检索结果-南通市图书馆

A precise monitoring of snow surface height in the region of Lambert Glacier basin-Amery Ice Shelf,East antarctica

Science China Earth Sciences 2005年第1期48卷 100-111页

作者： I.Allison australian antarctic division and antarctic Climate and Ecosystems crc

The net surface snow accumulation on the antarctic ice sheet is determined by a combination of precipitation, sublimation and wind redistribution. We present a one-year record of hourly snow-height measurements at LGB69 (70°50'S, 77°04'E, 1850 m a.s.l.). east side of Lambert Glacier basin (LGB), and 4 year record at G3 (70°53'S, 69°52'E, 84 m a.s.l.), Amery Ice Shelf (AIS). The measurements were made with ultrasonic sensors mounted on automatic weather stations installed at two sites. The snow accumulation at LGB69 is approximately 70 cm. Throughout the winter, between April and September, there was little change in surface snow height (SSH) at the two sites. The negative SSH change is due to densification at LGB69, and is due to both ablation and densification at G3. The strongest accumulation at two sites occurred during the period between October and March (accounting for 101.6% at LGB69), with four episodic increasing events occurring during 2002 for LGB69, and eight events during 1999-2002 for G3 (2 to 3 events per year). At LGB69, these episodic events coincided with obvious humidity 'pulses' and decreases of incoming solar radiation as recorded by the AWS. Observations of the total cloud amount at Davis station, 160 km NNE of LGB69, showed good correlation with major accumulation events recorded at LGB69. There was an obvious anti-correlation between the lowest cloud height at Davis and the daily accumulation rate at LGB69. Although there was no correlation over the total year between wind speed and accumulation at LGB69, large individual accumulation events are associated with episodes of strong wind (>7 m/s), we estimate drift snow may contribute to total SSH up to 35%. Strong accumulation events at LGB69 are associated with major storms in the region and inland transport of moist air masses from the coast.

关键词： antarctica, Lambert Glacier basin, Amery Ice Shelf, accumulation, katabatic wind.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The seasonal variations of δ^(18)O , Cl^- , Na^+ ,NO_3^- and Ca^(2+) in the snow and firn recovered from Princess Elizabeth Land, antarctica

引用

Chinese Science Bulletin 1999年第24期44卷 2270-2273页

作者： LI Zhongqin, ZHANG Mingjun, QIN Dahe, XIAO Cunde, TIAN Lide KANG Jiancheng and LI Jun Lanzhou Institute of Glaciology and Geocryology , Chinese Academy of Sciences , Lanzhou 730000, China Chinese Institute of Polar Research, Shanghai 200129, China antarctic crc and australian antarctic division , Hobart, Australia Corresponding author Lanzhou Institute of Glaciology and Geocryology Chinese Academy of Sciences Lanzhou China Chinese Institute of Polar Research Shanghai China antarctic crc and australian antarctic division Hobart Australia

Snow and firn samples recovered from two snow pits (2.5 and 4.5m deep) and one 50-m firn core along the route of the 1996/1997 Chinese First antarctic Inland Traverse Expedition in Princess Elizabeth Land, East antarctica, have been measured for chemical composition and oxygen isotope ratio. In the two snow pits, the variations of NO3- are partly in phase with that of δ18O, while the variations of Cl- and Na+ are in inverse phase with that of δ18O.

关键词： Princess Elizabeth Land ion δ18O seasonal variations.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Preliminary evidence indicating Dome A (antarctica) satisfying preconditions for drilling the oldest ice core

引用

Chinese Science Bulletin 2008年第1期53卷 102-106页

作者： XIAO CunDe LI YuanSheng HOU ShuGui lan ALLISON BIAN LinGen REN JiaWen State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research institute Chinese Academy of Sciences Lanzhou 730000 China Chinese Academy of Meteorological Sciences Beijing 100081 China Polar Research Institute of China Shanghai 200129 China australian antarctic division and antarctic Climate and Ecosystems crc Tasmania 7001 Australia

Lowest temperature and snow accumulation rate are preconditions for retrieving the oldest ice core from the polar ice sheets. The 10-m depth firn temperature at Dome A, the summit of the antarctic Ice Sheet, recorded by an automatic weather station (AWS) was -58.3℃ in 2005 and -58.2℃ in 2006, re-spectively. The 10-m firn temperature is an approximation of the annual mean air temperature (AMAT), and this is the lowest AMAT that has been recorded on the surface of the Earth. The stable isotopic ratios (δ 18O and δ D) of surface snow at Dome A are also lower than at other ice sheet domes along the East antarctic Ice Divide such as Dome C, Dome F, Dome B and Vostok. These facts indicate that Dome A is the "pole of cold" on the Earth. The total amount of snow accumulation rate in 2005 and 2006 was only 0.16 cm, equaling 0.016 m water equivalent per year, the lowest precipitation ever recorded from antarctica. Preliminary evidences indicate that Dome A is a candidate site for recovering the oldest ice core.

