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Magnetic cycles of Sun-like stars with different levels of coronal and chromospheric activity——comparison with the Sun
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作者 Elena Shimanovskaya Vasiliy Bruevich Elena Bruevich 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第9期123-136,共14页
The atmospheric activity of the Sun and Sun-like stars is analyzed involving observations from the HK-project at the Mount Wilson Observatory, the California and Carnegie Planet Search Program at the Keck and Lick Obs... The atmospheric activity of the Sun and Sun-like stars is analyzed involving observations from the HK-project at the Mount Wilson Observatory, the California and Carnegie Planet Search Program at the Keck and Lick Observatories and the Magellan Planet Search Program at the Las Campanas Observatory. We show that for stars of E G and K spectral classes, the cyclic activity, similar to the 11-yr solar cycle, is different: it becomes more prominent in K-stars. Comparative study of Sun-like stars with different levels of chromospheric and coronal activity confirms that the Sun belongs to stars with a low level of chromospheric activity and stands apart among these stars by its minimum level of coronal radiation and minimum level of variations in photospheric flux. 展开更多
关键词 sun activity -- sun-like stars activity
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Multiple cycles of magnetic activity in the Sun and Sun-like stars and their evolution
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作者 Elena Aleksandrovna Bruevich Vasily Vladimirovich Bruevich Boris Pavlovich Artamonov 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第7期21-36,共16页
The wavelet transform method for high-quality time-frequency analysis is applied to sets of observations of relative sunspot numbers and stellar chromosphere fluxes of 10 Sun-like stars. Wavelet analysis of solar data... The wavelet transform method for high-quality time-frequency analysis is applied to sets of observations of relative sunspot numbers and stellar chromosphere fluxes of 10 Sun-like stars. Wavelet analysis of solar data shows that in a certain interval of time there are several cycles of activity with pe- riods of duration which vary considerably from each other: from quasi-biennial cycles to lO0-yr cycles. Cyclic activity was detected in almost all Sun-like stars that we examined, even those that previously were not considered as stars with cyclic activity according to analysis using a Scargle periodogram. The durations of solar and stellar cycles significantly change during the observation period. 展开更多
关键词 sun activity - multiple cycles - sun-like stars activity
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Low-dimensional chaos and fractal properties of long-term sunspot activity
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作者 Shuang Zhou Yong Feng +2 位作者 Wen-Yuan Wu Yi Li Jiang Liu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第1期104-112,共9页
Two primary solar-activity indicators- sunspot numbers (SNs) and sunspot areas (SAs) in the time interval from November 1874 to December 2012 - are used to determine the chaotic and fractal properties of solar act... Two primary solar-activity indicators- sunspot numbers (SNs) and sunspot areas (SAs) in the time interval from November 1874 to December 2012 - are used to determine the chaotic and fractal properties of solar activity. The results show that (1) the long-term solar activity is governed by a low-dimensional chaotic strange attractor, and its fractal motion shows a long-term persistence on large scales; (2) both the fractal dimension and maximal Lyapunov exponent of SAs are larger than those of SNs, implying that the dynamical system of SAs is more chaotic and complex than SNs; (3) the predictions of solar activity should only be done for short- to mid-term behaviors due to its intrinsic complexity; moreover, the predictability time of SAs is obviously smaller than that of SNs and previous results. 展开更多
关键词 methods: data analysis -- sun activity -- sun sunspots
