Adhesion of Technical Lignin-Based Non-Isocyanate Polyurethane Adhesives for Wood Bonding

Lignin is the most abundant aromatic natural polymer,and receiving great attention in replacing various petro-leum-based polymers.The aim of this study is to investigate the feasibility of technical lignin as a polyol for the synthesis of non-isocyanate polyurethane(NIPU)adhesives to substitute current polyurethane(PU)adhesives that have been synthesized with toxic isocyanate and polyols.Crude hardwood kraft lignin(C-HKL)was extracted from black liquor from a pulp mill followed by acetone fractionation to obtain acetone soluble-HKL(AS-HKL).Then,C-HKL,AS-HKL,and softwood sodium lignosulfonate(LS)were used for the synthesis of technical lignin-based NIPU adhesives through carbonation and polyamination and silane as a cross-linker.Their adhesion per-formance was determined for plywood.FTIR spectra showed the formation of urethane bonds and the reaction between lignin and silane.The NIPU adhesives prepared with C-HKL showed the highest adhesion strength among the three lignin-based NIPU adhesives.As the silane addition level increased,the adhesion strength of NIPU adhesives increased whereas formaldehyde emission decreased for all NIPU adhesives prepared.These results indicate that NIPU adhesives based on technical kraft lignin have a great potential as polyol for the synth-esis of bio-based NIPU adhesives for wood bonding.

Analysis of wheel-rail adhesion redundancy considering the thirdbody medium on the rail surface

Purpose–In response to the problem of insufficient traction/braking adhesion force caused by the existence of the third-body medium on the rail surface,this study aims to analyze the utilization of wheel-rail adhesion coefficient under different medium conditions and propose relevant measures for reasonable and optimized utilization of adhesion to ensure the traction/braking performance and operation safety of trains.Design/methodology/approach–Based on the PLS-160 wheel-rail adhesion simulation test rig,the study investigates the variation patterns of maximum utilized adhesion characteristics on the rail surface under different conditions of small creepage and large slip.Through statistical analysis of multiple sets of experimental data,the statistical distribution patterns of maximum utilized adhesion on the rail surface are obtained,and a method for analyzing wheel-rail adhesion redundancy based on normal distribution is proposed.The study analyzes the utilization of traction/braking adhesion,as well as adhesion redundancy,for different medium under small creepage and large slip conditions.Based on these findings,relevant measures for the reasonable and optimized utilization of adhesion are derived.Findings–When the third-body medium exists on the rail surface,the train should adopt the low-level service braking to avoid the braking skidding by extending the braking distance.Compared with the current adhesion control strategy of small creepage,adopting appropriate strategies to control the train’s adhesion coefficient near the second peak point of the adhesion coefficient-slip ratio curve in large slip can effectively improve the traction/braking adhesion redundancy and the upper limit of adhesion utilization,thereby ensuring the traction/braking performance and operation safety of the train.Originality/value–Most existing studies focus on the wheel-rail adhesion coefficient values and variation patterns under different medium conditions,without considering whether the rail surface with different medium can provide sufficient traction/braking utilized adhesion coefficient for the train.Therefore,there is a risk of traction overspeeding/braking skidding.This study analyzes whether the rail surface with different medium can provide sufficient traction/braking utilized adhesion coefficient for the train and whether there is redundancy.Based on these findings,relevant measures for the reasonable and optimized utilization of adhesion are derived to further ensure operation safety of the train.

Oxalate regulates crystal-cell adhesion and macrophage metabolism via JPT2/PI3K/AKT signaling to promote the progression of kidney stones

