,the mass fraction of gas in the warm (F),unstable(G),and cold(H)phases is14%,5%,and80%,respectively.By volume,83%, 9%,and8%of the gas resides in the warm,unstable,and cold phases.From t=1.0to
t=2.5orbits(panels A and B of Figure3)the evolution is driven mainly by galactic shear. The size distribution of the clouds shifts to larger masses through mergers,but the density PDFs over this interval vary little.The fraction of gas in each phase changes by only a few percent during this time period.
In contrast,between t=2.5and t=5.0,Panels B and C of Figure3,the evolution changes from being driven primarily by galactic shear,to being driven primarily by the MRI. The model becomes fully turbulent,and this has a signi?cant e?ect on the detailed shape of the density PDF.The fractions of gas in the warm,unstable,and cold phases at t=5.0 are now10%,7%,and83%by mass,and84%,8%,and7%by volume.Near the end of the simulation,at t=9,the gas fractions are14%,18%,and67%percent by mass and 82%,10%,and6%percent by volume.From t=5to t=9,(Panel D of Figure3)the PDF remains very similar,indicating that the model has reached a quasi-steady state.At late times,gas is found at both lower and higher densities than was previously observed before the development of the MRI.Thus,the magnetized turbulence induces both strong compressions and signi?cant https://www.doczj.com/doc/2017059105.html,pared to the maximum(ρmax)and minimum (ρmin)densities before the onset of turbulence,ρmax increases by an order of magnitude andρmin decreases by a factor of about3.The fraction of gas in the intermediate density regime is a factor2–3larger after the full development of MRI compared to early on.The proportion of thermally-unstable gas is never greater than20%of the whole(for this set of parameters),but exceeds the proportion of thermally-stable warm gas during the turbulent stages of evolution.
To investigate properties of individual condensations in our model,we use an algorithm similar to that of CLUMPFIND(Williams et al.1994).The algorithm was developed and applied by Gammie et al.(2003)to identify clumps in simulations of turbulent molecular clouds.Brie?y,the algorithm?rst?nds all local maximum values of density in the compu-tational volume.All grid cells with a density higher than a chosen threshold density,n t,are assigned to the nearest local maximum.This set of continuous zones de?nes a clump.The only other parameter needed is a smoothing length,applied to the initial density data cube (see Gammie et al.2003);we set this to1.5grid zones.In Figure4we show the clump mass spectrum for two di?erent choices of threshold density,n t=8and20cm?3.This mass spectrum is computed at t=6.5orbits.Mass spectra from other late times are similar. With n t=8cm?3,812clumps were found,with a minimum clump mass of5.6M⊙,and a maximum mass of2800M⊙.For reference,the total mass in the simulation is2.51×105M⊙. Increasing the critical density to n t=20cm?3,we?nd168clumps,with a minimum mass of35M⊙,and a maximum mass of2200M⊙.For both cases,the peak of the mass spectrum is in the range100?300M⊙;the peak increases slightly for larger n t.
To describe their shapes,we compute diagonalized moment of inertia tensors for each clump,following Gammie et al.(2003).Figure5plots the ratios,for each clump,of the smallest(c)and intermediate(b)axes to the largest(a)axis.Prolate-shaped clumps lie near the diagonal line,oblate clumps lie near the right side vertical axis,and triaxial clumps lie in the https://www.doczj.com/doc/2017059105.html,ing two dotted lines to demarcate these groups,we?nd38%of the clumps are prolate,49%are triaxial,and14%are oblate.Although clumps are certainly not round, typical minimum to maximum axis ratios are about2:1.“Filaments”,with c/a=0.1are common,however,and these elongated structures are easy to pick out in Figure2.
3.3.Pressure and Temperature Structure
The pressure PDFs at t=1,2.5,5,and9orbits are presented in Figure6.At t=1, most of the gas falls within a narrow range of pressures,P/k=900-1300K cm?3.This is lower than P/k=2000K cm?3in the initial conditions,due to systematic cooling in the thermally unstable stage of evolution.The pressure PDF changes little from t=1to t=2.5orbits, shown in panels A and B of Figure6.With the development of MRI,however,gas is driven to both higher and lower pressures,as can be seen in Panels C and D,at t=5to t=9 orbits.The mean volume-weighted pressure at the end of the simulation is slightly lower than that after TI has developed,about P/k=1200K cm?3.The pressures in the cold and warm phases are approximately equal in the latter half of the simulation,while the pressure in the intermediate phase is slightly higher,about P/k=1300K cm?3.The dispersion in pressure early in the simulation is aboutδP/k～60K cm?3,while late in the simulation this increases to as much asδP/k～400K cm?3.
In Figure7we show scatter plots of pressure against density overlayed on our model cooling curve at t=1,2.5,5,and9orbits.We also show contours of constant temperature to indicate the transitions between di?erent phases of gas.Only a fraction of the zones are included because of the large number of cells contained in our3D simulations.Early in the simulation(Panels A and B),the gas is close to pressure equilibrium,although high density gas lies closer to the thermal equilibrium https://www.doczj.com/doc/2017059105.html,ter in the simulation(Panels C and D),strong interactions between clouds can drive gas far from pressure equilibrium.At low densities where the cooling time scale is longer than the dynamical time,gas can be found at pressures as high as P/k=3200K cm?3and as low as800K cm?3,a range of a factor four.Much of the low-density gas is not in thermal equilibrium.In high density regions there is also a wide range of pressures observed(P/k=800-4000K cm?3),but because the cooling time is very short(～104yr)this gas maintains thermal equilibrium.At early times, distributions of density and pressure are quite similar to the corresponding results from our
2D models(Paper I)after the nonlinear development of TI.At late times,however,these3D
turbulent models show much broader pressure distributions than our2D models.Overall,
the mean pressure averaged over orbits6-10is1206K cm?3.By phase the mean pressure is
P/k=1187,1324,and1195K cm?3in the warm,intermediate and cold phases.
Also of interest are the temperature PDFs,shown in Figure8at the same times as in
Figure3.In Panels C and D,the fraction of gas in the intermediate temperature phase
has increased,and gas is also found at colder temperatures than are present earlier in the
simulation.The minimum temperature is80K,and respectively60%and68%of the gas
mass is found between80-120K at t=1and2.5orbits.At t=5and9orbits,on the
other hand,respectively30%and18%of the gas is found at temperatures below80K,while
respectively another32%and31%of gas is at T=80-120K.The range of temperatures
in which the majority of cold gas is found increases by about a factor of two.The upper
limit on temperature increases slightly throughout the run,but in addition,the dispersion
of temperatures in the warm medium increases.At early times,～80%of the warm gas is
in the range T=6600-8600K,whereas at late times,80%is evenly distributed over twice as
large a spread in temperatures.
Figure9compares the volume-weighted temperature PDFs of four runs of di?erent
mean density.These four runs have average densities ofˉn=4.0,1.5,1.0,and0.67cm?3and,
as we shall discuss in§3.4,the mean velocity dispersion increases by an order of magnitude
from the highest to lowest mean density models.The PDFs in Figure9represent averages
from6.0-6.5orbits.At intermediate and high temperatures,the PDFs for these runs are
quite similar.Most of the warm gas is at T=6000-8000K,with T max≈10000K.Most of the cold phase is at temperatures near100K,possibly showing a slight trend towards
higher mean temperature asˉn is decreased.Overall there is less gas at lower temperature
whenˉn is reduced,because the total mass available for cold clouds is lower.In addition
to having similar warm and cold gas temperatures,the models with variousˉn are similar
in that the fractions of gas in the intermediate-and warm-temperature regimes are always
quite close.These results are illustrated in Figure10,which plots the mass fractions in the
various regimes as a function ofˉn(also including theˉn=0.25model).
Overplotted in Figure10are curves indicating the warm and cold gas mass fractions that
a pure two-phase medium would have.The mass fraction of cold gas in a perfect two-phase
medium in thermal and pressure equilibrium is f c=(1?n w/ˉn)/(1?n w/n c)≈1?n w/ˉn,
where n c is the cold density,n w is the warm density,andˉn is the mean density.The mass
fraction of warm gas is then f w≈n w/ˉn.The density of warm gas in our simulations is typically n w=0.25,which we use to compute the theoretical curves in Figure10.
