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Holocene grassland vegetation, climate and human impact in central eastern Inner Mongolia

Science china Earth Sciences 2005年第7期48卷 1025-1039页

作者： HUANG Fei1, Kealhofer Lisa2. xiONG Shangfa3 & HUANG Fengbao1 1. Nanjing Institute of geology and Paleontology,Chinese Academy of Sciences,Nanjing 2.0008,china 2. Anthropology and Sociology{2.,Santa Clara University,CA 95053,USA 3. Institute of geology and Geophysics,Chinese Academy of Sciences,Beijing 10002.,china Nanjing Institute of geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China Anthropology and Sociology department Santa Clara University CA 95053 United States Institute of geology and Geoohysics Chinese Academy of Sciences Beijina 100029 China

Phytolith and pollen preserved in the Taipusi Banner paleosol profile, central eastern Inner Mongolia, provide evidence of Holocene grassland vegetation, climate and human impact. The combined phytolith and pollen records reveal a major change in vegetation composition about 5000 a BP. Before 5000 a BP, the vegetation was dominated by Aneurolepidium Chinese-Stipa grandis grassland of C4 grasses. After 5000 a BP, C4 grasses rapidly retreated, indicating a shift to colder and more arid conditions. The gradual invasion of Stipa krylovii, Ag-ropyron desertorum, Ephedra, Chenopodiaceae and Caragana reveal the onset of grassland degeneration. Between 10000 and 872. a BP, the Aneurolepidium Chinese-Stipa grandis grassland included a small proportion of Artemisia shrub and Echionopos type plants, implying a strong winter monsoon and very weak summer monsoon. From 872. to 7000 a BP, C4 grasses were common, indicating a strengthening of the summer monsoon. Between 7000 and 5000 a BP, the Holocene thermal maximum was evident, with a significant expansion of C4 grasses and the presence of some trees (such as Pinus and Betula, and so on) in or near the study site. From 42.0?000 a BP, a sandy grassland of Artemisia and Agropyron desertorum together with Aster-type taxa occurred. Precipitation amelioration took place between 3000 and 2.70 a BP, with a rapid development of Echinops type plants and a small expansion of C4 grasses. From 2.70 a BP to present, human activities accelerated the process of grassland degeneration.

关键词： phytolith and pollen records grassland environment change human impact Holocene central eastern Inner Mongolia.

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Capture Efficiency Analysis in the Circular Restricted Three-body Problem

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Research in Astronomy and Astrophysics 2024年第5期24卷 198-210页

作者： Yu-Xuan Miao xi-Yun Hou department of Astronomy and Space Science Nanjing UniversityNanjing 210023China Institute of Space Environment and Astrodynamics Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics Ministry of EducationNanjing 210023China

Temporary capture efficiency is studied in the framework of the circular restricted three-body problem in two ***, a non-uniform distribution of test particles around the secondary's orbit is obtained by fully accounting the secondary's gravitational influence. Second, the capture efficiency is computed based on the non-uniform distribution. Several factors influencing the result are discussed. By studying the capture efficiency in the circular restricted three-body problem of different mass ratios, a power-law relation between the capture efficiency(p) and the mass ratio(μ) is established, which is given by p ≈ 0.2. × μ^(0.53), within the range of 3.0035 ×10^(-6)≤ μ ≤ 3.0034 × 10^(-5). Taking the Sun–Earth system as an example, the influence from the orbit eccentricity of the secondary on the non-uniform distribution and the capture efficiency is studied. Our studies find that the secondary's orbit eccentricity has a negative influence on the capture efficiency.

