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Learnware:small models do big

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Science China(Information Sciences) 2024年第1期67卷 39-50页

作者： zhi-Hua zhou zhi-Hao TAN National Key Laboratory for Novel Software Technology Nanjing University

There are complaints about current machine learning techniques such as the requirement of a huge amount of training data and proficient training skills,the difficulty of continual learning,the risk of catastrophic forgetting,and the leaking of data privacy/*** research efforts have been focusing on one of those concerned issues separately,paying less attention to the fact that most issues are entangled in *** prevailing big model paradigm,which has achieved impressive results in natural language processing and computer vision applications,has not yet addressed those issues,whereas becoming a serious source of carbon *** article offers an overview of the learnware paradigm,which attempts to enable users not to need to build machine learning models from scratch,with the hope of reusing small models to do things even beyond their original purposes,where the key ingredient is the specification which enables a trained model to be adequately identified to reuse according to the requirement of future users who know nothing about the model in advance.

关键词： artificial intelligence machine learning learnware

Miniaturized power detection module operating in millimeter wave band

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Journal of Electronic Science and Technology 2024年第2期22卷 69-76页

作者： Xiang zhou zhi-Yong Zhong School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China

The miniaturized broadband detection module can be embedded into the microwave application system such as the front end of the transmitter to detect the power or other parameters in real *** is highly prospective in military and scientific *** this paper,a broadband power detection module operating at 26.5 GHz-40.0 GHz is designed by using low-barrier Schottky diode as the detector and a comparator for threshold *** module can dynamically detect the power range between-10 dBm and 10 dBm with the detection accuracy of 0.1 ***,the temperature compensation circuit is also applied to improve the measurement *** a result,the resulted error low to±1 dB in the temperature range of -55℃ to +85℃ is *** designed module is encapsulated by a Kovar alloy with a small volume of 9 mm×6 mm×3 *** endows the designed module the advantages of small size,easy integration,and low cost,and even it is applicable to high-reliability environments such as satellites.

关键词： Diode Miniaturization Power detection Temperature compensation

Utilizing a metal-forging inspired chain combing strategy to enhance properties and expand applications of Nylon 66 plastic via heat inducing

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nano Research 2024年第3期17卷 2164-2171页

作者： Junyu Yang Jiangwei Zhang nan Wang Guangyuan zhou Division of Energy Materials Daglian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Innovation Center of Energy Material and Chemistry College of Chemistry and Chemical EngineeringInner Mongolia UniversityHohhot 010021China

The mechanical properties of engineering plastics can be enhanced through effective surface mechanical treatment(SMT),which can be applied to various types of engineering plastics,eliminating the limitations of conventional polymer processing and could potentially extend their applications and improve their performance and reliability as structural-functional *** by metal forging,this work proposes a simple and effective SMT strategy to enhance the mechanical properties of polyamide 66(PA66).Tensile tests have shown that SMTed PA66 samples exhibit significant improvements in both Young’s modulus and ultimate tensile strength(UTS),with a 2104 MPa Young’s modulus,almost double that of the pristine samples,and a 35.56%increase in UTS,reaching 183 ***,the modulus within the localized SMTed surface layer could reach up to 14 GPa,which is approximately 14 times higher than that of the pristine *** Vickers hardness within the localized SMTed surface layer can be doubled,reaching 10.72 Hv,and the crystallinity can increase by approximately 20%compared to the untreated ***,force field molecular dynamics(FFMD)simulations were conducted to investigate the ternary relationship between the SMT method,PA66’s molecular structure,and its *** combination of MD simulations and versatile structural characterizations provides evidence that the SMT method’s mechanism,under heat induction,results in a chain-combing procedure that changes the polymer’s molecular morphology microscopically and enhances its mechanical properties macroscopically.

关键词： Nylon 66 mechanical properties hardness crystallinity structural characterizations molecular dynamics simulation

Universal dynamic scaling and Contact dynamics in quenched quantum gases

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Frontiers of physics 2024年第2期19卷 213-220页

作者： Jia-nan Cui Zhengqiang zhou Mingyuan Sun School of Science Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Lab of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China

Recently universal dynamic scaling is observed in several systems,which exhibit a spatiotemporal self-similar scaling behavior,analogous to the spatial scaling near phase *** latter one arises from the emergent continuous scaling *** by this,we investigate the possible relation between the scaling dynamics and the continuous scaling symmetry in this *** derive a theorem that the scaling invariance of the quenched Hamiltonian and the initial density matrix can lead to the universal dynamic *** is further demonstrated both in a two-body system analytically and in a many-body system *** the latter one,we calculate the dynamics of quantum gases quenched from the zero interaction to a finite interaction via the non-equilibrium high-temperature virial expansion.A dynamic scaling of the momentum distribution appears in certain momentum-time windows at unitarity as well as in the weak interacting ***,this universal scaling dynamics persists approximately with smaller scaling exponents even if the scaling symmetry is fairly *** findings may offer a new perspective to interpret the related *** also study the Contact dynamics in the BEC−BCS ***,the half-way time displays a maximum near unitarity while some damping oscillations occur on the BEC side due to the dimer state,which can be used to detect possible two-body bound states in experiments.

