Lignin-derived hard carbon anode with a robust solid electrolyte interphase for boosted sodium storage performance

Hard carbon is regarded as a promising anode candidate for sodium-ion batteries due to its low cost,relatively low working voltage,and satisfactory specific capacity.However,it still remains a challenge to obtain a high-performance hard carbon anode from cost-effective carbon sources.In addition,the solid electrolyte interphase(SEI)is subjected to continuous rupture during battery cycling,leading to fast capacity decay.Herein,a lignin-based hard carbon with robust SEI is developed to address these issues,effectively killing two birds with one stone.An innovative gas-phase removal-assisted aqueous washing strategy is developed to remove excessive sodium in the precursor to upcycle industrial lignin into high-value hard carbon,which demonstrated an ultrahigh sodium storage capacity of 359 mAh g^(-1).It is found that the residual sodium components from lignin on hard carbon act as active sites that controllably regulate the composition and morphology of SEI and guide homogeneous SEI growth by a near-shore aggregation mechanism to form thin,dense,and organic-rich SEI.Benefiting from these merits,the as-developed SEI shows fast Na+transfer at the interphases and enhanced structural stability,thus preventing SEI rupture and reformation,and ultimately leading to a comprehensive improvement in sodium storage performance.

Unveiling the pressure-driven metal–semiconductor–metal transition in the doped TiS_(2)

Conventional theories expect that materials under pressure exhibit expanded valence and conduction bands,leading to increased electrical conductivity.Here,we report the electrical properties of the doped 1T-TiS_(2) under high pressure by electrical resistance investigations,synchrotron x-ray diffraction,Raman scattering and theoretical calculations.Up to 70 GPa,an unusual metal-semiconductor-metal transition occurs.Our first-principles calculations suggest that the observed anti-Wilson transition from metal to semiconductor at 17 GPa is due to the electron localization induced by the intercalated Ti atoms.This electron localization is attributed to the strengthened coupling between the doped Ti atoms and S atoms,and the Anderson localization arising from the disordered intercalation.At pressures exceeding 30.5 GPa,the doped TiS_(2) undergoes a re-metallization transition initiated by a crystal structure phase transition.We assign the most probable space group as P2_(1)2_(1)2_(1).Our findings suggest that materials probably will eventually undergo the Wilson transition when subjected to sufficient pressure.

Characterizing the luminescent properties of upconversion nanoparticles in single and densely packed state

Luminescent properties of Er^(3+)-and Yb^(3+)-co-doped CaF_(2)upconversion nanoparticles(UCNPs)were investigated in single particle and densely-packed states with a custom-built microscope.The single UCNPs exhibit linear dependency of luminescent intensity on excitation power while the densely-packed UCNPs exhibit a 2-order power law-dependency indicating a two-photon absorption process.Time-domain luminescence intensity measurements were performed and the curves were fitted to excitationnemission rate functions based on a simplified three-state model.The results indicate that the intermediates in single particles are much less and saturated in a short time,and there are strong couplings of the ground states and intermediate states between neighboring UCNPs in densely packed UCNPs.

High-fidelity structured illumination microscopy by point-spread-function engineering

Structured illumination microscopy(SIM)has become a widely used tool for insight into biomedical challenges due to its rapid,long-term,and super-resolution(SR)imaging.However,artifacts that often appear in SIM images have long brought into question its fidelity,and might cause misinterpretation of biological structures.We present HiFi-SIM,a high-fidelity SIM reconstruction algorithm,by engineering the effective point spread function(PSF)into an ideal form.HiFi-SIM can effectively reduce commonly seen artifacts without loss of fine structures and improve the axial sectioning for samples with strong background.In particular,HiFi-SIM is not sensitive to the commonly used PSF and reconstruction parameters;hence,it lowers the requirements for dedicated PSF calibration and complicated parameter adjustment,thus promoting SIM as a daily imaging tool.

