DIRECT NUCLEOPHILIC ACYLATION BY THE LOW-TEMPERATURE, IN SITU GENERATION OF ACYLLITHIUM REAGENTS; a-HYDROXY KETONES FROM KETONES: 3-HYDROXY-2,2,3-TRIMETHYLOCTAN-4-ONE FROM PINACOLONE

1990 ◽  
Vol 69 ◽  
pp. 114 ◽  
Keyword(s):  
Low Temperature ◽  
Hydroxy Ketones ◽  
In Situ Generation ◽  
Nucleophilic Acylation

Synthesis of .alpha.-hydroxy ketones by direct, low-temperature, in situ nucleophilic acylation of aldehydes and ketones by acyllithium reagents

1992 ◽  
Vol 57 (21) ◽  
pp. 5620-5629 ◽  
Author(s):  
Dietmar Seyferth ◽  
Robert M. Weinstein ◽  
Richard C. Hui ◽  
Wei Liang Wang ◽  
Colin M. Archer
Keyword(s):  
Low Temperature ◽  
Hydroxy Ketones ◽  
Aldehydes And Ketones ◽  
Nucleophilic Acylation

scholarly journals Detection of Microorganisms in Low-Temperature Water Environments by in situ Generation of Biogenic Nanoparticles

2020 ◽  
Vol 7 ◽  
Author(s):  
Dmitry A. Skladnev ◽  
Lina V. Vasilyeva ◽  
Yulia Yu. Berestovskaya ◽  
Oleg R. Kotsyurbenko ◽  
Sergei V. Kalenov ◽  
...  
Keyword(s):  
Low Temperature ◽  
Water Samples ◽  
Sampling Site ◽  
Ag Nps ◽  
Biological Objects ◽  
In Situ Generation ◽  
The Comparative Study ◽  
Biogenic Nanoparticles ◽  
Temperature Water

A new nanobiotechnological approach for the detection of extraterrestrial Earth-like biological forms is proposed. The approach is based on the ability of microbial cells to reduce artificially added cations with the generation of crystalline nanoparticles (NPs) from zero-valent atoms. The method is named DBNG (Detection of Biogenic Nanoparticles Generation). The subglacial low-temperature oligotrophic Lake Untersee in Antarctica was used as a model of putative extraterrestrial water environments inhabited by Earth-like type microorganisms. The DBNG protocol for the comparative study of microbial communities of low-temperature oligotrophic environments was optimized on the base of experiments with the pure culture of psychroactive bacterium Cryobacterium sp. 1639 isolated earlier from Lake Untersee. The formation of silver nanoparticles (Ag°NPs) has been conducted in natural water samples of three horizons at low temperature (+5°C), which was in the temperature range registered in the Lake Untersee. The generation of biogenic Ag°NPs was detected only at the presence of indigenous microorganisms in all studied samples. No Ag°NPs generation was observed in the lake water samples artificially free of cells or exposed to pasteurization (two types of controls). The miniature microfluidic chip for an automated version of the device, based on using different analytical methods for recording in situ-formed biogenic nanoparticles, is proposed. The device allows the detection of the biological objects directly at the sampling site.

scholarly journals In situ generation of indium catalysts to grow crystalline silicon nanowires at low temperature on ITO

2008 ◽  
Vol 18 (43) ◽  
pp. 5187 ◽  
Author(s):  
Pierre-Jean Alet ◽  
Linwei Yu ◽  
Gilles Patriarche ◽  
Serge Palacin ◽  
Pere Roca i Cabarrocas
Keyword(s):  
Low Temperature ◽  
Silicon Nanowires ◽  
Crystalline Silicon ◽  
In Situ Generation

ChemInform Abstract: Synthesis of α-Diketones by Direct, Low-Temperature, in situ Nucleophilic Acylation of Esters by Acyllithium Reagents.

ChemInform ◽  
2010 ◽  
Vol 23 (8) ◽  
pp. no-no
Author(s):  
D. SEYFERTH ◽  
R. M. WEINSTEIN ◽  
R. C. HUI ◽  
W.-L. WANG ◽  
C. M. ARCHER
Keyword(s):  
Low Temperature ◽  
Nucleophilic Acylation

Synthesis of .alpha.-diketones by direct, low-temperature, in situ nucleophilic acylation of esters by acyllithium reagents

1991 ◽  
Vol 56 (20) ◽  
pp. 5768-5773 ◽  
Author(s):  
Dietmar Seyferth ◽  
Robert M. Weinstein ◽  
Richard C. Hui ◽  
Wei Liang Wang ◽  
Colin M. Archer
Keyword(s):  
Low Temperature ◽  
Nucleophilic Acylation

In situ Tensile Experiments at Low Temperatures on Niobium Single Crystals by H.V.E.M.

1975 ◽  
Vol 33 ◽  
pp. 58-59
Author(s):  
F. H. Louchet ◽  
L. P. Kubin
Keyword(s):  
Electron Microscope ◽  
Transition Temperature ◽  
Low Temperature ◽  
Slip System ◽  
Low Temperatures ◽  
Tensile Axis ◽  
Image Intensifier ◽  
Screw Dislocations ◽  
Source Operation

Experiments have been carried out on the 3 MeV electron microscope in Toulouse. The low temperature straining holder has been previously described Images given by an image intensifier are recorded on magnetic tape.The microtensile niobium samples are cut in a plane with the two operative slip directions [111] and lying in the foil plane. The tensile axis is near [011].Our results concern:- The transition temperature of niobium near 220 K: at this temperature and below an increasing difference appears between the mobilities of the screw and edge portions of dislocations loops. Source operation and interactions between screw dislocations of different slip system have been recorded.

Role of boundaries in the crystallization of amorphous films

1988 ◽  
Vol 46 ◽  
pp. 626-627
Author(s):  
D. A. Smith
Keyword(s):  
Low Temperature ◽  
Amorphous State ◽  
Nucleation And Growth ◽  
Amorphous Films ◽  
Island Nucleation ◽  
Surface Steps ◽  
Transmission Electron ◽  
Component Systems ◽  
Temperature Deposition

The nucleation and growth processes which lead to the formation of a thin film are particularly amenable to investigation by transmission electron microscopy either in situ or subsequent to deposition. In situ studies have enabled the observation of island nucleation and growth, together with addition of atoms to surface steps. This paper is concerned with post-deposition crystallization of amorphous alloys. It will be argued that the processes occurring during low temperature deposition of one component systems are related but the evidence is mainly indirect. Amorphous films result when the deposition conditions such as low temperature or the presence of impurities (intentional or unintentional) preclude the atomic mobility necessary for crystallization. Representative examples of this behavior are CVD silicon grown below about 670°C, metalloids, such as antimony deposited at room temperature, binary alloys or compounds such as Cu-Ag or Cr O2, respectively. Elemental metals are not stable in the amorphous state.

Highly diastereo- and enantioselective organocatalytic synthesis of trifluoromethylated erythritols based on the in situ generation of unstable trifluoroacetaldehyde

2021 ◽  
Author(s):  
Kazumasa Funabiki ◽  
Toshiya Gotoh ◽  
Ryunosuke Kani ◽  
Toshiyasu Inuzuka ◽  
Yasuhiro Kubota
Keyword(s):  
Trifluoromethyl Group ◽  
In Situ Generation

A highly diastereo- and enantioselective organocatalytic method to synthesise erythritols bearing a trifluoromethyl group has been investigated.

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