检索结果-南通市图书馆

维普期刊数据库博看期刊

Effects of Water Stress on Reactive Oxygen Species Generation and Protection System in Rice During Grain-Filling Stage

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2010年第5期9卷 633-641页

作者： wang he-zheng ZHANG Lian-he MA Jun LI Xu-yi LI Yan ZHANG Rong-ping wang Ren-quan College of Agriculture Henan University of Science and Technology Luoyang 471003 P.R.China Rice Research Institute of Sichuan Agricultural University Wenjiang 611130 P.R.China

Rice is one of the main staple food crops in the world, but it may suffer serious water stress during growth period. Water stress during grain filling results in decreased grain yeild, but its mechanism generating and scavenging the active oxygen is unclear under continuance of the water stress. The experiment was carried out in growth chamber to investigate the effects of water stress on the production of superoxide free radical （O2）, hydrogen peroxide （H202）, malondialdehyde （MDA）, reduced glutathione （GSH）, ascorbic acid （AsA）, and antioxidative enzyme activities in three rice hybrids with differing drought resistant under both normal and drought conditions during grain-filling stage. The results showed that water stress aggravated the membrane lipid peroxidation in rice leaves, which was more severe in less drought resistant hybrids than that in more tolerant ones. Also O2＇ and H2O2 accumulated more rapidly in less drought resistant hybrids than that in more tolerant ones. During water stress, decreases of GSH, AsA, chlorophyll, and relative water contents in more drought resistant hybrids were obvious less than those in less tolerant ones. Activities of superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POD） in/eaves increased obviously in 0-14 d after heading and subsequently decreased rapidly, and those in more drought resistant hybrids were more than those in less tolerant ones. The results showed that changes of O2, H2O2, MDA, GSH, and AsA contents and antioxidative enzyme activities correlated significantly to drought resistance of rice hybrids, and more drought resistant hybrids possessed high ant oxidation capacity.

关键词： rice water stress reactive oxygen species protection system

Personalized federated few-shot node classification

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2025年第1期68卷 204-218页

作者： Yunfeng ZHAO Xintong he Guoxian YU Jun wang Yongqing zheng Carlotta DOMENICONI School of Software Shandong University Joint SDU-NTU Centre for Artificial Intelligence Research Shandong University Department of Mathematics National University of Singapore Department of Computer Science George Mason University

Personalized federated learning(PFL) aims to train customized models for individual clients in a decentralized setting, with the account of non-independent and identically distributed data across clients. However, most PFL methods adopt uniform classification layers for diverse clients and give rise to error-prone predictions, due to the task heterogeneity notably prominent in decentralized graph data scenarios. Although some PFL solutions setup client-specific classification layers for each client and optimize them only locally, they are corrupted with limited local training data. We propose an innovative solution called federated parameter decoupling and node augmentation(Fed PANo) to address these problems and to achieve personalized federated few-shot node classification, which is a prevalent and challenging but unexplored topic. Specifically, Fed PANo first separates the local model into the GNN and classifier to handle unique client-specific task variations. The GNN is trained through federated learning to capture shared knowledge of graph nodes across clients, while the classifier is custom-designed and trained individually for each client. Additionally, a generic classifier shared among clients is adopted to encourage the GNN's grasp of shared information. Then Fed PANo further proposes the node generator along with its local and collaborative training strategies to deal with the node scarcity of clients. Extensive experimental results on benchmark datasets confirm that Fed PANo outperforms eight competitive baselines across different settings.

关键词： personalized federated learning few-shot learning node classification task heterogeneity parameter decoupling node augmentation

Biodegradation of acetanilide herbicides acetochlor and butachlor in soil

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2002年第4期14卷 524-529页

作者： YE Chang ming, wang Xing jun, zheng he hui (Research Center for Eco Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Research Center for Eco-Environmental Sciences Chinese Academy of Sciences 北京 100085

The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matters addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil SDBS (sodium dodecylbenzene sulfonate) mixtures and soil HA (humic acid) mixtures. herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half life of acetochlor and butachlor in soil alone, soil SDBS mixtures and soil HA mixtures were 4.6d, 6.1d and 5.4d and 5.3d, 4.9d and 5.3d respectively. The biodegradation products were hydroxyacetochlor and 2 methyl 6 ethylaniline for acetochlor, and hydroxybutachlor and 2,6 diethylaniline for butachlor.

