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Development of a Front End Array for Broadband Phased Array Receiver

Research in Astronomy and Astrophysics 2024年第4期24卷 60-70页

作者： Kai Wang Liang Cao Jun Ma Xue-Feng Duan Hao Yan Mao-Zheng Chen Yun-Wei Ning Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 8300lChina University of the Chinese Academy of Sciences Beijing 100049China Xinjiang Key Laboratory of Microwave Technology Urumqi 830011China

The receiver is a signal receiving device placed at the focus of the *** order to improve the observation efficiency,the concept of phased array receiver has been proposed in recent years,which places a small phased array at the focal plane of the reflector,and flexible pattern and beam scanning functions can be achieved through a beamforming *** combined with the element multiplexing,all beams within the entire field of view can be observed simultaneously to achieve continuous sky *** article focuses on the front-end array of phased array receiver at 0.7-1.8 GHz for QiTai Telescope,and designs a Vivaldi antenna array of PCB structure with dual line *** polarization antenna is designed to arrange in a rectangle manner by 11×*** on the simulation results of the focal field,32,18,and eight elements were selected to form one beam at 0.7,1.25,and1.8 *** analog beamforming network was constructed,and the measured gains of axial beam under uniform weighting were 19.32,13.72,and 15.22 *** the beam scanning method of reflector antenna,the pattern test of different position element sets required for PAF beam scanning was carried out under independent *** pattern optimization at 1.25 GHz was carried out by weighting method of conjugate field *** with uniform weighting,the gain,sidelobe level,and main beam direction under conjugate field matching have been *** the above test and simulation results are slightly different,which is related to the passive array and laboratory testing condition,the relevant work has accumulated experience in the development of the front-end array for the phased array receiver,and has good guiding significance for future performance verification after the array is installed on the telescope.

关键词： telescopes instrumentation:detectors techniques:radar astronomy

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Sex-specific facilitation and reproduction of the gynodioecious cushion plant Arenaria polytrichoides on the Himalaya-Hengduan mountains,SW china

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Plant Diversity 2024年第2期46卷 247-255页

作者： Xufang Chen Yazhou Zhang Lishen Qian Renyu Zhou Hang Sun Jianguo Chen State Key Laboratory of Plant Diversity and Specialty Crops Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnanChina Yunnan Key Laboratory of Plateau Wetland Conservation Restoration and Ecological ServicesSouthwest Forestry UniversityKunmingYunnanChina

When benefiting other beneficiaries,cushion plants may reciprocally receive feedback *** feedback effects on different sex morphs,however,remains *** this study,taking the gynodioecious Arenaria polytrichiodes as a model species,we aimed to assess the sex-specific facilitation intensity of cushion plant by measuring the beneficiary cover ratio,and to assess the potential costs in cushion reproductive functions by measuring the flower and fruit cover *** total beneficiary cover ratio was similar between females and *** produced much less flowers but more fruits than *** results suggested that females and hermaphrodites possess similar facilitation intensity,and female cushion *** may allocate more resources saved from pollen production to seed production,while hermaphrodites possibly allocate more resources to pollen production hence reducing seed *** surface areas covered by beneficiaries produced less flowers and fruits than areas without *** addition,strong negative correlations between beneficiary cover and flower cover were detected for both females and hermaphrodites,but the correlation strength were similar for these two sex ***,the correlation between beneficiary cover and fruit cover was only significantly negative for females,suggesting that beneficiary plants negatively affect fruit reproduction of females while have neutral effects on *** the results suggest that to facilitate other beneficiaries can induce reproductive costs on cushion ***,with females possibly suffering greater cost than *** differentiation in reproductive costs between sex morphs,in long-term perspective,may imply sex imbalance in population dynamics.

