High mechanical strength Si anode synthesis with interlayer bonded expanded graphite structure for lithium-ion batteries

Despite advancements in silicon-based anodes for high-capacity lithium-ion batteries,their widespread commercial adoption is still hindered by significant volume expansion during cycling,especially at high active mass loadings crucial for practical use.The root of these challenges lies in the mechanical instability of the material,which subsequently leads to the structural failure of the electrode.Here,we present a novel synthesis of a composite combining expanded graphite and silicon nanoparticles.This composite features a unique interlayer-bonded graphite structure,achieved through the application of a modified spark plasma sintering method.Notably,this innovative structure not only facilitates efficient ion and electron transport but also provides exceptional mechanical strength(Vickers hardness:up to658 MPa,Young's modulus:11.6 GPa).This strength effectively accommodates silicon expansion,resulting in an impressive areal capacity of 2.9 mA h cm^(-2)(736 mA h g^(-1)) and a steady cycle life(93% after 100cycles).Such outsta nding performance is paired with features appropriate for large-scale industrial production of silicon batteries,such as active mass loading of at least 3.9 mg cm^(-2),a high-tap density electrode material of 1.68 g cm^(-3)(secondary clusters:1.12 g cm^(-3)),and a production yield of up to 1 kg per day.

Force-Regulated Adhesion and Activation Study of Integrin Targeting Polypeptides

Integrins are heterodimeric cell surface receptors that bind to ligands on another cell,e.g.intercellular adhesion molecule 1(ICAM-1),or the extracellular matrix.Integrins play an important role in immune system,and they participate in inflammation,thrombosis,and proliferation,migration and apoptosis of tumor cells.They mediate adhesion and transduce signals across the membrane usually under the influence of forces.A recent study has shown that integrins bind and activate transforming growth factorβisoform(TGF-β)which is involved in tumor suppression and growth,and blocking the binding of TGF-βto integrin can inhibit tumor growth.RGD(arginine-glycine-aspartate)small peptide,which competitively inhibits ligand binding to integrins,has been approved as an injectable drug.However,when the RGD is used to block cancer-related extracellular signaling pathways,it will also cause activation of integrins for a period,and stimulate the transduction of intracellular signals constantly.Therefore,it is necessary to explore for new drugs that can selectively control conformational state of integrins without activating or blocking all of them.In this study,we selected two small peptides,KQAGDV and RTDLDSLRT,that combined with integrins and do not contain an RGD sequence.The non-RGD polypeptide RTDLDSLRT has been reported to have a binding site with integrins and the binding affinity is on nanomolar scale.For the motif of the fibrinogen y chain C-terminal KQAGDV,it can adhere to the head of the integrins.The micropipette aspiration technique and electron microscopy techniques were used to study the adhesion and activation of integrins by peptides,respectively.Micropipette aspiration technique was used to investigate the adhesion frequency of peptide and integrin on Jurkat cell.The pressure system was used to supply a controllable negative pression to the microtube,and two micropipettes were used to absorb red blood cells and Jurkat cells,respectively.The red blood cells were coated with small peptides and can serve as a force sensor after being sucked when two cells were connected.The binding kinetics of integrin and peptides interactions was determined by fitting the curves constructed using adhesion probability between two cells as a function of time.The curves were fitted using a small system probabilistic kinetic model to estimate a pair of kinetic parameters,including the zero force reverse rate kr0,and the cellular binding affinity Acmrm1Ka0.The adhesion frequency yielded P(t)=75%and 57%for RGD and KQAG DV peptides,respectively.We obtained Acmrm1Ka0=1.40 and kr0=0.32 s-1,for RGD,and Acmrm1Ka0=0.85 and kr0=0.54 s-1 for KQAGDV.The RGD peptide has a higher adhesion frequency and lower dissociation rate than the KQAGDV peptide.Electron microscopy techniques was used to observe the activation of integrins by peptides.Jurkat cell expressing integrins was bound to a magnetic bead and bottom plate which were coated with different integrin-binding peptides.Then,we manipulated the beads in a controlled direction by changing the magnetic field nearby,and the forces were applied to the cell.The target cells were fixed and then observed by scanning electron microscope or transmission electron microscope.Jurkat cells contain abundant flexible microvilli of which there are many parallel bundles of actin filaments inside.By electron microscopy analysis,the cell connected with magnetic bead coated with RGD were found to be protruded and the size of microvilli increased up to#-fold of the length of the KQAGDV sample.The microvilli exhibited a curved agglomerate structure under a force-free condition.Moreover,a higher proportion of cells were activated in the presence of RGD than KQAGDV.In conclusion,the binding affinity of KQAGDV to integrin is weaker than RGD,and KQAGDV can bind with integrins effectively with a lower activated proportion.Our results indicate the peptides may selectively bind to integrins without activating them.

