13 resultados para Morton Grove

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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本论文主要包括以下两部分内容: 一、真菌诱导子对青蒿发根生长和青蒿素生物合成的影响 用3种真菌诱导子[大丽花轮枝孢(Verticillium dahliae Kleb.)、葡枝根霉(Rhizopus stolonifer (Ehrenb. ex Fr.) Vuill)和束状刺盘孢(Colleto trichumdematium (Pers.) Grove)]分别处理青蒿(Ar temisia annuaL.)的发根,这3种真菌诱导子均能促进发根中青蒿素的合成,其中以大丽花轮枝孢的诱导效果最好;对细胞生长均没有明显影响。经大丽花轮枝孢处理的发根中青蒿素含量达1. 12 mg/gDW,比对照(0. 77 mg/g DW)提高45%。诱导子的作用效果与诱导子浓度、诱导子作用时间及发根的生长状态有关。对大丽花轮枝孢来说,诱导子作用的最适浓度为每毫升培养基含糖0.4 mg;发根在指数生长末期对诱导作用最敏感:在加入诱导子4d后收获发根,发根中的青蒿素含量最高。 二、早花基因FPF1、co对青蒿开花时间的影响及开花与青蒿素生物合成的相关性 1.将来源于拟南芥的早花基因Flowering Promoting Factorl (FPFl)插入到植物表达载体pBI121中,构建CaMV 35S启动子控制下含FPFl基因的植物表达载体pBI121FPF/,用含有pBI121FPF/质粒的根癌农杆菌(Agrobacterium tumefaciens)LBA4404感染青蒿(Artemisia annua L.)叶片并诱导丛生芽,经卡那霉素筛选,获得转基因抗性植株。PCR、 PCR-Southem blot及Southern blot检测表明,外源基因FPFI已整合到青蒿基因组中:RT-PCR及RT-PCR Southern blot分析表明,外源基因在转录水平上已有表达。在短日照条件下,FPF1转基因植株的开花时间较对照提前20天左右,但提早开花的转基因植株与未开花的对照其青蒿素含量无明显差异,即提早开花并不能使开花植株的青蒿素含量有所提高,开花与青蒿素合成之间可能没有直接的关系。 2.将拟南芥的早花基因CONSTANS (CO)置于CaMV 35S启动子之下,通过根癌农杆菌(Agrobacterium tumefaciens)LBA4404介导转入青蒿(Artemisia annuaL.),使之在青蒿中表达,并得到了抗性植株。PCR、PCR-Southem blot及Southemblot检测表明,外源基因co已整合到青蒿基因组中;RT-PCR及RT-PCR Southemblot分析表明,外源基因在转录水平上已有表达。在短日照条件下,co转基因植株的开花时间较对照提前2周左右,但提早开花的转基因植株的青蒿素含量与未丌花的对照无明显差异,即植株开花前青蒿素含量的提高并不是由于开花本身引起的,再次证明,开花与青蒿素合成之间可能没有直接的关系。

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本文报道了轮藻科1新种、2新变种及4个中国新记录:不等丽藻 Nitella inaequabilis sP.nov,分叉丽藻齿网变种N.furcata var.dentireticulata var.nov.;普生轮藻等苞变种 Chara vulgaris var.aequibracteata var.nov.;裂顶丽藻 Nitella partita Nordst.;过渡丽藻N.transilis T.F.Allen;布洛丽藻 N.blowiana J.Grove;娇小丽藻 N.pulchella T.

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High quality cubic GaN was grown on Silicon (001) by metalorganic vapor phase epitaxy (MOVPE) using a GaAs nucleation layer grown at low temperature. The influence of various nucleation conditions on the GaN epilayers' quality was investigated. We found that the GaAs nucleation layer grown by atomic layer epitaxy (ALE) could improve the quality of GaN films by depressing the formation of mixed phase. Photoluminescence (PL) and X-ray diffraction were used to characterize the properties of GaN epilayers. High quality GaN epilayers with PL full width at half maximum (FWHM) of 130meV at room temperature and X-ray FWHM of 70 arc-min were obtained by using 10-20nm GaAs nucleation layer grown by ALE.