The possibility exists that our choice of initial conditions in the standard run,a uniform
medium at the average density,may have some e?ect on the amount of gas in the intermediate phase at late times.Due to TI,initially most of the gas collects into small,dense cold clouds, and only a small proportion of the gas remains in the thermally unstable https://www.doczj.com/doc/2017059105.html,ter in the simulation,the MRI drives a larger fraction of gas into the unstable phase.It is possible that if we had begun with a turbulent medium,this fraction would be even larger,from increased shock heating of moderate density clouds with larger collision cross sections.To investigate this,we initialized a simulation with the same mean density and magnetic?eld as our standard run,but evolved it with an isothermal equation of state.The sound speed was set so that the initial P/k matches late time averages from our standard run.After the isothermal evolution has proceeded for10orbits and reached a saturated turbulent state, heating and cooling are enabled.After a quasi-steady state is reestablished,we measure the mass fractions in the warm,intermediate,and cold regimes.The result is respective proportions of about11%,14%,and75%,which is similar to our results from standard run. Thus,we conclude that the long-term thermal history does not strongly a?ect the present state of the gas.
3.4.Turbulent Velocities
In Figure11we plot the mass-weighted Mach number M≡δv/c s of the gas in each thermal phase(warm,intermediate,cold)as a function of time for the duration of the simulation.We also include,for comparison,the mass-weighted Mach number of the cold medium for the high resolution run at2563.The isothermal sound speed c s=(kT/μ)1/2 is computed individually for all grid zones,and the galactic shear is subtracted from the azimuthal(v y)velocity before computingδv2=v2x+(δv y)2+v2z.Initially,motions in all three phases of the gas are subsonic,M<0.3,and remain so until the MRI begins to develop at about800Myr(～3orbits).Once the MRI saturates(at t～5orbits),the typical Mach numbers of the warm,intermediate and cold phases of the gas are0.4,1.8,and2.9.The peak value of M for the cold phase is about3.2.The mean late time velocity dispersion for all three phases of the gas is similar,approximately2.7km s?1.At late times,the individual velocity dispersions in the radial,azimuthal,and vertical directions are1.9,1.7,and0.7 km s?1,respectively.
To explore the dependence of saturated state turbulence on system parameters,for our ?ve simulations of varying mean densityˉn we have computed the average Mach number over t=5?10orbits.We plot the results,separating the three thermal phases,as a function ofˉn in Figure12.The relationships between M andˉn clearly follow power laws.The slopes for the warm,intermediate and cold phases are d ln M/d lnˉn=?0.67,?0.68and
-0.77.Since the cold component dominates the mass,this implies(δv)∝(ˉn)?0.77overall. For ourβ=1000model atˉn=1cm?3,the saturated state Mach numbers are0.3,1.1, and1.6for the warm,intermediate,and cold phases.Our results are thus consistent with general?ndings from previous MRI simulations that saturated-state turbulent amplitudes increase with increasing mean Alfv′e n speed.The detailed scalings,however,show interesting di?erences,which we shall discuss in§4.
We have found that the turbulence is quite insensitive to particularities of structure in initial conditions.Thus,our model which began with a two phase“cloudy”medium,with the same initial mean density as our standard run,saturates with nearly the same velocity amplitude as the standard run.The initially-isothermal run which was restarted with cooling also yielded similar results to the standard run,with Mach numbers of0.4,1.7,and2.8for the warm,intermediate and cold phases.The saturated state of the isothermal simulation itself has a Mach number of1.4,corresponding to mean velocity dispersion4.0km s?1, somewhat larger than for our cooling models at this?ducial mean density.Di?erences between isothermal and multiphase models are likely to depend onˉn,however.
The average Reynolds stress, ρv xδv y /P0,from t=5?10orbits is plotted against the mean density forˉn=4.0,1.5,1.0,0.67,and0.25cm?3in Figure13.The relationship again follows a power law,with a slope of-1.1.
The velocity power spectra are generally consistent with previous simulations of the MRI(Hawley,Gammie,&Balbus1995;Kim,Ostriker,&Stone2003).The largest scales dominate the simulation,generally following a Kolmogorov-like spectrum,～k?11/3.Our quoted values for the velocity dispersions therefore correspond to the largest scales in the simulations.On smaller scales,such as an individual cloud,the velocity dispersion would be smaller.We have tested the relation between linewidth and size directly,using the “ROC”analysis approach described in Ostriker,Stone,&Gammie(2001).Both for the cold component alone,and for the whole medium,we?nd that the velocity dispersion increases with the size of clouds,or sub-boxes of the computational volume.
3.5.Magnetic Fields
Similarly to the(random)kinetic energy,the magnetic energy increases as the MRI develops.In Figure14we plot the magnetic?eld strength as a function of time for each of the three phases of gas.In the initial conditions,B=B z=0.26μG.After TI develops,the ?eld strength is0.25μG for the warm phase,and about0.5μG for the(denser)unstable and cold phases.As the MRI develops,after t=5orbits,the?eld strength grows to range
over2?3μG for all three phases,reaching as high as4.1μG in the cold phase.The late time component magnetic?eld strengths, B2x 1/2, B2y 1/2,and B2z 1/2are1.3,1.9,and0.51μG,averaged over t=6?10orbits.Thus,the MRI enhances the magnetic?eld by an order of magnitude over its initial value.We note that if overdense clouds were to form by isotropic contraction of the ambient medium,then one would expect B2 1/2∝ρ2/3. With a cold medium density two orders of magnitude larger than that of the warm medium, the respective mean?eld strengths would di?er by a factor20.Since this is not the case, condensation evidently proceeds preferentially along?eld lines.
To explore dependence on mean properties,in Figure15the late time magnetic?eld strength,averaged over?ve orbits,is plotted against the mean density in the box for?ve simulations withˉn=4.0,1.5,1.0,and0.67cm?3.Unlike the turbulent velocity dispersions, the B?eld strength does not show any signi?cant trend withˉn,saturating between2and3μG.The?eld strength also does not di?er signi?cantly between the cold,intermediate,and warm phases for any of the models.As a marginal e?ect,the?eld strength in the warm medium decreases asˉn increases.
Unlike the magnetic energy density,the Maxwell stress does show dependence onˉn. This stress, ?B x B y/4π /P0,is averaged over t=5?10orbits and plotted against the mean density for?ve simulations withˉn=4.0,1.5,1.0,0.67and0.25cm?3in Figure16.For the data shown,a power law?t yields slope-0.42.Previous single-phase MRI simulations show somewhat di?erent scalings of Maxwell stresses and magnetic energies,as we shall discuss in§4.
The power spectra of the magnetic?eld,like the velocity power spectra,is consistent with previous simulations of the MRI(Hawley,Gammie,&Balbus1995;Kim,Ostriker, &Stone2003),dominated by the largest scales and generally following a Kolmogorov-like spectrum.
3.6.Energetics
Tracking the changes in various energies is key to understanding the interrelationships between dynamics and thermodynamics in turbulent?ows.For the models we have per-formed,the ultimate energy source is the shear?ow,which drives the MRI.In turn,tur-bulent dissipation can convert kinetic and magnetic energy to thermal energy,which can subsequently be lost to radiation.More formally,following HGB1,we consider the average
over the box of the total energy per unit volume,
ρ 1ρ?q?2x28π .(5)
H =
Changes to this energy can occur due to losses or gains from radiation,and from?uxes through and stresses on the surface of the computational volume.With shearing-periodic boundary conditions,the net rate of change should ideally obey
d
4π + ?ρL .(6) Thus,if quasi-steady state is reached,we would then expect d H /dt=0,and the sum of stresses times q?to equal the cooling rate.In steady state,from equation(3)the total rate of work done by the combination of compressions and shocks, ?P?·v + ?E
3.7.Synthetic Line Pro?les
Although the present simulations are highly idealized in many ways(e.g.they are vertically periodic rather than strati?ed),it is interesting to explore model properties that bear a close relation to observables.The pro?les of21cm HI absorption directly trace the density,temperature,and turbulent velocities of the atomic ISM via a line-of-sight https://www.doczj.com/doc/2017059105.html,ing our simulated“data,”we can generate analogous maps of line pro?les projected in any direction through the computational volume.Figures18,19,and20show synthetic emission pro?le maps for our standard model along the x,y,and z directions.We also present,paired with each line-of-sight velocity pro?le,the corresponding distribution of total emission with line-of-sight position.Each of the8×8windows on the map represents a volume of32×32×256zones,integrated over the projected area.For each zone,the contribution to emission is proportional to the density,with a Gaussian velocity distribution centered on the?ow velocity,and dispersion=
line-of-sight position pro?le(also in Figure21)shows that the warm gas is spatially much more uniformly distributed than the cold gas,which dominates the pro?les in Figures18-20.Interestingly,however,the intermediate-temperature gas is always associated with cold condensations.This is clearly seen in Figure22,which shows slices through the volume both before and after the onset of strong turbulence.
