Obtaining Sulfur from Sulfur Hexafluoride and Studying the Sulfur Isotopes Properties by Using Vibrational Spectroscopy

Scheme of isotopically enriched SF[6] to elemental sulfur with orthorhombic modification conversion is offered. This scheme includes SF[6] reduction to Li2S by using lithium. The yield of isotopically enriched sulfur is not less than 97% with chemical purity not less than 99.9%. The results which show the dependence of the experimental frequencies in the vibrational spectra on the molecular weight of the sulfur isotope have been obtained

Deep Reinforcement Learning with VizDoomFirst-Person Shooter

In this work, we study deep reinforcement algorithms forpartially observable Markov decision processes (POMDP) combined withDeep Q-Networks. To our knowledge, we are the first to apply standardMarkov decision process architectures to POMDP scenarios. We proposean extension of DQN with Dueling Networks and several other model-freepolicies to training agent using deep reinforcement learning in VizDoomenvironment, which is replication of Doom first-person shooter. We de-velop several agents for the following scenarios in VizDoom first-personshooter (FPS): Basic, Defend The Center, Health Gathering. We com-pare our agent with Recurrent DQN with Prioritized Experience Replayand Snapshot Ensembling agent and get approximately triple increase inper episode reward. It is important to say that POMDP scenario closethe gap between human and computer player scenarios thus providingmore meaningful justification for Deep RL agent performance

Deep Reinforcement Learning with VizDoomFirst-Person Shooter

In this work, we study deep reinforcement algorithms forpartially observable Markov decision processes (POMDP) combined withDeep Q-Networks. To our knowledge, we are the first to apply standardMarkov decision process architectures to POMDP scenarios. We proposean extension of DQN with Dueling Networks and several other model-freepolicies to training agent using deep reinforcement learning in VizDoomenvironment, which is replication of Doom first-person shooter. We de-velop several agents for the following scenarios in VizDoom first-personshooter (FPS): Basic, Defend The Center, Health Gathering. We com-pare our agent with Recurrent DQN with Prioritized Experience Replayand Snapshot Ensembling agent and get approximately triple increase inper episode reward. It is important to say that POMDP scenario closethe gap between human and computer player scenarios thus providingmore meaningful justification for Deep RL agent performance

Q-Ensemble for Offline RL: Don't Scale the Ensemble, Scale the Batch Size

Training large neural networks is known to be time-consuming, with the learning duration taking days or even weeks. To address this problem, large-batch optimization was introduced. This approach demonstrated that scaling mini-batch sizes with appropriate learning rate adjustments can speed up the training process by orders of magnitude. While long training time was not typically a major issue for model-free deep offline RL algorithms, recently introduced Q-ensemble methods achieving state-of-the-art performance made this issue more relevant, notably extending the training duration. In this work, we demonstrate how this class of methods can benefit from large-batch optimization, which is commonly overlooked by the deep offline RL community. We show that scaling the mini-batch size and naively adjusting the learning rate allows for (1) a reduced size of the Q-ensemble, (2) stronger penalization of out-of-distribution actions, and (3) improved convergence time, effectively shortening training duration by 3-4x times on average.Comment: Accepted at 3rd Offline Reinforcement Learning Workshop at Neural Information Processing Systems, 202

Separation of rare earth elements by zone recrystallization

The separation of holmium and cerium by zone recrystallization using a mixture of HoCl[3]6H[2]O and CeCl[3]6H[2]O was investigated. It is shown that holmium is enriched at the end of the crystal that the recrystallization zone moves to, while cerium is concentrated in the primary solidification zone. The possible reasons for the experimentally observed distribution of hydrated ions of cerium and holmium along the length of the ingot are discussed. Also the coefficients of enrichment and separation are calculated

Lithium and magnesium isotopes fractionation by zone melting

The process of changing isotopic composition of the lithium and magnesium salts was studied by using the process of zone melting. It was founded in the paper that the process of separation of the lithium isotopes is more effective than for magnesium isotopes when the conditions of process were the same. The coefficients of isotopes separation were calculated and have the next value: [alpha]=1.006 for 26Mg isotope and [alpha]=1.0022 for {6}Li isotope

Study of sulfur isotopes by vibrational spectroscopy and quantum chemistry

The results show the dependence of the experimental and calculated frequencies in the IR- and Raman spectra from the molecular mass of the sulfur isotope. The effect of a sulfur isotope shifts on the change of thermodynamic parameters. The results obtained demonstrate that the quantum-chemical calculations are sensitive to the isotopic shifts in the vibrational spectra of sulfur isotopes and are able to assess changes in their thermodynamic properties

Influence of Adding Ammonium Bifluoride when Leaching Monazite Using Sulphur Acid

The following shows the results of the leaching of monazite concentrate with sulfuric acid in the presence of ammonium bifluoride. It was established that the addition of ammonium bifluoride increases the degree of the leaching monazite concentrate and allows the separation of phosphorous from a mixture of rare earth and radioactive elements