检索结果-南通市图书馆

The Research on Adaptive Control Modeling of a Liquid Fertilizer Spreader

在线全文

学校读者我要写书评

暂无评论

engineering（科研） 2010年第2期2卷 113-117页

作者： z.D. Yang 不详

This paper describes a general modeling and control approach for steering wheel variable rate liquid fertilizer applicator. An adaptive numerical modeling approach for describing the system input-output dynamics is proposed, and an optimal control that accounts for the control hardware limits is developed. Field tests have demonstrated the effectiveness of the theoretical development.

关键词： Adaptive Control Variable Rate Fertilizer Precision Agriculture Optimal Control Manure Spreader

压电、压磁及电磁耦合弹性介质材料的弹性常数与工程材料常数之间的关系

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

四川大学学报（工程科学版） 2003年第6期35卷 26-30页

作者：关群何顺荣合肥工业大学土建学院安徽合肥230009

从横观各向同性的压电、压磁和电磁耦合弹性介质材料的平衡方程、梯度方程和本构方程出发,导出了三维压电、压磁和电磁耦合弹性介质材料的弹性常数在二维情况下的表达式。同时,讨论了平面应力、平面应变和轴对称情况下材料常数的对应关... 详细信息

从横观各向同性的压电、压磁和电磁耦合弹性介质材料的平衡方程、梯度方程和本构方程出发,导出了三维压电、压磁和电磁耦合弹性介质材料的弹性常数在二维情况下的表达式。同时,讨论了平面应力、平面应变和轴对称情况下材料常数的对应关系,进而分析了z轴极化的压电、压磁和电磁耦合弹性介质材料的弹性常数与工程常数之间的关系。分析结果表明压电、压磁和电磁耦合弹性介质材料的弹性常数和泊松比与弹性、压电、介电、压磁、电磁和磁通率等常数有关,这是由于该材料的机电耦合性导致其弹性常数和泊松比较单一材料的要复杂的多。

关键词：压电材料压磁材料电磁耦合弹性介质材料弹性常数工程材料常数平面应力平面应变智能材料

REVIEW AND PROSPECT OF HIGH STRengTH LOW ALLOY TRIP STEEL

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(english Letters) 2003年第6期16卷 457-465页

作者： L.Li P.Wollants Y.L.He B.C.DeCooman X.C.Wei z.Y.Xu SchoolofMat.Sci.＆eng. ShanghaiUniversityShanghai200072China Dept.MTM KatholiekeUniversiteitLeuvenB-3001LeuvenBelgium Dept.MetallurgyandMaterialsScience UniversiteitGentBelgium Dept.Mat.Sci＆eng. ShanghaiJiaotongUniversityShanghai200030China

Research status of high strength low alloy TRIP (transformation induced plasticity) steels for automobile structural parts is briefly described. Composition and microstruc-ture factors especially the morphology, size and volume fraction of retained austenite, which largely influence the strength and ductility of the steel, are reviewed and discussed one after another. Modelling of the inter-critical annealing and martempering processes as well as the designing of the TRIP steel aided by commercial software are introduced. Some special aspects of the dynamic mechanical properties of TRIP steel are firstly reported.

关键词： HSLA TRIP steel retained austenite dynamic mechanical prop-erty thermodynamics kinetics

Microwave-assisted Synthesis and Surface Modification of znO Nanoparticles

在线全文

学校读者我要写书评

暂无评论

Microwave-assisted Synthesis and Surface Modification of ZnO...