Oxalate is an organic dicarboxylic acid that is a common component of plant foods.The kidneys are essential organs for oxalate excretion,but excessive oxalates may induce kidney stones.Jupiter microtubule associated homolog 2(JPT2)is a critical molecule in Ca^(2+)mobilization,and its intrinsic mechanism in oxalate exposure and kidney stones remains unclear.This study aimed to reveal the mechanism of JPT2 in oxalate exposure and kidney stones.Genetic approaches were used to control JPT2 expression in cells and mice,and the JPT2 mechanism of action was analyzed using transcriptomics and untargeted metabolomics.The results showed that oxalate exposure triggered the upregulation of JPT2,which is involved in nicotinic acid adenine dinucleotide phosphate(NAADP)-mediated Ca^(2+)mobilization.Transcriptomic analysis revealed that cell adhesion and macrophage inflammatory polarization were inhibited by JPT2 knockdown,and these were dominated by phosphatidylinositol 3-kinase(PI3K)/AKT signaling,respectively.Untargeted metabolomics indicated that JPT2 knockdown inhibited the production of succinic acid semialdehyde(SSA)in macrophages.Furthermore,JPT2 deficiency in mice inhibited kidney stones mineralization.In conclusion,this study demonstrates that oxalate exposure facilitates kidney stones by promoting crystal-cell adhesion,and modulating macrophage metabolism and inflammatory polarization via JPT2/PI3K/AKT signaling.

Development of a cell adhesion-based prognostic model for multiple myeloma:Insights into chemotherapy response and potential reversal of adhesion effects

Multiple myeloma(MM)is a hematologic malignancy notorious for its high relapse rate and development of drug resistance,in which cell adhesion-mediated drug resistance plays a critical role.This study integrated four RNA sequencing datasets(CoMMpass,GSE136337,GSE9782,and GSE2658)and focused on analyzing 1706 adhesionrelated genes.Rigorous univariate Cox regression analysis identified 18 key prognosis-related genes,including KIF14,TROAP,FLNA,MSN,LGALS1,PECAM1,and ALCAM,which demonstrated the strongest associations with poor overall survival(OS)in MM patients.To comprehensively evaluate the impact of cell adhesion on MM prognosis,an adhesion-related risk score(ARRS)model was constructed using Lasso Cox regression analysis.The ARRS model emerged as an independent prognostic factor for predicting OS.Furthermore,our findings revealed that a heightened cell adhesion effect correlated with tumor resistance to DNA-damaging drugs,protein kinase inhibitors,and drugs targeting the PI3K/Akt/mTOR signaling pathway.Nevertheless,we identified promising drug candidates,such as tirofiban,pirenzepine,erlotinib,and bosutinib,which exhibit potential in reversing this resistance.In vitro,experiments employing NCIH929,RPMI8226,and AMO1 cell lines confirmed that MM cell lines with high ARRS exhibited poor sensitivity to the aforementioned candidate drugs.By employing siRNA-mediated knockdown of the key ARRS model gene KIF14,we observed suppressed proliferation of NCIH929 cells,along with decreased adhesion to BMSCs and fibronectin.This study presents compelling evidence establishing cell adhesion as a significant prognostic factor in MM.Additionally,potential molecular mechanisms underlying adhesion-related resistance are proposed,along with viable strategies to overcome such resistance.These findings provide a solid scientific foundation for facilitating clinically stratified treatment of MM.

Diamond-Like Carbon Depositing on the Surface of Polylactide Membrane for Prevention of Adhesion Formation During Tendon Repair

Post-traumatic peritendinous adhesion presents a significant challenge in clinical medicine.This study proposes the use of diamond-like carbon(DLC)deposited on polylactic acid(PLA)membranes as a biophysical mechanism for anti-adhesion barrier to encase ruptured tendons in tendon-injured rats.The results indicate that PLA/DLC composite membrane exhibits more efficient anti-adhesion effect than PLA membrane,with histological score decreasing from 3.12±0.27 to 2.20±0.22 and anti-adhesion effectiveness increasing from 21.61%to 44.72%.Mechanistically,the abundant C=O bond functional groups on the surface of DLC can reduce reactive oxygen species level effectively;thus,the phosphorylation of NF-κB and M1 polarization of macrophages are inhibited.Consequently,excessive inflammatory response augmented by M1 macrophage-originated cytokines including interleukin-6(IL-6),interleukin-1β(IL-1β),and tumor necrosis factor-α(TNF-α)is largely reduced.For biocompatibility evaluation,PLA/DLC membrane is slowly absorbed within tissue and displays prolonged barrier effects compared to traditional PLA membranes.Further studies show the DLC depositing decelerates the release of degradation product lactic acid and its induction of macrophage M2 polarization by interfering esterase and PLA ester bonds,which further delays the fibrosis process.It was found that the PLA/DLC membrane possess an efficient biophysical mechanism for treatment of peritendinous adhesion.

