A supramolecular self-assembly material based on cucurbituril and cationic TPE as ultra-sensitive probe of energetic pentazolate salts

The successful synthesis of the pentazolate anion(cyclo-N-5)has been a great breakthrough in the field of energetic materials.However,the detection methods for these energetic materials based on the pentazolate anion are quite rare.Herein,two fluorescent probes for cyclo-N-5anion were designed.Sensor 1(TPE2N)was synthesized with a tetraphenylethylene functionalized by two cationic groups which can generate strong electrostatic interactions with pentazolate anion and result in specific fluorescent changes.Sensor 2 was designed based on sensor 1 and supramolecular cucurbit[7]uril(CB[7]).The unique structural features of CB[7]provide sites for the interaction between the cations and N-5anion in its cavity,which would generate a platform for the detection and enhance the recognition performance.Isothermal titration calorimetry(ITC)experiment and fluorescence titration experiment indicate the binding molar ratio between sensor 1 with CB[7]is 1:2.Both sensors display typical aggregation-induced emission(AIE)features and good water-solubility.The sensors demonstrate excellent sensitivity to pentazole hydrazine salt with high enhancement constant(sensor 1:1.34×10^(6);sensor 2:3.78×10^(6))and low limit of detection(LOD:sensor 1=4.33μM;sensor 2=1.54μM).The formation of an AIE-based supramolecular sensor effectively improves the sensitivity to N-5anion.In addition,the probes also have good selectivity of N-5anion salts.The research would shed some light on the design of novel fluorescent sensors to detect pentazolate-based molecules and provides an example of supramolecular chemistry combined with fluorescent probes.

社会资本影响教育获得的四种范式

教育获得是社会科学研究的重要内容之一,社会资本对教育获得的影响日益受到重视。本文通过深度梳理社会资本对教育获得影响的理论和实证研究成果,归纳分析了“网络资源”范式、“社会闭合”范式、“群体资源”范式和“宏观社会资本”范式对教育获得的影响。在评析以往研究的基础上,倡导拓展社会资本影响教育获得的研究范式,用人类发展生态系统理论统筹社会资本影响教育获得的研究,关注个体教育获得的主体性和建构性,发掘教育获得的研究维度与结合多种研究方法进行多样化适切性的研究,以期更好地为教育公平实践提供借鉴。

光学技术在气体浓度检测中的应用

阐述了目前气体浓度检测的7种常用光学方法,针对每种光学方法给予了详细的原理说明,列举了各种光学方法现场应用中的优缺点,以及针对光学方法优缺点所做的改进工作,提出了方法改进中的新颖想法,讨论了各种光学方法的结合使用。这其中包括常规光学气体浓度检测方法:光干涉法、光声光谱法、相关光谱法;以及新型光学气体浓度检测方法:可调谐半导体激光吸收光谱法、倏逝场型光纤气体传感法、空芯光子带隙光纤传感法、光纤环衰荡光谱法。结论指出,小型化、智能化、便携式、低功耗、高准确度、快速响应性及分布式多组分遥测技术成为现阶段光学法检测气体浓度的发展趋势。

Composite surfactants aided solvothermal synthesis and catalytic hydrogenation property of oil soluble bimetallic CoMoS nanoparticles

Oil-soluble bimetallic CoMoS nanoparticles were successfully synthesized by a composite-surfactants-aided-solvothermal process.The surface hydrophilicity and functionality of the products were investigated through transmission electron microscopy （TEM）,Fourier transform infrared （FTIR） spectra,and Ultraviolet （UV） spectra analysis.The catalytic performance of hydrogenation on the CoMoS nanoparticles was studied with naphthalene as a model compound.It was found that CoMoS catalysts supported on active carbon （AC） was more active than conventional MoS2/γ-Al2O3.The activity of CoMoS/AC can be tailored through the change of the Co/（Co＋Mo） atomic ratio.

Bioinspired strategies for biomimetic actuators from ultrafast to ultraslow

Motile plant tissues can control their configurations and regulate their motion speed according to their specific requirements,which offer various protypes for biomimetic actuators with controlled motion speed.In this perspective,we focus on the speed control of plant tissues and the bioinspired strategies for speed regulation of artificial actuators.We begin with a summary to the strategies and mechanisms of motile plant tissues for controlling motion speed,ranging from ultrafast to ultraslow.We then exemplify the models for fabricating bioinspired artificial actuators and briefly discuss current application scenarios of actuators with varying speeds from ultrafast to ultraslow.Finally,we propose potential strategies for the speed regulation of actuators.

