Fabrication,characterization and evaluation of mesoporous activated carbons from agricultural waste: Jerusalem artichoke stalk as an example

This work explores the feasibility of Jerusalem artichoke stem (JAS), an agricultural waste, as an alternative precursor for fabrication of mesoporous activated carbon (MAC) via conventional ZnCl₂ activation. The as-prepared JAS-MACs were characterized by thermogravimetric, nitrogen gas adsorption isotherm and high resolution scanning electron microscopy analysis. The interacting effects of chemical dosage, activation temperature and time on the mesoporosity, mesopore volume and carbon yield were investigated, and further optimized by response surface methodology (RSM). The Brunauer-Emmett-Teller surface area, mesoporosity and mesopore volume of the JAS-MAC prepared under optimum condition were identified to be 1631 m²·g^-1, 90.16% and 1.11 cm³·g^-1, respectively. Compared with commercial activated carbons, this carbon exhibited a comparable monolayer adsorption capacity of 374.5 mg·g^-1 for Methylene Blue dye. The findings suggest that RSM could be an effective approach for optimizing the pore structure of fabricated activated carbons.     

微生物絮凝剂絮凝条件的响应曲面法优化

筛选出一株絮凝剂产生菌TF10,鉴定为巨大芽孢杆菌(Bacillus megaterium).以高岭土悬浊液为絮凝对象,研究了pH值、絮凝剂用量和不同阳离子对TF10产生的絮凝剂P-TF10絮凝效率的影响.结果表明,P-TF10在偏酸和微碱范围内活性较高;絮凝剂存在最佳用量,不足或过高会导致絮凝率下降;Ca2+和Al3+对絮凝的促进作用明显,而Mg2+和Na+对絮凝无作用.应用响应曲面法对P-TF10的絮凝条件进行了优化,得到最佳条件为:pH=4.7,CaCl2浓度为7.0mmol.l-1,P-TF10的用量为34.6 mg.l-1,该条件下絮凝率可达(95.5±1.0)%.     

不同海拔高寒放牧草甸的生态系统呼吸与环境因子的关系

在全球变化的背景下,为了研究藏北高寒放牧草甸的生态系统呼吸和土壤呼吸特征,沿着3个海拔高度（4 300、4 500和4 700 m）观测了2010年7-9月白天的呼吸通量。同时,观测了同期的土壤温度、土壤水分含量、空气温度和相对湿度,在定性分析土壤水分含量和呼吸通量关系的基础上,将其分成低、中和高3个水平,在此基础上,分析生态系统呼吸、土壤呼吸与土壤温度、土壤水分含量、空气温度以及相对湿度的关系。结果表明,空气温度是决定生态系统呼吸和土壤呼吸变异的主导因子;生态系统呼吸、土壤呼吸以及裸地的土壤呼吸的Q10值分别为1.83～3.07、1.54～4.13和1.29～2.89;总体而言,生态系统呼吸和土壤呼吸Q10值随着海拔的升高和土壤水分含量的增加而增大。     

2种终轧/开冷温度DSS 2304复合板复层组织与耐腐蚀性能对比研究

目的 对比研究2种不同终轧/开冷温度的2304/Q345C热轧双相不锈钢复合板复层组织和耐腐蚀性能。方法 分别采用金相显微镜和透射电镜观察复层组织形貌,采用铁素体测量仪分析计算复层远界面铁素体组织。分别采用化学浸泡法及电化学法测试复层抗点蚀和晶间腐蚀性能,并对其组织进行金相观察和透射分析。采用万能试验机对界面进行剪切强度测试,对界面附近进行线扫描测试分析,进一步分析剪切性能测试结果。结果 在其他热轧参数一定的情况下,终轧/开冷温度为1050/1020℃的复合板复层组织中的铁素体含量较高,奥氏体/铁素体相界更为规整,位错密度较低,晶界未发现析出相,界面剪切强度较高,复层的耐点腐蚀、晶间腐蚀及腐蚀电化学性能均较优。结论 终轧/开冷温度为1050/1020℃的热轧双相不锈钢复合板复层具有更优的耐腐蚀性能。     

基于组合赋权-可变模糊集的装配式建筑施工安全评价*

为解决装配式建筑施工安全影响因素的复杂性和模糊性,引入组合赋权和可变模糊集理论相结合的方法对装配式建筑施工安全进行评价。通过分析装配式建筑施工特点,以WSR方法论为基础,选取“人、机、法、环、管”5方面因素构建装配式建筑施工安全评价指标体系并划分指标等级标准;采用博弈论思想对G1法确定的主观权重和熵权法计算的客观权重进行最优组合,进而确定综合权重;根据可变模糊集理论量化后的级别综合特征值确定最终评价结果;将该方法用于甘肃省某装配式试点项目,评价结果与其他方法进行对比,并采用单因素轮换OAT法分析5个子系统内的指标敏感性,以便决策者识别出最敏感指标。结果表明:该实证项目安全等级为Ⅱ级,偏向Ⅲ级,与实际情况吻合;组合赋权-可变模糊集方法所得评价结果与灰色聚类分析、未确知测度方法基本一致,使评价结果准确性和稳定性得到有效提高。     

