氮磷添加对黑果枸杞(Lycium ruthenicum)营养器官非结构性碳水化合物特征的影响     

李金霞  朱亚男  孙小妹  韩国君  陈年来 《中国沙漠》2021,(2):200-211

非结构性碳水化合物(NSC)在植物生长、繁殖、防御和生存等方面发挥着基础性作用.为探究黑果枸杞(Lyciumruthenicum)NSC积累的器官间规律及其对土壤氮磷供应水平的响应,以3年生黑果枸杞为对象,测定了3个氮磷比例和供应量条件下根茎叶NSC含量.结果表明:(1)黑果枸杞根、茎、叶NSC组成均以可溶性糖为主,淀...  相似文献   

基于飞行阶段的精细化航空二氧化碳排放因子研究     

吕晨  刘浩  徐少东  杨楠  杜梦冰  蔡博峰 《气候变化研究进展》2022,18(2):196-204

航空运输是交通领域CO₂排放增长最快速的部门。文中选择中国民航使用频率较高的超大型、大型、中型和小型飞机的典型机型,基于不同飞机在起飞、爬升、巡航、接近和滑行阶段引擎油耗速率、运行时间和油耗量的变化,计算航空飞机CO₂排放因子。同时结合各机型碳排放因子、额定载客量与客座率评估旅客搭乘不同飞机时的人均CO₂排放量（即单位客运周转量CO₂排放因子)。结果显示,超大型飞机、大型飞机、中型飞机和小型飞机在其航程区间内的平均CO₂排放因子分别为49.8、31.7、16.2和8.5 kg CO₂/km;满载条件下单位客运周转量CO₂排放因子均值分别为102.6、95.2、81.7和112.4 g CO₂/(人∙km)。起飞和爬升阶段引擎油耗速率约为巡航阶段油耗速率的2.6~3.4倍和2.0~2.8倍,飞机CO₂排放因子随飞行里程的提高而降低。航空运输是高碳客运方式,相同里程条件下,航空单位客运周转量CO₂排放因子显著高于高铁、道路机动车等其他客运方式。提升燃油效率、减少短途航运、合理安排航线以提高客座率并减少中途转机是降低航空碳排放量的有效途径。  相似文献   

海水苦卤中可溶性糖的测定   总被引：3，自引：0，他引：3  

翁世兵  孙恢礼  李君  孙大儒  郑建禄 《热带海洋学报》2006,25(3):28-31

建立了一种海水苦卤中可溶性糖的测定方法。研究确定了苯酚-硫酸法测定海水苦卤样品中可溶性糖的最佳实验条件。在加入苯酚60mg、90℃水浴加热20min的条件下,显色体系在490nm处的吸光度达到最佳值,糖的浓度在1—100μg.ml-1范围内符合比尔定律,线性相关系数为0.999 7。该方法具有简便、快速、稳定性好、干扰因素少的特点,且样品基本无需预处理。用所拟方法对广东省徐闻县盐场制盐苦卤中的可溶性糖进行测定,相对标准偏差为1.73%(n=6),加标回收率在94.80%—102.70%之间,结果满意。应用该方法还成功测定了生态型人工海水添加剂———苦卤提取物中糖的含量。  相似文献   

青岛地区大气沉降物中碳水化合物初步研究   总被引：1，自引：0，他引：1  

张再峰  任素梅  张经 《海洋科学》1994,18(3):49-53

青岛地区大气沉降物中溶解态碳水化合物平均浓度为３．３ｍｇ／Ｌ，明显高于河水与海水。１９９１年６－１２月ＤＣＨＯ通过大气向海洋输送的通量为８４０．９ｍｇ／ｍ＾２，ＤＣＨＯ浓度与降雨量呈岁相关，且ＤＣＨＯ浓度及沉降量的季节变化明显。酸雨使得ＤＣＨＯ浓度升高，改变了碳水化合物在液固相间的分配。  相似文献   

Effects of desertification on the body temperature, activity and water turnover of Angora goats     

R.S. Hetem  B.A. de WittL.G. Fick  A. FullerS.K. Maloney  L.C.R. MeyerD. Mitchell  G.I.H. Kerley 《Journal of Arid Environments》2011,75(1):20-28

Globally, pastoral practices have transformed habitats, which often lead to desertification. With climate change predicted to exacerbate desertification, adaptation provides the best survival strategy for agriculturally important herbivores. We investigated body temperature, water turnover, physical activity and microclimate selection of Angora goats inhabiting transformed and intact sites in the Eastern Cape Province, South Africa. Although goats on both sites responded similarly under most environmental conditions, when goats were subjected to a thermal stress, imposed by shearing, those inhabiting the transformed site had a faster rate of rise in abdominal temperature (0.38 versus 0.31 °C h⁻¹, P = 0.0009), displayed an increased 24-h abdominal temperature amplitude (1.8 versus 1.6 °C, P = 0.01) and were generally less active (3.9 versus 5.2 activity units) compared to goats inhabiting the intact site. Post-shearing, goats inhabiting the transformed site had higher water turnover rates (P < 0.0001) and selected more variable microclimates (P < 0.0001) than goats inhabiting the intact site, despite obtaining less water from their diet (P = 0.01). Goats inhabiting the transformed site were more water dependent and more susceptible to thermal stresses in their environment than were those inhabiting the intact site. Coping with thermal challenges will be essential for Angora goats if the mohair industry is to thrive under future climate change scenarios.  相似文献   

