Yet a roadblock to discovering new and better superconductors is the near impossibility of chemical substitution to introduce charge carriers into other families of large gap insulators.
My proposal with this fellowship will use the novel method of applying an electric field gradient instead of chemical substitution to induce charge carriers in large gap insulators, and thereby create new superconductors.
The current best known superconductors have the unique property of evolving out of parent large gapinsulators on the introduction of charge carriers by chemical substitution, providing a clue to the discovery of new families of superconductors.
In many kinds of rock, most notably granite, the application of pressure and the resulting deformation of the rock's constituent crystals turn some of the oxygen atoms in those crystals into charge carriers.
Both carriers charge extra for these seats based on flight length.
Compared to US carriers, Chinese carriers charge much less for SMS messages, but the volume in China is so high that it has become a major revenue source.
Its 1 million users make one-third of all paid Net phone calls, paying a penny a minute for domestic long-distance and 4 cents a minute for calls to Paris (a quarter of what the big carriers charge).
Its 1 million users make one third of all paid Net phone calls in the U.S., paying a penny a minute for long-distance in the U.S. and 4 cents a minute for calls to Paris (a quarter of what the big carriers charge).
And since cellular carriers often charge as much as 10 cents per SMS, these communications represent a huge and growing revenue stream.
While carriers have to pay higher subsidies for smartphones such as the iPhone, such devices allow carriers to charge customers for data plans.
The SEC seems to harbor similar suspicions, and in March it asked WorldCom to list the carriers included in the big charge, how much each owed and how old their debts were.
My questions started with the basics: Are carriers cold war relics as critics charge?
We're getting pushback, obviously, from some of the bigger carriers who would like to be able to charge more fees and extract more money from wealthier customers.
Because of these benefits, mobile carriers stand to generate increased revenue because they are still able to charge the same per-minute fees they ordinarily charge, even if the user is communicating over the Skype service.
应用推荐