双层摊铺沥青路面层间抗剪性能试验研究

沥青路面层间结合状态是影响其力学性能与使用性能的关键因素。沥青路面双层连续摊铺技术是一种新型的施工技术,是将两种不同级配的沥青混合料同时摊铺碾压,与传统的摊铺方式相比,能够提升层间结合状态、施工周期较短等优点。为研究两种摊铺方式的沥青路面层间结合特性的差异,本文通过室内试验模拟传统分层摊铺条件下粘层油用量、污染程度和双层连续摊铺层间结合方式,研究其对层间抗剪性能的影响。试验结果表明:传统分层摊铺过程中,污染物是降低层间结合性能的主要原因。在所有层间处理方法中,双层连续摊铺得到的层间抗剪强度最高,是传统无粘层油分层摊铺的1.7倍;比传统分层摊铺最佳层间结合状态(最佳粘层油含量、无污染)下的抗剪强度提高27%。     

浅析橡胶沥青碎石应力吸收层在路面维修中的应用

在"低碳、环保"的政策要求下,橡胶沥青材料得到了广泛应用,不仅可以充分利用废弃轮胎,还能延缓沥青路面反射裂缝,增强层间粘结性能,对我国公路路面养护事业发展意义重大.在全面了解橡胶沥青碎石应力吸收层特点的基础上,结合具体案例,对路面维修中橡胶沥青碎石应力吸收层的应用要点进行了分析与探究.     

浅析复合改性橡胶沥青应力吸收层的应用

应力吸收层的设置主要是为了抑制或避免路面裂缝在行车荷载和自然因素作用下向面层扩展。因此,应力吸收层混合料的性能对路面的使用性能、耐久性影响较大。以复合改性橡胶沥青应力吸收层为研究对象,分析了其路用性能,并结合具体案例,对应力吸收层施工技术要点进行了分析与探讨。     

静态大载荷下典型沥青混凝土路面的响应试验

为获取静态大载荷下沥青混凝土路面的动态响应，以压缩空气为动力源，搭建了静态大载荷模拟加载装置用以模拟生成静态大载荷，在三维试槽中铺筑了2种低等级沥青混凝土路面，并在其中铺设位移传感器、土压力传感器，进行了模拟加载试验。在此基础上，对比分析了2种路面路表位移变化规律，研究了土层压应力与深度及载荷作用距离间的关系。试验结果表明：静态大载荷下路面发生弹性变形，可忽略静态大载荷卸载后对路面承载能力的影响；水稳碎石层可显著减小路面的峰值位移、土层峰值应力。     

基于串并联理论木材导热系数的初探研究

为定量表征木材纵向与横向导热系数,笔者基于木材宏观特征与微观构造,结合电阻串并联理论,建立了木材纵向和横向导热系数模型,系统分析了木材密度、水分及温度对木材纵横导热系数的影响规律。并以樟木为例,系统研究了不同温度及含水率状态下樟木导热规律,验证了木材纵横导热系数模型的准确性。利用该模型可以快速推导木材的导热系数,为量化分析木材干燥及热处理过程提供理论基础。     

LQFM防滑路面材料工艺在园林绿化项目中的应用价值

本文介绍了一种用于防滑路面的彩色结合料LQFM。LQFM路面是由聚合物、树脂、软化剂、外加剂和以陶瓷颗粒为骨料的防滑彩色路面。笔者通过多次反复试验,根据济南四季天气温度变化特点,按照一定的混配比例,基于马歇尔设计法进行的路用性能测试,结果表明：LQFM防滑路面材料在零下28摄氏度低温下的抗变性,超过60度高温下的稳定性,水稳定性和疲劳特性等都远远超过进口沥青混合料的性能。本文主要介绍了LQFM防滑路面材料的性能及在园林景观中的应用价值。     

含水率非均匀分布木材在热板加热下温度分布的变化规律

热作用下温度分布和含水率分布的变化规律,是实木层状压缩形成机制研究的基础。以初含水率处于非均匀分布状态下的毛白杨木材为对象,研究在180℃热板夹持加热过程中的温度分布变化规律,为揭示层状压缩形成机制提供科学依据。结果表明：初始含水率表层高、内部低的木材,在热板夹持加热过程中,厚度方向上始终存在一个明显的升温速率峰值。随着加热时间的延长,升温速率峰值和高含水率层逐渐向中心移动;高含水率区域内木材,温度较玻璃化转变温度高6.11～47.58℃,处于层状软化状态,是层状压缩形成的重要原因之一;采用多元线性回归分析方法建立的木材厚度方向温度预测多变量函数模型,决定系数为0.985,预测木材内部温度的标准误差为3.21℃,能够用于木材内部温度分布的预测。     

