南极光学望远镜的氧化铟锡薄膜多相交流电除霜方法

在极地环境(如南极Dome A)中的光学系统,氧化铟锡(ITO)薄膜加热除霜有突出的优势。简述了ITO薄膜除霜原理,指出了目前采用的直流电、点状电极的加热设计存在局部过冷、电极过热、整体加热不均的情况,影响成像质量与除霜效果。给出了加热除霜效果的评估指标,提出了多相交流电、线状电极的新设计,并采用"主路径"分析法进行论证。然后以南极巡天望远镜(AST)为背景,对500 mm口径镜面进行有限元模拟,在等功率条件下,对各加热设计进行评估。使用红外热像仪测量实际镜面:采用新设计后,镜面温度均方差降低了81.65%,峰谷值降低了76.31%。实验结果表明:新设计大幅提高了加热除霜的均匀性和效率,改善了视宁度,有望应用于南极光学望远镜工程中。

摇曳生姿 南极光

夜空中的缤纷色彩。强烈的火焰之波，动人心魄的诱惑欢迎来到神奇的极光世界。

中国科学家破解极光之谜

在人烟稀少的地球极地,时常会有璀璨壮丽、千变万化的美丽光带滑过夜空。出现在北极的,人们称它为"北极光",出现在南极则被称为"南极光"。极光出极地,生活在低纬度区域的居民难以一睹它的芳容,这让极光愈显神秘。

彗星激起木星明亮的北极光

彗星激起木星明亮的北极光１９９４年７月，当苏梅克－利维９号彗星撞击木星时，木星的北极光变得异常明亮。由于碰撞更靠近木星南极，所以这颗巨大的行星搅起的极光，向行星学家们证实了一个秘密。像地球的极光一样，木星的极光也发生在两磁极周围的椭圆形区域。极光是由...

Emissions of Biogenic Sulfur Gases(H2S,COS)from Phragmites australis Coastal Marsh in the Yellow River Estuary of China

Emissions of biogenic sulfur gases(hydrogen sulfide(H_2S) and carbonyl sulfide(COS)) from Phragmites australis coastal marsh in the Yellow River estuary of China were determined during April to December in 2014 using static chamber-gas chromatography technique with monthly sampling. The results showed that the fluxes of H_2S and COS both had distinct seasonal and diurnal variations. The H_2S fluxes ranged from 0.09 μg/(m^2·h) to 7.65 μg/(m^2·h), and the COS fluxes ranged from –1.10 μg/(m^2·h) to 3.32 μg/(m^2·h). The mean fluxes of H_2S and COS from the P. australis coastal marsh were 2.28 μg/(m^2·h), and 1.05 μg/(m^2·h), respectively. The P. australis coastal marsh was the emission source of both H_2S and COS over the whole year. Fluxes of H_2S and COS were both higher in plant growing season than in the non-growing season. Temperature had a dramatic effect on the H_2S emission flux, while the correlations between COS flux and the environmental factors were not found during sampling periods. More in-depth and comprehensive research on other related factors, such as vegetation, sediment substrates, and tidal action is needed to discover and further understand the key factors and the release mechanism of sulfur gases.

极光 “磁索”让我如此美丽

极光这种宏伟壮观的自然景象,颇具神秘色彩。其运动变化,就好像是自然界这个魔术大师,以天空为舞台上演的一出光的话剧,上下纵横成百上千千米,甚至还存在近万千米长的极光带。

企鹅宝贝

在四季被冰雪覆盖的南极,成千上万只企鹅排着整齐的队伍向它们的理想之地前进。一天、两天、三天……它们终于到了。到达目的地后。

诗书画苑

翠袖琼楼八十翁,平安晓宇看孤鸿。五湖图里添彭祖,南极光中约祝融。日日春山醉春色,年年黄菊饱西风。鹰扬但愿无施处,臣老婆婆一钓蓬。

A CIB1-LIKE transcription factor GmC IL10 from soybean positively regulates plant flowering

CRYPTOCHROME-INTERACTING basic helix-loop-helix 1(CIB1) is a well characterized transcriptional factor which promotes flowering through the physical interaction with the blue light receptor CRYPTOCHROME 2(CRY2) in Arabidopsis. However, the role of its counterpart in crop species remains largely unknown. Here, we describe the isolation and characterization of a CIB1 homolog gene, Glycine max CIB1-LIKE10(GmC IL10), from soybean genome. The m RNA expression of GmC IL10 in the unifoliate leaves shows a diunal rhythm in both long day(LD) and short day(SD) photoperiod, but it only oscillates with a circadian rhythm when the soybean is grown under LDs, indicating that the clock regulation of GmC IL10 transcription is LD photoperiod-dependent. Moreover, its m RNA expression varies in different tissue or organs, influenced by the develpomental stage, implying that GmC IL10 may be involved in the regulation of multiple developmental processes. Similar to CIB1, Gm CIL10 was evident to be a nuclei protein and ectopically expression of GmC IL10 in transgenic Arabidopsis accelerates flowering under both LDs and SDs, implying that CIBs dependent regulation of flowering time is an evolutionarily conserved mechanism in different plant species.

