subatomic particles

Synopsis: Domenii: Nuclear physics: Nuclear physics generale: Subatomic particles:

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'Relying on the fantastic structure and property, especially the extremely high mobility for both electrons and holes,

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This pressure-regulated fine-tuning of particle separation enables controlled investigation of distance-dependent optical and electrical phenomena.

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Once inside a living cell the particles mix and exchange their cargo. This interaction enables the energy transfer between the internalized molecules says Raymo director of the UM laboratory for molecular photonics.

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Intriguingly the bacterium produces Fe3+-based amorphous oxide particles (ca 3 nm diameter; Fe3+:+Si4+:

and easily-handled electrode material since its basic texture is composed of nanometric particles. The charge-discharge properties of simple L-BIOX/Li-metal cells were examined at current rates of 33. 3ma/g (0. 05c)

Notably the presence of minor components of Si and P in the original L-BIOX nanometric particles resulted in specific and well-defined electrode architecture.

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#Metal particles in solids aren't as fixed as they seem memristor study shows In work that unmasks some of the magic behind memristors and"resistive random access memory,

"or RRAMUTTING-edge computer components that combine logic and memory functionsesearchers have shown that the metal particles in memristors don't stay put as previously thought.

"Most people have thought you can't move metal particles in a solid material, "said Wei Lu, associate professor of electrical and computer engineering at the University of Michigan."

"Also the fact that we observed particle movement driven by electrochemical forces within dielectric matrix is in itself a sensation."

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when a single photon can excite multiple electrons. Quantum dots are novel nanostructures that can become the basis of the next generation of solar cells capable of squeezing additional electricity out of the extra energy of blue and ultraviolet photons.

Typical solar cells absorb a wide portion of the solar spectrum but because of the rapid cooling of energetic (or'hot')charge carriers the extra energy of blue and ultraviolet solar photons is wasted in producing heat said Victor Klimov director of the Center for Advanced Solar Photophysics

(CASP) at Los alamos National Laboratory. In principle this lost energy can be recovered by converting it into additional photocurrent via carrier multiplication.

In that case collision of a hot carrier with a valence-band electron excites it across the energy gap Klimov said.

In this way absorption of a single photon from the high-energy end of the solar spectrum produces not just one

but two electron-hole pairs which in terms of power output means getting two for the price of one.

but is enhanced appreciably in ultrasmall semiconductor particles also called quantum dots as was demonstrated first by LANL researchers in 2004 (Schaller & Klimov Phys.

The long lifetime of these energetic holes facilitates an alternative relaxation mechanism via collisions with core-localized valence band electron

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"We are talking about an imaging scale here that bridges the gap between conventional X-ray and electron tomography.

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#DNA-linked nanoparticles form switchable'thin films'on a liquid surface Scientists seeking ways to engineer the assembly of tiny particles measuring just billionths of a meter have achieved a new firsthe

if the same approach could be used to achieve designs of two-dimensional, one-particle-thick films."

the particles form a rather loosely arrayed free-floating viscous monolayer. Adding salt changes the interactions

when the particle sizes and the DNA chain sizes are comparablen the order of 20-50 nanometers,

"Creating these particle monolayers at a liquid interface is very convenient and effective because the particles'two-dimensional structure is very'fluid

'and can be easily manipulatednlike on a solid substrate, where the particles can easily get stuck to the surface,

"Gang said.""But in some applications, we may need to transfer the assembled layer to such a solid surface.

when particles are linked but move freely at the interface, they may allow an object moleculeo pass through the interface."

"However, when we induce linkages between particles to form a mesh-like network, any object larger than the mesh-size of the network cannot penetrate through this very thin film.""

Understanding how synthetic DNA-coated nanoparticles interact with a lipid surface may also offer insight into how such particles coated with actual genes might interact with cell membraneshich are composed largely of lipidsnd with one another in a lipid environment."

"Our study is the first of its kind to look at the structural aspects of DNA-particle/lipid interface directly using x-ray scattering.

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"Nanoparticles are extraordinarily small particles at the forefront of advances in many biomedical, optical and electronic fields,

it can precisely control nucleation temperature and the resulting size and shape of particles.""For the applications we have in mind,

the control of particle uniformity and size is crucial, and we are also able to reduce material waste,

"Combining continuous flow with microwave heating could give us the best of both worlds large, fast reactors with perfectly controlled particle size."

