期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
Can Asymmetry of Solar Activity be Extended into Extended Cycle? 被引量:1
1
作者 Ke-JunLi Jing-XiuWang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2002年第1期66-70,共5页
With the use of the Royal Greenwich Observatory data set of sunspot groups, an attempt is made to examine the north-south asymmetry of solar activity in the 'extended' solar cycles. It is inferred that the asy... With the use of the Royal Greenwich Observatory data set of sunspot groups, an attempt is made to examine the north-south asymmetry of solar activity in the 'extended' solar cycles. It is inferred that the asymmetry established for individual solar cycles does not extend to the 'extended' cycles. 展开更多
关键词 Sun: sunspot - Sun: active cycle - Sun: activity
在线阅读 下载PDF
Multiple cycles of magnetic activity in the Sun and Sun-like stars and their evolution
2
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
在线阅读 下载PDF
Activity Recording of Free-Ranging Tri-spine Horseshoe Crabs in the Southeastern Coast of Sabah,Borneo
3
作者 WATANABE Shinichi NELSON Bryan Raveen +1 位作者 MANCA Azwarfarid MOHAMAD Faridah 《Journal of Ocean University of China》 SCIE CAS CSCD 2022年第3期549-556,共8页
In Inderasabah(southeast Sabah),tri-spine horseshoe crab Tachypleus tridentatus was observed for their locomotion activity using data loggers from September to November in 2015.A female with acceleration and depth-tem... In Inderasabah(southeast Sabah),tri-spine horseshoe crab Tachypleus tridentatus was observed for their locomotion activity using data loggers from September to November in 2015.A female with acceleration and depth-temperature loggers and five males with acceleration loggers were recaptured between 10 and 49 days after their release.From the record of 194 activity days that involve all six T.tridentatus,four horseshoe crabs,including the female,were active throughout the 24.0 h cycle,whereas the activity of the remaining two males was consistent with the 12.4 h cycle.Using the 40-day recording,three horseshoe crabs,including the female,were primarily active around the new moon and full moon,but they were dormant around the first and third quarter moon days.The female spent much time in shallow shores(depth<0.3 m)during the new moon and full moon.This result indicated that the female attempted to spawn in a minimum of three spring tide periods while lingering in the vicinity.Meanwhile,after spawning,the female spent time foraging in shallow water(depth 0.3–18 m).As for the two male individuals,their activity was consistent with semi-lunar periodicity.Therefore,both of them were in amplexus.In addition,a solitary male individual was active only during the first and third quarter moon days.Through activity recording,all the T.tridentatus in Inderasabah was active during daytime and nighttime.This result was contrary to T.tridentatus activity cycles in western Japan,where the species was found to be primarily nocturnal.Perhaps,the regional differences in activity cycles for T.tridentatus were related to their population adaptation toward water temperature,depth,and prey-searching periods. 展开更多
关键词 acceleration logger activity cycle depth-temperature logger foraging behavior spawning behavior tropical region Tachypleus tridentatus
在线阅读 下载PDF
Study of Relation between Torrential Rain Days in Fuxin and Sunspot Cycle
4
作者 马晓刚 李辑 +2 位作者 李丽光 赵振宇 程肖侠 《Meteorological and Environmental Research》 CAS 2010年第11期26-27,共2页
The quasi 11-year cycle of sunspot activities and torrential rain days in Fuxin during 1951-2005 were studied.As was shown in the results,the relative number of sunspots and the torrential rain days in the sunspot cyc... The quasi 11-year cycle of sunspot activities and torrential rain days in Fuxin during 1951-2005 were studied.As was shown in the results,the relative number of sunspots and the torrential rain days in the sunspot cycle of trough value were significantly related with a correlation coefficient of 0.842.At the same time,the correlation coefficient between torrential rain days in Fuxin and the relative number of sunspots of certain year within the sunspot cycle of trough value reached 0.737.It was clear that the torrential rain days in Fuxin were closely related with solar activity.The conclusion would provide the favorable climate background and basis for the study of regularity of rainstorm outbreak,monitoring and forecasting of torrential rain and regularity of agricultural drought and flood. 展开更多
关键词 cycle of solar activities Torrential rain days Relational study China
在线阅读 下载PDF
Active Methyl Cycle and Transfer Related Gene Expression in Response to Drought Stress in Rice Leaves
5
作者 ZHANG Xiao-li ZHOU Jian +4 位作者 HAN Zhuo SHANG Qi WANG Ze-gang Gu Xiao-hui GE Cai-lin 《Rice science》 2012年第2期86-93,共8页
