维普中文期刊产品整合服务
125篇 您的检索式:作者名="MingXiang"
    题名 作者 年代 出处 被引量
1Effects of Temperature,Soil Moisture,Soil Type and Their Interactions on Soil Carbon Mineralization in Zoigê Alpine Wetland,Qinghai-Tibet Plateau显示文摘Wetland stores substantial amount of carbon and may contribute greatly to global climate change debate. However, few researches have focused on the effects of global climate change on carbon mineralization in Zoigê al-pine wetland, Qinghai-Tibet Plateau, which is one of the most important peatlands in China. Through incubation ex-periment, this paper studied the effects of temperature, soil moisture, soil type (marsh soil and peat soil) and their in-teractions on CO2 and CH4 emission rates in Zoigê alpine wetland. Results show that when the temperature rises from 5℃ to 35℃, CO2 emission rates increase by 3.3-3.7 times and 2.4-2.6 times under non-inundation treatment, and by 2.2-2.3 times and 4.1-4.3 times under inundation treatment in marsh soil and peat soil, respectively. Compared with non-inundation treatment, CO2 emission rates decrease by 6%-44%, 20%-60% in marsh soil and peat soil, respec-tively, under inundation treatment. CO2 emission rate is significantly affected by the combined effects of the tempera-ture and soil type (p < 0.001), and soil moisture and soil type (p < 0.001), and CH4 emission rate was significantly af-fected by the interaction of the temperature and soil moisture (p < 0.001). Q10 values for CO2 emission rate are higher at the range of 5℃-25℃ than 25℃-35℃, indicating that carbon mineralization is more sensitive at low temperature in Zoigê alpine wetland.GAO Junqin OUYANG Hua LEI Guangchun XU Xingliang ZHANG Mingxiang 2011Chinese Geographical Science2011,21,1:23
2Basic Lithofacies-Succession Model for the Wumishan Cyclothems: Their Markov Chain Analysis and Regularly Vertical Stacking Patterns in the Third-Order Sequences显示文摘The Mesoproterozoic Wumishan Formation in the Jixian section ofTianjin is a succession of 3300-m-thick carbonate strata formed in a period of about 100 Ma (1310 ± 20 Ma-1207 ± 10 Ma). In this succession of strata, the carbonate metre-scale cyclic sequences belonging to peritidal type with an approximately symmetrical lithofacies succession are best developed. The wide development of 1:4 stacking patterns shows that these metre-scale cyclic se quences are genetically related to the short-eccentricity cycles, which are called the Wumishan cyclothems that could truly represent sedimentary cycles. Generally, massive and thick-bedded calcareous dolomites and dolomitic limestones of stromatolite biostromes and thrombolite bioherms constitute the central part of the Wumishan cyclothems. The lower and upper parts consist of tidal flat dolostones, sandy-muddy dolostone and the top part is composed of lagoonal facies dolo mitic shales with a paleosol cap. Therefore, an approximately symmetrical lithofacies-succession is formed. Many features such as the clear deepening and shoaling vectors of cyclothems, and all kinds of marks of fresh-water diagenesis indicate that the Wumishan cyclothems are the product of autocyclic sedimentation governed by allocyclic high-frequency sea level changes. The results of a Markov chain analysis reaffirm the existence of the lithofacies-succession model of the Wumishan cyclothems. The boundaries of the Wumishan cyclothems are marked by the instantaneous exposed punctuated surface, which leads to the discrepancy between the cyclothems and the parasequences of the sequence stratigraphy ter minology system. It is difficult to form a judgment that the time span of the Milankovitch cycles in the Precambrian is certainly equal to that of the Phanerozoic, but the regularly vertical stacking patterns of the seventh-order rhythms, sixth order cyclothems and fifth-order parasequence sets still indicate their consistency with the duration of the Milankovitch cycles in the Phanerozoic.MEI Mingxiang, MA Yongsheng and GUO Qingyin Institute of Earth Sciences and Natural Resources, China University of Geosciences, Beijing 100083 China Petrochemical Corporation (SINOPEC), Beijing 100029 2001Acta Geologica Sinica(English Edition)2001,75,4:19
3Recombinant protein subunit vaccine booster following two-dose inactivated vaccines dramatically enhanced anti-RBD responses and neutralizing titers against SARS-CoV-2 and Variants of Concern显示文摘Dear Editor,As of October,2021,SARS-CoV-2 has infected more than 230 million people;promoting roll-out vaccinations could help build herd immunity for the pandemic.However,the waning of antibody in magnitude and decreased protective efficacy in multiple types of vaccines have been reported.Jingwen Ai Haocheng Zhang Qiran Zhang Yi Zhang Ke Lin Zhangfan Fu Jieyu Song Yuanhan Zhao Mingxiang Fan Hongyu Wang Chao Qiu Yang Zhou Wenhong Zhang 2022Cell Research2022,32,1:19
