胜人者有力 自强者强--宁夏美利纸业应对入世挑战 打造百年美利

总结了宁夏美利纸业集团公司发展的基本经验，介绍了其应对入世创建“百年美利”的战略构想。     

荆江分蓄洪区围堤内护工程方案选择

为了解分蓄洪区围堤非植物内护工程对防汛抢险的影响,以荆江分蓄洪区为例,进行了非植物内护工程出险堤段的水位、雨量、排水沟流量观测和注水试验。结果表明,非植物内护工程出险堤段排水沟流量的变化滞后于外江水位的变化1～2d,降雨时和降雨后出险堤段排水沟流量受降雨量的干扰较大;在有横沟的堤脚,出水部位的水色略清于注水水色,但距注水部位越远,流量损失越大;在未开横沟的堤脚,其流量和水色的变化无法观测。表明采用单一的非植物护坡不利于防汛抢险,宜在设计分蓄洪水位上、下采取复合护坡,并结合多层次防护林防浪,以满足分蓄洪区围堤外防洪兼具内防浪的双重需要。     

Direct electron transfer to hydrogenase for catalytic hydrogen production using a single-walled carbon nanotube forest

The production of hydrogen through the direct electron transfer from electrode to hydrogenase was successfully performed using hydrogenase combined with a single-walled carbon nanotube forest (SWNT-forest). The SWNT-forest has a unique structure comprising dense and vertically aligned SWNTs with millimeter-scale height. The vertically aligned SWNTs became rearranged into a wall-like architecture after immersing in water. Hydrogenase was spontaneously incorporated within the SWNT-forest and confined on the sidewall of the rearranged architecture. The SWNT-forest was a very stable protein carrier in aqueous solution, and an SWNT-forest integrated with hydrogenase could easily be constructed. With a hydrogenase assembled SWNT-forest we were able to electrochemically produce hydrogen with an electron transfer efficiency exceeding 30% without the use of any chemical mediator. Furthermore, a reverse oxidative reaction of hydrogen was also successfully performed using the same device. Thus, the SWNT-forest can work as an effective and direct electron mediator for the oxidation/reduction reaction of hydrogenase. The usefulness of the SWNT-forest as a beneficial material for electrochemistry was demonstrated, underlining the potential of protein assembled SWNT-forests in fabricating highly efficient biofuel cell devices.     

基于GRU-RF模型的太阳辐照度短时预测

针对现有太阳辐照度短期预测方法的建模复杂、准确度低等问题,提出一种基于深度学习的GRU-RF动态权值组合预测方法。大气因素与太阳辐照度数据融合,将运算速度较快且模型复杂度较低的随机森林（RF）模型与带有时序记忆的门控循环单元（GRU）神经网络进行动态权值的加权集成,分别将地表接收到的太阳辐照度、近地层气温、相对湿度、近地层风速和相对气压等变化特征进行预测研究。通过几种模型对比分析,结果表明使用GRU-RF模型预测短时（9 h）太阳辐照度结果较好,运行速度较快,在不同时间间隔（5、10以及15 min）下能够很好地预测太阳辐照度数据。     

基于随机森林算法的短期电力负荷预测

为了准确预测电力系统的短期负荷变化,为电力系统安全、经济、高效运行提供指导方向,提出了一种将模糊聚类以及随机森林回归算法进行组合的电力系统负荷预测方法,利用粗糙集构建补偿规则,对预测结果进行修正补偿。首先,通过对电力系统负荷的周期性、天气相关性等特征进行分析,利用C均值模糊聚类算法对历史样本进行聚类,在进行随机森林回归预测时,使用聚类后同类数据作为训练集样本构建决策树。考虑到随机森林回归预测偏保守、电力系统负荷在峰值处波动大的特征,在得到预测结果后利用粗糙集理论生成补偿规则,对负荷预测进行修正。利用所述方法对北爱尔兰地区进行一日24 h的负荷预测,结果跟实际负荷的平均绝对误差百分比为2.09%,验证了该预测方法的有效性。     

基于随机森林的区域水资源可持续利用评价

针对区域水资源可持续利用评价中指标多、噪声复杂和非线性的特点以及传统方法缺乏可操作性、难以解决稳健性低和过学习等问题,介绍了一种稳健性较高的智能学习方法——随机森林,将其应用于区域水资源可持续利用评价中,并以汉中盆地平坝区为例,对该方法的评价效果进行了验证。结果表明,与SP插值、人工神经网络(ANN)和支持向量机(SVM)模型评价结果相比,本文方法实用性强、稳健性较高、泛化性能高,在分类预测阶段和交叉验证阶段分类准确率均高达100%;同时可知,在影响区域水资源可持续利用的各评价指标中,水资源利用率和人均供水量的影响较为重要。     

