9,388 research outputs found
Electrotransformation of intact and osmotically sensitive cells of Corynebacterium glutamicum
No full textWolf H, Pühler A, Neumann E. Electrotransformation of intact and osmotically sensitive cells of Corynebacterium glutamicum. Applied Microbiology and Biotechnology. 1989;30(3):283-289
Steric demand of the Cp*Ga ligand: Synthesis and structure of Ni(Cp*Ga)(4) and of cis-M(Cp*Ga)(2)(CO)(4) (M = Cr, Mo)
No full textJutzi P, Neumann B, Schebaum LO, Stammler A, Stammler H-G. Steric demand of the Cp*Ga ligand: Synthesis and structure of Ni(Cp*Ga)(4) and of cis-M(Cp*Ga)(2)(CO)(4) (M = Cr, Mo). ORGANOMETALLICS. 1999;18(21):4462-4464.In the reaction of (eta(5)-pentamethylcyclopentadienyl)gallium (Cp*Ga) with Ni(COD)(2) (COD = 1,5-cyclooctadiene) and NorM(CO)(4) (Nor = norbornadiene; M = Cr, Mo) the complexes Ni(Cp*Ga)(4) (1) and cis- M(Cp*Ga)(2)(CO)(4) (M = Cr (2), Mo (3)), respectively, were obtained, Compounds 1-3 were characterized by NMR and IR data and by elemental analysis. In addition, an X-ray crystal structure analysis was performed on complexes 1 and 3. Cis-orientation of the Cp*Ga ligands is made possible by deviation of the Cp-centroid*-Ga-M vector from linearity. 1 is the first homoleptic complex with Cp*Ga as ligand
[{Fe(C5H4)(2)}(3){Ga(C5H5N)}(2)]: A trinuclear gallium-bridged ferrocenophane with a carousel structure
No full textJutzi P, Lenze N, Neumann B, Stammler H-G. [{Fe(C5H4)(2)}(3){Ga(C5H5N)}(2)]: A trinuclear gallium-bridged ferrocenophane with a carousel structure. ANGEWANDTE CHEMIE-INTERNATIONAL EDITION. 2001;40(8):1424-+
Artificial Neural Networks to Solve the Singular Model with Neumann–Robin, Dirichlet and Neumann Boundary Conditions
No full textThe aim of this work is to solve the case study singular model involving the Neumann–Robin, Dirichlet, and Neumann boundary conditions using a novel computing framework that is based on the artificial neural network (ANN), global search genetic algorithm (GA), and local search sequential quadratic programming method (SQPM), i.e., ANN-GA-SQPM. The inspiration to present this numerical framework comes through the objective of introducing a reliable structure that associates the operative ANNs features using the optimization procedures of soft computing to deal with such stimulating systems. Four different problems that are based on the singular equations involving Neumann–Robin, Dirichlet, and Neumann boundary conditions have been occupied to scrutinize the robustness, stability, and proficiency of the designed ANN-GA-SQPM. The proposed results through ANN-GA-SQPM have been compared with the exact results to check the efficiency of the scheme through the statistical performances for taking fifty independent trials. Moreover, the study of the neuron analysis based on three and 15 neurons is also performed to check the authenticity of the proposed ANN-GA-SQPM
GA-Fuzzy PID control simulation waveform diagram.
No full textAs is well known, the metal annealing process has the characteristics of heat concentration and rapid heating. Traditional vacuum annealing furnaces use PID control method, which has problems such as high temperature fluctuation, large overshoot, and long response time during the heating and heating process. Based on this situation, some domestic scholars have adopted fuzzy PID control algorithm in the temperature control of vacuum annealing furnaces. Due to the fact that fuzzy rules are formulated through a large amount of on-site temperature data and experience summary, there is a certain degree of subjectivity, which cannot ensure that each rule is optimal. In response to this drawback, the author combined the technical parameters of vacuum annealing furnace equipment, The fuzzy PID temperature control of the vacuum annealing furnace is optimized using genetic algorithm. Through simulation and comparative analysis, it is concluded that the design of the fuzzy PID vacuum annealing furnace temperature control system based on GA optimization is superior to fuzzy PID and traditional PID control in terms of temperature accuracy, rise time, and overshoot control. Finally, it was verified through offline experiments that the fuzzy PID temperature control system based on GA optimization meets the annealing temperature requirements of metal workpieces and can be applied to the temperature control system of vacuum annealing furnaces.</div
Synthesis, Properties and Application of Tetrakis(pentafluoroethyl)gallate, [Ga(C2F5)4].
