Comparison Analysis of Roundness Measurement of Small Cylindrical Workpieces with Different Styluses.

To investigate the high-accuracy roundness metrology of a needle roller 1.5 mm in diameter and 5.8 mm in length using the stitching linear scan method, a ruby ball stylus with a tip radius of 150 µm and a diamond stylus with a tip radius of 2 µm were employed to perform experiments under the same conditions. The precision coordinate data, derived from the needle roller's cross-sectional circumference, were segmented into uniform eighths, each scanned with the stylus of a roughness measuring machine. The roundness profile of the needle roller was obtained by stitching the arc profiles, which were characterized according to the precision coordinate data of the arcs. The cross-correlation function, Euclidean distance, residual sum of squares, position error, and curvature of the measured arcs were used to evaluate the results, which can reflect the performance of the stylus. A comparison of the results obtained using the ruby ball stylus versus the diamond stylus demonstrates the ruby ball stylus' greater suitability for use in the roundness metrology of the needle roller bearing examined in this paper.

An LLTO-containing heterogeneous composite electrolyte with a stable interface for solid-state lithium metal batteries.

The interaction between Li0.33La0.56TiO3 (LLTO) and metallic lithium leads to severe interfacial instability of LLTO-containing solid-state electrolytes with a lithium metal anode. To improve the interfacial stability, a heterogeneous composite electrolyte PVDF-HFP@LLTO/PEO (PLTP) is designed and fabricated with a PEO electrolyte layer adhered to the PVDF-HFP@LLTO (PLT) electrolyte membrane. The PLTP heterogeneous composite electrolyte exhibits a superior ionic conductivity of 3.23 × 10-4 S cm-1 at 60 °C and a highly stable electrochemical window of up to 4.7 V (vs. Li/Li+). Remarkably, taking advantage of the effective protection of the PEO electrolyte layer, the chemical stability at the electrolyte/lithium metal anode interface is significantly enhanced. As a result, solid-state Li||LiFePO4 and Li||LiNi0.6Co0.2Mn0.2O2 batteries with the heterogeneous electrolyte exhibit an impressive electrochemical performance with high Coulombic efficiency and stable cycling capability. The strengthened interfacial stability enables the heterogeneous electrolyte to be a promising alternative for the further development of solid-state lithium metal batteries.

Preparation of Buffered Nano-Submicron Hierarchical Structure Hollow SiOx @C Anodes for Lithium-Ion Battery Materials with Carboxymethyl Chitosan.

Silicon-based materials are among the most promising anode materials for next-generation lithium-ion batteries. However, the volume expansion and poor conductivity of silicon-based materials during the charge and discharge process seriously hinder their practical application in the field of anodes. Here, we choose carboxymethyl chitosan (CMCS) as the carbon source coating and binding on the surface of nano silicon and hollow silicon dioxide (H-SiO2 ) to form a hierarchical buffered structure of nano-hollow SiOx @C. The hollow H-SiO2 can alleviate the volume expansion of nano silicon during the lithiation process under continuous cycling. Meanwhile, the carbon layer carbonized by CMCS containing N-doping further regulates the silicon's expansion and improves the conductivity of the active materials. The as- prepared SiOx @C material exhibits an initial discharge capacity of 985.4 mAh g-1 with the decay rate of 0.27 % per cycle in 150 cycles under the current density of 0.2 A g-1 . It is proved that the hierarchical buffer structure nano-hollow SiOx @C anode material has practical application potential.

Electrochemical Performances of Nickel-Rich Single-Crystal LiNi0.83 Co0.12 Mn0.05 O2 Cathode Material for Lithium-Ion Batteries Synthesized by Tuning Li+ /Ni2+ Mixing.

