Hafnia-based ferroelectrics have emerged as promising materials for next-generation nanoelectronics owing to their robust nanoscale properties and compatibility with metal-oxide-semiconductor technology.However,their ...Hafnia-based ferroelectrics have emerged as promising materials for next-generation nanoelectronics owing to their robust nanoscale properties and compatibility with metal-oxide-semiconductor technology.However,their metastable nature remains a key challenge for practical implementation.Utilizing scanning transmission electron microscopy,we investigated the atomic-scale mechanisms governing ferroelectric transitions and the metastability of polar phases in 10-nm-thick Hf_(0.5)Zr_(0.5)O_(2)thin films.Our results demonstrate that oxygen vacancies,coupled with rhombohedral distortions of the cation lattice,facilitate ferroelectric phase transitions and enable robust polar switching through adaptive processes,including cell-by-cell oxygen displacement and domain-wall-mediated nucleation and growth.These findings underscore the pivotal role of oxygen vacancies and lattice distortions in stabilizing polar phases and provide detailed insights into the atomic structures and transition dynamics of polymorphic Hf_(0.5)Zr_(0.5)O_(2-x),thereby advancing its potential for practical device applications.展开更多
Heterointerfaces have been pivotal in unveiling extraordinary interfacial properties and enabling multifunctional material platforms.Despite extensive research on all-oxide interfaces,heterointerfaces between differen...Heterointerfaces have been pivotal in unveiling extraordinary interfacial properties and enabling multifunctional material platforms.Despite extensive research on all-oxide interfaces,heterointerfaces between different material classes,such as oxides and nitrides,remain underexplored.Here we present the fabrication of atomically sharp heterointerfaces between antiperovskite Ni_(3)InN and perovskite SrVO_(3).Leveraging layer-resolved scanning transmission electron microscopy and electron energy loss spectroscopy,we identified pronounced charge transfer across the well-ordered interface.First-principles calculations confirmed our experimental observations and further predicted an emergent magnetic moment within the Ni_(3)InN layer due to the charge transfer.These findings pave the way for novel electronic and spintronic applications by enabling tunable interfacial properties in nitride/oxide systems.展开更多
目的系统评价普瑞巴林治疗坐骨神经痛的有效性及安全性。方法计算机检索PubMed、Embase、Cochrane Library、Web of Science、Medline、CNKI、VIP、WanFang Data和SinoMed数据库,搜集有关普瑞巴林治疗坐骨神经痛的随机对照试验(RCT),检...目的系统评价普瑞巴林治疗坐骨神经痛的有效性及安全性。方法计算机检索PubMed、Embase、Cochrane Library、Web of Science、Medline、CNKI、VIP、WanFang Data和SinoMed数据库,搜集有关普瑞巴林治疗坐骨神经痛的随机对照试验(RCT),检索时限均从建库至2025年4月1日。由2名研究者独立筛选文献、提取资料并评价纳入研究的偏倚风险后,采用RevMan 5.3软件进行Meta分析。结果共纳入9个RCT,包括989例患者。Meta分析结果显示,普瑞巴林组与对照组相比在疼痛评分方面差异有统计学意义[SMD=-0.44,95%CI(-0.88,-0.01),P=0.05];亚组分析结果显示,普瑞巴林组的疼痛视觉模拟评分量表(VAS)评分较低[SMD=-0.73,95%CI(-1.04,-0.42),P<0.05],而2组的疼痛数字评价量表(NRS)评分差异无统计学意义[SMD=0.25,95%CI(-0.02,0.52),P=0.08],普瑞巴林的镇痛效果与安慰剂相当[SMD=0.25,95%CI(-0.02,0.52),P=0.08],但优于卡马西平[SMD=-0.85,95%CI(-1.07,-0.62),P<0.05];不同起始剂量、样本量的亚组分析结果显示,2组治疗后疼痛评分差异均无统计学意义(P>0.05);普瑞巴林组总有效率优于对照组[OR=3.86,95%CI(1.47,10.11),P<0.05];2组在Oswestry功能障碍评分、患者总体印象变化(PGIC)评分显著改善率及药品不良事件发生风险方面差异均无统计学意义(P>0.05),但使用普瑞巴林后头晕发生率[RR=2.59,95%CI(1.65,4.07),P<0.05],头痛、恶心、呕吐发生率[RR=1.99,95%CI(1.08,3.65),P=0.03]显著升高。描述性分析结果显示,普瑞巴林组与安慰剂或利马前列素组在生活质量改善方面差异无统计学意义(P>0.05)。结论现有证据表明,对于坐骨神经痛患者,普瑞巴林在降低疼痛评分及Oswestry功能障碍评分、改善PGIC评分和生活质量方面有效性不足,且存在显著的神经系统和胃肠道不良事件发生风险。受纳入研究数量和质量限制,上述结论尚需开展更多高质量研究予以验证。展开更多
In reliability analyses,the absence of a priori information on the most probable point of failure(MPP)may result in overlooking critical points,thereby leading to biased assessment outcomes.Moreover,second-order relia...In reliability analyses,the absence of a priori information on the most probable point of failure(MPP)may result in overlooking critical points,thereby leading to biased assessment outcomes.Moreover,second-order reliability methods exhibit limited accuracy in highly nonlinear scenarios.To overcome these challenges,a novel reliability analysis strategy based on a multimodal differential evolution algorithm and a hypersphere integration method is proposed.Initially,the penalty function method is employed to reformulate the MPP search problem as a conditionally constrained optimization task.Subsequently,a differential evolution algorithm incorporating a population delineation strategy is utilized to identify all MPPs.Finally,a paraboloid equation is constructed based on the curvature of the limit-state function at the MPPs,and the failure probability of the structure is calculated by using the hypersphere integration method.The localization effectiveness of the MPPs is compared through multiple numerical cases and two engineering examples,with accuracy comparisons of failure probabilities against the first-order reliability method(FORM)and the secondorder reliability method(SORM).The results indicate that the method effectively identifies existing MPPs and achieves higher solution precision.展开更多
