Laser welding is a highly promising joining method for Al alloys.However,certain limitations such as elevated thermal input and keyhole instability are associated with its application in medium-thickness aluminium all...Laser welding is a highly promising joining method for Al alloys.However,certain limitations such as elevated thermal input and keyhole instability are associated with its application in medium-thickness aluminium alloy plates.To address these issues,circular oscillating laser welding combined with post-weld heat treatment was employed to improve the formation quality and mechanical properties of the welds.The effects of the frequency of circular oscillating laser on the forming quality,microstructure,and properties of the welds were analyzed.At an oscillation frequency of 200 Hz,the grain size in the weld zone was reduced compared to single laser welding,and the maximum tensile strength of the weld was observed to reach(264.96±1.33)MPa,representing approximately 61.19%of the base metal.Following the post-weld heat treatment of"solid solution and artificial aging",the grain boundary segregation was diminished.Nanoscale precipitated phases are present in the weld zone.Furthermore,the tensile strength was augmented to(386.35±5.65)MPa,representing approximately 89.23%of the strength of the base metal.The results of this study can provide a theoretical basis and technological reference for the circular oscillating laser welding of medium-thickness 2219-T 6 aluminium alloy plates.展开更多
Acupuncture has been widely recognized for its significant therapeutic effects in treating a variety of conditions,including pain management,cerebrovascular diseases,cancer-related symptoms,respiratory disorders,and n...Acupuncture has been widely recognized for its significant therapeutic effects in treating a variety of conditions,including pain management,cerebrovascular diseases,cancer-related symptoms,respiratory disorders,and neurological diseases.A large body of clinical research demonstrates the substantial benefits of acupuncture,such as improving post-stroke recovery,alleviating chronic pain,reducing chemotherapy-induced symptoms,and promoting perioperative recovery.Mechanistic studies have shown that acupuncture influences multiple physiological systems,particularly the nervous,immune,and endocrine systems,providing insights into how acupuncture modulates neuroinflammation,neurotransmitter release,and immune responses.The role of acupuncture in integrative medicine is increasingly significant,with growing recognition of its therapeutic efficacy in regions outside China,particularly in Europe and the Americas.Acupuncture is expected to continue to expand its application,offering effective non-pharmacological treatment options in various fields,thereby consolidating its position in modern healthcare.Ongoing research holds the promise that acupuncture will play a key role in managing chronic diseases and supporting overall health.The 2024 acupuncture annual review will provide a comprehensive summary of the latest clinical applications and mechanistic research in acupuncture,with the aim of elucidating the current landscape and guiding future directions in the field.展开更多
P-stereogenic compounds play pivotal roles in natural products,pharmaceuticals,bioactive molecules,and catalysts/ligands,making their synthesis a highly researched area.Current studies have predominantly concentrated ...P-stereogenic compounds play pivotal roles in natural products,pharmaceuticals,bioactive molecules,and catalysts/ligands,making their synthesis a highly researched area.Current studies have predominantly concentrated on fully carbon-substituted P-stereogenic species,despite the fact that many therapeutically relevant compounds feature P-O,P-N,or P-S bonds.The catalytic and stereoselective nucleophilic substitution at the P-center is acknowledged as a highly efficient and straightforward approach for constructing high-value P-stereogenic compounds,offering significant potential for further development.This review provides an overview of advancements in the construction of P-stereogenic centers based on Pcentered nucleophilic substitution,highlighting key challenges,breakthroughs,and future opportunities in the field.展开更多
A ZM51 magnesium alloy joint with high intensity and thermal conductivity was fabricated using friction stir welding(FSW)followed by aging heat treatment(AG).During the FSW process,β_(1)'andβ_(2)'phases form...A ZM51 magnesium alloy joint with high intensity and thermal conductivity was fabricated using friction stir welding(FSW)followed by aging heat treatment(AG).During the FSW process,β_(1)'andβ_(2)'phases formed in the heat-affected zone(HAZ),yet new phases were absent in both the stirring zone(SZ)and thermal mechanical affected zone(TMAZ).After AG,numerousβ_(1)'andβ_(2)'phases emerged in the SZ and the TMAZ of the joint,while only theβ_(2)'phase precipitated in the HAZ.Due to precipitation strengthening,the average microhardness,yield strength and ultimate tensile strength of the joint reached up to 98%,94%and 88%those of the base metal(BM),respectively.Notably,basal slip{0001}<1120>,and twinning at 60°/<1010>and 86°/<1120>were more prevalent in TMAZ,contributing to the joint’s fracture.Furthermore,the precipitation ofβ_(1)'andβ_(2)'phases enhanced the joint’s thermal conductivity,averaging 121.7 W/(m·K),being 112%that of BM.展开更多
