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浙江宁波鱼山遗址出土木材的种属鉴定与分析
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作者 赵一凡 王树芝 +1 位作者 雷少 焦延静 《农业考古》 北大核心 2024年第4期15-25,共11页
鱼山遗址是浙江省宁波市镇海区以河姆渡文化和商周时期遗存为主体的一处遗址。在2013~2015年发掘中,采集了58个木材样品。经鉴定,出土木材分别属于柏木属(Cupressus sp.)、松属(Pinus sp.)、甜槠(Castanopsis eyrei)、青冈属(Cyclobalan... 鱼山遗址是浙江省宁波市镇海区以河姆渡文化和商周时期遗存为主体的一处遗址。在2013~2015年发掘中,采集了58个木材样品。经鉴定,出土木材分别属于柏木属(Cupressus sp.)、松属(Pinus sp.)、甜槠(Castanopsis eyrei)、青冈属(Cyclobalanopsis sp.)等15个属或种。研究表明,鱼山先民主要利用遗址周边的树木资源,而且松属、青冈属木材在先民生活中有重要作用,被广泛用作建材和生活用器用材;青冈属为代表的壳斗科树木在河姆渡文化、良渚文化时期可能是先民的食物资源而得到了先民的保护;先民选用甜槠制作木屐,利用榉属、糙叶树属、柿属木材修筑木构通道,利用青冈、甜槠制作木陀螺;在遗址区域发现了古松树遗存,可能是先民自然神信仰的体现。鱼山先民在木材利用上体现了就地取材、因材施用的特点,为探讨宁绍平原史前树木资源利用模式提供了新材料。 展开更多
关键词 鱼山遗址 木材考古 木材利用 木材解剖 考古学文化
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A dendritic Cu/Cu_(2)O structure with high curvature enables rapid and efficient reduction of carbon dioxide to C2 in an H-cell
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作者 lei shao Bochen Hu +3 位作者 Jinhui Hao Junjie Jin Weidong Shi Min Chen 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第8期144-153,共10页
Electrocatalytic reduction of CO_(2)(CO_(2)RR)to multicarbon products is an efficient approach for ad-dressing the energy crisis and achieving carbon neutrality.In H-cells,achieving high-current C_(2)products is chall... Electrocatalytic reduction of CO_(2)(CO_(2)RR)to multicarbon products is an efficient approach for ad-dressing the energy crisis and achieving carbon neutrality.In H-cells,achieving high-current C_(2)products is challenging because of the inefficient mass transfer of the catalyst and the presence of the hydrogen evolution reaction(HER).In this study,dendritic Cu/Cu_(2)O with abundant Cu^(0)/Cu^(+)interfaces and numerous dendritic curves was synthesized in a CO_(2)atmosphere,resulting in the high selectivity and current density of the C_(2)products.Dendritic Cu/Cu_(2)O achieved a C_(2)Faradaic efficiency of 69.8%and a C_(2)partial current density of 129.5 mA cm^(-2)in an H-cell.Finite element simulations showed that a dendritic structure with a high curvature generates a strong electric field,leading to a localized CO_(2)concentration.Additionally,DRT analysis showed that a dendritic struc-ture with a high curvature actively adsorbed the surrounding high concentration of CO_(2),enhancing the mass transfer rate and achieving a high current density.During the experiment,the impact of the electronic structure on the performance of the catalyst was investigated by varying the atomic ratio of Cu^(0)/Cu^(+)on the catalyst surface,which resulted in improved ethylene selectivity.Under the optimal atomic ratio of Cu^(0)/Cu^(+),the charge transfer resistance was minimized,and the desorption rate of the intermediates was low,favoring C_(2)generation.Density functional theory calculations indicated that the Cu^(0)/Cu^(+)interfaces exhibited a lower Gibbs free energy for the rate-determining step,enhancing C_(2)H4 formation.The Cu/Cu_(2)O catalyst also exhibited a low Cu d-band center,which enhanced the adsorption stability of*CO on the surface and facilitated C_(2)formation.This observa-tion explained the higher yield of C_(2)products at the Cu^(0)/Cu^(+)interface than that of H_(2)under rapid mass transfer.The results of the net present value model showed that the H-cell holds promising industrial prospects,contingent upon it being a catalyst with both high selectivity and high current density.This approach of integrating the structure and composition provides new insights for ad-vancing the CO_(2)RR towards high-current C_(2)products. 展开更多
关键词 Reduction of CO_(2) High current Dendritic structure Cu/Cu_(2)O H-cell
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Paleogene transgression process and environmental evolution in the deepwater area of the Baiyun Depression in the northern South China Sea
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作者 Peijun Qiao Yuchi Cui +2 位作者 Qiong Ma Qiang Yu lei shao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第4期15-24,共10页
