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Since the invention of the laser in 1960, nonlinear optics has aimed to broaden light’s spectral range and create new frequency components. Among the various techniques, supercontinuum (SC) generation stands out for its ability to produce light across a wide portion of the visible and infrared spectrum.

However, traditional SC sources rely on weak third-order optical nonlinearity, requiring long interaction lengths for broad spectral output. In , second-order optical nonlinearity offers far greater efficiency and lower power requirements, though mismatching in bulk crystals has historically limited its spectral coverage and overall efficiency.

In a study published in Light: Science & Applications, a collaborative research team from Aalto University, Tampere University, and Peking University, led by Professor Zhipei Sun, has demonstrated a revolutionary method for generating octave-spanning coherent light at the deep-subwavelength scale (100 nm). Their innovative approach employs phase-matching-free second-order nonlinear optical frequency down-conversion in ultrathin gallium selenide (GaSe) and niobium oxide diiodide (NbOI2) crystals.

In a significant step toward creating a sustainable and circular economy, Rice University researchers have published a study in the journal Carbon demonstrating that carbon nanotube (CNT) fibers can be fully recycled without any loss in their structure or properties. This discovery positions CNT fibers as a sustainable alternative to traditional materials like metals, polymers and the much larger carbon fibers, which are notoriously difficult to recycle.

“Recycling has long been a challenge in the materials industry—metals recycling is often inefficient and energy-intensive, polymers tend to lose their properties after reprocessing and carbon fibers cannot be recycled at all, only downcycled by chopping them up into short pieces,” said corresponding author Matteo Pasquali, director of Rice’s Carbon Hub and the A.J. Hartsook Professor of Chemical and Biomolecular Engineering, Materials Science and NanoEngineering and Chemistry.

“As CNT fibers are being scaled up, we asked whether and how these new materials could be recycled in the future so as to proactively avoid waste management problems that emerged as other engineered materials reached large-scale use. We expected that recycling would be difficult and would lead to significant loss of properties. Surprisingly, we found that fibers far exceed the recyclability potential of existing engineered materials, offering a solution to a major environmental issue.”

Fuel-cell technology is set to take a step forward as chemists have created a triple-headed metallic nanoparticle, FePtAu, which generates higher current per unit of mass than any other nanoparticle catalyst tested. In tests, researchers from Brown University found that the FePtAu catalyst reached 2809.9 mA/mg Pt and after 13 hours has a mass activity of 2600mA/mg Pt, or 93 percent of its original performance value.

Advances in fuel-cell technology have been stymied by the inadequacy of metals studied as catalysts. The drawback to platinum, other than cost, is that it absorbs carbon monoxide in reactions involving fuel cells powered by organic materials like formic acid.

Any substance that when dissolved in water, gives a pH less than 7.0, or donates a hydrogen ion.

Astronomers have made a remarkable discovery: a neutron star spinning at a staggering rate of 716 times per second, making it the fastest-spinning neutron star in the known universe, tied only with PSR J1748–2446. This stellar body, located in the binary system 4U 1820–30 within the NGC 6,624 globular cluster near the Milky Way’s center, is around 26 light-years from Earth in the constellation Sagittarius.

The discovery was made using NASA’s Neutron Star Interior Composition Explorer (NICER), an X-ray telescope mounted on the International Space Station. Gaurava K. Jaisawal from DTU Space shared that during observations of thermonuclear bursts, the team detected oscillations corresponding to a spin rate of 716 Hz, confirming the extreme speed.

Neutron stars, remnants of massive stars that have exhausted their nuclear fuel, are known for their rapid rotation and intense density. This newfound star is no exception, showcasing powerful thermonuclear blasts that briefly make it up to 100,000 times brighter than the Sun. These explosions occur as material from its companion star—a white dwarf in this case—accretes onto the neutron star’s surface, igniting under extreme pressure.

The National Weather Service issued a red flag warning (warm temperatures, strong winds and low humidity) for Southern California that spans from Tuesday to Wednesday in the Santa Barbara, Los Angeles and Ventura counties, and from Tuesday to Thursday in the San Bernadino, Orange, Riverside and San Diego counties.

Sporadic power outages have materialized in the San Fernando Valley, a highly populated area north of the Hollywood Hills, with the Los Angeles Department of Water and Power reporting a few thousand customers without power as of 5 p.m. PST.

Case Western Reserve University researcher advances zinc-sulfur battery technology. Rechargeable lithium-ion batteries power everything from electric vehicles to wearable devices. But new research from Case Western Reserve University suggests that a more sustainable and cost-effective alternative may lie in zinc-based batteries.

In a study published recently in Angewandte Chemie, researchers announced a significant step toward creating high-performance, low-cost zinc-sulfur batteries.

“This research marks a major step forward in the development of safer and more sustainable energy storage solutions,” said Chase Cao, a principal investigator and assistant professor of mechanical and aerospace engineering at Case School of Engineering. “Aqueous zinc-sulfur batteries offer the potential to power a wide range of applications — from renewable energy systems to portable electronics — with reduced environmental impact and reliance on scarce materials.”

Migrating bats cleverly harness the warm winds of storm fronts to reduce energy use during their long seasonal journeys, as revealed by innovative tracking technology.

Scientists found these tiny nocturnal travelers exhibit unexpected flexibility and adaptability in their migration patterns. Yet, they face mounting challenges from anthropogenic threats and environmental changes, underscoring the urgency for conservation efforts.

Bats Surfing Storm Fronts

Shooting a laser pulse at a porous silver target generates more intense x rays than previous targets, which will help studies of matter in extreme conditions.

Physicists rely on intense bursts of high-energy x rays to observe the progress of fusion experiments and to probe the dynamics of matter under conditions of extreme temperature and pressure. Current techniques for generating such bursts involve firing a laser pulse at a material target but typically turn only a small fraction of the laser energy into usable x rays, thereby limiting the burst energy and intensity. Now researchers have demonstrated a doubling of the efficiency by using a target made of a low-density metallic foam [1]. They expect that the new targets will lead to much brighter x-ray bursts capable of illuminating extreme physical processes under conditions that were previously inaccessible to x-ray observations.

When a powerful laser pulse strikes a foil of material such as silver, the laser strips away the electrons, leaving exposed the highly charged nuclei. Surrounding electrons then fall back into the lowest energy levels, creating high-energy x rays. However, most of the laser energy can be lost in the process, and the overall efficiency is very sensitive to the nature of the material target. Researchers have found, for example, that solid targets generally yield low efficiencies, as x rays emerge from only a small volume near the surface, while laser energy is otherwise consumed by stirring up plasma waves in the material. This low efficiency limits the x-ray intensity.