Comparison of long-term total ozone observations from space-and ground-based methods at Zhongshan Station,Antarctica

Total ozone errors for satellite observations at Zhongshan Station in Antarctica are characterized using their relative difference （RD） from ground-based Brewer observations during 1993-2015. All satellite total ozone observations slightly overestimated ground-based ones （with RD less than 4%）. This is in contrast to conclusions drawn from global-scale validation studies, where main ground-based reference stations are located in middle latitudes. Given multiple total ozone data per day at Zhongshan Station, observed by a sun synchronous orbit satellite, measurements at the lowest solar zenith angle （SZA） show greatest consistency with Brewer ones, having an overall RD of-0.02-1.15%. Algorithm-retrieved total ozone data from the Total Ozone Mapping Spectrometer （TOMS）, including Solar Backscatter Ultra Violet （SBUV）, TOMS-Earth Probe （EP）, Ozone Monitoring Instrument （OMI）-TOMS, show best agreement with ground-based values; followed by the Global Ozone Measurement Experiment-type Direct Fitting （GOD-FIT） algorithm for the GOME-2A, and finally the Differential Optical Absorption Spectroscopy （DOAS） --Algorithm retrieved products for satellites-detectors of Global Ozone Measurement Experiment （GOME）, Scanning Imaging Absorption spectroMetr for Atmospheric CHartographY （SCIAMACHY）, and OMI. Satellite total ozone RD presents some statistical characteristics, but no specific trends. DOAS and GOME-2A algorithms have values that significantly increase, when the SZA is above 60°-70°, whereas values for GOME-2A decrease, when the SZA is 80-85°. Satellite total ozone RD is a minimum, when the Brewer total ozone is 300-350 DU, with an obvious increase in RD values for DOAS- and GOME-2A, when the Brewer total ozone is 150-300 DU. Satellite total ozone RD obviously increases, as the time difference between satellite overpasses and Brewer measurements grows. Specifically, RD rises as the absolute time difference increases to more than 4 h, yielding an OMI-TOMS RD of more than 10% as this difference increases to 8 h. The DOAS- RD may be up to 15%, while GOME-2A RD does not exceed 10%. The satellite total ozone RD may reach -5%, as the distance between the satellite overpass pixel and the station become more than 100 km. Possibly because of the discrepancy in surface albedo, the TOMS-algorithm retrieved total ozone produced underestimation, when the pixel on the south-east side of the station （the Antarctica continent） is used, but overestimation on the north-west side of the station （the Indian Ocean）. Consistency between space and ground-based total ozone data is least for the ＂ozone hole＂. Typically, the RD of TOMS-algorittun retrieved total ozone is within 1%/10 yr. Thus, the SBUV and Brewer monthly averaged total ozone anomalies from 1996 to 2015 were 1%/10 yr and 0.9%/10 yr, respectively. Both indicate slight, but consistent, ozone layer recovery.

Surface velocity estimations of ice shelves in the northern Antarctic Peninsula derived from MODIS data

The ice shelves in the northern Antarctic Peninsula are highly sensitive to variations of temperature and have therefore served as indicators of global warming. In this study,we estimate the velocities of the ice shelves in the northern Antarctic Peninsula using co-registration of optically sensed images and correlation module(COSI-Corr) in the Environment for Visualizing Images(ENVI) based on Moderate Resolution Imaging Spectroradiometer(MODIS) images during 2000–2012,from which we conclude that the ice flow directions generally match the peninsulas pattern and the crevasse,ice flows mainly eastward into the Weddell Sea. The spatial pattern of velocity field exhibits an increasing trend from the western grounding line to the maximum at the middle part of the ice shelf front on Larsen C with a velocity of approximately 700 ma–1,and the velocity field shows relatively higher values in its southerly neighboring ice shelf(e.g. Smith Inlet). Additionally,ice flows are relatively quicker in the outer part of the ice shelf than in the inner parts. Temporal changes in surface velocities show a continuous increase from 2000 to 2012. It is worth noting that,the acceleration rate during 2000–2009 is relatively higher than that during 2009–2012,while the ice movement on the southern Larsen C and Smith Inlet shows a deceleration from 2009 to 2012.

AntarcticaLC2000：The new Antarctic land cover database for the year 2000

Antarctica plays a key role in global energy balance and sea level change.It has been conventionally viewed as a whole ice body with high albedo in General Circulation Models or Regional Climate Models and the differences of land cover has usually been overlooked.Land cover in Antarctica is one of the most important drivers of changes in the Earth system.Detailed land cover information over the Antarctic region is necessary as spatial resolution improves in land process models.However,there is a lack of complete Antarctic land cover dataset derived from a consistent data source.To fill this data gap,we have produced a database named Antarctic Land Cover Database for the Year 2000(AntarcticaLC2000) using Landsat Enhanced Thematic Mapper Plus(ETM+) data acquired around 2000 and Moderate Resolution Imaging Spectrometer(MODIS) images acquired in the austral summer of 2003/2004 according to the criteria for the 1:100000-scale.Three land cover types were included in this map,separately,ice-free rocks,blue ice,and snow/firn.This classification legend was determined based on a review of the land cover systems in Antarctica(LCCSA) and an analysis of different land surface types and the potential of satellite data.Image classification was conducted through a combined usage of computer-aided and manual interpretation methods.A total of 4067 validation sample units were collected through visual interpretation in a stratified random sampling manner.An overall accuracy of 92.3%and the Kappa coefficient of 0.836 were achieved.Results show that the areas and percentages of ice-free rocks,blue ice,and snow/firn are 73268.81 km2(0.537%),225937.26 km2(1.656%),and 13345460.41 km2(97.807%),respectively.The comparisons with other different data proved a higher accuracy of our product and a more advantageous data quality.These indicate that AntarcticaLC2000,the new land cover dataset for Antarctica entirely derived from satellite data,is a reliable product for a broad spectrum of applications.