Microstructures and properties of Co-based alloy coatings prepared on surface of H13 steel

The Co-based alloy coatings had been prepared by laser cladding and vacuum fusion sintering. Microstructures of the coatings were investigated and the performance of thermal cycling was also tested using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that the coatings and substrates combine well. The main phase compositions of laser cladding coating are γ-Co, Cr23C6 and Ni2.9Cr0.7Fe0.36, while vacuum fusion sintering coating consists of Co, Cr7C3 , and Ni2.9Cr0.7Fe0.36. After thermal cycling, the minimum hot cracking width of laser cladding coating is 14 μm; moreover, laser cladding coating maintains high hardness and hot-cracking susceptibility. Those are beneficial to high temperature wear resistance of hot work dies.     

小口径榴弹自然破片形成过程的数值模拟

采用AUTODYN软件中基于Mott分布生成自然破片的Stochastic材料破坏模型,对30mm小口径榴弹壳体膨胀和自然破碎过程进行了数值模拟,获得了破片初速、飞散角沿轴向曲线分布及破片质量分布,仿真结果与破碎性试验回收破片的统计结果吻合较好。     

含氟材料在皮革工业中的应用及研究进展

较全面地介绍了含氟材料在皮革应用中的分类、特性以及研究进展。提出了深化开发低氟高效性的含氟材料以降低成本,同时具备环保性和多功能性的含氟皮化材料的研究方向。     

26Cr2Ni4MoV钢组织遗传与晶粒细化工艺的研究

研究了低温预处理对２６Ｃｒ２Ｎｉ４ＭｏＶ钢组织遗传性的影响，提出了低温细化处理工艺。研究结果表明，６５０℃回火和７７０℃退火，均可通过减少残留奥氏体薄膜数量和α相再结晶的方式细化奥氏体晶粒。     

Experimental study of the burner for FAA fire test: NexGen burner

The NexGen (Sonic) burner is the new burner developed by the Federal Aviation Administration, FAA, to replace old oil burners used for the required fire certification tests on power plant‐related materials, as it provides the capability to control both air and fuel flow rates. During a fire test, the burner is supposed to simulate a certain fire condition, so the flame properties should be robust and repeatable. The NexGen burner can achieve this due to the precise fuel and air controls. However, the current calibration criterion (ISO2685:1998 and AC20‐135) may not be good enough to ensure consistent flame properties. In the presented work, the sensitivity of the burner performance to air and fuel flow rate, as measured by the temperature and heat flux for calibration purposes, was studied. Additionally, the influence of the turbulator and the thermocouple size used for flame calibration was also studied. The impact of varying fuel/air ratio and thermocouple sizes was studied by conducting fire tests on aluminum samples, to show the inadequacies in the current calibration standards.     

Enantioselective Additions of Aryltitanium Tris(isopropoxide) to Ketones: Structure of [(i‐PrO)2Ti{μ‐(S)‐BINOLate}(μ‐O‐i‐Pr)TiPh(O‐i‐Pr)2], Study of Mechanistic and Stereochemical Insights

Aryl addition reactions of ArTi(O‐i‐Pr)₃ to aromatic, heteroaromatic, or α,β‐unsaturated ketones are described, producing tertiary alcohols in good to excellent enantioselectivities of up to 97% ee. The structure of the dititanium complex [(i‐PrO)₂Ti{μ‐(S)‐BINOLate}(μ‐O‐i‐Pr)TiPh(O‐i‐Pr)₂] [(S)‐ 4 ] that simultaneously bears a chiral directing ligand and a nucleophile is reported. Complex (S)‐ 4 possesses a pocket structure and has been illustrated as the key active species for addition reactions of both aldehydes and ketones. Mechanistic and stereochemical insights concerning addition reactions of organometallic reagents to organic carbonyls are rationalized based on the pocket structure and pocket size of (S)‐ 4 .     

Synthesis and crosslinking of partially disulfonated poly(arylene ether sulfone) random copolymers as candidates for chlorine resistant reverse osmosis membranes

Biphenol-based, partially disulfonated poly(arylene ether sulfone)s synthesized by direct copolymerization show promise as potential reverse osmosis membranes. They have excellent chlorine resistance over a wide range of pHs and good anti-protein and anti-oily water fouling behavior. Crosslinking of these copolymers that have high degrees of disulfonation may improve salt rejection of the membranes for reverse osmosis performance. A series of controlled molecular weight, phenoxide-endcapped, 50% disulfonated poly(arylene ether sulfone)s were synthesized. The copolymers were reacted with a multifunctional epoxy resin and crosslinked thermally. The effects on network properties of various factors such as crosslinking time, copolymer molecular weight and epoxy concentration were investigated. The crosslinked membranes were characterized in terms of gel fraction, water uptake, swelling and self-diffusion coefficients of water. The salt rejection of the cured membranes was significantly higher than that for the uncrosslinked copolymer precursors.     

物流信息系统中应用jQuery实现表格数据的动态添加与统计

物流信息系统中应用jQuery实现表格数据的动态添加与统计。     

水剂法制油和饲用菜籽浓缩蛋白中试

本工艺有效地脱除了菜籽中的硫葡萄糖甙、单宁、芥子碱、水苏糖、棉子糖和皂甙等抗营养因子,防止了硫葡萄糖甙降解成异硫氰酸盐、硫氰酸盐、噁唑烷硫酮和腈类毒性物质对油脂、蛋白质和环境的污染,同时还有效地防止了菜籽蛋白质热劣变。因此,制得的菜籽油含硫量低,有利于加工开发利用,生产的饲用菜籽浓缩蛋白,通过养鸡试验,不仅可以代替豆饼,蚕蛹,而且也可以完全代替鸡日粮中的进口鱼粉。     

速溶高蛋白花生晶的研制

本文根据营养学原理及水剂法花生加工工艺研制优质营养食品。利用花生、蔗糖等原料生产速溶高蛋白花生晶,这是一种优质、新型的植物蛋白饮料。本文详细地介绍了速溶高蛋白花生晶研制的理论依据,生产配方及方法。