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19篇 您的检索式:作者名="LI YiYin"
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1Quantitative relationships between vegetation and several pollen taxa in surface soil from North China显示文摘According to the vegetation investigation and pollen analysis of surface samples sampled along a precipitation gradient of the Northeast China Transect (NECT), several pollen taxa, including Pinus, Betula, Quercus, Tilia, Acer, Ulmus, Artemisia, Chenopodiaceae, Gramineae and Cyperaceae, were chosen to make the regression and correlation analyses. The results indicated that there exists a close relationship between vegetation and pollen taxa in surface samples. The regression parameters for ten taxa in the forests in the eastern part of NECT were different from those in the steppes in the western part. Pinus, Betula, Artemisia and Chenopodiaceae, which have large slope and y-intercept terms, were over-representative taxa. Acer, Gramineae and Cyperaceae, which have small slope and y-intercept terms, were under-representative taxa. Quercus, Tilia and Ulmus whose slope terms have negative correlation with y-intercept terms were equi-representative taxa. The pollen taxa with large slope or large y-interceptLI Yiyin, ZHANG Xinshi & ZHOU Guangsheng1. Department of Urbon and Environmental Sciences, Peking University, Beijing 100871, China 2. Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 3. School of Urban and Environmental Sciences, Northeast Normal University, Changchun 130024, China Correspondence should be addressed to Li Yiyin 2000Chinese Science Bulletin2000,45,16:24
2Evidence of fire use of late Pleistocene humans from the Huanglong Cave, Hubei Province, China显示文摘Since 2004, three excavations have been carried out at a late Pleistocene human fossil site of Huanglong Cave in Yunxi County, Hubei Province of China, which unearthed seven human teeth, dozens of stone tools, mammal fossils and other evidence indicating human activities. During the third excavation in 2006, in the same layer as the human teeth, we found some patches of black materials embed- ded in the deposit. We doubted that this black deposit layer is the remains of burning or even human use of fire at the cave. To further explore the possibility of human fire use at the Huanglong Cave, we examined samples directly taken from the black deposit layer and compared them with samples taken from several places in the cave using three methods: micromorphology, element content determination and deposit temperature analysis. Our results indicate that the contents of carbon element in the black deposit reach 64.59%―73.29%. In contrast, contents of carbon element of the comparative samples from other parts in the cave are only 5.82%―9.49%. The micromorphology analysis of the black deposit samples reveals a plant structure like axial parenchyma, fibrocyte, uniseriate ray and vessel. High-temperature magnetic susceptibility measurements suggest that the stratum possibly underwent a high temperature in the nature. Based on these lab analyses, we are sure that the black layer in the Huanglong Cave is the remains of fire and combustion did occur in the cave 100000 years ago. Taking other evidence of human activities found in the Huanglong Cave into consideration, we believe that the evidence of fire from the Huanglong Cave was caused by the human activities of controlled use of fire.LIU Wu WU XianZhu LI YiYin DENG ChengLong WU XiuJie PEI ShuWen 2009Chinese Science Bulletin2009,54,2:8
3Vegetation reconstruction of Bronze Age by using microscopic structure of charcoals显示文摘The microscopic structure of charcoals was determined in two sites of Bronze Age, Chifeng area by using the scanning electronic microscope. The results showed that these charcoals are all timbers of Mongolian oak (Quercus mongolica). It has powerful climatic indicative significance. Based on the assemblage of pollen composition, their eco-climatic index and character of community, the vegetation reconstruction of Bronze Age was obtained. The reconstruction showed that the zonal vegetation was Mongolian oak forest and Chinese pine forest in the loess hills in the Chifeng area, which suggested that the climatic condition was warmer and wetter at that time than present time.CUI Haiting LI Yiyin HU Jinming YAO Xishen LI Yang 2002Chinese Science Bulletin2002,47,23:6