The line pro?les for runs with di?erent mean density are very similar to the standard run.They typically show a single component with occasional evidence for a weaker second component.As the mean density is decreased to n=0.67and0.25cm?3,the line widths increase to2.0,2.2,and1.9km s?1,and4.8,4.7,and4.5km s?1,respectively.Without thermal broadening the line widths are reduced to1.1,1.5,and0.74km s?1,and2.2,2.2, and1.1km s?1,respectively.A similar trend of decreasing line width with increasing mean density is also observed.
4.Summary and Discussion
In this paper,we present results from a set of numerical MHD simulations that focus on the interrelationship between turbulence and thermal structure.The models we have performed are three dimensional,and include sheared galactic rotation and magnetic?elds. Turbulence therefore is generated by the magnetorotational instability.We also include a radiative cooling function that,in pressure equilibrium,would yield a two-phase medium. The two fundamental issues we have addressed are(1)how cloudy structure alters the saturated-state properties and scalings of MRI-driven turbulence,compared to single-phase MRI models,and(2)how turbulence that is not driven by direct(stellar)thermal energy inputs a?ects the thermal balance and phase structure in the warm/cold atomic medium.
4.1.Summary of Model Results
Our primary?ndings are as follows:
1.Evolution and physical structure:A two-phase cloudy medium with many small clouds develops in the?rst20Myr of our simulations.Over time,due initially to galactic shear,and later(t>5orbits)to MRI-driven turbulence,these clouds undergo a continual series of mergers and disruptions,leading to a late-time state in which the mass function of condensations peaks at a few hundred M⊙.The dense condensations are triaxial,and typically have max:min axis ratios of2:1.They consist of cold gas lumps surrounded by envelopes of thermally-unstable gas;?lling all of the remaining volume is thermally-stable
warm gas.
2.Density and temperature distributions:For the range of parameters we have explored,
in late stages of evolution most of the gas mass is in the cold phase,while most of the volume
is occupied by the warm phase.While the proportion of thermally-unstable intermediate-
temperature gas in a given model increases after the advent of MRI,at all stages the density
and temperature PDFs show distinct warm and cold phases,with a varying amount of
material in the“non-equilibrium”valley between these peaks.The peaks,near T=100K
and T=8000K,also broaden as the turbulence develops.The relative proportions in
each phase depend on the mean density,varying from95%cold gas when the mean density
ˉn=4.0cm?3,to50%cold gas whenˉn=0.25cm?3.The fractions of thermally-unstable
gas and warm gas are always comparable to each other.Increasing levels of turbulence yield
increasing proportions of thermally-unstable gas.Relative to the proportions predicted for
a two-phase,quiescent medium in thermal and pressure equilibrium,increasing turbulence
also tends to increase the fraction of cold gas,while decreasing the fraction of warm stable
gas.
3.Pressure:We initialize our models at P/k=2000K cm?3,but secular cooling in the
stages before MRI develops leaves the gas in approximate pressure equilibrium(?P/ˉP<0.1)
at a lower mean pressure of P/k=1300K cm?3,near the minimum for which two stable gas
phases can be present.After MRI develops,pressures cover a much wider range of values
(?P/ˉP～0.5),with a maximum at P/k～4000K cm?3,but relatively unchanged mean
value(ˉP/k=1200K cm?3).
4.Turbulent velocities:After the MRI saturates at～5orbits,the turbulent velocity
dispersion reaches a quasi-steady plateau–albeit with?uctuations of～30%in amplitude.
For our?ducial model withˉn=1cm?3,the mean late time(3D)velocity dispersion is
δv≡ v2x+(δv y)2+v2z 1/2≈2.7km s?1for all three components.This velocity corresponds to mean Mach numbers of0.4,1.8and2.9in the warm,intermediate,and cold phases.We
examined the e?ect of mean density on the velocity dispersion,and found thatδv∝ˉn?0.77
overall,with slightly shallower slope for the warm gas alone.Our results show,additionally,
that the Reynolds stress, ρv xδv y ,varies with mean density∝ˉn?1.1.We?nd that the in-plane components of the velocity dispersion exceed the component perpendicular to the disk by about a factor of two.
5.Magnetic?elds:For the present set of models,we have adopted initial conditions
with a uniform vertical magnetic?eld of strength0.26μG.The MRI enhances the?eld by
an order of magnitude,so that B2 1/2is typically2?3μG late in the simulation.The?eld strength is similar(within～20%)in all three phases of gas,and there is no signi?cant trend of?eld strength with mean simulation densityˉn.However,we?nd that the Maxwell stress,
?B x B y/(4π) ,varies with mean density∝ˉn?0.4.
6.Synthetic line pro?les:As a demonstration of the potential for employing simulations to interpret observational diagnostics,we have computed maps of synthetic line pro?les from sample data cubes.We?nd that the line pro?les are generally single-peaked(although in some cases would require two or three components if a standard Gaussian?tting scheme were performed).In no case did we identify two distinct velocity components,even though there are distinct cloud structures present along many lines of sight.Because turbulence has a smooth power spectrum,this kind of overlap in velocity space is inevitable.
Our results have several interesting implications for interpreting ISM observations,and it is also interesting to compare with recent numerical and theoretical work on the ISM and on MRI dynamics.We conclude by discussing these connections.
4.2.The Multiphase MRI and Saturated-State Turbulence
High levels of turbulence are observed both in the atomic gas of the Milky Way,and in that of external spiral galaxies,and it has been suggested that the MRI could be an important contributor to this turbulence,especially in the outer parts of galaxies where there is little star formation.Our models are the?rst(to our knowledge)to address this issue directly with an appropriate physical model–namely,one that admits two stable thermal phases, such that the MRI must develop in a cloudy medium with density contrasts of100between clumps and di?use gas.While the turbulent velocity that develops in our?ducial model with mean densityˉn=1cm?3is relatively modest,the scaling of the turbulent amplitude withˉn is quite steep,such thatδv～8km s?1is predicted whenˉn=0.2cm?3.
The scaling of turbulent velocity dispersion with mean density indicates that MRI may play a signi?cant role in the outer regions of the galaxy.Beyond the point in the Milky Way where the stellar surface density drops,the gas scale height rapidly increases,and the volume density correspondingly decreases;this sort of disk?aring is also seen in external galaxies.In the Wol?re et al.(2003)Milky Way model,for example,ˉn falls below0.2cm?3at R=15kpc. The outer-galaxy pressure in the Wol?re et al.(2003)model is nevertheless high enough for cold-phase gas to be present,so that if it were not turbulent,then a thin gravitationally unstable layer would develop.1Our results suggest that the MRI could be maintaining high-
amplitude turbulence,and hence suppressing star formation,in the far outer Milky Way and
other spiral galaxies.We note that the increase in scale height is necessary for this to hold;
since the minimum MRI wavelength∝ˉn?1,MRI-driven turbulence can only be sustained in
a su?ciently thick disk.
Even in the inner disk,our results suggest that MRI may be a signi?cant contributor
to turbulence in the ISM.At a mean inner-Galaxy(R<10kpc)midplane density ofˉn=
0.6cm?3(Dickey&Lockman1990;Wol?re et al.2003),our results would predictδv≈
4km s?1.Away from the midplane where the density drops,the turbulent amplitudes
would increase.The mean inner-disk vertical magnetic?eld strength may also be somewhat
larger than the?ducial value we have adopted(Han,Manchester,&Qiao(1999)obtained
B z =0.37μG from pulsar observations),which would tend to increase the amplitude of the turbulence.A more extensive parameter survey–allowing for disk strati?cation,
varying scale height,and di?ering initial?eld strengths and distributions–is needed to
quantify more fully the expected contribution from MRI to turbulent amplitudes in the ISM.
Another important question is whether MRI development could be quantitatively altered by
interaction with large-scale pertubations driven by supernovae or spiral shocks.We defer
consideration of this interesting issue to future work.
Direct comparisons between simulations and observations regarding levels of turbulence
and magnetic?eld strength as a function of local parameters would be very useful.Unfor-
tunately,observations at this time do not permit such comparisons to be made.HI velocity
dispersions in the Milky Way can only be measured within～1kpc of the Sun(e.g.Lock-
man&Gehman(1991);Heiles&Troland(2003)).In external near-face-on galaxies,observed
(vertical)velocity dispersions combine both turbulent and thermal contributions,and these
values do not vary secularly with galactic radii(although dispersions are signi?cant)even
well beyond the optical disk(see§1).Magnetic?eld strengths in the Milky Way beyond～
10kpc have not been measured directly(i.e.with Faraday rotation;see e.g.Han,Ferriere,&
Manchester(2004)).For both the Milky Way and external galaxies,one may use synchrotron
emission(Beck2004)to obtain the product of the magnetic and cosmic ray energy densities
as a function of galactic radius,but since the equipartition assumption need not be satis?ed
everywhere,this does not yield a B-?eld strength except locally,where electron cosmic-ray
and gamma-ray observations can be https://www.doczj.com/doc/2017059105.html,ky Way outer-galaxy?eld strengths of2-3
μG are consistent with synchrotron/cosmic ray models of Strong,Moskalenko,&Reimer
(2000).