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n-type which are rich in electrons; and p-type which are poor in electrons. The problem? When exposed to the air n-type materials bind to oxygen atoms give up their electrons

and turn into p-type. Ning and colleagues modelled and demonstrated a new colloidal quantum dot n-type material that does not bind oxygen

when exposed to air. Maintaining stable n -and p-type layers simultaneously not only boosts the efficiency of light absorption it opens up a world of new optoelectronic devices that capitalize on the best properties of both light and electricity.

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but also blocks the semiconductor from absorbing light and keeps electrons from passing through to reach the catalyst that drives the reaction.

but allowed electrons to pass through with minimal resistance. On top of the Tio2 the researchers deposited 100-nanometer-thick islands of an abundant inexpensive nickel oxide material that successfully catalyzed the oxidation of water to form molecular oxygen.

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These minuscule particles are very effective at turning light into electricity and vice versa. Since the first progress toward the use of quantum dots to make solar cells Bawendi says The community in the last few years has started to understand better how these cells operate and

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"which measures how quickly electrons can move through the material.""We were pleased to find that the on/off ratio is

because it provides the electron and hole conduction necessary for making transistors with logic gates and other p-n junction devices,"said Argonne scientist and coauthor Anirudha Sumant.

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or particles that are bound to a cell and aid in the study of protein dynamics.

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or gold shell you could also vary the scattering ratio of the particles, "he says."

"This particle system was attempted because I was having difficulty with shelling the silica particles, "Mr Duczynski says."

"I was able to see some scattering of the iron oxide-gold core-shell nanoparticles,

meaning these particles could be used as a multimodal contrast agent for imaging techniques such as MRI magnetic resonance imaging. g

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The contrast agent being used is packaged inside or bonded to the surface of microscopic particles which can be designed to target certain regions of the body

If particles could be loaded with several types of contrast agents or dyes instead of one or a contrast agent along with another type of diagnostic aid or a medication doctors could more efficiently test for

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whereby two red photons can be annihilated to create a blue photon, creating blue light from red.

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#Scientists Make Photons Act Like Real-life Light Saber A quote from the press release on how this was done:

When the photon exits the medium its identity is preserved Lukin said. It's the same effect we see with refraction of light in a water glass.

As the photons exited the cloud they were clumped together. That's a result of the nearby atoms;

So when a photon comes in it excites nearby atoms but when the next photon enters the cloud it would excite nearby atoms to the same degree

--which it can't do. So the first photon has to move out of the way.

That's an interaction between photons sort of but with atoms as a mediator. What it means is that the two photons end up pushing

and pulling each other through the cloud of atoms and when they exit the cloud they're clumped like a molecule thanks to that continued interaction.

The scientists think this breakthrough could lead to improvements in quantum computing; photons are an excellent carrier for quantum information

but the lack of interaction between photons has limited the amount of information that can be carried.

The paper appears in the journal Nature t

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#Scientists'Eavesdrop'On A Brain A team of researchers from Stanford say they've created a system to eavesdrop on the brain allowing them to monitor a person's brain activity

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so particles of mud soot oil or wine stick right where they land. Over the next couple of months Ultratech a Florida-based company will roll out Ultra-Ever Dry a coating that repels most muck.

so that particles can roll right off. Base-coat dry time: 20â##30 minutestop-coat dry time:

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Both atoms have one proton in their nuclei but deuterium contains an extra neutron and it mostly forms under special conditions.#

#In interstellar space for example water ice contains lots of deuterium thanks to the freezing cold temperatures and ionizing radiation.

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electronics send signals via negatively charged electrons, whereas many of the communications carried out in living tissues take place through the movement of positively charged particles, such as calcium and potassium ions.

Now, though, scientists have discovered a new feature of a protein called reflectin, found in a group of animals called pencil squid.

It turns out reflectin conducts protons and may be able to bridge the communication divide between cells and biomedical implants.

Reflectin transported protons, they found, nearly as effectively as many of the best artificial materials. It's ability to move around these positive charges

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This field magnetised the nanoparticles leading to a particle re-arrangement in form of parallel lines.

The researchers then manufactured the tiny elongated structures out of the modified epoxy film via two-photon polymerisation.

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which include the ability of a particle to exist in more than one place at a time, have now been used by engineers at MIT to achieve a significant efficiency boost in a light-harvesting system.

a photon hits a receptor called a chromophore, which in turn produces an exciton a quantum particle of energy.

behaving more like a wave than a particle. This efficient movement of excitons has one key requirement:

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The cloak is a thin Teflon sheet (light blue) embedded with many small, cylindrical ceramic particles (dark blue.

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and moves data with photons of light instead of electrons would make today chips look like proverbial horses and buggies.

