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土壤水分平衡指标是衡量某一区域土壤水分状况的重要标志,正确掌握某一区域的土壤水分平衡指标.有利于该区农业生产的合理布局和各种农作物的合理配置。定量计算表明:常德市的几种主要土壤水分平衡指标为:年可能蒸散量Ep919mm,年实际蒸散量E.906mm,土壤年缺水量D13mm,土壤年余水量R473mm。通过对常德市全年土壤水分收支情况的分析,得到了较为满意的结果,为有关方面提供了借鉴材料。 相似文献
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为了克服降水强夯法处理深度小、降水时间长的缺陷,结合扬中灏港通用码头软土地基处理工程,改进了传统降水强夯工艺,采用水气分离集成井降水联合强夯法进行加固处理。通过在常规真空井点降水强夯和改进降水强夯两个试验区开展现场监测和检测试验,对加固效果进行了对比评价分析,研究结果表明:水气分离集成井降水强夯工艺降水深度可达地表以下5~6 m,夯后孔压消散时间约为1~2天;地基加固后总地表施工期最大沉降量为0.606 m,可有效减小工后沉降;与常规井点降水强夯法相比,改进法加固后土体强度和地基承载力均有较大提高,地基加固效果优势明显。 相似文献
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干旱少雨是制约榆林市农业发展的主要因素,绿豆的生长发育常常受到干旱胁迫,为了提高干旱地区绿豆的产量,本项研究采用随机区组的试验方法,分析了黄腐酸喷施(HP)、黄腐酸浸种+喷施(JP)、保水剂拌土(BT)、对照(CK)、黄腐酸浸种(HJ),不同处理对土壤含水率及对绿豆生长发育、产量的影响。结果表明,各处理提高了土壤含水率,HP处理土壤含水率最大,由高到低依次为:HP〉JP〉HJ〉BT〉CK,分别超出对照14.06%、10.47%、6.66%、2.33%;保水剂拌土提高了绿豆的株高、茎粗、百粒重、单株荚数,分别比对照提高了7.56%、8.89%、1.79%、20%;处理小区的产量大小:HP〈HJ〈JP〈BT〈CK。四种处理均可提高土壤含水率,但小区最终产量都低于对照,因此该技术还有待进一步研究。 相似文献
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以海南四大绿茶:白沙绿茶、水满乡绿茶、云雾绿茶、新伟绿茶为样品,利用常规方法测定了它们水分的含量,方法简单,容易实现. 相似文献
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蔡学敦 《电子科技大学学报(社会科学版)》1989,(6)
本文对绕成绞状纤维的微波测湿提出了一种归一化测量——单位线密度衰减,这样,对一定物质而言,在一定温度下,只需一条校准曲线,就可用于不同微波衰减、不同湿量、不同周长的绞状纤维的微波测湿。我们对生丝进行了试验,结果良好。 相似文献
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Staphylococcus aureus is a gram-positive, enterotoxin-producing coccus. It is a hardy organism and known to survive over a wide range of water activities, pH values, and temperatures. The objective of this study was to model the survival or gradual inactivation of S. aureus ATCC 13565 in intermediate moisture foods (IMFs). Various initial concentrations (approximately 10(1), 10(2), 10(3), and 10(4) CFU/g) were used to inoculate three different IMFs (beefsteak, bread, and chicken pockets). Viable counts were determined up to 60 days using tryptic soy agar. Inoculum size did not influence the survival or gradual inactivation of S. aureus in these foods. The rate of change (increase or decrease) in log CFU/day was calculated for every consecutive pair of data points and by linear regression for each inactivation curve. Both consecutive pair and linear regression rates of change were fit to logistic distributions (with parameters alpha and beta) for each food. Based on the distribution parameters, survival or gradual inactivation of S. aureus was predicted by computer simulation. The simulations indicated an overall decline in S. aureus population over time, although a small fraction of samples in the consecutive pair simulation showed a slight population increase even after 60 days, consistent with the observed data. Simulation results were compared to predictions from other computer models. The models of Stewart et al., were fail-safe, predicting the possibility of significant growth only after > 3,000 days. The USDA pathogen modeling program predictions were found to be fail-dangerous, predicting declines at least four times faster than observed. 相似文献
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土壤最大持水量与环境因子的关系 总被引:1,自引:0,他引:1
本文应用数量化理论Ⅰ方法,研究了土壤最大持水量与环境因子的相关关系。结果表明,影响土壤最大持水量的主导因子是坡向、地貌、土厚和部位。文中给出了土壤最大持水量的预测方程。 相似文献
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分析了通辽市近45 年降水、潜在蒸散及农田水分盈亏的变化,结果表明:年降水量在周期变化中具有减小的趋势,年降水量的稳定性增加,潜在蒸散波动上升。本世纪60 年代以来,春旱有所缓减,秋旱有所加剧 相似文献