The scalings we?nd for MRI amplitudes show interesting di?erences from those obtained
with single-phase gaseous media,in previous adiabatic and isothermal simulations.In the
shearing-box models of HGB1,HGB2,and Sano et al.(2004),all of the measures of turbu-
员工薪资管理系统 背景 企业的工资管理是公司管理的一个重要内容，随着企业人员数量增加，企业的工资管理工作也变得越来越复杂。工资管理既设计到企业劳动认识的管理，同时也是企业财务管理的重要组成部分，工资管理需要和人事管理相联系，同时连接工时考核和医疗保险等等，来生产那个企业每个职工的基本工资、津贴、医疗保险、保险费、实际发放工资等。资金是企业生存的主要元素，资金的流动影响到企业的整体运作，企业员工的工资是企业资金管理的一个重要的组成部分。早期的工资统计和发放都是使用人工方式处理纸质材料，不仅花费财务人员大量的时间且不易保存，往往由于个人的因素抄写不慎活计算疏漏，出现工资发放错误的现象。早期工资管理多采取纸质材料和具有较强的时间限制。基于以上原因，企业工资管理系统使用电脑安全保存、快速计算、全面统计，实现工资管理的系统化、规范化、自动化。企业工资管理系统极大的提高了工作效率，节省了人力和财力，最终满足企业财务管理、员工工资发放的需要，同时也成为现代化企业管理的标志。
需求分析 员工薪资管理系统的开题分析： 1、公司的员工各自只能不同，领取的工资也不相同，员工分为管理人员、财务人员、技术人员和工人； 2、下设几个部门，各部门人员领取的工资也不相同，有人事部、售会计部、广告部、售后服务部和生产车间等一系列部门 3、工资由基本工资、福利补贴和奖励工资构成，失业保险和住房公积金在工资中扣除 4、每个员工的基本资料有姓名、性别、年龄、单位、参加工作时间和职务（如经理、主任、科长、工程师、办事员和工人等）。 5、每月个人的最高工资不超过3000 元。工资每月按部门发放，实际发放的工资金额为工资总额减去失业保险和住房公积金。如果违反劳动纪律，每次扣除基本工资的10%，若扣除金额每月累计超过基本工资，下月工资停发。 员工薪资管理系统的功能分析： 1、员工信息的输入，包括员工的姓名、职工号、性别、年龄、职 务、工作时间、应得工资和实发工资 2、员工信息的查询，包括员工的姓名、职工号、性别、年龄、职 务、工作时间、应得工资和实发工资 3、员工信息的修改，包括员工的姓名、职工号、性别、年龄、职 务、工作时间、应得工资和实发工资 4、新增员工信息的插入，包括员工的姓名、职工号、性别、年龄、 职务、工作时间、应得工资和实发工资 5、离职员工信息的删除，包括员工的姓名、职工号、性别、年龄、
脐带间充质干细胞的研究进展 间充质干细胞（mesenchymal stem cells,MSC S ）是来源于发育早期中胚层 的一类多能干细胞[1-5]，MSC S 由于它的自我更新和多项分化潜能，而具有巨大的 治疗价值 ,日益受到关注。MSC S 有以下特点：(1)多向分化潜能，在适当的诱导条件下可分化为肌细胞[2]、成骨细胞[3、4]、脂肪细胞、神经细胞[9]、肝细胞[6]、心肌细胞[10]和表皮细胞[11, 12]；(2)通过分泌可溶性因子和转分化促进创面愈合；(3) 免疫调控功能，骨髓源（bone marrow ）MSC S 表达MHC-I类分子，不表达MHC-II 类分子，不表达CD80、CD86、CD40等协同刺激分子，体外抑制混合淋巴细胞反应，体内诱导免疫耐受[11, 15]，在预防和治疗移植物抗宿主病、诱导器官移植免疫耐受等领域有较好的应用前景；(4)连续传代培养和冷冻保存后仍具有多向分化潜能，可作为理想的种子细胞用于组织工程和细胞替代治疗。1974年Friedenstein [16] 首先证明了骨髓中存在MSC S ，以后的研究证明MSC S 不仅存在于骨髓中，也存在 于其他一些组织与器官的间质中：如外周血[17]，脐血[5]，松质骨[1, 18]，脂肪组织[1]，滑膜[18]和脐带。在所有这些来源中，脐血(umbilical cord blood)和脐带(umbilical cord)是MSC S 最理想的来源，因为它们可以通过非侵入性手段容易获 得，并且病毒污染的风险低，还可冷冻保存后行自体移植。然而，脐血MSC的培养成功率不高[19, 23-24]，Shetty 的研究认为只有6%，而脐带MSC的培养成功率可 达100%[25]。另外从脐血中分离MSC S ，就浪费了其中的造血干/祖细胞(hematopoietic stem cells/hematopoietic progenitor cells,HSCs/HPCs) [26, 27]，因此，脐带MSC S (umbilical cord mesenchymal stem cells, UC-MSC S )就成 为重要来源。 一．概述 人脐带约40 g, 它的长度约60–65 cm, 足月脐带的平均直径约1.5 cm[28, 29]。脐带被覆着鳞状上皮，叫脐带上皮，是单层或复层结构，这层上皮由羊膜延续过来[30, 31]。脐带的内部是两根动脉和一根静脉，血管之间是粘液样的结缔组织，叫做沃顿胶质，充当血管外膜的功能。脐带中无毛细血管和淋巴系统。沃顿胶质的网状系统是糖蛋白微纤维和胶原纤维。沃顿胶质中最多的葡萄糖胺聚糖是透明质酸，它是包绕在成纤维样细胞和胶原纤维周围的并维持脐带形状的水合凝胶，使脐带免受挤压。沃顿胶质的基质细胞是成纤维样细胞[32]，这种中间丝蛋白表达于间充质来源的细胞如成纤维细胞的，而不表达于平滑肌细胞。共表达波形蛋白和索蛋白提示这些细胞本质上肌纤维母细胞。 脐带基质细胞也是一种具有多能干细胞特点的细胞，具有多项分化潜能，其 形态和生物学特点与骨髓源性MSC S 相似[5, 20, 21, 38, 46]，但脐带MSC S 更原始，是介 于成体干细胞和胚胎干细胞之间的一种干细胞，表达Oct-4, Sox-2和Nanog等多
一、模块设计 （1）主登陆界面模块：该模块提供管理系统的主界面，是主系统的唯一入口和出口，该界面提供用户登陆并选择并调用各子模块 （2）员工界面：员工进入该模块进行选择查询操作。（3）工资管理人员界面：工资管理人员进入操作界面。 （4）工资浏览界面：管理人员浏览所有员工工资。（5）工资添加界面：管理人员添加员工工资信息。（6）工资删除界面：管理人员删除员工工资信息。（7）工资查询界面：在此模块中，管理人员有五种 查询方式，员工有3种查询方式。 （8）工资修改界面：管理人员修改员工工资信息。
三、需求分析 需求分析是软件定义的最后一个阶段，它的基本任务是回答“系统必须做什么”这个问题，需求分析的任务不是确定系统怎样完成它的工作，而仅仅是确定系统完成哪些工作，也就是对目标系统提出完整、准确、清晰、具体的要求。 2008年第1期胡娟基于B/S 模式的工资管理系统·33· 修改完毕后点确定则会提示修改成功。如图6.4(g)。 图6.4(g) 测试结果显示程序能够完成所需要的基本功能，该系统能够满足一般需求。 4.总结 4.1 系统可改进的地方 虽然该工资系统已经完成了一些基本功能，但是还 是有一些可以改进的地方。 （1）在查询的时候可以限定用户查询条件。例如，不让 用户输入年份和月，而是给出下拉表，让用户自由选择。 （2）在查询页面可以提供打印功能。当用户查询完自己 所需要的信息后可以将这些信息打印出来，对查询表格 字体、排版等方面可以做规范化的调整，增加“起始时 间”“终止时间”等格式，使打印出的格式清晰美观 （3）增加统计功能。该功能可以统计部门平均收入，一 段时间的收入，并将结果跟往年的比较，让员工对自己 的工资信息更加清楚，让管理人员对每个员工的工作情 况更加了解。 （4）增加用户定制信息，将员工关心的资料定期发送至 其邮箱或手机。 4.2 发展前景 新的管理思想和新技术的发展，信息技术的不断革 新，对管理软件的发展起到了决定性的促进作用。在网 络高速发展的今天，越来越多的企业、个人认识到网络 的便利，信息反馈的方便与快捷。电子商务的炒作热潮 虽然已经褪去，但电子商务开始"着陆"了，会有越来越 多的企业和个人投入到电子商务这一新的商务活动之 中，对电子商务网站的需求肯定是有增无减，真正的电 子商务应用时代到来了，无论是使用者，还是开发者， 都从电子商务热中得到了启迪：市场竞争的日益加剧， WTO 的日渐临近，企业的生存和发展每天都在接受着 新的挑战，要想应付竞争，就要扩大规模，要扩大规模， 就要提高管理。因此，作为电子商务发展基石的供应链 管理已得到中大型企业的密切关注并被提到应用日程。 由于现在企业的分支机构众多，而且很多分支机构的地 域范围很广，传统的办公模式已经不能很好的适应市场 发展的要求，同时人员的流动性也比较大，不能在传统 的办公模式下对每一个员工都要求在传统的办公环境下
