检索结果-南通市图书馆

Maschke-type theorem and Morita context over weak Hopf algebras

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2006年第5期49卷 587-598页

作者： zhang liangyun college of science, nanjing agricultural university, nanjing 2.0095, china Department of Mathematics, nanjing university, nanjing 210008, china college of science Nanjing Agricultural University Nanjing China Department of Mathematics Nanjing University Nanjing China

This paper gives a Maschke-type theorem over semisimple weak Hopf algebras,extends the well-known Maschke-type theorem given by Cohen and Fishman and constructs a Morita context over weak Hopf algebras.

关键词： weak Hopf algebra, smash product, Maschke-type theorem, Morita context.

L-R smash products for bimodule algebras

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2006年第6期16卷 580-587页

作者： zhang liangyun (Department of Mathematics, nanjing agricultural university, nanjing 2.0095, china Department of Mathematics, nanjing university, nanjing 210008, china) Department of Mathematics Nanjing Agricultural University Nanjing 210095 China Department of Mathematics Nanjing U-niversity Nanjing 210008 China

In this paper, we prove that the L-R smash product A(?)H is exactly the twisted smash product A * H if H is a finite dimensional cocommutative Hopf algebra, and give a sufficient and necessary condition for L-R smash products to be bialgebras (Hopf algebras) . For any finite dimensional coquasitriangular Hopf algebra (H,σ), we prove that the L-R smash product H(?)H is semisimple Artinian if H is semisimple and H * is unimodular. In particular, the L-R smash product D(H)* (?)D(H)* semisimple Artinian if the Drin-fel'd double D(H) is semisimple.

关键词： bimodule algebras L-R smash products coquasitriangular Hopf algebras Long bialgebras.

Differences between two wheat genotypes in the development of floret primordia and contents of pigments and hormones

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The Crop Journal 2024年第4期12卷 1196-1207页

作者： liangyun Wen Yaqun Liu Bingjin Zhou Wan Sun Xuechen Xiao Zhimin Wang Zhencai Sun Zhen zhang Yinghua zhang college of Agronomy and Biotechnology China Agricultural UniversityBeijing 100193China Engineering Technology Research Center for Agriculture in Low Plain Areas Cangzhou 061800HebeiChina

Promoting more floret primordia within a spike to acquire fertile potential during the differentiation and pre-dimorphism phases is critical for increasing the number of fertile florets per spike(NFFs).However,it is yet unknown the physiological mechanism regulating the complex and dynamic *** study aimed to clarify how intra-spike hormones,pigments,and assimilates coordinate with each other to regulate spike morphology and then floret primordia development.A two-year field experiment was conducted with two winter wheat genotypes:N50(big-spike with greater NFFs)and SM22(mediumspike with fewer NFFs).We monitored high temporal and spatial-resolution changes in the number and morphology of floret primordia within a spike,as well as in intra-spike hormones,pigments,and *** results revealed that the big-spike genotype had more NFFs than the medium-spike genotype,not only because they had more spikelets,but also because they had greater NFFs mainly at central *** floret primordia at central spikelets had sufficient time to develop and acquire fertile potential during the differentiation phase(167-176 d after sowing,DAS)and the pre-dimorphism phase(179 DAS)for the big-spike genotype than the medium-spike *** primordia with fertile morphology during the pre-dimorphism phase always developed into fertile florets during the dimorphism *** early-developed floret primordia most proximal and intermediate to the rachis in the big-spike genotype developed faster than the medium-spike ***,the spike dry matter and pigments(chlorophyll a,chlorophyll b,carotene,and carotenoids)content during 170-182 DAS,auxin(IAA)and cytokinin(CTK)content on 167 DAS were significantly higher in the big-spike genotype than in the medium-spike genotype,while jasmonic acid(JA)content was significantly lower in the big-spike genotype compared to the medium-spike genotype during 167-182 *** the significant differences in intra-s

关键词： Fertile florets Floret primordia development Intra-spike hormones Jasmonic acid Photosynthetic pigments

Large eddies induced by local impulse at wall of boundary layer with pressure gradients

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2008年第7期18卷 873-878页

作者： Changgen Lu a,b,*, Weidong Caob, Yanmei zhang b, Jintao Pengb a college of Atmospheric science, nanjing university of Information science & Technology, nanjing 210044, china b college of Environmental science and Engineering, Hohai university, nanjing 210098, china college of Atmospheric science Nanjing University of Information Science & Technology Nanjing 210044 China college of Environmental science and Engineering Hohai University Nanjing 210098 China

