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11.
For infinite horizon nonlinear optimal control problems in which the control term enters linearly in the dynamics and quadratically in the cost, well-known conditions on the linearised problem guarantee existence of a smooth globally optimal feedback solution on a certain region of state space containing the equilibrium point. The method of proof is to demonstrate existence of a stable Lagrangian manifold M and then construct the solution from M in the region where M has a well-defined projection onto state space. We show that the same conditions also guarantee existence of a nonsmooth viscosity solution and globally optimal set-valued feedback on a much larger region. The method of proof is to extend the construction of a solution from M into the region where M no-longer has a well-defined projection onto state space. 相似文献
12.
Carsten von Hänisch PD Dr. 《无机化学与普通化学杂志》2008,634(4):701-703
Synthesis and Metalation of the Diaminosiloxane O(SiiPr2NH2)2 The 1,3‐diaminoldisiloxane O(SiiPr2NH2)2 ( 1 ) was obtained from the reaction of O(SiiPr2Cl)2 with NH3. The reactions of 1 with AlEt3 or GaEt3 produced the compounds [O{SiiPr2N(H)MEt2}{SiiPr2NMEt}]2 ( 2 : M = Al; 3 : M = Ga). The crystal structures of 2 and 3 were determined by single crystal X‐ray diffraction, showing a polycyclic M4N4Si4O2 core structure of these molecules. 相似文献
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Gunter Heymann Jan F. Riecken Sudhindra Rayaprol Sandra Christian Rainer Pöttgen Prof. Dr. Hubert Huppertz PD Dr. 《无机化学与普通化学杂志》2007,633(1):77-82
The high‐pressure (HP) modification of CePdSn was synthesized under multianvil high‐pressure (10.5 GPa) high‐temperature (1100 °C) conditions from the normal‐pressure (NP) modification. The structures of both modifications were studied by X‐ray powder and single crystal diffraction: TiNiSi type, Pnma, a = 754.1(2), b = 470.6(1), c = 798.4(3) pm, wR2 = 0.0333, 945 F2 values, 20 variables for NP‐CePdSn and ZrNiAl type, , a = 760.03(5), c = 416.06(3) pm, wR2 = 0.0443, 248 F2 values, 13 variables for HP‐CePdSn. The structural chemistry of both modifications is goverened by platinum centered trigonal prisms. The platinum and tin atoms in NP‐CePdSn and HP‐CePdSn build up a three‐dimensional [PdSn] network in which the cerium atoms fill channels. Susceptibility measurements on HP‐CePdSn reveal an experimental magnetic moment of 2.55(1) μB/Ce atom in the paramagnetic region. At 5 K a paramagnetic‐to‐antiferromagnetic transition is evident from magnetization and specific heat measurements. 相似文献
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Matthias Weil PD Dr. 《无机化学与普通化学杂志》2007,633(8):1217-1222
Single crystals of a third modification of Ag2Te2O6 (denoted as Ag2Te2O6–III) and of Ag4TeO5 have been obtained as minor by‐products during hydrothermal phase formation experiments in the system Ag‐Hg‐Te‐O. The crystal structure of Ag2Te2O6–III (P21/c, Z = 4, a = 6.4255(10), b = 6.9852(11), c = 13.204(2) Å, β = 90.090(3)°, 1885 independent reflections, R[F2 > 2σ(F2)] = 0.0334, wR2(F2 all) = 0.0817) comprises tellurium in oxidation states +IV and +VI and is topologically related to the structure of the Ag2Te2O6–I modification, which consists of similar layers and interjacent layers of Ag+ cations. Ag4TeO5 (C2/c, Z = 8, a = 16.271(2), b = 6.0874(10), c = 11.4373(16) Å, β = 106.730(10)°, 2372 independent reflections, R[F2 > 2σ(F2)] = 0.0288, wR2(F2 all) = 0.0737) is made up of a layer‐like arrangement of isolated [TeVI2O10] double octahedra and of Ag+ cations situated both in layers parallel and inside the layers of the anionic moieties. 相似文献
16.
