枞树型核电轮槽精铣刀制造技术优化设计

以枞树型叶根精铣刀为例,阐述了可换硬质合金型线刀体和刀片精铣刀的优化设计、制造工艺、建模及优化设计,进行切削过程加工策略优化和加工过程模拟,设计制造了锥柄专用工装及检测环规、磨削刀片后角专用工装,采用NUMROTO软件编制刀片加工工步。该项目研制的可换刀片精铣刀型线精度完全能达到进口铣刀水平,能满足大部分轮槽与叶根加工对型线精度的要求,可以大幅度节约刀具费用。     

区域控制器的安全需求建模与自动验证

轨道交通区域控制器（ZC）是我国轨道交通信号系统选型的主流制式——基于通信的列车控制系统（CBTC）的核心子系统，其突出的安全性使得安全需求的形式化验证成为一个非常重要的问题.但是ZC自身的复杂性以及领域知识的繁杂难以掌握，使得形式化方法很难应用到安全需求的验证中去.针对这些问题，提出一种安全需求的自动验证方法，使用半形式化的问题框架方法（PF）来建模和分解安全需求，根据需求模型自动生成安全需求的验证模型和验证性质，在此基础上自动生成验证模型的Scade语言实现，并通过Design Verifier验证器对需求进行组合验证.最后，使用了某个实际案例ZC的一个子问题CAL_EOA进行了研究，实验结果证明了该方法的可行性与有效性，它能自动地将安全需求模型进行组合验证，改善了验证的效率.     

热冲压工艺参数对22MnB5马氏体钢汽车B柱性能影响的有限元模拟

通过有限元仿真软件Autoform分析了热冲压过程中工艺参数的变化对22MnB5马氏体钢B柱起皱、回弹、减薄、马氏体量以及强度的影响。结果表明:22MnB5马氏体钢B柱热冲压最优化工艺参数为加热温度930 ℃,冷却速率80 ℃/s。该工艺参数下,热冲压过程各处均完成马氏体转变,硬度分布均匀,材料减薄率较低,热冲压成形效果好,尺寸精度高,冲压件强度均大于1400 MPa。     

矿粉颗粒表面微观形貌对过滤性能的影响

为研究矿粉表面微观形貌对过滤性能的影响,将-200目80%的5种不同的铁精矿粉A、B、C、D、E在过滤压力0.06 MPa、过滤时间3 min的条件下进行过滤试验;并测定5种铁精粉的最大分子水和最大毛细水,用扫描电镜观察其微观形貌。试验结果表明:5种矿粉的滤饼水分、最大分子水和最大毛细水由大到小依次均是A、B、C、D、E,并且与矿粉的表面微观形貌密切相关。矿粉颗粒表面粗糙,吸附较多细小颗粒,其比表面积和表面能较大,毛细管作用较强,所含的最大分子水和最大毛细水较大;毛细管作用强使得过滤速率降低,毛细水的脱除难度增大,最终导致滤饼水分较高。     

PAN纤维共聚单体作用机理的光电离质谱研究

本工作以丙烯腈/衣康酸（IA）二元共聚原丝以及丙烯腈/IA/丙烯酸甲酯（MA）三元共聚原丝为研究对象，利用热重分析仪（TG）和热解-同步辐射真空紫外光电离质谱（Py-SVUV-PIMS）对其热稳定化过程进行研究。TG结果表明，氮气气氛下，二元共聚原丝（PAN/IA）和三元共聚原丝（PAN/IA/MA）分别呈现三阶段和两阶段的热分解过程，其中PAN/IA的第一和第二阶段均对应PAN线型分子链的断裂，但前者是由自由基环化反应放热引发的，后者则是由正常温度下的热分解所致，而单体MA的加入显著抑制了自由基环化反应，使得PAN原丝的热稳定化能够以单体IA诱导的离子型环化反应为主较平缓地进行，相应的热失重过程也由两阶段转变为了单阶段。Py-SVUV-MS的实验结果表明，两种共聚PAN原丝在程序升温过程中会生成包括含氮小分子、丙烯腈单体及低聚物、成环化合物在内的三类主要热解产物，对比各类产物的生成趋势和产量，推断单体MA通过降低PAN结构的规整度，使其无定形化，从而增加环化反应的引发点，促进PAN原丝向稳定的预氧丝转变，同时由典型热解产物——甲基丙烯腈的生成路径可知，MA本身并不参与PAN大分子的环化反应，属于中性共聚单体。空气气氛下，CO₂的产量差异也间接证明了MA单体能够有效提升PAN纤维的固碳能力，采用三元共聚方法制得的PAN纤维热稳定性能更佳。     

Effects of polysaccharides and polyphenolics fractions of Zijuan tea (Camellia sinensis var. kitamura) on α‐glucosidase activity and blood glucose level and glucose tolerance of hyperglycaemic mice

