44 resultados para 13627-011


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为结合一般白酒存在的杂醇油含量偏高或超标问题,作者试图寻找能嗜高醇类(含杂醇油)的有效菌株加以开发利用。本文研究了一株从富集分离、定向诱导得到的嗜异戊醇的W-2菌,该菌能以异戊醇或其它某些多碳醇作为唯一的碳源和能源进行生长。该菌在PH8.5的环境条件下,异戊醇的利用率可高达84.4%。此外,该菌还能广泛利用糖类、醇、有机酸、酯、盐等有机物作为唯一的碳源和能源。一般不利用—碳化合物。该菌具单极生鞭毛,呈杆状,适宜生长温度范围4℃—43℃。最适生长温度36℃,在PH4.0—11.0均能生长,最适生长PH为8.5—9.0,在培养基产生蓝绿色色素。W-2菌经形态,生理生化鉴定为假单胞菌属中的铜绿假单胞菌的一个变种。初步定名为Pseudomonas aeruginosa W-2。本文最后讨论了该菌的开发应用前景。

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Two bromo rhenium(I) carbonyl complexes with the formula of [Re(CO)(3)(L)Br], where L = 1,10-phenanthroline (Phen-Re) and 5-(1H-pyrrol-1-yl)-1,10-phenanthroline (Pyph-Re), were successfully synthesized with the aim to analyze the effect of the pyrrole (Py) moiety on the photophysical properties of Pyph-Re. It was found that the triplet metal-to-ligand charge-transfer d pi (Re) --> pi*(N-N) emission of Phen-Re and Pyph-Re centered at ca. 527 nm with the luminescence quantum yield (LQY) of 0.015 and ca. 578 nm with the LQY of 0.011, respectively. At the same time, the geometrical structures of the ground state and the absorption spectral properties of Phen-Re and Pyph-Re were also calculated with the 6-31G* basis set employed on C, H, N, O, and Br atoms, and LANL2DZ adopted on Re atom.

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A novel three-dimensional fluorinated gallium phosphate has been hydrothermally,synthesized by using diethylenetriamine as an organic structure-directing agent. X-ray single crystal structure analysis indicates this compound crystallizes in the orthorhombic space group P-bca, a = 1. 605 6 (7) nm, b = 1.011 4 (4) nm, c=1. 854 6(5) nm, V=3. 011 6(19) nm(3), Z=4. The three-dimensional framework based on linkage of corner-sharing polyhedron PO4, GaO4F and GaO4F2 delimit ten-ring channels along b axis in which the triply protonated amines are located serving as charge compensating guests and supporters.

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A nickel molybdenum phosphate, (NH3CH2CH2NH3)(4).(NH3CH2CH2NH2). Na .[Ni2Mo12O30(PO4)(HPO4)(4)(H2PO4)(3)]. 6H(2)O, invoicing molybdenum present in V oxidation, has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. Deep brown-red crystals are formed in the triclinic system, space group P (1) over bar, a = 12,011(2), b = 14,612(3), c = 21.252(4) Angstrom, alpha = 80.54(2)degrees, beta = 83.10(2)degrees, gamma = 76.29(2)degrees, V = 3561.4(12) Angstrom(3), Z = 2, lambda(MoK alpha) = 0.71073 Angstrom (R(F) = 0.0529 for 9880 reflections), Data mere collected on a Siemens P4 diffractometer at 20 degrees C in the range of 1.75 degrees < theta < 23.02 degrees using the omega-scan technique. The structure was solved by direct methods using the program SHELXTL-93 and refined with the method of fun-matrix least-squares on F-2. The structure of the title compound may be considered to be two [Mo6O15(HPO4)(H2PO4)(3)](5-) units bonded together with a nickel atom, although several P-O groups are not protonated on account of coordination with a Na+ cation, The one-dimensional tunnels were formed in the solid of the title compound. A probe reaction of the oxidation of acetaldehyde with H2O2 using the title compound as catalyst was carried out in a liquid- solid system, showing that the title compound had high catalytic activity in the reaction, (C) 1999 Academic Press.