Multiple borehole samples are collected from the Baiyun Depression in deep-water area of the northern South China Sea(SCS)in an effort to reconstruct transgression processes during the Paleogene based on palynalgal an... Multiple borehole samples are collected from the Baiyun Depression in deep-water area of the northern South China Sea(SCS)in an effort to reconstruct transgression processes during the Paleogene based on palynalgal analysis.This study indicates that the Baiyun Depression generated a large group of palynopore assemblages and fluvial/lacustrine-related algae during the early and middle Eocene when the Wenchang Formation was deposited.The entire depression was dominated by fluvial and lacustrine facies before transgression.Its eastern and southeastern sags transitioned to shallow marine environment by generating a large abundance of marine dinoflagellates during the Enping deposition of the late Eocene.Meanwhile,the southern uplift zone simply yielded fluvial/lacustrine-related palynopores and algae,and was dominated by the fluvial and lacustrine environment during the early stage of the Enping Formation,prior to shifting into transitional setting in the later period.Northwestern sags remained extensive fluvial and delta facies without existence of marine dinoflagellates.It was until the depositional stage of the Zhuhai Formation(Oligocene)that the overall depression was strongly impacted from transgression process.Both eastern and southeastern sags were mainly under deep marine setting on a continental slope while northwestern and southern areas developed transitional facies.Although distribution and accumulation patterns varied greatly among sub-sags,the overall Baiyun Depression was characterized by widespread development of marine dinoflagellates.It should be noted that the northwestern sag also partly generated large-scale river delta deposits.Due to the eustatic rise and change of SCS spreading axis,the overall Baiyun Depression was mostly influenced by the deep marine environment on a continental slope during the early Miocene.Both northwestern sag and southern uplift zone were found plentiful marine dinoflagellates.In summary,transgression initiated from the eastern and southeastern Baiyun Depression before subsequently progressing into the farther west.Evolution of transgression process is also greatly consistent with the gradual westward expansion of the SCS. 展开更多
关键词 South China Sea PALEOGENE TRANSGRESSION sedimentary environment plant ecology
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Carrimycin in the treatment of acute promyelocytic leukemia combined with pulmonary tuberculosis: A case report
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作者 Fu-Yu Yang lei shao +1 位作者 Jie Su Zhen-Meng Zhang 《World Journal of Clinical Cases》 SCIE 2024年第3期623-629,共7页
BACKGROUND Pulmonary tuberculosis(PTB)is prevalent in immunocompromised populations,including patients with hematologic malignancies,human immunodeficiency virus infections,and chronic diseases.Effective treatment for... BACKGROUND Pulmonary tuberculosis(PTB)is prevalent in immunocompromised populations,including patients with hematologic malignancies,human immunodeficiency virus infections,and chronic diseases.Effective treatment for acute promyelocytic leukemia(APL)combined with PTB is lacking.These patients show an extremely poor prognosis.Therefore,studies should establish efficient treatment options to improve patient survival and prognosis.CASE SUMMARY A 60-year-old male with pain in the right side of his chest and a fever for 4 d visited the outpatient department of our hospital.Peripheral blood smear revealed 54%blasts.Following bone marrow examinations,variant APL with TNRC18-RARA fusion gene was diagnosed.Chest computed tomography scan showed bilateral pneumonitis with bilateral pleural effusions,partial atelectasis in the lower lobes of both lungs,and the bronchoalveolar lavage fluid gene X-Pert test was positive,indicative of PTB.Carrimycin,ethambutol(EMB),and isoniazid(INH)were administered since he could not receive chemotherapy as the WBC count decreased continuously.After one week of treatment with carrimycin,the patient recovered from fever and received chemotherapy.Chemotherapy was very effective and his white blood cells counts got back to normal.After being given five months with rifampin,EMB and INH and chemotherapy,the patient showed complete remission from pneumonia and APL.CONCLUSION We report a case of PTB treated successfully with carrimycin with APL that requires chemotherapy. 展开更多
关键词 Carrimycin Hematologic disease Acute myeloid leukemia Acute promyelocytic leukemia Pulmonary tuberculosis Case report
