对高能碰撞末态粒子的阶乘矩拟合修正曲线的方法

高能碰撞末态粒子在相空间的动力学分布存在着非均匀因素的影响,通过对这种非均匀因素影响的仔细研究,引入了修正系数,得到了拟合修正曲线的判据,给出了计算修正系数的方法.     

Kinetic Spectrophotometric Determination of Hydrazine with Neutral Red-Nitrite System

 A new kinetic spectrophotometric method for the determination of hydrazine is described. The method is based on the inhibitory effect of hydrazine on the reaction of neutral red with nitrite in acidic media and 28 °C. A product from the reaction of neutral red with nitrite was used to monitor the reaction spectrophotometrically at 352 nm. Hydrazine can be determined in the range 4.7×10⁻⁶∼3.1×10⁻⁵mol/L with a detection limit of 3.1×10⁻⁶mol/L. The method was applied to the determination of hydrazine in water samples. Received July 23, 1999. Revision January 10, 2000.     

INA-X: An Advanced Instrument for Electron-Gas SNMS

 The design and the specifications of a prototype instrument for the electron gas version of secondary neutral mass spectrometry SNMS which will optionally enable measurements with X-ray induced photoelectron spectroscopy XPS, too, are described. By operating the SNMS plasma inside an ultra high vacuum vessel interfering signals from residual gas species are reduced to the level of the mass independent background. The influence of varying angular distributions of sputter-ejected neutrals at low ion energies for sample bombardment can be widely reduced by an oblique take-off for the postionized particles. First examples of SNMS-studies with the new system reveal a detection power well below 1 ppm. Analytically difficult elements as C or O become quantitatively detectable down to a level of several 10 ppm.     

Thermokinetic Research Method for Simple-order Reactions. Double-thermoanalytical curve method

A novel thermokinetic research method for determination of the rate constant of a reaction taking place in a batch conduction calorimeter under isothermal conditions is proposed: the double-thermoanalytical curve method. The method needs only the characteristic time parameter t _m, the peak height Δ_m at time t _m and the peak area a*_m after time t _m for two thermoanalytical curves measured with different initial concentrations of the reactants: it conveniently calculates the rate constants. The thermokinetics of four reaction systems were studied with this method, and its validity was verified by the experimental results. This revised version was published online in July 2006 with corrections to the Cover Date.     

Pyruvate Oxidase Biosensors Based on Glassy Carbon Electrodes Modified with Carbon Nanotubes and Poly(Neutral Red) Synthesized in Ethaline Deep Eutectic Solvent

A novel nanostructured platform for pyruvate oxidase biosensors comprises poly(neutral red) (PNR) prepared by electropolymerization of NR in ethaline deep eutectic solvent (DES) with acid dopant, on a multiwalled carbon nanotubes (MWCNT) modified glassy carbon electrode (GCE). Characterization was by cyclic voltammetry and electrochemical impedance spectroscopy and morphology was examined by scanning electron microscopy. Ascorbate and H₂O₂ gave a better response at PNR_DES/GCE than at PNR_aq/GCE. Biosensors for pyruvate and phosphate, immobilizing pyruvate oxidase onto PNR_DES/MWCNT/GCE enabled selective determination of pyruvate and phosphate, with micromolar limits of detection. Pyruvate was determined in onion samples and phosphate in water samples.     

瞬态大电流测量结温中校温曲线弯曲现象的研究

利用脉宽250 μs、占空比5%的0–1.5 A脉冲电流, 分别在50, 70, 90, 110, 130 ℃条件下, 对TO-247-2L封装型PIN快恢复二极管大电流下的校温曲线进行了测量分析. 研究发现, 恒定大电流条件下, 二极管的校温曲线随温度变化发生弯曲. 分析表明, 弯曲现象主要是由于串联电阻受迁移率的影响随温度发生变化而引起的. 通过实验测量及理论计算, 得到了准确的非线性校温曲线, 从而减小了瞬态大电流测量结温中的误差.     

Rheograms for asphalt from single viscosity measurement

Asphalt materials are used in a variety of applications such as road paving, waterproofing, roofing membranes, adhesive binders, rust proofing and water resistant coatings. There are available in a number of grades distinguished in terms of their softening point and flow resistance. The selection of the proper grade of asphalt for a particular application is governed by the desired flow behaviour. A knowledge of the complete flow curve depicting the variation of melt viscosity with shear rate at the relevant temperatures is necessary not only for proper grade selection, but also for specifying processing conditions for aggregate mixing and spraying. The rheological data are also useful in assessing end use performance. The scientific techniques for generating the rheological data involve the use of expensive, sophisticated instruments. Generation of the necessary flow data using these instruments is beyond the financial and technical means of most processors of asphalt materials. The engineering techniques involving the use of inexpensive vacuum viscometers are relatively easy, but provide a single point viscosity measurement at low shear rate. In the present work, a method is proposed for unifying the viscosity versus shear rate a data at various temperatures for a number of asphalt grades. A master curve has been generated that is independent of the grade of asphalt and the temperature of viscosity measurement. The master curve can be used to generate rheograms at desired temperatures for the asphalt grade of interest, knowing its zero-shear viscosity at that temperature.NCL Communication Number 2914.     

A note on the existence of stochastic integro‐differential equations with memory

In this study, we investigate the existence of mild solutions for a class of impulsive neutral stochastic integro‐differential equations with infinite delays, using the Krasnoselskii–Schaefer type fixed point theorem combined with theories of resolvent operators. As an application, an example is provided to illustrate the obtained result. Copyright © 2014 John Wiley & Sons, Ltd.     

Decay integral solutions for neutral fractional differential equations with infinite delays

Our aim in this work is to find decay integral solutions for a class of neutral fractional differential equations in Banach spaces involving unbounded delays. By constructing a suitable measure of noncompactness on the space of solutions and establishing new estimates for fractional resolvent operators, we prove the existence of a compact set of decay integral solutions to the mentioned problem. Copyright © 2014 John Wiley & Sons, Ltd.