Environment-adaptive phase-separation-porous fluorofilm for highperformance passive radiation cooling

Passive radiative cooling is widely recognized as an environmentally sustainable method for achieving significant cooling effects.However,the mechanical properties and environmental adaptability of current radiative cooling materials are not sufficient to maintain high cooling performance in external environments.Here we reported an environment-adaptive phase-separation-porous fluorofilm for high-performance passive radiation cooling.Compared to the homogenous fluoro-porous network with limited scattering efficiencies,we modulated the porous structure of the fluorofilm to achieve a strong emissivity of 95.2%(8-13μm)and a high reflectivity of 97.1%(0.3-2.5μm).The fluorofilm demonstrates a temperature drop of 10.5°C and an average cooling power of 81 W·m^(−2)under a sunlight power of 770 W·m^(−2).The high mechanical performance and environmental adaptability of fluorofilms are also exhibited.Considering its significant radiative cooling capability and robust environmental adaptability,the fluorofilm is expected to have a promising future in radiative temperature regulation.

A mechanically stable self-pumping organohydrogel dressing with aligned microchannels for accelerated diabetic wound healing

Self-pumping dressings(SPDs)have been developed as a new type of effective material for the drainage of excessive wound exudates based on the structure of asymmetric wettability.However,current SPDs are easy to lose their asymmetric wettability due to the weak interfacial mechanical stability between the hydrophobic and hydrophilic layers.Herein,we report an integrated self-pumping organohydrogel dressing with aligned microchannels(SPD-AM),prepared by an ice-templating-assisted wetting-enabled-transfer(WET)polymerization strategy,that can accelerate the healing process of diabetic wounds.The WET polymerization strategy enables strong interfacial mechanical stability between the hydrophobic organogel and hydrophilic hydrogel layers.The aligned microchannels greatly improve the draining capability of SPDs.Taking a diabetic rat model as an example,the SPD-AM can significantly reduce the bacterial colonization with low inflammatory responses,enhance dermal remodeling by about 47.31%,and shorten wound closure time by about 1/5 compared with other dressings,ultimately accelerating diabetic wound healing.This study is valuable for developing next-generation SPDs with stable mechanical performance for clinical applications.

Wettability-driven synergistic resistance of scale and oil on robust superamphiphobic coating

Disgusting deposits(e.g.,scale and crude oil)in daily life and industrial production are always serious problems,posing great threats to the safety and economic development.However,most of developed coatings can only conquer one part of these deposits such as superhydrophobic coatings possess antiscaling capacity but would adhere crude oil.To integrate scale resistance with oil repellence,we herein report a robust superamphiphobic(SAB)coating simultaneously reducing pollution of scale and oil for extended period of time(two weeks with over 98%reduction).Compared with single role of superhydrophobic and amphiphilic surfaces,the SAB coating can not only inhibit interfacial nucleation of scale but also reduce the adhesion of formed scale and polluted oil.The durability of the SAB coating is evaluated via mechanical tests(sandpaper abrasion,tape stripping and sand falling)and chemical corrosion(corrosive liquid immersing),revealed by sustainable high contact angles and low contact angle hysteresis of water and oil.The universality of this strategy can be further confirmed by adding different particles like kaolin,Al_(2)O_(3),and SiO_(2),resisting multiple types of scale(i.e.,CaSO_(4),BaSO_(4)and MgCO_(3))and oil(i.e.,glycerol,glycol,and mineral oil).Therefore,this study provides an ideal avenue for resisting scale and oil,which may be used for conquering the complexity of application environments(e.g.,oil production and transportation).