The effects of polysaccharides, theaflavins, thearubigins and theabrownin fractions of Zijuan tea on α‐glucosidase and blood glucose level and intolerance of hyperglycaemic mice were evaluated. The polysaccharides or theaflavins fraction exhibited greater inhibition rate of α‐glucosidase than acarbose positive control, thearubigins fraction or theabrownin fraction. The four fractions were delivered to the treatment mice through oval gavage each day for 15 days. The mice in polysaccharides and theaflavins high‐ and low‐dose and theabrownin high‐dose treatments significantly lowered their blood glucose levels while all the treatment mice gained body weight. The mice in polysaccharides, theaflavins and theabrownin high‐ and low‐dose treatments had greater glucose tolerance as well. Thus, the theaflavins and polysaccharides fractions of Zijuan tea effectively moderated the complications of hyperglycaemic mice. The lower effectiveness of thearubigins and theabrownin fractions may be caused by the highly polymerised polyphenolics which decreased their accessibility to α‐glucosidase and digestibility in mice.     

Effect of nonsolvent additives on PES ultrafiltration membrane pore structure

Different nonsolvent additives, namely, diethylene glycol, n-butyl alcohol (NBA), and ethylene glycol monomethyl ether, were added into the casting solution (polyethersulfone/dimethylformamide/lithium chloride) to prepare ultrafiltration (UF) membrane via phase inversion. The effects of different additives and their concentration on the pore structure of the prepared UF membrane were studied. The cross-sectional morphology of the membrane was observed via scanning electron microscopy. The addition of nonsolvent additives improved the large-cavity structure of the membrane. When the additive was low-content NBA (1–3 wt %), the membrane pore structure transformed from large-cavity structure to fully sponge-like structure. When the content of additive NBA was 3 wt %, the flux of the prepared UF membrane was 130.45 L (m⁻² h⁻¹), the rejection of PEG20000 was 95.54% and the flux remained high at 4 bar in long-term stability test. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47525.     

Novel hydrophilic N-halamine polymer with enhanced antibacterial activity synthesized by inverse emulsion polymerization

N-halamine-based antibacterial agents have high efficiency and rechargeable antibacterial properties. However, their applications are limited due to their complex synthetic process and fuzzy antibacterial mechanism. In this study, a novel N-halamine antibacterial polymer was synthesized by inverse emulsion polymerization and characterized by Fourier transform infrared, nuclear magnetic resonance, scanning electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Due to the difficulty of purification, most of the subjects studied previously were hydrophobic polymers, while little research on hydrophilic polymers. In this experiment, this difficulty was overcome by controlling the dosage of sodium hypochlorite and methods of dialysis. Because of the complex cell structure of Gram-negative bacteria, it is difficult for N-halamines to release the oxidizing chlorine into the cell. However, the hydrophilic N-halamines can solve this problem, which showed a stronger antibacterial effect on Gram-negative Escherichia coli synthesized in this study. In addition, the particle size and hydrophilic property of the polymer were changed by changing the amount of initiator, and the differences in their antibacterial properties were studied. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47419.     

建筑材料供应中断对承包商成本的冲击研究——基于鲁棒模型分析

为了揭示供应商与承包商为主体的二级供应链中，两者间耦合作用条件下发生的供应中断对供应商最优决策及对承包商成本的影响机制，且剖析供应中断对承包商成本的冲击效应，以供应商存在高退出风险为研究对象，在仅知产量均值与方差条件下，运用Scarf提出的“极大极小值”鲁棒决策方法，通过设定不同决策情况下的供应链系统反馈，分析了不同退出标准情况下二级供应链的博弈过程。基于理论支撑下的鲁棒模型数值仿真结果得出：在退出标准α为100时，中间变量在290~350范围内，供应商存在最优决策，但承包商最优决策无法确定；与α为0时相比，在订货量达到一定状态，即α为140时，承包商成本增加了1.5%，表明承包商成本与供应商退出标准呈正相关，退出标准越高，对承包商成本造成的冲击效应越大。此研究结论为供应链初期不稳定且信息不完整条件下发生的供应中断影响机理提供了新的视角。     

一种X煤在首钢的应用实践

针对当前优质炼焦煤资源越来越少，而高炉生产对焦炭质量指标要求越来越高的情况下，对具有低灰、高硫特点的X煤进行了系统的炼焦试验研究。结果发现，在炼焦生产中合理配加5%～8%的X煤不会造成焦炭硫分升高的不利影响，焦炭灰分下降明显，强度保持稳定。该研究成果成功应用于首钢炼焦生产，焦炭各项指标均达标，这不仅扩大了炼焦煤的使用范围，而且在资源使用方面为公司焦炭灰分的降低提供了支持。