Recent insights into the immune landscape of the brain tumor microenvironment shed new light on immunotherapy for various brain tumors.This study provides comprehensive overviews of the development trends of immunothe...Recent insights into the immune landscape of the brain tumor microenvironment shed new light on immunotherapy for various brain tumors.This study provides comprehensive overviews of the development trends of immunotherapy for four common brain tumors(brain metastasis,glioma,meningioma,and pituitary adenoma),for which immunotherapy-related clinical trials have been conducted.Publications spanning from January 1,2011,to December 31,2023,were retrieved from the Web of Science Core Collection for a bibliometric analysis aimed at visualizing research trends and hotspots in immunotherapy for brain metastases,gliomas,meningiomas,and pituitary adenomas.Additionally,ongoing clinical trials were reviewed to identify the frontiers of immunotherapy in brain tumors.Research activity has significantly increased for brain metastasis and glioma,while studies on meningioma and pituitary adenoma remain in the nascent stages.The United States and China are the leading countries in these four research areas.Keyword analysis and ongoing trials underscore the crucial role of immune checkpoint inhibitors,which are currently a focal point in the treatment of various brain tumors.This review outlines the knowledge structures and research priorities in immunotherapy over the past 13 years,providing valuable insights for researchers in these fields.展开更多
The optical soliton characteristics of GaSb-based~2μm wavelength integrated optical chips have broad application prospects in optoelectronic fields such as optical communications,infrared countermeasures,and gas envi...The optical soliton characteristics of GaSb-based~2μm wavelength integrated optical chips have broad application prospects in optoelectronic fields such as optical communications,infrared countermeasures,and gas environment monitoring.In the research of two-section integrated optical chips,more attention is paid to their passive mode-locked characteristics.The ability of its structure to generate stable soliton transmission has not yet been studied,which will limit its further application in high-performance near-mid infrared optoelectronic technology.In this paper,we design and prepare a GaSb-based~2μm wave-length two-section integrated semiconductor laser chip structure,and test and analyze its related properties of soliton,includ-ing power−injection current−voltage(P−I−V),temperature and mode-locked characteristics.Experimental results show that the chip can achieve stable mode-locked operation at nearly~2μm wavelength and present the working characteristics of near opti-cal soliton states and multi-peak optical soliton states.By comparing and analyzing the measured optical pulse sequence curve with the numerical fitting based on the pure fourth order soliton approximation solution,it is confirmed that the two-section integrated optical chip structure can generate stable transmission of multi-peak optical soliton.This provides a research direc-tion for developing near-mid infrared mode-locked integrated optical chips with high-performance property of optical soliton.展开更多
Refractory metals and their alloys have excellent properties such as high-temperature strength and corrosion resistance.It is widely used in aerospace,electronics industry and other fields.However,refractory alloys ar...Refractory metals and their alloys have excellent properties such as high-temperature strength and corrosion resistance.It is widely used in aerospace,electronics industry and other fields.However,refractory alloys are prone to oxidation and failure in high-temperature service environments.The preparation of a MoSi_(2) antioxidant coating is an effective method for improving the protective ability of refractory metals at high temperatures.However,although MoSi_(2) coatings have many advantages,it is difficult to meet the increasingly stringent service requirements.To address these challenges,researchers have used different elements to modify a single MoSi_(2) coating and improve its overall oxidation resistance.In this study,the roles of one or more elements(Si,B,N,Zr,Al,W,Hf,Y,Ti and Cr)in MoSi_(2) coatings are systematically reviewed.Simultaneously,the mechanism of single or multiple synergistic modification of MoSi_(2) coatings with different elements was discussed.Finally,the development prospects of MoSi_(2) coating modification of refractory metals and their alloys are discussed.展开更多
基金Projects(E2024203001,E2024203049,E2024203071)supported by the Hebei Natural Science Foundation of ChinaProject(236Z1805G)supported by the S&T Program of Hebei,China。
文摘Laser welding is a highly promising joining method for Al alloys.However,certain limitations such as elevated thermal input and keyhole instability are associated with its application in medium-thickness aluminium alloy plates.To address these issues,circular oscillating laser welding combined with post-weld heat treatment was employed to improve the formation quality and mechanical properties of the welds.The effects of the frequency of circular oscillating laser on the forming quality,microstructure,and properties of the welds were analyzed.At an oscillation frequency of 200 Hz,the grain size in the weld zone was reduced compared to single laser welding,and the maximum tensile strength of the weld was observed to reach(264.96±1.33)MPa,representing approximately 61.19%of the base metal.Following the post-weld heat treatment of"solid solution and artificial aging",the grain boundary segregation was diminished.Nanoscale precipitated phases are present in the weld zone.Furthermore,the tensile strength was augmented to(386.35±5.65)MPa,representing approximately 89.23%of the strength of the base metal.The results of this study can provide a theoretical basis and technological reference for the circular oscillating laser welding of medium-thickness 2219-T 6 aluminium alloy plates.
