合肥市董铺水库及临近区域鸟类多样性研究

2012年12月-2013年11月,采用样线调查和样点观察相结合的方法对合肥市董铺水库及其临近区域不同生境的鸟类资源进行了调查。共记录到鸟类14目31科87种,其中国家Ⅱ级保护鸟类1种、安徽省地方重点保护鸟类25种;古北界鸟类45种（占51.7%）,东洋种25种（占28.7%）,广布种17种（占19.5%）;留鸟33种（占37.9%）,夏候鸟19种（占21.8%）,冬候鸟21种（占24.1%）,旅鸟14种（占16.1%）鸟类群落多样性指数最大生境为水库周围灌丛、树林;而指数最小者为大面积水域。     

水通道蛋白9的研究进展

水通道蛋白9在机体内许多器官组织中表达,它对水、尿素、甘油等分子均有通透性,其基因结构、染色体定位、蛋白质结构、组织分布和生理功能也已得到了较为深入的研究。本文对水通道蛋白9基因的结构特点、分子结构、分布和生理功能作一综述,以期为相关疾病诊治和生产实践提供理论依据。     

Plankton abundance and size structure in the northern North Pacific Ocean in early summer

Phyto- and zooplankton abundance and size structure were investigated in the northern North Pacific Ocean (37.0–49.5^oN along 180^o longitude) during June of 1987. The area between 41.5^oN and 47.5^oN was expected to be abundant in phytoplankton since both water column stability and nutrient availability were favourable for phytoplankton growth. Actual phytoplankton abundance was, however, low between 41.5^oN and 45.5^oN. In particular, abundance of net phytoplankton (>10μm) was low although picophytoplankton (<2 μm) was abundant between 41.5^oN and 43.5^oN. The zooplankton community between 41.5^oN and 45.5^oN was characterized by a large amount of net zooplankton and a small amount of microzooplankton. This situation may be best explained by top-down control; that is, net zooplankton grazing suppressed net phytoplankton and microzooplankton abundance. The diminished microzooplankton promoted the increase of picophytoplankton. Because planktivorous Pacific saury were abundant between 40.0^oN and 41.0^oN, it is further speculated that the low biomass of net zooplankton south of 41.0^oN resulted from feeding by Pacific saury. The reduced grazing pressure of net zooplankton may have enhanced the growth of net phytoplankton and microzooplankton in this region.     

鱼鳞坑开沟双犁体翻转机构研究设计

双犁体翻转机构是对已有的发明专利机型即鱼鳞坑开沟犁装置的进一步优化设计,解决了在单犁体鱼鳞坑开沟犁返程时因开沟翻土方向不在坡下而是在开出的沟上面的作业问题。新研制翻转式鱼鳞坑开沟工作结构装置,应用机械、液压、电控装置实现了不同土壤类型的鱼鳞坑开沟间距式作业,生产效率高,性能可靠,市场前景广阔。     

阿拉善荒漠区蒙古扁桃的种群龄级结构与空间分布格局

根据样地调查数据,编制了阿拉善荒漠区敖隆敖包及乌兰腺吉蒙古扁桃种群静态生命表,并由此求得蒙古扁桃种群大小级结构图、存活曲线及死亡率曲线,从而对两地蒙古扁桃种群空间分布格局进行了比较研究。结果表明,两地蒙古扁桃种群幼龄和老龄级个体较少,中龄级个体较多。总体上,敖隆敖包蒙古扁桃种群年龄结构呈稳定型,而乌兰腺吉种群趋向衰退型。两地存活曲线处于DeeveyⅡ和DeeveyⅡ2。两地种群空间分布格局均呈聚集型分布。分析表明,草畜平衡在蒙古扁桃种群稳定型中发挥着重要作用。     

Using a stand-level model to predict light absorption in stands with vertically and horizontally heterogeneous canopies

