检索结果-南通市图书馆

Miocene Bahean stratigraphy in the Longzhong Basin, northern central China and its implications in environmental change

引用

Science China Earth sciences 2006年第12期49卷 1270-1279页

作者： LI Jijun1,2. ZHANG Jun1, SONG Chunhui1, zhao Zhijun2. ZHANG Yong1, wang Xiuxi 1, ZHANG Jianming1 & CUI Qiaoyu1 1. Key Laboratory of Western China’s Environmental Systems (Ministry of Education) & College of Earth and Environment {2., Lanzhou University, Lanzhou 730000, China 2. Jiangsu Key Laboratory of Environmental Change and Ecological Construction & College of Geography, nanjing Normal University, nanjing 2.0097, China 1. Key Laboratory of Western China’s Environmental Systems (Ministry of Education) & College of Earth and Environment sciences Lanzhou University Lanzhou 730000 China 2. Jiangsu Key Laboratory of Environmental Change and Ecological Construction & College of Geography Nanjing Normal University Nanjing 210097 China

Fossil mammal-riched Neogene strata are widely distributed in the southeast corner of the huge Longzhong Basin at Tianshui, Gansu Province, northern central China. Hipparion weihoense, a typical member of late Middle Miocene Bahean stage, was recently excavated at Yaodian along a well-exposed outcrop. Owing to the importance of the Bahean stage in the mammalian evolution and its potential for environmental change, we suggested a name of Yaodian Formation for the stratigra- phy, which is correlated to the Bahe Formation at Lantian, Shaanxi. High resolution paleomagnetic dating of the section shows that the Yaodian Formation covers the period between 11.67 Ma and 7.43 Ma, with the site bearing Hipparion weihoense being estimated at about 10.54―10.30 Ma, providing first magnetostratigraphic chronology for the Bahean Stage. The Yaodian Formation consists of fluvial channel deposits (11.67―10.40 Ma) at the bottom, floodplain deposits in the middle (10.40―9.2. Ma) and shallow lake sediments at the top (9.2.―7.43 Ma). This upward fining sequence suggests that the relief in nearby mountain ranges such as West Qinling to the south and Huajia Ling to the north was greatly reduced after long-term denudation, fluvial transport capacity was low, and finally the drainage system was disintegrated, replaced with broad-shallow lakes in which only fine sediments like mud and marlite were deposited, indicating an old stage of development of a planation surface. A remarkable shift in ecology and climatic environment was found at 7.4―7.7 Ma when paleoclimate changed from early warm humid to late dry as indicated by sedimentary facies changed from early shallow lake sequence to late eolian red clays and a former coniferous-deciduous mixed forest was replaced by grassland, leading to great growth of Hipparion Fauna of Baodean stage in the region. Therefore, it is estimated that the present high relief of Qinling and drainage pattern did not come into being until Late Pliocene in response

关键词： Bahean stage,magnetostratigraphy,Yaodian Formation,Neogene,Longzhong Basin.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Integrated precise orbit determination of Shenzhou IV unmanned spacecraft

引用

Science China(Technological sciences) 2004年第5期47卷 518-525页

作者： L Congmin1,2. GU Yidong3, LIN Baojun3 & GUO Jiong3 1. Center for Space Science and Applied Research, chinese academy of sciences, Beijing 100080, China 2. Graduate School of the chinese academy of sciences, Beijing 100039, China 3. General Establishment of Space Science and Application, chinese academy of sciences, Beijing 100080, China Correspondence should be addressed to L Congmin 1. Center for Space Science and Applied Research Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of the chinese academy of sciences 100039 Beijing China 3. General Establishment of Space Science and Application Chinese Academy of Sciences 100080 Beijing China

Considering the characteristic orbit of Shenzhou IV spacecraft and the advantages and disadvantages of several types of domestic orbit measurements, a scheme of IPOD is determined, which uses GPS, SLR and USB observation data jointly plus precise ionosphere corrections to GPS observation data. IPOD system and mathematic models of OD are introduced. The results of different joint OD are analyzed using true observation data, and show that radial accuracy is better than 2.m.

关键词： Shenzhou IV unmanned spacecraft integrated precise orbit determination GPS SLR USB.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

OUTBURSTS OF COMET HALE-BOPP

引用

中国科学院上海天文台年刊 2000年 87-91页

作者： Yang Benyou 1 Zhang Chunsheng 1 Fan Yixin 1 Cai Hongfang 1 Sun Shousheng 2.Zhang Yan 2.Sun Linan 2.(1. purple mountain {2., chinese academy of sciences, nanjing 2.0008) (2. Qingdao Station of purple mountain {2., Qingdao 2.6

In this paper, we present the observations of Comet Hale-Bopp by means of photoelectric and photographic photometry during the period from September to November of 1996. It is shown that there appears to have been 3 outbursts around 2. Sept., 2. Oct. and 13 Nov.; and it is also possible that an event of outburst has taken place around 9 Oct.

