第四纪异常气候下微生物的响应和反馈的研究不但对了解现代全球变暖背景下微生物与气候变化之间的关系具有启示作用,同时对也为地质历史时期微生物和环境之间的协同演化的假设提供验证的案例。因而,第四纪异常环境下地质微生物的研究是...第四纪异常气候下微生物的响应和反馈的研究不但对了解现代全球变暖背景下微生物与气候变化之间的关系具有启示作用,同时对也为地质历史时期微生物和环境之间的协同演化的假设提供验证的案例。因而,第四纪异常环境下地质微生物的研究是联系微生物作用的现代过程与地质过程的桥梁。该研究借助于洞穴沉积物、泥炭沉积物和长江中游的湖泊沉积等地质载体,建立评估不同环境典型微生物地质过程的分子和原子(同位素)水平的示踪技术方法,查明微生物通过影响碳循环等地质地球化学过程对地质环境的作用。在前期的研究基础上,2013年的研究取得以下重要进展:(1)利用石笋碳酸盐热释光对土壤生物过程进行了示踪,获得土壤有机质分解与微生物降解过程的信息,发现了温度对土壤呼吸的影响,为未来全球变暖下土壤碳库大小的评估提供依据;(2)对发生在全新世的一次气候异常事件进行了解剖,发现东亚季风区8.2 ka BP气候事件的石笋记录与著名的格陵兰冰芯氧同位素记录具有高度相似性,说明在北大西洋降温和东亚季风减弱之间存在密切气候耦合;(3)开发了GDGTs和霍类化合物两个表征古水文的指标,并成功地用于古环境的重建,有望为预测全球变暖过程中不断出现严重的洪灾和旱灾的预测和防范发挥作用;(4)建立了微生物脂类定量重建古温度的新方法,探索地球表层长期温度的波动,为评估自然条件下地球环境变化的频率和强度提供基础资料(;5)第四纪动物演化及其对环境变化的响应的研究,对当今全球变暖的适应性具有启示作用。展开更多
A δ^（44） Ca curve from shells of the planktonic foraminifera Globigerinoides sacculifer in calcareous biogenic oozes has been extracted from the Nintyeast Ridge in the Indian Ocean since 300 ka. By combining terrig...A δ^（44） Ca curve from shells of the planktonic foraminifera Globigerinoides sacculifer in calcareous biogenic oozes has been extracted from the Nintyeast Ridge in the Indian Ocean since 300 ka. By combining terrigenous inputs（e.g., grain size, magnetic susceptibility, and turbidite frequency） with the oceanic productivity（e.g., biogenic content and Neogloboquadrina dutertrei content）, it is found that the curve＇s variations are closely related to the historical evolution of the oceanic calcium cycle. The δ^（44）Ca value is in lower tendency and has small oscillation during Marine Isotope Stage（MIS） 6, when the supply of terrigenous detrital is highest. In contrast, during MIS 3,5 and 7, the δ^（44） Ca values are in higher tendency, and their fluctuations are consistent with the variations of the productivity proxies. These results suggest that the calcium isotopes are mainly influenced by the input of the Himalayan erosion products to the northern Indian Ocean. In addition, the developmental stages of calcareous planktons may have a secondary impact on the fluctuations of the calcium isotope ratio of sea water.展开更多
The internal-electrolysis (IE) process can be used as pretreatment to improve the biodegradability of yeast wastewater. The water before and after IE pretreatment was analyzed by UV, GPC, GC-MS to determine the change...The internal-electrolysis (IE) process can be used as pretreatment to improve the biodegradability of yeast wastewater. The water before and after IE pretreatment was analyzed by UV, GPC, GC-MS to determine the changes in its chemical composition. The mechanism on the improvement of biodegradability by the IE process was discussed in two aspects according to the changes of chemical composition. (i) Some reactions occurred during the IE process, such as hydrolytic reaction, cracking, and redox reaction. Thus, the cyclic structure opened and changed into chains, and the macromolecular compounds were spilt to small molecule substances. All these reactions tended to simplify the structure of molecules and increase the donating electron groups so as to improve the biodegradability. (ii) The small molecule acids and alcohols in raw water or produced by the internal electrolysis process could be removed through volatilization and electrochemical adhesion, which was conducive to the removal of COD and the improvement of biodegradability of yeast wastewater.展开更多
