Gas transport parameters of differently compacted granulated bentonite mixtures (GBMs) under air-dried conditions

Granulated bentonite mixtures (GBMs) have been regarded as effective buffer materials in the deep geological disposal of radioactive waste due to their operational advantages, such as ease of transportation and in-situ placement/backfilling. Many studies have been done to characterize the hydraulic and thermal properties of GBMs as well as their swelling properties. Only limited studies, however, have investigated their gas transport properties, even though these properties affect their compactness during in-situ placement/backfilling and subsequent gas diffusion and advection in the buffer zone. The aim of this study is to understand the gas transport parameters, i.e., air permeability (k_a) and gas diffusivity (D_p/D_o), of tested samples compacted at different dry densities (DDs) under air-dried conditions, linking them with the measured density distribution characteristics determined by microfocus X-ray computed tomography (MFXCT) analysis. Two types of GBMs were used in this study: 1) FE-GBM (prepared from National Standard® bentonite, Wyoming, USA): this material was used in the Full-scale Emplacement (FE) experiment at the Mont Terri rock laboratory, Switzerland) and 2) OK-GBM (prepared from a bentonite, originating from Japan, with the trade name of OK bentonite, Kunimine Industries). The tested samples were firstly packed in a 100-cm³ acrylic core with different DDs, ranging from loose to dense (1.09 to 1.75 g/cm³), and scanned by MFXCT. The weighting factors, w_f (fine fraction; lower density) and w_c (coarse fraction; higher density) (w_f + w_c = 1), were determined after the peak separation of the measured CT brightness histograms from the reconstructed three-dimensional multiplanar reconstruction (MPR) images of the MFXCT analysis. The measured k_a and D_p/D_o were highly dependent on the DDs, the k_a (?) values fitted well with a power law model, and the D_p/D_o (?) was predicted accurately by several previously proposed models. For both FE-GBM and OK-GBM, there were good linear relationships between the gas transport parameters and w_c × DD, implying that the weight of the coarse fraction controlled k_a and D_p/D_o. Moreover, the Kozeny-Carman model, incorporating the measured volumetric surfaces from the MFXCT analysis, was able to predict the k_a values well.     

1964年东京第18届奥运会对东京城市景观的影响

以1964年首次在亚洲举办的第18届东京奥运会为例，从正反两方面探讨奥运赛场及相关设施建设形成的景观，对东京城市景观的影响，评价奥运场馆与举办国城市环境建设的关系，同时指出，景观职能是国际性活动的策划、规划及实施中不可缺少的职能，它不仅要创造正面遗产，更要摈弃负面遗产，以免留下后患。     

施工企业如何参与工程项目代建

阐述了工程施工企业参与项目代建的优势，从与相关单位合作、注重人才培养、推行专业软件等方面，介绍了做好项目代建的重点，提出了做好工程项目代建应注意的几个问题。     

"Gebiet für Gesch?ftsbauten mit gemischtem Warenangebot"; Ausnutzbarkeit des Bauplatzes; Verkaufsfl?che; Immissionsschutz; (keine) subjektiv-?ffentlichen Nachbarrechte

Die Widmung "Gebiet für Gesch?ftsbauten mit gemischten Warenangebot" bietet keinen Immissionsschutz. Nachbarn kommt kein subjektiv-?ffentliches Recht auf Einhaltung der festgelegten Verkaufsfl?che für Einkaufszentren zu.     

潮白河地下水调蓄区水岩作用过程模拟

南水北调中线工程通水后,将有部分结余水量用于补给潮白河地下水调蓄区。由于南方地表水(以下简称南水)与北京当地地下水的水质存在一定差异,回灌过程中很有可能发生水岩相互作用。研究以潮白河地下水回灌区为例,通过静态摇瓶实验和水文地球化学模拟等研究方法,对南水补给北京深层地下水过程中产生的水岩作用过程和水质影响程度进行分析评价。研究结果表明:南水回灌过程中,地下水的主要离子成分会受到硝化作用、阳离子交换作用及包气带矿物质溶解等作用的综合影响。两种水混合过程中,土壤矿物相中的方解石和白云石不断溶解,Ca2+、Mg2+浓度逐渐升高,反应过程中还伴随强烈的阳离子交换作用,主要为Na+与Ca2+、Mg2+的交换。南水比例越大,溶解氧促进硝化作用越明显;在硝化作用和碳酸平衡的共同影响下,地下水的pH值呈现先降低后升高的趋势。     