Near-zero-adhesion-enabled intact wafer-scale resist-transfer printing for high-fidelity nanofabrication on arbitrary substrates

There is an urgent need for novel processes that can integrate different functional nanostructures onto specific substrates,so as to meet the fast-growing need for broad applications in nanoelectronics,nanophotonics,and fexible optoelectronics.Existing direct-lithography methods are difficult to use on fexible,nonplanar,and biocompatible surfaces.Therefore,this fabrication is usually accomplished by nanotransfer printing.However,large-scale integration of multiscale nanostructures with unconventional substrates remains challenging because fabrication yields and quality are often limited by the resolution,uniformity,adhesivity,and integrity of the nanostructures formed by direct transfer.Here,we proposed a resist-based transfer strategy enabled by near-zero adhesion,which was achieved by molecular modification to attain a critical surface energy interval.This approach enabled the intact transfer of wafer-scale,ultrathin-resist nanofilms onto arbitrary substrates with mitigated cracking and wrinkling,thereby facilitating the in situ fabrication of nanostructures for functional devices.Applying this approach,fabrication of three-dimensional-stacked multilayer structures with enhanced functionalities,nanoplasmonic structures with~10 nm resolution,and MoS2-based devices with excellent performance was demonstrated on specific substrates.These results collectively demonstrated the high stability,reliability,and throughput of our strategy for optical and electronic device applications.

Overview of the Synthesis, Characterization, and Application of Tannin-Glyoxal Adhesive for Wood-Based Composites

More than a century after its initial synthesis,urea-formaldehyde(UF)resins still have dominant applications as adhesives,paints,and coatings.However,formaldehyde in this industry produces formaldehyde emissions that are dangerous to health.Scientists have spent the last decade replacing formaldehyde and phenol with environmentally friendly substances such as glyoxal and tannin to create bio-based adhesives.This review covers recent advances in synthesizing glyoxal tannin-based resins,especially those made from sustainable raw material substitutes and changes made to synthetic processes to improve mechanical properties.The efficacy of using tannin-glyoxal adhesives in producing wood-based composites has been proven.The glyoxylate reaction forms cross-linked bridges between the aromatic sites of the tannin and glyoxal molecular structures.Glyoxal tannin adhesive with a greater percentage of glyoxal than tannin will produce an adhesive with better characteristics.The gel time reduces as the hardener concentration rises from 7.5%to 15%when glyoxal is used in adhesives.However,excessive amounts of glyoxal will result in a decrease in viscosity values.Glyoxal exhibits faster delivery degradation when it reaches a maximum temperature of approximately 130°C,although it initiates the curing process slightly slower at 110°C.Adding glyoxal to tannin-based adhesives can improve the mechanical properties of composite boards.The wet shear strength of the resulting plywood is increased by 105.4%with the addition of 5-weight percent tannin-based resin with glyoxal as a cross-linker in Soy Protein Adhesive.With glyoxal as a hardener,the panels produced showed good internal bond strengths(>0.35 MPa)and met the international standard specifications for interior-grade panels.

Adhesion strength of tetrahydrofuran hydrates is dictated by substrate stiffness

Understanding the hydrate adhesion is important to tackling hydrate accretion in petro-pipelines.Herein,the relationship between the Tetrahydrofuran(THF)hydrate adhesion strength(AS)and surface stiffness on elastic coatings is systemically examined by experimental shear force measurements and theoretical methods.The mechanical factor-elastic modulus of the coatings greatly dictates the hydrate AS,which is explained by the adhesion mechanics theory,beyond the usual factors such as wettability and structural roughness.Moreover,the hydrate AS increases with reducing the thickness of the elastic coatings,resulted from the decrease of the apparent surface elastic modulus.The effect of critical thickness for the elastic materials with variable elastic modulus on the hydrate AS is also revealed.This study provides deep perspectives on the regulation of the hydrate AS by the elastic modulus of elastic materials,which is of significance to design anti-hydrate surfaces for mitigation of hydrate accretion in petro-pipelines.