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The jinjiang oyster Crassostrea rivularis [Gould, 1861. Descriptions of Shells collected in the North Pacific Exploring Expedition under Captains Ringgold and Rodgers. Proc. Boston Soc. Nat. Hist. 8 (April) 33-40] is one of the most important and best-known oysters in China. Based on the color of its flesh, two forms of C rivularis are recognized and referred to as the "white meat" and 11 red meat" oysters. The classification of white and red forms of this species has been a subject of confusion and debate in China. To clarify the taxonomic status of the two forms of C. rivularis, we collected and analyzed oysters from five locations along China's coast using both morphological characters and DNA sequences from mitochondrial 16S rRNA and cytochrome oxidase 1, and the nuclear 28S rRNA genes. Oysters were classified as white or red forms according to their morphological characteristics and then subjected to DNA sequencing. Both morphological and DNA sequence data suggest that the red and white oysters are two separate species. Phylogenetic analysis of DNA sequences obtained in this study and existing sequences of reference species show that the red oyster is the same species as C. ariakensis Wakiya [1929. Japanese food oysters. Jpn. J. Zool. 2, 359-367.], albeit the red oysters from north and south China are genetically distinctive. The white oyster is the same species as a newly described species from Hong Kong, C. hongkongensis Lam and Morton [2003. Mitochondrial DNA and identification of a new species of Crassostrea (Bivalvia: Ostreidae) cultured for centuries in the Pearl River Delta, Hong Kong, China. Aqua. 228, 1-13]. Although the name C. rivularis has seniority over C. ariakensis and C. hongkongensis, the original description of Ostrea rivularis by Gould [1861] does not fit shell characteristics of either the red or the white oysters. We propose that the name of C. rivularis Gould [1861] should be suspended, the red oyster should take the name C. ariakensis, and the white oyster should take the name C. hongkongensis. (C) 2004 Elsevier B.V. All rights reserved.

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鸟类的个体发育是在双亲、雏鸟及巢组成的一种特殊环境中完成的,稳定的热环境是它们完成孵化和雏鸟生长发育的必要条件(White et al.,1974;Purdue,1976;Ellis,1982;Haftorn,1983;Morton et al.,1985;Schnace et al.,1991;Vatnick et al.,1998;张晓爱等,1995)。因此亲鸟的伴巢行为及时间是指亲鸟在繁殖期间,为筑巢、防御、抱卵、孵雏及递食而出现在巢中或附近的所有行为(Oppenhaim,1972)。亲鸟拌巢的时间分配与巢环境有密切关系,已有大量的报道(如Purdue,1976;Ellis, 1982;Schnace et al., 1991;张晓爱等,1995)。张晓爱等(1995)比较了高寒草甸地区的地面、灌丛及洞穴3种不同营巢类型亲鸟的伴巢时间分配模式,但是对亲缘关系较近,营巢生境相同鸟类之间的伴巢时间分配模式,以及坐巢行为与巢环境之间关系没有报道,国外对这方面的报道也甚少。本项研究选择高寒草甸的两种百灵科鸟:角百灵(Eremophila alpestris)和小云雀(Alauda gulgula)作为研究对象来比较亲鸟在卵化期坐巢行为与巢址微环境的关系,对研究鸟类繁殖行为与环境关系及从生活史进化角度研究相似种的共存机制提供理论依据。