4Pollen flux and vertical dispersion in coniferous and deciduous broadleaved mixed forest in the Changbai Mountains显示文摘The pollen flux in coniferous and deciduous broadleaved mixed forest in the Changbai Mountains is presented in one year's experiments. The results indicate that arboreal pollen percentages are more than 65% and pollen flux is higher than 5000 grain·cm-2·a-1,while less than 2% and lower than 1000 grain·cm-2·a-1 for shrubby pollen,and less than 20% and lower than 3000 grain·cm-1·a-1 for herbaceous pollen for most samples at different heights. The pollen assemblages are similar to those in the samples under 8 m height where Pinus and Ouercus are dominant and followed by the few non-local pollen types,and Fraxinus percentages are high with a few non-local pollen types at 16 m to 32 m height as well as non-local pollen clearly increased at 40 m height. Comparisons between pollen assemblages and vegetation composition suggest that similarities are higher for pollen trap samples than for surface moss samples.XU QingHai LI YueCong ZHOU LiPing LI YiYin ZHANG ZhenQing LIN FengYou 2007Chinese Science Bulletin2007,52,11:6
5On Laves phase in a 9Cr3W3CoB martensitic heat resistant steel when aged at high temperatures显示文摘9Cr3W3 CoB steels are developed to serve at the temperature range of 620-650℃,and have been recognized as the most promising martensitic heat-resistant steels for supercritical power plants.Due to the high W and Co contents,the Fe_(2)W Laves phase in such 9Cr3W3 CoB steel possesses some specialties in thermodynamics.In the present research,it was found that even when aged at 800℃in the 9Cr3W3 CoB steel,instead of dissolving,Laves phase formed after 50 h and kept on increasing in size and number density until 1000 h,indicating that the Laves phase was marching for the thermodynamic equilibrium during aging.In this thermodynamic process,the W-rich M_(3)B_(2)borides in as-received steel and M23C6 carbides were revealed to dissolve,supporting the growth of Laves phase.SEM investigation indicates that Laves phase tended to form clusters,and finally grow as a unit bulk Laves phase with an irregular shape.Besides,Laves phase nucleated next to M23C6 carbides and enwrapped them inside at 800℃.In addition,the growth processes of Laves phase and M23C6 carbides were a competitive procedure,the coarsening of M23C6 carbides was prior to the growth of Laves phase at 750℃while the growth of Laves phase was prior to the coarsening of M23C6 carbides at 800℃.Ye Liang Wei Yan Xianbo Shi Yanfen Li Quanqiang Shi Wei Wang Yiyin Shan Ke Yang 2021Journal of Materials Science & Technology2021,,26:1
6Effects of Different Flue-curing Technologies on Submicroscopic Structure of Flue-cured Tobacco Leaves显示文摘[Objective]This study aimed to compare the effects of low-temperature low-humidity tobacco flue-curing technology,moderate-temperature moderatehumidity tobacco flue-curing technology and moderate-temperature high-humidity tobacco flue-curing technology on submicroscopic structure of flue-cured tobacco leaves to provide theoretical basis for tobacco flue-curing. [Method] Middle leaves of tobacco cultivar K326 were collected in Pengshui County of Chongqing City for flue-curing experiment using three flue-curing technologies. Leaf samples were collected regularly in the flue-curing process,to investigate the submicroscopic structure of flue-cured tobacco leaves. [Result]Morphology changes and structural rupture of chloroplasts occurred at different time during three flue-curing processes. In low-temperature low-humidity flue-curing process,morphology changes and structural rupture of chloroplasts occurred late but rapidly; in moderate-temperature moderate-humidity flue-curing process and