Single-crystal nickel-rich materials are promising alternatives to polycrystalline cathodes owing to their excellent structure stability and cycle performance while the cathode material usually appears high cation mixing, which may have a negative effect on its electrochemical performance. The study presents the structural evolution of single-crystal LiNi0.83 Co0.12 Mn0.05 O2 in the temperature-composition space using temperature-resolved in situ XRD and the cation mixing is tuned to improve electrochemical performances. The as-synthesized single-crystal sample shows high initial discharge specific capacity (195.5 mAh g-1 at 1 C), and excellent capacity retention (80.1 % after 400 cycles at 1 C), taking account of lower structure disorder (Ni2+ occupying Li sites is 1.56 %) and integrated grains with an average of 2-3 µm. In addition, the single-crystal material also displays a superior rate capability of 159.1 mAh g-1 at the rate of 5 C. This excellent performance is attributed to the rapid Li+ transportation within the crystal structure with fewer Ni2+ cations in Li layer as well as intactly single grains. In sum, the regulation of Li+ /Ni2+ mixing provides a feasible strategy for boosting single-crystal nickel-rich cathode material.

Chemically Induced Activity Recovery of Isolated Lithium in Anode-free Lithium Metal Batteries.

The anode-free lithium metal battery is considered to be an excellent candidate for the new generation energy storage system because of its higher energy density and safety than the traditional lithium metal battery. However, the continuous generation of SEI or isolated Li hinders its practical application. In general, the isolated Li is considered electrochemically inactive because it loses electrical connection with the current collector. Here we show an abnormal phenomenon that the lost capacity appears to be recovered after cycles when the isolated Li reconnects with a deposited Li metal layer. The isolated Li reconnection is ascribed to the chemical induction of the block copolymer coating. The migration of Li+ is affected by the electron delocalization and the electron cloud density of the polymer, which determine the conversion direction of Li+. Based on the mechanism, we propose a strategy to slow down the capacity decay of the anode-free lithium metal battery.

Construction of a N,P doped 3D dendrite-free lithium metal anode by using silicon-containing lithium metal.

Lithium is thought to be an excellent anode material for next-generation Li metal batteries (LMBs). However, some problems with lithium anodes often lead to serious safety concerns and catastrophic failures due to the huge volume change, Li dendritic growth, and related side reactions. Therefore, in order to manufacture stable rechargeable batteries, the abovementioned serious problems must be effectively solved. In this paper, a three-dimensional N,P-doped silicon-containing lithium anode is designed and prepared by in situ metallurgy using low-cost Si3N4. The 3D stable composite anode (DLi/LiSix CA) was prepared by adding a small amount of Si3N4 to molten lithium to form N-doped silicon-containing lithium metal which was supported on a polyaniline modified carbon cloth (PMCC). The results show that the DLi/LiSix CA not only has high Li affinity but can also effectively inhibit lithium nucleation and lithium dendritic growth, so as to maintain good structural stability in the process of Li plating/stripping. The new lithium metal anode based on doping and 3D carbon cloth shows good cycling stability and low polarizability in both symmetrical and full cells.

Reaching Nearly 100% Quantum Efficiencies in Thin Solid Films of Semiconducting Polymers via Molecular Confinements under Large Segmental Stresses.

Quantum efficiencies remain a critical issue for general applications of semiconducting polymers in optoelectronics and others. In this work, we demonstrate that nearly 100% quantum efficiencies (η's) in thin solid films can be reached when the polymer molecules are mechanically stretched into molecular confinement. We selected three conjugated polymers of varied backbone stiffness and interchain coupling, prepared in both diluted and pristine states. All of the polymers when highly diluted (c = 0.1 wt %) exhibited massive η increases after stretching to very large strains (∼300-500%) via micronecking, with the rigid polyfluorene (PFO) and semirigid MEH-PPV both manifesting η ≈ 90%, while the most flexible yet regioregular polythiophene (P3HT-rr) exhibited a 10-fold increase to ∼21%. In the pristine state, molecular aggregation and interchain coupling curtail development of the molecular confinement, but the large-strain deformation still enhances η's significantly, to ∼90% (PFO) and ∼55% (MEH-PPV) despite no increases for the crystalline P3HT-rr. Moreover, upon substitution by a bulkier side-group to reduce interchain coupling, the pristine films of polythiophene (P3EHT) exhibited a ∼3-fold increase of η after the stretching. The nearly 100% of η's in fully stretched molecules indicates that the in situ self-trapping occurring via sub-picosecond backbone interactions can be mostly responsible for energy dissipations and quite suppressible by segmental stress control. The mechanical confinement effects also indicate the fundamental role of molecular mechanics during stabilization and migration of photoexcited charges.

