卸荷引起堆积体边坡变形的空间变异性分析

利用地质统计学原理和遗传算法,确定出卸荷条件下堆积体边坡变形的变异函数,对堆积体边坡进行卸荷条件下变形的时间变异性分析.采用角度误差限和距离误差限,对并不完全呈网格状的实际观测点布置进行网格化处理,求出各方向的变异函数,进行卸荷条件堆积体边坡变形的空间变异性分析,同时构造出方向综合变异指标,分析堆积体边坡卸荷条件下哪个方向的变异性最大,从而关注此方向的变形发展.利用熵权理论对普通克立格方程组的负权值进行修正,用修正后的权值对卸荷条件下堆积体边坡待估点的变形进行普通克立格估值.用所提理论对堆积体边坡卸荷时实际监测到的变形资料进行空间变异性分析,分析结果和实际监测情况较吻合,证明了分析理论的正确性和可行性,也为变形分析提供了一种新的分析方法和思路.     

浦城县水稻配方肥开发应用现状及发展方向

对近年来浦城县推广应用水稻配方肥状况及今后发展方向进行阐述。     

北京山区农村居民点整理用地转换方向模拟

农村居民点用地不同转换方向将对区域景观格局带来不同的环境效应,如何因地制宜地科学确定农村居民点整理方向是当前农村居民点整理工作中需解决的一个重要基础理论问题。该文使用CA-Markov模型对北京山区未来土地利用进行了多情景模拟,进而对其景观格局指数进行了比较分析,以反映不同农村居民点转换方向引起的不同环境效应。研究结果表明,山区农村居民点用地整理去向为耕地和园地时景观效应较差,而依靠适宜性评价结果或整理成林地则取得较好景观效应。因而,在当前北京山区农村居民点整理过程中,应审慎看待整理为耕地或者园地的普遍做法,在科学评价的基础上因地制宜地确定山区农村居民点的整理方向,使其与其周围基质相谐调以更好地优化土地利用总体格局获取最大环境效益。     

Effect of magnitude and direction of force on laryngeal abduction: Implications for the nerve‐muscle pedicle graft technique

Reasons for performing study: The nerve‐muscle pedicle graft technique is a treatment for recurrent laryngeal neuropathy (RLN), but the optimal placement of the pedicles within the cricoarytenoideus dorsalis (CAD) muscle is unknown. Hypothesis: The magnitude and direction of force placed on the muscular process of the left arytenoid cartilage affects the magnitude of laryngeal abduction. Methods: Five larynges were harvested from cadavers. Using increments of 0.98 N, a dead‐weight force generator applied a force of 0–14.7 N for 1 min each to the left muscular process at 0, 10, 20, 30, 40, 50, 60 and 70° angles. The rima glottis was photographed digitally 1 min after each force had been applied. Distances between biomarkers (Lines 1–4) and right to left angle quotient (RLQ) were used to assess the degree of left arytenoid abduction. Results: Increasing force from 0–14.7 N progressively and significantly increased the length of all lines and RLQ, indicating abduction. Furthermore, there was a significant interaction between force and angles. Applying forces of 7.84 N or greater (Lines 2–4 and RLQ) or 11.76 N or greater (Line 1) at angles 0, 10, 20 and 30° resulted in significantly greater abduction than applying the same forces at 40, 50, 60 and 70°. Angles of 0–30° correspond with the direction of pull exerted by the lateral compartment of the CAD muscle. Conclusion: In RLN, nerve‐muscle pedicle grafts should be placed preferentially in the lateral rather than in the medial compartment of the CAD muscle. Potential relevance: The information presented can be used to assist surgeons in the planning and application of the nerve‐muscle pedicle graft procedure.     

