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Assessment of the Implementation of Energy Conservation Opportunities Arising from Energy Audits;A Study of Four-Star and Five-Star Hotels in Nairobi Kenya
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作者 Nicholas Ogola Peter Musau Cyrus Wekesa 《Journal of Power and Energy Engineering》 2023年第9期15-44,共30页
This study assesses the implementation of energy conservation opportunities in four-star and five-star hotels in Nairobi. The Covid-19 pandemic had a significant impact on the Hospitality Industry. Currently, there is... This study assesses the implementation of energy conservation opportunities in four-star and five-star hotels in Nairobi. The Covid-19 pandemic had a significant impact on the Hospitality Industry. Currently, there is a growing inclination to furnish guests with superior and sustainable services in an energy-efficient and eco-friendly way. Comprehensive research was conducted from energy audits gathered from the establishments and contracted auditing companies, on top of this, hotel staff were given digital questionnaires. To add to the data, the researcher surveyed the hotels with engineering managers. The Energy Audits found that all 10 hotels had adopted Energy Conservation Opportunities (ECOs). After further analysis, the mean adoption rate of Energy Conservation Opportunities (ECOs) during the past three years was 55.83%, which was below the aim of 100%. According to studies, hotel staff manages energy to cut costs. The researcher found that hotels use up a lot of energy. However, they have conservation potential, depending on government policies, costs, ease of implementation, and management commitment to sustainable practices. Essentially, Energy Conservation Opportunities (ECOs) reduce energy expenditures and boost reliable revenues, especially during high energy prices and uncertainty. 展开更多
关键词 Energy Conservation Opportunities (ECOs) Energy Regulation 2012 Energy Audit 4-star Hotel 5-star Hotel Energy Management Environmental Sustainability Energy Efficiency
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超声介导瘤内注射99-star治疗肝癌实验病理研究 被引量:1
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作者 杨映红 林礼务 +3 位作者 杨发端 高上达 林秀芳 何以敉 《福建医药杂志》 CAS 2002年第1期74-75,F003,共3页
目的 观察人肝癌 smmc- 772 1裸小鼠模型经中药 99- star治疗的形态学变化。方法  99- star组 11只 ,酒精组 5只 ,生理盐水组 3只 ,分别于背部及肝等移植癌中注射 99- star、酒精和生理盐水等药液。结果 各组移植癌中均出现不同程度... 目的 观察人肝癌 smmc- 772 1裸小鼠模型经中药 99- star治疗的形态学变化。方法  99- star组 11只 ,酒精组 5只 ,生理盐水组 3只 ,分别于背部及肝等移植癌中注射 99- star、酒精和生理盐水等药液。结果 各组移植癌中均出现不同程度坏死 ,以生理盐水组最轻 ;坏死类型 ,注射酒精瘤细胞的蛋白变性呈脱水为特征 ,而 99- star致肿瘤坏死则固缩性和溶解性兼有且发现坏死区间质疏松 ,瘤细胞间距甚宽及有炎症反应。结论  99- star可作为 展开更多
关键词 肝癌 裸鼠 介入治疗 超声介导 瘤内注射治疗 99-star 实验研究
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Pulsations of Three Rapidly Oscillating Ap Stars TIC 96315731,TIC72392575,and TIC 318007796
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作者 Hai-Jian Zhong Dong-Xiang Shen +3 位作者 Chun-Hua Zhu He-Lei Liu Su-Fen Guo Guo-Liang Lü 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第8期157-168,共12页
