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A theoretical analysis on efficiency of some Newton-PCG methods

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Science china Mathematics 2005年第8期48卷 1046-1064页

作者： DENG Naiyang, ZHANG Jianzhong & ZHONG Ping china agricultural university, Beijing 100083, china City university of Hong Kong, Hong Kong, china china agricultural university Beijing China City university of Hong Kong Hong Kong China

In this paper, we study the efficiency issue of inexact Newton-type methods for smooth unconstrained optimization problems under standard assumptions from theoretical point of view by discussing a concrete Newton-PCG algorithm. In order to compare the algorithm with Newton's method, a ratio between the measures of their approximate efficiencies is investigated. Under mild conditions, it is shown that first, this ratio is larger than 1, which implies that the Newton-PCG algorithm is more efficient than Newton's method, and second, this ratio increases when the dimension n of the problem increases and tends to infinity at least at a rate In n/In 2 when n→∞, which implies that in theory the Newton-PCG algorithm is much more efficient for middle- and large-scale problems. These theoretical results are also supported by our preliminary numerical experiments.

关键词： unconstrained optimization, Newton's method, preconditioned conjugate gradient method, efficiency.

Decisive influence of the ionization strength of cosmic rays on the cavitation characteristics of pure water

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Science china(Technological Sciences) 2009年第6期52卷 1804-1808页

作者： CHANG JinShi College of Water Conservancy & Civil Engineering,china agricultural university,Beijing 100083,china College of Water Conservancy & Civil Engineering China Agricultural University

The experiment result in this article shows that the initial and critical cavitation pressure of pure water are both increasing along with the increase of height above sea level,and the ionization strength of cosmic rays in the lower aerosphere is the crucial factor which influences the cavitation pressure of pure *** author concludes the relationship between the cavitaion pressure of pure water and the height above sea ***,air particles in water caused by the radiation of cosmic rays can exist in the water for a long time and will not escape.

关键词： initial cavitaiton pressure critical cavitation pressure ionization strength of cosmic rays height above sea level

Tissue-specific expression of glutathione S-transferases induced by 2-tridecanone or quercetin in cotton bollworms, Helicoverpa armigera (Hübner)

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Progress in Natural Science:Materials International 2005年第11期15卷 988-992页

作者： TANG Fang, LIANG Pei and GAO Xiwu (Department of Entomology, china agricultural university, Beijing 100094, china) Department of Entomology China Agricultural University Beijing 100094 China

The tissue-specific expression of glutathione S-transferases (GSTs) in the cotton bollworm and the expression level induced by 2-tridecanone and quercetin were examined using the methods of biochemistry and the quantitative PCR. The relative expression level of GST mRNA was unanimous with the GSTs activity conjugaging with 1-chloro-2, 4-dimitro-benzene (CDNB) in fat bodies, midguts, heads and integuments of cotton bollworms. The GSTs activity in fat bodies was the highest, then midguts, heads and integuments in turn, which was in consistent with the relative expression level of GST mRNA. The specific activity of GSTs and the relative expression level of GST mRNA could be significantly induced by 2-tridecanone and quercetin, and after the induction the order of the GSTs activity and the relative expression level of GST mRNA in the above four tissues in cotton bollworms was not different from the control. The induction of GSTs by 2-tridecanone was stronger than by quercetin in all four tissues, which was in accordance with the relative expression level of GST mRNA. It suggested that the increase of GSTs activity induced by plant allelochemicals was associated with the elevated expression of GST mRNA in cotton bollworms.

关键词： Helicoverpa armigera glutathione S-transferase tissue-specific expression plant allelochemicals.

Efficient transformation and expression of gfp gene in the edible mushroom Pleurotus nebrodensis

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Progress in Natural Science:Materials International 2008年第7期18卷 819-824页

作者： Junfang Lin a,b, Mingyao Zheng a, Jie Wang a,b, Wei Shu c, Liqiong Guo a,b,* a Department of Biotechnology, College of Food Sciences, South china agricultural university, Guangzhou 510640, china b Institute of Biomass Research, South china agricultural university, Guangzhou 510640, china c Test and Experimental Center, South china agricultural university, Guangzhou 510640, china Department of Biotechnology College of Food Sciences South China Agricultural University Guangzhou 510640 China Institute of Biomass Research South China Agricultural University Guangzhou 510640 China Test and Experimental Center South China Agricultural University Guangzhou 510640 China

