In vito fber photometry is a powerful technique to analyze the dy namics of population neurons during fiunctional study of neuroscience.Here,we introduced a detailed protocol for fiber photometry-based calciun reordin...In vito fber photometry is a powerful technique to analyze the dy namics of population neurons during fiunctional study of neuroscience.Here,we introduced a detailed protocol for fiber photometry-based calciun reording in freely moving mice,covering from virus injection,fiber stub insertion,optogenetical stimulation to data procurement and analysis.Furthemnore,we applied this protocol to explore neuronal activity of mice latenal-posterior(LP)thalaric nucleus in response to optogenetical stimulation of primary visual cortex(V1)neurons,and explore axon clusters activity of optogenetically evoked V1 neurons.Final confirmation of virus-based protein expression in V1 and precise fber insertion indicated that the surgery procedure of this protocol is reliable for functional calcium recording.The scripts for data analysis and some tips in our protocol are provided in details.Together,this protocol is simple,low-cost,and effective for neuronal activity detection by fiber photometry,which will hep neuroscience researchers to carry out fiunctional and behavioral study in vivo.展开更多
In the central nervous system,the A6 noradrenaline(NA)and the B3 serotonin(5-HT)cell groups are well-recognized players in the descending antinociceptive system,while other NA/5-HT cell groups are not well characteriz...In the central nervous system,the A6 noradrenaline(NA)and the B3 serotonin(5-HT)cell groups are well-recognized players in the descending antinociceptive system,while other NA/5-HT cell groups are not well characterized.A5/A7 NA and B25-HT cells project to the spinal horn and form descending pathways.We recorded G-Ca MP6 green fluorescence signal intensities in the A5/A7 NA and the B25-HT cell groups of awake mice in response to acute tail pinch stimuli,acute heat stimuli,and in the context of a non-noxious control test,using fiber photometry with a calcium imaging system.We first introduced G-Ca MP6 in the A5/A7 NA or B25-HT neuronal soma,using transgenic mice carrying the tetracycline-controlled transactivator transgene under the control of either a dopamineβ-hydroxylase or a tryptophan hydroxylase-2 promoters and by the site-specific injection of adeno-associated virus(AAV-Tet O(3 G)-G-Ca MP6).After confirming the specific expression patterns of G-Ca MP6,we recorded G-Ca MP6 green fluorescence signals in these sites in awake mice in response to acute nociceptive stimuli.G-Ca MP6 fluorescence intensity in the A5,A7,and B2 cell groups was rapidly increased in response to acute nociceptive stimuli and soon after,it returned to baseline fluorescence intensity.This was not observed in the non-noxious control test.The results indicate that acute nociceptive stimuli rapidly increase the activities of A5/A7 NA or B25-HT neurons but the non-noxious stimuli do not.The present study suggests that A5/A7 NA or B25-HT neurons play important roles in nociceptive processing in the central nervous system.We suggest that A5/A7/B2 neurons may be new therapeutic targets.All performed procedures were approved by the Institutional Animal Use Committee of Kagoshima University(MD17105)on February 22,2018.展开更多
Manipulating and real-time monitoring of neuronal activities with cell-type specificity and precise spatiotemporal resolution during animal behavior are fundamental technologies for exploring the functional connectivi...Manipulating and real-time monitoring of neuronal activities with cell-type specificity and precise spatiotemporal resolution during animal behavior are fundamental technologies for exploring the functional connectivity, information transmission, and physiological functions of neural circuits in vivo. However, current techniques for optogenetic stimulation and neuronal activity recording mostly operate independently. Here, we report an all-fiber-transmission photometry system for simultaneous optogenetic manipulation and multi-color recording of neuronal activities and the neurotransmitter release in a freely moving animal. We have designed and manufactured a wavelength-independent multi-branch fiber bundle to enable simultaneous optogenetic manipulation and multi-color recording at different wavelengths. Further, we combine a laser of narrow linewidth with the lock-in amplification method to suppress the optogenetic stimulation-induced artifacts and channel crosstalk. We show that the collection efficiency of our system outperforms a traditional epi-fluorescence system. Further, we demonstrate successful recording of dynamic dopamine(DA) responses to unexpected rewards in the nucleus accumbens(NAc) in a freely moving mouse. We also show simultaneous dual-color recording of neuronal Ca2+ signals and DA dynamics in the NAc upon delivering an unexpected reward and the simultaneous optogenetic activating at dopaminergic terminals in the same location. Thus, our multi-function fiber photometry system provides a compatible, efficient, and flexible solution for neuroscientists to study neural circuits and neurological diseases.展开更多
Based upon broad-band CCD observation data of comet Hale-Bopp obtained by a 60cm telescope at Xinglong Station of Beijing Astronomical Observatory during March-August, 1996, the photometric results of comet Hale-Bopp ...Based upon broad-band CCD observation data of comet Hale-Bopp obtained by a 60cm telescope at Xinglong Station of Beijing Astronomical Observatory during March-August, 1996, the photometric results of comet Hale-Bopp are reported. Using the photometric results, the dust production rate, radius and mass of nucleus of comet Hale-Bopp are estimated as follows: dM/dt~1.5×10 5 kgs -1, R n~35.5km, and M n~5.65×10 16kg.展开更多