4Effect of Root Architecture on Structural Stability and Erodibility of Topsoils during Concentrated Flow in Hilly Loess Plateau显示文摘Traditional vegetation techniques for the control of concentrated flow erosion are widely recognized, whereas only a few studies have experimentally investigated the impacts of belowground roots on the erodibility of topsoils in semi-arid areas. To quantify the effects of root architectures on soil erodibility and its relevant structural properties, simulated flow experiments were conducted at six-week intervals from 18 July to 20 October in 2012 in the hilly Loess Plateau. Five treatments were: 1) bare(control), 2) purple alfalfa(Medicago sativa), representing tap roots(T), 3) switchgrass(Panicum virgatum), representing fibrous roots(F), 4) purple alfalfa and switchgrass, representing both tap and fibrous roots(T + F), and 5) natural recovery(N). For each treatment, soil structural properties and root characteristics were measured at an interval of six weeks. Soil anti-scouribility was calculated. Results showed that grass planting slightly reduced soil bulk density, but increased soil aggregate content by 19.1%, 10.6%, 28.5%, and 41.2% in the treatments T, F, T + F, and N, respectively. Soil shear strength(cohesion and angle of internal friction(φ)) significantly increased after the grass was planted. As roots grew, soil cohesion increased by 115.2%–135.5%, while soil disintegration rate decreased by 39.0%–58.1% in the 21 th week compared with the recorded value in the 9th week. Meanwhile, root density and root surface area density increased by 64.0%–104.7% and 75.9%–157.1%, respectively. No significant differences in soil anti-scouribility were observed between the treatments of T and F or of T + F and N, but the treatments of T + F and N performed more effectively than T or F treatment alone in retarding concentrated flow. Soil aggregation and root surface-area density explained the observed soil anti-scouribility during concentrated flow well for the different treatments. This result proved that the restoration of natural vegetation might be the most appropriate strategy in soil reinforcement in the hilly Loess Plateau.LI Qiang LIU Guobin ZHANG Zheng TUO Dengfeng XU Mingxiang 2015Chinese Geographical Science2015,25,6:13
5Genetic Types of Meter-Scale Cyclic Sequences and Fabric Natures of Facies Succession显示文摘Different genetic types of meter-scale cyclic sequences in stratigraphic records result from episodic accumulation of strata related to Milankovitch cycles. The distinctive fabric natures of facies succession result from the sedimentation governed by different sediment sources and sedimentary dynamic conditions in different paleogeographical backgrounds, corresponding to high-frequency sea-level changes. Naturally, this is the fundamental criterion for the classification of genetic types of meter-scale cyclic sequences. The widespread development in stratigraphic records and the regular vertical stacking patterns in long-term sequences, the evolution characters of earth history and the genetic types reflected by specific fabric natures of facies successions in different paleogeographical settings, all that show meter-scale cyclic sequences are not only the elementary working units in stratigraphy and sedimentology, but also the replenishment and extension of parasequence of sequence stratigraphy. Two genetic kinds of facies succession for meter-scale cyclic sequence in neritic-facies strata of carbonate and clastic rocks, are normal grading succession mainly formed by tidal sedimentation and inverse grading succession chiefly made by wave sedimentation, and both of them constitute generally shallowing upward succession, the thickness of which ranges from several tens of centimeters to several meters. The classification of genetic types of meter-scale cyclic sequence could be made in terms of the fabric natures of facies succession, and carbonate meter-scale cyclic sequences could be divided into four types: L-M type, deep-water asymmetrical type, subtidal type and peritidal type. Clastic meter-scale cyclic sequences could be grouped into two types: tidal-dynamic type and wave-dynamic type. The boundaries of meter-scale cyclic sequences are marked by instantaneous punctuated surface formed by non-deposition resulting from high-frequency level changes, which include instantaneous exposed punctuated surface, drowned punctuated surface as well as their relative surface. The development of instantaneous punctuated surface used as the boundary of meter-scale cyclic sequence brings about the limitations of Walter’s Law on the explanation of facies distribution in time and space, and reaffirm the importance of Sander’s Rule on analysis of stratigraphic records. These non-continuous surface could be traced for long distance and some could be correlative within same basin range. The study of meter-scale cyclic sequences and their regularly vertical stacking patterns in long-term sequences indicate that the research into cyclicity of stratigraphic records is a useful way to get more regularity from stratigraphic records that are frequently complex as well as non-integrated.Mei Mingxiang Xu Debin Zhou Hongrui Institute of Earth Sciences and Natural Resources, China University of Geosciences, Beijing 100083 2000Journal of Earth Science2000,19,4:12
