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Search Results: 1 - 10 of 115784 matches for " 黄登峰 "
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漂浮基柔性空间机械臂关节运动的分块神经网络控制及柔性振动模糊控制
,陈力
工程力学 , 2012,
Abstract: 讨论了载体位置不受控、姿态受控情况下,漂浮基柔性空间机械臂关节运动及柔性振动主动抑制的控制问题。由系统动量守恒关系及假设模态法,利用拉格朗日方法建立了漂浮基柔性空间机械臂的系统动力学方程。之后采用奇异摄动理论,将其分解为表示刚性运动的慢变子系统和柔性振动的快变子系统。据此,设计了柔性空间机械臂系统载体姿态及机械臂关节铰协调运动的组合控制器。针对慢变子系统——柔性空间机械臂的刚性运动,设计了分块神经网络控制器,以完成系统参数未知情况下关节空间协调运动的轨迹跟踪;而对于快变子系统——柔性臂的振动,则设计了模糊控制器来主动抑制柔性杆的振动。数值仿真证实了提出方法的有效性。
双臂空间机器人协调运动的模糊基函数网络控制
,陈力
工程力学 , 2012, DOI: 10.6052/j.issn.1000-4750.2010.11.0839
Abstract: 该文研究了在本体位置不受控、姿态受控的情况下,漂浮基双臂空间机器人系统惯性空间协调运动的轨迹跟踪问题。针对存在外部扰动和未知系统惯性参数的情况,设计了一种基于模糊基函数网络的自适应调节控制方案。用模糊基函数网络对双臂空间机器人系统建模,利用鲁棒技术处理建模误差和外部扰动在内的不确定性。所提控制方案的特点是:不需要动力学方程中的惯性参数符合线性规律,也无需预知系统的惯性参数;同时可以利用学习规则在线自适应调节模糊基函数网络的所有权值和参数,因此控制方案是灵活的。该文稳定性分析证明了控制方案的全局稳定性和良好的轨迹跟踪性能。仿真算例表明了该方案能有效地控制双臂空间机器人的本体姿态和末端爪手协调地跟踪期望的运动轨迹。
漂浮基空间机械臂姿态、关节协调运动的模糊小波神经网络控制
,陈力
空间科学学报 , 2011,
Abstract: 讨论了本体姿态受控、位置不受控制的漂浮基空间机械臂系统协调运动的动力学控制问题.根据系统位置几何关系、动量守恒关系和第二类拉格朗日方程,建立漂浮基空间机械臂系统的动力学方程.在此基础上,针对系统参数未知的情况,设计了一种采用小波基函数作为模糊隶属度函数的模糊神经网络控制器,以控制空间机械臂的本体姿态和机械臂两关节铰协调地完成各自在关节空间的期望运动.其特点是不要求系统动力学方程关于惯性参数呈线性函数关系,甚至不需要知道系统参数;而且网络权值是采用反向传播算法根据误差进行在线学习,使模糊神经网络获得更强的自学习和自适应能力,同时也节省了离线学习的时间.系统数值仿真的结果证实上述控制方案是行之有效的.
移动式矿井泥浆处理设备运行参数研究
Mobile Mine Mud Treatment Equipment Operation Parameters Optimization Research
 [PDF]

苗学敏, 国忠,, 王俊, 包丽洁, 周建情
Hans Journal of Chemical Engineering and Technology (HJCET) , 2014, DOI: 10.12677/HJCET.2014.41002
Abstract: 根据铜坑矿开采过程中所产生的矿井泥浆的性质特点,通过对泥饼含水率、干泥浆产量和固体回收率等测定分析,研究了移动式矿井泥浆处理设备主要运行参数投药量、压滤机滤带移动速度、滤带张力、进泥量以及进泥含水率对泥浆处理效果的影响。结果表明:投药量为3~4 mg/g (PAM/Al2(SO4)3 = 1:1)、滤带移动速度为2~3 m/min、滤带张力为3~3.5 kg/cm2、进泥量为0.8 L/S时,泥浆处理后泥饼呈固态饼状,固体回收率在92%以上,含水率降到40%以下。
 According to the characteristics of the mine slurry produced in process of Tongkeng Mine, through the determination of filter cake moisture content, dry mud yield and solid recovery rate, it examines the effects of mobile mine mud treatment of main operating parameters of equipment of the dosage, filter press moving speed, belt tension, mud volume and water content of sludge on sludge dewatering. The result shows that when the dosage is 3 - 4 mg/g (PAM/ Al2(SO4)3 = 1:1), belt moving speed is 2 - 3 m/min, belt tension is 3 - 3.5 kg/cm2 and mud volume is 0.8 L/S, mud becomes a solid pie after dehydration, solid recovery is above 92% and moisture content is below 40%.
