16 resultados para CONCESIONES 4G

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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用双丰8号的叶和幼胚为材料。以MSS为基本培养基进行组培试验和细胞学、组织学、形态学研究。试验发现不定芽以内起源为主,外起源在外相体大于1cm时,不定芽在气孔和表皮毛的位置产生,而当外植体小于0•5 cm时,外起源的位置效应消失,不定芽在球形愈伤组织状结构上形成。无丝分裂可能是产生变异的主要原因。不定芽启动时与维管束并无必然的联系,但在以后的发育过程中则需要维管束结节的存在为其输送各种营养物质。叶令对不定芽的发生没有影响。不定芽与淀粉的关系也再一次得到证实。 在被试的各种因素中,BA的浓度在诱导不定芽时起主导作用1mg/L时的效果最好,而且作用时间特别重要,只有在叶原基分化前施用BA,该叶在离体培养时才能产生不定芽。直接取自大田的叶不能产生不定芽。Z T、K T, NA A、GA、水解酪蛋白对不定芽的发生无明显的促进作用。5%蔗糖效果最佳。2 cm高的小苗在MS附加1mg/L N A A、 5 0 g/L蔗糖的生根培养基上根系发育良好。并能移栽成活。 首次利用甜莱幼胚在八个组合的培养基上获得松散和致密二种类型的愈伤组织。暗培养时,有利于松散愈伤组织的形成,但器官发生能力低。光培养时,有利于致密愈伤组织的形成,并能产生大量的球形胚状体。活性炭和蔗糖在相对高的浓度下有利于球形胚状体的产生,而2•4—D对愈伤组织的诱导和胚状体的形成都没有促进作用。球形胚瘫在附加BA1mg/L、NAA、0.5m g/L活性炭4g/L.蔗糖5 0 g/L的M S培养基上可以产生成熟胚状体,但大量的球形胚状体变异形成叶状结构叶状结构愈伤组织化后。 能产生大量不定芽和球形胚状体。致密愈伤组织在继代培养过程中仍能以较高的频率产生再生植株。小苗在生根培养基上形成良好报系后能移栽成活。

