a r X i v :a s t r o -p h /0509702v 1 23 S e p 2005
Draft version February 5,2008
Preprint typeset using L A T E X style emulateapj v.6/22/04
SEYFERT GALAXIES AND THE HARD X-RAY BACKGROUND:ARTIFICIAL CHANDRA OBSERVATIONS
OF z =0.3ACTIVE GALAXIES
K.C.Peterson,1S.C.Gallagher,1A.E.Hornschemeier,2M.P.Muno,1and E.C.Bullard 3
Draft version February 5,2008
ABSTRACT
Deep X-ray surveys have resolved much of the X-ray background radiation below 2keV into discrete sources,but the background above 8keV remains largely unresolved.The obscured (type 2)Active Galactic Nuclei (AGNs)that are expected to dominate the hard X-ray background have not yet been detected in su?cient numbers to account for the observed background ?ux.However,deep X-ray surveys have revealed large numbers of faint quiescent and starburst galaxies at moderate redshifts.In hopes of recovering the missing AGN population,it has been suggested that the de?ning optical spectral features of low-luminosity Seyfert nuclei at large distances may be overwhelmed by their host galaxies,causing them to appear optically quiescent in deep surveys.We test this possibility by arti?cially redshifting a sample of 23nearby,well-studied active galaxies to z =0.3,testing them for X-ray AGN signatures and comparing them to the objects detected in deep X-ray surveys.We ?nd that these redshifted galaxies have properties consistent with the deep ?eld “normal”and “optically bright,X-ray faint”(OBXF)galaxy populations,supporting the hypothesis that the numbers of AGNs in deep X-ray surveys are being underestimated,and suggesting that OBXFs should not be ruled out as candidate AGN hosts that could contribute to the hard X-ray background source population.
Subject headings:galaxies:active —galaxies:Seyfert —X-rays:di?use background —X-rays:
galaxies
1.INTRODUCTION
One of the fundamental pursuits of deep X-ray surveys is the identi?cation of the sources making up the ob-served X-ray background radiation (Brandt &Hasinger 2005).Because the X-ray powerhouses of the universe are energetically accreting super-massive black holes,or Active Galactic Nuclei (AGNs),this issue is inherently linked to another important topic:an understanding of the cosmic history of super-massive black hole (SMBH)accretion activity.X-ray surveys are arguably among the best methods for obtaining the least-biased samples of AGNs because X-rays are able to penetrate large col-umn densities of gas and dust,and because dilution by host galaxy light at X-ray energies is believed to be min-imal.
Using sensitive instruments such as the Chandra X-ray Observatory (Weisskopf et al.2002),astronomers have resolved ≈90%of the 0.5–2keV background radiation into discrete sources.The dominant contributors to the background in this soft energy band have been identi?ed via optical spectroscopy as type 1Seyfert galaxies and quasars,i.e.,moderate-luminosity (L 0.5?10keV ～1043–1045erg s ?1)AGNs recognized by their broad permit-ted emission lines in the optical (Schmidt et al.1998;Lehmann et al.2001;Worsley et al.2005).Deep sur-veys reveal that the integral number counts of resolved sources at soft energies ?atten at ?uxes below ≈10?14
1
Department of Physics &Astronomy,University of California –Los Angeles,Mail Code 154705,475Portola Plaza,Los Ange-les CA,90095–4705;kptrson@https://www.doczj.com/doc/628099341.html,,sgall@https://www.doczj.com/doc/628099341.html,,mmuno@https://www.doczj.com/doc/628099341.html, 2Laboratory for X-ray Astrophysics,NASA Goddard Space Flight Center,Code 662.0,Greenbelt,MD 20771;annh@https://www.doczj.com/doc/628099341.html,
3Center for Space Research,Massachusetts Institute of Technol-ogy,77Massachusetts Avenue,Cambridge,Massachusetts 02139;ebullard@https://www.doczj.com/doc/628099341.html,
erg cm ?2s ?1,con?rming that most of the population has already been detected (Rosati et al.2002).Above 8keV,however,only ≈50%of the X-ray background has been resolved,and,in the 5–10keV energy band,no turn-over in number counts is observed out to the ?ux limits of current X-ray surveys (Worsley et al.2005;Brandt &Hasinger 2005).This suggests that a substan-tial fraction of the hard X-ray background is coming from sources that are unrepresented at soft energies;indeed,14–20%of the 2–8keV sources are undetected in the 0.5–2keV band in deep X-ray surveys (Alexander et al.2003;Lehmer et al.2005).Furthermore,while the integrated light from the 1–10keV background can be ?t with a power-law model of the form F (E )∝E ?Γ,with photon index Γ=1.4(De Luca &Molendi 2004),the combined spectrum of the resolved X-ray background components is much softer.Worsley et al.(2004)measured an aver-age 0.2–12keV photon index of Γ～1.75for the resolved X-ray sources,with the slope being steeper (Γ～1.80)at hard energies and shallower (Γ～1.65)at soft energies.They also found that the photon index is harder (with a ?atter spectral slope)for the X-ray faint resolved sources than for the X-ray bright sources.All of this points to a population of as-yet undetected,faint,hard objects con-tributing signi?cantly to the hard (E >8keV)X-ray background.
Type 2(narrow optical emission line)Seyfert galaxies have emerged as the preferred candidates for this un-resolved population.While the intrinsic luminosities of Seyfert 2nuclei can be comparable to Seyfert 1nuclei,their continuum emission from the optical to the soft X-rays is highly obscured.Many of these objects are op-tically thick to Compton scattering (“Compton thick”,N H >1.5×1024cm ?2),and are therefore so heavily absorbed at soft X-ray energies that only reprocessed,indirect X-rays are observable,and the resulting spectra
2Peterson et al.
are hard,consistent with the expected properties of the unresolved background population.Even objects with smaller column densities may be highly obscured;for ex-ample,the observed2–10keV?ux of aΓ=2object with N H=5×1023cm?2would be only one-third of its unabsorbed?ux.Above～10keV,type2AGNs may appear much brighter than at soft energies because their higher energy emission is much less a?ected by obscuring gas(e.g.Beckmann et al.2004).Therefore,their contri-bution to the X-ray background above10keV cannot be estimated with a simple extrapolation of their lower en-ergy spectra.It is important to recognize the obscured AGN character of these objects so that their emerging hard X-ray?ux can be included in accounting for the X-ray background.
As it turns out,X-ray observers have not been able to identify a su?ciently large population of Seyfert2galax-ies at high redshifts to explain the observed hard X-ray background.Instead,deep surveys have revealed sev-eral new observational classes of X-ray sources,includ-ing optically bright,X-ray faint galaxies(OBXFs)and X-ray bright,optically normal galaxies(XBONGs).Nei-ther OBXFs nor XBONGs would be classi?ed as AGNs, based on their optical spectra.The OBXFs are dis-tinguished by their low X-ray–to–optical(R-band)?ux ratios(log(f X/f R)1042erg s?1)in the hard(2–8keV) X-ray band(Comastri et al.2002;Hornschemeier et al. 2005;Barger et al.2005).The X-ray brightness of these objects requires the presence of SMBH accretion activ-ity(i.e.,they must be AGNs),despite their quiescent optical spectra.There is an additional population of X-ray–detected objects with extremely faint optical coun-terparts that lack classi?cation altogether.These may include low-luminosity and optically obscured AGNs. To account for the apparent dearth of Seyfert2galax-ies in deep X-ray surveys,some of the X-ray galaxies that are optically classi?ed as“normal,”including the OBXFs and XBONGs,may contain AGNs that are going unrec-ognized because of the limited means of identifying the properties of distant objects from ground-based observa-tories.In particular,Moran et al.(2002)have suggested that the optical spectral characteristics of type2Seyferts may be drowned out by host galaxy light because many Seyfert2nuclei have low observable emission-line lumi-nosities(L[O iii] 1040erg s?1;Hao et al.2005).This is especially likely in observations of high redshift objects, for which it is impossible to spatially isolate the point-like nuclear light from the extended starlight regions of galax-ies.In a sample of nearby Seyfert2galaxies,Moran et al. (2002)found that60%of the objects would have been wrongly optically classi?ed as normal galaxies in deep ?eld surveys based on their integrated spectra because starlight overwhelmed their AGN emission in the optical band.This suggests that some of the galaxies detected
in deep X-ray surveys could be mistakenly identi?ed via optical spectroscopy as“normal”galaxies when,in fact, they harbor AGNs.If this is the case,then it is possible that part of the missing population of galaxies expected
to make up the hard X-ray background is hiding among the apparently normal galaxies of deep surveys.In the case of XBONGs,their high X-ray luminosities almost certainly require SMBH accretion activity.
As an X-ray analog to the study of Moran et al.(2002), and to further investigate the possibility that high-redshift type2AGNs are being detected but misidenti-
?ed in deep X-ray surveys,we have arti?cially redshifted
a sample of Chandra observations of well-studied,nearby, Seyfert and starburst galaxies to redshift z=0.3,cor-responding to a look-back time of≈3.5Gyr,an epoch where normal/starburst galaxy X-ray luminosity func-tions have already been assembled(Norman et al.2004).
In§2we describe the sample selection,data analysis, and arti?cial redshifting procedures.Section3presents the results of the arti?cial redshifting process.In§4we compare the results to those of deep?eld surveys,and in
§5we present our conclusions.
2.DATA ANALYSIS
2.1.Sample Selection and Observations
The initial galaxy sample was selected from the public Chandra data archive,correlated with the Veron-Cetty&Veron(2001)4catalog of quasars and active galaxies as of June2003,and?ltered to se-lect observations with the backside-illuminated S3CCD
of the Advanced CCD Imaging Spectrometer(ACIS; Garmire et al.2003)in which a L2?8keV=5×1039 erg s?1point source would have a≥7count detection (corresponding to exposure times of63s and106ks for objects with photon indices ofΓ=1.4at red-shifts of z=0.001and z=0.04,respectively).The
S3CCD is preferred because of its superior spectral res-olution and enhanced response at energies below1keV. These initial selection criteria yielded a set of29ob-jects,including one starburst galaxy(NGC2782),which appears to have been wrongly included in the cata-log of Veron-Cetty&Veron(2001).Most authors refer
to NGC2782only as a starburst(Kinney et al.1984; Jogee et al.1999),and Schulz et al.(1998)claim that there is no evidence of an AGN in this galaxy.We clas-sify it as a non-AGN starburst.In the course of our anal-ysis,eight sources,including?ve Seyfert1s,were elimi-nated for any of the following three reasons:having too few counts,having an angular size signi?cantly exceeding that of the8′×8′S3CCD,or showing evidence of severe data degradation by pile-up.Pile-up occurs when two or more photons arrive on a pixel between CCD read-outs, causing loss of counts,and diminishing both the spatial and spectral qualities of observations(see§2.2).One starburst galaxy(NGC4736)and one luminous Seyfert
1/starburst galaxy(Markarian231)were added to the initial sample.Our?nal sample consists of23galaxies with redshifts ranging from z～0.001to0.04.A list of the objects,including the details of their observations,is provided in Table1.Two of the galaxies are starbursts without AGN activity,the other21are Seyferts,six of
4http://www.obs-hp.fr/www/catalogues/veron210.html
Arti?cial z=0.3Chandra Observations3
which host starbursts.Ten of the galaxies also have lu-minous X-ray point source populations.
