Physiological but not morphological adjustments along latitudinal gradients in a human commensal species,the Eurasian tree sparrow     

Qian ZHANG  Mo LI  Yuan YIN  Shiyong GE  Danjie LI  Ibrahim M. AHMAD  Ghulam NABI  Yanfeng SUN  Xu LUO  Dongming LI 《Integrative zoology》2023,18(5):891-905

Human commensal species take advantage of anthropogenic conditions that are less likely to be challenged by the selective pressures of natural environments. Their morphological and physiological phenotypes can therefore dissociate from habitat characteristics. Understanding how these species adjust their morphological and physiological traits across latitudinal gradients is fundamental to uncovering the eco-physiological strategies underlying coping mechanisms. Here, we studied morphological traits in breeding Eurasian tree sparrows (ETSs; Passer montanus) among low-latitude (Yunnan and Hunan) and middle-latitude (Hebei) localities in China. We then compared body mass; lengths of bill, tarsometatarsus, wing, total body, and tail feather; and baseline and capture stress-induced levels of plasma corticosterone (CORT) and the metabolites including glucose (Glu), total triglyceride (TG), free fatty acid (FFA), total protein, and uric acid (UA). None of the measured morphological parameters varied with latitude except in the Hunan population, which demonstrated longer bills than those in other populations. Stress-induced CORT levels significantly exceeded baseline levels and decreased with increasing latitude, but total integrated CORT levels did not vary with latitude. Capture stress-induced significantly increased Glu levels and decreased TG levels, independent of site. However, the Hunan population had significantly higher baseline CORT, baseline and stress-induced FFA levels, but lower UA levels, which differed from other populations. Our results suggest that rather than morphological adjustments, physiological adjustments are mainly involved in coping mechanisms for middle-latitude adaptation in ETSs. It is worth investigating whether other avian species also exhibit such dissociation from external morphological designs while depending on physiological adjustments.  相似文献   

活性炭吸附汽油机冷起动HC排放的实验     

纪常伟  潘耀江 《农业机械学报》2007,38(3):61-64

为控制汽油机的冷起动HC排放，开发了一个活性炭吸附器，用于吸附车用汽油机冷起动阶段排放的HC。吸附材料采用煤质蜂窝状定型活性炭块，吸附器外表面用薄钢板焊接封装，整个吸附器串接在排气管上。进行汽油机冷起动排放实验，测量起动后200s内的HC排放量，实验结果表明，在冷却水温度为20U、40℃、60℃和85℃时，活性炭吸附器对HC的吸附率分别达到86．64％、70．34％、79．69％、77．45％。  相似文献   

Wavelet Edge Detection Method Based-on Multi-scale Fuzzy Logic     

ZHANG Qiang-jin  YANG Dan  ZHANG Xiao-hong  GE Yong-xin 《保鲜与加工》2005,(10):62-65

A novel edge detection algorithm is proposed by implementing fuzzy image enhancement at different scales.The implement of this algorithm can reduce the negative influence bring from the non-maximum suppression algorithm which select only one threshold.The success of the approach depends on the selection of a general fuzzy operator(GFO) for the enhancement of contrast of region after smoothing of image at different scales.Consequently,it is more obvious that coarse intensity changes are obtained at a large scale whereas the fine details of intensity changes are obtained at a small scale.A pretty performance is obtained by used this work.  相似文献   

区域经济系统的分形特征及模型研究     

于晓秋  葛家麒  徐中儒  仪秀琴 《农机化研究》2005,(6):84-86

通过对区域经济系统模型的研究,确定了经济系统的分形特征,并通过实例建立投入与产出的数学模型,验证了其分形特征,利用分维确定了各投入与产出量的变化趋势,揭示了区域经济系统的复杂变化,为了解和指导区域经济发展提供了新的方法和依据。  相似文献   

车辆发动机气门弹簧的设计方法探讨     

张俊海  郑兰霞  陈艳艳  葛玉萍 《拖拉机与农用运输车》2007,34(5):34-35

发动机气门弹簧多用圆柱形螺旋压缩弹簧,在气门关闭过程中用于克服气门及传动件的惯性力,保证气门及时落座并紧密贴合,防止气门在发动机振动时产生跳动。本文通过分析其优化设计的设计变量、目标函数和约束条件,提出并验证优化设计的数学模型,该方法简便易行,且可以达到预期的设计目的。  相似文献   

利用小波分析诊断农机产品变速箱齿轮故障     

田全忠  魏志宏  葛志伟  卢绰  史金钟 《中国农机化》2005,(4):64-66

介绍小波变换的基本原理，针对农机产品变速箱齿轮出现故障时产生的非稳态脉冲信号特点，选择合适的小波。应用小波变换准确地诊断变速箱齿轮裂纹故障，证明了小波分析的应用价值。  相似文献   

燃料添加剂对均质压缩燃烧影响的试验     

李超  纪常伟  何洪  沈自友  何超  李韫喆 《农业机械学报》2007,38(4):1-3

在一台改造的4缸柴油机的第4缸进行均质压燃（HCCI）燃烧试验，研究了添加剂对HCCI燃烧过程的影响。试验结果表明，在HCCI燃烧稳定工况下，没有添加剂的基础燃料PRF90（相当于90号汽油）着火滞后，燃烧放热峰值低，而混有添加剂的基础燃料则着火明显提前，燃烧放热峰值升高。在相同循环喷油量和相同转速的条件下，随着添加剂质量分数的增加，HCCI着火和燃烧放热提前，燃烧放热峰值提高，但过高的添加剂质量分数会使得发动机爆震，工作粗暴。  相似文献   

玉簪属植物光合作用研究进展     

葛新新  吴静妍  李海英  窦树军 《北方园艺》2021,(21):130-135

该文综述了近年来玉簪属植物光合作用的研究进展.主要从玉簪属植物光合作用的基本特性以及影响玉簪光合作用的内外因素等方面进行了分析总结,并讨论了玉簪属植物光合作用研究的发展趋势.  相似文献   

生物有机肥对黄州萝卜主要经济性状和效益的影响     

卢华平  闫良  熊鑫镭  徐丽荣  蒋艳艳  代俊芬  葛长军 《蔬菜》2021,(8):26-29

为了验证生物有机肥对蔬菜作物生长的促进作用与增产效应,以黄州萝卜为试验材料,探究不同生物有机肥对黄州萝卜产量及品质等方面的影响,设置3个施肥处理:每667 m~2分别施用200 kg生物有机肥+20 kg三元复合肥;200 kg灭活生物有机肥+20 kg三元复合肥;常规施肥(每667 m~2施200 kg饼肥+20 kg三元复合肥)以及空白对照。结果表明:每667 m~2施200 kg生物有机肥+20 kg三元复合肥处理的萝卜667 m~2产量最高,为2 921.5 kg;在品质方面,萝卜含粗纤维7 g/kg,可溶性糖42 g/kg,水分92.6%;综合667 m~2效益最优,达到4 567.3元,产投比最高,为3.5。  相似文献   

42.8％露娜森悬浮剂防治葡萄白腐病的田间药效试验     

戈大庆  张吉祥  李金山  李振山 《北方果树》2021,(5):18-19

作者以42.8％露娜森悬浮剂对葡萄白腐病进行田间防治试验.结果表明,42.8％露娜森悬浮剂对葡萄白腐病的防治效果较好,2000倍液药量第3次药后14 d防治效果依然能达到90.8％,3000倍液防效同健达2500倍液相当,明显高于大生800倍液的防效.  相似文献