Search

The reaction of tris(trimethylsilyl)phosphine and a mixture of two differentN,N-dimethylalkylamides (1a,b), followed by the treatment with dry hydrazine in situ, resulted in seven asymmetrical 3,5-disubstituted 1H-1,2,4-diazaphospholes (3a-g). Compounds3a-gare characterized by single crystal X-ray structural analysis. The present protocol provides a general route to this class of molecules without using phosphaalkynes or phosphaalkenes. [ABSTRACT FROM AUTHOR]

On July 22, 2013, an earthquake of Ms. 6.6 occurred at the junction area of Minxian and Zhangxian counties, Gansu Province, China. This earthquake triggered many landslides of various types, dominated by small-scale soil falls, slides, and topples on loess scarps. There were also a few deep-seated landslides, large-scale soil avalanches, and fissure-developing slopes. In this paper, an inventory of landslides triggered by this event is prepared based on field investigations and visual interpretation of high-resolution satellite images. The spatial distribution of the landslides is then analyzed. The inventory indicates that at least 2330 landslides were triggered by the earthquake. A correlation statistics of the landslides with topographic, geologic, and earthquake factors is performed based on the GIS platform. The results show that the largest number of landslides and the highest landslide density are at 2400m-2600m of absolute elevation, and 200m-300m of relative elevation, respectively. The landslide density does not always increase with slope gradient as previously suggested. The slopes most prone to landslides are in S, SW, W, and NW directions. Concave slopes register higher landslide density and larger number of landslides than convex slopes. The largest number of landslides occurs on topographic position with middle slopes, whereas the highest landslide density corresponds to valleys and lower slopes. The underlying bedrocks consisting of conglomerate and sandstone of Lower Paleogene (Eb) register both the largest number and area of landslides and the highest landslide number and area density values. Correlations of landslide number and landslide density with perpendicular- and along-strike distance from the epicenter show an obvious spatial intensifying character of the co-seismic landslides. The spatial pattern of the co-seismic landslides is strongly controlled by a branch of the Lintan-Dangchang fault, which indicates the effect of seismogenic fault on co-seismic landslides. In addition, the area affected by landslides related to the earthquake is compared to the relationship of "area affected by landslides vs. earthquake magnitude" constructed based on earthquakes worldwide, and it is shown that the area affected by landslides triggered by the Minxian-Zhangxian earthquake is larger than that of almost all other events with similar magnitudes. [ABSTRACT FROM AUTHOR]

In foreland thrust systems, the complex structural geometry creates greater difficulties in constraining the seismotectonics of moderate magnitude earthquakes without pronounced surface ruptures and in assessing future seismic risk. The 2013 M 5.1 Urumqi earthquake was a moderate event that occurred in the Urumqi foreland thrust system. Based on surface investigations, geological mapping, and interpretations of deep seismic reflection profiles, we suggest that the Urumqi foreland thrust belt is a typical active wedge thrust system. Two connected fault segments of the gently south-dipping blind fault ramp and the north-dipping Xishan back-thrust fault merge at a depth of ~11 km and bound the wedge-shaped fault block. Analyses of the focal mechanism and aftershock distribution indicate that the seismogenic fault responsible for the M 5.1 Urumqi event is the south-dipping Xishan fault ramp with a dip angle of ~10–30°, which highlights the potential seismic hazards of the unruptured north-dipping Xishan back-thrust ramp. The four fault branches on the hanging wall of the Xishan fault are interpreted as flexural-slip thrusts. Our results indicate that multiple surface ruptures over a 6 km-wide area may form if a large earthquake occurs along the Xishan fault system. • The seismogenic fault of the 2013 M 5.1 Urumqi event is the south-dipping blind Xishan fault ramp. • Four north-dipping fault branches on the hanging wall of the Xishan fault are flexural-slip thrusts. • Potential seismic hazard of the Urumqi foreland thrust system is estimated. [ABSTRACT FROM AUTHOR]

• Sandbox models show differences in deformation for mantle subduction vs indentation. • Mantle subduction enhances lateral expansion of the orogen and low-relief topography. • Indentation favors the development of doubly vergent orogens with high axial zones. • Changing convergence mode leaves structural relics that vary with convergence sequence. • The Qilian Shan thrust belt is consistent with combined indentation and mantle subduction. Subduction of mantle lithosphere can initiate in the continental interior and acts as an important mechanism for intraplate orogeny. However, the associated kinematic response in the upper crust is still poorly resolved, hindering identification and investigation of mantle subduction during intraplate orogeny. Here we conducted sandbox experiments incorporating mantle-subduction-type and traditional indentation-type convergence to explore their difference in crustal-level orogenic architecture and deformation kinematics. We demonstrate that mantle-subduction-type convergence enhances orogen expansion above the subducting plate, whereas indentation-type convergence promotes deformation propagation toward the overriding plate. Such contrast leads to systematic variations in deformation sequence, structural style, and the first-order orogen geometry. We also show that changes of convergence mode leave distinct structural relics. Out-of-sequence faulting occurs when indentation-type convergence replaces the mantle-subduction-type mode. Conversely, the overprinting of mantle subduction on an earlier indentation mode triggers immediate in-sequence, foreland-propagating thrusting. Additionally, the influence of mantle-subduction-type convergence concentrates within the subducting plate when under a combined convergence involving opposite-direction indentation and mantle-subduction. This creates a special pattern of deformation localization comparable to the distribution of present-day seismicity and topography observed in the active Qilian Shan fold-thrust (northern Tibetan Plateau), confirming a bi-directional compression state during its recent evolution. Our modeling results can provide insights into the geodynamics of other intraplate orogens. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) possess effective functions in controlling the phase and morphology of nanomaterials. However, it is still unclear how ILs affect the morphology control and what the origin of adsorption selectivity of ILs is on different crystal facets. It is a challenge to develop a simple method to select the suitable kinds of ILs for achieving the controllable synthesis of nanomaterials with designable shape. Herein, density functional theory (DFT) calculations were combined with experiment to study the interaction mechanism between ILs and crystal facets. An important relationship is proposed, named as the geometric matching principle, in which the adsorption site of substrate should not only need to meet the space requirement for interionic stacking of ILs, but also needs to maximize the interaction between adsorbed ILs and substrate. This new finding is meaningful for prediction of the adsorption selectivity of ILs and clarification of their shape-controlled chemistry. [ABSTRACT FROM AUTHOR]