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The Grove Mountains, including 64 nunataks, is situated on an area about 3200km2 in the inland ice cap of east Antarctica in Princess Elizabeth land (72o20'-73°101S, 73°50'-75o40'E), between Zhongshan station and Dome A, about 450km away from Zhongshan station (69°22'S, 76°22'E). Many workers thought there was no pedogenesis in the areas because of the less precipitation and extreme lower temperature. However, during the austral summer in 1999-2000, the Chinaer 16 Antarctic expedition teams entered the inland East Antarctica and found three soil spots in the Southern Mount Harding, Grove Mountains, East Antarctica. It is the first case that soils are discovered in the inland in East Antarctica. Interestingly, the soils in this area show clay fraction migration, which is different from other cold desert soils. In addition, several moraine banks are discovered around the Mount Harding. The soil properties are discussed as below. Desert pavement commonly occurs on the three soil site surfaces, which is composed of pebbles and fragments formed slowly in typical desert zone. Many pebbles are subround and variegated. These pebbles are formed by abrasion caused by not only wind and wind selective transportation, but also salt weathering and thaw-freezing action on rocks. The wind blows the boulders and bedrocks with snow grains and small sands. This results in rock disintegration, paved on the soil surface, forming desert pavement, which protects the underground soil from wind-blow. The desert pavement is the typical feature in ice free zone in Antarctica. There developed desert varnish and ventifacts in this area. Rubification is a dominant process in cold desert Antarctic soils. In cold desert soils, rubification results in relatively high concentrations of Fed in soil profile. Stained depth increases progressively with time. The content of Fed is increasing up to surface in each profile. The reddish thin film is observed around the margin of mafic minerals such as biotite, hornblende, and magnetite in parent materials with the microscope analyzing on some soil profiles. So the Fed originates from the weathering of mafic minerals in soils. Accumulations of water-soluble salts, either as discrete horizons or dispersed within the soil, occur in the soil profiles, and the salt encrustations accumulate just beneath surface stones in this area. The results of X-ray diffraction analyses show that the crystalline salts consist of pentahydrite (MgSO4-5H2O), hexahydrite (MgSO4-6H2O), hurlbutite (CaBe2(PO4)2), bloedite (Na2Mg(S04)2-4H2O), et al., being mainly sulfate. The dominant cations in 1:5 soil-water extracts are Mg2+ and Na+, as well as Ca2+ and K+, while the dominant anion is SO42-, then NO3-, Cl- and HCO3-. There are white and yellowish sponge materials covered the stone underside surface, of which the main compounds are quartz (SiO2, 40.75%), rozenite (FeSOKkO, 37.39%), guyanaite (Cr2O3-1.5H2O, 9.30%), and starkeyite (MgSO4-4H2O, 12.56%). 4) The distribution of the clay fraction is related to the maximum content of moisture and salts. Clay fraction migration occurs in the soils, which is different from that of other cold desert soils. X-ray diffraction analyses show that the main clay minerals are illite, smectite, then illite-smectite, little kaolinite and veirniculite. Mica was changed to illite, even to vermiculite by hydration. Illite formed in the initial stage of weathering. The appearance of smectite suggests that it enriched in magnesium, but no strong eluviation, which belongs to cold and arid acid environment. 5) Three soil sites have different moisture. The effect moisture is in the form of little ice in site 1. There is no ice in site 2, and ice-cement horizon is 12 cm below the soil surface in site 3. Salt horizon is 5-10 cm up to the surface in Site 1 and Site 2, while about 26cm in site 3. The differentiation of the active layer and the permafrost are not distinct because of arid climate. The depth of active layer is about 10 cm in this area. Soils and Environment: On the basis of the characteristics of surface rocks, soil colors, horizon differentiation, salt in soils and soil depth, the soils age of the Grove Mountains is 0.5-3.5Ma. No remnants of glaciations are found on the soil sites of Mount Harding, which suggests that the Antarctic glaciations have not reached the soil sites since at least 0.5Ma, and the ice cap was not much higher than present, even during the Last Glacial Maximum. The average altitude of the contact line of level of blue ice and outcrop is 2050m, and the altitude of soil area is 2160m. The relative height deviation is about 110m, so the soils have developed and preserved until today. The parental material of the soils originated from alluvial sedimentary of baserocks nearby. Sporepollen were extracted from the soils, arbor pollen grains are dominant by Pinus and Betula, as well as a small amount Quercus, Juglans, Tilia and Artemisia etc. Judging from the shape and colour, the sporepollen group is likely attributed to Neogene or Pliocene in age. This indicates that there had been a warm period during the Neogene in the Grove Mountains, East Antarctica.