moderate-temperature high-humidity flue-curing process,morphology changes and structural rupture of chloroplasts occurred early but slowly. Among these three flue-curing processes,the speed of changes in mitochondria morphology,cristae number and membrane rupture presented an upward order of low-temperature low-humidity flue-curing process < moderate-temperature high-humidity flue-curing process < moderate-temperature moderate-humidity flue-curing process. In low-temperature low-humidity flue-curing process,starch granules in chloroplasts ruptured after flue-curing for 36- 48 h;in moderate-temperature moderate-humidity flue-curing process,starch granules in chloroplasts ruptured after flue-curing for 24- 36 h; in moderate-temperature high-humidity flue-curing process,starch granules in chloroplasts ruptured after flue-curing for 12- 24 h. [Conclusion]Using low-temperature low-humidity fluecuring technology could prolong the maintenance duration of the submicroscopic structure integrity of flue-cured tobacco leaves,which was conducive to fully decomposing and transforming substances in tobacco leaves and obtaining high-quality flue-cured tobacco leaves.Guomin CUI Bojun WANG Rongchun LI Anding XU Yiyin CHEN Chao YANG Min PU 2014Agricultural Biotechnology2014,3,1:1
7Oxidation behavior of ferritic/martensitic steels in flowing supercritical water显示文摘The oxidation behavior of two Ferritic/Martensitic(F/M)steels including novel SIMP steel and commercial P91 steel were investigated by exposure to flowing deaerated supercritical water(SCW)at 700℃for up to 1000 h.The kinetic weight gain curves follow parabolic and near-cubic rate equations for SIMP and P91 steels,respectively.X-Ray Diffraction analysis showed the presence of magnetite and a spinel phase in flowing SCW for both steels.The morphology and structure of the oxide scales formed on these two steels were analyzed.The relationship between the microstructure and oxidation behavior and the reason that SIMP steel showed better oxidation resistance than P91 steel were discussed.Quanqiang Shi Wei Yan Yanfen Li Naiqiang Zhang Yiyin Shan Ke Yang Hiroaki Abe 2021Journal of Materials Science & Technology2021,,5:1
8Effects of Different Flue-curing Technologies on Microscopic Structure of Flue-cured Tobacco Leaves显示文摘[Objective]This study aimed to compare the effects of Chinese quality-improving fragrance-increasing tobacco flue-curing technology,Chinese threestage tobacco flue-curing technology and Zimbabwean tobacco flue-curing technology on microscopic structure of flue-cured tobacco leaves to provide theoretical basis for tobacco flue-curing. [Method]Middle leaves of tobacco cultivar K326 were collected in Pengshui County of Chongqing City for flue-curing experiment using three flue-curing technologies. Leaf samples were collected regularly in the flue-curing process,to investigate the microscopic structure of flue-cured tobacco leaves.[Result]During three flue-curing processes,leaves,palisade tissues and sponge tissues shrank gradually. Three flue-curing processes exhibited significant differences in the peak of tissue shrinkage: microscopic structure of flue-cured tobacco leaves in Chinese three-stage tobacco flue-curing process shrank earliest,follower by Chinese quality-improving fragrance-increasing tobacco flue-curing process; flue-cured tobacco leaves in Zimbabwean tobacco flue-curing process presented the latest shrinkage. At 84 h post-curing,leaf thickness in three flue-curing processes showed a descend order of Chinese three-stage tobacco flue-curing process >Chinese quality-improving fragrance-increasing tobacco flue-curing process > Zimbabwean tobacco flue-curing process. Upper and lower epidermal cells in Zimbabwean tobacco flue-curing process ruptured earlier than other two flue-curing processes; eventually,the majority of cells ruptured and mixed with palisade tissues and sponge tissues. In Chinese quality-improving fragrance-increasing tobacco flue-curing process,only a small number of epidermal cells in dried leaves ruptured.Among three