Large eddies induced by local impulse at the wall with pressure gradients in the boundary layer was studied by direct numerical sim- ulations. The results show that the amplitude evolution, the high and low speed stripes, the formation of streamwise vortices, the ejection and sweeping, inflexions and distortion at the mean velocity profiles, as well as other characteristics, are consistent with the experimental and other numerical results. It is also found that large eddies are easy to be excited with adverse pressure gradient in the boundary layer, and the growth of amplitudes, formation of streamwise vortices and the influencing area etc., are much larger than those with favorable pressure gradient in the boundary layer. In contrast, large eddies are hardly to be induced through local impulse disturbance at the wall with favorable pressure gradients in the boundary layer.

关键词： Boundary layer Pressure gradients Impulse Large eddies

Tsallis model-based separation of overlapped peak signals

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(Information sciences) 2010年第4期53卷 823-832页

作者： LI YuanLu*, zhang YingChao & TANG HuiQiang college of Information and Control, nanjing university of Information science & Technology, nanjing 210044, china college of Information and Control Nanjing University of Information Science & Technology Nanjing China

A simple scheme for separating overlapped peak signals (OPS) is proposed, with the Tsallis distribution as the model for OPS processing and fractional-order differentiation as tool for the signal analysis, the relationships of the maxima and zero-crossing values of the Tsallis peak signal, separately, to the order of differentiation are established, leading to two types of parameter estimators, which are utilized, by adjusting the peak-shape parameter, to calculate the parameters of position, height and width of the Gaussian, Lorentzian and Tsallis distribution. The obtained characteristic parameters can be employed to fit the peak signals to be treated, thereby fulfilling the OPS decomposition.

关键词： fractional differentials filter overlapped peak signal Tsallis model separation of overlapped peak signals

Constraints of authigenic carbonates on trace elements (Sr,Mg) of lacustrine ostracod shells in paleoenviron-ment reconstruction and its mechanism

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china Earth sciences 2008年第5期51卷 654-664页

作者： HU Guang1,2, JIN zhangDong1 & zhang Fei3 1 State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of sciences, Xi’an 710075, china 2 Graduate university of the Chinese Academy of sciences, Beijing 100049, china 3 college of Resources and Environmental science, nanjing agricultural university, nanjing 2.0095, china State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China Graduate university of the Chinese Academy of sciences Beijing China college of Resources and Environmental science Nanjing Agricultural University Nanjing China

Molar ratios of Mg/Ca and Sr/Ca were measured in two species of ostracod shells preserved in the upper core (15–55 m) of the Hequing Basin in Yunnan Province, southwest china. By correlating the molar ratios between Mg/Ca and Sr/Ca and comparing them with Sr concentrations of the sediments, we suggested that: (1) the molar Mg/Ca and Sr/Ca ratio variations in respective ostracod primo reflected the changes in its ambient water composition and ecology; (2) the molar Sr/Ca ratios responded better to the salinity change linearly than Mg/Ca without aragonite precipitation in the system, and otherwise there was no linear relation between them; and (3) the molar Sr/Ca ratios were mainly controlled by salinity and authigenic carbonate precipitation, whereas the molar Mg/Ca ratios were related to both salinity and temperature. In fact, the rate of ostracod growth owing to temperature controls the fluctuation of Mg/Ca in shells. Here, more attentions should be paid to the constraint of authigenic mineral precipitation processes on the trace elements in ostracod shells and to the correlation between these trace elements in biogenic carbonates and compositions of the sediments in systems and in future in vitro experiments.

关键词： ostracod shell molar Sr/Ca ratio molar Mg/Ca ratio environmental response Heqing Basin

Genotypic Differences in Grain Yield and Physiological Nitrogen Use Efficiency Among Rice Cultivars

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2009年第6期19卷 681-691页

作者： zhang Ya-Li, FAN Jian-Bo, WANG Dong-Sheng and SHEN Qi-Rong2college of Resources and Environmental sciences, nanjing agricultural university, nanjing 2.0095 (china) college of Resources and Environmental sciences Nanjing Agricultural University Nanjing 210095 (China)

