标准熵S_T~O的概念和求法

阐述了标准熵的概念，说明纯固体、液体、气体物质的标准熵是正值，离子的标准熵是相对于Ｈ＋离子的标准熵的相对值，有正值，也有负值。     

设备更新问题的一个评价模型

建立了解决设备更新问题的一个动态评价模型，指出在利用设备更新决策网络图来选择最优方案时应考虑货币的时间价值，并通过一个典型的算例说明了设备更新决策动态评价模型的求解步骤，还编制了用于评价设备更新问题的计算机软件。     

1nm级表面粗糙度的双频激光测量系统

研究了一种基于共外光路双频激光光外差原理的1nm级表面粗糙度的测量系统。从理论上论证了测定系统的原理和测量精度，并用实验结果证明了测量系统的分辨率。此测量系统没有测量基准误差，对测量环境要求不特别苛刻，适用于精密或超精密表面形貌的轮廓测量。     

烟幕初始云团半径变化规律理论模型及实验研究

为了评估烟幕的遮蔽效能,需要对烟幕云团初始参数进行计算,即烟幕云团在爆炸能量下形成的最大半径。本文中基于一种简单烟幕发生装置,把云团的膨胀过程分为2个阶段,分别为等熵膨胀阶段和自由膨胀阶段,建立了烟幕云团膨胀的理论模型,对模型进行分析建立了烟幕云团膨胀过程微分方程组。采用四阶龙格-库塔方法求解得到烟幕云团的半径变化规律。通过实验结果分析可知,该理论模型能够描述给定装置烟幕云团膨胀的基本规律。通过缩比效应,可将其用于爆炸发烟装置初始云团参数的计算。     

Preliminary results of the study on wind erosion in the Qinghai-Tibetan Plateau using 137Cs technique

The worldwide fallout of caesium-137 (137Cs) associated with the nuclear weapon tests during the 1950s and 1960s has provided a valuable man-made tracer for studies of soil erosion and sediment delivery. But relatively few researchers have used it to estimate wind erosion. In this note, the 137Cs technique is introduced into the studies of wind erosion and its modern processes in the Qinghai-Tibetan Plateau. Two 137Cs reference inventories of 982.11 and 2 376.04 Bq·m-2 were established preminarily, distributed in the south and middle-north parts of the studied area respectively. By analyzing the patterns of 137Cs depth profiles from sampling sites, the aeolian processes of erosion and deposition in nearly 40 years have been revealed, i.e. the shrub coppice dunes (S1) and semi-fixed dunefields (S3) experienced the alternation of erosion and deposition, while the grasslands (S4, S6 and S7) and dry farmlands (S5) suffered erosion only. By using 137Cs model, the average wind erosion rates for shrub coppice dune (S1), semi-fixed dune fields (S3), dry farmlands (S5) and grasslands (S4, S6 and S7) were estimated to be 84.14, 69.43, 30.68 and 21.84 t·ha-1·a-1 respectively, averaging 47.59 t·ha-1·a-1 for the whole plateau, which can be regarded as of the medium erosion standard. These results derived from 137Cs for the first time have significant implications for the further research of wind erosion and desertification control in the Qinghai-Tibetan Plateau.     

Mode entropy and dynamical analysis of irregularity for HFECG

A new algorithm-ModEn (mode entropy) is proposed by analyzing and modifying ApEn (approximate entropy), so that the irregular analysis can be applied to the time series of short-term signals with broad amplitude and slow fluctuation (SBS signals); and the ModEn is introduced in the irregular dynamic analysis of high frequency electrocardiogram (HFECG) on a myocardium infarction (MI) animal model. It is shown that the ModEn has a considerable dynamic change in MI. Hence there are potential application values of the algorithm in the early stage diagnosis of heart disease.     

铬镍奥氏体不锈钢焊接中气孔的影响因素

文章阐述了铬镍奥氏体不锈钢焊接焊条药皮中水分含量，焊缝的结晶模式，熔滴过渡，非金属杂因素对焊缝中气孔的影响规律。     

多坐标测量机用动态测头结构参数的理论分析

动态测头的各向异性是影响测头随机误差的主要因素,造成测头各向异性的原因主要是测头设计本身。本文通过建立测头空间力学方程,找到了减少测头各向异性的测头结构参数最佳设计的途径。     

A new measure to characterize multifractality of sleep electroencephalogram

Traditional methods for nonlinear dy-namic analysis,such as correlation dimension,Lyapunov exponent,approximate entropy,detrended fluctuation analysis,using a single parameter,cannot fully describe the extremely sophisticated behavior of electroencephalogram (EEG). The multifractal for-malism reveals more “hidden” information of EEG by using singularity spectrum to characterize its nonlin-ear dynamics. In this paper,the zero-crossing time intervals of sleep EEG were studied using multifractal analysis. A new multifractal measure Δasα was pro-posed to describe the asymmetry of singularity spec-trum,and compared with the singularity strength range Δα that was normally used as a degree indi-cator of multifractality. One-way analysis of variance and multiple comparison tests showed that the new measure we proposed gave better discrimination of sleep stages,especially in the discrimination be-tween sleep and awake,and between sleep stages 3 and 4.