A+H交叉上市股票间信息传递的不对称性研究
郭彦, , 魏宇, 林宇
中国管理科学 , 2010,
Abstract: ?研究交叉上市的香港H股与内地A股市场H股板块间信息传递的不对称性问题。以收益率和波动性作为信息流动的代理变量,采集2003年1月至2009年4月H股指数和H股板块指数的日收盘数据,通过Granger因果检验和动态条件相关二元GARCH模型进行实证检测。结果发现:收益信息由H股市场向H股板块市场单向传递,波动信息主要由H股板块市场向H股市场传递,信息传递呈现不对称性,并分别符合"国际中心"和"国内偏好"假说;H股市场与H股板块市场间的条件相关性是动态变化的,在内地A股市场引进合格的香港机构投资者后相关性逐渐增加。
基于政府角色定位的我国产学研合作促进机制研究
庆德,戴强,
科技进步与对策 , 2012, DOI: 10.6049/kjjbydc.2011120624
Abstract: 基于博弈理论分析了政府参与产学研合作的正确性和必要性,并运用安徽省产学研合作的调查数据验证了博弈结论。指出产学研合作中出现的问题仅靠自由竞争的市场制度或完全自发解决是远远不够的,政府有必要介入其中,并在合作中居中协调以及提供包括财政、法律法规等各种政策支持;在产学研合作的不同阶段,政府的角色和作用机制是不同的。政府角色产学研合作作用机制
微量Ag对CP276合金性能和组织的影响
,郑子樵,
材料工程 , 1996,
Abstract: 研究添加不同含量的Ag对CP276合金的拉伸性能和时效组织的影响。对拉伸强度、延伸率测试及透射电镜观察表明0.11wt%Ag的加入可促进T1相析出,使合金强度值升高;0.38wt%Ag的加入可在时效前期生成富Ag、Mg的稳定的GP区,从而降低合金中Cu的固溶度,阻碍Tl相析出,时效后期,GP区分解,生成大量Tl相,使合金强度值显着升高。
一种新型松香基表面活性剂在芳香醇常温水相氧化反应中的应用
梁辉,,申林
- , 2018, DOI: 10.13360/j.issn.2096-1359.2018.06.012
Abstract: 以松香为原料合成的表面活性剂具有良好的生态性能,符合“绿色化学”的要求。笔者设计合成了一种新型松香基表面活性剂(脱氢枞醇-聚乙二醇-550-琥珀酸单甲醚,DAPGS-550-M)。合成反应以脱氢枞醇为原料,分两步进行:脱氢枞醇在碱性条件下与琥珀酸酐反应得到脱氢枞醇琥珀酸酯,再与甲基聚乙二醇-550(PEG-550-M)进行酯化反应生成所需DAPGS-550-M。再利用DAPGS-550-M在水溶液中形成纳米胶束,分析各种芳香醇于室温水中的氧化反应,筛选获得最佳反应条件:室温下催化量为摩尔百分比2%的AgNO3和摩尔百分比0.5%的Bi(OTf)3,相同物质的量的K2S2O8,以及2% DAPGS-550-M的水溶液为反应介质。试验结果表明,在此反应条件下,反应底物适用性广,14种芳香醇顺利氧化得到较高产率的酮或醛产物,且均通过核磁共振进行了鉴定。此外,进一步对该新反应体系的E因子(废物与期望产物的质量比和原子经济性)以及催化体系的可循环性进行了研究,结果表明:E因子较低,且包括水、表面活性剂和催化剂在内的整个催化剂体系均易于回收利用,符合绿色化学要求。
The rosin-based surfactants, synthesized from rosin and modified rosin, have generally good ecological properties, meeting the requirements of “green raw materials” for surfactant. A novel rosin-based surfactant dehydroabietinol-polyethyleneglycol-550-succinate monomethyl ether(DAPGS-550-M)was prepared from dehydroabietinol in two steps: 1)synthesis of dehydroabietic alcohol succinate; and 2)synthesis of DAPGS-550-M. The mixture was refluxed using a Dean-Stark trap until completion. The synthesized surfactant DAPGS-550-M was then examined in the oxidatioin of aromatic alcohols in water at room temperature. After extensive screening with benzyl alcohol as a model substrate, the optimized oxidation reaction conditions were employing 2% AgNO3 and 0.5% Bi(OTf)3 together with a stoichiometric amount of K2S2O8 at room temperature. With the optimized conditions in hand, the substrate scope and generality of this oxidation methodology were further investigated under aqueous conditions at room temperature. Benzyl alcohol(1a)was completely oxidized within 20 min, delivering benzaldehyde(2a)in 96% yield. Notably, gram-scale oxidation of 1a furnished desired 2a in 89% yield. Excellent product yields were obtained within 2 h at room temperature in the oxidation of most benzylic alcohols bearing diverse substituents, including Cl(1b), Br(1c), MeO(1e and 1i), Me(1h), and