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Structure analysis of supported disordered molybdenum oxides using pair distribution function analysis and automated cluster modelling

Molybdenum oxides and sulfides on various low-cost high-surface-area supports are excellent catalysts for several industrially relevant reactions. The surface layer structure of these materials is, however, difficult to characterize due to small and disordered MoOx domains. Here, it is shown how X-ray total scattering can be applied to gain insights into the structure through differential pair distribution function (d-PDF) analysis, where the scattering signal from the support material is subtracted to obtain structural information on the supported structure. MoOx catalysts supported on alumina nanoparticles and on zeolites are investigated, and it is shown that the structure of the hydrated molybdenum oxide layer is closely related to that of disordered and polydisperse polyoxometalates. By analysing the PDFs with a large number of automatically generated cluster structures, which are constructed in an iterative manner from known polyoxometalate clusters, information is derived on the structural motifs in supported MoOx.




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Unit-cell response of tetragonal hen egg white lysozyme upon controlled relative humidity variation

The effects of relative humidity on a tetragonal crystal form of hen egg white lysozyme are studied via in situ laboratory X-ray powder diffraction.




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Full reciprocal-space mapping up to 2000 K under controlled atmosphere: the multipurpose QMAX furnace

This article presents the capability of the QMAX furnace, devoted to reciprocal space mapping through X-ray scattering at high temperature up to 2000 K.




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Takagi–Taupin dynamical X-ray diffraction simulations of asymmetric X-ray diffraction from crystals: the effects of surface undulations

Dynamical X-ray diffraction simulations of very asymmetric diffraction from single crystals of silicon were made to accompany an experimental rocking-curve topography study reported in a seperate paper. Effects on rocking curves were found and are reported. The development of Uragami [(1969), J. Phys. Soc. Jpn, 27, 147–154] for Takagi–Taupin simulations was followed and applied to the case of both convex and concave surface undulations.




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A closer look at superionic phase transition in (NH4)4H2(SeO4)3: impedance spectroscopy under pressure

The proton-conducting material (NH4)4H2(SeO4)3 is examined to check whether its conductivity spectra are sensitive to subtle changes in the crystal structure and proton dynamics caused by external pressure. The AC conductivity was measured using impedance spectroscopy, in the frequency range from 100 Hz to 1 MHz, at temperatures 260 K < T < 400 K and pressures 0.1 MPa < p < 500 MPa. On the basis of the impedance spectra, carefully analyzed at different thermodynamic conditions, the p–T phase diagram of the crystal is constructed. It is found to be linear in the pressure range of the experiment, with the pressure coefficient value dTs/dp = −0.023 K MPa−1. The hydrostatic pressure effect on proton conductivity is also presented and discussed. Measurements of the electrical conductivity versus time were performed at a selected temperature T = 352.3 K and at pressures 0.1 MPa < p < 360 MPa. At fixed thermodynamic conditions (p = 302 MPa, T = 352.3 K), the sluggish solid–solid transformation from low conducting to superionic phase was induced. It is established that the kinetics of this transformation can be described by the Avrami model with an effective Avrami index value of about 4, which corresponds to the classical value associated with the homogeneous nucleation and three-dimensional growth of a new phase.




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A closer look at superionic phase transition in (NH4)4H2(SeO4)3: impedance spectroscopy under pressure

The proton-conducting crystal (NH4)4H2(SeO4)3 is examined to check whether its conductivity spectra and the phase transition to the superprotonic phase are sensitive to subtle changes in the crystal structure and proton dynamics caused by various thermodynamic conditions. It is established that the kinetics of this transformation can be described using the Avrami model with an effective Avrami index value associated with homogeneous nucleation and three-dimensional growth of a new phase.




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Some unsolicited advice for future support techs




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How to move up out of the help desk and other questions




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Fossils of tiny cupuladriid colonies reveal extinction can lag more than one million years after its cause

A new Smithsonian study that examines 10 million years of the evolution of tiny coral-like organisms called cupuladriid bryzoans has revealed that some species of this organism lingered on earth for more than one million years after the event that ultimately caused their extinction: the rising of the Isthmus of Panama.