We analyze the frequencies of three known roAp stars,TIC 96315731,TIC 72392575,and TIC 318007796,using the light curves from the Transiting Exoplanet Survey Satellite.For TIC 96315731,the rotational and pulsational fr... We analyze the frequencies of three known roAp stars,TIC 96315731,TIC 72392575,and TIC 318007796,using the light curves from the Transiting Exoplanet Survey Satellite.For TIC 96315731,the rotational and pulsational frequencies are 0.1498360 day^(-1)and 165.2609 day^(-1),respectively.In the case of TIC 72392575,the rotational frequency is 0.25551 day^(-1).We detect a quintuplet of pulsation frequencies with a center frequency of135.9233 day^(-1),along with two signals within the second pair of rotational sidelobes of the quintuplet separated by the rotation frequency.These two signals may correspond to the frequencies of a dipole mode.In TIC318007796,the rotational and pulsational frequencies are 0.2475021 day^(-1),192.73995 day^(-1),and196.33065 day^(-1),respectively.Based on the oblique pulsator model,we calculate the rotation inclination(i)and magnetic obliquity angle(b)for the stars,which provide the geometry of the pulsation modes.Combining the phases of the frequency quintuplets,the pulsation amplitude and phase modulation curves,and the results of spherical harmonic decomposition,we conclude that the pulsation modes of frequency quintuplets in TIC96315731,TIC 72392575,and TIC 318007796 correspond to distorted dipole mode,distorted quadrupole mode,and distorted dipole mode,respectively. 展开更多
关键词 asteroseismology-techniques photometric-stars oscillations(including pulsations)-stars chemically peculiar
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GRB 210323A:Signature of Long-lasting Lifetime of Supra-massive Magnetar as the Central Engine from the Merger of Binary Neutron Star
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作者 Yingze Shan Xiaoxuan Liu +2 位作者 Xing Yang Haoyu Yuan Houjun Lü 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第8期32-41,共10页
Theoretically,a supra-massive neutron star or magnetar may be formed after the merger of binary neutron stars.GRB210323A is a short-duration gamma-ray burst(GRB)with a duration of lasting~1 s.The light curve of the pr... Theoretically,a supra-massive neutron star or magnetar may be formed after the merger of binary neutron stars.GRB210323A is a short-duration gamma-ray burst(GRB)with a duration of lasting~1 s.The light curve of the prompt emission of GRB 210323A shows a signal-peaked structure and a cutoff power-law model can adequately fit the spectra with E_p=1826±747.More interestingly,it has an extremely long-lasting plateau emission in the X-ray afterglow with a duration of~10^(4)s,and then follows a rapid decay with a decay slope~3.2.This temporal feature is challenging by invoking the external shock mode.In this paper,we suggest that the observed long-lasting X-ray plateau emission is caused by the energy injection of dipole radiation from supra-massive magnetar,and the abrupt decay following the longlasting X-ray plateau emission is explained by supra-massive magnetar collapsing into a black hole.It is the short GRB(SGRB)with the longest X-ray internal plateau emission powered by a supra-massive neutron star.If this is the case,one can estimate the physical parameters of a supra-massive magnetar,and compare with other SGRBs.We also discuss the possible gravitational-wave emission,which is powered by a supra-massive magnetar and its detectability,and the possible kilonova emission,which is powered by r-process and magnetar spin-down to compare with the observed data. 展开更多
关键词 (stars)gamma-ray burst general-(stars)gamma-ray burst individual(GRB 210323A)-stars MAGNETARS
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超声介导瘤内注射“99-star”治疗人肝癌smmc-7721裸鼠模型中Bcl-2蛋白表达
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作者 杨映红 林礼务 +3 位作者 杨发端 高尚达 林秀芳 何以敉 《福建医药杂志》 CAS 2001年第6期110-111,共2页
