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讨论了实Clifford分析中的一类高阶奇异积分,给出了这类高阶奇异积分的递推公式,计算公式.从而使实Clifford分析理论得以拓展. 相似文献
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茉莉酸甲酯对杜氏盐藻β-胡萝卜素含量的影响 总被引:1,自引:0,他引:1
研究甲基茉莉酸(MeJA)对杜氏盐藻生长、β-胡萝卜素含量及叶绿素含量的影响.在盐藻生长基本培养基中分别添加0μmol.L-1、50μmol.L-1、100μmol.L-1、200μmol.L-1、500μmol.L-1、1 000μmol.L-1和2 000μmol.L-1 MeJA,每隔2 d取样,测定盐藻细胞生长、β-胡萝卜素含量及叶绿素含量.研究结果表明:低MeJA浓度(50~500μmol.L-1)对盐藻的生长无显著的影响,高MeJA浓度(1000~2000μmol.L-1)对盐藻的生长有显著的抑制作用.盐藻β-胡萝卜素及叶绿素含量随着MeJA浓度的升高,呈现先升高后降低的趋势,100μmol.L-1 MeJA处理盐藻时其β-胡萝卜素含量最高,200μmol.L-1 MeJA处理盐藻时其叶绿素含量最高.方差分析结果表明:MeJA对盐藻的生长、类胡萝卜素及叶绿素含量有极显著影响(P0.01),MeJA是诱导盐藻次生代谢产物积累的一个有效的诱导因子. 相似文献
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Two new CdⅡ-based coordination polymers(CPs) with mixed adenine(Hade) nucleobase and 5-nitroisophathalate(nip) ligands, {[Cd(Hade)_(0.5)(H_2O)_2(nip)]·H_2O}n 1 and {[Cd(Hade)(H_2O)_(1.25)(CH_3OH)0.75(nip)]·0.75 CH_3OH·0.5H_2 O}_n 2, were successfully obtained by varying the preparation methods and structurally characterized. Crystal data for 1: monoclinic, C2/c space group with a = 10.5546(6), b = 17.3496(6), c = 16.1198(9) ?, β = 104.2800(10)o, V = 2860.6(2) ?3, Dc = 2.058 g/cm~3, Mr = 443.13, Z = 8, F(000) = 1752, μ = 1.585 mm~(–1), the final R = 0.0394 and wR = 0.1109 for 2285 observed reflections with I 2σ(I). For 2: triclinic, P1 space group with a = 10.2032(7), b = 10.5098(8), c = 11.0223(8) ?, a = 65.7050(10)o, β = 74.5750(10)o, g = 61.5280(10)o, V = 943.38(12) ?~3, Dc = 1.888 g/cm3, Mr = 536.24, Z = 2, F(000) = 537, μ = 1.225 mm~(–1), the final R = 0.0225 and wR = 0.0702 for 3143 observed reflections with I 2σ(I). 1 presents a crisscrossed layer with mutually orthogonal {Cd(nip)} chains aggregated by neutral m-N(7),N(9)-Hade connector. By contrast, 2 displays a linear chain with CdⅡ ions extended by bis-bidentate chelating-nip2–connectors, which are further assembled into a broad ribbon by N-H···N hydrogen-bonding interactions. Additionally, the two solid-state samples with comparable thermal stability exhibit favorable luminescent emissions at room temperature, suggesting their potential applications as fluorescence materials. 相似文献
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Testing the variation of the fine structure constant with strongly lensed gravitational waves 下载免费PDF全文
The possible variation of the electromagnetic fine structure constant, αe, at cosmological scales has aroused great interest in recent years. Strongly lensed gravitational waves(GWs) and their electromagnetic counterparts could be used to test this variation. Under the assumption that the speed of a photon can be modified,whereas the speed of a GW is the same as predicted by general relativity, and they both propagate in a flat FriedmanRobertson-Walker universe, we investigated the difference in time delays of the images and derived the upper bound of the variation of αe. For a typical lensing system in the standard cosmological models, we obtained B cosθ 1.85×10~(-5),where B is the dipolar amplitude and θ is the angle between observation and the preferred direction. Our result is consistent with the most up-to-date observations on αe. In addition, the observations of strongly lensed GWs and their electromagnetic counterparts could be used to test which types of alternative theories of gravity can account for the variation of α_e. 相似文献
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A code has been developed to simulate the neutralization and grazing process of slow highly charged ion Xe^q+ on Al(111) surface under the classical-over-the-barrier model. The image energy gain of Xeq+ ions are calculated and compared with experiment data. The simulation results of image energy gain are in good agreement with the experiment data. Meanwhile, in the present work, the reflection coefficient of incident Xe^q+ on Al(111) surface as a function of the incidence angle, energy and charge state is also studied. 相似文献
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用水热法合成了Tm3+/Er3+/Yb3+三掺杂YF3上转换发光粉末,并对其进行了结构和形貌表征.对上转换发射谱的研究表明,在相对低激发功率下,可以观察到比较明亮的近白色发光,且随着激发功率的增大,上转换发射强度迅速增大并达到饱和状态,继续增大激发功率,出现发光猝灭现象.退火温度对上转换发射强度的影响表明,随着退火温度的升高,Tm3+,Er3+的所有特征发射峰均相对增强.上转换发射谱随Tm3+浓度变化关系表明,在相对低Tm3+掺杂浓度下,Tm3+-Er3+相互作用占优势,Tm3+把能量传递给Er3+,Er3+发射相对增强;在相对高掺杂浓度下,Tm3+-Tm3+之间交叉弛豫过程占优势,Er3+发射相对减弱.从实验结果看出,该粉末的上转换发光非常丰富,从紫外到红外均有发射,是一种潜在的白色上转换发光及三维固体显示材料. 相似文献
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