空袭目标攻击方向判断的综合聚类方法

对空袭目标攻击方向的判断是水面舰艇编队防空作战情况判断和指挥决策的基本依据。利用聚类分析相关理论,建立了基于层次和密度的空袭目标攻击方向区分模型,解决了水面舰艇编队对空袭目标攻击方向判断的问题,对提高编队C31系统防空作战指挥决策的科学性、快速性和智能化水平具有一定的参考意义。     

Theoretical efficiency of realistic solar cells intended for thermophotovoltaic applications

The ideal and theoretical efficiencies of one-, two- and three-cell systems using GaAs, silicon and germanium semiconductor materials for thermophotovoltaic applications have been calculated to select the most suitable combination for these applications.It has been verified that, although the GaAsSiGe system is better than the SiGe system in the ideal case, this is no longer true in the theoretical case.     

海洋钻井平台中Q690E焊材的国产化

用于大型浮吊等海工产品的Q690E低合金高强钢焊接时易产生冷裂纹,热影响区受加热速度和冷却速度的影响易形成软化带和脆性组织。焊接时应采用焊前预热、焊后保温和较小的热输入。对比分析国产焊材和国外焊材的化学成分、熔敷金属的力学性能和焊后焊缝金属的力学性能,在可靠的焊接工艺规范下,国产焊材是完全能够替代进口焊材的。     

S模式应答信号多通道接收解码技术研究

为了解决单个天线覆盖范围和作用距离之间的矛盾，实现更广的空域覆盖和更高解码率的目标，采用多个通道进行S模式应答信号的接收、解码及融合纠错的方法，进行了两通道接收、解码及融合纠错实验，获得具有代表性的三批目标的解码数据。经过统计分析，结果表明多通道接收解码不仪可以覆盖更广的空域范围以增加数据量，同时在其中两个通道覆盖的交叠区域，采用信息融合纠错的方法可提供较好的相互纠错能力。     

CAST工艺处理市政污水的设计与运行

大连老虎滩污水处理厂采用CAST工艺处理市政污水,在处理水量超出设计值12.5%、进水浓度低于设计值的条件下,通过调整运行参数,使出水水质达到《城镇污水处理厂污染物排放标准》（GB 18918—2002）的一级B标准,综合运行电耗为0.126kW·h/m3,去除污染物单位电耗为2.73kW·h/kgBOD。     

Numerical simulation of low-concentration CO2 adsorption on fixed bed using finite element analysis

Accurately predicting distributions of concentration and temperature field in fixed-bed column is essential for designing adsorption processes.In this study,a two-dimensional (2D),axisymmetric,nonisothermal,dynamic adsorption model was established by coupling equations of mass,momentum and energy balance,and solved by finite element analysis.The simulation breakthrough curves fit well with the low-concentration CO2 adsorp-tion experimental data,indicating the reliability of the established model.The distributions of concentration and temperature field in the column for CO2 adsorption and separation from CO2/N2 were obtained.The sensitivity analysis of the adsorption conditions shows that the operation parameters such as feed flow rate,feed concentra-tion,pellet size,and column height-to-diameter ratio produce a significant effect on the dynamic adsorption performance.The multi-physics coupled 2D axisymmetric model could provide a theoretical foundation and guidance for designing CO2 fixed-bed adsorption and separation processes,which could be extended to other mixed gases as well.     

基于时频阈值的小波包语音增强算法

该文考虑小波域应用语音降噪中听觉掩蔽效应,提出了一种基于时频阈值的小波包语音增强算法。新算法首先通过频域增强方法得到语音粗估计,通过跟踪估计语音时频特性的细节变化,及时调节降噪阈值,然后利用时频阈值对小波包系数进行处理,以达到语音降噪的目的。实验表明,较传统小波域语音降噪方法,新算法在抑制平稳白噪声的同时减小了语音信息的损失,其增强语音的MOS(Mean Opinion Score)评分、输出信噪比、MBSD(Modified Bark Spectral Distortion)测度性能均有明显提高。     

BMP4 Protects Rat Pulmonary Arterial Smooth Muscle Cells from Apoptosis by PI3K/AKT/Smad1/5/8 Signaling

Bone morphogenetic protein-4 (BMP4), a member of the transforming growth factor β (TGF-β) family of growth factors, is activated and increased under hypoxic conditions, which plays an important role in the progression of pulmonary arterial hypertension (PAH). Previous studies have shown that BMP4 is involved in the regulation of proliferation, differentiation, migration and apoptosis of various cell types. However, the precise mechanisms involved in the regulation of pulmonary artery smooth muscle cells (PASMCs) in PAH are still incompletely understood. It has been reported that AKT is a critical regulator of cell survival and vascular remodeling. Therefore, there may be crosstalk between BMP4 anti-apoptotic processes and PI3K/AKT survival effect in rat PASMCs. To test this hypothesis, we performed confocal, cell viability measurement, mitochondrial potential, real-time polymerase chain reaction (PCR), and Western blot analysis to determine the role of BMP4 on cell survival and apoptosis. We found that hypoxia up-regulated the expression of BMP4. BMP4 promoted cell survival, reduced mitochondrial depolarization, and increased the expression of Bcl-2 and procaspase-3 in PASMCs under serum-deprived condition. These effects were reversed by PI3K/AKT inhibitors ({"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 and wortmannin). Thus, these findings indicate that BMP4 protects PASMCs from apoptosis at least in part, mediated via the PI3K/AKT pathway.     

计及转运业务交叉影响的附加网损分摊研究

基于潮流损耗增量法均忽略了各转运业务间的相互影响,而且对于反向潮流引起附加网损为负值的情况没有提出解决办法。对此采用网损交叉项矩阵描述业务之间的相互影响,对于交叉项网损采用平均分摊法,使得损耗增量法更具有公平性与合理性;同时在深入分析的基础上提出一种处理附加网损为负值的方法,处理后避免了各转运业务分摊到负值的可能。最后通过算例将本文的方法与以往方法算得的分摊结果进行比较,充分说明了本文方法的合理性与公平性。