正常小鼠血清通过抑制focal adhesion信号通路减轻小鼠放射性肺炎

目的探讨正常小鼠血清(NMS)对放射性肺炎的治疗作用及可能机制。方法建立胸腔照射诱导的放射性肺炎模型,将小鼠分为对照组、静脉注射血清组、照射组和照射后静脉注射血清组。注射血清组小鼠在照射后立即静脉注射正常小鼠血清100μL,对照组小鼠注射100μL生理盐水,隔天注射1次,共注射8次。照射后15 d取材,HE染色检测肺组织形态学变化,ELISA检测小鼠肺组织和血清中炎症因子肿瘤坏死因子-α(TNF-α)、转化生长因子-β(TGF-β)、白细胞介素-1α(IL-1α)、白细胞介素-6(IL-6)水平;流式细胞术检测肺组织内淋巴细胞比例变化。外泌体miRNA高通量测序探索处理后小鼠的信号通路变化,qRT-PCR检测免疫相关基因的表达水平,使用Western blotting检测黏着斑通路talin-1、tensin 2、FAK、vinculin、α-actinin和paxillin蛋白的表达。结果与照射组相比,照射后注射血清组小鼠肺脏器系数、血清及肺组织上清液中炎症因子TNF-α、TGF-β、IL-1α、IL-6水平显著降低(P<0.05),CD45^(+)、CD4^(+)、T_(reg)淋巴细胞在小鼠肺组织中的浸润程度显著下降(P<0.05);肺中Egfr和Pik3cd的mRNA和蛋白表达水平显著下调,talin-1、tensin 2、FAK、vinculin、α-actinin和paxillin蛋白的表达水平也显著降低(P<0.05)。结论正常小鼠血清通过抑制focal adhesion信号通路关键蛋白的表达减轻电离辐射诱发的小鼠放射性肺炎。

Mussel-inspired Methacrylic Gelatin-dopamine/Ag Nanoparticles/Graphene Oxide Hydrogels with Improved Adhesive and Antibacterial Properties for Applications as Wound Dressings

A novel strategy was developed to prepare the methacrylic gelatin-dopamine(GelMA-DA)/Ag nanoparticles(NPs)/graphene oxide(GO) composite hydrogels with good biocompatibility,mechanical properties,and antibacterial activity.Mussel-inspired DA was utilized to modify the GelMA molecules,which imparts good adhesive performance to the hydrogels.GO,interfacial enhancer,not only improves mechanical properties of the hydrogels,but also provides anchor sites for loading Ag NPs through numerous oxygencontaining functional groups on the surface.The experimental results show that the GelMA/Ag NPs/GO hydrogels have good biocompatibility,and exhibit a swelling rate of 202±16%,the lap shear strength of 147±17 kPa,and compressive modulus of 136±53 kPa,in the case of the Ag NPs/GO content of 2 mg/mL.Antibacterial activity of the hydrogels against both gram-negative and gram-positive bacteria is dependent on the Ag NPs/GO content derived from the release of Ag^(+).Furthermore,the GelMA/Ag NPs/GO hydrogels possess good adhesive ability,which is resistant to highly twisted state when stuck on the surface of pigskin.These results demonstrate promising potential of the GelMA-DA/Ag NPs/GO hydrogels as wound dressings for biomedical applications in clinical and emergent treatment.