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On the Imminent Regional Seismic Activity Forecasting Using INTERMAGNET and Sun-Moon Tide Code Data
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作者 Strachimir Cht. Mavrodiev Lazo Pekevski +5 位作者 Giorgi Kikuashvili Emil Botev Petar Getsov Garo Mardirossian Georgi Sotirov Dimitar Teodossiev 《Open Journal of Earthquake Research》 2015年第3期102-113,共12页
In this paper we present an approach for forecasting the imminent regional seismic activity by using geomagnetic data and Earth tide data. The time periods of seismic activity are the time periods around the Sun-Moon ... In this paper we present an approach for forecasting the imminent regional seismic activity by using geomagnetic data and Earth tide data. The time periods of seismic activity are the time periods around the Sun-Moon extreme of the diurnal average value of the tide vector module. For analyzing the geomagnetic data behaviour we use diurnal standard deviation of geomagnetic vector components F (North, East, Down) for calculating the time variance GeomagSignal. The Sun storm influence is avoided by using data for daily A-indexes (published by NOAA). The precursor signal for forecasting the incoming regional seismic activity is a simple function of the present and previous day GeomagSignal and A-indexes values. The reliability of the geomagnetic “when, regional” precursor is demonstrated by using statistical analysis of day difference between the times of “predicted” and occurred earthquakes. The base of the analysis is a natural hypothesis that the “predicted” earthquake is the one whose surface energy density in the monitoring point is bigger than the energy densities of all occurred earthquakes in the same period and region. The reliability of the approach was tested using the INTERMAGNET stations data located in Bulgaria, Panagurishte, PAG (Jan 1, 2008-Jan 29, 2014), Romania, Surlari, SUA (Jan 1, 2008-Jan 27, 2014), Italy, L’Aquila, AQU (Jan 1, 2008-May 30, 2013) in the time of EU IRSES BlackSeaHazNet (2011-2014) project. The steps of program for solving the “when, where and how” earthquake prediction problem are shortly described. 展开更多
关键词 Earthquakes GEOMAGNETISM Earth sun-Moon TIDE REGIONAL Seismic activity Forecasting
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Expression, Purification and Insecticidal Activity Analysis of Cry1Ac without Helix α-1
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作者 刘京国 郭蓓 +1 位作者 赵晓萌 师光禄 《Agricultural Science & Technology》 CAS 2012年第2期265-267,303,共4页
[Objective] This study aimed to analyze the expression, purification and insecticidal activity of Cry1Ac without helix α-1 of domain I in E. coli. [Method] Plasmid of B. thuringiensis HD-1 was used as the template fo... [Objective] This study aimed to analyze the expression, purification and insecticidal activity of Cry1Ac without helix α-1 of domain I in E. coli. [Method] Plasmid of B. thuringiensis HD-1 was used as the template for amplification of Cry1Ac gene, which was linked with pET28a vector to construct the recombinant plasmid. After transformation and IPTG induction, expression of target protein was detected by using SDS-PAGE method. Target protein was extracted and coated on the surface of feed for H. armigera to determine the insecticidal activity. [Result] Cry1Acdela1 gene could normally express the target protein in E. coli. However, the target protein existed in the form of inclusion body. Results of bioassay analysis showed that under the same concentration, fatality rate of activated Cry1Ac toxin reached above 75%, while that of Cry1Acdelα1 was only about 10%. [Conclusion] E. coli-expressed Cry1Acdelα1 had no insecticidal activity against H. armigera. 展开更多
关键词 CRY1AC α-1 fragment Insecticidal activity
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Evolution of the Level of Sunspot Activity in Solar Cycles I. Evolution in the Descending Phase 被引量:2
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作者 Jia-Long Wang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2006年第3期354-362,共9页