Carbon dots-enhanced pH-responsive lubricating hydrogel based on reversible dynamic covalent bondings

Due to the various pH liquid environment in nature,the pH-responsive lubricating hydrogel is widely investigated and developed for tissue interface substitute.However,the applied liquid environment will lead to poor mechanical property and weaken the pH-responsive capability.In this work,a carbon dotsenhanced pH-responsive lubricating hydrogel is developed by combining a pH-responsive section of dynamic PVA-borax network into a PAAm covalent polymer network.The formed hydrogel presents a partial gel-sol transition under controlled pH environments.At low pH environments(<6.0),the formed lubricating layer originated from dynamic disassembly of PVA-borax hydrogel,and brings the lubricating properties on the hydrogel surface.Moreover,the mechanical strength and lubrication properties are well promoted by introducing the carbon dots into the hydrogel,the blue sol layer can be observed more visually under the fluorescence microscope.The pH-response also exhibits well reversibility.The prepared hydrogel broadens the idea for designing pH-responsive soft materials for soft lubricating actuator or robot.

Fully umbilical cord-derived adhesive materials enable to recruit and segregate immune cells for the reversal of acute liver failure

Inflammatory cytokine storms can trigger disease exacerbation and even death and have reached a consensus in the clinical treatment of acute organ failure.However,the existing strategies remain a great challenge to efficiently suppress inflammatory cytokine storms for promoting organ repair and regeneration.Herein,fully human umbilical cord(UC)-derived adhesive materials(UCAM)that integrate decellularized extracellular matrix(ECM)nanofiber hydrogel and homologous mesenchymal stem cells(MSCs)are demonstrated to greatly suppress inflammatory cytokine storms,demonstrating high efficacy in treating acute liver failure(ALF)in rats with 90%hepatectomy.The UC-derived adhesive materials have the capacity to secrete a significant quantity of cytokines by MSCs to recruit activated immune cells to migrate into their ECM nanofiber networks,segregating them away from the infection area and thereby greatly suppressing the inflammatory cytokine storms.As expected,the UC-derived adhesive materials can significantly promote hepatocyte proliferation to achieve functional recovery and regeneration of the liver,significantly improving the survival rate in rats.Our fully human UC-derived adhesive materials provide a new avenue in suppressing inflammatory cytokine storms for promoting organ regeneration that would be really utility in clinical organ transplantation-related treatment.

Water-Excluding Underwater Glue Induced by Marangoni Effect

Marangoni effect at the two-phase interface with different surface tension as a unique mass transfer phenomenon has been widely used in daily life and industrialmanufacture.However,their marvelous liquid-driving capability between miscible liquids has long been ignored,especially in water environments.Here,we first reveal a distinct underwater Marangoni effect between the solvent of glues and the water layer on solid surfaces.Driven by the Marangoni effect,organic solvents with water solubility,high dielectric constant,and low diffusivity could effectively exclude the interfacial water layer,enabling direct and effective contact between glues and solid surfaces.Our experimental results and theoretical simulation proved that a relatively large ratio of the Marangoni number in the horizontal direction and to the vertical direction ensured an effective underwater adhesion of the water-excluding glue.This surface engineering approach provides an alternative to the traditional methods of molecular engineering for realizing underwater adhesion.

数字化转型助推中国式教育现代化:内在逻辑与发展路径

伴随第三轮技术革命的发展进程,通过数字化转型推动教育变革愈来愈成为国际国内社会的迫切需求。数字化转型是中国式教育现代化的一个重要维度,其重塑教育要素及关系,全方位影响教育方式、教育治理、教育功能、教育价值和教育理念,从而形成微观人与人、中观人与社会、宏观人与国家、宇观人与世界良好互动的教育新形态,推动我国教育走向现代化创生发展之路。在此过程中,数字化转型也不可避免地给中国式教育现代化带来诸多潜在和现实风险,可能异化教育主体全面自由发展、危及教育伦理生活、模糊教育治理责任、引发文明发展藩篱。因此,在享受数字化转型为教育带来巨大便利的同时,也必须关注数字逻辑与教育逻辑的对峙与抵牾,认识到数字化转型的限度与可能,以融合共生、伦理规约、公平负责、自主包容作为教育数字化转型的价值新方向,推动中国式教育现代化走向新发展阶段。

Supramolecular Semi-convertible Hydrogel Enabled Self-Healing Responsive Lubrication Under Dynamic Shearing

