Efficiency and marginal cost pricing in dynamic competitive markets with friction

This paper examines a dynamic general equilibrium model with supply friction. With or without friction, the competitive equilibrium is efficient. Without friction, the market price is completely determined by the marginal production cost. If friction is present, no matter how small, then the market price fluctuates between zero and the "choke-up" price, without any tendency to converge to the marginal production cost, exhibiting considerable volatility. The distribution of the gains from trading in an efficient allocation may be skewed in favor of the supplier, although every player in the market is a price taker.Dynamic general equilibrium model with supply friction, choke-up price, marginal production cost, welfare theorems

Modulational instability of two-component Bose-Einstein condensates in an optical lattice

We study modulational instability of two-component Bose-Einstein condensates in an optical lattice, which is modelled as a coupled discrete nonlinear Schr \"{o}dinger equation. The excitation spectrum and the modulational instability condition of the total system are presented analytically. In the long-wavelength limit, our results agree with the homogeneous two-component Bose-Einstein condensates case. The discreteness effects result in the appearance of the modulational instability for the condensates in miscible region. The numerical calculations confirm our analytical results and show that the interspecies coupling can transfer the instability from one component to another.Comment: 4 pages, 3 figures (to be published in Phys. Rev. A

Exact Zeros of the Partition Function for a Continuum System with Double Gaussian Peaks

We calculate the exact zeros of the partition function for a continuum system where the probability distribution for the order parameter is given by two asymmetric Gaussian peaks. When the positions of the two peaks coincide, the two separate loci of zeros which used to give first-order transition touch each other, with density of zeros vanishing at the contact point on the positive real axis. Instead of the second-order transition of Ehrenfast classification as one might naively expect, one finds a critical behavior in this limit.Comment: 13 pages, 6 figures, revtex, minor changes in fig.2, to be published in Physical Review

WHEAT IMPORT DEMAND IN THE JAPANESE FLOUR MILLING INDUSTRY: A PRODUCTION THEORY APPROACH

The translog cost function is used to analyze import demand for wheat differentiated by class and country of origin in the Japanese wheat flour milling industry. Results indicate that U.S. wheat faces strong competition in the Japanese wheat market, but its multiple classes and end-use characteristics enable the United States to preserve the largest market share in Japan.import demand, Japan, wheat, production theory, translog cost function, International Relations/Trade,

Directing cell migration and organization via nanocrater-patterned cell-repellent interfaces.

Although adhesive interactions between cells and nanostructured interfaces have been studied extensively, there is a paucity of data on how nanostructured interfaces repel cells by directing cell migration and cell-colony organization. Here, by using multiphoton ablation lithography to pattern surfaces with nanoscale craters of various aspect ratios and pitches, we show that the surfaces altered the cells focal-adhesion size and distribution, thus affecting cell morphology, migration and ultimately localization. We also show that nanocrater pitch can disrupt the formation of mature focal adhesions to favour the migration of cells towards higher-pitched regions, which present increased planar area for the formation of stable focal adhesions. Moreover, by designing surfaces with variable pitch but constant nanocrater dimensions, we were able to create circular and striped cellular patterns. Our surface-patterning approach, which does not involve chemical treatments and can be applied to various materials, represents a simple method to control cell behaviour on surfaces

Faint HI 21-cm Emission Line Wings at Forbidden-Velocities

We present the results of a search for faint HI 21-cm emission line wings at velocities forbidden by Galactic rotation in the Galactic plane using the Leiden/Dwingeloo HI Survey data and the HI Southern Galactic Plane Survey data. These ``forbidden-velocity wings (FVWs)'' appear as protruding excessive emission in comparison with their surroundings in limited (< 2 deg) spatial regions over velocity extent more than ~20 km/s in large-scale (l-v) diagrams. Their high-velocities imply that there should be some dynamical phenomena associated. We have identified 87 FVWs. We present their catalog, and discuss their distribution and statistical properties. We found that 85% of FVWs are not coincident with known supernova remnants (SNRs), galaxies, or high-velocity clouds. Their natures are currently unknown. We suspect that many of them are fast-moving HI shells and filaments associated with the oldest SNRs that are essentially invisible except via their HI line emission. We discuss other possible origins.Comment: 41 pages, 14 figures, to be published in apj

A new approximation scheme in quantum mechanics

An approximation method which combines the perturbation theory with the variational calculation is constructed for quantum mechanical problems. Using the anharmonic oscillator and the He atom as examples, we show that the present method provides an efficient scheme in estimating both the ground and the excited states. We also discuss the limitations of the present method.Comment: 14pages, to be published in Eur. J. Phy

A Search for X-Ray Bright Distant Clusters of Galaxies

We present the results of a search for X--ray luminous distant clusters of galaxies. We found extended X--ray emission characteristic of a cluster towards two of our candidate clusters of galaxies. They both have a luminosity in the ROSAT bandpass of $\simeq10^{44}{\rm \,erg\,s^{-1}}$ and a redshift of $>0.5$; thus making them two of the most distant X--ray clusters ever observed. Furthermore, we show that both clusters are optically rich and have a known radio source associated with them. We compare our result with other recent searches for distant X--ray luminous clusters and present a lower limit of $1.2\times10^{-7}\,{\rm Mpc^{-3}}$ for the number density of such high redshift clusters. This limit is consistent with the expected abundance of such clusters in a standard (b=2) Cold Dark Matter Universe. Finally, our clusters provide important high redshift targets for further study into the origin and evolution of massive clusters of galaxies. Accepted for publication in the 10th September 1994 issue of ApJ.Comment: 20 pages Latex file + 1 postscript figure file appende