Taking the 13-point smoothed monthly sunspot number,Ri, and the deviation of the 13 associated monthly sunspot numbers from the smoothed one, Di, as a number-pair describing the global level of sunspot activity, the e... Taking the 13-point smoothed monthly sunspot number,Ri, and the deviation of the 13 associated monthly sunspot numbers from the smoothed one, Di, as a number-pair describing the global level of sunspot activity, the evolution of the level is statistically studied for the period from the month which is just 48 months before the minimum to the minimum in the descending phase, using the observed data of Solar Cycles 10 to 22. Our results show (1) for 46 months (94%) of the studied 49 months it is found that for a given month, the distribution of the 13 pairs which come from the 13 solar cycles on a log Ri - Di plane may be fitted by a straight line with a correlation coefficient larger than the critical one at confidence level a = 5%, and for 36 months (73%) the fitting is even better, for a = 1%; (2) time variations of these two parameters and their correlations in the studied period can be described respectively by functions of time, whose main trends may be expressed by a linear or simple curvilinear function; (3) the evolutionary path of the level of sunspot activity may be represented by a logarithmic function as log/~ = 0.704 lnDi - 0.291. 展开更多
关键词 sun - sunspots - active level evolution
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ENSO Index Variations and Links with Solar and Volcanic Activity
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作者 Valentina V. Zharkova Irina Vasilieva 《Natural Science》 2024年第4期25-44,共20页
In this paper, we investigated the Oceanic Niño Index (ONI), for simplicity called in this paper an El Nino Southern Oscillation (ENSO) index in 1950-2023 by applying the wavelet spectral transform and the IBM SP... In this paper, we investigated the Oceanic Niño Index (ONI), for simplicity called in this paper an El Nino Southern Oscillation (ENSO) index in 1950-2023 by applying the wavelet spectral transform and the IBM SPSS correlations analysis. ONI follows the three months’ current measurements of the average temperature of the sea surface in the East-Central tropical part of the Pacific Ocean nearby the international line of the date change over the average sea surface temperature over the past 30 years. The ENSO index is found to have a strong (>87%) correlation with the Global Land-Ocean Temperature (GLOT). The scatter plots of the ENSO-GLOT correlation with the linear and cubic fits have shown that the ENSO index is better fit by the cubic polynomial increasing proportionally to a cubic power of the GLOT variations. The wavelet analysis allowed us to detect the two key periods in the ENSO (ONI) index: 4 - 5 years and 12 years. The smaller period of 4.5 years can be linked to the motion of tectonic plates while the larger period of 12 years is shown to have a noticeable correlation of 25% with frequencies of the underwater (submarine) volcanic eruptions in the areas with ENSO occurrences. Not withholding any local terrestrial factors considered to contribute to the ENSO occurrences, we investigated the possibility of the volcanic eruptions causing ENSO to be also induced by the tidal forces of Jupiter and Sun showing the correlation of the underwater volcanic eruption frequency with the Jupiter-Earth distances to be 12% and with the Sun-Earth distances, induced by the solar inertial motion, in January, when the Earth is turned to the Sun with the southern hemisphere where the ENSO occurs, to become 15%. Hence, the underwater volcanic eruptions induced by tidal forces of Jupiter and Sun can be the essential additional factors imposing this 12 year period of the ENSO (ONI) index variations. 展开更多
关键词 sun: Magnetic Field sun: Solar activity sun: Inertial Motion Earth: Temperature Earth: Sea Level Earth: Ice Area
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Activity of the Fungicide JS399-19 Against Fusarium Head Blight of Wheat and the Risk of Resistance 被引量:7