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Chinese National Antarctic Research Expedition (CHTNARE) has collected 4480 meteorite specimens in the Grove Mountains, East Antarctica, from 1998 to 2003. According to the location characteristics and the diversity of the classification, the paper concludes that the Grove Mountains is another important meteorite concentration area in the Antarctica. The Concentration mechanisms at the site could be related to the last glacier activity and katabatic wind. An empirical model was proposed: 1) Probably during the Last Glacial Maximum, ice flow overrided the Gale Escarpment range in the area. Formerly concentrated meteorites were carried by the new glacier and stayed in the terminal moraine when the glacier retreated. 2) Blown by strong katabatic wind, Newly exposed meteorites on the ablation zone were scattered on the blue ice at the lee side of the Gale escarpment. Some of them would be buried when they were moved further onto the firn snow zone. Many floating meteorites stopped and mustered at the fringe of the moraine. The chemical-petrographic of 31 meteorites were assigned based on electron probe microanalyses, petrography and mineralogy, including 1 martian lherzolitic shergottite, 1 eucrite, 1 extreme fine grain octahedron iron meteorite, and 28 ordinary chondrites (the chemical groups: 7 H-group, 13 L-group, 6 LL-group, 2 L/LL group; the petrographic types: 6 unequilibrated type 3 and 22 equilibrated type 4-6). GRV99028 meteorite has the komatiite-like spinifex texture consisting of acicular olivine crystals and some hornblende-family minerals in the interstitial region. Possibly it has crystallized from a supercooled, impact-generated, ultramafic melt of the host chondrite, then experienced the retrogressive metamorphism. Four typical chondrule textures were studied: porphyritic texture, radiative texture, barred texture and glass texture. The minerals are characteristically enriched in MgO content.

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This paper is concerned of the I0Be and 26A1 exposure ages of bedrocks in the Grove Mountains (GMs), inland of East Antarctica, and in the Larsemann Hills, peripheral alongshore of East Antarctica, respectively. The results of our study indicate that the higher bedrock samples in two profiles in the GMs have minimum exposure ages of-2 Ma, and their 26Al/10Be can be projected into the erosion island, which means they only have simple exposure history. The actual exposure ages may be mid-late Pliocene because the bedrocks should have erosion. The relationship between the altitudes and cosmogenic nuclide concentrations of those higher samples suggests that they have not reached secular equilibrium, means that a higher than -2300m East Antarctic Ice Sheet (EAIS) existed in the GMs before mid-Pliocene, and decreased monotonously for a period since mid-Pliocene. Lower samples of the two profiles have much younger exposure ages, and had been covered at least once obviously implicated by that their 26Al/10Be are projected down to the erosion island. Using a 10Be-26Al project figure to determine the history of the GMs samples shows that the lower samples have minimum total initial exposure and cover time of 1.7-2.8Ma, suggesting that those samples were exposed initially since about late Pliocene too, and the interior EAIS fluctuated after late Plicoene obviously. The altitudes and exposure ages of all the GMs samples indicate that the ice surface level of the interior EAIS in the GMs was >2300m during or before mid Pliocene (more than 200m higher than present ice surface level), and only rose to -2200m during the fluctuation occurred after late Pliocene, thus the elevation of the interior EAIS in the GMs after mid-Pliocene was never higher than during or before mid Pliocene even during the Quaternary Glacial Maximum. According to data from the GMs and other parts of East Antarctica, a larger East Antarctic Ice Sheet existed before mid-Pliocene, thus the elevation decrease of interior EAIS in the GMs after mid Pliocene may be a director of volume decrease of the EAIS. Since the Antarctic climate has a cooling trend since ~3Ma, similar to the global climate change, the volume decrease of the EAIS since mid-Pliocene may beause of moisture supply decrease directly rather than atmosphere temperature change. As for the Larsemann Hills, samples farther to the glacier have exposure age of 40~50ka, means they exposed in the early time of Last Glacier Cycle, obviously earlier than the Last Glacial Maximum (LGM). Samples nearer to the glacier have exposure ages younger than LGM. Thus, different to the GMs, exposure ages of the Larsemann Hills samples have more obvious relationship to their distance from the glacier margin rather than to the altitudes of the samples.

