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Diffusion of helium in FCT zircon

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Science China Earth Sciences 2019年第4期62卷 719-732页

作者： Shun YU Wen CHEN jingbo sun Ze SHEN Laboratory of Isotope Thermochronology Institute of Geology Chinese Academy of Geological Sciences Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources Institute of GeologyChinese Academy of Geological Sciences

To gain a better quantitative understanding of zircon(U-Th)/He ages and evaluate the applicability of zircon(U-Th)/He dating, the diffusion characteristics, He diffusion kinetics, helium partial retention zone(HePRZ), closure temperature, and(U-Th)/He ages were investigated using high-precision laboratory step heating experiments based on the thermally activated diffusion process. The ln(D/a^2) in Fish Canyon Tuff(FCT) zircons determined from laboratory step heating experiments was negatively correlated with reciprocal temperature, as expected for thermally activated volume diffusion. The zircon activation energies ranged from 144 to 184 kJ mol^(-1) with a mean of 169±12 kJ mol^(-1). The closure temperatures ranged from 144 to 216°C(a cooling rate of 10°C Ma^(-1) and an effective grain radius of 38–60 μm) with an average of 176±18°C. The calculated closure temperature increased with increasing cooling rate, yielding an average zircon He closure temperature of ～136°C at a slow cooling rate of 0.1°C Ma^(-1), whereas the closure value was ～199°C at a cooling rate of 100°C Ma^(-1). The closure temperature increased with the equivalent spherical radius assuming a constant cooling rate. The He ages from FCT zircons were negligibly affected by grain size because of the rapid cooling. He preserved in the zircon was sensitive to temperature and holding time, and the temperature range for zircon HePRZ gradually decreased with increasing holding time. The(U-Th)/He ages from 26 FCT zircons yielded an algorithmic mean of 28.3±0.3 Ma(S.E.) and a geometric mean of 28.4±0.3 Ma(S.E.), consistent with the ages of 28.4±1.9 Ma reported by other laboratories. The FCT zircons were characterized by rapid cooling, young(U-Th)/He ages with good reproducibility, and low alpha doses. Weak correlations between the He ages and effective uranium(eU) concentrations from the FCT zircons indicated radiation damage did not significantly affect He diffusivity.

关键词： Zircon Helium diffusion (U-Th)/He Closure temperature Thermochronometry

Metamaterials:From Engineered Materials to Engineering Materials

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Engineering 2022年第10期17卷 1-2页

作者： John Pendry Ji Zhou jingbo sun Department of Physics Imperial College LondonLondon SW72AZUK School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

As a new frontier in materials science,metamaterials have experienced a boom in the past two *** research field began with artificially structured materials exhibiting extraordinary electromagnetic properties unavailable in nature;now,it extends to a large family of artificial-material systems with wide-ranging,extraordinary,and outstanding properties for applications in fields such as electromagnetics,optics,mechanics.

关键词： Engine frontier optics

Late Mesozoic Tectono-Thermal History in the South Margin of Great Xing’an Range,NE China:Insights from Zircon and Apatite(U-Th)/He Ages

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Journal of Earth Science 2022年第1期33卷 36-44页

作者： Wen Zhang Shuangfeng Zhao jingbo sun Ze Shen Wen Chen Laboratory of Isotope Thermochronology Key Laboratory of Deep-Earth Dynamics of Ministry of Natural ResourcesInstitute of GeologyChinese Academy of Geological SciencesBeijing 100037China

The Late Mesozoic tectono-thermal evolution and geodynamic setting of the Great Xing’an Range(GXR),particularly in the south margin,are still *** this study,we present original low-temperature thermochronological data of six granitoid samples collected from Maanzi pluton in the south margin of the *** apatite and zircon(U-Th)/He ages vary of 70.8 ± 4.3-119.0 ±7.0 Ma and 120.0 ± 7.1-146.7 ± 8.7 Ma,*** numerical inverse modeling results reveal that the granitoid plutons experienced a rapid cooling and exhumation stage during Early Cretaceous with a rate of ~5.0-6.0 ℃/Ma and ~0.14-0.17 mm/yr,respectively,including the western minor pluton emplaced during Early Permian and the major pluton crystallized in latest Jurassic,corresponding to the extensional tectonics in NE *** rapid exhumation processes in the south margin of the GXR during the Early Cretaceous could be related to both the rollback of Paleo-Pacific oceanic plate and the collapse of thickened crust in the Mongol-Okhotsk Orogen.

