酶解条件对红枣汁主要成分的影响

以延川团枣为材料,在前期单因素试验的基础上采用正交设计试验方案,对温度、 提取时间和酶用量等提取红枣汁的工艺参数进行优化。结果表明：影响红枣汁中可溶性固形物、维生素C和总糖含量的因素大小顺序为温度、提取时间、酶用量。温度的影响达到显著,而提取时间和酶用量未达到显著。在温度40℃、提取时间4 h和酶用量2400 mg/L时,红枣汁中可溶性固形物含量13.9%、维生素C含量0.32 mg/(100 mL)、总糖含量9.37%,具有较好的提取效果。     

Effect of biochar amendment on soil carbon balance and soil microbial activity

We investigated the behavior of biochars in arable and forest soil in a greenhouse experiment in order to prove that these amendments can increase carbon storage in soils. Two qualities of biochar were produced by hydrothermal pyrolysis from ¹³C labeled glucose (0% N) and yeast (5% N), respectively. We quantified respiratory losses of soil and biochar carbon and calculated mean residence times of the biochars using the isotopic label. Extraction of phospholipid fatty acids from soil at the beginning and after 4 months of incubation was used to quantify changes in microbial biomass and to identify microbial groups utilizing the biochars. Mean residence times varied between 4 and 29 years, depending on soil type and quality of biochar. Yeast-derived biochar promoted fungi in the soil, while glucose-derived biochar was utilized by Gram-negative bacteria. Our results suggest that residence times of biochar in soils can be manipulated with the aim to “design” the best possible biochar for a given soil type.     

Cultivation and grazing altered evapotranspiration and dynamics in Inner Mongolia steppes

To examine the effects of cultivation and grazing on evapotranspiration (ET), continuous measurements of ET were conducted over almost two years, from December 2005 to September 2007, using the eddy-covariance technique in two paired ecosystems: a steppe and a cropland in Duolun and a fenced and a degraded steppe in Xilinhot, Inner Mongolia, China. The ET of the four ecosystems approached or exceeded precipitation in both years. During the growing season (May–September), cultivation reduced the ecosystem ET in Duolun by 15% in the wet year (2006) and 7% in the dry year (2007). Grazing reduced the ET of the steppe in Xilinhot by 13% during the growing season of 2006, while there was similar ET between the degraded and fenced steppes in 2007. The low soil moisture in the cropland and the degraded steppe compared with the steppe at each area was the reason for the decrease in ET of the steppe ecosystems. In addition, a shorter growing period during the growing season, due to the changes in type and phenology characteristics of the vegetation associated with cultivation, was suspected for the reduction in ET in Duolun. The low soil moisture, due to the low precipitation in the dry year, limited vegetation growth and decreased canopy surface conductance (g_c), resulting in reduced plant transpiration. In addition, cultivation and grazing increased the sensitivity of ET to soil moisture in the dry year, suggesting that future changes in precipitation would not only affect ET by changing soil moisture directly, but would also influence the relationship between ET and soil moisture.     

果桑大棚栽培试验调查

采用大棚覆膜栽培,桑果可提早13～20天成熟,使果型增大、大小均匀,达到增产、增效;并延长了桑果供应期,同时使大蚕期错开果桑旺采期,还可利用大棚养蚕.     

球虫消杀剂预防鸡球虫病的使用效果试验

本试验旨在得到球虫消杀剂在临床使用时的合适浓度。选择球虫发病较严重的鸡舍进行试验,分别用1∶25、1∶50和1∶100的球虫消杀剂消毒,密闭作用24 h,以不用球虫消杀剂处理的鸡舍作为对照,每种处理设两个重复。结果表明：1∶25和1∶50处理组料肉比与对照组相比差异显著（P〈0.05）,1∶100处理组与对照组相比差异不显著（P≥0.05）;球虫消杀剂各浓度处理组死亡率均小于对照组;1∶25和1∶50处理组在出栏时垫料中检出少量卵囊,但远低于对照组。各浓度球虫消杀剂处理组病变记分均小于平均值,而对照组处于平均值和高于平均值。结果提示,1∶50球虫消杀剂对球虫卵囊有着良好的杀灭作用。     