同步沥青碎石封层的关键技术及施工控制

同步沥青碎石封层技术是新兴起的一项公路施工养护技术,是近期我国从法国引入并在我国较为盛行的技术。通过实践比较,同步沥青碎石封层的防水性能、层间粘结力、路面反射裂缝性、层间排水功能以及抗裂性能等优势很突出,能够为延长路面使用寿命做出贡献,并且工程的成本也并不高昂。文章就同步沥青碎石封层新技术的要求及施工控制展开论述。     

北方寒带地区水泥混凝土路面配合比设计

本文结合寒带地区的气候特点,减少施工过程的断板率,提高路面抗冻耐久性,保证路面良好的使用状态是水泥砼路面配合比设计中的重点。     

温度场与应力场耦合作用的喷砼边坡变形分析与控制

采用有限元的方法考虑地应力与温度应力的耦合作用,分析了在不同的边界温度作用下边坡应力场的交变特性和作用特点;边坡喷层面与岩层结合面处的剪应力的分布规律.指出在温度应力与地应力的耦合作用下,喷砼边坡坡顶与坡脚均为容易发生破坏的地方,通常坡顶的破坏形式为拉张破坏而坡脚则为剪切破坏.分析所得的温度场变化和变形与观测值变化规律一致,当温度变化剧烈时,边坡的防护必须考虑温度应力的影响.在分析喷射混凝土边坡变形机制的基础上,提出了相应控制措施,为优化工程设计、施工方案提供可靠的、定量的科学依据.     

两种危害松类的新叶蜂(膜翅目, 广腰亚目, 松叶蜂科)

本文记述了中国松叶蜂昆虫两新种,马尾松吉松叶蜂和油松吉松叶蜂。文中附有形态特征图4幅。     

赣中北毛竹表型特征的地理变异初探

调查研究江西省中北部6个毛竹林（Ⅲ度竹）的胸径、全株杆鲜重、全株枝叶鲜重、杆长、全杆节数、枝下节数、枝盘数、枝下高、叶长和叶宽、叶片长宽比、胸径处竹壁厚度、竹腔径、壁腔比、竹材含水率等表型特征。运用SAS8.1软件进行多元线性回归分析和偏相关分析,研究表明：全株杆鲜重、全株枝叶鲜重和胸径处竹壁厚呈现随经度变化的地理模式,其它表型特征随经度的变化不明显;所调查的表型特征均没有表现随纬度和海拔的变化而变化的地理变异模式。     

Chemical study and medical application of saponins as anti-cancer agents

Saponins are a group of naturally occurring plant glycosides, characterized by their strong foam-forming properties in aqueous solution. The presence of saponins has been reported in more than 100 families of plants out of which at least 150 kinds of natural saponins have been found to possess significant anti-cancer properties. There are more than 11 distinguished classes of saponins including dammaranes, tirucallanes, lupanes, hopanes, oleananes, taraxasteranes, ursanes, cycloartanes, lanostanes, cucurbitanes and steroids. Due to the great variability of their structures, saponins always display anti-tumorigenic effects through varieties of antitumor pathways. In addition, there are a large amount of saponins that still either remain to be trapped or studied in details by the medicinal chemists. This article reviews many such structures and their related chemistry along with the recent advances in understanding mechanism of action and structure–function relationships of saponins at the molecular and cellular levels. These aglycones have been described and their classification and distribution have been listed in the review. Some special saponins with strong antitumor effects have also been exhibited. Ginsenosides, belonging to dammaranes, have been found beneficial targeted on inhibition of tumor angiogenesis by suppressing its inducer in the endothelial cells of blood vessels, and then on prevention of adhering, invasion, and metastasis of tumor cells. Dioscin, one of the steroidal saponins, and its aglycone diosgenin also have been extensively studied on its antitumor effect by cell cycle arrest and apoptosis. Other important molecules discussed include oleanane saponins such as avicins, platycodons, saikosaponins, and soysaponins along with tubeimosides.     