关键词：南极冰层温度雪堆积 MPT

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Seasonal variations of the near surfacelayer parameters over the antarctic ice sheet in Princess Elizabeth Land,East antarctica

引用

Chinese Journal of Polar Science 2007年第2期18卷 122-134页

作者：谌志刚卞林根效存德陆龙骅 Ian Allison Chinese Academy of Meteorological Sciences australian Arctic division and antarctic CRCHobartTasmania7001Australia

Analysis of sensible heat flux （ Qh ）, latent heat flux （ Qe ）, Richardson number （Ri） ,bulk transport coefficient （Cd） and katabatic windsare presented by using the meteorological data in the near surface layer from an automatic weather station （AWS） in Princess Elizabeth Land, East antarctica ice sheet and the data of corresponding period at Zhongshan station in 2002. It shows that annual mean air temperature at LGB69 is -25.6℃, which is 16.4℃ lower than that at Zhongshan, where the elevation is lower and located on the coast. The temperature lapse rate is about 1.0℃/110 m for the initial from coast to inland. The turbulence heat flux at LGB69 displays obvious seasonal variations with the average sensible heat flux -17.9 W/m^2 and latent heat flux -0.9 W/m^2. The intensity （Qh ＋ Qe ） of coolling source is - 18.8 W/m^2 meaning the snow surface layer obtains heat from atmosphere. The near surface atmosphere is near-neutral stratified with bulk transport coefficients （Cd） around 2.8 ×10^-3 ,and it is near constant when the wind speed higher than 8 m/s. The speed and the frequency of easterly Katabatic winds at LGB69 were higher than that at Zhongshan Station.

关键词： eastern antarctic ice sheet turbulent flux katabatic wind seasonal variation.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

东南极Princess Elizabeth冰盖近地层大气参数的年变化特征

引用

海洋学报 2006年第1期28卷 35-41页

作者：谌志刚卞林根效存德陆龙骅 IAN Allison 中国气象科学研究院北京100081 australian antarctic division and antarctic crc HobartTasmania7001Australia

利用2002年东南极Princess Elizabeth冰盖自动气象梯度观测点获得的近地层气象资料,分析了冰盖上的感热通量、潜热通量、大气稳定度、整体输送系数及有关气象要素特征,并与中山站同期的的气象要素进行了对比分析.结果表明,由于两站的海... 详细信息

利用2002年东南极Princess Elizabeth冰盖自动气象梯度观测点获得的近地层气象资料,分析了冰盖上的感热通量、潜热通量、大气稳定度、整体输送系数及有关气象要素特征,并与中山站同期的的气象要素进行了对比分析.结果表明,由于两站的海拔高度及地理位置的差异,LGB69站的年平均气温为-25.6℃,比中山站低16.4℃,进入内陆每10 km,海拔高度上升约110 m,温度下降约1℃.南极内陆冰盖的湍流热通量具有明显的年变化,感热通量年平均值为-17.9 W/m2,潜热通量为-0.9 W/m2,年平均冷源强度(Qh+Qe)为-18.8 W/m2,表明地表从大气吸收热量.LGB69站近地层大气以近中性层结为主,中性层结下的整体输送系数为2.6×10-3,当风速大于8 m/s后,整体输送系数趋于常数.LGB69站是南极地区典型下降风区,年平均风速比中山站大2.0 m/s,其下降风出现的风向频和风速均大于中山站.

