oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 181 )

2018 ( 4957 )

2017 ( 5036 )

2016 ( 5381 )

Custom range...

Search Results: 1 - 10 of 232941 matches for " 刘天中 "
All listed articles are free for downloading (OA Articles)
Page 1 /232941
Display every page Item
垂直轴无刷直流风力发电机风轮特性测试系统
The Wind Turbine Performance Testing System of Vertical Axis Wind Brushless DC Generator
 [PDF]

赵向阳,
Smart Grid (SG) , 2011, DOI: 10.12677/sg.2011.13013
Abstract: 为了环境的可持续发展,世界各国越来越重视新能源的开发与利用。风能就是其中一种被广泛关注并开发的新能源。在风能资源的开发中,离网型垂直轴风力发电机正逐渐成为研究的热点之一。在研制、设计垂直轴风力发电机的过程中,需要开发相应的测试系统来提供试验数据参考,便于风力发电机的进一步研制。本测试系统基于虚拟仪器是针对某型垂直轴无刷直流发电机组而设计的。本系统能够对该垂直轴风力发电机组的风轮特性进行测试,测试时利用无刷直流电机的特性,测试出多种不同工况下的风轮特性曲线,即转速与风轮的机械功率之间的关系曲线。设计者通过该曲线既可以选择最佳的设计工况,也可以确定切入风速的大小。
In order to achieve the sustainable development of energy and environment, almost every country pops into development of new energy resource. Wind power is one of new energy resource, which has been an advanced subject paid close attention extensively. And off-grid the vertical axis wind turbine system is becoming one of hot issuse of wind turbine system researching. In researching vertical axis wind turbine system, researcher needs a testing system supplying the data of experiment to get a new level. The testing system is desgined for a vertical axis wind brushless dc generator. The system could test the of wind tubine perfomance of the vertical axis wind brushless dc generator, and it could get many wind turbine perfomance curves which is the relationship curve between rotated speed and the mechanical power in different conditons. The designer could choose the best design plans and the cut-in wind speed by these curves.
CharacterizationoftheMechanicalPropertiesofUrea-FormaldehydeMicrocapsules

过程工程学报 , 2005,
Abstract: Themechanicalpropertiesofurea-formaldehyde(U-F)microcapsulesweredeterminedusingamicromanipulationtechniqueandatheoreticalmodel.Loading-unloading,compressingandholding,andcompressingtoburstingtestsatdifferentspeedsbetweentwoparallelplatesforsinglemicrocapsuleswerecarriedout.ItwasfoundthattheU-Fmicrocapsuleswerevisco-elastic(mainlyelastic)atsmallcompressivedeformation,andplasticunderlargedeformation.Thetransitionpointfromelastictoplasticoccurredatabout(14±0.2)%compressivedeformation.Allthemicrocapsuleswoulddisruptwhencompressedtoabout(17±0.2)%deformation,andtheburstforceincreasedlinearlywiththeirdiameter.Compressingspeedhadnoremarkableeffectonbothburstforceandburstdeformation.Liquidfillednon-permeableandlinearelasticsphericalmembranemodelwasusedtosimulatetheuniaxialcompressionofsinglemicrocapsule,anditsmembranemodulusEhwasdeterminedbyfittingmodelpredictiontoexperimentaldata.TheaveragevalueofEhwasestimatedtobe(478±8)N/m.
黄河河南段水量实时调度措施分析
,
人民黄河 , 2006,
Abstract: ?分析了在黄河河南段水量调度中强化实时调度的必要性,指出了采取的主要水调措施:①利用农业气象信息实时调整引水指标;②实施用水实时调整申报制度;③将重要的滩区引水口门纳入水量调度日常管理;④利用农作物灌溉制度轮流灌水;⑤实施滚动订单制度,进行日实时调度;⑥采取措施处理突发事件.同时建议:①对旬调度指标进行细化;②理由充分情况下应准许实时调整引水指标;③加强供水单位和用水户之间的沟通与协调.
在气升式可逆环流反应器中运用振荡气升操作进行甘油发酵
谢东明,刘德华,
应用与环境生物学报 , 2001,
Abstract: 摘要在耐高渗酵母candidakrusei发酵生产甘油的过程中,为在基本不增加投资或操作强度的基础上进一步提高甘油的产率,本文采用了一种气升式可逆环流反应器,空气可以通过反应器底部的中心喷嘴或环隙喷嘴交替地进入反应器内,从而形成振荡气升操作.实验表明,与最佳的稳态中心气升操作相比,周期性振荡气升操作可以显著提高甘油的产率,但对残糖消耗速度无明显影响.图2表1参8
SATURATED/UNSATURATED, UNSTEADY SEEPAGE ANALYSIS OF ROCK FRACTURED NETWORKS DUE TO THE PERCOLATION OF RAINFALL
降雨过程裂隙网络饱和/非饱和、非恒定渗流分析

