16,189 research outputs found
New Distribution Records of \u3ci\u3eSomatochlora Hineana\u3c/i\u3e (Odonata: Corduliidae)
New records for Somatochlora hineana in Michigan are reported, extending the known distribution of the species by nearly 200 km to the northeast. Habitats are rich fens with shallow creeks, springs, small pools, and marl deposits
Decline in Relative Abundance of Hippodamia convergens (Coleoptera: Coccinellidae) in Fall Shoreline Aggregations on Western Lake Superior
In the 1970s, migratory coccinellid aggregations on western Lake Superior shorelines consisted of over 90% Hippodamia convergens Guérin-Méneville. In 2014, the alien Harmonia axyridis (Pallas) accounted for over 80% of shoreline coccinellid aggregations and H. convergens declined to less than 10% of the total. Additional work is needed to elucidate the extent and cause of the decline of H. convergens in western Lake Superior shoreline aggregations
Geometric Stability Analysis for Periodic Solutions of the Swift-Hohenberg Equation
In this paper we describe invariant geometrical ~structures in the phase
space of the Swift-Hohenberg equation in a neighborhood of its periodic
stationary states. We show that in spite of the fact that these states are only
marginally stable (i.e., the linearized problem about these states has
continuous spectrum extending all the way up to zero), there exist finite
dimensional invariant manifolds in the phase space of this equation which
determine the long-time behavior of solutions near these stationary solutions.
In particular, using this point of view, we obtain a new demonstration of
Schneider's recent proof that these states are nonlinearly stable.Comment: 44 pages, plain tex, 0 figure
Non-Linear Stability Analysis of Higher Order Dissipative Partial Differential Equations
We extend the invariant manifold method for analyzing the asymptotics of
dissipative partial differential equations on unbounded spatial domains to
treat equations in which the linear part has order greater than two. One
important example of this type of equation which we analyze in some detail is
the Cahn-Hilliard equation. We analyze the marginally stable solutions of this
equation in some detail. A second context in which such equations arise is in
the Ginzburg-Landau equation, or other pattern forming equations, near a
codimension-two bifurcation
New Distribution Records for Minnesota Odonata
Several Minnesota state record Odonata, Aeshna subarctica, Ophiogomphus anomalus, Stylogomphus albistylus, Stylurus scudderi, and Coenagrion interrogatum are reported, along with notes on the distribution and habitat of Aeshna sitchensis. New county records for Minnesota Odonata are also reported
Unchartered Territory for the Bluegrass State : Lessons to be learned from over a Quarter-century of State Charter School Legislation
Charter school success or failure is not simply a matter of chance. Both the existence and aggregate quality of charter schools in a state depend on the provisions of state charter school laws. These laws address a wide range of issues and vary from state to state. But the experiences of states with significant charter sectors, as well as those with innovative charter policies, provide important lessons for the charter school movement as a whole
PC-based Multiple Information System Interface (PC/MISI) design plan
The general design plan for the implementation of a common user interface to multiple remote information systems within a microcomputer-based environment is presented. The intent is to provide a framework for the development of detailed specifications which will be used as guidelines for the actual development of the system
Absolute 1* quantum yields for the ICN A state by diode laser gain versus absorption spectroscopy
Absolute I* quantum yields were measured as a function of wavelength for room temperature photodissociation of the ICN A state continuum. The temperature yields are obtained by the technique of time-resolved diode laser gain-versus-absorption spectroscopy. Quantum yields are evaluated at seven wavelengths from 248 to 284 nm. The yield at 266 nm is 66.0 +/- 2% and it falls off to 53.4 +/- 2% and 44.0 +/- 4% at 284 and 248 respectively. The latter values are significantly higher than those obtained by previous workers using infrared fluorescence. Estimates of I* quantum yields obtained from analysis of CN photofragment rotational distributions, as discussed by other workers, are in good agreement with the I* yields. The results are considered in conjunction with recent theoretical and experimental work on the CN rotational distributions and with previous I* yield results
- …