科学与环境
Explaining the difference between brittle and ductile behavior in polymer glasses
来源: Phys.org - latest science and technology news stories · 发布于
Glasses are (mostly) brittle, metals can be ductile (plastic), and liquids flow easily. Polymers are interesting because they exhibit all three types of behavior, depending on their chemical nature, temperature, and deformation rate. If polymers are not able to crystallize, their
Glasses are (mostly) brittle, metals can be ductile (plastic), and liquids flow easily. Polymers are interesting because they exhibit all three types of behavior, depending on their chemical nature, temperature, and deformation rate. If polymers are not able to crystallize, their low-temperature state is glassy, and they are hard and transparent.
One example is poly(methylmethacrylate) [PMMA], which has been used as an artificial glass since the early 20th century.
相关报道
Three giant black holes discovered in a galaxy from the dawn of time
Astronomers have discovered three actively feeding black holes inside a single galaxy more than 12.5 billion light-years away, revealing a remarkable scene from the universe’s infancy. Two of the black holes are separated by just 620 light-years and are expected to eventually mer
All Top News -- ScienceDaily ·
One of Earth’s most powerful supervolcanoes is refilling with fresh magma
Deep beneath Japan’s Kikai caldera, a massive magma reservoir is refilling 7,300 years after one of the most powerful volcanic eruptions in Earth's recent geological history. Scientists used underwater seismic surveys to reveal a vast store of magma that appears to have accumulat
All Top News -- ScienceDaily ·
Here’s the latest.
One train rear-ended another, sending two carriages down an embankment.
NYT > World News ·
One year on, families seek justice after election violence
One year after Tanzania's deadly post-election violence, families are still seeking answers. A government inquiry recorded 518 deaths. DW research has documented apparent use of excessive force by security forces.
World | Deutsche Welle ·
Income tax: Healey’s budget leaves thresholds frozen again. How much more will you pay?
Tax policy means freezes reduce take-home pay as earnings rise in line with inflation Income tax thresholds are set to remain frozen after John Healey’s first budget as chancellor. One of the biggest tax rises in recent years has happened without a change in the rates at which pe
Business | The Guardian ·