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美国东南部边缘磷成因期与海洋δ^(13)C和δ^(18)O记录的联系
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作者 周立君 《海洋地质动态》 1997年第4期11-13,共3页
美国东南部边缘磷成因期与海洋δ ̄(13)C和δ ̄(18)O记录的联系DavidJ.Mallinson等海洋一大气储库中CO2的生物迁移在地质年代中受磷的可利用性限制。因此,为了推断出关于碳的生物地球化学循环和潜在的气... 美国东南部边缘磷成因期与海洋δ ̄(13)C和δ ̄(18)O记录的联系DavidJ.Mallinson等海洋一大气储库中CO2的生物迁移在地质年代中受磷的可利用性限制。因此,为了推断出关于碳的生物地球化学循环和潜在的气候控制,了解整个地质时代中磷通量是... 展开更多
关键词 大陆边缘 成因期 磷灰岩 Δ^13C Δ^18O
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川东涪陵地区大安寨段裂缝控制因素及期次分析 被引量:19
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作者 何龙 郑荣才 +1 位作者 梁西文 徐文礼 《岩性油气藏》 CSCD 2014年第4期88-96,共9页
川东涪陵地区大安寨段为典型的超低孔、低渗储层,其非均质性较强,裂缝可作为主要的油气赋存空间。根据野外露头、钻井岩心、薄片镜下鉴定、扫描电镜分析、成像测井等资料,以及对百余件样品进行了分析实验,认为大安寨段裂缝按成因可划分... 川东涪陵地区大安寨段为典型的超低孔、低渗储层,其非均质性较强,裂缝可作为主要的油气赋存空间。根据野外露头、钻井岩心、薄片镜下鉴定、扫描电镜分析、成像测井等资料,以及对百余件样品进行了分析实验,认为大安寨段裂缝按成因可划分为构造缝、成岩缝与溶蚀缝等3种类型,并详细描述了其主要参数,包括倾角、长度、密度和有效性等。针对各类型裂缝从多个方面分析了影响裂缝形成的主要因素,得出基质岩性、构造作用和沉积-成岩作用对裂缝的影响均较为明显。在岩心观察的基础之上利用稳定同位素分析与声发射实验等多种手段对裂缝形成期次做出初步的判断,认为至少存在燕山晚期、喜山早期和喜山晚期3期裂缝。 展开更多
关键词 页岩气 裂缝型储层 储集空间 控制因素 成因期 大安寨段 川东涪陵地区
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胶东西部灵山沟金矿床地质特征与成因探讨 被引量:3
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作者 王志军 王奎峰 +3 位作者 段会升 胡世利 李云平 刘传国 《矿产勘查》 2013年第1期33-42,共10页
灵山沟金矿床是招掖金矿带上的一个重要金矿床。文章通过搜集已有资料和综合近年来最新的研究成果,对该矿床的地质背景、矿体及矿石特征、赋存状态、围岩蚀变、同位素特征、包裹体特征、矿床成因等方面进行了系统的研究和分析。认为该... 灵山沟金矿床是招掖金矿带上的一个重要金矿床。文章通过搜集已有资料和综合近年来最新的研究成果,对该矿床的地质背景、矿体及矿石特征、赋存状态、围岩蚀变、同位素特征、包裹体特征、矿床成因等方面进行了系统的研究和分析。认为该金矿床受北东向断裂构造控制,具典型的中温热液蚀变特征,岩浆活动具多期次,成矿阶段温度变化不大,成矿流体为低盐度的H2O-NaCl-CO2-H2S体系,硫来源于深源地幔,成矿流体来源以岩浆水为主,混入不同程度的大气降水和变质水,矿床成因为中温热液脉状金矿床,属中成造山型金矿。 展开更多
关键词 胶东 灵山沟金矿床 地质特征 围岩蚀变成矿次矿床成因
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Identification and Selection of Wheat Genotypes with High Phosphorus Use Efficiency at Adult Stage in Huang-huai Wheat Area
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作者 袁园园 常芳 +3 位作者 董贝 郭凯 曹晓慧 郑洪蕊 《Agricultural Science & Technology》 CAS 2017年第2期223-230,共8页
[Objective] This study was conducted to select wheat varieties with high P use efficiency. [Method] A field experiment was carried out with 112 wheat germplasm varieties as experiment materials under normal (NP) and... [Objective] This study was conducted to select wheat varieties with high P use efficiency. [Method] A field experiment was carried out with 112 wheat germplasm varieties as experiment materials under normal (NP) and low phosphorus (LP) conditions, and with Jimai 22 as control, genotypes with high P use efficiency and excellent yield traits were selected. [Result] Compared with NP treatment, 8 wheat yield-related traits, spike number per plant, thousand-grain weight plant height, spike length, fertile spikelet number per spike, grain number per spike, grain weight per plant and above-land weight per plant, and 3 P content traits, grain, straw and above-land P contents per plant decreased significantly under LP condition (P〈〈 0.05), while 3 P utilization efficiency traits, grain, straw and aboveground P utilization efficiencies increased obviously, indicating that low P stress would greatly reduce yield and P content of wheat at adult stage, but would remarkably improve P utilization efficiency. Correlation analysis showed that plant height, fertile spikelet number per spike and grain weight per plant and straw and above-land P concentrations were in significant positive correlation with 3 P content traits, grain, straw and above-land P contents per plant, and in significant negative correlation with 2 Putilization efficiency traits, straw and above-land P utilization efficiencies (P〈0.01), and could serve as indexes for preliminary rapid evaluation of P use efficiency. Under NP treatment, 17 genotypes with high P use efficiency were selected, and among them, Hanxuan H28, 2010 Pin 4891 and Zhoumai 28 showed grain weights per plant higher than Jimai 22 by 36.07%, 31.96% and 37.44%, respectively, and above-land P utilization efficiency higher than Jimai 22 by 49.34%, 49.42% and 33.05%, respectively; and under LP treatment, 10 genotypes with high P use efficiency were selected, and among them, Henong 826 showed grain weight per plant and above-land P utilization efficiency higher than Jimai 22 by 37.60% and 20.42%, respectively. Furthermore, Hanxuan H23, Hanxuan H28 and Xumai 856 were identified as genotypes with high P use efficiency under both NP and LP treatments. [Conclusion] This study provides good parent materials for breeding of varieties with high P use efficiency. 展开更多
