新型量子霍尔电阻样品计量应用研究

采用AsGa砷化镓系材料研制了多种结构的新型量子霍尔电阻样品,介绍了该样品的特点及应用领域。使用常温电流比较仪和低温电流比较仪,用过渡比对法对新型的量子霍尔电阻与标准量子霍尔电阻样品进行了双重测量比对验证,在实验室内测量结果的相对偏差小于4×10^-8,验证了新型的量子霍尔电阻样品和测量系统的准确度满足当前计量应用需求。     

A New Linear Model for Stability Prediction

Abstract

Based upon Okusa's observation (Chem. Pharm. Bull. 1975) that the slopes of a linear plot of logo log fraction of active substance degraded vs log time for first order decay kinetics and a linear plot of log of drug remaining vs log time for a zero order decay kinetics are both unity, an algorithm has been developed to resolve both the energy of activation (E) and the rate constant (K_o or L_o) at the desired shelf-life temperature (T_o) by analysis of the y-intercepts of parallel slopes at more than one elevated temperature (T).

Preliminary estimates of both E and either K_o or L_o are then substituted into a series of mathematical expressions based upon well known Arrhenius relationship:

k = A ·exp -E/1.987) (1/T-l/T_o) where A = K_o or L_o

Using converging and interative techniques to treat elevated temperature data, the resulting mean loss rate (eithri K_o or L_o at the designated shelf-life temperature plus a residual error term thus obtained, is used to distinguish statistically between zero and first order treatments. A program called POTENCYLOSS, based upon the algorithm, has been written in business BASIC language for use with an IBM-PC micro-computer.

The program is ideally suited for use in preformulation studies or in assigning provisional expiration dating and overage requirements during the early stages of formulation development when there is limited potency stability test data available at accelerated, elevated temperature storage conditions.     

A New Low Cost Linear Resolver Converter

A new low cost converter topology is proposed for sinusoidal position encoders. The converter enables determination of the angle from the sine and cosine signals of the encoder. When used with resolvers, the implementation of the present scheme takes advantage of the available excitation signal used to operate the device. This trigonometric reference signal is optimally used to generate an analogue signal equivalent to a digital look-up table (LUT). This enables determination of the mechanical angle without using LUT, A/D, and D/A converters. The scheme is optimized in order to achieve highest possible precision. Beside simplicity of its implementation, the proposed converter offers the advantage of robustness to amplitude fluctuation of the transducer excitation signal. The converter was implemented using ordinary low-cost analog components. The theory of operation, computer simulation, and experimental results are given.      

A New Linear Model for Stability Prediction

Based upon Okusa's observation (Chem. Pharm. Bull. 1975) that the slopes of a linear plot of logo log fraction of active substance degraded vs log time for first order decay kinetics and a linear plot of log of drug remaining vs log time for a zero order decay kinetics are both unity, an algorithm has been developed to resolve both the energy of activation (E) and the rate constant (K_o or L_o) at the desired shelf-life temperature (T_o) by analysis of the y-intercepts of parallel slopes at more than one elevated temperature (T).

Preliminary estimates of both E and either K_o or L_o are then substituted into a series of mathematical expressions based upon well known Arrhenius relationship:

k = A ·exp -E/1.987) (1/T-l/T_o) where A = K_o or L_o

Using converging and interative techniques to treat elevated temperature data, the resulting mean loss rate (eithri K_o or L_o at the designated shelf-life temperature plus a residual error term thus obtained, is used to distinguish statistically between zero and first order treatments. A program called POTENCYLOSS, based upon the algorithm, has been written in business BASIC language for use with an IBM-PC micro-computer.

The program is ideally suited for use in preformulation studies or in assigning provisional expiration dating and overage requirements during the early stages of formulation development when there is limited potency stability test data available at accelerated, elevated temperature storage conditions.     

A New Kind of Linear NTC Sensitive Ceramics

［1］National Natural Science Foundation of China: Inorganic Nonmetal Material Science, Science Publishing House, Beijing, 1997, 31. (in Chinese) ［2］Mingtang WU and Xiaohua ZHOU: Inorganic Semiconductor Physics, Xi′an Communication University Publishing House, Xi′an, 1995, 126. (in Chinese) ［3］Shipu LI: Special Ceramics Technology, Wuhan University of Technology Publishing House, Wuhan, 1997,249. (in Chinese)     

浇注温度和ECAP对铝合金坯料组织的影响

采用近液相线法结合新SIMA法复合工艺制备半固态A356铝合金坯料,研究了浇注温度、等径角挤压(ECAP)和半固态处理温度、时间对坯料组织的影响.结果表明,适当的工艺参数可以制备出球状初生α-Al相晶粒的半固态A356铝合金坯料,其中较合理的工艺参数为:近液相线浇注温度为610℃,半固态保温温度为580℃,半固态保温时...     