Silvicultural treatments enhance growth rates of future crop trees in a tropical dry forest

Silvicultural treatments are often needed in selectively logged tropical forest to enhance the growth rates of many commercial tree species and, consequently, for recovering a larger proportion of the initial volume harvested over the next cutting cycle. The available data in the literature suggest, however, that the effect of silvicultural treatments on tree growth is smaller in dry forests than in humid forest tree species. In this study, we analyze the effect of logging and application of additional silvicultural treatments (liana cutting and girdling of competing trees) on the growth rates of future crop trees (FCTs; i.e., trees of current and potentially commercial timber species with adequate form and apparent growth potential). The study was carried out in a tropical dry forest in Bolivia where a set of 21.25-ha plots were monitored for 4 years post-logging. Plots received one of four treatments that varied in intensity of both logging and silvicultural treatments as follows: normal (reduced-impact) logging; normal logging and low-intensity silviculture; increased logging intensity and high-intensity silviculture; and, unlogged controls. The silvicultural treatments applied to FCTs involved liberation from lianas and overtopping trees. Results showed that rates of FCT stem diameter growth increased with light availability, logging intensity, and intensity of silvicultural treatments, and decrease with liana infestation degree. Growth rate increment was larger in the light and intensive silvicultural treatment (22–27%). Long-lived pioneer species showed the strongest response to intensive silviculture (50% increase) followed by total shade-tolerant species (24%) and partial shade-tolerant species (10%). While reduced-impact logging is often not sufficient to guarantee the sustainability of timber yields, application of silvicultural treatments that substantially enhanced the growth rates of FCTs will help move the management of these forests closer to the goal of sustained yield.     

曼稿自然保护区野生大花万代兰分布现状

在西双版纳曼稿自然保护区的4个天然植被亚型中选设了5条调查样线,以搞清自然保护区大花万代兰的垂直分布、生境选择及其附主植物．结果表明：曼稿自然保护区海拔1130～1600m范围均有野生大花万代兰分布,分布最为集中的是海拔1200～1450m的针阔混交林;多分布于林木上层郁闭度50％～60％的阳坡地段;主要附主植物有毛叶青冈、大叶栎、黑黄檀、银叶栲等．针对野生大花万代兰具有的保护价值及其目前所面临的各种威胁．提出加大管护力度、对其分布及种群数量进行长期性监测、开展人工培育技术研究等保护建议．     

浅谈农业信息传播方式

通过对我国农业信息化起步与现状的分析,结合发达国家农业信息传播领域的先进技术经验,从加强农业推广教育的功能、发挥大众新闻传播媒体的作用、加强农业信息传播自动化步伐三方面着手,预测我国农业信息传播未来的发展趋势需要。     

基于UG的汽车覆盖件冲压方向优化方法

为快速准确地获得覆盖件的冲压方向,在研究了影响冲压方向的主要因素之后,提出了以UG NX作为平台的冲压方向优化算法.建立以初始接触面积、极限拉延深度为冲压方向影响因素的目标函数,以无负角为约束条件求出冲压方向的可行域.通过线性加权和法将多目标函数转化为单目标函数,利用优化算法对可行域内的冲压方向进行优化,求出覆盖件的冲压方向,并以此算法编写了程序代码,最后通过Dynaform进行了实例验证,证明了算法的有效性.     

玉米叶片定向生长栽培研究

玉米叶片生长习性为互生,叶片生长方向受数量性状遗传和种胚发育特性双重因素控制。通过人为干预种胚在土壤中的空间位置,可实现玉米叶片的定向生长。试验通过不同种植密度,不同种植行向,不同品种类型对玉米叶片定向生长的影响进行研究。结果表明,人为控制种子种胚的播种方位,可有效提高叶片生长的定向率,进而合理增加种植密度至13.5万株hm2,提高产量15%左右。种植行向对定向率无影响,紧凑型品种定向率高于半紧凑型和平展型。      

台湾花东纵谷河床新兴地果园内之风向与风速变化

研究自2007年11月至2010年1月于台湾东部花东纵谷区域之台东县鹿野乡河床新兴地番荔枝栽植区,择定一面积32 000 m²之番荔枝果园为试区（22°56’56.4″N,121°8’56.4″E）,果树平均高度为2.2 m,树龄5 a以上。先利用观测铁塔于距离地面2.5 m及6 m处来测定风向及风速,再藉分析以探讨该果园内之气流行进分布特性。结果表明:花东纵谷南部区域河床新兴地于每日出现逐时平均风速趋近静风状态时,可作为区分昼夜间风场特性之依据,而昼夜间之时段分别为7:00—19:00及20:00至翌日6:00。当强盛偏北气流行进至花东纵谷区域河床新兴地之风场内,区域内风速会在1.0 h内激增,且于果园试区内果树冠层上0.3 m高度之风速达3.8 m/s,对于果树之枝干将产生摇曳不止的情形,将造成果实易受磨损及不利果树生长。