采用新控制和传动技术的汉堡地铁车辆

为了试验汉堡地铁今后车辆采用的新技术,将最近交货的17台DT4车辆装备了最新一代控制和传动技术,用MIRAC的控制技术系统取代以前DT4车辆应用的MICAS-S系统,变流器由GTO技术改为IGBT技术.新设计可以改造以前结构系列的DT4车辆.     

在阳光下奔跑 BMW 335i Convertible

2007年春天宝马会推出3系列的敞篷版，起初会有325i和335i，随后还会有更小排量的动力配置以及柴油发动机，宝马新的敞篷3系列有着多项创新，首次应用电动折叠硬顶，可以冷却皮革的阳光反射座椅等。     

玩音响先爱乐

很多人都知道，现在的汽车影音系统已把车载DVD、汽车后视系统、GPS导航系统等先进技术融为一体，而售车广告也长期把这些功能作为“高档次”的卖点。但由于高级轿车并不是人人都消费得起，所以改装就成了广大车主企望拥有“先进技术”与“高档”的另一选择!     

Climate–ocean variability and Pacific hake: A geostatistical modeling approach

Climate forcing of the California Current has been known to impact the distribution and abundance of a number of local fish populations, but the mechanisms involved remain poorly understood. Climate metrics such as the Pacific Decadal Oscillation (PDO) and the El Niño Southern Oscillation (ENSO) are usually used to represent climate processes and direct links are made between climate forcing and production variability. This involves aggregation of impacts across large spatial scales and range of species. However, fluctuations in productivity are often the result of changes in physical habitat. In order to fully understand the relationship between climate and productivity, habitat changes should be addressed. In this study we use a geostatistical approach to quantify adult Pacific hake habitat during different climate regimes. Several authors have suggested that the distribution and intensity of the sub-surface poleward flow (the undercurrent) plays a key role in defining adult hake habitat along the west coast of North America. Here we build a model designed to predict hake habitat distribution in space based on sub-surface poleward flow distribution and bottom depth. Our results show that hake habitat expands in 1998 El Niño year compared to 1995. Given the important predatory role that hake plays in the CC, the amount and distribution of adult hake habitat has large implications for the Pacific Northwest food web and could thus serve as an ecosystem indicator representing important physical–biological interactions. Spatially based ecosystem indicators such as the one we develop here address two important yet neglected areas in the ‘Ecosystem Indicators debate’: the importance of developing metrics explicitly representing spatial and environmental processes shaping ecosystem structure. Without these, our power to fully describe ecosystems will be limited.     

小精灵——Renault Twingo Concept

雷诺选择2005年巴黎汽车展揭幕Twingo概念车，此款车完全定位在体育、音乐和时尚的青年文化。虽然全车长3600毫米，宽1727毫米，高1411毫米，但是Twingo Concept不但有丰富的配备，同时也是一辆搭载不少全新的通讯科技，并且具有迷人魅力的小车。比例设计适中的车身呈现出一种漂亮的平衡感。     

Effect of wave boundary layer on sea-to-air dimethylsulfide transfer velocity during typhoon passage

A full-spectral third-generation ocean wind–wave model (Wavewatch-III) implemented in the South China Sea is used to investigate the effects of the wave boundary layer on the drag coefficient and the sea-to-air transfer velocity of dimethylsulfide (DMS) during passage of Typhoon Wukong (September 5–11, 2000) with a maximum sustained wind speed of 38 m s^− 1. The model is driven by the reanalyzed surface winds (1° × 1°, four times daily) from the National Centers for Environmental Prediction. It is found that the wave boundary layer evidently enhances (16.5%) the drag coefficient (in turn increases the momentum flux across the air–sea interface), and reduces (13.1%) the sea-to-air DMS transfer velocity (in turn decreases the sea-to-air DMS flux). This indicates the possibility of important roles of wave boundary layer in atmospheric DMS contents and global climate system.     

扬帆远航所必备的电子助航设备

2009年6月18日，8名来自大连、天津等地的帆船爱好者在大连名岛帆船俱乐部的组织下，齐聚星海湾，驾驶着LAGOON440号双体帆船，开始了大连到青岛的远洋航行。途遇八级阵风、5米海浪、电闪雷鸣；穿越了渔网密布的海域；绕过重重迷雾的成山角，经历了50多个小时的颠簸，于20日中午平安到达阳光灿烂的青岛奥帆基地。     

Dynamic threshold policy for delaying and breaking commitments in transportation auctions

In this paper we consider a transportation procurement auction consisting of shippers and carriers. Shippers offer time sensitive pickup and delivery jobs and carriers bid on these jobs. We focus on revenue maximizing strategies for the shippers in sequential auctions. For this purpose we propose two strategies, namely delaying and breaking commitments. The idea of delaying commitments is that a shipper will not agree with the best bid whenever it is above a certain reserve price. The idea of breaking commitments is that the shipper allows the carriers to break commitments against certain penalties. We evaluate the benefits of both strategies with simulation. In addition, we provide insight into the distribution of the lowest bid which is estimated by the shippers.