911 resultados para Ovidio Nasón, Publio, 43 a.C.-17 d.C.


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本文根据我们实验室建立的发酵产物中辅酶Q10定性定量检测方法,筛选得到一株可以代谢产生较多辅酶Q10的野生菌株放射形土壤杆菌(Agrobacterium radiobacter No.50)。 为了提高放射形土壤杆菌的辅酶Q10的产量,本实验利用液体培养研究了单因素对菌株辅酶Q10产量的影响,并用正交法确定了最佳液态发酵条件。最佳发酵培养基是:葡萄糖20g,蔗糖40g, 硫酸铵10g,玉米浆30g, 酵母膏3g,K2HPO4 3g,MgSO4.7H2O 1g,蒸馏水1000mL,pH 7.0-7.2。最佳发酵条件是:转接斜面菌种到种子培养基, 转速220r/min、温度28。C培养24h后,转入发酵培养基(250mL三角拼装液量为50mL,pH 7.0), 接种量为10%,转速220r/min、温度28。C,培养120h。在此条件下,菌体湿重约为50g/L,辅酶Q10含量约为20mg/L。 本文以放射形土壤杆菌为出发菌株进行诱变育种,以期获得辅酶Q10高产菌。根据微生物育种原理、参照辅酶Q10的代谢调控机制,以野生型放射形土壤杆菌(Agrobacterium radiobacter No.50)为出发菌株,采用紫外线和亚硝基胍复合诱变技术,依次筛选得到菌体提取物M抗性菌ARM-7、烟草提取物T抗性菌株ARMT-26、Vk3抗性菌株ARMTV-25、链霉素抗性菌株ARMTVS-32,菌株ARMTVS-32产量达到了36.8mg/L,与原始出发菌株相比,产量提高了77%。 研究了茄尼醇、对羟基苯甲酸、橘子皮提取物D、胡萝卜提取物E、烟草提取物对ARMTVS-32合成辅酶Q10的影响,结果表明这些物质对菌体合成辅酶Q10有一定促进作用,添加0.2g/L茄尼醇时,辅酶Q10含量提高了17%,达到了40.7mg/L;添加1.2g/L橘子皮提取物D时,辅酶Q10含量提高了13.8%,达到了39.6mg/L;添加0.5g/L胡萝卜提取物E时,辅酶Q10含量提高了25.3% ,达到了43.6mg/L;添加8g/L烟草提取物时,辅酶Q10含量提高了12.6%,达到了39.2mg/L。 Production of Coenzyme- Q10 (CoQ10) by fermentation is considered as a process with broad prospects.Quantitative Analysis of CoQ10 in the culture of microbe by TLC—UV spectrophotometry was developed, by using this method we got the strain Agrobacterium radiobacter,which was isolated from forest soil of southwest of China. The effect of the single factor on CoQ10-production ability of the strain was examined by liquid cultured, and its best optimum cultivation conditions were established by orthogonal method. The results showed that the optimum fermentation conditions were as following: carbon sources glucose 20g/L,sucrose 40g/L; nitrongen sources (NH4)2SO4 10g/L,maize liquid 30g/L;yeast extract 3g; K2HPO4 3g/L,MgSO4.7H2O 1g/L; initial pH was 7 and volume of medium(medium volume vs flask volume) was 50mL/500mL, incubating for 120h on a rotary shaker at 220 rpm and 28℃.Under these conditions, the biomass and CoQ10 concentration reached 50g/L and 20mg/L respectively. According to the biosynthesis mechanism of CoQ10 and breeding theory, CoQ10 over-production strains were screened by UV--NTG. mutation using Agrobacterium radiobacter No.50 as parent strain. A microbe-juice resistant mutant ARMTVS-32, which also could resist tobacco-juice, VK3 and streptomycin, was screened out from an agar plate. The CoQ10 content of ARMTVS-32 reached 36.8mg/L, which was 77% higher than the initial strain. In addition, We discussed the effects of some organic substrates on the synthesis of CoQ10 in ARMTVS-32. The results showed that solanesol, orange juice D, carrot juice E and tobacco juice could promote the CoQ10 accumulation in the cells. The CoQ10 content of ARMTVS-32 reached 40.7mg/L when added 0.2g/L solanesol,it reached 39.6mg/L when added 1.2g/L orange juice D,it reached 43.6mg/L when added 0.5g/L carrot juice E. it reached 39.2mg/L when added 8g/L tobacco juice.

