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Discovery of new MAX-phase-like layered ternary carbide V_(8)P_(6)C:Crystal structure,thermal expansion,and elastic properties

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Journal of Materials Science & technology 2024年第7期174卷 55-62页

作者： H.X.Chen l.Sheng Z.l.Zhang X.C.Wen D.l.Yang X.Y.Ye P.Q.Dai School of Materials Science and Engineering Fujian University of TechnologyFuzhou 350118China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of ScienceBeijing 100049China Fujian Provincial Key laboratory of Advanced Materials Processing and Application Fuzhou 350118China State Key laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China

Due to the laminated structure,MAX phases and MAX-phase-like compounds possess outstanding dam-age tolerance capability with good thermal/electrical conductivity and other charming functional prop-erties,showing a bright future for structural-functional ***,a new MAX-phase-like ternary car-bide V_(8)P_(6)C with layered characteristics was *** to the alternate stacking of hexagonal-arranged M/A/X atom layers in MAX phases,V_(8)P_(6)C has a layered structure formed by a repeated stacking of the slabs consisting of V_(6)C-octahedrons and VP 6-distorted-octahedrons in three-atomic layers *** thermal expansion anisotropy was revealed,with the thermal expansion coefficients(tECs)along a-axis,c-axis,and the average value,equal toα_(a)=8.55(5)μK^(−1),α_(c)=10.23(5)μK^(−1),andα_(l)=9.14(5)μK^(−1),*** dilation along the c-axis was mainly dominated by out-plane V-P bonds be-tween layered *** to the pressure-dependent lattice parameters,the polycrystalline bulk modulus(B_(0)=185(9)GPa)and high compressibility anisotropy factor(B_(a)/B_(c)=1.64)was ***-while,the second-order elastic constants were calculated,and the elastic moduli,E=303 GPa,B=198 GPa,G=122 GPa,andν=0.246,were *** the weak connection between layer slabs by out-plane V1-P bond was revealed by the bond stiffness model,with a bond stiffness close to the M-A bond in MAX ***,good damage tolerance capability was predicted according to Paugh’s ratio(G/B=0.616)and Cauchy pressure(P_(a)=0 GPa,P_(c)=-7.5 GPa),even better than those of typical MAX *** discovery of V_(8)P_(6)C provides a new member of MAX-phase-like damage-tolerant ceramic with relatively low density,moderate thermal expansion,and anisotropic compressibility,and the unique lay-ered structure is inspiring for exploring new layered ternary ceramics.

关键词： New ternary carbide MAX phase thermal expansion Elastic constants Anisotropy

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Decorating crystalline YFe_(2-x)Al_(x) on the Mg_(60)la_(10)Ni_(20)Cu_(10) amorphous alloy as “hydrogen pump” to realize fast de/hydrogenation

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Journal of Materials Science & technology 2024年第6期173卷 72-79页

作者： l.J.Huang H.Wang l.Z.Ouyang M.Zhu H.J.lin School of Materials Science and Engineering Key Laboratory of Advanced Energy Storage Materials of Guangdong ProvinceSouth China University of TechnologyGuangzhou 510641China Institute of Advanced Wear&Corrosion Resistance and Functional Materials Jinan UniversityGuangzhou 510632China

Mg-based amorphous alloys are one of the potential hydrogen storage materials but suffer from sluggish dehydrogenation/hydrogenation(de/hydrogenation)*** this work,as a new strategy,a hydrogen pump is built on the surface of amorphous alloys to solve this *** milling crystalline YFe_(2-x)Al_(x) hydrogen storage alloy with Mg_(60)la_(10)Ni_(20)Cu_(10) amorphous alloy,fine crystalline particles were seeded on amorphous alloy powder to form a“strawberry”*** to the tEM observation,a metallurgical bonding boundary formed between the Mg-based amorphous matrix and the Y-Fe-Al crystalline *** microstructure and de/hydrogenation kinetics investigation,the“hydrogen pump”effect of the seeded crystalline alloy was confirmed,which makes it much easier for the hydrogen to dissociate on and diffuse through the surface of the Mg-based amorphous *** such effect,the H absorption rate of Mg_(60)la_(10)Ni_(20)Cu_(10) amorphous alloy became almost eight times faster and it absorbs ~2.8 wt.% in 1 h at 130℃ under 4.5 MPa-H_(2).Further,fast hydrogenation can even achieve at 70℃ and the low-temperature dehydrogenation kinetics of the amorphous hydride can be also greatly *** present work proves that surface modification is of great importance for obtaining Mg-based amorphous alloy with ideal hydrogen storage performance.

