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Effects of Nitrogen Application Time on Caryopsis Development and Grain Quality of Rice Variety Yangdao 6

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Rice science 2008年第1期15卷 57-62页

作者： XIONG Fei WANG Zhong gu Yun-jie chen Gang ZHOU Peng Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology Yangzhou University Yangzhou 225009 China

A pot experiment was conducted to study the effects of different nitrogen application time （during the tillering or the booting stages） with the same nitrogen rates on the caryopsis development and grain quality of rice variety Yangdao 6. The increased nitrogen fertilizer （urea）, especially applied during the booting stage, could evidently increase the milled rice rate, head rice rate and protein content in rice grains compared with the control （no nitrogen application）, and decrease chalky grain rate and amylose content. Moreover, the increased nitrogen fertilizer significantly affected the caryopsis development and enhanced the grain weight when nitrogen applied during the tillering and the booting stages, especially during the booting stage. During caryopsis development the increased nitrogen fertilizer applied during the tillering and booting stages could obviously decrease the total starch and amylose contents, but not obviously for the amylopectin content in rice grain. Increased topdressing of nitrogen fertilizer, especially applied during the booting stage, had significant effect on the development and structures of amyloplasts and proteinoplasts. That is, it could change the distribution, number and shape of amyloplasts and proteinoplasts in the endosperm cells especially in grain abdomen, Compared with the control the arrangements of amyloplasts and proteinoplasts were closer, with more numbers, higher density and less interspaces each ohter. Furthermore, most amyloplasts showed polyhedron under the increased nitrogen fertilizer level.

关键词： caryopsis development rice quality amylose proteinoplast amyloplast starch nitrogen fertilizer fertilizer application time

Trinuclear gold-catalyzed site-selective alkylation of peptides

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Science China Chemistry 2025年第1期68卷 249-256页

作者： Qing-Yun Fang chengyihan gu Yinghan chen Wencheng Yan Yong Liang Weipeng Li chengjian Zhu jie Han Jin Xie State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic Materials Chemistry and Biomedicine Innovation Center (Chem BIC) School of Chemistry and Chemical Engineering Nanjing University Green Catalysis Center College of Chemistry Zhengzhou University State Key Laboratory of Natural Medicines China Pharmaceutical University

Selective modification of peptides has always been a challenging issue. The selective alkylation of peptides can alter the biological activity and physical properties of molecules, and it has gained significant research interest. We herein disclose an intriguing gold-catalyzed alkylation of peptides using bench-stable unactivated alkyl bromides under photoredox catalysis. A wide range of structurally diverse primary, secondary and tertiary alkyl bromides serve as effective coupling partners to precisely connect with the α-C(sp3)–H in glycine residue of peptides. This protocol demonstrates an exceptionally broad scope for alkyl halides and excellent tolerance for a wide range of useful functional groups. A series of relay transformations to construct cyclic peptides, to proceed click reaction and to realize peptide fluorescence labeling further enhance its synthetic practicality. In addition, mechanistic studies and density functional theory(DFT) calculations reveal an inner-sphere and subsequent outersphere single electron transfer(SET) mechanism.

关键词： gold catalysis peptide alkylation C-C coupling radical

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Cyano migration-mediated radical-polar crossover cyclopropanation

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Science China Chemistry 2025年第1期68卷 241-248页

作者： Ziqiang Wang Yasu chen jie Li chen Zhu Key Laboratory of Organic Synthesis of Jiangsu Province College of Chemistry Chemical Engineering and Materials ScienceSoochow University Frontiers Science Center for Transformative Molecules Zhangjiang Institute for Advanced Study and Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Shanghai Jiao Tong University

We report a novel cyano migration-mediated radical-polar crossover process, whereby both the sulfonylcyanation of aliphatic alkenes and the formation of cyclopropanes are concurrently achieved. This transformation yields a diverse array of multisubstituted cyclopropanes under mild photocatalytic conditions. Mechanistic studies elucidate that the reaction proceeds via intramolecular nucleophilic substitution, leading to the formation of the cyclopropane derivatives.