2.2.X-ray Data Reduction
Chandra ACIS data were retrieved from the Chandra data archive and reprocessed from the level1event?les using a scripted reduction pipeline to ensure uniform analysis of all the observations.This analysis employed the CIAO v.3.2,5HEASOFT v.5.3.1,6and IDL v.6.0soft-ware packages.
The ACIS data were?ltered to include only data from the S3chip.The CIAO tool acis events was used to remove the positional randomization that is in-troduced by the standard pipeline to avoid aliasing ef-fects in short exposures.To mitigate charge transfer in-e?ciency(CTI),we employed the ACIS CTI correction software package developed by Townsley et al.(2000). The data were?ltered on“good”ASCA grades(keep-ing grades0,2,3,4,and6to optimize the signal-to-background ratio)and on status.After examining each light curve for background?ares,we accordingly adjusted and?ltered on good time intervals to produce level2 event?les.
To avoid the adverse spatial and spectral e?ects of pile-up(see§2.1),we examined each image for read-out streaks and dark spots caused by pulse saturation, both of which are symptoms of pile-up.We also surveyed the literature for descriptions of Chandra data analyses of each of these sources,looking for any mention of pile-up.For those galaxies with evidence of pile-up,we used the PIMMS v.3.2a ACIS Pile up and Background Count Estimation tool7to determine whether the pile-up was signi?cant enough to a?ect our analysis.When possi-ble,we repaired the piled-up regions of galaxies using observations taken with shorter frame-times,which were therefore less prone to pile-up.Otherwise,galaxies with estimated pile-up count rates in excess of10%were re-moved from the sample.
2.3.X-ray Arti?cial Redshifting
In order to move the galaxies in our sample to z=0.3, we accounted for both the spatial and spectral e?ects of increased redshift on the observations.We assumed no redshift evolution.Throughout this paper we will use the terms“original observations”and“original images”to refer to the actual observations of the galaxies at their true,low redshifts.We will use“redshifted galaxies”and “redshifted images”to refer to the arti?cially redshifted observations produced by the analysis described below. We began by redshifting the energies of the detected photons,being mindful of the dependence of ACIS sen-sitivity on photon energy as described by the Auxiliary Response File(ARF)associated with each Chandra ob-servation.The ARF relates the expected detector count rate to the incident source spectrum,accounting for the e?ective area and quantum e?ciency of the telescope,?lter,and detector system.In general,the number of counts in a single Chandra energy band,E1?E2,is mea-5Chandra Interactive Analysis of Observations(CIAO), https://www.doczj.com/doc/628099341.html,/ciao/
6https://www.doczj.com/doc/628099341.html,/ftools/,(Blackburn1995)
7https://www.doczj.com/doc/628099341.html,/toolkit/pimms.jsp sured to be
N E
1?E2
= E2E1A(E)F(E)dE,(1)
where A(E)represents the ARF and F(E)the emission spectrum of the object.In redshifting each observation to z=0.3,we had to account for the fact that the redshifted emission spectrum from the source would encounter a non-redshifted ARF at the detector.Thus,to get the ap-propriate number of counts in the observed band E1?E2 for an arti?cially redshifted galaxy,we could not simply count the photons from the original observations in a blueshifted energy band,E1
orig
(1+z)?E2
orig
(1+z); the ARF also had to be e?ectively redshifted,i.e.,
N(E
1?E2)obs
= E2orig(1+z)
E1orig(1+z)
A E
A(E)
.(3)
Because this ratio varies signi?cantly over the range of energies to which Chandra is sensitive,we divided the ob-servations into narrow energy bands in which the ARF ratio varied by less than30%,then we multiplied each narrow-band image by its corresponding ratio.This re-sulted in images in energy bands as narrow as0.01keV at very soft energies(below～0.5keV)and bands as large as1.85keV at higher energies.The appropriate grating e?ciency was included in creating ARFs for the original gratings observations.
After redshifting the energy in this way,we ad-justed the angular extent of each narrow-band image to account for increased distance(Hogg2000),using aΛCDM cosmology with?M=0.3,?Λ=0.7and H0=70km s?1Mpc?1.Because this re-sizing com-bined many original pixels into each redshifted pixel,the background level,which is usually negligible even for very long Chandra observations,was high and unrealistic in the redshifted images.We accounted for most of the background by measuring the average background level per pixel in the original images,multiplying this value by an appropriate re-sizing factor and ARF ratio,and subtracting it from the redshifted images.
The?ux of each galaxy was decreased according to its increased distance,however this adjustment reduced the total detectable signal from most of the sources to 10 counts.In order to have numbers of counts comparable to those of deep?eld surveys,we arti?cially increased the exposure time of each observation(i.e.,linearly increased the number of counts per pixel)such that the brightest pixel in the0.5–8keV band image of each galaxy had100 counts.(Note:This did not change the luminosities of the objects since we kept track of the observation times. The total arti?cial exposure time for each redshifted im-age is listed in column5of Table1.)Even after this increase,all of the objects appeared as unresolved point sources.We then randomized the number of counts in each pixel based on a Poisson distribution and blurred each image by the energy-dependent,on-axis Chandra point spread function(PSF)to create a more realistic observation of a point source.
4Peterson et al.
The narrow-band images were added up to create a ?nal set of redshifted images in the following three observed-frame energy bands:full (0.5–8keV),soft (0.5–2keV),and hard (2–8keV).Above 8.0keV,the e?ective area of the Chandra mirrors rapidly declines while the background ?ux increases,reducing the signal-to-noise ratio;the lower limit of 0.5keV was chosen to match the well-calibrated part of the instrument response function.
2.4.X-ray Aperture Photometry
The CIAO tool wavdetect was used to locate the red-shifted galaxy in each full-band image.Aperture pho-tometry centered at the corresponding locations was per-formed in the soft-and hard-band images,using aper-tures based on the 95%encircled energy radius of the Chandra PSF (Feigelson et al.2000).The remaining lo-cal background in each redshifted image was measured in a surrounding region and subtracted,and appropriate aperture corrections were applied.When a source was not detected in a given band,an upper limit was calcu-lated using the Bayesian method of Kraft et al.(1991),for 90%con?dence.
Hardness ratios were calculated from the hard-and soft-band counts as follows:
HR =(hard ?soft )/(hard +soft ).The hard-and soft-band ?uxes and luminosities of each redshifted galaxy were estimated based on a spectral model of the form F (E )=N E 0E ?Γphoton cm ?2s ?1keV ?1,where the photon index,Γ,was determined from the measured hardness ratio (HR =0corresponds to Γ～0.5),and the appropriate normalization,N E 0,and ?ux in a given energy band were calculated based on the observed count rate using WebPIMMS.8The e?ects of Galactic neutral hydrogen absorption were negligible.
To avoid reporting anomalous values due to the Pois-son randomization in our redshifting procedure,and to determine the standard deviation in our values,we iter-ated the redshifting process 5,000times for each galaxy,calculating hardness ratio,?ux,and luminosity with each iteration.A Gaussian curve was ?t to the set of re-sults for each quantity,and we report the resulting mean values and standard deviations in Table 2.One of the sources (NGC 4507)had very few counts in the soft band;the distributions of 0.5–2keV ?ux and luminosity for this object were not Gaussian.We report approximate aver-age values of the soft ?ux and luminosity of this galaxy and uncertainties that span the range of possible values.
2.5.Optical data
Optical data were obtained from the HyperLeda database,9which provides total B -band magnitudes and B ?V colors of galaxies derived by ?tting Hubble-type-dependent curves to multiple aperture photometric data (Prugniel &Heraudeau 1998).Because observed-frame Cousins R band (λ=6700?A )at z =0.3cor-responds approximately to rest-frame Johnson V band (λ=5530?A ),we transformed the V magnitudes from LEDA into Cousins R magnitudes for z =0.3galaxies of the appropriate Hubble types.This transformation took into account the ?ux di?erence from the distance as well as a k-correction from the bandpass shift.The
8https://www.doczj.com/doc/628099341.html,/Tools/w3pimms.html 9
http://leda.univ-lyon1.fr/
k-corrections were calculated using the synthetic pho-tometry software package synphot 10and a galaxy spec-tral template matched in Hubble type to each object;k-correction values ranged from ?0.2to ?0.5.
B ?V colors were not available from LEDA for four of the galaxies in our sample (NG
C 424,NGC 2110,MCG-05-23-016,and IC 2560).For these objects,the colors typical of their various Hubble types were used (Fukugita et al.1995).
3.REDSHIFTED GALAXY PROPERTIES
The practice adopted here of calculating X-ray lumi-nosity from a simple spectral model,namely a hardness ratio and a photon count rate,is standard among deep ?eld observations where low numbers of detected X-ray photons prevent a more complicated analysis.We ?nd that the simply measured 2–8keV luminosities of our ar-ti?cially redshifted observations are consistent within a factor of ≈1–3with the luminosities determined by much more sophisticated spectral modeling,as available in the literature (see references in Table 1).
The exposure time necessary to detect 100counts in the brightest pixel of each full-band image (before blur-ring)is reported in columns 4and 5of Table 1.Clearly,some of these exposure times are unreasonably long.For comparison,we list the number of counts expected from a 1Ms Chandra ACIS-S observation of each of these ob-jects at z =0.3in columns 6and 7of Table 1.Estimat-ing that 10counts are required for a full-band detection,we ?nd that three sources (NGC 4395,NGC 4736,and Circinus)would not be detected near the aimpoint of a 1Ms Chandra ACIS-S observation.
