建设灾害韧性城市:全球五座城市韧性相关政策与地方实践比较研究

本研究通过对全球五个典型城市——南非开普敦、英国大曼彻斯特地区、中国长沙和汶川,以及波多黎各圣胡安市——的韧性相关政策和地方实践进行比较分析,探讨了向灾害韧性城市转型的途径.通过构建社会-环境系统下覆盖七个相互关联的维度的概念性框架,本文系统梳理了这些城市在政策文件和地方实践中如何感知灾害风险和处理韧性问题.通过横向对比政策文件,城市间的不同韧性策略得以展现:开普敦采用多种节水措施,通过提高水韧性来应对干旱;大曼彻斯特地区在灾害风险减少方面较为重视人和组织机构的影响与作用;长沙和汶川优先考虑特定的灾害响应措施,而圣胡安市则通过多方面行动来应对环境和社会经济挑战.通过梳理各城市的地方实践,本文展示了当地居民自下而上提升韧性的有效性,相关案例包括开普敦的家庭钻井和长沙的社区参与.然而,整体而言,各城市对文化/世界观维度和城乡空间维度考虑不足.弥合这一差距对于有效的风险管理和灾后恢复至关重要.本文强调应当将政策制定与地方实践相结合,并呼吁优先考虑具有针对性的灾后恢复计划,加强对城乡空间维度的投入.总体上,本研究为构建灾害韧性城市提供了宝贵思路,为城市政策制定者和规划者提供了应对未来挑战和提升城市韧性的基础.     

基于双视通路交互感知的轮廓检测方法

基于生物视觉系统存在双视通路(VP)交互感知的机制,该文提出一种图像轮廓检测的新方法。首先针对皮层下视通路中视觉刺激流经多级不同尺度的感受野,提出一种多尺度轮廓融合的轮廓感知模型;接着基于皮层上视通路的对比度适应机制和方向敏感特性,获取显著性视觉特征;然后模拟双视通路的交互感知机制,分别在V1皮层中,构建一种信息流交互引导的脉冲编码模型,提取显著性轮廓;在上丘(SC)浅层提出一种特征调制的非经典感受野侧抑制模型,实现纹理抑制;最后对双视通路中的轮廓响应结果进行修正融合,得到最终轮廓响应。针对RUG40图像库的测试,整个数据集的最优平均P指标和每张图的最优平均P指标分别为0.51和 0.57;针对BSDS500图像库的测试,数据集尺度上最优(ODS)为0.68。结果表明该文方法能有效突显主体轮廓并且抑制纹理背景。通过该文提出的轮廓感知方法,为后续基于视觉机制的图像理解和分析提供了一种新的思路。     

基于大鼠血清差异蛋白质组学小白杏杏仁油免疫调节作用研究

采用i TRAQ标记及高效液相色谱-电喷雾串联质谱(LC-ESI-MS/MS)技术对小白杏杏仁油干预试验大鼠血清差异表达蛋白进行定量鉴定,并通过表达模式及代谢通路聚类对鉴定获得的差异蛋白进行生化代谢途径和信号转导途径分析。结果表明,小白杏杏仁油可能通过调节血清中结合珠蛋白(HP)、角蛋白(KRT10、KRT42)、微管蛋白α-8链(TUBA8)、免疫球蛋白重(k)链VⅢ区(VH26、MOPC63)、α-1-抗蛋白酶(SERPINA1)及T-激肽原(KNG1)等蛋白的表达水平,作用于金黄色葡萄球菌感染、吞噬体、致病性大肠杆菌感染、原发性免疫缺陷、补体和凝血级联5条先天性免疫通路而展现其免疫调节作用。     

The influences of multi-walled carbon nanotube addition to the anode on the performance of direct methanol fuel cells

Different amounts of multi-walled carbon nanotubes (MWCNTs) are added to anode catalyst layer in the membrane electrode assemblies (MEAs) of direct methanol fuel cells (DMFCs). The MEA with 0.5 wt.% carbon nanotubes (CNTs) shows the best performance in DMFC. In the protonic conductivity tests, a 0.5 wt.% amount of MWCNTs results in the highest protonic conductivity. SEM and TEM observations show that a continuous and uniform distribution of Nafion ionomer layer is formed on the MWCNT surface. Therefore, the dispersed MWCNTs in the catalyst layer are considered to be helpful for developing the pathways of protons transport.     

