基于SVD和SSA-VMD降噪的轴承故障特征提取

针对强噪声背景下轴承故障特征提取困难的问题，提出一种基于奇异值分解和参数优化变分模态分解联合降噪的轴承故障特征提取方法(SSVMD)：首先，对原始信号进行奇异值分解(Singular Value Decomposition，SVD)处理，运用奇异值差分谱法选取有效奇异值并将原始信号重构得到初步降噪信号；其次，为防止故障信息丢失，将残余信号进行麻雀算法(Sparrow Search Algorithm，SSA)优化的变分模态分解(Variational Mode Decomposition，VMD）算法处理，得到最佳的模态个数K和惩罚参数α，选取峭度值最大、包络熵最小的IMF分量与初步降噪信号叠加得到最终降噪信号，并对信号进行包络分析；最后，通过仿真和试验数据分析得出，该方法能在信噪比很低的情况下降低噪声含量并提取轴承故障特征，为设备的状态监测和故障诊断提供理论依据。     

液相色谱-串联质谱技术在临床检验中的应用研究进展

液相色谱-串联质谱（LC-MS/MS）技术具有高灵敏度、高特异性、高分辨率和高效率的优点。近年来随着仪器灵敏度的提高，LC-MS/MS在常规临床检验中显示出极大的潜力，并在疾病早期预防和诊断中发挥着不可替代的作用。本文对LC-MS/MS在新生儿疾病筛查、维生素D检测、内分泌激素检测、肽类和蛋白质定量分析等临床检验方面的研究进展进行综述，并讨论了未来面临的挑战。     

Research on quinoline degradation in drinking water by a large volume strong ionization dielectric barrier discharge reaction system

Quinoline is widely used in the production of drugs as a highly effective insecticide, and its derivatives can also be used to produce dyes. It has a teratogenic carcinogen to wildlife and humans once entering into the aquatic environment. In this study, the degradation mechanism of quinoline in drinking water by a strong ionization dielectric barrier discharge(DBD) lowtemperature plasma with large volume was explored. High concentration of hydroxyl radical(·OH)(0.74 mmol l-1) and ozone(O3)(58.2 mg l-1) produced by strongly ionized discharge DBD system were quantitatively analyzed based on the results of electron spin resonance and O3 measurements. The influencing reaction conditions of input voltages, initial p H value, ·OH inhibitors, initial concentration and inorganic ions on the removal efficiency of quinoline were systematically studied. The obtained results showed that the removal efficiency and TOC removal of quinoline achieved 94.8% and 32.2%, degradation kinetic constant was 0.050 min-1 at 3.8 k V and in a neutral p H(7.2). The proposed pathways of quinoline were suggested based on identified intermediates as hydroxy pyridine, fumaric acid, oxalic acid, and other small molecular acids by high-performance liquid chromatography/tandem mass spectrometry analysis. Moreover, the toxicity analysis on the intermediates demonstrated that its acute toxicity, bioaccumulation factor and mutagenicity were reduced. The overall findings provided theoretical and experimental basis for the application of a high capacity strong ionization DBD water treatment system in the removal of quinoline from drinking water.     

基于参数预标定的长行程PMLSM无传感器控制

为了解决长行程定子不连续永磁直线同步电机存在的因无法全程安装位置传感器和不同动子和定子之间的电磁参数不固定所造成的控制性能下降的难题,提出一种在每一段定子内先进行参数标定,再进行速度控制的控制系统设计。首先,在动子进入过程中,对电机进行电磁参数标定,根据标定参数对控制器参数进行调整,以达到更好的控制效果。然后,使用无位置传感器控制系统使动子快速达到设定速度值并稳定运行。实验结果表明:动子进入过程参数标定精度分别为0.002Wb和0.000 4H;无位置传感器控制中位置估计精度为0.63mm,速度收敛时间为0.45s,稳态误差为0.02m/s。基本满足永磁直线同步电机用于长行程运输的控制快速性、稳定性等要求。     

