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Megafossils of Betulaceae from the Oligocene of Qaidam Basin and their paleoenvironmental and phytogeographic implications

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Plant Diversity 2024年第1期46卷 101-115页

作者： Tao Yang Jia-Hao Cai Yan-Zhi Dai Hong-Yu Chen Lei Han li Zhang Wei-Yu liang xu-jun li Wen-Jia li Jing-Yu Wu San-Ping Xie De-Fei Yan School of Earth Sciences and Key Laboratory of Mineral Resources in Western China(Gansu Province) Lanzhou UniversityLanzhou 730000China Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing 210008China Center for Research and Education on Biological Evolution and Environments School of Earth Sciences and EngineeringNanjing UniversityNanjing 210023China

Understanding the paleoenvironment and phytogeographical history of the Tibetan Plateau,China relies on discovering new plant *** Qaidam Basin has long been regarded as an ideal‘field laboratory’to investigate the paleoclimate and paleobiological evolution of the northern Tibetan ***,fossil angiosperms from the Qaidam Basin are rare,and our knowledge of its paleovegetation is ***,we report fossil leaves and fruits of Betulaceae found from the Oligocene Shangganchaigou Formation of northwestern Qaidam Basin(Huatugou area).Comparative morphological analysis led us to assign the fruits to the Betula subgenus Betula and the leaves to Carpinus *** findings,together with other reported fossil plants from the same locality,reveal a close floristic linkage between the Qaidam Basin and Europe during the *** northern pathway of this floristic exchange may have crossed through the Qaidam Basin during the late *** floristic linkage may have been facilitated by the continuous narrowing of the Turgai Strait and stronger westerlies,which transported moisture and provided favorable climatic ***,fossil plants collected from the Qaidam Basin suggest that during the Oligocene this region had warm and humid deciduous broad-leaf forest,which differs from the region’s modern vegetation and indicates that the Qaidam Basin may have been a suitable region for these plants to flourish and spread during the Oligocene.

关键词： Paleoenvironment Biogeography Betulaceous fossil Qaidam basin Tibetan Plateau Oligocene

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农地经营权强度能缓解新型农业经营主体供给型信贷配给吗?——基于fsQCA方法的路径分析

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财经问题研究 2024年第9期 103-118页

作者：王家兴米运生徐俊丽华南农业大学经济管理学院广东广州510642 江西师范大学商学院江西南昌330022

新型农业经营主体虽然有着强烈的机构贷款需求,但因缺乏有效抵押品,正规金融机构普遍对其施加严格的供给型信贷配给。“三权分置”从法律层面激活农地经营权,是破解供给型信贷配给难题的重要契机。本文从法律维度、事实维度、感知维度... 详细信息

新型农业经营主体虽然有着强烈的机构贷款需求,但因缺乏有效抵押品,正规金融机构普遍对其施加严格的供给型信贷配给。“三权分置”从法律层面激活农地经营权,是破解供给型信贷配给难题的重要契机。本文从法律维度、事实维度、感知维度对农地经营权强度展开维度化分析,厘清其影响新型农业经营主体供给型信贷配给的作用机理与具体路径,并使用组态视角的模糊集定性比较分析(fsQCA)方法进行实证检验。研究发现,新型农业经营主体的供给型信贷配给,既能由法律维度、事实维度和感知维度的农地经营权同时具有较高强度而得以缓解,也能仅凭法律维度或事实维度的农地经营权具有较高强度得以缓解,但感知维度的农地经营权具有较高强度尚不足以单独发挥缓解之效。为进一步释放农地经营权改革的信贷效应,既要完善农地经营权的法律赋权与保障转入农地的实际权利,也要强化主体对农地经营权的安全感知。本文既从理论上深化了对农地经营权强度的理解,揭示了法律赋权、事实拥有、先验认知等不同层面的产权排他性、稳定性和安全性的内涵,也在实践上拓宽了破解供给型信贷配给难题的现实途径。

关键词：农地经营权产权强度供给型信贷配给新型农业经营主体 fsQCA

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基于拉曼光谱技术的不同年份玉米成分分析

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光谱学与光谱分析 2024年第8期44卷 2166-2173页

作者：黄纪翀宋少忠刘春宇徐立君陈安亮鹿鸣郭雯静苗壮李长明谭勇刘哲长春理工大学物理学院吉林省光谱探测科学与技术重点实验室吉林长春130022 吉林工程技术师范学院数据科学与人工智能学院吉林长春130052 吉林大学生物与农业工程学院吉林长春130015