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Three soil spots were found in Grove Mountains, east Antarctica during 1999-2000, when the Chinare 16th Antarctic expedition teams entered the inland Antarctica. The characteristics of soils in Grove Mountains are desert pavement coating the surface, abundant water soluble salt, negligible organ matter, and severe rubification and salinization, scarces of liquid water, partly with dry permafrost, corresponding with the soils of McMurdo, Transantarctic. The soils age of Grove Mountains is 0.5-3.5Ma. Podzolization and redoximorphism are the main features in coastal Wilks region, in addition, there is strong enrichment of organic matter in many soils of this region. The main soil processes of Fildes Peninsula of King George Island include the intense physical weathering, decalcification and weakly biochemical processes. Peat accumulation is the main processes in Arctic because of humid and cold environment.Based on synthesis of heavy minerals, particle size, quartz grain surface textures, as well as pollen in soils, the soils parent materials of Grove Mountains derived from alluvial sediment of the weathering bedrocks around soils, and formed during the warm period of Pliocene. The detailed information is followed .l)The results of heavy minerals particle size showed the parent minerals derived form the weathering bedrocks around soils. 2)The quartz sand surface textures include glacial crushing and abrasion such as abrasive conchoidal fractures and grain edges, abrasive subparallel linear fractures and angularity, subaqueous environments produce V-shaped and irregular impact pits, polished surface, and chemical textures, such as beehive solution pits, which showed the water is the main force during the sediment of the soil parent minerals. 3)The pollen consist of 40 plant species, of which at least 5 species including Ranunculaceae, Chenopodiaceae, Artemisia, Gramineae, Podocarpus belong to the Neogene vegetation except the species from the old continent. Compared with Neogene vegetation of Transantarctic Mountains, Antarctic, we concluded that they grow in warm Pliocene.

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随着我国南极陨石的大量回收,对陨石的研究也越来越深入。本文主要对我国部分南极陨石和沙漠陨石开展了三方面的工作:(1)我国部分南极陨石的分类;(2)陨石中宇宙成因核素10Be和26Al的化学分离、纯化实验;(3)我国部分南极陨石和沙漠陨石的全岩化学组成分析和宇宙成因核素10Be和26Al的初步研究。 1、我国部分南极陨石的分类研究 通过对我国19次南极科考队回收的4448块陨石中24块南极普通球粒陨石的矿物、岩石分析,将这24块陨石化学-岩石类型进行了划分,分别为1个H3型(GRV 021603)、2个H4型(GRV 020200和GRV 021493)、4个H5型(GRV 020048、GRV 020078、GRV 020129和GRV 020236)、2个H6型(GRV 020075和GRV 020226)、1个L4型(GRV 021563)、8个L5型(GRV 020047、GRV 020283、GRV 020297、GRV 021547、GRV 021547、GRV 021581、GRV 021615和GRV 023771)、5个L6型(GRV 020103、GRV 020155、GRV 021505、GRV 021711和GRV 022171)、1个LL4型(GRV 020029)和1个LL6型(GRV 021496)。在此基础上,将我国的南极陨石和美国的南极陨石进行了类型和质量分布模型的对比。结果表明,我国南极陨石比美国南极陨石具有相对高的L群丰度;我国的南极陨石质量分布模型与美国南极陨石一致。 2、陨石中宇宙成因核素10Be和26Al的化学分离、纯化实验 在前人关于陨石中宇宙成因核素10Be和26Al的分离方法基础上,通过多次模拟样品的分离实验,成功地将陨石中Be和Al进行了分离、纯化。并且进一步改善了前人的分离方法,将Be的淋洗液由原来的120ml减少为90ml。在此基础上,用空白样品和吉林陨石的硅酸盐样品对整个化学分离实验进行了检验,并将所获得的BeO和Al2O3粉末用加速器质谱(AMS)进行了10Be和26Al的测试。根据所测定的10Be和26Al数据,计算得到吉林陨石的暴露年龄为0.52Ma,这一结果与前人所获得的吉林陨石第二阶段的暴露年龄0.4Ma接近。这一结果再次证明了陨石中宇宙成因核素10Be和26Al的分离流程是成功的,同时也说明本次所测的吉林陨石样品为吉林陨石第二阶段暴露辐射的样品。 3、我国部分南极陨石和沙漠陨石的全岩化学组成分析以及宇宙成因核素10Be和26Al的初步研究 对我国13块南极陨石和3块沙漠陨石进行了全岩化学成分的分析,其结果进一步证明了这些陨石由岩石、矿物分析所划分的类型的正确性。在这些陨石类型和全岩分析的基础上,对它们进行了宇宙成因核素10Be和26Al的初步分析。得到其中4块南极陨石和2块沙漠陨石的暴露年龄和居地年龄,这些陨石暴露年龄的范围为2.09-3.05Ma,居地年龄为0-0.23Ma。