Dr. Dominique Bruns Dr. Daniel Merk Dr. Karthiga Santhana Kumar PD Dr. Martin Baumgartner Prof. Dr. Gisbert Schneider 《ChemistryOpen》2019,8(10):1303-1308
Constructive machine learning aims to create examples from its learned domain which are likely to exhibit similar properties. Here, a recurrent neural network was trained with the chemical structures of known cell-migration modulators. This machine learning model was used to generate new molecules that mimic the training compounds. Two top-scoring designs were synthesized, and tested for functional activity in a phenotypic spheroid cell migration assay. These computationally generated small molecules significantly increased the migration of medulloblastoma cells. The results further corroborate the applicability of constructive machine learning to the de novo design of druglike molecules with desired properties. 相似文献
17.
Katrin Meier Raul Cardoso‐Gil Ulrich Burkhardt Caroline Curfs Michael Hanfland Yuri Grin PD Dr. Ulrich Schwarz 《无机化学与普通化学杂志》2012,638(10):1446-1451
The rare‐earth metal germanides RE2Ge9 (RE = Nd, Sm) have been prepared by thermal decomposition of the metastable high‐pressure phases REGe5 at ambient pressure. The compounds adopt an orthorhombic unit cell with a = 396.34(4) pm; b = 954.05(8) pm and c = 1238.4(1) pm for Nd2Ge9 and a = 395.46(7) pm; b = 946.4(2) pm and c = 1232.1(3) pm for Sm2Ge9. Crystal structure refinements reveal space group Pmmn (No. 59) for Nd2Ge9. The atomic pattern resembles an ordered defect variety of the pentagermanide motif REGe5 (RE = La; Nd, Sm, Gd, Tb) comprising corrugated germanium layers. These condense into a three‐dimensional network interconnected by eight‐coordinated germanium atoms. The resulting framework channels along [100] enclose the neodymium atoms. With respect to the atomic arrangement of the pentagermanides, half of the interlayer germanium atoms are eliminated in an ordered way so that occupied and empty germanium columns alternate along [001]. The rare‐earth metal atoms of both types of compounds, REGe5 and RE2Ge9, exhibit the electronic states 4f 3 and 4f 5 (oxidation state +3) for neodymium and samarium, respectively, evidencing that the modification of the germanium network leaves the electron configuration of the metal atoms unaffected. 相似文献
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19.
Alekseev VA van der Burgt PJ McCaffrey JG 《The journal of physical chemistry. A》2012,116(5):1333-1336
The I(2)(D'-A') luminescence in liquid C(7)F(16), C(8)F(18), C(9)F(20), and C(12)F(26) has been observed following irradiation with visible (within the I(2) X → B band region) and UV (λ < 300 nm) lasers. The band is shifted by ~2000 cm(-1) to the red relative to the gas phase and is significantly broader (fwhm ≈ 3000 cm(-1) vs 500 cm(-1) in the gas phase). Two-color excitation of other halogens in C(n)F(2n+2) solvents revealed similarly shifted and strongly broadened D'-A' bands of Br(2), IBr, and BrCl. The stability of the ion-pair states of halogens in room temperature liquids opens new experimental opportunities for condensed phase studies and may be of applied interest considering the increasing industrial applications of perfluorocarbons. 相似文献
20.
Florian Kleemiss Erna K. Wieduwilt Dr. Emanuel Hupf Ming W. Shi Dr. Scott G. Stewart Prof. Dylan Jayatilaka Dr. Michael J. Turner Prof. Kunihisa Sugimoto Prof. Eiji Nishibori Prof. Dr. Tanja Schirmeister Dr. Thomas C. Schmidt Prof. Dr. Bernd Engels PD Dr. Simon Grabowsky 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(10):3407-3419
The crystal interaction density is generally assumed to be a suitable measure of the polarization of a low-molecular weight ligand inside an enzyme, but this approximation has seldomly been tested and has never been quantified before. In this study, we compare the crystal interaction density and the interaction electrostatic potential for a model compound of loxistatin acid (E64c) with those inside cathepsin B, in solution, and in vacuum. We apply QM/MM calculations and experimental quantum crystallography to show that the crystal interaction density is indeed very similar to the enzyme interaction density. Less than 0.1 e are shifted between these two environments in total. However, this difference has non-negligible consequences for derived properties. 相似文献