Constructing the OCF2O moiety using BrF3

A general preparation for aromatic and aliphatic, cyclic as well as linear, symmetric and asymmetric difluoromethylenedioxy derivatives is described. The alcohols were reacted with thiophosgene to give thiocarbonates, which in turn were reacted with BrF3. The fluorination step is complete in seconds with moderate to high yields under mild conditions.     

An Information-Theoretic View of Mixed-Delay Traffic in 5G and 6G

Fifth generation mobile communication systems (5G) have to accommodate both Ultra-Reliable Low-Latency Communication (URLLC) and enhanced Mobile Broadband (eMBB) services. While eMBB applications support high data rates, URLLC services aim at guaranteeing low-latencies and high-reliabilities. eMBB and URLLC services are scheduled on the same frequency band, where the different latency requirements of the communications render their coexistence challenging. In this survey, we review, from an information theoretic perspective, coding schemes that simultaneously accommodate URLLC and eMBB transmissions and show that they outperform traditional scheduling approaches. Various communication scenarios are considered, including point-to-point channels, broadcast channels, interference networks, cellular models, and cloud radio access networks (C-RANs). The main focus is on the set of rate pairs that can simultaneously be achieved for URLLC and eMBB messages, which captures well the tension between the two types of communications. We also discuss finite-blocklength results where the measure of interest is the set of error probability pairs that can simultaneously be achieved in the two communication regimes.     

Dispersion polymerization of styrene in polar solvents: Effect of reaction parameters on microsphere surface composition and surface properties,size and size distribution,and molecular weight

Polystyrene microspheres were prepared by dispersion polymerization of styrene in a mixture of ethanol and 2-methoxy ethanol. Surface characterization of the formed particles was performed by x-ray photoelectron spectroscopy and critical surface tension measurements. The influence of different reaction parameters, i.e., monomer concentration, stabilizer type (polyvinylpyrrolidone, copolymers of vinylpyrrolidone and vinylacetate and polyvinylace tate), stabilizer concentration and molecular weight, and initiator type and concentration, on the molecular weight and on the size and size distribution of the formed polystyrene microspheres was investigated. The correlation between the surface composition and wett ability properties of the particles surface and their size and size distribution was also demonstrated. © 1996 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 34:1857–1871, 1996     

Isoscalar and Isovector Giant Resonances in Closed Shells Nuclei and Bulk Properties of Nuclear Matter

Physics of Atomic Nuclei - Centroid energies, $$E_{\textrm{CEN}}$$ , of the isoscalar ( $$T=0$$ ) and isovector ( $$T=1$$ ) giant resonances of multipolarities $$L_{m}=0$$ –3 in...     

Flavored surface defects in 4d $$\mathcal{N}=1$$ N = 1 SCFTs

We discuss supersymmetric surface defects in compactifications of six-dimensional minimal conformal matter of types SU(3) and SO(8) to four dimensions. The relevant field theories in four dimensions are \(\mathcal{N}=1\) quiver gauge theories with SU(3) and SU(4) gauge groups, respectively. The defects are engineered by giving space-time-dependent vacuum expectation values to baryonic operators. We find evidence that in the case of SU(3) minimal conformal matter, the defects carry SU(2) flavor symmetry which is not a symmetry of the four-dimensional model. The simplest case of a model in this class is SU(3) SQCD with nine flavors, and thus the results suggest that this admits natural surface defects with SU(2) flavor symmetry. We analyze the defects using the superconformal index and derive analytic difference operators introducing the defects into the index computation. The duality properties of the four-dimensional theories imply that the index of the models is a kernel function for such difference operators. In turn, checking the kernel property constitutes an independent check of the dualities and the dictionary between six- dimensional compactifications and four-dimensional models.

     

Additive-Free Electrophoretic Deposition of Graphene Quantum Dots Thin Films

The electrophoretic deposition (EPD) of graphene-based materials on transparent substrates is highly potential for many applications. Several factors can determine the yield of the EPD process, such as applied voltage, deposition time and particularly the presence of dispersion additives (stabilisers) in the suspension solution. This study presents an additive-free EPD of graphene quantum dot (GQD) thin films on an indium tin oxide (ITO) glass substrate and studies the deposition mechanism with the variation of the applied voltage (10–50 V) and deposition time (5–25 min). It is found that due to the small size (≈3.9 nm) and high content of deprotonated carboxylic groups, the GQDs form a stable dispersion (zeta-potential of about −35 mV) without using additives. The GQD thin films can be deposited onto ITO with optimal surface morphology at 30 V in 5 min (surface roughness of approximately (3.1±1.3) nm). In addition, as-fabricated GQD thin films also possess some interesting physico-optical properties, such as a double-peak photoluminescence at about λ=417 and 439 nm, with approximately 98 % visible transmittance. This low-cost and eco-friendly GQD thin film is a promising material for various applications, for example, transparent conductors, supercapacitors and heat conductive films in smart windows.     

Preliminary Investigation on the Effect of Production Parameters on the Strength of Large Tablets

A case study of large tablet manufacturing in the chemical industry is presented. Since the tablets are much larger than the usual scale in the pharmaceutical industry, common practice that was developed mainly for pharmaceutical tablets could not be applied directly. Customer complaints concerning damaged tablets were the reason for this comprehensive study, which was aimed first at evaluating a testing method for process control, then to provide some hints for stabilizing the manufacturing process and for producing stronger tablets. Three test methods were evaluated: measuring compression and tension crush strengths and wear tests in a rotating drum. It was shown that the wear test provides sufficient results faster and easier than the other methods. By testing hundreds of tablets, produced in various batches, production parameters such as granule aging, surrounding humidity, tableting pressure and tablet aging were evaluated in order to provide stronger tablets. The strongest tablets were achieved by using fresh granules at very high humidity and compacting pressure and by allowing the tablets to age for at least 2 weeks.     

Network approaches to climate science

<正>Climate and physics are closely related.The governing equations for both the atmosphere and ocean are the Navier-Stokes equations,which describe and quantify the physics of fluids.However,the atmosphere and ocean are very complex due to the interaction of many processes,not necessarily physical,and due to the need to model processes that are smaller than the grid resolution.In spite of this complexity,physicists have successfully addressed a wide swath of it using advanced statistical physics methods and techniques.Climate