干热河谷冲沟侵蚀劣地坡积区土体性质与裂缝形态发育特征

采用实地调查和室内分析等方法,并结合数字图像处理技术,研究了干热河谷冲沟侵蚀劣地坡脚堆积区(PJ)、坡底沉积区(PD)和平地漫流区(PM)土体性质和裂缝形态发育特征,并探讨了土体性质对裂缝形态特征的影响。结果表明,(1)侵蚀劣地坡积区不同部位土体性质差异显著,其中土壤体积质量及黏粒质量分数均表现为PDPJPM,毛管孔隙度为PMPDPJ,有机质为PMPJPD;不同部位土体性质极值比:黏粒质量分数最大(1.94),有机质(0.65)次之,再次是毛管孔隙度(0.27),土壤体积质量(0.09)最小;PJ、PD土体性质变化主要受物源特性和沉积方式的影响,而PM土体性质主要与植被分布以及漫流有关。(2)干热河谷侵蚀劣地不同部位土体裂缝形态特征差异也十分显著,其中裂缝长度密度(Lc)及连通性指数(K)均表现为PDPJ≤PM,面积率(Rc)、面积周长比(APc)及加权平均分形维数(AWMFRAC)则整体上表现为PD≥PJPM(Ⅲ号坡积区的Rc除外);表明裂缝发育强度(Rc)及复杂程度(APc、AWMFRAC)PD最高,其次为PJ,再次是PM。(3)相关分析表明,长度密度与土壤体积质量(p=-0.782)、黏粒质量分数(p=-0.626)均呈显著负相关,连通性指数与黏粒质量分数呈显著负相关(p=-0.618),这表明土壤体积质量及黏粒质量分数对裂缝发育产生了重要影响。     

Recruitment of burbot (Lota lota L.) in Lake Erie: an empirical modelling approach

Stapanian MA, Witzel LD, Cook A. Recruitment of burbot (Lota lota L.) in Lake Erie: an empirical modelling approach.
Ecology of Freshwater Fish 2010: 19: 326–337. Published 2010. This article is a US Government work and is in the public domain in the USA Abstract – World‐wide, many burbot Lota lota (L.) populations have been extirpated or are otherwise in need of conservation measures. By contrast, burbot made a dramatic recovery in Lake Erie during 1993–2001 but declined during 2002–2007, due in part to a sharp decrease in recruitment. We used Akaike’s Information Criterion to evaluate 129 linear regression models that included all combinations of one to seven ecological indices as predictors of burbot recruitment. Two models were substantially supported by the data: (i) the number of days in which water temperatures were within optimal ranges for burbot spawning and development combined with biomass of yearling and older (YAO) yellow perch Perca flavescens (Mitchill); and (ii) biomass of YAO yellow perch. Warmer winter water temperatures and increases in yellow perch biomass were associated with decreases in burbot recruitment. Continued warm winter water temperatures could result in declines in burbot recruitment, particularly in the southern part of the species’ range.     

氮磷钾肥料不同用量对济麦20号产量效应的试验

通过采用三元二次通用旋转回归设计,对济麦20号优质专用小麦氮磷钾肥料不同用量产量效应的试验研究,产量≥7500kg/hm2的最佳施用尿素量为424.5～522.0kg/hm2、过磷酸钙为328.5～396.0kg/hm2、氯化钾为259.5～342.0kg/hm2。氮磷、氮钾、磷钾间交互作用显著,肥效相互促进。     

冯契对毛泽东哲学思想的理性解读

冯契对毛泽东哲学思想的理性解读主要体现在 :充分肯定了毛泽东对中国近代哲学革命的历史总结 ,扬弃了毛泽东的辩证法思想 ,基本上肯定了毛泽东对社会理想的探索 ,坚持了毛泽东的义利观、完善了毛泽东的群己观     