A 3-color X-ray image of the starburst galaxy NGC 2782at its actual,low redshift is presented in Fig-ure 1.The colors in the image correspond to energy bands of 0.35–1.2keV (red),1.2–3.0keV (green),and 3.0–8.0keV (blue).Evident in this image are the di?use soft X-ray emission surrounding the central starburst and a collection of point sources of various colors.We also present a grayscale arti?cial image of the same starburst galaxy at z =0.3in the full (0.5–8.0keV)energy band.At this distance,the galaxy’s structure is unresolvable,and it appears as a point source.This is typical of the redshifted observations of this study.
In Figure 2we plot the hard-and soft-band luminosi-ties of the galaxies in our sample.We ?nd that the Seyfert 1galaxy is among the most luminous of the sam-ple,which is not surprising since Seyfert 2galaxies su?er from more X-ray absorption than Seyfert 1s.This ef-fect would have been more pronounced had not several X-ray bright Seyfert 1galaxies been eliminated from the sample due to pile-up.
In Figure 3we present a histogram of the hardness ra-tios of the galaxies in our sample,separated based on the presence or absence of starbursts.We ?nd that non-starburst AGNs cover a wide range of hardness ratios but are predominantly hard (HR >0).This trend toward harder spectra among AGNs is not surprising;SMBH ac-cretion produces a strong non-thermal continuum that is bright across the entire X-ray spectrum.In particular,Seyfert 2s (signi?ed by black dots in Figure 3)are of-ten highly absorbed at low X-ray energies and therefore
10
https://www.doczj.com/doc/628099341.html,/resources/software
Arti?cial z=0.3Chandra Observations5
have hard spectra.However,we?nd that about half of the Seyfert2s in this sample are soft(HR<0).In the case of galaxies hosting both an AGN and a starburst, the low hardness ratio is likely due to starburst emission a?ecting the shape of the spectrum(e.g.,Levenson et al. 2001).Starbursts contribute signi?cantly to the soft end of the X-ray spectrum,with a thermal component from supernova remnants and O and B star winds,in addi-tion to radiation from X-ray binaries that may be soft or hard,depending on the properties of the accreting systems.Both of the pure starburst galaxies in this sample have HR<0.The three non-starburst Seyfert 2s in this sample with the softest spectra,NGC4374, NGC4552,and NGC5194,all have signi?cant X-ray point source populations and luminous,extended,soft X-ray emission that a?ect their integrated spectral prop-erties(Finoguenov&Jones2001;Cappellari et al.1999; Terashima&Wilson2001).In addition,NGC4552and NGC5194are known to be very weak AGNs,so non-nuclear X-ray sources may dominate their X-ray emis-sion across the Chandra bandpass.It is also possible that some of the optically obscured(i.e.,type2)AGNs in this sample appear X-ray soft because they are not heavily absorbed at X-ray energies.
https://www.doczj.com/doc/628099341.html,PARISON WITH DEEP FIELD SURVEYS
4.1.Deep Field Survey Data
We compare our results with those of three X-ray sur-veys:the Chandra Deep Field North survey(CDF-N; Alexander et al.2003),the ROSAT Ultra Deep Survey (UDS;Lehmann et al.2001),and the Chandra Multi-wavelength Project(ChaMP;Green et al.2004).To-gether these three surveys sample over4orders of mag-nitude in X-ray?ux,allowing comparison with a broad range of X-ray source types.
The CDF-N survey comprises a2Ms Chandra obser-vation of a448arcmin2?eld,reaching on-axis?ux lim-its in the0.5–2keV and2–8keV bands of2.5×10?17 and1.4×10?16erg cm?2s?1,respectively.The main CDF-N catalog contains503X-ray-detected sources (Alexander et al.2003),for all of which optical coun-terparts were identi?ed using the8.2-meter Subaru tele-scope(Barger et al.2003).Follow-up optical spec-troscopy was performed on an OBXF(log(f X/f R) ?2) subset of these sources(Hornschemeier et al.2003).This subset was revealed to consist primarily of apparently normal galaxies,based on optical identi?cation.The me-dian redshift of the subset was z≈0.3,making it quite comparable to the redshifted galaxy sample of this paper.
A supplementary CDF-N catalog of79lower signi?cance X-ray sources was created by searching for X-ray coun-terparts to optically identi?ed sources;these were there-fore also OBXF galaxies.In Figures4and5we plot the main CDF-N catalog objects as small,solid,black trian-gles,the OBXF subset as large open triangles,and the lower-signi?cance supplementary objects as open circles. The ROSAT UDS consists of three independent sam-ples of sources observed in the direction of the Lock-man Hole with the ROSAT PSPC and/or HRI for207ks (PSPC)and1112ks(HRI),reaching a?ux limit of1.2×10?15erg cm?2s?1in the0.5–2keV energy band. Ninety-four X-ray sources were identi?ed in the survey (Lehmann et al.2001),and Cousins R-band optical mag-nitudes were obtained with the Low Resolution Imaging Spectrometer on the Keck I and II10-meter telescopes for most of the sources.More than half of the UDS sources are type I AGNs,and only one de?nitive“normal”galaxy was identi?ed.In Figure5,we plot77of the sources that have reliable R-band magnitudes as small black stars for comparison with the results of this project.
The ChaMP data used for comparison in Figure5in-clude125serendipitous X-ray sources detected in six Chandra observations(Green et al.2004).The observa-tions had exposure times ranging from29.1to114.6ks, and the serendipitous source0.5–2keV?uxes range from 3.3×10?16to8.7×10?13erg cm?2s?1.Follow-up op-tical imaging observations of the sources were performed with the NOAO4-meter telescope Mosaic CCD cameras, using an SDSS r′?lter.Based on optical spectroscopic observations of the ChaMP objects used for comparison in this paper,50%of them are type1AGNs,22%are narrow emission-line galaxies(including starbursts and AGNs),and18%are absorption-line galaxies.In Fig-ure5we plot the SDSS r′magnitudes versus the soft X-ray?uxes of each of these sources as large X s.
4.2.Discussion of Deep Field Survey Comparison When optical spectroscopy is not available,source clas-si?cation in deep?eld surveys is generally carried out using optical–to–X-ray?ux ratios,hardness ratios,and X-ray luminosity.The sample we have assembled may provide a useful prior for source classi?cation in such studies.As we have e?ectively illustrated in§3,a signif-icant number of“pure”Seyfert2s(roughly one-third of our sample)have HR<0.Notably,HR<0was one of the selection criteria applied to the Norman et al.(2004) Chandra Deep Field sample to separate normal galaxies from AGNs.Apparently,using simple combinations of parameters(such as L x and HR;see Figure2)cannot resolve this classi?cation issue.
The arti?cially redshifted galaxies of our sample span almost the entire range of soft and hard X-ray?uxes ob-served in the CDF-N,as can be seen in Figure4,and all but one(NGC4395)are within the?ux limits of that survey.The solid lines in Figure4indicate the hard-to soft-band?ux relation of various power-law models, includingΓ=1.4,which is characteristic of the X-ray background.We?nd that the CDF-N sources occupy a somewhat narrower range in hard-band?ux per unit soft-band?ux than the galaxies of our sample,cluster-ing aroundΓ=1.4.This is expected not only because Γ=1.4is a typical photon index,but also because the deep survey assumes aΓ=1.4power law for objects with low numbers of detected X-ray photons.(Both the X-ray faint objects of the CDF-N OBXF subset and the lower-signi?cance supplementary catalog objects were assigned a photon index ofΓ=2.0,a value more typical of normal galaxies,in cases of low number counts.)The spread in X-ray color of the redshifted galaxy population demon-strates that the spectral shape of a galaxy’s integrated X-ray emission is not necessarily indicative of its nature. For example,we?nd that obscured AGNs with signi?-cant star formation can appear quite soft,as discussed in§3.
Figure5plots optical–to–X-ray?ux ratios of the red-shifted galaxies in our sample and the deep?eld objects. These reveal that our redshifted Seyfert galaxies are sig-ni?cantly brighter at R band than the majority of the
6Peterson et al.
