预解算子控制的无穷时滞分数阶微分方程解的存在性

本文研究了一类预解算子控制的具有无穷时滞的分数阶泛函微分方程.利用解析预解算子理论和不动点定理,得到了具有无穷时滞分数阶微分方程适度解的存在性,推广和改进了一些已知的结果.     

c（Г）型空间单位球面之间的等距延拓

讨论c（Г）单位球面问等距算子的延拓问题,给出c（Г）单位球面间的等距算子可实线性等距延拓的充要条件．     

c(Γ)型空间单位球面之间的等距延拓

讨论c(Γ)单位球面间等距算子的延拓问题,给出c(Γ)单位球面间的等距算子可实线性等距延拓的充要条件.     

高温下黑索金（RDX）热分解动力学模拟

应用分子动力学模拟方法研究了黑索金(RDX)在纯高温下的分解机理, 研究结果表明RDX初始分解机理主要为N-N键的断裂形成NO2分子, 然后发生H原子转移反应形成H2O, HONO, HO和NO分子; 通过对RDX热分解反应物和生成物的研究结果表明N2和H2O分子是RDX分解过程中最稳定的生成物, NO2, HNO3, NO, NO3和HONO分子为RDX热分解过程中的中间产物; 在高温4500K, CO, CO2和OH分子出现的频率逐渐提高, 表明这几种分子在高温下更容易形成.     

一类半线性微分方程温和解的精确可控性

本文利用非紧测度研究了Banach空间中非局部项满足Lipschitz连续条件下半线性微分方程温和解的精确可控性.在研究过程中没有使用以往文献中关于非紧测度假设的正则性条件,而是利用不同拓扑空间中非紧测度的估计,并利用商空间的性质给出了合适的控制函数,得到了微分方程温和解的精确可控性.因此,我们的研究结果可以认为是可控性领域结论的推广.     

带有非紧条件的拟线性Schrodinger-Poisson系统非平凡解的存在性

本文研究了如下带有非紧条件的拟线性Schrodinger-Poisson系统{-△u+V(x)u+Фu+k/2u△u2=λ|u|^p-2u+f(u),x ∈R^3,-ΔФ=u^2,x∈R^3, 其中κ<0,λ>0,p≥12,f∈C(R,R),V∈C(R3,R).文中首先构造截断函数,利用集中紧性原理和逼近的方法,得到了截断后系统非平凡解的存在性;然后利用Moser迭代技巧,讨论上述系统非平凡解的存在性.     

铁系催化剂催化2,5-二甲酚合成2,3,6-三甲酚的研究

采用共沉淀法制备了用于2,5-二甲酚甲基化合成2,3,6-三甲酚的铁系催化剂,并对甲基化的工艺条件进行了单因素研究。结果表明,在反应温度320℃,原料配比n2,5-二甲酚∶n_(甲醇)=1∶10,液时空速2.4h-1时,2,5-二甲酚的转化率可达99.62%,2,3,6-三甲酚的选择性可达98.89%。     

WEB维文信息检索系统中维文的存储和特征项抽取

本文介绍了维文在存储和文档特征项抽取方面与中、英文的不同之处,在维文文档的特征项抽取、加权、相似度计算、模型的建立等方面做了一些探讨,提出了一种基于网络的维文信息处理(如:维文网页下载、网页内容信息的存储、以及无词典智能化维文抽词)的方法.文中论述了算法的设计思想和相关的实现技术.     

Crystal Structure and Thermal Decomposition Kinetics of 3-Nitro-4-diazo-5-oxygenpyrazole

A novel compound 3-nitro-4-diazo-5-oxypyrazole was synthesized by the nitration of 4-amino-3,5-dinitropyrazole using nitrification agents of fuming nitric acid and trifluoroacetic anhydride. The compound was purified by column chromatography and characterized by IR, NMR, MS and elemental analysis. Two different single crystals obtained by culturing with ethyl acetate as a solvent were measured by X-ray single-crystal diffractometer. The molecular weight of C_3HN_5O_3 is 155.09 and the two crystals belong to monoclinic system, space groups P21/n and P21/c. For 1: a = 5.5007(2), b = 9.0691(4), c = 11.4158(4) ?, β = 92.710°, V = 568.85 ?~3, Z = 4, Dc = 1.811 g/cm~3, μ = 0.162 mm-1, F(000) = 312 and the final deviation factor is 0.0213. Crystals 1 and 2 have similar unit cell parameters, except that a = 10.1828(12), b = 5.5925(6), c = 10.5574(10) ? and β = 108.330(4)° in crystal 2. The thermal behavior of the compound was studied by TG-DSC and melting endothermic peak and decomposition exothermic peak are at 425.7 and 534.5 K in DSC curve. The activation energy and pre-exponential factor of the exothermic decomposition reaction of the title compound obtained by Kissinger method and Flynn-Wall-Ozawa method are 50.38 k J/mol, 4.59 × 1022 s~(-1) and 55.89 k J/mol.     

Theoretical Studies on Intermolecular Hydrogen-bond Interactions between Hexamethylenetetramine and Nitric Acid

The structures of the complexes generated by hexamethylenetetramine and nitric acid have been fully optimized by B3LYP method at the 6-311++G** and aug-cc-pVTZ levels. The intermolecular hydrogen-bonding interactions have been calculated by the B3LYP/6-311++G**, B3LYP/aug-cc-pVTZ, MP2(full)/6-311++G** and CCSD(T)/6-311++G** methods, respectively. The NBO (nature bond orbital), AIM (atom in molecule), temperature effect and solvation effect have been analyzed to reveal the origin of the interactions. The results indicate that the stable hydrogen-bonded complexes could be generated by hexamethylenetetramine and nitric acid. The interactions follow the order of (a)>>(e)>(b)>(c)>(d)>(f)>(g). The C-N bonds which are adjacent to the methylene involving the hydrogen bonds tend to break in the chemical reaction. Due to the exothermic process, low temperature is conducive to the formation of the composition, which tallies with the experimental result.