Superhydrophobic Co/Fe sulfide nanoparticles and single-atoms doped carbon nanosheets composite air cathode for high-performance zinc-air batteries

Development of a high-performance bifunctional catalyst is essential for the actual implementation of zinc-air batteries in practical applications.Herein,a bifunctional cathode of Co_(3)S_(4)/FeS heterogeneous nanoparticles embedded in Co/Fe single-atom-loaded nitrogen-doped carbon nanosheets is designed.Cobalt-iron sulfides and single atomic sites with Co-N_(4)/Fe-N_(4)configurations are confirmed to coexist on the carbon matrix by EXAFS spectroscopy.3D self-supported super-hydrophobic multiphase composite cathode provides abundant active sites and facilitates gas–liquid-solid three-phase interface reactions,resulting in excellent electrocatalytic activity and batteries performance,i.e.,an OER overpotential(η_(10))of 260 mV,a half-wave potential(E_(1/2))of 0.872 V for ORR,aΔE of 0.618 V,and a discharge power density of 170 mW cm^(−2),a specific capacity of 816.3 mAh g^(−1).DFT analysis shows multiphase coupling of sulfide heterojunction through single-atomic metal doped carbon nanosheets reduces offset on center of electronic density of states before and after oxygen adsorption,and spin density of adsorbed oxygen with same spin orientation,leading to weakened charge/spin interactions between adsorbed oxygen and substrate,and a lowered oxygen adsorption energy to accelerate OER/ORR.

Family-level diversity of extracellular proteases of sedimentary bacteria from the South China Sea

Protease-producing bacteria and their extracellular proteases are key players in degrading organic nitrogen to drive marine nitrogen cycling and yet knowledge on both of them is still very limited. This study screened protease-producing bacteria from the South China Sea sediments and analyzed the diversity of their extracellular proteases at the family level through N-terminal amino acid sequencing. Results of the 16 S rRNA gene sequence analysis showed that all screened protease-producing bacteria belonged to the class Gammaproteobacteria and most of them were affiliated with different genera within the orders Alteromonadales and Vibrionales. The Nterminal amino acid sequence analysis for fourteen extracellular proteases from fourteen screened bacterial strains revealed that all these proteases belonged to the M4 family of metalloproteases or the S8 family of serine proteases. This study presents new details on taxa of marine sedimentary protease-producing bacteria and types of their extracellular proteases, which will help to comprehensively understand the process and mechanism of the microbial enzymatic degradation of marine sedimentary organic nitrogen.

Gas permeation properties of a metallic ion-cross-linked PIM-1 thin-film composite membrane supported on a UV-cross-linked porous substrate

Metallic ion-cross-linked polymer of intrinsic microporosity(PIM-1) thin-film composite(TFC) membranes supported on an ultraviolet(UV)-cross-linked porous substrate were fabricated. The UV-cross-linked porous substrate was prepared via polymerization-induced phase separation. The PIM-1 TFC membranes were fabricated via a dip-coating procedure. Metallic ion-cross-linked PIM-1 TFC membranes were fabricated by hydrolyzing the PIM-1 TFC membrane in an alkali solution and then cross-linking it in a multivalent metallic ion solution. The pore size and porous structures were evaluated by low-temperature N_2 adsorption–desorption analysis. The membrane structure was investigated by field-emission scanning electron microscopy. The effects of heat treatment and pore-forming additives on the gas permeance of the UV-cross-linked porous substrate are reported. The effects of different pre-coating treatments on the gas permeance of the metallic ion-cross-linked PIM-1 TFC membrane are also discussed. The metallic ion-crosslinked PIM-1 TFC membrane displayed high CO_2/N_2 selectivity(23) and good CO_2 permeance(1058 GPU).