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By electrocrystallization of 2,6-[4,5-bis(n-butylsulfanyl)-1,3-dithiol-2-ylidene]-4,8-bis(6-iodo-n-hexyloxy)-1,3,5,7-tetrathia-s-indacene (BHBDTI) and [NBu4](4)[SiMo12O40] in the mixed solvent CHCl2CH2Cl and CH3CN, the new radical-ion salt [C42H60Cl2O2S12](2)[SiMo12O40] was prepared. It was characterized by means of IR and ESR spectroscopy and X-ray diffraction. In the crystal structure, organic radical dications and silicomolybdate anions are alternatively arranged along the a axis to form a 1-D conducting layer. The organic layer consists of two isolated groups of BHBDTI divided by the (011) plane without short interatomic contacts. However, in each group, BHBDTI molecules associate with each other in a head to tail manner running along the [011] direction and face-to-face overlapping with a relative shift by approximately one TTF subunit along the long axis of the molecule and a slight shift along the short axis of the molecule with significantly short S ... S contacts. The room-temperature d.c. conductivity determined by the two-probe method is 10(-4) S cm(-1), suggesting that the compound is a semiconductor.

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The thermal properties and crystalline structure of the amphiphilic graft copolymers CR-g-PEG600, CR-g-PEG2000, and CR-g-PEG6000 using chloroprene rubber (CR) as the hydrophobic backbone and poly(ethylene glycol) (PEG) with different molecular weights as the hydrophilic side chains were studied by DSC and WAXD. The results showed that a distinct phase-separated structure existed in CR-g-PEGs because of the incompatibility between the backbone segments and the side-chain segments. For all the polymers studied, T-m2, which is the melting point of PEG crystalline domains in CR-g-PEG, decreased compared to that of the corresponding pure PEG and varied little with PEG content. For CR-g-PEG600 and CR-g-PEG2000, T-m1, which is the melting point of the CR crystalline domains, increased with increasing PEG content when the PEG content was not high enough, and at constant PEG content, the longer were the PEG side chains the higher was the T-m1. The crystallite size L-011 of CR in CR-g-PEGs increased compared to that of the pure CR and decreased with increasing PEG content. (C) 1997 John Wiley & Sons, Inc.

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研究海洋沉积有机物的早期成岩过程是海洋地球化学的重要内容,也是研究全球碳循环不可缺少的核心课题。本文通过模拟有机物在沉积物-海水界面的降解实验,研究了海洋藻类有机物在富含粘土沉积物中不同氧化还原条件下的降解过程及有机物稳定碳同位素比值的变化。通过为期245天的培养实验,我们分析测定了总有机碳(TOC)、脂肪酸、长链烷烃的含量随时间的变化以及总有机碳和单一脂肪酸化合物同位素组成的变化。结果表明粘土、沉积物氧化还原环境、微生物活动,化合物分子结构、有机物来源等是影响有机物降解的重要因素。藻类有机物在富含粘土沉积物中的降解是一个快速过程,其降解速率可以用简单的早期成岩公式(-dGt / dt = ∑kiGi)很好的描述。应用该模型计算了脂肪酸和长链烷烃的降解速率常数。其中脂肪酸的降解速率常数为0.011-0.119 d-1,低于已报道的用未添加粘土的海洋沉积物培养实验得到的速率常数值。该研究实验显示,粘土对沉积有机物有一定的吸附作用,从而对有机物的降解过程起到不同程度的保护作用。长链烷烃的降解速率常数比脂肪酸稍高,为0.013-0.158 d-1,该值与已报道的经水体降解后沉降到海洋沉积物中残余长链烷烃的降解速率常数相当。TOC,脂肪酸和长链烷烃的降解在氧化环境下比在还原环境下快。脂肪酸和长链烷烃的降解不仅受到环境因素的影响,其自身分子结构特征也是很重要的控制因素。脂肪酸化合物双键数目越多,降解的越快;长链烷烃的碳链越短,降解越快。沉积有机物的早期成岩过程对总有机碳及不同化合物的稳定碳同位素比值具有不同的影响。在245天的培养实验过程中,总有机碳稳定同位素比值(δ13C)有所降低,但变化范围不大且受环境影响较小。而几种主要脂肪酸的δ13C值有不同程度的变化趋势。14:0和16:1的δ13C值降低,18:1的δ13C值升高,而16:0和20:5的δ13C值基本保持不变。因此,在利用沉积物中的生物标志化合物碳稳定同位素研究有机物来源及古海洋生物地球化学过程时,应考虑到早期成岩作用对其同位素比值的影响。

