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Origin of the Yueguang gold deposit in Xinhua, Hunan Province, South China: insights from fl uid inclusion and hydrogen–oxygen stable isotope analysis
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作者 Hongxin Fan Qiang Wang +2 位作者 Yulong Yang Yao Tang hao zou 《Acta Geochimica》 EI CAS CSCD 2024年第2期235-254,共20页
The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,w... The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,west of the Baimashan granitic batholith.In order to discern the characteristics of the ore-formingfluids,the underlying mineralization processes,and establish a foundation for the origin of the Yueguang gold depositfluid inclusion micro-thermometry,as well as quartz hydrogen and oxygen isotope analysis,have been carried out on samples obtained from various stages of mineralization.The hydrothermal miner-alization stages within the Yueguang gold deposit can be categorized into three stages:(i)the barren,pre-ore quartz-pyrite stage(Stage Ⅰ),the quartz-pyrite-gold stage(Stage Ⅱ),and the post-ore quartz-carbonate stage(Stage Ⅲ),with the second stage being the main mineralization stage.Thefluid inclusions identified in samples from the main min-eralization stage can predominantly be described with the NaCl–H_(2)O and CO_(2)–NaCl–H_(2)O systems.These inclusions display homogenization temperatures ranging from 158.8 to 334.9℃,and thefluid salinity ranges from 0.3%to 4.0%(wt.%NaCl equiv.).Laser Raman spectroscopy analysis of individual inclusions further reveals the presence of gas-phases such as CO_(2),CH_(4),and N_(2).Isotopic analysis indicatesδ^(18)Ofluid values ranging from 3.95 to 6.7‰ and δDH_(2)O values ranging from-71.9 to-55.7‰.These results indi-cate that the ore-formingfluid of the Yueguang gold deposit belongs to metamorphic hydrothermalfluids of middle-low temperature and low salinity.In the process of ore formation,gold is transported in the form of Au(HS)2-complexes,with gold deposition being driven byfluid immiscibility.Therefore,the Yueguang gold deposit is categorized as an orogenic gold deposit dominated by metamorphic hydrother-malfluid.It may become a new target for gold exploration in the Baimashan region,central Hunan Province. 展开更多
关键词 Hunan province Yueguang gold deposit Fluid inclusions Hydrogen–oxygen isotopes Laser Raman Fluid immiscibility Orogenic gold deposit
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Classification of anatomical morphology of cystic duct and its association with gallstone
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作者 Jia-Hai Zhu Song-Ling Zhao +3 位作者 Qiang Kang Ya Zhu Li-Xin Liu hao zou 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第2期307-317,共11页
BACKGROUND Gallstones are common lesions that often require surgical intervention.Laparo-scopic cholecystectomy is the treatment of choice for symptomatic gallstones.Preoperatively,the anatomical morphology of the cys... BACKGROUND Gallstones are common lesions that often require surgical intervention.Laparo-scopic cholecystectomy is the treatment of choice for symptomatic gallstones.Preoperatively,the anatomical morphology of the cystic duct(CD),needs to be accurately recognized,especially when anatomical variations occur in the CD,which is otherwise prone to bile duct injury.However,at present,there is no optimal classification system for CD morphology applicable in clinical practice,and the relationship between anatomical variations in CDs and gallstones remains to be explored.AIM To create a more comprehensive clinically applicable classification of the morphology of CD and to explore the correlations between anatomic variants of CD and gallstones.METHODS A total of 300 patients were retrospectively enrolled from October 2021 to January 2022.The patients were divided into two groups:The gallstone group and the nongallstone group.Relevant clinical data and anatomical data of the CD based on magnetic resonance cholangiopancreatography(MRCP)were collected and analyzed to propose a morphological classification system of the CD and to explore its relationship with gallstones.Multivariate analysis was performed using logistic regression analyses to identify the independent risk factors using variables that were significant in the univariate analysis.RESULTS Of the 300 patients enrolled in this study,200(66.7%)had gallstones.The mean age was 48.10±13.30 years,142(47.3%)were male,and 158(52.7%)were female.A total of 55.7%of the patients had a body mass index(BMI)≥24 kg/m2.Based on the MRCP,the CD anatomical typology is divided into four types:Type I:Linear,type II:n-shaped,type III:S-shaped,and type IV:W-shaped.Univariate analysis revealed differences between the gallstone and nongallstone groups in relation to sex,BMI,cholesterol,triglycerides,morphology of CD,site of CD insertion into the extrahepatic bile duct,length of CD,and angle between the common hepatic duct and CD.According to the multivariate analysis,female,BMI(≥24 kg/m2),and CD morphology[n-shaped:Odds ratio(OR)=10.97,95%confidence interval(95%CI):5.22-23.07,P<0.001;S-shaped:OR=4.43,95%CI:1.64-11.95,P=0.003;W-shaped:OR=7.74,95%CI:1.88-31.78,P=0.005]were significantly associated with gallstones.CONCLUSION The present study details the morphological variation in the CD and confirms that CD tortuosity is an independent risk factor for gallstones. 展开更多
