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871.
Wu Tonghua Qin Yanhui Wu Xiaodong Li Ren Zou Defu Xie Changwei 《Theoretical and Applied Climatology》2018,132(3-4):1187-1199
Theoretical and Applied Climatology - The spatial and temporal changes of the ground surface freezing indices (GFIs), ground surface thawing indices (GTIs), air freezing indices (AFIs), and air... 相似文献
872.
为探究青藏高原东南部大气中多环芳烃(Polycyclic Aromatic Hydrocarbons,简称PAHs)的污染、源及输送特征,利用鲁朗地区(29.77°N,94.73°E)总悬浮颗粒物(Total Suspended Particles,简称TSP)和大气中的14种PAHs含量,结合同期气象环境数据进行了综合分析。结果表明,该地区TSP中PAHs和气相的PAHs质量浓度变化范围分别为0.22~5.05 ng m-3和0.83~63.75 ng m-3,平均值分别为2.13 ng m-3和11.33 ng m-3。薪柴和柴油的燃烧是污染的主要方式,汽油燃烧等其他排放为次要方式。PAHs来自本地污染和远距离传输(Long Range Transmission,简称LRT)共同的影响。本地污染在四季各个源地均不相同。冬春季本地污染大,源在东南及正南方,夏秋季受本地和外来输送共同作用,本地源在东南方且占比小,LRT占比大。LRT受西北气流、西风气流和西南气流三支气流影响,污染严重时西南气流占主导... 相似文献
873.
Qin Huan Guo Qingqing Liu Chenchen Li Fenglan Zhang Hua Chu Zihan Wang Jiangxin Lei Anping 《中国海洋湖沼学报》2020,38(6):1858-1866
Journal of Oceanology and Limnology - Euglena gracilis is a unicellular green eukaryotic microalga that features characteristics of both plants and animals. The photosynthetic function of its... 相似文献
874.
Huan-Xin Weng Yang-Ming Zhu Ya-Chao Qin Jian-Yu Chen Xun-Hong Chen 《Journal of Asian Earth Sciences》2008,31(4-6):522-532
Heavy metal and organic pollutants in sediments along the coastal zone of southeastern China have been investigated. Sediment samples are retrieved from three depositional environments: coast, estuary, and tide-affected river mouth. The relative abundance of heavy metal and organic pollutants is related to their geochemical properties as well as depositional environments and anthropogenic discharge. Based on a sequential extraction method, it is revealed that anthropogenic Pb, Cr, Cu, and Cd are mainly bound to Fe–Mn oxides, suggesting that adsorption and co-precipitation of Fe–Mn oxides are in the control of their transfer processes from water column to sediment. Heavy metal bound to carbonates is also an important pool especially for Cd, Mn, and Pb. The main organic pollutants found in the study area include petroleum-related alkanes, phthalic acid ester, organic silicon, chlorophenol, phenyl ether, and amine. The accumulation of heavy metals and organics in surficial sediments has a decrease tendency from estuarine environment to coastal environment and to tide-affected river mouth. 相似文献
875.
Wenfeng Wang Yong Qin Shuxun Sang Yanming Zhu Chaoyong Wang Dominik J. Weiss 《International Journal of Coal Geology》2008,76(4):309-317
Twenty-six samples including roof, bottom and coal plies of a marine influenced coal bed were collected from the Antaibao mining district, Shanxi, China. The rare earth elements (REEs) were determined in solids and organic solvent extracts. The distribution pattern showed three distinct patterns: shale-like, LREE-rich and HREE-rich. This is attributed to the variable microenvironment of peat-forming swamp, the degree of marine influences and different REE sources. REEs in the coal are mainly controlled by detrital minerals but also affected by seawater. The chondrite-normalized REE patterns of the organic solvent extracts are distinctly different from those of corresponding original coal samples, which show a negative Eu anomaly, a depletion of middle REEs and an enrichment of HREEs. The LREEs in coal extracts are likely adsorbed by hydrogen-containing functional groups, and HREEs are likely bonded to carbon atoms. 相似文献
876.
