用声学测量预报等温淬火球墨铸铁强度

等温淬火球墨铸铁的机械性能与其声学性能相关。本文将两种碳当量球铁在８４５，８９９和９４５℃温度进行奥氏体处理，在２６０，３１６和３７１℃温度进行等温淬火得到证实。声学性能测量包括共振频率，声速和内耗。由共振频率转换成动态模量表示出这种关系可以用来预报球墨铸铁不同热处理条件下的机械性能。     

An efficient and fast algorithm for estimating the parameters of two-dimensional sinusoidal signals

In this paper we propose a computationally efficient algorithm to estimate the parameters of a 2-D sinusoidal model in the presence of stationary noise. The estimators obtained by the proposed algorithm are consistent and asymptotically equivalent to the least squares estimators. Monte Carlo simulations are performed for different sample sizes and it is observed that the performances of the proposed method are quite satisfactory and they are equivalent to the least squares estimators. The main advantage of the proposed method is that the estimators can be obtained using only finite number of iterations. In fact it is shown that starting from the average of periodogram estimators, the proposed algorithm converges in three steps only. One synthesized texture data and one original texture data have been analyzed using the proposed algorithm for illustrative purpose.     

国有企业经营者监督约束机制

对国有企业经营者进行有效的监督是现代企业制度的客观要求。目前 ,国有企业经营者约束机制还不健全 ,公司法人治理结构不合理 ,国有资产管理体制存在不足 ,资本市场不完善 ,内外监督机制不配套。建立健全国有企业经营者监督约束机制 ,必须深化国有资产管理体制改革 ,完善公司法人治理结构 ,建立健全市场约束机制 ,实行各种监管方式的有效结合 ,形成监管合力     

高职可持续发展的基础：“双师型”师资队伍建设

加强教师队伍建设是教育事业发展最重要的基础工作。高等职业教育同时具有＂高等教育＂和＂职业教育＂的双重属性,因此加强＂双师型＂师资队伍建设是高等职业教育事业发展的最重要的基础工作,对高等职业教育的可持续发展具有十分重要的意义。     

“保险性质”期权定价模型及其应用研究

针对传统期权风险大的特点，以欧式看涨期权为基础提出一种风险小、价格低的特殊期权——“资产保险性质”期权，即期权买者出于对标的资产的保险目的，签订期权合约后，若标的资产价格上涨，期权买者将其一部分收益支付给期权卖者，以这种交易方式对传统期权产品进行改进并重新定价，从而得出“保险性质”期权及其定价公式。针对和传统期权的价格变动状况，用Excel进行了模拟比较，证明了“保险性质”期权价格低（吸引期权买者）、风险小（利于期权卖者的风险控制）的特点。“保险性质”期权产品的开发将对我国各类金融市场的建设具有现实意义。     

运用表面光电压技术对半导体表面光电特性的研究

对运用表面光电压技术(SPS)对半导体材料光电性质的研究进行了综述,系统阐述了表面光电压谱(SPS)和场诱导表面光电压谱(FISPS)在测定半导体类型、表面态及其能级位置、表面电荷分布、半导体的能带隙等方面所表现出的优越性质.研究了半导体能带隙所表现出的特有性质.     

日语听力教学刍议

培养听解能力 ,首先要把握听的对象 ,其次是听解过程的各种关键要素。除此之外 ,还要考虑听力为什么难、难在何处 ,并在全面了解听力的特性、特点和形式的基础上 ,进行适当的指导     

浅谈笑话语言的修辞方式与修辞效果

笑话,顾名思义,是一种通过幽默的文字或图示来达到令人会心一笑或捧腹大笑效果的文学形式。而这种通俗的文学形式主要是借助各种修辞手段来呈现。研究笑话中的修辞格,有助于我们更好地有意识地把修辞格运用到笑话幽默的创作当中,从而为人们提供更丰富的精神娱乐。     

Simultaneous sparse model selection and coefficient estimation for heavy-tailed autoregressive processes

We propose a sparse coefficient estimation and automated model selection procedure for autoregressive processes with heavy-tailed innovations based on penalized conditional maximum likelihood. Under mild moment conditions on the innovation processes, the penalized conditional maximum likelihood estimator satisfies a strong consistency, O_P(N^?1/2) consistency, and the oracle properties, where N is the sample size. We have the freedom in choosing penalty functions based on the weak conditions on them. Two penalty functions, least absolute shrinkage and selection operator and smoothly clipped average deviation, are compared. The proposed method provides a distribution-based penalized inference to AR models, which is especially useful when the other estimation methods fail or under perform for AR processes with heavy-tailed innovations [Feigin, Resnick. Pitfalls of fitting autoregressive models for heavy-tailed time series. Extremes. 1999;1:391–422]. A simulation study confirms our theoretical results. At the end, we apply our method to a historical price data of the US Industrial Production Index for consumer goods, and obtain very promising results.     

On Asymptotic Strategy-Proofness of Classical Social Choice Rules

We show that, when the number of participating agents n tends to infinity, all classical social choice rules are asymptotically strategy-proof with the proportion of manipulable profiles being of order O (1/n).