东方蝼蛄膜翅表面形态与润湿性

利用扫描电镜分析了东方蝼蛄膜翅的表面形态.在OCA20型接触角测量仪上测量了水与东方蝼蛄膜翅展开表面各部位的接触角,分析了东方蝼蛄膜翅表面几何微结构与润湿性的关系.研究表明,东方蝼蛄膜翅展开后各部位的几何微结构各不相同,水与东方蝼蛄膜翅展开表面各部位的接触角平均值为94.4°～118.6°,表现出疏水性能.东方蝼蛄膜翅表面几何微结构与疏水性能的综合作用是其折叠后表面不沾土壤和水的重要机理.     

东方蝼蛄口器结构与表皮纳米力学性能研究

利用扫描电镜及能谱仪观察了东方蝼蛄口器表面及断面几何结构特征,对口器的表皮组成成分进行了分析,发现口器组织中含有多种金属元素和微量元素;东方蝼蛄口器具有中空结构,断面材料呈层状复合结构;采用切片法对东方蝼蛄口器进行了外形重构;利用纳米力学测试系统对东方蝼蛄口器表皮材料进行了测试,发现东方蝼蛄口器的弹性模量和纳米硬度较高.经比较发现,东方蝼蛄口器表皮的纳米硬度大于雄臭蜣螂唇基表皮的纳米硬度.     

东方蝼蛄前足爪趾结构与表皮纳米力学性能

利用扫描电镜分析了东方蝼蛄前足爪趾表面及断面几何结构特征,得知东方蝼蛄前足爪趾具有中空结构,断面材料呈层状复合结构.利用切片法分析了前足爪趾中空结构.利用纳米力学测试系统对东方蝼蛄前足爪趾表皮材料进行了测试,可知东方蝼蛄爪趾内侧的弹性模量和纳米硬度明显高于其爪趾外侧.与已有研究结果比较表明,东方蝼蛄爪趾表皮的纳米硬度高于臭蜣螂、粪堆粪金龟、弧齿爪鳃金龟的前足胫节表皮的纳米硬度,并高于牛蹄、羊蹄和猪蹄蹄壁材料的纳米硬度.     

蜻蜓翅膀表面疏水性能耦合机

利用扫描电子显微镜、傅里叶红外光谱仪和视频光学接触角测量仪对蜻蜓翅膀表面的微观结构、物质成分以及疏水性进行了研究,分析了蜻蜓翅膀表面微观结构、物质成分与翅膀表面疏水性能间的关系.结果表明,蜻蜓翅膀表面分布大量纳米级乳突结构,致使液滴与翅膀表面形成复合接触,增强了翅膀表面的疏水性;翅膀表面覆盖的蜡质层对蜻蜓翅膀表面的疏水性起增强作用.此外,利用Cassie模型建立了蜻蜓翅膀表面疏水方程,并进行了蜻蜓翅膀表面疏水性能的多元耦合机理分析,认为蜻蜓翅膀表面的疏水性能是由其表面物质成分和微观结构共同耦合作用的结果.     

猪笼草内表面微观结构及其浸润性研究

测量了猪笼草内表面各部位的接触角,发现超滑区疏水,最大接触角(150±2)°;超滑区和消化区有明显的浸润分界线;消化区亲水,最低接触角(16±2)°。研究发现超滑区呈微米级新月形、纳米级片状的复合结构,消化区呈微米级凹坑、网状褶皱的复合结构。结合化学处理和直接复制成形分析了内表面微结构和成分对浸润性的影响。结果表明超滑区的纳米级片状、网状蜡质结构对其超疏水特性起决定作用,消化区的接近超亲水特性主要与其表面物质成分有关,两个区域浸润性的大跨度变化是化学组成和表面形貌共同作用的结果。     

抽水蓄能机组不锈钢过流表面无氟疏水改性及其阻垢性能

针对抽水蓄能机组在运行过程中,过流金属表面往往存在结垢、腐蚀等难题,以无氟硅烷偶联剂为疏水改性剂,以环境友好的乙醇为溶剂,采用化学接枝法在304不锈钢基底上构筑疏水表面.重点考察预处理对304不锈钢基底微观形貌、粗糙度、水滴接触角等表面性质的影响,并进一步分析了304不锈钢基底粗糙度对疏水改性后水滴接触角的影响.304...     

