两次双波长分光光度法同时测定钼和钨的研究

本文把等吸收双波长法和双峰双波长法结合起来。建立了一种新型高灵敏度的同时测定铝、钨的两次双波长光度法。测定Mo、W的摩尔吸光系数分别为1.9×10~5和1.7×10~5L·mol~(-1).cm~(-1),测定范围1.5～8.0μg/25ml和4.0～15μg/25ml,相互允许量Mo:W=2:1～1:10,该法用于合成水样及标准钢样中的Mo和W的同时测定,结果满意。     

Continuous on-line feedback based flow titrations. Complexometric titrations of calcium and magnesium

The methodology of continuous feedback-based flow titrations and the principle of compensating errors [Anal. Chem. 72 (2000) 4713; Anal. Chim. Acta 435 (2001) 289] were applied to the determination of calcium and magnesium ions with EDTA. The flow of the titrant, EDTA, varied linearly in response to a controller output voltage while the total flow (F_T, the sum of the metal ion sample flow and the titrant flow) was held constant. The sample was pre-doped with a metal ion indicator; the status of the indicator color in the mixed stream was monitored by an optical detector and was used for governing the controller output as well as for interpreting the results of the titrations. The titrant flow initially ramped upward linearly. As a change in the color corresponding to the equivalence point was sensed by the detector, the controller output (instantaneous value V_H) reversed its ramp direction, thus decreasing the titrant flow linearly at the same ramp rate. When the predefined absorbance corresponding to the equivalence point was sensed again, the controller voltage (instantaneous value V_L) was ramped in reverse once more, going upward. Because of the lag time between a change in the controller output and its effect being sensed by the detector, the controller voltage corresponding to the actual equivalence point was the average of V_H and V_L. Continuous sensor-governed operation of the controller resulted in a triangular waveform. The mean of this waveform during any cycle gives the equivalence point controller voltage V_E. This principle allowed true titrations with good reproducibility (0.2-0.7% R.S.D.) and throughput (33-42 s per titration).     

流动注射－双显色剂双波长分光光度法同时测定铝与铁

本文将流动注射与双波长双光束分光光度计联用，选择铬天菁Ｓ和亚硝基Ｒ盐双显色剂使Ａｉ（Ⅲ）和Ｆｅ（Ⅱ）同时显色。建立了同时测定铝、铁的流动注射－双波长等吸收法。方法用于岩矿样品中铝、铁的测定，结果满意。     

双波长和三波长分光光度法同时测定乙醛酸和乙二醛

利用醛基的成肟反应，用双波长法，三波长法同时测定乙醛酸、乙二醛的含量。它们的回收率分别为１００．９％－１０２．３％（ｎ＝６）和９６．８％－１０３．０％（ｎ＝１１）。     

广义系统动态输出反馈控制设计的新方法

对于连续时间的广义系统,基于线性矩阵不等式(LMI),提出了动态输出反馈H_∞控制设计的新方法.给出了广义系统动态输出反馈H_∞控制存在的充分条件.通过求解线性矩阵不等式和矩阵方程实现控制的设计.所提出确定控制的方法是简洁和易于实现的.一个数值例子说明了提出方法的设计过程和控制的有效性.     

On the use of fuzzy inference techniques in assessment models: part II: industrial applications

In this paper, we study the applicability of the monotone output property and the output resolution property in fuzzy assessment models to two industrial Failure Mode and Effect Analysis (FMEA) problems. First, the effectiveness of the monotone output property in a single-input fuzzy assessment model is demonstrated with a proposed fuzzy occurrence model. Then, the usefulness of the two properties to a multi-input fuzzy assessment model, i.e., the Bowles fuzzy Risk Priority Number (RPN) model, is assessed. The experimental results indicate that both the fuzzy occurrence model and Bowles fuzzy RPN model are able to fulfill the monotone output property, with the derived conditions (in Part I) satisfied. In addition, the proposed rule refinement technique is able to improve the output resolution property of the Bowles fuzzy RPN model.     

Robust static output feedback variable structure control for nonlinear systems

In this paper, a robust stabilization problem for nonlinearsystems is investigated using static output feedback. Matchedand mismatched uncertainties are considered and their boundingfunctions take general forms. Based on a Lyapunov analysis approachand sliding mode techniques, some conclusions are presented.Then, a robust nonlinear variable structure control scheme issynthesized to stabilize the system globally, and it is notnecessary for the nominal system to be linearizable globally.The conservatism is reduced by using uncertainty bounds in thecontrol design. Finally, a mass–spring system is employedto illustrate the effectiveness of the results.     

宏观经济均衡发展的数学理论(I)

研究了投入产出模型X( t) =AX( t+ 1 ) + B[X( t+ 1 ) - X( t) ]得到了可运行集及稳定解 .     

负反馈放大器输入、输出电阻的解析计算

根据电路原理，应用解析方法导出了四种形式负反馈放大器的输入、输出电阻关系式。能全面描述影响输入、输出电阻的电路参数。     

Low-threshold mid-IR MgO:PPLN optical parametric generation with high reflectivity mirror for signal wavelength

A low-threshold middle-infrared(mid-IR) MgO:PPLN optical parametric generation(OPG)pumped by a laser diode(LDl end-pumped Z-type Nd:YLF laser at 1047 nm is realized with high reflectivity(HR) mirror for signal.At repetition rate of 10 kHz,the OPG threshold of 50μJ has been achieved with HR mirror for signal.Compared with the threshold without mirror,the threshold decreases by 17%.Using HR mirror for pump at output side of crystal,the threshold of 40μJ is achieved.The 2.7-4.1μm continuous tunable output is produced with seven grating periods from 28.5 to 31.5μm and temperatures from 30 to 200℃.When the incident average pump power is 3 W.the OPG idler output power is 0.46 W at 3.26 μm,which corresponds to optical-to-optical conversion efficiency up to 15.3%.