deep?eld X-ray sources.This may in part re?ect the bias in our sample,which,being selected on the basis of availability in the Chandra archive,is likely to fa-vor well-known,optically bright galaxies.The slanted lines on this plot follow constant log(f X/f R)values, where log(f X/f R)=log(f X)+5.50+R/2.5,divid-ing the plot into regions of assumed typical X-ray–to–optical?ux ratios for di?erent source classes.According to the results of X-ray surveys in which source classi?-cation has been based on follow-up optical spectroscopy (and is therefore subject to the limitations of spectro-scopic identi?cation,as discussed in Moran et al.(2002) and in§1of this paper),AGNs generally fall in the re-gion?1 5.CONCLUSIONS We?nd that,when arti?cially redshifted to z=0.3, a sample of nearby AGNs has integrated X-ray prop-erties and X-ray–to–optical?ux ratios consistent with the“normal”galaxies of deep X-ray surveys.In addi-tion,we see evidence that non-AGN emission can signif-icantly a?ect the shapes of the X-ray spectra of galaxies, as demonstrated by the soft spectra of the AGNs host-ing starbursts in our sample(Figure3).Distinguishing obscured AGNs from the high-redshift X-ray detected galaxies whose X-ray emission is purely powered by X-ray binaries and hot gas from starbursts will require more sophisticated diagnostics than simple hardness ratios,X-ray–to–optical?ux ratios,and X-ray luminosities.We also?nd that longer X-ray observations(～3–10Ms)will be necessary to detect some of these interesting objects, including starbursts and low-luminosity Seyfert galaxies, at z=0.3. Recognizing that the redshifted galaxy sample pre-sented here is biased,and that objects such as these with R<23are relatively rare in deep?eld observations,we make no claims about the overall population of deep?eld objects.However,this work does o?er X-ray support to the optical?nding of Moran et al.(2002)that type 2AGNs could easily go unrecognized in observations of distant galaxies.This result has several possible impli-cations: 1.Some fraction of the missing population of type2 AGNs thought to comprise the unresolved hard X-ray background could be hidden among the so-called nor-mal,OBXF galaxies of deep X-ray surveys.Seyfert-luminosity AGNs such as the ones studied in this pa-per can be found at X-ray–to–optical?ux ratios<10?2, imitating quiescent and starburst galaxies.Their X-ray spectra may be dominated by star formation at the en-ergies to which Chandra and ROSAT are sensitive,and therefore the hardness ratio may not indicate the level of obscuration or the>10keV brightness of these objects. 2.X-ray selected studies of galaxies which use criteria such as X-ray luminosity,hardness ratio and X-ray–to–optical?ux ratio to segregate normal galaxies and AGNs (e.g.,Norman et al.2004)could have higher levels of AGN contamination than previously estimated.There-fore,studies of SMBH accretion may be misled in their analyses of AGN evolution by the incomplete identi?ca-tion of X-ray detected sources.These observational lim-itations must be worked out before the details of AGN evolution can be well understood. Mrk231,the only Seyfert1galaxy included in our sample,provides an interesting case study in poten-tial identi?cation problems with low signal-to-noise ra-tio X-ray survey data.With broad optical emission lines,L2?8keV～1042erg s?1,and a moderately hard HR=0.07,this source would likely be identi?ed as an X-ray absorbed Seyfert1galaxy at z～0.3.How-ever,the complex0.5–8.0keV X-ray spectrum includes soft starburst emission,and the direct X-ray continuum is blocked by a Compton-thick absorber(Braito et al. 2004).Extrapolating simply from the simulated0.5-8.0keV Chandra survey data would lead to a gross un-derestimate of the hard X-ray luminosity of this source. These results will bene?t from more careful study with a larger,well-de?ned sample of nearby galaxies.Overlap with the sample of Moran et al.(2002),and an exten-sion of their optical spectroscopy study would also be valuable. We thank J.C.McDowell for valuable advice regard-ing the arti?cial redshifting process.This work was made possible by Chandra X-ray Center grant G03-4137.Sup-port for SCG was provided by NASA through the Spitzer Fellowship Program,under award1256317.This work made use of images and/or data products provided by the Chandra Multiwavelength Project(ChaMP;Green et al.2002),supported by NASA.Optical data for the ChaMP are obtained in part through the National Op-tical Astronomy Observatory(NOAO),operated by the Association of Universities for Research in Astronomy, Inc.(AURA),under cooperative agreement with the Na-tional Science Foundation.This research has also made use of the NASA/IPAC Extragalactic Database(NED) which is operated by the Jet Propulsion Laboratory,Cal-ifornia Institute of Technology,under contract with the National Aeronautics and Space Administration. 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Arti?cial z=0.3Chandra Observations9 Fig.2.—Hard(2–8keV)versus soft(0.5–2keV)luminosities of the arti?cially redshifted galaxies of our sample.The solid blue hexagons signify Seyfert2galaxies;open,blue,six-pointed stars are Seyfert2galaxies with starbursts;solid magenta triangles are Seyfert1.5,1.8, and1.9galaxies;open,red,4-pointed stars are Seyfert1galaxies with starbursts;and open,green,nine-pointed stars are starbursts without evidence of AGNs.The solid lines follow photon indicesΓ=0.5,Γ=1.4(characteristic of the X-ray background),andΓ=2.0. 