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宁绍平原东部新石器遗址地层碱土金属元素地球化学特征以及对海水入侵事件的指示 被引量:1
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作者 潘昱 孙国平 +2 位作者 雷少 吴莹莹 王张华 《海洋地质与第四纪地质》 CSCD 北大核心 2023年第6期169-180,共12页
宁绍平原东部地区孕育了丰富灿烂的新石器时代文化,但目前发现的遗址地层中普遍存在着不同时期文化堆积中断现象。选择井头山遗址和鱼山遗址两个剖面进行AMS14C测年、有机地球化学和碱土金属元素分析,探讨稀醋酸提取的碱土金属元素含量... 宁绍平原东部地区孕育了丰富灿烂的新石器时代文化,但目前发现的遗址地层中普遍存在着不同时期文化堆积中断现象。选择井头山遗址和鱼山遗址两个剖面进行AMS14C测年、有机地球化学和碱土金属元素分析,探讨稀醋酸提取的碱土金属元素含量变化的特征和原因,同时通过与研究区其他新石器遗址地层记录对比,识别区域性的水文环境变化事件。研究结果显示,稀醋酸提取的碱土金属元素Sr和Ca含量对海岸带低地环境的海水入侵事件十分敏感,是海陆过渡带有效的水文环境代用指标;而Ba含量的变化更加复杂,在两个遗址的中全新世地层中普遍呈现为低值,显示其不仅受水体盐度影响,而且与本地河流输入的泥沙量密切相关。通过区域性地层对比,认为宁绍平原东部新石器时代中晚期存在3次大范围海水入侵事件,分别发生于大约6300、5300和4500 cal.aBP,主要由相对海平面上升或极端风暴事件造成,是新石器遗址文化堆积中断的主要原因。 展开更多
关键词 海岸带低地 Sr BA 水文环境 河流输入 极端风暴事件
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中-晚全新世姚江河谷平原古文化遗址分布变化及动因的GIS分析
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作者 林芳由 王张华 +5 位作者 宓欣芸 苗炳迪 雷少 李冬玲 沙龙滨 徐皓 《上海国土资源》 2023年第4期43-53,共11页
姚江河谷平原是河姆渡文化的发源地,文明演进历史悠久。此地区在全新世期间经历了复杂的环境演变,是研究人类如何适应环境变迁的理想区域。本研究收集了63处姚江河谷平原新石器时代与商周的人类遗址的地理位置、文化分期、遗址面积、文... 姚江河谷平原是河姆渡文化的发源地,文明演进历史悠久。此地区在全新世期间经历了复杂的环境演变,是研究人类如何适应环境变迁的理想区域。本研究收集了63处姚江河谷平原新石器时代与商周的人类遗址的地理位置、文化分期、遗址面积、文化层厚度、遗迹和遗物等信息,使用ArcGIS软件对其进行继承性、与山地距离、核密度和规模等属性的地理信息系统(GIS)空间分析,得到以下主要认识:(1)河姆渡文化一、二期遗址较少且继承性较高,叠置系数为0.83。河姆渡文化三、四期,遗址数量显著增加,但继承性相对降低,叠置系数降至0.73。良渚文化与商周遗址数量与继承性均呈现下降趋势,叠置系数降至0.43。上述结果反映了从河姆渡文化三期到四期、河姆渡文化四期到良渚文化以及良渚文化到商周这三个时间节点,发生了重要的环境和人群组成变化。(2)在空间分布上,遗址最早出现于平原中部并于河姆渡文化二期与四期先后向东部与西部扩散,直至占据整片姚江河谷平原;遗址普遍距山地不超过1500 m,且只在河姆渡文化四期与商周明显向平原低地扩散,反映这两个时间段姚江河谷平原陆地资源比较丰富,指示了比较广泛的海退。(3)从河姆渡文化一期到商周,姚江河谷平原经历了从残余古海湾到被充填的过程,同时还伴随古姚江的形成、变迁以及海岸线附近与平原内部的地势倒转。 展开更多
关键词 河谷平原 中晚全新世 古文化遗址 GIS空间分析 核密度 遗址规模
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植硅体视角下浙江宁波鱼山遗址的生业考察
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作者 夏秀敏 王力之 +4 位作者 雷少 王结华 郑晓蕖 赵志军 吴妍 《文物季刊》 2023年第3期75-85,共11页
鱼山遗址是宁绍平原河姆渡文化时期以来的重要遗存,其考古发现为探讨东部沿海地带长时间尺度的水稻驯化进程和人地关系提供了良好素材。高精度的植硅体分析表明,河姆渡时期以来水稻扇型个体呈现了变小稳定的趋势,并逐渐向中间型和长柄... 鱼山遗址是宁绍平原河姆渡文化时期以来的重要遗存,其考古发现为探讨东部沿海地带长时间尺度的水稻驯化进程和人地关系提供了良好素材。高精度的植硅体分析表明,河姆渡时期以来水稻扇型个体呈现了变小稳定的趋势,并逐渐向中间型和长柄型演化,暗示先民是以种植粳型化的水稻为主;水稻扇型植硅体鱼鳞状纹饰的变化揭示了在河姆渡文化晚期,水稻的驯化基本完成。受海平面变化的频繁影响,该地的水稻驯化具有一定的滞后性,驯化的周期也有所延长。结合植硅体分析和多种研究成果,推断在河姆渡文化时期,鱼山遗址的稻作生产获得了较大发展;在河姆渡文化晚期,水稻逐渐成为先民植食性资源的主体;在滨海多变的环境背景下,鱼山遗址形成了以水稻种植为主,采集和渔猎并行的多元化生业模式。良渚晚期,伴随着水稻驯化的完成和生产工具的进步,推测出现了系统的水田耕作系统。商周时期,依托暖干的环境,稻作生产向集约化发展,为古越国的兴起奠定了基础。 展开更多
关键词 鱼山遗址 宁绍平原 植硅体 水稻 生业模式
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New interpretation on the provenance changes of the upper Pinghu–lower Huagang Formation within Xihu Depression,East China Sea Shelf Basin 被引量:1
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作者 Jinshui Liu Shuai Li +7 位作者 Kaifei Liao Yuchi Cui lei shao Peijun Qiao Yi Lu Yuanli Hou Thian Lai Goh Yongjian Yao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第3期89-100,共12页
Both Pinghu and Huagang formations are important hydrocarbon reservoirs of the Xihu Depression in the East China Sea Shelf Basin.Clarifying the source suppliers and restoring source-to-sink transport routes are of gre... Both Pinghu and Huagang formations are important hydrocarbon reservoirs of the Xihu Depression in the East China Sea Shelf Basin.Clarifying the source suppliers and restoring source-to-sink transport routes are of great significance to the future petroleum and gas undertakings.Previous researchers were largely confined by either limitation of geological records,highly dependence on a singular method or low-precision dating techniques.Our study integrated heavy mineral assemblages,geochemical analyses and detrital zircon U-Pb dating to reconstruct multiple source-to-sink pathways,and to provide a better understanding on the provenance evolution for the upper Pinghu–lower Huagang depositions of the Xihu Depression.At least three major provenances have been confirmed and systematically investigated for their separate compositional features.The Hupijiao Uplift(or even farther northern area)was dominated by a major Paleoproterozoic population peaked at ca.1830 Ma along with minor Mesozoic clusters.The Haijiao Uplift to the west and the Yushan Low Uplift to the southwest,on the other hand,generate opposite U-Pb age spectra with apparently larger peaks of Indosinian and Yanshanian-aged zircons.To be noted,both Indosinian and Paleoproterozoic peaks are almost identical in proportion for the Haijiao Uplift.The overall sedimentary pattern of late Eocene-early Oligocene was featured by both spatial and temporal distinction.The Hupijiao Uplift was likely to cast limited impact during the late Eocene,whereas the broad southern Xihu Depression was transported by a large abundance of materials from the nearby Haijiao and Yushan Low Uplifts.The northern source substantially extended its influence to the farther south during the early Oligocene by delivering plentiful sediments of higher-degree metamorphic parent rocks.Combined with the proximal western and southwestern suppliers,the overall Xihu Depression was under control from both distant and local provenances. 展开更多