diaryl(1l). Slower rates were observed with the highly electron-deficient(4-(trifluoromethyl)phenyl)methanol(1d)and 1-(4-nitrophenyl)ethan-1-ol(1k), which afforded the desired products in 8 h and 18 h respectively. The transformations of(2,6-dichlorophenyl)methanol(1f)and 9H-fluoren-9-ol(1m)were more sluggish, possibly because of the steric hindrance. Finally, 1-(thiophen-2-yl)ethan-1-ol(1n)proceeded smoothly in 17 h. Furthermore, the whole catalyst system including water, the surfactant and catalysts can be easily recycled leading to a very low E factor(the mass ratio of waste to desired product and the atom efficiency). In summary, we have introduced a new class of rosin-based surfactant DAPGS, which enabled a
渭河流域气候变化及干湿状况时空分布分析
Climate change and spatiotemporal distribution of dry-wet status in Wei River basin

雷江群,,,
- , 2015,
Abstract: 【目的】揭示渭河流域气候要素变化规律,明晰干湿状况分布及演变规律,为该流域减灾防灾决策提供支持。【方法】利用渭河流域21个气象站1960-2010年共51年的气象观测资料,采用FAO Penman-Monteith公式计算该流域各气象站的潜在蒸散量和干燥指数,通过气候倾向率、Mann-Kendall法、R/S法、小波分析、滑动平均等方法,对该区域气候要素、干燥指数的变化特征及干湿状况进行分析。【结果】(1)渭河流域51年来的降水量以1.69 mm/年不显著线性趋势减少,潜在蒸散量以0.24 mm/年不显著线性趋势增加,两者均存在17年和28年左右的变化周期;降水量与潜在蒸散量空间分布差异较明显,均呈东多西少、南多北少、由东南向西北递减的格局。(2)干燥指数以0.005/年不显著线性趋势增加,且增加趋势具有正的持续性;有8年和28年左右的干湿周期;干湿状况为东湿西干,南湿北干,呈现由东南向西北逐渐变干的格局。(3)预测该流域2010年后最湿润年份出现在2024年左右,最干燥年份出现在2019年左右。【结论】渭河流域多年来有降雨减少、潜在蒸散变大、逐渐变干的趋势,应采取应对措施减轻旱涝灾害及其不利影响。
【Objective】The variation of climate elements and distribution of dry-wet status in Wei River basin were studied to support decision making in disaster prevention and reduction.【Method】Based on observation data at 21 meteorological stations in Wei River basin from 1960 to 2010 for a total of 51 years,potential evaporation and aridity index were calculated using Penman-Monteith model.Variations in climatic elements,aridity index and dry-wet status were investigated by climatic trend rate,Mann-Kendall method,R/S method,wavelet analysis method and moving average method.【Result】(1) The precipitation decreased by 1.69 mm per year and the potential evapotranspiration increased by 0.24 mm per year.The changing periods of precipitation and potential evapotranspiration were 17 years and 28 years,respectively.The spatial distributions of precipitation and potential evapotranspiration were different,and they decreased from the southeast to the northwest of the basin.(2)The aridity index increased by 0.005 per year,and the increasing trend had a positive sustainability.The dry wet status had periods of 8 years and 28 years.The climate became drier from the southeast to the northwest.(3)The most humid year would occur in 2024,and the driest year will be 2019 in the basin. 【Conclusion】The precipitation was decreasing,the potential evapotranspiration was increasing and the climate was becoming drier in recent years.Thus,measures should be taken to reduce the adverse effects of drought and waterlogging disasters
