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| 1 | Xiba Granitic Pluton in the Qinling Orogenic Belt, Central China: Its Petrogenesis and Tectonic Implications显示文摘Xiba granitic pluton is located in South Qinling tectonic domain of the Qinling orogenic belt and consists mainly of granodiorite and monzogranite with significant number of microgranular quartz dioritic enclaves. SHRIMP zircon U-Pb isotopic dating reveals that the quartz dioritic enclaves formed at 214±3 Ma, which is similar to the age of their host monzogranite (218±1 Ma). The granitoids belong to high-K calc-alkaline series, and are characterized by enriched LILEs relative to HFSEs with negative Nb, Ta and Ti anomalies, and right-declined REE patterns with (La/Yb) N ratios ranging from 15.83 to 26.47 and δEu values from 0.78 to 1.22 (mean= 0.97). Most of these samples from Xiba granitic pluton exhibit εNd(t) values of 8.79 to 5.38, depleted mantle Nd model ages (T DM ) between 1.1 Ga and 1.7 Ga, and initial Sr isotopic ratios ( 87 Sr/ 86 Sr) i from 0.7061 to 0.7082, indicating a possible Meso-to Paleoproterozoic lower crust source region, with exception of samples XB01-2-1 and XB10-1 displaying higher ( 87 Sr/ 86 Sr) i values of 0.779 and 0.735, respectively, which suggests a contamination of the upper crustal materials. Quartz dioritic enclaves are interpreted as the result of rapid crystallization fractionation during the parent magmatic emplacement, as evidenced by similar age, texture, geochemical, and Sr-Nd isotopic features with their host rocks. Characteristics of the petrological and geochemical data reveal that the parent magma of Xiba granitoids was produced by a magma mingling process. The upwelling asthenosphere caused a high heat flow and the mafic magma was underplated into the bottom of the lower continent crust, which caused the partial melting of the lower continent crustal materials. This geodynamic process generated the mixing parent magma between mafic magma from depleted mantle and felsic magma derived from the lower continent crust. Integrated petrogenesis and tectonic discrimination with regional tectonic evolution of the Qinling orogen, it is suggested that the granitoids are most likely products in a post-collision tectonic setting. | ZHANG Fan LIU Shuwen CHEN Xu LI Qiugen DAI Junzhi YANG Kai WU Fenghui CHEN Youzhang | 2012 | Acta Geologica Sinica(English Edition)2012,86,5: | 13 |
| 2 | Thermalization and relaxation mediated by phonon management in tin-lead perovskites显示文摘Understanding and control of ultrafast non-equilibrium processes in semiconductors is key to making use of the full photon energy before relaxation,leading to new ways to break efficiency limits for solar energy conversion.In this work,we demonstrate the observation and modulation of slow relaxation in uniformly mixed tin-lead perovskites(MASn_(x)Pb_(1-x)I_(3)and CsSn_(x)Pb_(1-x)I_(3)nanocrystals).Transient absorption measurements reveal that slow cooling mediated by a hot phonon bottleneck effect appears at carrier densities above~10^(18)cm^(−3)for tin-lead alloy nanocrystals,and tin addition is found to give rise to suppressed cooling.Within the alloy nanoparticles,the combination of a newly introduced high-energy band,screened Fröhlich interaction,suppressed Klemens decay and reduced thermal conductivity(acoustic phonon transport)with increased tin content contributes to the slowed relaxation.For inorganic nanocrystals where defect states couple strongly with carriers,sodium doping has been confirmed to benefit in maintaining hot carriers by decoupling them from deep defects,leading to a decreased energy-loss rate during thermalization and an enhanced hot phonon bottleneck effect.The slow cooling we observe uncovers the intrinsic photophysics of perovskite nanocrystals,with implications for photovoltaic applications where suppressed cooling could lead to hot-carrier solar cells. | Linjie Dai Junzhi Ye Neil C.Greenham | 2023 | Light(Science & Applications)2023,12,9: | 1 |
| 3 | Identification of cadmium-induced genes in maize seedlings by suppression subtractive hybridization显示文摘A maize variety,Huatian-1,had an unusuallylow translocation rate of cadmium(Cd)(59.6 mg·kg^(-1)inthe roots and 0.093 mg·kg^(-1)in the grain)compared to24 other varieties while being grown in soils with16.50 mg·kg^(-1)Cd.This indicates that this particularspecies may have special mechanisms that affect theabsorption and translocation pattern of Cd.In this paper,the technique of suppression subtractive hybridization(SSH)was used to isolate and identify Cd-induced genesfrom Huatian-1 hydroponically exposed to 0.1mMCdCl_(2) for 1 h,12 h,24 h,and 48 h.We found a total of15 differentially expressed genes in the four groups;2,3,4,and 6 genes were from the groups of 1 h,12 h,24 h,and48 h treatment,respectively.Phospholipase PLDb1mRNA,adenosine triphosphate(ATP)phosphoribosyltransferase 2,and Sp17 were turned on in the maize inresponse to Cd stress,and it might provide new clues toexplain the mechanism of maize tolerance to Cd. | Quanlin DAI Baifei HUANG Zhongyi YANG Jiangang YUAN Junzhi YANG | 2010 | Frontiers of Environmental Science & Engineering2010,4,4: | 0 |