关键词： dynamic scaling Contact dynamics quantum gases cold atom quench dynamics virial expansion continuous scaling symmetry

Kinetics and mechanism of propylene hydro-oxidation to acrolein on Au catalysts

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nano Research 2024年第1期17卷 354-363页

作者： Wei Du zhihua Zhang nan Song Xuezhi Duan Xinggui zhou State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China

Propylene epoxidation by H_(2)and O_(2)to propylene oxide(PO)over the Au-Ti bifunctional catalysts,as an ideal reaction for PO production,has attracted great *** the mechanism of acrolein formation is of great importance for understanding the mechanism of molecular oxygen activation and the formation of hydroperoxo species on the Au ***,we investigate the reaction mechanism of propylene oxidation to acrolein on the Au/uncalcined TS-1(Au/TS-1-B)catalyst through a combination of multiple characterization,H_(2)/D_(2)exchange,kinetics experiment,and *** Ti sites are found to be non-essential to acrolein ***,the acrolein formation on the Au/TS-1-B catalyst is confirmed to be promoted by H_(2)through hydroperoxo species formation,which includes two main steps:propylene dehydrogenation to*C_(3)H_(5)with the aid of*OOH species,and*C_(3)H_(5)oxidation by*OOH to *** latter step is determined to be the rate-determining step because the corresponding kinetics model gives the best description for experimental *** work not only provides kinetics insights for the propylene hydro-oxidation to acrolein on the Au-Ti bifunctional catalysts,but also facilitates the rational design of Au catalysts with high activity and selectivity in the direct propylene epoxidation with H_(2)and O_(2).

关键词： kinetics mechanism gold acrolein hydro-oxidation

Glycerol solutions of highly concentrated biomineral counter-ions towards water-responsive mineralization: Demonstration on bacterial cellulose and its application in hard tissue repair

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nano Research 2024年第3期17卷 2154-2163页

作者： Yunfei Zhao Xiaohao Liu zhi zhou Chaobo Feng nan Luo Jiajun Yan Shuo Tan Yang Lu Feng Chen Bing-Qiang Lu Shisheng He Department of Orthopedic Spinal Pain Research InstituteShanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghai 200072China Department of Preventive Dentistry Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyShanghai 200011China

Mineralization has found widespread use in the fabrication of composite biomaterials for hard tissue *** current mineralization processes are mainly carried out in neutral aqueous solutions of biomineral counter-ions(a pair of cation and anion that form the corresponding minerals at certain conditions),which are stable only at very low *** typically results in inefficient mineralization and weak control over biomineral ***,we find that,in the organic solvent glycerol,a variety of biomineral counter-ions(e.g.,Ca/PO_(4),Ca/CO_(3),Ca/SO_(4),Mg/PO_(4),or Fe/OH)corresponding to distinct biominerals at significantly high concentrations(up to hundreds-fold greater than those of simulated body fluid(SBF))are able to form translucent and stable solutions(mineralizing solution of highly concentrated counter-ions(MSCIs)),and mineralization can be triggered upon them with external solvents(e.g.,water or ethanol).Furthermore,with pristine bacterial cellulose(BC)membrane as a model,we demonstrate an effective and controllable mineralization performance of MSCIs on organic *** approach not only forms the homogeneous biominerals on the BC fibers and in the interspaces,but also provides regulations over mineralization rate,mineral content,phase,and *** resulting mineralized BC membranes(MBCs)exhibit high cytocompatibility and favor the proliferation of rat bone marrow mesenchymal stem cells(rBMSC).Following this,we prepare a mineralized bone suture(MBS)from MBC for non-weight bearing bone fixation,which then is tested on a rabbit median sternotomy *** shows firm fixation of the rabbit sternum without causing discernible toxicity or inflammatory *** study,by extending the mineralization to the organic solution system of highly concentrated counter-ions,develops a promising strategy to design and build targeted mineral-based composites.

