Topological phonon is a new frontier in the field of topological materials.Different from electronic structures,phonons are bosons and most topological phonons are metallic form.Previous studies about topological phon...Topological phonon is a new frontier in the field of topological materials.Different from electronic structures,phonons are bosons and most topological phonons are metallic form.Previous studies about topological phonon states were focused on three-dimensional(3D)materials.展开更多
Cyber attackers have constantly updated their attack techniques to evade antivirus software detection in recent years.One popular evasion method is to execute malicious code and perform malicious actions only in memor...Cyber attackers have constantly updated their attack techniques to evade antivirus software detection in recent years.One popular evasion method is to execute malicious code and perform malicious actions only in memory.Mali-cious programs that use this attack method are called memory-resident malware,with excellent evasion capability,and have posed huge threats to cyber security.Traditional static and dynamic methods are not effective in detect-ing memory-resident malware.In addition,existing memory forensics detection solutions perform unsatisfactorily in detection rate and depend on massive expert knowledge in memory analysis.This paper proposes MRm-DLDet,a state-of-the-art memory-resident malware detection framework,to overcome these drawbacks.MRm-DLDet first builds a virtual machine environment and captures memory dumps,then creatively processes the memory dumps into RGB images using a pre-processing technique that combines deduplication and ultra-high resolution image cropping,followed by our neural network MRmNet in MRm-DLDet to fully extract high-dimensional features from memory dump files and detect them.MRmNet receives the labeled sub-images of the cropped high-resolution RGB images as input of ResNet-18,which extracts the features of the sub-images.Then trains a network of gated recurrent units with an attention mechanism.Finally,it determines whether a program is memory-resident malware based on the detection results of each sub-image through a specially designed voting layer.We created a high-quality dataset consisting of 2,060 benign and memory-resident programs.In other words,the dataset contains 1,287,500 labeled sub-images cut from the MRm-DLDet transformed ultra-high resolution RGB images.We implement MRm-DLDet for Windows 10,and it performs better than the latest methods,with a detection accuracy of up to 98.34%.Moreover,we measured the effects of mimicry and adversarial attacks on MRm-DLDet,and the experimental results demonstrated the robustness of MRm-DLDet.展开更多
From birth to adulthood,we often align our behaviors,attitudes,and opinions with a majority,a phenomenon known as social conformity.A seminal framework has proposed that conformity behaviors are mainly driven by three...From birth to adulthood,we often align our behaviors,attitudes,and opinions with a majority,a phenomenon known as social conformity.A seminal framework has proposed that conformity behaviors are mainly driven by three fundamental motives:a desire to gain more information to be accurate,to obtain social approval from others,and to maintain a favorable self-concept.Despite extensive interest in neuroimaging investigation of social conformity,the relationship between brain systems and these fundamental motivations has yet to be established.Here,we reviewed brain imaging findings of social conformity with a componential framework,aiming to reveal the neuropsychological substrates underlying different conformity motivations.First,information-seeking engages the evaluation of social information,information integration,and modification of task-related activity,corresponding to brain networks implicated in reward,cognitive control,and tasks at hand.Second,social acceptance involves the anticipation of social acceptance or rejection and mental state attribution,mediated by networks of reward,punishment,and mentalizing.Third,self-enhancement entails the excessive representation of positive self-related information and suppression of negative self-related information,ingroup favoritism and/or outgroup derogation,and elaborated mentalizing processes to the ingroup,supported by brain systems of reward,punishment,and mentalizing.Therefore,recent brain imaging studies have provided important insights into the fundamental motivations of social conformity in terms of component processes and brain mechanisms.展开更多
