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961.
A new separation and preconcentration technique based on coprecipitation of Cu(II) and Ni(II) ions by the aid of Mo(VI)/di‐tert‐butyl{methylenebis[5‐(chlorobenzyl)‐4H‐1,2,4‐triazol‐3,4‐diyl]}biscarbamate (BUMECTAC) precipitate has been established. The Mo(VI)/BUMECTAC precipitate was dissolved by concentrated HNO3 and the solution was completed to 5.0 mL with distilled/deionized water. The levels of the analyte ions were determined by flame atomic absorption spectrometer. The effects of experimental conditions like HNO3 concentration, amount of BUMECTAC and Mo(VI), sample volume, etc. and also the influences of some foreign ions were investigated in detail on the quantitative recoveries of analyte ions. The preconcentration factors were found to be 40 for Cu(II) and 100 for Ni(II) ions. The detection limits for Cu(II) and Ni(II) ions based on 3σ (N:10) were 0.43 and 0.70 µg L?1, respectively. The relative standard deviations were found to be lower than 4.0% for both analyte ions. The accuracy of the method was checked by spiked/recovery tests and the analysis of two certified reference materials (Environment Canada TM‐25.3 and CRM‐SA‐C Sandy Soil C). The procedure was successfully applied to sea water and stream water as liquid samples and baby food as solid sample in order to determine the levels of Cu(II) and Ni(II) ions.  相似文献   
962.
Basement rocks that occur along the northern margin of the South Kitakami Terrane in Japan consist of Ordovician ultramafic rocks (Hayachine ultramafic complex), gneissose amphibolite (Kuromoriyama amphibolite), and mafic rocks (Kagura igneous rocks, KIR). The KIR are composed of metagabbro, metadolerite, metabasalt, and minor felsic–intermediate dikes. Although the KIR contain green hornblende due to metamorphism of greenschist to epidote–amphibolite facies, they rarely retain primary brown hornblende. Approximately 30% of the metabasalt shows porphyritic textures, with phenocrysts of saussuritized plagioclase and/or altered mafic minerals. The geochemistry of the common metadolerite and metabasalt of the KIR shows a tholeiite trend, a low TiO2 content, and high Th/Nb and Ti/V ratios. The KIR are therefore indicative of a supra‐subduction zone tectonic setting, which implies a backarc origin (as also indicated by discrimination diagrams). Trace element patterns of the KIR resemble those of the backarc‐basin basalt of the Japan and Yamato basins in the Japan Sea. We propose that the KIR formed during backarc spreading from the Ordovician to Early Silurian. This view is supported by the geochemical data, the tectonic setting of the Hayachine ultramafic rocks, and the provenance of clastics within Silurian sedimentary rocks.  相似文献   
963.
A 4.3 m‐long peat sequence from the shore of Lake Tiriara, Mangaia, Cook Islands, was analyzed using an ITRAX core scanner equipped with a magnetic susceptibility meter. Variations in the elemental profiles, providing insights into long‐ and short‐term environmental changes over the last 3500 years, are supported by grain size data and diatom assemblages. The scattering ratio (Mo Inc/Mo Coh) was evaluated and found to represent a good proxy for organic matter in peat. X‐Ray Fluorescence (XRF) data were processed by principal component analysis that confirmed the distinction of biogenic and detrital phases, organic matter and elements of marine origin. The record preserved in the peat sequence includes a peatland infilling stage followed by alternating drier and wetter periods. A notable steady increase in clay associated with high counts of detrital elements from 2000–1700 cal yr BP is attributed to increased erosion, which is most probably linked with human colonization and/or more intense chemical weathering linked with a wetter climate. Freshwater gastropods (Melanoides sp.), which were possibly introduced by humans, or are native, occupied the wetland during a period of lower water level about 1000–1100 cal yr BP. Short‐term changes in the elemental profiles are often linked with slight coarsening of the inorganic fraction that is, however, only revealed after grain size analysis. Peaks in marine indicators (Br, Cl, S, and/or Ca) associated with marine‐dominated diatom assemblages most probably represent marine incursions through the underground tunnel in the makatea, a fossilized, uplifted coral limestone rim. While none of the marine event units present characteristics typical of cyclone or tsunami deposits, the concurrent or absent peak of detrital elements (Fe, Si, Rb, Ti, K) attributed to increased erosion of the volcanic cone associated with a cyclone is used to distinguish both types of events, as also suggested by principal component analysis.  相似文献   
964.