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作者 CHEN Yu WANG Wen-xiang +3 位作者 ZHANG Ai-fang GU Chun-yan ZHOU Ming-guo GAO Tong-chun 《Agricultural Sciences in China》 CAS CSCD 2011年第12期1906-1913,共8页
This report reviews the characteristics of JS399-19, a novel cyanoacrylate fungicide. JS399-19 strongly inhibits the mycelial growth of the fungal plant pathogens of the genus Fusarium and exhibits great potential in ... This report reviews the characteristics of JS399-19, a novel cyanoacrylate fungicide. JS399-19 strongly inhibits the mycelial growth of the fungal plant pathogens of the genus Fusarium and exhibits great potential in controlling Fusarium head blight (FHB) on wheat and other cereals. The mode of action of JS399-19 is evidently different from that of benzimidazole (for example, carbendazim) and other sort of fungicides, making it a possible replacement for carbendazim in China to manage carbendazim-resistant subpopulations of Fusarium graminearum and F. asiaticum. JS399-t9 has excellent protective and curative activity against these pathogens. Incorrect use of this fungicide, however, is likely to select for resistance. Among JS399-19-resistant mutants of F. asiaticum induced in the laboratory, the resistant level of mutants was high and the phenotype of resistance against JS399-19 was conferred by a major gene by genetic analysis. The fitness of laboratory-induced JS399-19-resistant mutants of F. asiaticum was nearly equal to that of their parents. JS399-19 lacks cross resistance with other sort fungicides. To control FHB with JS399-19 and to delay the development of the fungicide-resistance, farmers should use tank mixtures containing JS399-19 and carbendazim, metconazole, tebuconazole, or prothioconazole. 展开更多
关键词 fungicide JS399-19 cyanoacrylate fungicide Fusarium head blight activity resistance risk
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Calculation of Activity Coefficients for Components in Ti-15-3 Melt 被引量:3
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作者 苏彦庆 刘源 +2 位作者 郭景杰 贾均 丁宏升 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1999年第1期54-57,共4页
Based on Kohler’s ternary solution model and Miedemaa’s model for calculating the heats of formation-△Hij of binary Systems, the integral equation has ben established for calculating the activity coefficients in te... Based on Kohler’s ternary solution model and Miedemaa’s model for calculating the heats of formation-△Hij of binary Systems, the integral equation has ben established for calculating the activity coefficients in ternarysolution. With the equation, the activity coefficients in Ti-15-3 melt have been calculated. The results show that allof components’ activity coefficients are less than 1, in other wolds, compared with ideal solution, all components takeon a negative deviation. At 2000K, the activity coefficients in Ti-15-3 melt are shown as: about 0.9 for Ti, about0.85 for V, about 0. 1 for Al, aboaut 0.5 for Cr and about 0.23 for Sn. me addition of V lowers the activity coefficient of Ti, but raise the ones of Al, Cr and Sn. These results can be directly used to calculate the evaporation loss ofAl, Cr and Sn during the ISM(Induction Skull Melting) process and at the same time estimate the reactivity betweenTi-15-3 melt and refractory during the cast production. 展开更多
关键词 activity COEFFICIENT Ti-15-3 alloy ISM process
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The relationships of solar flares with both sunspot and geomagnetic activity 被引量:1
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作者 Zhan-Le Du Hua-Ning Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2012年第4期400-410,共11页
