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Effect of Al content on the phase structure and the hydrogenation characteristic of La(Mg_(1-x)Al_x) alloys

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Rare Metals 2006年第6期25卷 654-658页

作者： HOU qingyu zhang qing＇an School of Materials Science and Engineering Anhui University of Technology Ma＇anshan 243002 China

La（Mg1-xAlx）（x=0.2, 0.4, 0.6, 0.8） alloys have been prepared using induction melting followed by annealing. It is found that partial substitution of Mg by Al does not lead to a change in crystal structure, and the alloys have a single LaMg phase when x 〈 0.4. The lattice parameter of the LaMg phase decreases obviously after the partial substitution of Mg by Al. However, further substitution of Mg by Al leads to the coexistence of multiple phases when x ≥ 0.6. The alloys consist of the LaMg, LaAl, LaAl2, and La5Al4 phases. The LaMg phase decreases, whereas the La5Al4 phase increases with the increase in x. The Al-substituted La（Mgo.6Al0.4） alloy can be hydrogenated into the tetragonal LaH3, cubic LaH3, MgH2, and LaPd under 5 MPa at 473 K for 5 d.

关键词： intermetallic compound phase structure hydrogenation characteristic X-ray diffraction

Asymptotics for null-timelike boundary problems for general linear wave equations

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Science China Mathematics 2021年第1期64卷 111-128页

作者： qing Han Lin zhang Department of Mathematics University of Notre DameNotre DameIN46556USA Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing100190China

We study the linear wave equation□gu=0 in Bondi-Sachs coordinates,for an asymptotically flat Lorentz metric *** consider the null-timelike boundary problem,where an initial value is given on the null surfaceτ=0 and a boundary value on the timelike surface r=*** obtain spacetime Hp-estimates of ru for r>r0 and derive an asymptotic expansion of ru in terms of 1/r as r→∞.

关键词： wave equations radiation field energy estimates asymptotic expansion

An analysis of TinyML@ICCAD for implementing AI on low-power microprocessor

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Science China(Information Sciences) 2024年第4期67卷 343-344页

作者： Guoqing LI Jingwei zhang Meng zhang tuo LI Tinghuan CHEN Jun YANG Shandong Yunhai Guochuang Cloud Computing Equipment Industry Innovation Co. Ltd. School of Integrated Circuits Southeast University Shandong Inspur Artificial Intelligence Research Institute Co. Ltd. School of Science and Engineering The Chinese University of Hong Kong

Tiny machine learning(ML) is an important application area of artificial intelligence(AI), which focuses on deploying AI on small hardware platforms with constrained resources [1, 2]. The high-level TinyML contests at high-level conferences promote the development of TinyML areas, such as DAC-SDC [3] and TinyML@ICCAD [4].

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Crystalline carbon nitride with in-plane built-in electric field accelerates carrier separation for excellent photocatalytic hydrogen evolution

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Chinese Chemical Letters 2024年第4期35卷 160-165页

作者： Wengao Zeng Yuchen Dong Xiaoyuan Ye Ziying zhang tuo zhang Xiangjiu Guan Liejin Guo International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong UniversityXi'an 710049China

Achieving a high carrier migration efficiency by constructing built-in electric field is one of the promising approaches for promoting photocatalytic activity. Herein, we have designed a donor-acceptor(D-A) crystalline carbon nitride(APMCN) with 4-amino-2,6-dihydroxypyrimidine(AP) as electron donor, in which the pyrimidine ring was well embedded in the heptazine ring via hydrogen-bonding effect during hydrothermal process. The APMCN shows superior charge-transfer due to giant built-in electric field(5.94times higher than pristine carbon nitride), thereby exhibiting excellent photocatalytic H_(2) evolution rate(1350 μmol/h) with a high AQY(62.8%) at 400 nm. Mechanistic analysis based on detailed experimental investigation together with theoretical analysis reveals that the excellent photocatalytic activity is attributed to the promoted charge separation by the giant internal electric field originated from the D–A structure.