关键词： Facilitation intensity Feedback effect Sex-specific facilitation Nurse plant Population dynamics Reproductive function

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Spatiotemporal Variability and Environmental Controls of Temperature Sensitivity of Ecosystem Respiration across the Tibetan Plateau

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Advances in Atmospheric Sciences 2024年第9期41卷 1821-1842页

作者： Danrui SHENG Xianhong MENG Shaoying WANG Zhaoguo LI Lunyu SHANG Hao CHEN Lin ZHAO Mingshan DENG Hanlin NIU Pengfei XU Xiaohu WEN Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Zoige Plateau Wetlands Ecosystem Research Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Warming-induced carbon loss via ecosystem respiration(R_(e))is probably intensifying in the alpine grassland ecosystem of the Tibetan Plateau owing to more accelerated warming and the higher temperature sensitivity of R_(e)(Q_(10)).However,little is known about the patterns and controlling factors of Q_(10)on the plateau,impeding the comprehension of the intensity of terrestrial carbon-climate feedbacks for these sensitive and vulnerable ***,we synthesized and analyzed multiyear observations from 14 sites to systematically compare the spatiotemporal variations of Q_(10)values in diverse climate zones and ecosystems,and further explore the relationships between Q_(10)and environmental ***,structural equation modeling was utilized to identify the direct and indirect factors predicting Q_(10)values during the annual,growing,and non-growing *** results indicated that the estimated Q_(10)values were strongly dependent on temperature,generally,with the average Q_(10)during different time periods increasing with air temperature and soil temperature at different measurement depths(5 cm,10 cm,20 cm).The Q_(10)values differentiated among ecosystems and climatic zones,with warming-induced Q_(10)declines being stronger in colder regions than elsewhere based on spatial *** was the most cardinal factor in predicting annual Q_(10)values,significantly and positively correlated with Q_(10).Soil temperature(Ts)was identified as the other powerful predictor for Q_(10),and the negative Q_(10)-Ts relationship demonstrates a larger terrestrial carbon loss potentiality in colder than in warmer regions in response to global *** that the interpretations of the effect of soil moisture on Q_(10)were complicated,reflected in a significant positive relationship between Q_(10)and soil moisture during the growing season and a strong quadratic correlation between the two during the annual and non-growing *** findings are conducive to imp

关键词： carbon cycle eddy covariance measurements ecosystem respiration Q_(10)value Tibetan Plateau climate change

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Electrical conductivity of multiphase garnet under high- temperature and high- pressure conditions

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Journal of Earth Science 2024年

作者： Kui Han Xinzhuan Guo Hanyong Liu Fengbao Ji Kay Laboratory of Earth Exploration and Information Techniques (Chengdu University of Technology)， Ministry of Education Bayerisches Geoinstitut， University of Bayreuth cas Key Laboratory of High-Temperature and High-Pressure Study of the Earth' Interior， Institute of Geochemistry， Chinese Academy of Sciences State Key Laboratory for Mineral Deposits Research， School of Earth Sciences and Engineering， Nanjing University Tibet Museum of Natural Science

Mineral mixing， a fundamental process during mantle convection， alters the chemical composition of mantle minerals. However， the impact of this process on the electrical conductivity of mineral assemblages remains poorly understood. We measured the electrical conductivity of three single-phase garnets and their corresponding mixtures at 1.5 GPa and varying temperatures using the impedance spectroscopy within frequency from10-1to 106Hz. The electrical conductivity of dehydrated garnets is primarily controlled by their iron content， exhibiting an activation energy about 1.0 eV， indicative of small polaron conduction. The garnet mixture displayed lower electrical conductivities and higher activation energies compared to their single-phase counterparts. This discrepancy of conductivity can be half order of magnitude at high temperatures （>1073 K）， suggesting formation of resistive grain boundaries during the mixing process. In the mantle transition zones， grain boundary conductivity could exert a limited impact on the bulk conductivity of the interface between the stagnant slab and ambient mantle.