Highlights: [•] Photocatalytic activity of the WO3 nanoplates is much higher than commercial WO3. [•] OH is proved the active species responsible for photocatalytic reactions over WO3. [•] The photocatalytic reaction mechanism of the WO3 nanoplates is confirmed. [•] The template-free hydrothermal route is facile, cost effective and can be scaled up. [Copyright &y& Elsevier]

Uncovering the reason for structure-dependent thermoelectric performance still remains a big challenge. A low-temperature and easily scalable strategy for synthesizing Bi2Te3 nanostring hierarchical structures through solution-phase reactions, during which there is the conversion of 'homo-hetero-homo' in Bi2Te3 heteroepitaxial growth, is reported. Bi2Te3 nanostrings are obtained through the transformation from pure Bi2Te3 hexagonal nanosheets followed by TeBi2Te3 'nanotop' heterostructures to Bi2Te3 nanostrings. The growth of Bi2Te3 nanostrings appears to be a self-assembly process through a wavy competition process generated from Te and Bi3+. The conversion of homo-hetero-homo opens up new platforms to investigate the wet chemistry of Bi2Te3 nanomaterials. Furthermore, to study the effect of morphologies and hetero/homo structures, especially with the same origin and uniform conditions on their thermoelectric properties, the thermoelectric properties of Bi2Te3 nanostrings and TeBi2Te3 heterostructured pellets fabricated by spark plasma sintering have been investigated separately. [ABSTRACT FROM AUTHOR]

Highlights: [•] Six 1H-1,2,4-diazaphospholes were prepared and structurally characterized. [•] All compounds are linked into oligomers via the bridges of NH⋯N hydrogen bonds in solid state. [•] The tetrameric feature represents a new motif of hydrogen-bonded 1H-1,2,4-diazaphospholes. [ABSTRACT FROM AUTHOR]

Novel α-Ag3VO4 nanostructures have been successfully synthesized via a facile and repeatable precipitation method by using n-BA as precipitant and complexing agent. Photocatalytic property tests for decomposition of RhB demonstrate that the as-prepared nanostructures have enhanced photocatalytic activity. [ABSTRACT FROM AUTHOR]

In the epicenter of the Lushan M7.0 earthquake there are several imbricate active reverse faults lying from northwest to southeast, namely the Gengda-Longdong, Yanjing-Wulong, Shuangshi-Dachuan and Dayi faults. Emergency field investigations have indicated that no apparent earthquake surface rupture zones were located along these active faults or their adjacent areas. Only brittle compressive ruptures in the cement-covered pavements can be seen in Shuangshi, Taiping, Longxing and Longmen Townships, and these ruptures show that a local crustal shortening occurred in the region during the earthquake. Combining spatial distribution of the relocated aftershocks and focal mechanism solutions, it is inferred that the Lushan earthquake is classified as a typical blind reverse-fault earthquake, and it is advised that the relevant departments should pay great attention to other historically un-ruptured segments along the Longmenshan thrust belt and throughout its adjacent areas. [ABSTRACT FROM AUTHOR]

Morphology-controllable ZnO rings with high crystallinity were synthesized by a simple hydrothermal approach, using ionic liquid (through surface energy conditioning) as a stabilizing agent or template. The growth mechanism of these ring-like ZnO crystals was explored based on first-principles calculations and a series of controlled experiments where the concentration of the ionic liquid 1-propyl-3-methylimidazolium bromide ([C3mim]Br) was tuned. With the increase of the concentration of [C3mim]Br, the aspect ratio of ZnO product increases, and the morphology changes from ring to tube. FTIR and theoretical calculations indicate that [C3mim]Br prefers to adsorb on the ZnO (101̅0) facets, which lowers the surface energy so as to protect the lateral facets from growing too fast to vanish and result in the formation of disk-like structures. Furthermore, the relatively high density of the defects and dislocations on the exposed (0001̅) facet at the center of ZnO disks results in a higher etching rate of (0001̅) facet by H+, driven by the reduction of strain energy associated with dislocations. Therefore, the selective etching of ZnO disks leads to formation of ring-like structure for final products. With the increase of the concentration of [C3mim]Br, the selective adsorption of [C3mim]Br will also promote the growth along the [0001] direction to form a tube-like structure. In addition, the photoluminescence spectra reveal that the as-prepared ZnO rings exhibit blue emission related to their oxygen vacancy as well as various other barely avoidable impurities and defects. [ABSTRACT FROM AUTHOR]

