Structure of polydisperse inverse ferrofluids: Theory and computer simulation

By using theoretical analysis and molecular dynamics simulations, we investigate the structure of colloidal crystals formed by nonmagnetic microparticles (or magnetic holes) suspended in ferrofluids (called inverse ferrofluids), by taking into account the effect of polydispersity in size of the nonmagnetic microparticles. Such polydispersity often exists in real situations. We obtain an analytical expression for the interaction energy of monodisperse, bidisperse, and polydisperse inverse ferrofluids. Body-centered tetragonal (bct) lattices are shown to possess the lowest energy when compared with other sorts of lattices and thus serve as the ground state of the systems. Also, the effect of microparticle size distributions (namely, polydispersity in size) plays an important role in the formation of various kinds of structural configurations. Thus, it seems possible to fabricate colloidal crystals by choosing appropriate polydispersity in size.Comment: 22 pages, 8 figure

A novel method for surface exploration: Super-resolution restoration of Mars repeat-pass orbital imagery

Higher resolution imaging data of planetary surfaces is considered desirable by the international community of planetary scientists interested in improving understanding of surface formation processes. However, given various physical constraints from the imaging instruments through to limited bandwidth of transmission one needs to trade-off spatial resolution against bandwidth. Even given optical communications, future imaging systems are unlikely to be able to resolve features smaller than 25 cm on most planetary bodies, such as Mars. In this paper, we propose a novel super-resolution restoration technique, called Gotcha-PDE-TV (GPT), taking advantage of the non-redundant sub-pixel information contained in multiple raw orbital images in order to restore higher resolution imagery. We demonstrate optimality of this technique in planetary image super-resolution restoration with example processing of 8 repeat-pass 25 cm HiRISE images covering the MER-A Spirit rover traverse in Gusev crater to resolve a 5 cm resolution of the area. We assess the “true” resolution of the 5 cm super-resolution restored images using contemporaneous rover Navcam imagery on the surface and an inter-comparison of landmarks in the two sets of imagery

Necessity of integral formalism

To describe the physical reality, there are two ways of constructing the dynamical equation of field, differential formalism and integral formalism. The importance of this fact is firstly emphasized by Yang in case of gauge field [Phys. Rev. Lett. 33 (1974) 445], where the fact has given rise to a deeper understanding for Aharonov-Bohm phase and magnetic monopole [Phys. Rev. D. 12 (1975) 3845]. In this paper we shall point out that such a fact also holds in general wave function of matter, it may give rise to a deeper understanding for Berry phase. Most importantly, we shall prove a point that, for general wave function of matter, in the adiabatic limit, there is an intrinsic difference between its integral formalism and differential formalism. It is neglect of this difference that leads to an inconsistency of quantum adiabatic theorem pointed out by Marzlin and Sanders [Phys. Rev. Lett. 93 (2004) 160408]. It has been widely accepted that there is no physical difference of using differential operator or integral operator to construct the dynamical equation of field. Nevertheless, our study shows that the Schrodinger differential equation (i.e., differential formalism for wave function) shall lead to vanishing Berry phase and that the Schrodinger integral equation (i.e., integral formalism for wave function), in the adiabatic limit, can satisfactorily give the Berry phase. Therefore, we reach a conclusion: There are two ways of describing physical reality, differential formalism and integral formalism; but the integral formalism is a unique way of complete description.Comment: 13Page; Schrodinger differential equation shall lead to vanishing Berry phas

Institutions and FDI location choice: The role of cultural distances

Using an extensive data set on foreign invested enterprises (FIEs) in the Chinese mainland, we compare the sensitivities of the location choice of foreign direct investment (FDI) from six major source countries/areas (Hong Kong, Taiwan, US, EU, Japan and Korea) toward the variation in the strength of economic institutions across China's regions. It is found that FIEs from the source countries/areas that are culturally more remote from China often exhibit a stronger aversion to regions with weaker economic institutions. Moreover, this pattern is often more salient when FDI takes the form of fully-owned enterprises (FOEs) than when it takes the form of joint ventures (JVs). © 2011 Elsevier Inc..preprin

Exporting behavior of foreign affiliates: Theory and evidence

Firms have increasingly conducted different stages of production in different countries. In particular, they may set up operations in low-cost countries (those operations are referred to as foreign affiliates in those countries) either as platforms for export or serving the growing markets there. What is the exporting behavior of foreign affiliates? In this paper, using data from China, we find that among foreign affiliates exporters are less productive than non-exporters. We then offer a theoretical explanation by incorporating into the standard firm heterogeneity model the possibility that firms could have different stages of production in different countries. © 2010 Elsevier B.V.postprin

Negotiable Instruments, in Particular Bills of Exchange in Macau, China

The rapid development of Information Technology has revolutionized the way people and businesstransfer funds and has led European nations to enact new laws to regulate payments conducted electronically. TheMacau law of negotiable instruments, mainly stipulated in Commercial Code of Macau and regulations concerningelectronic fund transfers, have been influenced by modern European Law and principles in the way of absorbing thecurrent legal expertise from western countries. In Macau, the Electronic Funds Transfer System provides a costeffectiveand efficient method to transfer funds electronically directly into a specified bank or building societyaccount. At the same time, it has significantly reduced the importance of the traditional negotiable instruments bothin domestic and in International trade

Why do firms conduct bi-sourcing?

In acquiring the same intermediate inputs, a firm often conducts bi-sourcing, i.e., simultaneously buying from external suppliers and self-producing in an internal manufacturer. We show that the firm achieves a better bargaining position in bisourcing than in outsourcing through cross threat effect, which enhances profitability. © 2006 Elsevier B.V. All rights reserved.preprin