园林建设过程中硬质材料设计方法研究

当前研究节约型园林建设过程中硬质材料设计问题已经成为园林建设的关键,园林绿化过程中必须突出节约性原则,做到投入最少的资金和材料,实现园林经济效益和社会效益最大化,从而保证城市园林绿化过程实现可持续性发展.现对园林建设过程中硬质材料使用的科学性、合理性、有效性进行综述.     

Construction of a lentiviral RNA interference vector targeting rat myocardin and its effect on vascular smooth muscle cell differentiation

AIM: To construct a lentiviral RNA interference(RNAi)vector targeting rat myocardin mRNA and to investigate its effect on the differentiation of vascular smooth muscle cells(VSMCs).METHODS: Three pairs of dsDNA targeting rat myocardin mRNA were designed, synthesized and cloned into lentiviral vector pGCSIL-GFP to generate pGCSIL-GFP-shMyocd lentvirus. A Flag-tagged myocardin-overexpression vector pEGFP-N1-Myocd was constructed with pEGFP-N1/X124G. After these two vectors were cotransfected into 293T cells, the flag protein was assessed by Western blotting to analyze the knockdown effect of pGCSIL-GFP-shMyocd. The expression of myocardin and SM22α was also detected by RT-PCR and Western blotting after the pGCSIL-GFP-shMyocd viruses were transfected into primary cultured rat aortal VSMCs.RESULTS: The rat myocardin lentviral RNAi vector pGCSIL-GFP-shMyocd and myocardin-overexpression vector pEGFP-N1-Myocd were successfully constructed. After these two kinds of vectors were cotransfected into 293T cells,the No.1 interfering vector displayed the highest inhibitory effect on flag expression.After the No.1 lentvirus at the titer of 1×10¹² TU/L was transfected into VSMCs, the myocardin and SM22α expression was significantly attenuated. CONCLUSION: The lentiviral pGCSIL-GFP-shMyocd RNAi vector is successfully constructed, which is useful for further study regarding the molecular mechanism of the phenotypic switching in VSMCs under special pathological conditions such as atherosclerosis. Inhibition of myocardin expression in VSMCs leads to the decrease in the expression of differentiation marker, and implies a crucial role of myocardin in VSMCs differentiation.     

工程机械新型传动系统的特性分析

介绍了静液压传动这一新型动力传动系统的特点.通过详细分析该系统液压元件类型的选择、排量与传动变速比关系及该类系统特性参数之间的关系,得出了在实际使用中,为了保证工程机械在大功率工况下,不降低经常工况的效率,提高传动变速比与其它传动形式的匹配方案.通过对匹配方案的分析为工程车辆的开发设计提供理论基础和方法.     

兰考县林业生态省重点建设工程实施成效初探

兰考县地处黄河故道沙区,从前,这里风沙盐碱肆虐,旱涝灾害频繁。兰考人民经过几十年不懈努力奋斗,林业建设取得了长足发展。去年,按照省委、省政府和省林业厅的工作部署,卓有成效地实施了"林业生态省项目工程建设,1年来,在以人为本、生态优先的思想指导下,6项林业生态工程建设同时开展,"点"、"线"、"面"植树造林同步推进,共营造生态林4 257 hm2,初步构成了以林业生态网络形式的国土安全保障体系,使昔日"风起沙飞扬"的景象成为历史。     

智能建筑系统的构成及造价确定

智能建筑应能提供安全、舒适、快捷的优质服务,有一个有利于提高工作效率、激发人的创造性的环境.智能建筑是楼宇自动化系统、通信自动化系统和办公自动化系统三者通过结构化综合布线系统和计算机网络技术的有机集成,其中建筑环境是智能建筑的支持平台.     

浙江诸暨城市林业建设思路探讨

城市林业是林业现代化建设的重要组成部分。结合诸暨实际,分析了林业建设的现状,阐述了诸暨城市林业建设的基本思路,提出要以构建生态安全体系和森林景观体系为重点的观点及其措施。     

云南哀牢山自然保护区南华片区项目建设必要性分析

对哀牢山国家级自然保护区南华片区的生物多样性、经营现状和经营管理进行评价,对项目建设必要性分析结果:项目建设有利于该保护区的整体效应;有利于对珍稀植物物种和生态系统的保护;有利于对候鸟迁徙通道的保护;有利于社会经济的可持续发展;是加强科研和宣教工作的需要。最后阐述了项目建设的主要内容。     

乌兰布和沙漠抗逆植物选择试验及利用

乌兰布和地区光，热，水，土资源丰富，在国家开发西北地区的大政策下，适合进行农，林，牧业开发，但是限于本地区干旱，少雨，风沙大的现状，开发要在以改善生态环境为目的的防护林建设的基础上进行，为本地区增选抗性强，生长快，见效快的灌木品种是当务之急，也是长远需要，本试验选取了干旱地区常见的8种沙旱生灌木进行造林实验，选择出最适于该地区生长的灌木品种主造林方式。     

Modeling spatial variability in the life-cycle costs of low-volume forest roads

Cost estimation is probably the most decisive factor in the process of computer-aided, preliminary planning for low-volume road networks. However, the cost of construction is normally assumed to be route-independent for a specific project area, resulting in sub-optimal layouts. This is especially true for mountainous terrain and in areas with unstable subsoil. Here, we present a model for more accurately estimating spatial variability in road life-cycle costs, based on terrain surface properties as well as geological properties of the subsoil. This parametric model incorporates four structural components: embankment, retaining structures, pavement, and drainage and stream-crossing structures. It is linked to a geo-database that allows users to derive location-specific parameter values as input. In applying this model, we have demonstrated that variability in costs ranges widely for mountainous areas, with the most expensive construction being approximately five times greater there than on more favorable sites. This variability strongly affects the optimal layout of a road network. First, when location-specific slope gradients are considered, costs are reduced by about 17% from those calculated via currently available engineering practices; when both slope gradient and geotechnical formations are included, those costs are decreased by about 20%. Second, the length of the road network is increased by about 4% and 10% respectively, compared with current practices.