Effect of system response on partial surge initiated instability in a transonic axial flow compressor

Partial surge is a type of instability inception in transonic compressors and occurs in the form of axisymmetric low-frequency disturbances localized in the hub region.Previous studies illustrate that the frequency of partial surge is set by the Helmholtz frequency of the entire system,which motivates to propose a hypothesis that the system response performs an important role in the formation of partial surge.For further verification,a series of experiments are conducted to explore the link between the propagating of the partial surge and the system feedback in this study.In the first case,an additional test point is set on the wall of the plenum to detect the system response.Combining the flow behaviors inside the plenum with the disturbances in the rotor tip and stator hub/tip regions,the effects of the system feedback on the occurrence of the continuous disturbances and the rotating stall cells are illustrated.In the second case,a screen is mounted at the compressor outlet to prevent positive feedback from the plenum.The experimental results demonstrate that in the absence of system feedback,it is the occurrence of spike-type stall inception that leads to the flow instability instead of that of partial surge.In addition,three flow phenomena in the second case are discussed,including the occurrence of the single pulse,the unstable process during the stall evolution and the switch of instability inception.

Switchable microwave photonic filter using a phase modulator and a silicon-on-insulator micro-ring resonator

A switchable microwave photonic filter(MPF) using a phase modulator(PM) and a silicon-on-insulator microring resonator(MRR) is proposed and demonstrated. By adjusting the polarization controller between the PM and the MRR, the filtering function of the MPF can be switched between a band-stop filter and a band-pass filter. In a proof-of-concept experiment, an MPF with a rejection ratio of 30 dB(or 15 dB) for the band-stop(or band-pass) response and a frequency tuning range from 9.6 to 20.5 GHz is achieved.

Effects of the radial blade loading distribution and B parameter on the type of flow instability in a low-speed axial compressor

Previous studies showed that an axisymmetric hub-initiated disturbance defined as partial surge may initiate the stall of a transonic compressor; to reveal the instability evolution under full-span incompressible flow for different levels of hub loading and B parameter, an experimental investigation is conducted on a single-stage low-speed compressor. Experimental results show that under a uniform inflow condition without inlet flow distortion, a modal-type stall inception dominates in this low-speed compressor. When an inlet screen introducing hub distortion is used to increase the hub loading, a compressor stall is initiated by a modal wave, but large disturbances are present in the hub region before the compressor stall, which become stronger as the hub loading increases. Under high hub loading and large B parameter（implemented by adding hub distortion through an inlet screen and enlarging the outlet plenum volume, respectively）, a compressor stall is triggered by an axisymmetric hub-initiated disturbance, which is much different from the modal-like disturbances. The beginning of this axisymmetric disturbance may be captured over 800 rotor revolutions prior to the onset of stall, and the amplitude grows with time. The disturbance is hub-initiated because the disturbance signal at the hub is detected much earlier than that at the tip; meanwhile, the frequency of this axisymmetric disturbance changes with the length of the inlet duct. The characteristics of instability evolution in the low-speed compressor are also compared with those in a transonic compressor.

Multi-3D hierarchical biomass-based carbon particles absorber for solar desalination and thermoelectric power generator

To meet challenges of the global energy crisis and the freshwater resources shortage,the interfacial solarto-steam conversion(ISSC)system was developed quickly in recent years.The photothermal materials play an important role in the ISSC system.We are devoted to developing a unique photothermal material integrating multiple 3 D design philosophy both at macroscopic and microscopic levels by employing the cost-effective and widespread resources like straw,rose and coffee grounds,for carbonization as solar absorbers.The biomass-based carbonized particles(CPs)possess three major advantages:(1)wide sizedistribution is accessible to form 3 D porous rough surface of absorber layer to enhance ability of light absorption;(2)the pristine hierarchical microstructure could absorb nearly all the incident light;(3)the intrinsic vascular bundles with pores on their lumen walls provide a rapid and omnidirectional transport for water and steam escape.A high-efficient solar steam device was fabricated based on the absorber material with its internal 3 D micro textures and external 3 D architectures.Under the illumination of 1 sun,the photothermal conversion efficiency of straw,rose and coffee CPs can reach 93.4%,92.8% and 76%,respectively.Simultaneously,a high-efficient solar thermoelectric generator(STEG)is made by coating CPs on a commercial thermoelectric generator and the maximum power of STEG can reach 538.0μW.Such scalable biomass-based photothermal materials and high-grade thermoelectric conversion capability could be applied to the water purification and the electricity production.

On the Combinatorics of Fibonacci-Like Non-renormalizable Maps

In this paper,we extend Fibonacci unimodal map to a wider class.We describe the combinatorial property of thesemaps by first return map and principal nest.We give the sufficient and necessary condition for the existence of this class ofmaps.Moreover,for maps with’bounded combinatorics’,we prove that they have no absolutely continuous invariant probability measure when the critical order ι is sufficiently large;for maps with reluctantly recurrent critical point,we prove they have absolutely continuous invariant probability measure whenever the critical order ι>1.

