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On the Formation of Higher Carbon Oxides in Extreme Environments
Chemical Physics Letters 465 (2008) 1–9 Contents lists available at ScienceDirect Chemical Physics Letters journal homepage: www.elsevier.com/locate/cplett FRONTIERS ARTICLE On the formation of higher carbon oxides in extreme environments Ralf I. Kaiser a,*, Alexander M. Mebel b a Department of Chemistry, University of Hawaii at Manoa, 2545 The Mall (Bil 301A), Honolulu, HI 96822, USA b Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA article info abstract Article history: Due to the importance of higher carbon oxides of the general formula COx (x > 2) in atmospheric chem- Received 15 May 2008 istry, isotopic enrichment processes, low-temperature ices in the interstellar medium and in the outer In final form 22 July 2008 solar system, as well as potential implications to high-energy materials, an overview on higher carbon Available online 29 July 2008 oxides COx (x = 3–6) is presented. This article reviews recent developments on these transient species. Future challenges and directions of this research field are highlighted. Ó 2008 Elsevier B.V. All rights reserved. 1. Introduction tion has no activation energy, proceeds with almost unit efficiency, and most likely involves a reaction intermediate. However, neither In recent years, the interest in carbon oxides of higher complex- reaction products (kinetics studies) nor the nature of the interme- 1 + ityP than carbon monoxide (CO; X R ) and carbon dioxide (CO2; diate (kinetics and dynamicsP studies) were determined. On the 1 þ 1 + 3 À X g ) of the generic formula COx (x > 2) has been fueled by com- other hand, a CO(X R )+O2(X g ) exit channel was found to have plex reaction mechanisms of carbon oxides with atomic oxygen in an activation energy between 15 and 28 kJ molÀ1 in the range of the atmospheres of Mars [1–4] and Venus [5]. -
Isotopic Exchange Between Carbon Dioxide and Ozone Via O1D in The
GEOPHYSICAL RESEARCH LETTERS, VOL. 18, NO. 1, PAGES 13-16, JANUARY 1991 ISOTOPICEXCHANGE BETWEEN CARBONDIOXIDE AND OZONEVIA O(!D) IN THE STRATOSPHERE Yuk L. Yung, W.B. DoMore,and Joseph P. Pinto Abstract. We proposea novelmechanism for isotopic Table 1 exchangebetween CO 2 and0 3 vi•aO(ID) + CO2 -->CO_•* followedby CO3' --> CO2 + O(aP). A one-•ensior•al List of essentialreactions used in the photochemicalmodel. model calculation shows that this mechanism can account for The units for photodissociationcoefficients and two-body theenrichment in 180 in thestratospheric CO2 observed by rateconstants are s -1 andcm 3 s-l, respectively.The coeffi- Gatnoeta!. [1989],using the heavy 0 3 profile-observed by cientsfor photolysisrefer to nfid-latitudedimally averaged Mauersberger[1981]. The implicationsof this mechanism values at 30 kan. All molecular kinetic data are taken frmn for otherstratospheric species and as a sourceof isotopically DoMore etal. [1990], except otherwise stated. Rate heavyCO 2 in thetroposphere are briefly discussed. constantsforisotopic species are estimated byus. Q = 180. h•troduction Rla O3+ bY-->O2 + O(1D) Jla=7.4x10 -5 RecentlyGamo et at. [1989] reportedmeasurements of Rib O2Q+ hv-->O2 + Q(!D) Jlb=1/2 J la heavyisotopes of CO2 in the stratosphereover Japan. Let O R2a O(ID)+ M--->O+ M k2a= 2.0x 10-11 e ll0/T = 160 andQ = 180.The fiQ of stratosphericCO2, as defined R2b Q(1D) + M --->Q + M k2b= k2a in Gatno et at., was found to be 2O/oo(two parts in a R3 O(ID)+ CO2---->CO2 + O k3 = 7.4x 10-11 e 120/T thousand)greater than that of troposphericCO 2 at 19 km, R4a Q(1D)+ CO2-->CO Q + O k4a= 2/3k 3 and appearsto continueto increasewith altitudeup to the R4b O(ID)+ COQ-->CO2 + Q k4b= 1/3k 3 highestaltitude (25 km) where sampleswere taken. -
April 16, 1963 M. TANENBAUM 3,085,981