The post Fossils of tiny cupuladriid colonies reveal extinction can lag more than one million years after its cause appeared first on Smithsonian Insider.




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Astronomers Find Super-Earth Using Amateur, Off-the-Shelf Technology

The newfound world, GJ1214b, is about 6.5 times as massive as the Earth. Its host star, GJ1214, is a small, red type M star about one-fifth the size of the Sun. GJ1214b orbits its star once every 38 hours at a distance of only 1.3 million miles. Astronomers estimate the planet's temperature to be about 400 degrees Fahrenheit. Although warm as an oven, it is still cooler than any other known transiting planet because it orbits a very dim star.

The post Astronomers Find Super-Earth Using Amateur, Off-the-Shelf Technology appeared first on Smithsonian Insider.





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Double Black-Hole Mystery: Dance Partners or Breakup Survivors?

Smithsonian astronomers have just discovered a rare example of a galaxy that appears to have a pair of giant black holes. Now they are trying to determine if those black holes are partners tied together by gravity, or if one of the two has been kicked out in a cosmic breakup.

The post Double Black-Hole Mystery: Dance Partners or Breakup Survivors? appeared first on Smithsonian Insider.




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Mergers of dense stellar remnants are likely trigger for many supernovae

The results show mergers of two dense stellar remnants are the likely cause of many of the supernovae that have been used to measure the accelerated expansion of the universe.

The post Mergers of dense stellar remnants are likely trigger for many supernovae appeared first on Smithsonian Insider.




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Astronomers see supernova from a new angle

"Just like mirrors in a changing room show you a clothing outfit from all sides, interstellar dust clouds act like mirrors to show us different sides of the supernova," Rest explains.

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Super sensitive telescope will detect “killer” asteroids and comets on collision course with Earth

This innovative facility will be at the front line of Earth defense by searching for "killer" asteroids and comets. It will map large portions of the sky nightly, making it an efficient sleuth for not just asteroids but also supernovae and other variable objects.

The post Super sensitive telescope will detect “killer” asteroids and comets on collision course with Earth appeared first on Smithsonian Insider.




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Yup’ik mask in “Infinity of Nations” exhibition at the American Indian Museum

This circa 1910 Yup'ik mask from Good News Bay, Alaska--made of driftwood, baleen, feathers, paint and cotton twine--is part of "Infinity of Nations: Art and History in the Collections of the National Museum of the American Indian," an exhibition at the National Museum of the American Indian, opening Saturday, Oct. 23.

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A Halloween roundup featuring recent articles on spiders, bats and rats

A roundup of recent articles featuring spiders, bats and rats....

The post A Halloween roundup featuring recent articles on spiders, bats and rats appeared first on Smithsonian Insider.




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Super-earth has an atmosphere, but is it steamy or gassy?

The extrasolar planet GJ 1214b has a radius of about 2.7 times that of the Earth and is about 6.5 times as massive putting it squarely into the class of exoplanets known as super-Earths.

The post Super-earth has an atmosphere, but is it steamy or gassy? appeared first on Smithsonian Insider.




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International team discovers alien planet that’s Jupiter-sized

This 'hot Jupiter', now named Qatar-1b, adds to the growing list of alien planets orbiting distant stars, or exoplanets. Its discovery demonstrates the power of science to cross political boundaries and increase ties between nations.

The post International team discovers alien planet that’s Jupiter-sized appeared first on Smithsonian Insider.




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Astronomers detect bizarre superfluid in core of neutron star

NASA's Chandra X-ray Observatory has discovered the first direct evidence for a superfluid, a bizarre, friction-free state of matter, at the core of a neutron star.

The post Astronomers detect bizarre superfluid in core of neutron star appeared first on Smithsonian Insider.




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Tiny creatures collected 100 years ago confirm accelerating carbon uptake in Antarctic Ocean

Tiny Antarctic marine creatures collected 100 years ago by British Royal Navy explorer Robert Falcon Scott are giving scientists new clues about polar environmental change.

The post Tiny creatures collected 100 years ago confirm accelerating carbon uptake in Antarctic Ocean appeared first on Smithsonian Insider.




