奇异三阶积分边值问题正解的全局分歧

研究带Riemann-Stieltjes积分边值条件的奇异三阶积分边值问题正解的全局分歧结构.首先,利用相关文献,获得了此类问题的格林函数并推证其满足的性质,同时可获得此类问题等价于一个全连续算子方程;其次,在满足所给的条件时,利用Krein-Rutmann定理建立了此类问题对应的线性问题存在简单的主特征值;最后,当非线性项在零和无穷远处满足非渐进线性增长条件、参数满足不同范围的值时,利用Dancer全局分歧定理、Zeidler全局分歧定理和序列集取极限的方法,建立了此类问题正解的全局结构,进而获得了正解的存在性.     

Molar Excess Volumes and Excess Isentropic Compressibilities of Ternary Mixtures Containing <Emphasis Type="Italic">o</Emphasis>-Toluidine

Molar excess volumes, V _ijk ^E, and speeds of sound, U _ijk , of o-toluidine (i) + benzene (j) + cyclohexane or n-hexane or n-heptane (k) ternary mixtures have been measured as a function of composition at 308.15 K. The observed speed of sound data have been utilized to determine the excess isentropic compressibilities, (K _S ^E) _ijk , of the ternary (i+j+k) mixtures. The Moelywn-Huggins concept (Huggins in Polymer 12: 389–399, 1971) of connectivity between the surfaces of the binary mixture constituents has been extended to ternary mixtures (using the concept of a connectivity parameter of third degree of molecules, ³ ξ, which in turn depends on its topology) to obtain an expression that describes well the measured V _ijk ^E and (K _S ^E) _ijk data. The observed data have also been analyzed in terms of Flory’s theory.     

一类奇摄动三阶非线性微分方程边值问题

以变换未知函数的方式研究一类奇摄动三阶非线性微分方程边值问题，在适当条件下，构造出问题的上下解，得出解的存在性和渐近估计。     

基于多层次模糊关联算法的通用航空产业知识挖掘研究

为挖掘通用航空产业领域知识的类型与发展规律,明确产业规划、推动产业健康发展,利用采集的3869份通用航空产业主题相关的网页资料,根据主题信息的关键词对通用航空产业领域知识进行分类,并基于多层次模糊关联算法进行知识挖掘分析.结果表明,通用航空产业领域知识中的通用航空产业主体与通用航空产业产品存在着紧密的联系和规则,而且采用的多层次模糊关联算法比精确的关联规则算法更容易操作,结果更容易理解、更容易被应用于指导通用航空产业领域的发展.     

零售商采购资金约束下第三方再制造闭环供应链决策研究

在原制造商有充足资金而零售商无资本禀赋的情形下,研究再制造商为零售商提供和不提供商业信用时闭环供应链的决策问题。研究发现,再制造商提供商业信用时,如果再制造商需要向原制造商借款维持企业运作,那么原制造商会提高专利授权费用;再制造商不提供商业信用、零售商未寻求外部融资时,再制造商会被淘汰,基于收益共享契约,闭环供应链能够实现协调运作;再制造商不提供商业信用、零售商通过银行贷款和股权融资外部融资时,随着股权融资比例系数的增加,零售商利润先增加后减少,再制造商利润增加,原制造商利润减少,整个供应链系统利润增加。     

基于高频波动率模型与R-vine copula的行业资产组合风险测度研究

相较于低频波动率模型,高频波动率模型在单资产的波动和风险预测中均取得了更好效果,因此如何将高频波动率模型引入组合风险分析具有重要的理论和现实意义。本文以沪深300指数中的6种行业高频数据为例,运用滚动时间窗技术建立9类已实现波动率异质自回归(HAR-RV-type)模型刻画行业指数波动,同时使用R-vine copula模型描述行业资产间相依结构,进一步结合均值-CVaR模型优化行业资产组合投资比例,构建组合风险的预期损失模型,并通过返回测试比较不同风险模型的精度差异。研究结果表明:将HAR族高频波动率模型引入组合风险分析框架,能够有效预测行业资产组合风险状况;高频波动率预测的准确性将进而影响组合风险测度效果,跳跃、符号跳跃变差以及符号正向、负向跳跃变差均有助于提高行业组合风险的预测精度。     

互联网发展与创新效率提升——来自中国高技术产业的经验证据

如何提升产业创新效率是学界关注的热点问题, 选取2009~2018年中国省际面板数据, 从直接影响和间接影响双视角探讨了互联网对高技术产业创新效率的影响机理。研究发现:互联网显著促进高技术产业创新效率提升, 在考虑内生性问题后结论依然稳健, 同时这种影响具有明显的滞后效应与区域差异, 有助于缩小落后地区与发达地区间的创新效率差距; 基于中介效应模型的检验结果表明, 互联网可以通过提升技术研发能力与成果转化能力对高技术产业创新效率产生促进作用。本研究可为有效推进“互联网+”战略与“创新驱动发展”战略提供启示。     

Selective Differential Spectrophotometric Methods for Determination of Niclosamide and Drotaverine Hydrochloride

ABSTRACT

Differential (ΔA), second derivative (ΔD²) and third derivative (ΔD³) differential ultraviolet spectrophotometric methods have been presented for the quantitation of niclosamide and drotaverine hydrochloride in pure forms and in their pharmaceutical formulations. For niclosamide, the method is based on measuring ΔΔ A, Δ ΔD², A ΔD³ of niclosamide in alkaline solutions against their neutral ethanolic solutions as blanks. For drotaverine hydrochloride, the acidic solutions of the drug are measured against their alkaline solutions as blanks. The proposed methods are sensitive, highly specific and advangageous over the conventional UV assays, since the interference of the excipients, impurities, degradation products or other accompanying drugs is nullified. Accuracy of the analysis with the proposed procedures is significantly greater than the classical spectrophotometric methods.     

Determination of some antioxidants by derivative spectrophotometric method and high-performance liquid chromatography

Abstract

The UV-derivative spectrophotometric method was used for assaying butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and propyl gallate (PG) in pure state and in laboratory mixtures. Ir; this paper the results are presented using zero-crdssing technique. In this way, thc interference of two components mixed together has been eliminated. That is the greatest advantage of derivative spectroscopy compared with the classical UV-spectrophotometric method. After analysing the criteria f o r the application of this method, the amounts of these substances were determined. Simul taneously, a highperformance liquid chromatography was used.     

A Non-Newtonian Fluid with Navier Boundary Conditions

We consider in this paper the equations of motion of third grade fluids on a bounded domain of or with Navier boundary conditions. Under the assumption that the initial data belong to the Sobolev space H ², we prove the existence of a global weak solution. In dimension two, the uniqueness of such solutions is proven. Additional regularity of bidimensional initial data is shown to imply the same additional regularity for the solution. No smallness condition on the data is assumed.