206 resultados para 11-105


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杂多酸是种类多,应用广的重要的无机化合物。其中有一类是12-系列化合物Z,(XM_(12-n)M_n′O_(40))·mH_2O,中心离子X可以是过渡元素或非过渡元素;M常是Mo、W;M′为V_(5+)、Mn_(2+)、CO_(2+)等;n=0,1,2…;Z为H~+或一价阳离子;y=1,2,…。它们同其相应氧化型化合物比较具有引人注目的特性,但迄今尚未见到还原型化合物晶体结构文章,只是

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本文采用低温技术,在—90℃的干燥氮气保护下,收集标题化合物晶体的衍射数据,用重原子法解出结构。P2_1/n空间群,a=17.504(2),b=27.323(5),c=21.616(4),β=104.49(2)°,z=4.8320个衍射参与精修,最后的R值为0.088。中心离子Pr(Ⅲ)同2个钼硅杂多酸根中的8个氧原子键合,形成正方反棱柱配位多面体。Pr—O的平均键长为2.44(2)。钼硅杂多酸根配体具有缺位的α型Keggin结构。

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Nd(C_8H_(11))Cl_2·3THF与不同烷基铝〔Et_3Al,i-Bu_3Al,HAl(i-Bu_2)〕组成的催化体系可催化丁二烯聚合。实验结果表明,催化剂活性取决于所用的烷基铝、铝钕比和催化剂用量,而溶剂对催化活性影响不大。聚合物的微观结构则不受烷基铝种类、溶剂、铬钕比和催化剂用量的影响,均可得到高顺式(97—98%)聚丁二烯。

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2,4-二甲基戊二烯基的金属配合物在一些性质上可与相应的环戊二烯配合物相比拟。已报道了许多d过渡金属以及碱金属钾的配合物的晶体结构。对于镧系金属,仅Ernst等得到了2,4-二甲基戊二烯钕的配合物并测定了晶体结构,其晶格中含有无序的乙醚溶剂分子。本文报道了不含溶剂分子的Gd(2,4-C_7H_(11))_3,配合物在低温下的晶体结构。

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标题化合物K_8H〔BW_(11)O_(39)〕·13H_2O属立方晶系,空间群P43m,a=10.710(1)A,V=1228.58A~3,Z=1;D_O=4.39g·cm~(-3),D_c=4.42g·cm~(-3)。(BW_(11)O_(3.9)~(9-)离子属于不饱和α-Keggin型结构,B原子位于O_a四面体的中心。测定并研究了化合物的IR和Raman光谱性质。

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MSTN, also known as growth and differentiation factor 8 (GDF8), and GDF11 are members of the transforming growth factor-beta (TGF-beta) subfamily. They have been thought to be derived from one ancestral gene. In the present study, we report the isolation and characterization of an invertebrate GDF8/11 homolog from the amphioxus (Branchiostoma belcheri tsingtauense). The amphioxus GDF8/11 gene consists of five exons flanked by four introns, which have two more exons and introns than that of other species. In intron III, a possible transposable element was identified. This suggested that this intron might be derived from transposon. The amphioxus GDF8/11 cDNA encodes a polypeptide of 419 amino acid residues. Phologenetic analysis shows that the GDF8/11 is at the base of vertebrate MSTNs and GDF11s. This result might prove that the GDF8/11 derived from one ancestral gene and the amphioxus GDF8/11 may be the common ancestral gene, and also the gene duplication event generating MSTN and GDF11 occurred before the divergence of vertebrates and after or at the divergence of amphioxus from vertebrates. Reverse transcriptase polymerase chain reaction results showed that the GDF8/11 gene was expressed in new fertilized cell, early gastrulation, and knife-shaped embryo, which was different from that in mammals. It suggested that the GDF8/11 gene might possess additional functions other than regulating muscle growth in amphioxus.