Plutonic rocks in the southern Abukuma Mountains include gabbro and diorite, fine‐grained diorite, hornblende–biotite granodiorite (Ishikawa, Samegawa, main part of Miyamoto and Tabito, Kamikimita and Irishiken Plutons), biotite granodiorite (the main part of Hanawa Pluton and the Torisone Pluton), medium‐ to coarse‐grained biotite granodiorite and leucogranite, based on the lithologies and geological relations. Zircon U–Pb ages of gabbroic rocks are 112.4 ±1.0 Ma (hornblende gabbro, Miyamoto Pluton), 109.0 ±1.1 Ma (hornblende gabbro, the Hanawa Pluton), 102.7 ±0.8 Ma (gabbronorite, Tabito Pluton) and 101.0 ±0.6 Ma (fine‐grained diorite). As for the hornblende–biotite granodiorite, zircon U–Pb ages are 104.2 ±0.7 Ma (Ishikawa Pluton), 112.6 ±1.0 Ma (Tabito Pluton), 105.2 ±0.8 Ma (Kamikimita Pluton) and 105.3±0.8 Ma (Irishiken Pluton). Also for the medium‐ to fine‐grained biotite granodiorite, zircon U–Pb ages are 106.5±0.9 Ma (Miyamoto Pluton), 105.1 ±1.0 Ma (Hanawa Pluton) and the medium‐ to coarse‐grained biotite granodiorite has zircon U–Pb age of 104.5 ±0.8 Ma. In the case of the leucogranite, U–Pb age of zircon is 100.6 ±0.9 Ma. These data indicate that the intrusion ages of gabbroic rocks and surrounding granitic rocks ranges from 113 to 101 Ma. Furthermore, K–Ar ages of biotite and or hornblende in the same rock samples were dated. Accordingly, it is clear that these rocks cooled down rapidly to 300 °C (Ar blocking temperature of biotite for K–Ar system) after their intrusion. These chronological data suggest that the Abukuma plutonic rocks in the southern Abukuma Mountains region uplifted rapidly around 107 to 100 Ma after their intrusion.  相似文献   
965.
The new result of SHRIMP U–Pb zircon dating of the Kinshozan Quartz Diorite from the Kanto Mountains, Japan, provides 281.5 ± 1.8 Ma. The age is 30 m.y. older than the available age of the Kinshozan Quartz Diorite obtained by hornblende K–Ar method. The new U–Pb zircon age represents the time of crystallization of the Kinshozan Quartz Diorite. The hornblende K–Ar age indicates the time that the Kinshozan Quartz Diorite cooled down to 500 °C which is the closure temperature of the systematics. Permian granites are found in small exposures in Japan, and frequently referred to as 250 Ma granites. The Kinshozan Quartz Diorite is considered as a type of the 250 Ma granites, and the age was influential in establishing a model of Paleozoic tectonic evolution for the Japanese Islands. The new age of the Kinshozan Quartz Diorite provides the opportunity to re‐examine the model. The Kinshozan Quartz Diorite and other Permian granites in the south of the Median Tectonic Line of Japan were constituents of the Paleo‐Ryoke Belt. The geochemical characteristics of the granitic rocks in the Paleo‐Ryoke Belt indicated that the granitic rocks were formed in a primitive island arc environment, and the new trace element data also support this interpretation. Examination of the available data and results of the present study suggests the late Paleozoic granitic activity in Japan as follows. At about 310–290 Ma, arc magmatism generated adakitic granites and other granites in the South Kitakami Belt. Quartz diorite and tonalites of primitive characteristic, such as the Kinshozan Quartz Diorite and granites in the Maizuru Belt appear to have been formed at the immature island arc, and accreted to the Japanese Islands at the end of Paleozoic or early Mesozoic era. During 260–240 Ma, granitic activity took place in the Hida and Maizuru Belts as a part of the Asian continent.  相似文献   
966.