目的 研究人肝瘤 smmc- 772 1裸小鼠模型经中药“99- star”治疗后 Bcl- 2蛋白表达。方法 于裸小鼠背部和肝等移植癌中 ,1 1只注射“99- star”,5只注射酒精和 3只注射生理盐水 ,动物处死后应用免疫组化方法检测移植癌组织中 Bcl- 2... 目的 研究人肝瘤 smmc- 772 1裸小鼠模型经中药“99- star”治疗后 Bcl- 2蛋白表达。方法 于裸小鼠背部和肝等移植癌中 ,1 1只注射“99- star”,5只注射酒精和 3只注射生理盐水 ,动物处死后应用免疫组化方法检测移植癌组织中 Bcl- 2蛋白表达。结果 对照组与各实验组移植癌和移植癌组织与药物注射引起肿瘤坏死的 Bcl- 2蛋白表达 ,在统计学上有显著差别。结论“99- star”可供 B超介导治疗肝癌的有效药物目的 研究人肝瘤 smmc- 772 1裸小鼠模型经中药“99- star”治疗后 Bcl- 2蛋白表达。方法 于裸小鼠背部和肝等移植癌中 ,1 1只注射“99- star”,5只注射酒精和 3只注射生理盐水 ,动物处死后应用免疫组化方法检测移植癌组织中 Bcl- 2蛋白表达。结果 对照组与各实验组移植癌和移植癌组织与药物注射引起肿瘤坏死的 Bcl- 2蛋白表达 ,在统计学上有显著差别。结论“99- star”可供 展开更多
关键词 肝癌 介导治疗 基因 BCL-2蛋白 99-star 动物实验
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基于Android的选矿破碎生产线PLC测控系统 被引量:1
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作者 杨帆 王钰涌 +2 位作者 张馨以 李博 刘水 《计算机技术与发展》 2023年第1期82-87,共6页
为解决选矿企业破碎生产线传统控制中出现的工人长时间现场操作对健康影响大、设备关联自动化程度低、出现故障不能快速诊断等缺点,提出设计与开发基于Android的PLC测控系统。首先概述了选矿企业破碎生产线的目前运行状况、Android与PL... 为解决选矿企业破碎生产线传统控制中出现的工人长时间现场操作对健康影响大、设备关联自动化程度低、出现故障不能快速诊断等缺点,提出设计与开发基于Android的PLC测控系统。首先概述了选矿企业破碎生产线的目前运行状况、Android与PLC各自特性及其在测控行业的优点,然后根据矿山企业选矿设备位置分散以及实时安全管理的要求设计出破碎生产线2-Star型网络拓扑结构,并给出了下星网络与上星网络中的具体设备传感器采集信号与连接接口方式等内容。进而重点论述了系统中需要设计的PLC软件、ICC软件、Android软件系统主要模块与流程图,并对它们涉及到的数字滤波、线性标度、故障诊断等关键算法进行了详细的介绍。实际开发应用表明:该系统极大地改善了工人的操作环境、提高了破碎设备运行的稳定性与安全性,尤其当出现故障后技术人员可以快速诊断并修复,很大程度上降低了选矿企业的设备运行维护成本。 展开更多
关键词 破碎生产线 2-star型网络 可编程控制器 故障诊断 安卓
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Variable Star Detection in the Field of Open Cluster NGC 188
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作者 Fang-Fang Song Hu-Biao Niu +2 位作者 Ali Esamdin Yu Zhang Xiang-Yun Zeng 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第9期162-170,共9页
This work presents the charge-coupled device(CCD)photometric survey of the old open cluster NGC 188.Timeseries V-band photometric observations were conducted for ten nights in 2017 January using the Nanshan Onemeter W... This work presents the charge-coupled device(CCD)photometric survey of the old open cluster NGC 188.Timeseries V-band photometric observations were conducted for ten nights in 2017 January using the Nanshan Onemeter Wide-field Telescope to search for variable stars in the field of the cluster.A total of 25 variable stars,including one new variable star,were detected in the target field.Among the detected variables,16 are cluster member stars,and the others are identified as field stars.The periods,radial velocities,effective temperatures,and classifications of the detected variables are discussed in this work.Most of the stars’effective temperatures are between 4200 and 6600 K,indicating their spectral types are G or K.The newly discovered variable is probably a W UMa system.In this study,a known cluster variable star(V21=V0769 Cep)is classified as an EA-type variable star based on the presence of an 0.5 mag eclipse in its light curve. 展开更多
关键词 (stars )binaries general-stars general-(Galaxy )open clusters and associations individual(NGC 188)-stars variables GENERAL
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Revise Thermal Winds of Remnant Neutron Stars in Gamma-Ray Bursts
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作者 Shuang Du Tingting Lin +1 位作者 Shujin Hou Renxin Xu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第9期142-147,共6页