flue-curing technologies,Zimbabwean tobacco flue-curing technology exhibited the greatest damage to epidermal cells,followed by Chinese three-stage tobacco flue-curing technology; Chinese quality-improving fragrance-increasing tobacco flue-curing technology had the minimum damage to epidermal cells. Mesophyll cross-section exhibited significant morphological changes in stomata. To be specific,at 0- 12 h post-curing,stomata of tobacco leaves closed with slightly prominent stomatal apparatuses on upper and lower epidermis; at 24- 72 h post-curing,stomata of tobacco leaves changed gradually from opening to closure with significantly prominent stomatal apparatuses on upper and lower epidermis; at 84 h post-curing,stomata of tobacco leaves closed,and the majority of stomatal apparatuses were significantly prominent. In Chinese quality-improving fragrance-increasing tobacco flue-curing process,only a small number of epidermal cells ruptured at 84 h post-flue-curing; palisade tissues and sponge tissues shrank almost simultaneously. Significant gaps were observed between palisade tissues and between palisade tissues and sponge tissues. Chinese quality-improving fragrance-increasing tobacco flue-curing technology exhibited lower disorder level compared with other two flue-curing technologies. [Conclusion]Chinese quality-improving fragrance-increasing tobacco flue-curing technology was conducive to maintaining the microscopic structure integrity of flue-cured tobacco leaves and obtaining high-quality flue-cured tobacco leaves.Guomin CUI Bojun WANG Rongchun LI Anding XU Yiyin CHEN Chao YANG Min PU 2014Agricultural Biotechnology2014,3,2:1
9GelNB molecular coating as a biophysical barrier to isolate intestinal irritating metabolites and regulate intestinal microbial homeostasis in the treatment of inflammatory bowel disease显示文摘Inflammatory bowel disease(IBD)is a chronic,immune-mediated inflammatory disease characterized by the destruction of the structure and function of the intestinal epithelial barrier.Due to the poor remission effect and severe adverse events associated with current clinical medications,IBD remains an incurable disease.Here,we demonstrated a novel treatment strategy with high safety and effective inflammation remission via tissue-adhesive molecular coating.The molecular coating is composed of o-nitrobenzaldehyde(NB)-modified Gelatin(GelNB),which can strongly bond with-NH_(2)on the intestinal surface of tissue to form a thin biophysical barrier.We found that this molecular coating was able to stay on the surface of the intestine for long periods of time,effectively protecting the damaged intestinal epithelium from irritations of external intestinal metabolites and harmful flora.In addition,our results showed that this coating not only provided a beneficial environment for cell migration and proliferation to promote intestinal repair and regeneration,but also achieved a better outcome of IBD by reducing intestinal inflammation.Moreover,the in vivo experiments showed that the GelNB was better than the classic clinical medication-mesalazine.Therefore,our molecular coating showed potential as a promising strategy for the prevention and treatment of IBD.Qijiang Mao Haoqi Pan Yiyin Zhang Yi Zhang Qiuwen Zhu Yi Hong Zhengze Huang Yang Li Xu Feng Yifeng Fang WenChao Chen Pengfei Chen Bo Shen Hongwei Ouyang Yuelong Liang 2023Bioactive Materials2023,,1:1
10Occurrence, Distribution and Sources of Organochlorine Pesticides (OCPs) in Surface Sediments from the Lijiang River, a Typical Karst River of Southwestern China显示文摘Dan Zhang Yinghui Wang Kefu Yu Pingyang Li Ruijie Zhang Yiyin Xu 2014Bulletin of Environmental Contamination and Toxicology2014,,5:1
11Plastic deformation and fracture behaviors of nitrogen-alloyed austenitic stainless steels显示文摘Songtao Wang Ke Yang Yiyin Shan Laifeng Li 2008Materials Science & Engineering A2008,,1:1
12Evaluation of Spatial Variability of Soil Properties in a Long-Term Experimental Tobacco Station in Southwest China显示文摘Jiang Houlong Wang Hongfeng Li Najia Xu Anding Yang Chao Chen Yiyin Li Yong Geng Lina Liu Guo-Shun 2014Journal of Agricultural Science and Technology(A)2014,4,9:1
