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Shoot Apex Demand Determines Assimilate and Nutrients Partitioning and Nutrient-uptake Rate in Tobacco Plants

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Journal of Integrative Plant Biology 2007年第11期49卷 1654-1661页

作者： Huai-Yu yang chun-Jian li Fu-Suo Zhang The Key Laboratory of Plant Nutrition Ministry of Agriculture Key Laboratory of Plant-Soil Interactions Ministry of Education Department of Plant Nutrition China Agricultural University Beijing 100094 China

Our previous experiment revealed that apex-removed plants have larger root systems but a lower K＋-uptake rates than intact tobacco plants. Since the apex is not only a center of growth and metabolism, but also an important place of auxin synthesis and export, the aims of this study were to distinguish whether the apex demand or auxin synthesized in the apex regulates assimilate and nutrients partitioning within plant, and to explain the reason for the lower K＋-uptake rate of the apex-removed plant. In comparison with the control plant, covering the shoot apex with a black transparent plastic bag reduced net increases in dry matter and nutrients; however, the distribution of the dry matter and nutrients between shoot and roots and nutrient-uptake rates were not changed. Removal of the shoot apex shifted the dry mass and nutrients distributions to roots, and reduced the rate of nutrient uptake. Application of 1-naphthylacetic acid （NAA） could partly replace the role of the removed apex, stimulated assimilate and nutrient deposition into the treated tissue, and enhanced the reduced plasma membrane ATPase activity of roots to the control level. However, treatment of the apex-removed plants with NAA could not rescue the reduced nutrient uptake rate and the shifted assimilates and nutrients partitioning caused by excision of the apex. Higher nutrient uptake rate of the intact plants could not be explained by root growth parameters, such as total root surface area and number of root tips. The results from the present study indicate that strong apex demand determined assimilates and nutrients partitioning and nutrient-uptake rate in tobacco （Nicotiana tabacum） plants.

关键词： assimilate and nutrient partitioning auxin nutrient uptake removal of the shoot apex shoot apex demand tobacco (Nicotiana tabacum).

Survey of antioxidant capacity and phenolic composition of blueberry,blackberry,and strawberry in Nanjing

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第2期13卷 94-102页

作者： Wu-yang HUANG Hong-cheng ZHANG Wen-xu liU chun-yang li Department of Functional Food and Bioactive Compounds Institute of Farm Product ProcessingJiangsu Academy of Agricultural SciencesNanjing 210014China Bee Research Institute Chinese Academy of Agricultural SciencesBeijing 100093China College of Food Science and Technology Nanjing Agricultural UniversityNanjing 210095China

Berries are a good source of natural antioxidants. In the present study, the total antioxidant capacity and phenolic composition of three berry fruits （blueberry, blackberry, and strawberry） cultivated in Nanjing were investigated. Blueberry, with a Trolox equivalent antioxidant capacity （TEAC） value of 14.98 mmol Trolox/100 g dry weight （DW） exhibited the strongest total antioxidant capacity using both the 2,2-azinobis（3-ethylbenzothiazoline-6-sulfonic acid） diammonium salt （ABTS） and the 2,2-diphenyl-l-picrylhydrazyl （DPPH） methods. Blueberry also had the highest total phenolic content （TPC, 9.44 mg gallic acid/g DW）, total flavonoid content （TFC, 36.06 mg rutin/g DW）, and total anthocyanidin content （TAC, 24.38 mg catechin/g DW）. A preliminary analysis using high performance liquid chromatography （HPLC） showed that the blueberry, blackberry, and strawberry samples tested contained a range of phenolic acids （including gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, p-coumaric acid, ferulic acid, eUagic acid, and cinnamic acid） and various types of flavonoids （flavone： luteolin; flavonols： rutin, myricetin, quercetrin, and quercetin; flavanols： gallocatechin, epigallocatechin, catechin, and catechin gallate; anthocyanidins： malvidin-3-galactoside, malvidin-3-glucoside, and cyanidin）. In particular, the blueberries had high levels of proanthocyanidins and anthocyanidins, which might be responsible for their strong antioxidant activities. These results indicate a potential market role for berries （especially blueberries） as a functional food ingredient or nutraceutical.

关键词： Berries Antioxidants Phenolics Flavonoids Anthocyanidins

Effect of Ultrasonic Impact on the Microstructure of Welded Joint of 2195 Al–li Alloy

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Acta Metallurgica Sinica(English Letters) 2016年第4期29卷 367-372页

作者： Qi-Hao Chen San-Bao lin chun-li yang Cheng-Lei Fan State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology

It is known that an ultrasonic impact during tungsten inert gas welding can refine the grains and improve the mechanical properties of the welded joints of aluminum alloys. However, the influence mechanism of the ultrasonic impact on the microstructures is still unclear. In this research, the effects of the mechanical and ultrasonic impact on the microstructures of the welded joint of 2195 Al-li alloy are analyzed. It is found that the mechanical impact could not refine the grains, but the ultrasonic impact could refine the grains. The grains become smaller in the weld center with an increase in the ultrasonic amplitude. Possible mechanisms for the grain refinement are discussed. The results show that the small temperature gradient promotes formation of the equiaxed grain and the cavitation promotes heterogeneous nucleation.