求解分块三对角线性方程组的一种新算法

本文根据分块三对角矩阵的特殊分解,给出了求解分块三对角线性方程组的一种新算法.     

求解分块三对角线性方程组的一种新算法

本文根据分块三对角矩阵的特殊分解,给出了求解分块三对角线性方程组的一种新算法。     

线位移传感器校准的一种新装置

在飞机系统综合试验中,线位移传感器的静态特性对保证试验数据的准确性、可靠性起着至关重要的作用.为此,我们研制了一种线位移传感器静态校准装置.本文主要叙述线位移传感器静态校准装置软、硬件组成及工作原理,并对其进行了测量不确定度分析.实践证明,该装置设计科学、合理,能够完全满足校准需求.     

一种新型的环氧聚酰胺胶粘剂

介绍了一种新型以环氧树脂和聚酰胺为主体材料的环氧胶粘剂。常规性能试验和配套性试验结果表明 ,该胶粘剂适合于钢板、油漆、橡胶板的粘接。     

求解分块五对角线性方程组的一种新算法

本文根据分块五对角矩阵的一种特殊分解给出了求解分块五对角线性方程组的一种新算法-变参数追赶法。     

新兴的广告形态--网络广告

随着信息技术，互联网络在全球的发展，全球经济朝向数字化经济迈进，Ｉｎｔｅｒｎｅｔ的出现及其广泛应用，给传统广告业带来了巨大的冲击，网络广告应运而生，并成当今世界最热门的广告形态。     

一种新型弹道过载传感器

目的　为了在导弹发射及飞行时的特殊环境条件下 ,精确地测量其发射及飞行中的过载参数 .方法　提出一种新型结构的过载传感器 .结果　在某型号导弹飞行试验中 ,该过载传感器准确测得了其过载参数 .结论　通过实践证明该过载传感器具有良好的实用性能     

一种新型的ATM-PON系统

介绍了一种新型的ＡＴＭ－ＰＯＮ系统,它采用在ＰＯＮ传输层上定义ＡＴＭＥ层的方法取代传统的ＡＴＭ层,并采用包含６ｂｙｔｅ信头的双向５４ｂｙｔｅ信元格式,可获得较高的传输容量。在ＶＰ级上控制上行信号的发送和管理连接资源,可实现灵活的动态带宽分配。     

红外光谱分析热固性树脂制样方法的改进

介绍了红外光谱分析热固性树脂的一种新的制样方法热裂解法。该方法是把试样置于裂解管中 ,在酒精灯上加热裂解 ,取裂解物的冷凝液在盐片上成膜。与传统的卤化物压片法制样比较 ,它排除了无机填料和低分子有机物的干扰 ,得到的红外谱图清晰 ,信息量大 ,能够准确地进行定性分析     

一种新型包装箱

研究了变箱内圆柱形容器整齐排列为交错排列及改变包装箱底的形状等提高圆柱形容器包装箱底面积利用率的方法。     

Phase II Multiple Linear Regression Profile with Small Sample Sizes

In some statistical process control applications, the quality of a process or product is best represented by a functional relationship between a response variable and one or more explanatory variables. Different methods have been proposed in the literature to monitor phase II multiple linear regression profile. Most of the existing approaches assume the number of sample observations to be greater than the number of explanatory variables, a condition needed to estimate the model parameters and establish chart statistics. In practice, however, the sample size can be smaller than the number of the multiple linear regression parameters. None of the previous studies of multiple regression profiles approaches have tackled this problem. In the current study, two methods are proposed to handle the problem of profile monitoring with sample sizes smaller than the number of regression parameters. Simulation results show that both methods outperform the existing methods in the literature used to monitor multiple linear regression profile. Moreover, both methods work satisfactorily when existing methods cannot be applied, that is, when the sample size is smaller than the number of profile parameters. Copyright © 2014 John Wiley & Sons, Ltd.     

The Construction of Good Linear Unbiased Estimates from the Best Linear Estimates for a Smaller Sample Size

A general procedure is found for constructing good unbiased linear estimators of the location and scale parameters of a distribution for use with an uncensored sample of size n.

It is presupposed that the coefficients of the best linear estimates are available for an uncensored sample of size m < n for the distribution under investigation. The coefficients of the proposed estimators are obtained as linear combinations of these with the aid of tabled values of the hypergeometric probability function.     

一种新型测距仪的研制

介绍了一种在中，小范围内，采用激光定位，超声测距的新型测量仪器，该仪器以单片微处理器为核心，对不同的测量距离，采用不同频率的超声波，结合信号处理方法，从而实现０．６～１４ｍ范围内高精度实时测量目标距离，其测量相对误差优于１％。