关键词 Cystic duct GALLSTONE CLASSIFICATION ANATOMY Magnetic resonance cholangiopancreatography Risk factor
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Source-to-sink of Late carboniferous Ordos Basin: Constraints on crustal accretion margins converting to orogenic belts bounding the North China Block 被引量:4
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作者 Anqing Chen hao zou +5 位作者 James G.Ogg Shuai Yang Mingcai Hou Xiuwei Jiang Shenglin Xu Xiaoxing Zhang 《Geoscience Frontiers》 SCIE CAS CSCD 2020年第6期2031-2052,共22页
The Upper Carboniferous Benxi Formation of the Ordos Basin is the lowest strata overlying Middle Ordovician above the major ca.150-Myr sedimentary gap that characterizes the entire North China Block(NCB).We apply an i... The Upper Carboniferous Benxi Formation of the Ordos Basin is the lowest strata overlying Middle Ordovician above the major ca.150-Myr sedimentary gap that characterizes the entire North China Block(NCB).We apply an integrated analysis of stratigraphy,petrography,and U-Pb dates and Hf isotopes on detrital zircons to investigate its provenance and relationships to the progressive collisions that formed the Xing’an-Mongolia Orogenic Belt to the north and the Qinling Orogenic Belt to the south.The results show that,in addition to regional patterns of siliciclastic influx from these new uplifted sources,the Benxi Formation is composed of two sequences corresponding to long-term glacial-interglacial cycles during the Moscovian to lower Gzhelian stages which drove global changes of eustatic sea level and weathering.The spatio-temporal distribution of sediment isopachs and facies indicate there were two sediment-infilling pulses,during which the southern and the northern Ordos Basin developed tidal-reworked deltas.The age spectra from detrital zircons,trace element patterns and εNd(t)values reveal that the siliciclastics forming the southern delta was sourced in the Qinling Orogenic Belt,whereas the northern delta was derived from the Xing’an-Mongolia Orogenic Belt.The source-to-sink evolution of this Upper Paleozoic system records the progressive development of orogenic belts and uplifts forming on the southern and northern margins of the NCB prior to its collisions with the South China and the Siberian plates,respectively. 展开更多
关键词 Benxi formation Detrital zircons Central asian orogen belt TECTONICS PALEOGEOGRAPHY Moscovian and kasimovian
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Fluorite deposits in China:Geological features,metallogenic regularity,and research progress 被引量:9
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作者 Bei-bei Han Peng-qiang Shang +6 位作者 Yong-zhang Gao Sen Jiao Chao-mei Yao hao zou Min Li Liang Wang Hou-yi Zheng 《China Geology》 2020年第3期473-489,共17页
Fluorite is one of the important mineral raw materials in the industry.In China,it is mainly distributed in the provinces and regions such as Hunan,Zhejiang,Jiangxi,Inner Mongolia,Fujian,and Henan provinces,boasting h... Fluorite is one of the important mineral raw materials in the industry.In China,it is mainly distributed in the provinces and regions such as Hunan,Zhejiang,Jiangxi,Inner Mongolia,Fujian,and Henan provinces,boasting huge reserves and large numbers of deposits.However,most of the fluorite deposits are on a small or medium scale.The main fluorite deposits in China were studied in this paper.Their geological features and metallogenic regularity were summarized and compared.Meanwhile,based on their main genetic factors including metallogenic fluid sources and main metallogenic geological processes,they were divided into two groups,namely meso-epithermal deposits and magmatic-hydrothermal deposits.Furthermore,based on the prospecting achievements and research progress obtained in fluorite deposits in recent years,prospecting potential predictions were made for the metallogenic prospect areas and major prospecting areas of fluorite in China.This aims to provide a theoretical basis and direction for future fluorite prospecting in China. 展开更多
关键词 FLUORITE Deposit type Metallogenic regularity Metallogenic belt Prospective prediction Mineral exploration engineering China