Efficient use of N in agricultural practice can increase yield, decrease production costs and reduce the risk of environmental pollution. Effects of N fertilizer application rates on grain yield and physiological N use efficiency (PE) in relation to the accumulation and redistribution of biomass and N in rice (Oryza sativa L.) cultivars were studied at two experimental farms of nanjing agricultural university, nanjing, china in 2004. Three high N use efficiency (NUE) rice cultivars (Wuyunjing 7, Nanguang and 4007) and one low NUE rice cultivar (Elio) with similar growth patterns were studied under seven N rates (0, 60, 120, 180, 240, 300 and 360 kg ha -1 ). Grain yield increased with the N application rate and attained plateau at 180 kg N ha -1 for rice cultivars at each site. Increasing N rate decreased PE for biomass and grain yield. Grain yield and PE of Elio were about 20% and 18% lower than those of high NUE cultivars. Differences in biomass, N accumulation and N redistribution were observed at the post-heading stage among rice cultivars with differing NUEs. The less reproductive tillers of Elio resulted in less demand for C and N during grain filling, thus leading to lower PE of Elio compared with the high NUE rice cultivars.

关键词： accumulation biomass N application rate redistribution

INFLUENCE OF SEEPAGE FACE OBLIQUITY ON DISCHARGE OF GROUNDWATER AND ITS POLLUTANT INTO LAKE FROM A TYPICAL UNCONFINED AQUIFER

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2007年第6期19卷 756-761页

作者： LI Yong WANG Chao YANG Lin-zhang LI Yi-ping State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China college of Environmental science and Engineering Hohai University Nanjing 210098 China Institute of Soil science Chinese Academy of Sciences Nanjing 210008 China

Lab experiment and mathematical simulation Modular three dimensional finite difference groundwater （MODFLOW） were performed in a soil tank to simulate the hydrogeochemical interaction between lake and typical unconfined aquifer. Results show that the velocity decreases exponentially with the transect distance on seepage face. The maximal velocity occurs at the top point of seepage face. The obliquity of seepage face has a great influence on the maximum and distribution of seepage velocity. With the increase of the obliquity of seepage face, the maximal velocity decreases quickly and the velocity distribution becomes much more even. Most of groundwater flow and pollutant flux discharges through a narrow portion near the top of seepage face. The flow and mass concentrated in the narrow portion increase with the decrease of the obliquity of seepage face. These will benefit to design a reasonable and economical scenario to manage lakeshore and to control the pollution of lake water near lakeshore.

关键词： shallow lake unconfined aquifer groundwater discharge velocity distribution chloride MODFLOW

b-DAZL:A novel gene in bovine spermatogenesis

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2008年第10期18卷 1209-1218页

作者： Qingbo zhang~a Qifa Li~(a,*) Jiahuang Li~b Xinfu Li~a Zhenshan Liu~a Dawei Song~a Zhuang Xie~a ~a Laboratory of Animal Reproductive Genetics and Molecular Evolution,college of Animal science and Technology,nanjing Agriculture university,nanjing 2.0095,china ~b Pharmaceutic Biotechnology Key Laboratory,college of Life science,nanjing university,nanjing 210093,china Laboratory of Animal Reproductive Genetics and Molecular Evolution College of Animal Science and Technology Nanjing Agriculture University Nanjing 210095 China Pharmaceutic Biotechnology Key Laboratory College of Life Science Nanjing University Nanjing 210093 China

The DAZL gene plays an important role in *** and mutation of this gene has been frequently associated with the sterility in both vertebrates and ***,a cDNA containing the complete open reading frame of DAZL gene,which encodes putative RRM RNA-binding protein,was isolated from bovine tissues by *** isolated gene was referred to as ***-based location analysis showed that b-DAZL is located near the end of chromosome *** b-DAZL gene and its vertebrate homologue shared a high nucleotide similarity (90-94%) in the coding region and in the genomic organization,each consisting of 10 exons and 9 *** protein products contained a highly conserved RNA-binding motif,a unique DAZ repeat, and PUM2 and PABP interacting ***-PCR assay revealed that b-DAZL was expressed in the testis and ***,no signals were detected in the testes of sterile male *** microstructure of the testes of sterile males showed very few spermat- ocytes but mostly somatic *** observations are consistent with the typical phenotype of testes with defective DAZL expression. Subsequent gene detection studies indicated that transcription arrest might lead to a b-DAZL transcript defect in testes of cattle-yaks. Our results suggest that b-DAZL may be involved in spermatogenesis,and that transcription arrest of the gene is associated with male sterility in cattle-yaks.

关键词： Cattle-yak b-DAZL Male sterility Sequence analysis Expression profile