Evaluating the pre-Jurassic marine source rocks in China has been difficult because these rocks are generally too highor over-maturated for most traditional methods to work.As to the remaining parameter TOC (%),its lo...Evaluating the pre-Jurassic marine source rocks in China has been difficult because these rocks are generally too highor over-maturated for most traditional methods to work.As to the remaining parameter TOC (%),its lower limit for recognizing the carbonate source rocks in China has been in dispute.Nineteen Phanerozoic sections in the Middle-Upper Yangtze Platform and the Guizhou-Hunan-Guangxi Basin have been studied in search for a different approach to complementing the traditional evaluation method for these source rocks.We have applied a geobiological approach to tracing the organic carbon (OC) output and accumulation from the living stage (primary productivity) to the post-mortem deposited remains,and finally to the preserved burial organics.Four biological and geological parameters are employed to represent the OC of the three stages.A series of proxies of these parameters are discussed and integrated to establish a geobiological evaluation system independent of TOC and other traditional methods.Here we use the Guangyuan section in Sichuan as an example for the geobiological evaluation.Our results indicate that in the argillaceous rocks,the geobiological parameters show the qualified source rocks in accordance with high TOC values;but in the carbonates,the good source rocks delineated by the geobiological parameters have a wide range of TOC,from 0.03% to 1.59%,mostly<0.3%.We suggest that it is still premature to set TOC=0.3% or 0.5% as the lower limit for the pre-Jurassic carbonate source rocks in South China.展开更多
In-situ seasonalδ18O measurements of section 236.3-235.6 cm of speleothem HS4, from Qingjiang Valley of the Middle reaches of Yangtze River, China, were performed by an Secondary Ionization Mass Spectrometry （SIMS）...In-situ seasonalδ18O measurements of section 236.3-235.6 cm of speleothem HS4, from Qingjiang Valley of the Middle reaches of Yangtze River, China, were performed by an Secondary Ionization Mass Spectrometry （SIMS） with Oka （Chinese primary calcite standard GBW04481） and UWC-3 （international calcite standard from University of Wisconsin）. The potential of using SIMS δ18O measurements to establish speleothem time series has been explored and the differences between conventional and SIMS δ18O values have been discussed. During a 3-day period, UWC-3 δ18O has been measured on Cameca IMS δ18O Ion Microprobe Mass Spectrometer against ＂Oka＂ external standard. The measured mean value of UWC-3 （δ18OVPDB= -17.85‰±0.22‰, 1SD） matches well with its recommended value （δ18OvPDB=-17.83‰±0.08‰）, suggesting that the instrument was stable. The same method applied on HS4 produced δ18O measurements at seasonal resolution with distinct annual cycles and the total cycle number in agreement with that from Mg/Ca cycles and lamination layer counting of the same section, so it offers an alternative for accessing speleothem time series. However, compared with conventional δ18O values of HS4, SIMS δ18O values are more negative by 0.90‰ with larger seasonal variation. The main reasons might come from the mi- cro-cracks, micro-pores or liquid inclusions existing in HS4, and organic materials in the speleothem might be another factor affecting the SIMS δ18O values, indicating that to obtain reliable speleothem SIMS δ18O values, both compaction and purity of samples are crucial.展开更多
Thermoluminescence(TL)in marine carbonate has been proposed as a potential proxy for reconstruction of paleoceanography history,and has already been used in defining the Quaternary environment.However,its availability...Thermoluminescence(TL)in marine carbonate has been proposed as a potential proxy for reconstruction of paleoceanography history,and has already been used in defining the Quaternary environment.However,its availability in the geological time scale,such as Permian,is still on debate.The mass extinction event caused by drastic changes of global marine environment in Middle-Late Permian provides a typical example to testify the applicability of this proxy.Here we measured the natural thermoluminescence of the carbonate-dominating marine sediments collected from the