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土壤氮素矿化是陆地生态系统氮素转化的重要组成部分。不同的土地利用(管理)方式会改变土壤氮素转化过程,影响土壤肥力的保持,进而可能造成土壤内氮素渗漏流失。为系统了解内蒙古农牧交错区土壤氮素转化的特点,本实验采用原位培养顶盖埋管法进行野外培养,每间隔一个月定期取样,于2004年7月-2006年10月在植物所恢复生态学实验站进行了两个试验,1:选择农牧交错区四种有代表性的土地类型(围封样地:FS,放牧样地:GS,弃耕地:AF,和农田:CF),比较土地利用方式之间氮素矿化的异同;2:在施肥样地通过不同施肥处理(F0: 1g N m-2, F1: 1g N m-2, F2: 2g N m-2, F3: 4g N m-2, F4: 8g N m-2, F5: 16g N m-2, F6: 32g N m-2, F7: 64g N m-2) 的土壤氮素转化动态,确定过度放牧的典型草原围封禁牧后,植被恢复过程中最适宜的施肥量。主要结论如下: 1. 与试验初期相比,整个非生长季围封样地、弃耕地和农田的铵态氮和无机氮含量逐渐降低,培养结束时铵态氮含量分别减少了67.04%,77.31%和70.54%,而放牧地的含量增加1.63%。围封样地、放牧地、弃耕地和农田的硝态氮含量分别增加了61.61%,376.43%,199.75%和133.16%。非生长季四种土地类型的土壤氮素转化速率主要受温度影响。围封样地、放牧地、弃耕地和农田非生长季矿化速率均值分别为-0.016,0.0429,-0.0051和-0.0030 μg g-1 d-1。硝化速率均值变幅为-0.43-0.17 μg g-1d-1。 2. 与没有冷冻而融化的土壤相比,冻融显著影响土壤无机氮含量的变化。只有在较低的土壤温度条件下冷冻以后,融化才会促进土壤氮素矿化。不同的冷冻时间长度下融化均会促进土壤硝化速率。土壤温度、土壤含水量变化是影响氮素转化速率的重要因子。 3. 四种土地类型的年日均矿化速率为放牧样地>农田>弃耕地>围封样地,分别为0.25,0.11,0.10,0.06μg g-1d-1,其年平均速率分别为11.65,5.50,5.00和2.46g m-2 y-1,而年日平均硝化速率分别为0.27,0.095,0.097和0.05μg g-1d-1。其中生长季日均矿化速率和日均硝化速率均为其年日均速率的两倍。因此,生长季形成的矿化氮是全年的93%,而形成的硝态氮占全年的86%。四种土地类型年均矿化氮的累积量平均为615.04 kg ha-1,而硝化作用的累积量变幅为230.44-1218.86 kg ha-1。四种土地类型的矿化速率和硝化速率的季节动态变化与气候因子的变化一致。 4. 不同施肥处理对典型草原土壤氮素转化均有显著影响。与对照相比,少量施肥(F1,F2)土壤铵态氮,硝态氮和无机氮含量分别减少20.57%,11.18%和17.18%。当施肥量大于F4(8g N m-2)时,随施肥量增加土壤铵态氮,硝态氮和无机氮含量增加18%-1191%。除F5(16g N m-2)外,与对照相比,随施肥量增加,土壤矿化速率增加了5-21倍。4 g N m-2 (F3)左右是典型草原生态系统比较合适的施肥量。 5. 氨气挥发速率的季节动态特征与气象因子的变化一致,其速率变幅为17.65 - 1228.39µg m-2 d-1,其中7月挥发量占全年的37%。与对照相比,少量施肥氨气挥发速率降低了1-2%,施肥量大于F3 (4g N m-2),速率增加了1-4倍。实验期间总的流失量变幅为23.76-84.91mg m-2,而且通过氨气挥发流失量低于土壤全氮的3%。氨气挥发不是典型草原过量氮素流失的主要方式。 6. 氮素限制的典型草原,植被恢复过程中外源氮素添加阈值为:4 g N m-2 (F3)。与对照相比,短期施肥(3年)不会显著影响根系碳储量和土壤碳氮储量。施肥处理的土壤硝态氮和无机氮含量显著增加,说明施肥显著刺激硝化作用。典型草原60%植物根系主要分布在地下0-10cm,这里的碳储量占地下储量(0-50cm)的63%以上。随土壤深度增加,土壤全氮,全碳,无机氮储量降低。而铵态氮储量和可利用的无机氮含量随土壤深度增加,说明植物根系主要吸收利用上层可利用氮素,而且下层氮素矿化速率降低。

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To search for compounds with superior anti-human immunodeficiency virus type 1 (HIV-1) activity, ten 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline sulfonates (4a-j) were synthesized and preliminarily evaluated as HIV-1 inhibitors in vitro for the first time. Some compounds demonstrated anti-HIV-1 activity, especially 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-ethylbenzenesulfonate (4g) and 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-chlorobenzenesulfonate (41) showed the more potent anti-HIV-1 activity with 50% effective concentration (EC50) values of 2.59 and 4.01 mu g/ml, and therapeutic index (TI) values of 31.77 and 24.51, respectively.

