Chemical reactions studied at ultra-low temperature in liquid helium clusters

2012 ◽  
Author(s):  
Friedrich Huisken ◽  
Serge A. Krasnokutski
Keyword(s):  
Low Temperature ◽  
Liquid Helium ◽  
Chemical Reactions ◽  
Helium Clusters

scholarly journals Advances in Cryochemistry: Mechanisms, Reactions and Applications

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 750
Author(s):  
Lu-Yan An ◽  
Zhen Dai ◽  
Bin Di ◽  
Li-Li Xu
Keyword(s):  
Low Temperature ◽  
Chemical Reactions ◽  
Common Sense ◽  
Reaction Rate ◽  
Concentration Effect ◽  
Biological Products ◽  
Freeze Concentration ◽  
New Strategy ◽  
The 1960S

It is counterintuitive that chemical reactions can be accelerated by freezing, but this amazing phenomenon was discovered as early as the 1960s. In frozen systems, the increase in reaction rate is caused by various mechanisms and the freeze concentration effect is the main reason for the observed acceleration. Some accelerated reactions have great application value in the chemistry synthesis and environmental fields; at the same time, certain reactions accelerated at low temperature during the storage of food, medicine, and biological products should cause concern. The study of reactions accelerated by freezing will overturn common sense and provide a new strategy for researchers in the chemistry field. In this review, we mainly introduce various mechanisms for accelerating reactions induced by freezing and summarize a variety of accelerated cryochemical reactions and their applications.

Charge transfer and fragmentation of liquid helium clusters that contain one or more neon atoms

1998 ◽  
Vol 109 (24) ◽  
pp. 10679-10687 ◽  
Author(s):  
Thomas Ruchti ◽  
Kirk Förde ◽  
Berton E. Callicoatt ◽  
Henrik Ludwigs ◽  
Kenneth C. Janda
Keyword(s):  
Charge Transfer ◽  
Liquid Helium ◽  
Helium Clusters

Systematics of liquid helium clusters

1987 ◽  
Vol 87 (8) ◽  
pp. 5021-5027 ◽  
Author(s):  
S. Stringari ◽  
J. Treiner
Keyword(s):  
Liquid Helium ◽  
Helium Clusters

scholarly journals On apparent barrier-free reactions

2020 ◽  
Vol 3 (1) ◽  
pp. 3-8
Author(s):  
Maikel Ballester
Keyword(s):  
Low Temperature ◽  
Chemical Reactions ◽  
Rate Constant ◽  
Kinetic Models ◽  
Rate Coefficient ◽  
Minimum Energy ◽  
Temperature Limit ◽  
Rate Coefficients ◽  
Minimum Energy Path ◽  
Full Dimension

Rate coefficients of bi-molecular chemical reactions are fundamental for kinetic models. The rate coefficient dependence on temperature is commonly extracted from the analyses of the reaction minimum energy path. However, a full dimension study of the same reaction may suggest a different asymptotic low-temperature limit in the rate constant than the obtained from the energetic profile.

Hydrogen Generation Using the Modular Helium Reactor

2004 ◽  
Author(s):  
Matt Richards ◽  
Arkal Shenoy
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Chemical Reactions ◽  
Nuclear Reactor ◽  
High Efficiency ◽  
Hydrogen Generation ◽  
Hybrid Process ◽  
Thermochemical Process ◽  
Process Heat ◽  
Splitting Water

Process heat from a high-temperature nuclear reactor can be used to drive a set of chemical reactions, with the net result of splitting water into hydrogen and oxygen. For example, process heat at temperatures in the range 850°C to 950°C can drive the sulfur-iodine (SI) thermochemical process to produce hydrogen with high efficiency. Electricity can also be used to split water, using conventional, low-temperature electrolysis (LTE). An example of a hybrid process is high-temperature electrolysis (HTE), in which process heat is used to generate steam, which is then supplied to an electrolyzer to generate hydrogen. In this paper we investigate the coupling of the Modular Helium Reactor (MHR) to the SI process and HTE. These concepts are referred to as the H2-MHR. Optimization of the MHR core design to produce higher coolant outlet temperatures is also discussed.

Low Temperature Oxide Deposition Equipment

1977 ◽  
Vol 14 (2) ◽  
pp. 125-128
Author(s):  
T. E. Price
Keyword(s):  
Low Temperature ◽  
Silicon Dioxide ◽  
Chemical Reactions ◽  
Oxide Deposition ◽  
Device Applications ◽  
Temperature Oxide

The equipment described uses silane to deposit silicon dioxide at 400°C on to a substrate 50 mm in diameter; the oxide may be doped with phosphorus or boron. Details are given of the chemical reactions involved, the construction and operation together with some examples of possible device applications.

Room Temperature Sample Scanning SQUID Microscope for Imaging the Magnetic Fields of Geological Specimens

2013 ◽  
Vol 475-476 ◽  
pp. 3-6 ◽  
Author(s):  
Qing Meng Wang ◽  
Hua Feng Qin ◽  
Qing Song Liu ◽  
Tao Song
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Magnetic Fields ◽  
Liquid Helium ◽  
Quantum Interference ◽  
Three Dimensional ◽  
Input Circuit ◽  
Pickup Coil ◽  
Weak Magnetic Fields ◽  
Scanning Squid

A microscope to image weak magnetic fields using a low-temperature superconducting quantum interference device (SQUID) had developed with a liquid helium consumption rate of ~0.5L/hour. The gradient pickup coil is made by a low-temperature superconducting niobium wire with a diameter of 66 μm, which is coupled to the input circuit of the SQUID and is then enwound on the sapphire bobbin. Both of the pickup coil and the SQUID sensor are installed in a red copper cold finger, which is thermally anchored to the liquid helium evaporation platform in the vacuum space of the cryostat. To reduce the distance between the pickup coil and sample, a 100 μm thick sapphire window is nestled up to the bottom of the cryostat. A three-dimensional scanning stage platform with a 50 cm Teflon sample rack under the sapphire window had the precision of 10 μm. To test the fidelity of the new facility, the distribution of the magnetic field of basalt slice specimens was determined. Results show that the spatial resolution of the newly-designed facility is 500 μm with a gradient magnetic field sensitivity of 380fT. This opens new opportunities in examining the distribution of magnetic assemblages in samples, which bear great geological and geophysical information.

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