关键词： acetochlor butachlor soil biodegradation kinetics degradation products

Construction Monitoring and Analysis of Asymmetric Prestressed Concrete Bridge Crossing Multiple-Line Railways

在线全文

学校读者我要写书评

暂无评论

Structural Durability & health Monitoring 2025年第2期19卷 385-398页

作者： Yi wang Bing wang Changwen Li Feng zheng Yong Liu Shaohua he Guangzhou Railway Investment Construction Group Co. Ltd.Guangzhou510000China China Railway Third Bureau Group Co. LtdTaiyuan030024China School of Civil and Transportation Engineering Guangdong University of TechnologyGuangzhou510006China

Complex bridge structures designed and constructed by humans often necessitate extensive on-site execution,which carries inherent ***,a variety of engineering practices are employed to monitor bridge *** paper presents a case study of a large-span prestressed concrete(PC)variable-section continuous girder bridge in China,proposing a feedback system for construction monitoring and establishing a finite element(FE)analysis model for the entire *** alignment of the completed bridge adheres to the initial design expectations,with maximum displacement and pre-arch differences from the ideal state measuring 6.39 and 17.7 mm,respectively,which were less than the 20 mm limit required by the ***,the stress monitoring showed that the maximum compressive stress was 10.44 MPa,which was 7.5%different from the finite element results,and better predicted the most unfavorable possible *** results demonstrate that a scientifically rigorous construction monitoring and feedback system can ensure the safety of bridge construction and meet the expected construction *** findings presented in this paper provide valuable insights for bridge construction monitoring practices.

关键词： Continuous girder bridge construction monitoring bridge alignment stress monitoring

Construction of N-doped copper metal-organic frameworks for promoting photocatalytic carbon dioxide reduction to ethylene

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第2期68卷 601-609页

作者： Fan Guo Zong-zheng he Peng wang Xiao-Yu Zhang Hongjian Yu Qin-Chao wang Wei-Yin Sun School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China Coordination Chemistry Institute State Key Laboratory of Coordination ChemistrySchool of Chemistry and Chemical EngineeringNanjing National Laboratory of MicrostructuresCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210023China

Engineering nonmetallic atom-doped metal-organic framework(MOF)catalyst to promote C−C coupling and realize conversion of CO_(2) into C_(2 )multi-carbon hydrocarbon products is still ***,with 2-methylimidazole as a dopant of N element,an N-doped NH_(2)-CuBDC catalyst was obtained via a facile and simple stirring *** illumination,compared with catalytic CO_(2) reduction to C1 product of CO by original MOF,N-doped NH_(2)-CuBDC can motivate generation of C_(2)H_(4),which is difficult to achieve in photocatalytic system by MOF-based *** transfer rates of photo-generated charges have been expedited due to the high electron density around Cu catalytic sites after *** importantly,C–C coupling intermediate CO–CHO*was identified by in situ Fourier transform infrared spectroscopy during the catalytic CO_(2) reduction reaction process,which further indicates the presence of Cu–N sites in the NH_(2)-CuBDC can facilitate the formation of C2H_(4) *** work uncovers a new paradigm to design photocatalysts for enhancing the reduction of CO_(2) to C_(2) products.

关键词： metal-organic frameworks C-C coupling doping photocatalytic CO_(2) reduction Cu-based catalysts

麦季耕作方式和玉米季氮肥用量对旱地麦-玉两熟区玉米产量和氮素利用的影响

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

植物营养与肥料学报 2025年第1期31卷 63-76页

作者：彭彦珉赵凯男李爽张军王荣荣肖慧淑姜沛沛王贺正付国占吴金芝黄明李友军河南科技大学农学院河南洛阳471023

【目的】在旱地麦-玉两熟区,关于麦季耕作方式与玉米季氮肥用量如何共同影响玉米产量及氮素利用效率的综合性研究相对较少。我们运用熵权法和TOPSIS法建立了综合评价模型,评价各处理方案间的差异,为麦-玉两熟区玉米高产高效生产提供理... 详细信息