Cartilage-inspired hydrogel has attracted great interest due to its tunable mechanics and low friction.However,it is incapable of self-healing under a complex dynamic shearing environment.In this work,a self-healing semi-convertible hydrogel(SHSCH)is developed,which can recover its unique active lubricating function under shearing.Based on the cooperating strategy of noncovalent and covalent bonding,the SHSCH is composed of three interpenetrated networks including:(1)shearresponsive N-fluorenylmethoxycarbonyl-L-tryptophan(FT)supramolecular network,(2)self-healing polyhydroxyethyl acrylamide(PHEAA)network,and(3)rigid polyvinyl alcohol(PVA)covalent network.The shearresponsive lubricating function and mechanical property can be self-healed under a shearing environment through the noncovalent hydrogen-bonding assembly of PHEAA associated by theπ–πassembly of FT.The asdeveloped SCH provides a self-healing model comparable with traditional self-healing lubricating materials through encapsulating lubricant microcapsules or infusing lubricants onto surfaces.We demonstrated a proofof-concept of the self-healing lubrication of a simplified artificial worn cartilage model under a dynamic shearing condition.This study will offer a potential strategy on designing the self-healing soft devices under dynamic stimuli far beyond the lubricating materials.

Building block copolymer particles via self‐assembly within a droplet

The self‐assembly of block copolymers(BCPs)within emulsion droplets is a flexible strategy for the preparation of polymer particles.This strategy permits the finetuning of shapes,internal structures,and surface nanostructures of the polymer particles,thus allowing many applications.Although some literature has reviewed the BCP preparation via self‐assembly within a droplet,a comprehensive summary including in‐depth understanding,controllable preparation,and application is lacked.In this review,we systematically delve into the multiple mechanisms that drive BCP self‐assembly within emulsion droplets,such as commensurability effects for minimizing total free energy,interfacial instability,organized spontaneous emulsification,phase separation of multiple components,and entropy effects between BCPs and nanoparticles.Additionally,a strategy combining selective cross‐linking and disassembly can further generate Janus particles featuring unique structures.Next,various applications across multiple disciplines are discussed,including drug delivery,display,biomedical imaging,macromolecular separation,and fuel cells.Finally,we present an overview of the current challenges and future directions for BCP emulsion self‐assembly,covering mechanism investigation,molecular design,stability control,and application exploration.We anticipate deeper understanding,more varieties,enhanced performance,and broader applications can be achieved with BCP emulsion self‐assembly after addressing the challenge.

数字技术赋能城乡义务教育共治:理论机理与实现路径

数字技术赋能城乡义务教育共治引发了教育治理的结构性变革,使得城乡义务教育治理模式从城镇学校单向输出资源走向城乡学校双向共治,治理关系从城镇学校治理权力主导走向城乡学校间对话治理,治理效率从城乡学校间低效输出转化走向精准高效算法治理。通过对数字技术赋能城乡义务教育共治进行价值透视,结合巴纳德社会协作理论对数字技术赋能城乡义务教育共治的理论机理进行分析,发现数字技术赋能所产生的城乡义务教育信息资源流动是达成共治目的与生成协作意愿的核心支撑,城乡义务教育一体化与个性化发展的治理目的有机统一是共治的必要前提,积极稳定的协作意愿是共治的内生动力和必要保障,三者有机统一才能构建系统协作的教育共治体系。基于此,在未来数字技术赋能城乡义务教育共治的过程中,应立足“一体化”顶层设计,多种数字技术组合联通共治信息流动渠道;强调“异质性”互补共进,多角色治理者平等协作融通共治边界;促进“共同体”合力升级,互镜式发展凝聚共治系统共同精神。

Cell adhesive spectra along surface wettability gradient from superhydrophilicity to superhydrophobicity

Surface wettability is important to design biointerfaces and fimctional biomaterials in various biological applications. However, to date, it remains some confusions about how cells would response to the surfaces with different wettabilities. Herein, we systematically explore the adhesive spectra of cells to the surface with wettability gradient from superhydrophilicity to superhydrophobicity, clarifying the effect of wettability on cell adhesion. We envision that this study may provide valuable information for the design of biomedical implants with controllable cell adhesion, such as neural interface devices and flexible implant.

