Research on Method of Health Assessment about the Destruction Equipment for High-risk Hazardous Chemical Waste

AbstractThe destroying tasks of high-risk hazardous chemical waste have a strict request to the health status of destruction equipment.The paper proposes the health status classification method based on time between failures for the destruction of equipment, set up health status assessment model based on Time-varying Bayesian Networks and the time slice, which can take advantage of history fault information and health status monitoring indicator information to health status assessment for the destruction equipment, and which provides a reliable and safe evaluation method

Boosting oxygen reduction and hydrogen evolution at the edge sites of a web-like carbon nanotube-graphene hybrid

Identifying catalytically active sites in graphene-based catalysts is critical to improved oxygen reduction reaction (ORR) electrocatalysts for fuel-cell applications. To generate abundant active edge sites on graphene-based electrocatalysts for superior electrocatalytic activity, rather than at their basal plane, has been a challenge. A new type of ORR electrocatalyst produced using fluidization process and based on a three-dimensional hybrid consisting of horizontally-aligned carbon nanotube and graphene (CNT-G), featured abundant active edge sites and a large specific surface area (863\ua0m\ua0g). The Pt-doped CNT-G exhibited an increase of about 55% in mass activity over the state-of-the-art commercial Pt/C and about 164% over Pt/N-graphene in acidic medium, and approximately 54% increase in kinetic limiting current than the Pt/C at low overpotential in alkaline medium. The higher mass activity indicates that less Pt is required for the same performance, reducing the cost of fuel cell electrocatalyst. In hydrogen evolution reaction (HER), both the metal-free CNT-G and Pt/CNT-G exhibited superior electrocatalytic activity compared to N-doped graphene and commercial Pt/C, respectively

Pressure-stabilized divalent ozonide CaO3 and its impact on Earth's oxygen cycles.

High pressure can drastically alter chemical bonding and produce exotic compounds that defy conventional wisdom. Especially significant are compounds pertaining to oxygen cycles inside Earth, which hold key to understanding major geological events that impact the environment essential to life on Earth. Here we report the discovery of pressure-stabilized divalent ozonide CaO3 crystal that exhibits intriguing bonding and oxidation states with profound geological implications. Our computational study identifies a crystalline phase of CaO3 by reaction of CaO and O2 at high pressure and high temperature conditions; ensuing experiments synthesize this rare compound under compression in a diamond anvil cell with laser heating. High-pressure x-ray diffraction data show that CaO3 crystal forms at 35 GPa and persists down to 20 GPa on decompression. Analysis of charge states reveals a formal oxidation state of -2 for ozone anions in CaO3. These findings unravel the ozonide chemistry at high pressure and offer insights for elucidating prominent seismic anomalies and oxygen cycles in Earth's interior. We further predict multiple reactions producing CaO3 by geologically abundant mineral precursors at various depths in Earth's mantle

Solution Structure of Tensin2 SH2 Domain and Its Phosphotyrosine-Independent Interaction with DLC-1

Background: Src homology 2 (SH2) domain is a conserved module involved in various biological processes. Tensin family member was reported to be involved in tumor suppression by interacting with DLC-1 (deleted-in-liver-cancer-1) via its SH2 domain. We explore here the important questions that what the structure of tensin2 SH2 domain is, and how it binds to DLC-1, which might reveal a novel binding mode. Principal Findings: Tensin2 SH2 domain adopts a conserved SH2 fold that mainly consists of five b-strands flanked by two a-helices. Most SH2 domains recognize phosphorylated ligands specifically. However, tensin2 SH2 domain was identified to interact with nonphosphorylated ligand (DLC-1) as well as phosphorylated ligand. Conclusions: We determined the solution structure of tensin2 SH2 domain using NMR spectroscopy, and revealed the interactions between tensin2 SH2 domain and its ligands in a phosphotyrosine-independent manner

Ni-based bimetallic heterogeneous catalysts for energy and environmental applications

Bimetallic catalysts have attracted extensive attention for a wide range of applications in energy production and environmental remediation due to their tunable chemical/physical properties. These properties are mainly governed by a number of parameters such as compositions of the bimetallic systems, their preparation method, and their morphostructure. In this regard, numerous efforts have been made to develop “designer” bimetallic catalysts with specific nanostructures and surface properties as a result of recent advances in the area of materials chemistry. The present review highlights a detailed overview of the development of nickel-based bimetallic catalysts for energy and environmental applications. Starting from a materials science perspective in order to obtain controlled morphologies and surface properties, with a focus on the fundamental understanding of these bimetallic systems to make a correlation with their catalytic behaviors, a detailed account is provided on the utilization of these systems in the catalytic reactions related to energy production and environmental remediation. We include the entire library of nickel-based bimetallic catalysts for both chemical and electrochemical processes such as catalytic reforming, dehydrogenation, hydrogenation, electrocatalysis and many other reactions

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Design of Unmanned Wing-in-ground Effect Vehicle with Tri-fold Main Wing

This paper proposed an innovative design of unmanned wing-in-ground effect vehicle with tri-fold main wing, aiming at optimizing the main wing of unmanned vehicles based on its current application. The design also takes into account the speed and load in an effort to improve efficiency and broaden the application of the vehicle. In addition, the unmanned GEV is driven by electric power and propelled by the main and auxiliary propellers, which is well supported by the ground effect. The design features energy conservation and emission reduction, which is worthy of promoting in the market

Research on UWB personnel positioning system in coal mine

In order to solve the problem that non-line-of-sight(NLOS) interference affects wireless signal transmission in complex underground environment of coal mines, an ultra wide band(UWB) personnel positioning system in coal mine is designed. The system uses asymmetric double-sided two-way ranging algorithm with return frame mechanism for ranging without clock synchronization, which ensures the ranging precision. The positioning area is divided by the area discrimination strategy and the area correction strategy, so that the tag can only communicate with the base station in the positioning area to achieve positioning, which avoids a large number of invalid frames in the positioning process and improves the positioning efficiency. The weighted least squares method and the unscented Kalman filter joint positioning algorithm are used to solve the tag position coordinates, which improves the positioning precision. A backup power supply is configured in the base station to ensure emergency power supply in case of power failure. Two communication modes, Ethernet and LoRa, are adopted. When the Ethernet is disconnected, the ranging data is transmitted in the LoRa mode, which ensures the emergency communication of the system. The test results show that the system has high dynamic and static positioning precision and strong anti-NLOS interference capability. When the base station is powered off or the Ethernet is disconnected, the system can realize emergency communication for a period of time