6Physico-Chemical Properties and Laboratory Hyperspectral Reflectance of Coastal Saline Soil in Shangyu City of Zhejiang Province, China显示文摘45 and 50 composite soil samples were collected, respectively, from two agricultural fields, that were enclosed and reclaimed from coastal tidal-fiat areas in 1996 and 1984 respectively, in Shemgyu of Zhejiang Province, China, to investigate the physico-chemical properties and the hyperspectral characteristics of the saline soils and to make an assessment on their relationships. The reflectance spectra of saline soils were measured using a spectroradiometer in laboratory. The mean spectral curves of the saline soils from the two sites different in reclamation year showed that the saline soil taken from the recently reclaimed land with higher salinity demonstrated a lower reflectance intensity in the spectral region from about 550 nm to 2300 nm. In addition, nine absorption bands, i.e., 488 nm, 530 nm, 670 nm, 880 nm, 940 nm, 1400 nm,1900 nm, 2 200 nm and 2 300 nm, were chosen as the spectral bands to investigate the relationships between soil physico-chemical properties by means of Pearson correlation analysis. Finally, the first two principal components were calculated from nine absorption bands and used to discriminate the saline soil samples taken from two sampled fields. The results indicate that it is feasible to detect physico-chemical properties of saline soils from fields reclaimed for varying time periods on the basis of the hyperspectral data.SHI ZHOU, HUANG MINGXIANG and LI YANInstitute of Agricultural Remote Sensing and Information System, Zhejiang University, Hangzhou 310029 (China) 2003Pedosphere2003,13,3:12
7Fischer Plots of Wumishan Cyclothems,Precambrian Records of Third-OrderSea-Level Changes显示文摘The Mesoproterozoic Wumishan Formation ((1310 ± 20 ) Ma - (l 207 ± 10) Ma) in Jixian, Tianjin represents a succession of 3 300 meter thick carbonate strata where are the best developed stromatolite biostromes and thrombolite bioherms. These biostromes and bioherms, together with tidal-flat dolomites and muddy dolostones, form Wumishan cyclothems with approximately symmetrical faciessuccession fabrics, which belong to carbonate meter-scale cyclic sequences of peritidal type. These cyclothems are overlain by lagoon dolomitic mudstones and shales and by frequently developed paleosol layers, indicating that the boundary of Wumishan cyclothems is marked by an instantaneously-exposed punctuated surface. Viewed form the regularly vertical stacking patterns of Wumishan cyclothems in long-term sequences, 26 third-order sequences may be discerned in Wumishan Formation. These thirdorder sequences may also be incorporated into six second-order sequences. In order to study the variation range of third-order sea-level changes and the formation period of third-order sequence, 626 cyclothems are discerned in the middle and upper parts of Wumishan Formation where the outcrops are well developed. In terms of the total thickness and the formation period of Mesoproterozoic Wumishan Formation, the crust subsidence rate in the sedimentary period of Wumishan Formation is supposed to be 3 meters at each interval of 100 thousands years. Based on this assumption, Fischer plot might be designed to simulate the third-order sea-level changing pattern.Mei Mingxiang Faculty of Earth Sciences and Mineral Resources, China University of Geosciences, Beijing 100083 Ma Yongsheng China Petrochemical Corporation (SINOPEC), Beijing 100029 Zhou Hongrui Du Benming Luo Zhiqing Guo Qingyin Faculty of Earth Sc 2001Journal of China University of Geosciences2001,12,1:11
8The Late Triassic Sequence-Stratigraphic Framework of the Upper Yangtze Region,South China显示文摘In the transitional period between the Middle and the Late Triassic, the Indochina orogeny caused two tectonic events in South China:(1) the formation and uplift of the Qinling-Dabie orogenic belt along the northern margin of the South China Plate, due to its collision with the North China Plate; and 2) the development of a 1300-km-wide intra-continental orogen in the southeastern part of the South China Plate, which led to a northwestward movement of the foreland thrust-fold zone. These tectonic events resulted in the ending of the Yangtze Platform, and were a stable paleogeographic factor from the Eidacaran to the end of the Middle Triassic. This platform was characterized by the widespread development of shallow-water carbonates. After the end of the Yangtze Platform, the upper Yangtze foreland basin(or Sichuan foreland