13Special tetrahedral twins in a cryogenically deformed CoCrFeNi high-entropy alloy显示文摘1.Introduction Equimolar multicomponent design and maximized configurational entropy cause high-entropy alloys(HEAs)to have outstanding mechanical performance over a large temperature range from cryogenic temperatures up to room temperature[1-9].According to previous studies,deformation-induced twinning and phase transformation are two athermal transformations that significantly improve the mechanical performance of HEAs,especially those with face-centered cubic(FCC)structure[8,10-19].Wei Li Hanyang Liu Peihua Yin Wei Yan Wei Wang Yiyin Shan Ke Yang 2022Journal of Materials Science & Technology2022,,5:0
14Electrically injected GeSn lasers with peak wavelength up to 2.7 μm显示文摘GeSn lasers enable the monolithic integration of lasers on the Si platform using all-group-Ⅳ direct-bandgap material.The GeSn laser study recently moved from optical pumping into electrical injection.In this work,we present explorative investigations of GeSn heterostructure laser diodes with various layer thicknesses and material compositions.Cap layer material was studied by using Si_(0.03)Ge_(0.89)Sn_(0.08) and Ge_(0.95)Sn_(0.05),and cap layer total thickness was also compared.The 190 nm SiGeSn-cap device had threshold of 0.6 kA/cm^(2) at 10 K and a maximum operating temperature(T_(max)) of 100 K,compared to 1.4 kA/cm^(2) and 50 K from 150 nm SiGeSn-cap device,respectively.Furthermore,the 220 nm GeSn-cap device had 10 K threshold at 2.4 kA/cm^(2) and T_(max) at 90 K,i.e.,higher threshold and lower maximal operation temperature compared to the SiGeSn cap layer,indicating that enhanced electron confinement using SiGeSn can reduce the threshold considerably.The study of the active region material showed that device gain region using Ge_(0.87)Sn_(0.13) had a higher threshold and lower T_(max),compared to Ge_(0.89)Sn_(0.11).The performance was affected by the metal absorption,free carrier absorption,and possibly defect density level.The maximum peak wavelength was measured as 2682 nm at 90 K by using Ge_(0.87)Sn_(0.13) in gain regions.The investigations provide directions to the future GeSn laser diode designs toward the full integration of group-Ⅳ photonics on a Si platform.YIYIN ZHOU SOLOMON OJO CHEN-WEI WU YUANHAO MIAO HUONG TRAN JOSHUA MGRANT GREY ABERNATHY SYLVESTER AMOAH JAKE BASS GREGORY SALAMO WEI DU GUO-EN CHANG JIFENG LIU JOE MARGETIS JOHN TOLLE YONG-HANG ZHANG GREG SUN RICHARD ASOREF BAOHUA LI SHUI-QING YU 2022Photonics Research2022,10,1:0
15Dual-Tone Radio Interferometric Positioning Systems for Multi-Target Localization Using a Single Mobile Anchor显示文摘In this paper,a low-cost dualtone radio interferometric positioning system using a single mobile anchor is proposed to locate multiple targets at the same time.We name it mDRIPS.In mDRIPS,each target continuously transmits a dual-tone signal with its dedicated frequencies,and the mobile anchor receives the signals at different positions along its trajectory.Neither time synchronization between the mobile anchor and the targets nor time synchronization among the targets is required.We take the instability of targets clocks into consideration and develop an ESPRIT-type algorithm to estimate frequencies of each dual-tone signal.Furthermore,the time of arrival(TOA) of each target signal is extracted from the phase estimates of the received dual-tone signals.After measuring several TOAs at different locations along the anchor's trajectory,each target can be located.Since the frequency difference of the two tones of each dualtone signal is designed to be smaller than the channel coherence bandwidth,the same fading effect on these two tones can be eliminated.Moreover,the integer ambiguity problem due to phase wrapping is investigated,and a localization algorithm to deal with a simplified ambiguity problem is proposed.Numerical results demonstrate the efficiency of the proposed mDRlPS.LI Li'an WANG Yiyin MA Xiaoli CHEN Cailian GUAN Xinping 2015China Communications2015,12,1:0