strata through the Guadalupian-Lopingian mass extinction boundary(G/LB)in the Penglaitan Section in Laibin,Guangxi,China.Our results reveal that TL intensities of carbonate are much higher than those of siliceous rocks,which indicates that the carbonate is the main contributor to the TL.The variation of TL intensities are related with Mn and Fe contents in the carbonate lattices while high Mn and low Fe(e.g.,high Mn/Fe ratio)in carbonate will release stronger TL.Due to the better storage of carbonate lattices for original information of Mn and Fe in seawater,thermoluminescence of carbonate-dominating sediments/rocks could sensitively reflect marine environment and biological productivity in geological time scale.展开更多
文摘第四纪异常气候下微生物的响应和反馈的研究不但对了解现代全球变暖背景下微生物与气候变化之间的关系具有启示作用,同时对也为地质历史时期微生物和环境之间的协同演化的假设提供验证的案例。因而,第四纪异常环境下地质微生物的研究是联系微生物作用的现代过程与地质过程的桥梁。该研究借助于洞穴沉积物、泥炭沉积物和长江中游的湖泊沉积等地质载体,建立评估不同环境典型微生物地质过程的分子和原子(同位素)水平的示踪技术方法,查明微生物通过影响碳循环等地质地球化学过程对地质环境的作用。在前期的研究基础上,2013年的研究取得以下重要进展:(1)利用石笋碳酸盐热释光对土壤生物过程进行了示踪,获得土壤有机质分解与微生物降解过程的信息,发现了温度对土壤呼吸的影响,为未来全球变暖下土壤碳库大小的评估提供依据;(2)对发生在全新世的一次气候异常事件进行了解剖,发现东亚季风区8.2 ka BP气候事件的石笋记录与著名的格陵兰冰芯氧同位素记录具有高度相似性,说明在北大西洋降温和东亚季风减弱之间存在密切气候耦合;(3)开发了GDGTs和霍类化合物两个表征古水文的指标,并成功地用于古环境的重建,有望为预测全球变暖过程中不断出现严重的洪灾和旱灾的预测和防范发挥作用;(4)建立了微生物脂类定量重建古温度的新方法,探索地球表层长期温度的波动,为评估自然条件下地球环境变化的频率和强度提供基础资料(;5)第四纪动物演化及其对环境变化的响应的研究,对当今全球变暖的适应性具有启示作用。
基金The National Programme on Global Change and Air-sea Interaction under contract Nos GASI-03-04-01-03 and GASI-GEOGE-03the Research Grant of Third Institute of Oceanography,State Oceanic Administration under contract No.2015015
文摘A δ^（44） Ca curve from shells of the planktonic foraminifera Globigerinoides sacculifer in calcareous biogenic oozes has been extracted from the Nintyeast Ridge in the Indian Ocean since 300 ka. By combining terrigenous inputs（e.g., grain size, magnetic susceptibility, and turbidite frequency） with the oceanic productivity（e.g., biogenic content and Neogloboquadrina dutertrei content）, it is found that the curve＇s variations are closely related to the historical evolution of the oceanic calcium cycle. The δ^（44）Ca value is in lower tendency and has small oscillation during Marine Isotope Stage（MIS） 6, when the supply of terrigenous detrital is highest. In contrast, during MIS 3,5 and 7, the δ^（44） Ca values are in higher tendency, and their fluctuations are consistent with the variations of the productivity proxies. These results suggest that the calcium isotopes are mainly influenced by the input of the Himalayan erosion products to the northern Indian Ocean. In addition, the developmental stages of calcareous planktons may have a secondary impact on the fluctuations of the calcium isotope ratio of sea water.
基金Supported by the Natural Science Foundation of Hubei Province(Grant No.2005ABA004)
文摘The internal-electrolysis (IE) process can be used as pretreatment to improve the biodegradability of yeast wastewater. The water before and after IE pretreatment was analyzed by UV, GPC, GC-MS to determine the changes in its chemical composition. The mechanism on the improvement of biodegradability by the IE process was discussed in two aspects according to the changes of chemical composition. (i) Some reactions occurred during the IE process, such as hydrolytic reaction, cracking, and redox reaction. Thus, the cyclic structure opened and changed into chains, and the macromolecular compounds were spilt to small molecule substances. All these reactions tended to simplify the structure of molecules and increase the donating electron groups so as to improve the biodegradability. (ii) The small molecule acids and alcohols in raw water or produced by the internal electrolysis process could be removed through volatilization and electrochemical adhesion, which was conducive to the removal of COD and the improvement of biodegradability of yeast wastewater.