basin) was formed during the Late Triassic and became a accumulation site of fluvial deposits that are composed of related strata of the Xujiahe Formation. In western Sichuan Province, the Xujiahe Formation overlies the Maantang Formation shallow-water carbonate rocks of the Xiaotangzi Formation siliciclastic rocks(from shelf shales to littoral facies). The sequence-stratigraphic framework of the Upper Triassic in the upper Yangtze foreland basin indicates a particular alluvial architecture, characterized by sequences composed of(1) successions of low-energy fluvial deposits of high-accommodation phases, including coal seams, and(2) high-energy fluvial deposits of low-accommodation phases, including amalgamated river-channel sandstones. The spatial distribution of these fluvial deposits belonging to the Xujiahe Formation and its relative strata is characterized by gradual thinning-out, overlapping, and pinching-out toward both the east and south. This sedimentary record therefore expresses a particular sequence-stratigraphic succession of fluvial deposits within the filling succession of the foreland basin. The sequence-stratigraphic framework for the Upper Triassic in the Upper Yangtze region provides a record of the end of the Yangtze Platform and the formation of the upper Yangtze foreland basin.MEI Mingxiang LIU Shaofeng 2017Acta Geologica Sinica(English Edition)2017,91,1:11
9Sedimentary Features and Implications for the Precambrian Non-stromatolitic Carbonate Succession:A Case Study of the Mesoproterozoic Gaoyuzhuang Formation at the Qiangou Section in Yanqing County of Beijing显示文摘摘要:在长前寒武纪的时期, stromatolitic 碳酸盐继任是很普通的。然而,由 subtidal 存款是显著的 non-stromatolitic 碳酸盐继任显示出一个鲜明对比到 stromatolitic 碳酸盐继任。non-stromatolitic 和 stromatolitic 碳酸盐继任是为演变碳酸盐世界的进一步的理解的重要线索前寒武纪。在在北京的西北的郊区的 Qiangou 节的 Mesoproterozoic Gaoyuzhuang 形成是能被划分成四个成员的一套超过 1000 个 m 厚的碳酸盐阶层(或 subformations ) ,在哪个 stromatolites 的缺乏标记的 non-stromatolitic 碳酸盐继任完成形成的第三个成员。这 non-stromatolitic 碳酸盐继任能进一步被细分进由沉积外形的常规继任是显著的三个第三顺序的序列。在第三顺序的序列,由中等床的 leiolite 石灰石和薄床的泥土组成的很多 subtidal 碳酸盐米规模周期组成他们的 transgressive 系统道( TST )和早高看台的系统道( EHST ),薄床的石灰石和泥土完成的很多米规模周期组成他们的压缩的节( CS ),并且对白云石完成晚高看台的系统道( LHST )的巨大的含白云石的石灰石或石灰厚床。特别地在 Qiangou 节完成 Mesoproterozoic Gaoyuzhuang 形成的第三个成员的 non-stromatolitic 碳酸盐继任可能是 non-stromatolitic 碳酸盐继任的代表因为它的特殊 lithological 特征和详细规格前寒武纪沉积结构,并且它的一般沉积特征对sophisticate 和 Precambri 的演变碳酸盐世界的进化规则的进一步的理解有用、有意义Gaoyuzhuang 形成的时间规模从 1600 妈作为那被推出到 1400 妈;因此,完成 Gaoyuzhuang 形成的第三个成员的沉积继任可以表明的 non-stromatolitic 发生在 ca 的一个 stromatolite 衰落事件。1450 妈原生地,除另外的三个事件以外,那在 ca 分别地发生了。2000 妈, ca。1000 妈和 ca。675 妈。Gaoyuzhuang 形成的第三个成员的沉积继任能通常是的这 non-stromatolitic 的形成的持续时间在北美洲与类似的沉积继任相关,即 non-stromatolitic 带超群的海伦娜形成的沉积继任,它建议 stromatolite 衰退发生在 ca。1450 妈可能是一个全球事件。因此,沉积继任在纸讨论了的 non-stromatolitic 为碳酸盐 sedimentology 的进一步的理解在提供一个重要例子前寒武纪。MEI Mingxiang 2008Acta Geologica Sinica(English Edition)2008,82,2:10
10Thermodynamic conditions of framework grain dissolution of clastic rocks and its application in Kela 2 gas field显示文摘Feldspar and clastic debris are the most important constituent framework grains of sedimentary clastic rocks and their chemical dissolution plays an essential role in the formation and evolution of the secondary pore in the reservoir rocks. On the basis of thermodynamic phase equilibrium, this study investigates the chemical equilibrium relationships between fluid and various plagioclase and K-feldspar in diagenesis of the sediments, particularly, the impact of temperature and fluid compositions (pH, activity of K+, Na+, Ca2+ and so on) on precipitation and dissolution equilibria of feldspars. Feldspar is extremely easily dissolved in the acid pore water with a low salinity when temperature decreases. The dissolution of anorthite end-member of plagioclase is related to the Ca content of the mineral and the fluid, higher Ca either in the mineral or in the fluid, easier dissolution of the feldspar. Moreover, the dissolution of albite end-member of plagioclase is related to Na of both the mineral and fluid, lower Na out of both the mineral and fluid, easier dissolution of the mineral. Similarly, lower-K fluid is more powerful to dissolve K-feldspar than the higher. The anorthite component of plagioclase is most easily dissolved in ground water-rock system, the albite is the secondary, and K-feldspar is the most stable. Selective dissolution of plagioclase occurs in diagenesis because of the plagioclase solid solution that is mainly composed of albite and anorthite end-members, Ca-rich part of which is preferentially dissolved by the pore water, in contrast to the Na-rich parts. Based on investigation of reservoir quality, secondary pore, dissolution structures of feldspar, clay minerals and ground water chemistry of the Kela 2 gas field of Kuqa Depression in the Tarim basin of Western China, we discovered that the secondary pore is very well developed in the highest quality section of the reservoir, and the