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海洋浮游纤毛虫是在海洋中浮游生活的一类单细胞原生动物,主要是指寡毛类纤毛虫(Oligotrich ciliates),隶属原生动物界(Protozoa)、纤毛门(Ciliophora)、寡毛纲(Oligotrichea),分属于Oligotrichina 和Tintinnina两个亚纲。它们个体微小,粒径在5-200 µm之间,是微型浮游动物和海洋微食物环(Marine Microbial Food Web)的重要组成部分。 2006年4月至2007年12月,在黄海(包括胶州湾)采样分析海洋浮游纤毛虫的种类组成(砂壳纤毛虫)、丰度和生物量,分析纤毛虫在这一海区的季节变化和空间变化。 纤毛虫丰度和生物量的研究方法为:Rosette采水器(胶州湾用Niskin采水器)采集水样,取1 L水样,加Lugol’s试剂固定(终浓度1%),Utermöhl方法100倍镜检。测量虫体的体长、体宽,按最接近的几何形状(圆柱体、球体和圆锥体)计算体积。生物量由体积乘转换系数(0.19 pgC/µm3)得到,砂壳纤毛虫的肉体体积按照壳体积的1/3近似。 本文的结果表明,胶州湾各站纤毛虫平均丰度于6月达到全年最高值6065 ind./L,12月为全年丰度最低值843 ind./L。平均生物量8月达全年最高值(18.5 µg C/L),6月为全年最低值(0.6 µg C/L)。砂壳纤毛虫种丰富度于8月达到最高值,共发现25种砂壳纤毛虫,1月种类最少(6种)。湾内站位的纤毛虫平均丰度比湾外的高(6月和8月除外)。砂壳纤毛虫在纤毛虫总丰度中的比例较小,平均为25%,范围为8-57%,分别于1月和8月达到最低和最高值。 两次冷水团大面调查结果表明,4月表层纤毛虫平均丰度(1490 ind./L)要高于10月(972 ind./L)。10月表层纤毛虫生物量0.14-5.33 µg C/L,14194站、15694站和15894站生物量较高,为4.08-5.33 µg C/L。无壳纤毛虫优势种Laboea strobila在两个航次中均呈现斑块分布,4月航次丰度0-10000 ind./L,10月航次丰度11-350 ind./L;砂壳纤毛虫优势种Ptychocylis obtusa仅在4月航次发现,最大丰度2895 ind./L,10月航次未发现。4月航次砂壳纤毛虫有百乐拟铃虫(Tintinnopsis beroidea),丰度为0-1920 ind./L;卡拉直克拟铃虫(Tintinnopsis karajacensis),丰度很小(10-93 ind./L)。10月航次砂壳纤毛虫优势种Tintinnidium primitivum,丰度为35-700 ind./L;也出现了尖底类瓮虫(Amphorellopsis acuta)和网纹虫(Favella spp.),但丰度不大(0-210 ind./L);运动类铃虫(Codonellopsis mobilis)、筒状拟铃虫(Tintinnopsis tubulosoides)和Eutintinnus sp.丰度也较低(35-105 ind./L);Craterella torulata丰度为0-120 ind./L,主要分布于15694站。10月航次已经出现了温跃层,位于30 m左右水层,纤毛虫主要分布于温跃层之上。 六次黄海断面航次表明:温跃层在5月已经出现,到12月消失。在有温跃层的5月、6月、8月、9月,纤毛虫主要分布于温跃层(30 m左右)之上。其中8月份航次纤毛虫丰度最高,表层平均丰度3103 ind./L。12月份纤毛虫丰度最低,表层平均丰度406 ind./L。纤毛虫生物量春夏季为0.02-5.5 µg C/L,冬季为0.04-1.99 µg C/L。小型无壳纤毛虫占优势,砂壳纤毛虫东方拟铃虫(Tintinnopsis orientalis)、筒状拟铃虫、运动类铃虫、Craterella torulata和Tintinnidium primitivum几乎在各个航次均有分布。