The relationships between solar flare parameters (total importance, time duration, flare index, and flux) and sunspot activity (R z ) as well as those between geomagnetic activity (aa index) and the flare parame... The relationships between solar flare parameters (total importance, time duration, flare index, and flux) and sunspot activity (R z ) as well as those between geomagnetic activity (aa index) and the flare parameters can be well described by an integral response model with the response time scales of about 8 and 13 months, respectively. Compared with linear relationships, the correlation coefficients of the flare parameters with R z , of aa with the flare parameters, and of aa with R z based on this model have increased about 6%, 17%, and 47% on average, respectively. The time delays between the flare parameters with respect to R z , aa to the flare parameters, and aa to R z at their peaks in a solar cycle can be predicted in part by this model (82%, 47%, and 78%, respectively). These results may be further improved when using a cosine filter with a wider window. It implies that solar flares are related to the accumulation of solar magnetic energy in the past through a time decay factor. The above results may help us to understand the mechanism of solar flares and to improve the prediction of the solar flares. 展开更多
关键词 sun activity -- sun sunspots -- sun flares -- geomagnetic activity
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Characterization and Anti-tumor Activity of Glycopeptides from Ganoderma sinensis 被引量:5
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作者 GAO Yang JIANG Ru-zhi +3 位作者 CHEN Ying-hong LUO Hao-ming XU Duo-duo GAO Qi-pin 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2009年第1期47-51,共5页
The water-soluble part(GS) of Ganoderma sinense Zhao, Xu et Zhang was divided into high molecular(GS-H) and low molecular(GS-L) parts by Cellulose Super Filtration, and GS was also fractionated into four fractio... The water-soluble part(GS) of Ganoderma sinense Zhao, Xu et Zhang was divided into high molecular(GS-H) and low molecular(GS-L) parts by Cellulose Super Filtration, and GS was also fractionated into four fractions, GS-1, 2, 3, and 4 by ethanol precipitation according to their molecular weights. Chemical analysis shows that GS and GS-1, 2, 3, 4 were complexes of polysaccharide and peptide. The fractions with molecular weights over 4000, GS-1, 2, 3, and GS-H show anti-tumor activities, however, the fractions with molecular weights lower than 4000, GS-4, and GS-L have no anti-tumor activity, indicating that the anti-tumor activity of Ganoderma Sinensis was caused by glucopeptides with molecular weight ranging from 4000 to 20000. Two purified glucopeptides, GS-6b and GS-7b were obtained from GS-H by ion-exchange and gel-permeation chromatography. Their molecular weights, glycosidic linkages, and configurations were detected by means of IR spectrum, sugar composition analysis, and methylation analysis. The polysaccharide parts of GS-6b and GS-7b had glucan backbone consisting of β-1→3 Glc, and side chain containing glucosyl, mannosyl, fucosyl, xylosyl, galactosyl, and glucuronic acid residues attached on 1-2, 1-4, 1-6 positions of the backbone of GS-6b, or 1-6, 1-4 positions of the backbone of GS-7b. The peptide parts in GS-6b and GS-7b were composed of 10 kinds of amino acids, including Asp, Ser, Arg, Gly, Thr, Pro, Ala, Val, Met, and Lys. 展开更多
关键词 Ganoderma sinense Zhao Xu et Zhang Anti-tumor activity Glucopeptide β- 1→3 glucan
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Synthesis, Crystal Structure and Antitumor Activity of (E)-4-tert-Butyl-N-(2,4-dichlorobenzylidene)-5-(1,2,4-triazol-1-yl)-thiazol-2-amine 被引量:5
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作者 胡艾希 覃智 +1 位作者 叶姣 夏曙 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第11期1680-1683,共4页
The title compound (E)-4-tert-butyl-N-(2,4-dichlorobenzylidene)-5-(1,2,4-triazol-1-yl)-thiazol-2-amine was synthesized by the reaction of 4-tert-butyl-5-(1,2,4-triazol-1-yl)-thiazol-2-amine with 2,4-dichlorobe... The title compound (E)-4-tert-butyl-N-(2,4-dichlorobenzylidene)-5-(1,2,4-triazol-1-yl)-thiazol-2-amine was synthesized by the reaction of 4-tert-butyl-5-(1,2,4-triazol-1-yl)-thiazol-2-amine with 2,4-dichlorobenzaldehyde, and its crystal structure was determined by singlecrystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 7.9748(4), b = 10.1803(5), c = 11.4603(6), α = 102.882(1), β = 100.253(1), γ = 104.457(1)°, V = 850.95(7)3, Z = 2, F(000) = 392, C16H15Cl2N5S, Mr = 380.29, Dc = 1.484 g/cm3, S = 1.095, μ = 0.512 mm-1, the final R = 0.0301 and wR = 0.0965 for 3334 observed reflections (I 〉 2σ(I)). The preliminary antitumor activity shows that for the title compound the IC50 of Hela is 0.175 μmol/mL and that of Bel7402 is 0.156 μmol/mL. 展开更多
