|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Characteristics of authigenic pyrites in shallow core sediments in the Shenhu area of the northern South China Sea: Implications for a possible mud volcano environment显示文摘Distinct pyrites have been recovered from a shallow sediment core from Site 4B in the Shenhu area of the northern South China Sea. Based on the lithology, texture and structure of sediments, the stable sulfur isotope of pyrite and the total organic carbon (TOC) concentration of the sediments, a distinctive sediment interface is identified at a depth of about 1 m below the seafloor in the core sediments. The pyrites only accumulate in the lower part of the core as rods and foraminifera-infillings, and mainly within three intervals marked by high pyrite concentrations. The amount of pyrite in the sediments shows no remarkable correlation with TOC in the Site 4B core sediments. The stable sulfur isotopes of the pyrite have extremely negative values ranging from 41.69‰ to 49.16‰. They are considered to be the mutual product of sulfate bacterial reduction and sulfur bacterial disproportionation. Our research proposes that Site 4B might be located in or near a possible mud volcano sedimentary environment; a large amount of methane could migrate from deep to shallow sediments in an active mud volcano and thereby play a key role in the intensity of sulfate bacterial reduction and the amount of pyrite formed at Site 4B. Further, the variation in flux of deep methane fluid by intermittent mud volcanic eruptions might result in the deposition of authigenic pyrite intervals. | XIE Lei WANG JiaSheng WU NengYou WU DaiDai WANG Zhou ZHU XiaoWei HU Jun CHEN HongRen LIN Qi | 2013 | Science China Earth Sciences2013，56，4： | 14 |
| 2 | Association of emergency room visits for respiratory diseases with sources of ambient PM2.5显示文摘Previous studies have reported associations of short-term exposure to different sources of ambient fine particulate matter(PM2.5)and increased mortality or hospitalizations for respiratory diseases.Few studies,however,have focused on the short-term effects of source-specific PM2.5 on emergency room visits(ERVs)of respiratory diseases.Source apportionment for PM2.5 was performed with Positive Matrix Factorization(PMF)and generalized additive model was applied to estimate associations between source-specific PM2.5 and respiratory disease ERVs.The association of PM2.5 and total respiratory ERVs was found on lag4(RR=1.011,95%CI:1.002,1.020)per interquartile range(76μg/m3)increase.We found PM2.5 to be significantly associated with asthma,bronchitis and chronic obstructive pulmonary disease(COPD)ERVs,with the strongest effects on lag5(RR=1.072,95%CI:1.024,1.119),lag4(RR=1.104,95%CI:1.032,1.176)and lag3(RR=1.091,95%CI:1.047,1.135),respectively.The estimated effects of PM2.5 changed little after adjusting for different air pollutants.Six primary PM2.5 sources were identified using PMF analysis,including dust/soil(6.7%),industry emission(4.5%),secondary aerosols(30.3%),metal processing(3.2%),coal combustion(37.5%)and traffic-related source(17.8%).Some of the sources were identified to have effects on ERVs of total respiratory diseases(dust/soil,secondary aerosols,metal processing,coal combustion and traffic-related source),bronchitis ERVs(dust/soil)and COPD ERVs(traffic-related source,industry emission and secondary aerosols).Different sources of PM2.5 contribute to increased risk of respiratory ERVs to different extents,which may provide potential implications for the decision making of air quality related policies,rational emission control and public health welfare. | Rui Chi Hongyu Li Qian Wang Qiangrong Zhai Daidai Wang Meng Wu Qichen Liu Shaowei Wu Qingbian Ma Furong Deng Xinbiao Guo | 2019 | Journal of Environmental Sciences2019，31，12： | 8 |