关键词 Xihu Depression East China Sea Shelf Basin detrital zircon U-Pb ages Pinghu–Huagang Formation PROVENANCE
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Late Eocene–early Miocene provenance evolution of the Crocker Fan in the southern South China Sea 被引量:1
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作者 Yuchi Cui lei shao +3 位作者 Wu Tang Peijun Qiao Goh Thian Lai Yongjian Yao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第3期215-226,共12页
There are many large-scale Cenozoic sedimentary basins with plentiful river deltas,deep-water fans and carbonate platforms in the southern South China Sea.The Crocker Fan was deposited as a typical submarine fan durin... There are many large-scale Cenozoic sedimentary basins with plentiful river deltas,deep-water fans and carbonate platforms in the southern South China Sea.The Crocker Fan was deposited as a typical submarine fan during the late Eocene–early Miocene,and stretches extensively across the entire Sarawak–Sabah of the northern Borneo area.However,systematic analyses are still lacking regarding its sediment composition and potential source suppliers.No consensus has been reached yet on the provenance evolution and sedimentary infilling processes,which seriously impeded the oil-and-gas exploration undertakings.By combining with sedimentaryfacies identification,heavy mineral assemblages,elemental geochemistry and detrital zircon U-Pb dating,this paper aims to generalize an integrated analysis on the potential provenance terranes and restore source-to-sink pathways of the Crocker Fan.In general,the Crocker Fan was initially formed over the Cretaceous–lower/middle Eocene Rajang Group by an angular Rajang unconformity.The continual southward subduction of the protoSouth China Sea resulted in magmatic activities and subsequent regional deformation and thrusting along the Lupar Line in the northern Borneo.The lowermost Crocker sequence is featured by a thick conglomerate layer sourced from in-situ or adjacent paleo-uplifts.From the late Eocene to the early Miocene,the Crocker Fan was constantly delivered with voluminous detritus from the Malay Peninsula of the western Sundaland.The Zengmu Basin was widely deposited with delta plain and neritic facies sediments,while the Brunei-Sabah Basin,to the farther east,was ubiquitously characterized by turbiditic sequences.The Crocker Fan successions are overall thick layers of modest-grained sandstones,which formed high-quality reservoirs in the southern South China Sea region. 展开更多
关键词 source-to-sink analysis zircon U-Pb age submarine fan Malay Peninsula southern South China Sea
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浙江大榭史前制盐遗址人工土台的堆土特征及来源分析 被引量:4
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作者 栗文静 雷少 +3 位作者 王张华 李月 岳伟 郑童童 《古地理学报》 CAS CSCD 北大核心 2018年第6期1102-1112,共11页
位于浙江省宁波市大榭岛的大榭遗址,是迄今所发现的中国最早的史前海盐业遗址,与一般遗址沉积地层不同,其主体区系人工堆筑土台。本研究在遗址发掘过程中,采集了泥质和砂质2种类型堆土、废弃陶器堆中的白色硬化物和盐灶坑表层白色硬化物... 位于浙江省宁波市大榭岛的大榭遗址,是迄今所发现的中国最早的史前海盐业遗址,与一般遗址沉积地层不同,其主体区系人工堆筑土台。本研究在遗址发掘过程中,采集了泥质和砂质2种类型堆土、废弃陶器堆中的白色硬化物和盐灶坑表层白色硬化物,同时采集本岛自然堆积物,进行了粒度、无机元素地球化学和重矿物分析,以探讨堆土的原料构成、古人的制盐工艺及制盐活动对堆土地层产生的影响。研究结果显示:来自盐灶遗迹附近的7个泥质堆土样品,其中5个具有陆相元素富集特征,但是后期受海水影响,另外2个显示滩涂盐泥特征;废弃陶器堆中的白色硬化物元素组成与盐泥相似,盐灶坑表层白色硬化物具高Ca、Sr、Ba含量,推测是烧煮卤水产生的沉淀物。砂质堆土的粒度和重矿物组成显示其属于河流冲积物,且具强烈的化学风化特征,推测其原始地层不仅限于全新统。该研究显示了钱山漾文化时期古人利用岛屿上的潮上带、山麓黄土、河流冲积物等原材料在滩涂营建土台,并在土台上利用"淋卤煎炼"工艺从事制盐活动。 展开更多
关键词 泥质堆土 砂质堆土 制盐活动 河流冲积物
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宁波鱼山遗址浮选结果及分析 被引量:6
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作者 郑晓蕖 雷少 +1 位作者 王结华 赵志军 《农业考古》 2019年第6期21-27,共7页
