外贸函电中礼貌用语的常用表达方式

在外贸函电的教学中,商务信函的礼貌原则,是教师重点强调的内容.根据近几年的外贸函电教学经验,总结了一些常用的礼貌用语,供广大教学工作者和学生参考借鉴.     

The selection of good search terms

This paper tackles the problem of how one might select further search terms, using relevance feedback, given the search terms in the query. These search terms are extracted from a maximum spanning tree connecting all the terms in the index term vocabulary. A number of different spanning trees are generated from a variety of association measures. The retrieval effectiveness for the different spanning trees is shown to be approximately the same. Effectiveness is measured in terms of precision and recall, and the retrieval tests are done on three different test collections.     

舰船电气设备剩余使用寿命评估方法

针对舰船电气设备在使用过程中的安全性、可靠性,简要分析了电气设备剩余使用寿命评估方法及理论,提出了实施剩余使用寿命评估的工作思路。     

Experiments in relevance weighting of search terms

Following successful initial tests of theoretically-based schemes for relevance weighting of search terms, further experiments were undertaken to validate these results. The experiments were designed to investigate weighting for a large document set, poor matching conditions, heterogeneous data, and limited relevance information, i.e. the use of weighting in more realistic conditions than the initial ones. The results confirm the earlier ones: very striking improvements in retrieval performance were obtained, especially for the theoretically best-founded weighting formula. The experiments illustrate a much more promising application of statistical methods to indexing and searching than any studied hitherto.     

从生理学角度浅谈幼儿教育

西藏的双语教育不仅是一个重要的课题，也是一个我国少数民族地区特有的教育制度，更是西藏教育工作中急需解决的一大难题。通过调查研究，论述了西藏双语教育的重要地位、双语教育的发展过程以及双语教育的现状，并对发展西藏双语教育提出了一些建议。     

Inverse dynamics control in terms of unnormalized quasi-velocities

In this paper a proposition of inverse dynamics control for a manipulator using the unnormalized quasi-velocities (UQV) is presented. These quasi-velocities introduced by Jain and Rodriguez (IEEE Trans. Robotics Automat,16, 2000, 517; 11, 1995, 571) are used here to show some performance obtained from the controller. It is shown that for a two d.o.f. planar manipulator one can assume UQV which are integrable with respect to time. The introduced controller in terms of UQV is exponentially convergent. As a consequence of using UQV inverse dynamics control, one can notice some interesting properties in comparison with the classical controller. Additionally, some geometrical interpretation based on Riemannian geometry is given.     

大连产业结构转换能力与转换速度分析

通过对辽宁省的数据分析,发现大连在具有较强产业结构转换能力的条件下,其转换速度却位居全省末位。针对此现状,探究大连产业结构转换中存在的问题及其根源,并进一步提出加快产业结构转换速度、优化地区产业结构的对策。     

The upper bound of minimum moment of inertia of equi-area convex domains

The problem of nontrivial bounds of moments of inertia for plane configurations is formulated. The Winternitz theorem is generalized to establish the bounds of the ratio of the Nth moment of areas of two subdomains created by any of the centroidal axes of a convex domain. For convex equi-area domains the upper bound of the minimum moment of inertia with respect to a general coordinate system is discussed. In particular, for the cases of the origin of coordinate axes coinciding with the centroid and coinciding with a point on the periphery, the upper bound of the minimum moment of inertia is proved to belong to an equilateral triangle and an isosceles 120° triangle, respectively.     

贫困农村低保对象的瞄准与识别

本文聚焦贫困农村低保对象的瞄准和识别过程,发现贫困地区农村低保存在较大瞄准偏差,通过分析两类低保户的家庭特征发现政策性转移收入、户主受教育程度、家中是否有残疾人作为识别指标具有显著性。提出通过统一贫困标准和低保标准、调整低保动态管理周期、开发农村低保识别技术形式等促进农村低保对象的识别。     

轨道交通对城郊之间房价梯度影响研究——以北京西南部为例

采用半对数特征价格模型,通过设置不同"参照区"对比分析,研究轨道交通运营前后不同时期对城区和郊区之间房价梯度的影响,并探讨其内在机理。研究表明:轨道交通对城区和郊区之间房价梯度起到"缓冲器"作用。但在研究期内,轨道交通沿线的房价梯度呈现先加速扩大再加速缩小的倒"U"型结构。跨越城区和郊区之间的轨道交通对其沿线房价梯度的影响呈现三阶段变化:在轨道交通开通前的短期内(阶段一),市区房价上涨高于郊区,城区和郊区之间的房价梯度扩大加剧;在轨道交通运营后的短期内(阶段二),市区房价上涨低于郊区,但城区和郊区之间的房价梯度继续加剧上升;在阶段三,即轨道交通投入使用的长期,市区房价涨幅远小于郊区,城区和郊区之间的房价梯度停涨下降,轨道交通促进房价扁平化效应才显著体现。城区和郊区之间房价梯度的演化是由于两个市场对轨道交通的响应不同引起的。本研究深化了轨道交通对房价影响认识,可为北京市跨越城区和郊区之间的地铁沿线住宅开发管理提供参考。     

一种圆弧形金属薄板滚压折边机的研发

文章研发了一种金属薄板折边机,主要用于金属薄板的折边,包括工作台、主滚筒、副滚筒和电机,其特点在于在主滚筒和副滚筒之间设置三角垫块,其优点在于金属薄板进入折边机后,碰到三角垫块的斜端面,在斜端面的作用下发生弯曲,折边完成。该设备结构简单,大大提高了工作效率。     

战略柔性对新产品开发速度的影响研究

本文研究战略柔性对新产品开发速度的影响作用。发现战略柔性的两个维度:资源柔性和协调柔性与新产品开发速度都呈正向关系。同时,技术不确定负向调节资源柔性和新产品开发速度的关系,但正向调节协调柔性和新产品开发速度的关系。本文研究不仅深入认识了战略柔性与新产品开发速度的关系,而且可以指导企业利用战略柔性来快速开发新产品,具有重要的理论和实践价值。     

知识经济条件下人力资源管理的现状及对策

知识经济时代，知识成为促进经济增长的第一要素，而目前中国劳动者体素质不高，人才短缺，人才竞争激烈，企业管理尤其是人力资源管理受到了挑战。本文针对知识经济条件下，就中国人力资源管理的现状，从具体环节上提出了科学合理进行人力资源管理的方法。     

The innovative performance of in-house and contracted R&D in terms of patents and utility models

The standard empirical framework for analysing the R&D-patents relationship is widened both by examining the different role of in-house and contracted R&D in the innovative performance of firms, and by considering patents and utility models counts as measures of innovation output. Patents and utility models are considered to approximate for significant and incremental innovations, respectively. Applying count data econometrics to a panel data set of Spanish manufacturing firms surveyed in the period 1990-1996, a transcendental production function is estimated, which allows for non-constant elasticities of the R&D inputs. The results indicate that significant innovations are mainly gestated in-house, whereas contracted R&D seems more orientated towards innovations of incremental nature.