气相色谱-质谱法分析树苔浸膏的成分

采用分子蒸馏法对树苔浸膏进行分级分离,用气相色谱-质谱法对各级馏分进行定性和定量分析。结果表明:三级馏分共鉴定出55种成分,主要成分是苔黑酚单甲醚、分歧扁枝衣素单甲醚、扁枝衣酸乙酯、柔扁枝衣酸甲酯、β-苔黑酚羧酸甲酯、赤星衣酸乙酯、苔黑酚羧酸乙酯、柔扁枝衣酸乙酯、棕榈酸乙酯、油酸乙酯、亚麻酸乙酯和亚油酸乙酯。     

Microlaser with Ramsey Separated Fields Cavity

In a novel microlaser configuration with Ramsey separated-field cavity, we investigate a two-level atomic beam interacting with a single-mode high-Q Ramsey cavity, which is composed by two separated resonators. By using the well-known Ramsey cavity, one can recover the characters of microlaser even with a high flux atomic beam.     

A Novel Mo—Doped Compound with Graphite—Like Structure：[H3O]2V3O8

1 INTRUDUCTION During the last few years, there has been much effort paid to the synthesis of new transition-metal oxides that might be active hosts for intercalation reactions. Vanadium and molybdenum in higher oxidation states with higher reacting ability tend to form polynuclear, anionic metal-oxygen clusters with an extraordinary variety of the relevant topology and electronic structures[1~3]. The preparation of the corresponding clusters is of special interest for different aspects …     

Synthesis and Structure of a New Dinuclear Molybdenum(Ⅰ)Compound with Cyclohexanthiolate Ligand,[Mo_2(SC_6H_(11)_2(CO)_8]

<正>Molybdenum( I )-compound [Mo2(SC6H11)2(CO)8] 1, crystallizes in monoclinic, space group P21/c with a = 9.5863(9), b = 9.4469(9), c = 13.869(1) A, β = 99.697(2)°, V= 1238.1(2) A3, Z = 2,DC= 1.734 g/cm3, μ = 12.23 cm-1 and F(000) = 644. The finalR = 0.0455 and wR = 0.1159 for 1590 observed reflections with I> 2σ(I). 1 possesses a rhombic bimetallic core MoS2Mo with the Mo-Mo bond length of 2.975(1) and Mo-S of 2.485(2) A.     

One-dimensional Coordination Polymers of rctt-1,3-Diphenyl-2,4-bis [2-（5-phenyl）- oxazolyl]cyclobutane with CuCI2 and COCl2

The Cu（Ⅱ） and Co（Ⅱ） supramolecular coordination polymers, [CuCl2（DPO）- （CH3CN）0.5（CH2Cl2）0.5]n （CuDPO, DPO = rctt-1,3-diphenyl-2,4-bis[2-（5-phenyl）oxazolyl]cyclo- butane） and [CoCl2（DPO）]n （CoDPO）, were synthesized and characterized by single-crystal X-ray diffraction method. CuDPO crystallizes in monoclinic, space group P21/n, with a = 11.243（5）, b = 16.070（8）, c = 19.872（9） A, β = 95.678（10）°, Z = 4, V= 3573（3） A3, C35.50H28.50Cl3CuN2.50O2, Mr = 692.00, Dc = 1.287 g/cm3, p = 0.868 mm^-1, F（000） = 1420, S = 1.089, （△/σ）max = 0.069, the final R = 0.0682 and wR = 0.1749. CoDPO is of monoclinie, space group P21/n, with a = 11.396（4）, b = 15.151（5）, c = 17.673（6） A, β = 90.528（6）°, Z = 4, V = 3051.4（17） A3, C34H26Cl2CoN2O2, Mr = 624.40, Dc = 1.359 g/cm3, μ = 0.770 mm^-1, F（000） = 1284, S = 0.981, （△/σ）max = 0.001, the final R = 0.0471 and wR = 0.0961. In each case, the metal cation is coordinated by two C1 anions and two N atoms from oxazole ring of the ligands, which leads to the formation of a one-dimensional polymeric structure. It is found that the cyclobutane ring of coordinated DPO adopts a distorted conformation in the crystal, which is attributed to the increased steric effect between adjacent aryl substituents for the coordination of oxazole ring to metal cation. Thermal gravimetric analysis of the two complexes was also observed.     

硝基吖啶酮差示脉冲伏安法测定核酸的研究

采用循环伏安法对合成的硝基吖啶酮(NACR)的电化学行为进行研究,建立硝基吖啶酮差示脉冲伏安法测定核酸的新方法。在pH 4.8的PBS缓冲液中,硝基吖啶酮与ctDNA能够相互作用形成超分子复合物,使硝基吖啶酮在0.043 V处的氧化峰电流下降,峰电流的下降值同ctDNA的浓度在5.0×10-5mg/L~6.5×10-6mg/L范围内呈良好的线性关系,检出限为2.0×10-7mg/L,相关系数为0.9974,已用于实际样品DNA的测定,故硝基吖啶酮有望成为一种新型的生物小分子电化学探针。     

马尔可夫链模型在信用卡账户行为变化预测中的应用

对信用卡账户行为变化的监控是降低信用卡风险的关键.论文在构建马尔可夫模型的基础上,讨论了在信用卡账户无新增贷款、新增贷款固定不变和新增贷款发生周期性变化的情况下,如何预测信用卡账户不同状态的金额、已偿付态和坏账态的金额、全部应收款的现值及它们的方差计算等内容,为信用卡账户行为变化的预测、管理提供了方法和依据.     

聚乳酸合成的研究现状

对生物降解可吸收材料聚乳酸的合成以及共聚改性等方面的研究现状作了综述     

Adatom self-diffusion on Pt (100) surface by an ad-dimer migrating

We study the self-diffusion of adatom on Pt(100) surface by molecular dynamics. The metal is modeled by the surface embedded-atom potential. Besides the conventional concerted exchange mechanism, a new exchange mechanism in which an ad-dimer diffuses by a concerted motion of three atoms is observed. The importance is that it could become a dominant diffusion mechanism in some cases.