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Search Results: 1 - 10 of 60543 matches for " 肖名涛 "
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油菜移栽机槽轮间歇式送苗机构的优化设计

湖南农业大学学报(自然科学版) , 2014,
Abstract: 针对油菜移栽机设计了一套槽轮间歇式送苗机构。通过建立送苗机构的运动学与动力学模型,确定以送苗机构驱动扭矩最小为优化目标,以落苗时间与槽轮间歇停顿时间关系、链接数目与苗杯数量关系为约束条件,通过Matlab数值分析,得出满足约束条件的较优方案,即二指六槽式槽轮间歇机构驱动扭矩为87.2 N?m,间歇停顿时间为0.4 s。试验表明,优化后的机构运动流畅,送苗准确率可达92.9%。
双立轴烟秆切割机构的设计与试验
张武金,孙松林,李军政,,杨彪,寻真福
湖南农业大学学报(自然科学版) , 2015,
Abstract: 设计了一种适合烟秆切割的双立轴圆盘式切割机构。在自制的烟秆切割试验台上,对切割速度、装置的前进速度、主从切割刀片的径向重叠量等进行了单因素试验和多因素正交试验。单因素试验结果表明,在切割速度350 r/min时,功耗为1 718.8 W,切断率为94.33%;在主从切割刀片的径向重叠量为15 mm时,功耗为1 500.73 W,切断率为95.6%;在装置的前进速度为0.6 m/s时,功耗为1 608.13 W,切断率为96.83%。正交试验结果表明,当切割速度为300 r/min,主从切割刀片的径向重叠量为15 mm,装置前进速度0.6 m/s时,功耗为1 480.26 W,切断率为97.21%。
妊娠高血压综合征危险因素分析
,温永顺,,,廖冬英
中国公共卫生 , 2006, DOI: 10.11847/zgggws2006-22-11-38
Abstract: ?妊娠高血压综合征(妊高征)是妊娠期特有的疾病.妊高征发病机制至今未明,研究该病的病因、病理和预防方法一直是产科的重要课题.本研究旨在探讨妊高征发生的危险因素,为有针对性地做好孕前及孕期保健,提高该病早期预警及干预效果,降低其发病率提供依据.
基于伺服压力机镁合金冷压缩组织和硬度研究
,小亭,程永奇,黄育忠,杨长毅
- , 2015, DOI: 10.11951/j.issn.1005-0299.20150318
Abstract: 为研究变速变形对镁合金微观组织和硬度的影响,采用1 100 kN机械伺服压力机,对AZ31镁合金在曲柄匀速驱动和曲柄单向减速驱动两种模式下进行了室温压缩实验,分析了两种速度模式不同变形量下试样的微观组织与硬度演化规律.研究表明:两种变速模式下,在压缩初始阶段,均有少量平行孪晶产生于粗大晶粒内,且孪晶宽度大;随着变形量增大,孪晶密度增大且呈细长化.在曲柄匀速驱动模式下,孪晶长而细且分布散乱,无规则交错;而曲柄单向减速驱动模式下孪晶由宽大转变为细长,多组平行孪晶相互交叉,均匀分布且孪晶密度增大.不同变形量下,曲柄单向减速驱动模式下的试样硬度均小于曲柄匀速驱动模式,但在接近极限压缩量(25%)时,其硬度值又趋于相同.
This paper is to study the influences of loading speed on the microstructure and hardness of magnesium alloy formed at room temperature.AZ31 magnesium alloy was compressed using a 1 100 kN servo presser under the crank at constant speed mode and unidirectional deceleration mode and the microstructure evolution and hardness change during the two processes were examined. The results showed that small amount of parallel and thicktwins can be observed in large sized grains at the beginning of both deformation processes. With the increase of strain,the density of the twins increases correspondingly and the twins tend to be stretched. When the metal was deformed in constant speed mode, the twin was long and thin and the distribution was non-uniform with the irregularity of interlacing. In contrast, when the metal was formed in the unidirectional deceleration mode, the twin was initially wide but was gradually transformed to long and thin, and the twin distributions were relatively more uniform and intersected. The density of twin increased and the overall hardness decreased when the metal was formed in the unidirectional decelerated mode. However, the hardness of the formed metal became very close under two speed modes when the reduction was approaching 25%.
武钢工业建(构)筑物状况分析及管理对策

工业建筑 , 1993, DOI: 10.13204/j.gyjz199308015
Abstract: 武钢共有总建筑面积达277万m~2的工业建筑物及包括近120座烟囱、各类设备基础、通廊、栈桥、矿槽在内的多种工业构筑物,是武钢生产发展的重要物质基础。1武钢工业建(构)筑物技术状况分析工业建(构)筑物技术状况是指其在安全性、适用性、耐久性方面的基本状况。它与设计、施工、使用密切相关,受各建设时期政治、经济形势、技术水平及后期使用状况、管理水平、技术改造等多种因素制约。技术状况优劣的主要标志是结构是否存在缺陷隐患,可靠性是否满足现行规范要求。全面掌握工
基于Copula函数的东江流域水文干旱特征分析
Hydrological Droughts Analysis Based on Copulas Function in the East River Basin, China
 [PDF]

