传统的超扫描技术无法直接揭示社会互动与脑间同步之间的因果关系。群脑刺激技术通过对交互个体特定脑区实施同步的非侵入性经颅电刺激(transcranial electrical stimulation,t ES),主动操纵脑间同步水平,为因果机制的解析提供了全新的...传统的超扫描技术无法直接揭示社会互动与脑间同步之间的因果关系。群脑刺激技术通过对交互个体特定脑区实施同步的非侵入性经颅电刺激(transcranial electrical stimulation,t ES),主动操纵脑间同步水平,为因果机制的解析提供了全新的实验途径。群脑刺激中,经颅交流电刺激(transcranial alternating current stimulation,t ACS)基于“跨脑夹带”机制,通过特定频率和相位施加交流电直接诱导多脑振荡的协同活动,从而优化跨脑信息传递,经颅直流电刺激(transcranial direct current stimulation,tDCS)则通过调节社会脑区的兴奋性,间接调控神经信息处理与行为协同。实证研究表明,群脑刺激能有效提升社会协作中的行为同步性、优化人际沟通效率以及增强社会学习效果,在多项研究中显示出对各类互动表现的改善作用。群脑刺激通过多层级机制影响社会互动:首先调节脑间同步水平,继而促进表征对齐、降低预测误差,并最终驱动互动行为。未来研究应致力于推动刺激参数标准化,提升复杂社会互动情境下的生态效度,并加速相关技术在教育优化、临床干预和组织管理等领域的应用转化,推动人际神经科学迈向因果解析与精准干预的新阶段。展开更多
High-performance graphite materials have important roles in aerospace and nuclear reactor technologies because of their outstanding chemical stability and high-temperature performance.Their traditional production meth...High-performance graphite materials have important roles in aerospace and nuclear reactor technologies because of their outstanding chemical stability and high-temperature performance.Their traditional production method relies on repeated impregnation-carbonization and graphitization,and is plagued by lengthy preparation cycles and high energy consumption.Phase transition-assisted self-pressurized selfsintering technology can rapidly produce high-strength graphite materials,but the fracture strain of the graphite materials produced is poor.To solve this problem,this study used a two-step sintering method to uniformly introduce micro-nano pores into natural graphite-based bulk graphite,achieving improved fracture strain of the samples without reducing their density and mechanical properties.Using natural graphite powder,micron-diamond,and nano-diamond as raw materials,and by precisely controlling the staged pressure release process,the degree of diamond phase transition expansion was effectively regulated.The strain-to-failure of the graphite samples reached 1.2%,a 35%increase compared to samples produced by fullpressure sintering.Meanwhile,their flexural strength exceeded 110 MPa,and their density was over 1.9 g/cm^(3).The process therefore produced both a high strength and a high fracture strain.The interface evolution and toughening mechanism during the two-step sintering process were investigated.It is believed that the micro-nano pores formed have two roles:as stress concentrators they induce yielding by shear and as multi-crack propagation paths they significantly lengthen the crack propagation path.The two-step sintering phase transition strategy introduces pores and provides a new approach for increasing the fracture strain of brittle materials.展开更多
文摘传统的超扫描技术无法直接揭示社会互动与脑间同步之间的因果关系。群脑刺激技术通过对交互个体特定脑区实施同步的非侵入性经颅电刺激(transcranial electrical stimulation,t ES),主动操纵脑间同步水平,为因果机制的解析提供了全新的实验途径。群脑刺激中,经颅交流电刺激(transcranial alternating current stimulation,t ACS)基于“跨脑夹带”机制,通过特定频率和相位施加交流电直接诱导多脑振荡的协同活动,从而优化跨脑信息传递,经颅直流电刺激(transcranial direct current stimulation,tDCS)则通过调节社会脑区的兴奋性,间接调控神经信息处理与行为协同。实证研究表明,群脑刺激能有效提升社会协作中的行为同步性、优化人际沟通效率以及增强社会学习效果,在多项研究中显示出对各类互动表现的改善作用。群脑刺激通过多层级机制影响社会互动:首先调节脑间同步水平,继而促进表征对齐、降低预测误差,并最终驱动互动行为。未来研究应致力于推动刺激参数标准化,提升复杂社会互动情境下的生态效度,并加速相关技术在教育优化、临床干预和组织管理等领域的应用转化,推动人际神经科学迈向因果解析与精准干预的新阶段。
基金Natural Science Foundation of Shanghai(24ZR1400800)he Natural Science Foundation of China(U23A20685,52073058,91963204)+1 种基金the National Key R&D Program of China(2021YFB3701400)Shanghai Sailing Program(23YF1400200)。
文摘High-performance graphite materials have important roles in aerospace and nuclear reactor technologies because of their outstanding chemical stability and high-temperature performance.Their traditional production method relies on repeated impregnation-carbonization and graphitization,and is plagued by lengthy preparation cycles and high energy consumption.Phase transition-assisted self-pressurized selfsintering technology can rapidly produce high-strength graphite materials,but the fracture strain of the graphite materials produced is poor.To solve this problem,this study used a two-step sintering method to uniformly introduce micro-nano pores into natural graphite-based bulk graphite,achieving improved fracture strain of the samples without reducing their density and mechanical properties.Using natural graphite powder,micron-diamond,and nano-diamond as raw materials,and by precisely controlling the staged pressure release process,the degree of diamond phase transition expansion was effectively regulated.The strain-to-failure of the graphite samples reached 1.2%,a 35%increase compared to samples produced by fullpressure sintering.Meanwhile,their flexural strength exceeded 110 MPa,and their density was over 1.9 g/cm^(3).The process therefore produced both a high strength and a high fracture strain.The interface evolution and toughening mechanism during the two-step sintering process were investigated.It is believed that the micro-nano pores formed have two roles:as stress concentrators they induce yielding by shear and as multi-crack propagation paths they significantly lengthen the crack propagation path.The two-step sintering phase transition strategy introduces pores and provides a new approach for increasing the fracture strain of brittle materials.
