两种高能球磨机制备Fe-Si合金磁粉的对比

分别采用行星球磨机和振动球磨机制备了Fe-6.5%Si合金磁粉.讨论了球磨时间、球料比、干、湿磨等因素对颗粒细化的影响.结果表明:颗粒尺寸随球磨时间的增加而减小,湿磨可缩短球磨时间、提高球磨效率;同等条件下,振动机的球磨效率大于行星球磨机的球磨效率.     

Petri网在代谢网络模块化分析中的应用

代谢网络的模块化分析有助于理解网络的结构和功能。然而,当前众多的模块化分析方法大多将代谢网络考虑为普通的复杂网络,所得模块的生物学意义较低。对枯草芽孢杆菌的核黄素代谢进行Petri网建模分析,研究结果表明：Petri网的T不变量可用于识别代谢网络中的功能模块,具备较好的生物学意义。     

一种新型的动态递归神经网络及其算法

通过对Elman网络的研究 ,提出了一种新型的基于输入层、隐层、输出层神经元递归的动态递归神经网络 ,并给出了其算法。通过在系统辨识中的应用表明 ,该网络收敛速度快 ,模型精度高 ,具有较为广阔的应用前景。     

ADS熔盐散裂靶中子学性能研究

与传统加速器驱动次临界系统（ADS）采用金属靶作为散裂中子靶的设计不同,加速器驱动次临界熔盐堆（AD-MSRs）采用靶堆一体的设计,直接使用燃料熔盐作为散裂中子靶。由于熔盐靶的中子学性能直接影响AD MSRs的能量放大系数、核废物的嬗变和核燃料增殖的效率,所以本研究基于MCNPX程序,详细计算了高能质子轰击氟盐和氯盐两种熔盐靶产生的散裂中子产额、散裂中子能谱、能量沉积分布以及散裂产物等中子学性能,并与液态Pb和铅铋共熔体（LBE）两种液态金属靶进行了对比。计算结果表明,熔盐靶在散裂中子产额上与液态金属靶有一定的差距,但熔盐靶内能量沉积分布的梯度较小,更有利于靶区的热量导出。与液态Pb和LBE靶相比,熔盐靶的散裂产物中包含更多的气体以及高质量数的α发射体核素。     

Numerical Simulation of Condensation of Bubbles under Microgravity Conditions by Moving Mesh Method in the Double-staggered Grid

A numerical 2D method for simulation of two-phase flows including phase change under microgravity conditions is presented in this paper, with a level set method being coupled with the moving mesh method in the double-staggered grid systems. When the grid lines bend very much in a curvilinear grid, great errors may be generated by using the collocated grid or the staggered grid. So the double-staggered grid was adopted in this paper. The level set method is used to track the liquid–vapor interface. The numerical analysis is fulfilled by solving the Navier–Stokes equations using the SIMPLER method, and the surface tension force is modeled by a continuum surface force approximation. A comparison of the numerical results obtained with different numerical strategies shows that the double-staggered grid moving-mesh method presented in this paper is more accurate than that used previously in the collocated grid system. Based on the method presented in this paper, the condensation of a single bubble in the cold water under different level of gravity is simulated. The results show that the condensation process under the normal gravity condition is different from the condensation process under microgravity conditions. The whole condensation time is much longer under the normal gravity than under the microgravity conditions.     

Inhibition of hIAPP Amyloid Aggregation and Pancreatic β‐Cell Toxicity by OH‐Terminated PAMAM Dendrimer

Human islet amyloid polypeptide (hIAPP, or amylin) forms amyloid deposits in the islets of Langerhans, a phenomenon that is associated with type‐2 diabetes impacting millions of people worldwide. Accordingly, strategies against hIAPP aggregation are essential for the prevention and eventual treatment of the disease. Here, it is shown that generation‐3 OH‐terminated poly(amidoamine) dendrimer, a polymeric nanoparticle, can effectively halt the aggregation of hIAPP and shut down hIAPP toxicity in pancreatic MIN6 and NIT‐1 cells as well as in mouse islets. This finding is supported by high‐throughput dynamic light scattering experiment and thioflavin T assay, where the rapid evolution of hIAPP nucleation and elongation processes is halted by the addition of the dendrimer up to 8 h. Discrete molecular dynamics simulations further reveal that hIAPP residues bound strongly with the dendrimer near the c‐terminal portion of the peptide, where the amyloidogenic sequence (residues 22–29) locates. Furthermore, simulations of hIAPP dimerization reveal that binding with the dendrimer significantly reduces formation of interpeptide contacts and hydrogen bonds, thereby prohibiting peptide self‐association and amyloidosis. This study points to a promising nanomedicinal strategy for combating type‐2 diabetes and may have broader implications for targeting neurological disorders whose distinct hallmark is also amyloid fibrillation.     

一种基于点集自适应分组构建Voronoi图的并行算法

论文提出一种基于点集自适应分组构建Voronoi图的并行算法,其基本思路是采用二叉树分裂的方法将平面点集进行自适应分组,将各分组内的点集独立生成Voronoi图,称为Voronoi子图;提取所有分组内位于四边的边界点,对边界点集构建Voronoi 图,称为边界点Voronoi图;最后,针对每个边界点,提取其位于Voronoi子图和边界点Voronoi 图内所对应的两个多边形,进行Voronoi多边形的合并,最终实现子网的合并.考虑到算法耗时主要在分组点集的Voronoi图生成,而各分组的算法实现不受其他分组影响,采用并行计算技术加速分组点集的Voronoi图生成.理论分析和测试表明,该算法是一个效率较高的Voronoi图生成并行算法.     

液相法制备无机纳米管的研究进展

综述了水热(溶剂热)法、溶胶-凝胶法、微波辅助法和低温溶液法制备无机纳米管的最新研究进展。分析了影响纳米管形貌的因素及纳米管的形成机理,对纳米管的应用进行了展望。     

空调冷水大温差系统设计方法研究

研究了大温差空调水系统供回水温差和空气处理过程、末端、水泵和输送管道、主机四个方面之间的关系,结果表明：空调冷水系统大温差不宜超过9℃。分析了采用大温差空调水系统的设计要点,并提出了针对大温差空调水系统的一些优化设计方法。     

手持式冰点测定仪(折射率法)校准方法

简述了目前手持式折射率法冰点测定仪的用途,国内外防冻液标准现状。现有计量技术规范无法满足手持式折射率法冰点测定仪的计量校准需求,且国内暂无专门针对手持式冷却液冰点测定仪(折射率法)的计量技术规范、标准溶液的配制参考方法。介绍了手持式折射率法冰点测定仪的原理和结构,探讨了此类仪器的校准方法,讨论了主要的校准项目,同时还介绍了校准用溶液的配制方法和校准时的注意事项。