10Peterson et al. Fig.3.—Histogram of redshifted galaxy hardness ratios,separated based on presence or absence of star formation activity.The closely spaced,crossed hatches are galaxies with only AGNs;the widely spaced hatches are galaxies with starbursts(six of these also host Seyfert nuclei).Seyfert2galaxies are marked with black dots. Arti?cial z=0.3Chandra Observations11 Fig. 4.—Hard versus soft X-ray?ux.Colored symbols represent arti?cially redshifted galaxies as in Fig.2.The main CDF-N objects are small triangles,the subset of OBXF objects are large,open triangles,and the supplementary,lower-signi?cance sources are open circles. The solid lines indicate photon indices ofΓ=0.5,Γ=1.4(characteristic of the X-ray background),andΓ=2.0. 12Peterson et al. Fig.5.—Optical R-band magnitude versus0.5–2keV X-ray?ux.Colored symbols represent arti?cially redshifted galaxies as in Fig.2. The main CDF-N objects are small triangles,the subset of OBXF objects are large,open triangles,and the supplementary,lower-signi?cance sources are open circles.Small black stars represent ROSAT UDS data,and large X’s represent ChaMP data.The slanted lines follow constant values of log(f X/f R)as follows:the solid line marks log(f X/f R)=0,the dotted lines mark log(f X/f R)=±1,and the dashed line marks log(f X/f R)=?2.The region below log(f X/f R)=?2is believed to be typically populated by quiescent galaxies. 14Peterson et al. TABLE2 Redshifted Galaxy Properties HR F0.5?2keV F2?8keV L0.5?2keV L2?8keV Galaxy(h?s)/(h+s)(10?16erg cm?2s?1)(10?16erg cm?2s?1)(1040erg s?1)(1040erg s?1) NGC4240.04±0.102.7±0.420±47.7±1.057±10 NGC1068?0.83±0.0413±14.5±1.537±413±4 NGC21100.79±0.0518±5330±4051±15950±120 MARKARIAN30.73±0.065.7±1.375±816±4220±20 NGC2782?0.38±0.071.2±0.13.1±0.53.6±0.38.9±1.5 MCG-05-23-0160.63±0.0665±11560±50190±301600±200 NGC3079?0.58±0.060.43±0.030.57±0.121.3±0.11.6±0.3 IC25600.14±0.080.27±0.032.6±0.40.79±0.107.6±1.2 NGC32270.71±0.061.5±0.318±24.4±1.051±6 NGC41510.40±0.074.3±0.682±912±2240±30 NGC4258?0.21±0.060.47±0.031.8±0.21.3±0.15.3±0.6 NGC4303?0.43±0.040.43±0.020.92±0.091.2±0.12.7±0.3 NGC4374?0.86±0.041.7±0.10.50±0.154.8±0.31.4±0.4 NGC43880.44±0.090.40±0.078.3±1.21.1±0.224±4 NGC43950.25±0.090.015±0.0020.19±0.030.043±0.0070.53±0.08 NGC45070.92±0.023.5±1.7220±2010±5630±60 NGC4552?0.74±0.051.1±0.10.74±0.183.3±0.22.1±0.5 NGC4736?0.70±0.070.11±0.010.083±0.0240.30±0.030.24±0.07 MARKARIAN2310.07±0.0913±2100±2038±5300±50 NGC5135?0.67±0.065.6±0.45.2±1.116±115±3 NGC5194?0.67±0.050.32±0.020.29±0.060.92±0.070.85±0.16 CIRCINUS GALAXY0.16±0.100.11±0.021.0±0.20.30±0.053.0±0.5 NGC55060.46±0.0981±16400±50230±501100±200 从劳厄发现晶体X射线衍射谈起 摘要：文章从劳厄发现晶体X射线衍射的前因后果谈起。劳厄的这个发现产生了两个新学科，即X射线谱学和X射线晶体学。文中还回顾了布拉格父子对这两个新学科所作的重大贡献，并阐述了X射线晶体学的深远影响。 今年是劳厄（von Lane M）发现晶体X射线衍射九秩之年。 从1895年伦琴（R0ntgen W C）发现X射线到1926年薛定愕（Schrodinger）奠定量子力学基础的30多年是现代物理学诞生和成长的重要时期。在此期间的众多重大发现中，1912年劳厄的发现发挥了极为及时而又十分深远的影响，是很值得我们通过回顾和展望来纪念它的。 我们先来了解一下劳厄发现的前因后果。1912年劳厄发现晶体X射线衍射时是在德国慕尼黑大学理论物理学教授索未菲（Sommerfeld）手下执教。除理论物理教授索未菲外，在这个大学中还有发现X射线的物理学教授伦琴和著名的晶体学家格罗特（Groth）。当时，劳厄对光的干涉作用特别感兴趣，索末菲则在考虑X射线的本质和产生的机制问题，而格罗特是晶体学权威之一，并著书Chemische KristallograPhic （化学晶体学）数卷。身在这样的学府中，劳厄当时通过耳闻目睹也就对 晶体中原子是按三维点阵排布以及X射线可能是波长很短的电磁波这样的想法不会感到陌生或难于接受了。而且看来正当而立之年的他是很想在光的干涉作用上做点文章的。真可谓机遇不负有心人了。这时，索末菲的博士生埃瓦尔德（Ewald P P）来请教劳厄，谈到他正在研究关于光波通过晶体中按三维点阵排布的原子会产生什么效应。这对劳厄有所触发并想到：如果波长短得比晶体中原子间距离更短时又当怎样？而X射线可能正是这样的射线。他意识到，说不定晶体正是能衍射X射线的三维光栅呢。现在劳厄需要考虑的大事是做实验来证实这个想法。当时索末菲正好有个助教弗里德里希（Friedrich W） ，他曾从伦琴教授那里取得博士学位。 他主动要去进行这样的实验。经过几次失败后，他终于取得了晶体的第一个衍射图「（见图1）」。晶体是五水合硫酸铜（CuSO4·5H2O）。 劳厄的发现经过进一步的工作很快取得了一箭双雕的效果：既明确了X射线的本质，测定了波长，开创了X射线谱学，又使测定晶体结构的前景在望，从而将观察晶体外形所得结论经过三维点阵理论发展到230个空间群理论的晶体学，提升为X射线晶体学。这个发现产生的两个新学科，几乎立即给出了一系列在科学中有重大影响的结果。英国的布拉格父子（Bragg W H和Bragg W L）在奠定这两个新学科的基础中起了非常卓越的作用。他们使工作的重心从德国转到英国。将三个劳厄方程（衍射条件）压缩成一个布拉格方程（定律）的小布拉格曾把重心转移的原因归之于老布拉格设计的用起来得心应手的电离分光计”。既然晶体是X射线的衍射光栅，那么，为了测定X射线的波长，光栅的间距当如何得出？1897年巴洛（Barlow W）预测过最简单的晶体结构型式，其中有氯化钠所属的型式。根据当时已知的NaCI的化学式量（58.46）和阿伏伽德罗常数（6.064×1023）以及晶体密度（2.163g/cm2），可以推算出氯化钠晶体（10）原子面的间距d＝2.814×10－8cm。 布拉格父子的工作是有些分工的：老布拉格用他的电离分光计侧重搞谱学，很快发现X射线谱中含有连续谱和波长取决于对阴极材料的特征谱线。此后，测定晶体结构主要依靠特征射线。同时还观察到同一跃迁系特征射线的频率是随对阴极材料在元素周期系中的排序递增的，这种频率的排序给出了原子序数。这是对化学中总结出来的元素周期律作出的呼应。小布拉格的工作是沿着X射线晶体学的方向发展的。他一生中从氯化钠和金刚石一直测到蛋白质的晶体结构。从1913年起，他在两年中一连测定了氯化钠、金刚石、硫化锌、黄铁矿、荧石和方解石等的晶体结构。这一批最早测定的晶体结构虽然极为简单，但很有代表性，而且都足以让化学和矿物学界观感一新。同时为测定参数较多和结构比较复杂的晶体结构也进行了理论和技术方面的准备。X射线晶体学能不断采用新技术和解决周相问题的新方法，使结构测定的对象 锂硫电池的研究现状 近年来，随着不可再生资源的逐渐减少，清洁能源的利用逐渐得到重视，而电池作为储能装置也受到越来越多的考验。锂硫电池与传统的锂离子电池相比，优势主要在于硫的高比容量，单质硫的理论比容量为1600mAh/g ，理论比能量2600Wh/kg。并且硫是一种廉价且无毒的原材料。而与此同时，硫作为锂电池的正极材料也存在着诸多问题[1]： 1、单质硫以及最终放电产物都是绝缘的，如果与正极中掺入的导电物质结合不好，就会导致活性物质不能参与反应而失效； 2、单质硫在反应过程中会生成长链的聚硫化物离子S n2-，这种离子容易溶解在电解液中，并与锂负极反应，产生“穿梭效应”，引起自放电并使库伦效率降低； 3、在每次放电过程结束之后，都会有一些Li2S2/Li2S沉淀在正极上，并且这些不溶物随着循环次数的增加，在正极表面发生团聚，并且正极结构也会发生变化，导致这部分活性物质不能参与电化学反应而失效，并且使电池的内阻增加； 4、硫正极随充放电的进行会产生约22%的体积变化，从而导致电池物理结构破坏而失效。 针对硫作为正极材料的种种弊端，研究者们分别采用了多种方法予以解决，其中将硫与碳材料复合的研究较多。针对几种典型方法，分别举例介绍如下：一、石墨烯-硫复合材料 Wang等人采用石墨烯包覆硫颗粒的方法制作复合材料电极[2]。如图1所示，他们首先采用化学方法制备了硫单质，并利用一种特殊的表面活性剂Triton X-100在硫颗粒的表面修饰了一些PEG高分子，然后再用导电炭黑和石墨烯的分散液对硫颗粒进行包覆。