关键词： cyclopropanation cyano migration radical-polar crossover radical reactions

Dynamic behaviors of graphene platelets-reinforced metal foam piezoelectric beams with velocity feedback control

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 63-80页

作者： jie chen Xinyue ZHANG Mingyang FAN School of Mathematics Statistics and Mechanics Beijing University of Technology College of Mechanical & Energy Engineering Beijing University of Technology

Graphene platelets(GPLs)-reinforced metal foam structures enhance the mechanical properties while maintaining the lightweight characteristics of metal foams. Further bonding piezoelectric actuator and sensor layers on the surfaces of GPLs-reinforced metal foam beams enables active vibration control, greatly expanding their applications in the aerospace industry. For the first time, this paper investigates the vibration characteristics and active vibration control of GPLs-reinforced metal foam beams with surfacebonded piezoelectric layers. The constant velocity feedback scheme is used to design the closed-loop controller including piezoelectric actuators and sensors. The effects of the GPLs on the linear and nonlinear free vibrations of the beams are numerically *** Newmark-β method combined with Newton's iteration technique is used to calculate the nonlinear responses of the beams under different load forms including harmonic loads,impact loads, and moving loads. Additionally, special attention is given to the vibration reduction performance of the velocity feedback control on the responses of the beam.

关键词： Piezoelectric actuators

AI-Enhanced Secure Data Aggregation for Smart Grids with Privacy Preservation

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Computers, Materials & Continua 2025年第1期82卷 799-816页

作者： Congcong Wang chen Wang Wenying Zheng Wei gu School of Software Nanjing University of Information Science and TechnologyNanjing210044China School of Information Science and Engineering Zhejiang Sci-Tech UniversityHangzhou310018China State Key Laboratory of Public Big Data Guizhou UniversityGuiyang550025China School of Computer Science and Technology(School of Artificial Intelligence) Zhejiang Sci-Tech UniversityHangzhou310018China School of Computer Science(School of Cyber Science and Engineering) Nanjing University of Information Science and TechnologyNanjing210044China

As smart grid technology rapidly advances,the vast amount of user data collected by smart meter presents significant challenges in data security and privacy *** research emphasizes data security and user privacy concerns within smart ***,existing methods struggle with efficiency and security when processing large-scale *** efficient data processing with stringent privacy protection during data aggregation in smart grids remains an urgent *** paper proposes an AI-based multi-type data aggregation method designed to enhance aggregation efficiency and security by standardizing and normalizing various data *** approach optimizes data preprocessing,integrates Long Short-Term Memory(LSTM)networks for handling time-series data,and employs homomorphic encryption to safeguard user *** also explores the application of Boneh Lynn Shacham(BLS)signatures for user *** proposed scheme’s efficiency,security,and privacy protection capabilities are validated through rigorous security proofs and experimental analysis.

关键词： Smart grid data security privacy protection artificial intelligence data aggregation

Rapid and scalable preparation of highly quaternized polymer networks to achieve efficient simultaneous adsorption of iodide and pertechnetate

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Science China Chemistry 2025年第1期68卷 337-349页

作者： Meiyun Xu Song gu Fulong chen Zhe Zhao Peng Liu Daoben Hua State Key Laboratory of Radiation Medicine and Protection School of Radiological and Interdisciplinary Sciences (RAD-X) Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions Soochow University

The efficient separation of fission products,such as TcO4-and I-,holds strategic significance for the management of radioactive wastes and environmental *** this study,we propose an ultrafast strategy for scalable preparation of a highly quaternized organic network to facilitate efficient and synchronous separation of iodide and *** network can be prepared within a few minutes at room temperature,using polyethylenimine and 1,2,4,5-tetrakis（bromomethyl）benzene as building *** chlorine replacement,the network,abundantly decorated with quaternary ammonium groups （Cl@QPN）,exhibits an ultrahigh positive charge density of 7.6 mmol/*** enables the rapid and efficient enrichment of target anions through strong electrostatic Coulomb *** a result,Cl@QPN exhibits significantly higher adsorption rate constants of 0.830 g/（mg min） for ReO4-（a nonradioactive surrogate of TcO4-） and 0.677 g/（mg min） for I-compared to other ***,it possesses high adsorption capacities,reaching 1,681 mg/g for ReO4-and 917.4 mg/g for I-.Cl@QPN also demonstrates good selectivity towards target ions and shows efficient adsorption for99TcO4-.Additionally,Cl@QPN exhibits high dynamic processing capacities,handling up to 3,100 and 7,400 kg of simulated streams per kilogram of material for I-and ReO4-,respectively.