疏水性表面流动减阻特性的试验

利用飞秒激光在si表面刻蚀具有不同宽度和深度的微槽形貌,经过硅烷化处理后,通过测量接触角和流变特性试验研究其疏水性与流动减阻特性关系.试验结果表明:接触角越大即疏水性愈强.减阻效果愈显著.因此,利用激光刻蚀表面方法可以在一定程度上调控固体表面的疏水性进而控制减阻特性.     

神农蜣螂前胸背板表面形态分形及润湿性

采用 3D SRAT 1型轮廓仪对神农蜣螂 (Catharsius molossus L innaeus)前胸背板表面形态进行了定量测量 ,在 JC2 0 0 0 A型表面张力 /接触角测量仪上测量了水与前胸背板表面的接触角 ,并基于分形理论对其表面轮廓进行了分析。研究表明 :神农蜣螂前胸背板表面呈现分形特征 ,由结构函数法和变分法估算的沿前胸背板表面纵向轮廓线的分形维数分别为 1.877和 1.86 8;水在神农蜣螂前胸背板表面上的表观接触角为 91°～ 10 6 .5°,其平均值为 97.2°,表现了很强的疏水性     

大豆播种机破碎式仿生覆土装置设计与试验

受东方蝼蛄刺状挖掘足能够高效挖掘土壤的启发,设计了大豆播种机破碎式覆土装置,以提高其碎土性能。对东方蝼蛄前足的趾爪趾长、趾尖角、趾间距、侧面的楔角进行测量,以此为依据设计了仿生碎土圆盘。破碎式仿生覆土装置由大小碎土圆盘、折弯法兰、固定机架、旋转副、减震弹簧和悬挂架组成。本覆土装置专为双行种子沟设计,可实现对大豆沟槽双侧进行覆土。对仿生碎土圆盘碎土齿进行了受力分析,并利用Ansys及Ls-Dyna软件对所设计部件进行仿真优化分析,得到碎土圆盘切削受力情况土壤的等效应力分布以及覆土过程中种子横向位移。田间试验结果表明破碎式仿生覆土装置完成了覆土功能要求,破碎率达到92.2%,平均覆土厚度为2.4 cm,平均种子行间距为10.1 cm。     

基于逆向工程的黄蜻膜翅几何数据采集与处理

利用激光三维扫描系统测量了黄蜻膜翅样品的几何外形,获取了黄蜻膜翅几何表面的外形数据点群.利用逆向工程软件对黄蜻膜翅点群数据删除跳点、坏点及与研究无关的数据点并进行平滑和精简处理.根据黄蜻膜翅的外形特征,通过框选点群命令,从点群数据中提取其边界曲线,并对曲线进行调整,将调整好的边界曲线两两拼接在一起,形成黄蜻膜翅较完整的边界曲线.采用由点和曲线形成曲面中的混合点群加边界曲线的造型方法,成功进行了黄蜻膜翅外形三维几何曲面模型的重构.     

沙棘、柠条和侧柏抗旱能力对比试验

为进一步探究沙棘、柠条和侧柏的抗干旱能力,选择2年生沙棘扦插苗和2年生柠条、侧柏播种苗,对3个树种的光合生理指标和水分生理指标进行了测试,分析了3个树种的抗旱能力。试验结果表明,侧柏相对于沙棘和柠条具有更好的抗旱能力,同一时期内,侧柏的含水量、束缚水和自由水比值和临界饱和亏数值最大。因此,侧柏在3个树种中更具备抗旱耐贫瘠能力,在青海省互助县荒山造林、干旱半干旱地区造林中应该优先考虑使用侧柏。      

马铃薯仿生挖掘铲片及其减阻特性研究

设计了一种马铃薯仿生挖掘铲片,研究其在土壤运动过程中的减阻性能。运用仿生手段对蝼蛄前爪第一趾进行仿生信息的提取,设计了一种马铃薯仿生挖掘铲片,利用EDEM对挖掘铲片进行挖掘土壤过程仿真。在EDEM仿真过程中,根据铲片对土壤的扰动情况分析可知:仿生挖掘铲片对土壤应力较分散,铲面具有碎土能力,挖掘方向所受平均阻力为118.212N;普通挖掘铲片对土壤应力较集中,铲面不具有碎土能力,挖掘方向所受平均阻力值为159.508N;仿生挖掘铲片较普通挖掘铲片所受平均阻力减小近35%,仿生挖掘铲更具优良的挖掘性能。     

黄土高原中部主要乡土树种生长过程分析

本文对黄土高原中部油松、侧柏、刺槐、沙棘、胡颓子和火炬树等乡土树种树高、胸径及材积生长量进行了测定,结果表明：研究区树高生长曲线分两种类型,以油松、侧柏等人工实生林为一种类型,即满足“慢一快一缓慢一稳降”生长规律,沙棘、火炬树等萌蘖林开始生长较快,之后逐渐降低并趋于稳定。6树种树高平均生长量为0．4518±0．2763...     