这种方法的优点在于：首先，石墨烯和导电炭黑具有优异的导电性能，可以克服硫以及硫反应产物绝缘的问题；第二，导电炭黑、石墨烯和PEG高分子对硫颗粒进行了包覆，可以解决硫在电解液中溶出的问题；第三，PEG高分子具有一定的弹性，可以在一定程度上缓解体积变化带来的影响。 二、碳纳米管-硫复合材料 Zheng等人用AAO做模板制备了碳纳米管阵列[3]，随后将硫加热使其浸入到碳纳米管中间，然后将AAO模板去掉，得到碳纳米管-硫复合材料，如图2所示。这种方法的优点在于碳纳米管的比表面积大，有利于硫化锂的沉积。并且长径比较大，可以较好地将硫限制在管内，防止其溶解在电解液中。碳纳米管的导电性好管壁又很薄，有利于离子导通和电子传输。同时，因为制备过程中先沉积硫，后去除模板，这样有利于使硫沉积到碳管内，减少硫在管外的残留，从而防止这部分硫的溶解。 全固态锂电池技术的研究进展与展望 周俊飞 （衢州学院化学与材料工程学院浙江衢州324000） 摘要：现有电化学储能锂离子电池系统采用液体电解质，易泄露、易腐蚀、服役寿命短，具有安全隐患。薄膜型 全固态锂电池、大容量聚合物全固态锂电池和大容量无机全固态锂电池是一类以非可燃性固体电解质取代传统锂离 子电池中液态电解质，锂离子通过在正负极间嵌入-脱出并与电子发生电荷交换后实现电能与化学能转换的新型高 安全性锂二次电池。作者综述了各种全固态锂电池的研究和开发现状，包括固态锂电池的构造、工作原理和性能特 征，锂离子固体电解质材料与电极/电解质界面调控，固态整电池技术等方面，提出并详细分析了该技术面临的主要 科学与技术问题，最后指出了全固态锂电池技术未来的发展趋势。 关键词：储能；全固态锂离子电池；固体电解质；界面调控 1 全固态锂电池概述 全固态锂二次电池，简称为全固态锂电池，即电池各单元，包括正负极、电解质全部采用固态材料的锂二次电池，是从20 世纪50 年代开始发展起来的[10-12]。全固态锂电池在构造上比传统锂离子电池要简单，固体电解质除了传导锂离子，也充当了隔膜的角色，如图 2 所示，所以，在全固态锂电池中，电解液、电解质盐、隔膜与黏接剂聚偏氟乙烯等都不需要使用，大大简化了电池的构建步骤。全固态锂电池的工作原理与液态电解质锂离子电池的原理是相通的，充电时正极中的锂离子从活性物质的晶格中脱嵌，通过固体电解质向负极迁移，电子通过外电路向负极迁移，两者在负极处复合成锂原子、合金化或嵌入到负极材料中。放电过程与充电过程恰好相反，此时电子通过外电路驱动电子器件。目前，对于全固态锂二次电池的研究，按电解区分主要包括两大类[13]：一类是以有机聚合物电解质组成的锂离子电池，也称为聚合物全固态锂电池；另一类是以无机固体电解质组成的锂离子电池，又称为无机全固态锂电池，其比较见表1。通过表1 的比较可以清楚地看到，聚合物全固态锂电池的优点是安全性高、能够制备成各种形状、通过卷对卷的方式制备相对容易，但是，该类电池作为大容量化学电源进入储能领域仍有一段距离，主要存在的问题包括电解质和电极的界面不稳定、高分子固体电解质容易结晶、适用温度范围窄以及力学性能有提升空间；以上问题将导致大容量电池在使用过程中因为局部温度升高、界面处化学反应面使聚合物电解质开貌发生变化，进而增大界面电阻甚至导致断路。同时，具有隔膜作用的电解质层的力学性能的下降将引起电池内部发生短路，从面使电池失效[14-15]。无机固体电解质材料具有机械强度高，不含易燃、易挥发成分，不存在漏夜，抗温度性能好等特点；同时，无机材料处理容易实现大规模制备以满足大尺寸电池的需要，还可以制备成薄膜，易于将锂电池小型化，而且由无机材料组装的薄膜无机固体电解质锂电池具有超长的储存寿命和循环性能，是各类微型电子产品电源的最佳选择[10]。采用有机电解液的传统锂离子电池，因过度充电、内部短路等异常时电解液发热，有自燃甚至爆炸的危险（图3）。从图 3 可以清楚地看到，当电池因为受热或短路情况下导致温度升高后，传统的锰酸锂或钴酸锂液体电解质锂离子电池存在膨胀起火的危险，而基于纯无机材料的全固态锂电池未发生此类事故。这体现了无机全固态锂电池在安全性方面的独特优势。以固体电解质替代有机液体电解液的全固态锂电池，在解决传统锂离子电池能量密度偏低和使用寿命偏短这两个关键问题的同时，有望彻底解决电池的安全性问题，符合未来大容量新型化学储能技术发展的方向。正是被全固态锂电池作为电源所表现出来的优点所吸引，近年来国际上对全固态锂电池的开发和研究逐渐开始活跃[10-12] 2 全固态锂电池储能应用研究进展 在社会发展需求和潜在市场需求的推动下，基于新概念、新材料和新技术的化学储能新体系不断涌现，化学储能技术正向安全可靠、长寿命、大规模、低成本、无污染的方向发展。目前已开发的化学储能装置，包括各种二次电池（如镍氢电池、锂离子电池等）、超级电容器、可再生燃料电池（RFC：电解水制氢-储氢-燃料电池发电）、钠硫电池、液流储能电池等。综合各种因素，考虑用于大规模化学储能的主要是锂二次电池、钠硫电池及液流电池，而其中大容量储能用锂二次电池更具推广前景。。 全固态锂电池、锂硫电池、锂空气电池或锂金属电池等后锂离子充电电池的先导性研究在世界各地积极地进行着，计划在2020 年前后开始商业推广。在众多后锂离子充电电池中，包括日本丰田汽车、韩国三星电子和德国KOLIBRI 电池公司对全固态锂电池都表现出特别的兴趣。图 4 为未来二十年大容量锂电池的发展路径，从图 4 可以看出，全固态电 全固态3D薄膜锂离子电池的研究进展 作者：邓亚锋钱怡崔艳华刘效疆来源：本站浏览数：289 发布时间：2013-8-8 16:28:16 0 引言 全固态薄膜锂离子电池主要由正/负极薄膜、电解质和集流器薄膜组成．整个电池厚约10 μm，可设计成任意形状和大小集成在IC电路中，是便携式电子设备、微电子机械系统(MEMS)以及微型国防技术装备(如微型智能武器)的理想能源。全固态平面薄膜电池(图1)受限于几何结构，能量和功率密度难以满足快速发展的MEMS、微型医疗器械、无线通信、传感器等领域对微电源的要求。全固态三维薄膜锂离子电池(简称3D锂电池)通过独特的构架设计(图2)，增大单位立足面积内电极活性物质负载量，并缩短锂离子扩散半径，提高了电池的容量和充放电速率。是解决未来微电子器件能量需求的一种有效方式，引起了人们的极大关注。 1 不同构架的全固态3D薄膜锂电池 1．1 叉指碳柱3D电池 叉指碳柱3D电池由加利福尼亚大学Wang小组于2004年首次提出(图3)，在Si/SiO2衬底上涂覆感光胶，光刻得到图形，再经过高温热解及后处理，即制得正/负极叉指状碳柱3D电池。叉指碳柱既可以直接作为电极，又可以作为集流器，在其表面沉积各种电化学活性物质。2008年，Min等研究了在叉指碳柱上电镀十二烷基苯磺酸盐掺杂聚吡咯(PPYDBS)导电聚合物薄膜的方法。结果表明，覆盖约10 μm厚PPYDBS的叉指阴极(C-PPYDBS)，电极电位从碳电极的3．2 V提高到了3．7 V(相对于Li/Li+)，但自放电较为严重，电池的放电容量远小于充电电容。 为改善叉指碳柱电极性能，Teixidor等制备出包覆中间相碳微球的叉指碳柱(C-MCMB)，有效提高了电极不可逆容量，但可逆容量仍较低。Chen等在叉指碳柱上包覆碳纳米管(CNT／C-MEMS)使单位立足面积电容达到8．3 F/cm2，充放电循环性能得到显著提高。 叉指碳柱电极成本低、热力学和化学稳定性好、易制成各种形貌、能包覆不同的活性材料(图4)，光刻-热解工艺较为成熟，适合工业化生产。但是，叉指结构放电不均匀、漏电流较大、碳柱在锂离子嵌入和脱出过程中易变形破损，这些问题需进一步研究解决。 1．2 微通道衬底3D电池 1998年，以色列特拉维夫大学的Peled小组首次报道了微通道衬底3D 电池(3D-MCP)；在Si片或玻璃上蚀刻出均匀分布、直径为15～50 μm的微通 论 著8 全固态薄膜锂离子二次电池的研究进展 耿利群任岳*朱仁江陈涛 （重庆师范大学物理与电子工程学院，重庆 400047） 摘 要：本文综述了全固态薄膜锂离子二次电池的研究进展，主要阐述了薄膜锂电池的结构设计以及正极、负极和固体电解质材料研究现状，并对其今后的发展趋势及研发热点进行了展望。 关键词：全固态薄膜锂离子二次电池；固体电解质；电池结构 DOI：10.3969/j.issn.1671-6396.2013.01.004 1 引言 随着电子信息工业和微型加工技术快速发展，对其所需的微型能源则提出了特殊微型化的要求。其中全固态薄膜锂离子二次电池因其高的能量密度、强的安全性、长的循环寿命、宽的工作电压和重量轻等优点，成为微电池系统需求的最佳选择[1]。本文主要介绍了全固态薄膜锂离子二次电池的关键性薄膜材料及电池结构的研究现状，并对其的开发应用及研究前景作了分析。 2 全固态薄膜锂离子二次电池结构的研究 薄膜电池结构的设计，对整个电池性能将产生直接的影响；同样对提高电池的能量密度、循环寿命和锂离子的传输速率也起到至关重要的作用。所以优化薄膜电池结构的设计，则是对构造高性能薄膜锂离子电池做到了强有力的支撑。 1993年美国橡树岭国家实验室（ORNL）Bates等[2]研制出了一种经典的薄膜锂离子电池叠层结构（见图1）。在衬底上先沉积两层阴阳极电流收集极薄膜，而后依次沉积阴极、固体电解质和阳极薄膜，最后在薄膜电池外表面上涂一层保护层，以此来防止阳极上金属锂和空气中的一些物质发生化学反应。 图1 薄膜锂离子电池结构剖面示意图 Baba等[3]研发出另一种典型的薄膜锂离子电池结构（见图2）。其较图1薄膜锂电池结构设计更为简单，制作更为容易。在不锈钢衬底上依次沉积各层薄膜电池材料，而在图示中有两个引线端子则是为了便于薄膜电池的连接使用。这种结构设计很好地提高了整个电池的有效面积，进而也极大地改善了薄膜电池的性能。 Nakazawa等[4]利用直流溅射和射频溅射的方法，研制出一种“直立型”全固态薄膜锂离子电池结构（见图3）。该研究小组利用该薄膜电池结构设计，成功制备出有效面积更大的全固态薄膜锂离子电池，这样也使得薄膜电池的能量密度和循环寿命等电化学性能得到大幅度提升。 图2 全固态薄膜锂离子电池结构剖面示意图 图3 “直立型”全固态薄膜锂离子电池剖面示意图 Hart等[5]设计了柱状电极交替排列的微型锂电池结构（见图4）。并对几种不同的正极、负极排列方式进行了相关的研究计算，得出了此薄膜电池的结构能够大大提升薄膜电池本身的能量密度。然而Eftekhari[6]则研制出了一种3-D微型锂电池结构的LiMn2O4电极，与以往微型锂电池结构的LiMn2O4电极在电池容量方面得到了提升。 图4 3-D微电池柱状结构示意图 [正极（灰色） 、负极（白色）交替排列分布] 晶体X射线衍射实验报告全解 中南大学 X射线衍射实验报告 材料科学与工程学院材料学专业1305班班级 姓名学号0603130500 同组者无 黄继武实验日期2015 年12 月05 日指导教 师 评分分评阅人评阅日 期 一、实验目的 1)掌握X射线衍射仪的工作原理、操作方法； 2)掌握X射线衍射实验的样品制备方法； 3)学会X射线衍射实验方法、实验参数设置，独立完成一个衍射实验测试； 4)学会MDI Jade 6的基本操作方法； 5)学会物相定性分析的原理和利用Jade进行物相鉴定的方法； 6)学会物相定量分析的原理和利用Jade进行物相定量的方法。 本实验由衍射仪操作、物相定性分析、物相定量分析三个独立的实验组成，实验报告包含以上三个实验内容。 二、实验原理 1 衍射仪的工作原理 特征X射线是一种波长很短(约为20～0.06nm)的电磁波，能穿透一定厚度的物质，并能使荧光物质发光、照相乳胶感光、气体电离。在用电子束轰击金属“靶”产生的X射线中，包含与靶中各种元素对应的具有特定波长的X射线，称为特征（或标识）X射线。考虑到X射线的波长和晶体内部原子间的距离相近，1912年德国物理学家劳厄(M.von Laue)提出一个重要的科学预见：晶体可以作为X射线的空间衍射光，即当一束X射线通过晶体时将发生衍射，衍射波叠加的结果使射线的强度在某些方向上加强，在其他方向上减弱。分析在照相底片上得到的衍射花样，便可确定晶体结构。这一预见随即为实验所验证。1913年英国物理学家布拉格父子(W. H. Bragg, W. L Bragg)在劳厄发现的基础上，不仅成功地测定了NaCl、KCl等的晶体结构，并提出了作为晶体衍射基础的著名公式──布拉格定律： 2dsinθ=nλ 式中λ为X射线的波长，n为任何正整数。当X射线以掠角θ（入射角的余角，又称为布拉格角）入射到某一点阵晶格间距为d的晶面面上时，在符合上式的条件下，将在反射方向上得到因叠加而加强的衍射线。 