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Growth responses of Picea mongolica seedlings to defoliation rate

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Journal of Environmental Sciences 2005年第2期17卷 232-236页

作者： ZOUChun-jing HANShi-jie QIShu-yan XUWen-duo lidao-tang CollegeofLifeScience＆Biotechnology ShanghaiJiaotongUniversityShanghai200030China／／InstituteofAppliedEcologyChineseAcademyofSciencesShenyang110016China InstituteofAppliedEcology ChineseAcademyofSciencesShenyang110016China NormalCollege ShenyangUniversityShenyang110016China CollegeofLifeScience＆Biotechnology ShanghaiJiaotongUniversityShanghai200030China

Picea mongolica W. D. Xu. is an endemic species in China. The spruce forest is only found in semi-arid habitat in Inner Mongolia Autonomous Region of China. Based on the simulative defoliation experiment, it was proved that Picea mongolica seedlings had the compensatory and overcompensatory effects under the certain defoliation rate. The results of variance analysis on growth indexes showed that in PM Ⅰ(natural regeneration seedlings under Picea mongolica forest), the differences of H 1(height in June 23) and H 2(height in September 3) were extremely significant, and the difference of D(diameter at the breast height) were not significant. In PM Ⅱ(artificial regeneration seedlings under Betula platyphylla Suk. forest), the difference of H 1 was significant, the difference of H 2 was not significant, and the difference of D was extremely significant. The regression equations were established and the compensatory and overcompensatory points were obtained. In PM Ⅰ, the compensatory points of H 1, H 2, and D were 0.7628, 0.7436, 0.5725, and the overcompensatory points were 0.6056, 0.5802 and 0.2909 respectively. In PM Ⅱ, the compensatory points of H 1, H 2, and D are 0.5012, 0.3421, 0.2488, and the overcompensatory points are 0.4137, 0.2633 and 0.0747 respectively. These results suggested that the induction of compensatory growth mechanisms in spruce seedlings required a threshold level of defoliation, and the insects in Picea mongolica forest could be controlled in a certain degree.

关键词： Picea mongolica W. D. Xu. compensate overcompensate growth defoliation rate

Topology modulation of tetraphenylethylene graphdiyne at a liquid-liquid interface

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Nano Research 2024年第6期17卷 4661-4667页

作者： Tingting Xu Pei Wen Ng Shaofei Wu Danjun Fu Yunhan Ma Yao Liu lidao Li Xiaofei Zhang Jun Zhu Department of Chemistry National University of SingaporeSingapore 117543Singapore Institute of Materials Research and Engineering(IMRE) Agency for ScienceTechnology and Research(A*STAR)Singapore 138634Singapore

Monomers with low symmetries can form different topological structures in the preparation of organic two-dimensional(2D)***,it remains challenging to modulate the topologies in practical *** theoretical insights into the formation energy of potential structural configurations,we report the topology modulation of a graphdiyne(GDY)derivative constructed from two-fold symmetric tetrakis(4-ethynylphenyl)ethene precursor by changing solvent combinations in a liquid-liquid interfacial *** aqueous-organic(water-dichloromethane)interface afforded GDY with a kagome topology while a rhombic topology was formed at an organic-organic(hexane-acetonitrile)interface.A comprehensive evaluation of their structures and optoelectronic properties was conducted through various characterization techniques and theoretical *** study provided new insights to modulate the topology of not only GDY but also other framework structures and obtain topologically pure materials in situations where different topologies are possible during practical synthesis.