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本文依据收集到的392个地面验潮站8个主要分潮(M2、S2、K1、O1、N2、K2、P1及Q1)的调和常数,对现有7个全球大洋潮汐模式的准确度进行了检验,结果显示各模式在深海区域均达到了比较高的准确度,相互之间差别也不大。经验模式GOT00和CSR4.0、同化模式NAO99、反演同化模式TPXO7.0、数值同化模式FES2002和FES2004的M2分潮均方根偏差在3 cm左右,其它分潮(S2、K1、O1、N2、K2、P1及Q1)大约在1~2 cm。本文还依据中国近海18个岛屿的调和常数对其中的5个大洋潮汐模式的准确度进行了检验,结果表明,M2分潮均方根偏差在6~14 cm,明显高于大洋部分的偏差,其中日本国家天文台的潮汐模式NAO99在中国近海的结果相对较准确。 我们利用1992年8月至2008年8月的TOPEX/POSEIDON和JASON-1(T/P-J)卫星高度计资料,对沿卫星轨道的302816个站点进行了14个分潮的潮汐调和分析,得到了全球大洋潮汐的8个主要分潮以及2个气象分潮Sa、Ssa的经验同潮图。主要结果有:(1)各分潮在卫星上升轨道与下降轨道的交叉点(约7000个)相关性分析表明:M2分潮的振幅和迟角的相关系数很高(分别为0.9965和0.9961);S2,K1,O1和Sa分潮也有较好的相关性(相关系数为0.94~0.99);(2)该结果与392地面个验潮站吻合较好,其中M2分潮的振幅、迟角和向量的均方根偏差分别为:1.73 cm,2.340和2.93 cm;S2,K1和O1分潮的振幅、迟角和向量的均方根偏差为1 cm左右,5.250~7.270和1.5~2.1 cm,该精度与最近几年国际上的主要大洋潮汐模式的准确度相近;(3)首次通过卫星资料获得了Sa、Ssa分潮的同潮图。周期为1年的Sa分潮与大洋105个地面站相比,振幅、迟角和向量的均方根偏差分别为1.50 cm、18.360和2.16 cm。在此基础上,进一步分析了构成Sa、Ssa气象分潮的两个主要因素(海水密度以及海面气压)在全球的分布。 在T/P-J等卫星资料无法覆盖到南大洋和北冰洋,本文利用Princeton Ocean Model(POM)进行了数值模拟,模拟结果与162个地面实测站(其中南大洋30个,北冰洋132个)的观测比较一致。基于卫星资料分析的结果和数值模拟结果合并得到了全球大洋的8个主要分潮同潮图。在此基础上通过全球潮汐能量耗散的计算得到潮能通量的分布,并得到全球M2、S2、K1和O1分潮的潮汐能量耗散率为2.431TW、0.401TW、0.336TW和0.176TW。 本文还利用卫星资料对南海潮汐进行了研究,在中国南海,获得了主要的半日潮、全日潮、四分日分潮和长周期分潮(M2,S2,N2,K2,K1,O1,P1,Q1,M4, MS4,Sa, Ssa)的经验同潮图。与南海沿岸94个地面验潮站的数据符合得比较好,M2,S2,K1及O1等4个主要分潮的平均振幅差为2~4 cm,均方根偏差分别是9~11 cm.其它4个主要分潮N2,K2,P1,Q1的平均振幅差为1~2 cm,均方根偏差为2~4 cm。此外,本文还利用卫星高度计资料潮汐分析结果沿卫星轨道进行高通滤波,分离得出中国近海的M2,S2,K1及O1分潮的内潮信息。