It seems that the wealth of information revealed by the multi-messenger observations of the binary neutron star(NS)merger event,GW170817/GRB 170817A/kilonova AT2017gfo,places irreconcilable constraints to models of th... It seems that the wealth of information revealed by the multi-messenger observations of the binary neutron star(NS)merger event,GW170817/GRB 170817A/kilonova AT2017gfo,places irreconcilable constraints to models of the prompt emission of this gamma-ray burst(GRB).The observed time delay between the merger of the two NSs and the trigger of the GRB and the thermal tail of the prompt emission can hardly be reproduced by these models simultaneously.We argue that the merger remnant should be an NS(last for,at least,a large fraction of 1 s),and that the difficulty can be alleviated by the delayed formation of the accretion disk due to the absorption of high-energy neutrinos emitted by the NS and the delayed emergence of effective viscosity in the disk.Further,we extend the consideration of the effect of the energy deposition of neutrinos emitted from the NS.If the NS is the central object of a GRB with a distance and duration similar to that of GRB 170817A,thermal emission of the thermal bubble inflated by the NS after the termination of accretion may be detectable.If our scenario is verified,it would be of interest to investigate the cooling of nascent NSs. 展开更多
关键词 (stars )gamma-ray burst general-(stars )gamma-ray burst individual(.. ...)-stars NEUTRON
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Timing and Single-pulse Study of Pulsar J1909+0122 Discovered by CRAFTS
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作者 Yutong Chen Pei Wang +27 位作者 Di Li Erbil Gügercinoğlu Rushuang Zhao Lingqi Meng Jianping Yuan Jiarui Niu Weiwei Zhu Yi Feng Chenchen Miao Chenhui Niu Qingdong Wu Na Wang Shen Wang Xiaoyao Xie Mengyao Xue Jumei Yao Mao Yuan Shanping You Xuhong Yu Youling Yue Jie Zhang Junshuo Zhang Lei Zhang Yabiao Wang Zhenye Gan Yuxi Li Zhongyi Sun Chengjie Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第8期319-331,共13页
We report the discovery of PSR J1909+0122 by the Five-hundred-meter Aperture Spherical Radio Telescope(FAST)as part of the Commensal Radio Astronomy FAST Survey.PSR J1909+0122 has a spin period of 1.257 s and a disper... We report the discovery of PSR J1909+0122 by the Five-hundred-meter Aperture Spherical Radio Telescope(FAST)as part of the Commensal Radio Astronomy FAST Survey.PSR J1909+0122 has a spin period of 1.257 s and a dispersion measure of 186.2 pc cm^(-3).The averaged pulse profile shows two distinct components.We performed a single-pulse study based on a one-hour observation at 1.25 GHz on 2021 August 23.We used a threshold of 5σ_(ep) to measure the nulling fraction(NF)as 63%±1.5%.The longitude-resolved fluctuation spectra and fast Fourier transform spectra of the binary sequences revealed the quasi-periodicity of nulling with a period of 30 rotation periods.We examined the reliability of the periodicity by comparing it to random noise injection.The NF,E,and modulation periodicity P_(M) of PSR J1909+0122 were compared with other periodic nulling pulsars,showing that the source of J1909+0122 has the second largest NF in the population.Long-term timing observations over six months were used to derive the phase-connected ephemeris of this pulsar.The measured P and P values disfavor dipolar geometry for polar gap models,and the prediction for a space-charge-limited flow model in the case of inverse Compton scattering is only just above the death line.In this work,PSR J1909+0122 has revealed possible correlations between nulling behavior and pulsar properties,which will help to shed light on the pulsar emission mechanism and its temporal evolution in future observations. 展开更多
关键词 (stars:)pulsars general-(stars:)pulsars individual(PSR J1909+0122)-stars NEUTRON
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Past and Future of a Type Ia Supernovae Progenitor Candidate HD 265435
