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A model of geometric delay in Space VLBI

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Research in Astronomy and Astrophysics 2014年第8期14卷 1029-1036页

作者： Shi-Long Liao Zheng-Hong Tang zhao-xiang qi Shanghai Astronomical Observatory Chinese Academy of Sciences University of Chinese Academy of Sciences

A model which includes the relativistic effect is derived that can be applied to space very long baseline interferometry （SVLBI） while taking observations of sources at infinite distance. In SVLBI, where one station is on a spacecraft, the length of the baseline and the orbiting station＇s maximum speed in an elliptical orbit around the Earth is much larger than the ground-based VLBI, which leads to a larger delay and higher delay rate. The delay models inside VLBI correlators are usually expressed as fifth-order polynomials during a limited time interval, which are evaluated by firmware in the correlator and track delays in the interferometer over the limited time interval. The higher SVLBI delay rate requires more accurate polynomial fitting and evaluation, as well as more frequent model updates.

关键词： astrometry -- interferometric -- analytical

Image Field Deformation of LAMOST due to Differential Atmospheric Refraction

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Chinese Journal of Astronomy and Astrophysics 2006年第4期6卷 495-502页

作者： Jin-Ling Li Bo Zhang Yong Yu zhao-xiang qi Ming zhao Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030

A vectorial expression of the image field deformation of LAMOST due to the differential atmospheric refraction is presented. The calculated results are compared with those from previous analyses based on the traditional spherical trigonometric formulas. It is demonstrated that different tangential displacements of star images during the observation tracking given by various authors are simply due to different reference points adopted. It is pointed out that the observational celestial pole is the center of the apparent diurnal motion, that, by referring to the observational celestial pole, the effect of the differential refraction on the image field of LAMOST during the 1.5-hour tracking period is approximately equivalent to a constant rotation of - 13.65″ for all declination belts. It is therefore unnecessary to design a particular tracking velocity for each observation, and this will be obviously advantageous to the observation implementation. If the maximum tracking error of the fibers is 0.2″, then the fibers are required to be able to re-position during observational tracking for sky regions south of declination ＋20° and north of declination ＋60°.

关键词： telescopes -- atmospheric effects -- methods: analytical-- methods: statistical-- astrometry

A compilation of known QSOs for the Gaia mission

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Research in Astronomy and Astrophysics 2019年第2期19卷 151-160页

作者： Shi-Long Liao zhao-xiang qi Su-Fen Guo Zi-Huang Cao Shanghai Astronomical Observatory Chinese Academy of Sciences School of Astronomy and Space Science University of Chinese Academy of Sciences National Astronomical Observatories Chinese Academy of Sciences

Quasars are essential for astrometry in the sense that they are spatially stationary because of their large distance from the Sun. The European Space Agency(ESA) astrometric satellite Gaia is scanning the whole sky with unprecedented accuracy up to the level of a few μas. However, Gaia's two-fields-ofview-observation strategy may introduce a parallax bias in the Gaia catalog. Since it presents no significant parallax, a quasar is the perfect natural object to detect such bias. More importantly, quasars can be used to construct a celestial reference frame in the optical wavelengths for the Gaia mission. In this paper, we compile a list of known quasars that have been published in the literatures. The final compilation(designated as Known Quasars Catalog for Gaia mission, KQCG) contains 1 842 076 objects, among which797 632 objects are found in Gaia DR1 after cross-identifications. Redshift, color information and position uncertainties of the objects are also provided if available. This catalog will be very useful for the Gaia mission.

关键词： quasars:general astrometry parallaxes proper motions reference systems catalogs

A new telescope with three fields of view to measure the orientation parameters of the Moon and terrestrial planets

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Research in Astronomy and Astrophysics 2021年第2期21卷 121-132页

作者： Li-Zao Sun Cheng-Li Huang Yong Yu zhao-xiang qi Zheng-Hong Tang Ming zhao De-Hua Yang Tong Wu Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China CAS Key Laboratory of Planetary Sciences Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China Key Laboratory of Space Photoelectric Detection and Sensing of Ministry of Industry and Information Technology College of AstronauticsNanjing University of Aeronautics and AstronauticsNanjing 211106China

For lots of scientific questions about lunar physics deep inside the Moon,in-situ observation on lunar physical libration is one of the most potential *** this paper,we propose a brand new optical telescope functioned with simultaneously observing multiple(here there are three)fields of view(FOVs)for in-situ observation of lunar physical *** telescope can be placed at any place with any attitude on the Moon and do not require manned install,control or *** passively,continuously and simultaneously observe stars in three FOVs along with rotation of the *** is to be measured and studied from celestial motion of the directions of three FOVs from image *** concept and design of this telescope are firstly introduced in this *** principle and feasibility of the method of insitu observation are also *** simulation,precision of the determined lunar physical libration is expected to be several milliarcsecs,about two orders of magnitude better than the current precision of libration by lunar laser ranging *** data with milliarcsec precision level can play a valuable role in the study of the physics and dynamics of the interior of the *** telescope can also be applied to observe the rotation of other terrestrial planets like Mars.