关键词： Comet Hale-Bopp - outburst - photometry

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

FRAGMENTS OF COMET HYAKUTAKE (C/1996 B2.

引用

中国科学院上海天文台年刊 2000年 249-250页

作者： Chen Daohan 1 zhao Aidi 1 Wu Oindi 1 Song Yi 1 Fan Yixin 1 Sun Shousheng 2.Zhang Yan 2.Sun Linan 2.(1. purple {2. observatory, chinese Acadeniy of sciences, nanjing 2.0008) (2. Qingdao Station of purple {2. observatory, Qingdao

Several fragments of Comet Hyakutake were observed in March and April of 1996. This leads to the impression that the splitting of Comet Hyakutake on a small scale occurred frequently. Data analysis points to a rotatio... 详细信息

关键词： Comet Hyakutake - fragment - rotation period

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Unusually Broadened Spectral Profiles Observed in Solar Prominences

引用

chinese Journal of Astronomy and Astrophysics 2004年第4期4卷 377-389页

作者： HuiLi Jian-QiYou EijiroHiei purplemountain{2. ChineseAcademyofSciencesNanjing210008 NationalAstronomicalobservatoryofJapan MitakaTokyo181-8588Japan

After surveying the spectra of 39 prominences observed by the Multi-channel Infrared Solar Spectrograph at purple mountain {2. and the 2. cm coronagraph at the Norikura Solar {2., we found that about 2.% of them show small spatial scale (6''–8'') and short time scale (tens of seconds to a few minutes), unusual large broadening and large shift velocities in spectral lines including Hα, Hβ, H, Ca II H, Ca II K, Ca II 8542., He I D3 and He I 10830?. We present in detail two typical events observed respectively on 2.02.May 2. and 1981 August 2. The full-width at half maximum of the widest profile of the 2.01 prominence is 1.8? for Hα and 2.9 ? for He I 10830?, while that of the 1981 prominence is 5.3 ? for Hβ, 3.6 ? for Ca II K, 4.0 ? for Ca II H and 2.8 ? for He I D3. Such broadenings generally occur at a level of several-thousand kilometres above the chromosphere. Further, most of these prominences manifest a rotation of (0.4–1.35)×10-2./SUP> rads s?1 pointing to the Sun and large line-of-sight velocities of 2.–2.0 km s?1. Some of these events correspond in time to an enhancement or a small peak in the GOES X-ray flux, indicating the existence of high energy process at work. These prominences generally display discernible changes in the Hα morphology around the time of large broadening, but do not show Hα brightening or overall eruption except for a few small surge-like events, hence, they are hardly observed in daily Hα patrols. According to the characteristics of their Hα structures and spectral properties, we infer these events are small-scale eruptions similar to nano-flares, which may contribute to the mass and energy transported into the corona. Large turbulent velocities of 2.–12. km s?1 are responsible for the observed broadenings.

关键词： sun: prominences line: profiles turbulence

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

RAPID FLUCTUATIONS OF WATER MASER EMISSION IN VY CMa

引用

南京大学学报(自然科学) 1999年第4期35卷 494-495页

作者： Zheng Xingwu 1) Eugenio Scalise Jr 2. Han Fu 3) (1)Department of Astronomy,nanjing University, 2.0093, nanjing, PRC 2.INDPE,Brasil 3){2. mountain observatory,2.0008,nanjing,PRC) 南京大学天文系江苏 INDPE 巴西中科院紫金山天文台江苏

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Development of a single transcript CRISPR/Cas9 toolkit for efficient genome editing in autotetraploid alfalfa

引用

The Crop Journal 2024年第3期12卷 788-795页

作者： Haixia zhao Siyi zhao Yingping Cao Xiping Jiang Lijuan zhao Zhimeng Li Mengqi wang Ruijuan Yang Chuanen Zhou zhaoming wang Feng Yuan Dongmei Ma Hao Lin Wenwen Liu Chunxiang Fu CAS Key Laboratory of Biofuels Shandong Provincial Key Laboratory of Energy GeneticsQingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101ShandongChina Shandong Energy Institute Qingdao 266101ShandongChina Qingdao New Energy Shandong Laboratory Qingdao 266101ShandongChina University of chinese academy of sciences Beijing 100049China The Key Laboratory of Plant Development and Environmental Adaptation Biology Ministry of EducationSchool of Life SciencesShandong UniversityQingdao 266101ShandongChina Key Laboratory of Forage Breeding and Seed Production of Inner Mongolia Inner Mongolia M-Grass Ecology and Environment(Group)Co.Ltd.Hohhot 010016Inner MongoliaChina School of Ecology Environment Ningxia UniversityYinchuan 750021NingxiaChina Biotechnology Research Institute Chinese Academy of Agricultural SciencesBeijing 100081China

