From allowing our eyes to see, to enabling green plants to harvest energy from the sun, photochemical reactions – reactions triggered by light – are both ubiquitous and critical to nature. Photochemical reactions also play essential roles in high technology, from the creation of new nanomaterials to the development of more efficient solar energy systems. Using photochemical reactions to our best advantage requires a deep understanding of the interplay between the electrons and atomic nuclei within a molecular system after that system has been excited by light. A major advance towards acquiring this knowledge has been reported by a team of researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley. Graham Fleming, UC Berkeley’s Vice Chancellor for Research, a faculty senior scientist with Berkeley Lab’s Physical Biosciences Division, and member of the Kavli Energy NanoSciences Institute at Berkeley, led the development of a new experimental technique called two-dimensional electronic-vibrational spectroscopy (2D-EV). By combining the advantages of two well-established spectroscopy technologies – 2D-electronic and 2D-infrared – this technique is the first that can be used to simultaneously monitor electronic and molecular dynamics on a femtosecond (millionth of a billionth
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In 2008, scientists at HP invented a fourth fundamental component to join the resistor, capacitor, and inductor: the memristor. Theorized back in 1971, memristors showed promise in computing as they can be used to both build logic gates, the building blocks of processors, and also act as long-term storage.
At its HP Discover conference in Las Vegas today, HP announced an ambitious plan to use memristors to build a system, called simply "The Machine," shipping as soon as the end of the decade. By 2016, the company plans to have memristor-based DIMMs, which will combine the high storage densities of hard disks with the high performance of traditional DRAM.
John Sontag, vice president of HP Systems Research, said that The Machine would use "electrons for processing, photons for communication, and ions for storage." The electrons are found in conventional silicon processors, and the ions are found in the memristors. The photons are because the company wants to use optical interconnects in the system, built using silicon photonics technology. With silicon photonics, photons are generated on, and travel through, "circuits" etched onto silicon chips, enabling conventional chip manufacturing to construct optical parts. This allows the parts of the system using photons to be tightly integrated with the parts using electrons.
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Researchers used quantum theory – usually invoked to describe the actions of subatomic particles – to identify an unexpected and strange pattern in how people respond to survey questions. By conventional standards, the results are surprising: The scientists found the exact same pattern in 70 nationally representative surveys from Gallup and the Pew Research center taken from 2001 to 2011, as well as in two laboratory experiments. Most of the national surveys included more than 1,000 respondents in the United States. “Human behavior is very sensitive to context. It may be as context sensitive as the actions of some of the particles that quantum physicists study,” said Zheng Wang, lead author of the study and associate professor of communication at The Ohio State University. “By using quantum theory, we were able to predict a surprising regularity in human behavior with unusual accuracy for the social sciences in a large set of different surveys.” The study appears online in the Proceedings of the National Academy of Sciences. Wang conducted the study with Tyler Solloway of Ohio State, and Richard Shiffrin and Jerome Busemeyer of Indiana University. These new findings involved an issue that has long faced researchers using survey data or any
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ESA’s Rosetta spacecraft has found that comet 67P/Churyumov–Gerasimenko is releasing the equivalent of two small glasses of water into space every second, even at a cold 583 million kilometres from the Sun.
Last week was marked by Graphene Week 2014, one of the largest graphene events. This year, the conference was hosted at Chalmers University of Technology in Gothenburg by the Graphene Flagship. With 450 participants, the conference was sold out.
Bringing together an impressive list of speakers, the meeting addressed fundamental studies of graphene and related two-dimensional materials, applications of graphene and 2D materials in electronics, photonics, spintronics, and sensing, applications of graphene in energy, including photovoltaics, energy storage, fuel cells and hydrogen storage, large scale graphene production, graphene-based composite materials, graphene-related health and environment research, and applications of graphene in biomedical solutions.
Some of the flagship work package leaders were on site, describing the aim and progress of their section of the billion-euro project. For example, Herre van der Zant of TU Delft talked about the work package “Sensors”, in which the industry sees great potential. Graphene can be made into a good sensor by exploiting any of its remarkable properties. For example the fact that the material is very thin allows for a large surface-to-volume ratio, enhancing sensitivity to trace chemicals.
The conference also hosted representatives of scientific journals, who scouted the progress of the field and learned about the flagship effort. Editors of Physical Review Letters, three journals of the Nature family, and the journal 2D Materials, gave tips on how to publish scientific research in their magazines.
Photo: Chalmers / Henrik Sandsjö
As part of the dissemination effort of the flagship programme, an exhibition about graphene was opened on the second day of the conference in the Science Center Universeum, which attracts more than half a million visitors yearly. The exhibition aims to educate the general public about the prospects of graphene, and about the flagship effort.
Also coinciding with the conference came the announcement of new admissions to the flagship, which doubled the size of the consortium. 66 new partners were invited to participate in the project, following a 9-million euro competitive call. The competition was fierce – less than 10% of the submitted proposals were accepted.
On our behalf, Amaia Zurutuza gave an invited talk on recent advances in graphene applications, Alba Centeno contributed a talk about graphene-reinforced ceramics, while Amaia Pesquera presented a poster on the latest results in transmission electron microscopy of graphene.
The Graphene Flagship certainly did an amazing job organizing the conference and the exhibition, and we are proud to be an integral part of the flagship effort as the largest supplier of graphene on board. We extend our congratulations to the organization and look forward to the many events in the next 9 years.
Submicroscopic particles that contain even smaller particles of iron oxide could make magnetic resonance imaging (MRI) a far more powerful tool to detect and fight disease. Silicon mesoporous particles, aka SiMPS, about 1,000 nanometers across contain thousands of much smaller particles of iron oxide. The SiMPs can be manipulated by magnets and gather at the site of tumors, where they can be heated to kill malignant tumors or trigger the release of drugs. The particles were created by an international team led by scientists at Rice University and The Methodist Hospital Research Institute in Houston. Courtesy of the Wilson Group Scientists at Rice University and The Methodist Hospital Research Institute (TMHRI) led an international team of researchers in creating composite particles that can be injected into patients and guided by magnetic fields. Once in position, the particles may be heated to kill malignant tissues or trigger the release of drugs at the site. The “nanoconstructs” should fully degrade and leave the body within a few days, they reported. The research appears online in the journal Advanced Functional Materials. The team led by Rice chemist Lon Wilson and TMHRI scientist Paolo Decuzzi was searching for a way to overcome the challenges presented
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