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Increased excitatory amino acid transporter 2 levels in basolateral amygdala astrocytes mediate chronic stress–induced anxiety-like behavior
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作者 Xirong Xu Shoumin Xuan +3 位作者 Shuai Chen Dan Liu Qian Xiao Jie Tu 《Neural Regeneration Research》 SCIE CAS 2025年第6期1721-1734,共14页
The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain functio... The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with emotions.Specifically, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal mice.After knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was obviously mitigated. Additionally, administration of an excitatory amino acid transporter 2 inhibitor in the basolateral amygdala yielded a notable reduction in anxiety level among mice subjected to stress. These results suggest that basolateral amygdala astrocytic excitatory amino acid transporter 2 plays a role in in the regulation of unpredictable chronic mild stress-induced anxiety-like behavior by impacting the activity of local glutamatergic neurons, and targeting excitatory amino acid transporter 2 in the basolateral amygdala holds therapeutic promise for addressing anxiety disorders. 展开更多
关键词 ANXIETY ASTROCYTES basolateral amygdala behavior dihydrokainic acid excitatory amino acid transporter 2 fiber photometry GLUTAMATE LDN-212320 TRANSPORTER
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Upgraded photometric system on the 85-cm telescope at Xinglong station 被引量:4
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作者 Chun-Hai Bai Jian-Ning Fu +8 位作者 Tao-Ran Li Zhou Fan Jiang-Hua Wu Yong Zhao Xian-Qun Zeng Wen-Zhao Zhang Peng Qiu Guo-Jie Feng Xiao-Jun Jiang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第9期21-30,共10页
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
关键词 TELESCOPE INSTRUMENTATION CCD photometry
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Inductively coupled plasma emission spectroscopic and flame photometric analysis of goat epididymal fluid 被引量:1
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作者 Meenakshi Gaur Vikas Pruthi +1 位作者 Ramasare Prasad Ben M.J.Pereira 《Asian Journal of Andrology》 SCIE CAS CSCD 2000年第4期288-292,共5页
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
关键词 goat epididymis epididymal luminal fluid elements spectroscopy flame photometry
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The wide-field photometric system of the Nanshan One-meter Telescope 被引量:2
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作者 Chun-Hai Bai Guo-Jie Feng +9 位作者 Xuan Zhang Hu-Biao Niu Abdusamatjan Eskandar Guang-Xin Pu Shu-Guo Ma Jin-Zhong Liu Xiao-Jun Jiang Lu Ma Ali Esamdin Na Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2020年第12期373-382,共10页
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
关键词 TELESCOPE FILTER CCD photometry
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Photometric Survey of Galactic Open Clusters 被引量:1
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作者 M.G. Lee 1, H.B. Ann 2, M.Y. Chun 3, S. L. Kim 3, Y. B. Jeon 3, B. G. Park 3, I. S. Yuk 3, H.Sung 4 1 (Dept. of Astronomy, Seoul National University, Seoul 151-742, Korea, mglee@astrog. snu. ac. kr) 2 (Department of Earth Science, Pusan Nat 《天文研究与技术》 CSCD 1999年第S1期213-217,共5页
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
关键词 open clusters C M DIAGRAM age DISTANCE photometry variable STARS
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Charge coupled devices (CCD) photometry and long-term optical variability of gamma-ray-loud BL Lacertae object Mkn 421 被引量:3
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作者 张雄 郑永刚 +2 位作者 张皓晶 胡绍明 谢照华 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第9期2185-2192,共8页
Evidence for the long-term optical curve variability and colour behaviour of the BL Lac object Mkn 421 is presented. Our results show that the amplitude of the optical variations of Mkn 421 is only about △B=4.7 magni... Evidence for the long-term optical curve variability and colour behaviour of the BL Lac object Mkn 421 is presented. Our results show that the amplitude of the optical variations of Mkn 421 is only about △B=4.7 magnitude in the B-band for its photometric history from 1899 to 2002. The results of optical photometric monitoring of the Mkn 421 from April 2000 to Jan 2002 are provided. During our observation, Mkn 421 shows significant rapid variations and exhibits short time variability of 2.42 hours in the B band. A strong correlation between the B - V colour index and the magnitude in the B band is found. Our charge coupled device (CCD) photometry of Mkn 421 shows that the measured results are in good agreement with the predicted optical variability period of about 23 years. 展开更多
关键词 BL Lac object Mkn 421 photometry mass of central black hole colour index
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All-fiber-transmission photometry for simultaneous optogenetic stimulation and multi-color neuronal activity recording 被引量:1