plagioclase of which was obviously selectively dissolved, in contrast to the overgrowth of K-feldspar. Chemistry of the ground water out of the highest quality section of the reservoir is consistent with the complete dissolution field of anorthite, partial dissolution field of albite component of plagioclase, and the precipitation of K-feldspar on the temperature-logK phase equilibrium diagram drawn from this study. The thermodynamic modeling calculation gave us an insight into formation of the secondary pore within the reservoir, and the dissolution of plagioclase an important cause of the secondary pore. It is assumed that the solvent to dissolve the plagioclase frame grains originated from the origin-enriched compacted fluid acids out of the mudstone buried beneath the top of geopressured zones in the Kuqa Depression.LAI Xingyun, YU Bingsong, CHEN Junyuan, CHEN Xiaolin, LIU Jianqing, MEI Mingxiang, JING Weiguang & CHENG Suhua School of Earth Sciences and Mineral Resources, China University of Geosciences, Beijing 100083, China Key Laboratory of Lithospheric Tectonics, Deep-level Process and Exploration of Ministry of Education, Beijing 100083, China 2005Science China Earth Sciences2005,48,1:9
11Effects of grain size on phase transition behavior of nanocrystalline shape memory alloys显示文摘We report recent advances in the experimental and theoretical study of grain size(GS)effects on the thermal and mechanical properties of nanostructured NiTi polycrystalline shape memory alloy(SMA).It is shown that when GS<60 nm,the superelastic stress-strain hysteresis loop area(H)of the polycrystal decreases rapidly with GS and tends to vanish as GS approaches 10 nanometers.At the same time,the temperature dependence of the transition stress also decreases with GS and eventually approaches zero,leading to a wide superelastic temperature window and breakdown of the Clausius-Claperyon relationship.Rate dependence of the stress-strain responses is significantly reduced and the cyclic stability of the material is improved by the nanocrystallization.It is proposed that the emergence of such significant changes in the behavior of the material with GS reduction originate from the large increase in the area-to-volume ratios of the nanometer-thick interfaces(grain boundary and Austenite-Martensite(A-M)interface)in the polycrystal.In particular,with GS reduction,interfacial energy terms will gradually become dominant over the bulk energy of the crystallite,eventually bring fundamental changes in the phase transition responses of the material.Modelling strategy leading to the establishment of quantitative relationships among GS,grain boundary,A-M interfaces and the macroscopic responses of the material are outlined.SUN QingPing ASLAN Ahadi LI MingPeng CHEN MingXiang 2014Science China(Technological Sciences)2014,57,4:9
12Liraglutide alleviates cardiac fibrosis through inhibiting P4hα-1 expression in STZ-induced diabetic cardiomyopathy显示文摘Diabetic cardiomyopathy is an important contributor to morbidity and mortality of diabetic patients by causing heart failure.Interstitial and perivascular fibrosis plays a crucial role in diabetic cardiomyopathy.However,there is a lack of effective specific treatments available for diabetic cardiomyopathy.In the present study,we aim to explore the effects of Liraglutide,a GLP-1 analogue,on diabetic cardiomyopathy in STZ-induced diabetic rats fed with high-fat diet.A total of 60 male Wistar rats were randomly assigned to three groups,i.e.normal group,model group,and Liraglutide group,with 20 rats in each group.Serum levels of TC,TG,LDL-C,NEFA,and hydroxyproline were measured using commercial kits.Cardiac function was evaluated by QRS waves,LVEDd,LVESd,and LVEF.Myocardial fibrosis was measured by immunohistochemistry.Our results demonstrated that chronic administration of Liraglutide decreased the level of blood glucose and significantly alleviated lipid metabolic disturbance compared with the model group.Furthermore,Liraglutide was found to improve the damaged cardiac function.In line with this,we also found that the alleviation of cardiac dysfunction was associated with the decreased fibrosis in diabetic myocardial tissues,which was reflected by the decreased expressions of P4hα-1,COL-1,COL-3,MMP-1,and MMP-9.Our results thus suggest that Liraglutide might have a myocardial protective effect by inhibiting P4hα-1-mediated myocardial fibrosis.Tong Zhao Huiqiang Chen Fei Xu Juan Wang Yusheng Liu Xiaowei Xing Linlin Guo Mingxiang Zhang Qinghua Lu 2019Acta Biochimica et Biophysica Sinica2019,51,3:9