April 16, 1963 M. TANENBAUM 3,085,981 Filed March 25, 1960 CDsY /W/AW7OAP M. 74WEWABAVMM A^ 477OAPAVE/ 3,085,981 United States Patent Office Patented Apr. 16, 1963 2 3,085,981 FIG. 1 is a sectional view of a portion of a typical FERRIMAGNETCCRYSTALS garnet crystal having surface characteristics after rough Morris Tanenbaum, Madison, N.J., assignor to Bell Tele polishing; phone Laboratories, Incorporated, New York, N.Y., a FIG. 2 is a sectional view of a portion of the same corporation of New York crystal during the first phase of the treatment of the Filed Mar. 25, 1960, Ser. No. 17,539 invention; 1. Claim. (C. 252-62.5) FIG. 3 is a sectional view of a portion of the same crystal at a subsequent stage of the operation; This invention relates to an improved ferrimagnetic FIG. 4 is a sectional view of a portion of the desired structure, particularly in ferrimagnetic garnets. More O finished crystal; and specifically, it relates to a structure wherein the demag FIG. 5 is a schematic view of an appropriate apparatus netizing effects on the crystal surface are minimized. used in obtaining the desired crystal. With the advent of more perfect crystal growing tech Referring to FIGS. 1 through 4 which show the crystal niques, particularly with respect to ferrimagnetic gar in various stages of treatment according to the invention, nets, superior resonance characteristics have been found 5 numeral 1 refers to the ferrimagnetic interior layer and to depend more and more on the surface characteristics 2 denotes the crystal surface. -
Subsurface Oxide Plays a Critical Role in CO2 Activation by Cu(111)
Subsurface oxide plays a critical role in CO2 activation by Cu(111) surfaces to form chemisorbed CO2, the first step in reduction of CO2 Marco Favaroa,b,c,1, Hai Xiaod,e,1, Tao Chengd,e, William A. Goddard IIId,e,2, Junko Yanoa,f,2, and Ethan J. Crumlinb,2 aJoint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; bAdvanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; cChemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; dJoint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena CA 91125; eMaterials and Process Simulation Center, California Institute of Technology, Pasadena CA 91125; and fMolecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 Contributed by William A. Goddard III, May 9, 2017 (sent for review January 26, 2017; reviewed by Charles T. Campbell and Bruce E. Koel) A national priority is to convert CO2 into high-value chemical sorbed form of CO2 was stabilized by a partial negative charge products such as liquid fuels. Because current electrocatalysts are δ− induced by electron capture (CO2 ) (Fig. 1A) (7, 8). The same not adequate, we aim to discover new catalysts by obtaining a experiments showed that no physisorption is observed upon detailed understanding of the initial steps of CO2 electroreduc- increasing the temperature of the Cu substrate to room temper- tion on copper surfaces, the best current catalysts. Using ambient ature -
Gas-Phase Boudouard Disproportionation Reaction Between Highly Vibrationally Excited CO Molecules
Chemical Physics 330 (2006) 506–514 www.elsevier.com/locate/chemphys Gas-phase Boudouard disproportionation reaction between highly vibrationally excited CO molecules Katherine A. Essenhigh, Yurii G. Utkin, Chad Bernard, Igor V. Adamovich *, J. William Rich Nonequilibrium Thermodynamics Laboratories, Department of Mechanical Engineering, The Ohio State University, Columbus, OH 43202, USA Received 3 September 2006; accepted 21 September 2006 Available online 30 September 2006 Abstract The gas-phase Boudouard disproportionation reaction between two highly vibrationally excited CO molecules in the ground elec- tronic state has been studied in optically pumped CO. The gas temperature and the CO vibrational level populations in the reaction region, as well as the CO2 concentration in the reaction products have been measured using FTIR emission and absorption spectroscopy. The results demonstrate that CO2 formation in the optically pumped reactor is controlled by the high CO vibrational level populations, rather than by CO partial pressure or by flow temperature. The disproportionation reaction rate constant has been determined from the measured CO2 and CO concentrations using the perfectly stirred reactor (PSR) approximation. The reaction activation energy, 11.6 ± 0.3 eV (close to the CO dissociation energy of 11.09 eV), was evaluated using the statistical transition state theory, by comparing the dependence of the measured CO2 concentration and of the calculated reaction rate constant on helium partial pressure. The dispro- À18 3 portionation reaction rate constant measured at the present conditions is kf =(9±4)· 10 cm /s. The reaction rate constants obtained from the experimental measurements and from the transition state theory are in good agreement. -
