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双真空系统──挤奶机械一项重要的技术进步 被引量:2
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作者 宋宝治 《中国奶牛》 1998年第1期47-48,共2页
双真空系统──挤奶机械一项重要的技术进步¥上海市燎原农场@宋宝治双真空系统挤奶机械一项重要的技术进步○上海市燎原农场(201408)宋宝治随着奶牛育种工作不断深入和饲养、管理工作不断改进,我国奶牛产奶量得到较大幅度的... 双真空系统──挤奶机械一项重要的技术进步¥上海市燎原农场@宋宝治双真空系统挤奶机械一项重要的技术进步○上海市燎原农场(201408)宋宝治随着奶牛育种工作不断深入和饲养、管理工作不断改进,我国奶牛产奶量得到较大幅度的增长,不少地区牛奶年单产由过去4000-... 展开更多
关键词 挤乳机械 双真空系统 使用 管理 改造
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双真空系统挤奶机的优点
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作者 蓝慈恩 王正 《中国奶牛》 1998年第2期49-50,共2页
双真空系统挤奶机的优点○广州市万日奶业机械公司(510405)蓝慈恩○广东省农科院畜牧研究所(510640)王正日本优利农机械株式会社研制生产的双真空系统挤奶机,具有单真空系统挤奶机所不能比拟的优点:1.吮吸奶头及脉... 双真空系统挤奶机的优点○广州市万日奶业机械公司(510405)蓝慈恩○广东省农科院畜牧研究所(510640)王正日本优利农机械株式会社研制生产的双真空系统挤奶机,具有单真空系统挤奶机所不能比拟的优点:1.吮吸奶头及脉动的真空度可以调节得比较低,而且不... 展开更多
关键词 挤乳机 双真空系统 优点
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WZC双室真空炉系统故障模式与故障树分析 被引量:1
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作者 李勇 周新宇 《金属热处理》 CAS CSCD 北大核心 2021年第10期248-251,共4页
以分系统、分部件的方式,对WZC双室真空油淬气冷炉系统展开故障模式与故障树分析,分别建立了炉胆、真空系统、机构和电控系统的故障模式与故障树模型,归纳出基本事件,并运用Fussel法得出了各故障树的最小割集。
关键词 WZC真空系统 故障模式 故障树分析法
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Local Smooth Solutions to the 3-Dimensional Isentropic Relativistic Euler equations 被引量:3
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作者 Yongcai GENG Yachun LI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2014年第2期301-318,共18页
The authors consider the local smooth solutions to the isentropic relativistic Euler equations in(3+1)-dimensional space-time for both non-vacuum and vacuum cases.The local existence is proved by symmetrizing the syst... The authors consider the local smooth solutions to the isentropic relativistic Euler equations in(3+1)-dimensional space-time for both non-vacuum and vacuum cases.The local existence is proved by symmetrizing the system and applying the FriedrichsLax-Kato theory of symmetric hyperbolic systems.For the non-vacuum case,according to Godunov,firstly a strictly convex entropy function is solved out,then a suitable symmetrizer to symmetrize the system is constructed.For the vacuum case,since the coefficient matrix blows-up near the vacuum,the authors use another symmetrization which is based on the generalized Riemann invariants and the normalized velocity. 展开更多
关键词 Isentropic relativistic Euler equations local-in-time smooth solutions Strictly convex entropy Generalized Riemann invariants
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The Asymptotic Behavior and the Quasineutral Limit for the Bipolar Euler-Poisson System with Boundary Efects and a Vacuum
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作者 Yeping LI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2013年第4期529-540,共12页
In this paper, a one-dimensional bipolar Euler-Poisson system (a hydrodynamic model) from semiconductors or plasmas with boundary effects is considered. This system takes the form of Euler-Poisson with an electric f... In this paper, a one-dimensional bipolar Euler-Poisson system (a hydrodynamic model) from semiconductors or plasmas with boundary effects is considered. This system takes the form of Euler-Poisson with an electric field and frictional damping added to the momentum equations. The large-time behavior of uniformly bounded weak solutions to the initial-boundary value problem for the one-dimensional bipolar Euler-Poisson system is firstly presented. Next, two particle densities and the corresponding current momenta are verified to satisfy the porous medium equation and the classical Darcy's law time asymp- totically. Finally, as a by-product, the quasineutral limit of the weak solutions to the initial-boundary value problem is investigated in the sense that the bounded L∞ entropy solution to the one-dimensional bipolar Euler-Poisson system converges to that of the cor- responding one-dimensional compressible Euler equations with damping exponentially fast as t → +∞. As far as we know, this is the first result about the asymptotic behavior and the quasineutral limit for the one-dimensional bipolar Euler-Poisson system with boundary effects and a vacuum. 展开更多
关键词 Bipolar hydrodynamic model Asymptotic behavior Quasineutral limit Entropy Energy estimate
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