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| 1 | A large carbon pool in lake sediments over the arid/semiarid region, NW China显示文摘Carbon burial in lake sediments is an important component of the global carbon cycle. However, little is known about the magnitude of carbon sequestered in lake sediments over the arid/semiarid region of China(ASAC).In this study, we estimate both organic and inorganic carbon burial since *AD 1800 based on nine lakes in ASAC,and discuss the most plausible factors controlling carbon burial. Our estimates show that the annual organic carbon burial rate(OCBR) ranges from 5.3 to 129.8 g cm-2year-1(weighted mean of 49.9 g cm-2year-1), leading to a standing stock of 1.1–24.0 kg cm-2(weighted mean of 8.6 kg cm-2)and a regional sum of *108 Tg organic carbon sequestered since *AD 1800. The annual inorganic carbon burial rate(ICBR) ranges from 11.4 to 124.0 g cm-2year-1(weighted mean of 48.3 g cm-2year-1), which is slightly lower than OCBR. The inorganic carbon standing stock ranges from2.4 to 26.0 kg cm-2(weighted mean of 8.1 kg cm-2),resulting in a sum of *101 Tg regional inorganic carbon burial since *AD 1800, which is slightly lower than the organic carbon sequestration. OCBR in ASAC shows a continuously increasing trend since *AD 1950, which is possibly due to the high autochthonous and allochthonous primary production and subsequently high sedimentation rate in the lakes. This increasing carbon burial is possibly related to both climatic changes and enhanced anthropogenic activities, such as land use change, deforestation, and eutrophication in the lake. Furthermore, OCBR and ICBR are expected to continuously increase under the scenario of increasing precipitation and runoff and enhanced anthropogenic activities.The results of this research show that the buried carbon in lake sediments of the ASAC region constitutes a significant and large carbon pool, which should be considered and integrated into the global carbon cycle. | Jianghu Lan Hai Xu Bin Liu Enguo Sheng Jiangtao Zhao Keke Yu | 2015 | Chinese Journal Of Geochemistry2015,34,3: | 10 |
| 2 | Water-driven photoluminescence reversibility in CsPbBr_(3)/PDMSPUa composite显示文摘Strong ionic character endows all-inorganic perovskite nanocrystals(NCs)with particular optoelectronic features when interacting with common polar solvents,such as water.However,the interaction mechanism of water affecting perovskite NCs is still lack of in-depth understanding.This study systematically explores the roles of water on CsPbBr_(3) nanocrystals(CNCs)by finely controlling the polymer coating degree of polydimethylsiloxane-based polyurea(PDMS-PUa).Through this coating,the effect of water on CNCs is found to experience from“fluorescence quenching”owing to irreversible crystal decomposition towards“forward fluorescence reversibility”by crystal destruction and recrystallization.With gradually enhanced coating,a phenomenon of“reverse fluorescence reversibility”is further observed in that water begins to passivate the CNCs’defect states.Finally,“fluorescent balance”can be achieved with a thick enough coating,where water can hardly contact with the CNCs.Inspired by the fluorescence reversible mechanism discovered,a new wearable intelligent sensing skin is demonstrated by using the CsPbBr_(3)/PDMS-PUa composite as raw material.Both water contact and humidity change can be perceived through photoluminescence(PL)intensity,corresponding to stimuli-responsive sensory nerves of human skin.It is expected that these findings will shed some new lights on perovskite NCs. | Junhu Cai Chenhui Wang Xinpei Hu Yuanyuan Ye Lijuan Zhong Enguo Chen Yun Ye Sheng Xu Jie Sun Qun Yan Tailiang Guo | 2022 | Nano Research2022,15,7: | 4 |
| 3 | Biogenic silica contents of Lake Qinghai sediments and its environmental significance显示文摘在在湖沉积的源於生物的硅石(BSi%) 的层次的变化广泛地被使用了以便学习湖生产率和 palaeoclimatic 变化。然而,源於生物的硅石(BSi ) 的起源需要为每个湖被调查,特别为大湖,作为做在 BSi 和相关环境因素的层次之间的关系。在这研究,我们测量了在金海湖集水以内在湖沉积,河沉积,和表面土壤包含的 BSi 的百分比,并且在抽取过程前后比较了硅藻和 phytoliths 的数量和形状。结果建议在湖沉积的 BSi 首先从内长的硅藻被导出;因此, BSi 层次能被用来在湖以内在主要生产率反映变化。进一步的比较证明在长期的 timescales 上,在 BSi% 的变化与在全部的器官的碳(TOC ) 和谷物尺寸的那些通常一致,反映在金海湖的主要生产率上的降水的主导的影响。然而,在短期的 timescales 上,在 BSi% 之间的关系和在 BSi% 和谷物尺寸之间的 TOC 和那不清楚或稳定。例如, BSi% 有时有谷物的 covaried 尺寸,而是它与谷物尺寸有关有时从阶段与或甚至相反地。我们推测那气候和环境过程例如冲淡效果,影响短期的 BSi% 和它的相关环境意义。作为结果, BSi% 应该在不同时间规模上有选择地被用作气候的变化的指示物。 | Bin LIU Hai XU Jianghu LAN Enguo SHENG Shuai CHE Xinying ZHOU | 2014 | Frontiers of Earth Science2014,8,4: | 4 |