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Crust-derived felsic magmatism in the Emeishan large igneous Province:New evidence from zircon U-Pb-Hf-O isotope from the Yangtze Block,China 被引量:3
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作者 hao zou Cheng-Hui Hu +7 位作者 M.Santosh Hai-Feng Chen Chang-Cheng Huang Xin-Wei Chen Hong-Kui Li Xin Jin Li-Ming Yu Min Li 《Geoscience Frontiers》 SCIE CAS CSCD 2022年第3期139-155,共17页
Numerous intrusive bodies of mafic–ultramafic to felsic compositions are exposed in association with volcanic rocks in the Late Permian Emeishan large igneous province(ELIP),southwestern China.Most of the granitic ro... Numerous intrusive bodies of mafic–ultramafic to felsic compositions are exposed in association with volcanic rocks in the Late Permian Emeishan large igneous province(ELIP),southwestern China.Most of the granitic rocks in the ELIP were derived by differentiation of basaltic magmas with a mantle connection,and crustal magmas have rarely been studied.Here we investigate a suite of mafic dykes and Ⅰ-type granites that yield zircon U-Pb emplacement ages of 259.9±1.2 Ma and 259.3±1.3 Ma,respectively.The εHf(t)values of zircon from the DZ mafic dyke are–0.3 to 9.4,and their corresponding TDM1 values are in the range of 919–523 Ma.The εHf(t)values of zircon from the DSC Ⅰ-type granite are between–1 and 3,with TDM1 values showing a range of 938–782 Ma.We also present zircon O isotope data on crust-derived felsic intrusions from the ELIP for the first time.The δ18O values of zircon from the DSC Ⅰ-type granite ranges from 4.87‰to 7.5‰.The field,petrologic,geochemical and isotopic data from our study lead to the following salient findings.(i)The geochronological study of mafic and felsic intrusive rocks in the ELIP shows that the ages of mafic and felsic magmatism are similar.(ii)The DZ mafic dyke and high-Ti basalts have the same source,i.e.,the Emeishan mantle plume.The mafic dyke formed from magmas sourced at the transitional depth between from garnet-lherzolite and spinel-lherzolite,with low degree partial melting(<10%).(iii)The Hf-O isotope data suggest that the DSC Ⅰ-type granite was formed by partial melting of Neoproterozoic juvenile crust and was contaminated by minor volumes of chemically weathered ancient crustal material.(iv)The heat source leading to the formation of the crust-derived felsic rocks in of the ELIP is considered to be mafic–ultramafic magmas generated by a mantle plume,which partially melted the overlying crust,generating the felsic magma. 展开更多
关键词 Emeishan Large Igneous Province Mafic and felsic magmatism Zircon U-Pb-Hf-O isotopes Crustal partial melting Mantle plume
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Early Cretaceous I-type granites in the Tengchong terrane:New constraints on the late Mesozoic tectonic evolution of southwestern China 被引量:2
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作者 Yi Fang Yun-Hui Zhang +3 位作者 Shou-Ting Zhang Hua-Wen Cao hao zou Jian-Hui Dong 《Geoscience Frontiers》 SCIE CAS CSCD 2018年第2期459-470,共12页
The Early Cretaceous granitoids that are widespread in the Tengchong terrane of Southwest China play a critical role in understanding the tectonic framework associated with the Tethyan oceans. In this study, we presen... The Early Cretaceous granitoids that are widespread in the Tengchong terrane of Southwest China play a critical role in understanding the tectonic framework associated with the Tethyan oceans. In this study, we present a detailed description of zircon U-Pb ages, whole-rock geochemistry and Hf isotopes for the Laoxiangkeng pluton in the eastern Tengchong terrane and elucidate their petrogenesis and geodynamic implications. Zircon U-Pb dating of the Laoxiangkeng pluton yields ages of 114 ± 1 Ma and 115 ± 1 Ma,which imply an Early Cretaceous magmatic event. The Laoxiangkeng pluton enriched in Si and Na, is calcalkaline and metaluminous, and has the characteristics of highly fractionated I-type granites. Zircons from the pluton have calculated ε_(Hf)(t) values of-12.7 to-3.7 and two-stage model ages of 1327-1974 Ma,respectively, indicating a mixed source of partial melting of Paleo-Neoproterozoic crust-derived compositions with some inputs of mantle-derived magmas. By integrating all available data for the regional tectonic evolution of the eastern Tethys tectonic domain, we conclude that the Early Cretaceous magmatism in the Tengchong terrane was produced by the northeastward subduction of the Meso-Tethyan Bangong-Nujiang Ocean. 展开更多
关键词 Zircon U-Pb dating GEOCHEMISTRY I-type granite Early Cretaceous Tengchong terrane
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DFT Calculation of Glycine with Methanols Clusters 被引量:1
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作者 hao zou Yong-jun Hu Da Xing 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第6期577-586,J0001,共11页