关键词： methods numerical-celestial mechanics-planets and satellites dynamical evolution and stability

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A paleontological perspective of vertebrate origin

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Chinese Science Bulletin 2003年第8期48卷 725-735页

作者： SHU Degan Early Life Institute & department of geology, Northwest University, xi抋n,{2., china School of Earth Sciences and Resources, china University of Geosciences, Beijing, 100083, china (e-mail: elidgshu@ ***) Early Life Institute & department of geology Northwest University China School of Earth Sciences and Resources China University of Geosciences

The Early Cambrian Haikouichthys and Haikouella have been claimed to be related to contribute in an important way to our understanding of vertebrate origin, but there have been heated debates about how exactly they are to be interpreted. New discoveries of numerous speci-mens of Haikouichthys not only confirm the identity of pre-viously described structures such as the dorsal and the ven-tral fins, and chevron-shaped myomeres, but also reveal many new important characteristics, including sensory or-gans of the head (e.g. large eyes), and a prominent notochord with differentiated vertebral elements. This 揻irst fish?ap-pears, however, to retain primitive reproductive features of acraniates, suggesting that it is a stem-group craniates. A new order (Myllokunmingiida) and a new family (Myllo-kunmingiidae) are erected, and a new species, Zhongjianich-thys rostratus (gen. et sp. nov.), is described herein. Over 1400 newly-discovered specimens of Haikouella provide a wealth of anatomical information on this organism. It differs from chordates in many organs and organ systems, including the skin, muscles, respiratory, circulatory and nervous sys-tems. In contrast, its body-design resembles that of vetuli-colians, and the presence of a 搕ransitional?nervous system with both dorsal and ventral nerve cords suggests an affinity with living hemichordates. On the basis of these and other recent findings of fossil deuterostomes, a five-step hypothesis for vertebrate origin is proposed, intended to bridge the long- standing gap between protostomes and vertebrates. Four of the five steps accord with established ideas current in modern evolutionary zoology. Evidence for the first step is obtainable only from fossils, and specifically from fossils found from South china, hence the crucial importance of S. china sites for our understanding of early vertebrate origins and evolution. Accordingly, South china is suggested as the oldest-known birthplace of the whole vertebrates.

关键词：脊椎动物动物起源寒武纪中国南部地区

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Traditional Chinese Medicine Integrated Responsive Microneedles for Systemic Sclerosis Treatment

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Research 2024年第1期2023卷 139-147页

作者： xi Luan xiaoxuan Zhang Min Nie Yuanjin Zhao department of Rheumatology and Immunology Nanjing Drum Tower HospitalSchool of PharmacyClinical College of Traditional Chinese and Western MedicineNanjing University of Chinese MedicineNanjing 210023China State Key Laboratory of Bioelectronics School of Biological Science and Medical EngineeringSoutheast UniversityNanjing 210096China

Traditional Chinese medicine,such as Tripterygium wilfordii and Paeonia lactiflora,has potential values in treating systemic sclerosis(SSc)and other autoimmune diseases,while their toxic side effect elimination and precise tropical drug delivery are still ***,we present multiple traditional Chinese medicine integrated photoresponsive black phosphorus(BP)microneedles(MNs)with the desired features for the SSc *** employing a template-assisted layer-by-layer curing method,such MNs with triptolide(TP)/paeoniflorin(Pae)needle tips and BP-hydrogel needle bottoms could be well *** combined administration of TP and Pae can not only provide anti-inflammatory,detoxification,and immunomodulatory effects to treat skin lesions in the early stage of SSc but also remarkably reduce the toxicity of single drug ***,the additive BPs possess good biocompatibility and near-infrared(NIR)responsiveness,imparting the MN photothermal-controlled drug release *** on these features,we have demonstrated that the traditional Chinese medicine integrated responsive MNs could effectively improve skin fibrosis and telangiectasia,reduce collagen deposition,and reduce epidermal thickness in the SSc mouse *** results indicated that the proposed Chinese medicine integrated responsive MNs had enormous potential in clinical therapy of SSc and other diseases.