13Sequence-stratigraphic frameworks and their palaeogeographic patterns for the Permian Lopingian of the Dianqiangui Basin and its adjacent areas of Southwestern China显示文摘The Permian Lopingian in the Dianqiangui Basin and its adjacent areas is marked by the coal measures of the Wuchiapingian and the carbonate strata of the Changhsingian stages. For the Lopingian of the Dianqiangui Basin and its adjacent areas,the diversity of sedimentary facies and the obviousness of facies change provide an advantaged condition on a study of sequence stratigraphy. Approximately,the Wuchiapingian stage constitutes a third-order sequence and the Changhsingian stage forms an-other. For the Wuchiapingian stage in the study area,coal-measures were developed on the attached platform and,in addition,a special coal-measure that is composed of both limestone beds and coal beds was also developed in the central part of some isolated platforms. Grain-bank grainstones and packstones were formed on the margin of the attached platform as well as in the windward part of iso-lated platforms. For the Changhsingian stage in the study area,open-platform limestones were formed on the attached platform,while sponge-reef limestones were developed both on the margin of the at-tached platform and on the isolated platforms. The Lopingian Series is a set of basin-facies muddy shales with interbeds of silicalites in the inter-platform basin,which appears a set of the large-thick coarse clastic strata of molasses covering direct the deep-water strata from the Devonian to the Per-mian Yangsingian in the Qinzhou-Fangcheng region in the southern part of the study area. All of these features indicate the complexity of temporal-spatial facies-changes. Sequence-stratigraphic frame-works could be established,which would illustrate two types of facies-changing surfaces and dia-chronisms in the stratigraphic records,based on the combination of both biostratigraphic and chronostratigraphic materials and the regularity reflected by temporal evolutionary succession of sediments as well as spatial distributional patterns of sedimentary facies. Ultimately,features of sedi-mentary succession and palaeogeographical evolution of the Permian Lopingian in the study area are revealed clearly in a series of the panel diagrams of sequence-stratigraphic frameworks and the outline maps showing the sedimentary-facies and palaeogeography. The Permian Lopingian formed by two third-order sequences differs from the stratigraphy of the same era characterized by the constant re-gression along Euramerica. Most specially,if the end-Guadalupian mass-extinction event is genetically related to a regressive event represented by the unconformity of the first episode of the Dongwumovement in the study area,the mass-extinction event at the turn from the Permian to the Triassic is genetically related to a rapid transgressive event re-flected by the drowning unconformity in the study area. These phenomena might reveal a complex rela-tionship between mass-extinction events and trans-gressive-regressive events.MEI MingXiang MA YongSheng DENG Jun CHU HanMin ZHENG KuanBing 2007Science China Earth Sciences2007,50,6:8
14Sedimentary Features and Their Implications of Microdigital Stromatolites from the Mesoproterozoic Wumishan Formation at the Jixian Section in North China显示文摘在在天津的 Jixian 节的 Mesoproterozoic Wumishan 形成是一套超过 3000-m-thick stromatolitic 碳酸盐继任。在这继任,几个岩相单位,也就是说 subtidal stromatolitic biostrome, thrombolitic bioherm,潮汐公寓的 micritic 白云石和泻湖含白云石的页岩,当 Wumishan 骑车,完成被提名了的 peritidal 碳酸盐类型的许多米规模周期。重要地,许多 microdigital stromatolites 在 Wumishan 形成的更低的部分完成 Wumishan 周期的 stromatolitic biostrome 单位。这些 microdigital stromatolites 被古生物学家作为一个 stromatolitic 集合组织了,也就是说 Pseudogymnosolen mopanyuensis-Scuphus-Yangzhuang columnaris 集合。当霰石(石灰华) 海地板由 sedimentologists 猛抛,这些 microdigital stromatolites 也被解释了,并且进一步从海地板霰石作为过渡时期的特殊产品被认为猛抛对 Neoproterozoic 的碎屑状、泥泞的碳酸盐太古代。尽管为 stromatolitic 集合的概念的 stratigraphic 意思有一些限制,由古生物学家的分类上的详细研究提供重要线索理解 microdigital stromatolites 的 sedimentological 意思。而且,为 microdigital stromatolites 的结束的一根重要、明显的地平线在 Jixian 节在 Mesoproterozoic Wumishan 形成被记录,它提供有用信息理解 stromatolite 衰落发生在 c.1250 妈和演变碳酸盐世界前寒武纪。MEI Mingxiang GAO Jinhan MENG Qingfen LIU Zhirong 2010Acta Geologica Sinica(English Edition)2010,84,3:8
15Interactions between wind and water erosion change sediment yield and particle distribution under simulated conditions显示文摘Wind and water erosion are among the most important causes of soil loss, and understanding their interactions is important for estimating soil quality and environmental impacts in regions where both types of erosion occur. We used a wind tunnel and simulated rainfall to study sediment yield, particle-size distribution and the fractal dimension of the sediment particles under wind and water erosion. The experiment was conducted with wind erosion firstly and water erosion thereafter, under three wind speeds(0, 11 and 14 m/s) and three rainfall intensities(60, 80 and 100 mm/h). The results showed that the sediment yield was positively correlated with wind speed and rainfall intensity(P<0.01). Wind erosion exacerbated water erosion and increased sediment yield by 7.25%–38.97% relative to the absence of wind erosion. Wind erosion changed the sediment