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本论文研究了胶洲湾、东海和渤海的蓝细菌(Synechococcus)、生物量、异养细菌生物量和生产力的生态学特点。并在汇泉湾、渤海和东海用分极增减法对海洋蓝细菌在微型食物环(the microbial loop)中的作用进行了初步研究。在以上海区调查研究的时间如下:胶州湾:1993年2月、5月、9月11月,1996年5月、1999年3月、5月和12月。汇泉湾:1996年4月至1998年4月。东海:1997年2-3月,1998年7月。渤海1998年9-10月,1999年4-5月。研究结果如下:胶州湾:蓝细菌生物量的变化范围是11.4-0.03 mgC/m~3,季节变化是夏季>秋季和春季>冬季。其水平分布是除夏季蓝细菌生物量是沿岸浅水区向湾外递减外,其它三季(春、秋和冬季)是由湾外向湾内至沿岸浅水区递减。蓝细菌生物量与海水温度周年变化正相关,与季节海水温度的关系是秋、冬季分布变化一致,春、夏季分布变化相反。海水温度是影响胶州湾蓝细菌生物量分布变化的主要原因。异养细菌生物量和生产力的变化范围分别是29.8-1.62 mgC/m~3; 129.12-1.92 mgC/m~3.d。季节变化都是夏季>秋季、春季>冬季。夏季的异养细菌生物量和生产力水平分布趋势与蓝细菌生物量的分布变化相同。海水温度对异养细菌生产力的影响较对异养细菌生物量的影响大。异养细菌生产力相比(BP:PP)的变化在0.58-0.02之间,季节分布变化是夏季>秋季、春季>冬季。夏季表层的BP:PP由沿岸浅水区向湾心、湾口和湾外递减。东海:蓝细菌生物量的变化范围是46.72-0.011 mgC/m~3,夏季高平均是23.59 mgC/m~3,冬季低平均是3.61 mgC/m~3。冬季蓝细菌生物量的水平分布明显受黑潮的影响,在表面和20米层是由东南向西北方向递减。其垂直分布是冬季表层和20米层>底层,夏季是20米层>表层>底层;在连续站冬111站和410站变化都是中层>底层>表层。异养细菌生物量和生产力的变化范围分别是17.2-4.4 mgC/m~3(1997.2);376.8-7.2 mgC/m~3.d。异养细菌生产力夏季高平均是35.1 mgC/m~3.d。异养细菌生物量的水平分布是由沿岸向外海递增(1997.2),异养细菌生产力的水平分布是冬季异养细菌生产力在32度断面有由沿岸向外递减趋势,PN断面的变化与冬季相似。垂直分布,冬季和夏季的异养细菌生产力的垂直变化在2断面是底层大于表面,PN断面则是表层大于底层,32度断面大多断站是底层大于表层。在连续站冬季111站异养细菌生产力的变化是底层>中层>表层,409站的变化是中层>底层>表层,夏季111站和410站都是中>底层>表层。异养细菌生物量(1997.2)表层分布变化与海水温度分布变化相似,底层变化相反。异养细菌生产力与初级生产力相比(BP:PP),冬季在0.04-0.30之间,平均为0.17;夏季在0.20-0.43之间平均0.32。冬季在长江口附近BP:PP有一个高值区是0.30,夏季在111站附近有一个高值区是0.43。从连续站111站和409’站观测发现底层的BP:PP明显高于表层。渤海:蓝细菌生物量秋季(16.6-0.37 mgC/m~3)比春季(0.44-0.015 mgC/m~3)高。其秋季的水平分布与海水盐度水平分布相同,与海水温度水平分布相反。异养细菌生产力秋季(189-62.2 mgC/m~3.d)与春季(193.2-49.8 mgC/m~3.d)相当。但秋季捕层BP普遍小于底层,而春季是表层普遍大于底层。根据颗粒分级培养实验结果,海洋蓝图细菌在微型食物环中的作用如下:在汇泉湾的春季和秋季蓝细菌可能主要被小型浮游动物(microzooplankton 20-200 μm)捕食。在渤海的春季和秋季也是同样结果。但在东海夏季的111站和410站附近(东海大陆架中部)微型浮游动物(nanozooplankton 2-20 μm)对蓝细菌的捕食压力明显。