In this article,the progress of marine geographic information system(MGIS) in China during 2006?2010 is reviewed with emphases on generic MGIS,advanced MGIS and MGIS-based applications.Generic MGIS can be divided into...In this article,the progress of marine geographic information system(MGIS) in China during 2006?2010 is reviewed with emphases on generic MGIS,advanced MGIS and MGIS-based applications.Generic MGIS can be divided into two categories:data-oriented MGIS and user-oriented MGIS,recent achievements of which by Chinese researchers are summarized respectively.Advanced MGIS mainly involves the establishment of 3D virtual marine environment and 'Digital Ocean'.An overview of the 3D MGIS based simulations in the context of ocean phenomena,ocean engineering and ocean battlefield is also presented.Several sug-gestions for future development of MGIS in China are proposed,and trends of development are addressed.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.12334001,52461160301,52322311,52427802,12222414)the National Key R&D Program of China (Grant Nos.2024YFA1208201,2021YFA1400500,2021YFA1400204)the Youth Innovation Promotion Association of the CAS (Grant Nos.Y2022003 and 2020009)。
文摘Hafnia-based ferroelectrics have emerged as promising materials for next-generation nanoelectronics owing to their robust nanoscale properties and compatibility with metal-oxide-semiconductor technology.However,their metastable nature remains a key challenge for practical implementation.Utilizing scanning transmission electron microscopy,we investigated the atomic-scale mechanisms governing ferroelectric transitions and the metastability of polar phases in 10-nm-thick Hf_(0.5)Zr_(0.5)O_(2)thin films.Our results demonstrate that oxygen vacancies,coupled with rhombohedral distortions of the cation lattice,facilitate ferroelectric phase transitions and enable robust polar switching through adaptive processes,including cell-by-cell oxygen displacement and domain-wall-mediated nucleation and growth.These findings underscore the pivotal role of oxygen vacancies and lattice distortions in stabilizing polar phases and provide detailed insights into the atomic structures and transition dynamics of polymorphic Hf_(0.5)Zr_(0.5)O_(2-x),thereby advancing its potential for practical device applications.
基金supported by the Beijing Natural Science Foundation(Grant No.JQ24002)the National Key Basic Research Program of China(Grant No.2020YFA0309100)+3 种基金the National Natural Science Foundation of China(Grant Nos.U22A20263,52250308,12304158,12325401,12274069,12404102,and 12474096)the Chinese Academy of Sciences(CAS)Project for Young Scientists in Basic Research(Grant No.YSBR-084)the CAS Youth Interdisciplinary Team,the Guangdong Basic and Applied Basic Research Foundation(Grant No.2022B1515120014)the Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology,and the International Young Scientist Fellowship of Institute of Physics,CAS.
文摘Heterointerfaces have been pivotal in unveiling extraordinary interfacial properties and enabling multifunctional material platforms.Despite extensive research on all-oxide interfaces,heterointerfaces between different material classes,such as oxides and nitrides,remain underexplored.Here we present the fabrication of atomically sharp heterointerfaces between antiperovskite Ni_(3)InN and perovskite SrVO_(3).Leveraging layer-resolved scanning transmission electron microscopy and electron energy loss spectroscopy,we identified pronounced charge transfer across the well-ordered interface.First-principles calculations confirmed our experimental observations and further predicted an emergent magnetic moment within the Ni_(3)InN layer due to the charge transfer.These findings pave the way for novel electronic and spintronic applications by enabling tunable interfacial properties in nitride/oxide systems.
基金National Natural Science Foundation of China(No.52375236)Fundamental Research Funds for the Central Universities of China(No.23D110316)。
文摘In reliability analyses,the absence of a priori information on the most probable point of failure(MPP)may result in overlooking critical points,thereby leading to biased assessment outcomes.Moreover,second-order reliability methods exhibit limited accuracy in highly nonlinear scenarios.To overcome these challenges,a novel reliability analysis strategy based on a multimodal differential evolution algorithm and a hypersphere integration method is proposed.Initially,the penalty function method is employed to reformulate the MPP search problem as a conditionally constrained optimization task.Subsequently,a differential evolution algorithm incorporating a population delineation strategy is utilized to identify all MPPs.Finally,a paraboloid equation is constructed based on the curvature of the limit-state function at the MPPs,and the failure probability of the structure is calculated by using the hypersphere integration method.The localization effectiveness of the MPPs is compared through multiple numerical cases and two engineering examples,with accuracy comparisons of failure probabilities against the first-order reliability method(FORM)and the secondorder reliability method(SORM).The results indicate that the method effectively identifies existing MPPs and achieves higher solution precision.
基金supported by the Natural Science Foundation of China under projects 40730530 and 41076115the National Basic Research Program of China under project 2009CB723903the National High-Tech Research and Development Program of China under project 2008AA121701
文摘In this article,the progress of marine geographic information system(MGIS) in China during 2006?2010 is reviewed with emphases on generic MGIS,advanced MGIS and MGIS-based applications.Generic MGIS can be divided into two categories:data-oriented MGIS and user-oriented MGIS,recent achievements of which by Chinese researchers are summarized respectively.Advanced MGIS mainly involves the establishment of 3D virtual marine environment and 'Digital Ocean'.An overview of the 3D MGIS based simulations in the context of ocean phenomena,ocean engineering and ocean battlefield is also presented.Several sug-gestions for future development of MGIS in China are proposed,and trends of development are addressed.
