检索结果-南通市图书馆

Dynamical intricacy and average sample complexity of amenable group actions

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2022年第6期65卷 1247-1266页

作者： Jie Li Siming tu School of Mathematics and Statistics Jiangsu Normal UniversityXuzhou 221116China School of Mathematics(Zhuhai) Sun Yat-sen UniversityZhuhai 519082China

In 2018,Petersen and Wilson introduced the notion of dynamical intricacy and average sample complexity for dynamical systems of Z-action,based on the past works on the notion of intricacy in the research of brain network and probability *** one wants to take into account underlying system geometry in applications,more general group actions may need to be taken into *** this paper,we consider this notion in the case of amenable group *** show that many basic properties in the Z-action case remain *** also show that their suprema over covers or partitions are equal to the amenable topological entropy and the measure entropy,using the quasitiling technique in the theory of the amenable group.

关键词： intricacy average sample complexity topological entropy amenable group

Effect of Particle Size and Distribution of Rapidly Quenching NdFeB Magnetic Powder on Magnetic Properties of Polymer-Bonded NdFeB Permanent Magnet

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 1999年第2期17卷 40-42页

作者： Liu, Ying tu, Mingjing Sichuan Univ Chengdu China

The effect of particle size and distribution of rapidly quenching NdFeB magnetic powder on the magnetic properties of polymerbonded NdFeB permanent magnet was studied. The results show that the particle size and the distribution of rapidly quenching NdFeB magnetic powder have significant effects on the magnetic properties of polymerbonded NdFeB permanent magnet. As long as the size and the distribution of rapidly quenching NdFeB powder are within the right range, high magnetic properties of polymerbonded NdFeB permanent magnet can be obtained. This is mainly because the rapidly quenching NdFeB magnetic powder has high hardness and is scaleshaped. The larger the size of rapidly quenching NdFeB particles is, the more difficult it is to obtain high density of bonded NdFeB magnet. However the structure will be destroyed if the size is too small. It results in the deterioration of magnetic properties. The mechanism is also discussed.

关键词： Rare earths NdFeB powder Particle size Particle distribution Magnetic properties

Development of Insect-Resistant Hybrid Rice by Introgressing the Bt Gene from Bt Rice Huahui 1 into Ⅱ-32A/B,a Widely Used Cytogenic Male Sterile System

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2014年第10期13卷 2081-2090页

作者： LAI Yun-song HUANG hai-qing XU Meng-yun WANG Liang-chao ZHANG Xiao-bo ZHANG Ji-wen tu Ju-min Institute of Crop Sciences College of Agriculture and BiotechnologyZhejiang University Institute of Pomology & Olericulture Sichuan Agricultural University Rice Research Institute of Enshi Academy of Agriculture Sciences

Huahui 1 is an elite transgenic male sterile restorer line of wild rice abortive-type that expresses a Bacillus thuringiensis （Bt） δ-endotoxin and provides effective and economic control oflepidopteran insects. To exploit Huahui 1 to develop a new Bt rice, the insertion site of the Bt gene was determined by thermal asymmetric interlaced PCR （TAIL-PCR）. Bt was located in the promoter region ofLOC. Os10g10360, approximately 5.35 Mb from the telomere of the short arm of chromosome 10. For the first time, a Bt cytoplasmic male sterile （CMS） system was developed by introgressing Bt from Huahui 1. The recipient CMS system used consisted of Indonesia paddy rice-type II-32B （maintainer line） and II-32A （male sterile line）. Marker-assisted selection was used to increase selection efficiency in the backcrossing program. In BC5F1, the Bt plant 85015-8 was selected for further analyses, as it had the highest SSR marker homozygosity. In addition, the linkage drag of the foreign Bt gene in 85015-8 was minimized to 8.01-11.46 Mb. The foreign Bt gene was then delivered from 85015-8 into II-32A. The resultant Bt II-32A and Bt II-32B lines were both resistant to lepidopteran in field trials, and agronomic traits were not disturbed. The maintainability of II-32B, and the male sterility and general combining ability of II-32A, were not affected by the Bt introgression. This study demonstrates a simple and fast approach to develop Bt hybrid rice.