particle distribution by influencing the micro-topography of the sloping land surface. The clay, silt and sand contents of eroded sediment were also positively correlated with wind speed and rainfall intensity(P<0.01). Wind erosion increased clay and silt contents by 0.35%–19.60% and 5.80%–21.10%, respectively, and decreased sand content by 2.40%–8.33%, relative to the absence of wind erosion. The effect of wind erosion on sediment particles became weaker with increasing rainfall intensities, which was consistent with the variation in sediment yield. However, particle-size distribution was not closely correlated with sediment yield(P>0.05). The fractal dimension of the sediment particles was significantly different under different intensities of water erosion(P<0.05), but no significant difference was found under wind and water erosion. The findings reported in this study implicated that both water and wind erosion should be controlled to reduce their intensifying effects, and the controlling of wind erosion could significantly reduce water erosion in this wind-water erosion crisscross region.TUO Dengfeng XU Mingxiang ZHAO Yunge GAO Liqian 2015Journal of Arid Land2015,7,5:8
16A Novel Recognition Method for Low SNR DSSS Signals Based on Four-Order Cumulant and Eigenvalue Analysis显示文摘At present it is very difficult to estimate the carrier frequency, spread spectrum code period and spread spectrum code pattern of Direct sequence spread spectrum(DSSS) signals with low Signal-to-noise ratio(SNR) accurately and simultaneously in the condition of Gaussian white noise. A novel method of estimation for carrier frequency and spread spectrum code period of DSSS signals based on four-order cumulant and eigenvalue analysis is presented. Compared with the correlative detection in time domain, square filtering detection and Hebbian rule, the proposal method in this study can realize the estimation for the carrier frequency and period of spread spectrum code of low SNR DSSS signals with a high accuracy simultaneously. In a priori condition of the spread spectrum code period the proposal method can calculate synchronization loss time between spread spectrum code and information symbol. The proposal method this paper has a strong ability to suppress Gaussian noise.GUAN Mingxiang WANG Le 2015Chinese Journal of Electronics2015,24,3:7
173-year Treatment of Tenofovir Alafenamide vs.Tenofovir Disoproxil Fumarate for Chronic HBV Infection in China显示文摘Background and Aims:Tenofovir alafenamide(TAF)has similar efficacy to tenofovir disoproxil fumarate(TDF)but with improved renal and bone safety in chronic hepatitis B patients studied outside of China.We report 3-year results from two phase 3 studies with TAF in China(Clinicaltrials.gov:NCT02836249 and NCT02836236).Methods:Chinese hepatitis B e antigen(HBeAg)-positive and-negative chronic hepatitis B patients with viremia and elevated alanine aminotransferase were randomized 2:1 to TAF or TDF treatment groups and treated in a double-blind fashion for 144 weeks(3 years).Efficacy responses were assessed by individual study while safety was assessed by a pooled analysis.Results:Of the 334 patients(180 HBeAg-positive and 154 HBeAg-negative)randomized and treated,baseline characteristics were similar between groups.The overall mean age was 38 years and 73%were male.The mean HBV DNA was 6.4 log10 IU/mL.The median alanine aminotransferase was 88 U/L,and 37%had a history of antiviral use.At week 144,the proportion with HBV DNA<29 IU/mL was similar among the two groups,with TAF at 83%vs.TDF at 79%,and TAF at 93%vs.TDF at 92%for the HBeAg-positive and-negative patients,respectively.In each study,higher proportions of TAF than TDF patients showed normalized alanine aminotransferase(via the American Association for the Study of Liver Diseases and the China criteria)and showed loss of HBsAg;meanwhile,the HBeAg seroconversion rates were similar.Treatment was well-tolerated among the TAF patients,who showed a smaller median decline in creatinine clearance(−0.4 vs.−3.2 mL/min;p=0.014)and less percentage change in bone mineral density vs.TDF at hip(−0.95%vs.−1.93%)and spine(+0.35%vs.−1.40%).Conclusions:In chronic hepatitis B patients from China,TAF treatment provided efficacy similar to TDF but with better renal and bone safety at 3 years.Jinlin Hou Qin Ning Zhongping Duan You Chen Qing Xie Fu-Sheng Wang Lunli Zhang Shanming Wu Hong Tang Jun Li Feng Lin Yongfeng Yang Guozhong Gong John FFlaherty Anuj Gaggar Shuyuan Mo Cong Cheng Gregory Camus Chengwei Chen Yan Huang Jidong Jia Mingxiang Zhang GS-US-320-0110 and GS-US-320-0108 China Investigators 2021Journal of Clinical and Translational Hepatology2021,9,3:7
