|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 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 | 全颗粒饲料对奶牛生产性能的影响显示文摘饲料中的中性洗涤纤维(NDF)含量和饲料颗粒直径是影响瘤胃功能的重要因素。试验评估了以颗粒饲料为主的奶牛瘤胃健康情况、NDF消化率和生产性能。选取8头荷斯坦母牛(336±30 d,体重346±35 kg),随机分配到交叉重复试验组中,奶牛安置于牛栏,自由采食。试验期为3周,前两周是适应期,最后一周为数据收集期。各组饲粮原料相同,但物理形式不同,分为全混合日粮(TMR)和颗粒料(直径=8 mm)。两组间物理有效NDF(pe NDF)不同,TMR组为39.8%,颗粒料组为11.8%。在试验过程中,干物质采食量(DMI)、饮水量、瘤胃反刍时间、瘤胃温度和pH情况均记录。3周后收集粪样,确定潜在的可消化NDF总消化率(pdNDF)。每阶段结束后计算平均日增重和饲料转化率。颗粒料组的DMI、DMI/体重和饮水量更高。而两组间平均日增重和饲料转化率无显著差异。颗粒料组的瘤胃反刍时间为241 min·d-1低于TMR组的507 min·d-1。饲料的不同物理外形对瘤胃温度、瘤胃pH无显著影响。TMR组的pdNDF总消化率为90.25%高于颗粒料组的86.82%。试验结果表明,动物易接受完整的颗粒饲料,DMI较高,且反刍时间减少,但瘤胃pH无显著变化。TMR组的pdNDF消化率显著增加。尽管两组奶牛在DMI和纤维消化方面表现不同,但总体表现相似,两组饲料的保存时间与其物理形式有关。在短期内,提供能满足NDF需求的完全颗粒饲料可改善瘤胃健康状况和动物生产性能,而较长时间的数据则需要进一步试验。 | Wang J Yang M Cao M Lin Y Che L Q Duraipandiyan V Al-Dhabi N A Fang Z F Xu S Y Feng B Liu G Wu D Bonfante E Palmonari A Mammi L Canestrari G Fustini M Formigoni A | 2016 | 饲料博览2016，0，12： | 2 |
| 3 | Terahertz Semiconductor Quantum Well Devices显示文摘For eventually providing terahertz science with compact and convenient devices,terahertz (1~10THz) quantum-well photodetectors and quantum-cascade lasers are investigated.The design and projected detector performance are presented together with experimental results for several test devices,all working at photon energies below and around optical phonons.Background limited infrared performance (BLIP) operations are observed for all samples (three in total),designed for different wavelengths.BLIP temperatures of 17,13,and 12K are achieved for peak detection frequencies of 9.7THz(31μm),5.4THz(56μm),and 3.2THz(93μm),respectively.A set of THz quantum-cascade lasers with identical device parameters except for doping concentration is studied.The δ-doping density for each period varies from 3.2×1010 to 4.8×1010cm-2.We observe that the lasing threshold current density increases monotonically with doping concentration.Moreover,the measurements for devices with different cavity lengths provide evidence that the free carrier absorption causes the waveguide loss also to increase monotonically.Interestingly the observed maximum lasing temperature is best at a doping density of 3.6×1010cm-2. | Liu H C Luo H Ban D Waichter M Song C Y Wasilewski Z R Buchanan M Aers G C SpringThorpe A J Cao J C Feng S L Williams B S Hu Q | 2006 | Journal of Semiconductors2006，27，4： | 2 |
| 4 | Transmembrane ICa contributes to rate-dependent changes of action potentials in human ventricular myocytes显示文摘 | Li GR Yang B Feng J Bosch RF Carrier M Nattel S | 1999 | Am J Physiol1999，276，12： | 2 |
| 5 | Converting ceria polyhedral nanoparticles into single-crystal nanospheres 显示文摘 | Feng X D Sayle D C Wang Z L Paras M S Santora B Sutorik A C Sayle T X T Yang Y Ding Y Wang X D Her Y S | 2006 | Science2006，312，5779： | 1 |
| 6 | A superior oxide ion electrolyte显示文摘 | Feng M Goodenough J B | 1994 | Eur J Solid State Inorg Chem1994，31，89： | 1 |