Mg基制氢材料具有来源广泛、反应温和、工艺简单、安全可控、理论产氢量高等优势,是当今的研究热点.本文提出采用高能球磨方法制备Mg-Bi系含氧酸盐Bi_(x)M_(y)O_(z)(M=Ti,V,Cr,Mo,W)复合材料以改善Mg水解制氢性能.本工作研究发现,掺杂Bi...Mg基制氢材料具有来源广泛、反应温和、工艺简单、安全可控、理论产氢量高等优势,是当今的研究热点.本文提出采用高能球磨方法制备Mg-Bi系含氧酸盐Bi_(x)M_(y)O_(z)(M=Ti,V,Cr,Mo,W)复合材料以改善Mg水解制氢性能.本工作研究发现,掺杂Bi_(2)Mo O_(6)的Mg基复合制氢材料具有较好的性能,Mg-7 wt%Bi_(2)Mo O_(6)在298.15 K的最大产氢速率为756.1 m L g^(-1)min(-1).通过引入多壁碳纳米管(CNTs)可以进一步改善Mg-Bi_(2)Mo O_(6)的产氢性能,Mg-7 wt%Bi_(2)Mo O_(6)/CNTs的最大产氢速率达2172.4 m L g^(-1)min(-1),产氢活化能下降至23.6 k J mol^(-1).X光电子能谱(XPS)分析表明Bi_(2)Mo O_(6)/CNTs与Mg在球磨过程中发生固相反应生成Bi单质.密度泛函理论(DFT)计算揭示Bi原子掺杂可改变Mg的局域电荷分布,增强Mg对H_(2)O的吸附能,并降低H_(2)O解离后H原子的吸附能,促进水解反应进行.展开更多
Safe,compact,lightweight and cost-effective hydrogen storage is one of the main challenges that need to be addressed to effectively deploy the hydrogen economy.LiAlH_(4),as a solid-state hydrogen storage material,pres...Safe,compact,lightweight and cost-effective hydrogen storage is one of the main challenges that need to be addressed to effectively deploy the hydrogen economy.LiAlH_(4),as a solid-state hydrogen storage material,presents several advantages such as high hydrogen storage capacity,low price and abundant sources.Unfortunately,neither thermodynamic nor kinetic properties of dehydrogenation for LiAlH_(4)can fulfill the requirements of practical application.Thus,a series of spinel ferrite nanoparticles such as XFe_(2)O_(4)(X=Ni,Co,Mn,Cu,Zn,Fe)were prepared by using the modified thermal decomposition method,and then doped into LiAlH_(4)by using ball milling.Our results show that LiAlH_(4)doped with 7 wt%NiFe_(2)O_(4)starts to release hydrogen at 69.1°C,and the total amount of hydrogen released is 7.29 wt%before 300°C.The activation energies of the two-step hydrogen release reactions of LiAlH_(4)doped with 7 wt%NiFe_(2)O_(4)are 42.32 kJ mol^(-1)and 71.42 k J mol,which are 59.0%and 63.6%lower than those of as-received LiAlH_(4),respectively.Combining the density functional theory(DFT)calculations,we reveal that both the presence of Ni FeOand in-situ formed AlNiin ball-milling decrease the desorption energy barrier of Al-H bonding in LiAlH_(4)and accelerate the breakdown of Al-H bonding through the interfacial charge transfer and the dehybridization of the Al-H cluster.Thus,the experimental and theoretical results open a new avenue toward designing high effective catalysts applied to LiAlH_(4)as a candidate for hydrogen storage.展开更多
Considering the current volume of materials data,it is impossible to investigate each compound by trial-and-error experiments involving labor-intensive efforts.The scientists in the Shenyang National Laboratory for Ma...Considering the current volume of materials data,it is impossible to investigate each compound by trial-and-error experiments involving labor-intensive efforts.The scientists in the Shenyang National Laboratory for Materials Science developed a home-made software,HT-PHONON,selecting over 5,000 topological phononic(TP)materials out of 13,000 materials within high-throughput computational materials design combined with a big data analysis.Furthermore,an online database for TP materials has been constructed,which is now freely open to the public community through the website www.phonon.synl.ac.cn.In this perspective,we review this platform and discuss exciting consequences of TP materials that are expected from manipulating the phonons,linking fundamental research to potential applications.展开更多
基金supported by the National Key R&D Program of China(Grant No.2021YFB3501503)the National Natural Science Foundation of China(Grant Nos.52271016 and 52188101)Liaoning Province(Grant No.XLYC2203080)。
文摘Topological phonon is a new frontier in the field of topological materials.Different from electronic structures,phonons are bosons and most topological phonons are metallic form.Previous studies about topological phonon states were focused on three-dimensional(3D)materials.
