搅拌摩擦对接焊6061铝合金的高周疲劳行为（英文）

对6061铝合金进行搅拌摩擦对接焊,其焊接工艺参数为:旋转速度600、800、1000、1200 r/min,前进速度80、100 mm/min,探针插入深度1.85 mm。基于搅拌摩擦焊参数计算得到的能量输入结果表明,在输入能量为196~405 kJ的情况下,接头在297~354 kJ的输入能量范围内有最大的抗拉强度。在不同的应力比(R=0.5,0.3,0.1,-0.3,-0.5)下,将高强度、低强度2种焊接头进行疲劳测试。结果表明,对于这2种焊接头,显微组织特征明显影响其疲劳性能,比如搅拌区、热力影响区(TMAZ)和热影响区。从接头的显微组织、裂纹扩展路径和断裂表面观察等方面对其疲劳强度进行讨论。     

搅拌摩擦对接焊6061铝合金的高周疲劳行为

对6061铝合金进行搅拌摩擦对接焊,其焊接工艺参数为：旋转速度600、800、1000、1200 r/min,前进速度80、100 mm/min,探针插入深度1.85 mm。基于搅拌摩擦焊参数计算得到的能量输入结果表明,在输入能量为196～405 kJ的情况下,接头在297～354 kJ的输入能量范围内有最大的抗拉强度。在不同的应力比（R=0.5,0.3,0.1,-0.3,-0.5）下,将高强度、低强度2种焊接头进行疲劳测试。结果表明,对于这2种焊接头,显微组织特征明显影响其疲劳性能,比如搅拌区、热力影响区（TMAZ）和热影响区。从接头的显微组织、裂纹扩展路径和断裂表面观察等方面对其疲劳强度进行讨论。     

新型PEO/纳米结构ZrO_2镁合金涂层的抗菌活性及腐蚀行为（英文）

为了增强镁合金的耐腐蚀性和抗菌活性,先采用等离子体电解氧化(PEO)在镁合金上制备一层结合层,再用空气等离子喷涂(APS)制备纳米结构ZrO_2表面涂层。采用电化学试验研究涂层样品的腐蚀行为,采用琼脂扩散法对其进行大肠杆菌病原菌抑菌活性评价,并与无涂层样品进行对比。与PEO涂层和无涂层镁合金相比,PEO/纳米ZrO_2涂层样品的腐蚀电流密度最低,电荷传递阻力最高,相位角和阻抗模量最高。PEO结合涂层被纳米ZrO_2表面涂层完全密封,能够显著延缓侵蚀性离子向镁合金表面迁移,显著提高镁合金在模拟体液(SBF)中的耐蚀性。此外,PEO/纳米ZrO_2涂层的抗菌活性也高于PEO涂层和无涂层镁合金,这是由于ZrO_2纳米颗粒通过作用于细胞膜而降低了大肠杆菌的生长速率。     

CHARACTERISTICS OF PINK PERCH (NEMIPTERUS JAPONICUS) SURIMI AT FROZEN TEMPERATURE

An investigation lasting 36 weeks was carried out on the frozen storage (?20C) behavior of surimi prepared from the fish pink perch (Nemipterus japonicus). Total volatile base nitrogen (TVBN), trimethylamine (TMA), peroxide value (PV) and total plate count (TPC) values of surimi increased gradually from 3.5 ± 0.1 to 5.60 ± 0.17 mg%, 0 to 2.8 ± 0.2 mg%, 0 to 0.8 ± 0.3 meq/kg and 5.25 × 10⁴to 9.58 × 10⁴ cfu/g, respectively, during frozen storage but were within the acceptable limit. Nonprotein nitrogen (NPN), free alpha‐amino nitrogen and surimi whiteness increased from 13.63 ± 0.09 to 22.35 ± 0.2 mg%, 0 to 8.55 ± 0.02 mg% and 61.83 to 63.48 degrees, respectively, with the passage of time. Moisture, crude protein, total nitrogen (TN), pH and gel strength of surimi decreased from 78.50 ± 0.14 to 76.55 ± 0.02%, 17.72 ± 0.18 to 14.57 ± 0.01%, 2.84 ± 0.02 to 2.14 ± 0.02%, 7.20 ± 0.1 to 6.05 ± 0.09, and 237 to 97.43 g × cm, respectively, during frozen storage. The surimi was acceptable at the end of the 36 week storage period.     

INFRARED AND HOT-AIR DRYING OF ONIONS

The combination of infrared (IR) and hot‐air drying of onion slices was explored, and the effects of processing conditions such as drying temperature, slice thickness, air temperature and velocity on onion slice characteristics were studied. The onion slice quality was evaluated on the basis of the color and the pyruvic acid content, an index of flavor. Drying of thin slices of onion (2 mm) at low temperature (60C) with a moderate air velocity (2 m/s) and air temperature (40C) retained greater flavor and color. An empiric equation developed to correlate the drying process variables and the onion slice moisture with the drying time provided a good fit (R² = 0.92). Similar equations developed to correlate the drying process variables and the drying time with the pyruvic acid content provided an excellent fit (R² = 0.96), while the equations fit for the total color change of onion slices were satisfactory (R² = 0.86). Combination drying resulted in shorter drying process time and in better onion slice quality as compared to IR and hot‐air drying applied individually.     

Effectiveness of macrogol and talcum base formulations of a new insect repellent N, N-diethyl phenyl acetamide

The effectiveness of macrogol and talcum base formulations of a new multi-insect repellent N, N-diethyl phenyl acetamide (DEPA) was studied against Aedes aegypti mosquitoes in the laboratory. The efficacy was compared with widely used repellent in India, viz. Dimethylphthalate. Twenty-five per cent DEPA incorporated macrogol ointment and talcum base formulation offered more than 8 h and 6 h protection, as compared to DMP for 3 h and 1 h 30 min, respectively. The ointment was found to be stable as more than 99% DEPA was recovered by gas liquid chromatography after 6 months of storage at room temperature. The repellent formulations have not shown any gross adverse effect to the skin of albino rabbits.

Résumé

L'efficacité d'un nouvel agent repousseur d'insectes (le N, N-diethyl phenyl acetamide) dans des formulations à base de macrogol et du talc
L'efficacité des bases formulées à partir de macrogol et de talc pour un nouvel insecticide, N, N-diethyl pnenyl acetamide (DEPA) a étéétudiée contre les moustiques Aedes aegypti en laboratoire. Cette efficacité a été comparée avec un insecticide couramment utilisé en Inde, le Dimethyl phthalate. 25% de DEPA incorporéà une base formulée à partir de pommade de macrogol et de talc a permis une protection respectivement de plus 5 h et de plus de8 h comparativement au DMP pour lequel la protection était respectivement de 3 h et 1 h 30. La pommade s'est avérée stable car plus de 99% de DEPA ont été identifiés par GLC après 6 mois de stockage à température ambiante. Les formulations d'insecticides n'ont révélé aucun effet adverse sur la peau des lapins albinos.