Changing profile of lung cancer clinical characteristics in China:Over 8-year population-based study

Background:Although examinations and therapies for bronchial lung cancer,also called lung cancer(LC),have become more effective and precise,the morbidity and mortality of LC remain high worldwide.Describing the changing profile of LC characteristics over time is indispensable.This study aimed to understand the changes in real-world settings of LC and its characteristics in China.Methods:In this study,119,785 patients were enrolled from 2012 to 2020 in the Shanghai Pulmonary Hospital.The patients’medical records were extracted from the hospital’s database.Demographic characteristics,general clinicopathological information,and blood coagulation indices at the initial diagnoses were analyzed using the Kruskal-Wallis,Nemenyi,chi-squared,and Bonferroni tests.Changes in demographic characteristics during the 8-year study period,namely dynamic changes among different stages and different pathological types,were evaluated.Results:The percentages of female(from 38.50%[323/839]in 2012 to 48.29%[5112/10,585]in 2020)and non-smoking LC(from 69.34%[475/685]to 80.48%[8055/10,009])patients increased significantly during the study period,with a trend toward a younger age at diagnosis(from 3.58%[30/839]to 8.99%[952/10,585]).Over the study period,the proportion and absolute number of lung adenocarcinoma cases increased(from 67.97%[433/637]to 76.31%[6606/8657])while the proportion of lung squamous cell carcinoma decreased(from 21.19%[135/637]to 12.08%[1046/8657]).Comprehensive driver gene mutation examination became more common,and epidermal growth factor receptor(EGFR)mutation occurred more frequently in female vs.male(62.03%[12793/20625]vs.29.90%[8207/27,447])and non-smoking vs.smoking(53.54%[17,203/32,134]vs.23.73%[3322/13,997])patients(both P<0.001).The distribution of the common driver genes differed among different stages of LC.EGFR mutation was detected most frequently at each stage,and other driver gene alterations were more common in advanced stages(P<0.001).The combination of chemotherapy,targeted ther-apy,and immunotherapy,as a comprehensive management regimen,gradually became predominant over the study period(P<0.001).A hypercoagulable state was shown in advanced-stage LC patients and patients with the anaplastic lymphoma kinase fusion,indicated by significantly elevated levels of d-dimer,fibrinogen,and fibrinogen degradation products.Conclusions:This study comprehensively depicted the changing characteristics of Chinese LC patients over an 8-year period to provide preliminary insights into LC treatment.Trial registration:ClinicalTrials.gov,NCT05423236.

“视觉真实”的悖论:社交互动中截屏传播引发的伦理反思

作为社交互动的媒介化工具,截屏的广泛使用对人际交往、媒介实践及公共讨论产生了深刻影响,也带来了新的道德难题。本文在伦理学批判的视野下,借助康德的绝对命令、韦伯的责任伦理及罗尔斯的正义论对社交互动中的非理性截屏行为进行审视,并在马克思伦理学思想的指导下,指出过度截屏行为产生的根源及社会后果,提出在具体的情境中,要从责任、法治和技术三个维度,调适截屏所塑造的媒介环境和道德秩序,在截屏实践与社会正义的讨论中形成责任自觉的伦理共识,以应对互联网交往行为悖论的冲击。

天津女红类非遗助力乡村振兴

非遗的保护和传承对于生态文明的建设有着重要意义。为进一步振兴乡村文化生态,结合数字化手段在文化传播中的广泛应用,在生态文明视角下,以非遗的数字化传播为研究论题,选取天津女红类非遗为研究对象,充分结合乡土资源优势和时代特点,通过对天津女红文化特性和传播方式的深入分析,提出适宜乡村生态文明发展的非遗数字化传播策略,为非遗元素富足的地区实现乡村振兴提供理论支撑,为天津区域内创造良好的文化生态环境指明方向。