一个世纪来黑龙江省森林景观动态研究

With the help of GIS tool of ARC/INFO,ARCVIEW and FRAGSTATS,the map of forest resource distribution of Heilongjiang Province was analyzed in 1896,1949 and 1981.Using total area,mean patch size,patch density,coefficient of patch size variation,mean patch fractal dimension and mean shape index,we studied the change of forest landscape pattem and the change of each patch types in this region.As a result,the total area of forest landscape and mean patch size decreased sharply,the quantity and density of patches increased,the juxtaposition of patches weakened,the shape of patch tended to become regular,and the border of patch simplified.All these showed that the forest landscape of this area tended to fragment gradually,and the fragment of Korean pine forest is the severest.the diversity of whole forest landscape and the eveness of landscape types distribution reduced gradually.Human impact,instead of climate change and forest community succession,is the most important reason for such dramatic chages.     

秃杉的物种确立、天然林种群特征、保护、引种和种源选择研究

根据秃杉有关的研究文献,对秃杉物种的确立,天然林的生物多样性、空间分布、动态和更新演替等种群特征,原生地保护与迁地保护,引种地气候和立地的适应性,速生性,抗寒、耐高温干旱、耐萌、抗风和抗病虫害能力等抗逆性,种源的遗传多样性,种源地理变异和生态适应性,种子、苗期及林木生长的变异,不同年龄林木生长性状的相关性,优良种源选择和种源区划等的研究进行了综合评述。     

论人本主义管理理念

组织最重要的资源是人,要实现组织目标就要有合理的管理,人本主义管理理念就是在管理过程中以人为本,以尊重人格,突出柔性管理,关心员工发展的双赢策略,确立员工的主人翁地位和注重员工培训为人本主义管理的思想内容。     

哈尔滨工程大学校园绿化改造方案

本文通过对哈尔滨工程大学绿化现状的分析,在规划中,提出了"一园、二区、三空间、四廊道、六组团"整体绿化景观,使设计更科学、布局更完整、结构更清晰。在新校区规划为体现学校从"发现—研究—收获"的这一发展历程。提出"新校区、新建筑、新景观"的思想,设计出简洁、现代、生态且充满创造精神的新景观。结合不同的区域特点分别提出了详细设计方案,展现出知识不断求索创新、积累升华的过程。     

中国林业战略的现状及可持续发展战略

本文通过对中国林业的现状及存在的一系列生态、环境、经济和社会问题的分析讨论,重点强调了森林及整个林业在我国社会和经济发展中的重要作用。同时,作者提出可持续发展,特别是林业的可持续发展是解决我国当前生态环境和经济社会问题的关键和必由之路。并从生态学、经济学和社会学的角度,论证和阐述了林业可持续发展的目标、准则,以及我国林业的可持续发展战略。参11。     

Decomposition and nutrient release in needle litter from nitrogen‐fertilized scots pine (pinus sylvestris) stands

Decomposition of Scots pine needle litter originating from five stands treated with different amounts of nitrogen fertilizer was measured over a 4‐year period in a mature Scots pine forest. The litter types, which differed in initial concentrations of nitrogen, phosphorus, potassium, and sulfur, but not in gross organic composition, were studied with respect to mass loss, ingrowth of total fungal mycelium, and net release of nutrients. During the first year of decomposition, rates of mass loss and ingrowth of fungal mycelium were highest in the nutrient‐rich litter. Phosphorus concentration was found to be the main factor affecting mass‐loss rate, and the rate of fungal ingrowth was positively correlated with initial nitrogen concentration. After this initial period, decomposition rates decreased, and after 4 years, accumulated mass loss and amounts of fungal mycelium were similar in all five litter types. These findings may be due, in part, to a lower rate of lignin decomposition in nitrogen‐enriched litter. Of the elements, potassium and magnesium were most rapidly lost from the litter, and their release was most pronounced during the first year. Calcium release was proportional to the loss in organic matter. Initially, the release of nitrogen and phosphorus was positively related to their concentrations in litter, however, during later stages of decomposition the differences among litter types levelled out. There was a tendency for concentrations of all elements, except nitrogen, in the different litters to approach similar levels as decomposition proceeded. Thus, after 4 years the nutrient composition of the various litter types was very similar, except for higher nitrogen concentrations in the originally most nutrient‐rich litters. The importance of the results in terms of substrate quality in fertilized as well as in non‐fertilized forests is discussed.     

竹业引领人类生活更美好

文章介绍了竹材在建筑、家具、交通、日用品等领域的应用现状,分析了竹材在性能、成本、资源量及环保等方面具有的多种优势,以及木材、塑料、钢材、陶瓷应用局限性和劣势,提出了竹木并举、以竹代塑、竹钢协同、竹瓷互补潜在的创新应用方向。在当前化石能源日益枯竭、环境压力越来越大的情况下,发展竹产业、应用竹产品是一项改变人类生活、促进绿色发展的重要举措,是健康生活、生态人居、绿色发展的正确方向。