【目的】在旱地麦-玉两熟区,关于麦季耕作方式与玉米季氮肥用量如何共同影响玉米产量及氮素利用效率的综合性研究相对较少。我们运用熵权法和TOPSIS法建立了综合评价模型,评价各处理方案间的差异,为麦-玉两熟区玉米高产高效生产提供理论依据。【方法】2020—2022年,在典型旱地麦-玉两熟区河南省洛阳市孟津区小浪底镇开展二因素裂区田间定位试验,以麦季旋耕(RT)、翻耕(PT)和深松(SS)3种耕作方式为主区,以玉米季基施氮0 kg/hm^(2)(N0)、150 kg/hm^(2)(N150)、210 kg/hm^(2)(N210)和270 kg/hm^(2)(N270)4个氮肥用量为副区,研究不同处理对玉米产量及其构成因素、成熟期地上部干物质和氮素积累量以及氮素利用效率的影响,并使用熵权法和TOPSIS法建模选优。【结果】麦季耕作方式和玉米季氮肥用量及二者互作对玉米产量、产量构成要素、干物质积累量、氮素积累量和氮素利用效率均有显著影响。与RT和PT处理相比,SS处理玉米平均产量分别提高10.4%和7.8%,干物质积累量分别提高12.4%和6.7%,氮肥偏生产力、氮肥农学效率、氮肥贡献率分别提高14.4%和10.3%、77.5%和50.9%、52.7%和34.5%。相同耕作方式下,随着氮肥用量的增加,玉米产量、干物质积累量、氮素积累量、氮肥农学效率和氮肥贡献率均表现为先增加后稳定,而氮肥吸收效率和氮肥偏生产力逐渐降低。与N270处理相比,N210处理玉米产量、干物质积累量、氮素积累量、氮素内在效率和氮肥贡献率在3年中均无显著差异,但氮肥吸收效率、氮肥偏生产力和氮肥农学效率分别显著提高29.2%、30.1%和33.0%。从互作效应看,3年中SSN210处理的产量、干物质积累量和氮素积累量虽与SSN270无显著差异,但均显著高于其他处理,平均增幅分别为10.1%~70.4%、7.0%~59.2%和6.1%~65.3%;氮肥农学效率除2021年低于SSN150处理外,其余年份均显著高于其他处理14.8%~237.9%;3年平均氮肥内在效率和氮肥贡献率也均高于其他处理。运用TOPSIS法进行综合评价后发现,在同一施氮量下3年中综合评价值均表现为SS>PT>RT,在同一耕作方式下均以N210处理显著高于其他氮肥用量处理,互作条件下均以SSN210处理最高。【结论】麦季深松配合玉米季施氮210 kg/hm^(2),是实现旱地麦-玉两熟区玉米高产高效的有效途径。

关键词：夏玉米麦前深松氮肥用量产量氮素利用效率 TOPSIS法

Reconstructing forest and grassland cover changes in China over the past millennium

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第1期68卷 94-110页

作者： Fanneng he Fan YANG Yafei wang Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China Key Research Institute of Yellow River Civilization and Sustainable Development Henan UniversityKaifeng475001China University of Chinese Academy of Sciences Beijing100049China

Historical forest and grassland cover changes not only are critical indicators for quantifying ecological and environmental change processes but also serve as fundamental data for long-term climate change simulations and terrestrial ecosystem carbon emission ***,because of limitations in historical data,quantitative estimations and spatially gridded reconstructions of these changes remain challenging,necessitating further methodological *** study focused on China's present-day land area over the past millennium,objectively capturing the characteristics and drivers of forest and grassland cover *** this basis,using the forest transition theory and the space-for-time substitution method,we depicted the historical deforestation process as an inverted“S”curve and developed a model to reconstruct historical forest area changes based on the functional relationship between the forest area and population size ***,a gridded forest allocation model was established on the basis of deforestation *** the grassland cover,we implemented regionspecific methods,such as the cropland area deduction method and the habitat constraint method,to quantitatively reconstruct historical ***,we obtained provincial forest and grassland area changes over the past millennium and mapped 10-km-resolution gridded data of forest and grassland *** results indicated the following.(1)The methods developed using population data as a proxy objectively reproduced the spatiotemporal evolution of forest and grassland cover in China over the past *** feasible methods offer a novel pathway for the quantitative reconstruction of historical forest and grassland cover changes.(2)The data indicated that China's forest area generally decreased over the past millennium,characterized by a“decrease-then-increase”*** forest area experienced three distinct phases:a slow decline(AD 1000–1650),a rapid decline(AD 16