可逆阴离子氧化还原反应和结构演变的共生P2/O3双相钠离子电池层状氧化物正极设计和开发

层状氧化物因在钠离子电池正极中表现出的优异性能而引起了前所未有的关注,其中两种典型的P2和03型材料各具优势.因此,设计和开发包含P2和03材料的复合材料成为一种新的选择.但对这种具有多相结构的复杂正极材料的阴离子/阳离子的行为和结构演变过程的研究仍缺乏全面且深入的研究.本文基于两种典型的具有相同元素组成但不同的晶体结构的正极材料:P2型Na0.67Ni0.33Mn0.67O2和O3型NaNi0.5Mn0.5O2,开发了一种成分为Na0.732Ni0.273Mg0.096Mn0.63O2的双相材料,其中包含78.39 wt%的P2相和21.61 wt%的O3相.晶体结构分析和密度泛函理论(DFT)计算结果表明,该复合材料倾向于形成原子水平上的共生结构,且形成的双相结构的复杂晶格条纹可以阻止电极过程中过渡金属和氧原子迁移.相对于单相结构,双相结构提高了正极材料的储钠容量和稳定性,并增强了阴离子O2-/n-氧化还原的可逆性.此外,P2和O3结构共生的类异质结结构具有共享相边界,其形成的互锁效应可有效缓解P2和03结构在电极过程产生的晶格滑移和Na+离子脱出/嵌入的晶格应力.因此,共生的P2/03复合材料表现出较高的容量、较好的循环性能(0.1 C倍率下约有130 mAh g-1容量,循环200次后容量保持率为73.1%)和可逆的晶体结构转变.本文研究证实合理设计的双/多相正极可用于高能钠离子电池的应用.

Spectrum-optimized direct image reconstruction of super-resolution structured illumination microscopy

Super-resolution structured illumination microscopy(SR-SIM)has become a widely used nanoscopy technique for rapid,long-term,and multi-color imaging of live cells.Precise but troublesome determination of the illumination pattern parameters is a prerequisite for Wiener-deconvolution-based SR-SIM image reconstruction.Here,we present a direct reconstruction SIM algorithm(direct-SIM)with an initial spatial-domain reconstruction followed by frequency-domain spectrum optimization.Without any prior knowledge of illumination patterns and bypassing the artifact-sensitive Wiener deconvolution procedures,resolution-doubled SR images could be reconstructed by direct-SIM free of common artifacts,even for the raw images with large pattern variance in the field of view(FOV).Direct-SIM can be applied to previously difficult scenarios such as very sparse samples,periodic samples,very small FOV imaging,and stitched large FOV imaging.

Controlled preparation and characterization of nano-sized hexagonal Mg(OH)_2 flame retardant

Nano-sized hexagonal magnesium hydroxide （Mg（OH）2） with good dispersibility was synthesized by a double injection-hydrothermal method, utilizing polyvinylpyrrolidone （PVP） as an additive and with optimized processing parameters. SEM and BET analysis showed that the mean particle size and specific surface area of the Mg（OH）2 particles were 174 nm and 50.77 m^2/g, respectively. The FT-IR spectra and the XRD patterns showed that PVP was adsorbed on the surface of the Mg（OH）2 crystal, thus effectively limiting particle agglomeration and hindering crystal growth along the （1 01 ） plane. TGA showed a decrease in the decomposition temperature and an increase in the weight loss of the Mg（OH）2 particles due to addition of PV/.

A novel preparation of nanosized hexagonal Mg（OH）2 as a flame retardant

Nanosized dispersive hexagonal magnesium hydroxide （Mg（OH）2） has been prepared using an ammonia- hydrothermal method. Citric acid and monoethanolamine （MEA） were added to the reaction system during the ammonia precipitation and hydrothermal processes, respectively, to improve the crystallinity and dispersion of the （Mg（OH）2） particles. The resulting Mg（OH）2 samples obtained under the opti- mum preparation conditions were characterized by scanning electron microscopy, X-ray diffraction and thermal gravity analysis, which showed that this newly developed procedure afforded well-dispersed hexagonal nanoolates of Mg（OH）2 with a mean diameter of 246 nm.

Detection and quantitative analysis of tumor-associated tertiary lymphoid structures

Tumor-associated tertiary lymphoid structures(TLSs)are ectopic lymphoid formations within tumor tissue,with mainly B and T cell populations forming the organic aggregates.The presence of TLSs in tumors has been strongly associated with patient responsiveness to immunotherapy regimens and improving tumor prognosis.Researchers have been motivated to actively explore TLSs due to their bright clinical application prospects.Various studies have attempted to decipher TLSs regarding their formation mechanism,structural composition,induction generation,predictive markers,and clinical utilization.Meanwhile,the scientific approaches to qualitative and quantitative descriptions are crucial for TLS studies.In terms of detection,hematoxylin and eosin(H&E),multiplex immunohistochemistry(mIHC),multiplex immunofluorescence(mIF),and 12-chemokine gene signature have been the top approved methods.However,no standard methods exist for the quantitative analysis of TLSs,such as absolute TLS count,analysis of TLS constituent cells,structural features,TLS spatial location,density,and maturity.This study reviews the latest research progress on TLS detection and quantification,proposes new directions for TLS assessment,and addresses issues for the quantitative application of TLSs in the clinic.