关键词 WHEAT Yield: Phosphorus use efficiency Adult stage GENOTYPE
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Involvement of MAPK/ERK kinase-ERK pathway in exogenous bFGF-induced Egr-1 binding activity enhancement in anoxia-reoxygenation injured astrocytes
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作者 刘颖 陆锦标 +1 位作者 陈琦 叶诸榕 《Neuroscience Bulletin》 SCIE CAS CSCD 2007年第4期221-228,共8页
Objective Intravenous administration of basic fibroblast growth factor (bFGF) is effective to reduce the volume of cerebral infract due to ischemia. This study was designed to investigate the molecular mechanism, es... Objective Intravenous administration of basic fibroblast growth factor (bFGF) is effective to reduce the volume of cerebral infract due to ischemia. This study was designed to investigate the molecular mechanism, especially the signal transduction pathways, involved in this protective role of bFGF. Methods Anoxia-reoxygenation treated atrocytes were used to study the role of mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MAPK/ERK kinase, MEK)-ERK signaling pathway after exogenous bFGF administration by Western blot. Electrophoretic mobile shift assay was used to detect the binding activity of early growth response factor-1 (Egr-1), an important transcription factor for endogenous bFGF. Results bFGF could protect some signal transduction proteins from the oxygen-derived free radicals induced degradation. ERK1/2 was activated and involved in Egr-1 binding activity enhancement induced by exogenous bFGF. Conclusion MEK-ERK MAPK cascade may be an important signal transduction pathway contributed to bFGF induced enhancement of Egr-1 binding activity in anoxia-reoxygenation injured astrocytes. 展开更多
关键词 extracellular signal-regulated kinase mitogen-activated protein kinase free radicals fibroblast growth factor 2 early growth response protein 1 ASTROCYTE
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On the genesis of granite pits on top of the Shigujian Peak of the Dayangshan Mountain in Jinyun County,Zhejiang Province 被引量:1
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作者 朱诚 崔之久 +6 位作者 李中轩 高洁 王立新 邬祥林 郑朝贵 沈庆凡 郑献章 《Journal of Geographical Sciences》 SCIE CSCD 2009年第2期239-248,共10页
On top of Shigujian Peak(1477 m a.s.l.) of the Dayangshan Mountain in Jinyun County, Zhejiang Province, large amounts of granite pits with diameters ranging from several dozens of centimeters to around one meter and d... On top of Shigujian Peak(1477 m a.s.l.) of the Dayangshan Mountain in Jinyun County, Zhejiang Province, large amounts of granite pits with diameters ranging from several dozens of centimeters to around one meter and depth from 10 cm to 45 cm are found on rock surface.These pits mainly appear on the NE and SE sides, and their drainage mouths are in the same direction.The identification results through micropolariscope and X-ray fluorescence spectrometer reveal that bedrock of pits is from middle to fine-grained moyite being apt to be weathered and modified.In Dayangshan region the annual mean temperature is 9.2℃ and annual precipitation is over 1700 mm.On the one hand, there always experiences a period of periglacial action with temperature oscillating near 0℃ for 4 months, i.e., from December to March next year.As a consequence, the freezing-thawing cycles may be remarkable to disintegrate the bedrock.On the other hand, the windward slope of Shigujian Peak meets typhoon of over force 10 on the Beaufort scale in summer, therefore, the blowing makes suspending