Alfalfa(Medicago sativa.L.)is a globally significant autotetraploid legume forage ***,despite its importance,establishing efficient gene editing systems for cultivated alfalfa remains a formidable *** this study,we pioneered the development of a highly effective ultrasonic-assisted leaf disc transformation system for Gongnong 1 alfalfa,a variety widely cultivated in Northeast ***,we created a single transcript CRISPR/Cas9(CRISPR_2.0)toolkit,incorporating multiplex gRNAs,designed for gene editing in Gongnong *** Cas9 and gRNA scaffolds were under the control of the Arabidopsis ubiquitin-10 promoter,a widely employed polymeraseⅡconstitutive promoter known for strong transgene expression in *** assess the toolkit’s efficiency,we targeted PALM1,a gene associated with a recognizable multifoliate *** the CRISPR_2.0 toolkit,we directed PALM1 editing at two sites in the wild-type Gongnong *** indicated a 35.1%occurrence of editing events all in target 2.alleles,while no mutations were detected at target 1 in the transgenic-positive *** explore more efficient sgRNAs,we developed a rapid,reliable screening system based on Agrobacterium rhizogenes-mediated hairy root transformation,incorporating the visible reporter *** screening system demonstrated that most purple visible hairy roots underwent gene ***,sgRNA3,with an 83.0%editing efficiency,was selected using the visible hairy root *** anticipated,tetra-allelic homozygous palm1 mutations exhibited a clear multifoliate *** palm1 lines demonstrated an average crude protein yield increase of 2..5%compared to trifoliolate *** findings highlight the modified CRISPR_2.0 system as a highly efficient and robust gene editing tool for autotetraploid alfalfa.

关键词： Alfalfa Gene editing CRISPR_2.0 toolkit Hairy root system Tetra-allelic homozygous mutants

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Unbalanced private set intersection with linear communication complexity

引用

Science China(Information sciences) 2024年第3期67卷 79-93页

作者： Quanyu zhao Bingbing JIANG Yuan ZHANG Heng wang Yunlong MAO Sheng ZHONG Department of Computer Science and Technology Nanjing University purple mountain Lab

The private set intersection(PSI) protocol allows two parties holding a set of integers to compute the intersection of their sets without revealing any additional information to each other. The unbalanced PSI schemes consider a specific setting where a client holds a small set of the size n and a server holds a much larger set of the size m(n ■ m). The communication overhead of state-of-the-art balanced PSI schemes is O(m + n) and the unbalanced PSI schemes are O(nlogm). In this paper, we propose a novel secure unbalanced PSI protocol based on a hash proof system. The communication complexity of our protocol grows only linearly with the size of the small set. In other words, our protocol achieves communication overhead of O(n). We test the performance on a personal computer(PC) machine with a local area network(LAN)setting for the network. The experimental results demonstrate that the client only takes 2.01 s of online computation, 4.2. MB of round trip communication to intersect 1600 pieces of 32.bit integers with 2.0pieces of 32.bit integers with the security parameter λ = 512. Our protocol is efficient and can be applied to resource-constrained devices, such as cell phones.

关键词： unbalanced private set intersection Hash proof system linear communication complexity small set resource-constrained devices

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

关于太阳底部贯穿对流区的延伸程度

引用

天文学报 2001年第2期42卷 121-124页

作者：熊大闰邓李才中国科学院紫金山天文台中国科学院北京天文台

The extension of the solar lower overshooting zone is discussed. There is no any near discontinuity of the derivatives of sound speed at the bottom of the lower overshooting zone, as described by the phenomenological non local mixing length theory. On the contrary, the temperature gradient turns smoothly from nearly adiabatic stratification into radiative one. In the lower overshooting zone the temperature gradient is sub adiabatic, but it is super radiative! Namely  rad 1.01) is around 0.63 H p (0.053 R ⊙ ).

关键词：恒星对流贯穿对流太阳恒星演化内部结构

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CHARACTERISTICS OF SUNSPOT GROUP 5395

引用

天文研究与技术 1990年第4期 25-27,319页

作者： zhao Aidipurple {2. observatory, chinese academy of sciences, nanjing 2.0008 China

1 INTRODUCTION The sunspot group 5395 was appeared in the east of the solar disc on 6 March anddisappeared in the west of the solar disc on 2. March in 1989. Its heliographiccoordinates were N34, L2.7. It has been the... 详细信息

关键词： latitude longitude moved appeared everyday spots downward Northeast rotation altitude

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：