Understanding the Molecular Arrangement and Orientation Characteristics of Mesophase Pitch and Its Fibers via a Polarized Light Microscope.

A polarized light microscope (PLM) was utilized to examine the optical textures of mesophase pitch (MP) and MP-derived fibers, which aimed to reveal the arrangement and orientation characteristics of pitch molecules and to clarify the evolution and transformation mechanism of carbonaceous microcrystalline from pitch fibers to graphitized fibers. The results found that there were distinct optical textures in MP, where one side exhibited a transition from a flattening plane to a mountain-like undulating plane. This transition corresponded to the arrangement of pitch molecules, resembling stacked lamellar structures reminiscent of curved paper.

Eco-Friendly Preparation of Carbon-Bonded Carbon Fiber Based on Glucose-Polyacrylamide Hydrogel Derived Carbon as Binder.

Lightweight, high-temperature-resistant carbon-bonded carbon fiber (CBCF) composites with excellent thermal insulation properties are desirable materials for thermal protection systems in military and aerospace applications. Here, glucose was introduced into the polyacrylamide hydrogel to form the glucose-polyacrylamide (Glu-PAM) hydrogel. The CBCF composites were prepared using the Glu-PAM hydrogel as a brand-new binder, and the synergistic effect between glucose and acrylamide was investigated.

In-Situ Doping BC Nanoparticles in Mesophase Pitch for Preparing Carbon Fibers with High Thermal Conductivity by Boron Catalytic Graphitization.

The boron carbide (BC) nanoparticles doping mesophase pitch (MP) was synthesized by the in-situ doping method with tetrahydrofuran solvent, and the corresponding MP-based carbon fibers (CFs) were successfully prepared through the melt-spinning, stabilization, carbonization and graphitization processes. The structural evolution and properties of boron-containing pitches and fibers in different processes were investigated for exploring the effect of BC on mechanical, electrical and thermal properties of CFs. The results showed that the BC was evenly dispersed in pitch fibers to provide active sites of oxygen, resulting in a homogeneous stabilization and ameliorating the split-ting microstructures of CFs.

Mesophase Pitch-Based Carbon Fibers: Accelerated Stabilization of Pitch Fibers under Effective Plasma Irradiation-Assisted Modification.

Stabilization is the most complicated and time-consuming step in the manufacture of carbon fibers (CFs), which is important to prepare CFs with high performance. Accelerated stabilization was successfully demonstrated under effective plasma irradiation-assisted modification (PIM) of mesophase pitch fibers (PFs). The results showed that the PIM treatment could obviously introduce more oxygen-containing groups into PFs, which was remarkably efficient in shortening the stabilization time of PFs with a faster stabilization heating rate, as well as in preparing the corresponding CFs with higher performance.

A Superior Potassium-Ion Anode Material from Pitch-based Activated Carbon Fibers with Hierarchical Pore Structure Prepared by Metal Catalytic Activation.

The pitch-based activated carbon fibers with nickel sulfide nanoparticles (ACF/NiS) were designed by in situ polymerization of ethylene tar with the addition of nickel nitrate followed by melt spinning, stabilization, carbonization, steam activation, and vulcanization processes. The ACF/NiS with hierarchical pore structure and abundant active sites was used as an anode material to improve Coulombic efficiency and increase capacity of potassium-ion batteries (PIBs). The results showed the obtained ACF/NiS with excellent specific surface area of 1552 m g and high mesopore volume contribution of 38%, which delivered a high initial Coulombic efficiency of 84.

How Confident Are We about Observational Findings in Healthcare: A Benchmark Study.

Healthcare professionals increasingly rely on observational healthcare data, such as administrative claims and electronic health records, to estimate the causal effects of interventions. However, limited prior studies raise concerns about the real-world performance of the statistical and epidemiological methods that are used. We present the "OHDSI Methods Benchmark" that aims to evaluate the performance of effect estimation methods on real data.