关键词： Bt rice male sterile line genome walker marker-assisted backcross (MAB) marker-assisted selection (MAS) SSR

Immobilization of Proteases on Nanoflower-Like Metal Organic Framework

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2023年第12期41卷 1504-1508页

作者： He Li Yunjie tu Tao tu Qi Zhang Department of Chemistry Fudan University Shanghai 200438 China

Proteases have been widely used in pharmaceutics and industry,and an economic,convenient and robust procedure for protease immobilization is of high *** this study,we report immobilization of proteases by the nanoflower-like zeolitic imidazole framework (nfZIF).Using trypsin,protease K,and Glu-C as model enzymes,we show nfZIF represents an excellent material for protease immobilization,and the resulting [email protected] composites exhibit activities comparable to or even higher than the free proteases in *** [email protected] composites are stable in high temperature and organic solvents,and retain almost fully active after several reaction *** studies demonstrate the great potential of nfZIF in the immobilization of proteases,which could be of interest in various industrial applications.

关键词： Metal-organic frameworks ZiF-8 Enzymes Immobilization Lamellar material

Flexible Bis(benzimidazole)-based Ligands Directed the Structure Characteristics of Coordination Polymers Based on Diphenic Acid Co-ligands:Syntheses, Structures and Properties

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 Structural Chemistry 2019年第1期38卷 155-164,5页

作者： tu Chang-Zheng YANG Yu-Ting XU Li-Li YAN Bang-ling WANG Fan College of Chemistry and Environmental Science Qujing Normal University

Two new coordination polymers [Cu_2(bbim)(dpa)_2(C_2H_5OH)_2](1), [Co(dpa)_2(bbbm)](2)(H_2dpa = diphenic acid, bbim = 1,1?-(1,6-hexanediyl)bis-1H-benzimidazole, bbbm = 1,1?-(1,4-butanediyl)bis-1 H-benzimidazole) constructed from bis(benzimidazole)-based ligands with different lengths and diphenic acid co-ligand have been synthesized under solvothermal *** 1 possesses Cu-dpa helical chains. The adjacent chains are connected by the bbim ligands into two-dimensional(2D) 3-connected(63) topology. Differently, the layer structure of 2 was consisted by one-dimensional chains containing alternated 8-and 18-membered rings. Furthermore,the thermal stability and fluorescence property for all crystalline materials have been investigated.

关键词： coordination polymer crystal structure diphenic acid bis(benzimidazole)-based ligands fluorescence

Gene mapping and candidate gene analysis of aberrant-floral spikelet 1(afs1) in rice(Oryza sativa L.)

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2020年第4期19卷 921-930页

作者： ZHANG Ting YOU Jing YU Guo-ling ZHANG Yi CHEN Huan LI Yi-dan YE Li YAO Wan-yue tu Yu-jie ling Ying-hua HE Guang-hua LI Yun-feng Chongqing Key Laboratory of Application and Safety Control of Genetically Modified Crops/Rice Research Institute Academy of Agricultural SciencesSouthwest UniversityChongqing 400715P.R.China

The spikelet is a unique inflorescence structure in grasses. However, the molecular mechanism that regulates its development remains unclear, and we therefore characterize a spikelet mutant of rice(Oryza sativa L.), aberrant-floral spikelet 1(afs1), which was derived from treatment of Xinong 1 B with ethyl methanesulfonate. In the afs1 mutant, the spikelet developed an additional lemma-like organ alongside the other normally developed floral organs, and the paleae were degenerated to differing degrees with or without normally developed inner floral organs. Genetic analysis revealed that the afs1 phenotype was controlled by a single recessive gene. The AFS1 gene was mapped between the insertion/deletion(In Del) marker Indel19 and the simple sequence repeat marker RM16893, with a physical distance of 128.5 kb on chromosome 4. Using sequence analysis, we identified the deletion of a 5-bp fragment and a transversion from G to A within LOC_Os04 g32510/LAX2, which caused early termination of translation in the afs1 mutant. These findings suggest that AFS1 may be a new allele of LAX2, and is involved in the development of floral organs by regulating the expression of genes related to their development. The above results provide a new view on the function of LAX2, which may also regulate the development of spikelets.