Crustal and uppermost mantle structure of Caucasus and surrounding regions

中国颗粒学会第六届学术年会暨海峡两岸颗粒技术研讨会

作者： R.Y.Hong~(1,2),J.H.Li~1,H.z.Li~2 (1.Chem.eng.Dept.& Key Lab.of Organic Synthesis of Jiangsu Prov.,Soochow Univ.,SIP,Suzhou 215123,China 2.State Key Lab.of Multiphase Reaction,Inst.of Proc.eng.,Chinese Academy of Sciences,Beijing 100080,China)

＜正＞Microwave was introduced in as a heat source during the homogeneous precipitation for the precursor of *** znO nanoparticles were obtained via calcination of the *** surface of the as-prepared znO nanoparticles was activated using silane coupling agent and then modified with polymethyl methacrylate by grafting *** electron microscopy and scanning electron microscopy exhibited the morphologies of znO *** crystalline structure of the nanoparticles was characterized by X-ray powder *** Transform infrared spectroscopy,lipophilic test,contact angle measurement and differential scanning calorimetry illustrated that znO nanoparticles were well *** results show that the microwave-assisted technique is a perfect method for nanoparticles synthesis and surface modification.

关键词： microwave znO nanoparticles surface modification surface properties

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Earthquake Science 2012年第5期25卷 505-515页

作者： Youshun Sun M Nafi Toksz Randolph J Martin Mary Krasovec Diming Yu Qingyun Liu Jun Liu State Key Laboratory of Geodesy and Earth's Dynamics Institute of Geodesy and GeophysicsChinese Academy of Sciences Department of Earth Atmospheric and Planetary SciencesMassachusetts Institute of Technology New england Research Inc.White River Jct. School of Civil engineering and Architecture Wuhan University of Technology

A 3-D P-wave velocity model is developed for the crust and uppermost mantle of Caucasus and the surrounding area by applying the tomographic method of zhao et al. using 300 000 high-quality P-wave first arrivals from 43 000 events between 1964 and 2005. This tomographic method can accommodate velocity discontinuities such as the Moho in addition to smooth velocity variations. The spatial resolution is 1°× 1° in the horizontal direction and 10 km in depth. The velocity images of the upper crust correspond well with the surface geology. Beneath the southern Caucasus high velocity anomalies are found in the middle crust and low velocity anomalies are found in the uppermost mantle. Relatively low Pn velocities are located under the Lesser Caucasus, eastern Turkey, and northern Iran. Higher Pn velocities occur under the eastern portion of the Black Sea and the southern Caspian Sea, and also extend into the eastern edge of Azerbaijan. Tomographic model significantly reduces the travel-time residuals.

关键词： Caucasus region crustal structure Pn velocity 3-D tomography

A METHOD FOR SOLVING DOA ESTIMATION AMBIGUITY IN ESPRIT ALGORITHM

在线全文

学校读者我要写书评

暂无评论

Journal of Electronics(China) 2000年第4期17卷 325-330页

作者： He zishu Li Yong Huang zhenxing (Iust. of Electron. eng., University of Electronic Science & Technology of China, Chengdu 610054) Inst. of Electron. eng. University of Electronic Science & Technology of China Chengdu

This paper introduces a method for solving DOA estimation ambiguity in ESPRIT algorithm with the conventional beamformer. With the help of it, for any space of two subarrays, the signal DOA in [-π/2 ,π/2] can be estimated effectively by using ESPRIT algorithm. Finally, some simulation results to verify the theoretical analyses are presented.

关键词： ESPRIT algorithm Solving ambiguity Signal DOA estimation

中药穴位注射治疗早中期膝关节骨性关节炎的近期疗效观察及肌力分析

在线全文

学校读者我要写书评

暂无评论

现代医药卫生 2018年第20期34卷 3114-3118页

作者：曾子全赵传喜刘文刚广东省第二中医院骨伤一科广州510095

目的观察中药穴位注射疗法对早中期膝关节骨性关节炎患者Western Ontario大学和McMaster大学关节炎量表(WOMAC)评分及膝关节屈伸肌力的影响。方法将2015年7月至2017年12月该科收治的80例患者按照随机数字表法分为中药穴位注射组和玻璃... 详细信息