| 3 | Methane seepage intensities traced by sulfur isotopes of pyrite and gypsum in sediment from the Shenhu area,South China Sea显示文摘The northern slope of the South China Sea is a gas-hydrate-bearing region related to a high deposition rate of organic-rich sediments co-occurring with intense methanogenesis in subseafloor environments.Anaerobic oxidation of methane(AOM) coupled with bacterial sulfate reduction results in the precipitation of solid phase minerals in seepage sediment,including pyrite and gypsum.Abundant aggregates of pyrites and gypsums are observed between the depth of 667 and 850 cm below the seafloor(cmbsf) in the entire core sediment of HS328 from the northern South China Sea.Most pyrites are tubes consisting of framboidal cores and outer crusts.Gypsum aggregates occur as rosettes and spheroids consisting of plates.Some of them grow over pyrite,indicating that gypsum precipitation postdates pyrite formation.The sulfur isotopic values(δ^(34) S) of pyrite vary greatly(from –46.6‰ to –12.3‰ V-CDT) and increase with depth.Thus,the pyrite in the shallow sediments resulted from organoclastic sulfate reduction(OSR) and is influenced by AOM with depth.The relative high abundance and δ^(34) S values of pyrite in sediments at depths from 580 to 810 cmbsf indicate that this interval is the location of a paleo-sulfate methane transition zone(SMTZ).The sulfur isotopic composition of gypsum(from–25‰ to –20.7‰) is much lower than that of the seawater sulfate,indicating the existence of a 34 S-depletion source of sulfur species that most likely are products of the oxidation of pyrites formed in OSR.Pyrite oxidation is controlled by ambient electron acceptors such as MnO_2,iron(Ⅲ) and oxygen driven by the SMTZ location shift to great depths.The δ^(34) S values of gypsum at greater depth are lower than those of the associated pyrite,revealing downward diffusion of 34 S-depleted sulfate from the mixture of oxidation of pyrite derived by OSR and the seawater sulfate.These sulfates also lead to an increase of calcium ions from the dissolution of calcium carbonate mineral,which will be favor to the formation of gypsum.Overall,the mineralogy and sulfur isotopic composition of the pyrite and gypsum suggest variable redox conditions caused by reduced seepage intensities,and the pyrite and gypsum can be a recorder of the intensity evolution of methane seepage. | ZHANG Mei LU Hongfeng GUAN Hongxiang LIU Lihua WU Daidai WU Nengyou | 2018 | Acta Oceanologica Sinica2018，37，7： | 4 |
| 4 | Detection and indication of 1,3,4-C27-29 triol in the sediment of northern South China Sea显示文摘After the detection of the 1,20,21-C_(29) long-chain triol in some sediments and freshwater pteridophytes, in this study, a new homologous long-chain triol, 1,3,4-C_(27-29), is detected for the first time in the Site4 B core sediment in the northern South China Sea. The hydroxyl location and length of the carbon chain of this newly discovered triol differ from those of 1,20,21-C_(29) triol. The test results of its molecular distribution and individual carbon isotope reveal that 1,3,4-C_(29) triol has a good correlation with n-C_(26-30) even carbon-numbered long-chain fatty alcohols, with R^2(n=68) values of 0.905, 0.929 and 0.903, respectively, and its carbon isotope composition, at –32.3‰±1.9‰, is similar to that of n-C_(26-30), at –29.13‰±0.87‰, –32.98‰±1.28‰, and –32.98‰±1.28‰. 1,3,4-C_(29) triol from the Site4 B core sediment and terrigenous long-chain fatty alcohol(n-C_(26-34)) show highly consistent distribution trends in the entire section; thus, the former could serve as a proxy indicator of the terrigenous input. Considering that the 1,20,21-C_(29) triol in previous research belongs to Azolla, which are fresh water pteridophytes, the 1,3,4-C_(27-29) triol identified in this study might have similar biogenetic derivation. Thus, determination of its biogenic area and growing environment could provide potential organic geochemical evidence supporting the terrigenous input and source in the northern South China Sea. | ZHU XiaoWei MAO ShengYi WU NengYou JIA GuoDong SUN YongGe GUAN HongXiang WU DaiDai | 2016 | Science China Earth Sciences2016，59，6： | 2 |