Background： Forest ecosystem functioning is strongly influenced by the absorption of photosynthetically active radiation （APAR）, and therefore, accurate predictions of APAR are critical for many process-based forest growth models. The Lambert-Beer law can be applied to estimate APAR for simple homogeneous canopies composed of one layer, one species, and no canopy gaps. However, the vertical and horizontal structure of forest canopies is rarely homogeneous. Detailed tree-level models can account for this heterogeneity but these often have high input and computational demands and work on finer temporal and spatial resolutions than required by stand-level growth models. The aim of this study was to test a stand-level light absorption model that can estimate APAR by individual species in mixed-species and multi-layered stands with any degree of canopy openness including open-grown trees to closed canopies. Methods： The stand-level model was compared with a detailed tree-level model that has already been tested in mixed-species stands using empirical data. Both models were parameterised for five different forests, including a wide range of species compositions, species proportions, stand densities, crown architectures and canopy structures. Results： The stand-level model performed well in all stands except in the stand where extinction coefficients were unusually variable and it appears unlikely that APAR could be predicted in such stands using （tree- or stand-level） models that do not allow individuals of a given species to have different extinction coefficients, leaf-area density or analogous parameters. Conclusion： This model is parameterised with species-specific information about extinction coefficients and mean crown length, diameter, height and leaf area. It could be used to examine light dynamics in complex canopies and in stand-level growth models.     

浅析钢结构稳定性设计

针对有待解决的目前建筑行业比较关注的钢结构稳定性问题,阐述了钢结构的基本相关概念,分析了影响钢结构稳定的因素、设计钢结构稳定性的特点和原则,并进一步探讨了在钢结构设计中必须要注意的一些问题。     

广西德保猪抵抗素基因的克隆与分析

[目的]克隆广西德保猪抵抗素（Resistin,RENT）基因并进行系统生物信息学分析,阐明德保猪脂肪细胞分化与脂肪生成的分子机制.[方法]根据NCBI已公布的猪RENT基因序列（NM 213783.2）设计特异性引物,以从德保猪血液中提取的总RNA为模板,PCR扩增RENT基因序列,T-A克隆至pEASY-T1载体后进行测序分析,并将所得测序结果用BLAST程序、MEGA 5.0软件、EXPASY服务器、SMART程序、SignIP程序、Softberry服务器和DNASTAR软件进行生物信息学分析.[结果]扩增获得468 bp的RENT基因序列片段,包含全长的德保猪RENT基因编码区和部分非编码区序列.多重序列比较分析结果显示,德保猪RENT基因编码区核酸序列与猪、牛、山羊、绵羊、人、兔、猕猴和豚鼠的同源性分别为100.0％、85.5％、85.5％、84.5％、81.2％、80.3％、80.0％和77.3％.德保猪RENT蛋白结构预测结果显示,其理论分子质量11.69 ku,等电点7.82,为弱碱性蛋白;N-末端存在信号肽,定位于胞质外,仅具有1个低复杂度结构域,包含1个α-螺旋、8个β-折叠、7个T-转角及两个无规则卷曲.[结论]RENT基因在德保猪中呈高度保守特征,是其脂肪细胞分化中的重要调控基因.     

光照和施肥对青钱柳幼苗叶片性状与解剖结构的影响

以青钱柳1年生幼苗为对象,研究光照和施肥对其复叶性状、气孔特征和叶片解剖结构的影响。结果表明,光照及光照和施肥2因子的交互作用对叶片性状和解剖结构各指标有显著或极显著影响,施肥仅对叶片厚度有显著影响;全光照下青钱柳叶面积最小,叶片较厚,栅栏组织和海绵组织排列紧密,叶片气孔小而密;光照强度减弱使叶片面积增加,叶片变薄,比叶质量下降,气孔密度减小,气孔变长变宽;全光照下,复叶面积、复叶干质量和比叶质量随施肥量增加而增加,叶片厚度也有一定的增加。中等光照下施肥20 g/株处理的复叶面积和复叶干质量最大,说明中等光照且适量施肥是青钱柳幼苗生长的最佳条件。     

菠萝叶纤维与其它植物纤维的吸湿性能对比测试及分析

利用扫描电镜、X射线衍射等测试方法对菠萝叶纤维、亚麻纤维、苎麻纤维和棉花纤维的微观形态结构进行了分析。分析认为:菠萝叶纤维的形态结构有区别于其它三种植物纤维,有较大的比表面积;菠萝叶纤维的结晶度与亚麻纤维和苎麻纤维接近,高于棉花纤维。在热带标准状态下,采用烘箱干燥法和回归模型分析法,对测试的四种进行了吸湿、放湿测试与分析。结果表明:在吸湿性能方面,菠萝叶纤维表现最佳,棉花纤维最差;在纤维吸湿平衡回潮率和吸湿速率方面,菠萝叶纤维与亚麻纤维和苎麻纤维相近,且高于棉花纤维;在纤维放湿平衡回潮率和放湿速率方面,菠萝叶纤维高于亚麻纤维、苎麻纤维和棉花纤维。