编者絮语

这一个月最热门的话题无疑是非典，小小的病毒，夺去了人的生命，造成了经济损失，带来了民众恐慌。一时间，交通出行少了，电话联络多了；单位上班的少了，在家工作的多了；餐馆聚会的少了，网上聊天的多了；见面握手的少了，短信问候的多了；去封闭场所娱乐的少了，去开敞空间锻炼的多了……     

樊文兴:细节成就品牌

在西方曾经流传过这样一首民谣: 丢了一颗钉子,坏了一只蹄铁坏了一只蹄铁,折了一匹战马;折了一匹战马,伤了一位骑士;伤了一位骑士,输了一场战斗;输了一场战斗,亡了一个帝国.     

城市水土保持——城市建设与水土保持理念

近些年来,城市建设出现了千篇一律的景象：宽阔的柏油马路,林立的钢筋混泥土结构,山削平了,湖填平了,树整齐了,人隔远了,很多城市少了灵气、少了韵味、少了传承,让人似曾相识,也就让人熟视无睹了。     

城市建设与水土保持理念

近些年来,城市建设出现了千篇一律的景象：宽阔的柏油马路,林立的钢筋混泥土结构,山削平了,湖填平了,树整齐了,人隔远了,很多城市少了灵气、少了韵味、少了传承,让人似曾相识,也就让人熟视无睹了。     

盘点城市

近些年,河南城乡建设取得长足进步,给我们留下太多的惊喜和惊奇。花园多了,建筑高了,广场大了,道路宽了,河道治理了,污水少了,绿化率提高了……     

运用多媒体技术,提高小学语文课堂教学效率

科学技术的日新月异发展,推进了素质教育的进程,多媒体技术已经走进了课堂,为教师教学开辟了广阔空间。多媒体技术激发了学生浓厚的学习兴趣,化解了教学难点,创设了丰富的教学情境,有效地进行了德育渗透,突出了学生主体地位,提高了课堂教学效率。本文试就小学语文教学运用多媒体技术问题进行了探讨。     

简论多媒体技术在小学语文教学中的应用

科学技术的日新月异发展,多媒体技术已经进入了课堂,优化了课堂教学,提高了教学效率,突出了学生主体地位,激发了学生学习欲望,调动了学生学习的积极性、主动性、创造性,扩大了知识容量,促进了学生想象思维的发展,实现了课堂教学过程的最优化。本文试就多媒体技术在小学语文教学中的应用进行了探讨。     

多媒体技术在小学数学教学中的作用

科学技术的日新月异发展,推动了素质教育的进程,多媒体技术已经走进了课堂,本文阐述了小学数学教学应用多媒体技术,激发了学生浓厚的学习兴趣,化解了教学重点难点,营造了良好的氛围,优化了课堂教学,提高了课堂教学效率。     

寂静春天里对“人居环境”的思考

正这个春天很寂静,少了城市的车水马龙、人头攒动,季节的鸟语花香、雨丝风片也被挡在了户外。然而,这个春天的"寂静"与美国女作家蕾切尔·卡森的《寂静的春天》却是不同的。主体被更换了,我们把城市让给了自然,把天空留给了飞鸟,把河流还给了鱼儿,自己却宅在了家里。水清了,天净了,草绿了,家成了我     

柳州市建委对房产办证程序进行改革和提速

5月8日，市民王先生一大早就来到了柳州市房产分厅办理房产办证业务，眼前的景象让王先生眼睛一亮，“仅仅过了7天，房产分厅旧貌换新颜了”。一是房产分厅的面积扩大了，更亮堂了；二是效能提高了，办事更方便了；三是更人性化了，增加了服务窗口，审核环节也减少了。     

Age articulation of U.S. inter-metropolitan migration flows

A fundamental divide in migration research has existed between aggregate studies of movement among geographic regions and micro studies of individual migrant behavior. Micro-scale studies have highlighted the importance of stage of life-cycle in predicting movement propensities, whereas many aggregate studies have focused on age-aggregated data summed over all origins for in-migration and over all destinations for out-migration. In this paper we show that if data for functional metropolitan-centered regions are employed, and if origin-destination specific streams of movement are analyzed, the age-specific patterns of inter-metropolitan migration within the United States cluster into distinctive patterns of flow representative of key stages of the life-course. In order to expose and portray a rich, age-articulated geography of U.S. migration we aggregate county-to-county migration flow data from the 1990 census for extended metropolitan regions: Bureau of Economic Analysis (BEA) Economic Areas. We calculate destination-specific out-migration rates broken down into 17 age groups for each origin-destination-specific migration stream between pairs of Economic Areas and present the results of a factor analysis of these flow-specific age profiles. We use the factor scores to cluster the very large number of origin-destination-specific age profiles and find that seven characteristic types emerge reflecting key mobility stages of the life course. We analyze the distinctive characteristics of the migration flows in each cluster and based on the prevalence of flows of each type within streams of gross in- and gross out-migration we present a typology of the 172 BEA Economic Areas. Our conclusion is that better understanding the age articulation of origin-destination-specific flow patterns would help advance regional science migration research. Received: January 2001/Accepted: June 2002 Earlier versions of this paper were presented at the 47^th North American Meetings of the Regional Science Association International, Chicago, Illinois, USA, November 9–12, 2000 and at the 12^th International Symposium Hosted by the Executive Secretariat of the Pacific Regional Science Conference Organization, Tokyo, Japan, October 1–3, 2000. The authors thank Joseph Persky, Roger Bolton, Hiroyuki Shibusawa, and Roger Stough for helpful suggestions made at those two presentations. The authors gratefully acknowledge the expert computer programming assistance of Lucy M. Carruthers of the Center for Computing and Information Technology of the University of Arizona. We also thank Chris Henrie, Ph.D. student, University of Arizona, for constructing our base map of BEA Economic Areas. Frank Heins would like to thank the National Research Council of Italy (Short-term Mobility Program 1999) for financially supporting a stay at the Department of Geography and Regional Development, University of Arizona. During his stay the groundwork for this research was laid. David Plane would like to acknowledge the support of the Population Division, U.S. Census Bureau for his 2001–2002 academic year visiting research position during which the final analyses and revisions were made.     