Cold-season soil respiration in response to grazing and warming in High-Arctic Svalbard     

Ditte Strebel  Bo Elberling  Elke Morgner  Heike E. Knicker  & Elisabeth J. Cooper 《Polar research》2010,29(1):46-57

The influence of goose grazing intensity and open-topped chambers (OTCs) on near-surface quantities and qualities of soil organic carbon (SOC) was evaluated in wet and mesic ecosystems in Svalbard. This study followed up a field experiment carried out in 2003–05 (part of the project Fragility of Arctic Goose Habitat: Impacts of Land Use, Conservation and Elevated Temperatures). New measurements of soil CO₂ effluxes, temperatures and water contents were regularly made from July to November 2007. SOC stocks were quantified, and the reactivity and composition measured by basal soil respiration (BSR) and solid-state ¹³C nuclear magnetic resonance (NMR) spectroscopy. Results reveal variations in soil carbon cycling, with significant seasonal trends controlled by temperature, water content and snow. Experimental warming (OTCs) increased near-surface temperatures in the growing season, resulting in significantly higher CO₂ effluxes. Different grazing intensities had no significant effects on observed soil respiration, but BSR rates at the mesic site (13–23 µg CO₂ g soil-C⁻¹ h⁻¹) were highest with moderate grazing and lowest in the absence of grazing. A limited effect of grazing on microbial respiration is consistent with a lack of significant differences in SOC quantity and quality. NMR data show that the composition of A-horizon SOC is dominated by O-N-alkyl C and alkyl C groups, and less by carboxyl C and aromatic C groups: but again no marked variation in response to grazing was evident. It can be concluded that two years after a goose grazing experiment, SOC cycling was less than the natural variation within contrasting vegetation types.  相似文献   

Distribution,inventory and turnover of benthic organic biomass in the Strait of Georgia,Canada, in relation to natural and anthropogenic inputs     

《Marine pollution bulletin》2014,83(1-2):155-166

Recently compiled databases facilitated estimation of basin-wide benthic organic biomass and turnover in the Strait of Georgia, an inland sea off western Canada. Basin-wide organic biomass was estimated at 43.1 × 10⁶ kg C and production was 54.6 × 10⁶ kg C yr⁻¹, resulting in organic biomass turnover (P/B) of 1.27 × yr⁻¹. Organic biomass and production for sub-regions were predictable from modified organic flux (r² > 0.9). P/B declined significantly with increasing modified organic flux, suggesting greater biomass storage in high flux sediments. Biomass and production were highest, and P/B lowest near the Fraser River. Annual basin-wide benthic production was 60% of previously estimated oxidized organic flux to substrates, which agrees with proportional measurements from a recent, localized study.Deviations from expected patterns related to organic enrichment and other stressors are discussed, as are potential impacts to benthic biomass and production, of declining bottom oxygen, increasing bottom temperature and potential changes in riverine input.  相似文献   

Distribution and abundance of demersal fish from trawl stations in the bay of plenty,New Zealand, 1961–63     

L. J. Tong  R. D. Elder 《新西兰海洋与淡水研究杂志》2013,47(1):49-66

Between March 1961 and January 1963 trawling surveys were carried out in the Bay of Plenty. Seasonal comparisons of catch weight were made for the four commercially important species, snapper, tarakihi, trevally, and gurnard, during 1962–63. Only trevally showed any marked seasonal variation in total catch. Tarakihi were most abundant in waters over 50 fathoms and snapper, trevally, and gurnard were most abundant in shallower depths. The best return for fishing effort came from the middle sector of the Bay. There was a marked absence of undersized tarakihi and trevally from the catches. A species composition list for the Bay of Plenty waters and a table of species abundance at the stations sampled has been compiled from the trawl catch data.  相似文献   

Lake Lucerne, Switzerland, a long term study of 1961-1992   总被引：1，自引：0，他引：1  

Heinrich Bührer  Heinz Ambühl 《Aquatic Sciences - Research Across Boundaries》2001,63(4):432-456

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塔北、塔中天然气中烷烃同系物碳同位素组成系列倒转现象的解释   总被引：4，自引：0，他引：4  

王国安  申建中  何宏  季美英 《沉积学报》2002,20(3):482-487

塔里木盆地塔北、塔中地区天然气中烷烃气碳同位素组成序列存在着局部倒转现象,通过对此的研究和解释,初步认为塔北、塔中天然气中的烷烃气可能是以有机成因气为主;轮台构造单元天然气烷烃系列的δ13C3＞δ13C4倒转可能是混入了偏腐泥型的烷烃气体;轮南低凸起构造单元的天然气烷烃同系物碳同位素组成序列正常,天然气来源单一;塔中地区天然气按CH₄和C₂H₆的碳同位素组成特征可分成两组,可能代表了两种不同的成因类。  相似文献