关键词： Great Xing’an Range tectono-thermal history (U-Th)/He dating extensional tectonics Mongol-Okhotsk collapse Paleo-Pacific subduction geochemistry

Zircon U-Pb Ages and Tectonic Implications of Late Paleozoic Volcanic Rocks in the Western Tianshan,North Xinjiang,China

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Journal of Earth Science 2022年第3期33卷 736-752页

作者： Zaili Tao Jiyuan Yin Wen Chen Yuelong Chen jingbo sun Zhihua Xu School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China Limited Liability Company TBEA DUSHANBE Mining IndustryChangji 831100China

The Late Paleozoic volcanic rocks are widespread in the Western Tianshan,and mainly consist of basalt,trachyte,trachy-andesite,andesite and ***,the formation timing and tectonic implications of the volcanic rocks remain *** obtain a comprehensive dataset with adequate spatial coverage,we collected the published zircon U-Pb age data of the Late Paleozoic volcanic rocks in the Western Tianshan,and mapped the temporal and spatial distribution of these volcanic *** compiled dataset indicates that the volcanic rocks in the Western Tianshan were formed in two major stages:Late Silurian-Early Carboniferous and Late Carboniferous-Middle *** southward subduction of the Northern Tianshan Ocean formed a large number of Late Silurian-Early Carboniferous volcanic *** flare-up of Late Carboniferous to Middle Permian magmatism in the NTOB was considered to be the response of the slab-roll back of the northern Tianshan ***,arc magma assemblage and spatial-temporal distribution are of great significance to identify the dynamic mechanism transformation of subduction zone.

关键词： volcanic rocks zircon Western Tianshan tectonic transformation slab-roll back

Large focal length planar focusing of Dyakonov polaritons in hyperbolic metamaterial

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Progress in Natural Science:Materials International 2024年第4期34卷 632-636页

作者： Xiaoyu Xiong Yihang Fan Weipeng Wang Yongzheng Wen Zhengjun Zhang jingbo sun Ji Zhou State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and Engineering Tsinghua University Key Laboratory of Advanced Materials (MOE) School of Materials Science and Engineering Tsinghua University

Achieving subwavelength optical focusing is of great importance in nanophotonics. However, achieving focusing with both a small focal spot size and a large focal length remains elusive so far. Here, a large focal length planar focusing device is presented, utilizing highly oriented Dyakonov polaritons in hyperbolic metamaterial with periodic silver rings as the excitation source. Experimental results show that by controlling the size of the excitation sources, the focal length can reach 6λ0（where λ0is the illumination wavelength）, and the focal spot size can be reduced to λ0/10. This method provides new prospects for planar polariton optical applications.

关键词： Subwavelength optical focusing Dyakonov polaritons In-plane hyperbolic metamaterials Near-field optics

Clathrin light chains regulate hypocotyl elongation by affecting the polarization of the auxin transporter PIN3 in Arabidopsis

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Journal of Integrative Plant Biology 2021年第11期63卷 1922-1936页

作者： Tianwei Hu Shoupeng Yin jingbo sun Yuting Linghu Jiaqi Ma Jianwei Pan Chao Wang Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations School of Life SciencesLanzhou UniversityLanzhou 730000China College of Chemistry and Life Sciences Zhejiang Normal UniversityJinhua 321004China College of Life Sciences Shaoxing UniversityShaoxing 312000China

PIN-FORMED(PIN)-dependent directional auxin transport is crucial for plant development. Although the redistribution of auxin mediated by the polarization of PIN3 plays key roles in modulating hypocotyl cell expansion, how PIN3 becomes repolarized to the proper sites within hypocotyl cells is poorly understood. We previously generated the clathrin light chain clc2-1 clc3-1 double mutant in Arabidopsis thaliana and found that it has an elongated hypocotyl phenotype compared to the wild type. Here, we performed genetic, cell biology, and pharmacological analyses combined with live-cell imaging to elucidate the molecular mechanism underlying the role of clathrin light chains in hypocotyl elongation. Our analyses indicated that the defects of the double mutant enhanced auxin maxima in epidermal cells, thus, promoting hypocotyl elongation. PIN3 relocated to the lateral sides of hypocotyl endodermal cells in clc2-1 clc3-1 mutants to redirect auxin toward the epidermal cell ***, the loss of function of PIN3 largely suppressed the long hypocotyl phenotype of the clc2-1 clc3-1 double mutant, as did treatment with auxin transport inhibitors. Based on these data, we propose that clathrin modulates PIN3 abundance and polarity to direct auxin flux and inhibit cell elongation in the hypocotyl, providing novel insights into the regulation of hypocotyl elongation.

