Brazil's current and future land balances: Is there residual land for bioenergy production?

This study presents a new database of land use categories in Brazil at a spatial resolution of 30 arc-second (about 1 km²). The spatial representation of current major land uses formally combines agricultural statistics from Brazil's latest census of the year 2006 at micro-region level and the Food and Agriculture Organization 2010 forest statistics with spatial land cover data sets. Spatial allocation (“downscaling”) algorithms were applied to obtain a spatial distribution of seven major land use categories. Remaining shares in each grid-cell were termed residual land, and were categorized according to legal protection status, biodiversity value, and whether they belong to the territory of the Amazon biome. We found a total of 84 Mha residual land of which 37 Mha occurred outside the territory of the Amazon biome and was neither legally protected nor categorized as highly biodiverse land. The 37 Mha “available residual land” equates to 4.4% of Brazil's geographical area and to 50% of its current cultivated land area. We assessed land quality using the Agro-ecological Zones modelling framework provides land suitability and productivity estimates of the available residual land. Nearly one-third of land emerged of prime quality and is therefore promising for biofuel feedstock production. Analysis of potential food-fuel competition suggests that until 2030 productivity improvements on current pastures could accommodate land demand for Brazil's increasing cattle herd and expanding croplands. If these productivity increases could be achieved on current agricultural land, residual land could provide areas for the sustainable expansion of biofuel feedstock production.     

基于实测数据的沉降预测方法综述

介绍了静态和动态两种基于实测数据的沉降外推预测方法,阐述了各种方法的适用范围和优缺点,指出基于实测数据的沉降预测法是针对建筑实测所得的离散沉降值,用数学模型预测地基的最终沉降量,具有较好的适用性。     

Rethinking urban transformation: Temporary uses for vacant land

As some cities grapple with economic decline and depopulating neighborhoods, a number of academics and professionals have focused their attention on the causes, conditions and patterns of the resultant vacant land, whereas others lay out broad programmatic, institutional, fiscal and design responses to address vacancy on site or citywide scales. We find that, regardless of condition and context, most responses advocate complex, officially sanctioned, formal programs and policies that call for or depend on implementation over several multi-year phases. While laudable in scope, we question whether “permanent” solutions are appropriate given the widely varying causes, durations, contexts and patterns of vacancy and the inability of similarly scoped government-led programs to thus far achieve intended goals or improve local quality of life. We present examples that make the case for temporary, incremental, flexible and experimental responses to urban vacant land, then conclude by outlining the potential benefits and drawbacks of this temporary use model.     

基于土地节约型的陕北山地聚落空间发展模式探究

陕北地区自然生态环境脆弱，加之城镇化进程的快速推进，制约了当地社会、经济、生态的协调发展。本文着眼于聚落空间可持续发展的目标，在土地节约的政策导向下，试图探索陕北山地聚落空间形态发展的适宜性模式。     

桥头跳车的成因及其处治措施探讨

对导致桥头跳车的原因进行了分析,从地基、路堤、路面三方面提出了桥头跳车的处治对策,以期针对桥头跳车的成因选择科学、合理的治理措施,减少桥头跳车对公路桥梁的影响,从而提高行车的安全性与舒适性。     

再现极乐净土——西方净土信仰寺院形制溯源

净土宗根源于大乘佛教西方净土信仰,是汉地佛教十宗唯一汉人开创的宗派,立宗及流行于隋唐时期,至今兴盛不衰。净土宗有《佛说无量寿经》、《佛说观无量寿经》及《佛说阿弥陀经》三部经典,分别对应敦煌壁画中无量寿经变、观无量寿经变以及阿弥陀经变,三种经变画又统称为西方净土变。通过对隋至盛唐时期(589AD~767AD)敦煌壁画中西方净土变的研读,分析总结早期西方净土信仰寺院形制的特点,解当代佛寺建筑设计创新之惑,还世人西方极乐净土庄严之精神,浪漫之意境。     

顶管施工过程中的地面沉降风险控制

顶管施工是一项系统性很强的复杂工程,在施工的每个环节都存在一定的风险。本文主要针对顶管施工过程中的地面沉降风险进行分析,总结了一些关于顶管施工过程中地面沉降风险控制的方法,可为类似顶管工程施工的地面沉降风险控制提供参考。     

江苏沿海滩涂开发优化的动力机制研究

江苏沿海滩涂开发具有悠久的历史,但是传统的滩涂开发模式已经不能适应江苏省"强富美高"的发展新理念,现有的滩涂开发模式亟需优化升级。经过对由经济发展、生产方式变革、自然环境等要素构成的滩涂优化开发内源动力以及由科技创新、资金保障、政策制度等要素构成的外源动力进行分析,并对其连续动力机制进行深入研究,发现滩涂开发在其内外源动力的共同作用下可以逐步缓解人地矛盾,实现经济效益和富民的效应;但是开发与环境之间互为影响,甚至可能与环境美的目标相反。研究结果表明:在滩涂开发过程中,应坚持生态优先、绿色发展,加强政府引导、理顺机制,注重高新产业、科技投入,围绕临海能源、绿化造林,只有这样才能推动滩涂开发动力机制不断正向循环,实现经济社会的可持续发展。     

新时期背景下阳曲县青龙片区用地权属的探讨

通过对新时期发展背景及太原工业新区与阳曲县的现实发展诉求的分析,对阳曲县青龙片区的用地权属问题进行了简单探讨,以求为二者未来发展战略的制定提供一定参考。     

Effects of land use and changes in cover on the transformation and transportation of iron:A case study of the Sanjiang Plain,Northeast China

Wetland reclamation has been ongoing in the Sanjiang Plain since the mid-1950s,which has resulted in major changes in wetlands and the agriculture ecosystem in the region that have influenced the iron output to the Sea of Okhotsk and limited the primary productivity in the North Pacific Ocean.This study was conducted to investigate the chemical forms of iron in different aquatic environments(agricultural water including groundwater,paddy water,and canal water;wetland water including marsh water,marsh stream...