Recent Progress of Mussel-Inspired Underwater Adhesives

Underwater adhesion is greatly desired in tissue transplantation, medical treatment, ocean transportation, and so on. However, common commercial polymeric adhesives are rather weakened and easily destroyed in water envi- ronment. In nature, some marine organisms, such as mussels, barnacles, or tube worms, exhibiting excellent under- water adhesion up to robust bonding on the rock of sea floor, can give exciting solutions to address the problem. Among these marine organisms, mussels exhibit unique underwater adhesion via the foot proteins of byssus. It has been verified that the catechol groups from the side chain of the mussel foot proteins is the main contribution to the unique underwater adhesion. Hence, inspired by the mussels＇ underwater adhesion, many mussel-mimetic polymers with catechol as end chains or side chains have been developed in the past decades. Here, we review recent progress of mussel-inspired underwater adhesives polymers from their catechol-functional design to their potential applica- tions in intermediates, anti-biofouling, self-healing of hydrogels, biological adhesives, and drug delivery. The re- view may provide basis and help for the development of the commercial underwater adhesives.

Nonswellable hydrogels with robust micro/nano-structures and durable superoleophobic surfaces under seawater

Hydrogels, composed mainly of water trapped in three dimensional cross-linked polymer networks, have been widely utilized to construct underwater superoleophobic surfaces. However, the swelling nature and instability of hydrogels under complex marine environment will weaken their underwater superoleophobicity. Herein, we synthesize structured poly （2-hydroxyethylmethacrylate） （PHEMA） hydrogels by using sandpaper as templates. The robust non-swelling of PHEMA hydrogel ensures that micro/nano-structures on the surface of PHEMA hydrogels can be well maintained. Moreover, when roughness Ra of about 3-4 bun, the surface has superior oil-repellency. Additionally, even after immersing in seawater for one-month, their breaking strength and toughness can be well kept. The non-swellable hydrogels with long-term stable under seawater superoleophobicity will promote the development of robust superoleophobic materials in marine antifouling coatings, biomedical devices and oil/water separation.

Preface

Multiply robust inference has attracted much attention recently in the context of missing response data. An estimation procedure is multiply robust, if it can incorporate information from multiple candidate models, and meanwhile the resulting estimator is consistent as long as one of the candidate models is correctly specified. This property is appealing, since it provides the user a flexible modeling strategy with better protection against model misspecification. We explore this attractive property for the regression models with a binary covariate that is missing at random. We start from a reformulation of the celebrated augmented inverse probability weighted estimating equation, and based on this reformulation, we propose a novel combination of the least squares and empirical likelihood to separately handle each of the two types of multiple candidate models,one for the missing variable regression and the other for the missingness mechanism. Due to the separation, all the working models are fused concisely and effectively. The asymptotic normality of our estimator is established through the theory of estimating function with plugged-in nuisance parameter estimates. The finite-sample performance of our procedure is illustrated both through the simulation studies and the analysis of a dementia data collected by the national Alzheimer's coordinating center.

Engineering subcellular-patterned biointerfaces to regulate the surface wetting of multicellular spheroids

Studying the wetting behaviors of multicellular spheroids is crucial in the fields of embryo implantation, cancer propagation, and tissue repair. Existing strategies for controlling the wetting of multicellular spheroids mainly focus on surface chemistry and substrate rigidity. Although topography is another important feature in the biological micro-environment, its effect on multicellular spheroid wetting has seldom been explored. In this study, the influence of topography on the surface wetting of multicellular spheroids was investigated using subcellular- patterned opal films with controllable colloidal particle diameters （from 200 to 1,500 nm）. The wetting of hepatoma carcinoma cellular （Hep G2） spheroids was impaired on opal films compared with that on flat substrates, and the wetting rate decreased as colloidal particle diameter increased. The decrement reached 48.5% when the colloidal particle diameter was 1,500 nm. The subcellular-patterned topography in opal films drastically reduced the cellular mobility in precursor films, especially the frontier cells in the leading edge. The frontier cells failed to form mature focal adhesions and stress fibers on micro-patterned opal films. This was due to gaps between colloidal particles leaving adhesion vacancies, causing weak cell-substrate adhesion and consequent retarded migration of Hep G2 spheroids. Our study manifests the inhibiting effects of subcellular-patterned topography on the wetting behaviors of multicellular spheroids, providing new insight into tissue wetting-associated treatments and biomaterial design.