检索结果-南通市图书馆

Effect of Nitrate on Activities and Transcript Levels of Nitrate Reductase and Glutamine Synthetase in Rice

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2008年第5期18卷 664-673页

作者： CAO yun FAN xiao-Rong SUN Shu-Bin XU Guo-hua hu Jiang SHEN Qi-Rong College of Resources and Environmental Sciences Nanjing Agricultural University Nanjing 210095 （China）.

Real-time polymerase chain reaction analysis was used to compare the effect of NO3^- on the activities of nitrate reductase （NR） and glutamine synthetase （GS）, and the transcript levels of two NR genes, OsNial and OsNia2, two cytosolic GS1 genes, OsGln1;1 and OsGln1;2, and one plastid GS2 gene OsGln2, in two rice （Oryza sativa L.） cultivars Nanguang （NG） and yunjing （Y J）. Both cultivars achieved greater biomass and higher total N concentration when grown in a mixed N supply than in sole NH4^＋ nutrition. Supply of NO3^- increased NR activity in both leaves and roots. Expression of both NR genes was also substantially enhanced and transcript levels of OsNia2 were significantly higher than those of OsNial. NO3 also caused an increase in GS activity, but had a complex effect on the expression of the three GS genes. In roots, the OsGln1;1 transcript increased, but OsGln1;2 decreased. In leaves, NO3^- had no effect on the GS1 expression, but the transcript for OsGln2 increased both in the leaves and roots of rice with a mixed supply of N. These results suggested that the increase in GS activity might be a result of the complicated regulation of the various GS genes. In addition, the NO3-induced increase of biomass, NR activity, GS activity, and the transcript levels of NR and GS genes were proportionally higher in NG than in Y J, indicating a stronger response of NG to NO3^- nutrition than YJ.

关键词： ammonium glutamine synthetase nitrate nitrate reductase Oryza sativa L.

Bayesian estimation-based sentiment word embedding model for sentiment analysis

在线全文

学校读者我要写书评

暂无评论

CAAI Transactions on Intelligence Technology 2022年第2期7卷 144-155页

作者： Jingyao Tang yun Xue Ziwen Wang Shaoyang hu Tao Gong Yinong Chen Haoliang Zhao Luwei xiao Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials School of Physics and Telecommunication EngineeringSouth China Normal UniversityGuangzhouChina College of Mathematics and Informatics&College of Software Engineering South China Agricultural UniversityGuangzhouChina School of Foreign Languages Zhejiang University of Finance&EconomicsHangzhouZhejiangChina Educational Testing Service PrincetonNew JerseyUSA School of Computing Informatics and Decision Systems EngineeringArizona State UniversityTempeUSA

Sentiment word embedding has been extensively studied and used in sentiment analysis ***,most existing models have failed to differentiate high-frequency and low-frequency ***,the sentiment information of low-frequency words is insufficiently captured,thus resulting in inaccurate sentiment word embedding and degradation of overall performance of sentiment analysis.A Bayesian estimation-based sentiment word embedding(BESWE)model,which aims to precisely extract the sentiment information of low-frequency words,has been *** the model,a Bayesian estimator is constructed based on the co-occurrence probabilities and sentiment proba-bilities of words,and a novel loss function is defined for sentiment word embedding *** experimental results based on the sentiment lexicons and Movie Review dataset show that BESWE outperforms many state-of-the-art methods,for example,C&W,CBOW,GloVe,SE-HyRank and DLJT1,in sentiment analysis tasks,which demonstrate that Bayesian estimation can effectively capture the sentiment information of low-frequency words and integrate the sentiment information into the word embedding through the loss *** addition,replacing the embedding of low-frequency words in the state-of-the-art methods with BESWE can significantly improve the performance of those methods in sentiment analysis tasks.

