台南市运河沿岸地区更新规划

台南运河是全台湾保存最完整的一条内陆运河,近年来由于沿岸地区产业结构的调整,航运功能逐渐淡化,沿岸地区也逐渐衰退.为了让运河再生并促进沿岸地区的复活.台南市政府着手对其进行更新.在更新规划中体现出来的复活机能构思、分段定位和面积控制等理念为其他滨水城市的更新规划提供了借鉴.     

岩土固化剂（YTG）在干渠防渗工程中的应用

1渠道防渗加固的某些现况目前我国已建成的渠道防渗工程仅占渠道总长18%,渠系水的利用系数平均不到0.5,即从渠首引进的水有50%以上是无效损失。浪费水量之大,确实惊人。在发展节水型技术中,渠道防渗的节水效益最大,它可以减少渗透损失70%~90%,从而引相同水量所需渠道的尺寸可减     

公路桥梁预制中的波纹管防堵控制

对波纹管预应力孔道常见的几种堵塞现象的原因进行了分析,并提出了相应的预防措施,工程实践表明,提出的防堵措施控制效果良好,最终达到防止堵孔现象发生的目的。     

寒区输水渠道衬砌与冻土相互作用的冻胀破坏试验研究

寒区输水渠道冻胀破坏直接影响着工程安全及效益发挥,基土冻胀变形及其与结构相互作用共同导致衬砌冻胀破坏发生。采用低温室循环供冷,模型槽底部砂砾石层补水,设计衬砌渠道低温冻胀模型试验,研究渠基土体的温度场、水分场、变形场和衬砌位移之间动态耦合规律,对比观测了冻融试验前后渠基土横剖面物理性状的变化。研究表明:引起基土冻胀变形的水分迁移量及结冰量受温度梯度、冻结速率控制,也受土体初始含水率的制约;渠道断面形状影响渠道的温度边界和热传导,使各部位冻结速率及冻胀变形不一致。渠基土冻结过程中兼有冻胀和挤密,土体受挤压程度同样受渠道衬砌及断面形状的影响,土体内应力复杂。渠基土冻胀与衬砌位移不协调,导致渠底衬砌与土体脱空且偏心受拉。土体冻结时与衬砌间形成接触分凝冰层,传递作用力;温升融化时,接触分凝冰层消融,表层土体强度丧失,造成渠坡滑动失稳破坏和衬砌结构大面积的滑塌。     

运河古镇传统空间格局的图解初探——以常州市孟城、万绥两镇为例

以常州市新北区孟城、万绥两座运河古镇为例,探寻古镇传统空间格局的解析方法。以点、线、面、自然基底四要素为切入点,从构成要素和组合方式两方面对比分析了在传统条件和现实状况下古镇空间构成要素的分布特征与组合方式之异同,以期了解古镇传统空间格局特质,并为日后的保护管控及规划提供依据。     

Comparison of river and canal water dissolved organic matter fluorescence within an urbanised catchment

Recently, growing interest has been shown in the study of canal water quality, yet no research using continuous fluorescence monitoring to characterise dissolved organic matter (DOM) has been performed. This paper evaluated DOM characteristics at hourly resolution. A comparison was made between canal and nearby urban river fluorescence spectra, to emphasise the specific nature of canal water DOM. Results showed that canal water had a significant proportion of microbially derived DOM, while the urban river had a greater proportion of terrestrially derived fractions. The microbial character of canal water DOM originated from the low flow of water, the nutrients predominance and continuous DOM processing. Hence, DOM fluorescence is invariant over a timescale of days, and recreational navigation and precipitation events have no major influence on DOM characteristics. Our results are expected to be applicable to future research on highly regulated freshwater systems for DOM quantity estimation or for water quality models.     

Influence of EDTA on Demineralization Rate of Dentine： Calcification Treatment in Root Canal Therapy

The aim of this study was to investigate the influence of ethylenediaminetetraacetic acid （EDTA） irrigation on demineralization rate of dentine located in the apical third of root canal walls. Teeth were divided into A and B two groups. In group A, all of the teeth was irrigated with EDTA and NaOCI （sodium hypochlorite）, followed by cutting the apical third into slices longitudinally to examine the influence of EDTA on different portions of apical third of root canal. In group B, the apical third of a tooth was firstly cut into slices longitudinally, followed by coating the root canal walls with EDTA to in-situ observe the demineralization of dentine with different time. It was found that the influence of EDTA on root-canal was gradually increased from the apical to the upper end of the apical third for group A. In addition, the demineralization rate of dentine was remarkable in the first 25 min for group B. The diffusion of EDTA into root dentine would lead to potential damage to the dentine. Furthermore, demineralization rate curve was calculated.     

Chitosan impregnated gutta-percha points: antimicrobial in vitro evaluation and mechanical properties

Chitosan-impregnated gutta-percha points (ChitGPP) were tested for their ability to inhibit the growth of microorganisms usually involved in root canal infections. Their mechanical properties were also studied and compared with the commonly used commercial points in endodontics. ChitGPP were more efficient in reducing the microbial load than those without chitosan. ChitGPP also possess better tensile and elastic properties than commercial ones. After six months of storage, ChitGPP’s were still able to reduce the bacterial load by 1 log, suggesting that impregnation of gutta-percha points with chitosan could be a good alternative to obtain gutta-percha points with improved antimicrobial properties.     

厦门市汀溪灌区总干渠洪水复核方法探讨

汀溪灌区作为汀溪水库群的农业供水对象,其灌溉用水量的大小直接关系到汀溪水库群向翔安、同安两区的水资源供需平衡,甚至影响厦门市水资源配置方案。但由于灌溉面积和渠道功能发生变化,有必要进行洪水分析复核从而重新确定工程规模。本文对汀溪灌区总干渠洪水复核方法进行探讨,供参考。