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Further support for a Cretaceous age for the feathered-dinosaur beds of Liaoning,China:New ^(40)Ar/^(39)Ar dating of the Yixian and Tuchengzi Formations

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Chinese Science Bulletin 2002年第2期47卷 135-138页

作者： C. C. Swisher III, WANG Xiaolin, zhou Zhonghe, WANG Yuanqing, JIN Fan, ZHANG Jiangyong , XU Xing, ZHANG Fucheng & WANG YuanDepartment of Geological Sciences, Wright Labs, Rutgers University, Piscataway, New Jersey 08854, USA (e-mail: cswish@rutgers. rci.e Department of Geological Sciences Wright Labs Rutgers University Piscataway NJ 08854 United States

We report new 40Ar/39Ar dating results ob-tained from total fusion and incremental-heating analyses of sanidine and biotite from three tuffs found interbedded within the fossil-bearing deposits of Liaoning, northeast China. The first is a new sample of the Bed 6 Sihetun tuff from the Yixian Formation, previously dated by our team as middle early Cretaceous, and recently considered by Lo et al., partially reset due to metamorphism from a nearby ba-saltic sill. The second is the Yixian Bed 9 tuff from Heng-daozi considered by Lo et al. to be unaffected by metamor-phism and whose age, based on total fusion 40Ar/39Ar dating of biotite, argues for a Jurassic age for the Yixian Formation. The third tuff is a previously undated tuff from the upper part of the underlying Tuchengzi Formation. Single crystal total fusion 40Ar/39Ar analyses of the Sihetun sanidine showed homogeneous radiogenic Ar, Ca/K ratios, excellent reproducibility and gave a mean age of 125.0 ± 0.18 (1SD) ± 0.04 (Se) Ma. Single sanidine

关键词： 40Ar/39Ar dating Cretaceous Yixian Formation Tu-chengzi Formation western Liaoning.

Cenozoic plant diversity of Yunnan： A review

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Plant Diversity 2016年第6期38卷 271-282页

作者： Yongjiang Huang Linbo Jia QiongWang Volker Mosbrugger Torsten Utescher Tao Su Zhekun zhou Key Laboratory for Plant Diversity and Biogeography of east Asia Kunming Institute of Botany Chinese Academy of Sciences Kunming 650201 China Key Laboratory of Tropical Forest ecology Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Mengla 666303 China Senckenberg Research Institute/BiK F (Loewe) Senckenberganlage 25 60325 Frankfurt am Main Germany State Key Laboratory of Paleobiology and Stratigraphy Nanjing Institute of Geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China Steinmann Institute University of Bonn Nassallee 8 53115 Bonn Germany

Yunnan in southwestern China is renowned for its high plant *** understand how this modern botanical richness formed,it is critical to investigate the past biodiversity throughout the geological *** this review,we present a summary on plant diversity,floristics and climates in the Cenozoic of Yunnan and document their changes,by compiling published palaeobotanical *** review demonstrates that thus far a total of 386 fossil species of ferns,gymnosperms and angiosperms belonging to 170 genera within 66 families have been reported from the Cenozoic,particularly the Neogene,of *** display the highest richness represented by 353 species grouped into 155 genera within 60 families,with Fagaceae,Fabaceae,Lauraceae and Juglandaceae being the most *** of the families and genera recorded as fossils still occur in Yunnan,but seven genera have disappeared,including Berryophyllum,Cedrelospermum,Cedrus,Palaeocarya,Podocarpium,Sequoia and *** regional extinction of these genera is commonly referred to an aridification of the dry season associated with Asian monsoon *** analyses indicate that in the late Miocene,Yunnan had three floristic regions:a northern subtropical floristic region in the northeast,a subtropical floristic region in the east,and a tropical floristic region in the *** the late Pliocene,Yunnan saw two kinds of floristic regions:a subalpine floristic region in the northwest,and two subtropical floristic regions separately in the southwest and the eastern *** floristic concepts are verified by results from our areal type analyses which suggest that in the Miocene southwestern Yunnan supported the most Pantropic elements,while in the Pliocene southwestern Yunnan had abundant Tropical Asia(Indo e Malaysia)type and east Asia and North America disjunct type that were absent from northwestern *** the late Miocene to late Pliocene through to the present,floristic compositio