Because of the 3D nature of galaxies, an algorithm for constructing spatial density distribution models of galaxies on the basis of galaxy images has many advan- tages over approximations of the surface density distri...Because of the 3D nature of galaxies, an algorithm for constructing spatial density distribution models of galaxies on the basis of galaxy images has many advan- tages over approximations of the surface density distribution. We present a method for deriving the spatial structure and overall parameters of galaxies from images and estimate its accuracy and derived parameter degeneracies on a sample of idealised model galaxies. The test galaxies consist component with varying proportions and of a disc-like component and a spheroidal properties. Both components are assumed to be axially symmetric and coplanar. We simulate these test galaxies as if they had been observed in the SDSS project through ugriz filters, thus gaining a set of realis- tically imperfect images of galaxies with known intrinsic properties. These artificial SDSS galaxies were thereafter remodelled by approximating the surface brightness distribution with a 2D projection of a bulge+disc spatial distribution model and the restored parameters were compared to the initial ones. Down to the r-band limiting magnitude of 18, errors in the restored integral luminosities and colour indices re- main within 0.05 mag and errors in the luminosities of individual components within 0.2 mag. Accuracy of the restored bulge-to-disc luminosity ratio (B/D) is within 40% in most cases, and becomes worse for galaxies with low B/D, but the general balance between bulges and discs is not shifted systematically. Assuming that the intrinsic disc axial ratio is ≤ 0.3, then the inclination angles can be estimated with errors 〈 5° for most of the galaxies with B/D 〈 2 and with errors 〈 15° up to B/D = 6. Errors in the recovered sizes of the galactic components are below 10% in most cases. The axial ratios and the shape parameter N of Einasto's distribution (similar to the Sersic index) are relatively inaccurate, but can provide statistical estimates for large samples. In general, models of disc components are more accurate than models of spheroidal components for geometrical reasons.展开更多
In this paper, surface photometry and dynamical properties of Lenticular galaxies will be developed and applied to NGC3245. In this respect, we established new relation between the intensity distribution I and the sem...In this paper, surface photometry and dynamical properties of Lenticular galaxies will be developed and applied to NGC3245. In this respect, we established new relation between the intensity distribution I and the semi-major axis a Moreover, some basic statistics of both independent and the dependent variables of the relation are also given. In addition to the I(a) relation , the Sérsic r1/n model is applied for the intensity profile I(r) resulting in an estimation of the effective radius, re, and the surface brightness it encloses, μe. Both relations (I(a) and I(r)) are accurate as judged by the precision criteria which are: the probable errors for the coefficients , the estimated variance of the fit and the Q value (the square distance between the exact solution and the least square estimated solution) where all very satisfactory. Correlation coefficients between some parameters of the isophotes are also computed. Finally as examples of applications of surface photometry we determined the dynamical properties: mass, density, potential distributions, as well as distributions of escape and circular speeds in terms of Sérsic model.展开更多
We present UBVI surface photometry over a 20.5' × 20.5' area of the late-type spiral galaxy NGC 300. We have derived isophotal maps, surface brightness profiles, ellipticity profiles, position angle profi...We present UBVI surface photometry over a 20.5' × 20.5' area of the late-type spiral galaxy NGC 300. We have derived isophotal maps, surface brightness profiles, ellipticity profiles, position angle profiles, and color profiles. By merging our I-band measurements with those of Boker et al. based on Hubble Space Telescope observations, we have obtained combined I-band surface brightness profiles for the region 0.02' < r < 500' and have decomposed the profiles into three components: a nucleus, a bulge, and an exponential disk.展开更多
Light emitting diode(LED)lighting is becoming more and more popular,as incandescent lamps are being phased out globally.LEDs have several advantages over incandescent lamps,including energy efficiency,robustness,long ...Light emitting diode(LED)lighting is becoming more and more popular,as incandescent lamps are being phased out globally.LEDs have several advantages over incandescent lamps,including energy efficiency,robustness,long lifetime,and good temporal stability.The three latter features make LEDs attractive candidates as new photometric standards.Because the spectra of white LEDs are limited to the visible wavelength range,a novel method for the realization of photometric units based on the predictable quantum efficient detector(PQED)can be utilized.The method eliminates the need of photometric filters that are traditionally used in photometry,and instead relies on carrying out the photometric weighting numerically based on the measured relative spectrum of the source.The PQED-based realization simplifies the traceability chain of photometric measurements significantly as compared with the traditional filter-based method.The measured illuminance values of a white LED deviate by only 0.03%when determined by the new and the traditional methods.The new PQED method has significantly lower expanded uncertainty of 0.26%(k=52)as compared with that of the traditional filter-based method of 0.42%(k=52).Furthermore,when filtered photometers that measure LED lighting are calibrated using LED lamps as calibration sources instead of incandescent lamps,a significant decrease in the uncertainty related to the spectral mismatch correction can be obtained.The maximum spectral mismatch errors of LED measurements decreased on average by a factor of 3 when switching from an incandescent lamp to an LED calibration source.展开更多