欠发达地区旅游业可持续发展技术路径选择研究

结合欠发达地区旅游业发展特点和经济学竞争优势相关理论认为,欠发达地区旅游业可持续发展通常遵循以下技术路径:即起步阶段充分发挥区域资源的绝对优势或比较优势,赢得起步发展空间;中期阶段充分利用后发优势,加速产业升级,实现跨跃式发展;成熟阶段加强资源整合,培育区域旅游业可持续发展的核心竞争优势。     

大豆新品种晋豆37选育技术分析

晋豆37系山西省农科院小麦研究所以晋豆11为母本,埂84为父本杂交选育而成,在山西省晚熟组大豆区试和生产试验中表现良好。介绍了晋豆37的选育过程、在山西省晚熟组大豆区试和生产试验中的产量表现、品种特征特性,并就选育过程谈了选育技术方面的体会。     

Near-shore distribution of Heaviside’s (Cephalorhynchus heavisidii) and dusky dolphins (Lagenorhynchus obscurus) at the southern limit of their range in South Africa

Photo-identification surveys over three years along 390 km of coastline north of Cape Town, revealed that Heaviside’s dolphin distribution was consistent between years and higher in areas more exposed to swells and with greater long-term availability of small hake Merluccius capensis (their principal prey). Dusky dolphin sighting rates varied considerably between years, but were generally higher in areas with lower hake availability and sandier shores (mostly straighter coastline). Large groups of 50–200 dusky dolphins were only seen in St Helena Bay, the site of a wind-driven upwelling zone. Heaviside’s dolphins were found in shallower, cooler water than dusky dolphins and were more likely to be seen during brighter phases of the moon (when nocturnal light conditions may influence the vertical migration patterns of prey) and in areas of high hake abundance. Near-shore fishing activity was higher in the northern half of the study area and clustered around harbours. Set netting occurred only at Yzerfontein and St Helena Bay, but due to changes in the industry is currently thought to be a low threat to the population. Interactions between Heaviside’s and dusky dolphins were usually neutral and sympatry appears to be mediated by differences in overall range and the type and size of prey species taken.     

赤潮研究中圆海链藻实时荧光定量PCR检测方法的建立

为建立快速、准确的鉴定和定量检测赤潮生物的方法,以圆海链藻为例，以其18S rDNA序列为寻找种特异性引物的靶区域，通过分析18S rDNA序列，设计出适合用于RFQ-PCR的引物与探针，并通过引物PCR验证确定其特异性，进而以圆海链藻荧光定量PCR的引物和探针（Primer Thalassiosira rotula和Taqman Thalassiosira rotula），建立了定量检测圆海链藻的实时荧光定量PCR检测方法（RFQ-PCR）。与传统的显微镜计数方法比较，两者所获结果无显著性差异，证明了本方法的可行性，从而为我国沿海水域赤潮问题的研究提供了良好的技术检测途径。     

Floral induction (FI) in longan (Dimocarpus longan, Lour.) trees. III: Effect of shading the trees on potassium chlorate induced FI and resulting hormonal changes in leaves and shoots

Previous experiments demonstrated that treatment of longan trees with potassium chlorate (KClO₃) induces “off season floral induction” (FI) even in the absence of the naturally required cool temperature [Manochai, P., Sruamsiri, P., Wiriya-alongkorn, W., Naphrom, D., Hegele, M., Bangerth, F., 2005. Year around off season flower induction in longan (Dimocarpus longan, Lour.) trees by KClO₃ applications: potentials and problems. Sci. Hortic. 104, 379–390]. Potassium chlorate, however, cannot replace the presence of functional mature leaves and sufficient light intensity. Here we examined in more detail the effect of shade (about 10% of natural sunlight) on KClO₃ affected hormone concentrations/transport of leaves and shoot apical buds (SAB) and their interactions with FI.     

基于虚拟装配技术的竹席编织设计

根据竹席编织的特点,推导出竹席编织机的工作原理,借助于虚拟装配技术创建体现功能的竹席编织机三维实体模型,通过动态演示及时发现问题并进行分析和改进,得出最佳的结构方案.