关键词： Ultrasound TIG welding Microstructure Al-li alloy

Microstructural evolution in electroformed nickel shaped-charge liners with nano-sized grains undergone deformation at ultrahigh strain rate

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International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 617-623页

作者： Feng yang chun-hua li Sheng-wei Cheng Lei Wang Wen-huai Tian School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Nickel shaped-charge liners with nano-sized grains were prepared by the electroforming technique, and the deformation at ultrahigh strain rate was performed by explosive detonation. The as-formed and post-deformed microstructures of electroformed nickel shaped-charge liners with nano-sized grains were observed by means of transmission electron microscopy, and the orientation distribution of the grains was analyzed by the electron backscattering pattern （EBSP） technique. The melting phenomenon in the jet fragment and the recovery and recrystallization in the slug after plastic deformation at ultrahigh-strain rate were observed in the ultrafine-grained nickel shaped-charge liners. The research evidence shows that dynamic recovery and recrystallization play an important role in plastic deformation at ultrahigh strain rate.

关键词： electroformed nickel nanosized plastic deformation electroformation microtexture dynamic recovery and recrystallization

Effect and Functional Mechanism of the Action of Exogenous Gibberellin on Flowering of Peach

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Agricultural Sciences in China 2008年第11期7卷 1324-1332页

作者： AN li-jun JIN liang yang chun-qin li Tian-hong Department of Fruit Science College of Agronomy and Biotechnology China Agricultural University Beijing 100193 P.R. China

This study was conducted to assess the effect of gibberellin and its possible mechanism of action on peach flower formation. At flower induction, 100 mg L^-1 of gibberellic acid 3 （GA3） was sprayed on the leaves of peach [Prunus persica （L.） Batsch.] cv. Bayuecui. Using anatomy, immunohistochemistry, and semi-quantitation, the in situ distribution of GAs and the expression of the key genes involved in peach flower formation in the apical meristem were studied during flowering differentiation. The results showed that induction of flowering in the Bayuecui peach occurred prior to 10 July in Beijing, China. Flower induction and further differentiation of the peach flower organs were significantly inhibited by leaf-spraying of GA3 at a concentration of 100 mg L^-1 during the induction stage. The flowering rate was only 11.67% after treatment. The distribution of GA1 in the apical meristem varied during the process of flower bud differentiation. From 13 June to 25 July, the GA1 signal from control plants was detected mainly in the vascular bundles at the base of the flower buds. No GA1 signal was detected in the apical meristem. After treatment with GA3, the distribution was similar to that of the control from 13 June to 3 July. On 13 July, a GA1 signal was detected in the apical meristem accompanied by an increase in the GA1 signal in the vascular bundles at the base of the flower buds. The GA1 signal weakened significantly in both the vascular bundles and the apical meristem on 25 July. The expression of the genes PpLEAFY and MADS6 in flower buds could be detected only on 10 October in the GA3-treated plants. The critical period for flower induction of Bayuecui peach in Beijing was in early July, during which time, leaf-spraying with 100 mg L-1 GA3 could effectively inhibit flower induction and further differentiation of the flower buds. GA1 in the gibberellin family was the suppressor for flower induction in peach. Its action was affected by the stage of flower bud di

关键词： peach [Prunus persica (L.) Batsch.] gibberellin flowering induction anatomy immunohistochemistry semiquantitation RT-PCR

Radical Addition and Substitution Reactions of (η6-Arene)-tricarbonylmetal Complexes

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有机化学 2003年第Z1期23卷 207-208页

作者： liN He-chun yang li li Chao-Zhong State Key Laboratory of Applied Chemistry Lanzhou University Lanzhou 730000 State Key Laboratory of Applied Chemistry Lanzhou University Lanzhou 730000 Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032

　　We report here the first alkyl radical additions of (η6-arene)tricarbonylmanganese complexes in the presence of alkylmercury chloride and NaI (Eq. 1). The mechanism was postulated to be the alkyl radical addition to ArMn- (CO)+3 cation to form the corresponding 17 valence electron intermediate, which was then reduced by alkylmercury chloride via a single electron transfer process to afford the product and regenerate an alkyl radical. [1]……

关键词： electron transfer process valence electron radical addition

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Defence Technology（防务技术） 2023年第9期27卷 138-153页

作者： Zeng liu Cheng-lei Fan chun-li yang Zhu Ming San-bao lin Lang-ping Wang State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin150001China Inner Mongolia Metal Material Research Institute Yantai264000China