| 7 | A Practical Simple Geometry and Gain/Phase Calibration Technique for An- tenna Array Processing显示文摘 | Ng B P Lie J P Er M H Feng A | 2009 | IEEE Transactions on Anten- nas and Propagation2009，57，7： | 1 |
| 8 | The barriers to energy efficiency in China: Assessing household electricity saving and consumer behavior in Liaoning Province 显示文摘 | FENG D SOCACOL B K VU K M | 2010 | Energy Policy2010，38，： | 1 |
| 9 | Molecular mechanism for the umami taste synergism显示文摘 | ZHANG Feng KLEBANSKY B FINE R M | | 0，，52： | 1 |
| 10 | IrrE, a global regulator of extreme radiation resistance inDeinococcus radiodurans, enhances salt tolerance in Escherichia coli and Brassica napus显示文摘 | Pan J Wang J Zhou Z Yan Y Zhang W Lu W Ping S Dai Q Yuan M Feng B Hou X Zhang Y Ma R Liu T Feng L Wang L Chen M Lin M | 2009 | PloS One2009，4，2： | 1 |
| 11 | Beyond the ABC-model:regulation of floral homeotic genes显示文摘 | Zahn L M Feng B M Ma H | 2006 | Advances in Botanical Research2006，44，： | 1 |
| 12 | Ligustilide prevents cognitive impairment and attenuates neurotoxicity in D-galactose induced aging mice brain显示文摘 | Li J J Zhu Q Lu Y P Zhao P Feng Z B Qian Z M | 2015 | Brain Res2015，1595，： | 1 |
| 13 | In stent restenosis and thrombosis assessment after EP224283 injection in a rat model 显示文摘 | MAUREL B FENG CHAI F MATON M | 2013 | Atherosclerosis2013，229，2： | 1 |
| 14 | The TIL commissioning and performance显示文摘 | X Zhang W Zheng X Wei F Jing Z Sui K Zheng Q Xu X Yuan X Jiang L Yang P Ma M Li J Wang D Hu S He F Li Z Peng B Feng H Zhou L Guo X Li X Zhang J Su Q Zhu H Yu R Zhao C Ma H He D Fan W Zhang | 2008 | Journal of Physics: Conference Series2008，，3： | 1 |
| 15 | Sol-gel synthesis of a new oxide-ion conductor Sr-and Mg-doped LaGaO3 perovskite显示文摘 | Huang K Q Feng M Goodenough J B | 1996 | J Am Ceram Soc1996，79，4： | 1 |
| 16 | A techniqueto in improve the empirical mode decomposition the Hilbert-Huang transform 显示文摘 | Chen Y B Feng M Q | 2003 | Earthquake Engineering and Engineering Vibration2003，1，： | 1 |
| 17 | TAP1 and TAP2 polymorphisms associated with ankylosing spondylitis in genetically homogenous Chinese Han population显示文摘 | Feng M Yin B Shen T | 2009 | Human immunology2009，70，4： | 1 |
| 18 | 查看详情显示文摘 | Feng M G Chen C Chen B | | 0，，： | 1 |
| 19 | A new HPV-DNA test for cervical-cancer screening in developing regions: a cross-sectional study of clinical accuracy in rural China显示文摘 | You-lin Qiao John W Sellors Paul S Eder Yan-ping Bao Jeanette M Lim Fang-hui Zhao Bernhard Weigl Wen-hua Zhang Roger B Peck Ling Li Feng Chen Qing-jing Pan Attila T Lorincz | 2008 | Lancet Oncology2008，，10： | 1 |
| 20 | FFA-Induced adipocyte in- flammation and insulin resistance: involvement of ER stress and IKK070705 pathways 显示文摘 | Ping J Jie M Feng B | 2011 | Obesity2011，19，3： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员