Nanoscale Soldering of Axially Positioned Single-Walled Carbon Nanotubes: A Molecular Dynamics Simulation Study

The miniaturization of electronics devices into the nanometer scale is indispensable for next-generation semi-conductor technology. Carbon nanotubes (CNTs) are considered to be the promising candidates for future interconnection wires. To study the carbon nanotubes interconnection during nanosoldering, the melting process of nanosolder and nanosoldering process between single-walled carbon nanotubes are simulated with molecular dynamics method. As the simulation results, the melting point of 2 nm silver solder is about 605 K because of high surface energy, which is below the melting temperature of Ag bulk material. In the nanosoldering process simulations, Ag atoms may be dragged into the nanotubes to form different connection configuration, which has no apparent relationship with chirality of SWNTs. The length of core filling nanowires structure has the relationship with the diameter, and it does not become longer with the increasing diameter of SWNT. Subsequently, the dominant mechanism of was analyzed. In addition, as the heating temperature and time, respectively, increases, more Ag atoms can enter the SWNTs with longer length of Ag nanowires. And because of the strong metal bonds, less Ag atoms can remain with the tight atomic structures in the gap between SWNT and SWNT. The preferred interconnection configurations can be achieved between SWNT and SWNT in this paper

Lead Iodide Thin Film Crystallization Control for High-Performance and Stable Solution-Processed Perovskite Solar Cells

PbI₂ thin film crystallization control is a prerequisite of high-quality perovskite thin film for sequentially solution-processed perovskite solar cells. An efficient and simple method has been developed by adding HCl to improve perovskite thin film quality, and an efficiency of 15.2% is obtained. This approach improves coverage, uniformity, and stability of pervoskite thin film

Corrosion Mechanisms for Electrical Fields Leading to the Acceleration of Copper Sulfide Deposition on Insulation Windings

Numerous failures of high-voltage transformers and reactors are caused by copper sulfide formation in oil-immersed insulations. This study explored the effect of electrical fields on copper sulfide formation. Accelerated aging experiments were conducted for mineral oil that contains dibenzyl disulfide, which was aged along with insulation windings under different conditions, including single thermal aging and electrical–thermal aging. The corrosive sulfur deposits were quantified using SEM/EDX and ICP-AES. The properties of the insulation oils were also measured and analyzed. Corrosion mechanisms for electrical fields leading to the acceleration of copper sulfide deposition on the oil-immersed insulation were proposed

Late Mesozoic magmatism and metallogeny in NE China: The Sandaowanzi–Beidagou example

<p>The Sandaowanzi (>22t Au) and Beidagou (>5t Au) tellurium–gold deposits are located in the northeastern Central Asian Orogenic Belt (Heilongjiang Province, NE China). The ore-hosting volcanic rocks unconformably overly monzogranite and were intruded by adakitic granodiorite. In this study, we report new-age, geochemical, and Sr–Nd–Pb isotopic data to elucidate the genetic link between the igneous rocks and the Te–Au mineralization. New-age data indicate that local magmatism occurred in the Early Jurassic (ca. 177.2 Ma) and Early Cretaceous (ca. 118.7 − 122.0 Ma). Geochemically, the igneous rocks are enriched in LREEs, Pb, K, and U, and depleted in Nb, P, and Ti, showing calc-alkaline affinity. The Early Jurassic monzogranite rocks are featured by ⁸⁷Sr/⁸⁶Sr = 0.7111−0.7118; <i>ε</i>_Nd(<i>t</i>) = −4.6 to −4.7; ²⁰⁶Pb/²⁰⁴Pb = 18.098−18.102, ²⁰⁷Pb/²⁰⁴Pb = 15.558−15.580, and ²⁰⁸Pb/²⁰⁴Pb = 37.781−37.928, whereas the Early Cretaceous adakitic granodiorite contains: ⁸⁷Sr/⁸⁶Sr = 0.7071−0.7073; <i>ε</i>_Nd(<i>t</i>) = − 3.4 to −3.2; ²⁰⁶Pb/²⁰⁴Pb = 17.991−18.080, ²⁰⁷Pb/²⁰⁴Pb = 15.483−15.508, and ²⁰⁸Pb/²⁰⁴Pb = 37.938−37.985. Initial isotopic ratios for the Early Cretaceous volcanic rocks: ⁸⁷Sr/⁸⁶Sr = 0.7061−0.7087; <i>ε</i>_Nd(<i>t</i>) = − 3.6 to −2.9; ²⁰⁶Pb/²⁰⁴Pb = 18.136−18.199, ²⁰⁷Pb/²⁰⁴Pb = 15.512−15.628, and ²⁰⁸Pb/²⁰⁴Pb = 38.064−38.155. The pyrite, chalcopyrite, and telluride grains yielded δ³⁴S of −6.52 ‰ to 2.13 ‰ (mean = − 0.82 ‰) and <i>δ</i>¹³C_PDB of the calcite samples are in the range of −6.64 ‰ to −5.24 ‰, implying the ore materials were derived from mantle. The geochemical and isotopic results indicate that primary melts of Late Mesozoic magmatic rocks have features by partial melting of the continental crust. The adakitic rocks may have been the products of the thickened lower crustal delamination and the subsequent asthenospheric upwelling during the intra-continental extension in NE China. Regionally, intrusive activity and molybdenum mineralization during the Jurassic was affected by subduction setting, whereas gold mineralization was controlled by the Early Cretaceous tectonothermal events associated with a superposition extension.</p

The HE stains result of injury of hippocampus in 21d neonate rat (400×).

<p>A, control group; B, hypoxic group; C, ischemia+hypoxic group.</p

HE staining result of brain injury around lateral ventricle (400×).

<p>A, control group; B, hypoxic 1d; C, hypoxic 3d; D, ischemia+hypoxic 1d; E, ischemia+hypoxic 3d.</p

Neural cell apoptosis testing by TUNEL, much more TUNEL positive cells were observed in hypoxic and ischemic+hypoxic group than the controls (400×).

<p>A, control group; B, hypoxic 1d; C, ischemia+hypoxic 1d.</p

Hippocampus brain injury HE staining result (400×).

<p>A, control group; B, hypoxic 1d; C, hypoxic 3d; D, ischemia+hypoxic 1d; E, ischemia+hypoxic 3d. </p

Nanospot Soldering Polystyrene Nanoparticles with an Optical Fiber Probe Laser Irradiating a Metallic AFM Probe Based on the Near-Field Enhancement Effect

With the development of nanoscience and nanotechnology for the bottom-up nanofabrication of nanostructures formed from polystyrene nanoparticles, joining technology is an essential step in the manufacturing and assembly of nanodevices and nanostructures in order to provide mechanical integration and connection. To study the nanospot welding of polystyrene nanoparticles, we propose a new nanospot-soldering method using the near-field enhancement effect of a metallic atomic force microscope (AFM) probe tip that is irradiated by an optical fiber probe laser. On the basis of our theoretical analysis of the near-field enhancement effect, we set up an experimental system for nanospot soldering; this approach is carried out by using an optical fiber probe laser to irradiate the AFM probe tip to sinter the nanoparticles, providing a promising technical approach for the application of nanosoldering in nanoscience and nanotechnology

The p-ERK levels in the brains tissues from the hypoxic group and the ischemic+hypoxic group were both lower than that in the brains from the controls by immunohistochemistry analysis.

<p> A, control group (400×); B, hypoxic 1d (400×); C, ischemia+hypoxic 1d (400×).</p