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1999年 6月至 2 0 0 0年 5月对武汉东湖湖球蚬进行了周年研究。湖球蚬年均密度和生物量分别为 10 0 2ind /m2 和12 1g/m2 ,密度和生物量的高峰分别出现在 4月 (2 97ind /m2 )和 3月 (4 3 8g/m2 ) ;湖球蚬为一年一代 ,其种群含有 3个年龄组 ,其中 1999年龄组占绝对优势。利用瞬时增长率法和体长频率法计算湖球蚬的周年生产量为带壳湿重4 2 79g/m2 ,去壳干重 2 4 4g/m2 ,P/B系数为 3 5 5。同时湖球蚬的生产力动态也被研究 ,

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采用三种方法对扁担塘长角涵螺的周年生产量进行了测算 ,结果表明 ,三种方法得到的生产量及P/B系数吻合较好。生产量的带壳湿重和去壳干重分别是 :体长频率法 ,2 .0 88g·m 2 ·a 1 ,0 .1 0 3g·m 2 ·a 1 ;Allen曲线法 ,2 .1 2 2g·m 2 ·a 1 ,0 .1 0 6g·m 2 ·a 1 ;瞬时生长率法 ,2 .2 73g·m 2 ·a 1 ,0 .1 1 4g·m 2 ·a 1 。对应的P/B系数为 4.3 ,4.3 ,4.0。

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Poyang Lake (Poyang Hu) is located at the junction of the middle and lower reaches of the Yangtze (Changjiang) River, covering an area of 3283 km(2). As one of the few lakes that are still freely connected with the river, it plays an important role in the maintenance of the unique biota of the Yangtze floodplain ecosystem. To promote the conservation of Poyang Lake, an investigation of the macrobenthos in the lake itself and adjoining Yangtze mainstream was conducted in 1997-1999. Altogether 58 benthic taxa, including, 22 annelids, 8 mollusks, 26 arthropods, and 2 miscellaneous animals, were identified from quantitative samples. The benthic fauna shows a high diversity and a marine affinity. The standing crops of benthos in the lake were much higher than those in the river, being 659 individuals/m(2) and 187.3g/m(2) (wet mass) in the main lake, and 549 individuals/m(2) and 116.6 g/m(2) in the lake outlet, but only 129 individuals/m(2) and 0.4g/m(2) in the river. The dominant roup in the lake was Mollusca, comprising 63.4% of the total in density and 99.5% in biomass. An analysis of the functional feeding structure indicated that collector-filterers and scrapers were predominant in the lake, up to 42.2% and 24.7% in density and 70.2% and 29.2% in biomass, respectively, while shredders and collector-gatherers were relatively common in the river. The present study was restricted to the northern outlet and the northeast part of Poyang Lake. A scrutiny is required for the remaining areas.

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Using remote sensing technique, we investigated real-time Nostoc sphaeroides Kiltz (Cyanobacterium) in Closed System under microgravity by SHENZHOU-2 spacecraft in January 2001. The experiments had 1g centrifuges in space for control and ground control group experiments were also carried out in the same equipments and under the same controlled condition. The data about the population growth of Nostoc sp. of experiments and temperature changes of system were got from spacecraft every minute. From the data, we can find that population growth of Nostoc sp. in microgravity group was higher than that of other groups in space or on ground, even though both the control I g group in space and I g group on ground indicated same increasing characteristics in experiments. The growth rate of 1.4g group (centrifuged group on ground) was also promoted during experiment. The temperature changes of systems are also affected by gravity and light. Some aspects about those differences were discussed. From the discussion of these results during experiment, it can be found that gravity is the major factor to lead to these changes. (C) 2004 Elsevier Ltd. All rights reserved.

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The structure and magnetic properties of the RCo5Ga7 (R = Y, Tb, Dy, Ho and Er) compounds with the ScFe6Ga6-type structure have been studied. The stability of RCo5Ga7 is closely related with the ratio of the metal radii R-RE/R-(Co,R-Ga). With R-RE/R-(Co,R-Ga) less than or equal to 1.36, the compounds can be stabilized in the ScFe6Ga6-type structure. The lattice of RCo5Ga7 shrinks as the atomic order of R increases, and it is consistent with the lanthanide contraction. The structure analysis based on X-ray diffraction patterns reveals that in the orthorhombic RCo5Ga7 (Immm), R occupies the 2a site, and Co enters into the 8k and the 4h sites, and Ga is at the 4e, 4f, 4g, 4h and 8k sites. The interatomic distances and the coordination numbers of RCo5Ga7 are provided from the refinement results. The short interatomic distance (less than 2.480 Angstrom) between the Co ions results in the negative magnetic interaction, which does not favor ferromagnetic ordering. The magnetic moment of YCo5Ga7 is absent, and RCo5Ga7 (R = Tb, Dy, Ho and Er) may have long-range magnetic ordering with the paramagnetic Curie temperature lower than 5 K. (C) 2004 Elsevier Inc. All rights reserved.