鱼山遗址位于浙江省宁波市镇海区,为一处以河姆渡和商周地层为主体的遗址。本次对鱼山遗址开展采样、浮选工作,获得了大量河姆渡时期、良渚时期和商周时期的植物遗存,包括水稻、菱角、芡实、橡子、葫芦等可食性植物资源遗存,以及近20种... 鱼山遗址位于浙江省宁波市镇海区,为一处以河姆渡和商周地层为主体的遗址。本次对鱼山遗址开展采样、浮选工作,获得了大量河姆渡时期、良渚时期和商周时期的植物遗存,包括水稻、菱角、芡实、橡子、葫芦等可食性植物资源遗存,以及近20种其他乔木类和杂草类遗存。根据浮选结果显示可知,在河姆渡文化时期,生业模式经历了一个以采集狩猎为主逐渐依赖农业的转变,对植物资源的利用也由野生植物资源逐渐转向以水稻为主。而商周时期,水稻则占据最主要的地位,遗址以种植水稻为单一的农业模式。鱼山遗址植物考古发现,为探讨河姆渡文化时期宁绍平原的植物资源利用模式提供了新的证据,也填补了长江下游商周时期植物考古研究的空白。 展开更多
关键词 鱼山遗址 河姆渡 浮选 稻作农业
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Reinterpretation of the northern South China Sea pre-Cenozoic basement and geodynamic implications of the South China continent: constraints from combined geological and geophysical records 被引量:16
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作者 Weilin Zhu Yuchi Cui +5 位作者 lei shao Peijun Qiao Peng Yu Jianxiang Pei Xinyu Liu Hao Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2021年第2期13-28,共16页
The pre-Cenozoic northern South China Sea(SCS)Basin basement was supposed to exist as a complex of heterogeneous segments,divided by dozens of N-S faulting.Unfortunately,only the Hainan Island and the northeastern SCS... The pre-Cenozoic northern South China Sea(SCS)Basin basement was supposed to exist as a complex of heterogeneous segments,divided by dozens of N-S faulting.Unfortunately,only the Hainan Island and the northeastern SCS region were modestly dated while the extensive basement remains roughly postulated by limited geophysical data.This study presents a systematic analysis including U-Pb geochronology,elemental geochemistry and petrographic identification on granite and meta-clastic borehole samples from several key areas.Constrained from gravity-magnetic joint inversion,this interpretation will be of great significance revealing the tectono-magmatic evolution along the southeastern margin of the Eurasian Plate.Beneath the thick Cenozoic sediments,the northern SCS is composed of a uniform Mesozoic basement while the Precambrian rocks are only constricted along the Red River Fault Zone.Further eastern part of the northern SCS below the Cenozoic succession was widely intruded by granites with Jurassic-to-early Cretaceous ages.Further western part,on the other hand,is represented by meta-sedimentary rocks with relatively sporadic granite complexes.To be noted,the western areas derived higher-degree and wider metamorphic zones,which is in contrast with the lowerdegree and narrower metamorphic belt developed in the eastern region.Drastic collisions between the Indochina Block and South China continent took place since at least late Triassic,resulting in large-scale suturing and deformation zones.At the westernmost part of the northern SCS,the intracontinental amalgamation with closure of the Meso-Tethys has caused fairly stronger and broader metamorphism.One metamorphic biotite granite is located on the suturing belt and yields a Precambrian U-Pb age.It likely represents the relict from the ancient Gondwana supercontinent or its fringes.Arc-continental collision between the Paleo-Pacific and the southeast China Block,on the other hand,results in a relatively narrow NE–SW trending metamorphic belt during the late Mesozoic.Within the overall geological setting,the Cenozoic SCS oceanic basin was subsequently generated from a series of rifting and faulting processes along the collisional-accretionary continental margin. 展开更多
关键词 South China Sea pre-Cenozoic basement U-Pb geochronology Paleo-Pacific subduction intracontinental collision metamorphic belt
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Optimal midcourse trajectory cluster generation and trajectory modification for hypersonic interceptions 被引量:11
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作者 Humin lei Jin Zhou +2 位作者 Dailiang Zhai lei shao Dayuan Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第6期1162-1173,共12页
The hypersonic interception in near space is a great challenge because of the target’s unpredictable trajectory, which demands the interceptors of trajectory cluster coverage of the predicted area and optimal traject... The hypersonic interception in near space is a great challenge because of the target’s unpredictable trajectory, which demands the interceptors of trajectory cluster coverage of the predicted area and optimal trajectory modification capability aiming at the consistently updating predicted impact point(PIP) in the midcourse phase. A novel midcourse optimal trajectory cluster generation and trajectory modification algorithm is proposed based on the neighboring optimal control theory. Firstly, the