关键词： rice aberrant-floral spikelet 1 spikelet gene mapping yield

Escape rate of an active Brownian particle in a rough potential

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2022年第12期74卷 118-123页

作者： Yating Wang Zhanchun tu Department of Physics Beijing Normal UniversityBeijing 100875China

We discuss the escape problem with the consideration of both the activity of particles and the roughness of *** derive analytic expressions for the escape rate of an active Brownian particle in two types of rough potentials by employing the effective equilibrium approach and the Zwanzig *** find that activity enhances the escape rate,but both the oscillating perturbation and the random amplitude hinder escaping.

关键词： escape rate active Brownian particle rough potential effective potential

Elastoplastic pipe-soil interaction analyses of partially-supported jointed water mains

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第11期9卷 1497-1506页

作者： Yu SHAO tu-qiao ZHANG Department of Civil Engineering Zhejiang University Hangzhou 310027 China

Water distribution networks are essential components of water supply systems. The combination of pipe structural deterioration and mechanics leads to the failure of pipelines. A physical model for estimating the pipe failure must include both the pipe deterioration model and mechanics model. Winkler pipe-soil interaction (WPSI), an analytical mechanics model developed by Rajani and Tesfamariam (2004), takes external and internal loads, temperature changes, loss of bedding support, and the elastoplastic effect of soil into consideration. Based on the WPSI model, a method to evaluate the elastic and plastic areas was proposed in the present study. An FEM model based on pipe-soil interaction (PSI) element was used to verify the analytical model. Sensitivity analyses indicate that the soft soil, long pipe and high temperature induced the axial plastic deformation more likely, which, however, may not occur in normal scenarios. The soft soil, pipes in small diameters, long unsupported bedding are prone to form flexural plastic area. The results show that the pipes subjected to the same loads have smaller stresses in the elastoplastic analysis than elastic analysis. The difference, however, is slight.

关键词： Elastoplastic soil Winkler pipe-soil interaction (WPSI) Jointed water mains

Identification and characterization of camptothecin tailoring enzymes in Nothapodytes tomentosa

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第6期66卷 1158-1169页

作者： Yin Chen Jian-Ping Huang Yong-Jiang Wang Meng-ling tu Junheng Li Bingyan Xu Guoqing Peng Jing Yang Sheng-Xiong Huang State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for Economic Plants and Biotechnology Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China

Camptothecin is a complex monoterpenoid indole alkaloid with remarkable antitumor *** that two C-10 modified camptothecin derivatives,topotecan and irinotecan,have been approved as potent anticancer agents,there is a critical need for methods to access other aromatic ringfunctionalized congeners(e.g.,C-9,C-10,etc.).However,contemporary methods for chemical oxidation are generally harsh and low-yielding when applied to the camptothecin scaffold,thereby limiting the development of modified *** herein,we have identified four tailoring enzymes responsible for C-9 modifications of camptothecin from Nothapodytes tomentosa,via metabolomic and transcriptomic *** consist of a cytochrome P450(Nt CPT9H)which catalyzes the regioselective oxidation of camptothecin to 9-hydroxycamptothecin,as well as two methyltransferases(Nt OMT1/2,converting 9-hydroxycamptothecin to 9-methoxycamptothecin),and a uridine diphosphate-glycosyltransferase(Nt UGT5,decorating 9-hydroxycamptothecin to9-β-D-glucosyloxycamptothecin).Importantly,the critical residues that contribute to the specific catalytic activity of Nt CPT9H have been elucidated through molecular docking and mutagenesis *** work provides a genetic basis for producing camptothecin derivatives through metabolic *** will hasten the discovery of novel C-9 modified camptothecin derivatives,with profound implications for pharmaceutical manufacture.

关键词： camptothecin biosynthesis enzymatic assay Nothapodytes tomentosa tailoring enzyme transcriptomic analysis