A Two-Step Graph Convolutional Decoder for Molecule Generation
A Two-Step Graph Convolutional Decoder for Molecule Generation Xavier Bresson Thomas Laurent School of Computer Science and Engineering Department of Mathematics NTU, Singapore Loyola Marymount University [email protected] [email protected] Abstract We propose a simple auto-encoder framework for molecule generation. The molec- ular graph is first encoded into a continuous latent representation z, which is then decoded back to a molecule. The encoding process is easy, but the decoding pro- cess remains challenging. In this work, we introduce a simple two-step decoding process. In a first step, a fully connected neural network uses the latent vector z to produce a molecular formula, for example CO2 (one carbon and two oxygen atoms). In a second step, a graph convolutional neural network uses the same latent vector z to place bonds between the atoms that were produced in the first step (for example a double bond will be placed between the carbon and each of the oxygens). This two-step process, in which a bag of atoms is first generated, and then assembled, provides a simple framework that allows us to develop an efficient molecule auto-encoder. Numerical experiments on basic tasks such as novelty, uniqueness, validity and optimized chemical property for the 250k ZINC molecules demonstrate the performances of the proposed system. Particularly, we achieve the highest reconstruction rate of 90.5%, improving the previous rate of 76.7%. We also report the best property improvement results when optimization is constrained by the molecular distance between the original and generated molecules. 1 Introduction A fundamental problem in drug discovery and material science is to design molecules with arbitrary optimized chemical properties. -
Assessing the Chemistry and Bioavailability of Dissolved Organic Matter from Glaciers and Rock Glaciers
RESEARCH ARTICLE Assessing the Chemistry and Bioavailability of Dissolved 10.1029/2018JG004874 Organic Matter From Glaciers and Rock Glaciers Special Section: Timothy Fegel1,2 , Claudia M. Boot1,3 , Corey D. Broeckling4, Jill S. Baron1,5 , Biogeochemistry of Natural 1,6 Organic Matter and Ed K. Hall 1Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, USA, 2Rocky Mountain Research 3 Key Points: Station, U.S. Forest Service, Fort Collins, CO, USA, Department of Chemistry, Colorado State University, Fort Collins, • Both glaciers and rock glaciers CO, USA, 4Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, CO, USA, 5U.S. Geological supply highly bioavailable sources of Survey, Reston, VA, USA, 6Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, organic matter to alpine headwaters CO, USA in Colorado • Bioavailability of organic matter released from glaciers is greater than that of rock glaciers in the Rocky Abstract As glaciers thaw in response to warming, they release dissolved organic matter (DOM) to Mountains alpine lakes and streams. The United States contains an abundance of both alpine glaciers and rock • ‐ The use of GC MS for ecosystem glaciers. Differences in DOM composition and bioavailability between glacier types, like rock and ice metabolomics represents a novel approach for examining complex glaciers, remain undefined. To assess differences in glacier and rock glacier DOM we evaluated organic matter pools bioavailability and molecular composition of DOM from four alpine catchments each with a glacier and a rock glacier at their headwaters. We assessed bioavailability of DOM by incubating each DOM source Supporting Information: with a common microbial community and evaluated chemical characteristics of DOM before and after • Supporting Information S1 • Data Set S1 incubation using untargeted gas chromatography–mass spectrometry‐based metabolomics. -
Recent Advances in Electrical Doping of 2D Semiconductor Materials: Methods, Analyses, and Applications