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本文主要是采用亲水性聚合物来研制缓效复合肥。首先对十几种亲水性材料进行筛选,选择出粘性适中、材料成膜质量好并且所研制肥料的氮素的初期溶出率相对较低的材料为控释材料。通过以上方法选择出两种控释材料:聚乙烯醇溶液和聚乙烯醇与聚丙烯酸钠的混合溶液。将聚乙烯醇配制成3个浓度(1%、2%、3%)并在这3个浓度中加入一定量的聚丙烯酸钠(100鲍聚乙烯醇加入4g聚丙烯酸钠)也配制成3个浓度梯度的溶液。然后用所配制的溶液研制出6种肥料:SRF-A1、SRF-A2、SRF-A3、SRF-B1、SRF-B2、SRF-B3(A1、A2、A3分别代表聚乙烯醇1%、2%、3%3个浓度;B1I、B2、B3代表聚乙烯醇与聚丙烯酸钠混合溶液的1%、2%、3%3个浓度)。利用水浸法和土柱淋溶法对所研制的6种肥料进行缓效性的评价,结果表明所研制的肥料与对照相比都有明显的缓释效果。并且通过测定结果发现SRF-A3和SRF-B3具有较好的缓释效果。通过水浸法和土柱淋溶法得知SRF-A3对N、K2O、P2O5的缓释效果要劣于SRF-B3肥料。通过这两种方法测定控释材料对磷的缓释效果最好,其次是氮素和钾素。试验继续通过肥料和上壤培养来检验缓释效果相对较好的SRF-A3和SRF-B3的缓效性,根据测定数据再一次证明了水浸法和土柱淋溶法的结果即SRF-A3和SRF-B3具有较好的缓释效果,SRF-B3的缓释效果好于SRF-A3。论文最后研究了温度和土壤水分对SRF-A3和SRF-B3的养分释放影响。结果表明:土壤水分对各个肥料养分释放影响显著,而温度对肥料养分释放影响不大,在所设置温度梯度内各个养分的释放差别不明显。

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为了提高糖蜜的可发酵性和氢转化率,采用批式发酵法研究了糖蜜前处理过程和发酵条件对Ethanoligenens sp B49生长和产氢的影响。结果表明去除煮沸驱氧过程可以大大提高Ethanoligenens sp B49发酵糖蜜产氢的性能和糖蜜的氢转化率。Ethanoligenens sp B49细胞生长和产氢的最佳COD为20.6g/L,可发酵糖蜜的最大耐受COD为41.2 g/L,酵母粉可以大大提高糖蜜的生物可利用性和比产氢率。COD为20.6g/L,外加酵母粉浓度为4g/L是Ethanoligenens sp B49发酵糖蜜产氢的最佳条件,单位体积产氢量达到78.97mmolH2/L培养基,比对照提高了76.2%。本研究改进糖蜜发酵前处理方法和发酵条件,可以大大提高了糖蜜制氢的生物可发酵性和比产氢率。

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在模拟降雨条件下(30-69mm/39min),对官厅水库流域玉米地和休闲地地表径流泥沙和生物可利用磷(BAP)流失进行了初步研究.累积泥沙产量受雨强、坡度和作物覆盖影响,变幅为305.1-24933.4g/10m2;径流平均颗粒态生物可利用磷(BPP)、溶解态磷(SP)浓度都超出水体允许临界值0.02mg/L,表明流域农田地表径流对库区水体存在潜在污染危害;径流累积BAP流失达0.08-4.804g/10m2,估算的农田径流BAP流失达0.49kg/(hm2.a)以上.79.7%以上的BAP是颗粒态的.