关键词： Cenozoic Fossil plants Floristic change Palaeobiodiversity Palaeoclimate Yunnan

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月壤参数对月面着陆气囊缓冲性能的影响

国防科技大学学报 2022年第4期44卷 69-80页

作者：周旋周仕明李道奎国防科技大学空天科学学院湖南长沙410073 空天任务智能规划与仿真湖南省重点实验室湖南长沙410073

为研究月壤参数对气囊缓冲性能的影响,根据“嫦娥三号”的着陆工况设计了月面着陆气囊,并基于可压溃泡沫模型建立了考虑月壤特性的气囊缓冲动力学模型。对不同月壤下气囊的缓冲过程进行分析,发现月壤越软有效载荷冲击加速度越小,但气囊... 详细信息

为研究月壤参数对气囊缓冲性能的影响,根据“嫦娥三号”的着陆工况设计了月面着陆气囊,并基于可压溃泡沫模型建立了考虑月壤特性的气囊缓冲动力学模型。对不同月壤下气囊的缓冲过程进行分析,发现月壤越软有效载荷冲击加速度越小,但气囊会陷入月壤中,不利于对外排气,影响其缓冲效果。因此,采用气囊峰值压力、有效载荷最大加速度和最大下落高度3个指标对气囊缓冲性能进行综合评价,定量研究了月壤参数的影响规律。结果表明:月壤密度、剪切模量及屈服参数a_(0)和a_(1)对缓冲性能的影响较大,且对前两个指标为正影响,对后一个指标为负影响。进一步研究发现,这4个月壤参数与3个缓冲性能指标之间均为指数函数关系。

关键词：气囊月面土壤着陆冲击缓冲性能

Variation in hydraulic conductivity of fractured rocks at a dam foundation during operation

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Journal of Rock Mechanics and Geotechnical engineering 2021年第2期13卷 351-367页

作者： Yi-Feng Chen Jun Zeng Hongtao Shi Yifan Wang Ran Hu Zhibing Yang Chuang-Bing zhou State Key Laboratory of Water Resources and Hydropower engineering Science Wuhan UniversityWuhan430072China Key Laboratory of Rock Mechanics in Hydraulic Structural engineering of the Ministry of education Wuhan UniversityWuhan430072China China Three Gorges Projects Development Co. Ltd.Chengdu610000China

Characterizing the permeability variation in fractured rocks is important in various subsurface applications,but how the permeability evolves in the foundation rocks of high dams during operation remains poorly *** permeability change is commonly evidenced by a continuous decrease in the amount of discharge(especially for dams on sediment-laden rivers),and can be attributed to fracture clogging and/or hydromechanical *** this study,the permeability evolution of fractured rocks at a high arch dam foundation during operationwas evaluated by inverse modeling based on the field timeseries data of both pore pressure and discharge.A procedure combining orthogonal design,transient flow modeling,artificial neural network,and genetic algorithm was adopted to efficiently estimate the hydraulic conductivity values in each annual cycle after initial reservoir *** inverse results show that the permeability of the dam foundation rocks follows an exponential decay annually during operation(i.e.K/K0=0.97e^(-0.59t)+0.03),with good agreement between field observations and numerical *** significance of the obtained permeability decay function was manifested by an assessment of the long-term seepage control performance and groundwater flow behaviors at the dam *** proposed formula is also of merit for characterizing the permeability change in riverbed rocks induced by sediment transport and deposition.

关键词： Permeability variation Fractured rock Fracture clogging Seepage control Dam engineering

Tracking historical storm records from high-barrier lagoon deposits on the southeastern coast of Hainan Island,China

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Acta Oceanologica Sinica 2021年第11期40卷 162-175页

作者： Liang zhou Xiaomei Xu Yaping Wang Jianjun Jia Yang Yang Gaocong Li Changliang Tong Shu Gao School of Geography Geomaticsand PlanningJiangsu Normal UniversityXuzhou 221116China Hainan Key Laboratory of Marine Geological Resources and environment Haikou 570206China State Key Laboratory of estuarine and Coastal Research East China Normal UniversityShanghai 200046China Ministry of education Key Laboratory for Coast and Island Development Nanjing UniversityNanjing 210023China School of Marine Science and engineering Nanjing Normal UniversityNanjing 210046China Department of Marine Technology Guangdong Ocean UniversityZhanjiang 524088China

