林木叶片最适养分状态的模拟诊断   总被引：16，自引：3，他引：16  

陈道东  李贻铨 《林业科学》1991,27(1):1-7

为研究叶片最适养分状态,提出了模拟诊断方法。将砂姜黑土上Ⅰ-69杨(Populus deltoides Bartr.cv.“Lux”)的改土培肥试验各处理作为模拟诊断的样地。用典型相关分析方法选择采样时间、确定与林木生长有密切关系的叶片养分元素。用抛物线函数作为叶片最适养分状态的诊断函数。选择变量同时考虑叶片养分的含量和养分之间的比例。经过4年多的研究得出Ⅰ-69杨最适叶片养分状态为:造林第1年7月叶片含P_2O_50.55—0.75％;造林后第2年7月叶片含N3.20—4.20％;造林后第3年5月含N3.00—3.70％;造林后第4年5月叶片中的N/K为1.00—1.60。  相似文献   

崇明东平森林公园游憩质量研究     

陈希  孔正红  王开运  赵敏  李宏庆 《林业资源管理》2007,(3):67-72

从空气保健和森林美学两方面初步研究了东平森林公园的游憩质量,选择空气负氧离子浓度和空气质量评价系数(CI)来评价空气保健功能;选择物种丰富度、生活型结构、观赏特性以及空间分布格局多样性这四个指标来定量评价森林美学功能。对12个具有代表性的样点进行调查研究,结果表明:目前东平森林公园整体游憩质量尚未达到最佳水平。为满足崇明未来旅游需求,东平森林公园在面积、树种配置以及景观格局方面都有待提高。  相似文献   

Determination of drought tolerance using root activities in Robinia pseudoacacia ''Idaho'' transformed with mtl-D gene     

Wang Hua-fang  Zhu Yi-hong  Sun Hai-jun 《中国林学(英文版)》2006,8(4)

Idaho locust (Robinia pseudoacacia 'Idaho') is an exotic multi-purpose tree used in landscaping, soil and water conservation, fodder sources and others. To improve its drought tolerance for reclaiming arid land, five lines of transformed mtl-D gene, as osmotic regulator in plant cells, have been selected and managed to determine their drought tolerance under experimental conditions.Qualitative and quantitative variables of transformed plants were studied. The critical value of drought tolerance was determined by detecting the 2,3,5-triphenyl tetrazolium chloride (TTC) reductants in roots and soil water content (SWC). The critical value for drought tolerance was SWC 6% while for the control plants the critical SWC was 8%; a moderate level of SWC is 13% and the highest SWC for plant endurance was 18%. The method proved to be reliable and sensitive in the evaluation of drought tolerance for forest trees.  相似文献   

杉木的受害允许水平及粗鞘双条杉天牛防治策略研究     

曾垂惠  周祖基 《四川林业科技》1997,18(3):18-22

本文在９年生人工纯林中，采用固定标准地、固定标准株连续３年对树高、胸径实测的方法，计算并比较阌 害与末受害木材积及单位面积材积的 失。  相似文献   

Assessment of the accuracy and precision of the i‐Smart 30 VET Electrolyte Analyzer in dogs,cats, cattle and pigs          下载免费PDF全文

Han‐Jun Kim  Hye‐Rim Lee  Yoon‐Seo Park  Soon‐Goo Kyung  Sun Hee Do 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2015,44(3):410-419

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Prognostic Indicators for Survival and Athletic Outcome in Critically Ill Neonatal Foals     

《Veterinary Clinics of North America: Equine Practice》2015,31(3):615-628

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Preliminary Investigation of the Area Under the l‐Lactate Concentration–Time Curve (LACAREA) in Critically Ill Equine Neonates          下载免费PDF全文

P.A. Wilkins  B.J. Sheahan  K.A. Vander Werf  C. Castagnetti  J. Hardy  A. Schoster  R.C. Boston 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(2):659-662

Background

A variety of measures of l‐lactate concentration ([LAC]) in the blood of critically ill neonatal foals have shown utility as prognostic indicators. These measures, evaluating either the severity of hyperlactatemia or the duration of exposure to hyperlactatemia, perform fairly well and have correctly classified 75–80% of foals examined in several studies. The area under the l‐lactate concentration versus time curve (LAC _Area) encompasses both severity and duration of hyperlactatemia and should improve correct classification of patient survival.