Based upon broad-band CCD observation data of comet Hale-Bopp obtained by a 60 cm telescope at Xinglong Station of Beijing Astronomical Observatory during March-August, 1996, the photometric results of comet Hale-Bopp...Based upon broad-band CCD observation data of comet Hale-Bopp obtained by a 60 cm telescope at Xinglong Station of Beijing Astronomical Observatory during March-August, 1996, the photometric results of comet Hale-Bopp are reported. Using the photometric results, the dust production rate, radius and mass of nucleus of comet Hale-Bopp are estimated as follows: dM/df ~ 1.5 × 105 kgs-1, Rn~35.5 km, and Mn~5.65×1016 kg.展开更多
The Wide Field Survey Telescope(WFST)is a dedicated time-domain multi-band(u,g,r,i,and z)photometric survey facility under construction.In this paper,we present a preliminary study that assesses the quality of photome...The Wide Field Survey Telescope(WFST)is a dedicated time-domain multi-band(u,g,r,i,and z)photometric survey facility under construction.In this paper,we present a preliminary study that assesses the quality of photometric redshifts based on WFST by utilizing mock observations derived with the galaxy catalog in the COSMOS/UltraVISTA field.We apply the template fitting technique to estimate photometric redshifts by using the ZEBRA photometric-redshift code and adopting a modified set of adaptive templates.We evaluate the bias(median relative offset between the output photometric redshifts and input redshifts),normalized median absolute deviation(σ_(NMAD))and outlier fraction(f_(outlier))of photometric redshifts in two typical WFST observational cases,the single 30 s exposure observations(hereafter shallow mode)and co-added 50 minutes exposure observations(hereafter deep mode).We find bias≲0.006,σ_(NMAD)≲0.03,and f_(outlier)≲5%in the shallow mode and bias≈0.005,σ_(NMAD)≈0.06,and f_(outlier)≈17%–27%in the deep mode,respectively,under various lunar phases.Combining the WFST mock observational data with that from the upcoming CSST and Euclid surveys,we demonstrate that the zphot results can be significantly improved,with f_(outlier)≈1%andσ_(NMAD)≈0.02.展开更多
Machine learning has become a crucial technique for classifying the morphology of galaxies as a result of the meteoric development of galactic data.Unfortunately,traditional supervised learning has significant learnin...Machine learning has become a crucial technique for classifying the morphology of galaxies as a result of the meteoric development of galactic data.Unfortunately,traditional supervised learning has significant learning costs since it needs a lot of labeled data to be effective.FixMatch,a semi-supervised learning algorithm that serves as a good method,is now a key tool for using large amounts of unlabeled data.Nevertheless,the performance degrades significantly when dealing with large,imbalanced data sets since FixMatch relies on a fixed threshold to filter pseudo-labels.Therefore,this study proposes a dynamic threshold alignment algorithm based on the FixMatch model.First,the class with the highest amount has its reliable pseudo-label ratio determined,and the remaining classes'reliable pseudo-label ratios are approximated in accordance.Second,based on the predicted reliable pseudo-label ratio for each category,it dynamically calculates the threshold for choosing pseudo-labels.By employing this dynamic threshold,the accuracy bias of each category is decreased and the learning of classes with less samples is improved.Experimental results show that in galaxy morphology classification tasks,compared with supervised learning,the proposed algorithm significantly improves performance.When the amount of labeled data is 100,the accuracy and F1-score are improved by 12.8%and 12.6%,respectively.Compared with popular semisupervised algorithms such as FixMatch and MixMatch,the proposed algorithm has better classification performance,greatly reducing the accuracy bias of each category.When the amount of labeled data is 1000,the accuracy of cigar-shaped smooth galaxies with the smallest sample is improved by 37.94%compared to FixMatch.展开更多
This is a prospective interventional clinical study evaluating intraocular inflammation developed after Ultrasound Cyclo Plasty(UCP) for the treatment of glaucoma. Eighteen eyes of 18 patients were treated with UCP se...This is a prospective interventional clinical study evaluating intraocular inflammation developed after Ultrasound Cyclo Plasty(UCP) for the treatment of glaucoma. Eighteen eyes of 18 patients were treated with UCP second-generation probes(Eye OP1). After treatment, the mean intraocular pressure(IOP) significantly decreased from 26.8±7.2 to 18.8±6.1 mm Hg at day 1 and to 14.7±3.4 mm Hg at month 6(all P<0.001). Mean laser flare-cell photometry value steeply increased after surgery from 12.1±7.5 to 64.1±53.9 ph/ms(P=0.001) at day 1, and then progressively decreased to respectively 60.6±49.7 at day 7, 43.5±38.5 at day 14 and 28.2±18.3 at month 1(all P<0.05), returning at levels similar to baseline ones at month 3 and month 6(respectively 16.7±6.2 and 12.8±10.2, both P>0.05). A significant negative correlation was found between postoperative increase of aqueous flare values and anterior chamber depth(R=-0.568, P=0.014). This timeframe may be considered reasonable for repeating UCP treatment, when required.展开更多
The 85-cm telescope at Xinglong station is a prime focus system that operates well with high science outputs. The telescope has been upgraded since 2014 with a new corrector, and new filters and camera, which are prov...The 85-cm telescope at Xinglong station is a prime focus system that operates well with high science outputs. The telescope has been upgraded since 2014 with a new corrector, and new filters and camera, which are provided by Beijing Normal University. The filter set is the Johnson-Cousins UBV RI system. We report the test results of the new system including bias, dark current, linearity, gain and readout noise of the CCD camera. Then we derive accurate instrumental calibration coefficients in UBV RI bands with Landolt standard stars during photometric nights. Finally, we give the limiting magnitudes with various exposure times and signal-to-noise ratios for observers as references.展开更多