16Research on Well Cellar Type Crop Transplanting Technology显示文摘Jiang Houlong Xu Chen Wang Daibin Wang Hongfeng Yang Chao Li Najia Chen Yiyin 2015Journal of Agricultural Science and Technology(B)2015,5,9:0
17A historical review of aggregation-induced emission from 2001 to 2020:A bibliometric analysis显示文摘Aggregation-induced emission(AIE)is a photophysical phenomenon that a certain group of luminescent materials that become highly luminous when aggregated in a bad solvent or solid state.This year is the 20th anniversary since the AIE concept firstly proposed in 2001.Many advanced applications were gradually being explored,covering optics,electronics,energy,and bioscience and so on.At present,bibliometrics can enlighten the researchers with comprehensive sights of the achievements and trends of a specific field,which is critical for academic investigations.Herein,we presented a general bibliometric overview of AIE covering 20 years of evolution.With the assistance of Web of Science Core Collection database and several bibliometric software tools,the annual publication and citation,most influential countries/regions,most contributing authors,journals and institutions,second near-infrared(NIR-Ⅱ)related hotspots,as well as the forecast of frontiers were demonstrated and systematically analyzed.This study summarizes the current research status in AIE research field and provides a reference for future research directions.Qiming Xia Yiyin Zhang Yiling Li Yirun Li Yixuan Li Zhe Feng Xiaoxiao Fan Jun Qian Hui Lin 2022Aggregate2022,3,1:0
18GROWTH AND YIELD MODELS FOR DAHURIAN LARCH PLANTATIONS显示文摘Growth and yield models were developed for individual tress and stands based on336 temporary plots with 405 stem analysis trees of dahurian larch(Larix gmelinii(Rupr.)Rupr.)plantations throughout Daxing’anling mountains.Several equations were selected using nonlinearregression analysis.Results showed that the Richards equation was the best model for estimatingtree height,stand mean helght and stand dominant height from age; The Power equation was thebest model for prediction tree volume from DBH and tree height; The logarithmic stand volumeequation was good for predicting stand volume from age,mean height,basal area and other standvariables.These models can be used to construct the volume table, the site index table and other for-estry tables for dahurian larch plantations.Li Changshcng Jiang Yiyin Yeh-chu Wang Northeast Forestry University 1991Journal of Northeast Forestry University1991,2,1:0
19Uniform nanoplating of metallic magnesium film on titanium dioxide nanotubes as a skeleton for reversible Na metal anode显示文摘To meet the low-cost concept advocated by the sodium metal anode,this paper reports the use of a pulsed electrodeposition technology with ionic liquids as electrolytes to achieve uniform nanoplating of metallic magnesium films at around 20 nm on spaced titanium dioxide(TiO_(2))nanotubes(STNA-Mg).First,the sodiophilic magnesium metal coating can effectively reduce the nucleation overpotential of sodium metal.Moreover,three-dimensional STNA can limit the volume expansion during sodium metal plating and stripping to achieve the ultrastable deposition and stripping of sodium metals with a high Coulombic efficiency of up to 99.5%and a small voltage polarization of 5 mV in symmetric Na||Na batteries.In addition,the comparative study of sodium metal deposition behavior of STNA-Mg and STNA-Cu prepared by the same route further confirmed the advantage of magnesium metal to guide sodium metal growth.Finally,the prepared STNA-Mg-Na metal anode and commercial sodium vanadium phosphate cathode were assembled into a full cell,delivering a discharge capacity of 110.2 mAh·g^(-1)with a retention rate of 95.6%after 110 cycles at 1C rate.Jinshan Wang Feng Li Si Zhao Lituo Zheng Yiyin Huang Zhensheng Hong 2023International Journal of Minerals,Metallurgy and Materials2023,30,10:0
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