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利用AFLP标记对海带在太平洋西北沿岸的6个主要栽培品系和6个野生地理隔离种群进行遗传多样性和亲缘关系分析。通过10对选择性引物总共检测到547个位点。在品系和种群水平,多态性位点比例(P),基因多样性(H)和香农指数(I)在大连野生种群中最高(P: 59.05%; H: 0.2057; I: 0.3062),而在连江栽培品系中最低(P: 9.87%; H: 0.0331; I: 0.0497)。在物种水平(即对所有品系和种群来说),P, H 和I 的值分别是85.01%,0.1948和0.3096。以个体间的相似系数(Dice)和种群间的遗传距离为基础,用非加权类平均法(UPGMA)分别构建个体和种群间的系统树图。AMOVA分析显示,大部分的遗传变异(60.21%)存在于品系和种群间,少部分(39.79%)存在于品系或种群内。遗传分化系数GST的值是0.6226,与FST的值(0.6021)非常接近,基因流(Nm)的值是0.1515,这三个值表明种群(品系)间存在高度的遗传分化。Mantel检验发现6个野生种群的遗传距离或遗传分化与地理距离呈正相关性(相关系数分别是r=0.8870, P=0.007 和 r=0.7962, P=0.011),符合“距离隔离(isolation by distance, IBD)”模型。总体来说,种群(品系)内的遗传多样性处于低到中等水平(大连种群除外),而它们之间的遗传分化程度非常高。 用AFLP和微卫星标记对裙带菜配子体克隆单一交配组合的孢子体后代的遗传一致性进行分析。在这项研究中,建立了2个配子体克隆单一交配系(M1和M2),2个自交系(S1和S2)并采集1个野生种群(W)。11组AFLP引物总共检测到318个位点。M1, M2, S1, S2 和W的多态性位点比例分别是4.7%,0.3%,17.9%,16.4%和36.5%。M1和M2个体间的遗传相似度(95.6-100%)要高于S1和S2(87.7-98.4%)以及W(81.5-92.1%)。在微卫星分析中,用了6个位点。M1在其中的5个位点基因型一致,而在Up-AC-2B2位点显示出不同的基因型。M2在所有6个微卫星位点的基因型都一致。而S1, S2和W都在2个以上的位点检测到不同的基因型。总之,AFLP与微卫星的分析结果一致,即配子体克隆单一交配组合的孢子体后代呈现高度遗传相似性,但也存在细微的差异。 对中国羊栖菜主产区浙江省洞头县的12个羊栖菜养殖品系的重要形态特征进行了比较研究,并利用AFLP技术对一个典型养殖种群的遗传多样性进行了分析。结果显示,这12个品系在全长、全湿质量、侧枝长、侧枝湿质量、侧枝密度等方面存在显著或极显著差异(P<0.05或P<0.01)。8组AFLP引物在这个典型养殖种群中扩增出198个片段,其中多态性片段为166个,多态性位点比例为83.8%。根据个体间的遗传距离,以UPGMA法构建了个体间的系统树图,27个羊栖菜个体聚为一枝,作为对照的铜藻为另一枝。本研究从形态和DNA分子水平说明了浙江洞头羊栖菜养殖种群具有高度遗传多样性。