立井过砂岩富含水层工作面预注浆分析

郑煤集团杨河煤业43采区樊寨副立井施工中需要穿过预计涌水量187 m³/h、厚57 m的砂岩含水层。针对第1回次采用普通水泥工作面预注浆、吸浆量少、升压快、效果差、达不到预期目的等不利情况，在后3回次采用大压力，白银水泥、超细水泥等新材料、单孔上下端正反同时注浆新工艺，采用压注清水、水玻璃，利用水玻璃的黏性，反复冲洗钻孔把细小裂隙中锈蚀颗粒带出，打开注浆通道，同时针对竖向裂隙多、横向裂隙不联系，加密钻孔布置，缩小注浆段高，取得了较好的注浆效果。     

Co?N graphene encapsulated cobalt catalyst for H2O2 decomposition under acidic conditions

Hydrogen peroxide (H₂O₂) has been listed as one of the 100 most important chemicals in the world. However, huge amount of residual H₂O₂ is hard to timely decomposed into O₂ and H₂O under acidic condition, easily resulting in explosion hazard. Here, we reported a core–shell structure catalyst, that is graphene with Co N structure encapsulated Co nanoparticles. Co N graphene shell serves as the active site for the H₂O₂ decomposition, and Co core further enhance this decomposition. Benefiting from it, the H₂O₂ decomposition were close to 100% after 6 cycles without pH adjustment, which increased 6 orders of magnitude compared with no catalyst. At the same time, the O₂ generation reached 99.67% in 2 h with little metal leaching, and ·OH has been greatly inhibited to only 0.08%. This work can cleanly remove H₂O₂ with little deep oxidation and protect the process of H₂O₂ utilization to achieve a safer world.     

塔河奥陶系隐蔽溶洞体地震精细识别

实际钻探结果表明，塔河奥陶系发育T₇⁴强轴屏蔽型溶洞体和强“串珠”屏蔽型溶洞体，部分溶洞体产能较高，初步显示了较大的开发潜力。由于该类储集体埋深大（超过5300m）、地震资料主频较低（约28Hz），地震分辨率为30m（约1/4波长）；同时小型溶洞体尺度小，地震响应较弱，地震异常特征不明显，预测强“串珠”储集体的方法明显不适用，亟需加强预测方法研究。为此，在钻、测井资料解释基础上，针对T₇⁴强轴屏蔽型溶洞体，首次采用主成分分析技术克服强子波匹配不足或匹配过度等稳定性问题，有效剥离T₇⁴强干扰，增强隐蔽缝洞体地震响应特征；针对强“串珠”屏蔽型溶洞体，采用低频模型优化的地质统计学反演去除强“串珠”子波旁瓣干扰，以增强隐藏在强子波旁瓣中的缝洞体的辨识度，精细预测隐蔽溶洞体。结果表明，对溶洞体的纵向辨识能力明显提高，可刻画8m厚的溶洞体，反演结果与钻测井符合率达83%，可靠性较高。     

低度艾草酒研制

以全脂乳粉、脱脂乳粉、咖啡为主要原料，添加蔗糖，以安琪酵母8型菌为发酵剂，酸奶感官品质评分和酸奶黏度的综合评分为考察指标，采用正交试验方法对凝固型咖啡酸奶配方进行优化，得到最佳的发酵咖啡酸奶的工艺与配方。结果表明，在发酵温度为42 ℃条件下发酵6 h，脂肪含量3.4%，咖啡添加量1.0%，蔗糖添加量6%，8菌型发酵剂添加量0.1%，发酵后在4 ℃条件下冷藏24 h，获得的发酵酸奶的感官品质评分为89分，黏度为5 640 mPa·s，产品组织状态均匀，口感细腻，略带有咖啡香味，感官评价最佳。最佳发酵条件下的酸度为88 °T，pH值为4.24，乳酸菌活菌数为1.25×108 CFU/mL，符合GB 19302—2010对酸奶品质的规定。