1-{[3-(2-Chloro-3,3,3-trifluoro­prop-1-en­yl)-2,2-dimethyl­cyclo­propan-1-yl]carbon­yl}-3-(methyl­sulfon­yl)imidazolidin-2-one

In the title mol­ecule, C13H16ClF3N2O4S, the imidazolidine ring is approximately planar, the largest deviation from this plane being 0.025 (3) Å. The cyclo­propane ring forms a dihedral angle of 64.1 (2)° with the imidazolidine ring. In the crystal, C—H⋯O hydrogen bonds are observed

Isolation an Antimicrobial Action of Endophytic Fungi from Sophora Flavescens and Effects on Microorganism Circumstances in Soil

AbstractThe aim of this study was to isolate the endophytic fungi from Sophora flavescens and define its antimicrobial action and structure. The effects of this active substance on soil microorganism circumstances were also conducted. Column chromatography and freeze drying were used to isolate and purify the antimicrobial substance. TLC biological autoradiography was applied to trace. HPLC method was employed to measure the purity. Analysis of the structure used 1H-NMR, 13C-NMR and LC-MS methods. Plate method was applied to measure the effect on microorganism circumstances. The results showed that after isolating and purifying the fermentation liquor of BS001, the structure of bacteriostatic active composition was 6,7-(2′E)dibutenyl-5,8-dihydroxy-(Z)-cyclooct-2-ene-1,4-dione, which was identified by spectroscopy. The substance could increase the number of bacteria and fungi while decreased the number of antinomies in soil. A new antimicrobial substance 6,7-(2′E)dibutenyl-5,8 -dihydroxy- (Z)- cyclooct - 2- ene-1,4-dione was extracted from fermenting liquor of BS001 which was an endophytic fungi of Sophora flavescens. It could promote the beneficial flora but detrimental flora. This conclusion provides exploiture foreground for biopharmaceuticals and biopesticide

COUPLAGE NON LINÉAIRE PHASE-AMPLITUDE DANS LES RÉSONATEURS

National audienc

N 1,N 4,3,6-Tetra­methyl-1,2,4,5-tetra­zine-1,4-dicarboxamide

The asymmetric unit of the title compound, C8H14N6O2, contains two independent mol­ecules. In one mol­ecule, the amide-substituted N atoms of the tetra­zine ring deviate from the plane [maximum deviation = 0.028 (1) Å] through the four other atoms in the ring by 0.350 (2) and 0.344 (2) Å, forming a boat conformation, and the mean planes of the two carboxamide groups form dihedral angles of 10.46 (13) and 20.41 (12)° with the four approximtely planar atoms in the tetra­zine ring. In the other mol­ecule, the amide-substituted N atoms of the tetra­zine ring deviate from the plane [maximum deviation = 0.033 (1) Å] through the four other atoms in the ring by 0.324 (2) and 0.307 (2) Å, forming a boat conformation, and the mean planes of the two carboxamide groups form dihedral angles of 14.66 (11) and 17.08 (10)° with the four approximately planar atoms of the tetra­zine ring. In the crystal, N—H⋯O hydrogen bonds connect mol­ecules to form a two-dimensional network parallel to (1-1-1). Intra­molecular N—H⋯N hydrogen bonds are observed

Numerical simulation of pressure pulse decay experiment on crushed low permeability rocks considering Klinkenberg effect and gas absorption/desorption

Pressure pulse decay method is widely used for permeability tests for low permeability rock plug samples. This method can be used for crushed grain samples by removing the downstream chamber in standard pulse decay tests. Processes in pulse decay tests for low permeability crushed shale are investigated using numerical simulation. Both the Klinkenberg slip effect for gas flows in low permeability rock and the gas absorption/desorption in the porous matrix are considered. The complete mathematical model is set up to include the two effects. Deviation of the numerical pulse decay curve from the analytical one with an assumption that the pressure keeps a constant in the porous sample is investigated. The relative importance of gas absorption/desorption and gas compressibility is also investigated quantitatively. According to the present investigation, gas compressibility and adsorption both make negative contributions to the permeating process. A potential two-curve method is proposed to decide absolute permeability and the Klinkenberg coefficient when these two parameters cannot be distinguished using one pulse decay curve during the inverse fitting procedure. These two parameters can be determined at the same time only if the experiment is conducted under big initial pressure difference and the Klinkenberg coefficient has at least the same order of magnitude as the pressure

2,5-Bis[(3-chloro­benz­yl)sulfan­yl]-1,3,4-thia­diazole

The complete mol­ecule of the title compound, C16H12Cl2N2S3, is generated by crystallographic twofold symmetry, with the S atom of the thiadiazole ring lying on the rotation axis. The dihedral angle between the mean planes of the 1,3,4-thia­diazole and benzene rings is 87.19 (7)°. In the crystal, mol­ecules are linked by C—H⋯N inter­actions and short S⋯S contacts [3.3389 (9) Å] occur

Stochastic Nonlinear Control via Finite-dimensional Spectral Dynamic Embedding

Optimal control is notoriously difficult for stochastic nonlinear systems. Ren et al. introduced Spectral Dynamics Embedding for developing reinforcement learning methods for controlling an unknown system. It uses an infinite-dimensional feature to linearly represent the state-value function and exploits finite-dimensional truncation approximation for practical implementation. However, the finite-dimensional approximation properties in control have not been investigated even when the model is known. In this paper, we provide a tractable stochastic nonlinear control algorithm that exploits the nonlinear dynamics upon the finite-dimensional feature approximation, Spectral Dynamics Embedding Control (SDEC), with an in-depth theoretical analysis to characterize the approximation error induced by the finite-dimension truncation and statistical error induced by finite-sample approximation in both policy evaluation and policy optimization. We also empirically test the algorithm and compare the performance with Koopman-based methods and iLQR methods on the pendulum swingup problem