, 张强, 陈晓宏, 陈永勤
Journal of Water Resources Research (JWRR) , 2012, DOI: 10.12677/JWRR.2012.13016
Abstract: 东江流域肩负着给珠三角及其周边城市与香港供水的重要任务,水文干旱特征的研究对于东江流域供水的不确定性及可持续性研究具有重要意义。基于此,本文利用Copula函数及第二重现期等方法对东江流域4个水文站1975~2009年的日流量数据进行了分析。研究结果表明,在东江流域,同时发生较高干旱强度与较长历时的干旱事件的风险由上游向下游逐渐减小;而发生较高干旱强度或较长干旱历时的干旱事件风险在上游最小,随着干旱强度或历时增大到一定程度,下游的风险相对降低。在进行水资源管理时,应将流域作为一个整体,全面考虑水文干旱风险在东江流域上中下游的异同,该文的研究对于东江流域水资源管理具有重要理论与现实意义
Variations of hydrological droughts largely decide the variability and availability of water resources of a river basin. The EastRiver basinbears the heavy responsibility for water supply for the megacities within the Pearl River Delta region and those in the vicinity of the Pearl River Delta such as Shenzhen andHong Kong. About 80% of the water consumption of Hong Kong has to be satisfied by the water supply from theEast River. In this case, the sustainable water supply from theEastRiver basinwill be greatly significant for the regional social stability. In this study, statistical behaviors and risks of the hydrological droughts of the East River basin are evaluated using copula functions and the secondary return periods based on the daily streamflow data covering the period of 1975-2009. The research results indicate that the hydrological droughts of high drought severity and long duration are subjected to the decreasing risks from the upper to the lower East River basin. However, the droughts of higher severity or long duration are subjected to the lower risk in the upperEastRiver basinwhen compared to those in the lowerEastRiver basin. Water resources management of theEastRiver basinshould be integrated by taking theEastRiver basinas a whole. And the results of this study will provide theoretical and scientific grounds for the basin-scale water resources management.
海棒槌胶原蛋白的酶解工艺及其产物清除自由基活性的研究
,
食品科学 , 2006,
Abstract: ?本文研究了低值的芋参科海参——海棒槌(paracaudinachinensvar.)的胶原蛋白肽的制备、分离纯化及其清除自由基的活性。利用菠萝蛋白酶对海棒槌胶原进行酶解,通过正交试验,确定菠萝蛋白酶水解海棒槌胶原蛋白的最佳酶解条件为:酶解温度40℃,加酶量240u/ml,底物浓度18mg/100ml(以羟脯氨酸计),ph5.2,酶解时间为4h。在此试验条件下所得产物对超氧阴离子自由基的清除率可达到52.20%。采用超滤和sephadexg-25凝胶柱对酶解液进行分离纯化,得到清除超氧阴离子和羟基自由基能力较强的组分。
气管切开导管置入失败至窒息成功复苏一例的报道
Successful Recovery from Suffocation after Tracheotomy and Catheter Insertions Failure: A Case Report
 [PDF]

, 金苗
Asian Case Reports in Emergency Medicine (ACREM) , 2013, DOI: 10.12677/ACREM.2013.13005
Abstract:

气道异常患者行急诊手术气管插管失败窒息,至心跳停止,后经及时有效地判断原因并处理。复苏成功。
A patient with airway anomalies suffocated form the failure of tracheal intubation when undergoing an emergency surgery, which led to a cardiac arrest. The patient was then successfully resuscitated after timely and effect- ive diagnosis and treatment.

氯诺昔康行超前镇痛在妇科手术中的临床应用
The Clinical Application of Preemptive Analgesia with Lornoxicam for Patients Undergoing Gynecological Operation
 [PDF]

, 金苗
Asian Case Reports in Anesthesiology (ACRA) , 2013, DOI: 10.12677/ACRA.2013.12002
Abstract:

目的:研究氯诺昔康行超前镇痛用于妇科手术的镇痛作用及效果和镇痛的不良反应。方法:50ASA(美国麻醉医师协会)I~II级择期行妇科手术的病人,随机分为两组,每组25例。在手术结束后,两组病人均安置硬膜外镇痛泵。I(氯诺昔康行组)术前5 min静脉缓慢注射氯诺昔康0.2 mg?kg1,并减少镇痛液中吗啡浓度至常规的一半;II(对照组

基于多变量概率分析的珠江流域干旱特征研究
,张强,陈晓宏
地理学报 , 2012, DOI: 10.11821/xb201201009
Abstract: 根据珠江流域42个站点1960-2005年的46年日降水资料,以6个月尺度的SPI值表征珠江流域干旱情况。通过Mann-Kendall趋势分析研究了珠江流域干旱时间演变特征,同时基于多变量Copula函数,在定义的两种不同干旱情景下,根据两变量联合重现期及其对应的第二重现期,比较性地研究了珠江流域的干旱风险。研究结果表明(1)珠江流域西部有变旱的趋势而东部有变湿润的趋势,其中显著的变旱趋势集中在11、12、1月,显著的变湿趋势集中在6、7月。同时除个别站点外,干旱历时和干旱严重程度趋势不显著;(2)珠江流域整体上干旱风险较大,东部要比西部干旱风险高。珠江流域内发生长历时干旱时,干旱严重程度也往往很大,对干旱风险管理很不利。在发生严重程度的干旱时,珠江流域东部的干旱高风险区域增加,威胁珠江三角洲地区水资源安全;(3)由于第二重现期综合考虑了各种情况,可能第二重现期对干旱风险分析的结果更稳健一些。
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