Voltammetric Determination of Vitamin B6 at Glassy Carbon Electrode Modified with Gold Nanoparticles and Multi-Walled Carbon Nanotubes

In this work, the gold nanoparticles (Au NPs)/multi-walled carbon nanotubes (MWCNTs) composite film modified glassy carbon electrode (GCE) was fabricated, and scanning electron microscopy (SEM) was used to investigate the assemble process of the composite film. In pH 7.0 PBS, a oxidation peak of the vitamin B6 (VB6) was only observed at composite film modified electrode. Under the optimized conditions, the current intensity was linear with the concentrations of VB6 in the range of 1.59 to 102.74 μg●mL–1 with a detection limit of 0.53 μg●mL–1 (S/N = 3). The modified electrode had been applied in medication analysis, and obtained good results.

Partial pore blockage and polymer chain rigidification phenomena in PEO/ZIF-8 mixed matrix membranes synthesized by in situ polymerization

Nanostructured zeolitic imidazolate frameworks(ZIF-8) was incorporated into the mixture of poly(ethylene glycol) methyl ether acrylate(PEGMEA) and pentaerythritol triacrylate(PETA) to synthesize mixed matrix membranes(MMMs) by in situ polymerization for CO_2/CH_4 separation. The solvent-free polymerization between PEGMEA and PETA was induced by UV light with 1-hydroxylcyclohexyl phenyl ketone as initiator. The chemical structural characterization was performed by Fourier transform infrared spectroscopy. The morphology was characterized by scanning electron microscope. The average chain-to-chain distance of the polymer chains in MMMs was investigated by X-ray diffraction. The thermal property was evaluated by differential scanning calorimetry. The CH_4 and CO_2 gas transport properties of MMMs are reported. The relationship between gas permeation–separation performances or physical properties and ZIF-8 loading is also discussed. However, the permeation–separation performance was not improved in Robeson upper bound plot compared with original polymer membrane as predicted. The significant partial pore blockage and polymer rigidification effect around the ZIFs confirmed by the increase in glass temperature and the decrease in the d-spacing, were mainly responsible for the failure in performance improvement, which offset the high diffusion induced by porous ZIF-8.

自发性颈内动脉海绵窦瘘二例报告及文献复习

颈内动脉海绵窦瘘(carotid-cavernous fistula,CCF)是一种罕见的脑血管疾病,发病率为0.17%~0.27%,其中大部分为外伤性CCF,自发性CCF仅占15%~25%。CCF的临床症状有结膜红肿、搏动或不搏动性突眼、眼眶疼痛、视力下降、复视、斜视等,其特征性体征是可闻及与血管搏动一致的颅内杂音或耳鸣。该疾病诊断的金标准是数字减影血管造影(digital subtraction angiography,DSA),同时它也是确定下一步治疗方案的关键。本文报道了2例自发性CCF患者,并对该疾病进行文献复习及总结,以提升临床医师对该疾病的认知度。

Wearable Leg Movement Monitoring System for High-Precision Real-Time Metabolic Energy Estimation and Motion Recognition

Comprehensive and quantitative assessment of human physical activity in daily life is valuable for healthcare,especially for those who suffer from obesity and neurological disorders or are at high risk of dementia.Common wearable devices,e.g.,smartwatches,are insufficient and inaccurate for monitoring highly dynamic limb movements and assessing human motion.Here,we report a new wearable leg movement monitoring system incorporating a custom-made motion sensor with machine learning algorithm to perceive human motion accurately and comprehensively during diverse walking and running actions.The system enables real-time multimodal perceptions of personal identity,motion state,locomotion speed,and energy expenditure for wearers.A general law of extracting real-time metabolic energy from leg movements is verified although individual gaits show differences.In addition,we propose a novel sensing configuration combining unilateral lower leg movement velocity with its angular rate to achieve high accuracy and good generalizability while simplifying the wearable system.Advanced performances in personal identification(accuracy of 98.7%)and motion-state recognition(accuracy of 93.7%)are demonstrated.The wearable system also exhibites high-precision real-time estimations of locomotion speed(error of 3.04%to 9.68%)and metabolic energy(error of 4.18%to 14.71%)for new subjects across various time-varying conditions.The wearable system allows reliable leg movement monitoring and quantitative assessment of bodily kinematic and kinetic behaviors during daily activities,as well as safe identity authentication by gait parameters,which would greatly facilitate smart life,personal healthcare,and rehabilitation training.

