双轴等拉低周疲劳实验装置

本文给出能在一般单向加载液压疲劳试验机上做双轴等拉低周疲劳实验研究的双向拉伸装置,并对有关影响因素进行了讨论。 本试验是在百吨液压低周疲劳试验机上进行的。双向拉体装置已经受近百万次疲劳载荷,其中交变载荷幅围5.5,t亦经受近20万次。在使用过程,各构件完好合手使用要求,将十字试样进行低周疲劳断裂试验,成功地开出合格裂纹,用它进行超速条件下叶轮材料性能研究亦取得初步结果。可以认为它适用于平而应力集中问题低周疲劳性能的研究。若使用液压高、中周疲劳试验机,它还可用于双轴载荷下裂纹试样裂纹扩展的研究。 本文指出了双向拉伸装置有待改进的方面。     

一种自制的蒸馏水器保护装置

本装置由检测、控制、执行、报警和电源五部分组成。检测部分采用了靠正常水位导通的两根信号线。当蒸馏水器在正常运行时遇停水,本装置可立即实现断电保护,同时发出声光报警,有效防止干烧,杜绝事故发生。本装置制作简便,元器件均为市售,成本低廉,性能可靠。     

Comparison of procedures for correction of matrix interferences in the multi-element analysis of soils by ICP-AES with a CCD detection system

Three procedures, matrix matching, plasma optimisation and single-point standard-addition, have been evaluated to ascertain the best procedure for simultaneous multi-element analysis of industrial soils by ICP-AES with CCD detection. A standard reference material, CRM143 from the Bureau Communautaire de Réference (BCR), has been analysed for Cd, Cr, Cu, Mn, Ni and Pb using the three different matrix interference correction procedures. All three procedures give comparable results which are in good agreement with the BCR values, except for Cr. The single-point standard addition procedure was chosen, on the basis of economy and ease of implementation, to correct for matrix interferences in the determination of Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sn and V in soil samples collected from an industrial site in England. Concentrations of some of the elements were found to vary greatly with sampling depth. For example, the concentration of Mn, determined using the atomic line at 279.920 nm, increased from 426 ± 3 g/g at a depth of 18–28 cm to 5996 ± 144 g/g at 60–85 cm.     

8-羟基喹啉对甲基苯酚合锌配合物的合成及光致发光和电致发光性能

有机电致发光 ( EL )技术作为一种有着广阔应用前景的显示技术 ,自 1 987年 [1] 以来已获得了空前迅速的发展 .部分发光器件的亮度、效率和寿命已经达到或接近实用化的程度 .许多有机化合物 [2～ 5] ,包括小分子和聚合物 ,已被用于制备有机 LEDs.应用于有机 EL的化合物很多 ,这为优化和筛选优秀的 EL材料提供了基础 .以 8-羟基喹啉铝为代表的有机金属配合物是一类重要的有机 EL材料 ,这类材料荧光效率高、易于提纯且性质比较稳定 .目前应用于有机 EL金属配合物的发光材料大多配位数均为偶数 ,四配位的 8-羟基喹啉锌配合物 ( Znq2 ) [6…     

氧化钨薄膜微型电化学器件的研究

本文论述了WO_3薄膜氢离子敏器件的结构、原理、制备技术和测试分析。利用WO_3薄膜在H+溶液中由绝缘转化为导电特性,成功地研制成氢离子敏器件。这是一种简易而经济的微型pH敏器件技术。     

Dynamic optimization problems with bounded terminal conditions

Bounded terminal conditions of nonlinear optimization problems are converted to equality terminal conditions via the Valentine's device. In so doing, additional unknown parameters are introduced into the problem. The transformed problems can still be easily solved using the sequential gradient-restoration algorithm (SGRA) via a simple augmentation of the unknown parameter vector . Three example problems with bounded terminal conditions are solved to verify this technique.This research was supported in part by the National Aeronautics and Space Administration under NASA Grant No. NCC 2-106.     

Isomorphic electron orbitals for vibronic flexibility in a cyclopropenyl radical molecular device

Summary The vibronic character of this molecular device has been studied using isomorphic electron orbitals. The leading role of the softest vibrational mode for the electron transport process is stressed by the quantum mechanical treatment of the rearrangement operator. The theory was used to investigate the possible function of the soliton valve, which has been suggested as a switching tip. The electronic flexibility of the cyclopropenyl radical with respect to molecular vibrations, which is important for the function of the molecular device, is well characterized by the hardness and softness of the electron structure in terms of the orbital energy-occupation number correlation diagram.     

A soluble and multichromic conducting polythiophene derivative

A new soluble polythiophene derivative was synthesized by both chemical and electrochemical oxidative polymerization of 1-4-nitrophenyl-2,5-di(2-thienyl)-1H-pyrrole (SNSNO₂). Chemical method produces a polymer which is completely soluble in organic solvents. The structures of both the monomer and the soluble polymer were elucidated by ¹H and ¹³C-NMR and FTIR. The average molecular weight has been determined by GPC to be Mn = 6.3 × 10³ for the chemically synthesized polymer. P(SNSNO₂) was also synthesized via potentiostatic electrochemical polymerization. Characterizations of the resulting polymer were performed by cyclic voltammetry CV, FTIR and UV-Vis spectroscopy. Four-probe technique was used to measure the conductivities of the samples. Moreover, the spectroelectrochemical and electrochromic properties of the polymer film were investigated. In addition, dual type polymer electrochromic devices ECDs based on P(SNSNO₂) with poly3,4-ethylenedioxythiophene (PEDOT) were constructed. Spectroelectrochemistry, electrochromic switching and open circuit stability of the devices were studied. They were found to have good switching times, reasonable contrasts and optical memories.     

Dependence of Performance of Organic Light-emitting Devices on Sheet Resistance of Indium-tin-oxide Anodes

IntroductionIndium-tin-oxide(ITO) has been widely used asthe anode material in organic light-emitting devices(OLEDs) because of its high transmittance in the visi-ble region and low electrical resistivity. In the pastyears, many investigations focused on …     

Preparation of a Star Network PEG-based Gel Polymer Electrolyte and Its Application to Electrochromic Devices

A star network polymer with a pentaerythritol core linking four PEG-block polymeric arms was synthesized, and its corresponding gel polymer electrolyte based on lithium perchlorate and plasticizers EC/PC with the character being colorless and highly transparent has been also prepared. The polymer host was characterized and confirmed to be of a star network and an amorphous structure by FTIR, ^1H NMR and XRD studies. The polymer host hold good mechanical properties for pentaerythritol cross-linking. Maximum ionic conductivity of the prepared polymer electrolyte has reached 8.83 × 10 ^-4 S·cm^-1 at room temperature. Thermogravimetry （TG） of the polymer electrolyte showed that the thermal stability was up to at least 150 ℃. The gel polymer electrolyte was further evaluated in electrochromic devices fabricated by transparent PET-ITO and electrochromically active viologen derivative films, and its excellent performance promised the usage of the gel polymer electrolyte as ionic conductor material in electrochrornic devices.