>> Nonlinear Landau damping and inviscid damping
Speaker: Prof. Lin Zhiwu (Georgia Institute of Technology)
Topic: Nonlinear Landau damping and inviscid damping
Venue: Room 1568, Natural Science Classroom Building NO.1, Peking University
Date: Dec. 27, 2010 (Monday)
Time: 10:30-12:00
Organizer: PKU School of Mathematical Science
Intro:
Consider electrostatic plasmas described by 1D Vlasov-Poisson with a fixed ion background. In 1946, Landau discovered the linear decay of electric field near a stable homogeneous state. The nonlinear Landau damping was recently proved for analytic perturbations by Villani & Mouhot and for general perturbations it is still largely open. With Chongchun Zeng at Georgia Tech, we construct nontrivial traveling waves (BGK waves) with any spatial period which are arbitrarily near any homogeneous state in H^s (s<3/2) Sobolev norm of the distribution function. Therefore, the nonlinear Landau damping is NOT true in H^s (s<3/2) spaces. We also showed that in small H^s (s>3/2) neighborhoods of linearly stable homogeneous states, there exist no nontrivial invariant structures. This suggests that the long time dynamics near stable homogeneous states in H^s (s>3/2) spaces might be much simpler and the nonlinear damping might be hoped for. We also obtained similar results for the problem of nonlinear inviscid damping of Couette flow, for which the linear decay was first observed by Orr in 1907.
Speaker: Professor Wu Xiangdong (Beijing Normal University)
Topic: Marx in the eyes of Rawls
Venue: 1st Floor Meeting Hall, Dept. of Philosophy, PKU
Date: Dec. 26, 2010 (Sunday)
Time: 16:00-18:00
Organizer: PKU Dept. of Philosophy
>> Cloud DB and Virtualization
Speaker: Mr. Chen Jidong/ Mr. Yang Ziye
Topic: Cloud DB and Virtualization
Venue: Room 2129, Natural Science Classroom Building NO.2, Peking University
Date: Dec. 24, 2010 (Friday)
Time: 15:10-17:00
Organizer: School of Electronics Engineering and Computer Science
Intro:
A few of hot IT technologies and their trends will be discussed.
>> Compressed sensing, variational methods and their application on image processing
Speaker: Dr. Yu Mao (IMA, University of Minnesota)
Topic: Compressed sensing, variational methods and their application on image processing
Venue: Room 1560, Natural Science Classroom Building NO.1, Peking University
Date: Dec. 23, 2010 (Thursday)
Time: 15:00-17:00
Organizer: PKU School of Mathematical Science
>> Design of Traceability Systems for Product Recall
Speaker: Dai Hongyan
Topic: Design of Traceability Systems for Product Recall
Venue: Meeting Room 608, Founder Building
Date: Dec. 23, 2010 (Thursday)
Time: 13:00-16:00
Organizer: PKU College of Engineering
Intro:
A product recall is enormously expensive, and its damage usually goes far beyond financial impact. A poorly executed recall can destroy a company’s reputation. Implementing a recall means finding the defective products, and this may be difficult in a long and complex supply chain. It is therefore important to design the supply chain’s traceability system to support potential recalls. In this paper, we consider several options for tracing products with different degrees of accuracy and different levels of coding. A rigorous model is proposed to determine the design parameters by quantifying the economics of the traceability systems with consideration of technology characteristics, cost effectiveness and willingness to participate by all stakeholders. Moreover, the paper investigates the impacts of pricing strategies on liability exposure for each self-interested party and the incentives to improve traceability. Our ultimate goal is to provide a systematic method to better manage product recalls by incorporating new technologies to improve the traceability of supply chains.
>>A Comparison Between the Chinese and Korean Company Tax Law
Topic: A Comparison Between the Chinese and Korean Company Tax Law
Venue: No. 4 Meeting Room, Yingjie Overseas Exchange Center, Peking University
Date: Dec. 23, 2010 (Thursday)
Time: 09:00-12:00
Organizer: Law School
>> Quantum Measurement and Quantum Thermodynamics
Speaker: Prof. Sun Changpu
Topic: Quantum Measurement and Quantum Thermodynamics
Venue: Room 201, Wen-shi Classroom Building, Peking University
Date: Dec. 22, 2010 (Wednesday)
Time: 18:40-20:30
Organizer: PKU School of Physics
Speaker: Prof. Jian Lu
Topic: Recent developments of multiscale solid mechanics for the study of the high strength and high ductility nanomaterials
Venue: Seminar 434, The Building of Mechanics, Peking University
Date: Dec. 22, 2010 (Wednesday)
Time: 15:00-16:30
Organizer: PKU College of Engineering
Intro:
The multiscale solid mechanics tools are the major keys for understanding, designing and achieving the new nanomaterials. The ability to create structural materials of high yield strength and yet high ductility has been a dream for materials scientists for a long time. We summarize the recent developments of the advanced nanomaterials with exceptional mechanical properties. The basic concept of surface nanocrystallization of materials will be presented. The computational models successfully simulate the enhanced ductility and strength and provide valuable information about the failure mechanisms of the nanostructured material. Based on the new concepts developed for toughening the high strength materials, different new categories of nanomaterials have been realized. The development of materials and structures with nano-, micro- and macro-scale functional gradients for generating different toughening mechanisms using the non localization approach will be presented. The applications in different industrial sectors (automotive, biomedical, civil structure, aerospace, energy) will be presented.
>> How Modulators are Modulated?
Speaker: Dr. Luo Minmin
Topic: How modulators are modulated?
Venue: Room 408,Classroom Building No.3, Peking University
Date: Dec. 21, 2010 (Tuesday)
Time: 15:10-17:00
Organizer: PKU Dept. of Psychology
>> From Medical Genomics to Personalized Healthcare
Speaker: Jun Wang
Topic: From Medical Genomics to Personalized Healthcare
Venue: Meeting Room 306, Yingjie Overseas Exchange Center, Peking University
Date: Dec. 21, 2010 (Tuesday)
Time: 14:30-15:30
Organizer: PKU Reseach Center for Molecular Medicine
>> Functional Nanostructured Materials For Energy Harvesting
Speaker: Dr. Yue Wu
Topic: Functional Nanostructured Materials For Energy Harvesting
Venue: Room A205, the Building of Chemistry, Peking University
Date: Dec. 21, 2010 (Tuesday)
Time:14:00-16:00
Organizer: PKU College of Engineering
Intro:
Semiconductor nanostructures with finite size and novel electric/optical properties have a great potential for energy harvesting. In this presentation, I will discuss the rational synthesis of these unique platforms of nanoparticles, nanorods, and nanowires and their applications in photovoltaic solar cells and thermoelectrics. A close look at the chemical reactions, including surface ligand exchange and cation insertion, shows an innovative way to improve the device performance and the efficiency in energy conversion.
>> Persistence of a single phytoplankton species
Speaker: Prof. Yuan Lou (Ohio State Univeristy)
Topic: Persistence of a single phytoplankton species
Venue: Room 1568, Natural Science Classroom Building No.1, Peking University
Date: Dec. 21, 2010 (Tuesday)
Time: 10:00-11:00
Organizer: PKU School of Mathematical Science
Intro:
We investigate a nonlocal reaction-diffusion-advection equation which models the growth of a single phytoplankton species in a water column where the species depends solely on light for its metabolism. We study the effect of sinking rate, water column depth and vertical turbulent diffusion rate on the persistence of a single phytoplankton species. This is based upon a joint work with Sze-Bi Hsu, National Tsing-Hua University.
Translated by: Chen Wei
Edited by: Zhang Chunlan
Source: Peking University Lecture Hall
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