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实验利用束流衰减法测量了43.7AMeV丰中子核17B与C靶反应的总截面σR=(1724±93)mb.用零程Glauber计算,假定17B具有核芯15B和两个价中子结构,输入GG和GO密度分布,计算的激发函数曲线与该实验数据很好符合,输入描述稳定核双参数Fermi密度分布,不能得到与实验数据符合的结果,表明17B是核芯15B+2n的假定是合理的.并且中子密度分布表现较大空间扩展-晕结构特征.

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应用透射法对中能区F同位素与C靶的反应总截面进行了测量 .发现17F的反应总截面比其邻近同位素的反应总截面稍有增强 .用Glauber模型和BUU模型对F同位素进行了差异因子d的分析 .17F的差异因子d比其附近同位素稍有增强 .分析结果表明17F可能存在质子皮结构 .

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A measurement of the inelastic component of the key astrophysical resonance in the 14O(α,p)17F reaction for burning and breakout from hot carbon-nitrogen-oxygen (CNO) cycles is reported. The inelastic component is found to be comparable to the ground-state branch and will enhance the 14O(α,p)17F reaction rate. The current results for the reaction rate confirm that the 14O(α,p)17F reaction is unlikely to contribute substantially to burning and breakout from the CNO cycles under novae conditions. The reaction can, however, contribute strongly to the breakout from the hot CNO cycles under the more extreme conditions found in x-ray bursters.

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The total reaction cross section (1724 +/- 93 mb) of B-17 at the energy of 43.7 A MeV on C target has been measured by using the transmission method at the Radioactive Ion Beam Line in Lanzhou (RIBLL). Assuming B-17 consists of a core B-15 plus two halo neutrons, the total cross section of B-17 on C target was calculated with the zero-range Glauber model, where double Gaussian density distributions and Gaussian plus HO density distributions were used. It can fit the experimental data very well. The characteristic of halo structure for B-17 was found with a large diffusion of the neutrons density distribution.

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The reaction cross section of B-17 on C-12 target at (43.7 +/- 2.4) MeV/u has been measured at the Radioactive Ion Beam Line in Lanzhou (RIBLL). The root-mean-square matter radius (R-rms) was deduced to be (2.92 +/- 0.10) fm, while the R-rms of the core and the valence neutron distribution are 2.28 fm and 5.98 fm respectively. Assuming a "core plus 2n" structure in B-17, the mixed configuration of (2s(1/2)) and (1d(5/2)) of the valence neutrons is studied and the s-wave spectroscopic factor is found to be (80 +/- 21)%.

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In this work, we systematically study the interaction of D* and nucleon, which is stimulated by the observation of Lambda(c)(2940)(+) close to the threshold of D* p. Our numerical result obtained by the dynamical investigation indicates the existence of the D* N systems with J(P) = 1/2(+/-), 3/2(+/-), which not only provides valuable information to understand the underlying structure of Lambda(c)(2940)(+) but also improves our knowledge of the interaction of D* and nucleon. Additionally, the bottom partners of the D* N systems are predicted, which might be as one of the tasks in LHCb experiment.

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Langmuir-Blodgett (LB) films of octadecylammonium octadecanoate (C(18)H(37)j7NH(3)(+)C(17)H(35)COO(-),ODASA) and octadecylammonium octadecanoate-d(35) (C18H37+NH3+C17D35COO-, ODASA-d(53)) were prepared and their thermal behaviors were investigated by variable-temperature Fourier transform infrared transmission spectroscopy. It was found that the two hydrocarbon chains of ODASA molecule in LB films are highly ordered while that protonated (H) chain in ODASA-d(35) is partially disordered with some gauche conformers introduced at room temperature.

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A bilayer CdS/ITO film was obtained. The dipped CdS was grown by an ultrasonic colloid deposition (USCD) method. Microstructure of the CdS film made by USCD has a wider transmission range and a higher transmittance. Amorphous indium-tin-oxide (ITO) thin film was deposited using d.c. magnetron-sputtering at room temperature. The ITO films exhibited good conductivity and maximum transmittance of 94%. The CdS/ITO bilayer was investigated by means of GIXD (grazing incidence X-ray diffraction) at different incidence angles (alpha = 0.20-5.00degrees) and XRD. We discuss a model for the thin bilayer film. SEM and AFM show that homogeneous CdS films with a bar-shaped ultrafine particles and ITO film with nanometer structure. The mechanism of the bilayer CdS/ITO film is discussed.

