In the present study, the tested hypereutectic Al-21wt.%Si alloys were prepared by modifying the melt using different proportions of P and Ce, and then applying T6 heat treatment. The modification effects and mechanis...In the present study, the tested hypereutectic Al-21wt.%Si alloys were prepared by modifying the melt using different proportions of P and Ce, and then applying T6 heat treatment. The modification effects and mechanism of P＋Ce complex modifier on the Si phase of hypereutectic Al-21wt.%Si alloy were studied, and the aging precipitation behavior after modification was characterized by means of tensile strength measurement, OM, SEM and TEM analysis. The results show that the massive primary silicon phase particles are significantly refined after modification, while the needle-like eutectic silicon crystals become fibrous and short. It was found that the mechanism of phosphorus modification on the primary silicon can be attributed to heterogeneous nucleation of AlP, while the modification mechanism of Ce can be explained by adsorbing-twinning theory. In the aged microstructure of the modified hypereutectic Al-21wt.%Si alloy, there existed some strengthening phases such as AI4Cu9, Al2Cu, AlCu3, and Al57Mn12. The P＋Ce complex modifier not only affected the size of primary silicon and eutectic silicon, but also the aging behavior of alloys under the heat treatment process. When Al-21wt.%Si alloy was modified using 0.08%wt.P ＋ 0.6wt.% Ce, the aging precipitates were dispersed uniformly in the alloy, and its mechanical properties at room and elevated temperatures are optimized （Rm = 287.6 MPa at RT, Rm = 210 MPa at 300 ℃）.展开更多
The surface modification of materials such as Ti-6Al-4V is necessary to improve their wear resistant properties for use in tribological applications. In this paper it is shown that a laser with low power and tungsten ...The surface modification of materials such as Ti-6Al-4V is necessary to improve their wear resistant properties for use in tribological applications. In this paper it is shown that a laser with low power and tungsten inert gas (TIG) can be combined together for surface modification of Ti-6Al-4V alloy, and when performed in a controlled atmosphere of pure nitrogen or a mixture of nitrogen and argon, can produce a wear-resistant surface alloy. Compared with laser processing, a cheaper surface modification process has been developed involving a shorter processing time, which is free of stringent requirements such as a vacuum system.展开更多
Cancer remains the leading cause of mortality worldwide.Radiotherapy(RT),a cornerstone of oncological treatment for over a century,has achieved great success in various cancers.However,radioresistance remains the prim...Cancer remains the leading cause of mortality worldwide.Radiotherapy(RT),a cornerstone of oncological treatment for over a century,has achieved great success in various cancers.However,radioresistance remains the primary factor leading to the failure of radiotherapy.Histone modifications in cancer cells are known to play a pivotal role in regulating radiosensitivity by modulating chromatin structure,either by loosening or tightening it.Here,we provide a comprehensive summary of the link between aberrant histone modifications and radiation resistance across various cancer and normal tissue cells.Furthermore,we discuss the regulatory mechanisms of histone modifications and the enzymes on the recruitment of proteins that recognize histone modifications.Consequently,these processes substantially affect the radiosensitivity of tumors.In addition to cancer cells,we highlight the intricate interplay between histone modification and radiosensitivity,both within and beyond the cancer cells.Meanwhile,various drugs targeting histone modifications emerge as a promising therapeutic strategy to overcome radioresistance of tumors as well as radioprotection.The combination of histone modification inhibitors with radiotherapy presents a novel approach to enhance cancer treatment outcomes in clinical practice.Nevertheless,the underlying mechanisms through which histone modifications influence cancer radiosensitivity require further elucidation to identify novel targets for radiotherapeutic intervention.展开更多
基金funded by the National Natural Science Foundation of China(51371077)
文摘In the present study, the tested hypereutectic Al-21wt.%Si alloys were prepared by modifying the melt using different proportions of P and Ce, and then applying T6 heat treatment. The modification effects and mechanism of P＋Ce complex modifier on the Si phase of hypereutectic Al-21wt.%Si alloy were studied, and the aging precipitation behavior after modification was characterized by means of tensile strength measurement, OM, SEM and TEM analysis. The results show that the massive primary silicon phase particles are significantly refined after modification, while the needle-like eutectic silicon crystals become fibrous and short. It was found that the mechanism of phosphorus modification on the primary silicon can be attributed to heterogeneous nucleation of AlP, while the modification mechanism of Ce can be explained by adsorbing-twinning theory. In the aged microstructure of the modified hypereutectic Al-21wt.%Si alloy, there existed some strengthening phases such as AI4Cu9, Al2Cu, AlCu3, and Al57Mn12. The P＋Ce complex modifier not only affected the size of primary silicon and eutectic silicon, but also the aging behavior of alloys under the heat treatment process. When Al-21wt.%Si alloy was modified using 0.08%wt.P ＋ 0.6wt.% Ce, the aging precipitates were dispersed uniformly in the alloy, and its mechanical properties at room and elevated temperatures are optimized （Rm = 287.6 MPa at RT, Rm = 210 MPa at 300 ℃）.
文摘The surface modification of materials such as Ti-6Al-4V is necessary to improve their wear resistant properties for use in tribological applications. In this paper it is shown that a laser with low power and tungsten inert gas (TIG) can be combined together for surface modification of Ti-6Al-4V alloy, and when performed in a controlled atmosphere of pure nitrogen or a mixture of nitrogen and argon, can produce a wear-resistant surface alloy. Compared with laser processing, a cheaper surface modification process has been developed involving a shorter processing time, which is free of stringent requirements such as a vacuum system.
基金supported by the National Natural Science Foundation of China(82404200 and 82473574)Projects from Sichuan Province(2024ZYD0126,China)+1 种基金Key Innovation Project from Tibet Province(XZ202501ZY0131,China)Sichuan Science and Technology Program(MZGC20240002,China).
文摘Cancer remains the leading cause of mortality worldwide.Radiotherapy(RT),a cornerstone of oncological treatment for over a century,has achieved great success in various cancers.However,radioresistance remains the primary factor leading to the failure of radiotherapy.Histone modifications in cancer cells are known to play a pivotal role in regulating radiosensitivity by modulating chromatin structure,either by loosening or tightening it.Here,we provide a comprehensive summary of the link between aberrant histone modifications and radiation resistance across various cancer and normal tissue cells.Furthermore,we discuss the regulatory mechanisms of histone modifications and the enzymes on the recruitment of proteins that recognize histone modifications.Consequently,these processes substantially affect the radiosensitivity of tumors.In addition to cancer cells,we highlight the intricate interplay between histone modification and radiosensitivity,both within and beyond the cancer cells.Meanwhile,various drugs targeting histone modifications emerge as a promising therapeutic strategy to overcome radioresistance of tumors as well as radioprotection.The combination of histone modification inhibitors with radiotherapy presents a novel approach to enhance cancer treatment outcomes in clinical practice.Nevertheless,the underlying mechanisms through which histone modifications influence cancer radiosensitivity require further elucidation to identify novel targets for radiotherapeutic intervention.
