Progress of Study on Oriented Growth of Carbon Nanotubes     

WANG Bi ben  WANG Wan lu  LIU Gao bin  Seungho Choi 《保鲜与加工》2002,(8):134-136

Owing to unique structure and characteristics of carbon nanotubes, much more are attracted attentions since they were discovered. In recent years, carbon nanotubes have been successfully synthesized by various methods. Especially, highly aligned carbon nanotubes were grown by chemical vapor deposition (CVD) and the oriented growth of carbon nanotubes became realized, resulting in many applications of carbon nanotubes and researches on them. In the work, the methods and mechanisms of orientation growth of carbon nanotubes were reviewed, and it was analyzed and discussed that different methods influenced on the process of growing carbon nanotubes. Simultaneously, it was emphatically analyzed that catalyst particles affected on orientation growth of carbon nanotubes during their growth.  相似文献   

Antimicrobial screening of Mentha piperita essential oils     

Işcan G  Kirimer N  Kürkcüoğlu M  Başer KH  Demirci F 《Journal of agricultural and food chemistry》2002,50(14):3943-3946

Essential oils of peppermint Mentha piperita L. (Lamiaceae), which are used in flavors, fragrances, and pharmaceuticals, were investigated for their antimicrobial properties against 21 human and plant pathogenic microorganisms. The bioactivity of the oils menthol and menthone was compared using the combination of in vitro techniques such as microdilution, agar diffusion, and bioautography. It was shown that all of the peppermint oils screened strongly inhibited plant pathogenic microorganisms, whereas human pathogens were only moderately inhibited. Chemical compositions of the oils were analyzed by GC and GC/MS. Using the bioautography assay, menthol was found to be responsible for the antimicrobial activity of these oils.  相似文献   

Hepatoprotective and TNF-α inhibitory activity of Zosima absinthifolia extracts and coumarins     

Bahadır O  Çitoğlu GS  Ozbek H  Dall'Acqua S  Hošek J  Smejkal K 《Fitoterapia》2011,82(3):454-459

Zosima absinthifolia (ZA) extracts and the coumarins (+)-columbianadin and (-)-deltoin were evaluated for their potential hepatoprotective and antiinflamatory effects in a CCl(4)-induced hepatotoxicity assay in rats and by the inhibition of TNF-α production on LPS-stimulated THP-1 macrophages, respectively. Both the ZA extracts and the coumarins showed hepatoprotective activity confirmed by monitoring the ALT/AST levels and by histopathological examination. The antiinflamatory activity, proved by the inhibition of TNF-α production, was found to be higher for the n-hexane root extract than for coumarins, suggesting synergic potential of the extract. The concentration of (-)-deltoin and (+)-columbianadin in extracts was determined by HPLC analysis.  相似文献   

Sources of winter hardiness in wild lentil     

A. Hamdi  I. Küsmenoĝlu  W. Erskine 《Genetic Resources and Crop Evolution》1996,43(1):63-67

Summary In high altitude areas (> c. 850 m elevation) in west Asia and north Africa, lentil (Lens culinaris) is grown as a spring crop to avoid severe winter cold. But late fall-sown lentil with winter hardiness has higher yield potential in these areas. In this study a total of 245 accessions of wild lentil, 10 of cultivated lentil and three accessions of Vicia montbretii (syn. L. montbretii) were evaluated for winter hardiness in Syria and Turkey during the 1991/92 season. The absolute minimum temperatures were-16°C in Syria and-18.9°C in Turkey and the susceptible indicators were killed at both locations showing that the cold was sufficient for screening. Although winter hardiness was assessed as percentage of survived plants in Syria and as a visual damage rating on a 1–9 scale in Turkey, there was agreement between the winter hardiness ratings with a correlation of r=–0.56, P<0.001. Accessions of L. culinaris ssp. orientalis exhibited the highest level of winter hardiness, on average; whereas accessions of L. nigricans ssp. ervoides were the most susceptible. Correlations revealed that winter hardiness was concentrated among accessions originating from high elevation areas.  相似文献   

中国北部高原地区谷子(粟)品种高产稳产性的评价   总被引：3，自引：0，他引：3  

古世禄  独俊娥  古兆明  马建萍  郭志利  刘子坚 《中国农业科学》2001,34(4):454-457

 利用回归系数法、稳定性参数法和高稳系数法 ,对我国北部高原地区新育成的 18个新品种 (系 )的高产稳产性进行了研究。结果表明 ,参试品种多数产量较高 ,占 5 5 .5 % ,但其中产量稳定性较差的占多数 ,高产稳产的品种较少 ,仅有铁 93- 115、95汾选 3和承谷 8号 ,占 16 .7% ,其余的均为低产稳产和低而不稳的类型 ,各占 2 2 .2 %。这可能与品种性状的适应性有关  相似文献   

