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| 1 | Effect of nitrogen fertilization on yield, N content, and nitrogen fixation of alfalfa and smooth bromegrass grown alone or in mixture in greenhouse pots显示文摘Planting grass and legume mixtures on improved grasslands has the potential advantage of realizing both higher yields and lower environmental pollution by optimizing the balance between applied N fertilizer and the natural process of legume biological nitrogen fixation. However, the optimal level of N fertilization for grass-legume mixtures, to obtain the highest yield, quality, and contribution of N2 fixation, varies with species. A greenhouse pot experiment was conducted to study the temporal dynamics of N2 fixation of alfalfa(Medicago sativa L.) grown alone and in mixture with smooth bromegrass(Bromus inermis Leyss.) in response to the addition of fertilizer N. Three levels of N(0, 75, and 150 kg ha–1) were examined using 15N-labeled urea to evaluate N2 fixation via the 15 N isotope dilution method. Treatments were designated N0(0.001 g per pot), N75(1.07 g per pot) and N150(2.14 g per pot). Alfalfa grown alone did not benefit from the addition of fertilizer N; dry matter was not significantly increased. In contrast, dry weight and N content of smooth bromegrass grown alone was increased significantly by N application. When grown as a mixture, smooth bromegrass biomass was increased significantly by N application, resulted in a decrease in alfalfa biomass. In addition, individual alfalfa plant dry weight(shoots+roots) was significantly lower in the mixture than when grown alone at all N levels. Smooth bromegrass shoot and root dry weight were significantly higher when grown with alfalfa than when grown alone, regardless of N application level. When grown alone, alfalfa's N2 fixation was reduced with N fertilization(R2=0.9376, P=0.0057). When grown in a mixture with smooth bromegrass, with 75 kg ha–1 of N fertilizer, the percentage of atmospheric N2 fixation contribution to total N in alfalfa(%Ndfa) had a maximum of 84.07 and 83.05% in the 2nd and 3rd harvests, respectively. Total 3-harvest %Ndfa was higher when alfalfa was grown in a mixture than when grown alone(shoots: |t|=3.39, P=0.0096; root: |t|=3.57, P=0.0073). We believe this was due to smooth bromegrass being better able to absorb available soil N(due to its fibrous root system), resulting inlower soil N availability and allowing alfalfa to develop an effective N2 fixing symbiosis prior to the 1st harvest. Once soil N levels were depleted, alfalfa was able to fix N2, resulting in the majority of its tissue N being derived from biological nitrogen fixation(BNF) in the 2nd and 3rd harvests. When grown in a mixture, with added N, alfalfa established an effective symbiosis earlier than when grown alone; in monoculture BNF did not contribute a significant portion of plant N in the N75 and N150 treatments, whereas in the mixture, BNF contributed 17.90 and 16.28% for these treatments respectively. Alfalfa has a higher BNF efficiency when grown in a mixture, initiating BNF earlier, and having higher N2 fixation due to less inhibition by soil-available N. For the greatest N-use-efficiency and sustainable production, grass-legume mixtures are recommended for improving grasslands, using a moderate amount of N fertilizer(75 kg N ha–1) to provide optimum benefits. | XIE Kai-yun LI Xiang-lin HE Feng ZHANG Ying-jun WAN Li-qiang David B Hannaway WANG Dong QIN Yan Gamal M A Fadul | 2015 | Journal of Integrative Agriculture2015，14，9： | 5 |
| 2 | ^(99m)Tc-AMD3100:A novel potential receptor-targeting radiopharmaceutical for tumor imaging显示文摘The chemokine CXCR4 receptor is over-expressed in a wide variety of tumors.In this study,AMD3100,which was a prototype non-peptide antagonist of CXCR4 receptor,was labeled with ^(99m)Tc.^(99m)Tc-AMD3100 was verified by thin layer radio chromatography(TLRC).The tumor-localizing properties of ^(99m)Tc-AMD3100 were evaluated and proved in mice bearing Hep-G2 tumor xenograft.^(99m)Tc-AMD3100 was a promising,novel receptor-specific radiopharmaceutical with potential application in the imaging of human tumors. | Jin Ming Zhang~(a,),Jia He Tian~a,Tian Ran Li~a, Hai Yu Guo~a,Li Shen~b a Department of Nuclear Medicine,The PLA General Hospital,Beijing,100853,China b Peking University Health Science Center,Beijing,100191,China | 2010 | Chinese Chemical Letters2010，21，4： | 3 |
