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SnS2/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 SnS2/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. Particularly, the storage stability of Na-Bp/THF and Na-Naph/DME in ambient air accompanied by their presodiation behavior on the SnS2/rGO anode has been investigated, and both reagents exhibited desirable ambient air-tolerant storage stability with favorable sodium supplement effects even after 20 days of storage. More importantly, the initial Coulombic efficiency (ICE) of SnS2/rGO electrodes could be controllably increased by immersing in a presodiation reagent for different durations. Consequently, with a facile chemical presodiation strategy of immersion in Na-Bp/THF solution for only 3 min in ambient air, the presodiated SnS2/rGO anode has exhibited an outstanding electrochemical performance with a high ICE of 95.6% as well as an ultrahigh specific capacity of 879.2 mAh g–1after 300 cycles (83.5% of its initial capacity), highly superior to the pristine SnS2/rGO anode. This efficient and scalable presodiation strategy provides a new avenue for the prevailing application of other anode candidates in high-energy SIBs.

An “off–on–off” fluorescent probe NapEbfor high selectivity and reversible response to H2O2and GSH was synthesized. Inspired by the role of GSH in the human body, the –Se–N– bond in ebselen was successfully used as the recognition site. The probe NapEbis sensitive (LOD = 8.4 µM) and fast for H2O2(within 200 s). It can be used not only for qualitative and quantitative detection of H2O2in real samples, but also has been successfully used for the imaging detection of H2O2in MCF-7 cells with good effect. Moreover, continuous fluorescence recognition of GSH has also achieved significant results, the process is reversible and can be repeated for 5 times. The experimental results show that satisfactory results can also be obtained by structural modification at the 3-position of naphthalimide.

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]-co-N-isopropylacrylamide) [P(METAC-co-NIPAM)] random copolymers. Our study demonstrates that the anion specificities of the P(METAC-co-NIPAM) copolymers are dependent on their chemical compositions. The specific anion effects on the copolymers with high mole fractions of poly(N-isopropylacrylamide) (PNIPAM) are similar to those on the PNIPAM homopolymer. As the mole fraction of PNIPAM decreases to a certain value, a V-shaped anion series can be observed in terms of the anion-specific cloud point temperature of the copolymer, as induced by the interplay between different anion–polymer interactions. Our study also suggests that both the direct and the indirect anion–polymer interactions contribute to the anion specificities of the copolymers. This work would improve our understanding of the relationship between the ion specificities and the ion–macromolecule interactions for naturally occurring macromolecules.

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 Hf0.87Ta0.13Fe2+x(x= 0) shows a giant NTE, which is gradually suppressed with increasing xand finally changed to near-zero thermal expansion (ZTE) at x≈ 0.4. The excess Fe was suggested to form anti-site defects by occupying the 4f sites. As revealed by electron spin resonance (ESR) spectra, the weakened NTE is closely related to a slower ferromagnetic (FM) ordering process than observed at x= 0. In addition, the CTE can be further tuned by introducing an extra α-Fe phase to achieve a low CTE (e.g., 3.3 ppm/K for x= 1.0) with markedly enhanced mechanical properties, beneficial to applications.

Hierarchically porous carbons (HPCs) with multimodal pores have attracted considerable attention due to their unique physical and chemical properties and various application potentials in heterogeneous catalysis, environmental treatment, and energy storage and conversion. Herein, we report a general and simple zinc salts-assisted method for the synthesis of HPCs with varied porosity and chemical functionalities by the direct carbonization of diverse biomass and wastes. During the carbonization, zinc salts are thermally decomposed into nanoparticles that serve as in-situ templates to introduce nanopores in carbons. The prepared HPCs exhibit high specific surface areas (up to 2432 m2 g−1), large pore volumes (up to 4.30 cm3 g−1), and broad pore size distributions. Moreover, the zinc salts can be recovered and recycled, supporting the sustainable production of HPCs on large scale. The prepared HPCs-supported catalysts with atomically dispersed metal sites exhibit promising electrocatalytic performance for the oxygen reduction reaction.

