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E. N. Bermingham K. Weidgraaf M. Hekman N. C. Roy M. H. Tavendale D. G. Thomas 《Journal of animal physiology and animal nutrition》2013,97(3):522-530
There is little information known about the energy requirements of cats in temperature climates. Energy requirement of domestic short‐haired cats was determined using three groups of mixed gender – old kept outside (approximately 9.9 years of age; 4.8 kg; n = 9), young kept outside (approximately 3.1 years of age; 3.9 kg; n = 8) or young kept inside (approximately 3.1 years of age; 3.9 kg; n = 8). Cats were housed individually for 5 weeks during summer (18.5 ± 0.5 °C) and winter (8.5 ± 0.4 °C) and were fed a commercially available maintenance diet ad libitum. In both periods, energy expenditure was determined from the rates of 2H and 18O elimination for blood H2O over a 12 day period, from a doubly labelled water bolus 2H2O (0.7 g/kg BW) and H218O (0.13 g/kg BW) administered intravenously. During the summer period, macronutrient digestibility was determined. Older cats had a reduction (p < 0.05) in apparent digestibility of dry matter (approximately 9%), energy (approximately 8%) and protein (6%). There was a significant effect of age and season on energy intake and energy expenditure. While lean mass was affected by age and season, there was no effect of age or season on energy expenditure when expressed as a proportion of lean mass. Possible seasonal differences in nutrient digestibility may explain these results. 相似文献
74.
休宁县21个乡镇的人居环境水平的评价结果表明:休宁县人居环境整体综合水平不高,且乡镇之间差异较大,全区呈现“中部凸起,外围凹陷”的空间分布格局。因而不同水平人居环境应实施差异化的优化策略,高水平区域应协调各个子系统实现全面提升,较高水平区域应注重建设用地的集约性,较低水平区域应着力于发展特色产业带动经济增长,低水平区域可以选择异地搬迁、发展生态农业。 相似文献
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76.
Seasonal changes in respiration rates of copepodite stage V Calanus finmarchicus (Gunnerus) 总被引:1,自引:0,他引:1
Copepodite stage V Calanus finmarchicus were collected at locations on the continental shelf north of Scotland, in the Faroe–Shetland Channel and west of Ireland on six occasions covering winter, spring and summer from October 1993 to June 1995. Oxygen consumption by the overwintering and active spring/summer population of animals was determined at temperatures close to in situ temperatures. Laboratory measurements of oxygen consumption were also made at standardized temperatures (0°C, 5°C, 7°C and 12.5°C) to determine the sensitivity of animals to temperature change in the different seasons. Rates of oxygen consumption were very low (7–30 μmol O2 gC−1 h−1 ) at in situ temperatures during the winter and early spring and significantly higher (105–219 μmol O2 gC−1 h−1 ) for the active surface population in May and June. Animals collected from the overwintering population showed no significant response to changes in temperature. Due to the low respiration rates, the calculated rate of decrease in carbon content in diapausing copepodite stage CV was very low (approximately 0.250 μgC day−1 ). The respiration rates were used to construct a model to estimate survival of the animals with an initial carbon content equivalent to that expected of animals in October. The results showed that in order to survive during winter and have enough energy for moulting and migration to the surface in the spring, these animals have to live at temperatures close to 0°C and be in a diapause state. 相似文献
77.
基于2018—2020年浙江省龙泉市900宗活立木交易数据,采用半对数多元线性回归模型研究木材市场价格、单位面积蓄积、林分质量等因素对活立木交易价格的影响。结果表明,龙泉市活立木交易平均价格为3 976元/hm2,木材市场价格、单位面积蓄积、单位面积株数、平均胸径对活立木交易价格有显著的正向影响;流入方性质和流出方性质对活立木交易价格有显著影响,且影响存在差异性。提出规范木材市场交易,加强森林资源评估工作,提升交易的公平性,全面推进林权抵押贷款等建议。 相似文献
78.
农村居民消费支出水平和结构的变化,可在一定程度上反映农村居民的生活质量和生活水平的状况。以天津市为例,根据2002—2012年天津市农村居民消费统计数据,从消费水平和消费结构两个角度对农村居民的消费变化特点和趋势进行了分析。从消费水平上看,近10年天津市农村居民总体消费水平呈现快速增长态势,10年间增长了2.85倍,平均年增长率达到14%以上;从消费结构上看,人均食品、衣着、居住的生存型消费支出都趋于下降或持平的状态,但三者之和所占支出比例超过了60%,而人均家庭设备及用品、交通通信、文教娱乐和医疗保健等享受型消费支出出现了快速增长的势头。 相似文献
79.
《Wood material science & engineering》2013,8(3-4):118-129
Abstract Twist in wood, being closely related to spiral grain, may cause serious problems in building structures, furniture and joinery. It is therefore of great interest to sort out, at an early stage in the manufacturing process, trees, logs and boards that have an excess of spiral grain. The spiral grain pattern is described by a helical deviation of the fibre direction in relation to the longitudinal direction of a living tree or a log and seems to be an indicator for other defects such as compression wood. Remote microwave sensing of spiral grain has received a lot of interest during the past two decades. Its development has been impeded by the large variation with moisture content of the microwave properties of wood and by the complexity in modelling the electromagnetic field in a log with spiral grain. A review is presented of a direct method with no requirement for information on moisture content for boards. This procedure has recently been generalized to cylindrical logs and trees having a constant slope of the grain. A further generalization is presented here to allow for the normal spiral grain pattern with radially changing slope of grain in wood under bark. Based on this theory, a measurement procedure is proposed for the detection of wood grain angle with radial dependence, requiring no information on moisture content in the sapwood, which is also applicable to completely or partially frozen wood. A suitable application would be an instrument to use in the forest for measurements on living trees or logs. 相似文献
80.
中亚鸢尾的花粉生活力及其授粉 总被引:6,自引:0,他引:6
以野生中亚鸢尾(Iris bloudowii)为试材,在一天不同时间采集花粉测定其生活力;同一时间采集花粉,测定花粉的贮藏能力;在一天的不同时间对去雄套袋的花朵进行人工异花授粉,测定最佳授粉时间;用套袈的方法测定该物种自花授粉是否结实。初步得出结论:当花朵开放后,随着时间的延长,花粉生活力逐渐下降;花粉贮藏时间在24h之内,能保持较强的生活力;最佳授粉时间在上午12时左右;初步测定:中亚鸢尾是自花授粉不亲和性植物。 相似文献