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能量代谢指动物在进行生理活动(如摄食、消化以及动物的活动等)时所消耗能量的总和,一般以动物的呼吸率利排泄率来估计动物的能量代谢。其主要研究内容是闸明生物能量代谢的基木规律以及与环境闪子的关系。菲律宾蛤仔(Ruditapesphil ippmarum)是我国一种重要的养殖贝类,关于其能量代谢的研究却较少,这种状况妨碍了菲律宾蛤仔养殖生态理论的完善和养殖技术的提高。本研究主要对菲律宾蛤仔呼吸率和排泄率的基本规律(能量代谢与体重的关系、能量代谢的昼夜变化)及其与环境因子(饵料浓度、水温、栖息底质环境)的关系进行探讨。研究结果如下:1.不同体重菲律宾蛤仔代谢率小同。实验川菲律宾蛤仔分三种大小:l(干肉重为0.07-0.14g)、ll(干肉重0.27-0.34g)、III(干肉重0.45~0.63g)。温度包括:26℃(八月)、20℃(十月)、1 5℃(十二月)、9℃(一月)。实验共设四个饵料浓度:2.28±0.25,6.454±0.44,10.284±0.82,15.414±1.56mgTPM/L(TPM,总颗粒物),饵料中POM(颗粒有机物)含量都为4.68±1.64 mg/L。常温下菲律宾蛤仔代谢率随着体重的增大而增大。15℃、20~C、26℃时蛤仔呼吸率与干肉重呈明显的幂函数关系R=aW~b,a值变动范围为0.1076-0.3309;b值变动范围为0.239l~0.8381;蛤仔排泄率与干肉重也呈明显的幂函数关系N=aW~b,a值变动范围为14.213~68.362:b值变动范围为0.3673-1.1 532。9℃(饵料浓度为2.28±0.25mgTPM/L)、20℃(饵料浓度为10.284-0.82mgTPM/L)、26℃(饵料浓度为6.454±0.44mgTPM/L)时不同体重蛤仔氧氮比差异显著,其它情况下不同体重蛤仔氧氮比差异不显著。2.常温下菲律宾蛤仔代谢率受饵料浓度的影响,不同大小蛤仔受饵料浓度的影响程度不同。I组蛤仔呼吸率受饵料浓度的显著影响,II组III组蛤仔呼吸率只在9℃(一月)和26~C(八月)时受饵料浓度的显著影响。26℃时影响最显著,26℃时I组蛤仔在饵料浓度为2.28±0.25,6.45±0.44,l0.28±0.82,15.4l±1.56mgTPM/L时呼吸率分别是O.086,0.146,0.073,0.093(mlO_2/h);ll组蛤仔在上述浓度饵料中呼吸率分别是0.138,0.214,0.J 26,0.12l(mlO_2/h);III组蛤仔在上述浓度饵料中呼吸率分别是0.129,0.266,0.186,0.192(mlO_2/h)。菲律宾蛤仔呼吸率在饵料浓度为6.45±0.44 mgTPM/L时最高,蛤仔呼吸率在其它饵料浓度时都会降低。菲律宾蛤仔排泄率在饵料浓度为10.28±0.82 mgTPM/L和15.4l士1.56mgTPM/L时显著高于其它浓度组,9℃时这种趋势更明显,9℃时饵料浓度为2.28±0.25,6.454±044,lO.284±0.82,15.41±1.56mgTPM/L中I组蛤仔排泄率分别是4.297,2.874,8.003,6.658(μgNH_3-N/h);II组蛤仔在上述浓度饵料中排泄率分别是4.011,3.609,10.427,12.732(μgNH_3-N/h);III组蛤仔在上述浓度饵料中排泄率分别是2.28 l,6.452,10.283,15.417(μgNH_3-N/h)。3.菲律宾蛤仔代谢率受自然温度的显著影Ⅱ向。I组蛤仔在9℃、15℃、20℃、26℃时呼吸率平均为0.057,0.085,0.039,O.099;II组蛤仔在上述四个温度中呼吸率平均为0.08,O.128,0.089,0.149(mlO_2/h),I组和II组蛤仔在9℃和20~C时呼吸率较低,在26℃时呼吸率最高。