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Quasar outflows carry mass, momentum and energy into the surrounding environment, and have long been considered a potential key factor in regulating the growth of supermassive black holes and the evolution of their host galaxies [1][2][3][4] . A crucial parameter for understanding the origin of these outflows and measuring their influence on their host galaxies is the distance (R) between the outflow gas and the galaxy center 5, 6 . While R has been measured in a number of individual galaxies 7-15 , its distribution remains unknown. Here we report the distributions of R and the kinetic luminosities of quasars outflows, using the statistical properties of broad absorption line variability in a sample of 915 quasars from the Sloan Digital Sky Surveys. The mean and standard deviation of the distribution of R are 10 1.4±0.5 parsecs. The typical outflow distance in this sample is tens of parsec, which is beyond the theoretically predicted location (0.01 ∼ 0.1 parsecs) where the accretion disc line-driven wind is launched 16,17 , but is smaller than the scales of most outflows that are derived using the excited state absorption lines 7-14 . The typical value of the mass-flow rate is of tens to a hundred solar masses per year, or several times the accretion rate. The typical kinetic-to-bolometric luminosity ratio is a few per cent, indicating that outflows are energetic enough to influence the evolution of their host galaxies.Nowadays, theoretical models for galaxy formation and evolution routinely invoke the concept of "quasar feedback"-the strong effect that the active supermassive black hole's (SMBH) energy output exerts on its host galaxy-to keep massive galaxies from forming many stars and becoming overly massive. In 10-40% of the quasars in which the central source and outflowing gas are both in the line of sight, outflows may manifest themselves as broad absorption lines (BALs) 18,19 and BAL outflows are therefore a candidate agent of quasar feedback. The importance of outflows to active galactic nucleus (AGN) feedback can be quantified using the mass-flow rate (Ṁout) and the kinetic luminosity (Ė k ) of the outflowing material. TheṀout and theĖ k of a BAL outflow can be estimated from the distance (R) between the out- * flowing gas and the galaxy center, the total hydrogen column density NH and the fraction Ω of the solid angle subtended by the outflowing gas. Because the ionization parameter UH of the plasma is inversely proportional to the product of hydrogen number density nH and R 2 , i.e., UH ∝ 1/(nHR 2 ), R can be obtained by measuring UH and nH. In general, nH can be determined from the absorption lines of the excited states of ions (e.g., Fe II*, Si II*, S IV*), but this method is hindered by line blending and is therefore only applicable to quasars with relatively narrow absorption lines. During the last decade or so, outflow distances have been measured for only about a dozen of individual quasars using this method 7-14 , while the distributions of primary properties of BAL outflows remain in unknown. ...

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A novel borate compound YBa(3)B(9)O(18) has crystallized in a melt of BaYB(9)O(16). Single-crystal X-ray diffraction measurements reveal that YBa(3)B(9)O(18) adopts a hexagonal space group P6(3)/m with cell parameters of a = 7.1761(6) A and c = 16.9657(6) A. The structure is made up of the planar B(3)O(6) groups parallel to each other along the (001) direction, regular YO(6) octahedra, and irregular BaO(6) and BaO(9) polyhedra to form an analogue structure of beta-BaB(2)O(4). A series of isostructural borate compounds RBa(3)B(9)O(18) (R = Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) were prepared by powder solid-state reactions. The DTA and TGA curves of YBaB(9)O(16) show an obvious weight loss at about 955 degrees C associated with a decomposition into YBO(3), B(2)O(3), and YBa(3)B(9)O(18) due to its incongruent melting behavior. The DTA and TGA curves of YBa(3)B(9)O(18) show that it is chemically stable and a congruent melting compound. A comparison of the structures of YBa(3)B(9)O(18) and beta-BaB(2)O(4) is presented.

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Large quantities of prism-shaped GaN nanorods were prepared by a thermal CVD reaction between Ga and NH3 on LaAlO3 crystal substrates. The distinct morphology of the GaN nanorods lies in their prism-like out shape and most of them have a quadrilateral cross section. The Raman spectrum of the GaN nanorods shows two additional bands at 255 and 419 cm-1. Moreover, a large red shift of A1(LO) phonon has been observed compared with that of bulk GaN crystals. Room-temperature photoluminescence measurement reveals a broad emission ranging from 2.5 to 3.5 eV with some fine structures, which are believed to be associated with the defect levels.

A new black hole X-ray binary (BHXRB) MAXI J1535-571 was discovered by MAXI during its outburst in 2017. Using observations taken by the first Chinese X-ray satellite, the Hard X-ray Modulation Telescope (dubbed as Insight -HXMT), we perform a joint spectral analysis (2-150 keV) in both energy and time domains. The energy spectra provide the essential input for probing the intrinsic Quasi-Periodic Oscillation (QPO) fractional rms spectra (FRS). Our results show that during the intermediate state, the energy spectra are in general consistent with those reported by Swift/XRT and NuSTAR. However, the QPO FRS become harder and the FRS residuals may suggest the presence of either an additional power-law component in the energy spectrum or a turn-over in the intrinsic QPO FRS at high energies.

A new heterojunction of Ti3C2/g-C3N4with rich Ti3+and pyri-N species can efficiently photoelectrocatalytically convert CO2into hydrocarbons.