不同水土保持模式下坡耕地的土壤水分特征

针对松嫩平原北部丘陵漫岗区坡耕地存在的干旱与水土流失并存的问题,选取了垄向区田、鼠道、鼠道+暗管、鼠道+垄向区田、鼠道+暗管+垄向区田、常规耕作等6种水土保持技术模式,研究了土壤水分变化特征。结果表明,从整体上看,不同水土保持技术模式0～100cm土层土壤储水量与时段降雨量变化趋势一致,土壤储水量大小的技术模式依次为,鼠道+暗管+垄向区田>鼠道+垄向区田>垄向区田>鼠道+暗管>鼠道>常规耕作。各水土保持技术模式的总蒸散量大小依次为:鼠道+暗管+垄向区田>鼠道+垄向区田>鼠道+暗管>鼠道>垄向区田>常规耕作。研究结果为松嫩平原北部丘陵漫岗区坡耕地水土保持技术模式的合理选择提供依据。     

Improving mole drainage channel stability in irrigated areas

Mole drains in flood irrigated agriculture can rapidly fail due to high flows of irrigation water entering the mole channel through the soil cracks formed during the moling process. Currently mole drains are formed using a straight leg mole plough that results in rapid irrigation water flow to the mole drain. The use of an angled leg mole plough to reduce the direct inflow of irrigation water and produce more stable mole channels was investigated. The leg of the angled leg mole plough comprised an upper vertical section to which an angled section carrying the mole foot was attached at a 30° angle. The trials were carried out on two contrasting clay soils in a flood irrigated area. One of the soil types was structurally stable on wetting, the other unstable. The quality of the mole channels formed at installation using the straight leg plough was good, but using the angled leg plough were only moderate due to some instability problems with the equipment. This was caused by the mole foot pitching and thus forming an oval channel.After installation, irrigation was applied to the mole channels to ascertain their stability on wetting. The angled leg moles proved more stable than the straight leg moles in the unstable soil. This was due to reduced water flow rates into the channel causing less erosion and to the prevention of the leg slot opening up directly into the mole channel, through shrinkage, during dry periods. The latter prevented significant soil wash and ingress into the channel during the following irrigation. This improved stability is of significant importance in that it may allow the adoption of mole drainage on sodic and swell/shrink soils where previously mole drainage would have been ineffective.In the structurally stable soil, the stability of the angled leg moles was found to be slightly worse than those installed with the straight leg plough. This was probably due to inadequate soil packing in the channel roof during installation.The trial results indicate that mole channels installed with angled leg plough have the potential for much greater stability on sodic and swell/shrink soils than moles installed with current straight leg mole ploughs. Before this potential can be fully achieved further development of the mole ploughing technique is required to ensure that high quality moles are consistently formed at installation. Suggestions are made for future improvements to the mole plough and the moling technique.     

Effect of mole submergence on the life of mole channels

It has been suggested that submergence of mole channels in field drainage systems will cause their premature collapse and lead to a failure of the system. Limited experience on Field Drainage Experimental Unit's sites has not supported this view.An experiment was set up on a clay soil with a good moling potential, and where a previous moling had lasted up to 5 years. In a pumped drainage scheme submergence was examined to determine if it was a cause of mole channel failure. Isolated plots were subjected to short (usually less than 3 h) and long periods (up to 20 days) of submergence. The hydrological performance and the condition of the mole channels was monitored for 5 years.Short periods of submergence did not appear to have a substantial effect on the mole drainage system and a 4–5-year life of the mole channels could be expected. Longer periods of submergence did not cause any immediate deterioration but the gradual collapse of the roof and side walls, which was the normal mode of failure, became more accentuated. This effect reduced the life of the mole channels to 3–4 years, although 3 years after moling the watertable control of the submerged plots was substantially better than similar adjacent undrained land.