Three rice varieties, Zhonghan 3, Shanyou 63 and Aizizhan, were used as materials in detecting differential active methyl cycle and transfer related gene expression in response to drought stress. The experiment was pe... Three rice varieties, Zhonghan 3, Shanyou 63 and Aizizhan, were used as materials in detecting differential active methyl cycle and transfer related gene expression in response to drought stress. The experiment was performed by gene chip and mRNA differential display technologies under the conditions of drought simulated with 10% PEG6000 solution. The results indicated that the methyl cycle could be activated in the leaves of Zhonghan 3 and Shanyou 63 but inhibited in the leaves of Aizizhan under drought stress. Furthermore, drought stress could induce the expression of a large number of methyltransferase genes, especially the transcription of Rubisco protein methylation related genes, which are beneficial for prevention of Rubisco protein oxidation and degradation, and drought stress could inhibit the transcription of DNA methyltransferase genes and histone methyltransferase genes. This result confirmed that the active methyl cycle and transfer related genes were involved in rice drought resistance. 展开更多
关键词 drought stress gene chip mRNA differential display gene transcription active methyl cycle transfer relatedgene expression
在线阅读 下载PDF
Rare Earths and Magnetic Refrigeration 被引量:20
6
作者 Karl A Gschneidner Vitalij K Pecharsky 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第6期641-647,共7页
Magnetic refrigeration is a revolutionary, efficient, environmentally friendly cooling technology, which is on the threshold of commercialization. The magnetic rare earth materials are utilized as the magnetic refrige... Magnetic refrigeration is a revolutionary, efficient, environmentally friendly cooling technology, which is on the threshold of commercialization. The magnetic rare earth materials are utilized as the magnetic refrigerants in most cooling devices, and for many cooling application the Nd2Fe14B permanent magnets are employed as the source of the magnetic field. The status of the near room temperature magnetic cooling was reviewed. 展开更多
关键词 magnetic refrigeration magnetocaloric effect GADOLINIUM Gd5 Si1- x Gex 4 La Fe 13 - x Six Hy Nd2 Fe14 B permanent magnets active magnetic regenerator cycle rare earths
在线阅读 下载PDF
Effects of arotinoid acid on induction of apoptosis and differentiation and telomerase activity and cell cycle in the HL 60 cell line
7
作者 刘小珊 娄陵生 +7 位作者 蒋纪恺 曾淑蓉 唐宗山 张彦 许湘儒 刘北忠 何渝军 康格非 《Chinese Medical Journal》 SCIE CAS CSCD 2000年第2期47-47,共1页
Objective To investigate the effects of arotinoid acid (Ro13 7410) on the morphological and functional alterations of leukemia HL 60 cell line and compared with those of RA Methods Differentiation of HL 60 ce... Objective To investigate the effects of arotinoid acid (Ro13 7410) on the morphological and functional alterations of leukemia HL 60 cell line and compared with those of RA Methods Differentiation of HL 60 cells was assessed by morphology and by NBT reduction Trypan blue exclusion was used to determine viability Apoptosis was assessed by changes in cell morphology and by measurement of fragmented DNA using the PCD assay kit Telomerase PCR ELISA kit tested telomerase activity The cell cycle was analyzed by flow cytometry Results Incubation of the HL 60 cells with 10 -6 10 -8 ?mol/L Ro13 7410 resulted in suppression of cell growth Apoptotic cells were detected following exposure to 10 -6 ?mol/LRo13 7410 for 3 hours by measurement of the “in situ” enzymatic labeling of DNA breaks with biotinylated dUTP Ultrastructural examination of Ro13 7410 treated samples showed cells with chromatin compaction and cytoplasm condensation and the presence of “apoptotic bodies” Cells induced into apoptosis were accompanied by Department of Hematology, the First Affiliated Hospital, Chongqing University of Medical Sciences, Chongqing 400016, China (Liu XS, Lou LS, Zeng SR and Tang ZH) Department of Clinical Biochemistry, Chongqing University of Medical Sciences, Chongqing 400046, China (Jiang JK, Zhang Y, Xu XG, Liu BZ, He YJ and Kang GF) increase of intracellular free Ca 2+ Percentage of HL 60 cells reduced NBT following incubation with Ro13 7410 was lower than with all trans retinoic acid (RA) (27% vas 85%) Telomerase PCR ELISA assay showed that HL 60 cells cultured in the absence of inducing agents had significant telomerase activity Telomerase activity declined gradually after 10 -6 ?mol/L Ro13 7410 treatment, and changes becoming evident at 1 day The inhibition of telomerase activity at day 5 of treatment with Ro13 7410 was less effective than with RA DNA flow cytofluorimetric analysis revealed that Ro13 7410 caused partial cell arrest in the G 2/M phase after a 2 day treatment and the percentage of cells arrested in the G 2/M phase increased after 4 days treatment With RA treated cells, a reduction in the percentage of cells in the G 2/M phase was observed after 2 day of treatment Conclusion Our study shows that Ro13 7410 suppresses HL 60 cells growth mainly via the induction of apoptosis and is less effective than RA in induction differentiation Ro13 7410 dramatically inhibits telomerase activity during the course of induction and results in G 2/M arrest within 2 days These findings suggest that Ro13 7410 is worthy of further study for its effects on leukemic cells 展开更多
