大藤峡水利枢纽及在珠江防洪与水资源综合利用中的地位与作用

大藤峡水利枢纽是珠江流域西江干流上的控制性水利枢纽工程，在流域防洪及水资源方面具有不可替代的作用，同时具有发电、航运与灌溉等综合利用效益。国务院在对《珠江流域防洪规划》的批复中要求抓紧做好前期工作．积极促进大藤峡水利枢纽建设。本文对大藤峡水利枢纽及在珠江防洪与水资源综合利用中的地位与作用进行了简要的介绍。     

Turning software into a service

The software as a service model composes services dynamically, as needed, by binding several lower-level services-thus overcoming many limitations that constrain traditional software use, deployment, and evolution.     

Detection of water ingress in composite sandwich structures: a magnetic resonance approach

Water ingress inside honeycomb sandwich panels during service has been linked to in-flight failure in some aircraft. There is an ongoing effort to develop nondestructive testing methods to detect the presence of water within the panels. Magnetic resonance (MR) represents an attractive approach in that it is sensitive to moisture. Using a unilateral MR sensor, testing can be applied directly to the surface of the panel. The viability of MR is demonstrated through laboratory imaging of both water within sandwich panels, as well as the adhesive itself. The detection of water using a one-sided handheld MR sensor is presented. It is shown that simple detection, as well as spatial localization of water within sandwich panels is possible.     

Side-outlet spouted bed with draft tube: Effect of varying the position of the outlet

The vector form of the Ergun equation was used to numerically predict gas phase streamlines, residence time distributions, chemical conversions and pressure drops in the annulus of a side-outlet spouted bed with an internal draft tube. By varying the position of the side-outlet, it was demonstrated that there exists an optimum location for this outlet at which conversion is a maximum and which shows a greatly improved gas phase residence time distribution in the annulus compared with a conventional spouted bed unit.     

An Improved Procedure for Determining the Work of Adhesion for Polymer-Solid Contact

Force-balance experiments in conjunction with the Johnson-Kendall-Roberts (JKR) theory have been used to determine the work of adhesion between solid systems. It has been shown that deficiencies in understanding the deformation behavior can lead to erroneous results. A modified procedure for determining the work of adhesion by force-balance experiments and JKR theory using normal displacement behavior has been introduced to address these deficiencies. This procedure involves improved experiental and data analysis protocols and has been applied to give more precise work of adhesion values for PDMS poly(dimethylsiloxane)-PDMS, PDMS-F(fluorinated silicon) and PDMS-Si (silicon) systems. The work of adhesion determinations are consistently less than those estimated by contact angle measurements.     

Circulating fluidized bed combustion of a high-sulphur eastern canadian coal

Combustion tests were carried out with Minto coal in combination with three different limestones in the University of British Columbia (UBC) pilot scale (152 mm square x 7.3 m tall) circulating fluidized bed combustion (CFBC) unit. Operating conditions were chosen to be typical of those employed in large-scale CFBC power boilers. Recycling of fine particles captured by the secondary cyclone was found to be of considerable importance in increasing sulphur capture, enhancing combustion efficiency and reducing the amount of calcium sulphide in the solids residues. NO_x emissions increased as the Ca:S ratio increased. Local gas concentrations inside the reactor were strongly influenced by the core-annulus solids distribution patterns which characterize circulating fluidized beds.     

The algorithmization of counterfactuals

Recent advances in causal reasoning have given rise to a computation model that emulates the process by which humans generate, evaluate and distinguish counterfactual sentences. Though compatible with the “possible worlds” account, this model enjoys the advantages of representational economy, algorithmic simplicity and conceptual clarity. Using this model, the paper demonstrates the processing of counterfactual sentences on a classical example due to Ernest Adam. It then gives a panoramic view of several applications where counterfactual reasoning has benefited problem areas in the empirical sciences.     

Refining the systematic literature review process—two participant-observer case studies

Systematic literature reviews (SLRs) are a major tool for supporting evidence-based software engineering. Adapting the procedures involved in such a review to meet the needs of software engineering and its literature remains an ongoing process. As part of this process of refinement, we undertook two case studies which aimed 1) to compare the use of targeted manual searches with broad automated searches and 2) to compare different methods of reaching a consensus on quality. For Case 1, we compared a tertiary study of systematic literature reviews published between January 1, 2004 and June 30, 2007 which used a manual search of selected journals and conferences and a replication of that study based on a broad automated search. We found that broad automated searches find more studies than manual restricted searches, but they may be of poor quality. Researchers undertaking SLRs may be justified in using targeted manual searches if they intend to omit low quality papers, or they are assessing research trends in research methodologies. For Case 2, we analyzed the process used to evaluate the quality of SLRs. We conclude that if quality evaluation of primary studies is a critical component of a specific SLR, assessments should be based on three independent evaluators incorporating at least two rounds of discussion.