TEMPERATURE EFFECT ON LOW-CYCLE FATIGUE BEHAVIOR OF NICKEL-BASED SINGLE CRYSTALLINE SUPERALLOY

The low-cycle fatigue （LCF） behavior of a nickel-based single crystal superalloy with [001] orientation was studied at an intermediate temperature of T0℃ and a higher temperature of To ＋ 250℃ under a constant low strain rate of 10^-3 s^-1 in ambient atmosphere. The superalloy exhibited cyclic tension-compression asymmetry which is dependent on the temperature and applied strain amplitude. Analysis on the fracture surfaces showed that the surface and subsurface casting micropores were the major crack initiation sites. Interior Ta-rich carbides were frequently observed in all specimens. Two distinct types of fracture were suggested by fractogaphy. One type was characterized by Mode-I cracking with a microscopically rough surface at To ＋ 250℃. Whereas the other type at lower temperature T0℃ favored either one or several of the octahedral {111} planes, in contrast to the normal Mode-I growth mode typically observed at low loading frequencies （several Hz）. The failure mechanisms for two cracking modes are shearing of γ＇ precipitates together with the matrix at T0℃ and cracking confined in the matrix and the γ/γ＇interface at To - 250℃.

Improving fatigue strength of bainite/martensite dual-phase steels in very high cycle fatigue regime by refining microstructures

Very high cycle fatigue behaviors of two bainite/martensite dual-phase steels were investigated.One of the steels was cyclic rapid heat treated and its microstructures were refined. Fatigue strength of the steel is 225 MPa higher than that without refining.Observation of fracture surfaces show that the fatigue cracks initiate at bainites for non-refined steel and at non-metallic inclusions for the refined steel.The size of inclusions is much smaller than that of bainites which results in the improvement of fatigue strength.

Countermeasures for the Protection and Sustainable Development of Forestry Resources

Firstly,the problems of the protection and sustainable development of forestry resources were analyzed,such as lack of overall planning for the protection of forestry resources,insufficient investment in the protection of forestry resources,etc.Afterwards,the corresponding countermeasures were proposed,such as making overall planning for sustainable forestry development,increasing the investment in the protection of forestry resources,improving the forestry management system,etc.

Effect of Shan Zha(Hawthorn or Crataegus)on gastrointestinal cancer:A network pharmacology and molecular docking study

Background Shan Zha(Hawthorn or Crataegus)is a traditional Chinese medicine(TCM)most commonly used for the treatment of hyperlipidemia.Gastrointestinal cancer is closely correlated with blood lipid levels.This study illustrates the potential anticancer effects of Shan Zha on gastrointestinal tumors based on network pharmacology and molecular docking.Methods Hawthorn's bioactive ingredients and drug targets were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP),Integrative Pharmacology-based Research Platform of Traditional Chinese Medicine version 2.0(TCMIP v2.0),and Herbal Ingredients'Targets Platform(HIT 2.0)databases.Validated disease targets of gastrointestinal cancer were obtained from the Therapeutic Targets Database(TTD)and HIT 2.0 databases.Protein–protein interaction analysis of intersecting genes was performed using the Search Tool for the Retrieval of Interacting Genes(STRING)database.The functions of these genes were further analyzed by performing gene ontology and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses.Molecular docking verification was performed using Molecular Operating Environment(MOE)software.Results Four main bioactive components were identified in Shan Zha.A total of 271 potential drug targets were identified,and 393 gastrointestinal-tumor targets were obtained.Through protein interaction analysis of intersecting targets,the main components of Shan Zha were found to interact more closely with proteins such as tumor protein p53(TP53),AKT serine/threonine kinase 1(AKT1),JUN proto-oncogene(JUN),interleukin 6(IL6),epidermal growth factor receptor(EGFR),and vascular endothelial growth factor A(VEGFA).KEGG pathway enrichment analysis showed a total of 127 pathways,mainly involving pathways in multiple types of cancer,the Phosphatidylinositol 3-kinase-Akt(PI3K-Akt)signaling pathway,and EGFR tyrosine kinase inhibitor resistance.Combined with The Cancer Genome Atlas(TCGA)differential analysis,key targets,including TP53,cyclin D1(CCND1),EGFR,and VEGFA,were screened.Molecular docking results showed that quercetin and kaempferol had the good binding potential for TP53,CCND1,EGFR,and VEGFA.Conclusion These findings suggest that Shan Zha exerts its effects on gastrointestinal cancers through a multitarget,multi-component,and a multi-pathway mechanism.

Study on polyurethane-based porous materials and their adsorption properties

The flexible superhydrophobic thermoplastic polyurethane(TPU)porous material was prepared by heat-induced phase separation method with two cooling steps.The influence of the preparation process on the microstructure of the material was discussed in depth.The microstructure,hydrophobicity and specific surface area of porous TPU materials were analyzed in detail.The surface wettability,separation selectivity,saturated adsorption capacity and adsorption rate,mechanical properties,environmental adaptability and cyclic properties of porous TPU materials were studied.The results show that the TPU-8%porous monolithic material prepared by heat-induced phase separation method shows good performance when the polymer concentration is 8%,the phase separation temperature is 0℃,the phase separation time is 30min,and the mixing solvent ratio is 9:1.

Reduced graphene oxide-modified Ni Co-phosphates on Ni foam enabling high areal capacitances for asymmetric supercapacitors

NiCo-phosphates can deliver high specific capacitances and high electrochemical activities as pseudocapacitive electrode material for supercapacitors.In this study,The NiCo-phosphates@reduced graphene oxide(NCPO@rGO)composite is directly loaded on Ni foam by a simple one-step hydrothermal process.The conductive rGO sheets provides continuous electron pathways between NCPO flowers and Ni foam,allowing active electrochemical reactions throughout the whole electrode.This can solve the difficulty of low active material utility and small areal capacitances in the Ni foam-supported electrodes.At the same time,the rGO sheets creates large amount of mesopores within the electrode,which can ensure a highly open structure for electrolyte attachment and ion transport.Because of the positive effect of rGO in improving charge transfe r,the NiCo-phosphates can be fully involved in the electrochemical reactions with high utility,ensuring high specific capacitances(1416.7 F g^(-1)at 1 A g^(-1))and high-rate performances.Specially,the areal capacitance of the NCPO@rGO electrode can reach as large as 3.69 F cm^(-2)at 1 A g^(-1),which is among the highest ones in Ni foam supported electrodes.An asymmetric supercapacitor is then fabricated by NCPO@rGO as the positive material with attractive energy densities and power densities,further proving its excellent electrochemical performance.