关键词： Arabidopsis auxin clathrin light chains hypocotyl elongation PIN3

Design and Synthesis of 3-Triazolo-coumarins and Their Applications in Scavenging Radicals and Protecting DNA

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Chemical Research in Chinese Universities 2015年第4期31卷 526-533页

作者： LIU Zhihui WANG Yingnan sun jingbo YANG Yang LIU Qingwen LIU Zaiqun SONG Zhiguang Hospital of Stomatology Jilin University Changchun 130021 P R. China Department of Organic Chemistry College of Chemistry Jilin University Changchun 130012 P 1L China

In this study, we synthesized a series of 3-triazolo-coumarins and evaluated their antioxidant activities respectively by two methods： trapping 2,2＇-azinobis（3-ethylbenzothiazoline-6-sulfonate） cationic radical（ABTS＋＋） and oxidation of DNA which was induced by Cu2＋/glutathione（GSH）, ·OH and 2,2＇-azobis（2-amidinopropane hydrochloride）（AAPH）. Among the nine 3-triazolo-coumarins, compounds 6c and 6f-6i were synthesized for the first time, which exhibited the capability of terminating radical propagation-chains in oxidation of DNA induced by AAPH. In this study, we found that phenethylamine moiety, hydroxyl and ortho-methoxy are the key groups to en- hance the antioxidant activities of compounds.

关键词： 3-Triazolo-coumarin Coumarin Free radical Oxidation Antioxidant DNA

Neuroprotective effect of the traditional Chinese herbal formula Tongxinluo: a PET imaging study in rats

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Neural Regeneration Research 2014年第13期9卷 1267-1274页

作者： Xiao Cheng Haoxuan Luo Lihua Zhou Lixin Wang jingbo sun Yan Huang Enli Luo Yefeng Cai Encephalopathy Center Guangdong Provincial Hospital of Traditional Chinese Medicine Department of Anatomy Zhongshan School of Medicine Sun Yat-Sen University

Tongxinluo has been widely used in China for the treatment of acute stroke and for neuroprotection. However, there are few positron emission tomography （PET） studies on the neuroprotective effect of Tongxinluo on cerebral ischemia/reperfusion in small animals. In the present study, Tongxinluo superfine powder suspension or its vehicle was administered intragastrically to rats for 5 successive days before middle cerebral artery occlusion, ^18Ffluorodeoxyglucose （FDG） small animal PET imaging showed that at 1 and 2 weeks after cerebral ischemia/reperfusion, glucose metabolism in the ischemic area was greater in rats that had received Tongxinluo than in those that had received the vehicle. Nissl staining showed that 2 weeks after cerebral ischemia/reperfusion, there was less neuronal loss in the prefrontal cortex in Tongxinluo-treated rats than in controls. In addition, Tongxinluo-treated animals showed better neurologic function and lower cerebral infarct volume than rats that received the vehicle. These findings suggest that Tongxinluo exhibits neuroprotective effects in cerebral ischemia/reperfusion injury and demonstrates that ^18F-FDG small animal PET imaging is a useful tool with which to study the molecular pharmacology of traditional Chinese medicine.

关键词： nerve regeneration cerebral ischemia/reperfusion Tongxinluo capsule middle cerebralartery occlusion positron emission tomography neuroprotection NSFC grant neural regeneration

New Changes in Business English Teaching System under the Background of Big Data

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教育研究前沿（中英文版） 2020年第3期10卷 216-221页

作者： jingbo sun Beijing Wuzi University No.1 Fuhe Street Tongzhou DistrictBeijing China

Big data,as an advanced form of information technology,not only brings challenges for business conductions,which is greatly influencing people’s live,but also triggers changes in business English *** paper,inspired by the rapid development of big data technology,attempts to probe the relationship between business English teaching and big data,the influences of big data technology on business English teaching *** changes in business teaching theories,notions,models and environment created by big data will be specifically discussed and analyzed in this paper in order to facilitate teachers to better carry out teaching innovations.

关键词： Big Data Business English Changes Business English Teaching System