18Facies-succession and architecture of the third-order sequences and their stratigraphic framework of the Devonian in Yunnan-Guizhou-Guangxi area,South China显示文摘The Caledonian orogeny at the end of the Silurian resulted in great changes in the palaeogeography in the Yunnan-Guizhou-Guangxi area of South China; the continental area of the Early Paleozoic evolved into the extensive Dian-Qian-Gui Sea in the Late Paleo-zoic. Early in the Devonian, as a result of a major transgression, seawater encroached gradually from the south to the north and clastic facies were deposited. Carbonate deposition was then established in the Yunnan-Guizhou-Guangxi area, with a palaeogeography marked by attached platforms, isolated platforms and narrow basins. As a result of the Ziyun movement towards the end of the Devonian, the Upper Devonian strata are regressive and thin out from the open-sea to the land areas. A study of the nature and distribution of sedimentary facies in space and time recognises 13 third-order sequences in the Devonian strata in Yunnan-Guizhou-Guangxi area, and these form two second-order sequences. The strata of the Lower Devonian comprise 5 third-order sequences (SQ1 to SQ5 ), which are dominated by transgressive clastics. 4 third-order sequences (SQ6 to SQ9 ) in the Middle Devonian are characterized by alternations of transgressive clastics and highstand carbonates. In the Upper Devonian, carbonates constitute 4 third-order sequences (SQ10 to SQ13 ), which are generally marked by the transgressive limestones and highstand dolomites. On the basis of earlier biostratigraphic studies, sea-level changes represented by the third-order sequences with their different facies successions are explored, and the sequence stratigraphic framework is established. There-fore, the Devonian strata in the study area provide an example for further understanding of depositional trends within the sequence-stratigraphic framework.Mei Mingxiang Maurice E.Tucker 2013Journal of Palaeogeography2013,2,1:6
19From Basin Black Shales to Platform Carbonate Rocks:A Study on Sequence Stratigraphy for the Lower Cambrian of the Upper-Yangtze Region in South China显示文摘在 Upper-Yangtze 区域,特别在贵州省和它的邻近的区域,更低寒武纪很好被开发并且由从盆外形的黑页岩的继任是显著的焦化站台外形的岩石。从 Sinian 发生在拐弯到的站台的淹死的事件寒武纪导致了一套黑页岩,即 Niutitang 形成,它完成底部部分更低寒武纪。与沉积环境变浅,一套碳酸盐摇,即 Qingxudong 形成,在最高的部分被形成更低寒武纪。因此,更低在学习区域寒武纪使能进一步的一个秒顺序序列起来细分进五个第三顺序的序列,并且形成违反回归的定期周期的继任。为在秒顺序顺序的第三顺序的序列有一个定期垂直的叠模式。从底部到顶,继任“ CS (压缩的节)+HST (高看台的系统道) ”第三顺序的序列被变成继任“ TST (transgressive 系统道)+CS+HST' 。相应地,淹死类型顺序边界被变成暴露类型那条。因此,秒顺序和第三顺序的序列有类似的沉积外形的体系结构。有这些时间的变化的伴随物,更低与包含五个第三顺序的序列的 1000 m 的厚度寒武纪被变成不能与加深沉积环境向东南识别第三顺序的序列的压缩继任。根据第三顺序的序列的基本特征,即整齐 o 在空间和沉积环境的变化的同步性的沉积外形的继任及时,在在不同 paleogeographical 背景的主要的记载的节的第三顺序的序列的详细部门成为基础建立能在 stratigraphic 记录表明改变外形的表面的二种类型和 diachronism 的二种类型的 sequence-stratigraphic 框架。这个 sequence-stratigraphic 框架从盆外形的黑页岩形成的压缩继任的库显示出碳酸盐平台的成长进程。从 Sinian 在拐弯源于快速的违反到寒武纪生态的空间变得开,它形成了为“寒武纪的生物爆炸”设定的 paleogeographical 的先前的条件。最终,在 depositional 事件之间的基因关系和生物差异的事件是很复杂的并且在那里仍然是以后需要推进研究的大量问题。MEI Mingxiang MA Yongsheng ZHANG Hai MENG Xiaoqing CHEN Yonghong 2007Acta Geologica Sinica(English Edition)2007,81,5:6
20esveratrol inhibits necroptosis by mediating the TNF-α/RIP1/RIP3/MLKL pathway in myocardial hypoxia/reoxygenation injury显示文摘Resveratrol(RES)protects myocardial cells from hypoxia/reoxygenation(H/R)-caused injury.However,the mechanism of this effect has not been clarified.Thus,in this study,we aimed to determine whether RES attenuates H/R-induced cell necroptosis by inhibiting the tumor necrosis factor-alpha(TNF-α)/receptor-interacting protein kinase 1(RIP1)/RIP3/mixed-lineage kinase domain-like(MLKL)signaling pathway.Rat myocardial ischemia/reperfusion(I/R)models and H/R-injured cell models were constructed.Our study showed that myocardial H/R injury significantly increased the levels of TNF-α,RIP1,RIP3,and p-MLKL/MLKL by western blot analysis.Cell viability assay and 4,6-dianmidino-2-phenylindole(DAPI)-propidium iodide staining showed that the cell viability was decreased,and necroptosis was increased after myocardial H/R injury.The expressions of TNF-α,RIP1,RIP3,and p-MLKL/MLKL in H/R myocardial cells treated with different concentrations of RES were significantly downregulated.In addition,we also found that the cell viability was increased and necroptosis was decreased in dose-dependent manners when H/R-injured cells were treated with RES.In addition,the enhanced effect of TNF-αon necroptosis in myocardial H/R-injured cells was improved by RES,and the effect of RES was confirmed in vivo in I/R rats.This study also showed that RES suppresses necroptosis in H9c2 cells,which may occur through the inhibition of the TNF-α/RIP1/RIP3/MLKL signaling pathway.Our data suggest that necroptosis is a promising therapeutic target and may be a promising therapeutic target for the treatment of myocardial I/R injury.Yongjun Hu Hongwei Pan Jianqiang Peng Jin He Mingxiang Tang Sulan Yan Jingjing Rong Junshan Li Zhaofen Zheng Haijun Wang Yanfu Liu Xin Zhong 2021Acta Biochimica et Biophysica Sinica2021,53,4:6
返回顶部 每页显示:
共7页 首页 上一页 第1页 下一页 末页 /7 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费