堆肥对重金属污染的水稻根际土壤细菌群落的剂量依赖性影响

在复合重金属污染的水稻土壤中分别添加1%、5%和10%(质量分数)的堆肥,150 d后观察土壤微生物群落的结构和组成变化。研究发现,堆肥对根际细菌群落的影响表现出剂量依赖效应。低等(1%)和中等(5%)堆肥添加量对根际细菌群落结构的影响比对非根际细菌群落的影响更大。根际土壤细菌多样性在添加堆肥后明显低于非根际土壤细菌多样性。冗余分析(RDA)结果表明,根际和非根际细菌群落对土壤理化性质(如p H、Pb、Cd和Cu含量)变化的响应不同,可能是根际和非根际细菌群落差异的原因之一。因此,在农业管理中应该考虑堆肥的施加对根际微生物的影响。

降钙素原指导抗菌药物临床合理应用的研究进展

降钙素原是具有较高的灵敏度和特异性的细菌感染炎症性指标之一。它在指导慢性阻塞性肺疾病、呼吸道感染、脓毒血症、外科手术感染等领域的抗菌药物合理应用方面,展现出了良好的应用前景。临床观察发现,它指导感染性疾病的治疗时,有效缩短抗菌药物使用时间,减少抗菌药物的使用量。

微纳米WC-10Co4Cr涂层在NaCl介质中的抗泥沙冲蚀性能研究

采用超音速火焰喷涂(HVOF)工艺制备了微纳米、纳米和普通结构WC-10Co4Cr金属陶瓷涂层,测量了涂层的显微硬度、孔隙率和开裂韧性,分析了三种WC-10Co4Cr涂层在3.5wt%NaCl溶液中的腐蚀电位和腐蚀电流密度,研究了喷涂层在NaCl介质中的抗泥沙冲蚀性能,并探讨了涂层在NaCl介质中的泥沙冲蚀机理。结果表明:微纳米WC-10Co4Cr涂层具有最优异的电化学性能;相比于纳米、微米涂层,微纳米涂层的抗泥沙冲蚀磨损性能分别提高了38%和78%。微纳米WC-10Co4Cr涂层致密的组织结构、高显微硬度(1126HV0.3)和高开裂韧性(4.66MPa·m1/2)有效减弱了泥沙冲蚀过程中的机械冲刷作用和电化学腐蚀作用。

纳米WC增强Ni基合金喷熔层在不同介质中抗泥浆冲蚀性能研究

采用氧乙炔火焰喷熔工艺制备了Ni60CuMo和纳米WC增强Ni60CuMo两种Ni基合金喷熔层,采用XRD、SEM方法分析了喷熔层的组织结构,测量了喷熔层的硬度和电化学性能;研究了两种喷熔层在淡水和3.5wt.%NaCl介质中的抗泥浆冲蚀磨损性能。结果表明,纳米WC增强Ni60CuMo合金喷熔层的组织结构为纳米WC呈块状均匀镶嵌在γ相固溶体和Cr23C6、Cr7C3等硬质相之间,形成弥散强化,使其硬度提高了约13%;纳米WC增强的Ni基合金喷熔层在3.5wt.%NaCl介质中比Ni60CuMo喷熔层具有更低的腐蚀电位与更高的腐蚀电流密度,它在淡水和3.5wt.%NaCl介质中的抗泥浆冲蚀磨损性能分别比Ni60CuMo喷熔层提高了约53%和20%。纳米WC的加入显著提高了Ni基合金喷熔层的抗泥浆冲蚀性能,但在3.5wt.%NaCl介质中,由于WC与NiCr合金之间形成了大量微电池,加速了喷熔层的腐蚀磨损,使其抗泥浆冲蚀性能的增强效果受到削弱。