midcourse trajectory optimization problem is introduced; the necessary conditions for the optimal control and the transversality constraints are given.Secondly, with the description of the neighboring optimal trajectory existence theory(NOTET), the neighboring optimal control(NOC)algorithm is derived by taking the second order partial derivations with the necessary conditions and transversality conditions. The revised terminal constraints are reversely integrated to the initial time and the perturbations of the co-states are further expressed with the states deviations and terminal constraints modifications.Thirdly, the simulations of two different scenarios are carried out and the results prove the effectiveness and optimality of the proposed method. 展开更多
关键词 neighboring optimal control(NOC) midcourse guidance trajectory cluster generation optimal trajectory modification
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Sacrificial microgel‑laden bioink‑enabled 3D bioprinting of mesoscale pore networks 被引量:8
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作者 lei shao Qing Gao +5 位作者 Chaoqi Xie Jianzhong Fu Meixiang Xiang Zhenjie Liu Liulin Xiang Yong He 《Bio-Design and Manufacturing》 CSCD 2020年第1期30-39,共10页
Three-dimensional(3D)bioprinting is a powerful approach that enables the fabrication of 3D tissue constructs that retain complex biological functions.However,the dense hydrogel networks that form after the gelation of... Three-dimensional(3D)bioprinting is a powerful approach that enables the fabrication of 3D tissue constructs that retain complex biological functions.However,the dense hydrogel networks that form after the gelation of bioinks often restrict the migration and proliferation of encapsulated cells.Herein,a sacrificial microgel-laden bioink strategy was designed for directly bioprinting constructs with mesoscale pore networks(MPNs)for enhancing nutrient delivery and cell growth.The sacrificial microgel-laden bioink,which contains cell/gelatin methacryloyl(GelMA)mixture and gelled gelatin microgel,is first thermo-crosslinked to fabricate temporary predesigned cell-laden constructs by extrusion bioprinting onto a cold platform.Then,the construct is permanently stabilized through photo-crosslinking of GelMA.The MPNs inside the printed constructs are formed after subsequent dissolution of the gelatin microgel.These MPNs allowed for effective oxygen/nutrient diffusion,facilitating the generation of bioactive tissues.Specifically,osteoblast and human umbilical vein endothelial cells encapsulated in the bioprinted large-scale constructs(≥1 cm)with MPNs showed enhanced bioactivity during culture.The 3D bioprinting strategy based on the sacrificial microgel-laden bioink provided a facile method to facilitate formation of complex tissue constructs with MPNs and set a foundation for future optimization of MPN-based tissue constructs with applications in diverse areas of tissue engineering. 展开更多
关键词 Sacrificial microgel Gelatin methacryloyl(GelMA) 3D bioprinting Mesoscale pore networks(MPNs) Tissue engineering
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Nonlinear differential geometric guidance for maneuvering target 被引量:3
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作者 Jikun Ye Humin lei +2 位作者 Dongfeng Xue Jiong Li lei shao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第5期752-760,共9页
Based on the idea of zeroing the line of sight rate(LOSR),a novel nonlinear differential geometric(DG) law for intercepting the agile target is proposed.In the first part,the DG formulations are utilized to descri... Based on the idea of zeroing the line of sight rate(LOSR),a novel nonlinear differential geometric(DG) law for intercepting the agile target is proposed.In the first part,the DG formulations are utilized to describe the relatively kinematics model of missile and target,and the nonlinear DG guidance(DGG) law is proposed based on the nonlinear control theory to eliminate the influence brought by target.Further,the missile guidance commands are derived to overcome the information loss caused by decoupling condition,the new necessary initial condition is developed to guarantee capture the agile target.Then,the designed nonlinear DGG commands are transformed from an arc-length system to the time domain.A desirable aspect of the designed guidance law is that it does not require rigorous information about target acceleration.Representative numerical results show that the designed guidance law obtain a better performance than the traditional DGG law for agile target. 展开更多
