Direct coagulation casting of silicon carbide suspension via polyelectrolyte dispersant crosslink reaction

A direct coagulation casting method for silicon carbide ceramic suspension using dispersant crosslink reaction is reported. Polymer electrolyte (polyethyleneimine, PEI) was used as dispersant to prepare silicon carbide suspension. Common food additives (carboxymethyl cellulose, CMC) were used to coagulate the electrosteric stabilized silicon carbide suspension. There was a well disperse silicon carbide suspension with 0.2 wt% PEI at pH = 5-6. Influence of coagulant on viscosity and zeta potential of the silicon carbide suspension was investigated. It indicates that the high solid loading silicon carbide suspension can be destabilized and coagulated at elevated temperature. It can be attribute to the gradual decrease of electrosteric force due to the crosslink reaction between PEI and CMC. Silicon carbide wet green body with compressive strength of 1.99 MPa could be demolded at 70°C which is higher than that prepared by traditional DCC and dispersant reaction method for nonoxide ceramics. Dense silicon carbide ceramics with relative density above 98.8% and 99.3% had been prepared by liquid phase pressureless and hot pressed sintering, respectively.     

Preparation of high-performance reverse osmosis membrane by zwitterionic polymer coating in a facile one-step way

Aiming at preparing high-performance polyamide (PA) reverse osmosis (RO) membrane in a facile and high effective way, the codeposition strategy of dopamine and zwitterionic polymer was first applied to modify PA RO membrane. The noncovalent bonds between dopamine and Poly [2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (PSPE) act to fix PSPE onto the membrane surface and simultaneously destroy the interaction force between dopamine aggregations so that the modified layer could equably form on the PA layer. PSPE significantly improved the hydrophilicity [the water contact angle (WCA) of S-D-3 is 25.3°] of the modified membrane. And, the smoother surface was noticed on the modified membrane. All of these endow the PSPE/dopamine modified membrane superb water flux (the maximum water flux is 51.86 L m⁻¹ h⁻¹ at 1.6 MPa and 25 °C) and impressive antifouling and anti-adhesion properties to bovine serum albumin (BSA) (protein), sodium dodecyl sulfate (anionic surfactant), and dodecyl trimethyl ammonium bromide (cationic surfactant) with salt retention was well maintained. Notably, in the BSA fouling test, nearly 100% of the flux recovery ratio was achieved. This method is promising to be employed in industrial scale-up production. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48355.     

Landau-Zener模型中纠缠演化及转移的研究

研究了受外场驱动的两个二能级系统分别与两个单模量子化光场相互作用模型中纠缠演化及转移问题。该工作主要是对外场驱动的Landau-Zener模型进行了研究，采用旋转波近似的方法，通过数值计算详细分析了二能级系统初始状态、能级间的耦合常数以及驱动外场的参数对子系统间纠缠和转移特性的影响。结果表明，适当调节模型中的参数，可以使系统初始纠缠完全转移为光腔场间的纠缠，实现二能级系统与光场间的最大纠缠转移。     

高品质热轧双相钢的开发

为了提高热轧双相钢的品质，研究了化学成分、轧制工艺、冷却工艺和不同季节水温等参数对热轧双相钢组织和性能的影响。结果表明，无Si成分设计显著提高了热轧双相钢的表面质量；较低的终轧温度和中间保温温度有利于获得更为细小的铁素体组织和弥散的马氏体组织；低的卷取温度（280 ℃）可以获得铁素体+马氏体双相组织；冷却水水温的降低显著提高马氏体含量并提高双相钢的强度。基于上述研究，邯钢实现了系列热轧双相钢的稳定生产，双相钢制作的汽车车轮性能良好。     

Investigation on the morphology and tensile behavior of β‐nucleated isotactic polypropylene with different stereo‐defect distribution

Large amount of work has been published on the tacticity‐properties relationship of isotactic polypropylene (iPP). However, the stereo‐defect distribution dependence of morphology and mechanical properties of β‐nucleated iPP (β‐iPP) is still not clear. In this study, two different iPP resins (PP‐A and PP‐B) with similar average isotacticity but different uniformities of stereo‐defect distribution were selected, their β‐iPP injection molding specimens were prepared, and the morphology evolution and tensile behaviors were studied by means of differential scanning calorimetry (DSC), 2D wide‐angle X‐ray diffraction (2D‐WAXD) and scanning electron microscope (SEM). DSC results showed that with the same concentration of β‐nucleating agent (0.3 wt % WBG‐II), PP‐B with more uniform stereo‐defect distribution exhibited more amount of β‐phase than that of PP‐A with less uniform stereo‐defect distribution, indicating that PP‐B is more favorable for the formation of β‐phase. SEM results showed that PP‐B formed more amount of β‐crystals with relatively high structural perfection, while in PP‐A a mixed morphology of α‐ and β‐phase with obviously higher amount of structural imperfection emerges. The results of room‐temperature tensile test indicated that the yield peak width of PP‐B was obviously wider, and the elongation at break of PP‐B was higher than that of PP‐A, showing a better ductile of PP‐B. The morphology evolution results of SEM, 2D‐WAXD and DSC suggest that, a combination of lamellar deformation and amorphous deformation occurred in PP‐A, while only amorphous deformation mainly took place in PP‐B, which was thought to be the reason for the different tensile behaviors of the samples. In the production of β‐PP products via injection molding, the uniformity of stereo‐defect distribution was found to be an important factor. PP with more uniform distribution of stereo‐defect favors the formation of large amount of β‐phase with high perfection, which exhibit superior ductile property. The related mechanism was discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40027.     

