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91.
[目的]定位监测高产膜下滴灌制种玉米田间土壤水分动态变化,为膜下滴灌制种玉米拔节后水分管理提供理论依据.[方法]采用时域反射仪(TDR)对膜下滴灌制种玉米田间土壤水分动态变化连续监测并分析干物质的积累情况,运用水分平衡法计算膜下滴灌制种玉米各生育时期耗水量和水分生产率.[结果]拔节期至灌浆期45d左右是玉米耗水高峰期,日平均耗水强度为6.4 mm;灌浆期日耗水强度为3.2 mm.[结论]制种玉米拔节后根区的土壤体积含水量总是维持在23.5;~31.4;(田间持水量的60;~80;). 相似文献
92.
DO Gough AG Kosovichev J Toomre E Anderson HM Antia S Basu B Chaboyer SM Chitre J Christensen-Dalsgaard WA Dziembowski A Eff-Darwich JR Elliott PM Giles PR Goode JA Guzik JW Harvey F Hill JW Leibacher MJPFG Monteiro O Richard T Sekii H Shibahashi M Takata MJ Thompson S Vauclair SV Vorontsov 《Science (New York, N.Y.)》1996,272(5266):1296-1300
Global Oscillation Network Group data reveal that the internal structure of the sun can be well represented by a calibrated standard model. However, immediately beneath the convection zone and at the edge of the energy-generating core, the sound-speed variation is somewhat smoother in the sun than it is in the model. This could be a consequence of chemical inhomogeneity that is too severe in the model, perhaps owing to inaccurate modeling of gravitational settling or to neglected macroscopic motion that may be present in the sun. Accurate knowledge of the sun's structure enables inferences to be made about the physics that controls the sun; for example, through the opacity, the equation of state, or wave motion. Those inferences can then be used elsewhere in astrophysics. 相似文献
93.
A simple spawning detection and alarm system for penaeid shrimp 总被引:1,自引:0,他引:1
94.
Pancreas disease (PD) is an economically important disease of European farmed Atlantic salmon. It can cause significant losses because of morbidity, mortality and reduced production. The disease is caused by an alphavirus, known as salmon PD virus (SPDV) or salmonid alphavirus subtype 1 in Ireland. To examine whether it is possible to improve the natural resistance of Atlantic salmon to SPDV by selective breeding, 6000 genotyped, tagged, pedigreed fish from 150 full‐sib families were exposed to a natural challenge during 2005 in a sea cage on a commercial salmon farm in the West of Ireland. Histopathological and serological examination was performed weekly on a proportion of all moribund fish to determine the onset of the infection and the likely cause of death. Heritabilities and genetic correlations are presented for resistance to a natural PD challenge and smolt input weight. The results indicate that the susceptibility of salmon to SPDV could be reduced by selective breeding based on the survival in a natural challenge to the virus. 相似文献
95.
Ng'ambi JW Norris D Matebesi PA Khitsane L 《Tropical animal health and production》2006,38(7-8):597-603
Production parameters were determined for kidding, offtake and mortality rates, and milk production and composition of Angora
goats in two communal agro-ecological zones, Mountains and Lowlands, of Molimo-nthuse area in Lesotho. True incidence rates
and risk rates as used in dynamic populations were used to calculate the different production parameters. A completely randomized
design was used to compare the differences between the two agro-ecological zones. Angora goats in the two agro-ecological
zones produced milk similarly (p > 0.05) in amounts and composition. There were no significant (p> 0.05) differences in annual kidding, mortality and offtake rates between Angora goats kept in the Lowlands and those in
the Mountains. However, high mortality rates and mortality risk rates were observed in both zones. Thus, the risk rates that
suckling Angora goats would die within their first 6 months after birth were 28% and 34% for the Mountains and Lowlands, respectively.
It is suggested that future emphasis should be on reducing kid mortality through better herding of the goats and improvement
of pre- and post-partum nutrition of the doe in this communal livestock farming system. 相似文献
96.
Workplace-based assessment (WBA) is the process of directly observing students' work within a clinical setting, assessing their performance, and providing specific, goal oriented feedback. Assessment methods used for workplace-based assessment include tools developed for clinical interaction (e.g., the mini clinical evaluation exercise [mini-CEX]), for procedural or technical skills (e.g., the direct observation of procedural skills [DOPS]), and multi-source feedback tools to assess interpersonal and technical skills. While several of these assessment methods are being adopted by veterinary schools to evaluate students' progress through their clinical rotations, there is little reported at this time about their utility and effectiveness within the veterinary context. This article provides an introduction to the use of these tools and offers guidance in selecting appropriate methods for assessment in the primary health care setting. 相似文献
97.
98.
Foley JE Norris CR Jang SS 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2002,16(3):238-243
We reviewed 14 cases of paecilomycosis in a tertiary care veterinary hospital and all reports of the disease in the veterinary literature. Paecilomycosis is a rare disease primarily of dogs, horses, reptiles, and humans. Clinical manifestations in veterinary patients vary but include disseminated disease and diskospondylitis, particularly in dogs: pneumonia in dogs, horses, and reptiles; keratitis in horses; and miscellaneous local infections. It is important to have an appropriate index of suspicion because the diagnosis can be difficult, particularly in localized disease where it is difficult to determine whether a positive culture represents an etiology or a contamination with an environmental saprophyte. Spinal radiographs, transtracheal washes, histopathology, and fungal culture have proven to be valuable diagnostic tools. The prognosis for paecilomycosis is poor, although some treatment success has been reported, and success rates could improve if additional information were available regarding fungal species occurring in veterinary patients and drugs to which these fungi are susceptible. 相似文献
99.
100.
The calcium carbonate in freshwater clam shells is simlilar in purity to that designated reagent grade. A simple reprecipitation of the shell extract results in a product having less Sr and Mg than reagent grade CaCO(3). Clams are harvested commercially, and discarded shells are a high-quality raw material for the production of CaCO(3). 相似文献