人类活动和气候变化对北洛河径流变化的影响
Impacts of climate change and human activity on runoff variation of Beiluo River

樊晶晶,,,,
- , 2016,
Abstract: 【目的】研究气候变化和人类活动对北洛河径流变化的贡献,分析径流变化的主要驱动因子,为北洛河流域水资源的合理利用提供决策依据。【方法】以北洛河流域1956-2011年共56年的降水量以及实测、还原径流深序列为研究对象,采用Mann-Kendall法、径流系数法、降水 径流双累积曲线法进行变异点诊断,量化分析气候变化、下垫面变化和其他人类活动对径流变异的贡献率。【结果】北洛河流域1956-2011年降水量变化不明显,但还原径流深呈现出不显著增加趋势,变异点出现在1964和2001年。以变异点为分界点,将第一阶段(1956-1963年)作为下垫面Ⅰ,第二阶段(1964-2000年)作为下垫面Ⅱ建立降水 径流关系式,模拟在下垫面Ⅰ和下垫面Ⅱ情景下第三阶段(2001-2011年)的径流序列,模拟结果显示,建立的降水 径流关系式能够很好地反映不同下垫面径流的变化情况。下垫面Ⅱ与下垫面Ⅰ情况下模拟径流的变化量为-7.00 mm,表明径流下垫面Ⅱ情况下的产流比下垫面Ⅰ大。定量分析下垫面变化、其他人类活动和气候变化对径流变异的贡献,发现气候变化的贡献率为40%;人类活动为主要影响因素,总贡献率为60%,其中下垫面变化的影响占19%,其他人类活动的影响占41%。【结论】人类活动是北洛河流域径流变异的关键驱动因子,下垫面变化的影响也不可忽视。
【Objective】This study quantified the contributions of climate change and human activities to runoff change and analyzed the main driving factors in Beiluo River basin to provide reference for water resources management.【Method】The precipitation,recorded and nature runoff depths from a total of 56 years (1956-2011) in Beiluo River were analyzed to detect the impacts of underlying surface,climate change and other human activities.Mann-Kendall method,runoff coefficient method and precipitation-runoff double cumulative curve method were used to analyze the variation points and obtain the contributions of climate change,underlying surface and human activities.【Result】The precipitation did not change significantly since 1956,while the runoff had insignificantly decreasing trend.The break points occurred at 1964 and 2001.Based on the break points,the runoff series were divided into 3 portions:underlying surface Ⅰ during 1956-1963,underlying surface Ⅱ during 1964-2000,and phase 3 during 2001-2011.Runoff and precipitation correlations were developed under underlying surface Ⅰ and underlying surface Ⅱ,and used to estimate the runoff series in period 2001-2011.The estimated results showed that the developed precipitation runoff relations can identify the runoff difference between different underlying surfaces.The difference between underlying surface Ⅰ and underlying surface Ⅱ was -7.00 mm,indicating that the runoff production in underlying Ⅰ was better.Climate change contributed to 40% of runoff change.Human activities were the main driving factor at Beiluo River basin with the contribution of 60%,among which 19% was from underlying surface change and 41% was from other human activities.【Conclusion】The main driving factor of runoff change was human activities at Beiluo River basin,and the impacts of underlying surface change were also significant
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