Bi_(2)S_(3) for Aqueous Zn Ion Battery with Enhanced Cycle Stability

Aqueous Zn ion batteries(ZIBs)are promising in energy storage due to the low cost,high safety,and material abundance.The development of metal oxides as the cathode for ZIBs is limited by the strong electrostatic forces between O2−and Zn2+which leads to poor cyclic stability.Herein,Bi2S3 is proposed as a promising cathode material for rechargeable aqueous ZIBs.Improved cyclic stability and fast diffusion of Zn2+is observed.Also,the layered structure of Bi2S3 with the weak van der Waals interaction between layers offers paths for diffusion and occupancy of Zn2+.As a result,the Zn/Bi2S3 battery delivers high capacity of 161 mAh g−1 at 0.2 A g−1 and good cycling stability up to 100 cycles with ca.100%retention.The battery also demonstrates good cyclic performance of ca.80.3%over 2000 cycles at 1 A g−1.The storage mechanism in the Bi2S3 cathode is related to the reversible Zn ion intercalation/extraction reactions and the capacitive contribution.This work indicates that Bi2S3 shows great potential as the cathode of ZIBs with good performance and stability.

Metal Organic framework derived carbon for ultrahigh power and long cyclic life aqueous Zn ion capacitor

In order to develop functional energy storage device,it is necessary to improve the energy and power density.As a potential candidate that can synergistically harmonize energy and power density,lithium ion capacitor(LIC)has shown exciting promises in recent years.However,in the recent years,alternative metal has been explored to replace lithium in such metal-ion capacitor system.Hence,in this work we present zinc ion capacitor(ZIC)in which zinc acts as negative electrode and Metal Organic framework(MOF)derived carbon as positive electrode.The assembled ZIC was able to demonstrate exceptional power density of 85.5 kW kg^-1 and a maximal energy density of 36.4W h kg^-1,together with 99%capacitance retention after cycling for 20000 cycles.

Direct ink writing of programmable functional silicone-based composites for 4D printing applications

Polydimethylsiloxane(PDMS)has been widely used in flexible electronics,soft robotics,and bioelectronics.However,the fabrication of PDMS-based devices has mostly relied on conventional approaches,such as casting and molding,thereby limiting their potential.Here we fabricate PDMS-based composites with programmable microstructures by direct ink writing and realize their practical functionalities of four-dimensional(4D)printing.The mechanical,thermomechanical and magnetic properties of the three-dimensional-printed composites can be well tailored by using carbon,metal,or ceramic functional fillers.By taking advantage of the printable,flexible,and magnetic PDMS composites,we demonstrate new practical functionalities of 4D printing by designing programmable architectures,including magnetic-field-driven battery cases and patchworks,as well as arbitrary morphing ceramic structures.In particular,4D-printed batteries are constructed by PDMS-based battery cases for the first time,which can be actuated via external magnetic field.This study broadens the paradigm of 4D printing for prospective applications,such as implant batteries,biomimetic engineering,and customized biomedical devices.

振动工况下粗颗粒垂直管道水力提升特性

该文采用CFD-DEM耦合方法,建立了适用于振动工况下的粗颗粒垂直管道水力提升数值模型,并针对粗颗粒水力提升特性开展了数值模拟研究,详细分析了振动频率及幅度对颗粒速度、浓度分布、碰撞及能量损失等特性的影响。研究结果表明:管道的振动使管内两相流特性呈与振动强度相对应的周期性变化;随着振动强度的增加,颗粒提升速度整体呈降低趋势,浓度分布表现出明显的波动性与不对称性,碰撞次数、能量损失及管道压力损失相应增加,为垂直管道中颗粒的提升带来不利影响。

Metal-organic frameworks for advanced drug delivery

Metal-organic frameworks(MOFs),comprised of organic ligands and metal ions/metal clusters via coordinative bonds are highly porous,crystalline materials.Their tunable porosity,chemical composition,size and shape,and easy surface functionalization make this large family more and more popular for drug delivery.There is a growing interest over the last decades in the design of engineered MOFs with controlled sizes for a variety of biomedical applications.This article presents an overall review and perspectives of MOFs-based drug delivery systems(DDSs),starting with the MOFs classification adapted for DDSs based on the types of constituting metals and ligands.Then,the synthesis and characterization of MOFs for DDSs are developed,followed by the drug loading strategies,applications,biopharmaceutics and quality control.Importantly,a variety of representative applications of MOFs are detailed from a point of view of applications in pharmaceutics,diseases therapy and advanced DDSs.In particular,the biopharmaceutics and quality control of MOFs-based DDSs are summarized with critical issues to be addressed.Finally,challenges in MOFs development for DDSs are discussed,such as biostability,biosafety,biopharmaceutics and nomenclature.