In this paper, the technological progress on Chinese gravity exploration satellites is presented. Novel features such as ultra-stable structure, high accurate thermal control, drag-free and attitude control, micro-thrusters, aerodynamic configuration, the ability to perform micro-vibration analyses, microwave ranging system and mass center trimmer are described.

Copper dendrites on the copper surface were successfully prepared by electrodeposition in acidic copper sulfate aqueous solution containing ethanol. The XRD (X-ray diffraction) patterns indicate that the Cu dendrites possess fcc (face-centered cubic) crystal structure. The contact angle of the as-prepared Cu dendrites surface without palmitic acid modification is almost 0° and the surface is completely wetted by water. After modified with palmitic acid, the Cu dendrite surface shows superhydrophobicity with a contact angle of 160°. The polarization curves reveal that the superhydrophobic Cu dendrites surface exhibits a distinct passivation phenomenon, which could provide enhanced corrosion resistance for the substrate in the aqueous solution. The weight loss measurements show that the corrosion values of superhydrophobic surface is much lower than that of the bare copper, further meaning that the as-prepared surface has the anticorrosion performance.

Triose phosphate isomerase (TIM) was prepared and purified from chicken breast muscle. The equilibrium unfolding of TIM by urea was investigated by following the changes of intrinsic fluorescence and circular dichroism spectroscopy, and the equilibrium thermal unfolding by differential scanning calorimetry (DSC). Results show that the unfolding of TIM in urea is highly cooperative and no folding intermediate was detected in the experimental conditions used. The thermodynamic parameters of TIM during its urea induced unfolding were calculated as G 3.54 kcal•mol-1, and mG 0.67 kcal•mol-1•M-1, which just reflect the unfolding of dissociated folded monomer to fully unfolded monomer transition, while the dissociation energy of folded dimer to folded monomer is probe silence. DSC results indicate that TIM unfolding follows an irreversible two-state step with a slow aggregation process. The cooperative unfolding ratio, Hcal/HvH, was measured close to 2, indicating that the two subunits of chicken muscle TIM unfold independently. The vant Hoff enthalpy, HvH, was estimated as about 200 kcal•mol-1. These results support the unfolding mechanism with a folded monomer formation before its tertiary structure and secondary structure unfolding.

Collapse and aggregation of poly(N-isopropylacrylamide) (PNIPAM) chains in aqueous solutions with polyethylene glycol (PEG) as the crowding agent have been investigated by using ultra-sensitive differential scanning calorimetry (US−DSC). For any PEG with a certain molecular weight, the transition temperature of PNIPAM decreases with PEG concentration (CPEG) due to the complexation between PEG chains and water molecules. A hysteresis has been observed in one heating-and-cooling cycle. As CPEGincreases, short PEG chains lead the hysteresis to enlarge, whereas longer PEG chains result in a decrease in the hysteresis. The facts indicate that longer PEG chains suppress the interchain aggregation of PNIPAM chains. When CPEGis above the overlap concentration (C), the hysteresis is almost independent of PEG concentration, suggesting that PEG chains form a transient network which locates PNIPAM chains in a number of pores. The widening of the transition with increasing CPEGat CPEG>Cindicates that the network is inhomogeneous. The fact that the enthalpy change (H) decreases with CPEGfurther indicates that PEG chains reduce the interchain aggregation of PNIPAM chains. The same Hin heating and cooling processes demonstrates that PNIPAM chains form small-scale aggregates in the presence of PEG.