Coupling of Adhesion and Anti‑Freezing Properties in Hydrogel Electrolytes for Low‑Temperature Aqueous‑Based Hybrid Capacitors

Solid-state zinc-ion capacitors are emerging as promising candidates for large-scale energy storage owing to improved safety,mechanical and thermal stability and easy-to-direct stacking.Hydrogel electrolytes are appealing solid-state electrolytes because of eco-friendliness,high conductivity and intrinsic flexibility.However,the electrolyte/electrode interfacial contact and anti-freezing properties of current hydrogel electrolytes are still challenging for practical applications of zinc-ion capacitors.Here,we report a class of hydrogel electrolytes that couple high interfacial adhesion and anti-freezing performance.The synergy of tough hydrogel matrix and chemical anchorage enables a well-adhered interface between hydrogel electrolyte and electrode.Meanwhile,the cooperative solvation of ZnCl2 and LiCl hybrid salts renders the hydrogel electrolyte high ionic conductivity and mechanical elasticity simultaneously at low temperatures.More significantly,the Zn||carbon nanotubes hybrid capacitor based on this hydrogel electrolyte exhibits low-temperature capacitive performance,delivering high-energy density of 39 Wh kg^(-1)at-60°C with capacity retention of 98.7%over 10,000 cycles.With the benefits of the well-adhered electrolyte/electrode interface and the anti-freezing hydrogel electrolyte,the Zn/Li hybrid capacitor is able to accommodate dynamic deformations and function well under 1000 tension cycles even at-60°C.This work provides a powerful strategy for enabling stable operation of low-temperature zinc-ion capacitors.

Preparation of Environmentally Friendly Urea-Hexanediamine-Glyoxal(HUG)Resin Wood Adhesive

Using non-toxic,low-volatile glyoxal to completely replace formaldehyde for preparing urea-glyoxal(UG)resin adhesive is a hot research topic that could be of great interest for the wood industry.However,urea-glyoxal(UG)resins prepared by just using glyoxal instead of formaldehyde usually yields a lower degree of polymerization.This results in a poorer bonding performance and water resistance of UG resins.A good solution is to pre-react urea to preform polyurea molecules presenting already a certain degree of polymerization,and then to condense these with glyoxal to obtain a novel UG resin.Therefore,in this present work,the urea was reacted with hexamethylene diamine to form a polyurea named HU,and then this was used to react it with different amounts of glyoxal to synthesize hexamethylenediamine-urea-glyoxal(HUG)polycondensation resins,and to use this for bonding plywood.The results show that the glyoxal can well react with HU polyuria via addition and schiff base reaction,and also the HUG resin exhibits excellent bonding strength and water resistance.The shear strength of the plywood bonded with this HUG at 160°C hot press temperature as high as 1.93 MPa,2.16 MPa and 1.61 MPa,respectively,which meets the requirement of the China national standard GB/T 9846-2015(≥0.7 MPa),and can be a good choice as a wood adhesive for industrial application.

The Clinical Value of Ultrasound Image Texture Analysis in the Diagnosis of Uterine Adhesions

Purpose: This review examines the diagnostic value of transvaginal 3D ultrasound image texture analysis for the diagnosis of uterine adhesions. Materials and Methods: The total clinical data of 53 patients with uterine adhesions diagnosed by hysteroscopy and the imaging data of transvaginal three-dimensional ultrasound from the Second Affiliated Hospital of Chongqing Medical University from June 2022 to August 2023 were retrospectively analysed. Based on hysteroscopic surgical records, patients were divided into two independent groups: normal endometrium and uterine adhesion sites. The samples were divided into a training set and a test set, and the transvaginal 3D ultrasound was used to outline the region of interest (ROI) and extract texture features for normal endometrium and uterine adhesions based on hysteroscopic surgical recordings, the training set data were feature screened and modelled using lasso regression and cross-validation, and the diagnostic efficacy of the model was assessed by applying the subjects’ operating characteristic (ROC) curves. Results: For each group, 290 texture feature parameters were extracted and three higher values were screened out, and the area under the curve of the constructed ultrasonographic scoring model was 0.658 and 0.720 in the training and test sets, respectively. Conclusion Relative clinical value of transvaginal three-dimensional ultrasound image texture analysis for the diagnosis of uterine adhesions.