2 物相定性分析原理 1) 每一物相具有其特有的特征衍射谱，没有任何两种物相的衍射谱是完全相同 的 2) 记录已知物相的衍射谱，并保存为PDF文件 3) 从PDF文件中检索出与样品衍射谱完全相同的物相 4) 多相样品的衍射谱是其中各相的衍射谱的简单叠加，互不干扰，检索程序能 从PDF文件中检索出全部物相 3 物相定量分析原理 X射线定量相分析的理论基础是物质参与衍射的体积活重量与其所产生的衍射强度成正比。 当不存在消光及微吸收时，均匀、无织构、无限厚、晶粒足够小的单相时，多晶物质所产生的均匀衍射环上单位长度的积分强度为： 式中R为衍射仪圆半径，V o为单胞体积，F为结构因子，P为多重性因子，M为温度因子，μ为线吸收系数。 三、仪器与材料 1)仪器：18KW转靶X射线衍射仪 2)数据处理软件：数据采集与处理终端与数据分析软件MDI Jade 6 3)实验材料：CaCO3+CaSO4、Fe2O3+Fe3O4 能源材料课程业 ——薄膜锂电池的研究进展 院系：材料科学与工程学院 专业：金属材料与成型加工 班级：2012级金属材成1班 学号：20120800828 姓名：吴贵军 薄膜锂电池的研究进展 摘要：微电子机械系统(MEMS)和超大规模集成电路(VLSI)技术的发展对能源的微型化、集成化提出了越来越高的要求.全固态薄膜锂电池因其良好的集成兼容性和电化学性能成为MEMS和VLSI能源微型化、集成化的最佳选择.简单介绍了薄膜锂电池的构造,举例说明了薄膜锂电池的工作原理.从阴极膜、固体电解质膜、阳极膜三个方面概述了近年来薄膜锂电池关键材料的研究进展.阴极膜方面LiCoO2依旧是研究的热点,此外对LiNiO2、LiMn2O4、LiNixCo1-xO2、V2O5也有较多的研究;固体电解质膜方面以对LiPON膜的研究为主;阳极膜方面以对锂金属替代物的研究为主,比如锡的氮化物、氧化物以及非晶硅膜,研究多集中在循环效能的提高.在薄膜锂电池结构方面,三维结构将是今后研究的一个重要方向.。 关键词：薄膜锂电池；微系统；薄膜：微电子机械系统随着电子集成技术的飞速发展，SO C (System on chi p) 成为 现实，电子产品在不断地小型化、微型化。以整合集成电路及机械系统，如各种传感器于同一块晶片上的技术，即微机电技术，受到了普遍重视。微小型飞行器、微小型机器人和微小型航天器等都在源源不断地出现和进一步地改进。这些微型系统的功能强大，必然对其能源系统提出了微型化的 要求。当电池系统被微型化，电池底面积小于10 m m2、功率在微瓦级以下时，被称为微电池。微电池的制备通常是将传统的电池微型化、薄膜化。目前，用于微电池的体系有：锌镍电池、锂电池、太阳能电池、燃料电池、温差电池和核电池。锂电池是目前具有较高比能量的实用电池体系，因此人们对薄膜化的锂电池投入了大量的研究。 优点： （1）成本低，根据Photon 的预测，预计到2012 年下降到2.08 美元/w；预计薄膜电池的平均价格能够从2.65 美元/w 降至1.11 美元/w，与晶体硅相比优势明显；而相关薄膜电池制造商的预测更加乐观，EPV 估计到2011 年，薄膜组件的成本将大大低于1 美元/w；Oerlikon 更估计2011 年GW 级别的电站其组件成本将降低于0.7 美元/w，这主要是由转化率提高和规模化带来的。 （2）弱光性好 （3）适合与建筑结合的光伏发电组件(BIPV)，不锈钢和聚合物衬底的柔性薄膜太阳能电池适用于建筑屋顶等，根据需要制作成不同的透光率，代替玻璃幕墙。 缺点： （1）效率低，单晶硅太阳能电池，单体效率为14%-17%(AMO)，而柔性基体非晶硅太阳电池组件（约1000平方厘米）的效率为 10-12%，还存在一定差距。 地理时间计算部分专题练习 1、9月10日在全球所占的围共跨经度90°，则时间为：( ) A. 10日2时 B. 11日2时 C. 10日12时 D. 11日12时 3、时间为2008年3月1日的2点，此时与处于同一日期的地区围约占全球的：( ) A. 一半 B. 三分之一 C. 四分之一 D. 五分之一 4、图中两条虚线，一条是晨昏线，另一条两侧大部分地区日期不同，此时地球公转速度较慢。若图中的时间为7日和8日，甲地为（ ） Ａ．７日４时 Ｂ．８日８时 Ｃ．７月８时 Ｄ．８月４时 2004年3月22日到4月3日期间，可以看到多年一遇的“五星连珠”天象奇观。其中水星是最难一见的行星，观察者每天只有在日落之后的1 小时才能看到它。图中阴影部分表示黑夜，中心点为极地。回答5—7题 5．图4中①②③④四地，可能看到“五星连珠”现象的是( ) A ．① B ．② C ．③ D ．④ 6．在新疆的吐鲁番（约890 E ）观看五星连珠现象，应该选择的时间段（时间）是( ) A ．18时10分至19时 B ．16时10分至17时 C ．20时10分至21时 Ｄ．21时10分至22时 7．五星连珠中，除了水星外，另外四颗星是( ) A ．金星、木星、土星、天狼星 B ．金星、火星、木星、海王星 C ．火星、木星、土星、天王星 D ．金星、火星、土星、木星 （2002年）下表所列的是12月22日甲、乙、丙、丁四地的白昼时间，根据表中数据回答下8-10题。 甲地 乙地 丙地 丁地 白昼长 5∶30 9∶09 11∶25 13∶56 8、四地中属于南半球的是（ ） A.甲地 B.乙地 C.丙地 D.丁地 9、四地所处纬度从高到低顺序排列的是（ ） A.甲乙丙丁 B.甲乙丁丙 C.丙丁乙甲 D.丁丙乙甲 10、造成四起白昼时间差异的主要因素是（ ） ①地球的公转 ②地球自转 ③黄赤交角的存在 ④地方时的不同 A.①② B.②③ C.③④ D.①③ 2002年1月1日，作为欧洲联盟统一货币的欧元正式流通，这将对世界金融的整体格局产生重要影响。回 答4-5题： 11、假定世界各金融市场均在当地时间上午9时开市，下午5时闭市。如果某投资者上午9时在法兰克福（东经8.50 ）市场买进欧元，12小时后欧元上涨，投资者想尽快卖出欧元，选择的金融市场应位于：（ ） A.东京（东经139.50 ） B.（东经1140 ） C.伦敦 D.纽约（西经740 ） ① ④ ② ③ 小学三年级数学《简单的时间计算》教案范文三篇时间计算是继二十四时计时法的学习之后安排的一个内容。下面就是小编给大家带来的小学三年级数学《简单的时间计算》教案范文，欢迎大家阅读! 教学目标： 1、利用已学的24时记时法和生活中对经过时间的感受，探索简单的时间计算方法。 2、在运用不同方法计算时间的过程中，体会简单的时间计算在生活中的应用，建立时间观念，养成珍惜时间的好习惯。 3、进一步培养课外阅读的兴趣和多渠收集信息的能力。 教学重点： 计算经过时间的思路与方法。 教学难点： 计算从几时几十分到几时几十分经过了多少分钟的问题。 教学过程： 一、创设情景，激趣导入 1、谈话：小朋友你们喜欢过星期天吗?老师相信我们的星期天都过得很快乐!明明也有一个愉快的星期天，让我们一起来看看明明的一天，好吗? 2、小黑板出示明明星期天的时间安排。 7：10-7：30 起床、刷牙、洗脸; 7：40-8：20 早锻炼; 8：30-9：00 吃早饭; 9：00-11：00 看书、做作业 …… 3、看了刚才明明星期天的时间安排，你知道了什么?你是怎么知道的?你还想知道什么? 二、自主探究，寻找方法 1、谈话：小明在星期天做了不少的事，那你知道小明做每件事情用了多少时间吗?每 个小组从中选出2件事情计算一下各用了多少时间。 (1)分组学习。 (2) 集体交流。 2、根据学生的提问顺序学习时间的计算。从整时到整时经过时间的计算。 (1)学生尝试练习9：00-11：00明明看书、做作业所用的时间。 (2)交流计算方法：11时-9时=2小时。 3、经过时间是几十分钟的时间计算。 (1)明明从7：40到8：20进行早锻炼用了多少时间呢? 出示线段图。 师：7：00-8：00、8：00-9：00中间各分6格，每格表示10分钟，两个线段下边 的箭头分别指早锻炼开始的时间和结束的时间，线段图涂色部分表示早锻炼的时间。谈话：从图上看一看，从7时40分到8时经过了多少分钟?(20分)从8时到8时20分又经过 了多少时间?所以一共经过了多少分钟。(20+20=40分)小朋友们，如果你每天都坚持锻炼 几十分钟，那你的身体一定会棒棒的。 (2)你还能用别的方法计算出明明早锻炼的时间吗?(7：40-8：40用了一个小时，去掉 多算的20分，就是40分。或者7：20-8：20用了1个小时，去掉多算的20分，就是 40分。) (3)练习：找出明明的一天中做哪些事情也用了几十分钟? 你能用自己喜欢的方法计算出明明做这几件事情用了几十分钟吗?你是怎么算的? 三、综合练习，巩固深化 1、想想做做1：图书室的借书时间。你知道图书室每天的借书时间有多长吗? 学生计算。 (1)学生尝试练习，交流计算方法。 (2)教师板书。 2、想想做做2。 (1)学生独立完成。 (2)全班交流。 中国古代时间的计算方法（1） 现时每昼夜为二十四小时，在古时则为十二个时辰。当年西方机械钟表传入中国，人们将中西时点，分别称为“大时”和“小时”。随着钟表的普及，人们将“大时”忘淡，而“小时”沿用至今。 古时的时（大时）不以一二三四来算，而用子丑寅卯作标，又分别用鼠牛虎兔等动物作代，以为易记。具体划分如下：子（鼠）时是十一到一点，以十二点为正点；丑（牛）时是一点到三点，以两点为正点；寅（虎）时是三点到五点，以四点为正点；卯（兔）时是五点到七点，以六点为正点；辰（龙）时是七点到九点，以八点为正点；巳（蛇）时是九点到十一点，以十点为正点；午（马）时是十一点到一点，以十二点为正点；未（羊）时是一点到三点，以两点为正点；申（猴）时是三点到五点，以四点为正点；酉（鸡）时是五点到七点，以六点为正点；戌（狗）时是七点到九点，以八点为正点；亥（猪）时是九点到十一点，以十点为正点。 古人说时间，白天与黑夜各不相同，白天说“钟”，黑夜说“更”或“鼓”。又有“晨钟暮鼓”之说，古时城镇多设钟鼓楼，晨起（辰时，今之七点）撞钟报时，所以白天说“几点钟”；暮起（酉时，今之十九点）鼓报时，故夜晚又说是几鼓天。夜晚说时间又有用“更”的，这是由于巡夜人，边巡行边打击梆子，以点数报时。全夜分五个更，第三更是子时，所以又有“三更半夜”之说。 时以下的计量单位为“刻”，一个时辰分作八刻，每刻等于现时的十五分钟。旧小说有“午时三刻开斩”之说，意即，在午时三刻钟（差十五分钟到正午）时开刀问斩，此时阳气最盛，阴气即时消散，此罪大恶极之犯，应该“连鬼都不得做”，以示严惩。阴阳家说的阳气最盛，与现代天文学的说法不同，并非是正午最盛，而是在午时三刻。古代行斩刑是分时辰开斩的，亦即是斩刑有轻重。一般斩刑是正午 竭诚为您提供优质文档/双击可除 excel表格日期计算 篇一：excel中几个时间计算公式 假设b2为生日 =datedif(b2,today(),"y") datediF函数，除excel2000中在帮助文档有描述外，其他版本的excel在帮助文档中都没有说明，并且在所有版本的函数向导中也都找不到此函数。但该函数在电子表格中确实存在，并且用来计算两个日期之间的天数、月数或年数很方便。微软称，提供此函数是为了与lotus1-2-3兼容。 该函数的用法为 “datediF(start_date,end_date,unit)”，其中start_date 为一个日期，它代表时间段内的第一个日期或起始日期。end_date为一个日期，它代表时间段内的最后一个日期或结束日期。unit为所需信息的返回类型。 “y”为时间段中的整年数，“m”为时间段中的整月数，“d”时间段中的天数。“md”为start_date与end_date日期中天数的差，可忽略日期中的月和年。“ym”为start_date 与end_date日期中月数的差，可忽略日期中的日和年。“yd” 为start_date与end_date日期中天数的差，可忽略日期中的年。比如，b2单元格中存放的是出生日期（输入年月日时，用斜线或短横线隔开），在c2单元格中输入 “=datedif(b2,today(),"y")”（c2单元格的格式为常规），按回车键后，c2单元格中的数值就是计算后的年龄。此函数在计算时，只有在两日期相差满12个月，才算为一年，假如生日是20xx年2月27日，今天是20xx年2月28日，用此函数计算的年龄则为0岁，这样算出的年龄其实是最公平的。 