Bernstein polynomial and discontinuous functions

We obtain new estimates of the rate of convergence of Bernstein operators for discontinuous functions on [0,1]$[0,1]$ which can be used to derive known results for continuous functions and functions of bounded variation.     

Self‐Assembly Structures of 1H‐Indazoles in the Solution and Solid Phases: A Vibrational (IR,FIR, Raman,and VCD) Spectroscopy and Computational Study

1H‐indazoles are good candidates for studying the phenomena of molecular association and spontaneous resolution of chiral compounds. Thus, because the 1H‐indazoles can crystallize as dimers, trimers, or catemers, depending on their structure and the phase that they are in, the difficulty in the experimental analysis of the structure of the family of 1H‐indazoles becomes clear. This difficulty leads us to contemplate several questions: How can we determine the presence of different structures of a given molecular species if they change according to the phase? Could these different structures be present in the same phase simultaneously? How can they be determined? To shed light on these questions, we outline a very complete strategy by using various vibrational spectroscopic techniques that are sensitive (VCD) and insensitive (IR, FIR, and Raman) towards the chirality, together with quantum chemical calculations.     

Experimental test of the EEC wind climatology model in a Mediterranean coastal area

Summary The analysis of 18 months of meteorological measurements collected in three stations located in Sardinia (Italy), is presented. The experimental wind distributions for 12 sectors of 30 degrees each have been fitted with the Weibull distribution function. The experimental Weibull parameters have been compared with the ones simulated by using the model produced within the EEC programme ?Wind Atlas for Europe?. Discrepancies between the experimental and simulated wind distributions have been discussed. Time series of the three stations have been compared to study the modification of the characteristics of the air flow from the coast to inland. Statistics of the atmospheric stratification, based on the concept of Pasquill stability classes has been produced by using semi-empirical methods. Further developments have been suggested.     

Microwave absorption studies of MgB2 superconductor

Microwave absorption studies have been carried out on MgB₂ superconductor using a standard X-band EPR spectrometer. The modulated low-field microwave absorption signals recorded for polycrystalline (grain size ∼ 10 μm) samples suggested the absence of weak-link character. The field dependent direct microwave absorption has been found to obey a ✓H dependence with two different slopes, which indicated a transition from strongly pinned lattice to flux flow regime.     

Anticooperative Supramolecular Oligomerization Mediated by V-Shaped Monomer Design and Unconventional Hydrogen Bonds

After more than three decades of extensive investigations on supramolecular polymers, strategies for self-limiting growth still remain challenging. Herein, we exploit a new V-shaped monomer design to achieve anticooperatively formed oligomers with superior robustness and high luminescence. In toluene, the monomer-oligomer equilibrium is shifted to the monomer side, enabling the elucidation of the molecular packing modes and the resulting (weak) anticooperativity. Steric effects associated with an antiparallel staircase organization of the dyes are proposed to outcompete aromatic and unconventional B−F⋅⋅⋅H−N/C interactions, restricting the growth at the stage of oligomers. In methylcyclohexane (MCH), the packing modes and the anticooperativity are preserved; however, pronounced solvophobic and chain-enwrapping effects lead to thermally ultrastable oligomers. Our results shed light on understanding anticooperative effects and restricted growth in self-assembly.     

D(+)-pi-A(-) charge-transfer molecules based on tricyanoquinodimethane and diphosphine metal complexes

A new family of D (+)-pi-A (-) chromophores in which the donor group is an organometallic complex and the acceptor group a tricyanoquinodimethane moiety has been synthesized by the reaction of diphosphinomethanide transition-metal complexes and 7,7',8,8'-tetracyanoquinodimethane.