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Cp2SmCl(THF) reacts with 0.5 equivalent disodium salts of trans-(+/-)-N,N'-bis(salicylidene)-1,2-cyclohexanediamine give the title complex [(eta(5)-C5H5)Sm(mu-OC20H20N2O)](2)(mu-THF)(THF)(2) (1). X-ray crystal determination shows that the molecule is a dimer, in which two (eta(5)C(5)H(5))Sm(mu-OC20H20N2O) units are connected via a THF oxygen and two bridging oxygen atoms of Schiff base ligands. The average Sm-C distance is 2.78(7) Angstrom, while those of Sm-O (bridging THF oxygen) and Schiff base oxygens are 2.79(3) and 2.43(4) Angstrom; respectively. (C) 1998 Elsevier Science Ltd. All rights reserved.

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The reaction of GdCl3 with 1 equiv of NaC5Me5 generates a neutral complex C5Me5GdCl2(THF)3 and a novel complex {Na(mu-2-THF)[(C5Me5)Gd(THF)]2(mu-2-Cl)3(mu-3-Cl)2}2.6THF whixh recrystallizes from THF in triclinic, the space group P1BAR with unit cell dimentions of a 12.183(4), b 13.638(6), c 17.883(7) angstrom, alpha-110.38(3), beta-94.04(3), gamma-99.44(3)-degrees, V 2721.20 angstrom-3 and D(calc) 1.43 g cm-3 for Z = 1. Least-squares refinement of 2170 observed reflections led to a final R value of 0.047. The title complex consists of two Na(mu-2-THF)[(C5Me5)Gd(THF)]2(mu-3-Cl)3(mu-3-Cl)2 units bridged together via two mu-2-THF to Na coordination. Each Gd ion is surrounded by one C5Me5 ligand, two mu-3-Cl, two mu-2-Cl and one THF in a distorted octahedral arrangement with average Gd-C(ring) 2.686(33), Gd-mu-2-Cl 2.724(7), Gd-mu-3-Cl 2.832(8) and Gd-O 2.407(11) angstrom. The sodium ion coordinates to two bridging THF, two mu-2-Cl and two mu-3-Cl to form a distorted octahedron with average Na-mu-2-O, Na-mu-2-Cl and Na-mu-3-Cl of 2.411(21), 2.807(15) and 2.845(12) angstrom, respectively.