关键词： Crystalline carbon nitride Built-in electric field Donor-acceptor structure Photocatalysis Hydrogen production

Simulation of an imaging system for internal contamination of lungs using MPA-MURA coded-aperture collimator

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Nuclear Science and Techniques 2021年第2期32卷 58-69页

作者： Ting zhang Lei Wang Jing Ning Wei Lu Xiao-Fei Wang Hai-Wei zhang Xian-Guo tuo Chengdu University of Technology Chengdu 610059China Sichuan University of Science&Engineering Zigong 643000China Beijing Institute of Radiation Medicine Beijing 100850China

The nuclides inhaled during nuclear accidents usually cause internal contamination of the lungs with low *** a parallel-hole imaging system,which is widely used in medical gamma cameras,has a high resolution and good image quality,owing to its extremely low detection efficiency,it remains difficult to obtain images of inhaled lung *** this study,the Monte Carlo method was used to study the internal lung contamination imaging using the MPA-MURA coded-aperture *** imaging system consisted of an adult male lung model,with a mosaicked,pattern-centered,and anti-symmetric MURA coded-aperture collimator model and a CsI(Tl)detector *** MLEM decoding algorithm was used to reconstruct the internal contamination image,and the complementary imaging method was used to reduce the number of *** full width at half maximum of the I-131 point source image reconstructed by the MPAMURA coded-aperture imaging reached 2.51 mm,and the signal-to-noise ratio of the simplified respiratory tract source(I-131)image reconstructed through MPA-MURA coded-aperture imaging was 3.98 *** the spatial resolution of MPA-MURA coded-aperture imaging is not as good as that of parallel-hole imaging,the detection efficiency of PMA-MURA coded-aperture imaging is two orders of magnitude higher than that of parallel-hole collimator *** the low activity level of internal lung contamination caused by nuclear accidents,PMA-MURA coded-aperture imaging has significant potential for the development of lung contamination imaging.

关键词： Lung internal contamination MPA-MURA Monte Carlo MLEM Spatial resolution Detection efficiency

Measuring H0 from low-z datasets

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Science China(Physics,Mechanics & Astronomy) 2020年第9期63卷 2-6页

作者： Xue zhang qing-Guo Huang CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China Synergetic Innovation Center for Quantum Effects and Applications Hunan Normal UniversityChangsha 410081China

The Hubble constant H0 represents the expansion rate of the Universe at present and is closely related to the age of the *** accurate measurement of Hubble constant is crucial for modern ***,different cosmological observations give diverse values of Hubble constant in *** to now,there are two methods to measure the Hubble *** is to directly measure the Hubble constant based on distance ladder estimates of Cepheids and so *** other is to globally fit the Hubble constant under the assumption of a cosmological model,for example the "standard" ACDM *** the low-redshift observational datasets,including the Pantheon sample of Type Ⅰa supernovae,baryon acoustic oscillation measurements,and the tomographic Alcock-Paczynski method,we determine the Hubble constant to be 67.95-1.03+0.78,69.81-2.70+2.22 and66.75-4.23+3.42 km s^-1 Mpc^-1 at 68% confidence level in the △CDM,wCDM and W0Wa CDM models,*** to the Hubble constant given by Riess et *** 2019,we conclude that the new physics beyond the standard △CDM model is needed if all of these datasets are reliable.

关键词： Hubble constant dark energy equation of state

Observer-Based Path Tracking Controller Design for Autonomous Ground Vehicles With Input Saturation

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IEEE/CAA Journal of Automatica Sinica 2023年第3期10卷 749-761页

作者： Heng Wang Tengfei zhang Xiaoyu zhang qing Li School of Automation and Electrical Engineering and also with the Key Laboratory of Knowledge Automation for Industrial Processes of Ministry of EducationUniversity of Science and Technology BeijingBeijing 100083China School of Automation and Electrical Engineering and also with the Key Laboratory of Knowledge Automation for Industrial Processes of Ministry of EducationUniversity of Science and Technology BeijingBeijing 100083

This paper investigates the problem of path tracking control for autonomous ground vehicles(AGVs),where the input saturation,system nonlinearities and uncertainties are ***,the nonlinear path tracking system is formulated as a linear parameter varying(LPV)model where the variation of vehicle velocity is taken into ***,considering the noise effects on the measurement of lateral offset and heading angle,an observer-based control strategy is proposed,and by analyzing the frequency domain characteristics of the derivative of desired heading angle,a finite frequency H_∞index is proposed to attenuate the effects of the derivative of desired heading angle on path tracking ***,sufficient conditions are derived to guarantee robust H_∞performance of the path tracking system,and the calculation of observer and controller gains is converted into solving a convex optimization ***,simulation examples verify the advantages of the control method proposed in this paper.

