721型分光光度计故障分析和维修

本文主要介绍了７２１型分光光度计所发生的一些故障现象和排除故障时分析，判断及检查结果。     

Piecewise shooting reproducing kernel method for linear singularly perturbed boundary value problems

In this letter, a new numerical method is proposed for solving second order linear singularly perturbed boundary value problems with left layers. Firstly a piecewise reproducing kernel method is proposed for second order linear singularly perturbed initial value problems. By combining the method and the shooting method, an effective numerical method is then proposed for solving second order linear singularly perturbed boundary value problems. Two numerical examples are used to show the effectiveness of the present method.     

The effect of a suppressor to environmental noise – A case study

The purpose of the study is to describe the effect of a suppressor to environmental noise with a typical Finnish rifle shooting range that has a shooting shelter and some noise berms. The noise measurements were carried out at Kyronpelto shooting range situated near Mikkeli in Finland. The range is equipped with wooden shooting shelter, the shooting distance is 150 m, and it has berms on sides and at the impact end. The terrain is relatively flat in the area. The best noise area reduction caused by a suppressor could be seen at angles of 315–45° from the shooting direction. The projectile noise dominates at angles 45–70°, and the effect of the suppressor is very small. To the side and back the shooting shelter has already gained significant noise attenuation, and therefore the suppressor cannot reduce the noise area much more. When there was a relatively tight shooting shelter to the side and back, the suppressor did not reduce the environmental noise area significantly any more. It can be calculated that the noise area of 65 dB (L_AImax) is reduced from 95 ha to 50 ha (0.95 km²–0.50 km²) with the help of a suppressor. However, most of the area is situated to the shooting sector and it has to be unoccupied for safety reasons.     

Numerical calculation of an asymmetric supply function equilibrium with capacity constraints

Producers submit offer curves to a procurement auction, e.g. an electricity auction, before uncertain demand has been realised. In the supply function equilibrium (SFE), every firm commits to the offer curve that maximises its expected profit, given the offer curves of competitors. The equilibrium is given by a system of differential equations. In practice, it has been very difficult to find valid SFE, i.e. non-decreasing solutions, from this system, especially for asymmetric producers. This paper shows that valid SFE can be calculated by means of a shooting algorithm that combines numerical integration with an optimisation procedure that searches for an end-condition. Multiple/parallel shooting is used for ill-conditioned cases.     

DV4／5光电直读光谱仪常风故障分析及处理

本文对美国贝尔德公司ＤＶ４／５光电直读光谱仪出现的常见故障进行了分析，并详细阐述了它的检修过程。     

Post-buckling of a hinged-fixed beam under uniformly distributed follower forces

Based on geometrically non-linear theory for extensible elastic beams, governing equations of statically post-buckling of a beam with one end hinged and the other fixed, subjected to a uniformly distributed, tangentially compressing follower forces are established. They consist of a boundary-value problem of ordinary differential equations with a strong non-linearity, in which seven unknown functions are contained and the arc length of the deformed axis is considered as one of the basic unknown functions. By using shooting method and in conjunction with analytical continuation, the non-linear governing equations are solved numerically and the equilibrium paths as well as the post-buckled configurations of the deformed beam are presented. A comparison between the results of conservative system and that of the non-conservative systems are given. The results show that the features of the equilibrium paths of the beams under follower loads are evidently different from that under conservative ones.     

Ground state solution for a problem with mean curvature operator in Minkowski space

In this paper we prove the existence of a radial ground state solution for a quasilinear problem involving the mean curvature operator in Minkowski space.     

PE—1100B原子吸收分光光度计常见故障分析

本文阐述了ＰＥ－１１００Ｂ原子吸收分光光度计常见的故障现象，故障分析和检查过程。     

HFP—2500F高频发生器故障诊断与维修

本文介绍了高频发生器在日常工作中经常出现的故障，以及诊断排除方法。