| 5 | Alcohol compounds in Azolla imbricata and potential source implication for marine sediments显示文摘This study investigated the composition of long-chain alkyl diols,triols,sec-alcohols,hydroxyl acids,and other hydroxylated compounds in Azolla imbricata and compared the organic alcohol components of Azolla filiculoides,Azolla microphylla,and South China Sea(SCS)sediments in order to investigate the possible indication of Azolla being the biological source of diols and triols in SCS sediment.Large amounts of diols,monohydroxy acids,and sec-alcohols with internal hydroxy groups atω20 were detected in the three types of Azolla.Among these,1,ω20-diol andω20-hydroxy acid exhibited strong even-odd predominance distribution,whereasω20-sec-alcohol exhibited strong odd-even predominance distribution.In addition,small amounts of diols,triols,and dihydroxy acids with internal hydroxy groups at 9,10 orω9,ω10 were detected,among which the chain length of C_(29)was predominate.Compounds having similar structures as those in Azolla reflected a similar biosynthetic pathway:ω20-hydroxy acid exhibiting even-odd predominance distribution is decarboxylated toω20-sec-alcohol exhibiting odd-even predominance distribution and converted to 1,ω20-diol with even-odd predominance distribution by acyl reduction;ω9,ω10-hydroxy acid is converted to 1,20,21(1,ω9,ω10)-triol by acyl reduction,and then converted to 9,10-diol by hydrogenation and dehydration.The alcohol components in A imbricata were clearly not the biological source of 1,13/1,14/1,15-C_(28,30,32)diols and 1,3,4-C_(27-29)triols in the SCS sediment.Certain marine diatoms might be the source of 1,14-C_(28,30)diol in inshore sediment,but the biological source of diols and triols in the SCS sediment requires further investigation. | MAO ShengYi ZHU XiaoWei WU NengYou JIA GuoDong SUN YongGe GUAN HongXiang WU DaiDai | 2017 | Science China Earth Sciences2017，60，2： | 1 |
| 6 | Sedimentary geochemical proxies for methane seepage at Site C14 in the Qiongdongnan Basin in the northern South China Sea显示文摘Recent studies have shown that specific geochemical characteristics of sediments can be used to reconstruct past methane seepage events.In this work,the correlation between the Sr/Ca and Mg/Ca ratios of sediment samples is analyzed and the sulfate concentration profile in Site C14 from cold-seep sediments in the Qiongdongnan Basin in northern South China Sea is obtained.The results confirmed that,sulfate at 0–247 cm below sea floor(Unit I)is mainly consumed by organic matter sulfate reduction(OSR),while sulfate at 247–655 cm(UnitⅡ)is consumed by both the OSR and the anaerobic oxidation of methane(AOM).In addition,the bottom sediment layer is affected by weak methane seepage.The Mo and U enrichment factors also exhibit similar trends in their respective depth profiles.The responses of trace elements,including Co/Al,Ni/Al,Cr/Al and Zn/Al ratios to methane seepage allowed the study of depositional conditions and methane seepage events.Based on the results,it is speculated that the depositional conditions of UnitⅡchanged with depth from moderate conditions of sulfidic and oxic conditions to locally anoxic conditions,and finally to suboxic conditions due to methane fluid leakage.The stable isotope values of chromium-reducible sulfide produced by AOM and those of sulfide formed by OSR in the early diagenetic environment suffered serious depletion of 34S.This was probably due to weak methane leakage,which caused the slower upward diffusion and the effect of early diagenesis on the samples.It is necessary to consider the effects of depositional environments and diagenesis on these geochemical parameters. | Tiantian Sun Daidai Wu Fei Yang Lihua Liu Xuegang Chen Ying Ye | 2019 | Acta Oceanologica Sinica2019，38，7： | 1 |
| 7 | Fatty-acids and their δ^(13)C characteristics of seep carbonates from the northern continental slope of Gulf of Mexico显示文摘Here we reported the fatty-acids and their δ13 C values in seep carbonates collected from Green Canyon lease block 185 (GC 185;Sample GC-F) at upper continental slope (water depth:~540 m),and Alaminos Canyon lease block 645 (GC 645;Sample AC-E) at lower continental slope (water depth:~2200 m) of the Gulf of Mexico.More than thirty kinds of fatty acids were detected in both samples.These fatty acids are maximized at C 16.There is a clear even-over-odd carbon number predominance in carbon number range.The fatty acids are mainly composed of n-fatty acids,iso-/anteiso-fatty acids and terminally branched odd-numbered fatty acids (iso/anteiso).The low δ13 C values (-39.99‰ to -32.36‰) of n-C 12:0,n-C 13:0,i-C 14:0 and n-C 14:0 suggest that they may relate to the chemosynthetic communities at seep sites.The unsaturated fatty acids n-C 18:2 and C 18:1 △9 have the same δ13 C values,they may originate from the Beggiatoa/Thioploca.Unlike other fatty acids,the terminally branched fatty acids (iso/anteiso) show lower δ13 C values (as low as -63.95‰) suggesting a possible relationship to sulfate reducing bacteria,which is common during anaerobic oxidation of methane at seep sites. | GUAN HongXiang FENG Dong WU NengYou CHEN DuoFu ROBERTS H H WU DaiDai | 2010 | Chinese Science Bulletin2010，55，8： | 0 |
