Cathodoluminescence, the emission of light when atoms excited by high-energy electrons return to their ground state, is analogous to UV-induced fluorescence, and some materials such as zinc sulfide and some fluorescent dyes, exhibit both phenomena.

Cathodoluminescence is most commonly experienced in everyday life as the light emission from the inner surface of the cathode ray tube in television sets and computer CRT monitors.

Cathodoluminescence is an optical and electrical phenomenon whereby a beam of electrons is generated by an electron gun and then impacts on a luminescent material such as a phosphor, causing the material to emit visible light.

Cathodoluminescence occurs because the impingement of a high energy electron beam onto a semiconductor will result in the promotion of electrons from the valence band into the conduction band, leaving behind a hole.

* Cathodoluminescence, an optical and electrical phenomenon

Cathodoluminescence and EBIC are referred to as " beam-injection " techniques, and are very powerful probes of the optoelectronic behavior of semiconductors, in particular for studying nanoscale features and defects.

Cathodoluminescence has been exploited as a probe to map the local density of states of planar dielectric photonic crystals and nanostructured photonic materials.

* B. G. Yacobi and D. B. Holt, Cathodoluminescence Microscopy of Inorganic Solids, New York, Plenum ( 1990 )

* C. M. Parish and P. E. Russell, Scanning Cathodoluminescence Microscopy, in Advances in Imaging and Electron Physics, V. 147, ed.

In the first instance, `` mimesis '' is here used to mean the recalling of experience in terms of vivid images rather than in terms of abstract ideas or conventional designations.

A dominant motive is the poet's longing for his homeland and its boyhood associations: `` Not men-folk, but the fields where I would stray, The stones where as a child I used to play ''.

So in these pages the term `` technology '' is used to include any and all means which could amplify, project, or augment man's control over himself and over other men.

But what a super-Herculean task it is to winnow anything of value from the mud-beplastered arguments used so freely, particularly since such common use is made of cliches and stereotypes, in themselves declarations of intellectual bankruptcy.

This text from Dr. Huxley is sometimes used by enthusiasts to indicate that they have the permission of the scientists to press the case for a wonderful unfoldment of psychic powers in human beings.

The men who speculate on these institutions have, for the most part, come to at least one common conclusion: that many of the great enterprises and associations around which our democracy is formed are in themselves autocratic in nature, and possessed of power which can be used to frustrate the citizen who is trying to assert his individuality in the modern world ''.

Properly used, the present book is an excellent instrument of enlightenment.

This prospect did not please Mrs. King any more than did the possibility that her daughter might marry a Bohemian, but she used it to suggest to Thompson that, `` It is not in her nature to love you ''.

On the other hand, the consensus of opinion is that, used with caution and in conjunction with other types of evidence, the native sources still provide a valid rough outline for the English settlement of southern Britain.

The trouble with this machinery is that it is not used and the reason that it is not used is the absence of a conscious sense of community among the free nations.

In addition to his experiments in reading poetry to jazz, Patchen is beginning to use the figure of the modern jazz musician as a myth hero in the same way he used the figure of the private detective a decade ago.

When different colors are used, she is just as likely to color trees purple, hair green, etc..

Berlin is merely being used by Moscow as a stalking horse.

The collection of information is meaningless unless it is understood and used for a definite purpose.

This is used as a reference for comparing the ohmic heating and the electrical energy obtained from the measured current through the element and the measured voltage across the element.

The heat transfer to the anode in free burning arcs is enhanced by a hot gas jet flowing from the cathode towards the anode with velocities up Af.

The pressure gradient producing the jet is due to the nature of the magnetic field in the arc ( rapid decrease of current density from cathode to the anode ).

It is apparent from the above and from experimental evidence that the cooling requirements for the anode of free burning arcs are large compared with those for the cathode.

The electron optical system ( see fig. 14-1 ) is based in principle on the focusing action of concentric spherical cathode and anode surfaces.

The current through a recharging battery is opposite to the direction of current during discharge ; In other words, the electrode which was the cathode during battery discharge becomes the anode while the battery is recharging.

* In a cathode ray tube, it is the positive terminal where electrons flow out of the device, i. e., where positive electric current flows in.