III组蛤仔在上述四个温度中呼吸率平均为0.09,O.1 59,O.143,O.193(mlO_2/h),在9℃时llI组蛤仔呼吸率显著低于其它温度组。温度为9℃、15℃、20℃、26℃时l组蛤仔排泄率平均为5.458,13.169,4.946,11.138(μgNH_3-N/h):II组蛤仔在上述温度中排泄率平均为7.695,23.578,8.319,23.90l(μgNH_3-N/h);III组蛤仔在上述温度中排泄率平均为11.738,27.443,15.658,35.407(μgNH_3-N/h),蛤仔排泄率在15℃和26℃时均高于9℃和20℃。4.摄食状态与饥饿状态菲律宾蛤仔代谢率有明显不同。26℃时蛤仔静止状态呼吸率平均为0.336(m102/g干重.h),摄食状态呼吸率平均为0.656(ml0_2干重.h),摄食状态呼吸率比静止状态平均升高了0 32(ml0_2/g干重.h);26℃时蛤仔静止状态排泄率平均为39.471(μgNH_3-N/g干重.h),摄食状态排泄率平均为88.08(μgNH_3-N/g干重.h),摄食状态排泄率比静止状态排泄率平均升高了48.6(μgNH_3-N/g干重.h)。摄食状态代谢率平均是静止状态的2~3倍。根据摄食引起的呼吸率和排泄率升高量得出每氧化产生lμgNH_3-N需0_2量平均为7.05μl。5.人工控制温度对菲律宾蛤仔代谢率有明显影响。不同大小蛤仔受温度的影响程度不同。在温度5℃、10℃、l 5℃、20℃、26℃,I组和II组蛤仔呼吸率都随着温度的升高而升高,在10℃~l5℃和20℃~26℃这二个温度变化范围内呼吸率变化最大,在20℃~26℃时I组蛤仔呼吸率变动范围为O.85~1.04(m10_2/g干重.h)、II组蛤仔变动范围为0.57~0.86(ml0_2/g干重.h)。III组蛤仔呼吸率只在5℃~l0℃时明显增高,变动范围为0.09~0.5l(m10_2/g干重.h),在10℃~26℃范围内变化不大。I组和II组蛤仔排泄率随着温度的升高而升高,变动幅度较大,在5℃~26℃范围内其排泄率变动范围为10.32~81.53(μgNH_3-N/g干重.h);而 III组蛤仔排泄率只在5℃~15℃时随着温度的升高而升高,其排泄率变动范围为6.75~23.77(μgNH_3-N/g干重.h),在15℃~26℃范围内几乎不变。III组蛤仔的适温范围比I组和II组蛤仔广。菲律宾蛤仔在5℃和10℃时氧氮比变化明显,变动范围为2.76~11.44,在15~26℃时变化不大。6.菲律宾蛤仔代谢率有明显的日节律性,呈正弦曲线型变化。蛤仔夜问代谢率明显升高。I组蛤仔夜间呼吸率平均为0.867(m10_2/g干重.h),白天呼吸率平均为O.504(m10_2/g干重.h);II组蛤仔夜间呼吸率平均为0.438(m10_2/g干重.h),白天呼吸率平均为0.36l(m102/g干重.h);III组蛤仔夜间呼吸率平均为0.409(m10_2/g干重.h),白天呼吸率平均为0.252(m102/g干重.h)。在22:00-23:00菲律宾蛤仔呼吸率最高。7.底质环境对菲律宾蛤仔的代谢率有明显影响。在饥饿状态下菲律宾蛤仔在泥沙底质中呼吸率平均为l 406(m10_2/g干重h),在无泥沙环境中呼吸率平均为O.963(ml0_2/g干重.h);摄食状态下菲律宾蛤仔在泥沙底质中呼吸率平均为1.59l(m102/g干重.h),在无泥沙环境中呼吸率平均为1.115(m10_2/g干重.h)。在饥饿状态下菲律宾蛤仔在泥沙底质中排泄率平均为78.934(μgNH_3-N/g 干重.h),在无泥沙环境巾排泄率平均为45.043(μgNH_3-N/g干重.h);摄食状态下菲律宾蛤仔在泥沙底质中排泄率平均为87.12l(μgNH_3-N/g干重.h),在无泥沙底质中排泄率平均为58.354(μgNH_3-N/g干重.h)。蛤仔在泥沙环境中呼吸率和排泄率都明显升高。