Aim: The elemental composition of the epididymal luminal fluid (ELF) in adult goat ( Capra indica) was investigat-ed. Methods: ELF was collected by micropuncture from twelve sites along the epididymal duct. The elemen...Aim: The elemental composition of the epididymal luminal fluid (ELF) in adult goat ( Capra indica) was investigat-ed. Methods: ELF was collected by micropuncture from twelve sites along the epididymal duct. The elementalcontents was analyzed with inductively coupled plasma (ICP) emission spectroscopy, a microanalytical technique thatcan simultaneously measure many elements in minute volumes of sample. The Na and K concentrations were determinedby flame photometry. Results: ICP spectroscopy showed the presence of copper, calcium, nickel, iron, magne-sium, chromium, titanium and zinc in ELF, with fluctuating levels at different sites along the length of the epididymis.Cadmium, cobalt, lead and manganese were not fotmd. The Na^+ / K^+ ratio was seen to be higher at the initial seg-ments of the epididymis and lower at the distal. Conclusion: It is proposed that the observed characteristic distribu-tion of elements in ELF may have far reaching implications in sperm maturation and storage known to occur in the epi-didymis. (Asian J Androl 2000 Dec; 2: 288-292)展开更多
The Nanshan One-meter Wide-field Telescope is a prime focus system that is located at Nanshan Station of Xinjiang Astronomical Observatories.The field of view was designed to 1.5°× 1.5°,and the Johnson-...The Nanshan One-meter Wide-field Telescope is a prime focus system that is located at Nanshan Station of Xinjiang Astronomical Observatories.The field of view was designed to 1.5°× 1.5°,and the Johnson-Cousins UBVRI system was chosen as the main filter set.The telescope has been providing observation services for astronomers since September 2013.Variable source searching and time-domain surveys are the main scientific goals.The system’s test results are reported including linearity,dark current,bias,readout noise and gain of the CCD camera.The accurate instrumental calibration coefficients in UBVRI bands were driven with Landolt standard stars during photometric nights.Finally,the limiting magnitudes are given with signal-to-noise ratios and various exposure times for observers.展开更多
We investigate the Luminosity Function (LF) of the cluster of galaxies Abell 566. The photometric data of 15 intermediate-bands are obtained from the Beijing-Arizona- Taiwan-Connecticut (BATC) photometric sky surv...We investigate the Luminosity Function (LF) of the cluster of galaxies Abell 566. The photometric data of 15 intermediate-bands are obtained from the Beijing-Arizona- Taiwan-Connecticut (BATC) photometric sky survey. For each of the 15 wavebands, the LF of cluster galaxies is well modelled by the Schechter function, with characteristic luminosities from -18.0 to -21.9 magnitude, from the α- to the p-band. Morphological dependence of the LF is investigated by separating the cluster members into 'red' and 'blue' subsamples. It is clear that late type galaxies have a steeper shape of LF than the early type galaxies. We also divided the sample galaxies by their local environment. It was found that galaxies in the sparser region have steeper shape of LF than galaxies in the denser region. Combining the results of morphological and environmental dependence of LFs, we show that Abell 566 is a well relaxed cluster with positive evidence of galaxy interaction and merger, and excess number of bright early type galaxies located in its denser region.展开更多
We present a progress of a long term project to obtain UBVI CCD photometry of open clusters which were little studied before, using the Doyak 1.8 m telecope of Bohyunsan Optical Astronomy Observatory operated by the K...We present a progress of a long term project to obtain UBVI CCD photometry of open clusters which were little studied before, using the Doyak 1.8 m telecope of Bohyunsan Optical Astronomy Observatory operated by the Korea Astronomical Observatory, in Korea. The primary goals of this project are (1) to make a catalog of UBVI photometry of open clusters, (2) to make an atlas of open clusters, and (3) to survey and monitor variable stars in open clusters.展开更多
Using the 1.26 m National Astronomical Observatory-Guangzhou University Infrared/Optical Telescope(NGT),we monitor one BL Lac object,OJ 287.For this source,we obtain 15094 gri observations(4900 at g band,5184 at r ban...Using the 1.26 m National Astronomical Observatory-Guangzhou University Infrared/Optical Telescope(NGT),we monitor one BL Lac object,OJ 287.For this source,we obtain 15094 gri observations(4900 at g band,5184 at r band and 5010 at i band)in 155 nights from 2014 December 13 to 2019 March15.Based on the upper observations,we obtain the following results.(1)The total variation amplitude is~2.3 mag.(2)There are intra-day variabilities(IDVs).The IDV timescales(△T)are in the range from 7.69 min(Δm=0.06±0.02 mag)to 371.09 min(Δm=0.26±0.04 mag).(3)There are strong correlations betweenΔT andΔm,△m=(2.91±0.66)×10^(-4)ΔT+(0.08±0.009),with r=0.52,p=5.33×10^(-5).(4)There are intra-day periods in this source,with the period P≈94 min on 2017 December 10.When we supplement the observations from the literature,we can obtain that the long-term period is about 12.02±0.41 yr.(5)The spectral properties of OJ 287 show the bluer-when-brighter behavior,whatever state the source is at.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.31371106 and 91632110)HZAU Independent Innovation Fund (2014BQ019).