A sandwich zwitterionic rutheniumcomplex (4) was prepared by an intramolecular 1,3-dipolarcycloaddition of the ruthenium azido isocyanide [CpMe5Ru(CNAr)2N3] (2). The reaction involved a formal1,3-migration mechanism along a highly conjugated system linking toa cyanamido group. [ABSTRACT FROM AUTHOR]

Abstract: The plant-pathogenic bacterium Xanthomonas oryzae pv. oryzae (Xoo) is the causal agent of bacterial blight, which is one of the most serious diseases of rice. Xoo has been studied for over one century, and much has been learned about it, but proteomic investigation has been neglected. In this study, proteome reference maps of Xoo were constructed by two-dimensional gel electrophoresis, and 628 spots in the gels representing 469 different protein species were identified with MALDI-TOF/TOF MS. The identified spots were assigned to 15 functional categories according to the Kyoto Encyclopedia of Genes and Genomes (KEGG) database and the annotations from the National Center for Biotechnology Information (NCBI) database. The data set has been deposited in the World-2DPAGE database (Database ID: 0044). In addition, comparative proteomic analysis revealed that proteins related to the TonB-dependent transportation system and energy metabolism are involved in the phenazine-1-carboxylic acid resistance in Xoo. In conclusion, we have established a proteome database for Xoo and have used this database in a comparative proteomic analysis that identified proteins potentially contributing to phenazine-1-carboxylic acid resistance in Xoo. [Copyright &y& Elsevier]

Highlights: [•] Carrier transport properties of a hexaalkoxydibenzo[a,c]phenazine discogen is studied. [•] The built-in donor–acceptor discogen exhibits ambipolar, non-dispersive carrier transport. [•] The hole and electronmobilitiesof the discogen in a highly ordered columnar structure are up to 10−3 cm2 V−1 s−1. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two kinds of 3D CuS nanospheres assembled by nanoflakes are purposely synthesized. • IL [Bmim]Cl act as an efficient template for the formation of flake-like building blocks. • [Bmim]Cl with special viscosity play a vital role in controlling the structure of the sample. • Compact CuS nanospheres possess better capacitive properties than loose CuS nanospheres. Two hierarchical CuS nanostructures assembled by nanoflakes with exposed (0 0 1) facets are purposely synthesized using ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) as solvent-template. [Bmim]Cl can act as efficient template for the formation of flake-like building blocks by adsorbing on the (0 0 1) facet of CuS. More importantly, the viscosity of [Bmim]Cl can be altered by changing the temperature; thereby, the self-assemble process of the building blocks can be controlled and accordingly the shapes of the products are "tailored". The structural properties of the as-formed compact CuS nanoflowers (C-CuS) and loose CuS nanoflowers (L-CuS) are tested by XRD, SEM, TEM, HRTEM, and XPS, and the growth mechanisms are discussed in depth. When used as the electrode materials for supercapacitors, C-CuS exhibit higher specific capacitance and better rate capability than L-CuS. The improved capacitive performance of C-CuS may be due to the structural synergistic effect of ultrathin building units and dense hierarchical nanostructure. [ABSTRACT FROM AUTHOR]

In the work presented here, well-dispersed ferric giniite microcrystals with controlled sizes and shapes are solvothermally synthesized from ionic-liquid precursors by using 1- n-butyl-3-methylimidazolium dihydrogenphosphate ([Bmim][H2PO4]) as phosphate source. The success of this synthesis relies on the concentration and composition of the ionic-liquid precursors. By adjusting the molar ratios of Fe(NO3)3 ⋅9H2O to [Bmim][H2PO4] as well as the composition of ionic-liquid precursors, we obtained uniform microstructures such as bipyramids exposing {111} facets, plates exposing {001} facets, hollow spheres, tetragonal hexadecahedron exposing {441} and {111} facets, and truncated bipyamids with carved {001} facets. The crystalline structure of the ferric giniite microcrystals is disclosed by various characterization techniques. It was revealed that [Bmim][H2PO4] played an important role in stabilizing the {111} facets of ferric giniite crystals, leading to the different morphologies in the presence of ionic-liquid precursors with different compositions. Furthermore, since these ferric giniite crystals were characterized by different facets, they could serve as model Fenton-like catalysts to uncover the correlation between the surface and the catalytic performance for the photodegradation of organic dyes under visible-light irradiation. Our measurements indicate that the photocatalytic activity of as-prepared Fenton-like catalysts is highly dependent on the exposed facets, and the surface area has essentially no obvious effect on the photocatalytic degradation of organic dyes in the present study. It is highly expected that these findings are useful in understanding the photocatalytic activity of Fenton-like catalysts with different morphologies, and suggest a promising new strategy for crystal-facet engineering of photocatalysts for wastewater treatment based on heterogeneous Fenton-like process. [ABSTRACT FROM AUTHOR]

