A study on the transient characteristics of a self-regulating Joule-Thomson cryocooler

An experimental and numerical study of transient characteristics for the self-regulating Joule-Thomson (J-T) cryocooler is developed in the present work. The modelling of the bellows control mechanism and the simulation of the cooler system are developed. It is proved by experiment that the most important transient behaviours can be accurately predicted by the present numerical simulation. In order to rectify the instability problem of the bellows controlled J-T cooler, this study also proposes a revised design to improve temperature stability. The revised dual-orifice J-T cooler can effectively reduce the phenomena of unstable temperature and mass flow rate, but sacrifices the expected gas consumption rise by approximately 5 percent. Through experimental evaluation, it becomes obvious that this revised type cooler would be a better design.     

含淀粉聚乙烯膜的时控光降解研究

使用复合光降解剂，得到了可光降解的生物降解膜。对膜的光降解进行了考察，并对影响光降解的因素进行了讨论，结果表明，我们所制得的膜是一种较好的时控光降解膜。     

CAD^2B—一个计算机辅助数据库设计系统

本文介绍了一个用Ｔｕｒｂｏ Ｃ语言在ＡＳＴ－２８６机器上实现的计算机辅助数据库设计系统ＣＡＤ＾２Ｂ。该系统提供了人机交互的环境，供设计者进行概念模型设计，并自动完成从概念模型逻辑模型的映射，创建满足规范化要求的关系表。该系统采用的概念模型是引入了事件和时间的扩展了的实体关系模型。该模型既能充分反映应用环境的静态和动态语义，又是向关系模式转化的基础。     

提高铌钽标准液显色反应能力并延长其有效贮存期的分光光度法研究

铌，钽的酒石酸，柠檬酸，草酸铵标准液的显色反应能力及有效贮存期，同铌，钽的原始标准溶液ｐＨ有很大关系，铌酒石酸标准液（原始溶液ｐＨ１．４），其显色反应能力仅在８０％～５０％之间（视放置时间长短而异），但如何采用ｐＨ４．５～５．０的铌酒石酸标准液，其显色反应能力达１００％，即使贮存４４０ｄ后，仍能保持原有的显色反应能力，铌柠檬酸标准液（原始溶液ｐＨ１．２），无论用本法（Ｎｂ－ＢＰＲ－ＣＰＢ法）还是用     

一种新的带优先权控制的ATM交换结构

本文在Ｋｎｏｃｋｏｕｔ交换结构的基础上，探讨一种新的ＡＴＭ交换结构，使其本身带有优先权控制功能，以适应不同业务对信元丢失率及时延的不同要求。这种结构既能最大限度地有效利用系统资源，又能满足不同用户对业务质量的不同要求，并能降低交换结构复杂度。     

Bimanual interference associated with the selection of target locations.

Four experiments were conducted to identify the locus of interference observed during the preparation of bimanual reaching movements. Target locations were specified by color, and the right-hand and left-hand targets could be either the same or a different color. Movements of different amplitudes (Experiment 1) or different directions (Experiment 2) to targets of the same color were initiated more quickly than symmetric movements to targets of different colors. These results indicate that costs observed during bimanual movements arise during target selection rather than during motor programming. Experiments 3 and 4 further examined the interference associated with target selection. Reaction time costs were found with unimanual movements when the target was presented among distractors associated with responses for the other hand. Interference observed during bimanual reaching appears to reflect difficulty in segregating the response rules assigned to each hand. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

鱼雷罐喷粉预处理优化研究

在已经得到的描述鱼雷罐喷粉处理基本参数具体表达式的基础上，运用多目标非线性优化方法，对工艺操作参数进行优化。     

波在PTL介质中传播的旅行时反演

本文对Byun(1990)的横向各向同性介质的旅行时反演方法作了两点改进:其一是根据优化后的V_r值计算一个初始的F值,然后再根据这个初始值进行最小均方误差分析;其二是对初始值进行优化分析时,提出用测量值(或由式(4)和式(10)计算的理论值)作为实际值进行拟合,而Byun的方法是用式(11)的计算来得到一个实际值。理论模型证明:本文所述方法有一个比较宽的适应性,而Byun方法只在弱各向异性时才可以得到较精确的结果。     

Application of Wavelet Packet De-noising in Time-Frequency Analysis of the Local Wave Method

The local wave method is a very good time-frequency method for nonstationary vibration signal analysis. But the interfering noise has a big influence on the accuracy of time-frequency analysis. The wavelet packet de-noising method can eliminate the interference of noise and improve the signal-noise-ratio. This paper uses the local wave method to decompose the de-noising signal and perform a time-frequency analysis. We can get better characteristics. Finally, an example of waveletpacket denoising and a local wave time-frequency spectrum application of diesel engine surface vibration signal is put forward.     

Pure perceptual-based sequence learning.

Learning a sequence of target locations when the sequence is uncorrelated with a sequence of responses and target location is not the response dimension (pure perceptual-based sequence learning) was examined. Using probabilistic sequences of target locations, the author shows that such learning can be implicit, is unaffected by distance between target locations, and is mostly limited to first-order transition probabilities. Moreover, the mechanism underlying learning affords processing of information at anticipated target locations and appears to be attention based. Implications for hypotheses of implicit sequence learning are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)