scholarly journals Catalytic defluorinative [3 + 2] cycloaddition of trifluoromethylalkenes with alkynes via reduction of nickel(ii) fluoride species

2015 ◽  
Vol 44 (45) ◽  
pp. 19460-19463 ◽  
Author(s):  
Takeshi Fujita ◽  
Tomohiro Arita ◽  
Tomohiro Ichitsuka ◽  
Junji Ichikawa
Keyword(s):  
Nickel Catalyst ◽  
Catalytic Synthesis ◽  
Additive System ◽  
System P

A catalytic synthesis of 2-fluoro-1,3-cyclopentadienes was achieved via [3 + 2] cycloaddition of 2-trifluoromethyl-1-alkenes and alkynes using a nickel catalyst and a diboron-based ternary additive system.

scholarly journals Nickel on nitrogen-doped carbon pellets for continuous-flow hydrogenation of biomass-derived compounds in water

2020 ◽  
Vol 22 (9) ◽  
pp. 2755-2766 ◽  
Author(s):  
Francesco Brandi ◽  
Marius Bäumel ◽  
Valerio Molinari ◽  
Irina Shekova ◽  
Iver Lauermann ◽  
...  
Keyword(s):  
Nickel Catalyst ◽  
Aqueous Phase ◽  
Continuous Flow ◽  
Flow System ◽  
Nitrogen Doped ◽  
System P ◽  
Nitrogen Doped Carbon ◽  
Carbon Pellets

A cheap, scalable and efficient nickel catalyst on nitrogen-doped carbon for the aqueous-phase hydrogenation of biomass-derived compounds in flow system.

scholarly journals Photochemical CO2 reduction in water using a co-immobilised nickel catalyst and a visible light sensitiser

2016 ◽  
Vol 52 (99) ◽  
pp. 14200-14203 ◽  
Author(s):  
Gaia Neri ◽  
Mark Forster ◽  
James J. Walsh ◽  
C. M. Robertson ◽  
T. J. Whittles ◽  
...  
Keyword(s):  
Visible Light ◽  
Nickel Catalyst ◽  
Co2 Reduction ◽  
System P

Dye-sensitised photocatalytic CO2 reduction in water using an immobilised Nickel catalyst operates with efficiencies greatly exceeding the equivalent solution based system.

Certain Ancient Number Systems

2016 ◽  
Author(s):  
Joseph Mazur
Keyword(s):  
Number System ◽  
Multiplication Tables ◽  
Additive System ◽  
Number Systems ◽  
Large Numbers ◽  
System P ◽  
History Of ◽  
Greek Alphabet

This chapter discusses ancient number systems, beginning with the Babylonian system. Almost every history of early Western mathematics begins with the Babylonian conception of number, a so-called sexagesimal (base 60) system for writing large numbers, formulations of multiplication tables, and ideas for astronomy. The current number system needs symbols for just ten numbers in order to represent any number we wish, compared to that of the Babylonians which needed just two symbols. The chapter also considers the early Egyptian number writing, which was an additive system, as well as the Greek alphabet and sequential number system, Roman numerals, Aztec numerals, and the Mayan system.

Catalytic synthesis of polyethylene-block-polynorbornene copolymers using a living polymerization nickel catalyst

2014 ◽  
Vol 5 (20) ◽  
pp. 6012-6018 ◽  
Author(s):  
Haiyang Gao ◽  
Yong Liu ◽  
Guiliang Li ◽  
Zefan Xiao ◽  
Guodong Liang ◽  
...  
Keyword(s):  
Nickel Catalyst ◽  
Living Polymerization ◽  
Catalytic Synthesis

Well-defined polyethylene-block-polynorbornene copolymers were synthesized using an amine–imine nickel catalyst.