关键词： Autonomous ground vehicles(AGVs) H_∞index input saturation observer-based controller path tracking control

TMEM16F may be a new therapeutic target for Alzheimer's disease

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Neural Regeneration Research 2023年第3期18卷 643-651页

作者： Zhi-Qiang Cui Xiao-Ying Hu tuo Yang Jing-Wei Guan Ying Gu Hui-Yuan Li Hui-Yu zhang qing-Huan Xiao Xiao-Hong Sun Department of Neurology The Fourth Affiliated Hospital of China Medical UniversityShenyangLiaoning ProvinceChina Department of Ion Channel Pharmacology School of PharmacyChina Medical UniversityShenyangLiaoning ProvinceChina

TMEM16F is involved in many physiological processes such as blood coagulation,cell membrane fusion and bone *** of TMEM16F has been studied in various central nervous system *** TMEM16F level has been also found to participate in microglial phagocytosis and ***-mediated neuroinflammation is a key factor in promoting the progression of Alzheimer’s ***,few studies have examined the effects of TMEM16F on neuroinflammation in Alzheimer’s *** this study,we established TMEM16F-knockdown AD model in vitro and in vivo to investigate the underlying regulatory mechanism about TMEM16F-mediated neuroinflammation in *** performed a Morris water maze test to evaluate the spatial memory ability of animals and detected markers for the microglia M1/M2 phenotype and NLRP3 *** results showed that TMEM16F was elevated in 9-month-old APP/PS1 *** TMEM16F knockdown in mice,spatial memory ability was improved,microglia polarization to the M2 phenotype was promoted,NLRP3 inflammasome activation was inhibited,cell apoptosis and Aβplaque deposition in brain tissue were reduced,and brain injury was *** used amyloid-beta(Aβ_(25-35))to stimulate human microglia to construct microglia models of Alzheimer’s *** levels of TMEM16F,inducible nitric oxide synthase(iNOS),proinflammatory cytokines and NLRP3 inflammasome-associated biomarkers were higher in Aβ_(25-35) treated group compared with that in the control ***16F knockdown enhanced the expression of the M2 phenotype biomarkers Arg1 and Socs3,reduced the release of proinflammatory factors interleukin-1,interleukin-6 and tumor necrosis factor-α,and inhibited NLRP3 inflammasome activation through reducing downstream proinflammatory factors interleukin-1βand *** inhibitory effect of TMEM16F knockdown on M1 microglia was partially reversed by the NLRP3 agonist *** findings suggest that TMEM16F participates i

关键词： Alzheimer’s disease Aβplaque inflammatory cytokines M1 phenotype M2 phenotype microglia polarization neuroinflammation NLRP3 inflammasome siRNA TMEM16F

FOLMS-AMDCNet:an automatic recognition scheme for multiple-antenna OFDM systems

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Journal of Systems Engineering and Electronics 2023年第2期34卷 307-323页

作者： zhang Yuyuan YAN Wenjun zhang Limin LING qing Academy of Aeronautical Operations Service Naval Aviation UniversityYantai 264001China

The existing recognition algorithms of space-time block code(STBC)for multi-antenna(MA)orthogonal frequencydivision multiplexing(OFDM)systems use feature extraction and hypothesis testing to identify the signal types in a complex communication ***,owing to the restrictions on the prior information and channel conditions,these existing algorithms cannot perform well under strong interference and noncooperative communication *** overcome these defects,this study introduces deep learning into the STBCOFDM signal recognition field and proposes a recognition method based on the fourth-order lag moment spectrum(FOLMS)and attention-guided multi-scale dilated convolution network(AMDCNet).The fourth-order lag moment vectors of the received signals are calculated,and vectors are stitched to form two-dimensional FOLMS,which is used as the input of the deep learning-based ***,the multi-scale dilated convolution is used to extract the details of images at different scales,and a convolutional block attention module(CBAM)is introduced to construct the attention-guided multi-scale dilated convolution module(AMDCM)to make the network be more focused on the target area and obtian the multi-scale guided ***,the concatenate fusion,residual block and fully-connected layers are applied to acquire the STBC-OFDM signal *** experiments show that the average recognition probability of the proposed method at−12 dB is higher than 98%.Compared with the existing algorithms,the recognition performance of the proposed method is significantly improved and has good adaptability to environments with strong *** addition,the proposed deep learning-based model can directly identify the pre-processed FOLMS samples without a priori information on channel and noise,which is more suitable for non-cooperative communication systems than the existing algorithms.

关键词： blind signal identification(BSI) space-time block code(STBC) orthogonal frequency-division multiplexing(OFDM) deep learning fourth-order lag moment spectrum(FOLMS)