Density functional theory (DFT) calculations are reported for the structures of neutral and zwitterionic glycine-(CHaOH)n where n=1-6. Initial geometries of the clusters of neutral and zwitterionic glycine with 1-... Density functional theory (DFT) calculations are reported for the structures of neutral and zwitterionic glycine-(CHaOH)n where n=1-6. Initial geometries of the clusters of neutral and zwitterionic glycine with 1-6 methanol molecules are fully optimized at B3LYP/6-31+G^* level of theory. The lowest energy configurations are located and their hydrogen bond structures are analyzed. Theoretical prediction reveals that the methanols prefer to locate near the carboxylic acid group for the small clusters (n_〈3) with the neutral form while the configurations with the methanols bridging the acid and the amino group are favorite in the zwitterionic form clusters. When the number of the methanol molecules in the clusters reaches five and six, the two forms tend to be isoenergetic. 展开更多
关键词 MICROSOLVATION Amino acid METHANOL DFT Hydrogen bond cluster
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Current oscillation in GaN-HEMTs with p-GaN islands buried layer for terahertz applications
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作者 Wen-Lu Yang Lin-An Yang +4 位作者 Fei-Xiang Shen hao zou Yang Li Xiao-Hua Ma Yue hao 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第5期738-742,共5页
A GaN-based high electron mobility transistor(HEMT)with p-GaN islands buried layer(PIBL)for terahertz applications is proposed.The introduction of a p-GaN island redistributes the electric field in the gate–drain cha... A GaN-based high electron mobility transistor(HEMT)with p-GaN islands buried layer(PIBL)for terahertz applications is proposed.The introduction of a p-GaN island redistributes the electric field in the gate–drain channel region,thereby promoting the formation of electronic domains in the two-dimensional electron gas(2DEG)channel.The formation and regulation mechanism of the electronic domains in the device are investigated using Silvaco-TCAD software.Simulation results show that the 0.2µm gate HEMT with a PIBL structure having a p-GaN island doping concentration(Np)of 2.5×10^(18)cm^(−3)–3×10^(18)cm^(−3)can generate stable oscillations up to 344 GHz–400 GHz under the gate–source voltage(V_(gs))of 0.6 V.As the distance(D_(p))between the p-GaN island and the heterojunction interface increases from 5 nm to 15 nm,the fundamental frequency decreases from 377 GHz to 344 GHz,as well as the ratio of oscillation current amplitude of the fundamental component to the average component I_(f1)/I_(avg) ranging from 2.4%to 3.84%. 展开更多
关键词 p-GaN island high electron mobility transistor(HEMT) ALGAN/GAN electron domain
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Effects of notch structures on DC and RF performances of AlGaN/GaN high electron mobility transistors
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作者 hao zou Lin-An Yang +1 位作者 Xiao-Hua Ma Yue hao 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第4期166-172,共7页
The effects of various notch structures on direct current(DC) and radio frequency(RF) performances of AlGaN/GaN high electron mobility transistors(HEMTs) are analyzed.The AlGaN/GaN HEMTs,each with a 0.8-μm gate lengt... The effects of various notch structures on direct current(DC) and radio frequency(RF) performances of AlGaN/GaN high electron mobility transistors(HEMTs) are analyzed.The AlGaN/GaN HEMTs,each with a 0.8-μm gate length,50-μm gate width,and 3-μm source-drain distance in various notch structures at the AlGaN/GaN barrier layer,are manufactured to achieve the desired DC and RF characteristics.The maximum drain current(I_(ds,max)),pinch-off voltage(V_(th)),maximum transconductance(gm),gate voltage swing(GVS),subthreshold current,gate leakage current,pulsed I-V characteristics,breakdown voltage,cut-off frequency(f_(T)),and maximum oscillation frequency(f_(max)) are investigated.The results show that the double-notch structure HEMT has a 30% improvement of gate voltage swing,a 42.2% improvement of breakdown voltage,and a 9% improvement of cut-off frequency compared with the conventional HEMT.The notch structure also has a good suppression of the current collapse. 展开更多
关键词 ALGAN/GAN high electron mobility transistors(HEMTs) barrier layer NOTCH
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Lipid droplet accumulation mediates macrophage survival and Treg recruitment via the CCL20/CCR6 axis in human hepatocellular carcinoma 被引量:1
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作者 Yongchun Wang Weibai Chen +8 位作者 Shuang Qiao hao zou Xing-juan Yu Yanyan Yang Zhixiong Li Junfeng Wang Min-shan Chen Jing Xu Limin Zheng 《Cellular & Molecular Immunology》 SCIE CAS CSCD 2024年第10期1120-1130,共11页
