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Adaptive projected gradient thresholding methods for constrained l0problems

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Science China Mathematics 2015年第10期58卷 2205-2224页

作者： ZHAO ZhiHua XU FengMin li xiangyang School of Mathematics and Statistics Xi'an Jiaotong University

In this paper, we propose and analyze adaptive projected gradient thresholding(APGT) methods for finding sparse solutions of the underdetermined linear systems with equality and box constraints. The general convergence will be demonstrated, and in addition, the bound of the number of iterations is established in some special cases. Under suitable assumptions, it is proved that any accumulation point of the sequence generated by the APGT methods is a local minimizer of the underdetermined linear system. Moreover, the APGT methods, under certain conditions, can find all s-sparse solutions for accurate measurement cases and guarantee the stability and robustness for flawed measurement cases. Numerical examples are presented to show the accordance with theoretical results in compressed sensing and verify high out-of-sample performance in index tracking.

关键词： projected gradient l0 constraints compressed sensing index tracking hard thresholding

Damage Production and Annealing During MeV He Ion RBS/Channeling Analysis of GaP

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Chinese Physics Letters 1994年第4期11卷 219-222页

作者： li xiangyang CHENG Huansheng YANG Fujia T.D.Lee Physics Laboratory Fudan UniversityShanghai 200433 Mailing address:Department of Nuclear Science Fudan UniversityShanghai 200433

The creation of defects in GaP bombarded with MeV 4He ions has been studied under ultra-high-vacuum condition by Rutherford backscattering/channeling(RBS/C)*** experimental results suggest that the defect generation rate is strongly related to the surface *** the GaP is covered with a thin amorphous layer,a significant ion beam annealing effect Will be *** present results show that for GaP the damage is produced mainly by nuclear collision.

关键词： GaP vacuum collision

China’s first deep manned submersible,JIAOLONG

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Science China Earth Sciences 2010年第10期53卷 1407-1410页

作者： liu, Feng Cui, WeiCheng li, xiangyang Beijing 100860 China Wuxi 214082 China

JIAOLONG's function and capability were fully tested during its 37 dives. The longest underwater time was 543 minutes, and the deepest dive of 3759 m was made on its 37th dive. The Chinese national flags and memorial 'Dragon Palaces' were placed on the seafloor. 525 mL of pressure-sustained seawater and two sea cucumbers were sampled. Test results have indicated that all the functions and capabilities were in good agreement with the design data. © 2010 Science China Press and Springer-Verlag Berlin Heidelberg.

关键词： Seawater

A Reverse-Design Strategy for the Track Error of the Qi Tai Telescope Based on Pointing Accuracy

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Engineering 2022年第6期8卷 209-216页

作者： Na li Baoyan Duan xiangyang li Bin Zheng Jiang Wu Key Laboratory of Electronic Equipment Structure Design Ministry of EducationXidian UniversityXi’an 710061China

The Qi Tai Telescope(QTT),which has a 110 m aperture,is planned to be the largest scale steerable tele-scope in the ***,the telescope’s repeated pointing accuracy error should be less than 2.5 arc seconds(arcsec);thus,the telescope structure must satisfy ultra-high precision *** this pur-suit,the present research envisages a reverse-design method for the track surface to reduce the difficulty of the telescope’s design and ***,the distribution characteristics of the test data for the track error were verified using the skewness coefficient and kurtosis coefficient *** to the distribution characteristics,the azimuth track error was simulated by a two-scale *** error of the long period and short amplitude was characterized as large-scale and described by a trigonometric function,while the short period and high amplitude error was characterized as small-scale and simulated by a fractal *** on the two-scale model,effect of the error on the pointing accuracy was ***,the relationship between the root mean square(RMS)of the track error and the RMS of the pointing accuracy error of the telescope was ***,the allowable RMS value of the track error was derived from the allowable pointing accuracy *** validate the effectiveness of the new design method,two typical radio telescopes(the Green Bank Telescope(GBT)and the Large Millimeter Telescope(LMT))were selected as experimental *** comparison,the theoretical calculated values of the pointing accuracy of the telescope were consistent with the measured values,with a maximum error of less than 10%.