An efficient transformation method mediated by PEG-protoplasts was developed for the newly commercial edible mushroom Pleu- rotus nebrodensis. Two plasmids were used to co-transform protoplasts of P. nebrodensis. One plasmid is pAN7-1 containing a positive selectable marker gene hph conferring hygromycin B resistance. Another plasmid is pBlue-GFP containing a reporter gene gfp conferring green fluorescent protein. PCR and Southern blot analysis showed that hph gene or/and gfp gene were integrated into the genome of P. nebrodensis transformants. The transformation efficiency of the positive selectable marker gene hph was 3 transformants per microgram of plasmid pAN7-1 DNA, which was about 30 times higher than that previously reported in thoroughly studied Pleurotus species such as Pleurotus ostreatus. The transformation efficiency of the reporter gene gfp was 9 transformants per microgram of plasmid pBlu-GFP DNA. The co-transformation efficiency was 23.68%. This is the first report that a "reporter" gene, green fluorescent protein gene can be successfully stably expressed in this Pleurotus species.

关键词： Pleurotus nebrodensis Protoplast-mediated transformation Green fluorescent protein GFP expression

Normality and shared values concerning differential polynomials

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Science china Mathematics 2010年第3期53卷 749-754页

作者： LEI ChunLin 1 & FANG MingLiang 2, 1 Department of Applied Mathematics, South china agricultural university, Guangzhou 510642, china 2 Institute of Applied Mathematics, South china agricultural university, Guangzhou 510642, china Department of Applied Mathematics South China Agricultural University Guangzhou China Institute of Applied Mathematics South China Agricultural University Guangzhou China

Let F be a family of functions meromorphic in a domain D, let P be a polynomial with either deg P≥3 or deg P = 2 and P having only one distinct zero, and let b be a finite nonzero complex number. If, each pair of fun... 详细信息

关键词： meromorphic function normality shared value

Genetic analysis on 3'- terminal flanking region of uncoupling protein 3 in different pig breeds

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Chinese Science Bulletin 2002年第18期47卷 1541-1543页

作者： FANG Meiying, ZHAO Xingbo, LI Ning & WU ChangxinCollege of Animal Science and Technology, china agricultural university, Beijing 100094, china State Key Laboratory for Agrobiotechnology, china agricultural university, Beijing 100094, china College of Animal Science and Technology China Agricultural University Beijing China State Key Laboratory for Agrobiotechnology China Agricultural University Beijing China

The 3’-terminal flanking region of porcine uncoupling protein 3 (UCP3) was cloned, the sequence data revealed 15 nucleotide substitutions among Landrace and three Chinese native pig breeds named Neijiang, Minpig and Erhualian. The continuous 9 polymorphic sites were checked by PCR-RFLP, the results indicated that Erhualian had extraordinary gene frequency, presented most significant difference by x2 test compared with Landrace, Largewhite, Neijiang and Minpig respectively, significant level compared with Meishan; and Meishan also had significant difference compared with Landrace and Minpig respectively. These results can be concluded that Taihu pigs have special genetic characteristics among pig breeds.

关键词： pig uncoupling protein gene clone PCR-RFLP.

Ramet population ecology of Panicum virgatum in the field–Competitively random growth of ramets and foraging behavior of ramet populations

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Progress in Natural Science:Materials International 2008年第7期18卷 901-906页

作者： Xinguo Yang a,*, Tianlong Wu b, Xu Chengb a College of Resources and Environmental Sciences, china agricultural university, Beijing 100193, P.R. china b College of Agriculture and Biotechnology, china agricultural university, Beijing 100193, P.R. china College of Resources and Environmental Sciences China Agricultural University Beijing 100193 P.R. China College of Agriculture and Biotechnology China Agricultural University Beijing 100193 P.R. China

The authors investigated the heterogeneous size patterns and dynamic growth of the ramet population of Panicum virgatum, a clonal caespitose plant, limited to the space occupied by a ramet bunch and the time of the ramet yearly life cycle, to understand the ecology of clonal caespitose plants in the field, where the ramet bunch generally consisted of more than one genet. Dynamic life tables for ramet populations were established by the replacement of living ramets at the present time with "dead" ones in past time. These tables revealed stable coexisting patterns of isometric and allometric growing processes of ramets in mass and height respectively, which approximately followed the historic trajectory of a density-independent population. The ecology of clonal caespitose plants is further discussed based on the competitively random growth of ramet individuals, including the scale of foraging behavior. In the field, the ramet population ecol- ogy of switchgrass may be a statistical result of competitively random growth of ramet individuals. The foraging behavior of a ramet population could then be presented as a process in which ramet individuals competed with each other for light and grew randomly, while at the same time a relatively stable dynamic growth pattern was apparent at the level of the ramet population, and the functional leaves were placed properly in time and space.

