沉积于硅纳米孔柱阵列上的铜纳米颗粒退火行为研究

以具有规则表面形貌的硅纳米孔柱阵列（Silicon Nanoporous Pillar Array,Si-NPA）作为还原性衬底和组装模板,采用浸渍技术制备了铜／Si-NPA（Cu／Si-NPA）纳米复合体系。将新鲜制备的Cu／Si-NPA样品分别在400℃、600℃和800℃氮气气氛中退火,对比研究了沉积于Si-NPA衬底之上的铜纳米颗粒的表面形貌、晶粒尺寸随温度的演化规律。在较低、较高温度下退火时,铜纳米颗粒所发生的定向迁移、颗粒长大及中心凝聚现象分别在Ostwald成熟理论和团簇扩散理论的框架下得到了解释。     

18wt%Cr–8wt%Ni不锈钢中增塑性MnO–Al2O3–SiO2基非金属夹杂物的演变及其浸泡性能

The properties of MnO–Al₂O₃–SiO₂-based plasticized inclusion are likely to change during soaking  process due to its low melting point. In this study, the evolution of the MnO–Al₂O₃–SiO₂-based inclusion of 18wt%Cr?8wt%Ni stainless steel under isothermal soaking process at 1250°C for different times was investigated by laboratory-scale experiments and thermodynamic analysis. The results showed that the inclusion population density increased at the first stage and then decreased while their average size first decreased and then increased. In addition, almost no Cr₂O₃-concentrated regions existed within the inclusion before soaking, but more and more Cr₂O₃ precipitates were formed during soaking. Furthermore, the plasticity of the inclusion deteriorated due to a decrease in the amount of liquid phase and an increase in the high-melting-point-phase MnO–Cr₂O₃ spinel after the soaking process. In-situ observations by high-temperature confocal laser scanning microscopy (CLSM) confirmed that liquid phases were produced in the inclusions and the inclusions grew rather quickly during the soaking process. Both the experimental results and thermodynamic analysis conclude that there are three routes for inclusion evolution during the soaking process. In particular, Ostwald ripening plays an important role in the inclusion evolution, i.e., MnO–Al₂O₃–SiO₂-based inclusions grow by absorbing the newly precipitated smaller-size MnO–Cr₂O₃ inclusions.     

Proteomics study of the effects of high pigment-1 on plastid differentiation during the ripening of tomato fruits

The chloroplast-to-chromoplast difference is a highly regulated process. Tomato （Solanum lycopersicum） high-pigment mutant hp-1 shows an enhanced accumula- tion of carotenoids coupled with an increase in the volume and number of plastids. However, how chromoplasts of hp-] acquire their specific metabolic characteristics is still unclear. A comparison of proteome profiles from plastids at the mature green, breaker, and red stages of tomato fruits showed 45 differentially expressed proteins. These identi- fied proteins fell into six different functional categories. Our results showed that most of the proteins related to the Calvin cycle increased transitorily only at the early breaker stage, and remained unchanged at the early red stage. We found 18 proteins that were differentially expressed between the wild type and hp-1. The abundance of GCPE in chromoplasts of hp-1 was higher than that in the wild type. Meanwhile, we found that heat shock proteins were only present specifically in the mature green stage chromoplasts of hp-1 but not in the wild type. This suggested that GCPE and heat shock proteins might play important roles in the accumulation of high carotenoids in hp-1. Overall, our results could be helpful for understanding chloroplast-to-chromoplast differentiation and the function of hp-1.     

不同留蔓数对薄皮甜瓜泰甜10号果实的影响

以源库理论为基础,以黑龙江省目前主栽薄皮甜瓜泰甜10号为实验材料,研究不同留蔓数对其熟期、果实品质和产量的影响.结果表明,泰甜10号留3蔓平均单果质量、总产量显著高于留2蔓;留3蔓熟期比留4蔓提前近一周,单果质量、单株结果数、早期产量、总产量、可溶性固形物显著高于留4蔓.综合熟期、品质、产量的影响,北方露地实际生产中留3蔓对泰甜10号最为适宜.     

用鞣酸和香兰素诱发乙醇饮料老熟的研究

本文报道了用植物材料的提取液处理含乙醇的饮料可促其老熟.处理乙醇饮料的原料成分,经分析有香兰素30～100mg/L、鞣酸8～42g/L、5-羟甲基糠醛0.5～50mg/L.这种原料它的 UV 光谱最大吸收在205和280nm 之间,其光密度值在225～230nm 有一凸起部分,它是从槲栎中提取出来的.本研究经实验取得了满意的结果,为乙醇饮料的人工催熟开辟了一条易于推广的途径.     

Mo含量对Ti–Mo系铁素体钢热稳定性影响

The effects of tempering holding time at 700°C on the morphology, mechanical properties, and behavior of nanoparticles in Ti–Mo ferritic steel with different Mo contents were analyzed using scanning electron microscopy and transmission electron microscopy. The equilibrium solid solution amounts of Mo, Ti, and C in ferritic steel at various temperatures were calculated, and changes in the sizes of nanoparticles over time at different Mo contents were analyzed. The experimental results and theoretical calculations were in good agreement with each other and showed that the size of nanoparticles in middle Mo content nano-ferrite (MNF) steel changed the least during aging. High Mo contents inhibited the maturation and growth of nanoparticles, but no obvious inhibitory effect was observed when the Mo content exceeded 0.37wt%. The tensile strength and yield strength continuously decreased with the tempering time. Analysis of the strengthening and toughening mechanisms showed that the different mechanical properties among the three different Mo content experiment steels were mainly determined by grain refinement strengthening (the difference range was 30–40 MPa) and precipitation strengthening (the difference range was 78–127 MPa). MNF steel displayed an ideal chemical ratio and the highest thermodynamic stability, whereas low Mo content nano-ferrite (LNF) steel and high Mo content nano-ferrite (HNF) steel displayed relatively similar thermodynamic stabilities.     

脊尾白虾Palaemon carinicauda人工促熟的初步研究

升温与切除单侧眼柄都能促进脊尾白虾的性腺成熟。切除左侧眼柄与切除右侧眼柄促熟效果相近，但优于升温促熟，切除单侧眼柄与升温两种方法同时使用促熟效果更佳。     

相场法模拟低体积分数下的Ostwald熟化

建立低体积分数下的Ostwald熟化过程的相场模型,采用Cahn-Hilliard方程和Allen-Cahn方程控制相对密度场和长程取向场的变化,研究体积分数对生长指数m、动力学系数k和粒径分布的影响.结果表明：低体积分数（小于10％）的Ostwald熟化中,生长指数函数中的生长指数m不依赖于体积分数的变化,m=3.o;而随着体积分数的增加,动力学系数k变化不大,在k=0.003附近.随着熟化相体积分数的增加,晶粒生长尺寸分布加宽.     

草莓果实成熟变化的研究

“拉瑞特”草莓采后成熟期间,花青素快速累积,呼吸速率逐渐下降,成熟后期产生少量乙烯。虽然总游离氨基酸含量不断增加,但各成熟期果实中均未检出蛋氨酸的存在。采后三天的果实硬度下降二倍,纤维素含量减少50％,而纤维素酶活性上升二倍。标记尿嘧啶核苷酸和亮氨酸掺入RNA和蛋白质的量随成熟明显增加。本文讨论了草莓成熟变软与纤维素酶活性上升的关系以及成熟期间RNA和蛋白质代谢的变化规律。