比较安全学的创立及其框架的构建研究

基于比较科学理论与安全科学学的原理,将比较方法应用于安全科学方法学研究;提出比较安全学的定义,分析其内涵,从安全科学的理论类别、灾害类别、安全管理类别、工程类别与安全学的纵向分支5个方面构建比较安全学的学科分支体系,并阐述了各分支体系研究内容,在此基础上构建了比较安全学学科体系框架;综合与比较安全学相关的文献资料,依据其应用的个案探讨比较学在安全科学中的应用,阐述比较安全学应用与研究的广阔前景。研究表明,多视角的比较安全学构建了诸多新的安全方法学思路和研究方向,为构建安全科学方法学体系提供了基础。     

安全管理力学分析方法(SMMA)及其应用研究

把自然科学中力的概念引入安全管理中,对其中的各种有形和无形联系进行研究,建立了一种安全管理系统的力学分析方法和实施程序。基于该方法把力学与轨迹交叉理论进行映射关联,建立"球体碰撞"模型。通过对比找出模型中存在的各种力,对模型进行受力分析并建立函数方程式。再据方程式及其参数对模型的各种状态进行分析,把分析结果反馈到安全管理系统中用以指导安全管理工作。最后,把安全管理力学分析法概括为定量分析法和定性分析法,并为研究安全管理提供了理论基础。由于力学具有准确、严谨、逻辑性强的特点,因此,引入力学后可以发挥力学与数学的优势。建立的安全管理力学分析方法是一种新方法,该方法对安全管理系统的定量化研究和实施有一定的促进作用。     

Exploring the use of computer models in participatory integrated assessment – experiences and recommendations for further steps

Integrated assessment (IA) can be defined as a structured process of dealing with complex issues, using knowledge from various scientific disciplines and/or stakeholders, such that integrated insights are made available to decision makers (J. Rotmans, Enviromental Modelling and Assessment 3 (1998) 155). There is a growing recognition that the participation of stakeholders is a vital element of IA. However, only little is known about methodological requirements for such participatory IA and possible insights to be gained from these approaches. This paper summarizes some of the experiences gathered in the ULYSSES project, which aims at developing procedures that are able to bridge the gap between environmental science and democratic policy making for the issue of climate change. The discussion is based on a total of 52 IA focus groups with citizens, run in six European and one US city. In these groups, different computer models were used, ranging from complex and dynamic global models to simple accounting tools. The analysis in this paper focuses on the role of the computer models. The findings suggest that the computer models were successful at conveying to participants the temporal and spatial scale of climate change, the complexity of the system and the uncertainties in our understanding of it. However, most participants felt that the computer models were less instrumental for the exploration of policy options. Furthermore, both research teams and participants agreed that despite considerable efforts, most models were not sufficiently user-friendly and transparent for being accessed in an IA focus group. With that background, some methodological conclusions are drawn about the inclusion of the computer models in the deliberation process. Furthermore, some suggestions are made about how given models should be adapted and new ones developed in order to be helpful for participatory IA. This revised version was published online in July 2006 with corrections to the Cover Date.     

KLUM@GTAP: Introducing Biophysical Aspects of Land-Use Decisions into a Computable General Equilibrium Model a Coupling Experiment

In this paper, the global agricultural land use model Kleines Land Use Model is coupled to an extended version of the computable general equilibrium model (CGE) Global Trade Analysis Project in order to consistently assess the integrated impacts of climate change on global cropland allocation and its implication for economic development. The methodology is innovative as it introduces dynamic economic land-use decisions based also on the biophysical aspects of land into a state-of-the-art CGE; it further allows the projection of resulting changes in cropland patterns on a spatially more explicit level. A convergence test and illustrative future simulations underpin the robustness and potentials of the coupled system. Reference simulations with the uncoupled models emphasise the impact and relevance of the coupling; the results of coupled and uncoupled simulations can differ by several hundred percent.

Incorporating environmental issues into optimum cut-off grades modeling at porphyry copper deposits

Cut-off grade is defined as the grade which discriminates between ore and waste within a given orebody. Determination of a complete optimum cut-off grade policy is a very important function during mine life. Using the modified optimum cut-off grade model presented in this paper not only the net present value of a porphyry copper mining project is maximized, but also the adverse environmental impacts of the project are minimized simultaneously. This methodology is more effective in long-range planning. For showing the effectiveness of the model, two scenarios are considered in a hypothetical deposit and the results show that incorporating the modified optimum cut-off grade policy, the net present value will be increased by 3.6% in comparison with the Base Case.