Well-dispersed ammonium aluminum carbonate hydroxide (NH4-Dw) and γ-AlOOH nanostructures with controlled morphologies have been synthesized by employing an ionic-liquid-assisted hydrothermal process. The basic strategies that were used in this work were: 1) A controllable phase transition from NH4-Dw to γ-AlOOH could be realized by increasing the reaction temperature and 2) the morphological evolution of NH4-Dw and γ-AlOOH nanostructures could be influenced by the concentration of the ionic liquid. Based on these experimental results, the main objective of this work was to clarify the effect models of the ionic liquids on the synthesis of NH4-Dw and γ-AlOOH nanostructures, which could be divided into cationic- or anionic-dominant effect models, as determined by the different surface structures of the targets. Specifically, under the cationic-dominant regime, the ionic liquids mainly showed dispersion effects for the NH4-Dw nanostructures, whereas the anionic-dominant model could induce the self-assembly of the γ-AlOOH particles to form hierarchical structures. Under the guidance of the proposed models, the effect of the ionic liquids would be optimized by an appropriate choice of cations or anions, as well as by considering the different effect models with the substrate surface. We expect that such effect models between ionic liquids and the target products will be helpful for understanding and designing rational ionic liquids that contain specific functional groups, thus open up new opportunities for the synthesis of inorganic nanomaterials with new morphologies and improved properties. In addition, these as-prepared NH4-Dw and γ-AlOOH nanostructures were converted into porous γ-Al2O3 nanostructures by thermal decomposition, whilst preserving the same morphology. By using HRTEM and nitrogen-adsorption analysis, the obtained γ-Al2O3 samples were found to have excellent porous properties and, hence, may have applications in catalysis and adsorption. [ABSTRACT FROM AUTHOR]

The development of high topography associated with the Indo-Asian collision plays a central role in ongoing debates over the linkages between development of the Tibetan Plateau and climate. In northeastern Tibet, the widespread appearance of coarse terrestrial sediment during the Oligocene is commonly interpreted to herald the development of a foreland basin in response to crustal thickening along the present-day margin of the plateau. However, a lack of direct observations relating sediment accumulation to fault activity leaves this interpretation uncertain. Here, we present new stratigraphic observations along the northern margin of the Longzhong basin that provide insight into the tectonic setting of basin development. A combination of field and subsurface observations, including the geometry of basin-bounding faults, sedimentary provenance, paleoflow direction, isopach and sedimentary facies distribution patterns, constrains basin evolution from the Middle Tertiary through Quaternary time. Our results suggest that NE-SW extension across normal faults controlled development of accommodation space in the northern Longzhong basin during the Oligocene to early Miocene. Continued sediment accumulation from the mid-Miocene through Pliocene occurred in a broad, shallow basin, consistent with thermal subsidence following extension. Basin inversion initiated between 10 Ma and 6 Ma, associated with the development of the modern Haiyuan fault system. Our results imply that the onset of Tertiary sedimentation in the Longzhong basin does not represent a developing fore-deep associated with a nascent Tibetan Plateau, but rather reflects transtensional deformation inboard of extensional basins along the East Asian margin. [ABSTRACT FROM AUTHOR]

In this work, a novel lead sulfide (PbS) hierarchical superstructure, denoted as octapodal dendrites with a cubic center, has been synthesized employing a simple single-source precursor route. Our experimental results demonstrate that the novel hierarchical superstructure was generated through the delicate balance between the kinetic growth and thermodynamic growth regimes. Moreover, the morphology of PbS crystals can be controlled by adjusting the solvent under a thermodynamically or kinetically controlled growth regime. It is highly expected that these findings will be useful in understanding the formation of PbS nanocrystals with different morphologies, which are also applicable to other face-centered cubic nanocrystals. [ABSTRACT FROM AUTHOR]

In this work, we have synthesized CoCO3 microaggregation, microcubes and nanoplates by an ionic liquid-assisted hydrothermal method. The morphologies of the CoCO3 crystals depend on the concentration of the ionic liquid and the reaction temperature. Moreover, the as-prepared CoCO3 crystals can serve as a useful precursor to obtain porous Co3O4 particles with similar morphology by means of calcinations. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

The Bi2S3nanomaterials with various morphologies such as nanorods, nanowires, nanowire bundles, urchin-like microspheres and urchin-like microspheres with cavities have been successfully synthesized through a simple hydrothermal method. Experimental results indicate that sulfur sources play crucial roles in determining the morphologies of Bi2S3products. Moreover, formation mechanisms of different Bi2S3nanostructures are discussed based on understanding of the growth habit of Bi2S3crystal. Finally, we also studied the morphologies-dependent electrochemical and optical properties of the as-synthesized Bi2S3nanomaterials. [ABSTRACT FROM AUTHOR]

Morphology control of bismuth sulfide (Bi2S3) nanostructures, from one-dimensional nanorods with various aspect ratios, to various kinds of two-dimensional nanofabrics (dense nanofabrics and spark nanofabrics) to three-dimensional urchin-like microspheres and crossed nanofabrics, has been achieved viaan ionic liquids-assisted hydrothermal route, by adjusting the active state of the BiOCl, the characteristics and concentration of the ionic liquid used and the reaction temperature. Reasonable growth mechanisms for the Bi2S3with different morphologies are proposed, based on active state of the intermediate BiOCl, characteristics of the ionic liquids used and the crystal growth habits of Bi2S3. More importantly, we introduce the concept of two different states of the intermediate BiOCl (active BiOCl and inert BiOCl) to explain the growth mechanisms of nanofabrics, nanorods and urchin-like microspheres, from different crystal growth processes. Moreover, electrochemical measurements demonstrate that Bi2S3nanofabrics and urchin-like microspheres possess higher initial Li intercalation capacity than graphitic materials (372 mA h g−1), and their cyclic performances are highly dependent on their morphologies. [ABSTRACT FROM AUTHOR]

