乌饭叶色素的稳定性研究

为了解乌饭叶色素的应用特性,以乌饭叶为原料,采用溶剂法提取色素,考察了乌饭叶色素的溶解性以及温度、光照、pH值、甜味剂、氧化剂、还原剂和金属离子等因素对其稳定性的影响。结果表明,乌饭叶色素易溶于水、乙醇等极性溶剂;耐高温,光照、还原剂及酸碱环境对其无明显影响,但对氧化剂较敏感;K+、Na+、Al3+和Ca2+对其无显著影响,而Fe3+、Mg2+、Cu2+和Fe2+对其有明显破坏作用,在使用时应注意避开;此外,葡萄糖、果糖的存在对色素影响不大,而高浓度蔗糖不利于其保存。     

降解地膜过早破裂对玉米地土壤水分和温度及产量的影响研究

生物降解膜是解决农业“白色污染”的重要途径,笔者针对降解膜过早破裂这一过程,开展了土壤温度、水分和作物产量的影响研究。研究结果显示：降解膜过早裂解对土壤温度和土壤水分不同阶段影响程度不同。对土壤温度的影响主要体现在苗期,降解膜地25 cm内土壤温度比PE膜降低14.1%;对土壤水分的影响主要体现在喇叭口期,降解膜地100 cm内土壤水分比PE膜降低13.1%;降解膜种植的玉米在株高、秃尖、穗行数、百粒重和产量等方面明显低于PE膜,减产27.2%。也即降解膜过早裂解显著影响土壤温度、土壤水分和作物产量。     

Analysis of Drought Characteristics and Its Trend Change in Shaanxi Province Based on SPEI and MI

【Objective】 At present, most drought studies were based on historical drought events to analyze the causes and trends. This paper sought to simulate the drought index method when outputting future meteorological data based on CMIP5 model, and explored the characteristics of past and future drought changes in Shaanxi Province, which could provide a basis for the future management of agricultural water resources in Shaanxi Province. 【Method】Based on the historical data of 18 meteorological stations in Shaanxi Province and CMIP5 model, the future meteorological data were output. The reference crop evapotranspiration (ET₀) was simulated by comparing three kinds of models. The standard precipitation evaporation index (SPEI) and relative moisture index (MI) were calculated based on the reference crop ET₀ and precipitation data to reflect the drought degree. The spatial and temporal characteristics of drought in the past (1958-2017) and in the future (2018-2100) were compared.【Result】Multiple linear regression (MLR) simulation could accurately predict the reference crop ET₀ (RMSE=0.457 mm·d ^-1). In the RCP2.6 and RCP8.5 scenarios, the future drought index showed an upward trend. Under the RCP8.5 scenario, there was a sudden change in the drought index in the 1940s. The degree of drought would decrease in the future of Shaanxi Province, and the distribution of drought would be more uneven during the year. In the future, the degree of drought would decrease during summer maize growth season, and the degree of drought would increase during winter wheat growth season.【Conclusion】The characteristics and extent of drought change were different under different RCP scenarios. The changes in drought characteristics reflected by SPEI and MI were basically the same, but there were differences in the changes in some time periods. In order to effectively cope with the negative impact of climate change on dry crop yields, it was necessary to enhance soil water storage and conservation capacity, especially to strengthen drought resistance during the winter wheat growing season.     

温度、酸碱度和培养基含水量对金福菇Tg-505菌丝生长的影响

分别在不同培养温度、培养基pH值、培养基含水量条件下培养金福菇Tg-505菌株,比较其菌丝的生长速度及生长势,探讨不同温度、酸碱度和培养基含水量对金福菇Tg-505菌丝生长的影响。结果表明:温度在15～35℃范围内,金福菇Tg-505菌丝均能生长,以25℃时菌丝生长势最佳,日平均生长速度最大为5.99 mm;酸碱度在pH 5.0～10.0范围内菌丝均能生长,以pH 7.0～8.0时菌丝生长势最佳,生长速度最快;培养基含水量在50%～75%范围内菌丝能够生长,含水量为65%～70%时,其菌丝洁白、粗壮、长势好,生长速度最快,达到3.77 mm/d以上。     

压前含水率对杉木间伐材压缩木性能的影响

通过对杉木间伐材压缩密化的水分和物理力学性能进行分析,并观察木材微观结构的变化,可得出以下结果：1)压缩木各方向的水分分布不均匀,容易翘曲变形;2)水分对压缩木的物理力学性能有影响,压前含水率50％左右,压缩木硬度、抗弯弹性模量和抗弯强度最大,但冲击韧性随着压前含水率的增加呈下降趋势。从微观结构的观察可知,杉木间伐材压缩木的细胞只是被挤压,细胞腔变小而细胞壁未受到破坏。为了降低压后含水率,使水分分布均匀,可以采取两种办法：一是使初始含水率尽可能低,二是热压时间尽可能长。     

城市污水处理厂二级出水用于城市绿化的研究

对废水浇灌景观植物进行可行性研究。评价指标为植物叶绿素、光合作用能力和呼吸作用能力。试验结果说明，经过生物处理的城市污水对植物有利无害，因此，城市污水经生物处理后可用于城市绿化。     

不同刈割时间收获后的羊草、芦苇水分和呼吸的变化

以多年生草本植物羊草和芦苇为实验材料,研究1d中不同时间（9∶00、13∶00、17∶00）刈割后含水量、气孔导度及呼吸速率的变化。结果表明：（1）羊草、芦苇刈割后水分散失均经历三个阶段：快速失水1d,缓慢失水2～3d,平稳期1d。芦苇叶片呼吸速率下降快,刈割5h后呼吸微弱,接近死亡;羊草叶片呼吸速率下降慢于芦苇,刈割7h后仍存在生理活动;（2）依据水分散失和呼吸代谢指标,三个刈割时间中,9∶00刈割能最大程度地减少干草调制过程中的养分损失,有益于制作优质干草。     

饲料水分的快速测定

叙述了饲料水分快速测定方法，用此法与国标法对饲料水分进行测定比较，筛选出以第2组烘干30min（135±2℃）为最佳组合，其测定结果准确，节省时间，重现性好。     

Influences of the Paddy Rices with Different Moistures on the Head Rice Recovery

A major component rice varietv of Xiangwanxian 9 (a late Indica variety) with 13.1%, 15.6% and 18.3% of the moisture was respectively mixed with three ad-ditive varieties in 13% of moisture at ration of 7:3 for processing assorted rices. Head rice recovery of the treatments was determined 24 hours later. Analysis indicated sig-nificant differences exist in the effects produced by the component varieties, their moistures and the component variety moisture.     

一枝蒿制剂对小鼠小肠运动作用研究

用两种一枝蒿制剂对小鼠进行小肠推进实验，以甲基硫酸新斯地明、盐酸吗啡和生理盐水为对照。结果表明：一枝蒿健胃促消化机制主要是促进小肠运动。经方差分析和多重比较，其效果相似于硫酸甲基新斯地明