Controlled Biosynthesis of ZnCdS Quantum Dots with Visible-Light-Driven Photocatalytic Hydrogen Production Activity.

The development of visible-light-responsive photocatalysts with high efficiency, stability, and eco-friendly nature is beneficial to the large-scale application of solar hydrogen production. In this work, the production of biosynthetic ternary ZnCdS photocatalysts (Eg = 2.35-2.72 eV) by sulfate-reducing bacteria (SRB) under mild conditions was carried out for the first time. The huge amount of biogenic S2- and inherent extracellular proteins (EPs) secreted by SRB are important components of rapid extracellular biosynthesis. The ternary ZnCdS QDs at different molar ratios of Zn2+and Cd2+ from 15:1 to 1:1 were monodisperse spheres with good crystallinity and average crystallite size of 6.12 nm, independent of the molar ratio of Cd2+ to Zn2+. All the ZnCdS QDs had remarkable photocatalytic activity and stability for hydrogen evolution under visible light, without noble metal cocatalysts. Especially, ZnCdS QDs at Zn/Cd = 3:1 showed the highest H2 production activity of 3.752 mmol·h-1·g-1. This excellent performance was due to the high absorption of visible light, the high specific surface area, and the lower recombination rate between photoexcited electrons and holes. The adhered inherent EPs on the ZnCdS QDs slowed down the photocorrosion and improved the stability in photocatalytic hydrogen evolution. This study provides a new direction for solar hydrogen production.

Quick extracellular biosynthesis of low-cadmium Zn x Cd1-x S quantum dots with full-visible-region tuneable high fluorescence and its application potential assessment in cell imaging.

The biosynthesis of metal nanoparticles/QDs has been universally recognized as environmentally sound and energy-saving, generating less pollution and having good biocompatibility, which is most needed in biological and medical fields. In the arena of chemical routes, however, biosynthesis has long been criticized for its low productivity, time-consuming process, and poor control over size, shape and crystallinity, keeping the much-needed technology away from practical application. In this work, a rapid and extracellular biosynthesis of multi-colour ternary Zn x Cd1-x S QDs by a mixed sulfate-reducing bacteria (SRB)-derived supernatant was carried out for the first time to solve the problems plaguing this field of biosynthesis. The results showed that about 3.5 g L-1 of Zn x Cd1-x S QDs with size of 3.50-4.64 nm were achieved within 30 minutes. The PL emission wavelength of Zn x Cd1-x S QDs increased from 450 to 590 nm to yield multicolor QDs by altering the molar ratio of Cd2+ to Zn2+. The SRB-biogenic Zn x Cd1-x S QDs have high stability in gastric acid and at high temperature, as well as excellent biocompatibility and biosafety, successfully entering growing HeLa cells and labelling them without detectable harm to cells. The SRB-secreted peculiar extracellular proteins (EPs) play a decisive function in the time-saving, high-yield biosynthesis of PL-tuned multicolor QDs, which cover an abnormally high concentration of acidic amino acids to provide tremendous negatively charged sites for the absorption of Cd2+/Zn2+ for rapid nucleation and biosynthesis. The strongly electrostatic connection between the QDs and the EPs and the increasing amount of EPs attached to the QDs in response to the increase of Cd2+ concentration account for their high stability and excellent biocompatibility.

A theoretical study on Na+ solvation in carbonate ester and ether solvents for sodium-ion batteries.

The electrochemical performance of sodium-ion batteries is strongly related to the electrolyte solvents. Na+ solvation in commonly used carbonate esters such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) as well as in ether solvents such as 1,3-dioxolane (DOL), tetrahydrofuran (THF), and dimethoxyethane (DME) is studied by the density functional theory for sodium-ion batteries. It is indicated that the thermodynamic equilibrium is reached when forming 4sol-Na+ in the EC, PC, DMC, EMC, DEC, and THF solvents by spontaneous stepwise solvation reactions, and the formation of 3sol-Na+ complexes will reach thermodynamic equilibrium in DOL and DME at room temperature. It is demonstrated that Na+ is more easily solvated by the carbonate ester-based solvents EC, PC, DEC, DMC and EMC compared with that for the ether-based solvents DOL, THF and DME. In addition, the cyclic carbonate ester solvents more easily form a solvation-Na+ complex compared with the linear carbonate ester solvents, and THF is the easiest to form the solvation-Na+ complex among the three ether-based solvents. It is also indicated that the C[double bond, length as m-dash]O and carbonate C-O bond stretching vibrations in carbonate ester solvation complexes move to higher and lower frequencies, respectively, with the decrease in Na+ concentration. In addition, the C-O stretching vibrations with or without Na+ interactions in the ether solvation complexes shift to higher and lower frequencies, respectively, and the shift in frequency is not obvious after forming the maximum innermost solvation shell.