sands or pebbles grind in swirling form.Based on field investigation and periglacial geomorphic theory, the pits on top of Shigujian Peak are attributed to freez-ing-thawing of periglacial action.Meanwhile, storm and strong wind accelerate the process.Observation shows that both the actions are still undergoing and variant directions of wind are the main cause for making different shapes of the pits.Because the top of Shigujian is 1500 m lower than the present snow line, some scholars considered that"glacial pothole"formed in the Quaternary is hard to work, even though in the Last Glacial Maximum(LGM). 展开更多
关键词 the Shigujian Peak in Dayangshan Mountain genesis of granite pits wind-water erosion freez- ing-thawing weathering
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An Arabidopsis embryonic lethal mutant with reducedexpression of alanyl-tRNA synthetase gene
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作者 SUN JIAN GE XIAo LI YAO +1 位作者 ZHI XING YANG ZHIPING ZHU(Department of Plant Development, Shanghai Institute of Plant Physiology, Chinese Academy of Sciences, Shanghai, China, 200032 E-mail:zhuiris.sipp.ac.cn) 《Cell Research》 SCIE CAS CSCD 1998年第2期119-134,共16页
In present paper, one of the T-DNA insertional embryonic lethal mutant of Arabidopsis is identifled and designated as acd mutant. The embryo development of this mutant is arrested in globular stage. The cell division ... In present paper, one of the T-DNA insertional embryonic lethal mutant of Arabidopsis is identifled and designated as acd mutant. The embryo development of this mutant is arrested in globular stage. The cell division pattern is abnormal during early embryogenesis and results in disturbed cellular differentiation. Most of mutant embryos are finally degenerated and aborted in globular stage. However, a few of them still can germinate in agar plate and produce seedlings with shorter hypocotyl and distorted shoot meristem. To understand the molecular basis of the phenotype of this mutant, the joint fragment of T-DNA/plant DNA is isolated by plasmid rescue and Dig-labeled as probe for cDNA library screening. According to the sequence analysis and similarity searching, a 936bp cDNA sequence (EMBL accession#: Y12555) from selected positive clone shows a 99.8 % (923/925bp) sequence homology with Alanyl-tRNA Synthetase (A1aRS) gene of Arabidopsis thaliana. Furthermore, the data of in sitll hybridization experiment indicate that the expression of AlaRS gene is weak in early embryogenesis and declines along with globular embryo ’development’ in this mutant.Accordingly, the reduced expression of AlaRS gene maybe closely related to the morphological changes in early embryogenesis of this lethal mutant. 展开更多
关键词 AlaRS gene embryonic mutant ARABIDOPSIS
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Angiogenesis at Different Stage of Pregnancy Ingoatplacenta
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作者 T. Diaz C.I. Merkis +5 位作者 D.S. Cots E.G. Sanchis A.L. Cristofolini M.C. Romanini A. Bozzo A. Rolando 《Journal of Life Sciences》 2015年第8期391-398,共8页
The increase intransplacental exchange depends primarily on the great development of the placental vascular bed. The aim of this study was to evaluate the pattern of placental vascular development at day 50 and 100 of... The increase intransplacental exchange depends primarily on the great development of the placental vascular bed. The aim of this study was to evaluate the pattern of placental vascular development at day 50 and 100 of pregnancyin goats and the relationship with the vascular endothelial growth factor (VEGF) immunolocalization. The placental morphometric variables: capillary area density, capillary perimeter density, capillary number density and average capillary perimeter of the caruncular (CAR) and cotyledonary (COT) tissues were measured at day 50 (n = 5) and 100 (n = 5) of gestation. Also, the immunolocalization of VEGF was performed. In the CAR and COT tissues a significant increase of capillary area