| 8 | Absorption of Arsenite on Several Iron (Hydro-)Oxides and Impact from Pre-processing Methods显示文摘Fe 上的亚砷酸盐的吸收反应(水疗院 --) 氧化物被学习。Thethree 吸收剂类型是 Fe (哦)_3 胶化和二 Fe (水疗院 --) 氧化物,在哪个 Fe (哦)_3 胶化在 80 deg C 在真空下面在微波炉被弄干。氢指数从 9.71 改变到 6 在 Fe 以后纪录的 10.36in,这被发现(哦)_3 胶化与 NaAsO_2 答案被混合,,亚砷酸盐在针铁矿和 Fe 代替 theOH^-( 哦)_3。在在反应的开始以后的第 40 分钟,因为,氢指数减少,它最可能是吸收亚砷酸盐的单音的有牙齿的表面建筑群变成了 mononuclear 有二齿的复杂、释放的质子。在 pH 的衰落显示并非吸收的结束但是在反应的一个变化打字。温度和溶解气体在反应的这二种类型上有小效果。在吸收剂以后的亚砷酸盐增加的全部的吸收与超声被照耀,它也在把固体与答案分开导致困难。为 Fe 的亚砷酸盐的吸收能力(哦) 在真空下面在微波炉弄干的 _3 胶化是 53.18% 和 17.22% 比 Fe 的分别地好(哦) 在 80 deg C 弄干的 _3 胶化和胶化。可能的原因是在胶化的水分子在微波照耀,从而生产的更高的孔和改进表面活性的效果下面与高频率颤动。 | YE Ying JI Shanshan WU Daidai LI Jun ZHANG Weirui | 2006 | Acta Geologica Sinica(English Edition)2006，80，2： | 0 |
| 9 | The influence of coupling mode of methane leakage and debris input on anaerobic oxidation of methane显示文摘Anaerobic oxidation of methane(AOM) is an important biogeochemical process, which has important scientific significance for global climate change and atmospheric evolution. This research examined the δ^(34)S, terrigenous clastic indices of TiO_(2) and Al_(2)O_(3), and times for formation of the Ba front at site SH1, site SH3 and site 973-4 in the South China Sea. Three different coupling mechanisms of deposition rate and methane flux were discovered. The different coupling mechanisms had different effects on the role of AOM. At site 973-4, a high deposition rate caused a rapid vertical downward migration of the sulphate–methane transition zone(SMTZ), and the higher input resulted in mineral dissolution. At site SH3, the deposition rate and methane flux were basically in balance,so the SMTZ and paleo-SMTZ were the most stable of any site, and these were in a slow process of migration. At site SH1, the methane flux dominated the coupled mode, so the movement of the SMTZ at site SH1 was consistent with the general understanding. Understanding the factors influencing the SMTZ is important for understanding the early diagenesis process. | Rui Xie Daidai Wu Jie Liu Guangrong Jin Tiantian Sun Lihua Liu Nengyou Wu | 2021 | Acta Oceanologica Sinica2021，40，8： | 0 |
| 10 | Last glacial terrestrial vegetation record of leaf wax n-alkanols in the northern South China Sea:Contrast to scenarios from longchain n-alkanes显示文摘Long-chain n-alkanols and n-alkanes in core sediments from the northern South China Sea(SCS)were measured to make a comparison during terrestrial vegetation reconstruction from~42 ka to~7 ka.The results showed that terrestrial vegetation record from long-chain n-alkanes matched well with previous studies in nearby cores,showing that more C_(4)plants developed during the Last Glacial Maximum(LGM)and C_(3)plants dominated in the interglacial period.However,these scenarios were not revealed by terrestrial vegetation reconstruction using long-chain n-alkanols,which showed C_(3)plant expansion during the LGM.The discrepancy during the interglacial period could be attributed to the aerobic degradation of functionalized long-chain n-alkanols in the oxygen-rich bottom water,resulting in poor preservation of terrestrial vegetation signals.On the other hand,the different advantages of functionalized n-alkanols and non-functional n-alkanes to record local and distal vegetation signals,respectively,may offer a potential explanation for the contradiction during the LGM when the SCS was characterized by low-oxygen deep water.Nevertheless,large variations on n-alkyl lipid compositions in C_(3)/C_(4)plants could play a part in modulating sedimentary long-chain n-alkanols and n-alkanes toward different vegetation signals,thereby suggesting that caution must be taken in respect to the terrestrial vegetation reconstruction using long-chain n-alkanes and long-chain n-alkanols. | Shengyi Mao Guodong Jia Xiaowei Zhu Nengyou Wu Daidai Wu Hongxiang Guan Lihua Liu | 2022 | Acta Oceanologica Sinica2022，41，8： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员