The relationship between storm activity and global warming remains *** better understand storm–climate relationships,coastal lagoon deposits are increasingly being investigated because they could provide high-resolution storm records long enough to cover past climate ***,site-specific sediment dynamics and high barriers may bias storm ***,we aimed to investigate these factors through the reconstruction of five distinct storm records(XCL-01,XC-03,XC-06,XC-07,XC-08)from different water depths in a lagoon with a high barrier(i.e.,Xincun Lagoon of Hainan Island).Sediment cores were characterized using high-resolution grain size and XRF measurements,to identify storm *** data were coupled with a numerical simulation to obtain bed shear stress data with high-spatial resolution to better understand storm-induced sediment transport mechanisms.^(210) Pb dating and Pb pollution chronostratigraphic markers indicated that the chronology of the storm deposit sequences of the cores span the period between 117 a and 348 *** grain size and XRF results indicated numerous,highly variable and short-duration fluctuations,suggesting that storm-induced coarse-grained sediments were deposited at these core *** inconsistent storm events recorded in these cores suggest that these sites have different preservation potentials for storm ***,the consistence between storm sediment records and historical documents for Core XCL-01 indicates that high-barrier lagoons could provide long-term storm event records with high preservation potential.

关键词： storm deposits preservation potential sediment dynamics high-barrier lagoon Hainan Island

estimation of endocarpon pusillum Hedwig carbon budget in the Tengger Desert based on its photosynthetic rate

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Science China(Life Sciences) 2013年第8期56卷 848-855页

作者： DING LiPing zhou QiMing WeI JiangChun State Key Laboratory of Mycology Institute of Microbiology Chinese Academy of Sciences University of Chinese Academy of Sciences

This study investigated the photosynthetic rate of the lichen endocarpon pusillum at the Chinese Academy of Sciences Shapotou Desert Research Station and estimated its annual contribution to the carbon budget in the ecosystem. The software SigmaPlot 10.0 with "Macro-Area below curves" was used to calculate the carbon fixation capacity of the lichen. The total carbon budget (ΣC) of the lichen was obtained by subtracting the respiratory carbon loss (ΣDR) from the photosynthetic carbon gain (ΣNP). Because water from precipitation plays an important role in photosynthesis in this ecosystem, the annual carbon budget of e. pusillum at the station was estimated based on the three-year average precipitation data from 2009 to 2011. Our results indicate that the lichen fixes 14.6 g Cm-2 annually. The results suggest that artificial inoculation of the crust lichen in the Tengger Desert could not only help reduce the sand and dust storms but also offer a significant carbon sink, fixing a total of 438000 t of carbon over the 30000 km2 of the Tengger Desert. The carbon sink could potentially help mitigate the atmospheric greenhouse effect. Our study suggests that the carpet-like lichen e. pusillum is an excellent candidate for "Bio-carpet engineering" of arid and semi-arid regions.

关键词： crust organisms carpet-like lichen carbon income carbon loss carbon sink

Single and double Auger decay of 4f-ionized mercury including cascade and direct processes

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Chinese Physics B 2018年第6期27卷 244-250页

作者： Yu-Long Ma Fu-Yang zhou Zhen-Qi Liu Yi-Zhi Qu College of Material Sciences and Optoelectronic Technology University of Chinese Academy of Sciences Beijing 100049 China Data Center for High energy Density Physics Institute of Applied Physics and Computational Mathematics Beijing 100088 China

Single（SA） and double（DA） Auger decay including cascade and direct processes are investigated for Hg 4 f^（-1） with multiconfiguration Dirac–Fock method and two-step approaches, i.e., knockout and shakeoff mechanisms. Due to the computational effort, only the major transitions are considered to describe the SA and DA decays for the Hg＋ions with complex electronic configurations. In order to estimate the Auger transition energies and amplitudes, the reference configuration sets producing the configuration state functions are carefully chosen for balancing electron correlations among the successive singly, doubly and triply ionized mercury. The Auger rates and electron spectra, DA probabilities as well as the populations of the final Hg^（3＋）states are obtained. Our results well explain the recent experimental data about the 4 f hole states of Hg[Palaudoux J et al., Phys. Rev. A 91 012513（2015）], and could provide guidance for further studies on complex *** for the DA decay, the contributions of the direct processes, which are neglected in their calculations, are found to be important, accounting for as high as about 38% and 34% of the total DA decays for the 4 f（7/2）^（-1） and 4 f（5/2）^（-1）, respectively.