Zhang Youtian,Liu Zhong,
张有
, 

岩石力学与工程学报 , 1997,
Abstract: Slide of rock slopes in rain seasons is mainly due to temporarily saturated region above groundwater level changed from unsaturated region induced by rainfall, which is in accordance with the change of pore pressure from nagative to positive values. The percolation of rainfall into fracture networks is a saturated/unsaturaded, unsteady seepage process. A method of analysis for the process is proposed and an analysis of percolating of rainfall into a rock slope is given as an example in this paper.
Characterization of the Mechanical Properties of Urea-Formaldehyde Microcapsules
LIU Tian-zhong,

过程工程学报 , 2005,
Abstract: 1 INTRODUCTION Microcapsule is a kind of important special functional material, which has been widely used in pharmaceutical and medical delivery1,2], adhesives and insecticides. Such microcapsules generally have a non-permeable or semi-permeable membrane wall, and a liquid-like core. As for its formulation, transportation and storage, the wall of capsules is desired to be more rigid. However, as for the applications such as drug delivery, prompt rupture is desired to make the endosome r…
Dissolution kinetics of alginate from Laminaria japonica
海带的碳酸钠消解过程动力学

代云法,陈晓琳,
海洋科学 , 2012,
Abstract: 以海带为原料, 考察了消解反应温度、碳酸钠浓度、搅拌速度及海带块尺寸对消解反应动力学、褐藻胶收率及产品黏度的影响。结果表明, 随温度、碳酸钠浓度、搅拌速度的升高, 消解反应速度明显加快, 褐藻胶提取速率随之增大。海带块大小对反应速率也存在一定的影响, 海带块越小, 褐藻酸钠提取反应速率越快。确定的较佳消解条件为: Na2CO3浓度为0.5%, 消解温度为60℃, 搅拌速度200r/min, 海带块尺寸为20 mm。在此条件下, 产品的产率可超过22%, 黏度超过了20 000 mPa·s。研究结果为优化传统海带消解工艺, 节约碱耗, 缩短反应时间、提高产品收率和品质提供了参考。
The Lipid accumulation of two oleaginous diatom species
两株硅藻筒柱藻和纤细角毛藻的油脂生产

彭小伟,张 维,
海洋科学 , 2013,
Abstract: The biomass, total lipids and Triacylglycerol contents of Cylindrotheca fusiformis and Chaetoceros gracilis were measured in batch, with bubble column photobioreactor. The results showed that the biomass and total lipid productivity were similar. The fatty acids composition of lipid from them were mainly C16:0 and C16:1. The composition of extracted lipid from C. fusiformis was mainly TAG, while in C. gracilis was mainly monoacylglycerol, phospholipids and glycolipids. Decreased the salinity of medium, the biomass, lipid prodcutivity, and TAG productivity were higher than which N or Si was limited. In these studies, TAG productivity can reach 0.36g/(L·d), more than half of dry biomass. C. fusiformis has good potential capacity to be the microalgae species for microalgae biofuel production.
液体喷射单相环流反应器周期振荡操作模拟
,刘德华,谢东明,欧阳藩
化工学报 , 1999,
Abstract: 液体喷射单相环流反应器在化学和生化工程中应用较多。有关其流动特性,Blanke已作了较为全面的综述。一般这种反应器的操作采取中心或环隙喷射的定态方式,Douglas和Baird等对反应器的研究认为,传统的定态操作并不能保证过程总处于最佳状态,在某些情况下进行非定态的振荡操作,可能更有利于反应和传递,其中确定合适的振荡周期是实现这一目的的关键。文献[5,6]利用内环流反应器中心气升和环隙气升的周期切换,实现了环流反应器的振荡操作,并较有效地提高了反应器溶氧传质系数。将这种操作方式用于面包酵母的培养,可增加细胞收率。环流反应器振荡操作时流体流动的特点不单表现为流动处于非定态,而且当喷射位置从中心切向环隙或相反时,流体流动方向都要反向变化一次。因此
海带的碳酸钠消解过程动力学
代云法,陈晓琳,
海洋科学 , 2012,
Abstract: 以海带为原料,考察了消解反应温度、碳酸钠浓度、搅拌速度及海带块尺寸对消解反应动力学、褐藻胶收率及产品黏度的影响。结果表明,随温度、碳酸钠浓度、搅拌速度的升高,消解反应速度明显加快,褐藻胶提取速率随之增大。海带块大小对反应速率也存在一定的影响,海带块越小,褐藻酸钠提取反应速率越快。确定的较佳消解条件为:Na2CO3浓度为0.5%,消解温度为60℃,搅拌速度200r/min,海带块尺寸为20mm。在此条件下,产品的产率可超过22%,黏度超过了20000mPa·s。研究结果为优化传统海带消解工艺,节约碱耗,缩短反应时间、提高产品收率和品质提供了参考。
Page 1 /232941
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.