OP技术在微机监控系统中的应用     

张琦黄成果  臧海霞c 《中国农村水利水电》2008,(5):133-135

介绍了水电站计算机监控系统的结构、软硬件配置、硬件通讯和系统功能,结合广西保明水电站实际,着重分析了OPC技术在水电站微机监控系统中的应用。OPC标准的制订,使得所有的通信连接问题变得简单,它提供了一种软件的总线形式,使得应用变得简单、轻巧、易于使用。应用程序只需知道如何从OPC数据源获取数据(OPC Client),设备的驱动程序只需知道如何以简单的格式提供数据(OPC Server)即可进行通信。采用基于OPC的接口通讯技术,使各种设备与上位机的数据通讯变得非常简单。在进行小水电站计算机监控系统的设计时,应综合可靠性、灵活性、先进性和投资规模等因素,根据小水电站自身的地位及特点加以考虑,以便选择适合小水电站的计算机监控系统。  相似文献   

烟草赤星病拮抗细菌Ata28菌株的诱变选育     

chgxiao@swau.cq.c 《中国农学通报》2006,22(5):377-377

（西南大学植物保护学院,重庆 400716）  相似文献   

贵州母岩（母质）对土壤类型及分布的影响   总被引：1，自引：0，他引：1  

黄会前a  何腾兵ab  牟力c 《浙江农业科学》2016,1(11):1816

岩石是形成土壤母质的原始物质。为了更深入地了解贵州母岩（母质）对贵州土壤类型及分布的影响,通过收集整理相关文献和资料,归纳总结母岩（母质）类型及其对贵州土壤类型的影响。结果表明,不同母质类型可形成不同的土类及亚类,如石灰土、紫色土。同一母质类型亦可形成不同类型的土壤,如砂页岩在不同的生物气候条件下可形成黄红壤、黄壤及黄棕壤。贵州碳酸盐岩母质与非碳酸盐岩母质（砂、页岩）相间带状分布,使贵州地带性土壤与非地带性土壤交错分布。  相似文献   

长季节岩棉栽培中番茄的叶片生长特性   总被引：2，自引：0，他引：2  

李亚灵  stangh.c 《山西农业大学学报(自然科学版)》1999,19(3):214-217

本文就长季节岩棉栽培中番茄叶片的生长特性进行了细致的观察及深入的研究, 认为番茄第一果穗下的基生叶, 光合养分主要用于自身建设, 随叶位提高叶片面积增大, 二者呈显著正相关（Ｒ２ ＝ ０－９９） 。两果穗之间的三片叶中以果穗上的第一叶叶面积较小, 这主要表现在叶宽的差异上, 而叶长相差不大, 这是由于养分竞争影响了叶宽的扩展而造成的。果穗之间充分成熟的叶片, 叶形比小于１ , 即叶长小于叶宽。而未充分成熟的叶片, 叶面积随叶位上升而减小, 并且叶形指数在增大, 表明叶长生长先于叶宽。在植株的整个生长期间, 最大的叶片通常出现在１ ～５ 穗果之间（ 第１０ ～２５ 片叶之间） , 这与前期座果少、冠层未封闭、见光好有关。叶片的这些生长特性受营养液组成（ＥＣ＝ １０ｄｓ／ｍ） 及蒸腾势处理的影响较小  相似文献   

Failed attempt of Cryptosporidium andersoni infection in lambs     

Kvác M  Ditrich O  Kouba M  Sak B  Vitovec J  Kvetonová D 《Folia parasitologica》2004,51(4):373-374

Four lambs 4 months old were inoculated with Cryptosporidium andersoni oocysts (bovine isolate) in a dose of 5 x 10(6) per animal followed later by 1 x 10(7) oocysts per animal. No animal shed Cryptosporidium oocysts during 56 days post infection, no lamb showed clinical symptoms of cryptosporidiosis and no macroscopic changes were detected in the abomasum immediately after autopsy. Histological examinations did not demonstrate the occurrence of Cryptosporidium in the abomasum and other selected organs.  相似文献   

Study of immune response in pigs fed with high vitamin E-dosages     

Mudron P  Levkut M  Revajová V  Kovác G 《DTW. Deutsche tier?rztliche Wochenschrift》2000,107(10):411-414

The effects of long-term vitamin E-supplementation on phagocytic cells, lymphocyte sub-populations, and SWC3+ cell count were studied in pigs. Eighteen weaned pigs were divided into three groups: 1) 100 mg DL-alpha tocopheryl acetate/kg diet, 2) 200 mg DL-alpha tocopheryl acetate/kg diet, 3) control group (basic feed with 10 mg DL-alpha tocopheryl acetate/kg diet). The examination of the immune indices was performed on day 120 of feeding the supplemented diets. The higher dietary levels of vitamin E resulted in increased serum concentration of alpha-tocopherol for both experimental groups (p < 0.05) and there were no significant differences in counts of CD2+, CD4+, CD8+, B lymphocytes nor SWC3+ cells among the groups. Similarly, vitamin E supplementation did not affect the functions of phagocytic cells tested.  相似文献   

The urinary excretion of selenium in sheep treated with a vasopressin analogue     

Leng L  Boldizárová K  Faix S  Kovác G 《Veterinary research》2000,31(5):499-505

The renal excretion of selenium was investigated in ewes with an excretion of hypotonic urine (control group) and in ewes with a formation of highly concentrated urine. Chronic stimulation of the urinary concentrating activity of sheep kidneys was induced by a long-term treatment with 1-desamino-8-D-arginine vasopressin (dDAVP), a synthetic analogue of vasopressin with prolonged effects. Young animals with 22 to 25 kg b.w. were fed a normal protein diet providing a daily intake of 129.25 g of crude protein, 12.03 MJ of digestible energy and 0.18 mg of selenium for 3 weeks. The vasopressin treated sheep (n = 11) were given subcutaneous injections of 12.5 micrograms of dDAVP in glycerol twice daily for one week before the clearance measurement of renal functions. The control group (n = 11) was treated with glycerol only. The administration of dDAVP resulted in a highly significant decrease of the urinary flow rate (from 3.19 +/- 0.50 in control group to 0.33 +/- 0.03 mL.min-1 in dDAVP animals, P < 0.001) without changes in the glomerular filtration rate (80.18 +/- 6.36 in controls vs. 77.86 +/- 6.26 mL.min-1, NS). No effects on plasma selenium level were observed (0.17 +/- 0.03 in controls vs. 0.20 +/- 0.03 mumol.L-1, NS) but the amounts of selenium excreted were found to be highly significantly reduced (from 0.29 +/- 0.05 in controls to 0.03 +/- 0.01 nmol.min-1, P < 0.001) in dDAVP treated sheep. Despite a large reduction in urinary flow rate, the selenium concentration in urine was actually the same in both groups (0.09 +/- 0.01 mumol.L-1) resulting in a sharp fall in the renal clearance of selenium (2.20 +/- 0.54 in controls vs. 0.18 +/- 0.03 mL.min-1, P < 0.01) due to dDAVP. This seems to be a consequence of the large increase in the selenium solvent drag induced by a vasopressin treatment. The results presented suggest that vasopressin may contribute to maintenance of the selenium balance in sheep via its effects on renal function.  相似文献   

First report of Enterocytozoon bieneusi infection on a pig farm in the Czech Republic     

Sak B  Kvác M  Hanzlíková D  Cama V 《Veterinary parasitology》2008,153(3-4):220-224

Enterocytozoon bieneusi infects humans and animals and can cause life-threatening diarrhea in immunocompromised people. The routes of transmission and its zoonotic potential are not fully understood. Pigs have been frequently reported to have E. bieneusi; therefore, we surveyed farm-raised pigs in the Czech Republic to determine its presence and genetic diversity. Spores were detected by microscopy in the faeces of 65 out of 79 examined animals (82%). A species-specific polymerase chain reaction (PCR) identified E. bieneusi in 94% of samples. Genotyping based on the ITS regions of the SSU rRNA gene identified that most pigs were infected with the species-specific genotype F, while two animals had the zoonotic genotype D and two had genotype Peru 9. This is the first report of E. bieneusi in swine in the Czech Republic, and demonstrated that most infections were with pig-specific genotypes. Nonetheless, swine may still play a role in the transmission of E. bieneusi to humans.  相似文献   

浅析荆岳长江公路大桥对河势及防     

石波堂唐昌焕  黎前查c 《中国农村水利水电》2007,(7):99-101

荆岳长江公路大桥桥位选址于湖南、湖北两省境内的城陵矶至螺山河段中的白螺矶附近，而城螺河段历来是长江上防最敏感的河段。研究大桥的建设对该河段的河势及防洪的影响以及如何将影响程度减小到最低是一项非常重要的工作。根据模拟各参数建立的数学模型实验，对设计提出的该河段不同的桥位和桥型结构形式进行计算分析，为大桥的建设最大限度地减小对该河段河势及防洪的影响提供了科学的依据；同时，对如何减小桥梁建设对河势和防洪的影响提出了合理化建设，以利于大桥设计部门和建设单位对桥位和桥型的结构形式进行进一步优化。  相似文献   

U形渠道断面测流及流速分布试验   总被引：1，自引：1，他引：1  

郝红科  贺军奇  雷新利c 《中国农村水利水电》2006,(8):113-115

从试验的角度使用断面测流方法，针对三种不同规格的U形渠道测量断面流速分布，运用数学拟合方法，探求U形渠道流速分布规律，并分析出了相应的U形渠道过水断面流量的积分求和公式，以求对以后的U形渠道量水工作有所帮助。  相似文献