Comparison of TEM and STM observations of small silver clusters on different carbon supports

1990 ◽  
Vol 48 (4) ◽  
pp. 264-265
Author(s):  
Bernd Tesche ◽  
Tobias Schilling
Keyword(s):  
Vibration Isolation ◽  
Pyrolytic Graphite ◽  
Carbon Film ◽  
Silver Clusters ◽  
Carbon Supports ◽  
Stacking Order ◽  
System P ◽  
High Resolution Tem ◽  
High Degree ◽  
Degree Of Order

The objective of our work is to determine:a) whether both of the imaging methods (TEM, STM) yield comparable data andb) which method is better suited for a reliable structure analysis of microclusters smaller than 1.5 nm, where a deviation of the bulk structure is expected.The silver was evaporated in a bell-jar system (p 10−5 pa) and deposited onto a 6 nm thick amorphous carbon film and a freshly cleaved highly oriented pyrolytic graphite (HOPG).The average deposited Ag thickness is 0.1 nm, controlled by a quartz crystal microbalance at a deposition rate of 0.02 nm/sec. The high resolution TEM investigations (100 kV) were executed by a hollow-cone illumination (HCI). For the STM investigations a commercial STM was used. With special vibration isolation we achieved a resolution of 0.06 nm (inserted diffraction image in Fig. 1c). The carbon film shows the remarkable reduction in noise by using HCI (Fig. 1a). The HOPG substrate (Fig. 1b), cleaved in sheets thinner than 30 nm for the TEM investigations, shows the typical arrangement of a nearly perfect stacking order and varying degrees of rotational disorder (i.e. artificial single crystals). The STM image (Fig. 1c) demonstrates the high degree of order in HOPG with atomic resolution.

Conclusion: What is Speculative Empiricism?

2018 ◽  
Author(s):  
Didier Debaise
Keyword(s):  
Social Groups ◽  
Speculative Philosophy ◽  
System P ◽  
History Of ◽  
Selection Of

Process and Reality ends with a warning: ‘[t]he chief danger to philosophy is narrowness in the selection of evidence’ (PR, 337). Although this danger of narrowness might emerge from the ‘idiosyncrasies and timidities of particular authors, of particular social groups, of particular schools of thought, of particular epochs in the history of civilization’ (PR, 337), we should not be mistaken: it occurs within philosophy, in its activity, its method. And the fact that this issue arises at the end of Process and Reality reveals the ambition that has accompanied its composition: Whitehead has resisted this danger through the form and ambition of his speculative construction. The temptation of a narrowness in selection attempts to expel speculative philosophy at the same time as it haunts each part of its system.

Pedestrian Oriented Vehicular Collision Avoidance Support System: P-VCASS

2010 ◽  
Vol E93-A (4) ◽  
pp. 679-688 ◽  
Author(s):  
Tomotaka WADA ◽  
Yuki NAKANISHI ◽  
Ryohta YAMAGUCHI ◽  
Kazushi FUJIMOTO ◽  
Hiromi OKADA
Keyword(s):  
Collision Avoidance ◽  
Support System ◽  
System P

Catalytic Synthesis of Cyclic Guanidines via Hydrogen Atom Transfer and Radical-Polar Crossover

2020 ◽  
Author(s):  
Shunya Ohuchi ◽  
Hiroki Koyama ◽  
Hiroki Shigehisa
Keyword(s):  
Hydrogen Atom ◽  
Functional Group ◽  
Hydrogen Atom Transfer ◽  
Catalytic Synthesis ◽  
Membered Ring ◽  
Biologically Active ◽  
Atom Transfer ◽  
Powerful Method ◽  
Protective Groups ◽  
The Common

A catalytic synthesis of cyclic guanidines, which are found in many biologically active compounds and natu-ral products, was developed, wherein transition-metal hydrogen atom transfer and radical-polar crossover were employed. This mild and functional-group tolerant process enabled the cyclization of alkenyl guanidines bearing common protective groups, such as Cbz and Boc. This powerful method not only provided the common 5- and 6-membered rings but also an unusual 7-membered ring. The derivatization of the products afforded various heterocycles. We also investigated the se-lective cyclization of mono-protected or hetero-protected (TFA and Boc) alkenyl guanidines and their further derivatiza-tions.

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