|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | U-Th-Pb behavior of zircons under high-grade metamorphic conditions:A case study of zircon dating of meta-diorite near Qixia,eastern Shandong显示文摘This paper carried out a study on U—Th—Pb behavior of zircons in a'dry'rock system during high-grade metamorphism in the Archean basement of eastern Shandong.The studied sample has a mineral assemblage of plagioclase + K-feldspar + clinopyroxene + biotite + quartz and its protolith is considered to be diorite.The zircons are stubby,equant or irregular in shape and show fir-leaf, sectorial,banded or oscillatory zoning.They contain inclusions,including mineral assemblages of clinopyroxene + orthopyroxene + hornblende + quartz and plagioclase + K-feldspar + biotite + quartz. Fifty SHRIMP analyses were performed on 34 zircon grains,which commonly yielded high Th/U ratios (mostly>0.5).Most analyses are distributed along concordia from 2.54 to 2.25 Ga,with the youngest age being~1.95 Ga.Compositions and ages show large variations even in a same zircon grain.Combined with early studies,conclusions can be drawn as follows:1) the diorite underwent two episodes of high-grade metamorphism.at the end of the Neoarchean and the Paleoproterozoic(~2.50 Ga and~1.95 Ga or slightly later):2) high-grade metamorphism in a'dry'rock system may partially reset the U—Th—Pb system of zircons and.in this case,the ages between the oldest and youngest | Yusheng Wan Dunyi Liu Chunyan Dong Shoujie Liu Shijin Wang | 2011 | Geoscience Frontiers2011，2，2： | 27 |
| 2 | Dynamic evaluation of water resources carrying capacity of the Dianchi Lake Basin in 2005-2015,based on DSPERM framework model and simulated annealing-projection pursuit model显示文摘With the intensi fed impact of human activities,most lakes have been severely disturbed and the lake ecosystem has been seriously damaged,which exerted a great impact on the living envi-ronment of human beings in the lake basins.The health of the lake ecosystem has gradually become one of the hot issues in recent years.In this study,the water resources carrying capacity(WRCC)was used to reveal the chain rel ationship between human activities and water environ-ment in the economic dewelopment of the Dianchi Lake Basin in Kunming City of China during 2005-2015.Specifically,we chose 25 ewaluation indicators related to the water environment and socialeconomic activities,classified them into six subsystems,Le,the driwing force subsystem(D),the water resources si tuation and consumption subsystem(S),the water resources pressure subsystem(P),the water environmental situation subsystem(E),the response subsystem(R),and the management subsystem(M),and built a comprehensive assessment system-DSPERM frame-work model.Si mulated annealing-projection pursuit model which reflects the structure or feature of high-dimensional data was adopted to calculate the WRCC of the Dianchi Lake Basin during 2005-2015 by weighting each evaluation indicator and each subsystem of the DSPERM frame work model.The resuls show that the WRCC of the Dlanchi Lake Basin was in level II(medium carying capacity)from 2005 to 2012.Since 2013,the WRCC has been at level II(strong carying capacity),and from 2005 to 2015,it showed a gradual upward trend.The evaluation indicators of each subsystem varied greatly and exhibited different development trends.The indicators of the water resources pressure subsystem had the greatest impact on the WRCC,followed by the in-dicators of the water environmental si tuation subsystem and the water resources situation and consumption subsystem.We recommend that the DSPERM framework model and the simulated anneal ing-projection pursuit model constructed in this work can be used to analyze the dynamic changes of the WRCC over the years.They have the advantages of practicability and feasibilty,and can provide the basis for the scienti fic decision-making and comprehensive management of regional water environment planning. | Jiayang Wang Xiaoqin Mu Shouji Chen Wei Liu Zhuo Wang Zhanfeng Dong | 2021 | Regional Sustainability2021，2，2： | 1 |