Hypothesis/Objectives

LAC _Area is larger in nonsurviving critically ill neonatal foals.

Animals

Forty‐nine foals admitted for critical illness to 1 of 4 referral hospitals.

Methods

Whole blood was obtained at admission and 6, 12, 18, and 24 hours after admission for measurement of l‐lactate using a handheld lactate meter. LAC _Area was calculated for: admission–6, 6–12, 12–18, 18–24 hours, and admission–24 hours using the trapezoidal method and summing the 6‐hours interval areas to determine total 24 hours area. Differences between survivors and nonsurvivors were determined using robust regression and Kruskal–Wallis testing, P < .05.

Results

LAC _Area was significantly larger in nonsurviving foals (n = 9) than in surviving foals (n = 40) at all time periods examined.

Conclusions and Clinical Importance

Differences in LAC _Area between surviving and nonsurviving critically ill neonatal foals are large and support further investigation of this method as an improved biomarker for survival in critically ill neonatal foals is indicated.  相似文献   

Sound Pressure Levels in 2 Veterinary Intensive Care Units          下载免费PDF全文

B. Fullagar  S.R. Boysen  M. Toy  C. Makwana  D.S.J. Pang 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(4):1013-1021

Background

Intensive care units (ICUs) in human hospitals are consistently noisy environments with sound levels sufficient to substantially decrease sleep quality. Sound levels in veterinary ICUs have not been studied previously, but environmental sound has been shown to alter activity in healthy dogs.

Hypothesis

Veterinary ICUs, like those in human medicine, will exceed international guidelines for hospital noise.

Animals

NA.

Methods

Prospective, observational study performed consecutively and simultaneously over 4 weeks in 2 veterinary ICUs. Conventional A‐weighted sound pressure levels (equivalent continuous level [a reflection of average sound], the sound level that is exceeded 90% of the recording period time [reflective of background noise], and maximum sound levels) were continuously recorded and the number of spikes in sound >80 dBA were manually counted.

Results

Noise levels were comparable to ICUs in human hospitals. The equivalent continuous sound level was higher in ICU1 than in ICU2 at every time point compared, with greatest differences observed on week day (ICU1, 60.1 ± 3.7 dBA; ICU2, 55.9 ± 2.5 dBA, P < .001) and weekend nights (ICU1, 59.9 ± 2.4 dBA; ICU2, 53.4 ± 1.7 dBA, P < .0001) reflecting a 50% difference in loudness. Similar patterns were observed for the maximum and background noise levels. The number of sound spikes was up to 4 times higher in ICU1 (162.3 ± 84.9 spikes) than in ICU2 (40.4 ± 12.2 spikes, P = .001).

Conclusions and Clinical Importance

These findings show that sound in veterinary ICUs is loud enough to potentially disrupt sleep in critically ill veterinary patients.  相似文献   

Ten Years of the Nepal Ambulance Service: Successful and Sustainable Efforts     

《The Forestry Chronicle》2022,33(4):454-459

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基于老年人心理行为特征的田园养老需求及发展对策分析     

徐亮  章佳婕  王佳琪  胡牮 《绿色科技》2021,(7):20-22,25

指出了近年来我国人口老龄化日益加快,老年人的养老需求也越发呈现多元化,田园养老作为一种新型的养老方式正在逐渐兴起。如何根据老年人的心理行为特征,设计适宜的田园养老生活环境与氛围,是一项迫在眉睫的重要任务。对当前老年人的心理行为特点、田园养老认知度、田园养老需求等方面进行了详细的调查与分析,并在此基础上为田园养老模式的发展和完善提出了相应的建议。  相似文献