Room-Temperature Electroreductiveα-Alkylation of N-Heteroarenes with Styrenes

Despite their interesting applications,direct and diverse syntheses of aryl-fused 2-alkyl cyclic amines still remain challenging.Here,the concept of incorporating a C–C coupling process into the N-heteroaryl reduction was successfully applied to fulfill such a synthetic purpose.Due to our use of controllable electroreduction coupled with proton abstraction,we can report a room-temperature reductiveα-alkylation of the inert N-heteroarenes with abundantly available styrenes in an undivided Zn(+)/C(−)cell.This proceeds with good substrate compatibility and operational simplicity,utilizes cost-effective sacrificial Zn-anode,exhibits high selectivity,and does not need pressurized H2 gas and transition-metal catalysts.This current work offers a useful platform for direct construction of valuable aryl-fused 2-alkyl cyclic amines that are difficult to access with conventional methods.

From individual elements to macroscopic materials: in search of new superconductors via machine learning

An approach to supervised classification and regression of superconductive materials is proposed which builds on the DeepSet technology.This enables us to provide the chemical constituents of the examined compounds as an input to the algorithm,while avoiding artefacts that could originate from the chosen ordering in the list.The performance of the method are successfully challenged for both classification(tag a given material as superconducting)and regression(quantifying the associated critical temperature).We then searched through the International Mineralogical Association list with the trained neural network.Among the obtained superconducting candidates,three materials were selected to undergo a thorough experimental characterization.Superconductivity has been indeed confirmed for the synthetic analogue of michenerite,PdBiTe,and observed for the first time in monchetundraite,Pd2NiTe2,at critical temperatures in good agreement with the theory predictions.This latter is the first certified superconducting material to be identified by artificial intelligence methodologies.

Polychronous automata and their use for formal validation of AADL models

This paper investigates how state diagrams can be best represented in the polychronous model of computation (MoC) and proposes to use this model for code validation of behavior specifications in architecture analysis & design language (AADL). In this relational MoC, the basic objects are signals, which are related through dataflow equations. Signals are associated with logical clocks, which provide the capability to describe systems in which components obey multiple clock rates. We propose a model of finite-state automata, called polychronous automata, which is based on clock relationships. A specificity of this model is that an automaton is submitted to clock constraints, which allows one to specify a wide range of control-related configurations, being either reactive or restrictive with respect to their control environment. A semantic model is defined for these polychronous automata, which relies on boolean algebra of clocks. Based on a previously defined modeling method for AADL software architectures using the polychronous MoC, the proposed model is used as a formal model for the AADL behavior annex. This is illustrated with a case study involving an adaptive cruise control system.

Silicon photonics phase and intensity modulators for flat frequency comb generation

Flat electro-optical frequency combs play an important role in a wide range of applications,such as metrology,spectroscopy,or microwave photonics.As a key technology for the integration of optical circuits,silicon photonics could benefit from on-chip,tunable,flat frequency comb generators.In this article,two different architectures based on silicon modulators are studied for this purpose.They rely on a time to frequency conversion principle to shape the comb envelope.Using a numerical model of the silicon traveling-wave phase modulators,their driving schemes are optimized before their performances are simulated and compared.A total of nine lines could be obtained within a 2 dB flatness,with a line-spacing ranging from 0.1 to 7 GHz.Since this tunability is a major asset of electro-optical frequency combs,the effect of segmenting the phase modulators is finally investigated,showing that the flat lines spacing could be extended up to 39 GHz by this method.

Quadratic mean-field reflected BSDEs

In this paper,we analyze mean-field reflected backward stochastic differential equations when the driver has quadratic growth in the second unknown z.Using a linearization technique and the BMO martingale theory,we first apply a fixed-point argument to establish the uniqueness and existence result for the case with bounded terminal condition and obstacle.Then,with the help of theθ-method,we develop a successive approximation procedure to remove the boundedness condition on the terminal condition and obstacle when the generator is concave(or convex)with respect to the second unknown.