No full textNiemann M, Neumann B, Stammler H-G, Hoge B. Synthesis, Properties and Application of Tetrakis(pentafluoroethyl)gallate, [Ga(C2F5)4]. Angewandte Chemie (International ed. in English). 2019;58(26):8938-8942.Weakly coordinating anions (WCA) are important for academic reasons as well as for technical applications. Tetrakis(pentafluoroethyl)gallate, [Ga(C2F5)4]-, a new WCA, is accessible by treatment of [GaCl3(dmap)] (dmap = 4-dimethylaminopyridine) with LiC2F5. The anion [Ga(C2F5)4]- proved to be reluctant towards deterioration by aqueous hydrochloric acid or lithium hydroxide. Various salts of [Ga(C2F5)4]- were synthesized with cations such as [PPh4]+, [CPh3]+, [(O2H5)2(OH2)2]2+ and [Li(dec)2]+ (dec = diethyl carbonate). Thermolysis of [(O2H5)2(OH2)2][Ga(C2F5)4]2 gives rise to a dihydrate of tris(pentafluoroethyl)gallane, [Ga(C2F5)3(OH2)2]. All products were characterized by NMR and IR spectroscopy, mass spectrometry, X-ray diffraction and elemental analysis. Furthermore an outlook for the application of [Li(dec)2][Ga(C2F5)4] as a conducting salt in lithium-ion batteries is presented. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Differing reactivities of Cp*Ga toward diazabutadienes: Synthesis of novel 1-galla-2,5-diazoles and of the known radical Ga[Bu-t-DAB](2)
No full textPott T, Jutzi P, Neumann B, Stammler H-G. Differing reactivities of Cp*Ga toward diazabutadienes: Synthesis of novel 1-galla-2,5-diazoles and of the known radical Ga[Bu-t-DAB](2). ORGANOMETALLICS. 2001;20(10):1965-1967.The heterocycles [([eta (1)-Cp*)GaN(Dipp)CH=CHN(Dipp)] (1) and [(eta (1)-Cp*)GaN(Dep)CH= CHN(Dep)] (2) were obtained by oxidative addition of (eta (5)-pentamethylcyclopentadienyl)gallium(I) (Cp*Ga) to Dipp-DAB (1,4-bis(2,6-diisopropylphenyl)-1,4-diazabuta-1,3-diene) and Dep-DAB (1,4-bis(2,6-diethylphenyl)-1,6diazabuta-1,3-diene), respectively. Compounds 1 and 2 are the first examples of monomeric gallium-containing heterocycles of the diazabutadiene (DAB) type. 1 was structurally characterized by X-ray crystallography. In contrast, the reaction of Cp*Ga with But-DAB (1,4-di-tert-butyl-1,4-diazabuta-1,3-diene) led to the formation of the known radical (Ga[Bu-t-DAB](2)) (3) in high yield, thus providing an alternative synthesis to the cocondensation technique used previously. Radical 3 was further characterized by H-1 NMR spectroscopy and cyclic voltammetric studies, which revealed two reversible oxidation steps and one reversible reduction step
Annulated Carbocyclic Gallylene and Bis-Gallylene with Two-Coordinated Ga(I) Atoms
No full textGhadwal R, Merschel A, Heda S, Vishnevskiy YV, Neumann B, Stammler G. Annulated Carbocyclic Gallylene and Bis-Gallylene with Two-Coordinated Ga(I) Atoms. Chemical Science. 2024.The first carbocyclic gallylene [(ADC)2Ga(GaI2)] and bis-gallylene [(ADC)Ga]2 (ADC = PhC{N(Dipp)C}2; Dipp = 2,6-iPr2C6H3) featuring a central C4Ga2 ring annulated between two 1,3-imidazole rings are prepared by KC8 reductions of...The first carbocyclic gallylene [(ADC)2Ga(GaI2)] and bis-gallylene [(ADC)Ga]2 (ADC = PhC{N(Dipp)C}2; Dipp = 2,6-iPr2C6H3) featuring a central C4Ga2 ring annulated between two 1,3-imidazole rings are prepared by KC8 reductions of [(ADC)GaI2]2. Treatment of [(ADC)Ga]2 with Fe2(CO)9 affords complex [(ADC)GaFe(CO)4]2 in which each Ga(I) atom serves as a two-electron donor. [(ADC)Ga]2 activates white phosphorus (P4) and the Csp2–F bond of aryl fluorides (ArF) to yield compounds [(ADC)Ga(P4)]2 and cis-/trans-[ADC)GaF(Ar)]2, respectively. [(ADC)Ga]2 undergoes oxidation with (Me2S)AuCl to give [(ADC)GaCl2]2, while with PhN=NPh it forms [1+4]-cycloaddition product [(ADC)GaN(Ph)N=C6H5]2 by the dearomatization of one of the phenyl rings
Exploring the Depth Distribution of Lunar Crustal Mass Anomalies Using GRAIL Gravity and LOLA Topography
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