关键词： astrometry-telescopes-methods observational-reference systems

LAMOST medium-resolution spectral survey of Galactic nebulae(LAMOST-MRS-N):subtraction of geocoronal Hαemission

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Research in Astronomy and Astrophysics 2021年第11期21卷 89-97页

作者： Wei Zhang Hong Wu Chao-Jian Wu Juan-Juan Ren Jian-Jun Chen Chih-Hao Hsia Yu-Zhong Wu Hui Zhu Jian-Rong Shi Zhong-Rui Bai zhao-xiang qi Yong-Heng zhao Yong-Hui Hou CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyTaipaMacaoChina Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Nanjing Institute of Astronomical Optics&Technology National Astronomical ObservatoriesChinese Academy of SciencesNanjing 210042China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

We introduce a method of subtracting geocoronal Hαemissions from the spectra of LAMOST medium-resolution spectral survey of Galactic nebulae(LAMOST-MRS-N).The flux ratios of the Hαsky line to the adjacent OHλ6554 single line do not show a pattern or gradient distribution in a *** interestingly,the ratio is well correlated to solar altitude,which is the angle of the Sun relative to the Earth’s *** is found that the ratio decreases from 0.8 to 0.2 with the decreasing solar altitude from–17 to–73 *** on this relation,which is described by a linear function,we can construct the Hαsky component and subtract it from the science *** method has been applied to the LAMOST-MRSN data,and the contamination level of the Hαsky to nebula is reduced from 40%to less than 10%.The new generated spectra will significantly improve the accuracy of the classifications and the measurements of physical parameters of Galactic nebulae.

关键词： techniques:spectroscopic instrumentation:spectrographs ISM:general

The regulatory network and critical factors promoting programmed cell death during embryogenesis

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Journal of Integrative Plant Biology 2025年第1期67卷 55-70页

作者： An Luo Ce Shi Pan Luo Zifu zhao Meng-xiang Sun College of Life Sciences Yangtze UniversityJingzhou 434023China State Key Laboratory of Hybrid Rice College of Life SciencesWuhan UniversityWuhan 430072China

Programmed cell death(PCD)is essential for animal and plant ***,the knowledge of the mechanism regulating PCD in plants remains limited,largely due to technical ***,we determined that the protease NtCP14 could trigger PCD in the embryonic suspensor of tobacco(Nicotiana tabacum),providing a unique opportunity to overcome the limitations by creating synchronous two-celled proembryos with ongoing PCD for transcriptome analysis and regulatory factor ***,we performed comparative transcriptome analysis using isolated two-celled proembryos and explored the potential regulatory network underlying NtCP14-triggered *** phytohormones,calcium,microtubule organization,the immunity system,soluble N-ethylmaleimide-sensitive factor attachment protein receptor proteins,long non-coding RNAs and alternative splicing are addressed as critical factors involved in the early stage of suspensor *** thought to play crucial roles in suspensor PCD are ***,decreased antioxidant gene expression and increased reactive oxygen species(ROS)levels during suspensor PCD suggest a critical role for ROS signaling in the initiation of NtCP14-triggered ***,five genes in the regulatory network are recommended as immediate downstream elements of ***,our analysis outlines an overall molecular network underlying protease-triggered PCD and provides a reliable database and valuable clues for targeting elements immediately downstream of NtCP14 to overcome technical bottlenecks and gain deep insight into the molecular mechanism regulating plant PCD.

