共查询到20条相似文献,搜索用时 15 毫秒
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在现代建筑节能体系中,暖通空调系统具有十分重要的作用。节能技术之研究与运用,是暖通空调系统节能的组成部分之一,而政府部门的关心与重视,则能充分节能,产生较为显著的社会效益,促进社会经济的快速发展。文章从不断提高系统的控制水平、应用变频技术实现节能效果、推广使用可再生能源的空调系统、尽量减少输送系统产生的动力能耗、使用新型节能的健康空调运行方式等五个方面探讨了暖通空调系统的节能措施。 相似文献
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Vujisić Ljubodrag V. Vučković Ivan M. Makarov Slobodan E. Ilić Bojan S. Antić Dragan Ž. Jadranin Milka B. Todorović Nina M. Mrkić Ivan V. Vajs Vlatka E. Lučić Luka R. Ćurčić Božidar P. M. Mitić Bojan M. 《Die Naturwissenschaften》2013,100(9):861-870
The Science of Nature - The geophilomorph centipede, Himantarium gabrielis, when disturbed, discharges a viscous and proteinaceous secretion from the sternal glands. This exudate was found by gas... 相似文献
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Bert Hölldobler Malu Obermayer Nicola J. R. Plowes Brian L. Fisher 《Die Naturwissenschaften》2014,101(7):527-532
Fisher and Robertson (Insect Soc 46: 78–83, 1999) discovered the production of silk-like secretions emerging from slit-shaped openings along the anterior margin of the ventral hypostoma of Melissotarsus ant workers. The current histological study describes a hitherto unknown hypostomal gland from which this silk-like substance originates. In addition, this study describes a new basitarsal gland in the three pairs of legs of Melissotarsus workers. 相似文献
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Dufour's gland secretion may allow worker honeybees to discriminate between queen-laid and worker-laid eggs. To investigate this, we combined the chemical analysis of individually treated eggs with an egg removal bioassay. We partitioned queen Dufour's gland into hydrocarbon and ester fractions. The bioassay showed that worker-laid eggs treated with either whole gland extract, ester fraction or synthetic gland esters were removed more slowly than untreated worker-laid eggs. However, the effect only lasted up to 20 h. Worker-laid eggs treated with the hydrocarbon fraction were removed at the same rate as untreated eggs. The amount of ester which reduced the egg removal rate was far higher than that naturally found on queen-laid or worker-laid eggs, and at natural ester levels no effect was found. Our results indicate that esters or hydrocarbons probably do not function as the signal by which eggs can be discriminated. 相似文献
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参考美国EPA标准对珠江干流河口表层水样颗粒相和溶解相有机氯农药进行定量分析,并对有机氯农药的含量及分布进行探讨,结果显示,洪季、枯季水体中有机氯农药总量(颗粒相和溶解相)分别是9.7~26.3ng/L、41.7~122.5ng/L;洪季、枯季HCHs总量分别为5.8~20.6ng/L、13.8~99.7ng/L, DDTs总量分别是0.52~1.13ng/L、5.85~9.53ng/L,其它有机氯农药总量分别为3.36~8.51ng/L、17.5~61.5ng/L.珠江干流河口水体的DDT/(DDE+DDD)比值向口门方向有逐渐递增趋势,表明沿程(特别是东江网河区)不断有浓度相对较高的DDT输入或仍有新使用的DDT农药进入珠江干流水体. 相似文献
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温泉宾馆室内PM_(10),PM_(2.5),CO_2和~(222)Rn的研究 总被引:1,自引:0,他引:1
对广东省 4座温泉宾馆室内外氡(222Rn)浓度和温泉水氡浓度进行研究,同时利用便携式探测器对室内外 PM10,PM2.5,CO2和CO 等污染物暴露水平进行直接测定.结果表明,温泉宾馆室内使用温泉水时氡浓度明显高于广东省室内平均氡浓度.除 CO 外,室内 PM10,PM2.5 和CO2 浓度都较高,其中 PM10 和 CO2 的超标率分别达到 67%和 89%.说明温泉宾馆室内不仅存在一般性污染物,而且存在高浓度的 Rn. 222 相似文献
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在室外条件下,对菊花江蓠(Gracilaria lichenoides)及龙须菜(G.Lemaneiformis)的N、P吸收动力学及生长动力学进行了研究.两海藻对NO3-N、NH4-N及PO4-P的最大吸收速率(Vmax)分别为55.88、35.17 μmol/(g·h)、3.106 μmol/(g·h)和53.17、32.24 、3.064 μmol/(g·h);半饱和常数(Ks)分别为7.762、3.414 、0.222 μmol/L和6.331、2.345、0.110 μmol/L,两海藻对N营养的竞争能力相似;从生长动力学结果看:菊花江蓠N、P的最大生长浓度为60 和30 μmol/L,龙须菜为100和40 μmol/L. 相似文献
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在实验室条件下研究了枝角类蒙古裸腹溞(Moina mongolica)对有毒赤潮生物塔玛亚历山大藻的摄食。结果表明,单一饵料试验中,蒙古裸腹溞摄食率在一定范围内随塔玛亚历山大藻细胞数的增加而增大,在塔玛亚历山大藻和亚心形扁藻组成的混合饵料试验中,当前者细胞数为低值时,摄食率不随后者细胞数的变化而变化,而当前者的细胞数高于1920/mL时,摄食率随亚心形扁藻细胞数的增大而升高。 相似文献
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The evolution of genome size has been discussed in relation to the evolution of various biological traits. In the present study, the genome sizes of 22 dictyopteran species were estimated by Feulgen image analysis densitometry and 6-diamidino-2-phenylindole (DAPI)-based flow cytometry. The haploid genome sizes (C-values) of termites (Isoptera) ranged from 0.58 to 1.90 pg, and those of Cryptocercus wood roaches (Cryptocercidae) were 1.16 to 1.32 pg. Compared to known values of other cockroaches (Blattaria) and mantids (Mantodea), these values are low. A relatively small genome size appears to be a (syn)apomorphy of Isoptera + Cryptocercus, together with their sociality. In some phylogenetic groups, genome size evolution is thought to be influenced by selective pressure on a particular trait, such as cell size or rate of development. The present results raise the possibility that genome size is influenced by selective pressures on traits associated with the evolution of sociality. 相似文献
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In this study, we used analyses of stable isotopes of nitrogen ('15N) and carbon ('13C) to determine the trophic ecology of the monitor lizard Varanus mabitang. Stable isotopes from claws, gut contents, and soft tissues were measured from the type specimen. Samples from Varanus olivaceus, Varanus prasinus, Varanus salvator, the herbivorous agamid lizard Hydrosaurus pustulatus, and some plant matter were included for comparison. Our data show a rapid decrease in '13C (about10) from food plants towards gut contents and soft tissues of herbivorous species. For the varanids, we found a significant linear correlation of decreasing '13C and increasing '15N from herbivorous towards carnivorous species. In terms of trophic isotope ecology, the type specimen of V. mabitang is a strict herbivore. Thus it differs significantly in its isotopic composition from the morphologically next closest related species V. olivaceus. The most highly carnivorous species is V. salvator, while '15N values for V. prasinus and V. olivaceus are intermediate. Claws provide very valuable samples for such measurements, because they can be sampled from living animals without harm. Additionally, their range of variability is relatively small in comparison with measurements from soft tissues. 相似文献