身份证号提取年龄 =datediF(--text((len(a1)=15)*19”即可获得当时的日期时间； 2、使用公式：用=now()而非=date()，=date()只有日期，然后进行菜单“工具->选项”，选择“重新计算”页，选中“人工重算”，勾不勾选“保存前自动重算”看自己的需要和想法了，如果勾选了，那日期时间那总是最后一次保存的日期时间，不勾选的话，如果你的表格中有公式记得准备存前按F9 篇二：excel中如何计算两个日期之间的月数 excel中如何计算两个日期之间的月数 X 射线衍射分析 1实验目的 1、 了解X 衍射的基本原理以及粉末X 衍射测试的基本目的； 2、 掌握晶体和非晶体、单晶和多晶的区别； 3、 了解使用相关软件处理XRD 测试结果的基本方法。 2实验原理 1、 晶体化学基本概念 晶体的基本特点与概念：①质点（结构单元）沿三维空间周期性排列（晶 体 定义），并有对称性。②空间点阵：实际晶体中的几何点，其所处几何环境和 物质环境均同，这些“点集”称空间点阵。③晶体结构 =空间点阵+结构单元。非 晶部分主要为无定形态区域，其内部原子不形成排列整齐有规律的晶格。 对于大多数晶体化合物来说，其晶体在冷却结晶过程中受环境应力或晶核数目、 成核方式等条件的影响，晶格易发生畸变。分子链段的排列与缠绕受结晶条件的 影响易发生改变。晶体的形成过程可分为以下几步：初级成核、分子链段的 图1 14 种Bravais 点阵 表面延伸、链松弛、链的重吸收结晶、表面成核、分子间成核、晶体生长、晶体 生长完善。Bravais 提出了点阵空间这一概念，将其解释为点阵中选取能反映空 间点阵周期性与对称性的单胞，并要求单胞相等棱与角数最多。满足上述条件棱 间直角最多，同时体积最小。1848年Bravais 证明只有14种点阵。 Bravais lattice Cryslal DerBCfliptlcn CSlnwle) cubic Cubic a - b=? E , a = = 90B BaO/-rentered F*韓?“nl ?喇 (Simple) T etr-Aa^n^ i = b*C i .a=g = 7=SCi , Boa^-tentered ler^go>nal CGlnwle) DfthDmunbic Orlharhanbir 目日即亡时恒创 Orlhorhcmbic Oase-ceMered Offliorhombic Fac$-LBnter$d OnhorhChibie (Simple) Rhombol*edrai Rhombohedr^i (Trigonal) R = b = (;&= p= 7^ 90' 闭卿闾扫D 城帕1 H 曲g 肿对 a = b?iC fc tt=ft=0I]-a 7=12D - ⑻側 1.) MOnlQClHiC Monoclinic a c s a = y= go ■，&4 ger Monodlnlc ： (Slrrwle)AnDithl￡： Anotlhic (Triclinic) a * ： UH p 9D" PDFhAAiNT uaes Ehe 他 dfescnbing lhe pallerrt I Ellice cubic tatnigond orthortiombic rhonibdhedral hdxa.goinal (trigcnal) anortluc (tricl i me) iriufiOchrr ic 高中地理计算公式 一、时间的计算 1、求时区： 时区数＝已知经度／15°（商四舍五入取整数，即为时区数） 2、求区时： 所求区时＝已知区时±时区差（东加西减） 3、求地方时： 所求地方时＝已知地方时±4分钟／度×经度差（东加西减） 二、太阳高度的计算 1、求正午太阳高度： H＝90°－︱纬度差︱（纬度差指当地纬度与太阳直射纬度之间的差） 2、求子夜太阳高度： H＝︱纬度和︱－90°（纬度和指当地纬度与太阳直射纬度之间的和） 3、求南北两楼的楼间距： L＝h?cotH (h为楼高，H为该地一年中最小的正午太阳高度) 三、昼夜长短的计算 1、求昼长： （1）昼长＝昼弧∕15° （2）昼长＝日落时间－日出时间 （3）昼长＝24－夜长 （4）昼长＝（12－日出地方时）×2 （5）昼长＝（日落地方时－12） 2、求夜长 （1）夜长＝夜弧∕15° （2）夜长＝24－昼长 （3）夜长＝（24－日落地方时）×2 （4）北半球某纬度的夜长＝南半球同纬度的昼长 四、日出、日落时刻的计算 １、求日出时刻： （1）日出时刻＝当地纬线与晨线交点的时刻（2）日出时刻＝12－昼长∕2 2、求日落时刻： （1）日落时刻＝当地纬线与昏线交点的时刻（2）日落时刻＝12＋昼长∕2 五、球面距离的计算 （1）赤道和经线上的距离111Km×度数 （2）纬线上的距离＝111Km×度数?COSθ(θ为当地的纬度) （3）对趾点的计算:经度互补,一东一西；纬度相等,一南一北。 六、比例尺的计算 （1）比例尺＝图上距离∕实地距离 （2）缩放图幅面积＝原图幅面积×比例尺缩放的平方 七、相对高度的计算 （1）陡崖相对高度：（n－1）d≤H＜(n＋1)d (n为等高线条数，d为等高距) （2）H＝T∕6°×1000米 (H为两地相对高度,T为两地温差) 1914年诺贝尔物理学奖——晶体的X射线衍射 1914年诺贝尔物理学奖授予德国法兰克福大学的劳厄（Max vonLaue，1879—1960），以表彰他发现了晶体的X射线衍射。 劳厄发现X射线衍射是20世纪物理学中的一件有深远意义的大事，因为这一发现不仅说明了X射线是一种比可见光波长短1000倍的电磁波，使人们对X 射线的认识迈出了关键的一步，而且还第一次对晶体的空间点阵假说作出了实验验证，使晶体物理学发生了质的飞跃。这一发现继佩兰（Perrin）的布朗运动实验之后，又一次向科学界提供证据，证明原子的真实性。从此以后，X射线学在理论和实验方法上飞速发展，形成了一门内容极其丰富、应用极其广泛的综合学科。 劳厄当时正在德国慕尼黑大学任教。他是1909年来到慕尼黑大学的，因为那时索末菲正在那里。索末菲的讲课和讨论班吸引了许多年轻的物理学家来到慕尼黑，讨论的主题都与当时物理学在理论和实验方面的新的概念和发现有关。其中有关X射线的本性的各种看法也是主题之一。劳厄在理论物理学方面有很深的造诣，同时也密切关注实际物理现象，特别是在光学和辐射方面。他很早就对狭义相对论发生了兴趣，曾从光学的光行差现象为相对论提供了独特的证明，并写了一本小册子介绍相对论。劳厄自从1909年来到慕尼黑大学后，由于受到伦琴的影响，注意力始终放在X射线的本性上。他完全了解有关这方面的研究现状和面临的困境，他倾向于波动说，知道问题的关键在于实现X射线的干涉或衍射。正好这时索末菲把编纂《数学科学百科全书》中“波动光学”条目的任务交给劳厄。为此劳厄研究了晶格理论。晶体的点阵结构在当时虽然还是一种假设，但是在劳厄看来却是合情合理的。他坚决站在原子论这一边，反对某些哲学家怀疑原子存在的观点。他认为：没有什么无懈可击的认识论论据能够驳斥这一事实，实际经验却不断地提供新鲜证据支持这一事实。由于他对晶体空间点阵有如此深刻的认识，所以当索末菲的博士研究生厄瓦尔德（P.Ewald）和他讨论晶体光学问题时，他敏锐地抓住了晶格间距的数量级，判定晶体可以作为X射线的天然光栅。他的灵感来自他日夜的苦思，同时也是由于他对这两个互不相干的假设都有明确具体的概念。劳厄不止一次地提到：如果不确信原子的存在，他永远也不会想到利用X射线透射的方法来进行实验。据劳厄和厄瓦尔德回忆，具体过程是这样的： 1912年2月的一天，厄瓦尔德来到劳厄的房间，求劳厄帮助解决如何用数学研究光对偏振原子点阵的作用。尽管劳厄帮不了他的忙，仍热心地建议他们第二天在研究所碰头，并去他家里在晚饭前后讨论。他们按约会面，步行穿过鲁德维希（Ludwig）大街后，厄瓦尔德开始向劳厄一般性地介绍他正在从事的课题，出乎他的意料，劳厄对这方面并不了解。他向劳厄解释，他是怎样依照色散的一般理论假设在点阵排列中振子的位置。劳厄反问他为什么要这样假设。厄瓦尔德回答说，人们认为晶体具有这种内部的规律性。看起来劳厄对此感到新奇。这时他们已经进入花园。劳厄问道：振子之间的距离多大？对此，厄瓦尔德回答说， X 射线衍射实验报告 材料科学与工程 学院 材料科学与工程 专业 班级 姓 名 学号 同组者 实验日期 年 月 日 指导教师 评分 分 评阅人 评阅日期 一 实验设计背景与实验目的 1 实验设计背景 Al-Zn-Mg 合金是中强可焊铝合金，σb 达到500MPa ，延伸率为15%，电导率为30IACS%，具有较好的强度和延伸率，抗腐蚀性能较好。用作航空航天和地面设备的结构材料。是目前材料研究的一个重要课题。 该合金是可热处理强化合金，合金通过固溶-淬火-时效，时效温度不同，析出GP 区、η'相或η相。后两者具有六方结构，基本化学组成为MgZn2。而GP 区为5-10nm 的球状粒子。析出相不同，其合金性能也不相同。 图1 Al-Zn-Mg 合金的不同处理态TEM 观察 a)Al 固溶态(基体) b) 120℃/24h 时效态 c)180℃/24h 时效态 同一合金，固溶态的物相应为单相，而时态效为双相（基体和析出相），因 0.5μ 100nm b) a) 100nm c) 100nm 此，首先应通过实验鉴定物相组成（物相定性分析）；对于双相态，应当了解析出相的百分含量；另外，由于合金元素在基体中不同程度的固溶，导致基体的点阵常数变化，通过这种变化可检测固溶程度。 2 实验目的 了解X射线衍射仪的结构，操作规程，掌握MDI JADE的使用方法； 掌握X射线在新材料开发中的实际应用方法（物相定性分析、物相定量分析和点阵常数精确测定）。 掌握新材料开发的最新进展和新实验方法和技巧。 二实验原理 1、X射线衍射仪 （1）X射线管 X射线管工作时阴极接负高压，阳极接地。灯丝附近装有控制栅，使灯丝发出的热电子在电场的作用下聚焦轰击到靶面上。阳极靶面上受电子束轰击的焦点便成为X射线源，向四周发射X射线。在阳极一端的金属管壁上一般开有四个射线出射窗口。转靶X射线管采用机械泵+分子泵二级真空泵系统保持管内真空度，阳极以极快的速度转动，使电子轰击面不断改变，即不断改变发热点，从而达到提高功率的目的 程序设计与算法课程设计 课程设计评语 对课程设计的评语: 平时成绩：课程设计成绩： 总成绩：评阅人签名： 注：1、无评阅人签名成绩无效； 2、必须用钢笔或圆珠笔批阅，用铅笔阅卷无效； 3、如有平时成绩，必须在上面评分表中标出，并计算入总成绩。 目录 课程设计评语 (2) 目录 (3) 1．课程论文题目.............................................................................................. 错误！未定义书签。2．程序设计思路.. (4) 3．功能模块图 (4) 4．数据结构设计 (5) 5．算法设计 (5) 6．程序代码 (6) 7．程序运行结果 (7) 8．编程中遇到的困难及解决方法.................................................................. 错误！未定义书签。9．总结及建议.................................................................................................. 错误！未定义书签。10．致谢. (8) 1.课程设计题目：日期计算器 【要求】 功能：计算输入日期是当年中的第几天 系统要求实现以下功能： 1. 由用户分别输入：年、月、日 2. 计算该日期是当年中的第几天 3. 输出计算出的天数 分步实施： 1、首先设计Dater对象构造器 2、判断此年是否为闰年。 3、计算从此年年初到此日的一共多少天 4、输入输出处理。 【提示】 需求分析：使用Dater对象构造器,用1判断为闰年,,0判断为不是闰年,使用累加的方法计算年初到此日共有多少天,进行输入输出处理. （1）主函数设计 主函数提供输入，处理，输出部分的函数调用。 （2）功能模块设计 模块：由用户自己录入年，月，日，、。计算该日期为一年的中德第几天。输出计算出的天数，返回主菜单。 3. 功能模块图 （1）输入模块 由用户分别输入：年、月、日从劳厄发现晶体X射线衍射谈
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