关键词： Hydrogen storage Mg-based amorphous alloy Hydrogen pump Composite structure

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盐胁迫下根施AMF和褪黑素对紫花苜蓿生长、光合特征以及抗氧化系统的影响

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草业学报 2024年第6期33卷 64-75页

作者：谭英尹豪北京市朝阳区四得公园管理处北京100016 北京林业大学园林学院北京100083 城乡生态环境北京实验室北京100083

本试验旨在探究盐胁迫下根施丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)和褪黑素处理对紫花苜蓿生长、光合特征和抗氧化系统的影响。设置盐胁迫下(100 mmol·l^(-1)NaCl)对紫花苜蓿根施褪黑素(0、50、100、150、200μmol·l^(-1)... 详细信息

本试验旨在探究盐胁迫下根施丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)和褪黑素处理对紫花苜蓿生长、光合特征和抗氧化系统的影响。设置盐胁迫下(100 mmol·l^(-1)NaCl)对紫花苜蓿根施褪黑素(0、50、100、150、200μmol·l^(-1))并接种AMF变形球囊霉以及不接种对照共10个处理。结果表明,AMF与紫花苜蓿能形成稳定共生关系,根施褪黑素能够增加AMF菌根侵染率以及泡囊数,菌根侵染率最高达65.2%。在根施褪黑素100μmol·l^(-1)水平下,与对照相比,接种AMF处理的紫花苜蓿总生物量、叶绿素a、叶绿素b含量分别提高5.4%、7.3%和45.3%,根冠比下降39.5%;净光合速率(Pn)、蒸腾速率(tr)、胞间CO_(2)浓度(Ci)和气孔导度(Gs)分别增加23.3%、28.3%、17.6%和14.1%;最大光化学效率(F_(v)/F_(m))和PSⅡ潜在活性(F_(v)/F_(o))分别提高19.6%和22.9%;叶片中氮、磷、钾含量分别是对照的1.4、1.1和1.2倍,钠含量比对照下降11.1%;紫花苜蓿铜锌超氧化物歧化酶(Cu/ZnSOD)基因表达量提高33.9%,POD基因表达量提高16.8%,CAt基因表达量提高6.4%,抗氧化酶系统中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAt)活性也表现为一定幅度的增加。结论认为,AMF和褪黑素均能够增加紫花苜蓿对氮、磷、钾等养分的吸收量而降低对钠的吸收量,进而提高光合作用能力以及叶绿素a、b含量和叶绿素荧光参数,上调Cu/Zn-SOD、POD、CAt基因表达量并显著增加SOD、POD、CAt等活性,其中以接种AMF配合根施100μmol·l^(-1)褪黑素改善紫花苜蓿生长状况、光合特征,提高抗盐性的作用最为显著。

关键词：丛枝菌根真菌褪黑素紫花苜蓿光合叶绿素养分

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Distributed swarm control for multi-robot systems inspired by shepherding behaviors

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Science China(technological Sciences) 2024年第7期67卷 2191-2202页

作者： SUN GuiBin GU HaiBo lÜJinHu School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Zhongguancun laboratory Beijing 100094China

Swarming behaviors play an eminent role in both biological and engineering research, and show great potential applications in many emerging fields. traditional swarming models still lack integrity, uniformity, and stability in swarm forming processes,resulting in fragmentation and void phenomena. Inspired by the shepherding behaviors observed in nature, we propose an integrated negotiation-control scheme for distributed swarm control of massive robots. the core idea of this scheme is that the robots at the boundary of the group herd the internal robots to form an equilibrium swarm. For this purpose, we introduce a concept of virtual group center towards which boundary robots herd internal robots. then, a distributed negotiation mechanism is designed to allow each robot to negotiate the virtual group center only through local interactions with its neighbors. After that, we propose a shepherding-inspired swarm control law to drive a group of robots to form an integrated, uniform, and stable configuration from any initial states. Both numerical and flight simulations are presented to verify the effectiveness of our proposed swarm control scheme.

关键词： swarm control multi-robot system negotiation-control scheme shepherding behavior

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Promoting Older Adults' Engagement in Disaster Recovery through Supportive Relationships, Partnerships, and Collaboration: Perspectives of Social Work Practitioners and Human Service Professionals

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International Journal of Disaster Risk Science 2024年第2期15卷 265-276页

作者： Julie l.Drolet Mahed Choudhury Faculty of Social Work University of CalgaryEdmontonAB T5J 4P6Canada