Microsphere-Like SiO2 /MXene Hybrid Material Enabling High Performance Anode for Lithium Ion Batteries.

To address the non-negligible volume expansion and the inherent poor electronic conductivity of silica (SiO2 ) material, microsphere-like SiO2 /MXene hybrid material is designed and successfully synthesized through the combination of the Stöber method and spray drying. The SiO2 nanoparticles are firmly anchored on the laminated MXene by the bonding effect, which boosts the structural stability during the long-term cycling process. The MXene matrix not only possesses high elasticity to buffer the volume variation of SiO2 nanoparticles, but also promotes the transfer of electrons and lithium ions. Moreover, the microsphere wrapped with ductile MXene film reduces the specific surface area, relieves the side reactions, and enhances the coulombic efficiency. Therefore, superior electrochemical performance including high reversible capacity, outstanding cycle stability, high coulombic efficiency, especially in the first cycle, excellent rate capability as well as high areal capacity are acquired for SiO2 /MXene microspheres anode.

Electrochemical Properties of the LiNi0.6Co0.2Mn0.2O2 Cathode Material Modified by Lithium Tungstate under High Voltage.

An amount (5 wt %) of lithium tungstate (Li2WO4) as an additive significantly improves the cycle and rate performances of the LiNi0.6Co0.2Mn0.2O2 electrode at the cutoff voltage of 4.6 V. The 5 wt % Li2WO4-mixed LiNi0.6Co0.2Mn0.2O2 electrode delivers a reversible capacity of 199.2 mA h g-1 and keeps 73.1% capacity for 200 cycles at 1 C. It retains 67.4% capacity after 200 cycles at 2 C and delivers a discharge capacity of 167.3 mA h g-1 at 10 C, while those of the pristine electrode are only 44.7% and 87.5 mA h g-1, respectively. It is shown that the structure of the LiNi0.6Co0.2Mn0.2O2 cathode material is not affected by mixing Li2WO4. The introduced Li2WO4 effectively restrains the LiPF6 and carbonate solvent decomposition by consuming PF5 at high cutoff voltage, forming a stable cathode/electrolyte interface film with low resistance.

Density Functional Theory Research into the Reduction Mechanism for the Solvent/Additive in a Sodium-Ion Battery.

The solid-electrolyte interface (SEI) film in a sodium-ion battery is closely related to capacity fading and cycling stability of the battery. However, there are few studies on the SEI film of sodium-ion batteries and the mechanism of SEI film formation is unclear. The mechanism for the reduction of ethylene carbonate (EC), propylene carbonate (PC), vinylene carbonate (VC), ethylene sulfite (ES), 1,3-propylene sulfite (PS), and fluorinated ethylene carbonate (FEC) is studied by DFT. The reaction activation energies, Gibbs free energies, enthalpies, and structures of the transition states are calculated. It is indicated that VC, ES, and PS additives in the electrolyte are all easier to form organic components in the anode SEI film by one-electron reduction. The priority of one-electron reduction to produce organic SEI components is in the order of VC>PC>EC; two-electron reduction to produce the inorganic Na2 CO3 component is different and follows the order of EC>PC>VC. Two-electron reduction for sulfites ES and PS to form inorganic Na2 SO3 is harder than that of carbonate ester reduction. It is also suggested that the one- and two-electron reductive decomposition pathway for FEC is more feasible to produce inorganic NaF components.

Novel Slurry Electrolyte Containing Lithium Metasilicate for High Electrochemical Performance of a 5 V Cathode.

