6-Bromo-2-(diprop-2-ynyl­amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione

The asymmetric unit of the title compound, C18H11BrN2O2, contains two independent mol­ecules in which the prop-2-ynyl­amino groups have different mutual orientations. In one mol­ecule, the Br atom is disordered over two positions, with refined occupancies of 0.742 (2) and 0.258 (2)

2′-Amino-1′-(4-chloro­phen­yl)-1,7′,7′-trimethyl-2,5′-dioxo-5′,6′,7′,8′-tetra­hydrospiro­[indoline-3,4′(1′H)-quinoline]-3′-carbonitrile dimethyl­formamide solvate dihydrate

In the mol­ecule of the title compound, C26H23ClN4O2·C3H7NO·2H2O, the indole and dihydro­pyridine rings are planar and make a dihedral angle of 89.86 (7)°. The dihydro­pyridine ring forms a dihedral angle of 79.95 (7)° with the attached benzene ring. In the crystal structure, inter­molecular N—H⋯O and O—H⋯O hydrogen bonds link the mol­ecules. Intermolecular C—H⋯N and C—H⋯Cl interactions are also present

Enhanced mechanical, thermal and flame retardant properties by combining graphene nanosheets and metal hydroxide nanorods for Acrylonitrile–Butadiene–Styrene copolymer composite

Three metal hydroxide nanorods (MHR) with uniform diameters were synthesized, and then combined with graphene nanosheets (GNS) to prepare acrylonitrile–butadiene–styrene (ABS) copolymer composites. An excellent dispersion of exfoliated two-dimensional (2-D) GNS and 1-D MHR in the ABS matrix was achieved. The effects of combined GNS and MHR on the mechanical, thermal and flame retardant properties of the ABS composites were investigated. With the addition of 2 wt% GNS and 4 wt% Co(OH)2, the tensile strength, bending strength and storage modulus of the ABS composites were increased by 45.1%, 40.5% and 42.3% respectively. The ABS/GNS/Co(OH)2 ternary composite shows the lowest maximum weight loss rate and highest residue yield. Noticeable reduction in the flammability was achieved with the addition of GNS and Co(OH)2, due to the formation of more continuous and compact charred layers that retarded the mass and heat transfer between the flame and the polymer matrix

Ethyl 6′-amino-5′-cyano-2′-methyl-2-oxospiro­[indoline-3,4′-pyran]-3′-carboxyl­ate

In the title compound, C17H15N3O4, the atoms of the spiro pyran ring are nearly planar with a maximum deviation of 0.0188 (14) Å. The benzene and pyrrole rings make a dihedral angle of 5.71 (6)°. The indole system and the pyran ring are oriented at a dihedral angle of 82.94 (3)°. The crystal structure is stabilized by inter­molecular classical and non-classical N—H⋯O, N—H⋯N and C—H⋯O hydrogen bonds

Interfacial Properties of Monolayer and Bilayer MoS2 Contacts with Metals: Beyond the Energy Band Calculations

Although many prototype devices based on two-dimensional (2D) MoS2 have been fabricated and wafer scale growth of 2D MoS2 has been realized, the fundamental nature of 2D MoS2-metal contacts has not been well understood yet. We provide a comprehensive ab initio study of the interfacial properties of a series of monolayer (ML) and bilayer (BL) MoS2-metal contacts (metal = Sc, Ti, Ag, Pt, Ni, and Au). A comparison between the calculated and observed Schottky barrier heights (SBHs) suggests that many-electron effects are strongly suppressed in channel 2D MoS2 due to a charge transfer. The extensively adopted energy band calculation scheme fails to reproduce the observed SBHs in 2D MoS2-Sc interface. By contrast, an ab initio quantum transport device simulation better reproduces the observed SBH in the two types of contacts and highlights the importance of a higher level theoretical approach beyond the energy band calculation in the interface study. BL MoS2-metal contacts have a reduced SBH than ML MoS2-metal contacts due to the interlayer coupling and thus have a higher electron injection efficiency.Comment: 36 pages, 13 figures, 3 table

Monitoring and Alarming System for Hydrate in Gas Wells

When the wellhead temperature for gas wells is low, freezing accident in wellbore could happen because of hydrate generation. Through designing the monitoring and alarming system, the freezing accident can be avoided. The pressure and temperature distribution along wellbore is computed through multi-phase flowing theory, based on the data acquired from the wellhead. Comparing to the hydrate P-T Graph by the picture interpreting means, the results can judge the situation of the hydrate and show the depth range with the hydrate in gas wells, so that the system can monitor and alarm hydrate. The system contains three main functions: calculating the pressure and temperature in wellbore during production or well shutting; forecasting the hydrate generation; design of the alarming and prevention. The software made up by these methods can realize the aim to real-time monitor and alarm hydrate. Finally, the software of the system is shown with the suggestion to avoid hydrate during gas well testing and production

Ethyl 2-amino-7,7-dimethyl-2′,5-dioxo­spiro­[5,6,7,8-tetra­hydro-4H-chromene-4,3′(2′H)-1H-indole]-3-carboxyl­ate

In the mol­ecule of the title compound, C21H22N2O5, the indole system and the spiro-pyran ring are almost planar [maximum deviations of 0.0447 (17) and 0.0781 (17) Å, respectively]; the dihedral angle between them is 84.6 (3)°. The remaining six-membered ring adopts a twisted conformation. Intra­molecular N—H⋯O hydrogen bonds occur. In the crystal structure, intera­molecular N—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules