基于虚拟仪器的湿增压实验台测控系统研究     

陈景锋  蒋德松 《安徽农业技术师范学院学报》2007,21(6):38-43

本文以湿增压动力装置实验台为物理模型，为进行相关实验完成了速度、流量、扭矩等重要参数的测量，并以N16221硬件为基础，基于虚拟仪器平台LabVIEW研制了实验台的测试软件。新设计的测试系统是基于虚拟仪器平台的模块化系统，使得研究人员的大部分精力集中于所要实现的功能上，而不是以往繁琐的算法和重复的编程上，参数易于修改，缩短了系统开发的周期，能满足实验需求。  相似文献   

Proceedings of the International Congress on Applied Ethology in Farm Animals,Kiel 1984: J. Unshelm,G. van Putten and K. Zeeb (Editors), KTBL,Bartningstr. 49, D-6100 Darmstadt 12, W. Germany, 1984, 428 pp., DIN A5, 80 tables, 69 figures,price 30 DM     

H. De Boer 《Livestock Production Science》1985,12(4):389

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The cost of Euphytica     

H. De Haan 《Euphytica》1962,11(1):87-94

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Spatial variability and change in soil organic carbon stocks in response to recovery following land abandonment and erosion in mountainous drylands     

S. De Baets  J. Meersmans  V. Vanacker  T. A. Quine  K. Van Oost 《Soil Use and Management》2013,29(1):65-76

This research investigates the impact of human activities on carbon (C) dynamics in a mountainous and semi‐arid environment. Despite the low C status of drylands, soil organic carbon (SOC) is the largest C pool in these systems and therefore may offer significant C sequestration potential in systems recovering from degradation. Nevertheless, quantification of this potential is limited by lack of knowledge concerning the magnitude of and controls on regional SOC stocks. Therefore, this study aimed to (i) investigate the variability of soil organic carbon in relation to recovery period and key soil and topographical variables, and (ii) quantify the effects of recovery period following abandonment on SOC stocks. Soil profiles were sampled in the Sierra de los Filabres (southeast Spain) in different land units along geomorphic and degradation gradients. SOC contents were modelled using recovery period and soil and topographical variables. Sample depth, topographic position, altitude, recovery period and stone content were identified as the main factors for predicting SOC concentrations. SOC stocks in 1 m depth of soil varied between 3.16 and 76.44 t/ha. Recovery period (years since abandonment), topographic position and altitude were used to predict and map SOC stocks in the top 0.2 m. The results show that C accumulates rapidly during the first 10–50 yr following abandonment; thereafter, the stocks evolve towards a steady‐state level. The erosion zones in the study area demonstrate greater potential to increase their SOC stocks when abandoned. Deposition zones have greater SOC values, although their C accumulation rate is lower compared with erosional landscapes in the first 10–50 yr following abandonment. Therefore, full understanding of the C sequestration potential of land use change in areas of complex topography requires knowledge of spatial variability in soil properties and in particular SOC.  相似文献   

Comparison of the persistent activity of ivermectin, abamectin, doramectin and moxidectin in cattle in Zambia     

P.F.M. Meeus  J. De Bont  J. Vercruysse 《Veterinary parasitology》1997,70(4):176-224

The persistent efficacy of four commercially available macrocyclic lactones (ML) in maintaining reduced faecal egg counts in cattle grazing naturally infested pastures was evaluated in 44 zebu animals aged 1–2 years in Zambia. The study started in February (rainy season) when the strongyle egg output was increasing. Four days before the start of the trial, all animals were treated with a double dose of oxfendazole. They were then divided into five groups which were again treated on day 0. Groups A, D, I and M received 0.2 mg kg⁻¹ of abamectin, doramectin, ivermectin and moxidectin, respectively. Animals of group C received albendazole (7.5 mg kg⁻¹). Faecal samples were collected twice a week for egg counts and larval differentiation. Faecal egg counts in the C group increased from day 21 onwards and plateaued from day 42 between 180 and 380 eggs per gram. The main genera found in cultures were Cooperia (90%) and Haemonchus (7%). Faecal egg excretion in groups M, A, D and I started on day 35, 42, 42 and 45, respectively. subsequently and until day 84, average counts in these four groups were always significantly lower than in group C. Compared with albendazole, all four ML gave over 95% reduction in cumulative faecal egg counts for 42 days after treatment. The percentage efficacy was still over 84% by day 84 when an average cumulative egg count of 11 320 eggs per gram faeces was calculated in group C. In addition, there was no significant difference in efficacy between the four ML groups at any of the sampling dates. During the trial no significant difference in weight gain between any of the groups was observed.  相似文献   

Gas chromatographic-mass spectrometric confirmation of 19-nortestosterone in the urine of untreated boars--effect of the administration of Laurabolin     

G Debruyckere  C Van Peteghem  H F De Brabander  M Debackere 《The Veterinary quarterly》1990,12(4):246-250

The presence of 17 beta-19-nortestosterone (nandrolone, NT, 17 beta-19-NT) and its epimer 17 alpha-19-nortestosterone (epiNT, 17 alpha-19-NT) was investigated in the urine of six untreated boars, obtained from experimental farms. The presence of 17 beta-19-nortestosterone was screened by RIA and HPTLC and confirmed by GC-MS analysis. Additionally, the two epimers (NT and epiNT) were investigated in the urine of a boar (two-year-old miniature male pig weighing 50 kg) before and after injection of 100 mg Laurabolin (nortestosterone laurate, Intervet N.V., Belgium). The isolation of the steroids was based on sample clean-up with solid phase extraction and subsequent high-performance liquid chromatography. Both gas chromatographic retention data and mass spectrometric data (selected ion monitoring and full spectrum) were used for detection and identification. The presence of 17 beta-19-nortestosterone in the urine of the boars that were not injected proves the endogenous production of the steroid. The absence of the 17 alpha-epimer in the urine of the injected boar suggests that 17 alpha-19-nortestosterone is not a major metabolite of 17 beta-19-nortestosterone.  相似文献   

Haemodynamic changes during sedation in ponies     

F. Gasthuys  A. De Moor  D. Parmentier 《Veterinary research communications》1990,14(4):309-327

The cardiovascular changes induced by several sedatives were investigated in five ponies with a subcutaneously transposed carotid artery by means of cardiac output determinations (thermodilution technique), systemic and pulmonary artery pressure measurements (direct intravascular method) and arterial blood analysis (blood gases and packed cell volume). The cardiovascular depression (decrease in systemic blood pressure and cardiac output) was long lasting (greater than 90 min) after administration of propionylpromazine (0.08 mg/kg intravenous (i.v.)) together with promethazine (0.08 mg/kg i.v.). The phenothiazine-induced sedation was not optimal. alpha 2-Agonists (xylazine (0.60 mg/kg i.v.) and detomidine (20 micrograms/kg i.v.)) induced initial but transient cardiovascular effects with an increase in systemic blood pressure and a decrease in cardiac output for about 15 min. Second degree atrioventricular blocks and bradycardia were seen during this period. The cardiovascular depression was more pronounced during detomidine sedation. Atropine (0.01 mg/kg i.v.) induced a tachycardia with a decrease in stroke volume but did not alter the cardiac output or other cardiovascular parameters. It prevented the occurrence of the bradycardia and heart blocks normally induced by xylazine or detomidine. Atropine potentiated the initial hypertension induced by the alpha 2-agonistic sedatives (especially detomidine). The decrease in cardiac output induced by xylazine, and to a lesser extent by detomidine, was partially counteracted when atropine was given in advance. The atropine-xylazine combination seemed the best premedication protocol before general anaesthesia as it only resulted in minor and transient cardiovascular changes.  相似文献   

Purification and relationships of some filamentous viruses from apple     

O A De Sequeira  R M Lister 《Phytopathology》1969,59(11):1740-1749

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Immunological Profile in Clinical Practice     

Pugliese  A.  De Majo  M.  Pugliese  M. 《Veterinary research communications》2007,31(1):121-124

Veterinary Research Communications - Pugliese, A., De Majo, M. and Pugliese, M., 2007. Immunological profile in clinical practice. Veterinary Research Communications, 31(Suppl. 1), 121–124  相似文献   

家禽肠道螺旋体病     

Koen De Gussem  Vereecken  陈晓清 《国外畜牧学(猪与禽)》2009,29(5):52-53

家禽肠道螺旋体病Avain Intestinal spirochaetosis，AIS）被普遍认为是家禽生产中一个越来越严重的疾病。本病由多种螺旋体引起。螺旋体为一类外形呈螺旋状的细菌，它们主要定殖在大多数哺乳动物和家禽（包括猪、人类和家禽）的大肠中。  相似文献