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Two New Flavone Glucosides fromSerratula strangulata

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Chemical Research in Chinese Universities 2001年第4期17卷 469-472页

作者： DAI Jing-qiu ZHU qi-xiu YANG Li LI Yu Institute of Organic Chemistry National Laboratory of Applied Organic ChemistryLanzhou UniversityLanzhou 730000P.R.China

Genus Serratula（Compositae）consists of about 70 species distributed throughout theworld[1]．Serratula species have been used as folk medicine to treat chickenpox，toxicosis，high cholesterol in China[2]. The phytochemical study of plant *** has not beenreported so *** the course of our searching for biologically active substances from thisplant，two new flavone glucosides（1，2）were *** present paper covers the isolationand structural elucidation of the two new compounds．

关键词： Serratula strangulata Compositae Flavone glucoside

Interference coupling analysis based on a hybrid method: application to a radio telescope system

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Research in Astronomy and Astrophysics 2018年第2期18卷 7-18页

作者： qing-Lin Xu Yang qiu Jin Tian qi Liu School of Mechano-Electronic Engineering Xidian University Xinjiang Astronomical Observatory Chinese Academy of Sciences

Working in a way that passively receives electromagnetic radiation from a celestial body, a radio telescope can be easily disturbed by external radio frequency interference as well as electro- magnetic interference generated by electric and electronic components operating at the telescope site. A quantitative analysis of these interferences must be taken into account carefully for further electro- magnetic protection of the radio telescope. In this paper, based on electromagnetic topology theory, a hybrid method that combines the Baum-Liu-Tesche （BLT） equation and transfer function is proposed. In this method, the coupling path of the radio telescope is divided into strong coupling and weak cou- pling sub-paths, and the coupling intensity criterion is proposed by analyzing the conditions in which the BLT equation simplifies to a transfer function. According to the coupling intensity criterion, the topological model of a typical radio telescope system is established. The proposed method is used to solve the interference response of the radio telescope system by analyzing subsystems with different coupling modes separately and then integrating the responses of the subsystems as the response of the entire system. The validity of the proposed method is verified numerically. The results indicate that the proposed method, compared with the direct solving method, reduces the difficulty and improves the efficiency of interference prediction.

关键词： telescopes -- methods: analytical - methods: numerical - waves

Stress field interaction during propagation of adjacent tensile twinning nuclei in magnesium

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Rare Metals 2019年第8期38卷 721-732页

作者： Zhe Li Ben Xu qi Sun qiu-Lin Li Wei Liu School of Materials Science and Engineering Tsinghua University Beijing 100084 China Daya Bay Nuclear Power Plant China Nuclear Power Engineering Co. Ltd Shenzhen 518000 China Joint Laboratory of Nuclear Materials and Service Safety Graduate School at Shenzhen Tsinghua University Shenzhen 518000 China

The shear stress field proximity to the twinning and prismatic/basal interfaces of {1012} tensile twins is shown by molecular dynamics *** stress field interacts and influences the twinning growth mode in the subsequent deformation process,which is simulated by changing the relative positions of the *** asymmetrical growth mode appears,in which the growth of one twin is predominant over the other when they are oriented at 45° to each *** growth mode is sensitive to the simulation temperature and strain rate and can be attributed to the interaction of the stress field proximity to the prismatic/basal interfaces and twinning planes.

关键词： Twinning Twin-twin interaction Stress field Molecular dynamics Magnesium

New process for production of ultra-thin grain oriented silicon steel

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Rare Metals 2006年第z1期25卷 454-457页

作者： GAO Xiuhua LIU En qiu Chunlin qi Kemin TIAN Yanwen The State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 China The State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 China The State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 China The State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 China School of Materials and Metallurgy Northeastern University Shenyang 110004 China

The Hi-B silicon steels were cold rolled by cross shear rolling (CSR) with different mismatch speed ratio(MSR)s and conventional rolling(CR) respectively, followed by primary recrystallization annealing. The effects of MSR and annealing temperature on magnetic properties of ultra-thin grain oriented silicon steel were analyzed. Experimental results show that, with the increase of MSR, the magnetic properties can be remarkably improved. The higher the annealing temperature is, the higher the magnetic induction and the lower the iron loss in ultra-thin silicon steel is.