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作者 Zhongyang Qi Qingchun Guo +4 位作者 Shu Wang Mingyue Jia Xinwei Gao Minmin Luo Ling Fu 《Opto-Electronic Advances》 SCIE EI CAS 2022年第12期20-34,F0004,共16页
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
关键词 fiber photometry all-fiber-transmission multi-color optogenetic NEUROSCIENCE
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In vivo fiber photometry of neural activity in response to optogenetically manipulated inputs in freely moving mice 被引量:1
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作者 Liang Li Yajie Tang +6 位作者 Leqiang Sun Khaista Rahman Kai Huang Weize Xu Jinsong Yu Jinxia Dai Gang Cao 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2017年第5期47-58,共12页
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
关键词 Fiber photometry surgical operation optogenetical stimulation neural activity freely moving recording
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The Simultaneous Three-channel Multicolor CCD Photometric System of the 1.2 m Telescope at Jilin Astronomical Observatory 被引量:1
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作者 Bing-Li Niu Cheng-Zhi Liu +2 位作者 Zhen-Wei Li Zhe Kang You Lv 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第5期75-86,共12页
We will introduce the construction and design of a new simultaneous three-channel multicolor CCD photometer.This photometer has been mounted on the 1.2 m telescope at Jilin Astronomical Observatory,and is applied to s... We will introduce the construction and design of a new simultaneous three-channel multicolor CCD photometer.This photometer has been mounted on the 1.2 m telescope at Jilin Astronomical Observatory,and is applied to study space debris,gamma-ray burst afterglows,asteroids and other rapidly variable objects.As one of the ground follow-up telescopes of the Chinese-French Space-based multi-band astronomical Variable Objects Monitor(SVOM)mission,it appears very essential to evaluate the performance of the photometry system of this photometer,which can achieve simultaneous imaging within a field of view of 21’.5×21’.5,21’.5×21’.5 and21’.3×21’.3 in the Sloan Digital Sky Survey(SDSS)g’,r’,i’bands,respectively.Photometric calibrations were carried out by using plenty of SDSS standard stars,and the relationship between the photometric system and the Johnson-Bessel filter system was also studied.The results of the performance evaluation from observing open cluster M67 are presented. 展开更多
关键词 astronomical instrumentation-photometer-photoelectric photometry
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Co-colouration Effects in the Systems of Metal(Ⅱ)-Rare Earth(Ⅲ)-Xanthene Dye and Their Influences on Photometric Determination of Metal Ions
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作者 陈华序 金倪 齐志刚 《Rare Metals》 SCIE EI CAS CSCD 1993年第4期295-300,共6页
After comparing the influences of each rare earth(Ⅲ),11 species of metal(Ⅱ)and 8 species of acidic triphenylmethane dye on the formation of coloured coordination compound in the system of Metal(Ⅱ)-RE (Ⅲ)-Dye,it wa... After comparing the influences of each rare earth(Ⅲ),11 species of metal(Ⅱ)and 8 species of acidic triphenylmethane dye on the formation of coloured coordination compound in the system of Metal(Ⅱ)-RE (Ⅲ)-Dye,it was proven that the co-colouration effect can be caused only by the xanthene dyes(XD)con- taining substituting hydroxy.group on the ortho-position of etheric oxygen group.Besides,the radius of met- al(Ⅱ)must not be smaller than a definite limit;otherwise,no co-colouration appears.Furthermore,the acid- ity of medium is another important factor to affect co-colouration,Bromopyrogallol red causes co-colouration of Pb(Ⅱ)-RE(Ⅲ)only,owing to its higher chromophoric acidity;while alizarin violet causes co-colouration of M(Ⅱ)-RE(Ⅲ)(M=Pb,Ca,Sr and Ba),due to its lower chromophoric acidity.The condi- tions causing co-colouration,the regularities of co-colouration and the influences of co-colouration in photometric determination of metals were discussed. 展开更多
关键词 Co-colouration Rare earth Xanthene dye photometry
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Extraction-spectrophotometric Determination of Dicyanoaurate(Ⅰ) with Crystal Violet
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作者 罗明标 张燮 黄文艳 《Rare Metals》 SCIE EI CAS CSCD 1998年第4期59-62,共4页
Extraction spectrophotometric determination of dicyanoaurate (Ⅰ) with Crystal Violet is described. At pH 2.6~10.7, dicyanoaurate (Ⅰ) can react with Crystal Violet and form a complex which can be extracted into iso... Extraction spectrophotometric determination of dicyanoaurate (Ⅰ) with Crystal Violet is described. At pH 2.6~10.7, dicyanoaurate (Ⅰ) can react with Crystal Violet and form a complex which can be extracted into isoamylacetate. The apparent molar absorptivity is 8.37×10 4 L·mol -1 ·cm -1 at 605 nm. Beer′s law is obeyed for 0~15 μg of Au(Ⅰ) per 5 ml of isoamylacetate. The interference from Ag(Ⅰ) and Cu(Ⅱ) can be eliminated with thiourea and EDTA. The method is applied to the determination of dicyanoaurate (Ⅰ) in sample solution with satisfactory results. 展开更多