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A series of new titanium complexes with two asymmetric bidentate beta-enaminoketonato (N,O) ligands (4b-t), [RN=CCF3)CHC(t-BU)O](2)TiCl2 (4b, R = -C6H4F(o); 4c, R = -C6H4F(m);4d, R = -C6H4F(p); 4e, R = - C6H3F2(2,3); 4f, R = -C6H3F2(2,4); 4g, R = -C6H3F2(2,5); 4h, R = -C6H3F2(2,6); 4i, R = -C6H3F2(3,4); 4j, R = -C6H3F2(3,5); 4k, R = -C6H2F3(2,3,4); 4l, R = -C6H2F3(3,4,5); 4m, R = -C6H4CF3(o); 4n, R =-C6H4CF3(m); 4o, R = -C6H4CF3(p); 4p, R = -C6H4Cl(p); 4q, R = -C6H4I(p); 4r, R = -C6H4NO2(P); 4s, R = -CH2C6H5; 4t, R = -C6H11), have been synthesized and characterized.

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The synthesis and luminescence properties of Zn2SiO4:Mn phosphor layers on spherical silica spheres,i.e.,a kind of core-shell complex phosphor,Zn2SiO4:Mn@SiO2 were described.Firstly,monodisperse silica spheres were obtained via the Stober method by the hydrolysis of tetraethoxysilane(TEOS)Si(OC2H5)4 under base condition (using NH4OH as the catalyst).Secondly,the silica spheres were coated with a Zn2SiO4:Mn phosphor layer by a Pechini sol-gel process.X-ray diffraction(XRD),scanning electron microscope(SEM),energy-dispersive X-ray spectrum(EDS) and photoluminescence(PL) were employed to characterize the resulting complex phosphor.The results comfirm that 1000℃ annealed sample consists of crystalline Zn2SiO4:Mn shells and amorphous SiO2 cores.The phosphor show the green emission of Mn2+ at 521nm corresponding 4T1(4G)-6A1(6S) transition,and the possible luminescence mechanism is proposed.

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本论文的主要实验测量工作可分为古地磁学与地球化学二大部分。在古地磁学方面。对JX91-2A(168),JX91-2B(80),JX91-3A(66)和JX91-3B(137)共451个样品进行了天然剩磁(NRM)及交变退磁测量,还进行了磁化率及磁化率各向异性的测量。对JX91-2A,JX91-2B和JX91-3A开展了岩石磁学研究,测量了非粘滞性剩磁(ARM),等温剩磁(ARM),饱和等温剩磁(FIRM)以及个别样品的FIRM衰减曲线,对JX91-3B求出了中间破坏强度(MDF)。在地球化学方面,对JX91-2A(79),JX91-3B(67),JX91-3m(50)和JX91-4G(27)共223个样品进行了X光萤光(XRF)分析。包括10种主要元素及21种向量元素,以及X光衍射(XRD)分析。还对JX91-2A进行了有机碳、微体古生物学及稳定碳氧同位素分析;对JX-91-3B进行了~(210)Pb 测量。另外还对此四岩芯测定了含水量及粒度分布等。所有实验数据都用计算机进行了分析处理,并做了广泛的多学科综合对比研究。在充分借鉴前人成果的基础上,本论文就以下四个方面的问题得到了一点新的认识。一、渤海黄河口外的浊流系统及浅水浊流沉积。这一浊流系统的存在具有多方面的证据。二、渤海沉积物的高精度年代学。对于渤海中央盆地沉积物主要采用了全新世以来的海平面变化曲线及古地磁场强度曲线确定年代,定出JX91-2A底部年代为距今8,500年。三、古地磁记录改正方法及渤海地区古地磁长期变样本曲线的建立。四、渤海古环境综合分析及黄河全新世以来的河道变迁。