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Molecular phylogeny and taxonomy of Phlomoides(Lamiaceae subfamily Lamioideae)in china:Insights from molecular and morphological data

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Plant Diversity 2024年第4期46卷 462-475页

作者： Yue Zhao Ya-Ping Chen Bryan T.Drew Fei Zhao Maryam Almasi Orzimat T.Turginov Jin-Fei Xiao Abdul G.Karimi Yasaman Salmaki Xiang-Qin Yu Chun-Lei Xiang cas Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201YunnanChina Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau&Inner Mongolia Key Laboratory of Grassland Ecology School of Ecology and EnvironmentInner Mongolia UniversityHohhot 010000Inner MongoliaChina Department of Biology University of Nebraska at KearneyKearneyNE 68849USA cas Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization&Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province Chinese Academy of SciencesChengdu Institute of BiologyChengdu 610042SichuanChina Center of Excellence in Phylogeny of Living Organisms Department of Plant ScienceCollege of ScienceUniversity of TehranP.O.Box 14155-6455TehranIran Institute of Botany Academy of Sciences of the Republic of UzbekistanTashkent 100047Uzbekistan Faculty of Biology Department of Botany and Plant PhysiologyNational University of Uzbekistan named after Mirzo UlugbekTashkent 100174Uzbekistan Faculty of Pharmacy Kabul University1006 KabulAfghanistan

Phlomoides,with 150-170 species,is the second largest and perhaps most taxonomically challenging genus within the subfamily Lamioideae(Lamiaceae).With about 60 species,china is one of three major biodiversity centers of *** some Phlomoides species from china have been included in previous molecular phylogenetic studies,a robust and broad phylogeny of this lineage has yet to be ***,given the myriad new additions to the genus,the existing infrageneric classification needs to be evaluated and ***,we combine molecular and morphological data to investigate relationships within Phlomoides,with a focus on Chinese *** observed that plastid DNA sequences can resolve relationships within Phlomoides better than nuclear ribosomal internal and external transcribed spacer regions(nrITS and nrETS).Molecular phylogenetic analyses confirm the monophyly of Phlomoides,but most previously defined infrageneric groups are not *** addition,morphological analysis demonstrates the significant taxonomic value of eight characters to the *** on our molecular phylogenetic analyses and morphological data,we establish a novel section Notochaete within Phlomoides,and propose three new combinations as well as three new *** study presents the first molecular phylogenetic analyses of Phlomoides in which taxa representative of the entire genus are included,and highlights the phylogenetic and taxonomic value of several morphological characters from species of Phlomoides from *** study suggests that a taxonomic revision and reclassification for the entire genus is necessary in the future.

关键词： Lamioideae Molecular phylogenetics Morphology Phlomideae Taxonomy

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Leaf habit differentiation explains trait tradeoffs across savanna woody plants

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Forest Ecosystems 2024年第3期11卷 287-295页

作者： Yangsiding Wang Da Yang German Vargas G. Guangyou Hao Jennifer S.Powers Yan Ke Qin Wang Yunbing Zhang Jiaolin Zhang cas Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan 666303China University of Chinese Academy of Sciences Beijing 100049China School of Biological Sciences University of UtahSalt Lake CityUT 84112USA cas Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Department of Ecology Evolution and BehaviorUniversity of MinnesotaSt PaulMN 55108USA

Identifying how leaf habit subdivisions link to the fast–slow and avoidance–tolerance trait tradeoffs can provide new insight into divergence in ecophysiological strategies among plant functional groups. Here, we tested a hypothesis that the differentiation across deciduous, semi-deciduous and evergreen woody species contributes to physiological trait tradeoffs in a dry-hot valley savanna. We investigated 11 photosynthetic, morphological and hydraulic traits of 24 species including 8 deciduous, 10 semi-deciduous and 6 evergreen species. Deciduous species were grouped in the fast and avoidance side associated with high values of maximum photosynthetic rates,stomatal conductance and leaf size, while evergreen species were grouped in the slow and tolerance side associated with high photosynthetic water use efficiency, leaf mass per area, sapwood density, Huber value, leaf water potential at turgor loss point and water potential causing 50% loss of stem hydraulic conductance. Semideciduous species generally had intermediate trait values and represented different physiological characteristics when compared to deciduous and evergreen species. The physiological trait tradeoffs showed a close linkage to the differentiation of these three leaf habits. Our findings clearly reveal trait tradeoffs related to fast–slow and avoidance–tolerance strategies among diverse savanna plants, suggesting a syndrome in multiple ecophysiology strategies across different leaf habits.

