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.     

THE PROLONGATION STRUCTURES AND NONLOCAL SYMMETRIES FOR MODIFIED BOUSSINESQ SYSTEM

The Wahlquist-Estabrook （WE） prolongation structures of modified Boussi-nesq （MB） system are studied from the coverings point of view. The realizations and classifications of one-dimensional coverings of this system are obtained completely. More-over the sufficient and necessary conditions for a vector field to be a nonlocal symmetry of this system are also demonstrated in the WE prolongation structures.     

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。     

Ni／丝光沸石覆盖物的特性

采用蒸气相法合成了Ｎｉ／丝光沸石覆盖物，用ＸＲＤ，ＳＥＭ，电子能谱证明了合成的材料为丝光沸石包覆于金属镍粉表面成的复合物。用二甲本异构化探针反应和ＮＨ３－ＴＰＤ考察了该包覆物的催化活性及酸性。结果表明，Ｎｉ／丝光沸石覆盖物具有良好的表面酸性，二甲苯异构化的活性均高于采用同样方法合成的Ｃｒ／丝光沸石覆盖物，间二甲苯异构化活性可以达到９７％。     

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.     

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.