Effect of enzymatic aroma release on the volatile compounds of white wines presenting different aroma potentials

Wines from Maria Gomes (Fernão Pires) and Bical varieties were treated with an enzymatic preparation, Lallzyme de Lalvin, with β‐glucosidase, pectinase, arabinosidase and rhamnosidase activity. The reference and enzyme‐treated wines were submitted to a process of continuous liquid–liquid extraction with dichloromethane and analysed by GC‐MS. The volatile contents of the wines were 199 and 188 mg l^?1, respectively, for Maria Gomes and Bical. Both varieties contained aliphatic and aromatic alcohols, terpenoids, esters, aliphatic acids and lactones. Enzymatically treated wines showed an increase of 9% in the total amount of volatile compounds of Maria Gomes, due, mainly, to the increase of geraniol (67%), terpendiols (96%), phenols and aromatic alcohols (26%) and esters (32%). Some of them were within their perception limits and may have a contribution to the floral and fruity notes. Conversely, no significant modifications were introduced by enzymatic treatment in the total amount of volatile compounds of Bical wine. The presence of aromatic alcohols in significant amounts, which may represent an interesting characteristic in Bical wines, was not increased by the treatment used. This study with two white varieties grown in the same Appellation shows that the effectiveness of aroma release by enzymatic treatment, using a broad range of enzymatic activities, is closely dependent on the varietal aroma potential, knowledge of which is a key determinant for full exploitation of wine qualities. Copyright © 2004 Society of Chemical Industry     

用Bethe Ansatz方法求解本征值

通过对SU(n)Hubbard可积模型的研究，求出该模型的能量本征值．用可积模型中的坐标Bethe Ansatz的方法，首先由薛定谔方程求得能量的本征方程，设定波函数的具体形式，求出本征能量，SU(n)Hubbard可积模型的本征能量可通过Bethe Ansatz的方法求得。     

光伏太阳能电池板组件火灾危险性研究

以太阳能电池板应用日趋广泛且其火灾时有发生为背景,通过实验分析太阳能电池板火灾发生的原因及其特点。实验以锥形量热仪为平台,分电池板正面朝上(模拟电池板自燃)、反面朝上(模拟电弧故障火灾)两种工况,每种工况进行辐射强度分别为30kW/m2、35kW/m2、40kW/m2的三组实验,多片11.2cm×11.2cm多晶硅太阳能电池板在热辐射下被电火花引燃并持续燃烧状态直至熄灭。通过对实验的数据分析可以得出太阳能电池板的基本燃烧规律。     

Study of the Volatile and Glycosidically Bound Compounds of Minority Vitis vinifera Red Cultivars from NW Spain

Aroma composition was analyzed in grape musts from five Vitis vinifera red cultivars (Pedral, Sousón, Caíño Redondo, Espadeiro and Mencía) grown in Galicia (NW Spain) with the aim to know the potential profile of these varieties. All cultivars were collected from Coto Redondo Winery vineyard (A.O.C. Rías Baixas) and grown under the same conditions. All cultivars (with a total of 96 aroma compounds, 35 free volatile and 61 glycosidically bound compounds) were identified and quantified by GC‐MS. The results showed that Caíño Redondo and Pedral had the highest concentrations of volatile compounds. The free fraction showed the highest concentration for all cultivars studied with the exception of Pedral. High concentrations of free C₆‐compounds and free alcohols were found for all red cultivars studied, especially for Caíño Redondo. Sousón and Mencía presented similar characteristics in the free fraction. Pedral showed an important contribution of glycosidically bound compounds. This cultivar showed the highest concentration of bound alcohols, terpenoids, volatile phenols, and C₁₃‐norisoprenoids. With terpenoids, higher levels were found in the bound fraction than in the free fraction. Regarding C₁₃‐norisoprenoids, Pedral also showed an important contribution of these varietal compounds. The principal component analysis (PCA) showed a good separation of the different grape cultivars, so they could be discriminated based on their potential volatile composition. The oenological potential of ancient and minority grape varieties from NW Spain, with the aim to provide genetic diversity, is illustrated with this work.     

Mapping Scales of Urban Identity

Ricky Burdett , Professor of Urban Studies at LSE where he is Director of the Urban Age programme, is engaged in studying cities at different scales and regional contexts. Here he looks at what gives a city like London its unique sense of scale, and how it might be possible to design in the sort of vibrancy and spatial complexity that evolve in informal neighbourhoods over time. Through examples of local initiatives in Cape Town and Mumbai, he gives concrete evidence of what constitutes this approach.