煤化工废水设备沉积物清洗剂的研制

针对煤化工废水流经设备中的沉积物,研发出一种具有良好清洗能力的清洗剂。该清洗剂以水作为主要溶剂,添加适量的表面活性剂(AEO-9:1%,AES:3%,OP-10:4%)、高沸点有机溶剂(乙二醇丁醚:20%)、清洗助剂(三聚磷酸钠:3%,硅酸钠:0.5%,适量氢氧化钠)。通过性能评价实验,测得沉积物溶解度能达到约75%。初步的工业试验结果表明,该清洗剂除垢能力较强。采用在线清洗装置,经过5 h的清洗,可较彻底地去除设备中的沉积物。     

高效疏水电荷诱导色谱介质的基团修饰及其色谱行为的初步研究

以粒径10μm、孔径300球形硅胶为载体,以γ-缩水甘油醚氧丙基三甲氧基硅烷(KH-560)为中间偶联剂,将4-巯基吡啶键合至硅胶上,制备了高效疏水电荷诱导色谱介质。通过单因素实验,探讨了反应温度、反应时间、KH-560的浓度对活化密度的影响,结果表明,在反应温度为75℃,反应时间为10 h条件下,KH-560的利用率大,可获得较宽范围的活化密度,此外还考察了缓冲液pH、反应温度、反应时间、4-巯基吡啶浓度对偶联密度的影响。结果表明,在pH=7.5的缓冲液,反应温度40℃,反应时间6 h下,4-巯基吡啶利用率高,通过控制4-巯基吡啶的浓度,可获得较宽范围的配基密度。最后,于高效液相色谱条件下,通过等度洗脱,考察了流动相pH对牛血清蛋白和溶菌酶保留因子的影响。并通过梯度洗脱,分离了不同等电点的牛血清蛋白和溶菌酶,验证了该介质的高效疏水电荷诱导色谱行为。     

铜表面纳尺度沟槽织构的摩擦学性能

目的 通过分子动力学（MD）模拟,揭示了纳尺度沟槽织构对单晶铜摩擦磨损的影响机理,为设计高耐磨超声电机（USM）定子材料提供理论指导方法 建立了金刚石-铜摩擦配副模型,首先研究了金刚石下压深度对铜基体摩擦学性能的影响,随后重点研究了铜表面沟槽织构的角度、深度、宽度对摩擦学性能的影响。通过提取摩擦过程中的摩擦因数、磨损原子数目、摩擦界面温度、体系能量、界面间相互作用力以及观察摩擦前后界面形貌变化,从原子尺度揭示沟槽织构对铜的减摩机理。结果 对于无织构铜表面,摩擦因数和磨损率等性能参数随着下压深度的增加而增加;有沟槽织构的铜表面,摩擦因数和磨损率相较于无沟槽织构有显著下降。在沟槽织构与摩擦方向成90°时,效果最佳,摩擦因数下降25%左右,磨损率下降50%。同时,摩擦因数和磨损率还随沟槽深度和宽度的增大而减小。其主要原因是：沟槽织构的引入,使得在金刚石和铜基体的摩擦过程中相互作用的原子数量明显减少,相互犁削和接触原子的数量也减少,从而导致摩擦因数、磨损率下降。结论 在铜表面进行沟槽织构化处理能够减少摩擦过程中的磨损,提高铜基体的耐磨性能。     

富CoCr含量CoCrNiAlTi中熵合金的高温强韧化行为及微观机制

本工作研究了富CoCr含量的CoCrNi基中熵合金的高温力学性能及其变形机制。研究发现,经过热锻以及时效热处理,成分为Co_33.3Cr_30.6Ni_26.1Al₅Ti₅ (at%)中熵合金在600～800℃的温度范围内具有优异的瞬时拉伸性能。特别是,在700℃条件下出现反常屈服,屈服强度高达为944 MPa,拉伸塑性为16%,优于大多数镍基以及钴基高温合金。通过X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和三维原子探针(3D-APT)等手段,发现高体积分数的多主元γ′[(Ni,Co,Cr)₃(Al,Ti)]相的有序强化以及晶界处生成的多主元富(Co,Cr)面心立方相(fcc)结构相引起的晶界强化是该合金在高温条件下实现强韧化的主要因素。     

单壁钢吊箱围堰施工技术

介绍江西省温（家圳）厚（田）高速公路龙王庙赣江大桥水中高承台的施工，针对深水急流施工条件，采用单壁钢吊箱围堰技术。阐明了设计思路、结构形式和施工技术，并对承台施工进行了详细叙述。施工承台封底混凝土时使用了水下不离散混凝土絮凝剂UWB，保证了施工质量。该项技术较好地解决了施工中的难题，其成功经验对今后类似工程的施工具有参考、推广价值。