&#9829; GLAM | XOXO &#9829; — @дневники: асоциальная сеть

пятница, 13 января 2012

04:17

"Sarcasm is just one more service I offer."

А я сегодня сидела в компании Троля, Учёного, Педика и Нуны.
Почаще бы в таких компаниях сидеть.
Люблю психопатов.

@темы: <333

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03:33

^^

"Sarcasm is just one more service I offer."

Не знаю, как конкретно описать это чувство, но в общем так:
Меня зовут Хару, и я танцевальное говно^^

@темы: ночные бдения

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02:38

о боже мой.

"Sarcasm is just one more service I offer."

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01:53

TOT & Stiv time

"Sarcasm is just one more service I offer."

Сидим сейчас со Стивом

Мы пока ждем пиццу

Вот вам пост с гифками

@настроение:

@темы: <333, Кола, из лав, Люди

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среда, 11 января 2012

10:40

"Sarcasm is just one more service I offer."

Nuclear physics is the field of physics that studies the building blocks and interactions of atomic nuclei. The most commonly known applications of nuclear physics are nuclear power generation and nuclear weapons technology, but the research has provided application in many fields, including those in nuclear medicine and magnetic resonance imaging, ion implantation in materials engineering, and radiocarbon dating in geology and archaeology.

The field of particle physics evolved out of nuclear physics and is typically taught in close association with nuclear physics.

History

The history of nuclear physics as a discipline distinct from atomic physics starts with the discovery of radioactivity by Henri Becquerel in 1896,^[1] while investigating phosphorescence in uranium salts.^[2] The discovery of the electron by J. J. Thomson
a year later was an indication that the atom had internal structure. At
the turn of the 20th century the accepted model of the atom was J. J.
Thomson's plum pudding model
in which the atom was a large positively charged ball with small
negatively charged electrons embedded inside of it. By the turn of the
century physicists had also discovered three types of radiation emanating from atoms, which they named alpha, beta, and gamma radiation. Experiments in 1911 by Lise Meitner and Otto Hahn, and by James Chadwick in 1914 discovered that the beta decay spectrum
was continuous rather than discrete. That is, electrons were ejected
from the atom with a range of energies, rather than the discrete amounts
of energies that were observed in gamma and alpha decays. This was a
problem for nuclear physics at the time, because it indicated that energy was not conserved in these decays.

In 1905, Albert Einstein formulated the idea of mass–energy equivalence. While the work on radioactivity by Becquerel
and Marie Curie predates this, an explanation of the source of the
energy of radioactivity would have to wait for the discovery that the
nucleus itself was composed of smaller constituents, the nucleons.

[edit] Rutherford's team discovers the nucleus

In 1907 Ernest Rutherford published "Radiation of the α Particle from Radium in passing through Matter."^[3] Geiger expanded on this work in a communication to the Royal Society^[4]
with experiments he and Rutherford had done passing α particles through
air, aluminum foil and gold leaf. More work was published in 1909 by Geiger and Marsden^[5] and further greatly expanded work was published in 1910 by Geiger,^[6]
In 1911-2 Rutherford went before the Royal Society to explain the
experiments and propound the new theory of the atomic nucleus as we now
understand it.

The key experiment behind this announcement happened in 1910 at the University of Manchester, as Ernest Rutherford's team performed a remarkable experiment in which Hans Geiger and Ernest Marsden under his supervision fired alpha particles (helium nuclei) at a thin film of gold foil. The plum pudding model
predicted that the alpha particles should come out of the foil with
their trajectories being at most slightly bent. Rutherford had the idea
to instruct his team to look for something that shocked him to actually
observe: a few particles were scattered through large angles, even
completely backwards, in some cases. He likened it to firing a bullet at
tissue paper and having it bounce off. The discovery, beginning with
Rutherford's analysis of the data in 1911, eventually led to the
Rutherford model of the atom, in which the atom has a very small, very
dense nucleus containing most of its mass, and consisting of heavy
positively charged particles with embedded electrons in order to balance
out the charge (since the neutron was unknown). As an example, in this
model (which is not the modern one) nitrogen-14 consisted of a nucleus
with 14 protons and 7 electrons (21 total particles), and the nucleus
was surrounded by 7 more orbiting electrons.

The Rutherford model worked quite well until studies of nuclear spin were carried out by Franco Rasetti at the California Institute of Technology
in 1929. By 1925 it was known that protons and electrons had a spin of
1/2, and in the Rutherford model of nitrogen-14, 20 of the total 21
nuclear particles should have paired up to cancel each other's spin, and
the final odd particle should have left the nucleus with a net spin of
1/2. Rasetti discovered, however, that nitrogen-14 has a spin of 1.