Stakeholder perspectives on converting forest biomass to energy in Oregon, USA

Within the state of Oregon, USA, there is considerable interest in the possibility of converting forest biomass to energy. A number of studies have assessed the technical feasibility of forest biomass energy, but few have focused on social aspects, an important consideration in projects involving public forests. This study explores the social context of converting forest biomass to energy, using qualitative research methods. Semi-structured interviews were conducted with forty individuals representing nine different stakeholder groups. Information gained through interviews was used to understand stakeholder views on forest biomass energy, including their perspectives on potential barriers and opportunities in Oregon. Findings indicate the most challenging barrier will be access to long-term, consistent supply. A related challenge is the long history of contention between parties over forest products coming from public lands. However, findings also show that there are many areas of common ground between these groups that have historically been at odds, such as agreement on the necessity of restoration treatments in certain forest types, the by-product of which could be used for biomass generation. Potential conflicts still exist, for instance over projects in mixed conifer forests. Development of policies and projects through inclusive, collaborative approaches could alleviate controversies, potentially allowing more activities to move forward. Information provided by this research creates a foundation for discussions as forest biomass energy becomes an increasingly prominent issue in Oregon, the western USA, and other regions of the world.     

Forest owner motivations and attitudes towards supplying biomass for energy in Europe

The European Commission expects the use of biomass for energy in the EU to increase significantly between 2010 and 2020 to meet a legally binding target to cover at least 20% of EU's total energy use from renewable sources in 2020. According to estimates made by the member states of the EU, the direct supply of biomass from forests is expected to increase by 45% on a volume basis between 2006 and 2020 in response to increasing demand (Beurskens LWM, Hekkenberg M, Vethman P. Renewable energy projections as published in the national renewable energy action plans of the European Member states. ECN and EEA; 2011. http://https://www.ecn.nl/docs/library/report/2010/e10069.pdf [accessed 25.04.2014]; Dees M, Yousef A, Ermert J. Analysis of the quantitative tables of the national renewable energy action plans prepared by the 27 European Union Member States in 2010. BEE working paper D7.2. Biomass Energy Europe project. FELIS – Department of Remote Sensing and landscape information Systems, University of Freiburg, Germany; 2011). Our aims were to test the hypotheses that European private forest owners' attitudes towards supplying woody biomass for energy (1) can be explained by their responses to changes in prices and markets and (2) are positive so that the forest biomass share of the EU 2020 renewable energy target can be met. Based on survey data collected in 2010 from 800 private forest owners in Sweden, Germany and Portugal our results show that the respondents' attitudes towards supplying woody biomass for energy cannot be explained as direct responses to changes in prices and markets. Our results, furthermore, imply that European private forest owners cannot be expected to supply the requested amounts of woody biomass for energy to meet the forest biomass share of the EU 2020 renewable energy target, at least if stemwood is to play the important role as studies by Verkerk PJ, Anttila P, Eggers J, Lindner M, Asikainen A. The realisable potential supply of woody biomass from forests in the European Union. For Ecol Manag 2011;261: 2007–2015, UNECE and FAO. The European forest sector outlook study II 2010–2030. United Nations, New York and Geneva; 2011 [abbreviated to EFSOS II] and Elbersen B, Staritsky I, Hengeveld G, Schelhaas MJ, Naeff H, Böttcher H. Atlas of EU biomass potentials; 2012. Available from: http://www.biomassfutures.eu [accessed 14.10.2013] suggest.     

Relationship between PM2.5 adsorption and leaf surface morphology in ten urban tree species in Shenyang,China

This study investigated the adsorption of particulate matter with a diameter <2.5 µm (PM_2.5) by leaves of ten tree species in Shenyang city. An aerosol generator was used to quantitatively determine PM_2.5 adsorption capacity. Atomic force microscopy was used to determine the micro-morphological characteristics of the leaf surface, including roughness parameters and the PM_2.5 absorption mechanism of the tree leaves. The results showed a positive correlation between PM_2.5 adsorption capacity and PM_2.5 concentration during different months: October (0.618 ± 0.16 μg· cm^?2) > September (0.514 ± 0.14 μg· cm^?2) > July (0.509 ± 0.14 μg· cm^?2) > August (0.487 ± 0.12 μg· cm^?2) > June (0.464 ± 0.08 μg· cm^?2) > May (0.359 ± 0.08 μg· cm^?2). PM_2.5 absorption capacity was higher on leaves where the folded leaf lamina was covered by fine hairs, as they were rough with many protrusions and fillisters on the leaf surface. The tree species with a smooth leaf surface and low stomatal density and stomatal opening had a weak ability to adsorb PM_2.5. The average roughness of the leaves was ranked according to PM_2.5 adsorption per unit leaf area, and leaf roughness was significantly correlated with PM_2.5 adsorption capacity per unit leaf area (R² = 0.706). Tree species with a leaf surface morphology that facilitates absorption of PM_2.5 and other particles, such as Pinus tabulaeformis and Platycladus orientalis, should be selected to improve the environmental effects of urban forest on air quality.