Polyurethane Hybrid-Based Wood Adhesive: Review

Based on commercially available polyvinyl alcohol (PVA) stabilised polyvinyl acetate (PVAc), emulsion adhesives are neither heat nor moisture-resistant and show weak strength at high relative humidity and high temperatures. Pre- or post-crosslinking is another method used to manufacture a conventional vinyl-based homopolymers or copolymers system with improved water resistance. Vinyl neodecanoate (VeoVa), N-methylolacrylamide (NMA), Methacrylamide, methacrylic acid (MAA), and other self-crosslinking comonomers are typically inserted to produce highly water-resistant vinyl based homopolymers or copolymers. Additionally, organic crosslinkers like glyoxal, glutaraldehyde, citric acid, tartaric acid, and the like, as well as inorganic crosslinkers like acidic metal salts like aluminium chloride, aluminium nitrate, boric acid, and the like, can be used to prepare the highly water-resistant vinyl based homopolymers or copolymers. It is also possible to combine the self-crosslinking comonomers with the organic crosslinkers. Recently, a different hybrid chemistry has been developed that improves lap shear strength, has outstanding water resistance, good durability, and doesn’t require any additional crosslinker agents. Two distinct polymers were combined to develop hybrid polymers. They usually involve mixing an organic polymer with a polymer. There are many capping agents that are used for polyurethanes to produce acrylics that are capped with polyurethane and used as an oligomer in PVAc wood glue. Here, in this paper, we reviewed the different hybrid chemistry based on polyurethane chemistry for wood bonding applications.

Polyvinyl Acetate and Vinyl Acetate-Ethylene Hybrid Adhesive: Synthesis, Characterization, and Properties

The goal is to develop a hybrid IPN network of polyvinyl acetate (PVAc) and ethylene-vinyl acetate (VAE). In this research work, the vinyl acetate (VAc)/ VAE hybrid emulsion and polyvinyl acetate emulsion (PVAc) were effectively synthesized. Emulsions with various characteristics have been developed by adjusting the weight ratios between the vinyl acetate monomer and the VAE component. The impacts on the mechanical, thermal, and physical properties of the films were investigated using tests for pencil hardness, tensile shear strength, pH, contact angle measurement, differential scanning calorimetry (DSC), and viscosity. When 5.0 weight percent VAE was added, the tensile shear strength in dry conditions decreased by 18.75% after a 24-hour bonding period, the heat resistance decreased by 26.29% (as per WATT 91) and the tensile shear strength decreased by approximately 36.52% in wet conditions (per EN 204). The pristine sample’s results were also confirmed by the contact angle test. The interpenetrating network (IPN) formation in hybrid PVAc emulsion as primary bonds does not directly attach to PVAc and VAE chains. The addition of VAE reduced the mechanical properties (at dry conditions) and heat resistance as per WATT 91. Contact angle analysis demonstrated that PVAc adhesives containing VAE had increased water resistance when compared to conventional PVA stabilised PVAc homopolymer-based adhesives. When compared to virgin PVAc Homo, the water resistance of the PVAc emulsion polymerization was enhanced by the addition of VAE.

A Boron-based Adhesion Aid for Efficient Bonding of Silicone Rubber and Epoxy Resin

We improved the adhesion between silicon based insulating materials and epoxy resin composites by adding the adhesion promoter cycloborosiloxane(BSi,cyclo-1,3,3,5,7,7-hexaphenyl-1,5-diboro-3,7-disiloxane).The experimental results show that the addition of BSi in the silicone rubber(SR)system significantly increases the tensile shear strength between BSi and epoxy resin(EP),reaching 309%of the original value.On this basis,the mechanism of BSi to enhance the adhesion effect was discussed.The electron deficient B in BSi attracted the electron rich N and O in EP to enhance the chemical interaction,combined with the interfacial migration behavior in the curing process,to improve the adhesion strength.This study provides the design and synthesis ideas of adhesive aids,and a reference for further exploring the interface mechanism of epoxy resin matrix composites.

