地面覆盖物对交通噪声衰减量的研究

就地面覆盖物（包括农作物、草地、裸露的土壤等）对交通噪声衰减量的影响进行了深入研究。通过大量现场测试、数据处理与分析，重新确定了衰减因子的取值，建立了由地面覆盖物所引起的交通噪声附加衰减量与水平距离之间更为合理的关系式，最后，对回归方程的精度进行了检验。     

覆盖物对低温热水地板辐射盘管散热影响分析

建立带有覆盖物的低温热水地板辐射盘管散热模型,利用F luent软件模拟不同覆盖物尺寸对低温热水地板辐射盘管散热的影响。研究结果表明:(1)在一定的覆盖物面积内,覆盖物面积增加造成地板局部升温。(2)在一定的覆盖物面积内,覆盖物的面积与地板的散热量减少成正比,但继续增加尺寸,其对低温热水地板辐射盘管散热的影响则不再明显。     

有机覆盖物在植物园的应用

本刊从2006年开始刊登“迎绿色奥运,从细节做起”系列报道,受到大家的关注,从2007年开始,本栏目改为“绿色北京,绿色奥运”,在介绍国外绿化经验的同时,也将介绍北京相关的绿化成绩。绿色奥运宣讲团:由首都精神文明办、市科委、市环保局、北京奥组委环境活动部、市科协、北京环保基金会主办;由专家、学者组成;以弘扬奥林匹克精神、宣传绿色奥运理念为基本宗旨。     

A case for mantle plumes

The existence of at least several plumes in the Earth＇s mantle can be inferred with few assumptions from well-established observations. As well, thermal mantle plumes can be predicted from well-established and quantified fluid dynamics and a plausible assumption about the Earth＇s early thermal state. Some additional important observations, especially of flood basalts and rift-related magmatism, have been shown to be plausibly consistent with the physical theory. Recent claims to have detected plumes using seismic tomography may comprise the most direct evidence for plumes, but plume tails are likely to be difficult to resolve definitively and the claims need to be well tested. Although significant questions remain about its viability, the plume hypothesis thus seems to be well worth continued investigation. Nevertheless there are many non-plate-related magmatic phenomena whose association with plumes is unclear or unlikely. Compositional buoyancy has recently been shown potentially to substantially complicate the dynamics of plumes, and this may lead to explanations for a wider range of phenomena, including “headless” hotspot tracks, than purely thermal plumes.     

河南地区西洋红南瓜栽培技术（中）

西洋红南瓜根系再生能力没有中国南瓜强，大苗定植缓苗慢，发棵迟，产量受影响。因此，多采用小苗定植。当苗具2叶1心时即可减少覆盖物降温炼苗，提高幼苗抗性，防止植株徒长。     

Mantle plumes： Why the current skepticism？

The present reappraisal of the mantle plume hypothesis is perhaps the most exciting current debate in Earth science. Nevertheless, the fundamental reasons for why it has arisen are often not well understood. They are that 1） many observations do not agree with the predictions of the original model, 2） it is possible that convection of the sort required to generate thermal plumes in the Earth＇s mantle does not occur, 3） so many variants of the original model have been invoked to accommodate conflicting data that the plume hypthesis is in practice no longer testable, and 4） alternative models are viable, though these have been largely neglected by researchers. Regardless of the final outcome, the present vigorous debate is to be welcomed since it is likely to stimulate new discoveries in a way that unquestioning acceptance of the conventional plume model will not.     

自然覆盖物对塔里木沙漠公路防护林土壤蒸发的影响

为了揭示塔里木沙漠公路防护林内覆盖物对土壤水分蒸发的影响,在塔克拉玛干沙漠腹地进行人工模拟蒸发实验,为其防护林水资源高效利用和灌溉制度优化提供科学依据.研究结果表明:(1)积沙层、盐结皮层、枯落物和积沙-枯落物混合层等覆盖物阻隔土壤蒸发,对土壤水分蒸发作用影响明显;日蒸发量、累积蒸发量和蒸发速率都较无覆盖物沙地大幅降低,而且覆盖物越厚,降低幅度越大;覆盖条件下蒸发受其他因素影响较小,日蒸发量变幅降低,累积蒸发呈线性分布,累计蒸发曲线近似直线,而裸沙地累积蒸发则呈正对数分布,累计蒸发曲线近似折线,蒸发受其他因素影响较大,日蒸发量变幅大,蒸发过程具有阶段性;(2)覆盖物的蒸发抑制效率明显,而且随覆盖物厚度增加而成对数函数增加,当覆盖物厚度增加到一定程度时,蒸发抑制效率增幅逐渐降低;各覆盖物在2cm厚度的蒸发抑制效率差别不大,最大蒸发抑制效率(根据灌溉第1天日蒸发量计算)则为:积沙-枯落物混合层(79.92%)>枯落物(78.96%)>盐结皮层(75.58%)>积沙层(74.11%),现实蒸发抑制效率(根据灌溉周期末(14天)的土壤累积蒸发量计算)则为:盐结皮层(67.78%)>积沙-枯落物混合层层(66.72%)...     

悬气室保温棚膜

悬气室保温棚膜的最大特点和优势在于选择了最佳保温介质——空气，利用了膜体自身结构的特征，形成一种无需空气不会泄气却能保持始终如一的高效保温层。悬气膜造价可与普通膜持平(指单位重量成本)。它的保温效果在外界气温为-17℃时，棚内为接近零度。一般可在外界气温最低为-10℃以上的地区。不加盖任何覆盖物即可保障棚温正常，和普通日光温室加盖草苫的效果相当。同期经济投入只有现行温室的不足三分之一。     

覆盖物对落叶松种苗生长的影响

在长白山森工集团四方山苗圃播种区,研究覆盖物对落叶松种苗的影响.试验结果表明,腐殖土和锯沫混合做落叶松覆盖物效果最好;马粪草炭混合做覆盖物效果也比较好,但是不能单独使用;河沙和锯沫混合可做为新改或易生杂草土地育苗地的播种覆盖物.     

夏玉米二点委夜蛾的防治

对于夏玉米二点委夜蛾，应以预防为主。麦收后要及时清除田内麦秸、麦糠和杂草，或在玉米出苗后及时清除玉米苗基部的麦秸、杂草等覆盖物，可把覆盖在玉米垄中的麦糠、麦秸全部清除到远离植株的玉米大行间并裸露地面，有条件的可把麦秸、