Dark-field line confocal imaging with point confocality and extended line field for bulk defects detection

Fabrication of high-quality optics puts a strong demand on high-throughput detection of macroscopic bulk defects in optical components.A dark-field line confocal imaging method is proposed with two distinct advantages:(ⅰ)a point-to-line confocal scheme formed by a columnar elliptical mirror and an optical fiber bundle breaks through the constraint on light collection angle and field of view in the traditional line confocal microscopy using an objective,allowing for an extended confocal line field of more than 100 mm while maintaining a light collection angle of 27°;(ⅱ)the bulk defects are independently illuminated as a function of time to eliminate the cross talk in the direction of the confocal slit,thus preserving point confocality and showing the optical section thicknesses to be 162μm in the axial direction,and 19 and 22μm in the orthogonal transverse directions.The experimental results verify that the method has a minimum detectable bulk defect of less than 5μm and an imaging efficiency of 400 mm2/s.The method shows great potential in high-throughput and highsensitivity bulk defects detection.

Ultrapermeable membranes based on connected cluster of hollow polydimethylsiloxane nanoparticles for gas separation

Mixed matrix membranes(MMMs)with the performance between the matrix and the filler is a promising strategy for membranes with excellent gas permeability-selectivity.In this study,the hollow polydimethylsiloxane nanoparticles were synthesized and then incorporated with the poly(oxide ethylene)monomer and tri-functional cross-linker to form mixed matrix membranes by in situ poly-merization.The hollow nanoparticles formed the independent closed nanocavities in membranes,which enhanced the gas permeability contributed by both the improved diffusivity and solubility.At high loading,the hollow polydimethylsiloxane nanoparticle was converted into the continuous phase with the cross-linked poly(oxide ethylene)as the dispersed phase.Gases preferred to permeate through the connected cluster of hollow polydimethylsiloxane nanoparticles,finally leading to ultrahigh gas per-meabilities far going beyond the instinct values of polydimethylsiloxane and the cross-linked poly(oxide ethylene).The optimized membrane with 34 wt%hollow nanoparticles loadings exhibited ultrahigh permeabilities with the values of 44186 Barrer for CO_(2) and 11506 Barrer for O_(2),accompanied with a CO_(2)/N_(2) selectivity of 9.9 and an O_(2)/N_(2) selectivity of 2.6,which exceeded the 2008 Robeson upper bound for O_(2)/N_(2) and located at the 2008 Robeson upper bound for CO_(2)/N_(2).

SCHEDULING WITH REJECTION AND NON-IDENTICAL JOB ARRIVALS

In this paper, we address the scheduling problem with rejection and non-identical job arrivals, in which we may choose not to process certain jobs and each rejected job incurs a penalty, Our goal is to minimize the sum of the total penalties of the rejected jobs and the maximum completion time of the processed ones, For the off-line variant, we prove its NP-hardness and present a PTAS, and for the on-line special case with two job arrivals, we design a best possible algorithm with competitive ratio （√5＋1/2） .

ON-LINE SCHEDULING WITH REJECTION ON IDENTICAL PARALLEL MACHINES

In this paper, we consider the on-line scheduling of unit time jobs with rejection on rn identical parallel machines. The objective is to minimize the total completion time of the accepted jobs plus the total penalty of the rejected jobs. We give an on-line algorithm for the problem with competitive ratio 1/2 （2 ＋√3） ≈ 1.86602.

ON-LINE SCHEDULING OF UNIT TIME JOBS WITH REJECTION ON UNIFORM MACHINES

The authors consider the problem of on-line scheduling of unit execution time jobs on uniform machines with rejection penalty. The jobs arrive one by one and can be either accepted and scheduled, or be rejected. The objective is to minimize the total completion time of the accepted jobs and the total penalty of the rejection jobs. The authors propose an on-line algorithm and prove that the competitive ratio is 1/2 （2 W √3） ≈ 1.86602.