[edit] James Chadwick discovers the neutron

In 1932 Chadwick realized that radiation that had been observed by Walther Bothe, Herbert L. Becker, Irène and Frédéric Joliot-Curie was actually due to a neutral particle of about the same mass as the proton, that he called the neutron (following a suggestion about the need for such a particle, by Rutherford). In the same year Dmitri Ivanenko
suggested that neutrons were in fact spin 1/2 particles and that the
nucleus contained neutrons to explain the mass not due to protons, and
that there were no electrons in the nucleus—only protons and neutrons.
The neutron spin immediately solved the problem of the spin of
nitrogen-14, as the one unpaired proton and one unpaired neutron in this
model, each contribute a spin of 1/2 in the same direction, for a final
total spin of 1.

With the discovery of the neutron, scientists at last could calculate what fraction of binding energy
each nucleus had, from comparing the nuclear mass with that of the
protons and neutrons which composed it. Differences between nuclear
masses were calculated in this way and—when nuclear reactions were
measured—were found to agree with Einstein's calculation of the
equivalence of mass and energy to high accuracy (within 1 percent as of
in 1934).

[edit] Proca's equations of the massive vector boson field

Alexandru Proca was the first to develop and report the massive vector boson field equations and a theory of the mesonic field of nuclear forces. Proca's equations were known to Wolfgang Pauli^[7]
who mentioned the equations in his Nobel address, and they were also
known to Yukawa, Wentzel, Taketani, Sakata, Kemmer, Heitler, and
Fröhlich who appreciated the content of Proca's equations for developing
a theory of the atomic nuclei in Nuclear Physics.^[8]^[9]^[10]^[11]^[12]

[edit] Yukawa's meson postulated to bind nuclei

In 1935 Hideki Yukawa proposed the first significant theory of the strong force to explain how the nucleus holds together. In the Yukawa interaction a virtual particle, later called a meson,
mediated a force between all nucleons, including protons and neutrons.
This force explained why nuclei did not disintegrate under the influence
of proton repulsion, and it also gave an explanation of why the
attractive strong force had a more limited range than the electromagnetic repulsion between protons. Later, the discovery of the pi meson showed it to have the properties of Yukawa's particle.

With Yukawa's papers, the modern model of the atom was complete. The
center of the atom contains a tight ball of neutrons and protons, which
is held together by the strong nuclear force, unless it is too large.
Unstable nuclei may undergo alpha decay, in which they emit an energetic
helium nucleus, or beta decay, in which they eject an electron (or positron).
After one of these decays the resultant nucleus may be left in an
excited state, and in this case it decays to its ground state by
emitting high energy photons (gamma decay).

The study of the strong and weak nuclear forces (the latter explained by Enrico Fermi via Fermi's interaction in 1934) led physicists to collide nuclei and electrons at ever higher energies. This research became the science of particle physics, the crown jewel of which is the standard model of particle physics which describes the strong, weak, and electromagnetic forces.

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10:30

хх

"Sarcasm is just one more service I offer."

Я никогда не чувствовала себя такой сонной.
Мне нельзя же не спать совсем( Хоть часик, но сна надо отхватить(
А тут на тебе уже больше 48 часов на ногах
оттоке-оттоке...

@темы: усталость, фоточки, гяру

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06:08

Yomei Ikkagetsu no Hanayome

"Sarcasm is just one more service I offer."

Люди, прочтите эту мангу, пожалуйста.

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04:50

Non-stop.

"Sarcasm is just one more service I offer."

Я не сплю второй день.
Сейчас доделываю контрольный глоссарий.
Нужно еще сделать 2 глосса по инструкции и по энциклопедическому тексту.
Хорошо бы записать на плеер все диалоги, что надо выучить к экзамену и слушать их неделю вместо k-pop и j-pop
Пчшки, вы вот даже не представляете, как я хочу сдать эту зимнюю сессию!
По-файтингуйте там, пожалуйста.

p.s. и еще. у меня полетел ворлд, поэтому я здесь буду чирикать черновые варианты глоссов.
не пугайтесь.

@музыка: лалала пушного

@темы: усталость, мечтать не вредно

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вторник, 10 января 2012

20:15

Omomo

"Sarcasm is just one more service I offer."

NUMBER POST TIME!

читать дальше

@настроение:

@темы: <333, h@ru, Новости

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