LLM-105太赫兹波吸收特性及理论计算

2,6-二氨基-3, 5-二硝基吡嗪-1-氧化物(LLM-105)是一种综合性能优良的新型高能钝感炸药,为了研究LLM-105的分子结构特性,利用太赫兹时域光谱技术对该炸药在0.2～2.4 THz频率范围内的吸收光谱进行了探测,结果表明LLM-105在该频率范围内出现了多个强度不同的特征吸收峰,分别位于1.27, 1.59, 2.00, 2.08, 2.20, 2.29 THz处。基于密度泛函理论(DFT),借助Materials Studio 6.0量子化学软件对LLM-105晶体在小于2.5 THz频率范围内的吸收光谱进行了模拟计算,计算结果中除了2.29 THz处吸收频率,其余5处与实验测得值均有很好的一致性,从理论角度验证了实验数据的准确性。完成了对实验太赫兹吸收光谱中特征吸收峰振动模式的分析和指认,结果表明LLM-105太赫兹吸收特征峰的形成与分子振动密切相关,进一步为其分子结构变化的研究提供重要的实验手段与技术支撑。对于没有计算频率对应的2.29 THz处特征吸收峰,分析认为是由晶格振动或其他原因导致。     

新型缓蚀剂对钻具在31%NaCl溶液中电化学行为研究

将聚醚表面活性剂(P)、硫酸锌、多聚磷酸钠和葡萄糖酸钙复配,制成用于以欠饱和盐水(31%,NaClby mass)作钻井泥浆的缓蚀剂.研究了该缓蚀剂对钻具钢G105的缓蚀作用机理极化曲线和交流阻抗(EIS).测试表明,80℃时该缓蚀剂是阳极型缓蚀剂,成分之间有较好的协同作用,并以总浓度为200×10-6g.L-1时缓蚀效果最好;缓蚀率随时间增加而增大,缓蚀剂在电极表面形成膜的致密度在试验范围内随时间延长而增大.缓蚀剂的作用机理因其浓度改变而不同:低浓度下以几何覆盖效应为主,高浓度下则以成膜为主.     

Preconcentration of cobalt with 8-hydroxyquinoline and gas chromatographic stationary phase Chromosorb 105 and its determination by graphite furnace atomic absorption spectrometry

This paper presents a study of the adsorption characteristics of a commercially available GC stationary phase Chromosorb 105 for Co²⁺, which can be successfully applied to the preconcentration of Co²⁺ in water samples followed by GFAAS determination. After reacting with 8-hydroxyquinoline to form a complex at pH 8.0, Co²⁺ in water can be retained on a minicolumn packed with Chromosorb 105 and eluted with 2.5 ml of a mixture of ethanol and 2 mol l⁻¹ HNO₃ (2+1, v/v). The recoveries of Co²⁺ from 200 ml of tap water, river water and bottled natural mineral water samples are quantitative. Conditions for quantitative and reproducible preconcentration, elution and subsequent GFAAS determination were studied. A highly sensitive, simple method for preconcentration and GFAAS determination of trace amount of cobalt in natural water samples using a Chromosorb 105 packed minicolumn has been proposed. The high retention efficiency (95%) for Co²⁺ provides a sensitivity enhancement of 80 for a 200 ml sample volume with a detection limit of 13.4 ng l⁻¹ (3σ) and a quantification limit of 44.5 ng l⁻¹ (10σ).     

Quasiasymptotic analysis in Colombeau algebra

We consider the main notions of G-quasiasymptotic (G-q.a.) analysis: G-q.a. behavior at zero, G-q.a. expansion at infinity, Sc-asymptotic and boundedness, Sc-expansion at infinity and their applications to the asymptotic behavior of the solution to some types of nonlinear PDEs in Colombeau algebra of generalized functions G.     

Selective preconcentration of thallium species as chloro and iodo complexes on Chromosorb 105 resin prior to electrothermal atomic absorption spectrometry

A selective preconcentration method was described for the determination of inorganic thallium species by electrothermal atomic absorption spectrometry (ETAAS). Thallium(III) and thallium(I) as chloro and iodo complexes were selectively retained by a column containing 0.5 g of Chromosorb 105 resin and quantitatively eluted by 10 mL of pure acetone. The calibration graph was linear with a correlation coefficient of 0.997 at levels near the detection limit and up to at least 0.8 μg L⁻¹. The detection limits for the determination of total thallium and thallium(III) employing the proposed method by ETAAS were estimated as three values of the standard deviations, 0.050 μg L⁻¹ and 0.034 μg L⁻¹, respectively. Verification of the accuracy was carried out by the analysis of standard reference materials (GBW 07402 soil, NIST 2710 Montana soil, GBW 07309 and GBW 07310 stream sediments). The relative errors were found to be in the range of −7.7% to +4.8%. The relative standard deviations were generally found to be below 10%. The effect of potential interfering ions on the determination was studied. The proposed method was successfully applied to the determination of total thallium in five different brand cements, soils around two cement plants and metallic zinc samples. The speciation of thallium(I) and thallium(III) was applied to synthetic solutions.     

Dielectric properties of Zr-Sn-Ti-O thin films prepared by pulsed laser deposition

Zr_0.26Sn_0.23Ti_0.51O₂ (ZSTO) films with a dielectric constant of about 40 have been prepared directly on silicon substrates by pulsed laser deposition at 600 °C. TEM observation showed that the as-deposited films are amorphous. Differential thermal analysis showed that the ZSTO films crystallize at about 620 °C. Capacitance-voltage (C-V) characteristics of metal-oxide-semiconductor (MOS) composed of Pt/ZSTO/Si prepared at different deposition temperature have been measured. The EOT of the MOS structures with the same ZSTO physical thickness increased slightly when the deposition temperature increased. The EOT is about 4.2 nm for the 40 nm ZSTO deposited at 600 °C. The leakage current characteristics of ZSTO films for the as deposited, post-annealed in oxygen ambient and post-annealed in nitrogen ambient by rapid thermal annealing have been studied comparatively. The films post-annealed in nitrogen ambient have the lowest leakage current and the as-deposited films have the largest leakage current characteristics. It is proposed that amorphous Zr-Sn-Ti oxide stabilized at 600 °C is a potential dielectric material for dynamic random access memory and high k dielectric gate applications.     

The equation on weakly pseudo-convex CR manifolds of dimension 3

Let M be a smooth, compact, orientable, weakly pseudoconvex manifold of dimension 3, embedded in (N2), of codimension one or more, and endowed with the induced CR structure. Assuming that the tangential Cauchy-Riemann operator has closed range in L²(M) in order to rule out the Rossi example, we push regularity up to show has closed range in H^s(M) for all s>0. We then use the Szegö projection to show there is a smooth solution for the problem given smooth data. The results are obtained via microlocalization by piecing together estimates for functions and (0,1) forms that hold on different microlocal regions.