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New candidate for “coldest star” is same temperature as a hot cup of coffee

There is a new candidate for coldest known star: a brown dwarf with about the same temperature as a hot cup of coffee. That’s cool enough to begin crossing the blurry line between small cold stars and big hot planets.

The post New candidate for “coldest star” is same temperature as a hot cup of coffee appeared first on Smithsonian Insider.






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The Carina Nebula, a local supernova factory, is ramping up production

A local supernova factory has recently started production, according to a wealth of new data from NASA's Chandra X-ray Observatory on the Carina Nebula.

The post The Carina Nebula, a local supernova factory, is ramping up production appeared first on Smithsonian Insider.




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New supernova remnant lights up!

In 1987, light from an exploding star in a neighboring galaxy, the Large Magellanic Cloud, reached Earth. Named Supernova 1987A, it was the closest supernova explosion witnessed in almost 400 years, allowing astronomers to study it in unprecedented detail as it evolves.

The post New supernova remnant lights up! appeared first on Smithsonian Insider.




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Dictionary captures traditional ice knowledge of the Inupiaq people of Wales, Alaska

To prevent the loss of Inupiaq words for ice and the knowledge that it embodies, Igor Krupnik, ethnologist at the Arctic Studies Center of the National Museum of Natural History, and Wales native Winton Weyapuk Jr., recently compiled an illustrated dictionary of some 120 Kingikmiut words used in Wales to describe different types of ice.

The post Dictionary captures traditional ice knowledge of the Inupiaq people of Wales, Alaska appeared first on Smithsonian Insider.




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Stellar eclipse gives glimpse of exoplanet: New data reveals a ‘super-Earth’ next door, astronomically speaking

The far-out planet, named 55 Cancri e, is twice as big as Earth and nearly nine times more massive. It is most likely composed of rocky material, similar to Earth, supplemented with light elements such as water and hydrogen gas. Scientists estimate the planet’s surface is much hotter than ours: close to 2,700 degrees Celsius.

The post Stellar eclipse gives glimpse of exoplanet: New data reveals a ‘super-Earth’ next door, astronomically speaking appeared first on Smithsonian Insider.




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Darkest known exoplanet, a Jupiter-sized gas giant, discovered

This Jupiter-sized world reflects less than one percent of the light that falls on it, making it blacker than any planet or moon in our solar system.

The post Darkest known exoplanet, a Jupiter-sized gas giant, discovered appeared first on Smithsonian Insider.




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Newly discovered supermassive black holes are just 160 million light years from Earth

Astronomers using NASA's Chandra X-ray Observatory discovered the first pair of supermassive black holes in a spiral galaxy similar to the Milky Way. Approximately 160 million light years from Earth, the pair is the nearest known such phenomenon.

The post Newly discovered supermassive black holes are just 160 million light years from Earth appeared first on Smithsonian Insider.




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Location matters: For invasive aquatic species, it’s better to start upstream

These green crabs have been doing a number on native shellfish. They eat a lot of clams. And they're a very cosmopolitan species—they've now spread all over, to places as far afield as the West Coast of the U.S. and South Africa.

The post Location matters: For invasive aquatic species, it’s better to start upstream appeared first on Smithsonian Insider.




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Members of small monkey groups more likely to fight, researchers find

Small monkey groups may win territorial disputes against larger groups because some members of the larger, invading groups avoid aggressive encounters.

The post Members of small monkey groups more likely to fight, researchers find appeared first on Smithsonian Insider.




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Remains of exploded star indicate supernova turned it inside out

A new X-ray study of the remains of an exploded star indicates that the supernova that disrupted the massive star may have turned it inside out in the process.

The post Remains of exploded star indicate supernova turned it inside out appeared first on Smithsonian Insider.




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Steady diet of binary star partners makes black holes grow “supermassive”

A new study by astrophysicists at the University of Utah and the Smithsonian Astrophysical Observatory in Cambridge, Mass., has found a new explanation for the growth of supermassive black holes: they repeatedly capture and swallow single stars from pairs of stars that get too close.

