一体化除氧器的应用和分析

随着火电机组向高参数,大容量方向发展.除氧器的设计也有改革性的突破,依从除氧器的发展趋势,提出了新型除氧器--一体化除氧器,因其具良好而广泛的市场前景,进而对一体化除氧器的原理、结构、安装、运行等方面作了扼要的介绍、分析和比较.     

韩国著名的电器街：衰退不振的龙山电器街应学习东京秋叶原

星期日的大白天,位于韩国首都首尔龙山电器街黄金位置的EtLand电子卖场里客人却很少,一片经营惨淡的景象。在1楼的家电产品区域,直到下午才有几位中年家庭主妇进来选购电视和洗衣机等。但是,结果还是没有成交。位于3、4层的电脑、手机卖场各有2～3名店员等候顾客的光临,由于罕有顾客身影,以至于店员的穿梭成为卖场唯一的人群,即便有客人光顾,店员比顾客多也几乎成为最常见的场景。电脑卖场自动扶梯前柜台的营业员向     

我国高考改革的现状分析与改革思路

高考制度自建立以来,在取得巨大成就的同时,其各个环节的弊端也不断显现.探索高考改革之路,要立足于高考现实,对其进行全方位的思考和把握,得出符合实际情况的高考改革最佳方案.     

第13届中国国际厨房卫浴设施展亮相上海

为期四天的2008年第13届中国国际厨房、卫浴设施展览会5月26日起在上海新国际博览中心举行,此次展会吸引来自中国、意大利、西班牙等33个国家及地区的众多中外著名建材、橱柜和卫浴厂家:科勒、TOTO、FAENZA、阿波罗、箭牌、四维、奥普、海尔厨房、华帝橱柜等品牌悉数登场。     

电视购物，家电渠道新宠？

2007年8月20日,CCTV中视购物在广州举行招商活动,向华南地区厂商伸出"橄榄枝"。据中视购物的负责人介绍,海尔、神州数码、海王、美的、格兰仕、金立、康佳等200多家制造商到场。而此前的6月份,中视购物在杭州举办了同样规模的洽谈会,供应商反应同样热烈。中视购物总经理黄艳荣     

海尔''08奥运风空调问鼎中国创新设计红墨奖

2007年度"中国创新设计红星奖"于本年11月10日在北京揭晓:共有64家企业的102件产品获奖.作为家电业龙头企业的海尔集团,其空调、电视、笔记本电脑、洗衣机均榜上有名.其中,海尔′08奥运风空调凭借出色的外观设计、独有的"自清扫"功能和奥运定位,一举夺得了"最具创意奖",成为该奖项中唯一一个空调产品.     

饮水消费从饮水机走向净水器——访百思买五星电器白小家电部经理徐红

太湖蓝藻事件的爆发、直饮式饮水机的推广、铜内胆饮水机的上市接连发生,这些都使水家电产品受到前所未有的关注.可以肯定的是,水设备市场具有全国上亿元销售能力,它自然也是厂商们展开激烈竞争,不会放弃的领域.但业界的疑问集中在:水家电是否会因为蓝藻事件而实现产品的更新换代呢?高端净水设备能否就因此而普及呢?高端净水设备的价位、推广等问题又如何解决呢?针对这一连串的问题,记者采访了百思买五星电器白小家电部经理徐红.     

小天鹅洗衣机自主创新再结硕果

洁净是一种状态,"苛求洁净"则升华为一种境界。以"苛求洁净"为最高理念的小天鹅洗衣机以"衣诺"高端滚筒系列,"雾态洗水魔方"波轮系列等多款新品于2007年11月10-12日亮相在由国家知识产权局主办的"2007创新盛典暨中国无锡国际工业设计博览会"上,引起中外专家和广大消费者的关注和好评。在11月11日晚举办的"2007     

变压器绝缘材料(27)

4液体绝缘材料 4.1变压器油 4.1.1变压器油的分子结构 变压器油是碳氢化合物.其主要的成分是环烷烃,占总量的80%以上,还有少量的芳香烃、烷烃等,其分子中碳原子个数为16～23.其分子量在250～300范围内.烷烃化学式为CnH2n 2,它是线型分子结构. 环烷烃为CnH2n,它是环状闭合结构,是饱和的,无双键,比较稳定.     

中国家电企业登陆非洲进行时

中非经贸正在以每年平均35的速度增长,这意味着中国和非洲的双边贸易进入了高速发展时期.而以制造著称于世界的中国家电业,能否在这条"高速路"上,利用非洲这个洲际市场的需求,获得更多更大的利益呢?     