nanomaterials Review Recent Advances in Electrical Doping of 2D Semiconductor Materials: Methods, Analyses, and Applications Hocheon Yoo 1,2,† , Keun Heo 3,† , Md. Hasan Raza Ansari 1,2 and Seongjae Cho 1,2,* 1 Department of Electronic Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, Korea; [email protected] (H.Y.); [email protected] (M.H.R.A.) 2 Graduate School of IT Convergence Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, Korea 3 Department of Semiconductor Science & Technology, Jeonbuk National University, Jeonju-si, Jeollabuk-do 54896, Korea; [email protected] * Correspondence: [email protected] † These authors contributed equally to this work. Abstract: Two-dimensional materials have garnered interest from the perspectives of physics, materi- als, and applied electronics owing to their outstanding physical and chemical properties. Advances in exfoliation and synthesis technologies have enabled preparation and electrical characterization of various atomically thin films of semiconductor transition metal dichalcogenides (TMDs). Their two-dimensional structures and electromagnetic spectra coupled to bandgaps in the visible region indicate their suitability for digital electronics and optoelectronics. To further expand the potential applications of these two-dimensional semiconductor materials, technologies capable of precisely controlling the electrical properties of the material are essential. Doping has been traditionally used to effectively change the electrical and electronic properties of materials through relatively simple processes. To change the electrical properties, substances that can donate or remove electrons are Citation: Yoo, H.; Heo, K.; added. Doping of atomically thin two-dimensional semiconductor materials is similar to that used Ansari, M..H.R.; Cho, S. -
Potential Ivvs.Gelbasedre
US010644304B2 ( 12 ) United States Patent ( 10 ) Patent No.: US 10,644,304 B2 Ein - Eli et al. (45 ) Date of Patent : May 5 , 2020 (54 ) METHOD FOR PASSIVE METAL (58 ) Field of Classification Search ACTIVATION AND USES THEREOF ??? C25D 5/54 ; C25D 3/665 ; C25D 5/34 ; ( 71) Applicant: Technion Research & Development HO1M 4/134 ; HOTM 4/366 ; HO1M 4/628 ; Foundation Limited , Haifa ( IL ) (Continued ) ( 72 ) Inventors : Yair Ein - Eli , Haifa ( IL ) ; Danny (56 ) References Cited Gelman , Haifa ( IL ) ; Boris Shvartsev , Haifa ( IL ) ; Alexander Kraytsberg , U.S. PATENT DOCUMENTS Yokneam ( IL ) 3,635,765 A 1/1972 Greenberg 3,650,834 A 3/1972 Buzzelli ( 73 ) Assignee : Technion Research & Development Foundation Limited , Haifa ( IL ) (Continued ) ( * ) Notice : Subject to any disclaimer , the term of this FOREIGN PATENT DOCUMENTS patent is extended or adjusted under 35 CN 1408031 4/2003 U.S.C. 154 ( b ) by 56 days . EP 1983078 10/2008 (21 ) Appl. No .: 15 /300,359 ( Continued ) ( 22 ) PCT Filed : Mar. 31 , 2015 OTHER PUBLICATIONS (86 ) PCT No .: PCT/ IL2015 /050350 Hagiwara et al. in ( Acidic 1 - ethyl - 3 -methylimidazoliuum fluoride: a new room temperature ionic liquid in Journal of Fluorine Chem $ 371 (c ) ( 1 ), istry vol . 99 ( 1999 ) p . 1-3 ; ( Year: 1999 ). * (2 ) Date : Sep. 29 , 2016 (Continued ) (87 ) PCT Pub . No .: WO2015 / 151099 Primary Examiner — Jonathan G Jelsma PCT Pub . Date : Oct. 8 , 2015 Assistant Examiner Omar M Kekia (65 ) Prior Publication Data (57 ) ABSTRACT US 2017/0179464 A1 Jun . 22 , 2017 Disclosed is a method for activating a surface of metals , Related U.S. Application Data such as self- passivated metals , and of metal -oxide dissolu tion , effected using a fluoroanion -containing composition . -
Some Unusual, Astronomically Significant Organic Molecules
'lL-o Thesis titled: Some Unusual, Astronomically Significant Organic Molecules submitted for the Degree of Doctor of Philosophy (Ph,D.) by Salvatore Peppe B.Sc. (Hons.) of the Department of Ghemistty THE UNIVERSITY OF ADELAIDE AUSTRALIA CRUC E June2002 Preface Gontents Contents Abstract IV Statement of Originality V Acknowledgments vi List of Figures..... ix 1 I. Introduction 1 A. Space: An Imperfect Vacuum 1 B. Stellff Evolution, Mass Outflow and Synthesis of Molecules 5 C. Astronomical Detection of Molecules......... l D. Gas Phase Chemistry.. 9 E. Generation and Detection of Heterocumulenes in the Laboratory 13 L.2 Gas Phase Generation and Characterisation of Ions.....................................16 I. Gas Phase Generation of Ions. I6 A. Positive Ions .. I6 B. Even Electron Negative Ions 17 C. Radical Anions 2t tr. Mass Spectrometry 24 A. The VG ZAB 2}lF Mass Spectrometer 24 B. Mass-Analysed Ion Kinetic Energy Spectrometry......... 