关键词 Extraction photometry Crystal Violet Gold (Ⅰ)
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Spectrophotometric Methods for Simultaneous Determination of Amlodipine Besylate and Atenolol in Their Tablet Dosage Form 被引量:1
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作者 Nesrine T.Lamie 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2015年第12期3538-3543,共6页
Three simple,specific,accurate and precise spectrophotometric methods are developed for simultaneous determination of amlodipine besylate(AM)and atenolol(AT)in tablets.The first method is dual wavelength spectrophotom... Three simple,specific,accurate and precise spectrophotometric methods are developed for simultaneous determination of amlodipine besylate(AM)and atenolol(AT)in tablets.The first method is dual wavelength spectrophotometry(DW).The second method is ratio subtraction(RS)which depends on subtraction of the plateau values from the ratio spectrum,coupled to first derivative of ratio spectra(1 DD).The third method applies bivariate calibration method using 210and 225nm as an optimum pair of wavelength for amlodipine and atenolol.The calibration curves are linear over the concentration range of 4~40μg·mL-1 for both drugs.The specificity of the developed methods is investigated by analyzing laboratory prepared mixtures of the two drugs and their combined dosage form.The two methods are validated as per ICH guidelines and can be applied for routine quality control testing. 展开更多
关键词 AMLODIPINE ATENOLOL RATIO SUBTRACTION Dual wavelength Derivative-ratio BIVARIATE Spectro-photometry
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Color-Redshift Relations and Photometric Redshift Estimations of Quasars in Large Sky Surveys
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作者 Xue-BingWu WeiZhang XuZhou 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2004年第1期17-27,共11页
With a recently constructed composite quasar spectrum and the χ<SUP>2</SUP> minimization technique, we describe a general method for estimating the photometric redshifts of a large sample of quasars by de... With a recently constructed composite quasar spectrum and the χ<SUP>2</SUP> minimization technique, we describe a general method for estimating the photometric redshifts of a large sample of quasars by deriving theoretical color-redshift relations and comparing the theoretical colors with the observed ones. We estimated the photometric redshifts from the 5-band SDSS photometric data of 18678 quasars in the first major data release of SDSS and compared them with their spectroscopic redshifts. The difference is less than 0.1 for 47 % of the quasars and less than 0.2 for 68 %. Based on the calculation of the theoretical color-color diagrams of stars, galaxies and quasars both on the SDSS system and on the BATC system, we expect that we would be able to select candidates of high redshift quasars more efficaciously with the latter than with the former, provided the BATC survey can detect objects with magnitudes fainter than 21. 展开更多
关键词 galaxies: photometry quasars: general quasars: emission lines surveys
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Preliminary Study of Photometric Redshifts Based on the Wide Field Survey Telescope
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作者 Yu Liu Xiao-Zhi Lin +1 位作者 Yong-Quan Xue Huynh Anh N.Le 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第12期138-152,共15页
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
关键词 GALAXIES distances and redshifts-galaxies high-redshift-galaxies photometry
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Photometric Redshifts and Galaxy Clusters for DES DR2, DESI DR9, and HSC-SSP PDR3 Data
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作者 Hu Zou Jipeng Sui +8 位作者 Suijian Xue Xu Zhou Jun Ma Zhimin Zhou Jundan Nie Tianmeng Zhang Lu Feng Zhixia Shen Jiali Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第6期1-21,共21页
Photometric redshift(photoz)is a fundamental parameter for multi-wavelength photometric surveys,while galaxy clusters are important cosmological probes and ideal objects for exploring the dense environmental impact on... Photometric redshift(photoz)is a fundamental parameter for multi-wavelength photometric surveys,while galaxy clusters are important cosmological probes and ideal objects for exploring the dense environmental impact on galaxy evolution.We extend our previous work on estimating photoz and detecting galaxy clusters to the latest data releases of the Dark Energy Spectroscopic Instrument(DESI)imaging surveys,Dark Energy Survey(DES)and Hyper Suprime-Cam Subaru Strategic Program(HSC-SSP)imaging surveys and make corresponding catalogs publicly available for more extensive scientific applications.The photoz catalogs include accurate measurements of photoz and stellar mass for about 320,293and 134 million galaxies with r<23,i<24 and i<25 in DESI DR9,DES DR2 and HSC-SSP PDR3 data,respectively.The photoz accuracy is about 0.017,0.024 and 0.029 