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High-efficient esterification of rosin and glycerol catalyzed by novel rare earth Lewis acidic ionic liquid: Reaction development and mechanistic study
Rosin glyceride Rare earth Lewis acidic ionic liquid Esterification DFT Catalysis
2023/12/7
Background: As one of the most important modified products of rosin, rosin glyceride was widely used in many aspects. However, the preparation of rosin glyceride is always unfriendly due to the use of...
The discovery of the Higgs boson at CERN’s Large Hadron Collider (LHC) in 2012 marked a significant milestone in particle physics. Since then, the ATLAS and CMS collaborations have been diligently inv...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Subsampling for Rare Events Data and maximum sampled conditional likelihood
罕见事件数据 子采样 最大采样 条件似然
2023/5/15
In this talk, we show that the available information about unknown parameters in rare events data is only tied to the relatively small number of cases, which justifies the usage of negative sampling. ...
The collapse of the Hittite Empire in the Late Bronze Age has been blamed on various factors, from war with other territories to internal strife. Now, an interdisciplinary collaboration used tree ring...
If she hits just the right pitch, a singer can shatter a wine glass. The reason is resonance. While the glass may vibrate slightly in response to most acoustic tones, a pitch that resonates with the m...
Study shows how machine learning could predict rare disastrous events, like earthquakes or pandemics（图）
机器学习 自然灾害 顺序采样技术
2023/6/26
Researchers from Brown and MIT suggest how scientists can circumvent the need for massive data sets to forecast extreme events with the combination of an advanced machine learning system and sequentia...
At CERN’s Large Hadron Collider (LHC), studies of rare processes allow scientists to infer the presence of heavy particles, including undiscovered particles, that cannot be directly produced. Such par...
Astronomers discover a rare “black widow” binary, with the shortest orbit yet（图）
“黑寡妇”双星 恒星 伴星环 银河系
2023/6/9
The flashing of a nearby star has drawn MIT astronomers to a new and mysterious system 3,000 light years from Earth. The stellar oddity appears to be a new “black widow binary” — a rapidly spinning ne...
Stronger environmental adaptation of rare rather than abundant bacterioplankton in response to dredging in eutrophic Lake Nanhu
Lake Nanhu Cyanobacterial blooms bacterioplankton
2021/7/27
Deciphering responses of rare versus abundant bacterioplankton to environmental change, crucial for understanding and mitigating of cyanobacterial blooms, is an important but poorly investigated subje...
“Magic-angle” trilayer graphene may be a rare, magnet-proof superconductor（图）
三层石墨烯 防磁超导体 MRI机器 量子计算机
2023/6/7
MIT physicists have observed signs of a rare type of superconductivity in a material called magic-angle twisted trilayer graphene. In a study appearing today in Nature, the researchers report that the...
A356铝合金因其具有良好的铸造性能、焊接性能、耐腐蚀性能以及综合力学性能，因此被广泛应用于航空航天和汽车运输行业。但随着应用领域技术进步和发展，对A356合金性能提出了更高的要求，然而由于其铸态组织中含有粗大枝晶结构和针状共晶硅组织限制了A356合金性能的进一步提高，从而限制了A356合金的应用。
Rare lichen unique to Florida discovered in museum collection, may be extinct（图）
Rare lichen unique Florida discovered museum collection may be extinct
2021/1/28
Scientists have found a new species of fleshy verdigris lichen, thanks to DNA analysis of museum specimens. Misidentified by its original collectors, the lichen is only known from 32 specimens collect...
In early July, Comet NEOWISE approached the sun for the first time in nearly 4,500 years. For observers in the Northern Hemisphere, it is now faintly visible toward the Northwest after sunset. When vi...
Nearly 40% of plant species are very rare, and vulnerable to climate change（图）
plant species very rare vulnerable climate change
2019/12/13
Almost 40% of global land plant species are categorized as very rare, and these species are most at risk for extinction as climate continues to change, according to new NSF-funded research.The finding...
The Atomic Dynamics of Rare Everlasting Electric Fields（图）
Atomic Dynamics Rare Everlasting Electric Fields
2018/1/31
By ricocheting neutrons off the atoms of yttrium manganite (YMnO3) heated to 3,000 degrees Fahrenheit, researchers have discovered the atomic mechanisms that give the unusual material its rare electro...