汽车覆盖件冲压工艺/模具计算机辅助技术的发展现状

系统全面地论述了汽车覆盖件冲压模具数字化技术CAD／CAM／CAPP的发展现状，总结了目前存在的问题，并指出了未来的研究发展方向。     

EXPERIMENTAL TESTING OF DRAW—BEAD RESTRAINING FORCE IN SHEET METAL FORMING

Due to complexities of draw-bead restraining force calculated according to theory and depending on sheet metal forming properties experiment testing system, a simplified method to calculate draw-bead restraining force is put forward by experimental method in cup-shaped drawing process. The experimental results were compared with numerical results and proved agreement. It shows the method is effective.     

板料成形优化技术进展与质量工程研究

板料成形过程的优化研究对于改进模具设计、提高产品质量具有重要意义。综述了板料成形工艺优化的研究现状。考虑到在有约束的设计优化中,最优结果常位于约束边界附近,随机因素的波动易导致产品质量不稳定甚至失效,难以保持产品的可靠性和稳健性。为此,本文应用质量工程学中的6σ理念,提出了基于数值模拟的板料成形6σ稳健设计优化方法。     

隔焰辊道窑碳化硅板的研究

本文主要对隔焰辊道窑碳化硅板的配方选择、热震损伤、抗氧化性能和结构形状进行探讨.     

聚铝溶液pH值及盐基度的相关性研究

为聚铝溶液进行了ＰＨ值和盐基度的分析和估算,给出了聚铝溶液的极限ＰＨ值和极限盐基度与总溶解铝浓度的关系曲线,最终计算结果表明：在平衡条件下,聚铝溶液的ＰＨ值和盐基度具有相关性,即当基中一个参数发生变化时。另一个参数必然要发生相应的改变。     

Quantitative X-ray powder diffraction analysis of clay minerals in Australian coals using Rietveld methods

The mineralogy of clay-rich mineral matter isolated from a range of Australian bituminous coals has been evaluated in quantitative terms from X-ray powder diffraction (XRD) patterns using a Rietveld-based data processing technique. The chemical composition of coal ash derived from this mineral matter has been calculated and compared to the directly determined composition of the ash prepared from the same coal samples. Although there are some minor differences due in part to uncertainty regarding the actual composition of several minerals, the compositions indicated by the two methods show a relatively high correlation, suggesting that the Rietveld technique provides mineralogical analyses that are consistent with independently determined chemical data. Comparison of the normalised clay mineral percentages from the Rietveld analysis to quantitative interpretations based on a peak intensities in glycolated and heat-treated oriented aggregates of the respective clay fractions also shows a high correlation, confirming mutual consistency of the two different mineralogical analysis methods. Such quantitative mineralogical data are significant to a range of coal exploration, mining and utilization activities, including seam correlation, material handling and ash and slag formation in combustion processes.     

转盘反应器固定米根霉的L－乳酸发酵

研究了米根霉的固定化方法，研制了用吸附法固定米根霉的生物转盘反应器，考察了在该反应器中培养基组成及其它操作条件对Ｌ－乳酸发酵的影响。实验结果表明，应用吸附法固定化的米根霉及生物转盘反应器进行Ｌ－乳酸发酵具有发酵速率快，Ｌ－乳酸得率高及既能用于连续发酵又能用于间歇发酵等优点     

Comparison of the construction of a 3-D model for human thromboxane synthase using P450cam and BM-3 as templates: implications for the substrate binding pocket

A 3-D model of human thromboxane A₂ synthase (TXAS) was constructedusing a homology modeling approach based on information fromthe 2.0 crystal structure of the hemoprotein domains of cytochromeP450BM-3 and P450cam. P450BM-3 is a bacterial fatty acid monooxygenaseresembling eukaryotic microsomal cytochrome P450s in primarystructure and function. TXAS shares 26.4% residue identity and48.4% residue similarity with the P450BM-3 hemoprotein domain.The homology score between TXAS and P450BM-3 is much higherthan that between TXAS and P450cam. Alignment between TXAS andthe P450BM-3 hemoprotein domain or P450cam was determined throughsequence searches. The P450BM-3 or P450cam main-chain coordinateswere spplied to the TXAS main chain in those sements where thetwo sequences were well aligned. These segments were linkedto one another using a fragment search method, and the sidechains were added to produce a 3-D model for TXAS. A TXAS substrate,prostaglandin H₂ (PGH₂) was docked into the TXAS cavity correspondingto the arachidonic acid binding pocket in P450BM-3 or camphorbinding site in P450cam. Regions of the heme and putative PGH2binding cavities in the TXAS model were identified and analyzed.The segments and residues involved in the active-site pocketof the TXAS model provide reasonable candidates for TXAS proteinengineering and inhibitor design. Comparison of the TXAS modelbased on P450BM-3 with another TXAS model based on the P450BM-3with another TXAS model based on the P450cam structure indicatedthat P450BM-3 is a more suitable template for homology modelingof TXAS.     

高效节能热泵错流多效蒸发复杂系统

为了大幅降低错流多效蒸发过程的能耗,首次将蒸汽喷射式热泵技术、冷凝水闪蒸和溶液闪蒸等3种节能措施同时运用到错流多效蒸发系统中,并建立了用矩阵方程描述的该系统的数学模型。模型具有很强的通用性,可实现热泵在任意效抽汽的功能,可简化为只有其中若干种节能措施组合或无上述节能措施的错流、并流、逆流多效蒸发系统的模型。在满足约束条件的前提下,模型存在最佳的热泵喷射系数和抽汽位置,同时采用上述3种节能措施且在最佳条件下模型是高效节能的。浓缩氢氧化钠溶液的热泵错流五效蒸发系统的模拟结果表明,当热泵的喷射系数为0.15、抽汽位置在第2效,采用冷凝水闪蒸和溶液闪蒸时系统节省的生蒸汽消耗量高达32.51%。     

自适应布谷鸟搜索算法

为了使布谷鸟搜索算法(Cuckoo Search,CS)在保持强大的全局搜索能力的同时,尽可能地提高局部搜索能力,在深入分析CS算法机理的基础上,将CS算法中影响布谷鸟搜索路径步长的参数β和布谷鸟蛋被发现(淘汰)的概率p_a由固定值改为随搜索过程自适应变化的动态参数,将越界的鸟窝折返回边界内、在当前代最优鸟窝附近的区域随机建立1个新的鸟窝、而非折返回边界上重新建立鸟窝,以提高算法的局部搜索能力和收敛速度。改进后的CS算法称为自适应布谷鸟搜索算法(Adaptive Cuckoo Search,ACS)。通过8个标准测试函数分别测试了CS算法和ACS算法的性能,结果表明,无论是简单的单峰函数还是复杂的多峰函数,无论是小型的低维函数还是大型的高维函数,ACS算法的寻优性能均超过CS算法。