Unraveling the advances of trace doping engineering for potassium ion battery anodes via tomography

Doping have been considered as a prominent strategy to stabilize crystal structure of battery materials during the insertion and removal of alkali ions.The instructive knowledge and experience acquired from doping strategies predominate in cathode materials,but doping principle in anodes remains unclear.Here,we demonstrate that trace element doping enables stable conversion-reaction and ensures structural integrity for potassium ion battery(PIB) anodes.With a synergistic combination of X-ray tomography,structural probes,and charge reconfiguration,we encode the physical origins and structural evolution of electro-chemo-mechanical degradation in PIB anodes.By the multiple ion transport pathways created by the orderly hierarchical pores from "surface to bulk" and the homogeneous charge distribution governed in doped nanodomains,the anisotropic expansion can be significantly relieved with trace isoelectronic element doping into the host lattice,maintaining particle mechanical integrity.Our work presents a close relationship between doping chemistry and mechanical reliability,projecting a new pathway to reengineering electrode materials for next-generation energy storage.

Porous conductive interlayer for dendrite-free lithium metal battery

Lithium(Li) metal,possessing ultrahigh theoretical capacity and the lowest electrode potential,is regarded as a promising new generation anode material.However,the uncontrollable growth of Li dendrites during cycling process gives rise to problems as capacity decay and short circuit,suppressing the cycling and safety performances of Li metal battery.In this contribution,porous conductive interlayer(PCI),composed of carbon nanofibers(CNFs) and polyisophthaloyl metaphenylene diamine(PMIA),is developed to suppress Li dendrites and stabilize Li metal anode.PCI possesses the excellent conductive ability of CNFs and the preeminent mechanical properties of PMIA at the same time.When Li metal contacts with PCI during cycling process,an equipotential surface forms on their interface,which eliminates the tip effect on Li anode and homogenizes Li-ions flux in combination with the uniform porous structure of PCI.Employed PCI,the Li|Cu cell exhibits a remarkable cycling stability with a high average Coulombic efficiency of 97.5% for 100 cycles at 0.5 mA cm^(-2).And the Li|LiFePO_4 cell exhibits improved rate capability(114.7 mAh g^(-1) at 5.0 C) and enhanced cycling performance(78.9% capacity retention rate over 500 cycles at 1.0 C).This work provides a fresh and effective solving strategy for the problem of dendrites in Li metal battery.

Synthesis and Antimicrobial Activity of Boron-doped Titania Nano-materials

Antibacterial activity of boron-doped TiO2(B/TiO2) nano-materials under visible light irradiation and in the dark was investigated. A simple sol-gel method was used to synthesize TiO2 nano-materials. X-ray diffraction pattern of B/TiO2 nano-materials represents the diffraction peaks relating to the crystal planes of TiO2(anatase and rutile). X-ray photoelectron spectroscopy result shows that part of boron ions incorporates into TiO2 lattice to form a possible chemical environment like Ti O B and the rest exist in the form of B2O3. The study on antibacterial effect of B/TiO2 nano-materials on fungal Candida albicans(ATCC10231), Gram-negative Escherichia coli(ATCC25922) and Gram-positive Staphylococcus aureus(ATCC6538) shows that the antibacterial action is more significant on Candida albicans than on Escherichia coli and Staphylococcus aureus. Under visible light irradiation, the antibacterial activity is superior to that in the dark.

BRAF and KRAS mutations in metastatic colorectal cancer:future perspectives for personalized therapy

Colorectal cancer(CRC)is one of the most commonly diagnosed cancers worldwide and 30%of patients with CRC experience metastasis.Patients with metastatic colorectal cancer(mCRC)have a 5-year overall survival rate of<10%.V-raf murine sarcoma viral oncogene homolog B1(BRAF)and V-Ki-ras2 Kirsten ratsarcoma viral oncogene homolog(KRAS)mutations are mostly studied in mCRC,as clinical trials found that first-line chemotherapy with anti-epidermal growth factor receptor agent confers limited efficacy for mCRC.Treatment decisions for early-stage mCRC do not consider BRAF or KRAS mutations,given the dramatically poor prognosis conferred by these mutations in clinical trials.Thus,it is necessary to identify patients with mCRC harboring BRAF or KRAS mutations to formulate rational therapeutic strategies to improve prognosis and survival.BRAF and KRAS mutations occur in10%and44%of patients with mCRC,respectively.Although the survival rate of patients with mCRC has improved in recent years,the response and prognosis of patients with the aforementioned mutations are still poor.There is a substantial unmet need for prospective personalized therapies for patients with BRAF-or KRAS-mutant mCRC.In this review,we focus on BRAF and KRAS mutations to understand the mechanisms underlying resistance and improving the response rate,outcomes,and prognosis of patients with mCRC bearing these mutations and to discuss prospective personalized therapies for BRAF-and KRAS-mutant mCRC.

Bainite Transformation of Low-carbon and Boron-containing Steel under Continuous Cooling

The effects of deformation temperature and strain on bainite transformation of low carbon steel and boron- containing steel were investigated under continuous cooling conditions by means of dilatometric measurement and mi- crostructure observation. The results show that with decreasing the deformation temperature from 1000 to 800 ℃ and increasing strains, bainite start temperature for boron-containing low carbon steel increases, whereas it decreases for low carbon steel under the same condition. The bainite microstructures are easily obtained for boron-containing steel deformed at different temperatures and different strains compared with plain low carbon steel. With increasing the continuous cooling rate, the bainite start temperature under deformed condition is about 20 ℃ higher than that under undeformed condition for boron-containing steel, but it changes slightly when the cooling rate is 20 ℃/s or more.