Abstract: A mild hydrothermal process to prepare Ba2SbLnO6 (Ln =Pr, Nd, Sm, Eu) perovskite-type oxides are presented. These perovskites were characterized on the basis of X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), inductively-coupled plasma spectra (ICP) techniques. Primary structure was confirmed using Rietveld method based on XRD data shows that the likely space groups of Ba2SbLnO6 are R-3 for Ln =Pr and Nd and F m-3m for Ln =Sm and Eu, respectively. The measurement of Mössbauer effect of the 37.2keV γ transition of 121Sb indicates that the isomer shift of these perovskites falls in the region of the Sb5+ and reflects some hybridized-orbital behavior in Sb–O bonds. [Copyright &y& Elsevier]

Abstract: In this study, rutile films consisting of rectangular nanorods were facilely deposited on glass substrates from strongly acid solution of TiCl4. The highly ordered array of nanorods was realized in presence of ionic liquid (IL) of [Bmim]Br by following a hydrothermal process. In this process, Degussa P25 nanoparticles served as seeds that were pre-deposited on the substrates to facilitate the array of rutile nanorods. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectrum were used to characterize the obtained nanorod films. The measurements showed that the nanorods were rectangular with width of 100–200nm and length of more than 1μm, and grew up typically along c-axis to form the arrays against the substrate. The presence of IL was found vital for the formation of rutile nanorods, and the suitable molar ratio of [Bmim]Br to TiCl4 ranged from 500:1 to 1500:1. The excessive [Bmim]Br may hinder the precipitation of rutile particles. [Copyright &y& Elsevier]

Abstract: Cubic MnSe2 and octahedral α-MnSe microcrystals were successfully synthesized through a convenient hydrothermal method with N2H4·H2O as a reductant and SeO2 and MnCl2 as precursors. The crystalline structure, morphology, and chemical composition of the resulting samples were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectrometer (EDS), and the results indicated that the cubic MnSe2 has an edge size ranging from 5 to 10μm and the surfaces of these cubes have layer desquamation phenomenon; the α-MnSe has an average size of about 10μm and the most of these microcrystals are in octahedral shapes. It was also found that the phases and morphologies of the manganese selenides can be controlled by changing the content of N2H4·H2O, reaction temperature, and reaction time. The potential formation mechanism of MnSe2 and α-MnSe was discussed. [Copyright &y& Elsevier]

A directional borehole radar consists of one transmitting antenna in the borehole and four receiving antennas distributed at equal angles in a ring. The receiving antennas can determine the depth and orientation of targets beside the borehole. However, the problem of target orientation determination and 3D imaging algorithms remains a technological challenge. The MUSIC (multiple signal classification) algorithm requires a peak search, so the accuracy of the operation is limited by the angle interval. Based on the MUSIC algorithm, the Root-MUSIC algorithm is proposed and implemented. By replacing the spectral peak search with calculating the roots of the polynomials greatly improves the orientation recognition accuracy. Finally, the results obtained using the above algorithm are verified with synthetic data and compared with the results of the MUSIC algorithm. The results show that both the MUSIC algorithm and the Root-MUSIC algorithm can achieve very good orientation determination and 3D imaging results. In terms of accuracy, the Root-MUSIC algorithm has an obvious improvement compared with the MUSIC algorithm. [ABSTRACT FROM AUTHOR]

Abstract: Dispersible ZnSe hollow microspheres with an average diameter of about 1.0μm have been successfully prepared by the ionic liquid-assisted complex-solvothermal method. The structure and morphology of the as-prepared ZnSe hollow microspheres were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). The results indicated that the ZnSe hollow microspheres had the zinc blende structure and were composed of ZnSe nanoparticles of about 18.8nm. Additionally, results from photoluminescence (PL) showed that the obtained product had two strong emission peaks centered at 425 and 440nm. The application of the ionic liquid 1-butyl-3-methylimidazolium bromide ([Bmim]Br), which has high ionic conductivity and low surface tension, affected the morphologies of the products and allowed the reactions to be carried out under mild conditions. The growth mechanism of ZnSe hollow microspheres has been discussed. [Copyright &y& Elsevier]

Abstract: The N-, P-containing five-membered heterocyclic compound 1H-3,5-di-phenyl-1,2,4-diazaphosphole (1) was prepared in good yield and has been structurally characterized. 1H-3,5-Di-phenyl-1,2,4-diazaphosphole (1), crystallizing in two unexpected cyclic dimers with N–H⋯N hydrogen bonds, presents in the solid state a dynamic proton disorder implying a dynamic equilibrium within both dimers. The conformations of the phenyl rings, the disorder of the NH protons, and the intermolecular hydrogen bond of several 1,2,4-diazaphospholes (1–5) in the solid state have been rationalized by DFT [B3LYP/6-311++G(d,p)] calculations. [Copyright &y& Elsevier]