Metabolic changes play a crucial role in determining the status and function of macrophages,but how lipid reprogramming in macrophages contributes to tumor progression is not yet fully understood.Here,we investigated ... Metabolic changes play a crucial role in determining the status and function of macrophages,but how lipid reprogramming in macrophages contributes to tumor progression is not yet fully understood.Here,we investigated the phenotype,contribution,and regulatory mechanisms of lipid droplet(LD)-laden macrophages(LLMs)in hepatocellular carcinoma(HCC).Enriched LLMs were found in tumor tissues and were associated with disease progression in HCC patients.The LLMs displayed immunosuppressive phenotypes(with extensive expression of TREM2,PD-L1,CD206,and CD163)and attenuated the antitumor activities of CD8^(+)T cells.Mechanistically,tumor-induced reshuffling of cellular lipids and TNFα-mediated uptake of tumoral fatty acids contribute to the generation of triglycerides and LDs in macrophages.LDs prolong LLM survival and promote CCL20 secretion,which further recruits CCR6^(+)Tregs to HCC tissue.Inhibiting LLM formation by targeting DGAT1 and DGAT2,which catalyze the synthesis of triglycerides,significantly reduced Treg recruitment,and delayed tumor growth in a mouse hepatic tumor model.Our results reveal the suppressive phenotypes and mechanisms of LLM enrichment in HCC and suggest the therapeutic potential of targeting LLMs for HCC patients. 展开更多
关键词 Lipid droplets Macrophage survival CCL20 Treg Hepatocellular carcinoma
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Integrating machine learning and CALPHAD method for exploring low-modulus near-β-Ti alloys
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作者 hao zou Yue-Yan Tian +5 位作者 Li-Gang Zhang Ren-hao Xue Zi-Xuan Deng Ming-Ming Lu Jian-Xin Wang Li-Bin Liu 《Rare Metals》 SCIE EI CAS CSCD 2024年第1期309-323,共15页
Traditional theoretical and empirical calculation methods can guide the design of β-and metastable β-alloys for bio-titanium. However, it is still difficult to obtain novel near-β-Ti alloys with low modulus. This s... Traditional theoretical and empirical calculation methods can guide the design of β-and metastable β-alloys for bio-titanium. However, it is still difficult to obtain novel near-β-Ti alloys with low modulus. This study developed a method that combines machine learning with calculation of phase diagrams(CALPHAD) to facilitate the design of near-β-Ti alloys. An elastic modulus database of Ti–Nb–Zr–Mo–Ta–Sn system was constructed first, and then three features(the electron to atom ratio, mean absolute deviation of atom mass, and mean electronegativity) were selected as the key factors of modulus by performing a three-step feature selection. With these features, a highly accurate model was built for predicting the modulus of near-β-Ti alloys. To further ensure the accuracy of modulus prediction, machine learning with the elastic constants calculated was leveraged by CALPHAD database. The root mean square error of the well-trained model can be as low as 6.75 GPa. Guided by the prediction of machine learning and CALPHAD, three novel near-β-Ti alloys with elastic modulus below 50 GPa were successfully designed in this study. The best candidate alloy(Ti–26Nb–4Zr–4Sn–1Mo–Ta) exhibits an ultra-low modulus(36.6 GPa) after cold rolling with a thickness reduction of 20%. Our method can greatly save time and resources in the development of novel Ti alloys, and experimental verifications have demonstrated the reliability of this method. 展开更多
关键词 Near-β-Ti alloy Machine learning Calculation of phase diagram Low-modulus alloy Feature selection
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Evolution of Paleozoic West Junggar Basin,NW China:Seismic data,detrital zircon evidence from Earth’s oldest alkali lake deposit
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作者 Dongming Zhi Deyu Gong +5 位作者 Mingxin Liu M.Santosh Zhijun Qin Qiang Ren Xinwei Chen hao zou 《Geoscience Frontiers》 SCIE CAS CSCD 2024年第6期137-155,共19页