醌氢醌的制备及其对作物生长及根系活力的影响     

李清禄  柯玉琴 《福建农林大学学报(自然科学版)》2001,30(4):552-556

结果表明 :制备的醌氢醌产率达 88% ,纯度达 98% ;应用在作物上能促进花生、黄豆、小麦、甘薯以及水稻地上部和地下部的生长 ,提高其叶片叶绿素含量 ,增强根系活力 ,使豆科作物根瘤数目增加 ,有利作物生长 ;醌氢醌对作物的作用效果为 ,质量浓度为 10 mg· L-1的醌氢醌 >质量浓度为 5 mg· L-1的 >质量浓度为 0的 (CK) ;醌氢醌对水稻幼苗芽鞘生长以及根系生长的最佳质量浓度为 18- 30 mg· L-1.本文还简要探讨了醌氢醌影响作物生长的作用机理  相似文献   

烯唑醇防治香蕉叶斑病试验   总被引：1，自引：1，他引：1  

黄思良  晏卫红  岑贞陆  谢玲  李清标 《云南农业大学学报(自然科学版)》2002,17(4):405-407

 对烯唑醇防治香蕉叶斑病效果进行试验,结果表明,烯唑醇对香蕉叶斑病有显著的防治效果,而且对香蕉生长没有抑制作用,是一个防治香蕉叶斑病优良的杀菌剂,值得在香蕉生产上推广应用。  相似文献   

磁控摆开式呼吸阀     

黄起陆  周林书 《油气储运》1997,16(4):12-16

机械呼吸阀是油罐的重要附件，几址年来我国油库使用的机械呼吸阀基本形式是阀盘在水平面内，靠自重或弹力控制罐内压力，阀盘工作时沿导杆升降。这种呼吸阀的主要问题是：沿导杆运动引起的机械故障多；阀盘自重大，使阀盘工作时开度小，通气量小，严重时造成油罐受损。  相似文献   

柑橘属2n花粉自然发生与沙由柚2n花粉诱导研究     

向素琼龚桂枝  郭启高汪卫星李春艳  李晓林梁国鲁 《西南大学学报(自然科学版)》2005,27(5):616-620

果树2n配子育种较其他植物起步晚，尤其是利用2n花粉进行育种的研究在柑橘上还无先例。试验中初步观察了柑橘属部分品种的2n花粉自然发生情况，证实了柑橘属内未减数花粉的存在。同时通过秋水仙碱不同浓度与作用时间处理促进了柑橘2n花粉的发生，将长寿沙田柚2n花粉发生比例由当年的自然发生率0．87％提高到9.76％。初步观察了2n花粉离体萌发状况，其萌发率与花粉管伸长速度较为正常，但萌发启动比单倍性花粉慢。  相似文献   

The efficacy of selected biological and chemical control agents against Heterobasidion abietinum on Abies cilicica     

A. Lehtijärvi  H. T. Doğmuş‐Lehtijärvi  A. G. Aday  F. Oskay 《Forest Pathology》2011,41(6):470-476

The efficacy of 30% aqueous urea solution, borax powder and spore suspensions of Phlebiopsis gigantea and Trichoderma harzianum against establishment of artificially inoculated Heterobasidion abietinum on Abies cilicica was tested both in the field and in a simulated stump treatment experiment carried out in a growth chamber. In the field, in each of the four selected stands 20 fresh stumps per control agent were treated and 20 stumps were left as untreated controls. In two of the stands, the treatments were applied in June and in the two others in November. Stumps were sampled twice, at 6‐ and 12‐months after treatment. In the growth chamber, 10 log pieces per treatment and control were used, and sampling performed after 6‐week incubation. Results of the urea and borax treatments were consistent between the experiments; the mean efficacies were 98.8 and 99.4% in the growth chamber, and 80.2–91.3 and 89.4–90.1% in the two samplings of the field experiment, respectively. Despite the high efficacies of the P. gigantea (85.9%) and T. harzianum (97.5%) treatments in the growth chamber, efficacies of these biological control agents in the field were 47.1–49.2 and 61.3–65.5%, respectively.  相似文献