关键词：东南极冰盖湍流通量下降风季节变化

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Long-Term Effect of Photoperiod, Temperature and Feeding Regimes on the Respiration Rates of antarctic Krill (<i>Euphausia superba</i>)

引用

Open Journal of Marine Science 2013年第2期3卷 40-51页

作者： Matthew Brown So Kawaguchi Steven Candy Toshihiro Yoshida Patti Virtue Steve Nicol australian antarctic division Kingston Australia australian antarctic division Kingston Australia antarctic Climate and Ecosystems Cooperative Research Centre Hobart Australia Institute for antarctic and Marine Studies University of Tasmania Hobart Australia Institute of antarctic and Southern Ocean Studies University of Tasmania Hobart Australia Institute of antarctic and Southern Ocean Studies University of Tasmania Hobart Australia australian antarctic division Kingston Australia antarctic Climate and Ecosystems Cooperative Research Centre Hobart Australia

antarctic krill is thought to undergo an annual cycle of biological processes to cope with seasonal changes in their environment. The question of whether, and to what degree, seasonal environmental parameters such as photoperiod, food availability and temperature govern metabolism in krill is not clear. In this long-term laboratory study, respiration rates were determined in krill incubated under simulated natural light cycle or total darkness, subjected to fed or starved conditions and on krill kept at different temperatures (-1°C, 1°C and 3°C). There was a strong and significant increasing trend of respiration rates with month in all experimental treatments. In August (late winter), the mean respiration rates ranged between 0.22 - 0.35 μL O2 ***-1 for krill in both simulated seasonal light and complete darkness, and 0.25 - 0.26 μL O2 ***-1 for both fed and starved krill. Mean maximal respiration rates were recorded in October and December for all light and feeding treatments (0.46 - 0.56 μL O2 ***-1). Mean respiration rates for krill in the temperature treatments ranged between 0.24 - 0.30 μL O2 ***-1 in September reaching mean maximal rates in November and February (0.60 - 0.71 μL O2 ***-1). The covariate total length of krill was found to be non-significant and there was generally no significant interaction of experimental treatment with month and only for photoperiod comparison was the treatment main effect significant. The dark treatment gave higher respiration rates, and this needs careful interpretation. Results here suggest that, although light, food availability and temperature significantly affect metabolic rates,

关键词： antarctic Krill Aquarium Maturity Endogenous Rhythm Overwintering Strategy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Development and Operational Testing of an Underwater Bait Setting System to Prevent the Mortality of Albatrosses and Petrels in Pelagic Longline Fisheries

引用

Open Journal of Marine Science 2015年第1期5卷 1-12页

作者： Graham Robertson Phillip Ashworth Peter Ashworth Ian Carlyle Steven G. Candy australian antarctic division Kingston Australia Amerro Engineering Warana Australia

Longline fisheries for tunas and tuna-like species present an existential threat to many populations of albatrosses and petrels worldwide. To prevent this form of mortality we developed a new technology designed to deploy baited hooks underwater beyond the dive depths of?seabirds (6 - 10 m for the species most commonly caught). The underwater bait setter is a stern-mounted, hydraulically-operated and computer-controlled?device that catapults?baited hooks underwater in a steel capsule?connected to hydraulic winches by Spectra®rope. Baits are flushed from the capsule by water pressure through a spring-loaded bait release door. The chief engineering challenges in the developmental stageswere ensuring:?1) bait delivery?to target depths with cycle times (time from release to recovery) that were practical for fishing operations;?2) bait retention in the capsule (no drop-outs) on the descent phase of the cycle;?3) baits, upon?release at target depth, were not drawn up the water column on the capsule recovery phase (from possible hook-ups and/or suction);and?4) the retention of baits?on?hooks post-release from the capsule was not affected by the mechanical release underwater. Operational trials with the final version of the capsule yielded?satisfactory cycle times to depths of 6 - 10 m. All baits were retained?in the capsule on the descent and?released as required?at target depths (n = 606 deployments). Bait retention on hooks post release from the capsule and retention on hooks hand-set at the surface (the conventional method) were statistically indistinguishable.?The underwater bait setter is modular in construction and can be fitted to all types of vessel sterns.

关键词： Seabird Bycatch Longline Fisheries Underwater Setting Marine Engineering Innovation Co-Operative Research

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Serum ferritin and the risk of early-onset colorectal cancer

引用

World Journal of Gastrointestinal Oncology 2024年第8期16卷 3496-3506页

作者： Adam L Urback Kylee Martens Hannah Stowe McMurry Emerson Y Chen Caitlin Citti Anil Sharma Adel Kardosh Joseph J Shatzel division of Internal Medicine Oregon Health&Science UniversityPortlandOR 97239United States division of Hematology and Medical Oncology Knight Cancer InstituteOregon Health&Science UniversityPortlandOR 97239United States division of Gastroenterology&Hepatology Oregon Health&Science UniversityPortlandOR 97239United States