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文昌鱼是头索动物,被认为是现存的与脊椎动物最接近的无脊椎动物,经常被看作是分析从无脊椎动物到脊椎动物进化过程的一种重要的模式动物。在本研究中,我们克隆了青岛文昌鱼的GDF8/11、ACTIVIN和NM23-Bbt2基因,并对这些基因在不同胚胎发育时期和不同成体组织中的表达情况进行了分析,同时分析了这些基因的进化情况。 文昌鱼GDF8/11的基因组全长为9.9 kb,包括五个外显子和四个内含子,比其他物种多出两个外显子和两个内含子。在多出的第三个内含子中,我们分离出一个可能的转座因子,这表明这个内含子可能来源于转座子。文昌鱼GDF8/11 cDNA编码一个419个氨基酸的前体多肽,这个前体多肽与软体动物、硬骨鱼类、鸟类和哺乳动物的MSTN以及哺乳动物和斑马鱼的GDF11具有高同源性。系统分析表明文昌鱼GDF8/11位于脊椎动物MSTN和GDF11的根部,这个结果证实MSTN/GDF11来源于同一个祖先基因,并且文昌鱼GDF8/11可能就是他们的共同祖先,产生MSTN和GDF11的基因复制事件发生在脊椎动物分离之前和文昌鱼与脊椎动物分离之后或者分离时。RT-PCR结果表明GDF8/11基因在新受精的细胞、早原肠胚和刀形胚胎中表达,这与哺乳动物中的情况不同。这表明GDF8/11在文昌鱼中除了调节肌肉生长外还可能拥有其他的功能。 文昌鱼ACTIVIN的基因组序列长为6.1 kb,启动子大约长为447 bp,其基因组包括两个外显子和一个内含子,外显子/内含子边界严格遵守GT…AG的原则。文昌鱼ACTIVIN基因编码一个410个氨基酸的前体蛋白,前体蛋白包括信号肽、N-末端结构域和C-末端结构域。文昌鱼ACTIVIN基因演绎的氨基酸序列与脊椎动物比较发现ACTIVIN基因比较保守,特别是C-末端生物活性区。系统进化分析表明脊椎动物和无脊椎动物的ACTIVIN基因分别聚在一起,文昌鱼的ACTIVIN则位于脊椎动物ACTIVIN分支的根部,这表明文昌鱼ACTIVIN基因可能是脊椎动物ACTIVIN同源基因的祖先基因。 文昌鱼NM23-Bbt2 cDNA包括一个编码171个氨基酸的开放阅读框,序列分析表明文昌鱼NM23-Bbt2与其他物种高度保守,他们都包含高度保守的基元,并且这些基元在NM23的功能中扮演着重要的角色。RT-PCR分析表明文昌鱼NM23-Bbt2在所检测的组织和胚胎发育时期中的非特异性的表达模式。系统分析表明脊椎动物和无脊椎动物NM23-H2分别聚在一起,而文昌鱼NM23-Bbt2位于脊椎动物NM23-H2分支的根部,这表明文昌鱼NM23-Bbt2可能是脊椎动物NM23-H2同源基因的祖先基因。从无脊椎动物到脊椎动物的基因组结构比较表明五个外显子和四个内含子的基因组结构可能产生在文昌鱼与脊椎动物分离之前。

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以HNO_3-HClO_4回流消解样品,采用氢化物发生无色散原子荧光光谱法测定青藏高原药用动物角中的微量元素砷和汞。方法简便、快速、灵敏、准确。在实验条件下,26种共存元素其含量低于允许存在量,对测定无影响。检出限As 1.5 ng·mL~(-1),Hg 0.80 ng·mL~(-1);RSD (n = 11) As 1.2%~2.3%,Hg 2.5%~4.7%;标准回收率As 98.9%~103.8%,Hg 95.4%~105.0%。

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On a reversed phase Hypersil BDS C-18 (200 mm x 4. 6 mm, 5 mu m) column, 20 amino acids, which were derivatized using 2-(11H-benzo [a] carbazol-11-yl) ethyl carbonochloridate (BCEC-Cl) as pre-column derivatization reagent, were separated in conjunction with a gradient elution. Optimum derivatization was obtained by reacting of amino acids with BCEC-Cl at room temperature for 5 min in the presence of sodium borate catalyst in acetonitrile solvent. The fluorescence excitation and emission wavelengths were 279 nm and 380 nm respectively. The identification of amino acid derivatives from hydrolyzed bovine serum albumin and bee pollen was carried out by post-column mass spectrometry with electrospray ion source in positive ion mode. Linear correlation coefficients of the amino acid derivatives were > 0.9990, and detection limits (at signal to noise of 3:1) were 1.49 - 19.74 fmol for the labeled amino acids.