In the present paper, we report a novel hydrothermal synthesis process for the preparation of A-site deficient perovskite-type solid solution in (1−x)BaTiO3·xLa2/3TiO3 (x=0.1–1.0). The synthesized (1−x)BaTiO3·xLa2/3TiO3 have been characterized by powder X-ray diffraction (XRD), ICP elemental analysis, infrared spectroscopy and scanning electron microscopy. The diffractions of samples with x≤0.7 were well indexed as a cubic structure, which is the same as a cubic perovskite-type BaTiO3. In the compositions of x ≥0.8, the crystal structure changes from the cubic to an orthorhombic one. The effect of hydrothermal conditions has also been examined. In this work, it was observed that the optimum ratios of KOH/Ti, La/Ti, and La/Ba were 90, 0.6x and 0.9(1−x), respectively, and the optimum crystallization temperature was 240–260 °C. [Copyright &y& Elsevier]

• A novel P-CoS 1.097 @MoS 2 /CC heterostructure is employed for enhanced hydrogen evolution reaction (HER). • The [BMIm]+ in ionic liquid is the key to the formation of CoS 1.097 @MoS 2 /CC heterostructure ultrathin nanosheets. • The fabrication of heterogeneous interface between CoS 1.097 and MoS 2 is in favor of optimizing active sites and adjusting electron distribution. • The introduction of sulfur vacancies by phosphorus doping stimulates the activity on the inert plane of MoS 2. Reasonable design of non-precious metal electrocatalysts with high catalytic activity plays a crucial role in promoting the sustainable development of hydrogen energy. Herein, to improve both the active sites and intrinsic conductivity of molybdenum disulfide (MoS 2), a facile ionic liquid-assisted hydrothermal method and subsequent phosphorization treatment are fabricated for advanced electrochemical hydrogen evolution reaction (HER) performance. The obtained P-CoS 1.097 @MoS 2 /CC heterostructure exhibits a low overpotential of 98 mV and 88 mV at the current density of 10 mA cm−2 in 0.5 M H 2 SO 4 and 1 M KOH, respectively. The remarkable performance is due to the synergistic effects of the constructed heterogeneous interface between CoS 1.097 and MoS 2 as well as sulfur vacancies generated by the phosphorus doping. Therefore, fast electron transfer and large number of catalytic active sites can be achieved by means of such advantageous strategy. This research paves the way for the development of MoS 2 -based catalysts through the cooperative design of doping and interface engineering toward efficient HER process. [Display omitted] [ABSTRACT FROM AUTHOR]

The directional borehole radar can accurately locate and image the geological target around the borehole, which overcomes the shortcomings that the conventional borehole radar can only detect the depth of the target and the distance from the borehole. The directional borehole radar under consideration consists of a transmitting antenna and four receiving antennas equally distributed on the ring in the borehole. The nonuniformity caused by the borehole and sonde, as well as the mutual coupling among the four receiving antennas, will have a serious impact on the received signal and then cause interference to the azimuth recognition for the targets. In this paper, Finite difference time domain (FDTD), including the subgrid, is applied to study these effects and interferences, and the influence of borehole, sonde, and mutual coupling among the receiving antennas is found. The results show that, without considering the sonde and the fluid in the borehole, the one transmitting and one receiving borehole radar system does not have resonance, but the wave pattern of the reflected wave will have obvious distortion. For the four receiving antennas of the borehole radar system, there is obvious resonance, which is caused by the multiple reflections between the receiving antennas. However, when the fluid in the borehole is water and the relative permittivity of the sonde is low to a certain extent, the resonance disappears; that is, the generation of resonance requires a large relative permittivity material between the receiving antennas. When the influence of the sonde is considered, the resonance disappears because the relative permittivity of the sonde is low, which makes the propagation speed of the electromagnetic wave between the antennas accelerate and lose the conditions for resonance. In addition, the diameters of the sonde and the circular array of the receiving antennas can affect the received signal: the higher the diameter of the sonde and the higher the diameter of the circular array are, the better the differentiation of the received signal. The development of the research provides scientific guidance for the design and application of borehole radar in the future. [ABSTRACT FROM AUTHOR]

The steep rhombohedra MnCO3microcrystals and their large-scale assembly into regular elongated patterns are obtained viaa novel surfactant-free route by adjusting the proportion of the mixed solvent (methanol and DMF). We hope this synthetic strategy can provide a new approach to synthesize metal carbonates. [ABSTRACT FROM AUTHOR]

Ferrimagnetic Fe3S4nanowalls and triple hierarchical microspheres have been fabricated viaan ionic liquid-modulated solution–phase process, respectively. Magnetic hysteresis measurements demonstrate that their morphology–dependent magnetic properties might be originated from their unique nanostructures. [ABSTRACT FROM AUTHOR]

Abstract: A rare macrocyclic hexazirconium(IV) complex with bisaryloxyl N-heterocyclic carbene ligand {(L)Zr(OSiMe3)(k2-[N^O])}6 (2) ( H[N^O]=) was prepared from a mononuclear complex [(L)ZrCl2(THF)] (1). Complex 2 was structurally characterized and shows higher catalytic ethylene polymerization activities in the presence of methylaluminoxane (MAO). [Copyright &y& Elsevier]

