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1.
Abstract

The new guanidine alkaloid Dendrobeaniamine A (1) was isolated from the organic extract of the Arctic marine bryozoan Dendrobeania murrayana. The chemical structure of 1 was elucidated by spectroscopic experiments, including 1D and 2D NMR and HRESIMS analysis. Compound 1 is a lipoamino acid, consisting of a C12 fatty acid anchored to the amino acid arginine. The bioactivity of 1 was evaluated using cellular and biochemical assays, but the compound did not show cytotoxic, antimicrobial, anti-inflammatory or antioxidant activities  相似文献   
2.
The brominated flame retardants hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) are high-production-volume chemicals. In recent years, their presence has been reported in sediment and biota from the marine environment. In this study, an analytical method was developed for the simultaneous determination of HBCD, TBBPA, and the possible metabolite dimethyl-TBBPA. The method was applied in a preliminary screening of egg, liver, and adipose tissue of marine biota from Greenland and the Faroe Islands. α-HBCD was detected in 35 of 36 analysed samples from the Arctic, indicating a ubiquitous presence of α-HBCD in the environment. β- and γ-HBCD were found in 10 and 14 samples, respectively. TBBPA and dimethyl-TBBPA were not detected in any of the samples indicating limited or no transport of these compounds to remote areas.  相似文献   
3.
《Analytical letters》2012,45(4):729-738
ABSTRACT

Soil samples collected in the following areas: Greenland, Svalbard and North Siberia have been analyzed. Seventeen micro and trace elements were determined by ICP-AES.  相似文献   
4.
Ground-based solar absorption infrared spectra were recorded in the Canadian Arctic during the early spring of 2004 using a moderate-resolution Fourier transform spectrometer, the Portable Atmospheric Research Interferometric Spectrometer for the Infrared (PARIS-IR). As part of the Canadian Arctic Atmospheric Chemistry Experiment (ACE) validation campaign, the PARIS-IR instrument recorded solar absorption spectra of the atmosphere from February to March 2004 as the Sun returned to the Arctic Stratospheric Ozone Observatory (AStrO) near Eureka, Nunavut, Canada (80.05°N, 86.42°W). In this paper, we briefly outline the PARIS-IR instrument configuration and data acquisition in the high Arctic. We discuss the retrieval methodology, characterization and error analysis associated with total and partial column retrievals. We compare the PARIS-IR measurements of N2O and O3 column amounts with those from the Fourier transform spectrometer (ACE-FTS) onboard the Canadian SCISAT-1 satellite and the ozonesonde data obtained at Eureka during the validation campaign.  相似文献   
5.
Natural products from endolichenic fungi, isolated from different lichen species, have been attracting much attention because of their potential to produce metabolites with activities and/or new structures. The filamentous fungus M227‐2 isolated from lichen in Ny‐Alesund Arctic showed significant anti‐microbial activity and was identified as Cochliobolus kusanoi based on 18S rDNA. Secondary metabolites of M227‐2 were investigated in order to exploit them as lead compounds for new antibiotics. Chemical investigation on M227‐2 led to the isolation of three phomalone derivatives (products 1 – 3) . Their structures were elucidated on the basis of their NMR and MS spectral data. Product 2 was new, whereas products 1 and 3 were isolated for the first time from the species. The biosynthetic pathway is also proposed.  相似文献   
6.
Seventeen classic organochlorine pesticides in surface seawater were studied in terms of their composition pattern as well as their distribution pattern in the areas covering the Japan Sea,Okhotsk Sea,Bering Sea,Chukchi Sea and Arctic Ocean.Their concentrations varied,but roughly two levels were seen with one ranging between 0.1 and 1 ng L-1 for most HCH isomers and the other lower than 0.1 ng L-1 for other chemicals.Of the 17 target compounds,HCHs were dominant with a total concentration percentage general...  相似文献   
7.
刘式达  付遵涛  刘式适 《物理学报》2014,63(21):214701-214701
本文利用球坐标系(λ,φ,r)中的球面地转风关系,说明当等压线形成最简单的纬向分布时,此时南极是低压,北极是高压. 但是,当在地转风关系中加入摩擦力后,则南北极由闭合涡旋变成螺旋涡旋,且两极之间形成一条球面上的三维异宿轨道. 关键词: 北极高压 南极低压 摩擦力 异宿轨道  相似文献   
8.
The fungus strain SCSIO 40433 was isolated from an Arctic-derived glacier sediment sample and characterized as Tolypocladium cylindrosporum. A new compound, cylindromicin (1), and seven known secondary metabolites (2–8) were isolated from this strain. The chemical structures of these compounds were elucidated by comprehensive spectroscopic analyses. Cylindromicin (1) featured a 3,4-dihydro-2H-pyran skeleton. The absolute configuration of compound 1 was assigned via interpretation of key Nuclear Overhauser Effect Spectroscopy (NOESY) correlations and Electronic Circular Dichroism (ECD) calculation. Cylindromicin (1) exhibited significant tyrosinase inhibition activity. This study highlights Polar fungi as a potential resource for new bioactive natural products.  相似文献   
9.
谭靖骞  曹宇  黄海宁  郭慧 《应用声学》2020,39(5):690-696
北极海域海洋环境噪声的特殊性在于具有偶发的尖脉冲声,为分析其特性与规律,首先建模仿真分析不同脉冲噪声下高斯分布与α稳定分布的拟合效果,验证后者的鲁棒性。再从实测北极海域噪声中选取三种典型环境噪声为样本,通过对其非高斯性判定及不同分布模型对比,验证α稳定分布在北极海域环境噪声统计特性建模中的有效性,同时研究不同深度、不同频段对模型参数的影响,最后通过各月参数的统计结果与海冰密集度分析冰下噪声成因。由于通道数量有限,没有给出所有深度的变化规律。结果表明,北极海域冰下环境噪声具有明显脉冲成分和非高斯性,利用α稳定分布能更好的描述其统计特性;100Hz可作为冰下环境噪声脉冲性干扰源的划分界限;结冰期环境噪声具有强烈的非高斯性,而冰封期则高斯性较强。  相似文献   
10.
Concentration levels, potential sources and bioavailability of trace elements in marine sediments from Kongsfjorden (Svalbard Islands, Norwegian Arctic) were assessed and discussed. Surface sediments were collected by a Ponar grab and characterised in terms of mineralogical composition, grain-size distribution, total organic carbon and nitrogen percentage contents, and major and trace elements concentrations. Anthropogenic and natural sources of trace elements were inferred from lead isotope ratios, while the potential metal bioavailability was evaluated by size-fractionation and solid-phase speciation studies and by the analysis of acid-volatile sulphides (AVS) and simultaneously extracted metals (SEM). Concentrations of metals, their enrichment factors and solid speciation patterns collectively indicated that the anthropogenic impact of trace elements in the fjord is generally low, with a minor enrichment with respect to crustal values (by a factor of 2–11) for As, Cr, Ni and V. The lead isotope ratios (208Pb/207Pb: 2.474–2.498 and 206Pb/207Pb: 1.206–1.212) were close to the natural signature except in the outer fjord, due to the influence of the Atlantic marine circulation. Many elements of toxicological concern (e.g. Pb, V, Zn) were enriched in the finest sediment fraction, which was by far the preponderant one, especially in the inner fjord. However, less than 15% of most trace elements (exceptions Cd and Mn) in the finest fraction was actually associated with easily leachable sediment phases. Finally, the high SEM/AVS ratios determined on samples from sites close to the glacier fronts (11–15), due to low AVS content, highlighted that the sediment in that zone cannot remove additional inputs of heavy metals by sulphide precipitation.  相似文献   
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