插入式铜条转子并头套电阻硬钎焊工艺

为提高电动机中插入式铜条转子并头套的焊接质量,采用了电阻硬钎焊工,这样在改善劳动环境、降低劳动强度的同时提高了生产效率。     

一种软件演化活动波及效应混合分析方法

确定演化活动潜在影响的过程称之为波及效应分析.波及效应分析已经被公认为影响软件演化项目成败的一个关键因素.针对当前波及效应分析准确率不高、各方法存在固有缺陷的问题,提出了一种混合波及效应分析方法,该方法将动态分析方法与文本分析方法相结合,在保持高召回率的基础上,基于演化软件领域知识降低了噪声对分析结果的不利影响,约简了分析范围,提高了查准率.为验证方法的有效性,对开源软件jEdit分别使用动态、静态、基于文本、基于历史演化知识和混合分析方法进行波及效应分析.通过比对实验结果,表明混合波及效应分析方法具有较好的综合性能.     

Detection of alpha-fetoprotein through biological signal amplification by biosensor based on imaging ellipsometry

High sensitive and quantitative detection of alpha-fetoprotein (AFP) by biosensor based on imaging ellipsometry (BIE) through biological amplification was investigated. AFP firstly reacted with the rat monoclonal antibody (rat-mAb) initially immobilized on glutaraldehyde modified silicon surface, then rabbit anti-human AFP polyclonal antibodies (Rabbit-pAb) and goat anti-rabbit IgG (goat-IgG) were sequentially applied to amplify signal. Results revealed that signal was enhanced approximately six fold. The linear range of AFP detection was 20.0-200.0 ng/ml with a low limit of 5.0 ng/ml (S/N = 3). The cross-reaction rate was less than 5.2% evaluated by biomarker (carcinoembryonic antigen, carbohydrate 19-9 and carbohydrate antigen 242) and two common proteins (human serum albumin, fibrinogen) and their mixture. Coefficient variation (CV) for intra-slide and inter-slide reproducibility were 10.3%, 6.6%, 6.3% and 10.7%, 7.9%, 6.4% for 41.6 ng/ml, 83.2 ng/ml and 128.4 ng/ml AFP. In clinic application, cut-off value at 28.6 ng/ml was also determined with sensitivity 0.72 and specificity 0.94. Results of 47 clinic patient samples detected by BIE were in good agreement with those of electrochemiluminescence immunoassay (ECLIA) (R2 = 0.9949).The area under receiver operating characteristic curve (ROC) curve is 0.89. Statistical analysis showed that BIE is high agreement with ECLIA (Kappa = 0.733, U = 3.21>U0.01). It shows a potential for hepatocellular carcinoma (HCC) diagnosis.     

医院改扩建中的功能环重铸

多组空间组合是综合医院的基本特性，在组合的过程中形成了功能环。医院发展到一定程度就会使之破裂，需要依据新的功能关系，重铸功能环。     

KOH modified Nafion112 membrane for high performance alkaline direct ethanol fuel cell

A polymer electrolyte membrane for alkaline direct ethanol fuel cell (ADEFC) was prepared by dipping Nafion112 membrane into KOH solution for some time at room temperature. The obtained membrane (Nafion112/KOH) exhibited higher mechanical properties and thermal stability than Nafion112 membrane. The ionic conductivity of Nafion112/KOH in 1 M, 2 M and 6 M KOH solutions was 0.011 S/cm, 0.026 S/cm, 0.032 S/cm, respectively, depending on internal OH⁻ concentration and the volume fraction of the internal aqueous phase. Single cell performance suggested that active ADEFC with Nafion112/KOH membrane can deliver a peak power density of 58.87 mW/cm² at 90 °C, meanwhile, it can stably run for at least 12 h above 0.2 V. On the other hand, Pt-free air breathing ADEFC with Nafion112/KOH can output a peak power density of 11.5 mW/cm² at 60 °C, and the corresponding lifetime was as long as 473 h above 0.3 V.     

基于改进VMD去噪的Prony-GSO联合谐波检测方法

针对传统Prony谐波检测方法在噪声条件下存在局限性,提出了一种能够在较大噪声条件下准确进行谐波检测的方法。通过对采样信号进行自适应的VMD分解,利用平均周期能量进行噪声模态的选择并予以剔除,将剩余模态重组后得到适合Prony算法的平稳信号;对平稳信号进行Prony谐波分析得到初步的谐波特征信息;对谐波特征信息进行循环筛选与GSO寻优,得到最终的谐波与间谐波特征信息。利用该方法进行谐波检测仿真实验,仿真结果表明,该方法有效提高了Prony算法在较大噪声条件下的辨识准确度,具有自适应性,能够自动筛选真实频率成分,具有高效、精确等优点。     

基于无线传感器网络的电力变压器监测系统

项目将无线ZigBee技术和GPRS技术相结合,设计了基于ZigBee和GPRS的电力变压器监测系统,提出了以ZigBee无线传感器网络为核心,以GPRS移动网为骨干网,采用CC2430芯片为电力变压器信号采集节点的方案。本设计既实现了系统的灵活性,也解决了由于ZigBee是一种近距离传输技术而使监测数据传输不远的问题,是一种技术结合的创新,在监测领域将有广阔的应用前景。     

Experimental study on grinding force and grinding temperature of Aermet 100 steel in surface grinding

This paper investigates grinding force and grinding temperature of ultra-high strength steel Aermet 100 in conventional surface grinding using a single alumina wheel, a white alumina wheel and a cubic boron nitride wheel. First, mathematical models of grinding force and grinding temperature for three wheels were established. Then, the role of chip formation force and friction force in grinding force was investigated and thermal distribution in contact zone between workpiece and wheel was analyzed based on the mathematical model. The experimental result indicated that the minimum grinding force and the maximum grinding force ratio under the same grinding parameters can be achieved when using a CBN wheel and a single alumina wheel, respectively. When the phenomenon of large grinding force and high grinding temperature appeared, the workpiece material would adhere locally to the single alumina wheel. Grinding temperature was in a high state under the effect of two main aspects: poor thermal properties of grinding wheel and low coolant efficiency. The predicted value of grinding force and grinding temperature were compared with those experimentally obtained and the results show a reasonable agreement.     

Preparation of W–Sc2O3 targets and scandate cathodes with film prepared by pulsed laser deposition

Sub-micrometer Sc₂O₃–W powder with a narrow particle size distribution has been obtained by a sol–gel method combined with two-step hydrogen reduction process. Based on the obtained powder, the W–Sc₂O₃ targets have been sintered via spark plasma sintering (SPS) at 1300 °C. The W–Sc₂O₃ targets have the average grain size of about 1 μm. Both the sintering temperature and holding time are much lower than those of the targets prepared with micrometer sized powders. The obtained W–Sc₂O₃ targets have a high comparative density of 96.4% and rockwell hardness of 86.4 HRC. Using the target, the scandate cathode deposited with a film containing 5% Sc₂O₃ and 95% W has been obtained by pulsed laser deposition (PLD) method. This cathode has good emission property, i.e., the highest thermionic emission current density reaches 43.09 A/cm² of J_div at 900 °C_b after being activated for 8 h, which is much higher than that of scandate cathode without film. Scandium (Sc) supplied by the film on the surface during the activation forms a Ba–Sc–O active layer, which helps to the emission.