APPROXIMATION SCHEMES FOR SCHEDULING A BATCHING MACHINE WITH NONIDENTICAL JOB SIZE

In this paper we study the problem of scheduling a batching machine with nonidentical job sizes. The jobs arrive simultaneously and have unit processing time. The goal is to minimize the total completion times. Having shown that the problem is NP-hard, we put forward three approximation schemes with worst case ratio 4, 2, and 3/2, respectively.

Uniform Parallel-Machine Scheduling with Time Dependent Processing Times

We consider several uniform parallel-machine scheduling problems in which the processing time of a job is a linear increasing function of its starting time.The objectives are to minimize the total completion time of all jobs and the total load on all machines.We show that the problems are polynomially solvable when the increasing rates are identical for all jobs;we propose a fully polynomial-time approximation scheme for the standard linear deteriorating function,where the objective function is to minimize the total load on all machines.We also consider the problem in which the processing time of a job is a simple linear increasing function of its starting time and each job has a delivery time.The objective is to find a schedule which minimizes the time by which all jobs are delivered,and we propose a fully polynomial-time approximation scheme to solve this problem.

Relationship between iNOS expression and apoptosis in cerebral tissue, and the effect of Sini injection in endotoxin shock rats

OBJECTIVE: To investigate the dynamic changes and relationship of inducible nitric oxide synthase (iNOS) and apoptosis in endotoxin shock rats, as well as the effects of Sini injection. METHODS: In total, 102 Sprague-Dawley (SD) rats were randomly divided into a normal group (n=6, NG), sham operation group (n=24, OG), model group (n=24, MG), dexamethasone group (n=24, DG), and Sini group (n=24, SG). The endotoxin shock model was induced by an intravenous injection of lipopolysaccharide (LPS) (8 mg/kg). Rats in the OG, MG, DG, and SG groups were further divided into 4 groups: 1, 2, 3 and 6 h after shock groups (n=6 per group). iNOS expression was detected by immunohistochemistry. Terminal Deoxynucleotidyl Transferase Mediated Deoxyuridine Triphosphate-biotin Nick End Labeling was employed to measure apoptosis. RESULTS: No iNOS expression was found in the OG group. Compared with the OG group, iNOS expres-sion in the MG group was markedly elevated, reached a peak at 1 h (P<0.01), decreased at 2 and 3 h, and rebounded at 6 h. Compared with the MG group, iNOS expression decreased significantly in both the DG (P<0.05) and SG (P<0.01) groups at 6 h. Thenumberofapoptoticcellsin the MG group was markedly increased than that in the NG and OG (P<0.01) groups, and reached a peak at 6 h. The number of apoptotic cells in the DG group at 1 and 2 h (P<0.01) and SG group at 2, 3 and 6 h (P<0.01) decreased when compared with the MG group. CONCLUSION: Sini injection can significantly inhibit NO generation, which decreases apoptosis and subsequently protects the brain from endotoxic shock.

Preparation and characterization of alumina hollow fiber membranes

With the rapid development of membrane technology in water treatment,there is a growing demand for membrane products with high performance.The inorganic hollow fiber membranes are of great interest due to their high resistance to abrasion,chemical/thermal degradation,and higher surface area/volume ratio therefore they can be utilized in the fields of water treatment.In this study,the alumina(Al_(2)O_(3))hollow fiber membranes were prepared by a combined phase-inversion and sintering method.The organic binder solution(dope)containing suspended Al_(2)O_(3) powders was spun to a hollow fiber precursor,which was then sintered at elevated tempera-tures in order to obtain the Al_(2)O_(3) hollow fiber membrane.The dope solution consisted of polyethersulfone(PES),N-methyl-2-pyrrolidone(NMP)and polyvinylpyrrolidone(PVP),which were used as polymer binder,solvent and additive,respectively.The prepared Al_(2)O_(3) hollow fiber membranes were characterized by a scanning electron microscope(SEM)and thermal gravimetric analysis(TG).The effects of the sintering temperature and Al_(2)O_(3)/PES ratios on the morphological structure,pure water flux,pore size and porosity of the membranes were also investigated extensively.The results showed that the pure water flux,maximum pore size and porosity of the prepared membranes decreased with the increase in Al_(2)O_(3)/PES ratios and sintering temperature.When the Al_(2)O_(3)/PES ratio reached 9,the pure water flux and maximum pore size were at 2547L/m 2$h and 1.4μm,respectively.Under 1600℃ of sintering temperature,the pure water flux and maximum pore size reached 2398L/(m^(2)@h)and 2.3μm,respectively.The results showed that the alumina hollow fiber membranes we prepared were suitable for the microfiltration process.The morphology investigation also revealed that the prepared Al_(2)O_(3) hollow fiber membrane retained its’asymmetric structure even after the sintering process.