Comparative safety and effectiveness of alendronate versus raloxifene in women with osteoporosis.

Alendronate and raloxifene are among the most popular anti-osteoporosis medications. However, there is a lack of head-to-head comparative effectiveness studies comparing the two treatments. We conducted a retrospective large-scale multicenter study encompassing over 300 million patients across nine databases encoded in the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM).

Boosting the Potassium-Ion Storage Performance in Soft Carbon Anodes by the Synergistic Effect of Optimized Molten Salt Medium and N/S Dual-Doping.

Soft carbon is attracting tremendous attention as a promising anode material for potassium-ion batteries (PIBs) because of its graphitizable structure and adjustable interlayer distance. Herein, nitrogen/sulfur dual-doped porous soft carbon nanosheets (NSC) have been prepared with coal tar pitch as carbon precursors in an appropriate molten salt medium. The molten salt medium and N/S dual-doping are responsible for the formation of nanosheet-like morphology, abundant microporous channels with a high surface area of 436 m g, expanded interlamellar spacing of 0.

MIL/Aptamer as a Nanosensor Capable of Resisting Nonspecific Displacement for ATP Imaging in Living Cells.

Fluorescent probes physisorbed on nanomaterials have emerged as a kind of useful and facile sensing platform for biological important molecules. However, nonspecific displacement in the physisorption systems is a non-negligible problem for the intracellular analysis. MIL (Materials of Institut Lavoisier), a subclass of metal-organic frameworks (MOFs), has high porosity, large surface area, and intriguing three-dimensional (3D) nanostructure with promising biological and biomedical applications such as molecular detection and drug delivery.

Ablation Behavior of the SiC-Coated Three-Dimensional Highly Thermal Conductive Mesophase-Pitch-Based Carbon-Fiber-Reinforced Carbon Matrix Composite under Plasma Flame.

This study is focused on a novel high-thermal-conductive C/C composite used in heat-redistribution thermal protection systems. The 3D mesophase pitch-based carbon fiber (CF) preform was prepared using CF in the X (Y) direction and polyacrylonitrile carbon fiber (CF) in the Z direction. After the preform was densified by chemical vapor infiltration (CVI) and polymer infiltration and pyrolysis (PIP), the 3D high-thermal-conductive C/C (C/C) composite was obtained.

A Comparison of Ethylene-Tar-Derived Isotropic Pitches Prepared by Air Blowing and Nitrogen Distillation Methods and Their Carbon Fibers.

Two isotropic pitches were prepared by air blowing and nitrogen distillation methods using ethylene tar (ET) as a raw material. The corresponding carbon fibers were obtained through conventional melt spinning, stabilization, and carbonization. The structures and properties of the resultant pitches and fibers were characterized, and their differences were examined.

KO Bu-Promoted C4 Selective Coupling Reaction of Phenols and [60]Fullerene: One-Pot Synthesis of 4-[60]Fullerephenols under Transition-Metal-Free Conditions.

A KO Bu-promoted direct coupling reaction of phenols and [60]fullerene was disclosed. The reaction occurs exclusively at the C4-position of phenols with high regioselectivity and provides an efficient and inexpensive manner to various 4-[60]fullerephenols in good yields. The electrochemical properties of the products render the method attractive and valuable.

Evolution of Phosphorus-Containing Groups on Activated Carbons during Heat Treatment.

Two types of activated carbons have been prepared by HPO activation of lignocellulose and by HPO modification of activated carbon, and then heat-treated at temperatures from 400 to 900 °C in an atmosphere of N or H to investigate the evolution of phosphorus-containing groups. Elemental analysis, X-ray photoelectron spectroscopy, P nuclear magnetic resonance, nitrogen adsorption, and scanning electron microscopy have been used to analyze the physicochemical properties of the activated carbons. The results show that C-O-P linkages of phosphorus-containing groups can progressively evolve into C-P-O, C-P═O, C-P, and eventually elemental phosphorus as a result of heat treatment.