基金supported by National Basic Research Program of China(Grant No.2011CB808800)Key Project of China Petroleum&Chemical Corporation(Grant No.G0800-06-2S-319)+1 种基金NSFC Program for Innovative Research Team(Grant No.40621002)the"111"Project(Grant No.B08030)
文摘Evaluating the pre-Jurassic marine source rocks in China has been difficult because these rocks are generally too highor over-maturated for most traditional methods to work.As to the remaining parameter TOC (%),its lower limit for recognizing the carbonate source rocks in China has been in dispute.Nineteen Phanerozoic sections in the Middle-Upper Yangtze Platform and the Guizhou-Hunan-Guangxi Basin have been studied in search for a different approach to complementing the traditional evaluation method for these source rocks.We have applied a geobiological approach to tracing the organic carbon (OC) output and accumulation from the living stage (primary productivity) to the post-mortem deposited remains,and finally to the preserved burial organics.Four biological and geological parameters are employed to represent the OC of the three stages.A series of proxies of these parameters are discussed and integrated to establish a geobiological evaluation system independent of TOC and other traditional methods.Here we use the Guangyuan section in Sichuan as an example for the geobiological evaluation.Our results indicate that in the argillaceous rocks,the geobiological parameters show the qualified source rocks in accordance with high TOC values;but in the carbonates,the good source rocks delineated by the geobiological parameters have a wide range of TOC,from 0.03% to 1.59%,mostly<0.3%.We suggest that it is still premature to set TOC=0.3% or 0.5% as the lower limit for the pre-Jurassic carbonate source rocks in South China.
基金supported by the Open Project Program of State Key Laboratory of Geological Processes and Mineral Resources(Grant No.GPMR201201)National Natural Science Foundation of China(Grant No.41371216)
文摘In-situ seasonalδ18O measurements of section 236.3-235.6 cm of speleothem HS4, from Qingjiang Valley of the Middle reaches of Yangtze River, China, were performed by an Secondary Ionization Mass Spectrometry （SIMS） with Oka （Chinese primary calcite standard GBW04481） and UWC-3 （international calcite standard from University of Wisconsin）. The potential of using SIMS δ18O measurements to establish speleothem time series has been explored and the differences between conventional and SIMS δ18O values have been discussed. During a 3-day period, UWC-3 δ18O has been measured on Cameca IMS δ18O Ion Microprobe Mass Spectrometer against ＂Oka＂ external standard. The measured mean value of UWC-3 （δ18OVPDB= -17.85‰±0.22‰, 1SD） matches well with its recommended value （δ18OvPDB=-17.83‰±0.08‰）, suggesting that the instrument was stable. The same method applied on HS4 produced δ18O measurements at seasonal resolution with distinct annual cycles and the total cycle number in agreement with that from Mg/Ca cycles and lamination layer counting of the same section, so it offers an alternative for accessing speleothem time series. However, compared with conventional δ18O values of HS4, SIMS δ18O values are more negative by 0.90‰ with larger seasonal variation. The main reasons might come from the mi- cro-cracks, micro-pores or liquid inclusions existing in HS4, and organic materials in the speleothem might be another factor affecting the SIMS δ18O values, indicating that to obtain reliable speleothem SIMS δ18O values, both compaction and purity of samples are crucial.
基金supported by National Basic Research Program of China (Grant No.2011CB808800)National Fund for Geological Talents Training(Grant No. J0830520)
文摘Thermoluminescence(TL)in marine carbonate has been proposed as a potential proxy for reconstruction of paleoceanography history,and has already been used in defining the Quaternary environment.However,its availability in the geological time scale,such as Permian,is still on debate.The mass extinction event caused by drastic changes of global marine environment in Middle-Late Permian provides a typical example to testify the applicability of this proxy.Here we measured the natural thermoluminescence of the carbonate-dominating marine sediments collected from the strata through the Guadalupian-Lopingian mass extinction boundary(G/LB)in the Penglaitan Section in Laibin,Guangxi,China.Our results reveal that TL intensities of carbonate are much higher than those of siliceous rocks,which indicates that the carbonate is the main contributor to the TL.The variation of TL intensities are related with Mn and Fe contents in the carbonate lattices while high Mn and low Fe(e.g.,high Mn/Fe ratio)in carbonate will release stronger TL.Due to the better storage of carbonate lattices for original information of Mn and Fe in seawater,thermoluminescence of carbonate-dominating sediments/rocks could sensitively reflect marine environment and biological productivity in geological time scale.