The Permian Fengcheng Formation of the Western Junggar region in the Southwestern Central Asian Orogenic Belt(CAOB)represents one of Earth’s oldest alkali lake deposits.Here,we present a comprehensive study of the st... The Permian Fengcheng Formation of the Western Junggar region in the Southwestern Central Asian Orogenic Belt(CAOB)represents one of Earth’s oldest alkali lake deposits.Here,we present a comprehensive study of the stratigraphy,petrography,two-dimensional seismic data,U–Pb geochronology,and Hf isotope analysis of detrital zircons of this deposit.The results,in conjunction with published data,reflect the tectonic evolution of southwestern CAOB.The ages of detrital zircons indicate that the Fengcheng Formation deposition is inferred to have concluded the early Permian Kungurian.The Hf isotopes of detrital zircons indicate that the detritus for the Fengcheng Formation was derived from upper crustal magmatic sources.The West Junggar Basin preserves the records of three Paleozoic tectonic stages.The first stage occurred in the Early Paleozoic and involved intraoceanic subduction and arc-continent collision.The second stage involved the Carboniferous closure of the Junggar Ocean following successive filling of oceanic basins.The final stage occurred in the Early Permian and was related to intracontinental rifting and tectonic inversion.The results of comparing the comprehensive data of U–Pb ages and Hf isotopes of 2537 zircons from West Junggar,Tianshan and Altay show that the orogenic belts to the south of the CAOB experienced similar plate kinematics and vertical crustal growth in the Paleozoic. 展开更多
关键词 Detrital zircon dating Alkali lake deposit Multiple tectonic events Crustal growth Central Asian Orogenic Belt
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The Early-Middle Triassic Supervolcano in the Yangtze Block,South China and associated obstacles to biotic recovery
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作者 Haifeng Chen hao zou +4 位作者 MSantosh Huawen Cao Franco Pirajno Changcheng Huang Mingcai Hou 《Geoscience Frontiers》 SCIE CAS CSCD 2024年第1期69-83,共15页
The end-Permian mass extinction was one of the major global crises spanning the entire Early Triassic or longer.Eruptions of volcanos were one of the factors that delayed the biotic recovery after this event.Supervolc... The end-Permian mass extinction was one of the major global crises spanning the entire Early Triassic or longer.Eruptions of volcanos were one of the factors that delayed the biotic recovery after this event.Supervolcano eruptions can cause catastrophic effects on global environment,climate,and life.Here we investigate the tuff layers from Early-Middle Triassic boundary in the Yangtze Block and identify a supervolcano eruption event.The zircon U-Pb ages of the section-Langdai,section-Daijiagou and section-Longmendong tuff samples are 247.1±1.9 Ma,247.6±2.0 Ma and 247.7±1.7 Ma,respectively.These ages mark the Olenekian-Anisian boundary.The zircon grains from the tuff layers have negativeεHf(t)(-15.3 to-0.8),two-stage Hf model(TDM2)ages(1.7 to 2.2 Ga)and display high-δ18O values(mostly>10‰).Clay minerals and quartz dominate the rock composition.The whole rock compositions show that the tuff layers were derived from magma of intermediate to felsic composition,which formed by the remelting of Paleoproterozoic materials of continental crust.The volcanic eruption site is located in the Jinshajiang-Ailaoshan-Song Ma suture zone in the southwestern margin of the Yangtze Block.A combination of the closure of the Paleo-Tethys Ocean Basin and the collision of the Indochina Block and South China contributed to the eruption,which was a supervolcano eruption under the active continental margin arc settings.We speculate that this supervolcano eruption might have contributed to the delayed biotic recovery after the end-Permian mass extinction. 展开更多
关键词 Early-Middle Triassic Tuff layer Supervolcano Yangtze Block Biotic recovery
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Fecal microbiota reveal adaptation of herbivores to the extreme environment of the Qinghai–Tibet Plateau
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作者 hao zou Qi Li +4 位作者 Jie Liu Xiangtao Wang Qun Gao Yunfeng Yang Xinquan Zhao 《Grassland Research》 2024年第2期155-170,共16页
Background:Gut microbiota is pivotal in regulating hosts'biological processes and maintaining homeostasis,but knowledge about its role in wild herbivores in extreme environments remains limited.Methods:Gut bacteri... Background:Gut microbiota is pivotal in regulating hosts'biological processes and maintaining homeostasis,but knowledge about its role in wild herbivores in extreme environments remains limited.Methods:Gut bacteria and fungi were sequenced in ruminant(Chiru and Yak)and nonruminant(Kiang)herbivores on the Qinghai–Tibet Plateau,and their community structure,co-occurrence networks,functions,and assembly mechanisms were investigated using multivariate ecological and statistical methods.Results:Kiang had lower gut microbial diversity than Chiru and Yak.Bacterial host-specific exclusivity was greater than that of fungi.In addition to the evidence of glycan biosynthesis and carbohydrate metabolism,Chiru had a high Firmicutes/Bacteroidetes ratio and low animal pathogen abundance,suggesting better adaptation to the plateau's harsh environment.Additionally,members of gut microbiota tended to co-occur rather than co-exclude in all herbivores.Different network complexity and stability patterns were observed between bacterial and fungal communities.Furthermore,gut bacterial assembly was primarily controlled by stochastic dispersal limitation and drift,whereas fungal assembly was primarily controlled by deterministic homogeneous selection except in Chiru.Conclusions:On the Qinghai–Tibet Plateau,Chiru and Yak exhibit more diverse gut microbiota and more diverse metabolic functions than Kiang,and gut bacteria are more divergent than gut fungi in these herbivores. 展开更多