外教一对一英语口语的重要性 随着2008北京奥运、2010上海世博会，中国与国际融合的脚步加快，而英语作为搭建国际化沟通的重要桥梁，受到中国社会各界尤其是企业界的追捧。从长远来看，双语人才，尤其是英语人才，不论在企业国际化人才架构中，还是在中国国际化和平崛起的进程中，都是不可或缺的“基础设施”。外教1对1的培训能很快的提高口语水平，加速双语人才进程。 正是在这样一个国际化浪潮汹涌澎湃的背景下，外教1对1培训的重要性和紧迫性再次被突显，而英语培训过程中经常出现的“缺乏方向”、“缺乏标准”和“缺乏绩效考核”成为企业挥之不去的心病。正是因为这样，我们就不难理解为何“让英语培训机构按企业特定岗位的语言需求培养人才，真正实现企业英语培训与岗位语言胜任能力的无缝对接”、“如何借助第三方语言测评机构的专业力量完善企业英语培训外包机制”、“如何更有效地向英语培训机构下订单”等话题会被企业HR们所关心和热议。 在很多有经验的HR看来，外教英语1对1培训更多是源于改善或提高员工岗位语言胜任能力的直接需求，而企业只有将培训需求和考核标准量化后，才能精准地向英语培训机构提出“订制人才”的标准和要求，这也就是我们常听到的“订单式培训”。在企业内部英语培训的外包操作上，记者最近也注意到越来越多涉外企业的HR们倾向采用“第三方语言测评机构+英语培训机构”的二元培训模式。
那么，HR们又是如何借助英语外教1对1推进企业英语培训的需求下单、绩效考核及效果评估的？首先，企业借助第三方测评机构的专业化力量和专家资源，例如北京的速恩英语，先设计好公司各部门相应的岗位英语胜任标准，然后在培训之前组织相关岗位员工通过相应的英语考试测评，将考试测评的成绩与既定的岗位英语胜任标准进行比照，找出能力与胜任之间的差距，并以此量化成培训需求和向英语培训机构下培训订单的考核标准；其次，英语培训机构根据企业培训订单的培训需求和考核标准，量身定做相应的培训方案，对参训人员进行培训；最后，在培训结束时，再次组织参训人员参与英语测评考试，通过培训前、培训后两次成绩对照以检验“本次英语培训的是否达到既定的预期”、“员工的英语胜任能力通过培训是否得到改善或提高”，做到企业内部英语培训可量化考核和整体绩效评估，避免主观判断。
工资管理系统需求分析 一、开发背景 随着公司业务的扩展，人员的增多，传统的手工作业已经不再适合公司发展的需要。所以引进计算机技术对企业内部员工进行方便的管理，这样有诸多好处，各层管理人员可以对企业众多的员工信息进行动态的管理，例如基本资料的修改，添加，删除，查询等。有利于减少错误，减轻人事部门的任务，提高效率，节约人力资源，降低企业成本。 二、系统的功能需求包括以下几个方面。 (1)每个员工有用户名和密码，能够方便的按照某种关键字对自己的工资及个人信息进行查询。 (2)系统管理员有唯一的用户名和密码，完成对员工资料的增、删、改、查以及对系统的维护。 (3)上级主管部门可以对员工信息的查询，增加，修改，删除，汇总及打印。打印员工的信息，工资发放报表，工资历史报表，奖惩报表。 满足上述需求的系统主要包括以下几个模块。 (1)基本数据维护模块。提供了使用者录入，修改并维护基本数据的 途径。例如对员工信息的更新与修改。 (2)基本信息模块。主要用于实现对员工工资的管理。还有每个员工 的工资是根据你本月是否违纪，是否犯错和你进公司的时候的确定工资 来确定。 (3)数据库管理模块。在系统中，所有员工的信息都要统一管理，工 资的发放情况和有多少工资要有详细的记录，所以要用统一的数据库平 台进行。 (4)信息查询模块。主要用于查询工资信息和员工信息。下图所示表 示了工资管理系统的功能需求。
1. 基本数据维护模块。包括如图所示的几个方面。 (1)数据备份。将数据进行复制。 (2)数据恢复。对数据进行恢复。 (3)数据导入。将数据导入到数据库中。 (4)数据导出。将数据从数据库中导出。 2. 基本业务模块。包括如图所示的几个方面。
脐带血造血干细胞库管理办法（试行） 第一章总则 第一条为合理利用我国脐带血造血干细胞资源，促进脐带血造血干细胞移植高新技术的发展，确保脐带血 造血干细胞应用的安全性和有效性，特制定本管理办法。 第二条脐带血造血干细胞库是指以人体造血干细胞移植为目的，具有采集、处理、保存和提供造血干细胞 的能力，并具有相当研究实力的特殊血站。 任何单位和个人不得以营利为目的进行脐带血采供活动。 第三条本办法所指脐带血为与孕妇和新生儿血容量和血循环无关的，由新生儿脐带扎断后的远端所采集的 胎盘血。 第四条对脐带血造血干细胞库实行全国统一规划，统一布局，统一标准，统一规范和统一管理制度。 第二章设置审批 第五条国务院卫生行政部门根据我国人口分布、卫生资源、临床造血干细胞移植需要等实际情况，制订我 国脐带血造血干细胞库设置的总体布局和发展规划。 第六条脐带血造血干细胞库的设置必须经国务院卫生行政部门批准。 第七条国务院卫生行政部门成立由有关方面专家组成的脐带血造血干细胞库专家委员会（以下简称专家委
员会），负责对脐带血造血干细胞库设置的申请、验收和考评提出论证意见。专家委员会负责制订脐带血 造血干细胞库建设、操作、运行等技术标准。 第八条脐带血造血干细胞库设置的申请者除符合国家规划和布局要求，具备设置一般血站基本条件之外， 还需具备下列条件： （一）具有基本的血液学研究基础和造血干细胞研究能力； （二）具有符合储存不低于1 万份脐带血的高清洁度的空间和冷冻设备的设计规划； （三）具有血细胞生物学、HLA 配型、相关病原体检测、遗传学和冷冻生物学、专供脐带血处理等符合GMP、 GLP 标准的实验室、资料保存室； （四）具有流式细胞仪、程控冷冻仪、PCR 仪和细胞冷冻及相关检测及计算机网络管理等仪器设备； （五）具有独立开展实验血液学、免疫学、造血细胞培养、检测、HLA 配型、病原体检测、冷冻生物学、 管理、质量控制和监测、仪器操作、资料保管和共享等方面的技术、管理和服务人员； （六）具有安全可靠的脐带血来源保证； （七）具备多渠道筹集建设资金运转经费的能力。 第九条设置脐带血造血干细胞库应向所在地省级卫生行政部门提交设置可行性研究报告，内容包括：
公司员工工资管理系统课程设计 （一）可行性分析 1.1项目背景及意义：随着我国国民经济建设的蓬勃发展和具有中国特色的社会主义市场经济体制的迅速完善，各个行业都在积极使用现代化的手段，不断改善服务质量，提高工作效率，这些都在很大程度上给企业提出越来越严峻的挑战，对企业体系无论是在行政职能、企业管理水平以及优质服务上都提出更高的要求。建设一个科学高效的信息管理系统是解决这一问题的必由之路。企业部财务管理是该企业运用现代化技术创造更多更高的经济效益的主要因素之一。工资管理作为企业部的一种财务管理也是如此，由于企业职工人数较多，每一位职工的具体实际情况也不尽相同，各项工资条款的发放，如果没有一个完整的工资管理系统对员工工资等进行系统的管理，很难实现企业高效运转。 意义： （1）本系统提供了基本的人员信息管理，同时对员工的基本工资、浮动工资和工资发放进行系统管理，同时配以查询、修改、删除、添加功能，以便能真正适用于各类中小企业及事业单位。 经过自己认真的思考和同学的讨论使我对该类管理系统有了进一步的认识，同时也可以应用平时学习中所学到的东西。 1.2可行性研究报告及信息系统目标：员工工资管理系统的主要目的是利用计算机对员工的各种工资信息进行日常的管理，如查询、修改、添加、删除以及存储等，迅速准确地完成各种工资信息的统计计算和汇总工作，针对系统服务对象的具体要求，设计了企业工资管理系统。企业工资管理系统主要有以下几大功能：
对单位人员的变动进行处理。一个单位的职工不会是一成不变的，总是在不断的变化：有调出、有调入、也有职工在本单位部调动。因此，设计系统是应考虑到这些情况。 对职工的工资进行计算、修改。可以对职工的工资档案进行个别、部分和批量修改，同时，能对各职工的工资进行计算，即计算基本工资、岗位工资、水电费及实发金额等。 查询统计功能。要求即可以单项查询，比如查看某个职工的工资情况等；也可以多项查询，比如某个部门所有的员工的工资信息。 （二）系统分析部分 2.1系统功能模块图
职工工资管理信息系统设计与实现 学院：经济与管理学院 班级：09信管 姓名：王友兴 学号：090403010043
目录 1 引言 (2) 1.1问题的提出 (3) 1.2任务与分析 (3) 2设计方案 (4) 2.1程序功能设计 (4) 2.1.1程序功能描述 (4) 2.1.2程序结构分析 (4) 2.1.3 数据表结构分析 (5) 2.1.4程序流程分析 (7) 2.2程序界面和代码设计 (7) 2.2.1项目设计框架 (7) 2.2.2主要表单及代码设计 (9) 3 结果分析 (20) 结论 (25) 致谢 (26) 参考文献 (27)