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作者 Wei-Zhong Qi Dong-Dong Liu Bo Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第1期83-90,共8页
As one of the most useful cosmological distance indicators,type Ia supernovae(SNe Ia)play an important role in the study of cosmology.However,the progenitors of SNe Ia are still uncertain.It has been suggested that ca... As one of the most useful cosmological distance indicators,type Ia supernovae(SNe Ia)play an important role in the study of cosmology.However,the progenitors of SNe Ia are still uncertain.It has been suggested that carbonoxygen white dwarf(CO WD)+He subgiant systems could produce SNe Ia through the double-degenerate(DD)model,in which the He subgiant transfers He-rich matter to the primary CO WD and finally evolves to another CO WD.Recently,a CO WD+He star system(i.e.,HD 265435)has been discovered to be a new SNe Ia progenitor candidate based on the DD model.The orbital period of the system is about 0.0688 days,and the masses of the CO WD and the He star are 1.01±0.15 M_(⊙) and 0.63_(-0.12)^(+0.13)M_(⊙),respectively.In this work,we evolve a large number of primordial binaries to the formation of CO WD+He star systems and investigate the evolutionary history of HD265435.We find that HD 265435 may originate from a primordial binary that has a 5.18 M_(⊙) primary and a3.66 M_(⊙) secondary with an initial orbital period of 5200 days.The CO WD+He star system would be formed after the primordial binary experiences two common-envelope ejection processes.We also find that HD 265435 would evolve to a double WD system with a total mass of 1.58 M⊙after a stable mass-transfer process,and the double WD system would merge driven by gravitational wave radiation.We estimate that it would take about 76 Myr for HD 265435 to form an SN Ia.In addition,HD 265435 would be a potential target of space-based gravitational wave observatories(e.g.,LISA,Taiji and TianQin). 展开更多
关键词 (stars:)binaries(including multiple) close-stars individual(HD 265435)-stars evolution-(stars:)supernovae general-(stars:)white dwarfs
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磁共振检测重型β-地中海贫血患者内分泌腺体铁过载的临床意义 被引量:7
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作者 裴夫瑜 井远方 +4 位作者 李春富 冯晓勤 温建芸 何岳林 吴学东 《生物医学工程与临床》 CAS 2013年第2期128-131,共4页
目的联合肝脏、胰腺、垂体磁共振T2-star(MRI T2*)评估重型β-地中海贫血(β-TM)患者相关脏器铁过载的临床意义,分析去铁酮治疗前后的肝脏、胰腺、垂体MRI T2*变化的临床意义。方法选择长期(输血史≥1年,输血次数>10次)治疗β-TM患... 目的联合肝脏、胰腺、垂体磁共振T2-star(MRI T2*)评估重型β-地中海贫血(β-TM)患者相关脏器铁过载的临床意义,分析去铁酮治疗前后的肝脏、胰腺、垂体MRI T2*变化的临床意义。方法选择长期(输血史≥1年,输血次数>10次)治疗β-TM患者中年龄≥10岁26例,其中男性7例,女性19例。2010年7月~2011年7月规律输血,仅口服去铁酮去铁治疗,治疗前、服用去铁酮满1年时分别赴香港威尔斯亲王医院进行胰腺MRI T2*(胰腺T2*)、肝脏MRI T2*(肝脏T2*)、垂体MRIT2*(垂体T2*)检测。结果服用去铁酮治疗前,肝脏铁浓度(LIC)(22.42±7.21)mg/g;服用去铁酮满1年时,肝脏LIC(21.46±7.69)mg/g。治疗前后肝脏、胰腺、垂体MRI T2*值[(1.48±1.23)ms vs(1.55±1.18)ms,(9.09±9.96)ms vs(9.51±13.00)ms,(9.74±4.46)ms vs(10.14±4.76)ms]比较,差异无明显统计学意义(P>0.05)。治疗前后肝脏与胰腺MRI T2*值均呈正相关(P<0.05);治疗前后LIC与胰腺T2*值均呈负相关(P<0.05)。肝脏与垂体、胰腺与垂体MRI T2*值治疗前后均不相关(P>0.05)。年龄与肝脏、胰腺及垂体的MRI T2*值无相关关系(P>0.05)。结论 MRI T2*可以作为评估β-TM患者胰腺、垂体铁负荷有效、安全的检测工具;可通过肝脏铁负荷来推测胰腺铁负荷,胰腺铁负荷与年龄无关;但肝脏负荷并不能作为垂体铁负荷的推测手段。去铁酮的临床疗效难以定论,有待进一步研究。 展开更多
关键词 重型Β-地中海贫血 铁过载 胰腺 垂体 肝脏 磁共振T2-star 去铁酮
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γ暴研究的重大突破:余辉的发现与观测研究 被引量:8
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作者 黄永锋 《天文学进展》 CSCD 北大核心 1998年第4期330-345,共16页
由于BeppoSAX卫星的独特贡献,最近观测到了若于Υ暴在X射线、光学甚至射电波段上的对应体,一度陷入困境的Υ暴研究再次取得了突破性的进展。目前已经观测到了Υ暴GRB970228持续六个月以上的光学余辉,发现它可能位于一个暗弱的宿主星... 由于BeppoSAX卫星的独特贡献,最近观测到了若于Υ暴在X射线、光学甚至射电波段上的对应体,一度陷入困境的Υ暴研究再次取得了突破性的进展。目前已经观测到了Υ暴GRB970228持续六个月以上的光学余辉,发现它可能位于一个暗弱的宿主星系中;GRB970508的光学余辉有较为复杂的表现,并测出其红移范围0.85<z<2.1。在该暴发生约五、六天之后,还观测到了射电耀发现象。观测上的重大突破比较有力地支持了Υ暴的宇宙学起源及火球模型。 展开更多