采用十六烷基三甲基溴化铵(HDTMAB)对蛭石精矿进行了有机改性,利用X射线衍射法(XRD)、红外光谱(IR)、差示扫描量热法(DSC)和热失重分析(TG)对蛭石精矿和有机改性蛭石进行了表征。实验结果表明,当反应液中蛭石与水的质量比为1∶10、反应温度在60~70℃时,HDTMAB的阳离子HDTMA进入绝大部分蛭石晶粒的晶层,将蛭石的晶层间距撑大,蛭石的(001)晶面间距d001从1.45986 nm增大到3.70134 nm。HDTMA进入了单晶颗粒之间,将蛭石颗粒分散成单晶颗粒。 相似文献
877.
878.
Comparative proteome analysis of butachlor-degrading bacteria 总被引:1,自引:0,他引:1
A Pseudomonas putida strain, named ER1, was isolated from an agricultural soil and found to actively degrade the herbicide butachlor. The enzyme
extracted from ER1 could degrade butachlor. Furthermore, incubation of ER1 in a medium containing 50 mg/kg of butachlor after
3 days resulted in the high butachlor-degrading enzyme activity of ER1. Response of ER1 to butachlor might be related to changes
in protein composition at both quantitative and qualitative levels. Total proteins were extracted from control strain (incubated
in the medium without butachlor) and the treated strain (incubated in the medium with butachlor). The proteins were separated
by two-dimensional gel electrophoresis. Of the total number of ER1 protein, 11 spots were significantly changed under butachlor
stress. Analysis by matrix-assisted laser desorption/ionization mass spectrometry and tandem mass spectrometry coupled with
database searching allowed the function of some proteins which were similar to the hydrolases activity or oxidoreductase activity. 相似文献
879.
Variations in the abundance of iron in the mantle may have important consequences for mantle dynamics and geochemistry. The abundance of iron in lavas derived from mantle source regions varies during partial melting and subsequent fractionation, so that source heterogeneities are not easily resolved in iron abundances alone. However, manganese is a geochemically similar element, so that the planetary Fe/Mn ratio is approximately constant. Here, we report new Fe/Mn results for mid-oceanic ridge basalts (MORBs), oceanic island basalts (OIBs) and komatiites using a precise inductively coupled plasma mass spectrometric (ICP-MS) method to measure Fe/Mn to better than 0.5% (2σ). As a measure of reproducibility of Fe/Mn, five olivine and five orthopyroxene grains from a Kilbourne Hole peridotite xenolith yielded Fe/Mn 69.8 ± 0.4 and 44.3 ± 0.2, respectively. To avoid ubiquitous secondary Fe-Mn oxides, Fe/Mn ratios in Pacific, Atlantic, and Indian MORBs were determined by Laser Ablation ICP-MS. MORB Fe/Mn (53-56) corrected for crystal fractionation yielded a value of 54.0 ± 1.2 (1σ). Icelandic basalts and picrites (MgO 10-29%) had Fe/Mn ratios 56-61, with a single exception. Six relatively fresh komatiites from Belingwe (MgO 20-29%) yielded Fe/Mn values of 58.3 ± 0.2 (1σ). Basalts from Tahiti and Reunion exhibited high Fe/Mn (>65), like Hawaii. This implies that the mantle source regions of Tahiti and Reunion lavas may have been enriched in Fe relative to other mantle reservoirs (e.g., MORBs, Iceland, Belingwe). Combined with previous results for Hawaii, we now find that Fe/Mn > 65 is characteristic of at least two plumes from the Pacific Superswell. It is conceivable that this is evidence for excess Fe due to core-mantle interaction in these mantle plumes, although partial melting of secondary pyroxenites may cause similar variations in Fe/Mn. Heterogeneity of Fe/Mn in mantle-derived lavas is now clearly documented. 相似文献
880.
研究伪距定位中衰减记忆无迹卡尔曼滤波(MAUKF)方法,针对衰减记忆UKF滤波器可能因衰减因子引入造成滤波精度降低、滤波收敛速度并没有得到改善的问题,本文依据预测残差的统计量,对衰减记忆UKF滤波算法进行了改进。仿真结果表明,该算法相比衰减记忆UKF算法提高了定位精度和收敛速度。 相似文献