某燃机热电减温水喷嘴频繁堵塞原因分析及防治措施

某燃气轮机电站运行中制冷站减温水喷嘴频繁堵塞,喷嘴需经常人工清理,管道输送泵压力、频率和开度增大,电耗增加,严重影响制冷机系统正常运行状态。通过现场系统查定、减温水水质分析、堵塞物能谱分析等技术手段,分析发生异常现象的原因并得出初步结论,并针对性提出合理有效的防治措施。     

Low voltage operating organic light emitting transistors with efficient charge blocking layer

Charge injection/blocking layers play important roles in the performances of organic electronic devices. Their incorporation into organic light emitting transistors has been limitted, due to generally high operating voltages (above 60 V) of these devices. In this work, two hole blocking molecules are integrated into tris-(8-hydroxyquinoline) aluminum (Alq₃) based light emitting transistors under operating voltage as low as 5 V. The effects of hole blocking and electron injection are decoupled through the differences in the energy levels. Significantly improved optical performance is achieved with the molecule of suitable energy level for electron injection. Surprisingly, a decreased performance is observed in the case of another hole blocking molecule evidencing that charge injection overweighs charge blocking in this device architecture.     

基于高斯混合隐马尔科夫模型与人工神经网络的紧急换道行为预测方法

为了有效降低因驾驶员紧急换道行为而诱发的交通事故，提高道路交通事故链阻断效率，提出一种基于高斯混合隐马尔科夫模型（GMM-HMM）和人工神经网络（ANN）的紧急换道行为预测方法。首先利用GMM-HMM对车辆行驶状态以及驾驶行为连续观察序列进行换道意图辨识，采用ANN预测下一时段的驾驶行为，再预测换道过程中的横向加速度变化率，从而判断紧急换道的危险程度。驾驶员在环仿真实验及实车实验结果表明，该方法预测避险成功率达92.83%，实验避险成功率达90.32%。该方法能有效地对紧急换道行为进行提前警告与干预。     

新型喷射态塔盘开发及工业应用

针对目前酸性水汽提装置普遍存在因塔盘堵塞导致装置运行周期短、能耗高的技术问题，中国石化抚顺石油化工研究院开发了一种具有抗堵功能的新型塔盘（SDMP），利用CFD模拟技术对塔盘的帽罩布局进行了优化，确定了合理的帽罩布局方式。水力学试验结果表明，相比F1浮阀塔盘，SDMP塔盘的压降可降低10%，通量可提高26%，操作弹性基本不变。工业应用结果表明，SDMP具有良好的抗堵塞性能，酸性水汽提装置运行周期大于18个月且继续平稳运行，而且蒸汽单耗不随运行时间的延长而增大，平均蒸汽单耗显著低于F1浮阀塔盘。     

遇水快速膨胀胶凝堵漏技术在长宁页岩气区块的应用

长宁页岩气区块地表为喀斯特地貌，地下溶洞暗河发育，在表层钻进过程中地层出水严重且常发生失返性漏失。针对表层出水漏失难题，先后采用桥浆、高失水堵漏材料、水泥浆、智能凝胶等系列堵漏材料，但堵漏效果差且容易出现复漏。为此室内研发出一种遇水快速膨胀胶凝的堵漏材料，堵漏机理为“膨胀+交联+充填”，堵漏材料遇到地层水后可以与其混合发生交联反应，同时发生膨胀反应，释放CO₂气体促使堵漏材料快速膨胀数倍体积，形成不透水的无毒弹性胶状体；借助CO₂气体压力可将未固化的弹性胶状体进一步压入并充填漏层的孔隙，起到膨胀与弹性堵水的效果。通过配方优化形成遇水快速膨胀胶凝堵漏浆，性能评价表明，堵漏浆胶凝时间在15～70 min范围内可控，膨胀率为250%～350%，可以锁住3倍体积的蒸馏水和5倍体积水基钻井液；在CDL-Ⅱ型高温高压堵漏试验仪中对4～3 mm、5～4 mm模拟漏失通道承压分别达到3.8、1.7 MPa，复合桥浆堵漏后承压能力提高至6.25、5.2 MPa。现场应用一次性封堵出水漏层，提高承压能力5.8 MPa，解决表层出水漏失难题并保障了安全钻进。      

