安哥拉山羊羊纤维鳞片特征

应用单侧观察法和旋转观察法在扫描电镜下对安哥拉山羊羊毛鳞片特征进行了研究。结果表明，安哥拉山羊毛纤维鳞片在直径１５微米下呈环形排列，鳞片多为四边形；在较粗的羊毛中，鳞片排列为非环形，鳞片形状多为三角形或多边形。两类鳞片实质上都呈复瓦状排列方式。鳞片的形状具有多态性。鳞片表面光滑，具有浅而直的纵向条纹，自然边缘逐渐变薄，紧贴毛干。     

单板层积材热效应的表征

单板层积材具有强度性能变异系数小、抗蠕变和阻燃性能好的优点,但也存在一些缺点,如单板层积材使用过程中遇到的分层开裂等.该文针对其缺点,做了关于单板层积材热效应表征的理论分析和推导.设定单板层积材主要由铺层和界面组成,根据复合材料细观力学理论及胶层和单板的弹性力学性质,采用材料力学分析方法推导出铺层纵向、横向热膨胀系数,单板和胶层热应力,及界面纵向、横向热膨胀系数.为单板层积材的实际生产使用提供一定的依据.     

连云港城市扩展及其驱动力分析

利用多时相遥感影像、社会经济统计数据以及其他辅助资料,在基于遥感影像专题信息提取和GIS空间叠置分析技术的基础上对连云港市1978～2005年的城市扩展及其侵占周围土地的情况进行了系统的分析,并对连云港市扩展的驱动力进行了初步的探讨.结果表明,连云港的城市扩展很快,2005年的城市面积是1978年的4倍多,而且在不同的空间位置城市扩展的速度和规模也有较大的差异,城市扩展主要是侵占周边的优质农田.连云港市临海的地理位置和快速的经济发展决定着城市扩展的空间方位和速度,是城市扩展的主要驱动力.     

Fractal几何的理论形成及应用发展

在阐述Ｆｒａｃｔａｌ几何由来和应用发展的基础上，分析了它在应用过程中对其理论体系的完善过程。着重指出目前Ｆｒａｃｔａｌ几何理论不再局限于对自然形体的形态描述及形成过程的分析上。而已开始用于对抽象表现空间的自然现象及的评价。Ｆｒａｃｔａｌ一词也在理论和应用发展过程中扩展了内涵。这充分说明理论和实践相辅相承共同发展这一哲学观点的正确性。     

Improving ‘Bing’ sweet cherry fruit quality with plant growth regulators

Final fruit diameter is the prime determinant of sweet cherry fruit value. Previous research has shown that mesocarp cell size accounts predominantly for variability in final fruit size, within a genotype. Our research program evaluated the potential to improve sweet cherry fruit size/weight with growth regulators to affect cell division and/or cell expansion stages. In the current study we screened 8 plant growth regulators (PGRs), including cytokinins, gibberellins, and auxins, and their combinations for their ability to increase ‘Bing’ fruit weight. Each PGR was mixed in lanolin paste and applied to fruit pedicels at 9 or 30 days after full bloom (DAFB), to coincide with estimated peak in cell division and cell expansion activity, respectively. Several cytokinins applied 30 DAFB improved fruit weight significantly (ca. +15%) with N-(2-Chloro-4-pyridyl)-N′-phenylurea (CPPU) and 6-(3-hydroxybenzylamino) purine (mt-Topolin) at 100 mg l⁻¹ being the most effective. Gibberellins, applied alone, improved fruit size and delayed fruit maturation and exocarp coloration. GA₃ at 200 mg l⁻¹ applied at 9 DAFB was the most effective and improved final fruit weight by 15%. Fifty-six percent of the fruit from this treatment were ≥9 g compared to 15% of similar weight fruit from untreated limbs. Both GA₃ and GA_4/7 treatments applied 9 DAFB increased fruit radial expansion. 4-Chlorophenoxyacetic acid, a synthetic auxin, also stimulated higher fruit growth rates at stage I and stage II, and fruit color development, but did not improve final fruit size.     

