To aim at prototype parts fabricated with fused deposition modeling （FDM） process, the problems how to improve and enhance their surface micro-precision are studied. The producing mechanism of surface roughness is e...To aim at prototype parts fabricated with fused deposition modeling （FDM） process, the problems how to improve and enhance their surface micro-precision are studied. The producing mechanism of surface roughness is explained with three aspects concretely including the principle error of rapid prototyping （RP） process, the inherent characteristics of FDM process, and some mi- cro-scratches on the surface of the extruded fiber. Based on the micro-characters of section shape of the FDM prototype, a physical model reflecting the outer shape characters is abstracted. With the physical simplified and deduced, the evaluating equations of surface roughness are acquired. According to the FDM sample parts with special design for experimental measurement, the real surface roughness values of different inclined planes are obtained. And the measuring values of surface roughness are compared with the calculation values. Furthermore, the causes of surface roughness deviation between measuring values and calculation values are respectively analyzed and studied. With the references of analytic conclusions, the measuring values of the experimental part surface are revised, and the revised values nearly accord with the calculation values. Based on the influencing principles of FDM process parameters and special post processing of FDM prototype parts, some concrete measures are proposed to reduce the surface roughness of FDM parts, and the applying effects are better.展开更多
Bi-directional BLAST is a simple approach to detect, annotate, and analyze candidate orthologous or paralogous sequences in a single go. This procedure is usually confined to the realm of customized Perl scripts, usua...Bi-directional BLAST is a simple approach to detect, annotate, and analyze candidate orthologous or paralogous sequences in a single go. This procedure is usually confined to the realm of customized Perl scripts, usually tuned for UNIX-like environments. Porting those scripts to other operating systems involves refactoring them, and also the installation of the Perl programming environment with the required libraries. To overcome these limitations, a data pipeline was implemented in Java. This application submits two batches of sequences to local versions of the NCBI BLAST tool, manages result lists, and refines both bi-directional and simple hits. GO Slim terms are attached to hits, several statistics are derived, and molecular evolution rates are estimated through PAML. The results are written to a set of delimited text tables intended for further analysis. The provided graphic user interface allows a friendly interaction with this application, which is documented and available to download at http：//moodle.fct.unl.pt/course/view.php？id=2079 or https：//sourceforge.net/projects/bidiblast/ under the GNU GPL license.展开更多
基金This project is supported by National Natural Science Foundation of China (No. 50575139)
文摘To aim at prototype parts fabricated with fused deposition modeling （FDM） process, the problems how to improve and enhance their surface micro-precision are studied. The producing mechanism of surface roughness is explained with three aspects concretely including the principle error of rapid prototyping （RP） process, the inherent characteristics of FDM process, and some mi- cro-scratches on the surface of the extruded fiber. Based on the micro-characters of section shape of the FDM prototype, a physical model reflecting the outer shape characters is abstracted. With the physical simplified and deduced, the evaluating equations of surface roughness are acquired. According to the FDM sample parts with special design for experimental measurement, the real surface roughness values of different inclined planes are obtained. And the measuring values of surface roughness are compared with the calculation values. Furthermore, the causes of surface roughness deviation between measuring values and calculation values are respectively analyzed and studied. With the references of analytic conclusions, the measuring values of the experimental part surface are revised, and the revised values nearly accord with the calculation values. Based on the influencing principles of FDM process parameters and special post processing of FDM prototype parts, some concrete measures are proposed to reduce the surface roughness of FDM parts, and the applying effects are better.
文摘Bi-directional BLAST is a simple approach to detect, annotate, and analyze candidate orthologous or paralogous sequences in a single go. This procedure is usually confined to the realm of customized Perl scripts, usually tuned for UNIX-like environments. Porting those scripts to other operating systems involves refactoring them, and also the installation of the Perl programming environment with the required libraries. To overcome these limitations, a data pipeline was implemented in Java. This application submits two batches of sequences to local versions of the NCBI BLAST tool, manages result lists, and refines both bi-directional and simple hits. GO Slim terms are attached to hits, several statistics are derived, and molecular evolution rates are estimated through PAML. The results are written to a set of delimited text tables intended for further analysis. The provided graphic user interface allows a friendly interaction with this application, which is documented and available to download at http：//moodle.fct.unl.pt/course/view.php？id=2079 or https：//sourceforge.net/projects/bidiblast/ under the GNU GPL license.
