Design and verification of a piezoelectric-driven locking and handover mechanism for space-based gravitational wave detection.

Space inertial sensors, comprising a test mass and its surrounding framework, are pivotal for high-precision gravitational wave detection. The precise locking and handover of the test mass are crucial, particularly during launch and orbital insertion phases. Given the necessity for ultra-stable locking mechanisms in space inertial sensors to ensure mission success, this paper presents a novel locking and handover mechanism driven by a rotating piezoelectric motor and lead screw.

ADP-Based Orbit Tracking Control for Deep Space Probe Flying Around Unknown Asteroid.

This article investigates the orbit tracking control problem for the deep space probe flying around an unknown asteroid under completely unknown dynamics. First, an orbit tracking control model for the relative motion of the probe to the asteroid is established. Then, a model-based controller is designed for the optimal tracking control problem and the asymptotic stability of the closed-loop system is proved.

Ultrasensitive Differential Scanning Calorimetric (US-DSC) Study of the Thermal-Induced Dynamic Transition Behaviors of PEO-PPO-PEO in Aqueous Solution.

Temperature-responsive macromolecules can provide insights into the mechanisms of the aggregation and precipitation processes of proteins. In this study, the PEO-PPO-PEO triblock copolymer, Pluronic P123, has been utilized as a protein model to investigate the thermally induced dynamic transition behavior by ultrasensitive differential scanning calorimetry (US-DSC). The results of US-DSC reveal hysteresis in the disaggregation process of P123 micelles.

Thermal properties of glycinin in crowded environments.

Crowded environments, commonly found in the food system, are utilized to enhance the properties of soybean proteins. Despite their widespread application, little information exists regarding the impact of crowded environments on the denaturation behaviors of soybean proteins. In this study, we investigated how crowding agents with varying molecular weights, functional groups, and topology affect the denaturation behavior of glycinin under crowded conditions.

A novel fluorescent probe based on naphthimide for HS identification and application.

In view of the superior chemical activity of selenoether bond (-Se-) and the excellent optical properties of naphthimide, a novel fluorescent probe (NapSe) with near-rectangular structure, which contains double naphthimide fluorophores linked by selenoether bond, is designed for specific fluorescence detection of hydrogen sulfide (HS). NapSe has excellent optical properties: super large Stokes Shift (190 nm) and good stability in a wide pH range. The selectivity of NapSe fluorescence detection of HS is high, and displays excellent "turn-on" phenomenon and strong anti-interference.

Study on the Voltage Reference Noise at Sub-Millihertz Frequencies for Developing an Ultra-Stable Temperature Measurement Subsystem.

A temperature measurement subsystem (TMS) is a critical piece of infrastructure of the space gravitational wave detection platform, necessary for monitoring minuscule temperature changes at the level of 1μK/Hz1/2 within the electrode house, in the frequency range of 0.1mHz to 1Hz. The voltage reference (VR), a key component of the TMS, must possess low noise characteristics in the detection band to minimize the impact on temperature measurements.

Facile and High-Efficiency Chemical Presodiation Strategy on the SnS/rGO Composite Anode for Stable Sodium-Ion Batteries.

SnS/reduced graphite oxide (rGO) composite materials show great potential as high-performance anode candidates in sodium-ion batteries (SIBs) owing to their high specific capacities and power densities. However, the repeated formation/decomposition of the solid electrolyte interface (SEI) layer around composite anodes usually consumes additional sodium cations, resulting in poor Coulombic efficiency and decreasing specific capacity upon cycling. Therefore, in order to compensate for the large irreversible sodium loss of the SnS/rGO anode, this study has proposed a facile strategy by implementing organic solutions of sodium-biphenyl/tetrahydrofuran (Na-Bp/THF) and sodium-naphthylamine/dimethoxyethane (Na-Naph/DME) as chemical presodiation reagents.

Experimental study of a tapered fiber temperature sensor with a liquid seal based on multimode interference.

Studying high-sensitivity fiber-optic temperature sensors is vital in pursuing high-precision temperature measurement. We propose a liquid-sealed multimode interference fiber temperature sensor with a double-taper structure. The influence of structure and sealed-liquid material on the temperature sensitivity of the sensor is analyzed experimentally.

Structure and dynamics of supercooled water in the hydration layer of poly(ethylene glycol).

The statics and dynamics of supercooled water in the hydration layer of poly(ethylene glycol) (PEG) were studied by a combination of quasi-elastic neutron scattering (QENS) and molecular dynamics (MD) simulations. Two samples, that is, hydrogenated PEG/deuterated water (h-PEG/DO) and fully deuterated PEG/hydrogenated water (d-PEG/HO) with the same molar ratio of ethylene glycol (EG) monomer to water, 1:1, are compared. The QENS data of h-PEG/DO show the dynamics of PEG, and that of d-PEG/HO reveals the motion of water.