关键词 community assembly composition and diversity gut microbiota Qinghai-Tibet Plateau ruminant and nonruminant herbivores
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炎热气候下基于光谱管理和辐射制冷的温室薄膜材料
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作者 邹豪 王晨曦 +3 位作者 余佳琦 黄丹枫 杨荣贵 王如竹 《Science Bulletin》 SCIE EI CAS CSCD 2023年第14期1493-1496,M0003,共5页
炎热气候下,温室内部热量过度累积、气温过高的问题经常发生,严重影响温室内作物的生长发育,大大降低了温室的周年利用率和经济效益.为此,有效调节温室内气温已经成为炎热地区温室栽培需要解决的首要问题.基于光谱管理和辐射制冷原理,... 炎热气候下,温室内部热量过度累积、气温过高的问题经常发生,严重影响温室内作物的生长发育,大大降低了温室的周年利用率和经济效益.为此,有效调节温室内气温已经成为炎热地区温室栽培需要解决的首要问题.基于光谱管理和辐射制冷原理,本文提出两种不同属性薄膜分别作为温室覆盖材料和地膜,在不牺牲植物光合作用的前提下,减少温室内部热积累,从而延长温室可用生产周期.作为覆盖材料的透明辐射制冷薄膜(T-RC)具有大气窗口波段高发射率,光合有效辐射波段高透过率和近红外辐射波段高反射率,在田间试验中可较PO薄膜温室降温18.6℃,并使樱桃萝卜产量提高62.7%.作为地膜的高反射辐射制冷薄膜(RC)在大气窗口波段具有高发射率,同时在太阳光谱波段保持高反射率.覆盖RC薄膜后,地温可较空白土壤降低12.5℃,并使杭白菜产量增加127.35%.这两种薄膜为炎热气候条件下的温室增产提供了一种被动式、零能耗的新路径. 展开更多
关键词 温室栽培 樱桃萝卜 炎热气候 辐射制冷 近红外辐射 高反射率 大气窗口 室内气温
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Solidification segregation behavior of Nb-containing 310S steel
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作者 Yu-tuo Zhang hao zou 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2023年第1期82-87,共6页
The solidification characteristics and segregation behavior of solute elements Nb,Ni,Mn,Si,Cr and C in 0.3 wt.%Nb-310S steel were investigated using the isothermal solidification quenching experiment and Thermo-Calc c... The solidification characteristics and segregation behavior of solute elements Nb,Ni,Mn,Si,Cr and C in 0.3 wt.%Nb-310S steel were investigated using the isothermal solidification quenching experiment and Thermo-Calc calculation.The phase transformation for 0.3%Nb-310S steel under equilibrium condition can be summarized as follows:liquid(L)→L+γ(1406℃)→γ(1334℃)→γ+NbC(1322℃)→γ+NbC+M_(23)C_(6)(1006℃)→γ+NbC+M_(23)C_(6)→σ(755℃).The results showed that the solidification began with the formation of primary austenite dendrite.The volume fraction of the liquid phase decreased rapidly as the temperature decreased in the initial solidification stage,and then,the liquid phase fraction decreased slowly.When austenite formed,Mn and Ni were enriched in the solid phase,while Nb and C were rejected into the liquid.Nb was present the highest segregation coefficient in 0.3%Nb-310S austenitic stainless steel.The segregation of Nb was the most serious,followed by Mn,Ni and C.Cr and Si exhibited slight segregation during the solidification.The solidification was terminated by the formation of NbC phase. 展开更多
关键词 310S steel Nb SOLIDIFICATION SEGREGATION Thermo-Calc calculation
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下一代互联网互联设备关键技术专利导航研究综述 被引量:2
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作者 贾宏君 周静 +12 位作者 乔开文 张丹 谢祥 刘杰 娄颖 张铭 马跃 张柏秋 何笑冬 张凌宇 郑晔晴 邹昊 刘科 《中国科学:信息科学》 CSCD 北大核心 2022年第5期765-783,共19页
下一代互联网是全球各国推动科技产业革命和重塑国家长期竞争力的基础设施和先导领域,同样也是高科技密布、专利密集的战略性新兴产业领域,技术研发与创新竞争异常激烈.本文运用专利导航方法对全球下一代互联网互联设备相关技术进行了分... 下一代互联网是全球各国推动科技产业革命和重塑国家长期竞争力的基础设施和先导领域,同样也是高科技密布、专利密集的战略性新兴产业领域,技术研发与创新竞争异常激烈.本文运用专利导航方法对全球下一代互联网互联设备相关技术进行了分析,通过对本导航领域多位技术专家的访谈,澄清和界定了下一代互联网互联设备关键技术的基本定义与范畴,从总体趋势、地域、核心申请人、核心发明人、专利强度、我国向国外申请专利,以及技术分支等方面分析了全球及我国下一代互联网互联设备关键技术的专利布局现状、竞争前沿和未来趋势,结合本导航领域国内外典型案例的总结,对研发创新和专利运用提出了相应的导航建议. 展开更多
关键词 下一代互联网 未来网络 互联技术 专利导航
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价格竞争下风险规避对闭环供应链决策的影响研究
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作者 邹浩 秦进 《数学的实践与认识》 2021年第1期277-287,共11页
基于零售商销售价格与回收价格竞争情形,构建了一个可持续的闭环供应链.考虑决策者风险规避行为,研究了闭环供应链成员的定价决策问题.利用博弈论,在风险中性与风险规避特性下分别探讨了批发价格,零售价格和回收价格的最优决策,并建立... 基于零售商销售价格与回收价格竞争情形,构建了一个可持续的闭环供应链.考虑决策者风险规避行为,研究了闭环供应链成员的定价决策问题.利用博弈论,在风险中性与风险规避特性下分别探讨了批发价格,零售价格和回收价格的最优决策,并建立了它们的表达式.研究结论表明,仅当零售商具有风险规避时,制造商决策不受零售商的影响,而仅当制造商具有风险规避时,零售商决策会受制造商的影响.同时,当二者都具有风险规避特性时,他们之间的决策会相互影响. 展开更多
关键词 价格竞争 风险规避 闭环供应链 决策分析
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Phase relations,microstructure,and valence transition studies on CaZr1-xCexTi2O7(0.0≤x≤1.0)system 被引量:1
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作者 Weimin Li Faqin Dong +2 位作者 Liang Bian hao zou Mianxin Song 《Journal of Rare Earths》 SCIE EI CAS CSCD 2018年第11期1184-1189,共6页