China-CIMMYT collaboration enhances wheat improvement in China

China and CIMMYT have collaborated on wheat improvement for over 40 years and significant progress has been achieved in five aspects in China.A standardized protocol for testing Chinese noodle quality has been established with three selection criteria, i.e.,gluten quality, starch viscosity and flour color are identified as being responsible for noodle quality.Genomic approaches have been used to develop and validate genespecific markers, leading to the establishment of a KASP platform, and seven cultivars have been released through application of molecular marker technology.Methodology for breeding adult-plant resistance to yellow rust, leaf rust and powdery mildew, based on the pleiotropic effect of minor genes has been established, resulting in release of six cultivars.More than 330 cultivars derived from CIMMYT germplasm have been released and are now grown over 9% of the Chinese wheat production area.Additionally, physiological approaches have been used to characterize yield potential and develop high-efficiency phenotyping platforms.CIMMYT has also provided valuable training for Chinese scientists.Development of climate-resilient cultivars with application of new technology will be the priority for future collaboration.

QoE-Driven DASH Multicast Scheme for 5G Mobile Edge Network

Dynamic adaptive streaming over HTTP(DASH)can adaptively select the appropriate video bitrate for mobile users.Mobile edge computing(MEC)scenario is of great benefit to improve the performance of mobile networks by providing computing and storage capabilities.And the utilization of spectrum resources can be improved by multicast transmission,but the performance of the multicast transmission will be directly affected by the selected grouping algorithm and resource allocation algorithm.In order to improve the quality of experience(QoE)of video users in the 5G MEC scenario,this paper proposes a QoE-driven DASH multicast scheme,which mainly covers the grouping algorithm and the adaptive bitrate(ABR)algorithm.First of all,we take the optimized target QoE as the basis for grouping and propose an adaptive grouping algorithm that can dynamically adjust the grouping results.Besides,we design a joint optimization ABR algorithm based on the prediction of QoE,which comprehensively considers the process of resource allocation and bitrate decision-making based on the prediction of QoE of video segments in a certain forward-looking field of view.The simulation results show that the proposed DASH multicast scheme performs well in QoE and fairness.

Factors Associated with SARS-CoV-2 Repeat Positivity—Beijing,China,June–September 2020

Introduction:Repeat positive severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)following COVID-19 initial viral clearance(repositivity)poses a public health management challenge.The objective was to determine factors associated with neutralizing antibody(Nab)level and re-positivity among patients infected with a single strain SARS-CoV-2.Methods:During a single strain SARS-CoV-2 cluster in Beijing,China,longitudinal individual clinical,virological,and immunological data were collected from 368 infections from June 13 to September 22,2020.Factors associated with Nab level and re-positivity were analyzed using generalized estimating equations.Results:A total of 353(96%)SARS-CoV-2 infections had demographic,clinical,and laboratory data available.Among the 353 infections,55(15.5%)were re-positive,and blood draws were taken from 346 individuals(98.0%)during hospitalization and/or during the follow-up period.Symptoms were milder for the second-time admission for the re-positives,although 36.4%of re-positives presented with radiographic appearance of pneumonia manifestation.Compared to non-re-positive patients,NAb titers were lower among re-positives;NAb was positively associated with clinical severity.Samples from the lower respiratory tract manifested higher viral load than that from the upper respiratory tract.Multivariable analysis showed re-positivity was positively associated with being female[odd ratio(OR)=1.7,95%confidence interval(CI)1.1–2.8]and being aged<18 years(OR=5.2,95%CI 1.5–18.1);having initially asymptomatic infection(OR=13.7,95%CI 1.6–116.3);and negatively associated with a higher NAb level(OR=0.9,95%CI 0.5–1.7).Conclusions:NAb may be important for sustained viral clearance.Lower respiratory tract infection was associated with higher viral load among all infections when compared to upper respiratory tract infection.Continuous lower respiratory and intermittent upper respiratory viral shedding among COVID-19 infections may occur.