关键词 (E)-4-tert-butyl-N-(2 4-dichorobenzylidene)-5-(1 2 4-triazl-1-yl)-thiazol-2-amine crystal structure synthesis antitumor activity
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Synthesis, Crystal Structure and Fungicidal Activity of N-(4-tert-buty)-5-(1,2,4-triazol-1-yl)thiazol-2-yl)propionamide 被引量:3
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作者 叶姣 孙晓潇 +1 位作者 邱慎意 胡艾希 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第3期429-433,共5页
The title compound has been synthesized by the reaction of 4-tert-butyl-5-(1,2,4- triazol-1-yl)-2-aminothiazole with propionic anhydride, and its crystal structure was determined by single-crystal X-ray diffraction.... The title compound has been synthesized by the reaction of 4-tert-butyl-5-(1,2,4- triazol-1-yl)-2-aminothiazole with propionic anhydride, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system, space group Pbca with α = 18.441(2), b = 8.3284(9), c = 19.257(2) A, Z = 8, V = 2957.5(5) A3, Mr = 279.37, Dc = 1.255 mg/m3, S = 1.033, μ =0.219 mm^-1, F(000) = 1184, the final R = 0.0349 and wR = 0.0876 for 2629 observed reflections (I 〉 2σ(I)). X-ray crystal structure presents the intermolecular N–H···N hydrogen bond, which plays an important role in stabilizing the crystal structure. The preliminary bioassay indicates that the title compound exhibits potent fungicidal activity against R. Solani (25 mg/L) with inhibition rate of 80.0%. 展开更多
关键词 N- 4-tert-buty)-5-(1 2 4-triazoi- l-yl)thiazol-2-yl)propionamide SYNTHESIS crystal structure fungicidal activity
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Studies on Condensed Heterocyclic Compounds(Ⅲ)——Synthesis and Antibacterial Activity of 3-(4-Pyridyl)-6-Alkyl/Aromatic Heterocyclyl-s-Triazolo[3,4-b]-1, 3,4-Thiadiazoles and 1,4-Bis [6-(4-Pyridyl)-s-Triazolo [3,4-b]-1, 3,4-Thiadiazol-3-yl]-n-Butane 被引量:2
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作者 Zhang Ziyi, Chen Xin, Wei Lulin and Ma Zhaoli (Department, of Chemistry, Lanzhou University, Lanzhou) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1991年第2期129-133,共5页
In recent years, fused heterocycles have been reported to possess important properties in synthesis and pharmacology. Especially, s-triazolo, 3,4-thiadiazole derivatives have been attracting much attention for chemist... In recent years, fused heterocycles have been reported to possess important properties in synthesis and pharmacology. Especially, s-triazolo, 3,4-thiadiazole derivatives have been attracting much attention for chemists and pharmacologists because they show broad spectra of biological activities, such as antifungal, antibacterial, hy- 展开更多
关键词 s-Triazolo[3 4-b]-1 3 4-thiadiazoles SYNTHESIS Antibacterial activity
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Synthesis,Crystal Structure and Antitumor Activity of N-(4-tert-butyl-5-(4-chlorobenzyl)thiazol-2-yl)-2,6-difluorobenzamide 被引量:2
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作者 申坤 彭俊梅 +2 位作者 李婉 颜晓维 胡艾希 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第6期855-858,共4页
The title compound was synthesized by the reaction of 4-tert-butyl-5-(4-chlorobenzyl)-2-aminothiazole with 2,6-difluorobenzoic acid. The crystal structure of the title compound, C21H19ClF2N2OS, was determined by sin... The title compound was synthesized by the reaction of 4-tert-butyl-5-(4-chlorobenzyl)-2-aminothiazole with 2,6-difluorobenzoic acid. The crystal structure of the title compound, C21H19ClF2N2OS, was determined by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group Pbca with a = 12.6479(13), b = 13.1204(13), c = 14.1341(15), Z = 4, V = 2011.5(4)3, Mr = 420.89, Dc = 1.390 g/cm3, S = 1.023, μ = 0.326 mm-1, F(000) = 872, the final R = 0.0365 and wR = 0.0880 for 6101 observed reflections(I 〉 2σ(I)), and R = 0.0507, wR = 0.0978 for 7779 independent reflections. X-ray crystal structure displays that the hydrogen bonding interactions observed link the molecules to form a dimeric unit. The preliminary biological test of the title compound shows good antitumor activity, with IC50 of 0.046 μmol/mL against the Hela cell line. 展开更多