基金supported by the Youth Innovation Promotion Association CAS(No.2019163)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDC02040100)the Key Laboratory of Network Assessment Technology at Chinese Academy of Sciences and Beijing Key Laboratory of Network security and Protection Technology.
文摘Cyber attackers have constantly updated their attack techniques to evade antivirus software detection in recent years.One popular evasion method is to execute malicious code and perform malicious actions only in memory.Mali-cious programs that use this attack method are called memory-resident malware,with excellent evasion capability,and have posed huge threats to cyber security.Traditional static and dynamic methods are not effective in detect-ing memory-resident malware.In addition,existing memory forensics detection solutions perform unsatisfactorily in detection rate and depend on massive expert knowledge in memory analysis.This paper proposes MRm-DLDet,a state-of-the-art memory-resident malware detection framework,to overcome these drawbacks.MRm-DLDet first builds a virtual machine environment and captures memory dumps,then creatively processes the memory dumps into RGB images using a pre-processing technique that combines deduplication and ultra-high resolution image cropping,followed by our neural network MRmNet in MRm-DLDet to fully extract high-dimensional features from memory dump files and detect them.MRmNet receives the labeled sub-images of the cropped high-resolution RGB images as input of ResNet-18,which extracts the features of the sub-images.Then trains a network of gated recurrent units with an attention mechanism.Finally,it determines whether a program is memory-resident malware based on the detection results of each sub-image through a specially designed voting layer.We created a high-quality dataset consisting of 2,060 benign and memory-resident programs.In other words,the dataset contains 1,287,500 labeled sub-images cut from the MRm-DLDet transformed ultra-high resolution RGB images.We implement MRm-DLDet for Windows 10,and it performs better than the latest methods,with a detection accuracy of up to 98.34%.Moreover,we measured the effects of mimicry and adversarial attacks on MRm-DLDet,and the experimental results demonstrated the robustness of MRm-DLDet.
基金supported by the National Natural Science Foundation of China(32271126,31900757,32020103008,31920103009)Natural Science Foundation of Guangdong Province(2021A1515010746)+1 种基金the Major Project of National Social Science Foundation(20&ZD153)Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions(2019SHIBS0003).
文摘From birth to adulthood,we often align our behaviors,attitudes,and opinions with a majority,a phenomenon known as social conformity.A seminal framework has proposed that conformity behaviors are mainly driven by three fundamental motives:a desire to gain more information to be accurate,to obtain social approval from others,and to maintain a favorable self-concept.Despite extensive interest in neuroimaging investigation of social conformity,the relationship between brain systems and these fundamental motivations has yet to be established.Here,we reviewed brain imaging findings of social conformity with a componential framework,aiming to reveal the neuropsychological substrates underlying different conformity motivations.First,information-seeking engages the evaluation of social information,information integration,and modification of task-related activity,corresponding to brain networks implicated in reward,cognitive control,and tasks at hand.Second,social acceptance involves the anticipation of social acceptance or rejection and mental state attribution,mediated by networks of reward,punishment,and mentalizing.Third,self-enhancement entails the excessive representation of positive self-related information and suppression of negative self-related information,ingroup favoritism and/or outgroup derogation,and elaborated mentalizing processes to the ingroup,supported by brain systems of reward,punishment,and mentalizing.Therefore,recent brain imaging studies have provided important insights into the fundamental motivations of social conformity in terms of component processes and brain mechanisms.