High He-ion irradiation resistance of CrMnFeCoNi high-entropy alloy revealed by comparison study with Ni and 304SS

High entropy alloys(HEAs) have presented potential applications in nuclear power plants owing to their novel atomic structure based high irradiation resistance. However, understanding of He-ion irradiation of HEAs is still lacking. In this work, we reveal He-ion irradiation resistance of HEA CrMnFeCoNi by comparison study with a pure Ni and a 304 stainless steel(304SS). It is found that the damage structure in the three materials can be characterized with He bubbles and stacking faults/stacking fault tetrahedrons((SFs/SFTs), which show a similar depth distribution after He-ion irradiation at both RT and 450℃.Although the He bubbles have a similar size about 2nm after irradiation at RT, the He bubble sizes of the HEA, 304SS, and Ni increase to 4.0±0.9,5.3±1.0 and 6.7 ±1.0 nm after irradiation at 450℃, respectively. Moreover, the density of SFs/SFTs displays in an order of Ni < 304 SS < HEA at both RT and 450℃.The He-ion irradiation at RT causes significant hardness enhancement for the three materials, however,compared to RT, after irradiation at 450℃, the Ni presents softening, while the 304SS, especially the HEA,shows further hardening. Thus, the HEA CrMnFeCoNi possesses the smallest He bubble size, the densest SFs/SFTs, and the highest hardening, indicating the best structural stability, as well as the best He-ion irradiation resistance, which can be attributed to its low mobility of He atoms and point defects.

Faceted Kurdjumov-Sachs interface-induced slip continuity in the eutectic high-entropy alloy,AlCoCrFeNi_(2.1)

Recently,the eutectic high-entropy alloy(EHEA),AlCoCrFeNi_(2.1),can reach a good balance of strength and ductility.The dual-phase alloy exhibits a eutectic lamellar microstructure with large numbers of interfaces.However,the role of the interfaces in plastic deformation have not been revealed deeply.In the present work,the orientation relationship(OR)of the interfaces has been clarified as the Kurdjumov-Sachs(KS)interfaces presenting〈111〉_(B2) 〈110〉_(FCC)and {110} _(B2){111}_(FCC) independent of their morphologies.There exist three kinds of interfaces in the EHEA,namely,The dominating interface and the secondary interface are both non-slip planes and atomistic-scale faceted,facilitating the nucleation and slip transmission of the dislocations.The formation mechanism of the preferred interfaces is revealed using the atomistic geometrical analysis according to the criteria of the low interfacial energy based on the coincidence-site lattice(CSL)theory.In particular,the ductility of the dual-phase alloy originates from the KS interface-induced slip continuity across interfaces,which provides a high slip-transfer geometric factor.Moreover,the strengthening effect can be attributed to the interface resistance for the dislocation transmission due to the mismatches of the moduli and lattice parameters at the interfaces.

Atomic scale structure dominated FCC and B2 responses to He ion irradiation in eutectic high-entropy alloy AlCoCrFeNi_(2.1)

Radiation-tolerant materials are widely desired in nuclear reactors. High-entropy alloys(HEAs) exhibiting superior mechanical performance and swelling tolerance are being considered as next-generation nuclear structural materials. However, an understanding of HEAs irradiation tolerance at an atomic scale is still lacking. In this study, the atomic scale irradiation response of AlCoCrFeNi_(2.1), composed of face-centered cubic(FCC) phase and B2 phase, has been systematically investigated at 298 and 723 K. The bubble volume ratio of the B2 phase is much larger than that of the FCC phase under the same irradiation conditions, and hence, the FCC phase has superior swelling tolerance than the B2 phase. Also, order-disorder transformation occurred in both L12and B2 phases. The different irradiation responses between the FCC and B2 phases, depend firstly on composition and secondly on crystal structure. The higher compositional complexity and complicated atomic-level lattice environment of the FCC phase contribute to better radiation performance than B2 phase. The results pave a way for exploring radiation-tolerant structural high-entropy alloys.