公共基础化学实验微型化教学改革探讨

将微型实验与常规实验仪器规格和试剂用量进行了对比,并进行了试验。微型化学实验具有减少环境污染、节约实验经费、节省实验时间和实验室空间、培养学生科学创新的能力等优点,微型化化学实验为研究性学习提供了一个崭新的化学实验教学模式,有利于学生综合素质的提高。     

改革兽医药理学实验教学，培养实用型兽医专业人才

兽医药理学实验是一门实践性很强的实验课程,其教学效果直接影响该专业整体教学质量的高低。在药理学实验教学中,从丰富教学内容,提高教学质量;改善教学方法,提高授课水平;增加实践机会,提高实践技能三个方面对兽医药理学实验教学进行改革,为培养实用型兽医专业人才提供保证。     

耕作方式对新垦沙地农田杂草群落结构的影响

通过田间调查的方式,研究了黑河中游边缘绿洲新垦沙地农田杂草分布状况,并对不同耕作方式下农田杂草群落结构特征进行了分析。调查中共记录杂草16种,隶属10科。新垦沙地农田杂草群落基本组成为藜(Chenopodium album)+牛筋草(Eleusineindica)+狗尾草(Setaria viridis)+反枝苋(Amaranthus retroflexus)。与当地传统的地膜覆盖、秋耕和玉米连作耕作方式相比,秸秆覆盖、减少秋耕和玉米-大豆轮作均可增加农田杂草物种丰富度、多样性指数和群落优势度(P0.05)。与当地传统耕作方式相比,秸秆覆盖可增加杂草群落中牛筋草优势度比,降低藜和反枝苋优势度比;减少秋耕可增加狗尾草、反枝苋、灰绿藜(C.glaucum)和米瓦罐(Silene conoidea)优势度比,降低牛筋草优势度比;玉米-大豆轮作可增加米瓦罐优势度比。不同耕作方式对偶见种杂草在田间的分布和组成影响不明显。可以看出,新垦沙地农田杂草物种较少,群落组成单一;不同耕作方式对新垦沙地农田杂草物种多样性和群落结构组成有明显影响,进一步深入研究对沙地农田杂草合理防除具有重要的指导意义。     

喷施不同浓度的混合液对辣椒产量和品质的影响

研究了3种不同浓度的植物生长物质混合液对辣椒产量及品质的影响。结果表明:喷施混合液能提高辣椒的产量,使开花期和结果期提前,并且提高了辣椒中Vc、可溶性固形物、可滴定酸的含量。但浓度不同,作用效果也不同,2倍和4倍稀释液对辣椒产量和品质的改善要明显些,8倍稀释液无明显作用。     

郁金香引种栽培研究

从荷兰引进4个郁金香品种,调查并比较了各品种的植物学特性、物候期、生长发育规律和种球繁殖特性。结果表明:品种LargeCopper的种球最矮,茎上柔毛最长;品种Toronto的种球膜质鳞片为桔红色,无光泽,叶片上有红褐色条纹,种球最高、最重,内外轮花瓣长最长,花径、花高、雌蕊高、花药长和花丝长均最大,但内、外轮花瓣最窄;品种Pink Impression植株最高,叶片长而宽。供试4个品种郁金香均在4月上旬萌芽,1周后展叶,4月末现蕾,5月上旬开花。花期一般为10 d,品种Toronto的花期最短,仅为1周;品种Apricot Beauty花期最长,可达2周。4个品种在现蕾前后到盛花期生长迅速。品种Apricot Beauty的种球繁殖系数最高,达4.91。品种Pink Impression的一级子球产量较高,为31.1%。