关键词： Caespitose clone Ramet population Panicum virgatum Life table Phenotypic plasticity Foraging behavior

Tn5-mutagenesis and identification of atr operon and trpE gene responsible for indole-3-acetic acid synthesis in Azospirillum brasilense Yu62

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Progress in Natural Science:Materials International 2006年第4期16卷 366-372页

作者： XIE Baoen and CHEN Sanfeng State Key Laboratory for Agrobiotechnology, College of Biological Sciences, china agricultural university, Beijing 100094, china State Key Laboratory for Agrobiotechnology College of Biological Sciences China Agricultural University Beijing 100094 China

To bring more information about synthesis of indole-3-acetic acid (IAA) from Azospirillum brasilense, a Tn5-insertion library of A. brasilense Yu62 was constructed and subjected to screening for IAA producing mutants. Two mutants with decreased IAA levels, named as A3 and A24, were isolated. The sequence analysis of loci tagged showed that the Tn5-1063a was located in the atrA gene encoding GntR family transcriptional regulator and trpE gene encoding component I of anthranilate synthase respectively. At the same time. atrB encoding phosphotransferase and atrC encoding aminotransferase were cloned downstream the atrA gene and atrA, atrB and atrC were clustered in an operon. Mutagenesis and complementation studies showed that atrA and atrC were involved in IAA synthesis. IAA levels of trpE mutant and wild-type strain could be improved by adding anthranilate into the medium.

关键词： indole-3-acetic acid (IAA) IAA mutants Azospirillum brasilense atrABC cluster trpE Tn5 transposon.

Study on Tibetan Chicken embryonic adaptability to chronic hypoxia by revealing differential gene expression in heart tissue

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Science china(Life Sciences) 2009年第3期52卷 284-295页

作者： LI Mei & ZHAO ChunJiang College of Animal Science and Technology,china agricultural university,Beijing 100193,china College of Animal Science and Technology China Agricultural University Beijing China

Oxygen concentration is essential for appropriate *** can exert a significant impact on physiological alteration of the cell and *** Chicken(Gallus gallus) is a Chinese indigenous breed inhabiting in Tibetan areas,which is also a chicken breed living at high altitude for the longest time in the *** has developed an adaptive mechanism to hypoxia,which is demonstrated by that Tibetan Chicken has much higher hatchability than low-land chicken breeds in high-altitude areas of *** the present study,Tibetan Chicken fertilized full sib eggs were incubated up to Hamburger-Hamilton stage 43 under 13% and 21% oxygen concentration,*** Chicken and Dwarf Recessive White Chicken were used as control *** hearts in all of the 3 chicken breeds under hypoxic and normoxic conditions were isolated and hybridized to Genechip Chicken Genome Array to study molecular mechanisms underlying the adaptation to high altitude of Tibetan *** a result,50 transcripts highly expressed in hypoxia are screened *** up-regulated genes,some are involved in the gene ontology(GO) such as cell growth,cell difference,muscle contraction and signal ***,the expression levels of 21 transcripts are lower in hypoxia than those in *** down-regulated genes take part in cell communication,ion transport,protein amino acid phosphorylation and signal ***,gene enrichment analyses of these differential gene expressions are mainly associated with immune system response and ion channel activity in response to ***,the transcriptional expression profiles analyzed by hierarchical clustering and CPP-SOM software in all of the 3 different chicken breeds revealed that Tibetan Chicken is much closely related to Shouguang Chicken rather than Dwarf Recessive White *** addition,12 transcripts of Tibetan Chicken breed-specific expressed genes were identified,which seem to result in a more

关键词： adaptation chronic hypoxia gene chip chicken genome array Tibetan Chicken(Gallus gallus) differential gene expression