蟋蟀视觉系统的解剖结构与生理机能

蟋蟀视觉系统由单眼、复眼、视叶三部分组成。蟋蟀的单眼为背单眼,由角膜、角膜生成细胞、视网膜等组成,是提高昆虫复眼所感知的视觉刺激的兴奋水平部位;复眼是最主要的视觉器官,由角膜、晶锥、感杆束和网膜细胞、基膜组成,是光电转导和视觉级联反应的中心;视叶由神经节层、外髓和内髓组成,是视觉神经系统的中心。     

珍稀濒危植物蒙古扁桃花生物学特性

蒙古扁桃的植株可分为长花丝植株、短花丝植株和中花丝植株。群落花期约50d,单花花期约8d,分为露粉、微开、盛开、凋谢4个时期。过氧化物法测定4个时期花粉均具活力,可保持30d左右,联苯胺-过氧化氢测定柱头可授性,花粉活力与柱头可授性重叠,长花丝植株为8d左右,而中花丝约为5d。蒙古扁桃花一般在9:00开始泌蜜,11:00分泌量达到高峰,之后产蜜量减少直至停止,日泌蜜和散粉集中在10:00～14:00。蒙古扁桃开花受环境的影响。     

小叶臭黄皮叶挥发油化学成分的研究

采用水蒸气蒸馏法提取小叶臭黄皮叶挥发油,运用毛细管气相色谱-质谱联用法对挥发油成分进行了分析,共分离出84个峰,鉴定了其中的66种成分,所鉴定成分占挥发油总量的94.52%.其主要化学成分为α-芹子烯(15.76%)、石竹烯(15.05%)、β-芹子烯(9.54%)、α-蒎烯(6.43%)和α-石竹烯(5.39%)等.     

黄河流域棉区转Bt基因棉种植对根际土壤微生物数量及细菌多样性的影响

采用传统培养与PCR-DGGE相结合的方法研究了黄河流域棉区4个省份种植的转Bt基因棉在4个生长时期（播种后第30天、第60天、第90天和第120天）的根际土壤微生物数量及细菌多样性.结果表明：同一省份同一生长时期转Bt基因棉根际土壤微生物数量与常规棉相比均无显著差异,其数量主要受不同生长时期影响,而不同省份间主要受地域条件的影响.4个省份转Bt基因棉根际土壤细菌多样性较丰富,同一省份同一生长时期内转Bt基因棉与常规棉根际土壤细菌多样性指数、均匀度和丰富度均无显著差异.不同省份间细菌多样性主要因地域条件而有所不同,但差异较小.     

果胶酶制剂中花色素酶的去除

以皂土为吸附剂,将花色素酶从粗果胶酶制剂中除去。分离效果受pH和皂土用量影响。皂土还具有一定的脱色作用。黑曲霉AS3.316麦麸固体曲用5倍重量的自来水于室温下抽提4小时。粗果胶酶拙提液中加入3％皂土,调pH至4.1,于室温下放置30分钟。过滤所得部分提纯酶液含果胶酶258u/ml,酶活力回收为88％。 100ml山楂汁和387u(1.5ml)上述部分提纯的果胶酶于50℃保温3小时后,澄清度由65％提高到98％;相对粘度由12.5下降到1.2;果胶完全水解;红色素完全保留着。     

Operation of the CO dehydrogenase/acetyl coenzyme A pathway in both acetate oxidation and acetate formation by the syntrophically acetate-oxidizing bacterium Thermacetogenium phaeum

Thermacetogenium phaeum is a homoacetogenic bacterium that can grow on various substrates, such as pyruvate, methanol, or H2/CO2. It can also grow on acetate if cocultured with the hydrogen-consuming methanogenic partner Methanothermobacter thermautotrophicus. Enzyme activities of the CO dehydrogenase/acetyl coenzyme A (CoA) pathway (CO dehydrogenase, formate dehydrogenase, formyl tetrahydrofolate synthase, methylene tetrahydrofolate dehydrogenase) were detected in cell extracts of pure cultures and of syntrophic cocultures. Mixed cell suspensions of T. phaeum and M. thermautotrophicus oxidized acetate rapidly and produced acetate after addition of H2/CO2 after a short time lag. CO dehydrogenase activity staining after native polyacrylamide gel electrophoresis exhibited three oxygen-labile bands which were identical in pure culture and coculture. Protein profiles of T. phaeum cells after sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the strain exhibited basically the same protein patterns in both pure and syntrophic culture. These results indicate that T. phaeum operates the CO dehydrogenase/acetyl-CoA pathway reversibly both in acetate oxidation and in reductive acetogenesis by using the same biochemical apparatus, although it has to couple this pathway to ATP synthesis in different ways.     

温度植被干旱指数在蒙古高原干旱监测中的应用

以蒙古高原为研究区,选择2000-2019年植物生长季的MODIS归一化植被指数(NDVI)和陆地表面温度(LST)构建NDVI-LST特征空间,由该特征空间计算蒙古高原温度植被干旱指数(TVDI);利用Theil-Sen Median趋势分析、Mann-Kendall检验及Hurst指数方法分析蒙古高原TVDI的时空...