关键词： graphdiyne derivative tetraphenylethylene topology modulation aggregation-induced emission(AIE)two-dimensional(2D)polymers interfacial synthesis

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基于小波自编码器的图像盲去噪算法

华中科技大学学报（自然科学版） 2024年第2期52卷 62-68页

作者：马自萍谭力刀北方民族大学数学与信息科学学院宁夏银川750021 北方民族大学计算机科学与工程学院宁夏银川750021

为解决基于深度学习图像去噪方法在图像盲去噪任务中去噪能力有限和去噪效果不佳的问题,构造了小波自编码器(Wavelet-AE),并用于图像盲去噪.首先,使用Haar小波构造小波卷积层(DWT)与逆小波卷积层(IDWT);然后,分别使用DWT和IDWT构建下采... 详细信息

为解决基于深度学习图像去噪方法在图像盲去噪任务中去噪能力有限和去噪效果不佳的问题,构造了小波自编码器(Wavelet-AE),并用于图像盲去噪.首先,使用Haar小波构造小波卷积层(DWT)与逆小波卷积层(IDWT);然后,分别使用DWT和IDWT构建下采样块和上采样块;最后,使用下采样块和上采样块构造小波自编码器.Wavelet-AE可以建立噪声图像与干净图像在特征空间中的映射关系,进而具备更好的图像盲去噪能力.为定量评价所提方法的图像盲去噪能力,将峰值信噪比和结构相似性作为评价指标.在Kodak和SIDD数据集上的图像盲去噪实验结果表明:Wavelet-AE与一些先进的传统方法和深度网络去噪方法相比具有更好的盲去噪能力,平均峰值信噪比(PSNR)最大可提高4.58 dB,平均结构相似性(SSIM)最大可提高0.149.

关键词：图像处理图像盲去噪小波自编码器综合噪声真实噪声

Topologically protected entanglement switching around exceptional points

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Light(Science & Applications) 2024年第8期13卷 1631-1644页

作者： Zan tang Tian Chen Xing tang Xiangdong Zhang Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements of Ministry of Education Beijing Key Laboratory of Nanophotonics&Ultrafine Optoelectronic SystemsSchool of PhysicsBeijing Institute of Technology100081 BeijingChina

The robust operation of quantum entanglement states is crucial for applications in quantum information,computing,and communications^(1–3).However,it has always been a great challenge to complete such a task because of decoherence and ***,we propose theoretically and demonstrate experimentally an effective scheme to realize robust operation of quantum entanglement states by designing quadruple degeneracy exceptional *** encircling the exceptional points on two overlapping Riemann energy surfaces,we have realized a chiral switch for entangled states with high *** to the topological protection conferred by the Riemann surface structure,this switching of chirality exhibits strong robustness against perturbations in the encircling ***,we have experimentally validated such a scheme on a quantum walk *** work opens up a new way for the application of non-Hermitian physics in the field of quantum information.

关键词： exceptional quantum Riemann

An economic way to achieve all-weather CO2 reduction

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National Science Review 2024年第3期11卷 46-47页

作者： Junwang tang Department of Chemical Engineering University College London

Utilising solar power to convert carbon dioxide（CO2） into hydrocarbon fuels presents an eco-friendly method to address dependence on fossil fuels and contribute to a net-zero CO2emission goal[1,2].

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UAV-assisted data collection for wireless sensor networks with dynamic working modes

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Digital Communications and Networks 2024年第3期10卷 805-812页

作者： Jie Chen Jianhua tang Shien-Ming Wu School of Intelligent Engineering South China University of TechnologyGuangzhou511442China

Wireless Sensor Network(WSN)is a cornerstone of Internet of Things(IoT)and has rich application *** this work,we consider a heterogeneous WSN whose sensor nodes have a diversity in their Residual Energy(RE).In this work,to protect the sensor nodes with low RE,we investigate dynamic working modes for sensor nodes which are determined by their RE and an introduced energy ***,we employ an Unmanned Aerial Vehicle(UAV)to collect the stored data from the heterogeneous *** aim to jointly optimize the cluster head selection,energy threshold and sensor nodes’working mode to minimize the weighted sum of energy con-sumption from the WSN and UAV,subject to the data collection rate *** this end,we propose an efficient search method to search for an optimal energy threshold,and develop a penalty-based successive convex approximation algorithm to select the cluster *** we present a low-complexity iterative approach to solve the joint optimization problem and discuss the implementation *** results justify that our proposed approach is able to reduce the energy consumption of the sensor nodes with low RE significantly and also saves energy for the whole WSN.