density and capillary perimeter density at day 100 of the gestation was observed. In the COT tissue, this was due to the increase in the capillary number density; however in the CAR tissue this was due to the increase in the capillary size. We can conclude that in both tissues there were different strategies to increase the capillary area and, thereby, the nutrients exchange. The immunolocalization of VEGF in the COT tissue showed the endothelial cells of blood vessels and trophoblastcells surrounding the villi intensely inmunostained, which would indicate the involvement of VEGF in the placental vascular development. 展开更多
关键词 ANGIOGENESIS GOAT PLACENTA VEGF
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乳化炸药线型切割器对薄壳弹药销毁效果的数值模拟研究 被引量:4
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作者 王敏 龙源 +1 位作者 钟明寿 谢兴博 《爆破器材》 CAS 北大核心 2018年第2期39-43,共5页
针对目前的弹药销毁状况,为了减轻直接爆破的环境压力,利用理论分析及数值模拟的方法,首先对设计的简易乳化炸药线型切割器的药型罩材料进行确定,数值模拟表明:铝质药型罩所形成的射流侵彻能力要比紫铜材质的提高28%,而后利用ANSYS数值... 针对目前的弹药销毁状况,为了减轻直接爆破的环境压力,利用理论分析及数值模拟的方法,首先对设计的简易乳化炸药线型切割器的药型罩材料进行确定,数值模拟表明:铝质药型罩所形成的射流侵彻能力要比紫铜材质的提高28%,而后利用ANSYS数值模拟得出该切割器最佳炸高为15 mm。最后对乳化炸药线型切割器切割薄壳弹药的过程进行数值模拟,证明该切割器可以达到切去弹药外壳而不产生剧烈爆轰及高速破片的效果。 展开更多
关键词 聚能射流 切割器设计 冲击起爆 数值模拟
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Atg5 regulates late endosome and lysosome biogenesis 被引量:6
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作者 PENG JunYa ZHANG Ran +11 位作者 CUI YiTong LIU HaoDong ZHAO XiaoXin HUANG Lei HU MingXu YUAN XiaoXi MA BenYu MA XiaoWei TAKASHI Ueno MASAAKI Komatsu LIANG XingJie YU Li 《Science China(Life Sciences)》 SCIE CAS 2014年第1期59-68,共10页
Autophagy is an evolutionarily conserved lysosome-based degradation process.Atg5 plays a very important role in autophagosome formation.Here we show that Atg5 is required for biogenesis of late endosomes and lysosomes... Autophagy is an evolutionarily conserved lysosome-based degradation process.Atg5 plays a very important role in autophagosome formation.Here we show that Atg5 is required for biogenesis of late endosomes and lysosomes in an autophagy-independent manner.In Atg5 cells,but not in other essential autophagy genes defecting cells,recycling and retrieval of late endosomal components from hybrid organelles are impaired,causing persistent hybrid organelles and defective formation of late endosomes and lysosomes.Defective retrieval of late endosomal components from hybrid organelles resulting from impaired recruitment of a component of V1-ATPase to acidic organelles blocks the pH-dependent retrieval of late endosomal components from hybrid organelles.Lowering the intracellular pH restores late endosome/lysosome biogenesis in Atg5 cells.Our data demonstrate an unexpected role of Atg5 and shed new light on late endosome and lysosome biogenesis. 展开更多
关键词 endosome/lysosome biogenesis atg5 AUTOPHAGY
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Influences of a periodic signal on a noisy synthetic gene network
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作者 LIU Yan LI Nan 《Science China Chemistry》 SCIE EI CAS 2011年第6期992-997,共6页
The effects of noise and a periodic signal on a synthetic gene network have been investigated. By tuning the distance of a parameter from the Hopf bifurcation point, both implicit internal signal stochastic resonance ... The effects of noise and a periodic signal on a synthetic gene network have been investigated. By tuning the distance of a parameter from the Hopf bifurcation point, both implicit internal signal stochastic resonance and explicit internal signal stochastic resonance can be induced by noise. Furthermore, a switch process can also be elicited. When a periodic signal is coupled to the gene network, two interesting phenomena occur with the modulation of the frequency of the signal: the effect of noise amplifying cellular signal can be inhibited or even destroyed, and "locked" coherence resonance occurs. 展开更多
关键词 FLUCTUATION periodic signal synthetic gene network stochastic resonance
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