When electrons move through the basic parts of a computer chipogic circuits that manipulate data,

That not the case with photons, which travel together with no resistance, and do so at, well, light speed.

Researchers have made already photon-friendly chips, with optical lines that replace metal wires and optical memory circuits.

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and youe continually popping particles where you think they should levitate, and then watching them continually drop down.

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#Faster, smaller, more informative A new technique invented at MIT can measure the relative positions of tiny particles as they flow through a fluidic channel,

As cells or particles flow through the channel, one at a time, their mass slightly alters the cantilever vibration frequency.

The masses of the particles can be calculated from that change in frequency. In this study, the researchers wanted to see

if they could gain more information about a collection of particles, such as their individual sizes and relative positions. ith the previous system,

when a single particle flows through we can measure its buoyant mass, but we don get any information about whether it a very small, dense particle,

or maybe a large, not-so-dense particle. It could be a long filament, or spherical, says grad student Nathan Cermak, one of the paper lead authors.

Postdoc Selim Olcum is also a lead author of the paper; Manalis, the Andrew and Erna Viterbi Professor in MIT departments of Biological engineering and Mechanical engineering,

and to measure how each particle affects the vibration frequency of each mode at each point along the resonator.

but also the position of each particle. ll these different modes react differently to the distribution of mass,

The particles flow along the entire cantilever in about 100 milliseconds, so a key advance that allowed the researchers to take rapid measurements at each point along the channel was the incorporation of a control system known as a phase-locked loop (PLL).

which changes as particles flow through. Each vibration mode has its own PLL, which responds to any changes in the frequency.

This allows the researchers to rapidly measure any changes caused by particles flowing through the channel.

In this paper, the researchers tracked two particles as they flowed through a channel together, and showed they could distinguish the masses

and positions of each particle as it flowed. Using four vibrational modes, the device can attain a resolution of about 150 nanometers.

Inertial imaging could allow scientists to visualize very small particles, such as viruses or single molecules. ultimode mass sensing has previously been limited to air or vacuum environments,

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Superfluids are thought to flow endlessly, without losing energy, similar to electrons in a superconductor. Observing the behavior of superfluids

Atoms of rubidium are known as bosons, for their even number of nucleons and electrons. When cooled to near absolute zero

bosons form what called a Bose-Einstein condensate a superfluid state that was discovered first co by Ketterle,

and for which he was awarded ultimately the 2001 Nobel prize in physics. After cooling the atoms,

which mimics the regular arrangement of particles in real crystalline materials. When charged particles are exposed to magnetic fields,

their trajectories are bent into circular orbits, causing them to loop around and around. The higher the magnetic field, the tighter a particle orbit becomes.

However, to confine electrons to the microscopic scale of a crystalline material, a magnetic field 100 times stronger than that of the strongest magnets in the world would be required.

The group asked whether this could be done with ultracold atoms in an optical lattice. Since the ultracold atoms are charged not,

as electrons are, but are instead neutral particles, their trajectories are unaffected normally by magnetic fields. Instead, the MIT group came up with a technique to generate a synthetic

ultrahigh magnetic field, using laser beams to push atoms around in tiny orbits, similar to the orbits of electrons under a real magnetic field.

In 2013, Ketterle and his colleagues demonstrated the technique, along with other researchers in Germany, which uses a tilt of the optical lattice

In this scenario, atoms could only move with the help of laser beams. ow the laser beams could be used to make neutral atoms move around like electrons in a strong magnetic field

or loop around, in a radius as small as two lattice squares, similar to how particles would move in an extremely high magnetic field. nce we had the idea,

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and his colleagues are now working to demonstrate full-scale multi-core computing with an entire computer that uses only photons to communicate with memory,

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Some have used tiny particles of glass, melded together at a lower temperature in a technique called sintering.

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like a dust particle, to start the process of nucleation, the bubbles formed by boiling water also require nucleation.

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The PNNL study shows how to create particles with a similar reactivity to platinum that replace some of the platinum with Earth-abundant metals.

and solvent molecules that are unavoidable with particles synthesized in solution. The process begins when the scientists load 1-inch-diameter metal discs into an instrument that combines particle formation and ion deposition.

Once the metals are locked into a vacuum chamber in the aggregation region argon gas is introduced. In the presence of a large voltage the argon becomes ionized

The mass spectrometer filters the ionic particles, removing those that don't meet the desired size. The filtered particles are landed then soft onto a surface of choice,

such as glassy carbon, a commonly used electrode material. Creating the alloy particles in the gas phase provides a host of benefits.

The conventional solution-based approach often results in clumps of the different metals rather than homogeneous nanoparticles with the desired shape.