关键词： Unmanned aerial vehicle Wireless sensor networks Cluster heads Dynamic working modes

Highly effective design of high GFA alloys with different metalbased and various components by machine learning

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Science China(Technological Sciences) 2024年第5期67卷 1431-1442页

作者： tang YiChuan HE YiFan FAN ZhuoQun WANG ZhongQi tang ChengYing Guangxi Key Laboratory for Informational Materials School of Materials Science and EngineeringGuilin University of Electronic TechnologyGuilin541004China

The glass-forming ability(GFA)is of great significance for the development of novel functional metal-based metallic *** this study,seven popular machine learning(ML)algorithms were employed to design novel M-based(M=Fe,Co,Ni,Ti,Zr,and rare earth metal(RE))and X-component(X=2,3,4,5,6,and>6)alloys with excellent GFA.A GFA containing 6957 data points with structural analysis was *** engineering was used to analyze the importance and correlation of *** algorithms were utilized for GFA prediction,revealing that Xtreme Gradient Boosting Trees exhibited the strongest predictive capability,achieving a high accuracy of 94.0%,a true positive rate of 97.6%,and a root mean squared error of 0.3705 across the entire ***,the GFA of ternary to hexahydroxy alloys based on Fe,Co,Ni,Zr,Ti,and Y was predicted using all possible compositions generated through ***,a series of alloys with good GFA was successfully designed and *** present work suggests that the proposed ML method can be utilized to design novel multiple-M-based amorphous alloys with high GFA.

关键词： machine learning amorphous alloy feature engineering materials design glass forming ability

Nuclear charge radius predictions by kernel ridge regression with odd-even effects

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Nuclear Science and Techniques 2024年第2期35卷 94-102页

作者： Lu tang Zhen-Hua Zhang Mathematics and Physics Department North China Electric Power UniversityBeijing 102206China Hebei Key Laboratory of Physics and Energy Technology North China Electric Power UniversityBaoding 071000China

The extended kernel ridge regression(EKRR)method with odd-even effects was adopted to improve the description of the nuclear charge radius using five commonly used nuclear *** are:(i)the isospin-dependent A^(1∕3) formula,(ii)relativistic continuum Hartree-Bogoliubov(RCHB)theory,(iii)Hartree-Fock-Bogoliubov(HFB)model HFB25,(iv)the Weizsacker-Skyrme(WS)model WS*,and(v)HFB25**** the last two models,the charge radii were calculated using a five-parameter formula with the nuclear shell corrections and deformations obtained from the WS and HFB25 models,*** each model,the resultant root-mean-square deviation for the 1014 nuclei with proton number Z≥8 can be significantly reduced to 0.009-0.013 fm after considering the modification with the EKRR *** best among them was the RCHB model,with a root-mean-square deviation of 0.0092 *** extrapolation abilities of the KRR and EKRR methods for the neutron-rich region were examined,and it was found that after considering the odd-even effects,the extrapolation power was improved compared with that of the original KRR *** strong odd-even staggering of nuclear charge radii of Ca and Cu isotopes and the abrupt kinks across the neutron N=126 and 82 shell closures were also calculated and could be reproduced quite well by calculations using the EKRR method.

关键词： Nuclear charge radius Machine learning Kernel ridge regression method

Controlled synthesis of one-dimensional segmented heteronanostructures

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Science China Materials 2024年第8期67卷 2715-2716页

作者： Zhiyong tang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China

Telluride materials possess distinctive advantages,including the high theoretical volume capacity and electrical conductivity,rendering them promising candidates for a range of energy storage and optoelectronic applications[1].Heterogeneous compositions and interfaces in heteronanostructures have significant implications on the electron transport,magnetic coupling,and phonon scattering,thereby promoting the performances in photocatalysis,and thermoelectrics[2].

关键词： synthesis rendering thereby