目的观察中药穴位注射疗法对早中期膝关节骨性关节炎患者Western Ontario大学和McMaster大学关节炎量表(WOMAC)评分及膝关节屈伸肌力的影响。方法将2015年7月至2017年12月该科收治的80例患者按照随机数字表法分为中药穴位注射组和玻璃酸钠组,每组40例。中药穴位注射组采用膝关节穴位注射舒血宁注射液治疗,玻璃酸钠组采用关节腔注射玻璃酸钠治疗,每组均每周注射1次,5次为1个疗程,同时使用BIODEX System 4等速肌力测试系统测试等速向心/向心模式下的患膝关节屈、伸肌力矩峰值。观察2组治疗前后的WOMAC评分及膝关节屈、伸肌力矩峰值的变化情况。结果 2组治疗疗效比较,差异无统计学意义(P>0.05);2组治疗后的WOMAC评分均较同组治疗前下降,且中药穴位注射组治疗后WOMAC评分较玻璃酸钠组低,差异均有统计学意义(P0.05);在低速角速度(60°/s)下,2组治疗后膝关节屈肌力矩峰值与治疗前比较,差异均有统计学意义(P0.05)。结论中药穴位注射疗法治疗早中期膝关节骨性关节炎的疗效确切,可以减轻疼痛,改善膝关节功能,提高膝关节伸肌肌力,是一种治疗早中期膝关节骨性关节炎的有效方法。

关键词：骨关节炎,膝选穴膝关节骨性关节炎中药穴位注射 WOMAC评分等速肌力测定临床观察

A STEEL MATRIX WEAR RESISTANT COMPOSITE REINFORCED BY IN-SITU GRANULAR EUTECTICS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(english Letters) 2001年第2期14卷 79-84页

作者： z.M. Xu, T.X. Li and J.G. Li (School of Materials Science and engineering, Shanghai Jiao Tong University, Shanghai 200030, China) Sch. of Mat. Sci. and eng. Shanghai Jiaotong Univ. Shanghai 200030 China

A new steel matrix wear resistant composite reinforced by in situ granular eutectics can be obtained by modifying with a Si-Ce-Ti compound in the steel melt. The result indicates that the in situ granular eutectic is a pseudo-eutectic of austenite and (Fe,Mn)3C, which is formed between austenite dendrites during solidification due to the segregation of C and Mn impelled by modifying elements. The quantity of in situ granular eutectic reaches up to 8%-12% and its grain size is in the range from 10um to 20um. The austenite steel matrix wear resistant composite reinforced by in situ granular eutectic (abbreviated AGE composite) and austenite-bainite steel mains wear resistant composite reinforced by in situ granular eutectic (abbreviated ABGE composite) are obtained in the as-cast state and by air hardening, respectively. The wear resistance of the AGE and ABGE composites can be more greatly increased than that of their matrix steels under low and medium impact working condition.

关键词： steel matrix composite Si-Ce-Ti compound in situ granular eutectic mechanical property

在线全文

学校读者我要写书评

暂无评论

直接金属选区激光多道烧结温度场有限元模拟

四川大学学报（工程科学版） 2005年第1期37卷 47-51页

作者：沈显峰王洋姚进杨家林四川大学制造科学与工程学院四川成都610065 中国工程物理研究院机械制造工艺研究所四川绵阳621900

局部输入的集中移动激光热源势必造成直接金属选区激光烧结过程中温度场分布不均匀、不稳定。研究多道激光烧结对掌握烧结过程中温度场动态分布及不同烧结道的相互影响规律具有重要意义。在考虑随温度变化而变化的热传导、比热容等热物... 详细信息

局部输入的集中移动激光热源势必造成直接金属选区激光烧结过程中温度场分布不均匀、不稳定。研究多道激光烧结对掌握烧结过程中温度场动态分布及不同烧结道的相互影响规律具有重要意义。在考虑随温度变化而变化的热传导、比热容等热物性参数的作用下,建立直接金属多道烧结的三维温度场有限元模型。采用AN SYS参数化设计语言模拟多道烧结的热源移动,用焓处理相变潜热的影响。模拟结果显示:随着烧结过程的进行,随后的烧结道具有越来越大的热影响区域,且热影响区域的不均衡性越来越明显;极大的温度梯度发生在激光束扫描方向改变时的烧结件边沿区域。模拟结果的最高温度、平均温度与先前的实验结果一致。

关键词：快速原型/制造选区激光烧结数值模拟有限元分析温度场潜热