关键词： single Auger cascade double Auger direct double Auger Hg 4f^-1

Isoflavones’effects on pharmacokinetic profiles of main iridoids from Gardeniae Fructus in rats

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Journal of Pharmaceutical Analysis 2020年第6期10卷 571-580页

作者： Ruirui Chang Jialin Liu Yusha Luo Taohong Huang Qiang Li Jun Wen Weidong Chen Tingting zhou School of Pharmacy Second Military Medical UniversityShanghai200433China School of Pharmacy Anhui University of Chinese MedicineHefei230031China Shimadzu China Co.LTD. Shanghai200233China d Shanghai Key Laboratory for Pharmaceutical Metabolite Research School of PharmacySecond Military Medical UniversityShanghai200433China

Gardeniae Fructus(GF)and Semen Sojae Praeparatum(SSP)are both medicine food homologies and widely used in Chinese clinical prescriptions *** research investigated the pharmacokinetics of four iridoids in normal rats and isolfavones-fed rats,which were administered with isolfavones from SSP for 7,14,21 and 28 consecutive days.A validated LC-MS/MS method was developed for determining shanzhiside,genipin-1-gentiobioside,geniposide and their metabolite genipin in rat *** samples were pretreated by solid-phase extraction using paeoniflorin as the internal *** chromatographic separation was performed on a Waters Atlantis T3(4.6 mm×150 mm,3 mm)column using a gradient mobile phase consisting of acetonitril and water(containing 0.06%acetic acid).The mass detection was under the multiple reaction monitoring(MRM)mode via polarity switching between negative and positive ionization *** calibration curves exhibited good linearity(r>0.997)for all *** lower limit of quantitation was in the range of 1 e10 ng/m *** intra-day and inter-day precisions(RSD)at three different levels were both less than 12.2%and the accuracies(Re)ranged fromà10.1%to 16.4%.The extraction recovery of them ranged from 53.8%to 99.7%.Pharmacokinetic results indicated the bioavailability of three iridoid glycosides and the metabolite,genipin in normal rats was higher than that in rats exposed to *** the longer time of administration of isoflavones,plasma concentrations of iridoids decreased,while genipin sulfate,the phase II metabolite of genposide and genipin-1-gentiobioside,appeared the rising *** pharmacokinetic profiles of main iridoids from GF were altered by isoflavones.

关键词： Iridoids Gardeniae fructus Isoflavones Rat Pharmacokinetics LC-MS/MS

Magnetic properties of Mn-doped GaN with defects:ab-initio calculations

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Chinese Physics B 2011年第8期20卷 297-303页

作者： e.Salmani A.Benyoussef H.ez-Zahraouy e.H.Saidi LMPHe Departement de PhysiqueFacult'e des SciencesUniversit'e Mohammed V-AgdalRabatMorocco LPHe Departement de PhysiqueFacult'e des SciencesUniversit'e Mohammed V-AgdalRabatMorocco

According to first-principles density functional calculations, we have investigated the magnetic properties of Mn- doped GaN with defects, Ga1-x-yVGxMny N1-z-tVNzOt with Mn substituted at Ga sites, nitrogen vacancies VN, gallium vacancies VG and oxygen substituted at nitrogen sites. The magnetic interaction in Mn-doped GaN favours the ferromagnetic coupling via the double exchange mechanism. The ground state is found to be well described by a model based on a Mn3＋-d5 in a high spin state coupled via a double exchange to a partially delocalized hole accommodated in the 2p states of neighbouring nitrogen ions. The effect of defects on ferromagnetic coupling is investigated. It is found that in the presence of donor defects, such as oxygen substituted at nitrogen sites, nitrogen vacancy antiferromagnetic interactions appear, while in the case of Ga vacancies, the interactions remain ferromagnetic; in the case of acceptor defects like Mg and Zn codoping, ferromagnetism is stabilized. The formation energies of these defects are computed. Furthermore, the half-metallic behaviours appear in some studied compounds.

关键词： diluted magnetic semiconductor GaN:Mn defects ab-initio magnetic properties