寡糖类物质诱导黄瓜根结线虫抗病性作用初探

鉴于生产中黄瓜根结线虫病的危害性及目前防控手段的局限性,利用寡糖类物质作为激发子诱导植物抗病性这一方法来寻求黄瓜根结线虫病的防治新途径。盆钵试验结果表明,根结线虫侵染会导致黄瓜生长缓慢、植株矮小并提前衰老;而寡糖类物质处理会缓解根结线虫对黄瓜根系活力的破坏作用,降低根结线虫对黄瓜生长的影响。田间防效试验表明,寡糖类物质处理可以较好的防治黄瓜根结线虫病的发生,0.2%寡糖物质处理可以使瓜条数和产量分别比对照增加32.73%和33.16%。对于产量和防效而言,灌根处理是较为适宜的施用方式。     

试论创作原动力对美术创作的影响

影响创作活动的一个重要因素是原动力．美术创作的原动力不外乎主动和被动两种，或称有意识和无意识。主动创作的美术作品其艺术表现力有一定的局限性，被动（无意识）驱动下创造出的美术作品（被动创作作品）其艺术感染力更强烈、震撼，艺术韵味更深远、悠长，是美术创作领域的灵魂。     

航运服务集聚区的发展演化机理

为研究航运服务集聚区的发展演化机理,在对服务集聚区研究分析的基础上,对航运服务业的类别,航运服务集聚区的内涵、发展演化机理、发展演化阶段、发展演化的分析框架和发展演化动力进行较为系统的定性分析.通过上海市北外滩航运服务集聚区案例对航运服务集聚区的发展演化机理进行实证分析,并在此基础上提出我国航运服务集聚区的未来发展思路...     

试论第二战场开辟的作用

第二战场的开辟对于整个反法西斯战争的结局起着至关重要的作用。它的开辟打击和消耗了德军的军事力量，加强了苏美英之间的团结合作，减轻了苏德战场上苏军的压力，增强了欧洲人民反法西斯斗争的信心和勇气，从而保证了欧洲反法西斯战争取得全面胜利。     

论拍胸舞的表现力及其体育健身价值

文章以闽南拍胸舞为研究对象,它是先民以舞蹈的形式,体现驱疾逐疬,迎吉纳福为内核的一种古巫现象。通过它实现人与神灵的交流。现今,它仍被广为流传,尤其在泉州地区。拍胸舞作为祭祀的主要手段的同时,还有强身健体的作用。本文从体育保健学,运动生理学和体育心理学的视角探讨拍胸舞。通过分析一个原来纯为宗教祭祀的民间舞蹈之所以能逐步发展成为以娱乐和体育健身为主的大众活动项目的原因,进而体现出拍胸舞所蕴涵的体育健身功能。     

激电在新疆索尔库都克东铜矿勘查中的应用

激发极化法是以不同岩、矿石激电效应之差异为物质基础,通过观测和研究大地激电效应探查地下情况的一种方法。该方法在我国金属与非金属固体矿产勘查中有着广泛的应用,效果显著。本文主要讲述了以激电法为主要手段结合区域地质资料对新疆富蕴县索尔库都克东铜矿区进行勘探和解释。根据这些岩石的物性(电阻率、激发极化率)差异明显的特点,通过激电中梯方法,对1961个测点进行数据采集。其数据处理的过程主要是采用绘图软件对所测量的数据绘制相关图件,并解释分析。通过分析对比,进而推测探矿远景区。     

Schumacher meets Schumpeter: Appropriate technology below the radar

Innovation and technological change play an important role in poverty reduction through their contribution to growth, their use of factors of production, their environmental spillovers, the social relations associated with production and the characteristics of the products which they produce. It was only after the 1960s that these linkages were identified, with the recognition that much of global technological progress was directed to meet the needs of the global rich, and was best-suited to operation in high-income environments. The development and diffusion of “appropriate technologies” was an agenda largely pursued by the not-for-profit Appropriate Technology movement. However, with the global diffusion of innovative capabilities, and the rapid rise of incomes of the very poor - the “second bottom billion” - innovation for the poor and innovation appropriate for production in low-wage and poor-infrastructure environments has increasingly become an arena for profitable production. The very large size of China and India, coupled with their growing technological capabilities and the rapid growth of low-incomes, makes it likely that they will become the dominant sources of innovation for the poor.     

The influence of cadence and power output on force application and in-shoe pressure distribution during cycling by competitive and recreational cyclists

The aim of this study was to determine the response of cyclists to manipulations of cadence and power output in terms of force application and plantar pressure distribution. Two groups of cyclists, 17 recreational and 12 competitive, rode at three nominal cadences (60, 80, 100 rev min -1 ) and four power outputs (100, 200, 300, 400 W) while simultaneous force and in-shoe pressure data were collected. Two piezoelectric triaxial force transducers mounted in the right pedal measured components of the pedal force and orientation, and a discrete transducer system with 12 transducers recorded the in-shoe pressures. Force application was characterized by calculating peak resultant and peak effective pedal forces and positive and negative impulses. In-shoe pressures were analysed as peak pressures and as the percent relative load. The force data showed no significant group effect but there was a cadence and power main effect. The impulse data showed a significant three-way interaction. Increased cadence resulted in a decreased positive impulse, while increased power output resulted in an increased impulse. The competitive group produced less positive impulse but the difference became less at higher cadences. Few between-group differences were found in pressure, notable only in the pressure under the first metatarsal region. This showed a consistent pattern of in-shoe pressure distribution, where the primary loading structures were the first metatarsal and hallux. There was no indication that pressure at specific sites influenced the pedal force application. The absence of group differences indicated that pressure distribution was not the result of training, but reflected the intrinsic relationship between the foot, the shoe and the pedal.     

Use of ‘chalk’ in rock climbing: sine qua non or myth?

Magnesium carbonate, or ‘chalk’, is used by rock climbers to dry their hands to increase the coefficient of friction, thereby improving the grip of the holds. To date, no scientific research supports this practice; indeed, some evidence suggests that magnesium carbonate could decrease the coefficient of friction. Fifteen participants were asked to apply a force with the tip of their fingers to hold a flattened rock (normal force), while a tangential force pulled the rock away. The coefficient of friction – that is, the ratio between the tangential force (pulling the rock) and the normal force (applied by the participants) – was calculated. Coating (chalk vs no chalk), dampness (water vs no water) and rock (sandstone, granite and slate) were manipulated. The results showed that chalk decreased the coefficient of friction. Sandstone was found to be less slippery than granite and slate. Finally, water had no significant effect on the coefficient of friction. The counter-intuitive effect of chalk appears to be caused by two independent factors. First, magnesium carbonate dries the skin, decreasing its compliance and hence reducing the coefficient of friction. Secondly, magnesium carbonate creates a slippery granular layer. We conclude that, to improve the coefficient of friction in rock climbing, an effort should be made to remove all particles of chalk; alternative methods for drying the fingers are preferable.