以松原粮食集团提供不同年份的玉米储备粮为实验样品,采用三级显微拉曼光谱检测仪对不同状态下的玉米单籽粒进行光谱采集,并结合密度泛函理论(DFT)得到分子光谱,研究其内部成分随时间变化的规律。通过DFT理论优化分子结构和分析,将求得... 详细信息

以松原粮食集团提供不同年份的玉米储备粮为实验样品,采用三级显微拉曼光谱检测仪对不同状态下的玉米单籽粒进行光谱采集,并结合密度泛函理论(DFT)得到分子光谱,研究其内部成分随时间变化的规律。通过DFT理论优化分子结构和分析,将求得分子中每个键对应的振动频率与实际测得的玉米籽粒拉曼光谱进行对比,完成部分峰位指认;对不同储存年份的玉米籽粒外表面拉曼光谱进行了测量,对原始光谱进行预处理后分别在476、1006、1156、1459、1519、1597和1633 cm^(-1)这几处发现了较强的拉曼峰,表征着玉米淀粉、叶黄素、木质素的存在;对不同年份玉米籽粒纵切面的拉曼光谱进行测量,将此部分光谱归一化处理后得到了对应峰位的相对峰强与相对峰面积。通过比较发现除在表面得到的拉曼峰外,在850~1450 cm^(-1)附近处还发现了新的拉曼峰。其中位于475、863、944、1260、1338和1378 cm^(-1)几处表征淀粉含量的拉曼峰峰强、峰面积、半高宽(FWHM)值随储存年份的增加产生了或增加或减少的现象,表明其物质组成、成分含量、分子结构均发生了不同改变,基本与玉米淀粉老化的机理一致。其中在1080和1130 cm^(-1)拉曼峰在三个不同年份玉米纵切面拉曼光谱中的变化差距较大:1080 cm^(-1)的拉曼峰只存在于2018年、2019年储存的玉米光谱中,1192 cm^(-1)处的拉曼峰只存在于2020年份的玉米光谱中,且峰强、Full Width at the half of the maximum(FWHM)值有不同程度的变化,可能表示淀粉内某种糖类物质之间的相互转换,可作为鉴定不同年份玉米样品的特征峰。对叶黄素含量相关峰位的物理参数进行了比较,并将其中的峰强、峰面积值与年份做线型拟合分析,拟合程度较好,相关系数均达到了0.9以上,表明叶黄素含量随储存时间延长呈线性下降的趋势。通过与理论计算得到的叶黄素光谱对比分析,发现叶黄素的流失对化学键振动均有不同程度的影响,其中对C═C双键的伸缩振动影响最大。该研究使用密度泛函理论的计算与实验比对结果,探讨玉米的拉曼光谱随时间推移的变化规律,通过分析不同年份玉米的内部成分变化,为使用拉曼光谱鉴别玉米年份提供了一定的依据,拓展了光谱在农产品质量检测分析上的应用。

关键词：拉曼光谱密度泛函理论玉米储备粮成分分析

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Characterization of heat shock protein 90, 70 and their transcriptional expression patterns on high temperature in adult of Graphofita molesta （Busck）

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Insect Science 2014年第4期21卷 439-448页

作者： Hao Chen Xiang-li xu Yi-Ping li jun-Xiang Wu Key Laboratory of Plant Protection Resources and Pest Management (Northwest A&F University) Ministry of Education Key Laboratoryof Appfied Entomology Northwest A&F University Yangling Shaanxi China

Grapholita molesta （Busck） is a worldwide insect pest damaging stone and pome fruits. High temperature can significantly affect insect survival, development and fecundity. Heat shock protein （Hsp） genes were speculated to possess a pivotal function in response to high temperature stress. In this study, two full-length Hsp genes, Gmhsp90 and GmhspTO, were cloned from G. molesta using rapid amplification of complementary DNA ends （RACE）. The open reading frames of Gmhsp90 and Gmhsp70 obtained were 2 148 bp and 1 998 bp in length, respectively. Their deduced amino acids showed high homology to Hsp genes of other species. Subsequently, the transcriptional expression of Gmhsp90 and Gmhsp70 in G. molesta adults exposed at various temperatures （26, 29, 32, 35, 38, 41 and 44℃） for 1 h and at 41℃ for various time duration （0, 15, 30, 45, 60, 75, 90 and 105 min） were investigated via real time quantitative polymerase chain reaction （qPCR）. The relative expression levels of Gmhsp90 and Gmhsp70 in G. molesta adults were both up-regulated with the rise of temperature and time duration. In addition, the Gmhsp70 usually showed a higher transcription accumulation than Gmhsp90. Interestingly, Gmhsp90 and Gmhsp 70 in female adults could be induced much earlier than that in males, and the effective induction temperature in females was also lower than that in males. The distinct expression profiles of Gmhsp90 and Gmhsp 70 indicated that Gmhsp90 and Gmhsp 70 may play important roles in G. molesta adults responding to a thermal threat, and there is difference on induction between sexes.