日本老年公寓的规划与设计

本文通过实例介绍和事例研究对日本老年公寓的规划与设计进行了简要论述。     

MARK-36型154吨电动轮自卸汽车的制动装置及其特点

MARK-36型154吨电动轮自卸汽车制动装置及性能的研究是我院承担的国家“七五”科技攻关项目。本文在消化研究进口样机的基础上,对该车制动装置的构造、功能及特点进行了较完整的论述。     

The agglomeration of U.S.-owned and foreign-owned plants across the U.S. States

Agglomeration in U.S. manufacturing is more common than initially thought. This clustering arises from location natural advantages and spillovers. Extant studies on agglomeration do not distinguish the activities of U.S.-owned plants from those that are foreign owned. This distinction is crucial since policies seem to have differential impacts on both types of plants. I find that industry scale, resource intensity and urbanization economies have larger impacts on foreign plant agglomeration whereas knowledge intensity has a larger effect on domestic plant agglomeration. Received: September 2001/Accepted: April 2002 I would like to thank the UNO University Committee on Research for support of this project and Ke Yang for invaluable research assistance. The paper has benefited from the comments made by an anonymous referee. The usual caveats apply.     

The evolution of the U.S. industrial landscape, 1969–1995

The industrial landscape of the U.S. has undergone major changes in the last three decades, which have affected the location of the work-force as much as sector location. This paper adopts a dynamic approach in order to analyse the principal characteristics of this process in the time-period 1969–1995 among the twenty two-digit SIC industries. Two main conclusions have emerged. First, we find that, in general, industries are tending to reduce their degree of concentration. Secondly, the classification of industries according to different economic criteria allows us to test the degree of compliance with various theoretical propositions and to detect relevant empirical regularities. Received: July 2001/Accepted: August 2002 The authors would like to express their thanks to two anonymous referees for their valuable comments and observations on an earlier version of this work. Similarly, they are grateful for the financial support provided by the University of Zaragoza under Project UZ2001-SOC-09.     

扭剪型高强度螺栓连接接头检测及长期工作性能

结合对宝钢工程的调查,开展了扭剪型高强度螺栓及其连接的工作性能检测与试验研究.在采集大量数据基础上,分析了滞后断裂和疲劳破坏机理,阐明了已有螺栓断裂的原因和今后的风险预测.     

Bond strength of steel bars embedded in high-performance fiber-reinforced cementitious composite before and after exposure to elevated temperatures

Interfacial bond strengths of steel reinforcing bars embedded in a high-performance fiber-reinforced cementitious composite (HPFRCC) are investigated in this paper. Out of 303 pullout specimens, 48 HPFRCC and 3 normal concrete specimens were tested without any heat treatment, and 240 HPFRCC and 12 normal concrete specimens were heated at 200, 400, 600, or 800 °C in a furnace for 2 h prior to testing. The effects of bar shape, diameter, and length embedded in HPFRCC on the bond strength of HPFRCC specimens were investigated. The bond strength decreased with the heating temperature and with the size and embedded length of steel bars. It was reduced further when the heated specimens were cooled in water instead of air. It was disaggregated into chemical adhesion and mechanical interlock from a comparative study of plain and deformed bars. The mechanical properties and microstructures of HPFRCC specimens before and after heat treatment were compared to understand the mechanisms of interfacial bonding degradation due to heat treatment.     

Modeling of small-diameter rotary drilling tests on marbles

In this paper, continuum mechanics and discrete modeling are applied to investigate numerically rotary drill cutting experimental results on four marbles. Rock-cutting tests were performed by a new portable rotary microdrilling tool currently employed in practice for the quasi-non-destructive characterization of strength properties of rocks. The objectives of this research work are twofold, namely: (a) to gain insight in the cutting mechanism of cohesive-frictional rocks, and (b) to examine the comparability of numerical models predictions with experimental results by solving the forward problem. In the first type of model, a plane strain continuum calculation is done with a non-hardening, elastic–plastic, linear Mohr–Coulomb model with non-associative flow rule. In the second type of numerical model, discrete element calculations are done on a simulated plane strain sample of 540 discs. In both models, estimations are made on components of force applied to the cutting face of the bit and are compared with measurements taken with the data-acquisition system of the portable microdrilling tool during specially designed tests on marbles. It is found that the predictions of the continuum model are in full accordance with measured forces during drilling. It is also shown that the cohesion and internal friction angle are the most important parameters affecting the rock drilling resistance, as is depicted by the limit analysis theory of plasticity. Moreover, the calibration of the discrete element model on the experimental data permits the approximate estimation of the mode-I fracture toughness for each type of marble.     

沉淀法制备氧化锌超细粉体的研究

采用沉淀法在水—乙醇介质中用氨水沉淀法制备出超细() Zn OH2和粉体, Zn0 采用正交试验确定了适宜的工艺条件,讨论了介质对产物粒径的影响。