Ar-N_(2)-O_(2)ternary shielding gas is employed in dissimilar welding between high nitrogen steel and low alloy *** effect of O_(2)and N_(2)is investigated based on the systematical analysis of the metal transfer,nitrogen escape phenomenon,weld appearance,nondestructive detection,nitrogen content distribution,microstructure and mechanical *** are two nitrogen sources of the nitrogen in the weld:high nitrogen base material and shielding *** effect of shielding gas is mainly reflected in these two *** change of the droplet transfer mode affects the fusion ratio,N2in the shielding gas can increase nitrogen content and promote the nitrogen uniform *** addition of 2%O_(2)to Ar matrix can change the metal transfer from globular transfer to spray transfer,high nitrogen base material is thereby dissolved more to the molten pool,making nitrogen content increase,ferrite decrease and the mechanical properties *** applying N2-containing shielding gas,arc stability becomes poor and short-circuiting transfer frequency increases due to the nitrogen escape from droplets and the molten *** of the joints is improved with N_(2)increasing,but internal gas pores are easier to appear because of the poor capacity of low alloy steel to dissolve nitrogen,The generation of pores will greatly reduce the impact resistance.4-8%N2content in shielding gas is recommended in this study considering the integrated properties of the dissimilar welded joint.

关键词： High nitrogen steel Dissimilar steel joints Shielding gas Metal transfer Microstructure Mechanical properties

Effect of Ultrasound on Heterogeneous Nucleation in TIG Welding of Al–li Alloy

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Acta Metallurgica Sinica(English Letters) 2016年第12期29卷 1081-1088页

作者： Qi-Hao Chen San-Bao lin chun-li yang Cheng-Lei Fan Hong-liang Ge State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology

The effect of ultrasound on heterogeneous nucleation in a tungsten inert gas （TIG） weld pool of 2195 Al-li alloy has been investigated by a series of experiments. An ultrasonic vibration was imposed on the surface of base material before turning off the welding arc during the TIG welding implemented at a fixed point. The results suggest that ultrasound could promote heterogeneous nucleation in the TIG weld pool of 2195 Al-li alloy. The grain around the fusion zone is changed from a column grain to an equiaxed grain after applying the ultrasonic treatment. To study the influencing mechanism of ultrasound on heterogeneous nucleation, further investigations were implemented where the welding arc was turned off after turning off the ultrasonic power. The results show that the equiaxed grain around the fusion zone disappeared gradually with an increase in heat input after turning off the ultrasonic power. It suggests that ultrasound could promote the heterogeneous nucleation particle to nucleate in advance before turning off the welding arc and the crystal nucleus could again be melted with an increase in heat input after turning off the ultrasonic power. Moreover, the effects of the welding current and ultrasonic amplitude on heterogeneous nucleation in the weld pool of 2195 Al-li alloy were also investigated. Possible influencing mechanism of the welding current and ultrasonic amplitude on heterogeneous nucleation was discussed.

关键词： Ultrasound TIG welding Grain Al-li alloy

Perilipin Gene 1237 T>C Polymorphism is not Associated with Obesity Risk in Northern Chinese Han Adults

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Biomedical and Environmental Sciences 2009年第5期22卷 442-447页

作者： DONG-SHENG HU JING XIE DA-HAI YU GuO-HENG XU JIE LU JIN-XIU yang chun-yang li YAN-YAN li Department of Epidemiology College of Public Health Zhengzhou University Zhengzhou 450001 Henan China Population Health Unit Centre for Eye Research Australia University of Melbourne Level 132 Gisborne Street East Melbourne VIC 3002 Australia Department of Evidence-Based Medicine and Division of Population Genetics Cardiovascular Institute and Fuwai Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100037 China Department of Physiology Beijing University Medical Sciences Center Beijing 100083 China

Objective To identify the association between PliN 1237 polymorphism and obesity in Chinese Han adults. Methods A total of 994 adults （157 obese subjects, 322 overweight subjects, and 515 normal controls） were recruited from two rural communities. PliN 1237 polymorphism was genotyped by polymerase chain reaction-restriction-fragment-length-polymorphism （PCR-RFLP）. Association between PliN polymorphisms and obesity status was estimated by ordinal logistic regression. Results The three genotypes of,PliN 1237 were detected with a percentage of 54.3%, 37.1%, and 8.6% in TT, TC, and CC genotypes, respectively. For the PliN 1237 polymorphism locus, the frequency of alleles T and C was 0.73 and 0.27, respectively. The PliN 1237 polymorphisms were in Hardy-Weinberg equilibrium. PliN 1237 polymorphism was not associated with obesity. The odds ratio for overweight or obesity for the CC＋TC genotype was 0.8（0.4, 1.4） in women （P=-0.4） and 0.6 （0.3, 1.3） in men （P=-0.2） after adjustment for age, education, household income and alcohol consumption, smoking, and physicalactivity. Conclusion Chinese Han adults have a lower frequency of variant-allele C in PliN1237. PliN1237 T〉C polymorphism is not significantly associated with obesity in northern Chinese adults.

关键词： Perilipin Polymorphism Obesity