关键词： Grapholita molesta heat shock protein high temperature sex difference

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呼伦贝尔饲草产业发展现状、问题与可持续发展对策

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草地学报 2024年第3期32卷 661-666页

作者：敖特根肖燕子孙林徐丽君吴清秀其力格尔李光风润苏都呼伦贝尔学院内蒙古呼伦贝尔021000 中国农业科学院农业资源与农业区划研究所/内蒙古呼伦贝尔草原生态系统国家野外科学观测研究站北京100081 内蒙古自治区农牧业科学院内蒙古呼和浩特010031 呼伦贝尔市农牧局内蒙古呼伦贝尔021000 呼伦贝尔农垦浩特陶海农牧场有限公司内蒙古呼伦贝尔021000 海拉尔区农牧技术推广中心内蒙古呼伦贝尔021000 呼伦贝尔市农牧局综合保障中心内蒙古呼伦贝尔021000

饲草是草食畜牧业良性发展的重要物质基础,饲草产业是其发展之路上的重要组成部分,对于优化农业结构有着举足轻重的作用。目前,呼伦贝尔饲草产业资源(年产量为2796万t),主要有三大板块(天然牧草、人工饲草和秸秆饲草),占有效利用资源量... 详细信息

饲草是草食畜牧业良性发展的重要物质基础,饲草产业是其发展之路上的重要组成部分,对于优化农业结构有着举足轻重的作用。目前,呼伦贝尔饲草产业资源(年产量为2796万t),主要有三大板块(天然牧草、人工饲草和秸秆饲草),占有效利用资源量的32.8%。但聚焦到产业层面,仍存在很多问题:分类分级没有量化标准、草资源损耗、浪费、市场供求信息不对称、饲草产业科技水平、产业链条难以形成等,同时也面临着资源、技术、政策等方面的难题。本文梳理了呼伦贝尔天然牧草、人工饲草和秸秆饲草产业生产现状,综合分析了呼伦贝尔饲草产业发展存在的问题,提出呼伦贝尔优化饲草产业加强饲草储备库建设减少浪费损失、多元化草产品技术研发、人工草地建设降低草原承载压力、饲草产业龙头企业扶持力度等对策和建议,以期为呼伦贝尔饲草产业高质量发展提供参考。

关键词：呼伦贝尔饲草产业发展现状发展对策

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A parametric bootstrap approach for one-way classification model with skew-normal random effects

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Applied Mathematics(A Journal of Chinese Universities) 2019年第4期34卷 423-435页

作者： YE Ren-dao xu li-jun LUO Kun JIANG ling School of Economics Hangzhou Dianzi UniversityHangzhou 310018China Alibaba Business College Hangzhou Normal UniversityHangzhou 310016China

In this paper,several properties of one-way classification model with skew-normal random effects are obtained,such as moment generating function,density function and noncentral skew chi-square distribution,*** on the EM algorithm,we discuss the maximum likelihood(ML)estimation of unknown *** testing problem of fixed effect,a parametric bootstrap(PB)approach is ***,some simulation results on the Type I error rates and powers of the PB approach are obtained,which show that the PB approach provides satisfactory performances on the Type I error rates and powers,even for small *** illustration,our main results are applied to a real data problem.

关键词： parametric bootstrap EM algorithm one-way classification model skew-normal distribution skew chi-square distribution

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A modern survey method for determining live loads based on multi-source and open-access data on the Internet

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Frontiers of Structural and Civil Engineering 2024年第8期18卷 1135-1147页

作者： Chi xu jun CHEN Jie li School of Civil Engineering Tongji UniversityShanghai 200092China The State Key Laboratory on Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China

Sufficient survey data are required to describe the stochastic behaviors of live ***,due to manual and on-site operation required by traditional survey methods,traditional surveys face challenges like occupant resistance,high costs,and long implementation *** study proposes a new survey method to access live load data online and *** samples are acquired from multi-source,open-access and dynamically updated data on the *** change intervals,geometrical dimensions and object quantities are obtained from transaction information,building attributes and virtual reality models on real estate websites,*** object weights are collected from commodity information on e-commerce *** integration of the aforementioned data allows for the extraction of necessary statistics to describe a live load *** proposed method is applied to a live load survey in China,covering 20040 m^(2),with around 90000 samples acquired for object weights and load *** survey results reveal that about 70%−80%of the amplitude statistics are attributable to 1/6 of the total object types.