关键词 N-(4-tert-butyl-5-(4-chlorobenzyl)thiazol-2-yl)-2 6-difluorobenzamide SYNTHESIS crystal structure antitumor activity
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Synthesis,Crystal Structure and Fungicidal Activity of(E)-2-[(4-tert-Butyl-5-(4-methoxybenzyl)thiazol-2-ylimino)methyl]phenol 被引量:2
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作者 胡艾希 曹高 +2 位作者 马颍绮 张建宇 欧晓明 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第10期1235-1239,共5页
The title compound (E)-2-[(4-tert-butyl-5-(4-methoxybenzyl)thiazol-2-ylimino)methyl]phenol was synthesized by the reaction of 5-(4-methoxybenzyl)-4-tert- butylthiazol-2-amine with salicylaldehyde, and its crys... The title compound (E)-2-[(4-tert-butyl-5-(4-methoxybenzyl)thiazol-2-ylimino)methyl]phenol was synthesized by the reaction of 5-(4-methoxybenzyl)-4-tert- butylthiazol-2-amine with salicylaldehyde, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 5.9362(8), b = 11.5070(15), c = 29.460(4)A, β= 97.326(3)°, V = 1995.9(5) A^3, Z = 4, F(000) = 808, C22H24N2O2S, Mr= 380.49, De= 1.266 g/cm^3, S = 1.031,μ = 0.181 mm^-1, the final R = 0.0474 and wR = 0.1441 for 4327 observed reflections (I 〉 2σ(I)). Intramolecular O-H…N hydrogen bond is observed in the crystal. The preliminary bioassay showed that the title compound exhibits 95% inhibition rate against Rhizoctonia solani at the test concentration of 500 mg/L. 展开更多
关键词 crystal structure SYNTHESIS fungicidal activity (E)-2- [(4-tert-butyl-5-(4-methoxybenzyl)thiazol-2-ylimino)methyl]phenol
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Synthesis, Crystal Structure and Antidepressant Activity of 5-[4-(Benzyloxy)phenyl]-9-(n-propyl)-4,6-dioxa-1-azabicyclo[3.3.1]nonane Hydrochloride 0.5Hydrate 被引量:1
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作者 付二霞 曹高 +1 位作者 石磊 胡艾希 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第5期709-713,共5页
The title compound 2(C22H28N+O3)·H2O·2Cl-was synthesized by the reaction of 2-bromo-1-[4-(benzyloxy)phenyl]-1-pentone with 2,2'-azanediyldiethanol. The crystal determined by X-ray diffraction analysis ... The title compound 2(C22H28N+O3)·H2O·2Cl-was synthesized by the reaction of 2-bromo-1-[4-(benzyloxy)phenyl]-1-pentone with 2,2'-azanediyldiethanol. The crystal determined by X-ray diffraction analysis belongs to the monoclinic system, space group Pc with a = 18.312(3), b = 14.838(3), c = 7.6227(14) , β = 97.981(4)°, Z = 2, Mr = 797.82, V = 2051.1(6) 3, Dc = 1.292 g/cm3, S = 0.956, μ = 0.21 mm-1, F(000) = 852, the final R = 0.0625 and wR = 0.1428 for 5683 observed reflections (Ⅰ 〉 2σ(Ⅰ)). Flack parameter is 0.10(9). The title compound is composed by four non-coplanar ring systems, two benzenes and two morpholines. One morpholine ring (C(3)-C(4)-N(1)-C(1)-C(2)-O(1)) forms a chair conformation, while the other (C(4)-C(3)-O(2)-C(6)-C(5)-N(1)) assumes a boat conformation. X-ray crystal structure displays extensive N-H…Cl and O-H…Cl intermolecular hydrogen bonds. The preliminary antidepressant activity test indicates that the inhibition ratio of SERT (5-HT Transporter) was 35.9% at the dosage of 10.0 mg/L. 展开更多
关键词 5-[4-(benzyloxy)phenyl]-9-propyl-4 6-dioxa-l-azabicyclo [3.3.1] nonanehydrochloride SYNTHESIS crystal structure antidepressant activity
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Synthesis, Crystal Structure and Fungicidal Activity of (Z)-3,3-Dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one O-2-Chlorobenzyl Oxime Nitrate 被引量:2
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作者 叶姣 玄文静 胡艾希 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第9期1265-1268,共4页