Adjusting the interfacial adhesion via surface modification to prepare high-performance fibers

Ultra-high molecular weight polyethylene(UHMWPE)fiber is a new kind of high-performance fiber.Due to its excellent physical and chemical characteristics,it is widely used in various fields.However,the surface UHMWPE fiber is smooth and demonstrates no-polar groups.The weak interfacial adhesion between fiber and resin seri-ously restricts the applications of UHMWPE fiber.Therefore,the surface modification treatments of UHMWPE fiber are used to improve the interfacial adhesion strength.The modified method by adding nanomaterials elu-cidates the easy fabrication,advanced equipment and proper technology.Thus,the progress of UHMWPE nanocomposite fibers prepared via adding various nanofillers are reviewed.Meanwhile,the effects of other various methods on surface modification are also reviewed.This work advances the various design strategies about nano technologies on improving interfacial adhesion performance via treatment methodologies.

Silk fibroin-based biopolymer composite binders with gradient binding energy and strong adhesion force for high-performance micro-sized silicon anodes

Micro-sized silicon anodes have shown much promise in large-scale industrial production of high-energy lithium batteries.However,large volume change(>300%)of silicon anodes causes severe particle pulverization and the formation of unstable solid electrolyte interphases during cycling,leading to rapid capacity decay and short cycle life of lithium-ion batteries.When addressing such issues,binder plays key roles in obtaining good structural integrity of silicon anodes.Herein,we report a biopolymer composite binder composed of rigid poly(acrylic acid)(PAA)and flexible silk fibroin(SF)tailored for micro-sized silicon anodes.The PAA/SF binder shows robust gradient binding energy via chemical interactions between carboxyl and amide groups,which can effectively accommodate large volume change of silicon.This PAA/SF binder also shows much stronger adhesion force and improved binding towards high-surface/defective carbon additives,resulting in better electrochemical stability and higher coulombic efficiency,than conventional PAA binder.As such,micro-sized silicon/carbon anodes fabricated with novel PAA/SF binder exhibit much better cyclability(up to 500 cycles at 0.5 C)and enhanced rate capability compared with conventional PAA-based anodes.This work provides new insights into the design of functional binders for high-capacity electrodes suffering from large volume change for the development of nextgeneration lithium batteries.

Enhancing surface adhesion of polytetrafluoroethylene induced by two-step in-situ treatment with radiofrequency capacitively coupled Ar/Ar+CH_(4)+NH_(3) plasma

Although some progress in plasma modification of the polytetrafluoroethylene(PTFE) surface has been made recently,its adhesion strength still needs to be further improved.In this work,the surface of a PTFE sample was treated with a two-step in-situ method.Firstly,the PTFE surface was treated with capacitively coupled Ar plasma to improve its mechanical interlocking performance;then,Ar+NH_(3)+CH_(4) plasma was used to deposit an a-CNx:H cross-linking layer on the PTFE surface to improve the molecular bonding ability.After treatment,a high specific surface area of 2.20 and a low F/C ratio of 0.32 were achieved on the PTFE surface.Its surface free energy was increased significantly and its maximum adhesion strength reached77.1 N·10 mm^(-1),which is 56% higher than that of the single-step Ar plasma-treated sample and32% higher than that of the single-step Ar+CH_(4)+NH_(3) plasma-treated sample.

水资源-能源-粮食-生态系统耦合协调及驱动力分析

为加深对我国水资源、能源、粮食、生态系统协同演变趋势的认识,构建水资源-能源-粮食-生态多维系统指标体系,运用耦合协调度模型对我国2005—2020年水资源-能源-粮食-生态系统耦合协调度进行评价,并采用多因素归因分析法进行驱动力分析。结果表明:我国水资源-能源-粮食-生态系统耦合协调度从2005年的0.55增长到2020年的0.84,各地区耦合协调度从勉强协调发展水平过渡到中级协调发展水平,各子系统对耦合协调度上升的驱动分别经历了由粮食子系统到生态子系统再到水资源子系统主导的过程;能源子系统的贡献率虽然比较小,但是未来可能是各地区提升水资源-能源-粮食-生态系统多维系统协调发展水平的突破口。