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陨石分类是一项基础性的工作,是开展深入研究的前提。磁化率(χ)的测量提供了一种快速简单、无损的陨石分类方法,国外已有一些学者开始对陨石的磁性分类开展了研究,但国内尚无这方面研究的报导。本文主要对从南极格罗夫山回收的陨石开展了磁性分类的初步研究,论文主要工作包括以下几个方面: 1) 进行了磁化率测量模拟实验:由于陨石样品具有不规则和大小不等的形状,通过对模拟样品测量,了解上述几何因素对磁化率测量精度和准确性的影响,并作出MS2磁化率测量系统MS2D探头与MS2B传感器测量值之间的校正曲线。对模拟样品测量结果的分析表明,不同形状和大小的样品(所含磁性矿物分布均一)在进行MS2D测量时,测量相对偏差可控制在2%以内,表明上述测量系统可以用于陨石的磁化率测量。 2) 对所选600块南极格罗夫山陨石用MS2D探头进行了磁化率测量,得出这600块陨石的磁化率㏒χ(10-9m3/kg)数据,并用MS2B探头测量其中375块用来作岩石矿物学分类用的小块劈分样品的磁化率㏒χ(10-9m3/kg)。这600块格罗夫山陨石磁化率分布模式与南极其他区域收集的陨石较吻合,对应H、L、LL群呈3个明显的峰分布。相同的陨石用MS2D与MS2B两种探头测量,将它们的磁化率数据进行对比,显示它们的结果相当一致(相关系数R2=0.97),也同时证明MS2D用于磁化率测量是行之有效的。 3)测量了44块沙漠陨石和9块降落型陨石的磁化率,在此基础上对南极格罗夫山陨石、沙漠陨石及降落型陨石数据做了对比讨论。格罗夫山陨石、沙漠陨石及降落型陨石磁化率值分布出现不同程度的偏移,总体来说磁化率㏒χ平均值为降落型陨石>南极陨石>沙漠陨石,这主要是由于陨石所受风化程度的差异造成的。风化作用使陨石部分金属发生氧化,因而降低了磁化率。 4)基于陨石的岩石矿物学分类,172块平衡型普通球粒陨石的磁化率分布,与文献上南极陨石磁化率分布基本一致,不过格罗夫山H、L、LL型普通球粒陨石磁化率分布范围更为狭窄,反映了南极不同地区陨石风化程度的差异。 5)讨论了陨石磁化率分类的有效性,分析了部分异常值出现的原因。磁化率分类结果与部分格罗夫山陨石的岩石矿物学分类(申请者作为陨石分类小组成员完成了其中的部分工作)结果相当吻合,仅在群之间约有5%的重叠,表明磁化率可作为化学群分类的重要参考数据。由于各陨石所受风化程度的差异,风化程度较强的少量陨石在磁性分类的基础上,还需其他工作加以证实。部分小质量(小于3g)且有部分或完整熔壳的陨石,磁化率受熔壳的影响达10%以上,偏离了其初始矿物的磁化率值,不能反映其真实的化学群类型,这部分磁化率数据仅供参考。