A Top-Down Templating Strategy toward Functional Porous Carbons.

Nanostructured carbon materials with high porosity and desired chemical functionalities are of immense interest because of their wide application potentials in catalysis, environment, and energy storage. Herein, a top-down templating strategy is presented for the facile synthesis of functional porous carbons, based on the direct carbonization of diverse organic precursors with commercially available metal oxide powders. During the carbonization, the metal oxide powders can evolve into nanoparticles that serve as in situ templates to introduce nanopores in carbons.

A novel interlayer-expanded tin disulfide/reduced graphene oxide nanocomposite as anode material for high-performance sodium-ion batteries.

As a kind of negative electrode material for sodium-ion batteries (SIBs), tin-based active compounds have attracted numerous research efforts in recent years due to relatively high theoretical capacity. However, sluggish reaction kinetics for large-radius sodium ions hinders the practical application of layered tin-based anodes such as tin disulfide (SnS) in SIBs. In this study, polyethylene glycol (PEG) is introduced as an intercalant and reduced graphene oxide (rGO) is utilized as the substrate to prepare a novel PEG-SnS/rGO composite with expanded layer spacing (0.

Encapsulating Fe O Nanotubes into Carbon-Coated Co S Nanocages Derived from a MOFs-Directed Strategy for Efficient Oxygen Evolution Reactions and Li-Ions Storage.

The development of high-efficiency, robust, and available electrode materials for oxygen evolution reaction (OER) and lithium-ion batteries (LIBs) is critical for clean and sustainable energy system but remains challenging. Herein, a unique yolk-shell structure of Fe O nanotube@hollow Co S nanocage@C is rationally prepared. In a prearranged sequence, the fabrication of Fe O nanotubes is followed by coating of zeolitic imidazolate framework (ZIF-67) layer, chemical etching of ZIF-67 by thioacetamide, and eventual annealing treatment.

Synthesis of carbon-supported sub-2 nanometer bimetallic catalysts by strong metal-sulfur interaction.

Small-sized bimetallic nanoparticles that integrate the advantages of efficient exposure of the active metal surface and optimal geometric/electronic effects are of immense interest in the field of catalysis, yet there are few universal strategies for synthesizing such unique structures. Here, we report a novel method to synthesize sub-2 nm bimetallic nanoparticles (Pt-Co, Rh-Co, and Ir-Co) on mesoporous sulfur-doped carbon (S-C) supports. The approach is based on the strong chemical interaction between metals and sulfur atoms that are doped in the carbon matrix, which suppresses the metal aggregation at high temperature and thus ensures the formation of small-sized and well alloyed bimetallic nanoparticles.

Specific Anion Effects on Charged-Neutral Random Copolymers: Interplay between Different Anion-Polymer Interactions.

The study of ion specificities of charged-neutral random copolymers is of great importance for understanding specific ion effects on natural macromolecules. In the present work, we have investigated the specific anion effects on the thermoresponsive behavior of poly([2-(methacryloyloxy)ethyl trimethylammonium chloride]---isopropylacrylamide) [P(METAC--NIPAM)] random copolymers. Our study demonstrates that the anion specificities of the P(METAC--NIPAM) copolymers are dependent on their chemical compositions.

Hierarchically Porous Carbons Derived from Nonporous Coordination Polymers.

Hierarchically porous carbons (HPCs) with multimodal pore systems exhibit great technological potentials, especially in the fields of heterogeneous catalysis, energy storage, and conversion. Here, we establish a simple and general approach to HPCs by carbonization of nonporous coordination polymers that are produced by mixing metal salts with polytopic ligands in alkaline aqueous solutions at room temperature. The proposed approach is applicable to a wide scope of ligand molecules (18 examples), thus affording the synthesized HPCs with high diversity in porosity, morphology, and composition.

Ultrastable Li-ion battery anodes by encapsulating SnS nanoparticles in sulfur-doped graphene bubble films.

As an anode electrode material for lithium-ion batteries, SnS has high specific capacity and has received widespread attention, but its practical application is still hindered by the low reversibility of the conversion reaction and the large irreversible capacity caused by the solid electrolyte interphase (SEI). In this paper, SnS nanoparticles are encapsulated into a sulfur-doped graphene bubble film (SnS@G) by a scalable electrostatic self-assembly of SnS/graphene oxide and hexadecyl trimethyl ammonium bromide, followed by the thermal decomposition of SnS and sulfur doping in graphene. Due to electrostatic attraction, the SnS nanoparticles are tightly wrapped in multilayer graphene sheets to form a flake-graphite-like structure.

