复方单硝酸异山梨酯-阿司匹林双缓释微丸胶囊的研制(Ⅱ)

以乙基纤维素、丙烯酸树脂Ⅱ和丙烯酸树脂Ⅲ为骨架材料分别制备单硝酸异山梨酯和阿司匹林混合骨架缓释微丸，并通过包薄膜衣进一步控制药物的释放。通过测定微丸的释放度对处方工艺进行评价，选择最佳微丸灌装胶囊．胶囊中两种药物均达到良好的缓释效果。符合中国药典对缓释制剂的要求．其体外释放过程同时符合Higuchi方程和一级释药方程，R^2值均在0．995以上。     

金属表面生成氧化膜在电解质中的电位

测量金属表面生成氧化膜在电解质中的电位时,金属/氧化膜/电解质/参比电极构成了多电极体系,其中包括3个电池,由3个电池之间的关系、电池过程中所有的电化学反应、电荷传输步骤和化学反应步骤,导出电位的普遍适用的公式: E=E_a⁰+sum from s=1 to 3|η_t,s|-1/(ne)v₇ΔG₇, E=E_c⁰-sum from s=4 to 6|η_t,s|+1/(ne)v₈ΔG₈.当金属/氧化膜/电解质电池受到不同的步骤控制时,可以得到不同的简化公式.     

拉长截面等离子体垂直位移不稳定性及其动力稳定

本文研究了拉长截面Tokamak上等离子体的垂直位移不稳定性。计算表明,其快速振荡部分由周围导体中感生的涡流稳定;其慢速漂移部分则需由主动稳定系统予以控制。本文提出一种动力稳定的方法。它在物理上是可行的,并具有技术上简单、较低的功率要求及有利的频率效应等优点。这些说明,这种动力控制方法是一种有吸引力的控制垂直位移不稳定性的手段。     

一类系统构造问题的多输入-多输出基本方程与多目标优化

Renato Pennachi 讨论了以 S(M,N,C,λ_0)表示的参数系统抽象化定义,给出了参数系统的矩阵表示.Franz R.Pichler 总结 Salovara,Blomberg,Messarovic,Ma-cko,Windeknecht,Klir,Kalman,Zadeh 等人的工作,介绍了一般系统理论中若干以集合论与代数体系为基础的较有成效的动态系统建造与实现理论.G.M.Ostrovsky 等人在大规模复杂系统的优化问题中,运用了带有0—1变量的系数,研究了具有复杂平行序列的结构问题.     

Quantum Inequality Bounds for Free Rarita-Schwinger Field in Flat Spacetime

Although quantum field theory allows the local energy density negative, it also places severe restrictions on the negative energy. One of the restrictions is the quantum energy inequality (QEI), in which the energy density is averaged over time, or space, or over space and time. By now temporal QEIs have been established for various quantum fields, but less work has been done for the spacetime quantum energy inequality. In this paper we deal with the free Rarita-Schwinger field and present a quantum inequality bound on the energy density averaged over space and time.Comparison with the QEI for the Rarita-Schwinger field shows that the lower bound is the same with the QEI. At the same time, we find the quantum inequality for the Rarita-Schwinger field is weaker than those for the scalar and Dirac fields. This fact gives further support to the conjecture that the more freedom the field has, the more easily the field displays negative energy density and the weaker the quantum inequality becomes.     

Differential determination of arsenic(III) and total arsenic using flow injection on-line separation and preconcentration for graphite furnace atomic absorption spectrometry

Arsenic(III) can be quantitatively extracted using sodium diethyldithiocarbamate (NaDDTC) as the complexing agent and C18 reversed phase packing as the column material for solid phase extraction. Arsenic(V) must be reduced to its trivalent oxidation state prior to extraction. A mixture of sodium sulphite, hydrochloric acid, sodium thiosulphate and potassium iodide was found to be optimum for on-line reduction. When the sorbent extraction is carried out without and with the addition of the reduction mixture, arsenic(III) and total arsenic can be determined sequentially by graphite furnace atomic absorption spectrometry with detection limits (3 σ) of 0.32 ng for As(III) and 0.43 ng for total arsenic. A 7.6-fold enhancement in peak area compared to direct injection of 40 μl samples was obtained after 60 s preconcentration. Results obtained for sea water standard reference materials, using aqueous standards for calibration, agree well with certified values. A precision of 5.5% RSD was obtained for total arsenic in a sea water sample (1.65 As). Results obtained for synthetic mixtures of trivalent and pentavalent arsenic agreed well with expected values.     

Studies on self-pumped phase conjugation in Cu-doped (K0.5Na0.5)0.2(Sr0.61Ba0.39)0.9Nb2O6 crystals

The use of Cu-doped (K_0.5Na_0.5)_0.2(Sr_0.61Ba_0.39)_0.9Nb₂O₆ as self-pumped phase conjugators using internal reflection is reported. Reflectivities as high as 63% at 5145.5 nm and 60% at 632.8 nm were realized. It was found that the photorefractive response changes significantly at different doping concentration. The responses of the crystals to the laser wavelength, incident angle and dopant concentration are studied.     

解抛物问题的一类新的瀑布型多重网格法

本文推广石钟兹 ,许学军对椭圆问题提出的新的瀑布型多重网格法到抛物问题 ,建立了相应的理论结果 .     

混沌经济学——混沌与分形

本文给出作为混沌经济学的数学基础的混沌与分形的简短介绍 .     

Effect of Pulse Temporal Profile on Autler-Townes Splitting in Photoelectron Spectrum

The effect of pulse temporal profiles on the Autler-Townes （AT） splitting in photoelectron spectra is theoretically studied by employing the time-dependent wave packet method for a rotational Na2 molecule. The AT splitting which results from the sufficient Rabi oscillations is affected by the pulse profile and molecular alignment. The AT splitting may be observed only by utilizing proper pulse profiles with a certain intensity.