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试验结果表明 ,温室后墙悬挂反光膜进行补光后 ,对温室内测定点处最大光照度值无影响 ,但平均提高测定点处水平光照度值 15 4 8% ;温室内凌晨时气温、地温、墙温和被反光膜遮掩处墙温分别比对照温室低 1 1℃、1 5℃、0 9℃和 1 8℃ ,但正午时分别比对照温室高 1 6℃、1 4℃、0 3℃和低 11 4℃。温室经济产量增加 7 4 % ,当期经济效益增加 2 1元 /m2 。 相似文献
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不同栽培模式及施氮量对半旱地冬小麦氮素累积及分配的影响 总被引:6,自引:0,他引:6
【目的】研究不同栽培模式和施氮量对半旱地栽培条件下冬小麦-夏玉米轮作体系中冬小麦地上部氮素累积、分配及利用效率的影响。【方法】在陕西关中地区进行了田间试验,以常规栽培为对照,比较了补灌、覆草和垄沟等栽培模式及0,120,240 kg/hm2施氮水平,对冬小麦连续2年(2004和2005年)不同生长期各部位氮素累积量的影响。【结果】在补灌模式下,2004和2005年成熟期冬小麦叶片和茎秆的氮素累积量较其他模式低,氮素分配率也较低,而籽粒的氮素分配率较高;施用氮肥显著增加了各生长时期冬小麦叶片、茎秆、颖壳和穗轴以及籽粒的氮素累积量,当氮肥施用量由120增加到240 kg/hm2时,除籽粒外,成熟期冬小麦叶片、茎秆、颖壳和穗轴的氮素残留量均随之明显增加。与不同栽培模式相比,施用氮肥对冬小麦不同器官中氮素分配的影响较小。随着氮肥施用量的增加,氮肥利用效率、氮肥农学效率和氮肥生理效率均呈降低趋势。在不同栽培模式中,连续2年补灌栽培模式下冬小麦的氮肥利用效率、氮肥农学效率以及氮肥生理效率均较高,而其他栽培模式下这3个指标年际间的变化较大。【结论】施用氮肥可显著增加冬小麦各生长时期不同器官的氮素累积量,但对氮素在不同器官中分配比例的影响较小;与施用氮肥相比,不同栽培模式对冬小麦氮素的累积、分布无明显影响;冬季补灌有利于提高冬小麦的氮素效率。 相似文献
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Neer TM Breitschwerdt EB Greene RT Lappin MR 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2002,16(3):309-315
Within the past several decades, the number of Ehrlichia spp. recognized to infect cats, dogs, and human beings has expanded substantially. The recent application of advanced techniques in molecular biology has changed how ehrlichiosis is diagnosed and has provided new tools for the assessment of treatment. As these techniques are applied, the numerous questions that relate to the management of dogs and cats with ehrlichiosis ultimately will be answered. We hope this consensus statement will assist veterinarians in the management of their patients. 相似文献
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Christine V Fiorello Mark W Cunningham Shauna L Cantwell Julie K Levy Erin M Neer Kenneth Conley Paul M Rist 《Journal of zoo and wildlife medicine》2007,38(2):317-322
A free-ranging, adult male Florida panther (Puma concolor coryi) was immobilized and evaluated for hematuria following routine capture. Prior to anesthetic recovery, the panther was fitted with a telemetry collar. After an initially quiet recovery, the panther began thrashing in the transport cage, and was again immobilized. Pink foam was evident from the nostrils, and crackles were ausculted over the chest, indicating pulmonary edema. Postobstructive pulmonary edema was diagnosed based on history, clinical signs, radiographic evaluation, and blood gas analysis. The animal was treated intensively for several hours with diuretics, oxygen, and manual ventilation. The panther responded rapidly to therapy and was released back into the wild 48 hr after presentation. Postobstructive pulmonary edema, also called negative-pressure pulmonary edema, may be underrecognized in veterinary medicine. In this case, the telemetry collar, in conjunction with anesthetic recovery in a small transport crate, may have contributed to tracheal obstruction. Wildlife veterinarians and biologists should be aware of the risk of airway obstruction when placing tracking collars, and animals should be continuously monitored during anesthetic recovery to ensure the presence of a patent airway. 相似文献
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Effects of Body Condition and Protein Supplementation on LH Secretion and Luteal Function in Sheep 总被引:1,自引:0,他引:1
CA Meza-Herrera T Ross D Hallford D Hawkins A Gonzalez-Bulnes 《Reproduction in domestic animals》2007,42(5):461-465
In ruminants, nutrition is one of the exogenous inputs affecting reproductive function at different levels of the hypothalamic-hypophyseal-gonadal axis. However, the exact mechanisms or even the identification of the signalling metabolic compounds by which nutrition affects reproductive function still need further clarification. The role of static body condition (BC) and its interaction with a short-term protein supplementation (PL), on secretion of metabolic hormones [growth hormone (GH), insulin and insulin-like growth factor-1 (IGF-1)], as well as on secretion of LH and progesterone (P4) was evaluated in sheep. Twenty-four Rambouillet ewes divided into two groups, with lower (LBC) and higher body condition (HBC), were randomly assigned within BC to one of two PL levels: low (LPL, 24% of crude protein; 14 g/animal/day), and high (HPL, 44% of crude protein; 30 g/animal/day). The secretion of GH, insulin, IGF-1 and LH was evaluated on day 10 of the oestrous cycle; appearance and timing of oestrous behaviour were previously detected using rams. Progesterone secretion was evaluated on day 13 of the same cycle. No differences were found (p > 0.05) between PL groups on serum GH concentrations during the sampling period (overall mean of 4.0 +/- 0.3 ng/ml), but a trend for lower values in HBC sheep was found (3.6 +/- 0.4 vs 4.4 +/- 0.4 ng/ml, p = 0.06). A BC effect was observed (p < 0.05) on serum IGF-1 level, with higher values in HBC sheep (p < 0.05). Neither BC nor PL affected (p > 0.05) secretion of LH and the number of corpora lutea, nor serum P4 and insulin concentrations. Results indicate a predominance of the static component of nutrition on sheep metabolic hormone responses, GH and IGF-1, with no effect of short-term PL on secretion of pituitary and ovarian hormones as well as luteal number and activity. 相似文献