关键词 GUIDANCE differential geometric nonlinear control STABILITY maneuvering target
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Comparative Study of Global Seismicity on the Hot Engine Belt and the Cooling Seismic Belt—Improvement on Research Ideas of Earthquake Prediction 被引量:5
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作者 Lijun Chen Xiaofeng Chen +2 位作者 Fangfang Wan Pinzhong Li lei shao 《International Journal of Geosciences》 2015年第7期741-749,共9页
The study in this paper analyzes and compares the distribution on the global engine active seismic zone and cooling seismic belt basing on the ANSS earthquake catalog from Northern California Earthquake Data Center. A... The study in this paper analyzes and compares the distribution on the global engine active seismic zone and cooling seismic belt basing on the ANSS earthquake catalog from Northern California Earthquake Data Center. An idea of the seismogenesis and earthquake prediction research is achieved by showing the stratigraphic structure in the hot engine belt. The results show that the main engine and its seismic cones are the global seismic activity area, as well as the subject of global geological disaster. Based on the conjecture of other stratum structure, the energy of crustal strong earthquake and volcano activities probably originates from the deep upper mantle. It is suggested that the research on earthquake and volcano prediction should focus on the monitor and analysis on the sub-crustal earthquake activities. 展开更多
关键词 The HOT ENGINE BELT the COOLING SEISMIC BELT SEISMIC Cone Seismo-Geothermics Theory Earthquake Prediction
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Liquid-solid mass transfer in a rotating packed bed reactor with structured foam packing 被引量:2
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作者 Yazhao Liu Zhi hao Li +3 位作者 Guangwen Chu lei shao Yong Luo Jianfeng Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第10期2507-2512,共6页
A rotating packed bed(RPB) reactor has substantially potential for the process intensification of heterogeneous catalytic reactions. However, the scarce knowledge of the liquid–solid mass transfer in the RPB reactor ... A rotating packed bed(RPB) reactor has substantially potential for the process intensification of heterogeneous catalytic reactions. However, the scarce knowledge of the liquid–solid mass transfer in the RPB reactor is a barrier for its design and scale-up. In this work, the liquid–solid mass transfer in a RPB reactor installed with structured foam packing was experimentally studied using copper dissolution by potassium dichromate. Effects of rotational speed, liquid and gas volumetric flow rate on the liquid–solid mass transfer coefficient(kLS) have been investigated. The correlation for predicting kLSwas proposed, and the deviation between the experimental and predicted values was within±12%. The liquid–solid volumetric mass transfer coefficient(kLSaLS) ranged from 0.04–0.14 1^-1, which was approximately 5 times larger than that in the packed bed reactor. This work lays the foundation for modeling of the RPB reactor packed with structured foam packing for heterogeneous catalytic reaction. 展开更多
关键词 Rotating packed bed Liquid–solid mass transfer Structured foam packing Process intensification
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Discrete element simulation of crushable rockfill materials 被引量:1
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作者 lei shao Shi-chun CHI +1 位作者 Liang-jing ZHOU Yu-zan WANG 《Water Science and Engineering》 EI CAS CSCD 2013年第2期215-229,共15页