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正确认识降水中的化学组分是评价酸雨和大气环境质量的重要途径,降水中低分子有机酸的研究是认识C、H、O等元素生物地球化学循环和酸雨成因的重要内容。贵州省遵义市作为我国酸雨高发地区,是降水化学组成尤其是低分子有机酸地球化学循环研究的典型区域。我们在遵义市进行了为期一年(2006年5月~2007年4月)的降水采集(共76个样品),对pH值、电导率和主要的阴离子(包括有机和无机)、阳离子进行了测定,并进行了分析和讨论。 (1) pH和电导率的雨量加权平均值分别为4.11(范围:2.30~ 6.04)和62.10 μs•cm-1 (范围:6.60 ~ 1630.00 μs•cm-1),酸雨频率高达93.2%,pH存在着显著的季节变化,其中冬季pH值最低,表明遵义市酸雨污染较为严重,冬季为最。 (2) 遵义市监测期间离子浓度的大小顺序为SO42-> Ca2+> H+> NH4+> NO3-> Cl-> F->HCOO-> Mg2+> K+> CH3COO-> Na+> (COO)22-> PO43-> NO2-,其中SO42-、Ca2+、H+、NH4+、NO3-是最主要离子,浓度分别为148.15 μmol•L-1、81.89 μmol•L-1、77.74 μmol•L-1、43.80 μmol•L-1和31.50μmol•L-1,它们分别占离子总量的31.97%、17.67%、16.78%、9.45%和6.54%;遵义市大气降水中主要的致酸物质是SO42-和NO3-,主要的缓冲物质是Ca2+和NH4+,大气污染类型属硫酸钙型。相对酸度和中和因子结果表明降水中仅有77%的降水酸度被碱性物质(以Ca2+和NH4+为主)中和;因子分析中H+、NO3-、nss-SO42-(非海源性硫酸根)、NH4+归为一组,再次表明SO42-和NO3-对降水酸度的重要贡献。富集系数和源的贡献分析表明,SO42-和NO3-主要来自人为活动的贡献,SO42-来源主要包括工业、民用的燃煤燃烧释放的SO2,NO3-主要是遵义市电厂和其它工厂向大气中排放的NOx的化学转化而成。Ca2+主要来自于遵义市的土壤及水泥厂等的排放;Mg2+主要来自陆源输入,部分来自海水的贡献。氮肥生产、大面积农田化肥的使用以及生物排放源很可能是该地区降水中NH4+的主要污染源。值得注意的是,作为海盐性离子的Cl-,在遵义市降水中重要的部分还是人为活动,主要是遵义工厂(如碱厂和钛厂)向大气中排放的HCl和Cl2转化而成。无机离子浓度的季节变化表明,对于遵义市,需要逐步改变能源结构尤其是冬季工业、居民燃煤的使用,才能有效地改善遵义市当前的环境污染。 (3) 遵义市降水中含量较高的常见有机酸是[HCOO-]T、[CH3COO-]T和[(COO)22-]T,它们的雨量加权平均值各为9.29 μmol•L -1、6.47 μmol•L-1和5.06 μmol•L-1;遵义市区降水中有机酸总浓度为22.28 μmol•L-1,占阴离子总量的9.39 %;遵义市降水中四季的有机酸浓度由高到低分别为:春季>冬季>秋季>夏季。以上结果表明,遵义市的有机酸是降水中的重要组成部分,其浓度存在明显的季节性变化。在一次降雨事件中,有机酸的浓度一般随降雨时间的延长而降低,但在降雨中后期有时会出现上升的现象,表明有机酸主要来自云下淋滤作用,少数情况下来自大气远距离的传输。 (4) 相关性分析发现甲酸和乙酸具有强烈的正相关(r= 0.86),表明甲酸和乙酸具有共同的来源。有机酸与降水中的主要无机离子NO3-、nss-SO42-、K+、Na+、Ca2+等存在着中度相关,表明有机酸的来源与人为活动有着重要的关系。应用气液平衡的原理,提出了降水中甲酸、乙酸比值(F/A)aq的有机酸来源判定方法。发现遵义降水中的有机酸春季和冬季主要来自人类活动的释放,其中春季主要来自遵义市南郊的工业污染,由南方水汽(占春季总量的54%)将其污染物传输至遵义市中心城区,冬季主要是大量燃煤的燃烧释放;夏季和秋季则主要来自植物的释放,其中秋季中的部分有机酸也受到华中和华东地区(其气团占秋季总量的45%)的远距离影响。而遵义市区的山间盆地地形、高湿度、高静风率和低风速、以尘埃为主的大气污染物和有机酸的短生命周期(几小时~几天)为有机酸来源于当地创造了有利条件。 (5) 根据热力学平衡计算新方法,发现遵义市pH≤5的降水中甲酸和乙酸对自由酸度的贡献分别为14.79% (范围:0.42~91.14%)、3.66% (范围:0.02~31.55%)。对比显示,遵义市的有机酸贡献量低于边远地区,主要由于遵义市降水的低pH值和高无机酸度所致。在春、夏、秋、冬季节,降水中的有机酸对自由酸度的平均贡献值分别为31.95%、26.16%、8.02%、11.17%,表明有机酸酸度有着明显的季节性差异,春季有机酸的高贡献量主要受降水中的有机酸高含量、低水温和高pH值的共同作用,夏季受高pH值的影响,而秋季和冬季的低贡献量主要受降水的低pH值所控制。 (6) 在遵义市的沉降通量中,无机离子的湿沉降通量占所有离子湿沉降总量的94%,并存在明显的季节性变化。SO42-、Ca2+、H+、NH4+、NO3-为最主要的贡献者,分别为90.1、49.8、47.3、26.0和19.2 mmol•m-2•yr-1。对比显示,SO42-、Ca2+、H+的沉降量均属于我国的高值区,而NO3-的沉降量属于我国中值区,NH4+的沉降量属我国低值水平。营养元素总无机氮TIN(TIN= NH4+ -N+ NO3- -N+ NO2- -N)的湿沉降总量为45.7 mmol•m-2•yr-1,其中NH4+和NO3-分别占TIN的57.0%和41.9%,遵义地区高TIN值当地氮肥的施用量和工业NOx的释放量密不可分;营养元素P的沉降量为1.97 mmol•m-2•yr-1,由于P的来源较少,促使P的湿沉降通量较低。有机酸占湿沉降总量的6%,其四季的湿沉降量顺序由高到低依次为:春>秋>冬>夏,这是有机离子的浓度和四季的降雨量共同作用的结果。根据气液平衡理论可知,挥发性有机酸(HCOO-、CH3COO-和CH3CH2COO-)的干沉降量占总沉降量的47.2%,表明遵义市有机酸沉降方式包括干湿沉降两种。因此在研究遵义市的污染物尤其是有机酸类对生态系统和城市建设的影响时,有必要同时收集气样和水样。

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2005

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Schofield, Phillipp, and N. J. Mayhew, eds., Credit and Debt in medieval England, c.1180-c.1350 (Oxford: Oxbow Books, 2002), pp.x+164 RAE2008

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Rothwell, W., S. Gregory and David Trotter, Anglo-Norman Dictionary: revised edition, A-C; D-E (MHRA, 2005) RAE2008