Synthesizing plans that contain actions with context-dependent effects1

This paper presents a method of solving planning problems that involve actions whose effects change according to the situations in which they are performed. The approach is an extension of the conventional planning methodology in which plans are constructed through an iterative process of scanning for goals that are not yet satisfied, inserting actions to achieve them, and introducing subgoals to these actions. This methodology was originally developed under the assumption that one would be dealing exclusively with actions that produce the same effects in every situation. The extension involves introducing additional subgoals to actions above and beyond the preconditions of execution normally introduced. These additional subgoals, called secondary preconditions, ensure that the actions are performed in contexts conducive to producing the effects we desire. This paper defines and analyzes secondary preconditions from a mathematically rigorous standpoint and demonstrates how they can be derived from regression operators.     

基于AutoCAD2000的图解法确定工艺转角

提出了基于AutoCAD2 0 0 0的图解法求解机械加工过程中工艺转角的问题 ,并针对具体的应用实例给出了圆满的解答 ,并验证了其精度。     

Boussinesq方程的永形波的级数解

对于用层平均速度势(或速度)与波高给出的非线性等水深Boussinesq方程,与KdV方程一样,存在两类永形波—孤立波和周期波。不同的是,对于Boussinesq方程,孤立波和周期波一样,是以反函数的积分形式给出的,这在使用上是不方便的。本文对这两类波,分别给出了相应的级数形式的正函数解。对于孤立波,级数的收敛速度是十分快的,且文中还给出了一个具有高精度的十分简单的近似解,对于周期波,只要有关参数选得合适,解的收敛速度也是相当快的。这就有效地克服了反函数形式解在使用上的不方便。     

Effects of Substrate Temperatures on the Structure and UV-shielding Properties of TiO_2-CeO_2 Films Deposited on Glass by Radio-frequency Magnetron Sputtering

1Introduction Theultravioletrays(UV)insunlight(-4%)cantransmitintoroomthroughcommonfloatglass,theUVcanmakethematerialsintheroom,eg,paper,furni ture,textilefabricandplastics,becoloredanddeterio rated.ShieldingfromUVirradiationisofinterestinmanyfields.Formu…     

痕量分析中金溶液的稳定性

评述了痕量分析中,金标准溶液和天然水试样中痕量金贮存的稳定性及影响贮存的重要因素,提出了标准溶液配制和贮存的方法。     

发电机同轴励磁机电刷火花过大的原因及处理方法

本文对发电机同轴励磁机电刷火花过大的原因进行了分析．并针对这些原因提出了相应的处理办法。对规范励磁机的运行维护有很大的帮助。     

Nodally exact Ritz discretizations of 1D diffusion–absorption and Helmholtz equations by variational FIC and modified equation methods

This article presents the first application of the Finite Calculus (FIC) in a Ritz-FEM variational framework. FIC provides a steplength parametrization of mesh dimensions, which is used to modify the shape functions. This approach is applied to the FEM discretization of the steady-state, one-dimensional, diffusion–absorption and Helmholtz equations. Parametrized linear shape functions are directly inserted into a FIC functional. The resulting Ritz-FIC equations are symmetric and carry a element-level free parameter coming from the function modification process. Both constant- and variable-coefficient cases are studied. It is shown that the parameter can be used to produce nodally exact solutions for the constant coefficient case. The optimal value is found by matching the finite-order modified differential equation (FOMoDE) of the Ritz-FIC equations with the original field equation. The inclusion of the Ritz-FIC models in the context of templates is examined. This inclusion shows that there is an infinite number of nodally exact models for the constant coefficient case. The ingredients of these methods (FIC, Ritz, MoDE and templates) can be extended to multiple dimensions     

Electrochemical noise analysis for estimation of corrosion rate of carbon steel in bicarbonate solution

We have investigated the electrochemical noise behavior of carbon steel in fully deaerated aqueous bicarbonate solutions, and discussed the optimum conditions of the noise analysis for estimating corrosion rate of the steel. Noise of the potential difference and of the short-circuit current between two identical steel coupons were successfully measured. The time-series noise patterns were transformed into frequency domain by fast Fourier transformation, and then their power spectrum densities (PSDs) at a frequency were determined to be compared with the corrosion rate. The PSDs of the potential and of the current varied with changing environmental factors of bicarbonate concentration, pH, and immersion time. The factors also controlled the corrosion rate of the steel. The PSDs were associated with the corrosion rate, and then it was found that the PSDs of the potential and of the current showed linear correlation with the corrosion rate in log-log scale. There was also linear relationship between the corrosion rate and a spectral noise resistance obtained from the PSDs of the potential and the current. The linearities of the three correlations were better at a lower analyzed frequency. Furthermore, the PSDs of the current and the noise resistance indicated more linear correlation with the corrosion rate than that of the potential. As the simplicity of the measurement system is additionally considered, it is concluded that the PSD of the current noise at an analyzed frequency of 3 mHz is the optimum conditions for estimating the corrosion rate from 10⁻² to 10⁰ A m⁻² in this study.     

佛尔哈德法测定氯化除汞上清液中的氯量

控制pH4-6，用锌粉还原氯化除汞上清液中的汞（Ⅱ）离子，取置换后液加入过量的硝酸银标准溶液，以硫酸铁铵溶液作指示剂，用硫氰酸钾标准滴定溶液滴定来测定氯量。该方法的检出限：0．25mg／100mL，回收率：98％-101％。     

带化学反应的膛口温度场方程分歧解

提出膛口系统是一种准耗散结构，并分析了符合耗散结构的条件，在分析分歧解线性稳定性的基础上，使用高维定态投影解定态分歧解，分歧解与实验结果吻合较好。