A discrete element method was used to study the evolution of particle crushing in a rockfill sample subjected to triaxial shear. A simple procedure was developed to generate clusters with arbitrary shapes, which resem... A discrete element method was used to study the evolution of particle crushing in a rockfill sample subjected to triaxial shear. A simple procedure was developed to generate clusters with arbitrary shapes, which resembled real rockfill particles. A theoretical method was developed to define the failure criterion for an individual particle subjected to an arbitrary set of contact forces. Then, a series of numerical tests of large-scale drained triaxial tests were conducted to simulate the behaviors of the rockfill sample. Finally, we examined the development of micro-characteristics such as particle crushing, contact characteristics, porosity, deformation, movement, and energy dissipation. The simulation results were partially compared with the laboratory experiments, and good agreement was achieved, demonstrating that the particle crushing model proposed can be used to simulate the drained triaxial test ofrockfill materials. Based on a comparison of macro behaviors of the roekfill sample and micro structures of the particles, the microscopic mechanism of the rockfill materials subjected to triaxial shear was determined qualitatively. It is shown that the crushing rate, rather than the number of crushed particles, can be used to reflect the relationship between macro- and micro-mechanical characteristics of rockfill materials. These research results further develop our understanding of the deformation mechanism of rockfill materials. 展开更多
关键词 discrete element simulation triaxial shear test roclcfill material geometric construction of particles particle flow code microscopic mechanism
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Changing provenance of late Cenozoic sediments in the Jianghan Basin 被引量:4
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作者 lei shao Shengyuan Yuan +4 位作者 Chang'an Li Chunguo Kang Wenjing Zhu Yindi Liu Jietao Wang 《Geoscience Frontiers》 SCIE CAS CSCD 2015年第4期605-615,共11页
The Yangtze River is one of the most important components of the East Asia river system. In this study, sediments in the Jianghan Basin, middle Yangtze River, were selected for trace element and rare earth element (... The Yangtze River is one of the most important components of the East Asia river system. In this study, sediments in the Jianghan Basin, middle Yangtze River, were selected for trace element and rare earth element (REE) measurements, in order to decipher information on the change of sediment provenance and evolution of the Yangtze River. According to the elemental variations, the late Cenozoic sediments of the Jianghan Basin could be divided into four parts. During 2.68-2,28 Ma and 1.25-0 Ma, proveJ nance of the sediments was consistent, whereas sediments were derived from variable sources during 2.28-1.25 Ma. Comparison of the elemental compositions between the Pliocene and Quaternary sediments revealed a change in sediment source from a more felsic source area to a more basic source area around the Pliocene--Quaternary boundary. Input from the Emeishan LIP should account for this provenance change, Based on the provenance analysis of sediments in the Jianghan Basin, we infer that the Yangtze River developed into a large river with its drainage basin extended to the Emeishan LIP no later than the Pliocene-Quaternary boundary. 展开更多
关键词 Yangtze River Jianghan Basin Trace element REE Provenance
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Synthesis and Photoconductivity of Nanosized Phthalocyanine 被引量:1
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作者 Shuguang BIAN Xianggao LI +1 位作者 lei shao Jianfeng CHEN 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2006年第4期533-535,共3页
Functional phthalocyanine (Pc) compounds of H2Pc, TiOPc, FePc and CIAIPc were synthesized with a yield of 46.7%, 91.2%, 37.4% and 34.0%, respectively. Nanosized TiOPc was synthesized via a one-step sol-gel method an... Functional phthalocyanine (Pc) compounds of H2Pc, TiOPc, FePc and CIAIPc were synthesized with a yield of 46.7%, 91.2%, 37.4% and 34.0%, respectively. Nanosized TiOPc was synthesized via a one-step sol-gel method and effects of surfactant doses, nucleation temperature on TiOPc particle size and photoconductivity were investigated. When re(PEG): m(TiOPc) was 0.1 and nucleation temperature was 0℃, the as-obtained TiOPc had the smallest particle size and largest specific surface area, which were 60 nm and 83m^2/g, respectively. TiOPc synthesized under these conditions also exhibits excellent photoconductivity with charging potential V0, dark decay speed Rd and energy for half-discharging of potential E1/2 being 1160 V, 30 V/s and 0.6 1x.s, respectively. 展开更多
关键词 PHTHALOCYANINE NANOSIZE SYNTHESIS PHOTOCONDUCTIVITY
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