| 3 | An implicit relation between temperature and reaction rate in the SLFM显示文摘The Arrhenius law implies that reaction rate is a continuous function of temperature. However,the steady laminar flamelet model(SLFM) does not explicitly give this functional relationship. The present study addresses this relation in the SLFM.It is found that reaction rate is not continuous in the mixture-fraction space.As a result,the SLFM is unable to predict local extinction and reignition.Furthermore,we use the unstable branch of the'S-curve'to fill the gap between steady burning branch and extinctio... | Jian Zhang,~(a)) Guowei He,~(b)) and Guodong Jin LNM,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China | 2011 | Theoretical & Applied Mechanics Letters2011，1，1： | 2 |
| 4 | Identification of c-myc as a target of APC pathway显示文摘 | He T C Sparks A B Rago C | 1998 | Science1998，281，5382： | 1 |
| 5 | MicroRNA-221 mediates the effects of PDGF-BB on migration, proliferation, and the epithelial-mesenehymal transition in pancreatic cancer cells 显示文摘 | Su A He S Tian B | 2013 | PLoS One2013，8，71： | 1 |
| 6 | Reverse genetics of negative-strand RNA viruses:Closing the circle显示文摘 | Pekosz A He B Lamb R A | 1999 | Proc Natl Acad Sci1999，96，16： | 1 |
| 7 | Percutaneous ethanol injection therapy in the treatment ofthyroid and parathyroid diseases显示文摘 | B E N N E D B A E K F N K A R S T R U P S HE G E D U S L | 1997 | Eur J Endocrinol1997，136，3： | 1 |
| 8 | Lymphoma B cells evade apoptosis through the TNF family members BAFF/BLyS and APRIL显示文摘 | He B Chadburn A Jou E | 2004 | J Immunol2004，172，5： | 1 |
| 9 | AIDA: Adaptive application independent data aggregation in wireless sensor networks显示文摘 | He T Blum B M Stankovic J A | 2004 | ACM Transaction on Embedded Computing System2004，3，2： | 1 |
| 10 | Gefitinib enhances the radiosensitivity of nasopharyngeal carcinoma cell line CNE2in vitro显示文摘 | HE B F SUN A M HUANG B Y | 2011 | Nan Fang Yi Ke Da Xue Xue Bao2011，31，： | 1 |
| 11 | Discrete time analysis of MAP/PH/1 multiclass general preemptive priority queue显示文摘 | Alfa A Liu B He Q | 2003 | Naval Research Logistics2003，50，： | 1 |
| 12 | Experimental optimization of a continuous-flow reactive distillation reactor for biodiesel production显示文摘 | HE B B SINGH A P THOMPSON J C | 2005 | Transactions of the ASAE2005，48，6： | 1 |
| 13 | Estimation of electrical con- ductivity distribution within the human head from mag- netic flux density measurement 显示文摘 | Gao N Zhu S A He B | 2005 | Physics in Medicine and Biology2005，50，11： | 1 |
| 14 | A novel continuous - flow reactor using reactive distillation for biodiesel produc- tion 显示文摘 | HE B A SINGH A P THOMPSON J C | 2006 | Transactions of the ASAE2006，49，1： | 1 |
| 15 | A novel continuous-flow reactor using reactive distillation for biodiesel production显示文摘 | HE B B SINGH A P THOMPSON J C | 2006 | Transactions of the ASAE2006，49，1： | 1 |
| 16 | Themml characterization of an epoxy- I)ast underfill material for flip chip packaging 显示文摘 | He Y Moreira B E Overson A el al | 2000 | llmnnochinfiea Aeta2000，3573，14： | 1 |
| 17 | AIDA:Adaptive application independent data aggregation in wireless sensor networks 显示文摘 | He T Blum B M Stankovic J A | 2004 | ACM Transactions on Embedded Computing System( Speccial Issue on Dynamically Adaptable Embedded Systems)2004，3，2： | 1 |
| 18 | FOXO3A genotype is strongly associated with human longevity显示文摘 | Willcox B J Donlon T A He O | 2008 | PNAS2008，105，13： | 1 |
| 19 | Inhibition of calcium carbonate precipita?tion in Na Cl brines from 25 to 90℃显示文摘 | He S L Kan A T Tomson M B | 1999 | Applied Geochemistry1999，14，： | 1 |
| 20 | Early Cretaceous adakitic granites in the Northern Dabie complex, central China: Implications for partial melting and delamination of thickened lower crust 显示文摘 | Wang Q Wyman D A Xu J F Jian P Zhao Z H Li C F Xu W Ma J L He B | 2007 | Geochim Cosmochim Acta2007，71，10： | 1 |
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