关键词： Reverse design Track error Large radio telescope Two-scale model Pointing accuracy

On a novel tracking differentiator design based on iterative learning in a moving window

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Control Theory and Technology 2023年第1期21卷 46-55页

作者： xiangyang li Rafal Madonski Zhiqiang Gao Senping Tian Key Laboratory of Autonomous Systems and Network Control Ministry of EducationSchool of Automation Science and EngineeringSouth China University of TechnologyGuangzhou 510641China Energy and Electricity Research Center Jinan UniversityZhuhai 519070China Department of Electrical and Computer Science Cleveland State UniversityClevelandOH 44115USA

Differential signals are key in control engineering as they anticipate future behavior of process variables and therefore are critical in formulating control laws such as proportional-integral-derivative(PID).The practical challenge,however,is to extract such signals from noisy measurements and this difficulty is addressed first by *** in the form of linear and nonlinear tracking differentiator(TD).While improvements were made,TD did not completely resolve the conflict between the noise sensitivity and the accuracy and timeliness of the *** two approaches proposed in this paper start with the basic linear TD,but apply iterative learning mechanism to the historical data in a moving window(MW),to form two new iterative learning tracking differentiators(IL-TD):one is a parallel IL-TD using an iterative ladder network structure which is implementable in analog circuits;the other a serial IL-TD which is implementable digitally on any computer *** algorithms are validated in simulations which show that the proposed two IL-TDs have better tracking differentiation and de-noise performance compared to the existing linear TD.

关键词： Tracking differentiator(TD) Iterative learning Iterative learning tracking differentiator(IL-TD) Active disturbance rejection control(ADRC)-Two-dimensional system(2-D system)

Harnessing the power of artificial intelligence for human living organoid research

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Bioactive Materials 2024年第12期42卷 140-164页

作者： Hui Wang xiangyang li Xiaoyan You Guoping Zhao Master Lab for Innovative Application of Nature Products National Center of Technology Innovation for Synthetic BiologyTianjin Institute of Industrial BiotechnologyChinese Academy of Sciences(CAS)Tianjin300308PR China Henan Engineering Research Center of Food Microbiology College of food and bioengineeringHenan University of Science and TechnologyLuoyang471023PR China Haihe Laboratory of Synthetic Biology Tianjin300308PR China CAS-Key Laboratory of Synthetic Biology CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032PR China CAS Key Laboratory of Quantitative Engineering Biology Shenzhen Institute of Synthetic BiologyShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518055PR China Engineering Laboratory for Nutrition Shanghai Institute of Nutrition and HealthChinese Academy of SciencesShanghai200031PR China

As a powerful paradigm,artificial intelligence(AI)is rapidly impacting every aspect of our day-to-day life and scientific research through interdisciplinary *** human organoids(LOs)have a great potential for in vitro reshaping many aspects of in vivo true human organs,including organ development,disease occurrence,and drug *** date,AI has driven the revolutionary advances of human organoids in life science,precision medicine and pharmaceutical science in an unprecedented ***,we provide a forward-looking review,the frontiers of LOs,covering the engineered construction strategies and multidisciplinary technologies for developing LOs,highlighting the cutting-edge achievements and the prospective applications of AI in LOs,particularly in biological study,disease occurrence,disease diagnosis and prediction and drug screening in preclinical ***,we shed light on the new research trends harnessing the power of AI for LO research in the context of multidisciplinary *** aim of this paper is to motivate researchers to explore organ function throughout the human life cycle,narrow the gap between in vitro microphysiological models and the real human body,accurately predict human-related responses to external stimuli(cues and drugs),accelerate the preclinical-to-clinical transformation,and ultimately enhance the health and well-being of patients.