文摘In vito fber photometry is a powerful technique to analyze the dy namics of population neurons during fiunctional study of neuroscience.Here,we introduced a detailed protocol for fiber photometry-based calciun reording in freely moving mice,covering from virus injection,fiber stub insertion,optogenetical stimulation to data procurement and analysis.Furthemnore,we applied this protocol to explore neuronal activity of mice latenal-posterior(LP)thalaric nucleus in response to optogenetical stimulation of primary visual cortex(V1)neurons,and explore axon clusters activity of optogenetically evoked V1 neurons.Final confirmation of virus-based protein expression in V1 and precise fber insertion indicated that the surgery procedure of this protocol is reliable for functional calcium recording.The scripts for data analysis and some tips in our protocol are provided in details.Together,this protocol is simple,low-cost,and effective for neuronal activity detection by fiber photometry,which will hep neuroscience researchers to carry out fiunctional and behavioral study in vivo.
基金supported by JSPS KAKENHI grants(Nos.19K17093 to SM20K06858 to AYamashita16H05130 to TK)and CREST JST(No.JPMJCR1656 to AYamanaka)。
文摘In the central nervous system,the A6 noradrenaline(NA)and the B3 serotonin(5-HT)cell groups are well-recognized players in the descending antinociceptive system,while other NA/5-HT cell groups are not well characterized.A5/A7 NA and B25-HT cells project to the spinal horn and form descending pathways.We recorded G-Ca MP6 green fluorescence signal intensities in the A5/A7 NA and the B25-HT cell groups of awake mice in response to acute tail pinch stimuli,acute heat stimuli,and in the context of a non-noxious control test,using fiber photometry with a calcium imaging system.We first introduced G-Ca MP6 in the A5/A7 NA or B25-HT neuronal soma,using transgenic mice carrying the tetracycline-controlled transactivator transgene under the control of either a dopamineβ-hydroxylase or a tryptophan hydroxylase-2 promoters and by the site-specific injection of adeno-associated virus(AAV-Tet O(3 G)-G-Ca MP6).After confirming the specific expression patterns of G-Ca MP6,we recorded G-Ca MP6 green fluorescence signals in these sites in awake mice in response to acute nociceptive stimuli.G-Ca MP6 fluorescence intensity in the A5,A7,and B2 cell groups was rapidly increased in response to acute nociceptive stimuli and soon after,it returned to baseline fluorescence intensity.This was not observed in the non-noxious control test.The results indicate that acute nociceptive stimuli rapidly increase the activities of A5/A7 NA or B25-HT neurons but the non-noxious stimuli do not.The present study suggests that A5/A7 NA or B25-HT neurons play important roles in nociceptive processing in the central nervous system.We suggest that A5/A7/B2 neurons may be new therapeutic targets.All performed procedures were approved by the Institutional Animal Use Committee of Kagoshima University(MD17105)on February 22,2018.
基金supported by Beijing Municipal Governmentsupported by the National Natural Science Foundation of China(Grant Nos.61890952)the Director Fund of WNLO。
文摘Manipulating and real-time monitoring of neuronal activities with cell-type specificity and precise spatiotemporal resolution during animal behavior are fundamental technologies for exploring the functional connectivity, information transmission, and physiological functions of neural circuits in vivo. However, current techniques for optogenetic stimulation and neuronal activity recording mostly operate independently. Here, we report an all-fiber-transmission photometry system for simultaneous optogenetic manipulation and multi-color recording of neuronal activities and the neurotransmitter release in a freely moving animal. We have designed and manufactured a wavelength-independent multi-branch fiber bundle to enable simultaneous optogenetic manipulation and multi-color recording at different wavelengths. Further, we combine a laser of narrow linewidth with the lock-in amplification method to suppress the optogenetic stimulation-induced artifacts and channel crosstalk. We show that the collection efficiency of our system outperforms a traditional epi-fluorescence system. Further, we demonstrate successful recording of dynamic dopamine(DA) responses to unexpected rewards in the nucleus accumbens(NAc) in a freely moving mouse. We also show simultaneous dual-color recording of neuronal Ca2+ signals and DA dynamics in the NAc upon delivering an unexpected reward and the simultaneous optogenetic activating at dopaminergic terminals in the same location. Thus, our multi-function fiber photometry system provides a compatible, efficient, and flexible solution for neuroscientists to study neural circuits and neurological diseases.
文摘Based upon broad-band CCD observation data of comet Hale-Bopp obtained by a 60cm telescope at Xinglong Station of Beijing Astronomical Observatory during March-August, 1996, the photometric results of comet Hale-Bopp are reported. Using the photometric results, the dust production rate, radius and mass of nucleus of comet Hale-Bopp are estimated as follows: dM/dt~1.5×10 5 kgs -1, R n~35.5km, and M n~5.65×10 16kg.