Shifting demographics—that is, the growing number of older adults in Canada and internationally—and intersecting climatic risks create a complex landscape of aging in place in disaster contexts. Some older adults are vulnerable due to their underlying health conditions and limited physical mobility. Yet they also exhibit resilience in a distinct manner, owing to their wealth of knowledge, wisdom, and ability to navigate adversities. this article elucidates potential avenues for promoting the involvement of older adults in disaster recovery efforts. Our intention is to recognize and foster older adult resilience and mitigate vulnerability by drawing upon insights from the study titled “In the Aftermath of the 2016 Alberta Wildfires: the Role of Social Work Practitioners and Human Service Professionals in long-term Disaster Recovery.” Employing a qualitative research approach, that study recruited 51 participants for semistructured interviews and focus groups. A thematic analysis of the collected data unveiled the pivotal roles played by social workers and human service practitioners in facilitating recovery from the 2016 wildfires in the research. Notably, three overarching themes emerged concerning the promotion of older adults' involvement in disaster recovery: fostering supportive relationships, building partnerships and enhancing collaboration, and addressing ongoing challenges. these findings offer valuable insights into how social work practitioners and human service professionals can effectively facilitate the engagement of older adults in disaster recovery initiatives. this article emphasizes the significance of actively promoting the participation of older adults in disaster mitigation efforts, thereby fostering greater resilience within communities.

关键词： Alberta wildfires Canada Disaster recovery Older adults Partnerships and collaboration Social work

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Crocus genome reveals the evolutionary origin of crocin biosynthesis

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Acta Pharmaceutica Sinica B 2024年第4期14卷 1878-1891页

作者： Zhichao Xu Shanshan Chen Yalin Wang Ya tian Xiaotong Wang tianyi Xin Zishan li Xin Hua Shengnan tan Wei Sun Xiangdong Pu Hui Yao Ranran Gao Jingyuan Song Key lab of Chinese Medicine Resources Conservation State Administration of Traditional Chinese Medicine of the People's Republic of ChinaInstitute of Medicinal Plant DevelopmentChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100193China State Key laboratory of Basis and New Drug Development of Natural and Nuclear Drugs Engineering Research Center of Chinese Medicine ResourceMinistry of EducationBeijing 100193China College of life Science Northeast Forestry UniversityHarbin 150040China Key laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine China Academy of Chinese Medical SciencesInstitute of Chinese Materia MedicaBeijing 100700China Analysis and testing Center of Northeast Forestry University Harbin 150040China School of Pharmacy Anhui Medical UniversityInflammation and Immune Mediated Diseases Laboratory of Anhui ProvinceHefei 230032China

Crocus sativus (saffron) is a globally autumn-flowering plant, and its stigmas are the most expensive spice and valuable herb medicine. Crocus specialized metabolites, crocins, are biosynthesized in distant species, Gardenia (eudicot) and Crocus (monocot), and the evolution of crocin biosynthesis remains poorly understood. With the chromosome-level Crocus genome assembly, we revealed that two rounds of lineage-specific whole genome triplication occurred, contributing important roles in the production of carotenoids and apocarotenoids. According to the kingdom-wide identification, phylogenetic analysis, and functional assays of carotenoid cleavage dioxygenases (CCDs), we deduced that the duplication, site positive selection, and neofunctionalization of Crocus-specific CCD2 from CCD1 members are responsible for the crocin biosynthesis. In addition, site mutation of CsCCD2 revealed the key amino acids, including I143, l146, R161, E181, t259, and S292 related to the catalytic activity of zeaxanthin cleavage. Our study provides important insights into the origin and evolution of plant specialized metabolites, which are derived by duplication events of biosynthetic genes.

关键词： Crocus sativus WGt Crocin biosynthesis Carotenoids Apocarotenoids CCDs

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Variational data encoding and correlations in quantum-enhanced machine learning

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Chinese Physics B 2024年第9期33卷 298-306页

作者： Ming-Hao Wang Hua l¨u School of Physics Hubei UniversityWuhan 430062China School of Science Hubei University of TechnologyWuhan 430068China

leveraging the extraordinary phenomena of quantum superposition and quantum correlation,quantum computing offers unprecedented potential for addressing challenges beyond the reach of classical *** paper tackles two pivotal challenges in the realm of quantum computing:firstly,the development of an effective encoding protocol for translating classical data into quantum states,a critical step for any quantum *** encoding strategies can significantly influence quantum computer ***,we address the need to counteract the inevitable noise that can hinder quantum *** primary contribution is the introduction of a novel variational data encoding method,grounded in quantum regression algorithm *** adapting the learning concept from machine learning,we render data encoding a learnable *** allowed us to study the role of quantum correlation in data *** numerical simulations of various regression tasks,we demonstrate the efficacy of our variational data encoding,particularly post-learning from instructional ***,we delve into the role of quantum correlation in enhancing task performance,especially in noisy *** findings underscore the critical role of quantum correlation in not only bolstering performance but also in mitigating noise interference,thus advancing the frontier of quantum computing.