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本论文选择乌江流域普定水库、东风水库作为研究对象,对两个水库系统中汞的环境地球化学循环做了较为完整深入的探讨。具体来说本论文包括以下几方面的工作:(1)揭示普定和东风水库水体各种形态汞的含量、时空分布规律。(2)水库水体水质参数的分布机制研究,明确与水质参数相联系的流域环境对水库水体汞分布的影响。(3)弄清普定水库、东风水库沉积物以及孔隙水各种汞形态的含量、分布规律。(4)建立普定水库、东风水库水体汞循环的质量平衡模型,对水体中汞形态的源、汇及其迁移通量进行定量研究。(5)分析了水库对河流甲基汞输送的源效应产生原因,以理解水库-河流系统中汞的环境地球化学循环的作用。通过本论文的研究,取得以下成果: 1、普定、东风水库水库各形态汞丰水期(夏季)普遍高于枯水期(冬、春季)。普定水库夏季总汞、总甲基汞平均浓度分别为4.48和0.32 ng/L,分别是其它两季平均浓度的2.53倍和3.05倍。东风水库夏季总汞、总甲基汞平均浓度分别为2.94和0.33ng/L,分别是其它两季平均浓度的2.53倍和2.64倍。夏季地表径流带来的汞的输入是引起这种季节差异的重要原因。 2、空间分布表明,普定、东风水库无机汞在由河流输入后经过水库系统内的迁移转化,在水库下游段其浓度已有所下降,表现了水库对于无机汞的 “清除”能力。甲基汞浓度在河流经水库蓄水后,在水库库体内得到升高和“蓄集”,并且峡谷型水库在丰水期水流输送作用下库体内的下游段水体具有更强的甲基汞“蓄集”能力。 3、相关矩阵分析表明,两个水库的水质参数悬浮颗粒物(SPM)、水温(T)和硝酸盐(NO3-)与各形态汞之间普遍存在显著的正相关关系,表明这些参数对于各形态汞的季节分布起着重要作用。夏季丰水期,河流由于雨水带进大量的农田和土壤颗粒,而成为普定、东风水库水体汞的一个重要输入源,同时夏季流域相对活跃的农业耕作活动可能是引起普定、东风水库水体汞水平升高的一个重要原因。 4、普定水库、东风水库沉积物总汞全年平均分别为0.198mg/kg和0.204mg/kg,两者没有显著差异,但明显的高于其它没有污染的水体沉积物,低于处于同一流域的红枫湖水库。沉积物甲基汞浓度峰值主要出现在硫酸盐还原细菌活动区域,有机质含量在某种程度上也影响着甲基汞浓度和分布。 5、两个水库沉积物孔隙水中溶解态无机汞、溶解态甲基汞含量明显大于上覆水体。普定水库沉积物4个剖面孔隙水中溶解态总汞向上扩散对上覆水体的影响程度均为夏季>冬季,而溶解态甲基汞向上扩散对水体的影响程度是冬季>夏季。东风水库沉积物溶解态总汞、溶解态甲基汞扩散对上覆水体的影响程度的季节变化没有规律。 6、水库水体总汞质量平衡模型的估算结果表明,普定水库水体的汞总源为19088.2 g.a-1,总汇为19087.4g.a-1。东风水库水体的汞总源为17116.5 g.a-1,总汇为22562.9g.a-1。河流输入都是两个水库总汞最大的源,普定水库最大的汇是水体是向沉积物的沉降,东风水库最大的汇下泄河流总汞的输出。 7、对水库在河流甲基汞输送过程中的“源”效应分析表明沉积物孔隙水向水体释放甲基汞是水库内部甲基汞产生的重要环节,是水库对河流形成甲基汞源效应的重要原因。