基金supported by the Estonian Science Foundationprojects IUT26-2 and IUT40-2support by the Centre of Excellence of Dark Matter in(Astro)particle Physics and Cosmology(TK120)+3 种基金Funding for SDSS-Ⅲ has been provided by the Alfred P.Sloan Foundationthe Participating Institutionsthe National Science Foundationthe U.S.Department of Energy Office of Science
文摘Because of the 3D nature of galaxies, an algorithm for constructing spatial density distribution models of galaxies on the basis of galaxy images has many advan- tages over approximations of the surface density distribution. We present a method for deriving the spatial structure and overall parameters of galaxies from images and estimate its accuracy and derived parameter degeneracies on a sample of idealised model galaxies. The test galaxies consist component with varying proportions and of a disc-like component and a spheroidal properties. Both components are assumed to be axially symmetric and coplanar. We simulate these test galaxies as if they had been observed in the SDSS project through ugriz filters, thus gaining a set of realis- tically imperfect images of galaxies with known intrinsic properties. These artificial SDSS galaxies were thereafter remodelled by approximating the surface brightness distribution with a 2D projection of a bulge+disc spatial distribution model and the restored parameters were compared to the initial ones. Down to the r-band limiting magnitude of 18, errors in the restored integral luminosities and colour indices re- main within 0.05 mag and errors in the luminosities of individual components within 0.2 mag. Accuracy of the restored bulge-to-disc luminosity ratio (B/D) is within 40% in most cases, and becomes worse for galaxies with low B/D, but the general balance between bulges and discs is not shifted systematically. Assuming that the intrinsic disc axial ratio is ≤ 0.3, then the inclination angles can be estimated with errors 〈 5° for most of the galaxies with B/D 〈 2 and with errors 〈 15° up to B/D = 6. Errors in the recovered sizes of the galactic components are below 10% in most cases. The axial ratios and the shape parameter N of Einasto's distribution (similar to the Sersic index) are relatively inaccurate, but can provide statistical estimates for large samples. In general, models of disc components are more accurate than models of spheroidal components for geometrical reasons.
文摘In this paper, surface photometry and dynamical properties of Lenticular galaxies will be developed and applied to NGC3245. In this respect, we established new relation between the intensity distribution I and the semi-major axis a Moreover, some basic statistics of both independent and the dependent variables of the relation are also given. In addition to the I(a) relation , the Sérsic r1/n model is applied for the intensity profile I(r) resulting in an estimation of the effective radius, re, and the surface brightness it encloses, μe. Both relations (I(a) and I(r)) are accurate as judged by the precision criteria which are: the probable errors for the coefficients , the estimated variance of the fit and the Q value (the square distance between the exact solution and the least square estimated solution) where all very satisfactory. Correlation coefficients between some parameters of the isophotes are also computed. Finally as examples of applications of surface photometry we determined the dynamical properties: mass, density, potential distributions, as well as distributions of escape and circular speeds in terms of Sérsic model.
文摘We present UBVI surface photometry over a 20.5' × 20.5' area of the late-type spiral galaxy NGC 300. We have derived isophotal maps, surface brightness profiles, ellipticity profiles, position angle profiles, and color profiles. By merging our I-band measurements with those of Boker et al. based on Hubble Space Telescope observations, we have obtained combined I-band surface brightness profiles for the region 0.02' < r < 500' and have decomposed the profiles into three components: a nucleus, a bulge, and an exponential disk.
基金The research leading to these results has received partial funding from the European Metrology Research Programme(EMRP)project SIB57‘New Primary Standards and Traceability for Radiometry’The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union.
文摘Light emitting diode(LED)lighting is becoming more and more popular,as incandescent lamps are being phased out globally.LEDs have several advantages over incandescent lamps,including energy efficiency,robustness,long lifetime,and good temporal stability.The three latter features make LEDs attractive candidates as new photometric standards.Because the spectra of white LEDs are limited to the visible wavelength range,a novel method for the realization of photometric units based on the predictable quantum efficient detector(PQED)can be utilized.The method eliminates the need of photometric filters that are traditionally used in photometry,and instead relies on carrying out the photometric weighting numerically based on the measured relative spectrum of the source.The PQED-based realization simplifies the traceability chain of photometric measurements significantly as compared with the traditional filter-based method.The measured illuminance values of a white LED deviate by only 0.03%when determined by the new and the traditional methods.The new PQED method has significantly lower expanded uncertainty of 0.26%(k=52)as compared with that of the traditional filter-based method of 0.42%(k=52).Furthermore,when filtered photometers that measure LED lighting are calibrated using LED lamps as calibration sources instead of incandescent lamps,a significant decrease in the uncertainty related to the spectral mismatch correction can be obtained.The maximum spectral mismatch errors of LED measurements decreased on average by a factor of 3 when switching from an incandescent lamp to an LED calibration source.
文摘Based upon broad-band CCD observation data of comet Hale-Bopp obtained by a 60 cm telescope at Xinglong Station of Beijing Astronomical Observatory during March-August, 1996, the photometric results of comet Hale-Bopp are reported. Using the photometric results, the dust production rate, radius and mass of nucleus of comet Hale-Bopp are estimated as follows: dM/df ~ 1.5 × 105 kgs-1, Rn~35.5 km, and Mn~5.65×1016 kg.
