铝塑型材锯铣加工中心锯切机的气动系统设计

自动锯切机作为锯铣加工中心的主要组成部分，将先进的计算机智能控制与诊断技术、气动控制技术融为一体，实现了型材锯切过程的数字化、柔性化。采用气动控制方式来实现铝塑型材的自动加工，符合绿色制造原则。实际应用证明，自动锯切机性能稳定，可显著提高生产效率。     

虚拟样机技术在牵引机装配设计中的应用

介绍了虚拟样机技术的基本概念及应用概况，简单概括了电力布线牵引机械的发展过程，并结合电力布线工程的实际分析了虚拟样机技术在液压自驱动牵引机设计中应用的必要性。着重阐述了利用SOLIDEDGE软件进行CAD三维建模的方法，提出了成功解决复杂环境下工程机械系统仿真的方法。     

Leptin promotes proliferation and invasion of osteosarcoma cells by upregulating the expression of SIRT1

Osteosarcoma (OS) is a primary high-grade malignant bone neoplasm, and the prognosis of OS remains poor due toearly metastasis. Leptin plays an essential role in tumorigenesis, but the role of leptin in the development of OS is still not fullyunderstood. In this study, we used a human osteosarcoma MG-63 cell line as an experimental model. MG-63 cells were treatedwith leptin, and cell proliferation, apoptosis, adhesion, invasion, and gene expression, were evaluated. The results showed thatleptin promoted proliferation, decreased adhesion, suppressed apoptosis, and promoted invasion, of MG-63 cells. Moreover,the expression of SIRT1 was upregulated in MG-63 cells exposed to leptin. Furthermore, MMP-2, 8, and 9 were significantlyupregulated by SIRT1, while SIRT1 knockdown inhibited the proliferation and invasion of MG-63 cells. In conclusion, ourresults suggest that leptin promotes OS cell proliferation and invasion by inducing the expression of SIRT1.     

CoMoP-EG/ Al2O3催化剂的表征及其柴油加氢精制催化性能

在CoMoP共浸渍液中加入乙二醇(EG)制备CoMoP-EG/γ-Al2O3系列催化剂。采用UV-Vis、TG/DTG、FT-IR、低温N2吸附、H2-TPR、HRTEM等手段对其进行表征,并以直馏柴油为原料,采用高压微反装置评价催化剂的加氢脱硫和加氢脱氮活性。结果表明,浸渍液中的乙二醇未与活性金属离子形成新的配合物。乙二醇与载体发生相互作用形成Al-O-C键,减弱了活性组分与载体的相互作用,提高了活性组分的分散性。与未加乙二醇制备的硫化态CoMoP/γ-Al2O3相比,硫化态CoMoP-EG/γ-Al2O3催化剂中MoS2晶粒的堆垛层数增加,片层长度减少,有利于Ⅱ型Co-Mo-S活性相的形成。在反应温度350℃、氢分压6.0 MPa、空速1.5h-1、氢/油体积比400条件下,采用最佳乙二醇加入量制备的CoMoP-EG/γ-Al2O3催化剂,可使直馏柴油的硫质量分数由13298μg/g降至6μg/g,氮质量分数由169.7μg/g降至0.4μg/g。     

辣椒油中苯并芘参考标准物质的制备与定值

为建立辣椒油中苯并芘标准物质的研制和定值方法,向辣椒油中添加一定量的苯并芘标准溶液,搅拌均匀后分装100 瓶,随机抽取10 瓶样品进行样品均匀性检验,在95% 置信区间内,检验结果同时通过F 检验和t 检验。在恒温4℃冷藏和常温20℃条件下,在8 周内进行样品的稳定性检验,检验结果通过t 检验,在95% 置信区间内。并通过分析标准物质制备过程中的不确定度来源,计算出不确定度分量、合成标准不确定度及扩展不确定度。制备的辣椒油中苯并芘采用同位素稀释气相色谱- 质谱联用法进行辣椒油中苯并芘定值,定值后的辣椒油样品中苯并芘含量为(9.98 ± 0.914)μg/kg(k ＝ 2)。本标准物质对于植物油中苯并芘检测的方法验证和质量控制具有重要意义。     

