帽儿山天然次生林融雪径流可溶性有机碳时间动态及垂直分布

融雪期是北方地区可溶性有机碳(DOC)通过融雪径流从陆地生态系统向河流输出的关键时期,因此观测融雪径流DOC动态对分析流域碳流失至关重要。在帽儿山生态站选取东北东部典型天然次生林建立25 m×25 m的水量平衡场,测定分析2014年融雪期不同土层(5、35、65和95 cm)融雪径流DOC含量和通量的时间动态和垂直分布规律。结果表明: 1) 该融雪期土壤水量输入和输出分别为74.2和15.6 mm,径流率高达21%;融雪期DOC输出量与冬季大气输入量基本持平,分别为0.25和0.22 g/m2。2)高峰期DOC含量与其瞬时流量的相关性随土层而变。5和35 cm土层DOC含量与瞬时流量之间均无显著关系(P0.05);65 cm土层则表现出弱负对数关系(R2=0.29,P0.05),而95 cm土层呈现显著线性正相关(R2=0.43,P0.05)。不同土层DOC瞬时通量与瞬时流量之间均极显著正相关(R20.9,P0.001),且产流量越大的土层,其正相关回归方程的斜率也越大,表明水文驱动土壤DOC流失。3)融雪径流产流量和输出DOC通量大小均表现出35 cm5 cm95 cm65 cm土层趋势,其中5和35 cm土层是DOC的主要输出层,占总输出量的70%,而在融雪高峰期可高达90%。由于土壤的滞留作用,DOC含量波动范围随土层加深而向低浓度收敛。      

托木尔峰自然保护区地衣的补充研究

我们根据多年的研究并结合前人的工作进一步地整理了分布在新疆托木尔峰自然保护区的地衣种类。分析该地区的地衣种有１２０个,分别隶性于４９属,其中有１１个变种和４个变型。调查中我们还发现该地区地衣随着海拔高度的升高而有所不同,北坡和南坡也有明显的差异。     

风力发电场进场道路曲线设计应注意的问题

风能已成为世界上增长最快的清洁可再生能源,风力发电世界各国争相发展.然而我省风力发电项目进展较为缓慢,主要原因在于,我省公路网密度较低,许多公路等级偏低,平面线性较差,运输风电设备的长货车通行较困难.风电路的设计有一定的特殊性,我们在进行风电路设计时不能照搬规范上的数据,特殊数值需要通过计算求得,以保证风电设备的顺利运输.     

Assessment of the profile of powdery mildew and its damage function at low disease intensities in field experiments with winter wheat

Damage by mildew to winter wheat was studied in 11 field experiments in the Netherlands. Damage is described by the simple function: –0.013 (SE=0.003) kg are^–1 per pustule-day of mildew per leaf, from second node stage to early dough at yield levels of 70 to 90 kg are^–1, in diseasefree plots. No deviations from linearity at disease stresses from zero to two thousand pustuledays per leaf were observed. Years, cultivars or soil types did not affect the damage function significantly. The effects of mildew on some yield components were suggested.Mildew profiles in untreated plots could be described by the equation: CM=CLA^b, in which CM and CLA are the cumulative pustule number and the cumulative leaf area, respectively, calculated both from top to bottom of the canopy, and totals standardized at unity. Estimates of the gradient parameter b aveaged 3.4 (SE=0.9). Observed differences in steepness of the profiles did not affect the damage function significantly.Samenvatting Opbrengstderving van wintertarwe door meeldauw werd bestudeerd in 11 veldproeven in Nederland. De schade bedroeg gemiddeld 0.013 (SE=0.003) kg are^–1 per puistdag meeldauw per blad, vanaf het tweede-knoop stadium tot begin deegrijp bij opbrengstniveaus van 70 tot 90 kg are^–1, in de blanco. Bij een ziektestress van 0 tot 2000 puistdagen meeldauw per blad werd geen afwijking van een rechtlijnig verband gevonden. De schaderelatie werd niet significant beïnvloed door de verschillende jaren, rassen of grondsoorten. Het effect van meeldauw op enkele opbrengstcomponenten werd aangetoond.Meeldauwprofielen in de onbehandelde veldjes konden worden beschreven met de vergelijking: CM=CLA^b, waarin CM het cumulatieve aantal puistjes is en CLA het cumulatieve bladoppervlak, beide berekend van bovenin het bladerdek naar beneden, de totalen gestandaardiseerd op één. De gradiënt parameter b bedroeg gemiddeld 3.4 (SE=0.9). Waargenomen verschillen in steilte van de meeldauwprofielen beïnvloedde de schaderelatie niet aantoonbaar.     

