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1.
第三版API682标准冲洗方案Plan53解析   总被引:1,自引:0,他引:1  
文章介绍了第三版API682标准冲洗方案Plan53,对该方案的3种选择方案lan53A/53B/53C,进行比较分析,阐述了各种冲洗方案的工作原理,及在使用中要注意的一些事项,对其优缺点进行说明。  相似文献   
2.
采用事件平均浓度(EMC)和M(V)曲线初期冲刷效应判识方法,对2011年4月北京市中心城区和远郊区县降雨径流污染特征进行分析.结果表明,受城郊环境差异影响,径流污染物种类、浓度和初期冲刷效应存在明显分异,城区COD、TP、TN污染物浓度低于郊区,氨氮浓度高于郊区;城区径流存在初期冲刷效应,郊区无明显初期冲刷效应.  相似文献   
3.
冬季猪舍通风管理方式影响猪舍内的环境质量以及污染物的排放,为确定改造后猪舍侧窗负压通风系统6阶段管理对冬季舍内环境质量以及氨气和温室气体排放的影响,对舍内温度、湿度和空气流速等环境指标进行了测定,采用水分平衡方程确定了不同通风阶段猪舍的通风率,利用INNOVA 1412多气体分析仪-连续采样测试技术,对冬季猪舍NH_3、N_2O、CH_4和CO_2的排放进行了测定,确定了不同通风量条件下氨气和温室气体的排放率。结果表明,冬季侧窗通风密闭式育肥猪舍平均温度为13.7℃,湿度为69.7%,舍内最大温度与湿度差值分别为3.2℃和39.6%,平均通风率为6 207 m~3·h~(-1)(单头生猪通风量:24.9 m~3·h~(-1)),舍内平均空气流速为0.28 m·s~(-1),满足了育肥猪生长的要求;冬季试验猪舍中NH_3平均浓度范围在8.42~15.63 mg·m~(-3),CO_2平均浓度范围保持在2 509~5 303 mg·m~(-3)之间,CH_4浓度变化在1.11~5.90 mg·m~(-3),可满足冬季育肥猪生长的需求;单头生猪NH_3、CO_2和CH_4的平均排放率分别为250.0 mg·h~(-1)、79.9 g·h~(-1)、57.7 mg·h~(-1),单头生猪累积日排放量分别为6.0 g·d~(-1)、1.92 kg·d~(-1)和1.39 g·d~(-1),试验期间没有监测到N_2O的排放;采用的6级通风管理模式显著影响NH_3、CO_2的平均排放率,对CH_4的排放影响不显著。  相似文献   
4.
某建设场地位于岷江上游大沟流域,为山洪泥石流多发区。从主、支沟山洪泥石流特征、泥石流暴发规模及支沟泥石流对主沟山洪特征的影响等方面分析了场地可能遭受山洪泥石流灾害的危险性,并以此为基础对场地按危险程度进行了分区。结果表明,该场地主体位于基本无危险区,其建设计划是可行的。  相似文献   
5.
The impacts of thinning, fertilization and crown position on seasonal growth of current-year shoots and foliage were studied in a 13-year-old loblolly pine (Pinus taeda L.) plantation in the sixth post-treatment year (1994). Length of new flushes, and their needle length, leaf area, and oven-dry weight were measured in the upper and lower crown from March through November. Total shoot length was the cumulative length of all flushes on a given shoot and total leaf area per shoot was the sum of leaf areas of the flushes.

By the end of June, first-flush foliage reached 70% of the November needle length (14.3 cm) and 65% of the final leaf area (15.0 cm2). Cumulative shoot length of first- and second-flush shoots achieved 95% of the annual length (30.3 cm), whereas total leaf area per shoot was 55% of the final value (75.3 dm2). Fertilization consistently stimulated fascicle needle length, dry weight, and leaf area in the upper crown. Mean leaf area of upper-crown shoots was increased by 64% six years after fertilization. A significant thinning effect was found to decrease mean leaf area per shoot in the crown. For most of the growing season, the thinned-fertilized trees produced substantially more leaf area per shoot throughout the crown than the thinned-nonfertilized trees. These thinned-fertilized trees also had greater needle length and dry weight, longer first flush shoots, and more leaf area per flush than trees in the thinned-nonfertilized plots. Needle length and leaf area of first flush shoots between April and July were linearly related to previous-month canopy air temperature (Ta). Total shoot length strongly depended on vertical light gradient (PPFD) within the canopy, whereas shoot leaf area was a function of both PPFD and Ta. Thus, trees produced larger and heavier fascicles, more and longer flush shoots, and more leaf area per shoot in the upper crown than the lower crown. We conclude that thinning, fertilization, and crown position regulate annual leaf area production of current-year shoots largely by affecting the expansion of first flush shoots and their foliage during the first half of the growing season.  相似文献   

6.