关键词： function embedding estimation

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

On Strebel points

Science China Mathematics 2009年第9期52卷 2019-2026页

作者： hu yun SHEN YuLiang Department of Mathematics Soochow UniversitySuzhou 215006China

Any Beltrami coefficient μ on a hyperbolic Riemann surface X of infinite type represents a point [μ]T in the Teichmüller space T (X) and a point [μ]B in the tangent space of T (X) at the base point as well. The paper deals with the problem of determining whether that [μ]T is a Strebel point is equivalent to that [μ]B is an infinitesimal Strebel point.

关键词： Teichmüller space Strebel point infinitesimal Strebel point 32G15 30C62 30F60

Two-dimensional CoNi@mesoporous carbon composite with heterogeneous structure toward broadband microwave absorber

在线全文

学校读者我要写书评

暂无评论

Nano Research 2022年第9期15卷 7769-7777页

作者： yun Qiu Haibo Yang Fanfan hu Ying Lin Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials School of Materials Science and EngineeringShaanxi University of Science and TechnologyXi’an 710021China Jiangsu Product Quality Testing&Inspection Institute Nanjing 210007China

Constructing composites with heterogeneous structure and dual loss mechanism shows great potential in designing microwave *** this work,two-dimensional cobalt and nickel alloys@mesoporous carbon(CoNi@MC)composites were constructed via using CoNi layered double hydroxide@mesoporous polydopamine(CoNi LDH@MPDA)as sacrifice *** the pyrolysis process,the MPDA is transformed into mesoporous carbon coated the surface of CoNi LDH that is further reduced to CoNi *** mesoporous structure is conducive to the multi-reflection of electromagnetic waves and facilitates optimizing impedance *** interfaces between CoNi alloys and mesoporous carbon induce interface *** attenuation mechanism promotes the electromagnetic waves *** maximum reflection loss of CoNi@MC composite is−70.86 dB and the widest effective absorption bandwidth is 7.74 GHz covering almost the entire Ku *** strategy will be a guidance for designing electromagnetic absorbers.

关键词： CoNi alloys mesoporous carbon microwave absorption broad efficient frequency

Payne Effect and Weak Overshoot in Rubber Nanocomposites

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

Chinese Journal of Polymer Science 2022年第1期40卷 85-92页

作者： Zhi-yun Li Yi-hu Song Qiang Zheng MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

Payne effect and its associated weak overshoot are of importance for understanding and regulating the softening of rubber nanocomposites under large amplitude ***,Payne effect in diverse filled vulcanizates is investigated for generalizing the common *** curves of strain amplitude dependent storage modulus are created with respect to microscopic strain amplitude of the matrix,revealing a matrix-dominated elastic nonlinearity being independent of type and dispersity of filler,crosslinking density and sol fraction of matrix and filler-rubber interfacial ***,carbonaceous fillers with higher affinity to the rubber matrices yield lower strain amplification and higher overshoot behavior in comparison with siliceous *** investigation would be illuminating for preparing rubber nanocomposites with optimized reinforcement and softening performances.

关键词： Vulcanizate nanocomposites Payne effect Weak overshoot

The New Methods for Characterization of Molecular Weight of Supramolecular Polymers

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第10期42卷 1403-1413,I0006页

作者： hui Liu Rui hu Zi-Qing hu xiao-Fan Ji Key Laboratory of Materials Chemistry for Energy Conversion and Storage Ministry of EducationHubei Key Laboratory of Materials Chemistry and Service FailureHubei Engineering Research Center for Biomaterials and Medical Protective MaterialsSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074China

Supramolecular polymers,as a type of dynamic polymers,are subordinate to the interdisciplinary field of polymer chemistry and supramolecular chemistry,whose development has greatly promoted the prosperity of new ***,molecular weight is one of the most important parameters of supramolecular polymers,which affects the physical/chemical properties and processing applications of *** new methods for characterizing the molecular weight of supramolecular polymers is crucial for advancing the development of supramolecular *** this review,we elaborate and summarize three strategies for characterizing the molecular weight of supramolecular polymers that recently reported by our research group according to the characteristics of supramolecular polymers,including(1)the molecular weight distinction corresponding to variable fluorescence colors,(2)matching different molecular weights with different fluorescence lifetime,(3)transforming supramolecular polymers into mechanically interlocked polymers or covalent ***,we also discuss the limitations of current methods for characterizing supramolecular *** hope that this review can promote the development of supramolecular polymers and significantly inspire to exploit new methods to characterizing molecular weight of supramolecular polymers.