关键词： magnetic properties ultra-thin grain oriented silicon steel cross shear rolling primary recrystallization

A simple and Efficient Algorithm to Identify the Chirality of Polymer Knots Based on the Alexander Polynomial

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Chinese Journal of Polymer Science 2024年第12期42卷 2030-2037,I0012页

作者： qi-Yuan qiu Yong-Jian Zhu Zhong-Tao Wu Liang Dai Department of Physics City University of Hong KongHong Kong999077China Shenzhen Research Institute City University of Hong KongShenzhen518057China Department of Mathematics The Chinese University of Hong KongHong Kong999077China

Recent experimental observations of knotting in DNA and proteins have stimulated the simulation studies of polymer *** studies usually identify knots in polymer conformations through the calculation of the Alexander ***,the Alexander polynomial cannot directly discriminate knot chirality,while knot chirality plays important roles in many physical,chemical,and biological *** this work,we discover a new relationship for knot chirality and accordingly,develop a new algorithm to extend the applicability of the Alexander polynomial to the identification of knot *** algorithm adds an extra step in the ordinary calculation of the Alexander *** extra step only slightly increases the computational *** correctness of our algorithm has been proved mathematically by *** implication of this algorithm in physical research has been demonstrated by our studies of the tube model for polymer *** this algorithm,we would be unable to obtain the tubes for polymer knots.

关键词： Polymerentanglement Polymer knot Polymerconformation Tubemodel Monte Carlo simulation

An H-phosphonate strategy for the synthesis of 2',3'-dideoxynucleoside triphosphates and homodinucleotides

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Chinese Chemical Letters 2014年第3期25卷 427-430页

作者： qi Sun si Liu Jian Sun Shan-Shan Gong Jiangxi Key Laboratory of Organic Chemistry Jiangxi Science and Technology Normal University

The triphosphates and homodinucleotides of AZT and d4T have been efficiently synthesized from the corresponding nucleoside 5-H-phosphonate monoesters via the reactive pyridinium phosphoramidate intermediates.

关键词： 2' 3'-DideoxynucleosidesNucleoside triphosphateHomodinucleotideH-Phosphonate

High-elevation Adaptation of Motion Visual Display Modifications in the Toad-Headed Agamid Lizards(Phrynocephalus)

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Asian Herpetological Research 2022年第1期13卷 53-63页

作者： qiaohan HU Yusong LIN Xia qiu Jinzhong FU Yin qi Chengdu Institute of Biology Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 101400China Departments of Integrative Biology University of GuelphGuelphOntario N1G 2W1Canada

Understanding the process of adaptation is a key mission in modern evolutionary *** living at high elevations face challenges in energy meta bolism due to several environmental constraints(e.g., oxygen supply, food availa bility,and movement time). Animal behavioral processes are intimately related to energy meta bolism, and therefore, behavioral modifica tions are expected to be an important mechanism for high-elevation adaptation. We tested this behavioral adaptation hypothesis using va ria tions of motion visual displays in toad-headed agamid lizards of the genus Phr ynocephalus. We predicted tha t complexity of visual motion displays would decrease with the increase of elevation, because motion visual displays are energetically costly. Displays of 12 Phr ynocephalus species were collected with elevations ranging from sea level to 4600 m. We quantified display complexity using the number of display components, display duration, pathways of display components, as well as display speed for each species. Association between display complexity and elevation was analyzed using the phylogenetic generalized least squares(PGLS)model. We found that both the number of display components and the average value of tail coil speed were negatively correlated with elevation, suggesting that toad-headed lizards living at high-elevation areas reduced their display complexity to cope with the environmental constraints. Our research provides direct evidence for high-elevation adaptation from a behavioral aspect and illustrates the potential impacts of environment heterogeneity on motion visual display diversification.