1 引言 1.1 问题的提出 为适合现代企业的需要,职工工资管理已经成为企业管理的一个难题,由于其费时和繁琐性，企业迫切需要一种专门为职工工资管理而服务的工具。为此,简单的职工工资管理系统为此而制造出来。本简单程序是为职工工资管理而设计的,内容简单，使用方便。程序稍加变更可以适合对资源分配方面的杂事加以处理。 作为当代大学生，熟练的操作计算机是一种必备的素质。本次设计会让我们更加熟悉VF编程，把以前学过的一些东西又重新复习了一遍，并与实际结合起来，对我们能力的提升有了很大的帮助，还能促使我们在以后的实际应用中更好的应用VF编程来设计一些数据库管理系统。 1.2 任务与分析 分析你的设计任务，有什么难点？怎么解决？完成的步骤！ 职工工资管理系统是典型的信息管理系统，其开发主要包括后台数据库的建立和维护以及前端应用程序的开发两个方面。对于前者要求建立起数据一致性和完整性强、数据安全性好的库。而对于后者则要求应用程序功能完备,易使用等特点. 本系统主要完成对学生选课信息的管理，包括数据库中表的添加、删除等。系统可以完成对各类信息的浏览、修改、查询和工资信息对工资进行计算的功能。系统的核心是数据库中各个表联系，每一个表的修改都将联动的影响其它的表，当完成对数据的操作时系统会自动地完成数据库的修改。查询功能也是系统的核心之一，在系统中即有单条件查询和多条件查询，也有精确查询和模糊查询，系统不仅有静态的条件查询，也有动态生成的条件查询，其目的都是为了方便用户使用。本系统有完整的用户添加、删除和密码修改功能，并具备报表打印功能.
1、编写目的 随着当今企业规模不断变大，企业人员数量的增加，企业工资的计算也变得越来越复杂。在企业里每天都要处理大量的数据信息，为了提高工资管理的工作效率，降低出错概率。本系统的开发宗旨以及总体任务就是帮助企业提高工作效率，实现企业工资信息管理的自动化、规范化和系统化。 2、编写依据 依据图书馆管理系统软件的方案书。 4.1软件总体描述 本系统可运行于windows xp及以上版本，具有较高的安全性、可维护性及可操作性，对于一般人用户使用需具简单、直观、易操作性的特点。 4.2软件设计约束及有关说明 开发环境：windows操作系统、SQL server 。 编程语言：c或一些通俗易懂的语言 遵循的规范： 测试环境： 软件交付日期：16周 4.3使用者特点 4.3.1对服务端后台管理人员： 要求有网站维护的技能，能够对服务端后台处理进行管理，能捕获系统异常。 要求掌握SQL数据库操作，能够对后台数据库进行日常维护与管理，例如：对数据 库的备份与恢复，对冗余数据的删除等； 要求有一定的Linux服务器配置与管理技能，能够阻止非法攻击，优化服务器配置， 保证服务器的安全畅通地运行。 4.3.2对客户端用户：能够通过web浏览器进行网络访问。 5.功能定义 5.1员工基本信息的录入，修改，删除。 5.2工资标准设定功能。具体包括职务工资，工龄工资以及其它工资标准的设定。 5.3工资信息浏览。 5.4员工工资表创建。 5.5工资调整管理。 5.6工资统计。 5.7用户级别设定以及口令修改： 为完善系统管理功能，增加工资系统用户管理功能，包括系统用户数据的天价，修改和
删除。教职员工为系统普通用户，只能运行系统个人工资查询功能；系统管理员则能运行系统所有功能，从而有效保证系统数据的安全性。 6.详细需求 6.1功能需求：主要分为5大模块
薪酬管理体系作为保护和提高员工工作热情的最有效的激励手段，是现代企业管理制度中不可欠缺的一部分。企业经营者只有站在经营管理的高度，系统性地认识薪酬体系的定位、管理对象、实施手段，才能全面把握薪酬管理体系在企业中发挥的管理作用。 工资的发放是企业最核心的一个流程，是企业留住人才，培养人才的最核心的过程。而相对于以前，现在越来越多的企业开始重视使用工资管理系统了，让薪酬工资管理工作更加的流程，更具有可操作性。 目前市场上被广泛运用的薪酬工资管理系统主要目的就是实现工资的集中管理。核心功能是提供供财务人员对该企业的员工以及工资进行增加、删除、修改、查询等操作。同时支持对人事的管理及工资发放中对于应发工资合计等项目的具体核算工作。 1、自定义薪酬结构设置 薪酬工资管理系统一般都会支持按企业工资表自定义薪酬结构，也就是我们可以根据企业已有的工资表中的薪酬项进行选择，同时我们也可以自定义的去添加、重命名以及填写备注事项。 通俗点说就是根据不同的岗位选择不同的薪酬结构，比如销售人员的基本工资+绩效工资；而后勤员工的固定工作+基本工资等不同的薪酬结构的选择。 2、自动生成薪酬图标 工资管理不仅仅只是发放工资，同时我们还需要做好每个月，每个季度的企业员工工资的核算报表，这样做不仅仅可以方便我们清楚
的了解每一个月的具体工资详情，同时也方便以后查询。 3、电子工资条发放 工资管理系统还有一个功能就是电子工资条的发放，工资条的作用是为了告诉员工本月工资明细，员工确认签名后即表示接受上月工资所得，是降低用工风险的一种有效方式。而电子工资条不仅有和传统裁剪出来的工资条有一样的作用，同时具备省时省力、环保的特点。 上海喔趣信息科技有限公司，作为中国劳动力综合管理专家品牌，致力于为大中型企业实现劳动力预测、劳动力管理、劳动力满足全过程的信息化、数字化、智能化，是一家大型为企业提供人事管理、智能排班、智慧考勤、绩效薪资、数据罗盘，灵活用工服务等全链劳动力综合管理与满足的云服务商。目前，使用喔趣科技产品服务，累计超过12万家中国企业，覆盖员工超过400万，主要涵盖了国企事业单位、生产制造、餐饮服务、零售连锁、教育培训、医疗美容等多个行业。
卫生部办公厅关于印发《脐带血造血干细胞治疗技术管理规 范(试行)》的通知 【法规类别】采供血机构和血液管理 【发文字号】卫办医政发[2009]189号 【失效依据】国家卫生计生委办公厅关于印发造血干细胞移植技术管理规范(2017年版)等15个“限制临床应用”医疗技术管理规范和质量控制指标的通知 【发布部门】卫生部(已撤销) 【发布日期】2009.11.13 【实施日期】2009.11.13 【时效性】失效 【效力级别】部门规范性文件 卫生部办公厅关于印发《脐带血造血干细胞治疗技术管理规范（试行）》的通知 （卫办医政发〔2009〕189号） 各省、自治区、直辖市卫生厅局，新疆生产建设兵团卫生局： 为贯彻落实《医疗技术临床应用管理办法》，做好脐带血造血干细胞治疗技术审核和临床应用管理，保障医疗质量和医疗安全，我部组织制定了《脐带血造血干细胞治疗技术管理规范（试行）》。现印发给你们，请遵照执行。 二〇〇九年十一月十三日
脐带血造血干细胞 治疗技术管理规范（试行） 为规范脐带血造血干细胞治疗技术的临床应用，保证医疗质量和医疗安全，制定本规范。本规范为技术审核机构对医疗机构申请临床应用脐带血造血干细胞治疗技术进行技术审核的依据，是医疗机构及其医师开展脐带血造血干细胞治疗技术的最低要求。 本治疗技术管理规范适用于脐带血造血干细胞移植技术。 一、医疗机构基本要求 （一）开展脐带血造血干细胞治疗技术的医疗机构应当与其功能、任务相适应，有合法脐带血造血干细胞来源。 （二）三级综合医院、血液病医院或儿童医院，具有卫生行政部门核准登记的血液内科或儿科专业诊疗科目。 1.三级综合医院血液内科开展成人脐带血造血干细胞治疗技术的，还应当具备以下条件： （1）近3年内独立开展脐带血造血干细胞和（或）同种异基因造血干细胞移植15例以上。 （2）有4张床位以上的百级层流病房，配备病人呼叫系统、心电监护仪、电动吸引器、供氧设施。 （3）开展儿童脐带血造血干细胞治疗技术的，还应至少有1名具有副主任医师以上专业技术职务任职资格的儿科医师。 2.三级综合医院儿科开展儿童脐带血造血干细胞治疗技术的，还应当具备以下条件：
4、4数据库设计 4、1数据库分析 通过系统管理，能够增强员工之间得沟通,更好地协调员工之间得协作关系；对员工基础信息管理与薪资管理更加科学；能够全程跟踪员工得培训,通过信息得记录,更好地作出员工培训方案.在设计工资管理信息系统时，主要从模块组成、数据连接、功能实现、应用意义等方面着手。模块组成主要包括该工资管理信息系统得主要组成模块以及每个模块所要达到得功能。每个模块基本上脱离不了数据,所以在数据库设计时，要充分考虑数据得高效性,减少数据冗余，保证系统运行速度。 ４、2数据库概念设计 根据以上各节对系统所做得需求分析与系统设计,规划出本系统中使用得数据库实体分别为管理员实体、招聘人员实体、员工信息管理实体、薪资管理实体、培训信息实体及部门信息实体。系统总体ER图如图所示: 下面将介绍几个关键实体得E－R图. 1、管理员实体 管理员实体包括管理员帐号、管理员密码及管理员级别属性.其中管理员级别信息中，１代表系统管理员，0代表普通管理员。