基金supported by the National Key Research and Development Program of China(No.2022YFC3500601)the National Natural Science Foundation of China(Nos.82474395 and 81973755)+1 种基金the Project on Hebei Administration of Traditional Chinese Medicine(Nos.2022091 and 2025424)the Graduate Innovation Projects of Hebei University of Chinese Medicine(Nos.XCXZZBS2024005 and XCXZZBS2025029).
文摘Acupuncture has been widely recognized for its significant therapeutic effects in treating a variety of conditions,including pain management,cerebrovascular diseases,cancer-related symptoms,respiratory disorders,and neurological diseases.A large body of clinical research demonstrates the substantial benefits of acupuncture,such as improving post-stroke recovery,alleviating chronic pain,reducing chemotherapy-induced symptoms,and promoting perioperative recovery.Mechanistic studies have shown that acupuncture influences multiple physiological systems,particularly the nervous,immune,and endocrine systems,providing insights into how acupuncture modulates neuroinflammation,neurotransmitter release,and immune responses.The role of acupuncture in integrative medicine is increasingly significant,with growing recognition of its therapeutic efficacy in regions outside China,particularly in Europe and the Americas.Acupuncture is expected to continue to expand its application,offering effective non-pharmacological treatment options in various fields,thereby consolidating its position in modern healthcare.Ongoing research holds the promise that acupuncture will play a key role in managing chronic diseases and supporting overall health.The 2024 acupuncture annual review will provide a comprehensive summary of the latest clinical applications and mechanistic research in acupuncture,with the aim of elucidating the current landscape and guiding future directions in the field.
基金financial support from the National Natural Science Foundation of China(Nos.22171187 and 22001173)the Project of Department of Education of Guangdong Province(No.2020KTSCX116)+3 种基金the Shenzhen Science and Technology Foundation(Nos.20200812202943001 and KQJSCX20180328100401788)Frontiers Science Center for Asymmetric Synthesis and Medicinal Molecules,Department of Education,Guizhou Province(No.Qianjiaohe KY(2020)004)the Central Government Guides Local Science and Technology Development Fund Projects(Nos.Qiankehezhongyindi(2024)007,(2023)001)Singapore National Research Foundation under its NRF Competitive Research Program(No.NRFCRP22–2019–0002)。
文摘P-stereogenic compounds play pivotal roles in natural products,pharmaceuticals,bioactive molecules,and catalysts/ligands,making their synthesis a highly researched area.Current studies have predominantly concentrated on fully carbon-substituted P-stereogenic species,despite the fact that many therapeutically relevant compounds feature P-O,P-N,or P-S bonds.The catalytic and stereoselective nucleophilic substitution at the P-center is acknowledged as a highly efficient and straightforward approach for constructing high-value P-stereogenic compounds,offering significant potential for further development.This review provides an overview of advancements in the construction of P-stereogenic centers based on Pcentered nucleophilic substitution,highlighting key challenges,breakthroughs,and future opportunities in the field.
基金supported by the Key Research and Development Program of Shaanxi Province,China(No.2017ZDXM-GY-037)the National Natural Science Fund for Excellent Young Scholars,China(No.52222410)+3 种基金the National Natural Science Foundation of China(Key Program)(No.52034005)the National Natural Science Foundation of China(No.52227807)the National Key Research and Development Program of China(No.2021YFB3700902)the Shaanxi Province Qinchuangyuan“Scientist+Engineer”Team Program,China(No.2022KXJ-072).
文摘A ZM51 magnesium alloy joint with high intensity and thermal conductivity was fabricated using friction stir welding(FSW)followed by aging heat treatment(AG).During the FSW process,β_(1)'andβ_(2)'phases formed in the heat-affected zone(HAZ),yet new phases were absent in both the stirring zone(SZ)and thermal mechanical affected zone(TMAZ).After AG,numerousβ_(1)'andβ_(2)'phases emerged in the SZ and the TMAZ of the joint,while only theβ_(2)'phase precipitated in the HAZ.Due to precipitation strengthening,the average microhardness,yield strength and ultimate tensile strength of the joint reached up to 98%,94%and 88%those of the base metal(BM),respectively.Notably,basal slip{0001}<1120>,and twinning at 60°/<1010>and 86°/<1120>were more prevalent in TMAZ,contributing to the joint’s fracture.Furthermore,the precipitation ofβ_(1)'andβ_(2)'phases enhanced the joint’s thermal conductivity,averaging 121.7 W/(m·K),being 112%that of BM.