The concentration (C) effect on association and dissolution of linear poly(N-isopropylacrylamide) (PNIPAM) chains in dilute and semidilute aqueous solutions was investigated by using ultrasensitive differential scanning calorimetry (US-DSC). When Cis below the overlap concentration (C), both the phase-transition temperature (Tp) and enthalpy change (H) in the heating process decrease as the solution becomes more dilute, while Tpand Hbecome independent of Cin the semidilute regime (C> C). Such a difference can be attributed to different contributions of interchain association and intrachain contraction in dilute and semidilute solutions. In the cooling process, Tpnearly remains a constant, but Hdecreases as Cincreases in dilute solutions, but both of them slightly vary in the range C> C. A hysteresis was observed in one heating-and-cooling cycle. Such a hysteresis becomes more obvious as Cincreases. The effect of scanning rate on both Tpand Hfurther confirms that the hysteresis is due to incomplete disruption of additional hydrogen bonds formed when the chains are in the collapsed state.

The special thermosensitive copolymer with lower critical solubility temperature near human heat of 37°C in aqueous solution has been prepared successfully by copolymerizing N‐isopropylacrylamide (NIPAM) and N‐isopropylmethacrylamide (NIPMAM) randomly at an appropriate monomer ratio. The self‐association behavior of the poly[NIPAM‐ran‐NIPMAM] copolymer has been studied by dynamic laser light scattering (DLLS) at a concentration higher than the critical concentration of the self‐association calculated from viscosity data according to cluster theory. The effect of the concentration and temperature on the self‐association behavior in water has been discussed respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 583–588, 2005

The space thermal environment is one of the important factors that affect the image quality of a space optical remote sensor (SORS), so discussing the relationship between image quality and the temperature field of a SORS is necessary for thermal control to improve image quality. In this paper, a new thermo-optical analysis method is proposed for the optostructural system of a SORS. Thermal-elastic distortions of all components of an optostructural system, resulting from temperature field changes, cause dimensional instability of the system. This instability is described in terms of changes of position (translations along and rotations around coordinate axes), equation parameters, and roughness of optical surfaces. Then, the theory of homogeneous coordinate transformations and linear fitting of revolving conicoid surfaces are applied to processing of data from finite-element analysis to obtain all the thermally induced dimensional instabilities. Finally, these instabilities were incorporated in optical models (e.g., Zemax) to calculate the thermally induced degradation of image quality (modulation transfer function, wavefront error, etc.). The results of thermo-optical tests suggest that this method is effective. © 2004 Society of Photo-Optical Instrumentation Engineers.

Single crystalline Te nanowires with diameters ranging from a few nanometers to ˜30 nm and lengths ranging from hundreds of nanometers to several micrometers were produced with a yield of ˜95% via a hydrothermal-reduction process using Na2TeO3and glucose as reactants and sodium dodecyl benzenesulfonate (SDBS) as surfactant at 180 °C.

For Abstract see ChemInform Abstract in Full Text.

An algorithm for on-orbit calibration of K band ranging (KBR) system phase center of the low-low satellite-to-satellite tracking (SST-LL) gravity satellite was proposed. Firstly, the attitude control algorithm was designed according to the calibration maneuver design, and the satellite control procedure was divided into thruster maneuver control procedure and stabilization control procedure. Secondly, the observation of KBR, GPS and star sensor were used to estimate the phase center of KBR based on extended Kalman filter. The pitch and yaw attitude control error are better than 1mrad, and the roll error is better than 3mard which indicates that the calibration attitude stabilization control can be realized. The calibration accuracy of three axises are all better than 1mm, which verify the fast convergence rate and the steady accuracy of the algorithm. [ABSTRACT FROM AUTHOR]

A method for on-orbit calibration of center of mass for gravity satellite was proposed, based on a predictive filter fusing extended Kalman filter estimation algorithm. Firstly, a periodic magnetic torque which was more larger than other external torques was applied to the satellite. Secondly, the observation of gyro was used to estimate angular acceleration based on the predictive filter. Finally, an extended Kalman filter was used to estimate the satellite's center of mass. The numerical results indicate that the angular acceleration and center of mass can be real time estimated. The calibration accuracy of three axes is [0.0628 0.0324 0.0414]mm, which demonstrates the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]