图 5-1 管理员实体 2、员工信息管理实体 员工信息管理实体包括员工编号、员工姓名、员工年龄、员工性别、出生日期、员工身份证号、民族、婚姻状况、政治面貌、籍贯、联系电话、家庭住址、员工毕业学校、员工所学专业、文化程度、上岗时间、部门名称、部门工种、登记人、登记时间及备注信息属性。 3、薪资管理实体 薪资管理实体包括员工编号、工资发放时间、基本工资、加班次数、工龄、全勤奖、旷工费及保险费等属性。 4、3数据库逻辑结构 数据得概念结构设计完之后,可以将上面得数据库概念结构转化为某种数据库系统所支持得实际数据模型,也就就是数据库得逻辑结构.系统数据库中各表得详细ＳQL语句。 CRＥATE TＡBLＥ｀ｄｅp` ( //部门表 `iｄ` ｉｎｔ(10） unsｉｇned ＮOＴＮＵLL auto_ｉnｃｒeｍent MENT ’自动编号’， `dep_id` varchar（1６） dｅfauｌｔＮULL MENT '部门编号＇， `dｅp_ｎaｍe` ｖaｒchar(16）ｄｅｆauｌｔNＵLL MENT '部门名称＇，`deｐ_info` ｖarchar(５１2） dｅfａｕlt NULL ＭENT ’部门简介’,
企业工资管理系统需求分析
引言 随着社会经济的迅速发展和科学技术的进步，以计算机和软件工程为基础的信息系统正是蓬勃发展的时期。企业工资管理系统的内容对于企业的管理者来说都至关重要,所以企业工资管理系统应该能够为用户提供充足的信息和快捷的查询手段。所以工资管理信息系统能够为高层领导者提供准确的人员信息，以便领导者了解企业各个部门的人员构成，计算好人力成本，安排好工作计划，使企业变的更高效，更具有生命力。因此，开发工资管理系统更具有一定的社会现实意义。 1.业务概述 1.1传统模式处理业务介绍 在计算机诞生之前，人们对帐目的管理一直采用的是纸质材料记录，人工统计和计算。这样的管理不但费时费力，也容易产生计算上的错误和各种疏漏；随着时代的变迁，这种混乱的情形有所改善，但采取的依然是人工操作，工作量大的时候，出现错误的机率也随之升高。目前我国还有一部分企业停留在原始的人力管理职工工资的方式上，这样的机制既不能适应时代的发展，又不利于企业自身的发展，这种管理方式存在着许多缺点,如:效率低、保密性差,另外时间一长,将产生大量的文件和数据,这对于查找、更新和维护都带来了不少的困难。 当今社会，资金是企业生存的主要元素，资金的流动影响到企业的整体运作，企业员工的工资是企业资金管理的一个重要的组成部分，因为企业每个月都要涉及发放企业员工工资的问题。而随着企业人员数量的增加，企业的工资管理也变得越来越复杂。企业员工的人数越多，工资的统计工作就越多，工资的发放困难就越大。如果能够实现工资管理的自动化，无疑将给企业管理部门带来很大的方便。传统的纸介材料的数据信息管理方式已经不适合现代企业公司的发展了，实现工资管理的系统化、规范化、自动化，将成为现代公司管理工资的首选。
SQL数据库员工工资管理系统设计 实验七：数据库设计 数据库名称：职职员资治理系统 姓名：胡少帅 班级：2011级网络工程 学号：20110441021024 1 需求分析 工资治理系统是提供工资治理人员和职工工资进行治理的系统。它能自动对不同职务，不同出勤及各个月份的工资进行治理并生成财务表。 工资治理系统的用户需求要紧功能有： 1各部门的信息情形 2各职工的信息情形 3考勤信息情形 4工资信息情形 5定义登陆用户和用户的权限 2 概念分析 部门E-R图
职工信息E-R图 职务信息E-R图 考勤信息E-R图 用户E-R图 工资情形E-R图 总E-R图 3 逻辑设计 关系模型： 部门（部门编号（主键），部门名称，经理，电话） 职工信息（职工编号（主键），职务编号，姓名，性不，电话，住址，部门编号（外键）） 考勤情形（职工编号（主键），出勤天数，加班天数，出勤奖金，月份）职务（职务编号（主键），职务名称（主键），差不多工资） 工资运算（职工编号（主键），考勤情形，工资，月份） 用户（用户名，密码，权限） 4 物理设计 1 给职工信息表建立非集合索引“职工” /*给职工信息表非建立集合索引*/
create nonclustered index 职工on 职工信息(职工编号) go SELECT * FROM sys.indexes WHERE name='职工' 2给工资表建立唯独索引“工资” /*给工资表建立唯独索引“工资”*/ create unique index 工资on 工资情形(职工编号) go SELECT * FROM sys.indexes WHERE name='工资' Go 3给考勤信息表建立集合索引“考勤” /*给考勤信息表建立非集合索引*/ create nonclustered index 考勤on 考勤信息(职工编号) go SELECT * FROM sys.indexes WHERE name='考勤' 5 实施过程 创建表结构 1 职工信息表 create table 职工信息
企业员工工资管理系统课程设计 1
仲恺农业工程学院 课程设计报告 **************************** 课程面向对象课程设计 姓名 院 (系) 专业年级 学号 指导教师 日期 仲恺农业工程学院教务处制
目录 1 需求与功能分析 (1) 2 系统框架图 (2) 3 类的设计与分析 (2) 4 非成员函数的设计与分析 (4) 5 特色算法分析 (4) 6 存在的问题及对策 (8) 7 用户手册及测试结果 (8) 7.1 用户手册 (8) 7.2 测试结果 (8) 8 心得体会 (11) 9 附:程序源代码 (11)
1 需求与功能分析 在信息技术高速发展的今天,传统的数据统计方式在处理庞大繁杂的信息量时显得力不从心,于是,人们对于运用计算机来辅助和管理工作的需求正在逐步提高。 随着各个企业业务的逐步扩展,企业的员工人数也在迅速增加,由于管理人员水平有限,导致某些员工纪录管理并不完善,特别是繁杂的员工工资管理纪录,不易查询、修改,极易导致错误,而落后的员工管理方法随着社会的日益竞争,必将被淘汰。 由计算机来管理庞大而繁杂的企业员工纪录是非常合适的,不但查询和修改方便,而且效率高,速度快,完全能够满足现代化企业管理的需要,同时也更利于实现全面办公自动化。因此开发一套企业员工工资管理系统软件势在必行。 企业员工工资管理系统是企业管理系统中的一个重要组成部分,它为企业合理的员工调配与编制,以及有关问题的决策能够提供各种必要的基础数据,是公司管理现代化的一个重要方面。利用微机对庞杂而繁锁的员工工资系统实现自动化管理,是计算机公司信息管理系统的重要内容。我在陈勇老师指导下开发了<企业员工工资管理系统>。 1
卫生部关于印发《脐带血造血干细胞库设置管理规范(试行)》的通知 发文机关：卫生部(已撤销) 发布日期： 2001.01.09 生效日期： 2001.02.01 时效性：现行有效 文号：卫医发(2001)10号 各省、自治区、直辖市卫生厅局： 为贯彻实施《脐带血造血干细胞库管理办法（试行）》，保证脐带血临床使用的安全、有效，我部制定了《脐带血造血干细胞库设计管理规范（试行）》。现印发给你们，请遵照执行。 附件：《脐带血造血干细胞库设置管理规范（试行）》 二○○一年一月九日 附件： 脐带血造血干细胞库设置管理规范（试行） 脐带血造血干细胞库的设置管理必须符合本规范的规定。 一、机构设置 （一）脐带血造血干细胞库（以下简称脐带血库）实行主任负责制。 （二）部门设置 脐带血库设置业务科室至少应涵盖以下功能：脐带血采运、处理、细胞培养、组织配型、微生物、深低温冻存及融化、脐带血档案资料及独立的质量管理部分。 二、人员要求
（一）脐带血库主任应具有医学高级职称。脐带血库可设副主任，应具有临床医学或生物学中、高级职称。 （二）各部门负责人员要求 1．负责脐带血采运的人员应具有医学中专以上学历，2年以上医护工作经验，经专业培训并考核合格者。 2．负责细胞培养、组织配型、微生物、深低温冻存及融化、质量保证的人员应具有医学或相关学科本科以上学历，4年以上专业工作经历，并具有丰富的相关专业技术经验和较高的业务指导水平。 3．负责档案资料的人员应具相关专业中专以上学历，具有计算机基础知识和一定的医学知识，熟悉脐带血库的生产全过程。 4．负责其它业务工作的人员应具有相关专业大学以上学历，熟悉相关业务，具有2年以上相关专业工作经验。 （三）各部门工作人员任职条件 1．脐带血采集人员为经过严格专业培训的护士或助产士职称以上卫生专业技术人员并经考核合格者。 2．脐带血处理技术人员为医学、生物学专业大专以上学历，经培训并考核合格者。 3．脐带血冻存技术人员为大专以上学历、经培训并考核合格者。 4．脐带血库实验室技术人员为相关专业大专以上学历，经培训并考核合格者。 三、建筑和设施 （一）脐带血库建筑选址应保证周围无污染源。 （二）脐带血库建筑设施应符合国家有关规定，总体结构与装修要符合抗震、消防、安全、合理、坚固的要求。 （三）脐带血库要布局合理，建筑面积应达到至少能够储存一万份脐带血的空间；并具有脐带血处理洁净室、深低温冻存室、组织配型室、细菌检测室、病毒检测室、造血干/祖细胞检测室、流式细胞仪室、档案资料室、收/发血室、消毒室等专业房。 （四）业务工作区域应与行政区域分开。