| 3 | Eastern Ancient Terrane of the North China Craton显示文摘Based on the spatial distribution of ancient rocks and zircons, three ancient terranes older than ca. 2.6 Ga have recently been identified in the North China Craton, namely the Eastern, Southern, and Central Ancient Terranes. The Eastern Ancient Terrane is the best studied and understood of the three ancient terranes. It has a long geological history back to ca. 3.8 Ga ago and includes the areas of Anshan-Benxi, eastern Hebei, eastern Shandong and western Shandong. In Anshan-Benxi, several different types of 3.8 Ga rocks were discovered together with 3.1-3.7 Ga rocks, whereas 2.9-3.0 Ga K-rich granites and 2.5 Ga syenogranite occur on larger scales. In eastern Hebei, 3.0-3.4 Ga rocks and older detrital and xenocrystic zircons were identified. In eastern Shandong, there are a large volumes of 2.7 Ga and 2.9 Ga rocks. In western Shandong, early Neoarchean(2.6-2.7 Ga) intrusive and supracrustal rocks are widely distributed. Whole-rock Nd and zircon Hf isotope data suggest that both mantle additions and crustal recycling played important roles within the Eastern Ancient Terrane during almost every tectono-magmatic event. Most BIFs in the North China Craton are late Neoarchean in age and are distributed on continental crust along the western margin of the Eastern Ancient Terrane, probably suggesting that a stable environment was one of the key factors for the formation of large-scale BIFs. | WAN Yusheng LIU Shoujie Alfred KRONER DONG Chunyan XIE Hangqiang XIE Shiwen BAI Wenqian REN Peng MA Mingzhu LIU Dunyi | 2016 | Acta Geologica Sinica(English Edition)2016，90，4： | 1 |
| 4 | Geochemistry and SHRIMP U-Pb Zircon Dating of Mafic Rocks North of Zunhua City, Eastern Hebei, North China Craton: Paleoproterozoic Gabbro rather than Neoarchean Ophiolite显示文摘Abundant mafic-ultramafic blocks and dikes occur in the area north of Zunhua City, eastern Hebei Province, and were previously suggested to be part of a late Archean ophiolitic assemblage. We employed SHRIMP zircon dating and a geochemical study on these mafic and surrounding rocks to test the ophiolite hypothesis. The SHRIMP data suggest that three metagabbro samples were metamorphosed at ~1.8 Ga. Numerous ~2.5 Ga zircons display strong oscillatory zoning, characteristic of zircons from granitoid rocks but not from gabbro, so we suggest that these are xenocrystic grains. The age of these xenocrystic zircons and their metamorpbic rims suggests that these mafic blocks formed in Paleoproterozoic. The surrounding gneiss of intermediate composition also contains 2.5 Ga zircons with oscillatory zoning and 1.8 Ga metamorphic rims. Fractionated REE patterns and Nb, Ta, Zr, Hf negative anomalies to variable extent were observed in the mafic blocks and surrounding rocks, also supporting a significant difference in the chemistry of ophiolitic rocks. Our data suggest that many mafic blocks in northern Zunhua are not part of a late Archean ophiolite complex but part of a tectonically dismembered Paleoproterozoic intrusive gabbro complex. This study shows that late Paleoproterozoic metamorphism occurred in the western part of eastern Hebei Province. | XIE Hangqiang DONG Chunyan Alfred KRONER LIU Shoujie BAI Wenqian LIU Dunyi WAN Yusheng | 2018 | Acta Geologica Sinica(English Edition)2018，92，3： | 1 |
| 5 | 3esign and Implementation of EARTH Operating System显示文摘 | LIANG Hongliang LI Shoupeng DONG Shouji YUAN Chunyang NIU Shaozhang | 2012 | Chinese Journal of Electronics2012，21，1： | 0 |
| 6 | Study on Extraction of Effective Aroma Components from Formula Tobacco by the Supercritical CO2 Extraction Method and Its Aroma Composition显示文摘[Objectives]This study was conducted to improve the sensory quality and industrial availability of tobacco extracts.[Methods]The L9(34)design was adopted to carried out an extraction experiment,in which formula tobacco was extracted using supercritical CO2,and the extract was concentrated by vacuum distillation.Through sensory evaluation and chemical analysis,the function determination and chemical composition analysis of the tobacco extracts were carried out,and the optimal supercritical fluid extraction process was finally determined.[Results]The obtained optimal supercritical fluid extraction conditions were as follows:extraction temperature 55℃,extraction pressure 25 MPa,CO2 flow rate of 20 L/h,and entrainer of 95%ethanol.The tobacco extract obtained under the optimal conditions endowed the cigarettes with full and delicate aroma,less irritation and clean aftertaste and made the flavor of the cigarettes overall coordinated and softer,so the sensory quality was significantly improved.[Conclusions]The tobacco extract obtained by the supercritical CO2 extraction method from formula tobacco can effectively improve the quality of cigarettes. | Shoujie NIE Guangyu MENG Shoutao CAO Shuaicheng TIAN Zhiguang LIU Cuishu LENG Guofeng YU Qiulin LIU Xulun WEI Quanjiang DONG | 2020 | Agricultural Biotechnology2020，9，5： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员