关键词： quantum machine learning variational data encoding quantum correlation

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Stability and performance analysis of the compressed Kalman filter algorithm for sparse stochastic systems

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Science China(technological Sciences) 2024年第2期67卷 380-394页

作者： lI RongJiang GAN Die XIE SiYu lüJinHu Key laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China Zhongguancun laboratory Beijing 100049China School of Aeronautics and Astronautics University of Electronic Science and Technology of ChinaChengdu 611731China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

this paper considers the problem of estimating unknown sparse time-varying signals for stochastic dynamic *** deal with the challenges of extensive sparsity,we resort to the compressed sensing method and propose a compressed Kalman filter(KF)*** algorithm first compresses the original high-dimensional sparse regression vector via the sensing matrix and then obtains a KF estimate in the compressed low-dimensional ***,the original high-dimensional sparse signals can be well recovered by a reconstruction *** ensure stability and establish upper bounds on the estimation errors,we introduce a compressed excitation condition without imposing independence or stationarity on the system signal,and therefore suitable for feedback *** further present the performance of the compressed KF ***,we show that the mean square compressed tracking error matrix can be approximately calculated by a linear deterministic difference matrix equation,which can be readily evaluated,analyzed,and ***,a numerical example demonstrates that our algorithm outperforms the standard uncompressed KF algorithm and other compressed algorithms for estimating high-dimensional sparse signals.

关键词： sparse signal compressed sensing Kalman filter algorithm compressed excitation condition stochastic stability tracking performance

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Neural-network-based fully distributed formation control for nonlinear multi-agent systems with event-triggered communication

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Science China(technological Sciences) 2024年第1期67卷 209-220页

作者： ZHU Guoliang lIU KeXin GU HaiBo lÜJinHu School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Zhongguancun laboratory Beijing 100094China

this paper investigates the consensus-based formation control problem for multi-agent systems with unknown nonlinear *** achieve the desired formation,we propose two formation controllers to achieve the desired formation,one based on system states and the other on system *** proposed controllers utilize adaptive gains to avoid global information and neural networks to estimate and compensate for *** proposed event-triggered schemes avoid continuous communication among agents and exclude the Zeno *** analysis reveals that formation errors are bounded,and numerical simulations are used to validate the effectiveness of the proposed approaches.

关键词： formation control neural network adaptive control event-triggered communication multi-agent systems

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Nitrite-driven anaerobic ethane oxidation

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Environmental Science and Ecotechnology 2024年第5期21卷 361-368页

作者： Cheng-Cheng Dang Yin-Zhu Jin Xin tan Wen-Bo Nie Yang lu Bing-Feng liu De-Feng Xing Nan-Qi Ren Guo-Jun Xie State Key laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin150090China Key laboratory of the three Gorges Region's Eco-Environment Ministry of EducationCollege of Environment and EcologyChongqing UniversityChongqing400044China Water Innovation and Smart Environment laboratory School of Civil and Environmental EngineeringFaculty of EngineeringQueensland University of TechnologyBrisbaneQueensland4001Australia

Ethane,the second most abundant gaseous hydrocarbon in vast anoxic environments,is an overlooked greenhouse *** anaerobic oxidation of ethane can be driven by available electron acceptors such as sulfate and ***,despite nitrite being a more thermodynamically feasible electron acceptor than sulfate or nitrate,little is known about nitrite-driven anaerobic ethane *** this study,a microbial culture capable of nitrite-driven anaerobic ethane oxidation was enriched through the long-term operation of a nitrite-and-ethane-fed *** continuous operation,the nitrite removal rate and the theoretical ethane oxidation rate remained stable at approximately 25.0 mg NO_(2) eN l^(-1) d^(-1) and 11.48 mg C2H6 l^(-1) d^(-1),*** tests demonstrated that ethane is essential for nitrite removal in this microbial *** function analysis revealed that a species affiliated with a novel genus within the family Rhodocyclaceae,designated as'Candidatus Alkanivoras nitrosoreducens',may perform the nitrite-driven anaerobic ethane *** the proposed metabolic model,despite the absence of known genes for ethane conversion to ethyl-succinate and succinate-CoA ligase,'***'encodes a prospective fumarate addition pathway for anaerobic ethane oxidation and a complete denitrification pathway for nitrite reduction to *** findings advance our understanding of nitrite-driven anaerobic ethane oxidation,highlighting the previously overlooked impact of anaerobic ethane oxidation in natural ecosystems.

关键词： Anaerobic ethane oxidation Denitrification Microbial culture Fumarate addition pathway Greenhouse gas

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