Glycoside scutellarin enhanced CD-MOF anchoring for laryngeal delivery

It is essential to develop new carriers for laryngeal drug delivery in light of the lack of therapy in laryngeal related diseases.When the inhalable micron-sized crystals ofγ-cyclodextrin metal-organic framework(CD-MOF)was utilized as dry powder inhalers(DPIs)carrier with high fine particle fraction(FPF),it was found in this research that the encapsulation of a glycoside compound,namely,scutellarin(SCU)in CD-MOF could significantly enhance its laryngeal deposition.Firstly,SCU loading into CD-MOF was optimized by incubation.Then,a series of characterizations were carried out to elucidate the mechanisms of drug loading.Finally,the laryngeal deposition rate of CD-MOF was 57.72±2.19%improved by SCU,about two times higher than that of CD-MOF,when it was determined by Next Generation Impactor(NGI)at 65 L/min.As a proof of concept,pharyngolaryngitis therapeutic agent dexamethasone(DEX)had improved laryngeal deposition after being co-encapsulated with SCU in CDMOF.The molecular simulation demonstrated the configuration of SCU in CD-MOF and its contribution to the free energy of the SCU@CD-MOF,which defined the enhanced laryngeal anchoring.In conclusion,the glycosides-like SCU could effectively enhance the anchoring of CD-MOF particles to the larynx to facilitate the treatment of laryngeal diseases.

Design of a renewable hydroxyapatite-biocarbon composite for the removal of uranium(Ⅵ)with high-efficiency adsorption performance

The hydroxyapatite-loaded swine manure derived-biocarbon was successfully prepared by pyrolysis method for the adsorption of uranium(Ⅵ).The results of the adsorption experiments displayed that the adsorption behaviors for uranium(Ⅵ)of biocarbon did almost not depend on the interfering ions except Al^(3+),Ca^(2+)and CO_(3)^(2−),showing the high selectivity of the composites for uranium(Ⅵ).The maximum static and dynamic removal capacity of the hydroxyapatite-biocarbon composites to uranium(Ⅵ)were 834.8 and 782.8 mg/g(pH=3,m/V=0.1 g/L and T=298 K),far exceeding other reported biocarbon and hydroxyapatite materials,which indicated that the hydroxyapatite-biocarbon composites possessed an application potential in adsorption.After five cycles of adsorption-desorption processes,the removal efficiency of the hydroxyapatite-biocarbon composite for uranium(Ⅵ)was 93.2%(C_(i)=5 mg/L,pH=3,m/V=0.1 g/L and T=298 K),revealing that the composite had excellent stability and reusability.Moreover,the capture mechanisms of the hydroxyapatite-biocarbon composite for uranium(Ⅵ)included ion exchange and complexation,which was ascribed to the ample active adsorption sites(-OH and PO_(4)^(3−)).Therefore,the hydroxyapatite-loaded swine manure derived-biocarbon would be a potential material to effectually separate uranium(Ⅵ)from solution.

Ni-Based Metallic Glass Composites Containing Cu-Rich Crystalline Nanospheres

In this work, a quaternary Ni-Cu-Nb-Ta system has been designed to obtain composite microstructure with sphericalcrystalline Cu-rich particles embedded in amorphous Ni-rich matrix. The alloy samples were prepared by using single-roller melting-spinning method. The microstructure and thermal properties of the as-quenched alloy samples were char-acterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, anddifferential scanning calorimetry. It shows that the spherical crystalline Cu-rich particles are embedded in the amorphousNi-rich matrix. The average size of the Cu-rich particles is strongly dependent upon the Cu content. The effect of the alloycomposition on the behavior of liquid-liquid phase separation and microstructure evolution was discussed. The phaseformation in the Ni-based metallic glass matrix composite was analyzed.

Brønsted acid-catalyzed 1,6-hydrophosphination of propargylic para-quinone methides and aza-para-quinone methides for the rapid construction of phosphorus-substituted quaternary carbon centers

An intriguing Brønsted acid-catalyzed 1,6-hydrophosphination of in situ generated propargylic para-quinone methides(p-QMs)and aza-para-quinone methides(aza-p-QMs)with H-phosphorus oxides via dehydration/1,6-addition under ultrasonic irradiation is described.This methodology provides a rapid and green approach for the construction of diarylmethyl phosphorus oxides bearing phosphorus-substituted quaternary carbon centers in high yields(up to 98%yield)within merely 5min.This environmentally benign protocol represents a unique example of 1,6-conjugate additions of propargylic p-QMs and aza-p-QMs for site-selective C-P bond formation in an operationally simple and atom-economical manner.The use of readily available Brønsted acid catalyst,operationally simplicity,high yields,and high atom economy make this protocol very facile,practical,easily scaled-up and environmentally friendly.