关键词： Dry-hot habitat Gas exchange Hydraulics Phenology Tolerance Valley savanna

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DNA damage chemotherapeutic drugs suppress basal-like breast cancer growth by down-regulating the transcription of the FOXO1-KLF5 axis

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Genes & Diseases 2024年第1期11卷 91-94页

作者： Qiuxia Cui Jian Sun Jingping Yuan Juanjuan Li Chuanyu Yang Guangshi Du Chengang Zhou Pu Qiu Jidong Gao Yuanqi Zhang Dewei Jiang Ceshi Chen Affiliated Hospital of Guangdong Medical University Science&Technology of china ZhanjiangGuangdong 524000China Department of Breast Surgical Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital and Shenzhen HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeShenzhenGuangdong 518116China Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province Kunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650223China Department of Pathology Renmin Hospital of Wuhan UniversityWuhanHubei 430060China Department of Breast and Thyroid Surgery Renmin Hospital of Wuhan UniversityWuhanHubei 430060China Translational Medicine Research Center of Guizhou Medical University GuiyangGuizhou 550025China Department of Breast Surgical Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Yunnan Cancer Hospital and the Third Affiliated Hospital of Kunming Medical University and Yunnan Cancer Center KunmingYunnan 650500China Academy of Biomedical Engineering Kunming Medical UniversityKunmingYunnan 650500China

Most basal-like breast cancers(BLBCs)have a poor prognosis and high crossover with triple-negative breast cancers(TNBCs).However,approximately 50%of TNBC patients develop chemoresistance.^(1) Dexamethasone reportedly induces Krüppel-like factor 5(KLF5)and can cause docetaxel and cisplatin resistance in TNBC.A super-enhancer can maintain the transcription of KLF5.

关键词： FOXO1 drugs damage

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FAST Observations of Four Comets to Search for the Molecular Line Emissions between 1.0 and 1.5 GHz Frequencies

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Research in Astronomy and Astrophysics 2024年第10期24卷 130-140页

作者： Long-Fei Chen Chao-Wei Tsai Jian-Yang Li Bin Yang Di Li Yan Duan Chih-Hao Hsia Zhichen Pan Lei Qian Donghui Quan Xue-Jian Jiang Xiaohu Li Ruining Zhao Pei Zuo School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550025China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guiyang 550025China Research Center for Astronomical Computing Zhejiang LaboratoryHangzhou 311100China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Key Laboratory of Radio Astronomy and Technology Chinese Academy of SciencesBeijing 100101China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 519082China Núcleo de Astronomía Facultad de Ingenieríay CienciasUniversidad Diego PortalesChile Department of Astronomy College of Physics and Electronic EngineeringQilu Normal UniversityJinan 250200China Department of Electronic and Optical Engineering Space Engineering UniversityBeijing 101416China Laboratory for Space Research Faculty of ScienceThe University of Hong KongHong Kong(SAR)China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China cas Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China

We used the Five-hundred-meter Aperture Spherical radio Telescope(FAST)to search for the molecular emissions in the L-band between 1.0 and 1.5 GHz toward four comets,C/2020 F3(NEOWISE),C/2020 R4(ATLAS),C/2021 A1(Leonard),and 67P/Churyumov-Gerasimenko during or after their perihelion *** of molecular transition lines fall in this low-frequency range,many attributed to complex organic or prebiotic *** conducted a blind search for the possible molecular lines in this frequency range in those comets and could not identify clear signals of molecular emissions in the *** several molecules have been detected at high frequencies of greater than100 GHz in comets,our results confirm that it is challenging to detect molecular transitions in the L-band frequency *** non-detection of L-band molecular lines in the cometary environment could rule out the possibility of unusually strong lines,which could be caused by the masers or non-LTE *** the line strengths are predicted to be weak,for FAST,using the ultra-wide bandwidth receiver and improving the radio frequency interference environments would enhance the detectability of those molecular transitions at low frequencies in the future.