关键词： needle precise template

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EPR studies of Mn^(2.) in the Loess Plateau of central china: Implication for variation of the East Asia summer monsoon

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Chinese Science Bulletin 1998年第1期43卷 72-75页

作者： CHEN Jun\+1, JI Junfeng\+1, SU Yuanxia\+2.and LU Huayu\+31. department of Earth Sciences, Nanjing University, Nanjing 2.0093, china 2. Center of Material Analysis, Nanjing University, Nanjing 2.0093, china 3. xi’an Laboratory of Loess and Qu department of Earth Sciences Nanjing University Nanjing China Center of Material Analysis Nanjing University Nanjing China xi’an Laboratory of Loess and Quaternary geology Chinese Academy of Sciences Xi’an China

Mn 2. EPR intensity recorded in the Chinese loess_paleosol sequence shows close correlation with magnetic susceptibility and Sr content as well as the oscillation of paleoclimate. Thus Mn 2. EPR signal can serve as an... 详细信息

关键词： paleomonsoon loess paleosol EPR signal of Mn 2.

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Synthesis, crystal structure and properties of binuclear manganese complex [(bipy)_2.n_2./J-O)(/i-Ac)_2.H_2.)_2.(ClO_4)_2

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Chinese Science Bulletin 2000年第12期45卷 1079-1082页

作者： LI Jun, YANG Shuming, ZHANG Fengxing, TANG Zongxun, SHI Qizhen & ZHOU Zhongyuan1. department of Chemistry, Northwest University, xi’an{2., china 2. Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, china Correspondence should be addressed to Li Jun department of Chemistry Northwest University Xi’an China Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu China

Binuclear manganese complex [(bipy)2.n2.μ-O)(μ-Ac)2.H2.)2.(CIO4)2.was synthesized by the reaction of MnAc3 · 2.2. with 2.2.-bipyridine in the HAc-NaAc buffer (pH = 4.0). X-ray diffraction result for the single crystal shows that the crystal is monoclinic, space group C2.C, with a = 3.4082.7), 6 = 0.8644(2., c= 2.174 9(4) nm,β= 105.2., V =6.186(2. nm3, Z= 8. There are two very strong peaks of UV-Vis spectrum in the range of 400-600 nm, which are similar to those of Mn catalase and Mn ribonuleotide reductase extracted from organisms. Cyclic voltammogram shows that the complex in CH3CN undergoes quasi-reversible one-electron reduction and oxidation at E1/2.1.15V.

关键词： binuclear manganese complex crystal structure synthesis properties.

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Geochemistry of high-Mg andesites from the early Cretaceous Yixian Formation, western Liaoning: Implications for lower crustal delamination and Sr/Y variations

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Science china Earth Sciences 2006年第9期49卷 904-914页

作者： WANG xiaorui1, GAO Shan1,2. LIU xiaoming1, YUAN Honglin1, HU Zhaochu1, ZHANG Hong1,3 & WANG Xuance4 1. State Key Laboratory of Continental Dynamics, department of geology, Northwest University, xi`an{2., china 2. State Key Laboratory of Geological Processes and Mineral Resources, china University of Geosciences, Wuhan 430074, china 3. Shenyang Institute of geology and Mineral Resources, Shenyang 110032. china 4. Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, china State Key Laboratory of Continental Dynamics Department of Geology Northwest University Xi’an China State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan China Shenyang Institute of geology and Mineral Resources Shenyang China Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China

85 volcanic rocks of the Yixian Formation from the Sihetun type section werecollected and analyzed for geochemical and isotopic compositions. Major element compositionsindicate that the Sihetun volcanic rocks are high magnesium andesites with some basalts occurring atthe bottom of section. The Sihetun high magnesium andesites (SiO_2.= 52.82.59.31 wt%, Al_2._3=14.15-16.35wt%) show many characteristics of adakites such as depletion in heavy rare-earth elements(HREE; Yb = 1.03-1.88 μg/g) and Y(12.2. μg/g) and high Sr (62.-132. μg/g) and Sr/Y(32.88), withhigh La_N/Yb_N ratio (10-2.). They share similar major and trace element characteristics to volcanicrocks from the xinglonggou Formation except their lower Nd isotope ratios (^(143)Nd/^(144)Nd(130Ma) = 0.5118-0.5119, ε_(Nd) (130Ma) = -11.6-13.8, ^(87)Sr/^(86)Sr (130 Ma) = *** were interpreted in a way that eclogite that formed at the base of thickened Archean lowercrust of the North china craton foundered into the convecting mantle and subsequently melted andinteracted with peridotite. However, compared to the xinglonggou volcanic rocks, the source of theSihetun magma contained more ancient continental crustal material in order to explain its evolved Ndisotopes. The age of the Sihetun Formation was 12. to 130 Ma, and this indicates that delaminationlasted to the early Cretaceous period. The Sr contents and Sr/Y ratios of the Sihetun high-Mgandesites show significant negative correlations with SiO_2.for samples with SiO_2.> 56%. Thesesuggest that the Sr and Sr/Y values were reduced due to fractional crystallization of ***, the effect of crystallization on volcanic Sr and Sr/Y ratio has to be taken intoaccount.