In this study, Ce-doped zirconolite was synthesized through high-temperature solid-state reaction at 1250 ℃ in air for 96 h. The crystal phase, microstructure and valence transition were studied by X-ray diffraction ... In this study, Ce-doped zirconolite was synthesized through high-temperature solid-state reaction at 1250 ℃ in air for 96 h. The crystal phase, microstructure and valence transition were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Phase relations of CaZrl xCexTi207 systems were determined by XRD analyses and Rietveld refinements. Four different phases are identified, namely zirconolite, perovskite, pyrochlore, and cerianite. The phase transformation (2M-zirconolite → 4M-zirconolite →Ce-pyrochlore) is caused by cations rearrangement as cerium content increases. The solubility limit of cerium ions in CaZrl .xCexTi207 system is estimated to be approximately 0.80. Under sintering air atmosphere, partial reduction of Ce^4+ in Ce^3+ is detected in Ce 3d XPS soectra, and the ratio of Ce^3+ and Ce^4+ significantly decreases as cerium content increases. 展开更多
关键词 ZIRCONOLITE Ce-pyrochlore Phase relations Valence transition Rare earths
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Effects of Paclitaxel-conjugated N-SuccinyI-Hydroxyethyl Chitosan Film for Proliferative Cholangitis in Rabbit Biliary Stricture Model
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作者 Tao Wang hao zou +1 位作者 Yun-Xia Liu Xiao-Wen Zhang 《Chinese Medical Journal》 SCIE CAS CSCD 2018年第6期696-703,共8页
Background: Paclitaxel (PTX) could inhibit the growth of fibroblasts, which occurs in proliferative cholangitis and leads to biliary stricture. However, its use has been limited due to poor bioavailability and loca... Background: Paclitaxel (PTX) could inhibit the growth of fibroblasts, which occurs in proliferative cholangitis and leads to biliary stricture. However, its use has been limited due to poor bioavailability and local administration for short time. This study designed and synthesized a new PTX-conjugated chitosan film (N-succinyl-hydroxyethyl chitosan containing PTX [PTX-SHEC]) and evaluated its safety and efficiency using in vivo and in vitro experiments. Methods: The SHEC conjugated with PTX was confirmed by nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FT-IR) measurements. Drug releases in vitro and in vivo were determined using high-performance liquid chromatography. Cell viability in vitro was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. Rabbit biliary stricture model was constructed. All rabbits randomly divided into five groups (n = 8 in each group): the sham-operated rabbits were used as control (Group A), Groups B received laparotomies and suture, Group C received laparotomies and covered SHEC suture without the PTX coating, Group D received laparotomies and covered PTX-SHEC suture, and Group E received laparotomies and 1000 μmol/L PTX administration. Liver function tests and residual dosage of PTX from each group were measured by enzyme-linked immunosorbent assay. Histological data and a-smooth muscle actin (SMA) immunohistochemical staining of common bile duct were examined. Results: NMR and FT-1R indicated that PTX was successfully introduced, based on the appearance of signals at 7.41-7.99 ppm, 1.50 ppm, and 1.03 ppm, due to the presence of aromatic protons, methylene protons, and methyl protons of PTX, respectively. No bile leak was observed. The PTX-conjugated film could slowly release PTX for 4 weeks (8.89 ± 0.03/ag at day 30). The in vitro cell viability test revealed significantly different levels of toxicity between films with and without PTX ([ 11.7± 4.0% vs. 68. l±6.0%, P 〈 0.001 ), whereas no statistically significant difference was observed among the three sets of PTX-contained films (67.7 ± 5.4%, 67.2±3.4%, and 59.1± 6.0%, P 〉 0.05). Histological examinations revealed that after 28 days of implantment, Groups D and E (but not Group C) had less granulation tissue and glandular hyperplasia in the site ofbiliary duct injury than Group B. The pattern was more obvious in Group D than Group E. Less α-SMA-positive cells were found in tissue from Groups D and E. Comparing with Group E, the liver function was improved significantly in Group D, including total bilirubin (2.69± 1.03 μmol/L vs. 0.81 ± 0.54 μmol/L, P = 0.014), alanine aminotransferase (87.13 ± 17.51 U/L vs. 42.12 ± 15.76 U/L, P = 0.012), and alkaline phosphatase (60.61± 12.31 U/L vs. 40.59 ± 8.78 U/L, P 〈 0.001). Conclusions: PTX-SHEC film effectively inhibites the myofibroblast proliferation and extracellular matrix over-deposition during the healing process of biliary reconstruction. This original film might offer a new way for reducing the occurrence of the benign biliary stricture. 展开更多
关键词 Biliary Stricture CHITOSAN PACLITAXEL ProliferativeCholangitis Slow-Releasing
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