BACKGROUND The incidence of early-onset colorectal cancer(EO-crc)is rising in the United States,and is often diagnosed at advanced *** serum ferritin is often incidentally discovered in young adults,however,the indication for endoscopy in EO-crc is *** To compare serum ferritin between patients with EO-crc and healthy controls(HCs),and examine the association of serum ferritin in EO-crc with patient-and disease-specific *** A retrospective study of patientscrc was conducted from 1/2013-12/*** were included if serum ferritin was measured within 2 years prior to 1 year following crc histologic *** supplement the analysis,a cohort of HCs meeting similar inclusion and exclusion criteria were identified for comparison.A sensitivity analysis including only patients with serum ferritin obtained at or before diagnosis was separately performed to minimize risk of *** Among 85 patients identified with EO-crc(48 females),the median serum ferritin level was 26 ng/mL(rangecrc with serum ferritincrc,particularly at earlier *** studies defining the optimal serum ferritin threshold and routine incorporation of serum ferritin in screening algorithms is essential to develop more effective screening strategies for EO-crc.

关键词： Early-onset Young-onset Colorectal cancer Age Ferritin Iron deficiency

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The study on the depositional styles of major ions and the climatic effect of nssSO_4^(2-)in Princess Elizabeth Land, antarctica

引用

Chinese Journal of Polar Science 2000年第2期11卷 107-112页

作者：张明军李忠勤秦大河效存德康建成李军 Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of SciencesLanzhou 730000 China Polar Research Institute of China Shanghai 200129 China antarctic crc and australian antarctic division Hobart 7001 Australia

Snow samples collected from a 50 m firn core and two snow pits along the route of the 1996/1997 Chinese First antarctic Inland Traverse Expedition in Princess Elizabeth Land, East antarctica, have been analyzed for chemical composition and oxygen isotope ratio. Analyzing the relationship between the concentration and flux of major ions and accumulation rate can draw the following conclusions. 1) The concentrations of major ions in the atmosphere in the study region is big enough so that the concentrations of the ions do not vary with snow accumulation rate, that is to say, the concentrations of major chemical species are independent of snow accumulation rate. 2) The results of analyzing the depositional styles of major chemical species suggest that wet deposition dominates the major ions flux. In addition, there is no apparent correlation between nssSO 2- 4 fluctuations and isotope profile. This would indicate the short-term climatic effect of volcanism is not evident in the region.

关键词： ion dry deposition wet deposition volcanic.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

东南极洲冰盖表层雪的地球化学特征和分带

引用

科学通报 2004年第17期49卷 1755-1761页

作者：康建成刘雷保秦大河汪大立温家洪谭德军李忠勤李军张小伟中国极地研究中心中国科学院寒区旱区环境与工程研究所 australian antarctic division and antarctic Climate and Ecosystems crc Tasmania7001Australia

依据在东南极洲冰盖采集的表层雪样品, 分析获得氢氧稳定同位素比值、可溶性杂质——阴阳离子含量、不可溶性杂质——微粒含量, 探讨东南极洲冰盖表层雪的地球化学特征. 目的是研究东南极洲冰盖表层雪的地球化学分区以及不同区域对应的... 详细信息

依据在东南极洲冰盖采集的表层雪样品, 分析获得氢氧稳定同位素比值、可溶性杂质——阴阳离子含量、不可溶性杂质——微粒含量, 探讨东南极洲冰盖表层雪的地球化学特征. 目的是研究东南极洲冰盖表层雪的地球化学分区以及不同区域对应的物质来源和水汽输运途径. 研究发现, 从冰盖边缘到内陆, 反映水汽来源的氢氧稳定同位素比率系数S1, d1 (d D = S1d 18O + d1) 的关系在海拔2000 m附近出现转折; 表层雪中Cl-/Na+的重量比值在海拔2000 m以下接近海盐中Cl-/Na+的重量比值, 2000 m以上则高于海盐中的比值达两倍; 非海盐性的Ca2+离子和细颗粒微粒含量在2000 m以上升高. 2000 m以下随海拔增高, 可溶-不可溶性杂质含量减少. 在海拔800 m以下的大陆冰盖沿岸区为高杂质含量区. 结合物质输运过程, 上述特征说明, 在东南极洲冰盖海拔2000 m以上是大尺度经向环流作用区, 物质来源于远源输运. 2000 m以下是中尺度高纬海洋和冰盖边缘带强气旋作用区, 输运的物质来源于高纬海区. 其中, 800 m以下是沿岸气旋作用区.

关键词：冰盖东南极物质来源表层地球化学特征气旋海盐比值含量可溶性

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：