关键词： High-Mg andesite, Adakite, Yixian Formation, North china Craton, delamination.

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The Dilution/Crystallization Kinetics of RDX and HMX

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含能材料 2002年第3期10卷 100-103页

作者： HU Rongzu1, LI Zhibin2. CHEN xijün2. GAO Shengli1, FANG Yan1, SHI Qizhen1(1. department of Chemistry, Northwest University, xi′an 710069,{2. 2. xi′an Modern Chemistry Research Institute, xi′an 710065,{2.) department of Chemistry Northwest University Xi'an 710069 xi'an Modern Chemistry Research Institute Xi'an 710065

Three thermokinetic equations describing the crystal growth process and two relationships between the parameters and the constants of the kinetic equations are derived. The thermokinetic data of crystal growth processes of RDX and HMX are treated based on the derived equations and relationships. The results show that the exothermic dilution / crystallization processes of RDX and HMX are the first order reaction and accord with the dislocation theory.

关键词：位错理论结晶动力学晶体生长

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A new ordered phase forming during ageing in Cu-Ti alloys

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Chinese Science Bulletin 1997年第19期42卷 1671-1672页

作者： WEI Yinghui and WANG xiaotian1. department of Materials Science, Taiyuan University of Technology, Taiyuan 03002., china 2. College of Materials Science,{2. Jiaotong University,{2. 710049, china Ion Beam Laboratory Shanghai Institute of Metallurgy Chinese Academy of Sciences Shanghai 200050 China

AGE-hardened Cu-Ti has been an important alloy of investigation in the field of continuousphase transformation due to its complicated transformation processes which involve short rangeordering (SRO), spinodal decomposition (SD), long range ordering (LRO), etc. So far, ithas been a controversial topic whether each process exists, and in what sequence they pro-ceed.

关键词： Ti Cu A new ordered phase forming during ageing in Cu-Ti alloys

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Metallogenic geochemistry of Sb-mineralization in southern margin of North china platform

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Chinese Science Bulletin 1999年第S2期44卷 17-18页

作者： YANG xiaoyong~1, YANG Xueming~1, ZHANG Jianjun~2. CAO Gaoshe~2.and ZHANG Zhengwei~2.1. department of Earth and Space Sciences, University of Science and Technlogy of china, Hefei 2.002., china 2. Institute of geology, Henan Bureau of geology and Mineral Resources, Zhengzhou 450053, china department of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China Institute of geology Henan Bureau of Geology and Mineral Resources Zhengzhou 450053 China

1 Geological setting THE Sb mineralization zone in the south margin of North china platform is located in the transitional edgeof North china plate and Yangtze plate, belonging to Qinling fold system, whose tectonic line is inNWW-SEE direction regionally. Because of the huge compression caused by the collision of the twoplates, the rocks undergone strong deformation and metamorphism have very complicated structures. Theregional deep fault-Shuanghuaishu fault-controls Sb-mineralization zone belt, and all the Sb-oredeposits or mineralized spots appear alone at the very southern margin of the fault. The lithostragraphirunits in the mineralized zone are relatively simple, mainly composed of Jiebei Group （Pt2./sub>J2./sup>） of QinglingFormation （with middle-high metamorphsim） and the upper Triassic system （with little metamorphism）.

关键词： Sb-mineralization metallognic geochemistry North china plateform.

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