基金supported by the National Key R&D Program of China(2022YFF0503401)the National Natural Science Foundation of China(12203047,12025303,11890693,12003031)+1 种基金the science research grants from the China Manned Space Project with NO.CMSCSST-2021-A06the Fundamental Research Funds for the Central Universities(WK3440000006,WK2030000057)。
文摘The Wide Field Survey Telescope(WFST)is a dedicated time-domain multi-band(u,g,r,i,and z)photometric survey facility under construction.In this paper,we present a preliminary study that assesses the quality of photometric redshifts based on WFST by utilizing mock observations derived with the galaxy catalog in the COSMOS/UltraVISTA field.We apply the template fitting technique to estimate photometric redshifts by using the ZEBRA photometric-redshift code and adopting a modified set of adaptive templates.We evaluate the bias(median relative offset between the output photometric redshifts and input redshifts),normalized median absolute deviation(σ_(NMAD))and outlier fraction(f_(outlier))of photometric redshifts in two typical WFST observational cases,the single 30 s exposure observations(hereafter shallow mode)and co-added 50 minutes exposure observations(hereafter deep mode).We find bias≲0.006,σ_(NMAD)≲0.03,and f_(outlier)≲5%in the shallow mode and bias≈0.005,σ_(NMAD)≈0.06,and f_(outlier)≈17%–27%in the deep mode,respectively,under various lunar phases.Combining the WFST mock observational data with that from the upcoming CSST and Euclid surveys,we demonstrate that the zphot results can be significantly improved,with f_(outlier)≈1%andσ_(NMAD)≈0.02.
基金supported by China Manned Space Program through its Space Application Systemthe National Natural Science Foundation of China(NSFC,grant Nos.11973022 and U1811464)the Natural Science Foundation of Guangdong Province(No.2020A1515010710)。
文摘Machine learning has become a crucial technique for classifying the morphology of galaxies as a result of the meteoric development of galactic data.Unfortunately,traditional supervised learning has significant learning costs since it needs a lot of labeled data to be effective.FixMatch,a semi-supervised learning algorithm that serves as a good method,is now a key tool for using large amounts of unlabeled data.Nevertheless,the performance degrades significantly when dealing with large,imbalanced data sets since FixMatch relies on a fixed threshold to filter pseudo-labels.Therefore,this study proposes a dynamic threshold alignment algorithm based on the FixMatch model.First,the class with the highest amount has its reliable pseudo-label ratio determined,and the remaining classes'reliable pseudo-label ratios are approximated in accordance.Second,based on the predicted reliable pseudo-label ratio for each category,it dynamically calculates the threshold for choosing pseudo-labels.By employing this dynamic threshold,the accuracy bias of each category is decreased and the learning of classes with less samples is improved.Experimental results show that in galaxy morphology classification tasks,compared with supervised learning,the proposed algorithm significantly improves performance.When the amount of labeled data is 100,the accuracy and F1-score are improved by 12.8%and 12.6%,respectively.Compared with popular semisupervised algorithms such as FixMatch and MixMatch,the proposed algorithm has better classification performance,greatly reducing the accuracy bias of each category.When the amount of labeled data is 1000,the accuracy of cigar-shaped smooth galaxies with the smallest sample is improved by 37.94%compared to FixMatch.
文摘This is a prospective interventional clinical study evaluating intraocular inflammation developed after Ultrasound Cyclo Plasty(UCP) for the treatment of glaucoma. Eighteen eyes of 18 patients were treated with UCP second-generation probes(Eye OP1). After treatment, the mean intraocular pressure(IOP) significantly decreased from 26.8±7.2 to 18.8±6.1 mm Hg at day 1 and to 14.7±3.4 mm Hg at month 6(all P<0.001). Mean laser flare-cell photometry value steeply increased after surgery from 12.1±7.5 to 64.1±53.9 ph/ms(P=0.001) at day 1, and then progressively decreased to respectively 60.6±49.7 at day 7, 43.5±38.5 at day 14 and 28.2±18.3 at month 1(all P<0.05), returning at levels similar to baseline ones at month 3 and month 6(respectively 16.7±6.2 and 12.8±10.2, both P>0.05). A significant negative correlation was found between postoperative increase of aqueous flare values and anterior chamber depth(R=-0.568, P=0.014). This timeframe may be considered reasonable for repeating UCP treatment, when required.
基金support from the staff at the Xinglong 85-cm telescopesupport from the National Natural Science Foundation of China(NSFC)through grant 11673003+3 种基金the National Basic Research Program of China(973 program,2014CB845700)partially supported by the Open Project Program of the Key Laboratory of Optical Astronomy(National Astronomical Observatories)NSFC under Grant Nos.11403088 and 11273051(Xinjiang Astronomical Observatory)Chinese Academy of Sciences and Department of Astronomy,Beijing Normal University
文摘The 85-cm telescope at Xinglong station is a prime focus system that operates well with high science outputs. The telescope has been upgraded since 2014 with a new corrector, and new filters and camera, which are provided by Beijing Normal University. The filter set is the Johnson-Cousins UBV RI system. We report the test results of the new system including bias, dark current, linearity, gain and readout noise of the CCD camera. Then we derive accurate instrumental calibration coefficients in UBV RI bands with Landolt standard stars during photometric nights. Finally, we give the limiting magnitudes with various exposure times and signal-to-noise ratios for observers as references.
