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| 1 | Sr-Nd isotope geochemistry of eolian dust of the arid-semiarid areas in China: Implications for loess provenance and monsoon evolution显示文摘Minerals and rocks have distinct 87Sr/86Sr and 143Nd/144Nd ratios, depending on their geological origin and ages, and these isotope ratios are less altered than elemental composition during transport in the atmosphere or after deposition as sediments, thus stable isotopes of Sr and Nd have great potential as tracers for provenance and trans- port of materials. During the hypergene process, Sr isotope ratios of sediments are controlled by their parent rocks, particle sizes and chemical weathering. In general, the higher the Sr isotope ratios of parent rocks, and/or the more the fine-grained fractions, and/or the stronger the chemical weathering, thus the higher the Sr isotope ratios of sediments. On the contrary, there are lower Sr isotope ratios of sedi- ments. Nd isotope ratios of sediments, independent of their particle sizes and chemical weathering, are only associated with parent rocks. For the prove- nance of the Chinese Loess Plateau, different re- seachers drew discordant and even contradictory conclusions by using the method of Sr-Nd isotopic tracing. From the previous Nd isotope data, it is con- sidered that the Tarim Basin, deserts in the central and west parts of Inner Mongolia and the Tibetan Plateau are the main sources of the Chinese Loess Plateau, and are also manufacturers for eolian dust of the Far East regions, together with the Chinese Loess Plateau. Sr isotope ratios of eolian dust are solely affected by wind sorting and weather- ing-pedogenesis due to its homogeneous composi- tion in the Chinese Loess Plateau. Wind sorting isrelated to the East Asian winter monsoon but weath- ering-pedogenesis is mainly associated with the East Asian summer monsoon. Studies on Sr isotopic compositions of the loess-paleosol sequence suggest that 87Sr/86Sr ratios in acid-soluble materials are an index for chemical weathering intensity of the Chi- nese Loess Plateau, indicating the East Asian sum- mer monsoon variations, whereas 87Sr/86Sr ratios in acid-insoluble materials are significantly controlled by particle sizes, and can be used as a proxy indicator reflecting the East Asian winter monsoon variations. Variations of 87Sr/86Sr ratios in acid-insoluble materi- als in the past 2.6Ma further demonstrate that the East Asian winter monsoon gradually strengthened since the beginning of the Quaternary period. This result agrees with the prior conclusion that climate gradually cooled since the onset of the Quaternary Ice Age. | RAO Wenbo YANG Jiedong CHEN Jun LI Gaojun | 2006 | Chinese Science Bulletin2006，51，12： | 21 |
| 2 | Effects of droplet size and spray interval on root-to-shoot ratio,photosynthesis efficiency,and nutritional quality of aeroponically grown butter head lettuce显示文摘The proper selection of the atomizer(droplet size)and nutrient solution spray interval is one of the most important factors to be investigated in aeroponics system for sustainable agriculture.The aim of this study was to research the effects of four aeroponics atomizing nozzles(one air-assisted;A_(1),two air-less;A_(2) and A_(3),and one ultrasonic fogger;A_(4))with droplet sizes of 11.24μm,26.35μm,17.38μm,and 4.89μm,respectively,four spray intervals(15 min(I_(1)),30 min(I_(2)),45 min(I_(3))and 60 min(I_(4)))at a 5 min of constant spray time by atomizing the Hoagland’s nutrient solution on growth,root-to-shoot ratio,photosynthesis characteristics,pigments,and nutritional quality of the aeroponically grown lettuce.The experimental results demonstrated that in A_(1) atomizer and I_(2) interval,the growth,photosynthesis efficiency,chlorophyll,carotenoids,and nutritional values of the lettuce were significantly higher compared to that grown in A_(2) and A_(3) atomizers at all spray intervals.The shoot developments were more constrained than root,prominent to the alteration of root-to-shoot ratio(fresh and dry)in the influence of different droplet sizes and spray intervals.Moreover,the plants did not grow well in A_(4) atomizer associated with proposed spray intervals.The results disclosed that there was an obvious interaction between droplet sizes(atomizers)and spray intervals for growth,the ratio of root to shoot,photosynthesis efficiency,pigments,and nutritional quality of the aeroponically grown lettuce.This research study increases the awareness of the proper droplet size(atomizer)and the regulation of nutrient solution spray interval for leafy vegetables grown in an aeroponics system. | Mazhar Hussain Tunio Jianmin Gao Waqar Ahmed Qureshi Sher Ali Sheikh Jiedong Chen Farman Ali Chandio Imran Ali Lakhiar Kashif Ali Solangi | 2022 | International Journal of Agricultural and Biological Engineering2022，15，1： | 1 |
| 3 | Nd and Sr isotopic characteristics of Chinese deserts: Implications for the provenances of Asian dust显示文摘 | Jun Chen Gaojun Li Jiedong Yang Wenbo Rao Huayu Lu William Balsam Youbin Sun Junfeng Ji | 2007 | Geochimica et Cosmochimica Acta2007，，15： | 1 |
| 4 | Variations in 87Sr/86Sr ratios of calcites in Chinese loess:a proxy for chemical weathering associated with the East Asian summer monsoon 显示文摘 | Chen Jun An Zhisheng | 2000 | Palaeogeography Palaeoclimatology Palaeoecology2000，157，： | 1 |
| 5 | Variation in 87Sr/86Sr ratios of calcites in Chinese loess:A proxy for chemical weathering associated with the East Asian summer monsoon显示文摘 | Chen Jun An Zhisheng | 2000 | Palaeogeography Palaeoclimatology Palaeoecology2000，157，： | 1 |
| 6 | Sm-Nd isotopic ages of Tiqiushan eclogites in Xinyi region and its geological significance显示文摘GEOLOGICAL scientists have paid much attention to the suture zones formed by collision between the Sino-Korean and Yangtze blocks because of the discovery of the ultrahigh pressue metamorphic (UHPM) rocksfrom northern Jiangsu Province (Su), southern Shandong Province (Lu) and the Dabie Mountains.Although the age of 200-240 Ma is probably the best estimation for UHPM metamorphism in the DabieMountains, the primary intrusive and metamorphic ages of the complex from northern Jiangsu Provincehave not been determined before. Using the Sm-Nd isotopic dating method, our study is aimed at datingthe UHPM metanorphic event of northern Jiangsu Province and researching a probable relation between theUHPM rocks from the Dabie Mountains and the UHPM rocks from northern Jiangsu Province. | WANG Yinxi~(1,2), YANG Jiedong~(1,2), TAO Xiancong~(1,2), GE Ningjie~4, CHEN Peirong~3, FAN Chunfang~3 and LI Jianhua~5 1. Center of Modern Analysis, Nanjing University, Nanjing 210093, China 2. State Key Laboratory for Research of Mineral Deposits, Nanjing University, Nanjing 210093, China 3. Department of Earth Science, Nanjing University, Nanjing 210093, China 4. Department of Earth and Space Sciences, University of Science and Technology of Chian, Hefei 230026, China 5. No.5 Geological Party of Jiangsu Province, Xuzhou 221005, China | 1999 | Chinese Science Bulletin1999，44，S2： | 0 |
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