The title compound has been synthesized by the reaction of 3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one oxime with 2-chlorobenzyl chloride, and then treated with 65~68% HNO3. Its crystal structure was determin... The title compound has been synthesized by the reaction of 3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one oxime with 2-chlorobenzyl chloride, and then treated with 65~68% HNO3. Its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 14.5481(8), b = 9.3351(5), c = 13.1911(7) , β = 98.9450(10)°, Z = 4, V = 1769.67(17) 3, Mr = 369.81, Dc = 1.388 g/cm3, S = 1.06, μ = 0.247 mm-1, F(000) = 776, the final R = 0.0352 and wR = 0.0960 for 3069 observed reflections (I 2σ(I)). X-ray crystal structure presents the intramolecular N–H…O hydrogen bond. The packing is nearly parallel without π-π stacking interactions between two adjacent phenyl rings and stabilized by Van der Waals force. The preliminary bioassay shows that the title compound possesses fungicidal activity against Gibberella zeae at the dosage of 25 mg/L. 展开更多
关键词 (Z)-3 3-dimethyl-1-(1H-1 2 4-triazol-1-yl)butan-2-one O-2-chlorobenzyl oxime nitrate crystal structure synthesis fungicidal activity
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Synthesis, Crystal Structure and Antitumor Activity of 4-tert-Butyl-N-(2-fluorophenyl)-5- (1H-1,2,4-triazol-1-yl)-thiazol-2-amine 被引量:1
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作者 李婉 叶姣 +2 位作者 沈芳 彭俊梅 胡艾希 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第12期1782-1786,共5页
The title compound has been synthesized by the reaction of 1-bromo-3,3-dime- thyl- 1 - (1 H- 1,2,4-triazol- 1 -yl)butan-2-one with 1 -(2-fluorophenyl)thiourea, and its crystal struc- ture was determined by single-... The title compound has been synthesized by the reaction of 1-bromo-3,3-dime- thyl- 1 - (1 H- 1,2,4-triazol- 1 -yl)butan-2-one with 1 -(2-fluorophenyl)thiourea, and its crystal struc- ture was determined by single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system, space group Pbca with a = 15.2568(6), b = 12.1533(5), c = 16.7307(7) A, Z = 8, V = 3102.2(2) A3, Mr = 317.39, Dc = 1.359 g/cm3, S = 1.05, μ = 0.223 mm-1, F(000) = 1328, the final R = 0.034 and wR = 0.097 for 2590 observed reflections (I 〉 2σ(I)). X-ray crystal structure presents the intramolecular N-H…N hydrogen bond, which plays an important role in stabilizing the crystal structure. In addition, the preliminary biological test on the title compound shows good antitumor activity, with IC50 of 0.122 μmol/mL against the Hela cell line. 展开更多
关键词 4-tert-butyl-N-(2-fluorophenyl)-5-(1H-1 2 4-triazol-1-yl)thiazol-2-amine SYNTHESIS crystal structure antitumor activity
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A study of short-period variation in solar activity
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作者 Ji-Long Chen Juan Zhao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第8期1011-1018,共8页
We introduce two methods to detect short-period variation in solar activity. These are called amplitude of low frequency fluctuation (ALFF) and fractional am- plitude of low frequency fluctuation (FALFF). We find ... We introduce two methods to detect short-period variation in solar activity. These are called amplitude of low frequency fluctuation (ALFF) and fractional am- plitude of low frequency fluctuation (FALFF). We find a positive correlation between short-period variation and 11-year variation of solar activity using these two methods. Through ALFF, we find that solar activity over a short period becomes intensive when the 11-year solar activity is intensive. The ALFF value of the short period activity varies with the peak in sunspot number as a quadratic function. Through FALFF we find that the ratio of short-period spectral intensity to intensity over the whole period of solar activity will increase when the 11-year period of solar activity is intensive. The short-period FALFF value varies with the peak in sunspot number according to a cubic function. Using ALFF, we obtain a yearly series of solar activity that varies over a short period of 1-5 yr from 1860 to 2003, which shows an obvious periodicity of about 22 yr, 33 yr, 11 yr and a century. These short period variations show good correlations with long term variations in solar activity. 展开更多
关键词 sun activity -- sun sunspots -- methods data analysis
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