低剂量γ射线辐照对人淋巴母细胞基因表达转录谱的影响

为探讨低剂量电离辐射生物效应作用机制,本文研究了不同剂量单次辐照后,人淋巴母细胞基因表达转录谱的变化。采用0．1Gy、0．5Gy和1．0Gy剂量的γ射线照射人淋巴母细胞,未照射细胞为对照组。照射后4h提取细胞总RNA,用含有45033个基因的人类全基因组表达谱芯片检测分析。对差异表达基因进行层次聚类分析、基因本体论分析和通路分析,并用实时荧光定量PCR验证。结果表明,3个剂量组均上调表达的基因1330个,下调表达的基因1002个。基因表达量与吸收剂量相关的基因共18个,其中与剂量正相关的基因16个,负相关的基因2个。层次聚类分析结果表明,4个实验组中,0．1Gy和1．0Gy照射组差异表达基因相似程度最高。这些差异表达的基因涉及到多条通路,如细胞周期、p53信号通路、碱基切除修复、RNA转运和内质网蛋白加工等。实时荧光定量PCR检测结果表明,CASP9（caspase9）mRNA在照射后4h随吸收剂量表达变化与基因芯片检测结果一致。基因芯片筛选出的差异表达基因有助于阐明低剂量辐射生物效应作用机理,与辐射剂量相关的差异表达基因有可能成为低剂量辐射暴露的生物剂量计。     

海洋生物通过海水途径对铯,钴,锌的浓集与排出研究

本文报道了海洋生物通过海水途径对铯，钴，锌的浓集与排出研究的实验结果。实验生物为珍珠贝，梭子蟹，黑鲷和扇贝，均取自广东大亚湾海域，在分别含一定浓度的Ｃｓ，Ｃｏ或Ｚｎ的海水中培养７ｄ。进行浓集实验，然后以浅海挂养或清洁海水池养的方式进行排出实验，用原子吸收分光光度计测定生物不同组织或器官中元素的含量。     

Ascorbate enhances iron uptake into intestinal cells through formation of a FeCl3–ascorbate complex

It has been well documented that ascorbate enhances iron uptake, with a proposed mechanism based on reduction to the more absorbable ferrous form. We have performed a study on the effects of ascorbate on ferric iron uptake in the human epithelial Caco-2 cell-line. Ascorbate increased uptake in a concentration-dependent manner with a significant difference between iron uptake and reduction. Uptake kinetics are characteristic of a non-essential activator and the formation of an Fe³⁺–ascorbate complex. This investigation provides evidence that ascorbate enhances the apical uptake of ferric iron into Caco-2 cells through the formation of a Fe³⁺–ascorbate complex.     

Formation of Bromate Ion Through a Radical Pathway in a Continuous Flow Reactor

The contribution of ozone and hydroxyl radical to the formation of bromate ion was investigated in a continuous flow reactor. Experiments were conducted under a wide range of ozone dose (0.7 ～ 3.8 mgL), pH (6.5 ～ 8.5), and t-butanol concentration (0 ～ 0.5 mM). The formation of bromate ion was found to depend on radical reaction pathway, because the amount of bromate ion formed increased with pH and decreased with t-butanol, a radical scavenger, even when dissolved ozone concentrations were almost the same. In fact, the amount of bromate ion formed was reduced by 90% in the presence of t-butanol. Furthermore, the formation of bromate ion occurred even when dissolved ozone was not significantly detected in the presence of organic matter (TOC of 1 mgCL). The second-order reaction rate constant of hydroxyl radical with bromide ion, k _HO,Br^? of 1.7 × 10⁹ (M^?1s^?1), was obtained on the assumption that the reactions of bromide ion and t-butanol with hydroxyl radical were competitive with each other in the presence of t-butanol and that the formation of bromate ion depended on the reaction of bromide ion with hydroxyl radical. Therefore, it is concluded that the reaction of bromide ion with hydroxyl radical dominated in the overall reaction from bromide ion to bromate ion in the continuous flow reactor.