关键词 Γ射线 中子星 γ星线天文学 Γ暴
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A search for metal-poor stars pre-enriched by pair-instability supernovae I. A pilot study for target selection from Sloan Digital Sky Survey
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作者 Jing Ren Norbert Christlieb Gang Zhao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2012年第12期1637-1648,共12页
We report on a pilot study on identifying metal-poor stars pre-enriched by Pair-Instability Supernovae(PISNe).Very massive,first generation(Population Ⅲ) stars(140 M⊙≤M≤260 M⊙)end their lives as PISNe,which... We report on a pilot study on identifying metal-poor stars pre-enriched by Pair-Instability Supernovae(PISNe).Very massive,first generation(Population Ⅲ) stars(140 M⊙≤M≤260 M⊙)end their lives as PISNe,which have been predicted by theories,but no relics of PISNe have been observed yet.Among the distinct characteristics of the yields of PISNe,as predicted by theoretical calculations,are a strong odd-even effect,and a strong overabundance of Ca with respect to iron and the solar ratio.We use the latter characteristic to identify metal-poor stars in the Galactic halo that have been pre-enriched by PISNe,by comparing metallicites derived from strong, co-added Fe lines detected in low-resolution(i.e.,R=λ/△λ~2000)spectra of the Sloan Digital Sky Survey(SDSS),with metallicities determined by the SDSS Stellar Parameters Pipeline(SSPP).The latter are based on the strength of the CaⅡ K line and assumptions on the Ca/Fe abundance ratio.Stars are selected as candidates if their metallicity derived from Fe lines is significantly lower than the SSPP metallicities.In a sample of 12 300 stars for which SDSS spectroscopy is available,we have identified 18 candidate stars.Higher resolution and signal-to-noise ratio spectra of these candidates are being obtained with the Very Large Telescope of the European Southern Observatory and the XSHOOTER spectrograph,to determine their abundance patterns,and to verify our selection method.We plan to apply our method to the database of several million stellar spectra to be acquired with the Guo Shou Jing Telescope (LAMOST)in the next five years. 展开更多
关键词 stars:PopulationⅡ PopulationⅢ-stars:supernovae(PISNe)-stars: abundance-stars:chemically peculiar-method:data analysis-techniques:spec- troscopic-instrumentation:spectrographs
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Absolute parameters and physical nature of two W-UMa type binaries:V1123 Tau and V1128 Tau
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作者 Xiao-BinZhang An-BinReni +1 位作者 Chang-QingLuc Yang-PingLuo 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2011年第5期583-593,共11页
We present high-precision, multi-band CCD photometry of two less-studied close binaries V1123 Tau and V1128 Tau. Complete covered light curves and a number of new times of light minima of the two eclipsing systems wer... We present high-precision, multi-band CCD photometry of two less-studied close binaries V1123 Tau and V1128 Tau. Complete covered light curves and a number of new times of light minima of the two eclipsing systems were obtained, based on which, revised orbital elements and new ephemerides were given. By adopting the Wilson-Devinney method, the light curves were analyzed. The photometric solutions confirm the W UMa-type nature of the binary systems. With the less-massive secondary slightly cooler than the primary, V1123 Tau could be classified as an A- type contact