25 III. Characterisation of Ions.......... 26 A. CollisionalActivation 26 B. Charge Reversal.... 28 C. Neutralisation - Reionisation . 29 D. Neutral Reactivity. JJ rv. Fragmentation Behaviour ....... 35 A. NegativeIons.......... 35 Preface il B. Charge Inverted Ions 3l 1.3 Theoretical Methods for the Determination of Molecular Geometries and Energetics..... ....o........................................ .....39 L Molecular Orbital Theory........ 39 A. The Schrödinger Equation.... 39 B. Hartree-Fock Theory ..44 C. Electron Correlation ..46 D. Basis sets............ .51 IL Transition State Theory of Unimolecular Reactions ......... ................... 54 2. Covalently Bound Complexes of CO and COz ....... .........................58 L Introduction 58 tr. Results and Discussion........... 59 Part A: Covalently bound COz dimers (OzC-COr)? ............ 59 A. Generation of CzO¿ Anions 6I B. NeutralCzO+........ -
High-Pressure Synthesis of Boron-Rich Chalcogenides B12S and B12se
High-pressure synthesis of boron-rich chalcogenides B12S and B12Se 1,2 1 3,4 Kirill A. Cherednichenko, Vladimir A. Mukhanov, Aleksandr Kalinko, 1, and Vladimir L. Solozhenko 1,* 1 LSPM–CNRS, Université Sorbonne Paris Nord, Villetaneuse, 93430, France 2 Department of Physical and Colloid Chemistry, Gubkin University, Moscow, 119991, Russia 3 Photon Science – Deutsches Elektronen-Synchrotron (DESY), 22607 Hamburg, Germany 4 Institute of Solid State Physics, University of Latvia, Riga, LV-1063, Latvia * [email protected] ABSTRACT Two boron-rich chalcogenides B12S and B12Se isostructural to α-rhombohedral boron were synthesized by chemical reaction of the elements at high-pressure – high-temperature conditions. The crystal structures and stoichiometries of both compounds were confirmed by Rietveld refinement and elemental analysis. The experimental Raman spectra of B12S and B12Se were investigated for the first time. All observed Raman bands have been attributed to the theoretically calculated phonon modes, and the mode assignment has been performed. INTRODUCTION Boron-rich compounds isostructural to the α-rhombohedral boron (α-B12) have become the subject of extensive theoretical 1-11 and experimental 12-23 studies due to their unusual properties and potential technical applications.14,18,24 One of the most attractive features of boron-rich compounds is their outstanding mechanical properties. For instance, the reported hardness values of boron 25-31 suboxide (B12O2) varies from 24 to 45 GPa. Thus, boron suboxide is believed to be the hardest known oxide. Numerous works have been devoted to the investigation of its phase stability,3,32 compressibility,32-34 phonon 35-37 and thermal 34,38 properties, etc. -
OXIDE: ELECTRODE POTENTIAL from 20" to 30"; SOLUBILITY in NEUTRAL and ALKALINE SOLUTIONS at 25"G
SOME THERMODYNmiG PROPERTIES OF SILVER(II)OXIDE: ELECTRODE POTENTIAL FROM 20" to 30"; SOLUBILITY IN NEUTRAL AND ALKALINE SOLUTIONS AT 25"G DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By JAMES FREDERICK BONK, B.S. The Ohio State University 1958 Approved by: Depart Chemistry AGKNOWLEDGM0JT The author wishes to express his sincere appreciation to Professor A. B. Garrett for his supervision and counsel during the course of this investigation. I wish to thank him for his interest in my welfare while I was a student at The Ohio State University and especially for his guidance and encouragement in my teaching career. I also wish to thank the DuPont Chemical Company for granting me the DuPont Teaching Fellowship for the 1956-1957 academic year. I wish to thank The Ohio State University for the Assistantship, Assistant Instructorship, and Instructorship granted me during the course of this investigation. TABLE OF CONTENTS Page I. INTRODUCTION 1 II. HISTORICAL a. Methods of Preparation of t/ Silver(II)oxide 2 b. Properties of Silver(II)oxide 7 c. Uses of Silver(II)oxide 13 III. THE SOLUBILITY OF SILVER(II)OXIDE IN NEUTRAL AND ALKALINE SOLUTIONS AT 25“G 1? a. Experimental 17 1. Preparation of Reagents 17 2. Preparation of Samples 19 3. Equilibration 23 4. Sedimentation 23 5. Filtration 23 6. Potentiometric Analysis 23 7. Analysis of Solid Phase 26 b. Solubility Data for Silver(II)oxide 27 c . Discussion 34 111 CONTENTS (continued) Page IV. A STUDY OF THE SILVER (I) OXIDE- SILVER (II) OXIDE ELECTRODE 39 a.