关键词： programmed cell death protease reactive oxygen species suspensor transcriptome

The effect of fine grits and fine debris concentrations on the MLVSS/MLSS ratio of an activated sludge system

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Journal of Environmental Sciences 2025年第1期147卷 607-616页

作者： zhao Jiang Zhiheng Xia Shuai Liu qiWei Haitao Fan Lu qi Guohua Liu Hongchen Wang Low-carbon Water Environment Technology Research Center School of Environment&Natural ResourcesRenmin University of ChinaBeijing 100872China

This study embarks on an explorative investigation into the effects of typical concentrations and varying particle sizes of fine grits(FG,the involatile portion of suspended solids)and fine debris(FD,the volatile yet unbiodegradable fraction of suspended solids)within the influent on themixed liquor volatile suspended solids(MLVSS)/mixed liquor suspended solids(MLSS)ratio of an activated sludge *** meticulous experimentation,it was discerned that the addition of FG or FD,the particle size of FG,and the concentration of FD bore no substantial impact on the pollutant removal efficiency(denoted by the removal rate of COD and ammonia nitrogen)under constant operational ***,a notable decrease in the MLVSS/MLSS ratio was observed with a typical FG concentration of 20 mg/L,with smaller FG particle sizes exacerbating this ***,variations in FD concentrations influenced both MLSS andMLVSS/MLSS ratios;a higher FD concentration led to an increased MLSS and a reduced MLVSS/MLSS ratio,indicating FD accumulation in the system.A predictive model for MLVSS/MLSS was constructed based on quality balance calculations,offering a tool for foreseeing the MLVSS/MLSS ratio under stable long-term influent conditions of FG and *** model,validated using data from the BXH wastewater treatment plant(WWTP),showcased remarkable accuracy.

关键词： Fine grits and fine debris Activated sludge system MLVSS/MLSS ratio Predictive model

Design Considerations on Voltage and Current Transfer Ratio of High-Frequency Transformers

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CSEE Journal of Power and Energy Systems 2025年第1期11卷 447-457页

作者： Chen Liu Lei qi xiang Cui China Electric Power Planning&Engineering Institute Beijing100120China State Key Laboratory for Alternate Electrical Power System Renewable Energy Sources(North China Electric Power University)Beijing102206China

A high frequency(HF)transformer is key equipment for dc-dc converter to achieve galvanic isolation and voltage *** operating frequency increases,voltage and current transfer ratio of HF transformer may significantly deviate from the turn ratio due to parasitic effects,failing to transfer expected voltage and current from the primary side to the secondary *** this paper,design considerations on voltage and current transfer ratio of the HF transformer are investigated to obtain expected transfer *** revealing parasitic effects on transfer characteristic(TC)of the HF transformer with load,deviation between voltage/current transfer ratio and turn ratio is correlated with the ratio of voltage/current TC resonant frequency and operating ***,constraints for parasitic parameters to obtain expected transfer ratio are proposed,and practical measures to achieve improvements in transformer design are discussed.A 20kHz HF transformer prototype is used as an application,by which evaluations on deviation of voltage/current transfer ratio and turn ratio are verified,and voltage/current transfer performance of the prototype are effectively improved by optimal design based on the proposed principles.

关键词： Capacitance transfer functions transformers

Taurine: A Comprehensive Review of Its Origin， Pharmacological Properties， Potential Health Benefits， Therapeutic Applications， and Safety Profile

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Food Science and Human Wellness 2025年

作者： Pengfei zhao Ying qi Department of Pharmacology， School of Pharmacy， China Medical University (Shenyang) Department of Radiology， Shengjing Hospital of China Medical University

Taurine， a multifunctional sulfur-containing amino acid and conditionally essential nutrient for humans， plays a key role in various biological processes and has attracted significant attention for its therapeutic potential. Originally isolated from ox bile， taurine has broad applications， but a comprehensive understanding of its pharmacological properties， health benefits， and safety profile remains incomplete. In this review， we critically evaluate the existing evidence on taurine’s effects based on an extensive literature search of multiple databases， including PubMed， Web of Science， Scopus， ScienceDirect， Google Scholar， CNKI， and Baidu Scholar， up to May 2024. Taurine demonstrates a range of beneficial effects， including antioxidant and anti-inflammatory activities， modulation of lipid metabolism， neuroprotection， and cardiovascular protection. It has shown substantial impacts on anti-tumor activity， immune system modulation， blood pressure and lipid regulation， glycemic control， hepatobiliary protection， and potential anti-aging effects. However， the precise regulatory pathways underlying these benefits are not yet fully understood. Epidemiological studies indicate a correlation between high taurine dosage and a reduced risk of diseases. However， direct evidence from interventional studies remains insufficient， and existing clinical trials require further in-depth investigation. Concerns about improper use and potential health risks also highlight the need for thorough safety assessments. To address these gaps， we recommend conducting well-designed， long-term randomized controlled trials to establish effective doses for disease prevention and assess taurine’s potential as a primary or adjunct therapy. This review aims to guide future research and support public health efforts， ultimately improving health outcomes.

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