system. While V1128 Tau is typically considered a W-type W UMa star, the surface temperature of its secondary component is determined to be absolutely higher than the primary by about 270 K. Combining with the results of radial-velocity solutions, we determined absolute parameters of the two systems. The mass, radius and luminosity for each component of V1123 Tau were derived as: 1.36 ±0.05M⊙, 1.37 ± 0.02R⊙, and 2.01± O.07L⊙ and 0.40±0.02M⊙, 0.80±0.01R⊙, and 0.67±0.04L⊙, respectively. For V1128 Tau, the absolute parameters were computed to be 1.09±0.03M⊙, 1.01±0.01R⊙, and 1.34±0.06Le and 0.58 ± 0.01M⊙, 0.76±0.01R⊙, and 0.91±0.05L⊙, respectively. Based on these results, the evolutionary status and the physical nature of the two binary systems are discussed, while also connecting with the theoretical models. 展开更多
关键词 binaries: eclipsing-stars: late-type-stars: activity -stars: individ-ual (V1123 Tau Vl128 Tau)
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Measuring the Distance of VX Sagittarii with SiO Maser Proper Motions
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作者 Xi Chen Zhi-Qiang Shen Ye Xu 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2007年第4期531-538,共8页
We report on 43 GHz v=1, J=1-0 SiO maser proper motions in the circumstellar envelope of the M-type semi-regular variable star VX Sgr, observed by Very Long Baseline Array (VLBA) at 3 epochs during 1999 April-May. A... We report on 43 GHz v=1, J=1-0 SiO maser proper motions in the circumstellar envelope of the M-type semi-regular variable star VX Sgr, observed by Very Long Baseline Array (VLBA) at 3 epochs during 1999 April-May. Applying the statistical parallax analysis to these proper motions, we estimated a distance of VX Sgr of 1.57±0.27kpc, which is consistent with that based on the proper motions of H20 masers, or on the assumption that VX Sgr belongs to the Sgr OB1 association. At this distance, VX Sgr can be classified as a red supergiant. Comparing the statistical parallax method with those of model fitting and annual parallax, we think that the statistical parallax method may be a good way of estimating SiO maser distances at present. 展开更多
关键词 methods: statistical - masers -stars: individual (VX Sgr)- stars: distances
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Discovery of 13 New Variable Stars in the Field of the Open Cluster NGC 2168 (M35)
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作者 Juei-Hwa Hu Wing-Huen Ip +3 位作者 Xiao-Bin Zhang Zhao-Ji Jiang Jun Ma Xu Zhou 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2005年第4期356-362,共7页
A wide-field time-series CCD photometric survey of variable stars in the field of the open cluster NGC 2168 was carried out using the BATC Schmidt telescope. In total 13 new variable stars are discovered with three W ... A wide-field time-series CCD photometric survey of variable stars in the field of the open cluster NGC 2168 was carried out using the BATC Schmidt telescope. In total 13 new variable stars are discovered with three W UMa systems,one EA type and two EB type eclipsing binaries (one of them could be a W UMa system), and seven pulsating stars including three candidates of δ Scuti stars. 展开更多
关键词 open clusters: individual (NGC 2168)-stars: variables (general)-binaries: general
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星图S_4的交叉数
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作者 吕波 徐喜荣 +2 位作者 杨元生 张科 郑百功 《大连理工大学学报》 EI CAS CSCD 北大核心 2014年第4期469-476,共8页
研究网络拓扑结构图星图S4的交叉数问题.首先构造星图S4好的画法,得到了S4交叉数的上界,然后给出了S4交叉数下界的数学证明,最终得到S4的交叉数的精确值为8.同时给出了与其具有同构关系的图S4,3和图A4,3的交叉数.