基于自适应融合的手掌静脉增强方法

针对掌脉轮廓不清晰，图像对比度低、亮度低，进而导致识别性能降低的现象，提出一种自适应融合的手掌静脉增强方法。首先，基于暗原色先验（DCP）去雾算法，根据掌脉图像变异系数自适应选择去雾系数，得到DCP增强图像，并且基于部分子块重叠直方图均衡（POSHE）算法得到POSHE增强图像；然后，将图像分为16个子块，依据图像灰度均值与标准差确定各子块权重；最后，根据各子块权重对DCP和POSHE增强图像进行自适应融合，得到最终增强图像。该方法既保留了DCP算法在增强图像对比度和亮度的同时不引入明显噪声的优点，又保留了POSHE算法在增强图像对比度和亮度的同时不损失局部细节的特点；同时，两者的自适应融合既解决了DCP图像阴影部分掌脉缺失现象，又削弱了POSHE产生的块效应。在对两个公开库和自建库分别进行的实验中，三个数据库的等错误率分别为0.0004、0.0472、0.0579，识别率分别为99.98%、94.27%、92.05%。实验结果表明，与现有的图像增强方法相比，该方法降低了等错误率，提高了识别精度。     

Advantage of InGaN-based light-emitting diodes with trapezoidal electron blocking layer

In this study, a trapezoidal-shaped electron blocking layer is proposed to improve efficiency droop of InGaN/GaN multiple quantum well light-emitting diodes. The energy band diagram, carrier distribution profile, electrostatic field, and electron current leakage are systematically investigated between two light-emitting diodes with different electron blocking layer structures. The simulation results show that, when traditional AlGaN electron blocking layer is replaced by trapezoidal-shaped electron blocking layer, the electron current leakage is dramatically reduced and the hole injection efficiency in markedly enhanced due to the better polarization match, the quantum-confined Stark effect is mitigated and the radiative recombination rate is increased in the active region subsequently, which are responsible for the alleviation of efficiency droop. The optical performance of light-emitting diodes with trapezoidal-shaped electron blocking layer is significantly improved when compared with its counterpart with traditional AlGaN electron blocking layer.     

Throughput-based fair bandwidth allocation in OBS networks

Fair bandwidth allocation (FBA) has been studied in optical burst switching (OBS) networks, with the main idea being to map the max-min fairness in traditional IP networks to the fair-loss probability in OBS networks. This approach has proven to be fair in terms of the bandwidth allocation for differential connections, but the use of the ErlangB formula to calculate the theoretical loss probability has made this approach applicable only to Poisson flows. Furthermore, it is necessary to have a reasonable fairness measure to evaluate FBA models. This article proposes an approach involving throughput-based-FBA, called TFBA, and recommends a new fairness measure that is based on the ratio of the actual throughput to the allocated bandwidth. An analytical model for the performance of the output link with TFBA is also proposed.     

基于改进卷积神经网络的化纤丝饼表面缺陷识别

针对传统人工检测化纤丝饼表面缺陷方法的不足,提出改进的卷积神经网络对正常以及3种常见缺陷丝饼进行分类识别。首先对采集的丝饼图像进行分块处理,然后利用改进的卷积神经网络进行特征提取,采用全局最大池化层代替全连接层,增强了图像对空间变换的鲁棒性,减少了模型参数,并利用softmax分类器进行分类。最后在网络学习过程中提出主动学习方法,用少量标注样本对网络进行训练,选出对提升网络性能最具价值的样本进行标注并加入到训练样本中进行训练检测。结果表明,该方法可有效实现丝饼的缺陷识别,识别准确率达到97.1%,并有效减少了网络所需的标注样本数量,节省大量的标注成本,具有一定的通用性。     

Peculiar electric properties of polarized layer in alkaline silicate glasses

Broadband dielectric spectroscopy (BDS) was applied to study polarization phenomena in alkaline silicate glasses, in particular, properties and structure of subsurface (anodic) polarized layers forming in poling with deposited film electrodes of different structures. A model of poled glasses which does not contradict experimental data is proposed. In accordance with the model, a poled glass is presented as two resistor-capacitor circuits in a series connection, one of which is the polarized layer and another is the rest of the sample. It is found that the electric properties of the layers essentially depend on the structure of the anodic electrode used in glass poling. It is also shown that the dielectric response of poled glass samples is mainly determined by the electric properties of the submicron polarized layers and this gives an opportunity to reveal specific properties of the layers rather than ones of the glass sample bulk. Revealed temperature dependence of DC conductivity of the polarized layers obeys Arrhenius's law, and determining activation energy does not depend on the electrode. Finally, it is noted that today above-mentioned information about polarized layers can be obtained only by BDS.