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通过野外控制实验,研究了高寒矮嵩草草甸群落植物多样性、初级生产力对模拟降雨条件的响应.结果表明:(1)在植物生长期(6月),增加降雨20%、增加降雨40%,植物群落物种多样性指数(H)和均匀度指数(J)分别比对照提高了0.188和0.011、0.735和0.076,生长期(7月)增加降雨20%物种H和J提高了0.409和0.07;(2)禾草类:增加降雨20%处理的地上生物量与对照相比没有明显的显著性差异(P>0.05),增加降雨40%处理的地上生物量与对照相比差异显著(P<0.05),说明过多增加降雨会抑制禾草的生长发育.杂类草:减少降雨50%处理的地上生物量与对照相比差异显著(P<0.05),其地上生物量对减少降雨的反映比较敏感.莎草类:其地上生物量对增加和减少降雨都没有显著变化;(3)0~10 cm和0~30 cm土层地下生物量均在增加降雨20%时最高,地下生物量的总量也在增加降雨20%时最高;(4)矮嵩草草甸地下生物量与地上生物量、总生物量的比值接近于生长季末时最大,且在模拟增加降雨20%的水平时,7、8、9月份地下和地上生物量较其它处理组高.

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在恩施富硒碳质岩和土壤样品中硒矿物学研究的基础上,提出了硒连续化学提取的改进方案。化学操作上定义为7个连续步骤:水溶态(MQ 水提取) 、可交换态(0. 1 mol/ L 的K2 HPO4 + KH2 PO4 ,p H = 7. 0) 、有机结合态(011 mol/ L NaOH) 、元素态(1 mol/ L Na2 SO3 溶液) 、酸溶性提取态(15 % CH3CO2 H 溶液) 、硫化物/ 硒化物态(1 mol/ L CrCl2 + HCl 溶液) 和残渣态硒( HNO3 + HF + H2O2 混合消化液) 。使用HGOAFS 法检测了各结合态中的硒形态和总硒,上述流程提取硒加和与总硒间显著一致,平均回收率为9912 % ,符合平行样品间变异系数低于10 %的精度要求。该方法简单易行,能够准确地揭示富硒地质样品中硒的形态信息。

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Objective: Type 2 diabetes patients’ performances of action memory , semantic memory and working memory and the related factors were explored. Methods: 60 Type 2 diabetes patients were compared with 60 age and gender and level of education matched non-diabetes controls. Mood were tested by SAS and SDS, MMSE was used to test the basic cognitive function, Trail Making Test A and B, Verbal fluency test, Go-No/Go test, and Stroop color-word test were used to investigate the executive function of Type 2 diabetes patients and normal controls (NC). Patients’ GLU, TG, TCH, HbA1c, insulin and Cp were tested and correlated with their action memory and working memory. Results: There was no difference between NC group and Type 2 diabetes patients in MMSE scores. There is depression and anxiety mood in Type 2 diabetes patients. Type 2 diabetes patients get lower score in action memory test. Comparing to NC group, Type 2 diabetes patients performed significantly worse in Trail Making Test A and B and verbal fluency test. In Stroop Test, NC group showed significant Stroop Effect and Repeated Distraction Promotion Effect and Negative Priming Effect. However, In Type 2 diabetes group, only the Stroop Effect appeared, but no Repeated Distraction Promotion Effect and Negative Priming Effect. There is no difference between Type 2 diabetes and NC in Stroop Effect. In Go-No/Go test, both of two groups showed significant Stroop Effect, however, there was no difference between them. And also there is no difference on error rate of all levels between them. The course of disease, GL, HbA1c, TG, TCH, INS and Cp affected action memory and working memory. Conclusion: Type 2 diabetes patients’ action memory, semantic memory and working memory were partially impaired. Controlling the levels of GLU, TG and TCH can delay these kinds of impairment.