Structural phase transformation from SnS/reduced graphene oxide to SnS/sulfur-doped graphene and its lithium storage properties.

In this work, we demonstrate an interesting structural phase transition from SnS2/reduced graphene oxide to SnS/sulfur-doped graphene at a moderate calcination temperature of 500 °C under an inert atmosphere. It is discovered that SnS2 chemically bound to rGO with a weakened C-S bond is easier to break and decompose into SnS, whereas it is difficult for pure-phase crystalline SnS2 to experience phase transformation at this temperature. Moreover, the thin-layered structure of SnS2 and rGO is an important factor for the effective doping of the dissociated Sx into graphene.

Temperature-Invariant Superelastic and Fatigue Resistant Carbon Nanofiber Aerogels.

Superelastic and fatigue-resistant materials that can work over a wide temperature range are highly desired for diverse applications. A morphology-retained and scalable carbonization method is reported to thermally convert a structural biological material (i.e.

Low Thermal Expansion Modulated by Off-Stoichiometric Effect in Nonstoichiometric Laves Phase HfTaFe Compounds.

Materials with a low coefficient of thermal expansion (CTE) are extremely demanded in many fields, varying from microelectronics to space technology. Here we report a novel method to achieve low CTE, which differs essentially from the conventional way that uses additives with negative thermal expansion (NTE) to compensate for the positive CTE of the matrix. The stoichiometric HfTaFe ( = 0) shows a giant NTE, which is gradually suppressed with increasing and finally changed to near-zero thermal expansion (ZTE) at ≈ 0.

Transition metal-assisted carbonization of small organic molecules toward functional carbon materials.

Nanostructured carbon materials with large surface area and desired chemical functionalities have been attracting considerable attention because of their extraordinary physicochemical properties and great application potentials in catalysis, environment, and energy storage. However, the traditional approaches to fabricating these materials rely greatly on complex procedures and specific precursors. We present a simple, effective, and scalable strategy for the synthesis of functional carbon materials by transition metal-assisted carbonization of conventional small organic molecules.

Wood-Derived Ultrathin Carbon Nanofiber Aerogels.

Carbon aerogels with 3D networks of interconnected nanometer-sized particles exhibit fascinating physical properties and show great application potential. Efficient and sustainable methods are required to produce high-performance carbon aerogels on a large scale to boost their practical applications. An economical and sustainable method is now developed for the synthesis of ultrathin carbon nanofiber (CNF) aerogels from the wood-based nanofibrillated cellulose (NFC) aerogels via a catalytic pyrolysis process, which guarantees high carbon residual and well maintenance of the nanofibrous morphology during thermal decomposition of the NFC aerogels.

Developing a novel dual PI3K-mTOR inhibitor from the prodrug of a metabolite.

This study presents a process of developing a novel PI3K-mTOR inhibitor through the prodrug of a metabolite. The lead compound (compound 1) was identified with similar efficacy as that of NVP-BEZ235 in a tumor xenograft model, but the exposure of compound 1 was much lower than that of NVP-BEZ235. After reanalysis of the blood sample, a major metabolite (compound 2) was identified.

Mechanic Insight into Aggregation of Lysozyme by Ultrasensitive Differential Scanning Calorimetry and Sedimentation Velocity.

Folding and aggregation of proteins profoundly influence their functions. We have investigated the effects of thermal history, concentration and pH on the denaturation and refolding of lysozyme by using ultrasensitive differential scanning calorimetry (US-DSC) and sedimentation velocity (SV) via analytical ultracentrifugation (AUC). The former is sensitive to small energy change whereas the latter can differentiate the oligomers such as dimer and trimer from individual protein molecules.

A population-based study on health-related quality of life among urban community residents in Shenyang, Northeast of China.

Background: Due to the rising standard of living environment and advances in public health and medical care in China, it has been a tendency in recent years that health-related quality of life (HRQoL) has been increasingly acknowledged in community health management. However, large-scale population-based study on evaluating HQRoL in northeast of China was not conducted. This article aims to investigate the HRQoL in community residents in Northeast China and explore the associated factors.

The mediating effects of burnout on the relationship between anxiety symptoms and occupational stress among community healthcare workers in China: a cross-sectional study.

Background: Several occupational stress studies of healthcare workers have predicted a high prevalence of anxiety symptoms, which can affect their quality of life and the care that they provide. However, few studies have been conducted among community healthcare workers in China. We attempted to explore whether burnout mediates the association between occupational stress and anxiety symptoms.