On a wing and a prayer

The article talks about recent Defense Research Projects Agency (DARPA) presolicitation notice in the area of hybrid insect micro-electromechanical systems (MEMs). DARPA's goal is to fund promising interdisciplinary research that will permit the creation of "insect-cyborgs"     

利用光伏电池给蓄电池充电

磷酸锂铁（LiFePO4）电池对比钻基德Li离子/聚合物电池,具有安全性性高、浮充电压小、自放电率低、使用寿命长等一系列优点。本文所述LT36521C为可实现太阳能跟踪、单块式补偿蓄电池充电的集成电路。当LT3652由单块太阳能电池板供电时,其输入调节回路能确保在最大输出功率下工作,充分体现出这一新型太阳能充电器的优越特性。     

Making a Case for a New Connector

The emergence of quick lock connectors, particularly quick lock versions of the SMA and N connectors (QMA and QN, respectively), was an inevitable development in the RF connector industry and is of significant importance in that nearly 50% of all practical applications for RF connectors are currently supported by either SMA or N. Once QMA and QN can achieve similarity in cost and performance to the present SMA and N connectors, they will take the place of their predecessors in most applications, creating a huge new market. Our RF team has long been dedicated to research and development of these two connector types in the hopes of creating an optimal design. In this article, we will show some of the results of our research.     

Chaos in a series circuit with a nonlinear capacitor and a nonlinear inductor

This paper proposes a nonlinear circuit that generates chaotic oscillations. The proposed nonlinear circuit includes a nonlinear capacitor and a nonlinear inductor by using Generalized Impedance Converters. Both computational experiments and experiments on real circuits show that the region for chaotic oscillation is very wide, demonstrating that the proposed circuit is effective as a chaos generator. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(2): 35–42, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10361     

Electric potential near a tip of a local discharge on a conductive film

To develop a propagation model of a local discharge on a wet polluted insulator, the authors have examined characteristics of the local discharge on an electrolytic solution simulating the wet polluted insulator surface. The local discharge was propagated on the solution under the impulse voltage. A shape of a contacting surface between the local discharge and the solution has been already obtained by the authors. By using the contacting surface, an electric potential near a tip of the local discharge on a conductive film of 1 mm in thickness was calculated. Furthermore, the potential was measured with a probe. The calculated values and the measured values of the electric potential agreed well regardless of the propagation length of the local discharge, the width of the conductive film, the resistivity of the conductive film, the peak value of the applied voltage and the applied voltage waveform.     

Power losses in a conducting ring enclosing a conductor with a transient current

Contents In the paper Joule power losses are calculated in a conducting ring enclosing a conductor with a transient current having an alternating component.—Theoretical calculation and numerical computation are worked out basing on a link Bubnov-Galerkin method in its numerical version using the finite elements for the conductor with the Time-Stepping algorithm for the time discretization.—On the basis of numerical computation, graphs of the relative power losses are plotted as a time function.

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Leistungsverluste in einem leitenden Ring, der einen Leiter mit einem instationären Strom umschließt

Übersicht In diesem Beitrag werden die Joulschen Leistungsverluste in einem leitenden Ring berechnet, der einen Leiter umschließt, in dem ein instationärer Strom mit Wechselanteil fließt. Die theoretischen Betrachtungen und numerischen Berechnungen hat man in Anlehnung an die Bubnov-Galerkin-Methode (in ihrer numerischen Variante, die von einen Leiter unter Verwendung der Methode der finiten Elemente realisiert wird) in Verbindung mit einem Schritt-Algorithmus mit der diskretisierten Zeit ausgeführt. Auf der Grundlage numerischer Berechnungen sind Diagramme für die relative Leistung in Abhängigkeit von der Zeit dargestellt.

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List of symbols Symbol Unit Physical parameter - B Wb/m² magnetic induction vector - H A/m magnetic field intensity vector - H, H A/m -component of the magnetic field vector - E V/m electrical field vector - E _r ,E _z V/m components of the electric field - f s^–1 frequency - I A current intensity (r.m.s. value) - L H inductance - P W power losses - P ₀ W power losses for d.c. - R resistance - t sec time - ^–1 m_–1 electric conductivity of the conductor - Hm^–1 magnetic permeability - _ijk m² finite element area - basis function - rad s^–1 pulsation - N _i ,N _j ,N _k function of finite element shape - 3.141593... - region - ² Laplace's operator - r, ,z cylindrical coordinates - ^h region approximating the region - ^e finite element region - M number of discretization points of the region - V number of finite elements - (N–1) number of steps - i, j, k indices of vertices of triangular finite element     

Simulation of a generator for a wind-power unit

Analysis of excitation systems of generators for wind-power units is carried out, a software package for generator simulation is presented, and the sequence of the generator design is presented.     

Development of a deceleration control system for a winding machine based on a microcontroller

The development of an automatic deceleration system for a winding machine in a siderurgy factory is presented in this paper. The proposed system controls the speed of a winding machine in order to obtain the optimum stop point in terms of security and fast production. The system is based on a microcontroller and an extremely simple hardware. The system has been tested for two years and results evince a very good mean time between failures.     

When a feature detector becomes a feature generator

The neural network approach is reviewed in the context of studies in the animal and human visual systems. An attempt is made to explain perception, memory, and learning as a feedback loop similar to the one used in the ALOPEX optimization concept. Applications in pattern recognition and image processing are discussed. Experiments using visual evoked potentials in humans are described.