| 4 | Late Holocene hydroclimatic variations and possible forcing mechanisms over the eastern Central Asia显示文摘Hydroclimatic variations over the eastern Central Asia are highly sensitive to changes in hemispheric-scale atmospheric circulation systems. To fully understand the long-term variability and relationship between hydroclimate and atmospheric circulation system, we present a high-resolution lascustrine record of late Holocene hydroclimate from Lake Sayram, Central Tianshan Mountains, China, based on the total organic carbon, total nitrogen, and carbonate contents, carbon/nitrogen ratios, and grain size. Our results reveal four periods of substantially increased precipitation at the interval of 4000–3780, 3590–3210, 2800–2160, and 890–280 cal yr BP, and one period of slightly increased precipitation from 1700–1370 cal yr BP. These wetter periods broadly coincide with those identified in other records from the mid-latitude Westerlies-dominated eastern Central Asia, including the northern Tibetan Plateau. As such, a similar hydroclimatic pattern existed over this entire region during the late Holocene. Based on a close similarity of our record with reconstruction of North Atlantic Oscillation indices and solar irradiance, we propose that decreased solar irradiance and southern migration of the entire circum-North Atlantic circulation system, particularly the main pathway of the mid-latitude Westerlies, significantly influenced hydroclimate in eastern Central Asia during the late Holocene. Finally, the inferred precipitation at Lake Sayram has increased markedly over the past 100 years, although this potential future changes in hydroclimate in Central Asia need for further investigation. | Jianghu LAN Hai XU Keke YU Enguo SHENG Kangen ZHOU Tianli WANG YuANDa YE Dongna YAN Huixian WU Peng CHENG Waili ABULIEZI Liangcheng TAN | 2019 | Science China Earth Sciences2019,62,8: | 3 |
| 5 | Variations in monsoon precipitation over southwest China during the last 1500 years and possible driving forces显示文摘Understanding hydroclimatic patterns and their possible driving mechanisms during distinct climate periods over the last 1500 years—such as the Medieval Warm Period(MWP),the Little Ice Age(LIA),and the Current Warm Period—is crucial for predicting future changes to monsoon precipitation in southwest China under global warming scenarios.In this study,based on ^(210)Pb and ^(137)Cs dating of surface sediments and AMS ^(14)C dating of terrestrial plant residues,we establish a robust age model that covers the last~1500 years(AD 439–2012)at Lake Yihai in southwest China.We use analyses of multiple geochemical proxy indices,including loss on ignition at 550℃,total organic carbon,total nitrogen,C/N ratios,and stable carbon isotopes of organic matter to reconstruct changes in summer monsoon precipitation at Lake Yihai during the last~1500 years.The results show that,over southwest China,warm and dry climate conditions prevailed during the MWP(AD 1000–1400)and the past 200 years,whereas conditions during the LIA(AD 1400–1800)were cold and wet.This is consistent with evidence from other geological records over southwest China,such as stalagmite and lake sediment data.Similar hydroclimatic patterns have occurred over the last 1500 years in adjacent tropical/subtropical monsoon regions where the climate is similarly dominated by the Indian summer monsoon(e.g.,South China,the South China Sea,Southeast Asia,Northeast India).We suggest that the meridional migration of the mean position of the Inter-tropical Convergence Zone,and El Niño/Southern Oscillation conditions which are linked to tropical Pacific sea surface temperature,are responsible for centennial-scale hydroclimatic patterns over southwest China and adjacent areas during the last 1500 years. | Bin LIU Enguo SHENG Keke YU Kang’en ZHOU Jianghu LAN | 2022 | Science China Earth Sciences2022,65,5: | 0 |