关键词 交叉数 画法 Star图 (n k)-star Arrangement图
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炼化企业氢管网设计与集成优化技术应用研究
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作者 张英 王阳峰 张胜中 《中外能源》 CAS 2016年第9期76-80,共5页
随着加氢处理深度不断增加,炼化企业氢气用量和氢气品质需求不断提高,氢气管网集成优化已成为炼化企业高效利用氢气资源,实现节能减排、降本增效的重要措施。介绍了氢气管网系统的构成与特点,分析了氢气管网与供氢单元、用氢单元、氢回... 随着加氢处理深度不断增加,炼化企业氢气用量和氢气品质需求不断提高,氢气管网集成优化已成为炼化企业高效利用氢气资源,实现节能减排、降本增效的重要措施。介绍了氢气管网系统的构成与特点,分析了氢气管网与供氢单元、用氢单元、氢回收单元之间的相互关系,介绍了氢气管网集成优化研究的目标、原则、方法与技术。抚顺石油化工研究院研究开发了集成加氢反应动力学模型的氢气系统优化专业软件(H2-STAR),根据各用氢单元氢分压、流量、循环氢纯度等适宜参数,并采用夹点分析与多目标综合优化相结合的方法,完成氢源、氢阱的合理匹配与整个系统的集成优化设计。某炼油厂氢气管网优化改造项目的工业应用表明,利用H2-STAR技术开展炼化企业氢管网优化设计与研究,有助于以较少的投资实现氢气梯级利用、提高氢气利用率和经济效益的目标。 展开更多
关键词 炼化企业 加氢处理 氢气管网 H_2-star 集成 优化
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PS Vir:a short-period solar-like contact binary 被引量:1
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作者 Hui-Yu Yuan Hai-Feng Dai Yuan-Gui Yang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第7期45-52,共8页
We present multi-color photometric observations and a one-dimensional spectrum, acquired from March 2016 to May 2017, for the short-period eclipsing binary PS Vir, by using the 2.16-m, 85-cm and 60-cm telescopes at Xi... We present multi-color photometric observations and a one-dimensional spectrum, acquired from March 2016 to May 2017, for the short-period eclipsing binary PS Vir, by using the 2.16-m, 85-cm and 60-cm telescopes at Xinglong station, which is administered by National Astronomical Observatories, Chinese Academy of Sciences. The spectral type was determined as G2V from the one-dimensional spectrum. The photometric solution was reduced from BVRc light curves. The results imply that PS Vir is a W-subtype contact binary with a mass ratio of q - 0.305(zk0.008) and a fill-out factor of f = 14.4(+1.8)%. The orbital period may be undergoing a cyclic oscillation with an ampli-tude of A = 0.0027(~0.0001)d and a modulated period of 11.7(4-0.2) yr, which may result from the light-time effect due to a third body. The lower limit on mass for the assumed component is 0.12 Me. Moreover, the more massive component of PS Vir may be a bit more evolved star as determined from the mass-luminosity diagram. 展开更多
关键词 BINARIES close-binaries eclipsing-stars individual(PS Vir)-stars
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Optical flare events on the RS Canum Venaticorum star UX Arietis
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作者 Dong-Tao Cao Sheng-Hong Gu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2017年第6期55-66,共12页
Based on long-term high-resolution spectroscopic observations obtained during five observing runs from 2001 to 2004, we study optical flare events and chromospheric activity variability of the very active RS CVn star ... Based on long-term high-resolution spectroscopic observations obtained during five observing runs from 2001 to 2004, we study optical flare events and chromospheric activity variability of the very active RS CVn star UX Ari. By means of the spectral subtraction technique, several optical chromospheric activity indicators (including the He IDa, Na I D1, D2 doublet, Ha and Ca II IRT lines) covered in our echelle spectra were analyzed. Four large optical flare events were detected on UX Ari during our observations, which show prominent He I D3 line emission together with great enhancement in emission of the Ha and Ca II IRT lines and strong filled-in or emission reversal features in the Na ! D1, D2 doublet lines. The newly detected flares are much more energetic than previous discoveries, especially for the flare identified during the 2002 December observing run. Optical flare events on UX Ari are more likely to be observed around two quadratures of the system, except for our optical flares detected during the 2004 November observing run. Moreover, we have found rotational modulation of chromospheric activity in the Ha and Ca II IRT lines, which suggests the presence of chromospherically active longitudes over the surface of UX Ari. The change in chromospherically active longitudes among our observing runs, as well as the variation in chromospheric activity level from 2001 to 2004, indicates a long-term evolution of active regions. 展开更多
关键词 STARS activity - stars chromospheres - stars BINARIES spectroscopic -stars flare -stars individual (UX Ari)
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