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A pre-column derivatization method for the sensitive determination of amines using a labeling reagent 2-(11H-benzo[a]-carbazol-11-yl) ethyl chloroformate (BCEC-Cl) followed by high-performance, liquid chromatography with fluorescence detection has been developed. Identification of derivatives was carried out by LC/APCI/MS in positive-ion mode. The chromophore of 1,2-benzo-3,4-dihydrocarbazole-9-ethyl chloroformate (BCEOC-Cl) reagent was replaced by 2-(11H-benzo[a]-carbazol-11-yl) ethyl functional group, which resulted in a sensitive fluorescence derivatizing reagent BCEC-Cl. BCEC-Cl could easily and quickly label amines. Derivatives were stable enough to be efficiently analyzed by HPLC and showed an intense protonated molecular ion corresponding m/z [M+ H](+) under APCI/MS in positive-ion mode. The collision-induced dissociation of the protonated molecular ion formed characteristic fragment ions at m/z 261.8 and m/z 243.8 corresponding to the cleavages of CH2O-CO and CH2-OCO bonds. Studies on derivatization demonstrated excellent derivative yields over the pH 9.0-10.0. Maximal yields close to 100% were observed with three- to four-fold molar reagent excess. In addition, the detection responses for BCEC-derivatives were compared to those obtained using 1,2-benzo-3,4-dihydrocarbazole-9-ethyl chloroformate (BCEOC-Cl) and 9-fluorenyl methylchloroformate, (FMOC-Cl) as labeling reagents. The ratios I-BCEC/I-BCEOC = 1.94-2.17 and I-BCEC/I-FMOC = 1.04-2.19 for fluorescent (FL) responses (here, I was relative fluorescence intensity). Separation of the derivatized amines had been optimized on reversed-phase Eclipse XDB-C-8 column. Detection limits calculated from 0.50 pmol injection, at a signal-to-noise ratio of 3, were 1.77-14.4 fmol. The relative standard deviations for within-day determination (n = 11) were 1.84-2.89% for the tested amines. The mean intra- and inter-assay precision for all amines levels were < 3.64% and 2.52%, respectively. The mean recoveries ranged from 96.6% to 107.1% with their standard deviations in the range of 0.8-2.7. Excellent linear responses were observed with coefficients of > 0.9996. (C) 2006 Elsevier B.V. All rights reserved.

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To assess carbon budget for shrub ecosystems on the Qinghai-Tibet Plateau, CO2 flux was measured with an open-path eddy covariance system for an alpine shrub ecosystem during growing and non-growing seasons. CO2 flux dynamics was distinct between the two seasons. During the growing season from May to September, the ecosystem exhibited net CO2 uptake from 08:00 to 19:00 (Beijing Standard Time), but net CO2 emission from 19:00 to 08:00. Maximum CO2 uptake appeared around 12:00 with values of 0.71, 1,19, 1.46 and 0.67 g CO2 m(-2) h(-1) for June, July, August and September, respectively. Diurnal fluctuation Of CO2 flux showed higher correlation with photosynthetic photon flux density than temperature. The maximum net CO2 influx occurred in August with a value of 247 g CO2 m(-2). The total CO2 uptake by the ecosystem was up to 583 g CO2 m(-2) for the growing season. During the non-growing season from January to April and from October to December, CO2 flux showed small fluctuation with the largest net CO2 efflux of 0.30 g CO2 m(-2) h(-1) in April. The diurnal CO2 flux was close to zero during most time of the day, but showed a small net CO2 eff lux from 11:00 to 18:00. Diurnal CO2 flux, is significantly correlated to diurnal temperature in the non-growing season. The maximum monthly net CO2 eff lux appeared in April, with a value of 105 g CO2 m(-2). The total net CO2 eff lux for the whole non-growing season was 356 g CO2 m(-2).