Batch Scheduling with Deteriorating Jobs to Minimize the Total Completion Time

We consider bounded parallel-batch scheduling with proportional-linear deteriorating jobs and the objective to minimize the total completion time.We give some properties of optimal schedules for the problem and present for it a dynamic programming algorithm running in O(b^(2)m^(2)2^(m))time,where b is the size of a batch and m is the number of distinct deterioration rates.

Electrospinning in membrane contactor:manufacturing Elec-PVDF/SiO2 superhydrophobic surface for efficient flue gas desulphurization applications

In membrane contactors,maintaining a high SO_(2)absorption flux and an excellent wetting resistance are crucial for hazardous gas removal.In this study,we adopted an electrospinning strategy to fabricate highly robust superhydrophobic dual-layer Elec-PVDF/SiO_(2)composite membrane contactors used for flue gas desulfurization.The composite membrane contactor consisted of a durable and ultrathin three-dimensional(3D)superhydrophobic surface and a porous supporting layer,where the formulation was optimized by regulating the PVDF concentration,solvent ratio and SiO_(2)particles content in electrospinning solution.The scanning electronic microscopy(SEM),EDS-mapping,water contact angle(WCA)and surface roughness of as-prepared Elec-PVDF/SiO_(2)composite membrane contactors were conducted to explore the physical and chemical structure.The SiO_(2)nanoparticles were uniformly loaded in ElecPVDF/SiO_(2)composite membrane contactor,and constructed micro-nano dual-coarse lotus-leaf-like morphology,which noticeably elevated surface roughness(Ra).The SiO_(2)nanoparticles also functioned as hydrophobic modifiers,which boosted the WAC up to 155.The SO_(2)absorption fluxes and SO_(2)removal efficiencies were investigated.In particular,the membrane contactor doped with 20 wt%SiO_(2)nanoparticles significantly elevated the stability of desulfurization performance.Besides,the membrane mass transfer coefficient(Km)and corresponding membrane mass transfer resistance(H/Km)were explored.

The Nord Stream pipeline gas leaks released approximately 220,000 tonnes of methane into the atmosphere

Sudden mega natural gas leaks of two Nord Stream pipelines in the Baltic Sea(Denmark)occurred from late September to early October 2022,releasing large amounts of methane into the atmosphere.We inferred the methane emissions of this event based on surface in situ observations using two inversion methods and two meteorological reanalysis datasets,supplemented with satellite-based observations.We conclude that approximately 220±30 Gg of methane was released from September 26 to October 1,2022.

Preparation and characterization of EVAL hollow fiber membrane adsorbents filled with cation exchange resins

EVAL hollow fiber membrane adsorbents filled with powder D061-type cation exchange resin were prepared through dry-wet spinning process,using hydrophilic copolymer EVAL as the fiber substrate.The microstructures of the membrane adsorbents were observed,and the pure water fluxes,BSA rejection,and static adsorption capacities of membrane adsorbents for BSA were measured.The effect of the resin-filled content on membrane performance has been discussed.The results showed that EVAL hollow fiber membrane adsorbents filled with D061-type cation exchange resins had good adsorption capacity,and the adsorption capacity increased with the quantity of the resin-filled content.The static protein adsorption capacity was 77.14 mg BSA/g membrane adsorbents when D061 resin loading content was 65%at pH 4.5.