《JAVA程序设计》 课程设计报告 设计题目：职工工资管理系统设计与实现学院名称： 专业班级： 姓名： 学号：
目录 一需求分析。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。3 二概要设计。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。3 三详细设计。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。5 3.1 数据库设计。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。3 3.2 模块及窗体设计。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。3 3.2.1 数据库模块设计。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。5 3.2.2 用户登录识别模块。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。6 3.2.3管理员模块。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。8 职工基本信息管理。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。9 职工工资管理。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。20 3.2.4 普通用户模块。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。28 职工信息。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。28 3.2.5 系统管理模块。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。15 3.2.5 主窗体菜单设计。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。15 四软件测试。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。36 五总结。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。36 参考资料：．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．。。。。。。．．17
员工工资管理系统c语言 编程 The latest revision on November 22, 2020
#include<> #include<> #include<> #include<> #define null 0 typedef struct Info1 { char num[10]; char name[10]; char depar[10]; char yfsalary[10]; char aband[10]; char tax[10]; char sfsalary[10]; struct Info1 *next; }Info2; typedef struct Info1 *Info; Info head; void display(); void find(); void modify(); void add(); void del(); void list(); void listOne(Info s); Info isExists(char *num); void init(); void init() { head=(Info)malloc(sizeof(Info2)); head->next=null; } void main() { init(); while(1) { char c;
display(); scanf("%c",&c); switch(c) { case '1':find();break; case '2':add();break; case '3':modify();break; case '4':del();break; case '5':list();break; case '6':printf("\t\t...退出系统！\n");return; default: printf("\t\t输入错误！请按任意键返回重新选择（1-7）\n");getchar(); } } } void display() { printf("\n\t** 欢迎使用员工信息管理系统 **\n\n"); printf("\t请选(1-7):\n"); printf("\t============================================\n"); printf("\t\t1.查询员工信息\n"); printf("\t\t2.录入员工信息\n"); printf("\t\t3.修改员工信息\n"); printf("\t\t4.删除员工信息\n"); printf("\t\t6.显示所有员工信息\n"); printf("\t\t7.退出系统\n"); printf("\t============================================\n"); printf("\t您的选择是: "); } void listOne(Info p) { printf("\n该员工信息记录如下: "); printf("\n===================================================== =====\n\n"); printf("%-12s%-10s%-10s%-7s%-7s%-10s%-10s%\n","员工编号","姓名","部门","应付工资","保险","税金","实付工资"); printf("%-12s%-10s%-10s%-7s%-7s%-10s%-10s%\n",p->num,p->name,p->depar,p->yfsalary,p->aband,p->tax,p->sfsalary); } Info isExists(char *num)
公司员工工资管理系统课程设计 1
公司员工工资管理系统课程设计 （一）可行性分析 1.1项目背景及意义: 随着中国国民经济建设的蓬勃发展和具有中国特色的社会主义市场经济体制的迅速完善, 各个行业都在积极使用现代化的手段, 不断改进服务质量, 提高工作效率, 这些都在很大程度上给企业提出越来越严峻的挑战, 对企业体系无论是在行政职能、企业管理水平以及优质服务上都提出更高的要求。建设一个科学高效的信息管理系统是解决这一问题的必由之路。企业内部财务管理是该企业运用现代化技术创造更多更高的经济效益的主要因素之一。工资管理作为企业内部的一种财务管理也是如此, 由于企业职工人数较多, 每一位职工的具体实际情况也不尽相同, 各项工资条款的发放, 如果没有一个完整的工资管理系统对员工工资等进行系统的管理, 很难实现企业高效运转。 意义: （1）本系统提供了基本的人员信息管理, 同时对员工的基本工资、浮动工资和工资发放进行系统管理, 同时配以查询、修改、删除、添加功能, 以便能真正适用于各类中小企业及事业单位。经过自己认真的思考和同学的讨论使我对该类管理系统有了进一步的认识, 同时也能够应用平时学习中所学到的东西。 1.2可行性研究报告及信息系统目标: 员工工资管理系统的主要目的是利用计算机对员工的各种工资信息进行日常的管理, 如查询、 2
修改、添加、删除以及存储等, 迅速准确地完成各种工资信息的统计计算和汇总工作, 针对系统服务对象的具体要求, 设计了企业工资管理系统。企业工资管理系统主要有以下几大功能: 对单位人员的变动进行处理。一个单位的职工不会是一成不变的, 总是在不断的变化 : 有调出、有调入、 也有职工在本单位内部调动。因此, 设计系统是应考虑到这些情况。 对职工的工资进行计算、修改。能够对职工的工资档案进行个别、部分和批量修改, 同时, 能对各职工的工资进行计算, 即计算基本工资、岗位工资、水电费及实发金额等。 查询统计功能。要求即能够单项查询, 比如查看某个职工的工资情况等; 也能够多项查询, 比如某个部门所有的员工的工资信息。 （二）系统分析部分 2.1系统功能模块图