关键词： astrochemistry ISM:molecules comets:general line:identification

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Salicylic acid positively regulates maize defenses against lepidopteran insects

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Plant Diversity 2024年第4期46卷 519-529页

作者： Yohannes Besufekad Setotaw Jing Li Jinfeng Qi Canrong Ma Mou Zhang Cuilian Huang Lei Wang Jianqiang Wu Department of Economic Plants and Biotechnology Yunnan Key Laboratory for Wild Plant ResourcesKunming Institute of BotanyChinese Academy of SciencesKunming 650201China cas Center for Excellence in Biotic Interactions University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Plant Diversity and Specialty Crops Beijing 100093China

In response to insect attack,plants use intricate signaling pathways,including phytohormones,such as jasmonate(JA),ethylene(ET),and salicylic acid(SA),to activate ***(Zea mays)is one of the most important staple food crops around the *** studies have shown that the JA and ET signaling play important roles in maize defense against insects,but little is known about whether and how SA regulates maize resistance to insect *** this study,we ectopically expressed the NahG(salicylate hydroxylase)gene in maize plants(NahG maize)to block the accumulation of *** was found that compared with the wild-type(WT)maize,the NahG-maize exhibited decreased resistance to the generalist insects Spodoptera litura and Spodoptera frugiperda and the specialist Mythimna separata,and the compromised resistance in the NahG maize was associated with decreased levels of defensive metabolites benzoxazinoids(Bxs)and chlorogenic acid(CA).Quantification of simulated *** feedinginduced JA,JA-isoleucine conjugate(JA-Ile),and ET in the WT and NahG maize indicated that SA does not regulate JA or JA-Ile,but positively controls *** provide evidence suggesting that the SA pathway does not crosstalk with the JA or the ET signaling in regulating the accumulation of Bxs and *** analysis revealed that the bHLH,ERF,and WRKY transcription factors might be involved in SAregulated *** study uncovers a novel and important phytohormone pathway in maize defense against lepidopterous larvae.

关键词： Benzoxazinoids Salicylic acid Herbivory Maize Transcriptome

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The RFI Fast Mitigation Algorithm Based on Block LMS Filter

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Research in Astronomy and Astrophysics 2024年第1期24卷 265-272页

作者： Han Wu Hai-Long Zhang Ya-Zhou Zhang Jie Wang Xu Du Ting Zhang Xin-Chen Ye Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China National Astronomical Data Center Beijing 100101China

The radio telescope possesses high sensitivity and strong signal collection *** receiving celestial radiation signals,it also captures Radio Frequency Interferences(RFIs)introduced by human ***,as signals originating from sources other than the astronomical targets,significantly impacts the quality of astronomical *** paper presents an RFI fast mitigation algorithm based on block Least Mean Square(LMS)*** enhances the traditional adaptive LMS filter by grouping L adjacent time-sampled points into one block and applying the same filter coefficients for filtering within each *** transformation reduces multiplication calculations and enhances algorithm efficiency by leveraging the time-domain convolution *** algorithm is tested using baseband data from the Parkes 64 m radio telescope's pulsar observations and simulated *** results confirm the algorithm's effectiveness,as the pulsar profile after RFI mitigation closely matches the original pulsar profile.

关键词： methods:data analysis techniques:interferometric (stars:)pulsars:individual(J0437-4715)

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