关键词： Supramolecular polymers Molecular weight Self-assembly Mechanically interlocked polymers Dynamic polymers

3D motion and geometric information system of single-antenna radar based on incomplete 1D range data

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2011年第3期22卷 412-420页

作者： Yingkang Zhang Yang xiao Shaohai hu Institute of Information Science Beijing Jiaotong UniversityBeijing 100044P.R.China

A 3D motion and geometric information system of single-antenna radar is proposed,which can be supported by spotlight synthetic aperture radar（SAR） system and inverse SAR（ISAR） system involving relative 3D motion of the rigid *** this system,applying the geometry invariance of the rigid target,the unknown 3D shape and motion of the radar target can be reconstructed from the 1D range data of some scatterers extracted from the high-resolution range *** with the current 1D-to-3D algorithm,in the proposed algorithm,the requirement of the 1D range data is expanded to incomplete formation involving large angular motion of the target and hence,the quantity of the scatterers and the abundance of 3D motion are ***,with the three selected affine coordinates fixed,the multi-solution problem of the reconstruction is solved and the technique of nonlinear optimization can be successfully utilized in the *** simulations are implemented which verify the higher robustness of the system and the better performance of the 3D reconstruction for the radar target with unknown relative motion.

关键词： 3D reconstruction radar 1D range data geometry invariance inverse synthetic aperture radar(ISAR) bundle adjustment.

EFFECT OF SULPhuRIZING-OXIDIZING ENVIRONMENT ON CREEP CRACK GROWTH OF Ni-BASE SUPERALLOY GH30

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1992年第1期5卷 43-47页

作者： ZHANG Yuanhu ZHANG yun hu Shanghai Jiaotong Univ Shanghai China

An investigation was made on the creep crack growth behaviour under static load at 1023 K for Ni-base superalloy GH30 exposed to air and air+10% SO_*** results showed that in the region of low stress intensity factor,the creep crack growth rate is higher in air+10% SO_2 than in air only,while in the high region,it is *** fractograph of specimens has been analyzed,and the mechanism of creep crack growth together with the influences of sul- phur and oxygen has been discussed as well.

关键词： Ni-base superalloy creep crack growth environment

Experimental study on the seismic performance of new sandwich masonry walls

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2013年第1期12卷 77-86页

作者： xiao Jianzhuang Pu Jie hu Yongzhong Department of Building Engineering Tongji University State Key Laboratory for Disaster Reduction in Civil Eng. Tongji University

Sandwich masonry walls are widely used as energy-saving panels since the interlayer between the outer leaves can act as an insulation *** types of sandwich walls are continually being introduced in research and applications,and due to their unique bond patterns,experimental studies have been performed to investigate their mechanical properties,especially with regard to their seismic *** this study,three new types of sandwich masonry wall have been designed,and cyclic lateral loading tests were carried out on five *** results showed that the specimens failed mainly due to slippage along the bottom cracks or the development of diagonal cracks,and the failure patterns were considerably influenced by the aspect *** was undertaken on the seismic response of the new walls,which included ductility,stiffness degradation and energy dissipation capacity,and no obvious difference was observed between the seismic performance of the new walls and traditional *** were made between the experimental results and the calculated results of the shear *** is concluded that the formulas in the two Chinese codes（GB 50011 and GB 50003） are suitable for the calculation of the shear capacity for the new types of walls,and the formula in GB 50011 tends to be more conservative.

关键词： sandwich wall seismic performance shear behavior cyclic loading test