杆式除草器的土壤反作用力

为了改进杆式除草器的入土性能并减少其牵引阻力,在实验室土槽内对四种不同形状的除草器的土壤反作用力进行了测试。本试验采用了裂区实验设计;土壤类型为主区,除草器的形状,转速、前进速度及耕深在小区内。实验数据是由一个计算机化六分力式数据采集系统采集的。在测试的四种形状中,十字形截面的除草器所受到的牵引阻力和垂直支反力最小,具有良好的入土性能,优于圆形、方形和三角形截面的除草器。     

一种驻车制动器固定座切边、冲孔复合模

介绍了驻车制动器固定座切边、冲孔模具的结构,分析了在成型中的受力情况,提出了模具结构设计方法,为驻车制动器固定座的成形问题提供了一种解决方案。     

杭州城区高架桥绿化现状与植物的选择

分析了杭州市城区高架桥(含立交桥，下同)绿化植物品种，探讨了高架桥绿化植物品种的选择方法，并提出了高架桥绿化养护保水第一的观点。     

钻孔灌注桩竖向承载力浅析

介绍了钻孔灌注桩竖向承载力常用的确定方法 ,并对各种方法做出了简单的评价 ,指出了各种方法的局限性和适用条件。可以为设计人员在桩基设计中提供有价值的参考。     

湖南秋季大棚无籽西瓜品种立架栽培技术研究

根据湖南秋季的气候特点,2012～2014年在湖南省岳阳市农业科技示范园、长沙市农作物品种展示基地（浏阳市淳口镇黄荆坪村）进行大棚秋季无籽西瓜品种立架栽培试验研究,参试品种为泉蜜308无籽、金丽黄无籽、博达隆一号无籽、黑童宝无籽、博帅无籽、神玉无籽、博达隆三号无籽、绿虎无籽、金蜜红无籽、蜜童无籽。试验结果表明,所有参试品种均表现出耐高温性强、抗性强、果皮外观漂亮、商品率高、瓤色鲜艳、口感好、无籽性能好、品质上佳、产量高等优点,适宜湖南丘陵地区与洞庭湖区等地秋季大棚立架栽培种植。     

Eulerian views of layered water currents, vertical distribution of some larval fishes, and inferred advective transport over the continental shelf off North Carolina, USA, in winter

Currents that effect the shoreward transport of the larvae of estuarine-dependent fishes spawned in winter in Onslow Bay, North Carolina, USA, were driven by winds and pressure gradients, and influenced by the Gulf Stream. Aside from storms, winds over the continental shelf in Onslow Bay blew predominantly alongshore with velocities approaching 14 m s^-1 during February and March 1986, and January and February 1989. Water masses and currents observed at two current-meter moorings, one at mid-shelf and the other on the outer shelf, reflected the onshore (or offshore) advection of interior water in compensation for the offshore (or onshore) advection of wind-driven surface water. Winds and currents reversed direction approximately every 4 to 6 days. The larvae of Atlantic menhaden, Brevoortia tyrannus , spot, Leiostomus xan- thurus, and Atlantic croaker, Micropogonias undulatus , were most abundant in 17–19^oC and 20–21^oC water of the outer shelf and Gulf Stream fronts. There was little indication of diel vertical migration; larval Atlantic menhaden were most abundant in mid- and surface water, while spot and Atlantic croaker were most abundant in mid- and deep water. Given this distribution, the inferred advective transport of larvae was at times onshore, but at other times it was offshore. Within a spawning season, the prevalence of either reciprocation could determine the number of larvae that reach coastal inlets.