关键词： biomineralization organic solvent bacterial cellulose(BC) hard tissue repair

Monitoring of Cell Membrane Microenvironment Based on DNA nanodevices

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Chemical Research in Chinese Universities 2024年第2期40卷 255-267页

作者： nan Hexin CAI Ming KUANG Shi NIE zhou State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan Provincial Key Laboratory of Biomacromolecular Chemical BiologyHunan UniversityChangsha410082P.R.China

The cell membrane is a critical barrier for cellular homeostasis,integral to signaling and intercellular communication,and vital for understanding cellular functions and disease *** its microenvironment is crucial for uncovering the molecular basis of physiological and pathological processes associated with the cell membrane,driving the development of bioanalytical toolkits capable of dynamically monitoring the cell surface *** the continuous advancement of functional nucleic acids and dynamic DNA nanotechnology,DNA nanodevices with controllable nanosized geometry,specific molecular recognition,and selective membrane-localization properties offer a versatile platform for probing the cell membrane *** this review,we summarize the current biosensing and membrane-anchoring mechanisms of DNA nanodevices and highlight their use in studying key cell membrane events,including membrane lipid dynamics,transmembrane transport,receptor dimerization,and signal ***,we discuss the challenges and potential future applications of DNA nanodevices in advancing cell membrane biology research and biomedical applications.

关键词： DNA nanodevice Cell membrane Cellular micro-environment Monitoring

Single thiolate replacement of metal nanoclusters

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Science China Chemistry 2024年第2期67卷 523-528页

作者： Ambreen Ambreen Yue zhou Wanmiao Gu Qing You Liang Fang Guoqing Bian nan Yan nan Xia zhikun Wu Key Laboratory of Materials Physics Anhui Key Laboratory of Nanomaterials and NanotechnologyInstitute of Solid State PhysicsHefei Institutes of Physical Science(HFIPS)Chinese Academy of SciencesHefei230031China University of Science and Technology of China Hefei230601China Institute of Physical Science and Information Technology Anhui UniversityHefei230601China

Surface thiolates play important roles in evincing the structures and properties of thiolated metal nanoclusters—one type of recently emerging inorganic-organic hybrids,and thus the thiolate substitution,especially single thiolate substitution,is highly desirable for subtly tailoring the structures and properties of metal ***,such a single-thiolate substituting is challenging,and its influence on the metal-metal and metal-sulfur bonds remains mysterious due to the absence of the singlethiolate-substituted ***,we developed a combined method,concurrently synthesized the single-thiolate-substituted nanocluster and its parent nanocluster,and successfully resolved their structures by single crystal X-ray crystallography,which reveals that the single thiolate substitute has an obvious influence on the metal-metal and metal-sulfur bond lengths although it has no effect on the absorption ***,the metal-metal and metal-sulfur bonds show various thermal extensibility and even the negative thermal expansion phenomena of the Au–S bond were observed in the single-thiolate-substituted *** bond length-related stability was also ***,this study highlights a novel synthesis method and offers novel structural insights and an in-depth structure-property correlation of thiolated metal nanoclusters.

关键词： metal nanoclusters single thiolate replacement thermal expansion stability intercluster interaction

Ecological effect of the plantation of Sabina vulgaris in the Mu Us Sandy Land,China

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Journal of Arid Land 2024年第1期16卷 14-28页

作者： nan Weige DONG zhibao zhou Zhengchao LI Qiang CHEN Guoxiang School of Geography and Tourism Shaanxi Normal UniversityXi'an 710062China Shaanxi Key Laboratory of Ecological Restoration in Shaanbei Mining Area Yulin UniversityYulin 719000China College of Prataculture Gansu Agricultural UniversityLanzhou 730070China

Vegetation restoration through artificial plantation is an effective method to combat desertification,especially in arid and semi-arid *** study aimed to explore the ecological effect of the plantation of Sabina vulgaris on soil physical and chemical properties on the southeastern fringe of the Mu Us Sandy Land,*** collected soil samples from five depth layers(0-20,20-40,40-60,60-80,and 80-100 cm)in the *** plantation plots across four plantation ages(4,7,10,and 16 years)in November 2019,and assessed soil physical(soil bulk density,soil porosity,and soil particle size)and chemical(soil organic carbon(SOC),total nitrogen(TN),available nitrogen(AN),available phosphorus(AP),available potassium(AK),cation-exchange capacity(CEC),salinity,p H,and C/N ratio)*** results indicated that the soil predominantly consisted of sand particles(94.27%-99.67%),with the remainder being silt and *** plantation age increased,silt and very fine sand contents progressively *** 16 years of planting,there was a marked reduction in the mean soil particle *** initial soil fertility was low and declined from 4 to 10 years of planting before witnessing an *** positive correlations were observed for the clay,silt,and very fine sand(mean diameter of 0.000-0.100 mm)with SOC,AK,and p *** contrast,fine sand and medium sand(mean diameter of 0.100-0.500 mm)showed significant negative correlations with these *** findings ascertain that the plantation of *** requires 10 years to effectively act as a windbreak and contribute to sand fixation,and needs 16 years to improve soil physical and chemical ***,these improvements were found to be highly beneficial for vegetation restoration in arid and semi-arid *** research can offer valuable insights for the protection and restoration of the vegetation ecosystem in the sandy lands in China.

关键词： Sabina vulgaris plantation age soil physical and chemical properties soil particle size soil fertility vegetation restoration Mu Us Sandy Land