基金supported by the National Natural Science Foundation of China(No.82273328)Hubei Province Key Research&Development Program(No.2021BCA143)。
文摘Recent insights into the immune landscape of the brain tumor microenvironment shed new light on immunotherapy for various brain tumors.This study provides comprehensive overviews of the development trends of immunotherapy for four common brain tumors(brain metastasis,glioma,meningioma,and pituitary adenoma),for which immunotherapy-related clinical trials have been conducted.Publications spanning from January 1,2011,to December 31,2023,were retrieved from the Web of Science Core Collection for a bibliometric analysis aimed at visualizing research trends and hotspots in immunotherapy for brain metastases,gliomas,meningiomas,and pituitary adenomas.Additionally,ongoing clinical trials were reviewed to identify the frontiers of immunotherapy in brain tumors.Research activity has significantly increased for brain metastasis and glioma,while studies on meningioma and pituitary adenoma remain in the nascent stages.The United States and China are the leading countries in these four research areas.Keyword analysis and ongoing trials underscore the crucial role of immune checkpoint inhibitors,which are currently a focal point in the treatment of various brain tumors.This review outlines the knowledge structures and research priorities in immunotherapy over the past 13 years,providing valuable insights for researchers in these fields.
基金the National Natural Science Foundation of China(Grant Nos.62274048,62464006,62174046)the Ministry of Education,Singapore(Grant No.MOE-T2EP50121-0005)+1 种基金Hainan Province Science and Technology Special Fund(Grant No.ZDYF2025GXJS007)National Key R&D Program of China(Grant No.2023YFF0722400).
文摘The optical soliton characteristics of GaSb-based~2μm wavelength integrated optical chips have broad application prospects in optoelectronic fields such as optical communications,infrared countermeasures,and gas environment monitoring.In the research of two-section integrated optical chips,more attention is paid to their passive mode-locked characteristics.The ability of its structure to generate stable soliton transmission has not yet been studied,which will limit its further application in high-performance near-mid infrared optoelectronic technology.In this paper,we design and prepare a GaSb-based~2μm wave-length two-section integrated semiconductor laser chip structure,and test and analyze its related properties of soliton,includ-ing power−injection current−voltage(P−I−V),temperature and mode-locked characteristics.Experimental results show that the chip can achieve stable mode-locked operation at nearly~2μm wavelength and present the working characteristics of near opti-cal soliton states and multi-peak optical soliton states.By comparing and analyzing the measured optical pulse sequence curve with the numerical fitting based on the pure fourth order soliton approximation solution,it is confirmed that the two-section integrated optical chip structure can generate stable transmission of multi-peak optical soliton.This provides a research direc-tion for developing near-mid infrared mode-locked integrated optical chips with high-performance property of optical soliton.
基金supported by the National Natural Science Foundation of China(No.52374401 and 52404409)the Key R&D Plan of Shaanxi Province(Nos.2024QCYKXJ-116 and 2023JBGS-14)+3 种基金the Scientific and Technological Innovation Team Project of Shaanxi Innovation Capability Support Plan(No.2022TD-30)Xi’an Science and Technology Plan Project(No.2023JHGXRC-0020)the“Young Talent Support Project”of China Association for Science and Technology of China.The Natural Science Foundation of Shaanxi Provincial(No.2024JC-YBQN-0367)China Postdoctoral Science Foundation(2024MD753961).
文摘Refractory metals and their alloys have excellent properties such as high-temperature strength and corrosion resistance.It is widely used in aerospace,electronics industry and other fields.However,refractory alloys are prone to oxidation and failure in high-temperature service environments.The preparation of a MoSi_(2) antioxidant coating is an effective method for improving the protective ability of refractory metals at high temperatures.However,although MoSi_(2) coatings have many advantages,it is difficult to meet the increasingly stringent service requirements.To address these challenges,researchers have used different elements to modify a single MoSi_(2) coating and improve its overall oxidation resistance.In this study,the roles of one or more elements(Si,B,N,Zr,Al,W,Hf,Y,Ti and Cr)in MoSi_(2) coatings are systematically reviewed.Simultaneously,the mechanism of single or multiple synergistic modification of MoSi_(2) coatings with different elements was discussed.Finally,the development prospects of MoSi_(2) coating modification of refractory metals and their alloys are discussed.