关键词： Artificial intelligence Human living organoids Organoid intelligence In vitro miniature organ models Multidisciplinary techniques Preclinical-to-clinical transformation

Diffusion of Silver in Nanometer Ni-B Amorphous Alloy

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Chinese Physics Letters 1994年第9期11卷 577-580页

作者： li xiangyang CHENG Huansheng HE Wenquan YANG Fujia T.D.Lee Physics Laboratory Fudan UniversityShanghai 200433 Department of Nuclear Science Fudan UniversityShanghai 200433

Diffusion of Ag in nanometer Ni-B amorphous alloy,has been studied by heavy-ion Rutherford backscattering *** values of the diffusion coefficient which were found at 293,323 and 373K,are 3.5×10^(-16),4.3 ×10^(-15) and 5.0×10^(-14) cm^(2)/s,***,small values for the activation energy,0.58 eV,and the pre-exponential factor of the diffusion coefficient,3.9×10^(-16) cm^(2)/s,were derived from Arrhenius ***,a possible free volume controlled diffusion mechanism was discussed.

关键词： spectroscopy alloy Diffusion

China's Economic Diplomacy:Concept,Organization,Implementation Mechanisms and the BRI

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China Economist 2022年第3期17卷 21-42页

作者： li xiangyang National Institute of International Strategy Chinese Academy of Social Sciences(NIIS CASS)BeijingChina

Based on the existing research regarding China’s economic diplomacy,this study creates a theoretical structure for economic diplomacy with Chinese characteristics that encompasses soft power,the two competitive concepts of justified ought and self interests,and the Belt and Road Initiative(BRI).By introducing soft power,this paper argues that the goal of economic diplomacy with Chinese characteristics for the new era is to achieve the conversion of hard power to soft *** the“carrot and stick”principle often followed by Western powers in their economic diplomacy with political strings attached,the conversion between hard power and soft power in China’s economic diplomacy hinges upon the two competitive concepts of justified ought and self interests,which is the basic principle that guides China’s economic diplomacy *** argue that in creating an implementation mechanism for China’s economic diplomacy,policymakers must consider China’s unique national condition as a large economy not yet rich in per capita terms,while drawing upon the experiences of other major nations.

关键词： Chinese economic diplomacy soft power the greater good national self-interest the Belt and Road Initiative(BRI)

Two-dimensional bipolar magnetic semiconductors with high Curie-temperature and electrically controllable spin polarization realized in exfoliated Cr(pyrazine)_(2) monolayers

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Science China Chemistry 2021年第12期64卷 2212-2217页

作者： xiangyang li Haifeng Lv Xiaofeng liu Tong Jin Xiaojun Wu Xingxing li Jinlong Yang Hefei National Laboratory of Physical Science at the Microscale Department of Chemical PhysicsSynergetic Innovation Center of Quantum Information&Quantum PhysicsUniversity of Science and Technology of ChinaHefei230026China Department of Chemistry Key Laboratory of Functional Inorganic Materials of Anhui ProvinceAnhui UniversityHefei230601China

Exploring two-dimensional(2D)magnetic semiconductors with room-temperature magnetic ordering and electrically controllable spin-polarization is a highly desirable but challenging task for ***,through first-principles calculations,we propose to realize such a material by exfoliating the recently synthesized organometallic layered crystal li0.7[Cr(pyz)_(2)]Cl0.7·0.25(THF)(pyz=pyrazine,THF=tetrahydrofuran).The feasibility of exfoliation is confirmed by the rather low exfoliation energy of 0.27 J m^(−2),even smaller than that of *** exfoliated Cr(pyz)_(2)monolayers,each pyrazine ring grabs one electron from the Cr atom to become a radical anion,and then a strong d-p direct-exchange magnetic interaction emerges between Cr cations and pyrazine radicals,resulting in room-temperature ferrimagnetism with a Curie temperature of 342 ***,the Cr(pyz)_(2)monolayer is revealed to be an intrinsic bipolar magnetic semiconductor where electrical doping can induce half-metallic conduction with controllable spin-polarization direction.

关键词： two-dimensional material ferrimagnetism bipolar magnetic semiconductor half metal first principles