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结构可观性与石油分馏塔的观测计算 被引量:9
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作者 丛松波 袁璞 沈复 《石油学报(石油加工)》 EI CAS CSCD 北大核心 1998年第1期66-72,共7页
分析了具有不可测输入和状态时间滞后的非线性系统的结构可观性和可重构性,给出了一种判断结构可观性和可重构性的简易方法。结构可观性只能给出系统可观的必要条件,但对于很多实际工程系统,它也是充分条件。以石油分馏塔为例,以速... 分析了具有不可测输入和状态时间滞后的非线性系统的结构可观性和可重构性,给出了一种判断结构可观性和可重构性的简易方法。结构可观性只能给出系统可观的必要条件,但对于很多实际工程系统,它也是充分条件。以石油分馏塔为例,以速率方程的非相平衡的动态模型为基础,对可观性进行了分析,给出了测点布局设计的原则,分析了在线实时观测计算产品组成(质量指标)的途径。分析的实时计算结果已用于几个炼油厂产品质量的在线计算与闭环控制,取得了明显的经济效益。 展开更多
关键词 时间滞后 结构可观性 石油分馏塔 炼油厂
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结构可观的换热网络温度测点分析及控制系统设计 被引量:4
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作者 罗雄麟 侯本权 孙琳 《化工学报》 EI CAS CSCD 北大核心 2012年第1期146-156,共11页
复杂换热网络中间温度状态变量众多且变量间耦合严重,若不加以控制与观测,往往不利于物流间的热量传递与安全监测。换热网络的温度测点设置是实施控制的基础,为保证全部状态的可观性,凭经验设置的温度测点往往过多,经济性差,也缺乏理论... 复杂换热网络中间温度状态变量众多且变量间耦合严重,若不加以控制与观测,往往不利于物流间的热量传递与安全监测。换热网络的温度测点设置是实施控制的基础,为保证全部状态的可观性,凭经验设置的温度测点往往过多,经济性差,也缺乏理论论证与分析。因此从控制理论的角度,基于结构可观性理论分析换热网络的结构特性。分析旁路设置对换热网络结构可观性的影响,权衡可观性与经济性两方面因素,为实现设置最少的温度测点以满足全部状态的可观性要求,提出了换热网络全部状态可观的温度测点优化设计法。然后,基于相对增益分析,将已有旁路与优化得出的温度测点进行配对,构成换热网络的常规控制系统。最后,以某常减压蒸馏装置脱盐前换热网络为例验证了方法的可行性。 展开更多
关键词 换热网络 结构可观性 温度测点 控制系统 优化设计
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Experimental and numerical studies on aluminum-stainless steel explosive cladding 被引量:10
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作者 ELANGO E SARAVANAN S RAGHUKANDAN K 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第6期1742-1753,共12页
In this study,the effect of varied loading ratio(mass of the explosive/mass of flyer plate)on the nature of interface,temperature and pressure developed in aluminum-steel explosive cladding is presented.Increase in th... In this study,the effect of varied loading ratio(mass of the explosive/mass of flyer plate)on the nature of interface,temperature and pressure developed in aluminum-steel explosive cladding is presented.Increase in the loading ratio,R,enhances the pressure developed,kinetic energy utilization and deformation work performed.Interfacial microstructures exhibit the formation of molten layer at few spots,owing to the increase in temperature beyond the melting point of parent alloy.The increase in temperature and the quantum of pressure developed were determined by numerical simulation performed in Ansys AUTODYN by employing smoothed particle hydrodynamics(SPH)method.The positioning of the experimental conditions on the weldability window is presented as well. 展开更多
关键词 explosive cladding dissimilar metals numerical simulation MICROSTRUCTURE weldability window
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Influence of SiO_2 nano-particles on microstructures and properties of Ni-W-P/CeO_2-SiO_2 composites prepared by pulse electrodeposition 被引量:2
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作者 王军丽 徐瑞东 章俞之 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第5期839-843,共5页
Ni-W-P base composites containing CeO2 and SiO2 nano-particles were prepared on common carbon steel surface by pulse co-deposition of Ni,W,P,CeO2 and SiO2 nano-particles.The influence of SiO2 concentrations in bath on... Ni-W-P base composites containing CeO2 and SiO2 nano-particles were prepared on common carbon steel surface by pulse co-deposition of Ni,W,P,CeO2 and SiO2 nano-particles.The influence of SiO2 concentrations in bath on microstructures and properties of Ni-W-P/CeO2-SiO2 composites was studied,and the characteristics were assessed by chemical compositions,element distribution,surface morphologies,deposition rate and microhardness.The results indicate that when SiO2 concentration in bath is controlled at 20 g/L,the composites possess the fastest deposition rate,the highest microhardness,compact microstructures,smaller crystallite sizes and uniform distribution of W,P,Ce and Si within Ni-W-P matrix metal.Increasing SiO2 concentration in bath from 10 to 20 g/L leads to the refinement in grain size and the inhomogeneity of microstructures.While when SiO2 concentration is increased to 30 g/L,the crystallite sizes increase again and some bosses with nodulation shape appear on the surface of composites. 展开更多
关键词 pulse electrodeposition NANO-PARTICLE composite microstructure and property
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Recent advances of the Bergman cyclization in polymer science 被引量:2
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作者 Shudan Chen Aiguo Hu 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第11期1710-1723,共14页
The Bergman cyclization has strongly impacted on a number of fields including pharmaceutics, synthetic chemistry, and material science. The diradical intermediates stemmed from enediynes can not only cause DNA cleavag... The Bergman cyclization has strongly impacted on a number of fields including pharmaceutics, synthetic chemistry, and material science. The diradical intermediates stemmed from enediynes can not only cause DNA cleavage under physiological conditions but also function as monomer or initiator participants in polymer science. The homo-polymerization of enediynes through the Bergman cyclization to fabricate conjugated polymers is a fascinating strategy due to the advantages of facial operation, high efficiency, tailored structure, and catalyst-free operation. Moreover, conjugated polymers generated through the Bergman cyclization show many remarkable properties, such as excellent thermal stability, good solubility, and processability, which enables these polymers to be further manufactured into carbon-rich materials. Recent times have seen extensive efforts devoted to the application of the Bergman cyclization in polymer science and materials chemistry. A variety of synthetic strategies have been developed to fabricate structurally unique materials via the Bergman cyclization, including the fabrication of rod-like polymers with polyester, dendrimers and chiral imide side chains, functionalization of carbon nanomaterials by surface-grafting conjugated polymers, formation of nanoparticles by intramolecular collapse of single polymer chains, and the construction of carbon nanomembranes with different morphologies. Future developments involving the Bergman cyclization in polymer science, probably by altering the reaction mechanism to precisely control the microstructure of polymeric products, are also proposed in this review article. 展开更多
关键词 Bergman cyclization ENEDIYNES conjugated polymer carbon material
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