关键词 cell line and telomerase activity and cell cycle in the HL Effects of arotinoid acid on induction of apoptosis and differentiation
原文传递
Drosophila melanogaster as a model system of aluminum toxicity and aging 被引量:2
8
作者 Ewelina Kijak Ezio Rosato +1 位作者 Katarzyna Knapczyk Elzbieta Pyza 《Insect Science》 SCIE CAS CSCD 2014年第2期189-202,共14页
The aim of this study was to investigate the toxic effects of aluminum (A1) on the model organism-Drosophila melanogaster. The study is especially concerned with the effects of aluminum on the fruit fly's developme... The aim of this study was to investigate the toxic effects of aluminum (A1) on the model organism-Drosophila melanogaster. The study is especially concerned with the effects of aluminum on the fruit fly's development, life span, and circadian rhythm in rest and activity. Flies were exposed to aluminum in concentrations from 40 to 280 mg/kg in rearing media or the flies were raised on control medium. Moreover, the life span of insects exposed to aluminum containing 40, 120, or 240 mg/kg of A1 in the medium, only during their larval development, during the whole life cycle and only in their adult life was tested. To check if aluminum and aging cause changes in D. melanogaster behavior, the locomotor activity of flies at different ages was recorded. Results showed that aluminum is toxic in concentrations above 160 mg/kg in the rearing medium. Depending on A1 concentration and time of exposure, the life span of the flies was shortened. At intermediate concentrations (120 mg/kg), however, A1 had a stimulating effect on males increasing their life span and level of locomotor activity. At higher concentration the aluminum exposure increased or decreased the level of locomotor activity ofD. melanogaster depending on age of flies. In addition, in the oldest insects reared on aluminum supplemented media and in mid-aged flies reared on the highest concentration of A1 the daily rhythm of activity was disrupted. 展开更多
关键词 circadian rhythms DEVELOPMENT life-span locomotor activity rest/activity cycle SURVIVAL
原文传递
A Powerful Simulation Language for Large and Complex Models
9
作者 LIN Jian The Management School, Beijing University of Aeronautics & Astronautics Beijing, 100083, China 《Systems Science and Systems Engineering》 CSCD 1998年第2期106-114,共9页
To tackle large and complex problems, a modern simulation modeling system must posses six characteristics: simplicity, user extensibility, object orientation, flexibility, capability, and initialization. Simplicity al... To tackle large and complex problems, a modern simulation modeling system must posses six characteristics: simplicity, user extensibility, object orientation, flexibility, capability, and initialization. Simplicity allows those users who are nonprofessionals in simulation modeling to use the system to build their models. User extensibility is a self perfection mechanism by which the user is able to extend the abilities of the system for large and complex problems. Object oriented methodology is a natural way of simulation modeling. Flexibility can increase the range to which the system can be applied. Powerful systems satisfy demand for ever growing complicated problems. Efficient facilities for the initialization of a model reduces the pain of initializing complicated models. The GPMS language owns each of these features. It is an English like user extensible simulation language, providing simplicity for less experienced users and allowing new data types to be defined to increase its ability. It gives the user a choice between object oriented and function oriented modeling style. Its flexibility in building models prevents the user from obeying strict rules. Its powerful constructs allow the user to describe arbitrarily complicated models. Intelligent model initialization reduces the user’s effort greatly. 展开更多
关键词 simulation language simulation modeling user extensibility object orientation GPMS activity cycle diagram the Three Phase Approach
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部