以毛新杨无性系TB0 1×毛白杨无性系LM5 0的回交子代 12 0株个体为作图群体 ,对控制叶片表型性状如叶长、叶宽、叶面积和叶柄长以及春季萌芽时间共 5个性状的数量性状位点 (quantitativetraitloci,QTLs)进行分析。运用AFLP标记技术结合拟测交作图策略构建了含有 393个AFLP标记的毛白杨及毛新杨的遗传连锁框架图。毛白杨遗传图上共含有 2 4 7个AFLP标记位点 ,连锁位点覆盖毛白杨基因组总长约 32 6 5 1cM ,而毛新杨遗传连锁图上共含有 14 6个标记位点 ,连锁位点覆盖毛新杨基因组总长约 1992cM ,这些连锁图的每一连锁群上含有的标记数为 4~ 30个。在此基础上 ,利用区间作图软件共检测到控制叶片表型性状的QTLs14个 ,位于 9个连锁群上 ;而对于春季萌芽时间共检测到 3个QTLs,分别位于 3个不同的连锁群上。在检测到的 17个QTLs中 ,每一QTL可解释表型变异的 7 6 %~ 15 8%。此外 ,发现控制叶长、叶宽和叶面积等相关性状的QTLs位于相同的基因组区域 ,这些QTLs主要位于毛白杨遗传连锁图的TLG2和TLG11以及毛新杨连锁图的TBLG1连锁群上。据控制叶片表型和春季萌芽时间的QTLs所处的基因组区域 ,可推测叶片表型和春季萌芽时间这两类性状是由各自相应的基因控制。  相似文献   
7.
基于Bayes判别分析法的密云县山洪泥石流预报模型   总被引:2,自引:2,他引:0  
针对密云水库上游密云县境内山洪泥石流灾害多发的特点,首次将Bayes判别分析法原理运用于自然灾害的预测预报.运用系统科学和山洪泥石流预报原理,对密云水库上游密云县境内影响山洪泥石流发生的系统内部要素和系统外部环境条件进行分析,确定用影响山洪泥石流发生的前15 d的实效雨量和当日雨量作为预报模型因子,并建立起一组山洪泥石流预报模型,经自身验证法和交互验证法对模型进行检验,其判断正确率均为82.4%,达到了Bayes判别分析要求的判别模型自身验证正确率>80%的要求,两种方法检验结果一致,模型表现稳定,表明所建立的模型可靠,可以投入使用.研究结果可为该地区的山洪泥石流预测预报提供一种较为简单易行的方法,为密云县山洪泥石流灾害防治提供一定的支撑,以减少山洪泥石流发生所导致的灾害损失.  相似文献   
8.
Beech trees occur in significantly lower latitudes in continental East Asia than in Europe and North America. They are common deciduous trees in the deciduous forests of the temperate zone in Europe, the eastern part of North America and Japan. In continental East Asia, however, they are absent in the deciduous forests of the temperate zone, but occur in the forests of mountains in the moist subtropical zone, south of 34° Northern Latitude. The lower limits of their distribution in these mountains show a significantly different pattern from the usual distribution pattern of plants and vegetation: it declines as the latitude decreases. The altitudinal belts of beech species lie higher in the northern than in the southern parts of their distribution areas in China. Based on an analysis of the climate and the phenology of these deciduous trees, we show that the prevailing monsoon conditions are the main factor affecting the distribution of the Chinese beech species.  相似文献   
9.
干燥和重新湿润过程引起土壤CO_2激发释放的模拟研究   总被引:5,自引:1,他引:5  
应用短期培养实验研究了干燥和重新湿润引起的土壤CO2激发释放及其动力学过程.结果表明,不经干燥和重新湿润处理土壤CO2释放速率基本不随时间变化,其CO2释放过程可以用零级反应动力学方程(y=k0t)描述;干燥和重新湿润处理过程能够引起明显的土壤CO2激发释放,这是干燥和重新湿润引起的土壤呼吸激发效应(一级反应)和土壤基本呼吸(零级反应)相互叠加的结果,可以用两库叠加模型y=at+Ao(1-e-kt)很好描述.本实验条件下扰动、干燥和重新湿润引起的(蝼)土CO2净激发释放量为23.05~59.90 mg CO2-C·kg-1,主要与不同培肥措施长期实施造成的土壤性质和肥力差异,特别是有机质数量和质量的差异有密切关系.  相似文献   
10.
Most woody ornamentals exhibit episodic growth flushes and nitrogen (N) uptake has also been demonstrated to be seasonal. However, there is little information on N uptake in relationship to plant growth cycle. In this study, N uptake and allocation of sweet viburnum during periods of low and high root elongation rates were studied. Plants were fertilized with ammonium nitrate (15NH4 15NO3) and after 6 d N absorption was determined. Significantly more N was absorbed by plants with low root elongation rate compared with plants with high root elongation rate. About 70% of the N absorbed by plants with low root elongation rate was allocated to the mature leaves compared to 35% on plants with high root elongation rate. It was evident that root growth activity influenced N absorption and allocation. Although only a small amount of the N absorbed by plants with low root elongation rates was allocated to the immature leaves, significantly more N was allocated to the immature leaves by plants with high root elongation rates. It is possible that the N necessary to support immature leaf growth, when root elongation rate is low, is provided by mobilization from other parts, possibly mature leaves.  相似文献   
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