We report a novel slurry electrolyte with ultrahigh concentration of insoluble inorganic lithium metasilicate (Li2SiO3) that is exploited for lithium ion batteries to combine the merits of solid and liquid electrolytes. The safety, conductivity, and anodic and storage stabilities of the eletrolyte are examined, which are all enhanced compared to a base carbonate electrolyte. The compatibility of the elecrolyte with a LiNi0.5Mn1.5O4 cathode is evaluated under high voltage. A discharge capacity of 173.8 mAh g(-1) is still maintained after 120 cycles, whereas it is only 74.9 mAh g(-1) in the base electrolyte. Additionally, the rate capability of the LiNi0.5Mn1.5O4 cathode is also improved with reduced electrode polarization. TEM measurements indicate that the electrode interface is modified by Li2SiO3 with a thinner solid electrolyte interphase film. Density functional theory computations demonstrate that LiPF6 is stabilized against its decomposition by Li2SiO3. A possible path for the reaction between PF5 and Li2SiO3 is also proposed by deducing the transition states involved in the process using the DFT method.

Sphere-shaped hierarchical cathode with enhanced growth of nanocrystal planes for high-rate and cycling-stable li-ion batteries.

High-energy and high-power Li-ion batteries have been intensively pursued as power sources in electronic vehicles and renewable energy storage systems in smart grids. With this purpose, developing high-performance cathode materials is urgently needed. Here we report an easy and versatile strategy to fabricate high-rate and cycling-stable hierarchical sphered cathode Li(1.2)Ni(0.13)Mn(0.54)Co(0.13)O2, by using an ionic interfusion method. The sphere-shaped hierarchical cathode is assembled with primary nanoplates with enhanced growth of nanocrystal planes in favor of Li(+) intercalation/deintercalation, such as (010), (100), and (110) planes. This material with such unique structural features exhibits outstanding rate capability, cyclability, and high discharge capacities, achieving around 70% (175 mAh g(-1)) of the capacity at 0.1 C rate within about 2.1 min of ultrafast charging. Such cathode is feasible to construct high-energy and high-power Li-ion batteries.

New synthesis of a Foamlike Fe3O4/C composite via a self-expanding process and its electrochemical performance as anode material for lithium-ion batteries.

A novel foamlike Fe3O4/C composite is prepared via a sol-gel type method with gelatin as the carbon source and ferric nitrate as the iron source, following a postannealing treatment. Its lithium storage properties as anode material for a lithium-ion battery are thoroughly investigated in this work. With the interaction between ferric nitrate and gelatin, the foamlike architecture is attained through a unique self-expanding process. The Fe3O4/C composite possesses abundant porous structure along with highly dispersed Fe3O4 nanocrystal embedment in the carbon matrix. In the constructed architecture, the 3D porous network property ensures electrolyte accessibility; meanwhile, nanosized Fe3O4 promotes lithiation/delithiation, owing to numerous active sites, large electrolyte contact area, and a short lithium ion diffusion path. As a result, this Fe3O4/C composite electrode demonstrates an excellent cycling stability with a reversible capacity of 1008 mA h g(-1) over 400 cycles at 0.2C (1C = 1000 mA g(-1)), as well as a superior rate performance with reversible capacity of 660 and 580 mA h g(-1) at 3C and 5C, respectively.

[Role of the IGF-1/PI3K pathway and the molecular mechanism of Fuzhenghuayu therapy in a spontaneous recovery rat model of liver fibrosis].