and the general redshift coverage is z<1,z<1.2 and z<1.6,respectively for those three surveys.The uncertainty of the logarithmic stellar mass that is inferred from stellar population synthesis fitting is about 0.2 dex.With the above photoz catalogs,galaxy clusters are detected using a fast cluster-finding algorithm.A total of 532,810,86,963 and 36,566 galaxy clusters with the number of members larger than 10 is discovered for DESI,DES and HSC-SSP,respectively.Their photoz accuracy is at the level of 0.01.The total mass of our clusters is also estimated by using the calibration relations between the optical richness and the mass measurement from X-ray and radio observations.The photoz and cluster catalogs are available at Science DB(https://www.doi.org/10.11922/sciencedb.o00069.00003)and Paper Data Repository(https://doi.org/10.12149/101089). 展开更多
关键词 GALAXIES CLUSTERS general-galaxies distances and redshifts-galaxies photometry
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THE BROAD-BAND CCD PHOTOMETRY AND DUST PRODUCTION RATES OF COMET HALE-BOPP
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作者 Huang Keliang 1 Hu Jingyao 2 Zhou Hongnan 1 (1. Department of Physics, Nanjing Normal University, Nanjing 210097) (2. Beijing Observatory, Chinese Academy of Sciences, Beijing 100080) 《中国科学院上海天文台年刊》 2000年第S1期44-50,共7页
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: dM/dt~1.5×10 5 kgs -1, R n~35.5km, and M n~5.65×10 16kg. 展开更多
关键词 COMET HALE-BOPP - CCD photometry - DUST production rate
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Surface Photometry and Dynamical Properties of Lenticular Galaxies: NGC3245 as Case Study
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作者 Mohamed Adel Sharaf K. Mahmoud +1 位作者 E. Aly A. A. Alshaery 《International Journal of Astronomy and Astrophysics》 2012年第1期39-51,共13页
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
关键词 SURFACE photometry DYNAMICAL GALAXIES
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Characterization and color rendering enhancement of some LEDs for photometric application
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作者 A Al-Kamel F M EL-Sharkawy E M El-Moghazy 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2017年第4期364-370,共7页
The new standards for the photometric characterization of light-emitting diode(LED)sources and luminaries require the measurement evaluation of photometric and colorimetric quantities.This present work studies the per... The new standards for the photometric characterization of light-emitting diode(LED)sources and luminaries require the measurement evaluation of photometric and colorimetric quantities.This present work studies the performance of some types of LED light sources in different spectra and different color temperature for photometric and colorimetric applications.The study depends on mixed spectra of these different types of LEDs to enhance the color rendering index(CRI)to be near as possible to standard sources.Characterization of LED sources requires the evaluation of some photometric and colorimetric quantities such as luminous flux(),chromaticity coordinates(x,y)and(u′,v′),correlated color temperature(CCT)and color rending indices(CRI). 展开更多
关键词 photometry light-emitting diodoes (LEDs) CHROMATICITY color rendering indices
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Recovering 3D structural properties of galaxies from SDSS-like photometry
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作者 Elmo Tempel Antti Tamm +1 位作者 Rain Kipper Teeter Tenjes 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2015年第10期1613-1628,共16页
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
关键词 methods: numerical -- galaxies: general -- galaxies: photometry --galaxies: structure
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THE CCD PHOTOMETRIC OBSERVATIONS OF COMET C/1995 O1 (HALE-BOPP)
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作者 Zhou Hongnan 1 Huang Keliang 2 Wang Yu 1 Zhou Qinglin 1 (1. Department of Astronomy, Nanjing University, Nanjing 210093) (2. Department of Physics, Nanjing Normal University, Nanjing 210097) 《中国科学院上海天文台年刊》 2000年第S1期51-54,共4页
The CCD photometric observation of secular periodic comet C/1995 O1 (Hale-Bopp) was carried out at the Sheshan Station of Shanghai Observatory of China. We obtained 23 CCD images on 1996 March 11, April 22 and May 22.... The CCD photometric observation of secular periodic comet C/1995 O1 (Hale-Bopp) was carried out at the Sheshan Station of Shanghai Observatory of China. We obtained 23 CCD images on 1996 March 11, April 22 and May 22. We derived the magnitude of the cometary nucleus in V, R bands, and estimated the lower limits of cometary mass and size. The results show that the diameter of nucleus ≈ 5 ~ 10km, which corresponds to a mass of 2 × 10 12~ 3 × 10 13 kg for different parameters when the bulk density is assumed to 1000 kg·m -3. 展开更多
关键词 Comet: C/ 1995 O1 (Hale-Bopp) - CCD photometry - Mass and size of cometary nucleus
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