基于邻域相关性小波去噪的滚动轴承包络解调及故障分类

将邻域相关性的冗余第二代小波应用于滚动轴承信号降噪,用Hilbert包络解调法提取的故障特征频率,比较不同转速和载荷下的提取效果,提出包络幅值峭度指标,并将其输入BP神经网络进行故障诊断。结果表明:基于邻域相关性的冗余第二代小波降噪方法能很好的抑制噪声,保留原信号的信息;降噪后的故障信号经过Hilbert包络解调能找到特征频率及其倍频,其效果优于原始信号的包络解调分析。工况会影响分析效果,且速度对提取效果的影响大于载荷。包络幅值峭度指标能很好区分不同工况的故障信号,结合BP人工神经网络诊断正确率为100%。     

The control of size and areal density of InAs self-assembled quantum dots in selective area molecular beam epitaxy on GaAs (0 0 1) surface

The growth of InAs quantum dots (QDs) on GaAs (0 0 1) substrates by selective area molecular beam epitaxy (SA-MBE) with dielectric mask is investigated. The GaAs polycrystals on the mask, which is formed during growth due to low GaAs selectivity between dielectric mask and epitaxial region in MBE, strongly affect the distribution of InAs QDs on the neighbouring epitaxial regions. It is found that the GaAs polycrystalline regions strongly absorb indium during QD growth, confirmed by microscopic and optical studies. GaAs polycrystalline deposit can be reduced under low growth rate and high-temperature growth conditions. Almost no reduction in QD areal density is observed when there is minimal polycrystalline coverage of the mask.     

Passively mode-locked Er3+ fiber laser using asemiconductor nonlinear mirror

A nonlinear mirror consisting of an InGaAs/InP multiple-quantum-well saturable absorber integrated with a Bragg reflector stack has been used to passively mode-lock a fiber laser in an extremely simple and advantageous linear-cavity configuration. To date, pulses as short as 7.6 ps have been observed     

Genetic regulation of commitment to interleukin 4 production by a CD4(+) T cell-intrinsic mechanism

The dysregulated expression of interleukin 4 (IL-4) can have deleterious effects on the outcome of infectious and allergic diseases. Despite this, the mechanisms by which naive T cells commit to IL-4 expression during differentiation into mature effector cells remain incompletely defined. As compared to cells from most strains of mice, activated CD4(+) T cells from BALB mice show a bias towards IL-4 production and T helper 2 commitment in vitro and in vivo. Here, we show that this bias arises not from an increase in the amount of IL-4 produced per cell, but rather from an increase in the proportion of CD4(+) T cells that commit to IL-4 expression. This strain-specific difference in commitment was independent of signals mediated via the IL-4 receptor and hence occurred upstream of potential autoregulatory effects of IL-4. Segregation analysis of the phenotype in an experimental backcross cohort implicated a polymorphic locus on chromosome 16. Consistent with a role in differentiation, expression of the phenotype was CD4(+) T cell intrinsic and was evident as early as 16 h after the activation of naive T cells. Probabilistic gene activation is proposed as a T cell-intrinsic mechanism capable of modulating the proportion of naive T cells that commit to IL-4 production.     

Encoding pictures in scene contexts: Does task demand influence effects of encoding congruity?

Three experiments examined the role of task demand in accounting for the effect of encoding congruity in levels-of-processing research. The effect of encoding congruity refers to the likelihood of remembering items associated with yes responses better than items associated with no responses. Ss made yes responses if target pictures were congruous with prior scene contexts or if targets and prior contexts were incongruous. Congruous contexts yielded better incidental cued recall and name recognition than incongruous ones, independently of response type. However, effects of encoding congruity and response type were not significant for picture recognition. It is suggested that the effect of encoding congruity depends on the ability to integrate target items into consistent contexts. However, encoding congruity facilitates remembering pictures' identity, but not their visual details. The relevance of the results to scene schema research is also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)