Subset threshold autoregression

We develop in this paper an efficient way to select the best subset threshold autoregressive model. The proposed method uses a stochastic search idea. Differing from most conventional approaches, our method does not require us to fix the delay or the threshold parameters in advance. By adopting the Markov chain Monte Carlo techniques, we can identify the best subset model from a very large of number of possible models, and at the same time estimate the unknown parameters. A simulation experiment shows that the method is very effective. In its application to the US unemployment rate, the stochastic search method successfully selects lag one as the time delay and five best models from more than 4000 choices. Copyright © 2003 John Wiley & Sons, Ltd.     

缓凝砂浆螺旋输送理论研究

缓凝预应力筋包覆装置是将新型独特的缓凝材料应用于预应力混凝土体系的一种施工设备．通过对缓凝砂浆的流变性能分析，建立了螺旋输送物理模型，运用粘性流体力学的运动微分方程研究缓凝砂浆螺旋输送的速度场和流率，从而对其装置的设计和运行参数的合理选择提供了理论依据．     

建筑砖砌体裂缝原因及其防治

砖砌体由于各种各样的原因可能会产生一定数量的裂缝.本文根据理论和施工经验对其裂缝产生的原因进行分析,并且提出相应的治理的原则.     

CFG桩施工引起桩周土体开裂的原因探讨

由于郑东新区特殊的工程地质条件，长螺旋CFG（Cement Flyash Gravel）桩施工常常引起桩周土体开裂和周围建筑物开裂等施工事故。本文通过郑州某工地现场试验分析，否定了空桩效应引起桩周土体开裂的猜想，并分析了郑东新区由于CFG桩施工引起桩周土体开裂的原因。     

上饶市区地表水水质现状调查与水源保护措施

上饶市中心城区地表水水质现状对于上饶市的经济发展与社会稳定，生态环境与人类健康，具有重要的意义。全面、系统、准确地了解上饶市中心城区地表水质量现状，提出切实可行的污染防治措施与对策，是走可持续发展道路，创建和谐社会的重要举措。     

提高裸根植苗造林成活率探讨

从掌握造林基本要点、积累栽树窍门、加强后期林地管护3个方面介绍了提高裸根植苗造林成活率的经验。     

电工学中交变电流一些难点释疑

对电工学中有关交变电路学习的一些难点,如交流电的有效值,电感、电容对交变电流的作用,感应电动机的工作原理及输电等进行了阐述。     

饲育条件下Semisulcospiens decipiens的生长

在饲育温度条件下研究了Ｓ．ｄｅｃｉｐｉｅｎｓ的生长和产仔数及与饲育水温的关系。结果表明水温在上升期和下降期，新生贝和稚贝的生长速度较快，产仔数也较多．成体贝在水温１１℃～２９℃时，都可产出新生贝，以１８℃～２４℃时产出较多．在高温饲育条件下，成体贝的生长速度缓慢。     

消费与储蓄的有关问题之探讨

应用控制理论与方法分析消费、储蓄、工资收入与利率之间的关系,建立相应的数学模型。利用此模型,可以确定合理的消费与储蓄的比例关系,为制定相应的宏观经济政策提供依据。     

Preparation and properties of the SmOx/Rh(100) model surface

The preparation of SmOx/Rh(100) and CO adsorption on this model surface have been investigated with Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption spectroscopy (TDS). The oxygen adsorption on the SmRh alloy surface leads to the aggregation of Sm on the surface. The thermal treatment of this oxidized surface induces the further agglomeration of SmOx on the Rh(100) surface. Compared with CO TDS on the clean Rh(100) surface, three additional CO desorption peaks can be observed at 176, 331 and 600 K on the SmOx/Rh(100) surface. The CO desorption peak at 176 K may originate from CO adsorbed on SmOx islands, while the appearance of the CO adsorption peaks at 331 and 600 K, depending on the oxidation state of Sm, is attributed to CO species located at the interface of SmOx/Rh(100).