时间分数阶扩散方程的并行高效Legendre谱方法

研究了两类时间分数阶扩散方程的并行高效Legendre谱方法,分数阶导数分别代替标准的扩散方程的二阶空间导数和一阶时间导数。空间方向采用高效的Legendre谱方法,时间方向使用了基于Fourier级数展开的Laplace数值逆,并对其参数进行了优化。给出了两类时间分数阶扩散程的数值格式和数值例子,与其他方法比,该方法数值结果更优。     

Monitoring the gravitational reflex of the ectoparasitic mite Varroa destructor: A novel bioassay for assessing toxic effects of acaricides

We investigated the effect of several acaricides on Varroa destructor by monitoring the rhythmic expansion of the sternum, followed by a strong flexion of the legs, initiated when the mite was placed in a dorsal side-down position, as an indication of a mite’s vitality. The pulses generated by the force of the rhythmic expansions had an average duration of 3.11 s, force (amplitude) of 73 μN, and frequency of 0.228 Hz. These parameters remained constant for the first 10 h of recording, whilst significant changes occurred after 15 h. The rhythmic sternal expansion is an indication of a Varroa mite’s gravitational reflex, or attempt to return to an upright position; this reflex is observed in all invertebrates and vertebrates. The sternal expansion can be recorded for over 20 h, or for as long as the Varroa mite remains alive, and the expansion stops as soon as the mite is placed in a normal, upright position. Proper function of the chain of proprioceptors, interneurons, motorneurons, neuromuscular junctions, and muscles of Varroa is required for the initiation and maintenance of such a behavioural motor pattern. Any deleterious effect of synthetic chemicals or natural compounds (acaricides) may have a direct effect on one or more of these links, thereby disturbing or even inhibiting the reflex. Topical application of 1.81 × 10⁻³ mg/mite of amitraz completely inhibited the gravitational reflex within 60–70 min for all mites tested. The volatile acaricides formic acid (13.83 mg), thymol crystals (250 mg), and Apiguard® (1000 mg) eliminated the reflex within 10–35 min. This bioassay, based on the gravitational reflex, could be a useful tool for accurate assessment of the acaricidal action of numerous compounds under laboratory conditions, saving money and time necessary to conduct field trials.     

What genetics tell us about the conservation of the critically endangered Balearic Shearwater?

The Balearic shearwater Puffinus mauretanicus is one of the most critically endangered seabirds in the world. The species is endemic to the Balearic archipelago, and conservation concerns are the low number of breeding pairs, the low adult survival, and the possible hybridization with a sibling species, the morphologically smaller Yelkouan shearwater (P. yelkouan). We sampled almost the entire breeding range of the species and analyzed the genetic variation at two mitochondrial DNA regions. No genetic evidence of population decline was found. Despite the observed philopatry, we detected a weak population structure mainly due to connectivity among colonies higher than expected, but also to a Pleistocene demographic expansion. Some colonies showed a high imbalance between immigration and emigration rates, suggesting spatial heterogeneity in patch quality. Genetic evidence of maternal introgression from the sibling species was reinforced, but almost only in a peripheral colony and not followed, at least to date, by the spread of the introgressed mtDNA lineages. Morphometric differences were not correlated with mtDNA haplotypes and introgression is probably due to a secondary contact between the two species several generations ago. Overall, results suggested that the very recent demographic decline in this critically endangered species has not yet decreased its genetic variability, and connectivity found among most colonies should help to reduce species extinction risk. Spreading of introgression should be monitored, but the species is not jeopardized at the moment by genetic factors and the major conservation actions should concentrate at enhancing adult survival.     

温室黄瓜叶面积扩展与光合特性对土壤水分的响应研究

温室盆栽试验研究土壤水分对黄瓜叶面积扩展与光合特性的影响结果表明,黄瓜叶片扩展经历了指数生长(EG)、线性生长(LSG)和稳定生长(SCG)3个阶段。随土壤含水量的增加,叶面积(LA)显著增大,叶片生长速率(LGR)的最大值明显提前。叶片相对扩展速率(RER)在指数生长阶段迅速增加,但在线性生长和稳定生长阶段则逐渐减小。土壤含水量显著影响了叶片的扩展和光合特性。叶片生长进程中,叶绿素含量和净光合速率(Pn)逐渐增加,处理间差异明显,不同水分处理的叶片净光合速率日变化均表现为单峰曲线,其表观量子效率(AQY)、羧化效率(CE)具有显著差异。     

武夷山风景名胜区景观类型空间关系及其尺度效应初探

对武夷山风景名胜区景观类型空间关系及其尺度效应研究结果表明 ,景观类型空间关系存在尺度效应 ,尺度变化对破碎化程度高的景观类型空间关系影响较大 ,而对破碎化程度低的景观类型空间关系影响较小。研究景观类型空间关系时其取样尺度不宜太大 ,武夷山风景名胜区以 2 0 0m× 2 0 0m取样尺度最佳。武夷山风景名胜区景观类型空间关系特征为低海拔高度区呈现出以居民点为中心的由农田、河流等向周围扩散的干扰景观格局 ,而中高海拔高度区则呈以近成熟、成过熟林占优势的天然马尾松林为主体的人为干扰较小的天然景观格局