An electrode through which current flows the other way ( out of the device ) is termed a cathode.

The flow of electrons is always from anode to cathode outside of the cell or device, regardless of the cell or device type and operating mode, with the exception of diodes, where electrode naming always assumes current in the forward direction ( that of the arrow symbol ), i. e., electrons flow in the opposite direction, even when the diode reverse-conducts either by accident ( breakdown of a normal diode ) or by design ( breakdown of a Zener diode, photo-current of a photodiode or solar cell ).

Internally the positively charged cations are flowing away from the anode ( even though it is negative and therefore would be expected to attract them, this is due to electrode potential relative to the electrolyte solution being different for the anode and cathode metal / electrolyte systems ); but, external to the cell in the circuit, electrons are being pushed out through the negative contact and thus through the circuit by the voltage potential as would be expected.

In electronic vacuum devices such as a cathode ray tube, the anode is the positively charged electron collector.

In a tube, the anode is a charged positive plate that collects the electrons emitted by the cathode through electric attraction.

The opposite of an anode is a cathode.

When the current through the device is reversed, the electrodes switch functions, so anode becomes cathode, while cathode becomes anode, as long as the reversed current is applied, with the exception of diodes where electrode naming is always based on the forward current direction.

Inside the sealed lamp, filled with argon or neon gas at low pressure, is a cylindrical metal cathode containing the element of interest and an anode.

A high voltage is applied across the anode and cathode, resulting in an ionization of the fill gas.

The gas ions are accelerated towards the cathode and, upon impact on the cathode, sputter cathode material that is excited in the glow discharge to emit the radiation of the sputtered material, i. e., the element of interest.

In the Earth's atmosphere, is made by cosmic ray activity, primarily with.

The course of the rays in the meridional section is no longer symmetrical to the principal ray of the pencil ; and on an intercepting plane there appears, instead of a luminous point, a patch of light, not symmetrical about a point, and often exhibiting a resemblance to a comet having its tail directed towards or away from the axis.

The mental ray engine was included in rendering and therefore it is possible to do quality renderings.

Radioactive cosmogenic < sup > 10 </ sup > Be is produced in the atmosphere of the Earth by the cosmic ray spallation of oxygen

Because boron is produced entirely by cosmic ray spallation and not by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust.

Cosmic ray spallation ( fragmentation ) of carbon, nitrogen, and oxygen is important to the production of lithium, beryllium and boron.

The cathode ray tube ( CRT ) is a vacuum tube containing an electron gun ( a source of electrons or electron emitter ) and a fluorescent screen used to view images.

Therefore, four loose families of more-efficient light transport modelling techniques have emerged: rasterization, including scanline rendering, geometrically projects objects in the scene to an image plane, without advanced optical effects ; ray casting considers the scene as observed from a specific point-of-view, calculating the observed image based only on geometry and very basic optical laws of reflection intensity, and perhaps using Monte Carlo techniques to reduce artifacts ; and ray tracing is similar to ray casting, but employs more advanced optical simulation, and usually uses Monte Carlo techniques to obtain more realistic results at a speed that is often orders of magnitude slower.

In ray casting the geometry which has been modeled is parsed pixel by pixel, line by line, from the point of view outward, as if casting rays out from the point of view.

Rough simulations of optical properties may be additionally employed: a simple calculation of the ray from the object to the point of view is made.

Once the ray either encounters a light source, or more probably once a set limiting number of bounces has been evaluated, then the surface illumination at that final point is evaluated using techniques described above, and the changes along the way through the various bounces evaluated to estimate a value observed at the point of view.

In path tracing, however, only a single ray or none is fired at each intersection, utilizing the statistical nature of Monte Carlo experiments.

As a brute-force method, ray tracing has been too slow to consider for real-time, and until recently too slow even to consider for short films of any degree of quality, although it has been used for special effects sequences, and in advertising, where a short portion of high quality ( perhaps even photorealistic ) footage is required.

However, efforts at optimizing to reduce the number of calculations needed in portions of a work where detail is not high or does not depend on ray tracing features have led to a realistic possibility of wider use of ray tracing.

There is now some hardware accelerated ray tracing equipment, at least in prototype phase, and some game demos which show use of real-time software or hardware ray tracing.