关键词： quaternized polymer networks adsorption pertechnetate iodide liquid radioactive streams

Inexact proximal gradient algorithm with random reshuffling for nonsmooth optimization

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Science China(Information Sciences) 2025年第1期68卷 219-237页

作者： Xia JIANG Yanyan FANG Xianlin ZENG Jian SUN jie chen National Key Lab of Autonomous Intelligent Unmanned Systems School of AutomationBeijing Institute of Technology Beijing Institute of Technology Chongqing Innovation Center School of Electronic and Information Engineering Tongji University

Proximal gradient algorithms are popularly implemented to achieve convex optimization with nonsmooth regularization. Obtaining the exact solution of the proximal operator for nonsmooth regularization is challenging because errors exist in the computation of the gradient; consequently, the design and application of inexact proximal gradient algorithms have attracted considerable attention from researchers. This paper proposes computationally efficient basic and inexact proximal gradient descent algorithms with random reshuffling. The proposed stochastic algorithms take randomly reshuffled data to perform successive gradient descents and implement only one proximal operator after all data pass through. We prove the convergence results of the proposed proximal gradient algorithms under the sampling-without-replacement reshuffling *** computational errors exist in gradients and proximal operations, the proposed inexact proximal gradient algorithms can converge to an optimal solution neighborhood. Finally, we apply the proposed algorithms to compressed sensing and compare their efficiency with some popular algorithms.

关键词： proximal operator random reshuffling inexact computation compressed sensing nonsmooth optimization

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光载波条纹自动化图像处理

中国激光 1994年第6期21卷 499-503页

作者：顾杰陈方奥克兰大学机械系

本文提出一种全自动的光载波条纹处理方法，只需要一幅光载波调制的条纹图就能提取出完整的信息。先用ＦＦＴ滤波求出带有光载波的初始位相，接着用反复平均法提高位相信息的质量，然后用是小二乘法构造光载波的位相，两位相相减得出信... 详细信息

本文提出一种全自动的光载波条纹处理方法，只需要一幅光载波调制的条纹图就能提取出完整的信息。先用ＦＦＴ滤波求出带有光载波的初始位相，接着用反复平均法提高位相信息的质量，然后用是小二乘法构造光载波的位相，两位相相减得出信息的位相。

关键词：光载波条纹图像处理自动化

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三亚城市生态修复的探索与思考

中国园林 2017年第11期33卷 19-24页

作者：王忠杰束晨阳顾晨洁中国城市规划设计研究院风景园林和景观研究分院中国城市规划设计研究院

当前,中国正处在城镇化快速发展期。一方面,城市病集中爆发,另一方面,既有的增长模式难以维系,转型发展刻不容缓。城市生态修复是新时期城市转型发展的重要方法,是破解城市病的重要手段。结合中规院在三亚开展的山、河、海等一系列城市... 详细信息

当前,中国正处在城镇化快速发展期。一方面,城市病集中爆发,另一方面,既有的增长模式难以维系,转型发展刻不容缓。城市生态修复是新时期城市转型发展的重要方法,是破解城市病的重要手段。结合中规院在三亚开展的山、河、海等一系列城市生态修复工作,提出工作框架,总结实践体会,对城市生态修复的概念、范畴、实施路径、存在问题等进行探索思考,为全面系统地开展城市生态修复工作提供参考,助力城市转型发展。

关键词：风景园林城市生态修复三亚修复工作框架