Further, the particles lack a capping layer. This eliminates the need to remove these layers and clean the particles,

which makes them more efficient to use.""An important benefit is that it allows us to skirt certain thermodynamic limitations that occur

when the particles are created in solution, "said Johnson.""This allows us to create alloys with consistent elemental constituents and conformation.

"The coverage of the resulting surface is controlled by how long the particles are aimed at the surface and the intensity of the ion beam.

With longer times and a surface with defects, the particles cluster on the imperfections, providing a way to tailor surfaces with particle-rich areas and adjacent open spaces.

The characterization experiments were done using the atomic force microscope scanning and transmission electron microscopes, as well as other tools in DOE's EMSL, a national scientific user facility.

They plan on further studying these particles in the new in situ transmission electron microscope, planned to open in EMSL in 2015,

to understand how the particles evolve in reactive environments. Explore further: New nanomaterials will boost renewable energy More information:"

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#Physicists tune Large hadron collider to find'sweet spot'in high-energy proton smasher As protons collide,

physicists will peer into the resulting particle showers for new discoveries about the universe, said Ryszard Stroynowski, a collaborator on one of the collider's key experiments and a professor in the Department of physics at Southern Methodist University,

Dallas."The hoopla and enthusiastic articles generated by discovery of the Higgs boson two years ago left an impression among many people that we have succeeded,

and therefore the Higgs mechanism of generating the mass of fundamental particles is possible.""There is much more to be learned during Run 2 of the world's most powerful particle accelerator."

when its global collaboration of thousands of scientists discovered the Higgs boson fundamental particle. The Large hadron collider's first run began in 2009.

gigantic particle detectors at four interaction points along the ring record the proton collisions that are generated

In routine operation, protons make 11,245 laps of the LHC per second producing up to 1 billion collisions per second.

We must be very careful that it's the right 200 the 200 that might tell us more about the Higgs boson, for example.

A powerful and reliable workhorse, the link is one of thousands of critical components on the LHC that contributed to discovery and precision measurement of the Higgs boson.

Fine-tuning the new, upgraded machine will take several weeksthe world's most powerful machine for smashing protons together will require some"tuning"before physicists from around the world are ready to take data,

Sekula said. 10 times as many Higgs particles means a flood of data to sift for gems LHC Run 2 will collide particles at a staggering 13 teraelectronvolts (Tev),

which you make Higgs bosons goes way up. We're going to get 10 times more Higgs than we did in run 1 at least."

During Run 1, the LHC delivered about 8, 500 Higgs particles a week to the scientists,

but also delivered a huge number of other kinds of particles that have to be sifted away to find the Higgs particles.

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#Tiny terahertz accelerator could rival huge free-electron lasers Physicists in the US, Germany and Canada have built a miniature particle accelerator that uses terahertz radiation instead of radio waves to create pulses of high-energy electrons.

A single accelerator module of the prototype is just 1. 5 cm long and 1 mm thick,

Potential applications include free-electron lasers, whereby the electrons are used to create coherent pulses of X-rays.

However, the team cautions that much more work is needed to develop the technology so it can be used in medicine,

and microwaves are used to accelerate charged particles. In this latest work Emilio Nanni and colleagues at the Massachusetts institute of technology (MIT), the Center For free-Electron Laser Science (CFEL) at DESY in Germany and the University of Toronto have created a terahertz accelerator module with the aim

of advancing experiments that use ultrafast electron diffraction to reveal the structure and dynamics of matter.

Their prototype accelerator uses optically generated pulses centred at 450 GHZ and a bandwidth of 20000 GHZ.

Steep gradients The terahertz accelerator module increased the energy of electrons fired into it by 7 kev.

and cost of accelerators and improve the quality of the electron beams they produce.""Steven Jamison of the UK's Accelerator Science and Technology Centre (ASTEC), who wasn't involved in the research,

it is an important first step to obtaining relativistic energy electrons with terahertz waves.""More power needed The main barrier to faster accelerating gradients is the power of terahertz pulses that can be generated."

The researchers now plan to focus on developing a free-electron laser (FEL) based on terahertz technology,

FELS fire high-speed electrons down an undulating path, which causes them to emit intense flashes of X-ray light.

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and work out how Alice is encoding a series of photons sent to her by Bob that will constitute the secret key.

if Alice sets up a detector to measure the energy of the incoming photons, which sounds an alarm

"Alice and Bob share a key encoded using photon polarization, while Eve inserts a device into the polarized beam that very slightly tilts the beam

which detectors are used to measure which photons, and by doing so to steal the key unnoticed.

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