关键词： live load online survey method data acquisition data integration

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Formation of Na_(1+x)V_3O_8 Nanoribbon Thin Film from V_2O_5 Xerogel on Sodium Silicate Glass Substrate

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Chemical Research in Chinese Universities 2007年第4期23卷 381-383页

作者： GUO Yi xu Jin-jie li jun YANG Wen-sheng College of Chemistry Jilin University Changchun 130012 P. R. China

Na1＋xV3O8 nanoribbon thin film was successfully fabricated by annealing the V2O5 xerogel film on sodium sili-cate glass substrate at 450℃. It has been identified that the amount of sodium ions diffused into the V2O5 xerogel film increases with the high temperature of annealing treatment. The sodium glass substrate serves as a limited sodium source to induce the transformation from V2O5 to Na1＋xV3O8.

关键词： Vanadium pentoxide Sodium silicate glass Nanoribbon Cathode materials

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Glacier changes since the early 1960s, eastern Pamir, China

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Journal of Mountain Science 2016年第2期13卷 276-291页

作者： ZHANG Zhen xu jun-li liU Shi-yin GUO Wan-qin WEI jun-feng FENG Tong State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China University of Chinese Academy of Sciences Beijing 100049 China

Glaciers in the eastern Pamir are important for water resources and the social and economic development of the *** the last 50 years,these glaciers have shrunk and lost ice mass due to climate *** order to understand recent glacier dynamics in the region,a new inventory was compiled from Landsat TM/ETM+ images acquired in2009,free of clouds and with minimal snow cover on the glacierized *** first glacier inventory of the area was also updated by digitizing glacier outlines from topographical maps that had been modified and verified using aerial *** glacier area decreased by 10.8%±1.1%,mainly attributed to an increase in air temperature,although precipitation,glacier size and topographic features also combined to affect the general shrinkage of the *** 19.3–21.4 km^3 estimated glacier mass loss has contributed to an increase in river runoff and water resources.

关键词： Glacier change Glacier inventory Eastern Pamir Remote sensing Mass loss

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Mass Loss from Glaciers in the Chinese Altai Mountains between 1959 and 2008 Revealed Based on Historical Maps, SRTM, and ASTER Images

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Journal of Mountain Science 2015年第2期12卷 330-343页

作者： WEI jun-feng liU Shi-yin xu jun-li GUO Wan-qin BAO Wei-jia SHANGGUAN Dong-hui JIANG Zong-li State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences University of Chinese Academy of Sciences Department of Geography University of Zürich Hunan Province Key Laboratory of Coal Resources Clean-Utilization and Mine Environment Protection Hunan University of Science and Technology

Mass loss of glaciers in the Chinese Altai was detected using geodetic methods based on topographical maps(1959), the Shuttle Radar Topography Mission(SRTM) Digital Elevation Model(DEM)(2000), and the Advanced Space-borne Thermal Emission and Reflection Radiometer(ASTER) stereo images(2008). The results indicate that a continued and accelerating shrinkage has occurred in the Chinese Altai Mountains during the last 50 years, with mass deficits of 0.43 ± 0.02 and0.54 ± 0.13 m a-1 water equivalent(w.e.) during the periods 1959-1999 and 1999-2008, ***, the Chinese Altai Mountains have lost 7.06 ±0.44 km3 in ice volume(equivalent to-0.43 ± 0.03 m a-1 w.e.) from 1959-2008. The spatial heterogeneity in mass loss was potentially affected by comprehensive changes in temperature and precipitation, and had a substantial correlation withglacier size and topographic settings. Comparison shows that in the Chinese Altai Mountains glaciers have experienced a more rapid mass loss than those in the Tianshan and northwestern Tibetan Plateau(TP), and the mass balance of glaciers was slightly less negative relative to those in the Russian Altai, Himalaya, and southern TP.

关键词： Altai Mountains Geodetic method Glacier change Mass balance

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