文摘Aim: The elemental composition of the epididymal luminal fluid (ELF) in adult goat ( Capra indica) was investigat-ed. Methods: ELF was collected by micropuncture from twelve sites along the epididymal duct. The elementalcontents was analyzed with inductively coupled plasma (ICP) emission spectroscopy, a microanalytical technique thatcan simultaneously measure many elements in minute volumes of sample. The Na and K concentrations were determinedby flame photometry. Results: ICP spectroscopy showed the presence of copper, calcium, nickel, iron, magne-sium, chromium, titanium and zinc in ELF, with fluctuating levels at different sites along the length of the epididymis.Cadmium, cobalt, lead and manganese were not fotmd. The Na^+ / K^+ ratio was seen to be higher at the initial seg-ments of the epididymis and lower at the distal. Conclusion: It is proposed that the observed characteristic distribu-tion of elements in ELF may have far reaching implications in sperm maturation and storage known to occur in the epi-didymis. (Asian J Androl 2000 Dec; 2: 288-292)
基金supported by the program of the light in China’s Western Region(LCWRGrant Nos.2015-XBQN-B-04,2015-XBQN-A02)+5 种基金the National Natural Science Foundation of China(Grant Nos.11803076,11873081,11661161016 and U1831209)the 13th Five-year Informatization Plan of Chinese Academy of Sciences(Grant No.XXH13503–03–107)the Youth Innovation Promotion Association CAS(Grant Nos.2014050,2018080)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB23040100)2017 Heaven Lake Hundred-Talent Program of Xinjiang Uygur Autonomous Region of Chinathe Open Project Program of the Key Laboratory of Optical Astronomy(NAOC)。
文摘The Nanshan One-meter Wide-field Telescope is a prime focus system that is located at Nanshan Station of Xinjiang Astronomical Observatories.The field of view was designed to 1.5°× 1.5°,and the Johnson-Cousins UBVRI system was chosen as the main filter set.The telescope has been providing observation services for astronomers since September 2013.Variable source searching and time-domain surveys are the main scientific goals.The system’s test results are reported including linearity,dark current,bias,readout noise and gain of the CCD camera.The accurate instrumental calibration coefficients in UBVRI bands were driven with Landolt standard stars during photometric nights.Finally,the limiting magnitudes are given with signal-to-noise ratios and various exposure times for observers.
基金Supported by the National Natural Science Foundation of China.
文摘We investigate the Luminosity Function (LF) of the cluster of galaxies Abell 566. The photometric data of 15 intermediate-bands are obtained from the Beijing-Arizona- Taiwan-Connecticut (BATC) photometric sky survey. For each of the 15 wavebands, the LF of cluster galaxies is well modelled by the Schechter function, with characteristic luminosities from -18.0 to -21.9 magnitude, from the α- to the p-band. Morphological dependence of the LF is investigated by separating the cluster members into 'red' and 'blue' subsamples. It is clear that late type galaxies have a steeper shape of LF than the early type galaxies. We also divided the sample galaxies by their local environment. It was found that galaxies in the sparser region have steeper shape of LF than galaxies in the denser region. Combining the results of morphological and environmental dependence of LFs, we show that Abell 566 is a well relaxed cluster with positive evidence of galaxy interaction and merger, and excess number of bright early type galaxies located in its denser region.
文摘We present a progress of a long term project to obtain UBVI CCD photometry of open clusters which were little studied before, using the Doyak 1.8 m telecope of Bohyunsan Optical Astronomy Observatory operated by the Korea Astronomical Observatory, in Korea. The primary goals of this project are (1) to make a catalog of UBVI photometry of open clusters, (2) to make an atlas of open clusters, and (3) to survey and monitor variable stars in open clusters.
基金partially supported by the National Natural Science Foundation of China(Grant Nos.U1831119,U1531245,U1431112,11733006,11503004 and 11403006)Science and Technology Program of Guangzhou(201707010401)。
文摘Using the 1.26 m National Astronomical Observatory-Guangzhou University Infrared/Optical Telescope(NGT),we monitor one BL Lac object,OJ 287.For this source,we obtain 15094 gri observations(4900 at g band,5184 at r band and 5010 at i band)in 155 nights from 2014 December 13 to 2019 March15.Based on the upper observations,we obtain the following results.(1)The total variation amplitude is~2.3 mag.(2)There are intra-day variabilities(IDVs).The IDV timescales(△T)are in the range from 7.69 min(Δm=0.06±0.02 mag)to 371.09 min(Δm=0.26±0.04 mag).(3)There are strong correlations betweenΔT andΔm,△m=(2.91±0.66)×10^(-4)ΔT+(0.08±0.009),with r=0.52,p=5.33×10^(-5).(4)There are intra-day periods in this source,with the period P≈94 min on 2017 December 10.When we supplement the observations from the literature,we can obtain that the long-term period is about 12.02±0.41 yr.(5)The spectral properties of OJ 287 show the bluer-when-brighter behavior,whatever state the source is at.