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1.
赵声衡 《湖南农业大学学报(自然科学版)》1993,20(6)
本文阐述了有源负载恒温槽的工作原理,推导了描述其静态特性的缩减因数表达式,并对这种恒温槽的性能和应用作出了评价。 相似文献
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We examine the influence of spatial scale on studies of nektonic patchiness at the north edge of the Gulf Stream by altering the grain size of acoustic cross sections and applying a patch-finding algorithm. From original pictures of 180 pixels deep by 540–1260 pixels long, we averaged depth and length, to give 9 scales ranging from fine grain (1 m vertical × 25 m horizontal sized pixels) to coarse grain (12 m × 300 m sized pixels). Measures of overall echo intensity within patches were the most predictable and showed little change with scale. Measures of variability of the echo within patches showed simple negative trends with scale and were best measured at fine spatial scales. Patch size and shape related variables have a more complex relationship with scale with differences between day and night transects more pronounced at intermediate scales. This suggests behavioral patch forming mechanisms within the nekton occur at a specific grain size (4 m vertical × 100 m horizontal) within the Gulf Stream front. 相似文献
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Henk-jan Schoonbeek Johannes G.M. van Nistelrooy Maarten A. de Waard 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(9):1003-1011
The role of multiple ATP-binding cassette (ABC) and major facilitator superfamily (MFS) transporter genes from the plant pathogenic fungus Botrytis cinerea in protection against natural fungitoxic compounds was studied by expression analysis and phenotyping of gene-replacement mutants. The expression of 11 ABC (BcatrA–BcatrK) and three MFS genes (Bcmfs1, Bcmfs2 and Bcmfs4) was studied. All genes showed a low basal level of expression, but were differentially induced by treatment with cycloheximide and the plant defence compounds camptothecin, eugenol, psoralen, resveratrol and rishitin. The latter compounds induced expression of BcatrB at a high level. Eugenol was more toxic to BcatrB gene-replacement mutants than to the control isolates. Eugenol also caused an instantaneous increase in mycelial accumulation of the fungicide fludioxonil, a known substrate of BcatrB. However, there was no difference in virulence between the wild-type and BcatrB gene-replacement mutants on Ocimum basilicum, a plant known to contain eugenol. The results indicate that BcatrB is a transporter of lipophilic compounds, such as eugenol, but its role in virulence remains uncertain. 相似文献
5.
冰核细菌对仁用杏胚珠超微结构的影响 总被引:10,自引:0,他引:10
应用透射电镜对两个仁用杏品种‘白玉扁’和‘一窝蜂’接种冰核细菌并低温处理后的胚珠超微结构进行了观察, 发现冰核细菌对胚珠的超微结构有一定影响: (1) 使珠心细胞发生严重的质壁分离,细胞质中存在大量泡状结构, 线粒体的内部结构完全被破坏, 呈透明状, 而且有些珠心细胞中形成同心圆状的多膜内含物; (2) 使胚囊中卵细胞的细胞核外膜膨胀, 甚至核膜局部解体, 细胞质中细胞器减少。这些变化致使胚珠发育不正常, 影响受精而导致减产或绝收。接种冰核细菌并低温处理比单纯低温处理对胚珠超微结构的破坏程度重。 相似文献
6.
稻瘟菌激发子CSB I专化性及相关性质研究 总被引:5,自引:1,他引:5
以一套水稻抗稻瘟病近等基因系为材料,接种稻瘟菌(Magnaporthe grisea)细胞壁来源的糖蛋白激发子CSB I,其诱导植保素的积累在高度非亲和性互作水稻远高于亲和性互作水稻;研究同时表明,CSB I可专化性诱导完全非亲和性互作和高度非亲和性互作水稻的过敏性坏死反应;表明该激发子具有小种-品种专化性。经热、胰蛋白酶和过碘酸钠处理后的生物活性检测结果表明,CSB I的活性位点为糖基部分。经pH稳定性检测,CSB I在酸性及相对弱碱性条件下较稳定;而在强碱性条件下,激发子活性下降较多,甚至完全丧失。对CSB I诱导活性的有效浓度测定表明,激发子诱导水稻叶片酶活性升高的最低有效浓度为0.07~0.70 nmol/L。 相似文献
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牛奶中含有丰富的活性营养物质,包括乳铁蛋白、免疫球蛋白、乳过氧化物酶、α-乳白蛋白、β-乳球蛋白等。传统工艺生产的酸奶经过高温杀菌,活性营养物质几乎完全损失。为了避免这一情况,本文推出一种新的酸奶生产工艺,生产出的酸奶可保留大部分活性营养物质。首先将牛奶的乳脂进行分离,乳脂部分进行125 ℃、5 s杀菌,脱脂牛奶部分进行75 ℃、15 s杀菌,将两部分料液混合后加入菌种发酵至酸度75~85°T,破乳后冷却后熟8 h以上。经测定,新工艺酸奶中α-乳白蛋白、β-乳球蛋白、乳铁蛋白、免疫球蛋白、乳过氧化物酶含量分别为966 mg/L、1 963 mg/L、23.4 mg/L、102 mg/L、1 025 U/L,远高于传统工艺酸奶的68 mg/L、200 mg/L、0.7 mg/L、14 mg/L、0 U/L。通过对比新工艺与传统工艺酸奶保质期内的活菌数、黏度、酸度和口感,并无显著差异。 相似文献
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ZHANG Ling-ling YUE Yao-jing FENG Rui-lin LI Hong-feng GUO Ting-ting YUAN Chao NIU Chun-e LIU Jian-bin SUN Xiao-ping HAN Ji-long LIU Shan-bo YANG Bo-hui 《中国畜牧兽医》2016,43(8):2156-2163
In this study, an indirect ELISA method was established to detect inhibin hormone (INH) epitope peptide vaccine antibody, it would provide oretical reference for the determination of Fine-wool sheep after active immune body INH epitope peptide vaccine antibody. On the basis of the predecessors, using indirect ELISA method to determinate serum INH epitope peptide antibody levels of sheep, and through control different experimental conditions to look for the best experimental conditions. Through explorating the experimental conditions, finally, the testing experiment conditions were determined, which was blocked solution with skimmed milk powder, INH and GnIH synthetic peptides dilution degrees for 20 000 times, the optimum reaction time was 60 min, the best color action time was 15 min. In this experiment, a kind of method to detection antibody in the body after INH active immune sheep was built, it would provide a reference for future research. 相似文献