Abstract: Wurtzite CdSe nanoparticles-assembled microspheres with macropores have been successfully synthesized through a modified hydrothermal method with Cd(NO3)2 and Na2SeO3 as precursors and hydrazine hydrate as a reductant in the presence of 1-n-butyl-3-methylimidazolium bromide ([Bmim]Br). The crystalline structure and morphology of the resulting samples were investigated by means of X-ray powder diffraction (XRD) and scanning electron microscope (SEM). The results indicated that the CdSe microspheres have an average size of about 3 μm and were assembled by CdSe nanoparticles with size ranging from 20 to 40 nm. It was found that the pH and [Bmim]Br have influence on the morphologies of the products, and the potential formation mechanism of CdSe was discussed. [Copyright &y& Elsevier]

Abstract: The palladium-catalyzed Heck reaction was effected with two ruthenium complexes bearing unique heterocyclic 1,2,4-diazaphospholide ligands that contain sp2-hybridized phosphorus atoms. [Copyright &y& Elsevier]

• NiSe/MoSe 2 /MoO 2 3D hierarchical hollow microsphere hybrid material was synthesized. • The influences of reaction time and Ni/Mo mole ratio on the morphology was studied. • NiSe/MoSe 2 /MoO 2 3D HHM showed superior electrochemical performance for supercapacitor. • The NiSe/MoSe 2 /MoO 2 3D HHM-based ACS displayed a high energy density of 48.1 Wh kg−1. The application of hybrid materials with well-designed composition and morphology is an effective approach towards enhanced electrochemical performance of asymmetric supercapacitors (ASCs). Here a facile two-step growth-annealing strategy to construct a NiSe/MoSe 2 /MoO 2 three-dimensional (3D) hierarchical hollow architecture comprising two-dimensional (2D) thin nanoflakes is reported. The reaction time and Ni/Mo mole ratio of precursor are crucial for the construction of NiSe/MoSe 2 /MoO 2 3D hierarchical hollow microsphere (HHM). The as-synthesized NiSe/MoSe 2 /MoO 2 3D HHM with large specific surface area and well-developed mesoporous can increase contact area between active material and electrolyte, and shorten the path and time for electrolyte ions transport, thereby achieving outstanding electrochemical performance. The NiSe/MoSe 2 /MoO 2 3D HHM shows a high specific capacitance of 1061 F g−1 at a current density of 2 A g−1, exceptional rate capability (maintaining 57% of its initial capacitance at 20 A g−1) and stable long-term cycling performance (retaining 93.9% of its initial capacitance after 10,000 cycles at 3 A g−1). Moreover, the NiSe/MoSe 2 /MoO 2 3D HHM-based ASC provides a high energy density of 48.1 Wh kg−1 at a power density of 428 W kg−1, and still maintains 20.4 Wh kg−1 even at a high power density of 7.3 kW kg−1, suggesting its great potential in superior-performance ASCs. [ABSTRACT FROM AUTHOR]

A simple and effective red phosphorus self-templated wet-chemical method was proposed to fabricate hierarchical nanoporous metal phosphides, whose pore sizes and porosities can be easily modulated by changing the addition of ionic liquids (ILs). The resultant products possess large specific surface areas (206.8 m2 g−1) and big pore volume (0.7145 cm3 g−1 nm−1), which endowed the as-synthesized nickel phosphides with outstanding electrocatalytic activities for OER in terms of Tafel slopes (46 mv dec−1), the operating potential at the benchmark current density of 10 mA cm−2 (246 mV) and long term electrocatalytic stability. These interesting results will promote the use of ILs as controlling agent for the preparation of porous catalysts in the electrocatalytic OER and the development of synthesis of porous nanomaterials. [ABSTRACT FROM AUTHOR]

Repeating earthquakes are key evidence for understanding earthquake recurrence and help improve long-term seismic risk assessment. In 1986 and 2016, two Ms6.4 earthquakes occurred in Menyuan region, near the middle segment of Qilian-Haiyuan fault zone, NE Tibetan Plateau. Long period waveforms of the two events at teleseismic stations show high degree of similarity, however, previous solutions on earthquake location and focal mechanism show remarkable discrepancies, especially for the 1986 event, as well the ruptured faults also remain ambiguous. In this study, we determined the source parameters of these two earthquakes, including the relative location, focal depth, focal mechanism, source duration and rupture directivity. The results show that two earthquakes are thrust events in shallow crust and are located within 15 km, and the 2016 earthquake ruptured down-dip for ~6 km along the southwest dipping plane. Combing the source parameters, geological data and deep seismic-reflection profiles, we infer that these two earthquakes occurred on the same secondary fault of Lenglong Ling fault (the middle segment of Qilian-Haiyuan fault), but they ruptured on different sections of the fault. Although the two events are probably not repeating earthquakes of Qilian-Haiyuan fault zone, the seismic risk of ~M6 thrust earthquake on these secondary faults and even larger strike-slip earthquake on Lenglong Ling fault are not negligible based on the source parameters and ten-year GPS observations. • Both earthquakes are thrust events in shallow crust and are located within 15 km. • Occurred on the secondary fault (SW-dipping) and ruptured on different sections • Seismic risk of ~M6 thrust earthquake on these secondary faults is not negligible. [ABSTRACT FROM AUTHOR]

