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This paper introduces a news processing method for geomagnetic anomaly field data: envelope mode magnetic field, which can weaken the influence caused by geomagnetic polarity reversal during rock magnetization, reflect the magnetic change of crustal rocks, and locate the crustal structures. According to the characteristics of the magnetic anomaly field, the envelope mode magnetic field is calculated in three different ways: full anomaly envelope, positive anomaly envelope, and negative anomaly envelope. The simulation test of seismic signal and magnetic anomaly model has achieved good results. During the calculation of the real-world data, because the magnetization directions of the geomagnetic field in the southern and northern hemispheres are opposite, we use the full envelope or positive envelope method for the northern hemisphere and the negative envelope method for the southern hemisphere. The experiment using EMAG2 global satellite magnetic anomaly data demonstrates that the strong anomaly of the envelope mode magnetic field is consistent with the spatial distribution of cratonic tectonic units, confirming its application effect. [ABSTRACT FROM AUTHOR]

The self-attraction of nanowires (NWs) would lead to NWs bunching up together when fabricated in high density and the short circuit of NW-based devices during service. However, the underlying mechanism of the self-attraction of NWs remains debatable due to the lack of in situ characterization of the attraction. In this study, a versatile method of in situ investigating the self-attraction of NWs was developed. The attractive force between two NWs and their distance can be determined quantitatively in the process of attraction under an optical microscope, eliminating the influence of electron beam in electron microscopes. With this approach, the self-attraction of SiC NWs was investigated and a two-stage mechanism for the self-attraction was proposed. The electrostatic force between two individual SiC NWs increased as their distance decreased, and acted as the initial driving force for the attraction of NWs. SiC NWs remained in contact under van der Waals force until they separated when external force exceeded van der Waals force. The charge density and the Hamaker constant of SiC NWs were determined to be 1.9 × 10−4 C·m−2 and 1.56 × 10−19 J, which played an important role in the attraction of NWs. The results shed light on the mechanism of self-attraction among NWs and provide new insights into fabricating high-quality NWs and developing high-performance NW-based devices. [ABSTRACT FROM AUTHOR]

Subsurface parameter reconstruction using full waveform inversion is highly nonlinear with nonunique solutions. When the initial model with high precision is missing, the cycle skipping problem will be encountered, especially for the strong scattering media like salt structures. In order to adapt to the inversion of strong scattering media, direct envelope inversion (DEI) using directly the envelope Fréchet derivatives was proposed to avoid the weakly nonlinear assumption for the model updating. In the original DEI method, the envelope polarity is not considered. To further improve the effectiveness of DEI, signed envelope inversion with polarity detection can be used. In this work, we develop a new polarity detection technique on the basis of seismic attributes, which can provide more accurate polarity information for the seismic envelope. Based on the above technique, the new multi-scale signed DEI method is proposed. The new technique is applied to the SEG/EAGE salt model. The numerical examples verified the effectiveness of this method. [ABSTRACT FROM AUTHOR]

A novel three-dimensional ball-flower-like g-C3N4/NiO (GN) photocatalyst was firstly fabricated by a simple two-step calcination method for enhanced degradation capability. Our investigation focuses on the construction of p–n heterojunction and specific ball-flower-like structure to overcome limitations of single-component semiconductors, such as low surface area, poor light response and fast recombination of the photogenerated electrons and holes. Detailed photocatalytic experiments revealed that the novel ball-flower-like GN (50%) exhibited much higher activity for the removal of TC and Cr6+ than single g-C3N4, NiO and traditional layered GN. The trapping experiments proved that the superoxide radicals ( · O 2 - ), holes (h+) and electrons (e−)were the main active species in the photodegradation process. Moreover, three different degradation pathways and fourteen intermediate products of TC were also determined by the LC/MS analysis and these intermediates could be further degraded completely into CO2, H2O, NH 4 + , carboxylic acids and any other inorganic intermediates. These results will benefit the fabrication of other 3D p–n heterojunction photocatalysts and their potential application in treatment of organic pollutants. [ABSTRACT FROM AUTHOR]

Template-free synthesis of TiO architectures with controlled morphology evolution has been developed through solvothermal reaction in 1,4-dioxane. By simply varying the molar ratio of the concentrated HCl over Titanium isopropoxide (TTIP) from 0 to 5.0, series of morphologies including nanoparticle-built microspheres, nanoparticle-built microspheres decorated with nanorods, nanorod cauliflowers, and nanorod dendrites have been obtained. The influence of several key factors on the morphology control of TiO has been systematically investigated. These parameters include the mass (molar) ratio of HCl/TTIP, solvothermal reaction temperature and time, acid species (concentrated nitric acid), and solvent type (tetrahydrofuran and 1,3-dioxane). The mechanism for the formation of the TiO architectures with controlled morphology evolution has been discussed. The application of the TiO architectures as water splitting photocatalyst and lithium-ion battery anode has been demonstrated. And the corresponding structure-property correlation has been discussed. [ABSTRACT FROM AUTHOR]

This paper is concerned with the problems of stability and H performance for a class of switched stochastic neutral delay systems. By applying the average dwell time method, sufficient condition is first derived to guarantee the mean-square exponential stability of the switched stochastic neutral system. Then, the condition on a weighted H performance is proposed. The corresponding results are all formulated in terms of linear matrix inequalities (LMIs). Finally, a numerical example is provided to illustrate the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

Rechargeable lithium batteries are the most practical and widely used power sources for portable and mobile devices in modern society. Manipulation of the electronic and ionic charge transport and accumulation in solid materials has always been crucial for rechargeable lithium batteries. The transport and accumulation of lithium ions in electrode materials, which is a diffusion process, is determined by the concentration distribution of lithium ions and the intrinsic structure of the electrode material and thus far has not been manipulated by an external force. Here, we report the realization of controllable two-dimensional movement and redistribution of lithium ions in metal oxides. This achievement is one kind of centimeter-scale control and is achieved by a magnetic field based on the 'current-driving model'. This work provides additional insight for building safe and high-capacity rechargeable lithium batteries. Ion transport properties are critical to some emerging technologies. Here, the authors show the controllable 2D movement and redistribution of Li-ions in metal oxides such as WO3 by a magnetic field. The success is based on a current-driving model which also works for other cations including H+, Na+, Zn2+ and Ca2+. [ABSTRACT FROM AUTHOR]

A novel three-dimensional ball-flower-like g-C3N4/NiO (GN) photocatalyst was firstly fabricated by a simple two-step calcination method for enhanced degradation capability. Our investigation focuses on the construction of p–n heterojunction and specific ball-flower-like structure to overcome limitations of single-component semiconductors, such as low surface area, poor light response and fast recombination of the photogenerated electrons and holes. Detailed photocatalytic experiments revealed that the novel ball-flower-like GN (50%) exhibited much higher activity for the removal of TC and Cr6+ than single g-C3N4, NiO and traditional layered GN. The trapping experiments proved that the superoxide radicals ( · O 2 - ), holes (h+) and electrons (e−)were the main active species in the photodegradation process. Moreover, three different degradation pathways and fourteen intermediate products of TC were also determined by the LC/MS analysis and these intermediates could be further degraded completely into CO2, H2O, NH 4 + , carboxylic acids and any other inorganic intermediates. These results will benefit the fabrication of other 3D p–n heterojunction photocatalysts and their potential application in treatment of organic pollutants. [ABSTRACT FROM AUTHOR]