OBJECTIVE: To determine the role of IGF-1/PI3K pathway and investigate the molecular mechanism of Fuzhenghuayu (FZHY) therapy in a spontaneous recovery rat model of liver fibrosis. METHODS: The liver fibrosis model was induced in male Wistar rats by administering 8 weeks of twice weekly CCL4 intraperitoneal injections without (untreated model) or with once daily FZHY (treated model). Normal, untreated rats served as the control group. At weeks 4, 6 and 8 (fibrosis) and 10, 12 and 14 (spontaneous recovery) after modeling initiation, effects on protein (a-SMA, IGF-1, PI3K) and mRNA (IGF-1, PI3K) expression levels were evaluated by immunohistochemistry and RT-PCR, respectively. Serum markers of liver function (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)) and liver cell damage (alkaline hydrolysis, HYP) were measured. Histology was performed to assess the degree of inflammation and fibrosis (Ishak scoring system). RESULTS: In the untreated model group, progression of liver fibrosis (weeks 4, 6 and 8) was accompanied by gradual increases in inflammation, necrosis, serum ALT and AST, and hepatic expression of a-SMA protein and IGF-1 and PI3K protein and mRNA; however, during the spontaneous recovery period (weeks 10, 12 and 14) the IGF-1 and PI3K protein and mRNA levels rapidly decreased and the HYP level, Ishak score, and a-SMA hepatic expression also decreased. The FZHY-treated model group showed significantly lower fibrosis-related up-regulation of IGF-1 and PI3K protein and mRNA expression, HYP level, Ishak score, and a-SMA hepatic expression at each time point (vs. untreated model group). CONCLUSION: The IGF-1/PI3K pathway may contribute to progression of liver fibrosis. The mechanism by which FZHY prevents liver fibrosis in a rat model may involve blocking of the IGF/PI3K pathway and inhibiting HSC activation.

Enhanced electrochemical performance of ZnO-loaded/porous carbon composite as anode materials for lithium ion batteries.

ZnO-loaded/porous carbon (PC) composites with different ZnO loading amounts are first synthesized via a facile solvothermal method and evaluated for anode materials of lithium ion batteries. The architecture and the electrochemical performance of the as-prepared composites are investigated through structure characterization and galvanostatic charge/discharge test. The ZnO-loaded/PC composites possess a rich porous structure with well-distributed ZnO particles (size range: 30-100 nm) in the PC host. The one with 54 wt % ZnO loading contents exhibits a high reversible capacity of 653.7 mA h g(-1) after 100 cycles. In particular, a capacity of 496.8 mA h g(-1) can be reversibly obtained when cycled at 1000 mA g(-1). The superior lithium storage properties of the composite may be attributed to its nanoporous structure together with an interconnected network. The modified interfacial reaction kinetics of the composite promotes the intercalation/deintercalation of lithium ions and the charge transfer on the electrode. As a result, the enhanced capacity of the composite electrode is achieved, as well as its high rate capability.

Downregulation of TIPE2 mRNA expression in peripheral blood mononuclear cells from patients with chronic hepatitis C.

PURPOSE: Hepatitis C virus (HCV) infection causes chronic hepatitis in approximately 80 % of cases. Although it is well recognized that the immune system plays an important role in determining the outcomes of HCV infection, the underlying molecular mechanisms of persistent HCV infection and hepatic injury are incompletely understood. Tumor necrosis factor-α-induced protein 8-like 2 (TNFAIP8L2, TIPE2) is a newly identified negative regulator of innate and adaptive immunity. The goal of the present study is to investigate the potential role of TIPE2 in chronic hepatitis C (CHC) infection. METHODS: We used quantitative real-time reverse transcription polymerase chain reaction to examine the mRNA expression levels of TIPE2, Toll-like receptor (TLR) 2, and TLR4 in peripheral blood mononuclear cells from 60 CHC patients and 30 healthy controls. RESULTS: The TIPE2 mRNA expression was significantly downregulated, whereas that of TLR2 and TLR4 was upregulated in CHC patients compared with healthy controls. TIPE2 mRNA expression levels were negatively correlated with serum ALT, AST, and HCV RNA levels. TIPE2 mRNA expression was also negatively correlated with TLR2 and TLR4 mRNA levels in CHC patients. Moreover, TIPE2 mRNA expression was upregulated, whereas that of TLR2 and TLR4 was downregulated after treatment of patients with interferon-α and ribavirin. CONCLUSIONS: These results indicate that HCV may promote chronic hepatitis by decreasing TIPE2 expression while enhancing TLR signaling.

Method of compensating for pixel migration in volume holographic optical disc (VHOD).

Volume holographic optical disc (VHOD) technology is simpler than the angular multiplexing holographic system. However, disc rotation usually causes pixel migration, thus reducing signal quality. This study proposes a special geometrical arrangement to counteract pixel migration. Using paraxial approximation analysis, an optimal geometrical distance ratio, K, is calculated to compensate for pixel migration and improve image quality during disc rotation. The results of approximation analysis are confirmed by both simulation and experimental results.