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In order to discover the distribution law of the remaining oil, the paper focuses on the quantitative characterization of the reservoir heterogeneity and the distribution law of the fluid barrier and interbed, based on fine geological study of the reservoir in Liuhuall-1 oil field. The refined quantitative reservoir geological model has been established by means of the study of core analysis, logging evaluation on vertical well and parallel well, and seismic interpretation and prediction. Utilizing a comprehensive technology combining dynamic data with static data, the distribution characteristics, formation condition and controlling factors of remaining oil in Liuhuall-1 oil field have been illustrated. The study plays an important role in the enrichment regions of the remaining oil and gives scientific direction for the next development of the remaining oil. Several achievements have been obtained as follows: l.On the basis of the study of reservoir division and correlation,eight lithohorizons (layer A, B_1, B_2, B_3, C, D, E, and F) from the top to the bottom of the reservoir are discriminated. The reef facies is subdivided into reef-core facies, fore-reef facies and backreef facies. These three subfacies are further subdivided into five microfacies: coral algal limestone, coralgal micrite, coral algal clastic limestone, bioclastic limestone and foraminiferal limestone. In order to illustrate the distribution law of remaining oil in high watercut period, the stratigraphic structure model and sedimentary model are reconstructed. 2.1n order to research intra-layer, inter-layer and plane reservoir heterogeneity, a new method to characterize reservoir heterogeneity by using IRH (Index of Reservoir Heterogeneity) is introduced. The result indicates that reservoir heterogeneity is medium in layer B_1 and B_3, hard in layer A, B_2, C, E, poor in layer D. 3.Based on the study of the distribution law of fluid barrier and interbed, the effect of fluid battier and interbed on fluid seepage is revealed. Fluid barrier and interbed is abundant in layer A, which control the distribution of crude oil in reservoir. Fluid barrier and interbed is abundant relatively in layer B_2,C and E, which control the spill movement of the bottom water. Layer B_1, B_3 and D tend to be waterflooded due to fluid barrier and interbed is poor. 4.Based on the analysis of reservoir heterogeneity, fluid barrier and interbed and the distribution of bottom water, four contributing regions are discovered. The main lies on the north of well LH11-1A. Two minors lie on the east of well LH11-1-3 and between well LH11-1-3 and well LH11-1-5. The last one lies in layer E in which the interbed is discontinuous. 5.The parameters of reservoir and fluid are obtained recurring to core analysis, logging evaluation on vertical well and parallel well, and seismic interpretation and prediction. Theses parameters provide data for the quantitative characterization of the reservoir heterogeneity and the distribution law of the fluid barrier and interbed. 6.1n the paper, an integrated method about the distribution prediction of remaining oil is put forward on basis of refined reservoir geological model and reservoir numerical simulation. The precision in history match and prediction of remaining oil is improved greatly. The integrated study embodies latest trend in this research field. 7.It is shown that the enrichment of the remaining oil with high watercut in Liuhua 11-1 oil field is influenced by reservoir heterogeneity, fluid barrier and interbed, sealing property of fault, driving manner of bottom water and exploitation manner of parallel well. 8.Using microfacies, IRH, reservoir structure, effective thickness, physical property of reservoir, distribution of fluid barrier and interbed, the analysis of oil and water movement and production data, twelve new sidetracked holes are proposed and demonstrated. The result is favorable to instruct oil field development and have gotten a good effect.

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利用硝酸盐氮氧同位素讨论地下水硝酸盐来源和转化是地下水硝酸盐研究的热点之一。本研究利用燃烧管法测试了贵阳地下水、部分地表水, 以及雨水中硝酸盐氧同位素, 结果表明地下水中硝酸盐D18O 冬季平均值为+ 12. 6‰±5. 6 (n= 17) , 夏季为+ 11. 1‰±4. 8 (n= 22)。结合氮同位素揭示了贵阳市地下水硝酸盐污染来源的季节性转化, 郊区地下水夏季主要受硝态氮肥等影响, 而市区地下水受人为排污影响严重。