关键词： high-elevation adaptation lizard motion visual display Phrynocephalus signal complexity

Patterns,magnitude,and controlling factors of hydraulic redistribution of soil water by Tamarix ramosissima roots

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Journal of Arid Land 2013年第3期5卷 396-407页

作者： TengFei YU qi FENG JianHua si HaiYang XI Wei LI Research School of Arid Environment and Climate Change Lanzhou University Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Gansu Hydrology and Water Resources Engineering Research Center

Tamarix spp. （Saltcedar） is a facultative phreatophyte that can tolerate drought when groundwater is not accessed. In addition to deep water uptake, hydraulic redistribution （HR） is another factor contributing to the drought tolerance of Tarnarix spp. In this study, data on soil volumetric moisture content （0）, lateral root sap flow, and relevant climate variables were used to investigate the patterns, magnitude, and controlling factors of HR of soil water by roots of Tamarix ramosissima Ledeb. in an extremely arid land in Northwest China. Results showed evident diurnal fluctuations in 0 at the depths of 30 and 50 cm, indicating ＂hydraulic lift＂（HL）. 0 increased remarkably at 10 and 140 cm but decreased at 30 and 50 cm and slightly changed at 80 cm after rainfall, suggesting a possible ＂hydraulic descent＂（HD）. However, no direct evidence was observed in the negative flow of lateral roots, supporting HR （including HL and HD） of T. ramosissima. The HR pathway unlikely occurred via lateral roots; instead, HR possibly occurred through adventitious roots with a diameter of 2-5 mm and a length of 60-100 cm. HR at depths of 20-60 cm ranged from 0.01-1.77 mm/d with an average of 0.43 mm/d, which accounted for an average of 22% of the estimated seasonal total water depletion at 0-160 cm during the growing season. The climate factors, particularly vapor pressure deficit and soil water potential gradient, accounted for at least 33% and 45% of HR variations with depths and years, respectively. In summary, T. ramosissima can be added to the wide list of existing species involved in HR. High levels of HR may represent a considerable fraction of daily soil water depletion and substantially improve plant water status. HR could vary tremendously in terms of years and depths, and this variation could be attributed to climate factors and soil water potential gradient.

关键词： drought tolerance phreatophyte hydraulic redistribution root sap flow Tamarix ramosissima

A venom protein of ectoparasitoid Pachycrepoideus vindemiae, PvG6PDH, contributes to parasitism by inhibiting host glucose-6-phosphate metabolism

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Insect Science 2022年第2期29卷 399-410页

作者： Lei Yang Liming qiu qi Fang Shaoying Wu Gongyin Ye Hainan University Haikou570228 China State Key Laboratory of Rice Biology&Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects Institute of Insect SciencesZhejiang UniversityHangzhou310058 China

To achieve successful development,female parasitoids,while laying eggs,introduce various virulence factors,mainly venoms,into host insects to manipulate their *** numerous studies have been conducted to characterize the components of venoms that regulate host immune responses,few systematic investigations have been conducted on the roles of venom proteins in host metabolic *** this investigation,we characterized a novel venom protein in Pachycrepoideus vindemiae called glucose-6-phosphate dehydrogenase(PvG6PDH)and showed it has a vital role in regulating host carbohydrate ***6PDH encodes 510 amino acids and features a signal peptide and two conserved“G6PDH”*** sequence alignment showed it has high amino acid identity with G6PDH from other pteromalids,and quantitative polymerase chain reaction analysis and immunofluorescent staining demonstrated a significantly higher expression of PvG6PDH in the venom apparatus compared with the *** report that PvG6PDH contributes to parasitism by inhibiting the glucose-6-phosphate(G6P)metabolism of host Drosophila melanogaster,as demonstrated by PvG6PDH injection and RNA interference *** tests revealed that the accumulation of host G6P was caused by the transcriptional inhibition of G6P-metabolism-related *** findings greatly contribute to our understanding of venom-mediated host metabolic regulation,further laying the foundation for the development of venom proteins as biological agents for pest control.

关键词： biological control metabolism Pachycrepoideus vindemiae parasitoid venom