文摘Mg基制氢材料具有来源广泛、反应温和、工艺简单、安全可控、理论产氢量高等优势,是当今的研究热点.本文提出采用高能球磨方法制备Mg-Bi系含氧酸盐Bi_(x)M_(y)O_(z)(M=Ti,V,Cr,Mo,W)复合材料以改善Mg水解制氢性能.本工作研究发现,掺杂Bi_(2)Mo O_(6)的Mg基复合制氢材料具有较好的性能,Mg-7 wt%Bi_(2)Mo O_(6)在298.15 K的最大产氢速率为756.1 m L g^(-1)min(-1).通过引入多壁碳纳米管(CNTs)可以进一步改善Mg-Bi_(2)Mo O_(6)的产氢性能,Mg-7 wt%Bi_(2)Mo O_(6)/CNTs的最大产氢速率达2172.4 m L g^(-1)min(-1),产氢活化能下降至23.6 k J mol^(-1).X光电子能谱(XPS)分析表明Bi_(2)Mo O_(6)/CNTs与Mg在球磨过程中发生固相反应生成Bi单质.密度泛函理论(DFT)计算揭示Bi原子掺杂可改变Mg的局域电荷分布,增强Mg对H_(2)O的吸附能,并降低H_(2)O解离后H原子的吸附能,促进水解反应进行.
基金financially supported by the National Key Research and Development Program of China(Nos.2018YFB1502103,2018YFB1502105)the National Natural Science Foundation of China(Nos.U20A20237,51863005,51462006,51102230,52101245,51871065 and 51971068)+4 种基金the Scientific Research and Technology Development Program of Guangxi(Nos.AA19182014,AD17195073,AA17202030–1,AB21220027)the Guangxi Natural Science Foundation(Nos.2021GXNSFBA075057,2018GXNSFDA281051,2014GXNSFAA118401 and 2013GXNSFBA019244)Guangxi Bagui Scholar Foundation,Guangxi Collaborative Innovation centre of Structure and Property for New Energy and Materials,Guangxi Advanced Functional Materials Foundation and Application Talents Small Highlands,Chinesisch-Deutsche Kooperationsgruppe(No.GZ1528)the Study Abroad Program for Graduate Student of Guilin University of Electronic Technology(No.GDYX2019020)the Innovation Project of Guet Graduate Education(Nos.2020YCXS119,2019YCXS114 and 2018YJCX88)。
文摘Safe,compact,lightweight and cost-effective hydrogen storage is one of the main challenges that need to be addressed to effectively deploy the hydrogen economy.LiAlH_(4),as a solid-state hydrogen storage material,presents several advantages such as high hydrogen storage capacity,low price and abundant sources.Unfortunately,neither thermodynamic nor kinetic properties of dehydrogenation for LiAlH_(4)can fulfill the requirements of practical application.Thus,a series of spinel ferrite nanoparticles such as XFe_(2)O_(4)(X=Ni,Co,Mn,Cu,Zn,Fe)were prepared by using the modified thermal decomposition method,and then doped into LiAlH_(4)by using ball milling.Our results show that LiAlH_(4)doped with 7 wt%NiFe_(2)O_(4)starts to release hydrogen at 69.1°C,and the total amount of hydrogen released is 7.29 wt%before 300°C.The activation energies of the two-step hydrogen release reactions of LiAlH_(4)doped with 7 wt%NiFe_(2)O_(4)are 42.32 kJ mol^(-1)and 71.42 k J mol,which are 59.0%and 63.6%lower than those of as-received LiAlH_(4),respectively.Combining the density functional theory(DFT)calculations,we reveal that both the presence of Ni FeOand in-situ formed AlNiin ball-milling decrease the desorption energy barrier of Al-H bonding in LiAlH_(4)and accelerate the breakdown of Al-H bonding through the interfacial charge transfer and the dehybridization of the Al-H cluster.Thus,the experimental and theoretical results open a new avenue toward designing high effective catalysts applied to LiAlH_(4)as a candidate for hydrogen storage.
基金We are grateful for support from the National Natural Science Fundation for Outstanding Young Scholars(Grant No.51725103).
文摘Considering the current volume of materials data,it is impossible to investigate each compound by trial-and-error experiments involving labor-intensive efforts.The scientists in the Shenyang National Laboratory for Materials Science developed a home-made software,HT-PHONON,selecting over 5,000 topological phononic(TP)materials out of 13,000 materials within high-throughput computational materials design combined with a big data analysis.Furthermore,an online database for TP materials has been constructed,which is now freely open to the public community through the website www.phonon.synl.ac.cn.In this perspective,we review this platform and discuss exciting consequences of TP materials that are expected from manipulating the phonons,linking fundamental research to potential applications.