关键词： Land use and land cover change Forest Grassland Quantitative reconstruction Gridded reconstruction China historical period

Constraints on holographic QCD phase transitions from PTA observations

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 67-74页

作者： Song he Li Li Sai wang Shao-Jiang wang Center for Theoretical Physics and College of Physics Jilin UniversityChangchun 130012China School of Physical Science and Technology Ningbo UniversityNingbo 315211China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences(UCAS)Hangzhou 310024China Theoretical Physics Division Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Physical Sciences University of Chinese Academy of Sciences(UCAS)Beijing 100049China Max Planck Institute for Gravitational Physics(Albert Einstein Institute) Am Muhlenberg 1Golm 14476Germany

The underlying physics of QCD phase transition in the early Universe remains largely unknown due to its strong-coupling nature during the quark-gluon plasma/hadron gas transition,yet a holographic model has been proposed to quantitatively fit the lattice QCD data while with its duration of the first-order phase transition(FoPT)left *** specific baryon chemical poten-tial,the first-order QCD phase transition agrees with the observational constraint of baryon ***,therefore,provides a scenario for phase transition gravitational waves(GWs)within the standard model of particle *** these background GWs could contribute dominantly to the recently claimed common-spectrum red noise from pulsar timing array(PTA)observations,the duration of this FoPT can be well constrained,and the associated primordial black holes are still allowed by current observations.

关键词： pulsar timing array QCD phase transition gravitational waves primordial black holes

Rising frequency of ozone-favorable synoptic weather patterns contributes to 2015-2022 ozone increase in Guangzhou

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2025年第2期148卷 502-514页

作者： Nanxi Liu Guowen he Haolin wang Cheng he Haofan wang Chenxi Liu Yiming wang Haichao wang Lei Li Xiao Lu Shaojia Fan School of Atmospheric Sciences Sun Yat-sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Guangdong Provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary Key Laboratory of Tropical Atmosphere-Ocean System(Sun Yat-sen University)Ministry of EducationZhuhai 519082China

Objective weather classification methods have been extensively applied to identify dominant ozone-favorable synoptic weather patterns(SWPs),however,the consistency of different classification methods is rarely *** this study,we apply two widely-used objective methods,the self-organizing map(SOM)and K-means clustering analysis,to derive ozone-favorable SWPs at four Chinese megacities in *** find that the two algorithms are largely consistent in recognizing dominant ozone-favorable SWPs for four Chinese *** the case of classifying six SWPs,the derived circulation fields are highly similar with a spatial correlation of 0.99 between the two methods,and the difference in themean frequency of each SWP is less than 7%.The six dominant ozone-favorable SWPs in Guangzhou are all characterized by anomaly higher radiation and temperature,lower cloud cover,relative humidity,and wind speed,and stronger subsidence compared to climatology *** find that during 2015-2022,the occurrence of ozone-favorable SWPs days increases significantly at a rate of 3.2 days/year,faster than the increases in the ozone exceedance days(3.0 days/year).The interannual variability between the occurrence of ozone-favorable SWPs and ozone exceedance days are generally consistent with a temporal correlation coefficient of *** particular,the significant increase in ozone-favorable SWPs in 2022,especially the Subtropical High type which typically occurs in September,is consistent with a long-lasting ozone pollution episode in Guangzhou during September *** results thus reveal that enhanced frequency of ozone-favorable SWPs plays an important role in the observed 2015-2022 ozone increase in Guangzhou.

关键词： Ozone(O3) Objective weather classification methods Synoptic weather patterns Trends Guangzhou