The post Steady diet of binary star partners makes black holes grow “supermassive” appeared first on Smithsonian Insider.




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One supernova type, two different sources

Two very different models explain the possible origin of Type Ia supernovae, and different studies support each model. New evidence shows that both models are correct - some of these supernovae are created one way and some the other.

The post One supernova type, two different sources appeared first on Smithsonian Insider.




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Astronomers discover X-rays from a young supernova remnant

Astronomers using NASA's Chandra X-ray Observatory have detected X-rays emitted by the debris from the explosion of supernova 1957D.

The post Astronomers discover X-rays from a young supernova remnant appeared first on Smithsonian Insider.




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Klondike, puppy born from a frozen embryo, fetches good news for endangered animals

The process of freezing materials such as fertilized eggs – cryopreservation – provides researchers with a tool to repopulate endangered species.

The post Klondike, puppy born from a frozen embryo, fetches good news for endangered animals appeared first on Smithsonian Insider.




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With no credit to Cupid, white-naped crane couples remain faithful for life

Chris Crowe, keeper of the National Zoo’s 15 white-naped cranes, is well acquainted with the strong attachments these graceful Asian birds form with their mates.

The post With no credit to Cupid, white-naped crane couples remain faithful for life appeared first on Smithsonian Insider.




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Highly distorted supernova remnant seen by Chandra X-ray Observatory

New data from NASA's Chandra X-ray Observatory suggest a highly distorted supernova remnant (shown here) may contain the most recent black hole formed in the Milky Way galaxy.

The post Highly distorted supernova remnant seen by Chandra X-ray Observatory appeared first on Smithsonian Insider.




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Browsing suburbia: Virginia’s parceled-up farms and forests are ideal refuge for white-tailed deer

Forget the deep forest, “today the highest densities of deer in the state of Virginia are in suburbia,” says William McShea, ecologist and research scientist at the Smithsonian’s Conservation Biology Institute in Front Royal, Va.

The post Browsing suburbia: Virginia’s parceled-up farms and forests are ideal refuge for white-tailed deer appeared first on Smithsonian Insider.





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Astronomers discover a new kind of supernova

Until now, supernovas came in two main “flavors.” A core-collapse supernova is the explosion of a star about 10 to 100 times as massive as […]

The post Astronomers discover a new kind of supernova appeared first on Smithsonian Insider.





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Chandra X-ray Observatory turns up black hole bonanza in galaxy next door

Using data from NASA’s Chandra X-ray Observatory, astronomers have discovered an unprecedented bonanza of black holes in the Andromeda Galaxy, one of the nearest galaxies […]

The post Chandra X-ray Observatory turns up black hole bonanza in galaxy next door appeared first on Smithsonian Insider.





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Chandra Observatory searches for trigger of nearby supernova

New data from NASA’s Chandra X-ray Observatory offer a glimpse into the environment of a star before it exploded earlier this year, and insight into […]

The post Chandra Observatory searches for trigger of nearby supernova appeared first on Smithsonian Insider.




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A first: Ground-based telescope detects super-earth transit

Astronomers have measured the passing of a super-Earth in front of a bright, nearby Sun-like star using a ground-based telescope for the first time. The […]

The post A first: Ground-based telescope detects super-earth transit appeared first on Smithsonian Insider.




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Swarms of Pluto-size objects kick up dust around adolescent star

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) may have detected the dusty hallmarks of an entire family of Pluto-size objects swarming around an adolescent […]

The post Swarms of Pluto-size objects kick up dust around adolescent star appeared first on Smithsonian Insider.




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Super-Earths Have Long-Lasting Oceans

For life as we know it to develop on other planets, those planets would need liquid water, or oceans. Geologic evidence suggests that Earth’s oceans […]

The post Super-Earths Have Long-Lasting Oceans appeared first on Smithsonian Insider.




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Asteroids: Breaking up is Hard to Do

Hundreds of thousands of asteroids are known to orbit our Sun at distances ranging from near the Earth to beyond Saturn. The most widely known […]

The post Asteroids: Breaking up is Hard to Do appeared first on Smithsonian Insider.