We describe the detailed sedimentary characteristics of a tsunami deposit associated with the 2011 Tohoku‐oki tsunami in Hasunuma, a site on the Kujukuri coastal plain, Japan. The thick tsunami deposit was limited to within 350 m from the coastline whereas the inundation area extended about 1 km from the coastline. The tsunami deposit was sampled by excavation at 29 locations along three transects and studied using peels, soft‐X imaging and grain‐size analysis. The deposit covers the pre‐existing soil and reached a maximum measured thickness of 35 cm. It consists mainly of well‐sorted medium to fine sand. On the basis of sedimentary structures and changes in grain size, we divided the tsunami deposit into several sedimentary units, which may correspond to multiple inundation flows. The numbers of units and their sedimentary features vary among the three transects, despite the similar topography. This variation implies a considerable influence of local effects such as elevation, vegetation, microtopography, and distance from footpaths, on the tsunami‐related sedimentation.  相似文献   
967.
碳约束下中国县域尺度农业全要素生产率比较研究   总被引:4,自引:1,他引:3  
揭懋汕  郭洁  陈罗烨  雪燕  薛领 《地理研究》2016,35(5):898-908
基于2183个县级单元,利用SFA方法对1992-2011年碳约束下中国县域农业生态TFP及其分解项进行研究,并与不考虑碳排放的传统TFP进行比较。结果表明:第一,农业生态TFP年平均增长4.47%,低于传统TFP,但两者差距有缩小的趋势,2011年前者超过后者。第二,农业生态TFP贡献了中国农业总产值增长的54.9%,比传统TFP的份额低了3.6%,要素投入贡献为45.1%。第三,分解项上,前沿技术进步率是农业生态TFP的主要驱动因素,也是生态TFP与传统TFP差距缩小的动因。第四,空间分布上,生态TFP大于传统TFP的地区主要分布在胡焕庸线东南的地区;西部由于生态TFP和传统FTP都较低,呈现出“双重恶化”现象;除了嵊泗县以外,农业生态TE和TEC均低于传统TE和TEC,生态FTP也整体低于传统FTP。  相似文献   
968.
Accompanying the rapid growth of China’s population and economy, energy consumption and carbon emission increased significantly from 1978 to 2012. China is now the largest energy consumer and CO2 emitter of the world, leading to much interest in researches on the nexus between energy consumption, carbon emissions and low-carbon economy. This article presents the domestic Chinese studies on this hotpot issue, and we obtain the following findings. First, most research fields involve geography, ecology and resource economics, and research contents contained some analysis of current situation, factors decomposition, predictive analysis and the introduction of methods and models. Second, there exists an inverted “U-shaped” curve connection between carbon emission, energy consumption and economic development. Energy consumption in China will be in a low-speed growth after 2035 and it is expected to peak between 6.19–12.13 billion TCE in 2050. China’s carbon emissions are expected to peak in 2035, or during 2020 to 2045, and the optimal range of carbon emissions is between 2.4–3.3 PgC/year (1 PgC=1 billion tons C) in 2050. Third, future research should be focused on global carbon trading, regional carbon flows, reforming the current energy structure, reducing energy consumption and innovating the low-carbon economic theory, as well as establishing a comprehensive theoretical system of energy consumption, carbon emissions and low-carbon economy.  相似文献   
969.
Kaya恒等式的碳排放驱动因素分解及其政策含义的局限性   总被引:2,自引:0,他引:2  
Kaya恒等式是目前分析碳排放驱动因素的主流分析方法,在解释全球历史排放变化原因方面具有重要的作用。Kaya恒等式具有数学形式简单、分解无残差、对碳排放变化推动因素解释力强等优点,但也存在一定的局限性:第一,Kaya恒等式只能解释碳排放量流量变化,无法解释存量变化;第二,Kaya恒等式中的驱动因素多为表象驱动因素,对排放总量的实际影响难以确定;第三,利用Kaya恒等式理论得出的政策建议具有模糊性和非理性,需要结合其他因素分析检验。  相似文献   
970.
YRY-4型钻孔应变仪观测的P波剪应变   总被引:2,自引:0,他引:2  
邱泽华  池顺良 《地震》2013,33(4):64-70
传统地震仪观测的是一个点的位移随时间的变化, 而应变仪观测的是位移的空间导数随时间的变化。 在四川姑咱台用YRY-4型四分量钻孔应变仪进行的每秒100次采样观测实验, 记录到三次地方震。 在这样高的采样率下, YRY-4型四分量应变仪观测数据保持了令人满意的自洽和足够高的信度。 观测表明, P波的应变不仅有面应变成分, 而且有剪应变成分。 这为澄清P波的性质, 给出了直接的观测证据。 根据弹性波理论, P波无旋转, 可以有体应变和剪应变成分。  相似文献   
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