The southern Liupanshan fault zone (SLFZ) has been active during the Holocene and accommodates complex deformation between the compressional Liupanshan Mountain and the extensional Weihe Graben. We characterized the active faulting of the SLFZ using interpretations of high-resolution satellite images, digital elevation models derived from structure-from-motion models, combined with field investigations. The presence of well-preserved linear fault troughs, scarps, knickpoints, offset streams and ridges, and landslides along the SLFZ indicate that surface-rupturing earthquakes have occurred along the SLFZ in the Holocene. Evidence from paleoseismic trenching indicates that the most recent earthquake occurred between 1607 ± 77 BCE and 1070 ± 90 CE, and thus may have been the 600 CE historical earthquake. The estimated magnitude of this earthquake is Mw 6.7. Radiometric dating of an offset fluvial terrace indicates a late Pleistocene to Holocene left-lateral slip rate of ~1.5 ± 0.3 mm/yr. Our geologic and geomorphic observations show that the SLFZ may extend into the Weihe Graben where the slip is transferred onto other active faults within the Weihe Graben. • The southern Liupanshan fault zone is a major block-bounding fault in NE Tibet. • Remote sensing and fault trenching were used to analyze paleoseismic activity. • Faulting spans the late Quaternary, including the 1607 BCE–1070 CE earthquake. • Late Quaternary faulting is left-lateral with a slip rate of ~1.5 mm/yr. • The fault zone accommodates deformation along the Liupanshan Range and Weihe Graben. [ABSTRACT FROM AUTHOR]

Ni 3 C is very promising in electrocatalytic field. However, it is rarely reported due to its harsh synthesis conditions. Herein, pure metallic Ni 3 C nanoparticles in situ embedded in two-dimensional (2D) nitrogen-doped carbon nanoflakes (Ni 3 C/NC nanoflakes) are successfully prepared through one-step pyrolyzing Ni-urea complex at a relatively mild temperature at 350 °C. The composition and nanostructure of the catalyst can be easily controlled by adjusting the synthetic conditions, such as pyrolysis temperature and reactant concentration. The NC nanoflakes with a large specific surface area and massive mesopores present a 2D morphology, which is beneficial to disperse Ni 3 C nanoparticles to maintain their high conductivity. Based on advantage of nanostructure, Ni 3 C/NC nanoflakes exhibit high electrocatalytic performance with a low overpotential of 309 mV, small Tafel slope of 72 mV dec−1, as well as good stability. Furthermore, this study could provide a new strategy for the design and fabrication of other transition-metal carbides. [ABSTRACT FROM AUTHOR]

The spatial pattern of crustal shortening along the eastern and western Qilian Shan, northeastern Tibetan Plateau is crucial for understanding the process and mechanism of growth and propagation of the plateau. Here we present a detailed record of seven strath terraces of the Tongziba River in the southern Zhangye Basin, which document the history of active deformation of the Minle-Damaying Fault (MDF) and Yonggu anticline, and six strath terraces of the Xie River, which document the history of active deformation of the MDF in the North Frontal Thrust (NFT) system at the eastern Qilian Shan mountain front. Based on the measured longitudinal profiles of terraces and the formation ages dated by AMS 14C and optically stimulated luminescence (OSL) dating methods, the total of shortening rates across the eastern Qilian Shan mountain front is estimated to be about 2.7 ± 0.8 mm/yr, much higher than the rate of ~1 mm/yr across the western Qilian Shan mountain front. In contrast, no significant difference in the total shortening rate across the whole Qilian Shan Block is observed on GPS data. Thus we propose that the inner part of the western Qilian Shan could have absorbed more crustal shortening than the inner part of the eastern Qilian Shan. Such a spatial pattern of crustal shortening is consistent with the result form GPS data across the whole eastern and western Qilian Shan along N30°E. The different crust structure, especially the existence of a low-velocity layer in the mid-crust of the western Qilian Shan orogen, may account for the observed spatial pattern of crustal shortening in the Qili [ABSTRACT FROM AUTHOR]

Available data from the Qilian Shan in north-east Tibet suggested that decadal-scale erosion rates were closely correlated with local topographic gradient, but not with climatic factors. However, a climatic change to more arid condition was proposed to explain the discrepancy between short-term and long-term erosion rates. In order to re-evaluate the topographic, tectonic and climatic influences on erosion, we adopted five parameters (slope, mean local relief, historical cumulative seismic moment, runoff coefficient of variation and fault density) to study 11 drainage basins in north-east Tibet. Our results showed that terrain gradient, rock fracture density and rainstorm intensity had strong influence on erosion rates while 60-year cumulative seismic moments of historical earthquakes showed weaker correlations. There was a spatial variation in the erosional mechanisms across the basin, with detachment-limited dominance around the ridges (slope > 20°) and deposition dominant in the flat areas. The variation may lead to the discrepancy between short-term and long-term erosion rates. In general, our study supports the 'bath-tub' model for low relief intermountain basins, hence providing new insights into the landscape evolution of the Qilian Shan in northeastern Tibetan Plateau. [ABSTRACT FROM AUTHOR]

Review: 85 refs. [ABSTRACT FROM AUTHOR]