粒子群优化三相桥式整流电路故障诊断

针对三相桥式整流电路中晶闸管出现断路故障的问题,提出采用粒子群优化BP网络的故障诊断方法和蚁群粒子群混合算法优化BP网络的故障诊断方法。首先采用Matlab软件对电路建立仿真模型,通过仿真得到电路故障信息;然后将故障信息输入到BP网络中,对比网络输出与期望输出,得出故障诊断率;最后分别采用粒子群算法和蚁群粒子群混合算法优化BP网络,采用相同的诊断方法,分别得出两种优化网络的故障诊断率。通过对比三种网络的输出信息可以看出,未优化的、PSO优化的和混合算法优化的BP网络,收敛时迭代次数分别为6000、2750和715,网络故障诊断率分别为68.2、81.8%和95.5%。采用神经网络对整流电路中的晶闸管进行断路故障诊断时,通过对网络的优化,能减少诊断时间和提高诊断率。

CALIBRATION OF A 6-DOF SPACE ROBOT USING GENETIC ALGORITHM

The kinematic error model of a 6-DOF space robot is deduced, and the cost function of kinematic parameter identification is built. With the aid of the genetic algorithm （GA） that has the powerful global adaptive probabilistic search ability, 24 parameters of the robot are identified through simulation, which makes the pose （position and orientation） accuracy of the robot a great improvement. In the process of the calibration, stochastic measurement noises are considered. Lastly, generalization of the identified kinematic parameters in the whole workspace of the robot is discussed. The simulation results show that calibrating the robot with GA is very stable and not sensitive to measurement noise. Moreover, even if the robot＇s kinematic parameters are relative, GA still has strong search ability to find the optimum solution.

2019年四川省食品安全监督抽检不合格样品结果分析

对2019年度四川省食品安全抽样和检验结果分析研究,为食品安全监管部门提供科学的分析方法和数据支撑。以该省17509批次食品抽检样品为基础,分析不合格食品样品的种类,食品样品的不合格指标,不合格样品的来源业态以及抽检地市。结果发现2019年度四川省食品安全在蜂产品,食品添加剂,农贸市场方面暴露出的食品安全风险较高。可以作为下一年食品安全风险控制的基础。

2017—2020年四川省食品安全监督抽检结果分析及时空聚集性研究

为了有针对地科学开展食品安全监管,本文通过研究四川省食品安全抽检结果和时空分布规律,采用参数检验、差异检验、空间自相关分析和时空扫描分析等统计方法,对四川省级食品监管部门2017—2020年公开发布的食品安全监督抽检数据进行分析.结果表明:2017—2020年四川省省级监管部门公布的监督抽检结果总体合格率为97.23%.不合格指标中超范围、超限量使用食品添加剂的项次数连续4年显著高于年度平均值(t=-4.47~-3.32,P<0.05).空间自相关分析显示,4年总体食品抽检合格率呈正向空间相关分布特征(Moran’s I>0,Z>1.96,P<0.05),各年度的食品抽检合格率存在局部空间自相关聚集分布.时空扫描表明食品抽检合格率在时间和空间上存在明显聚集性.四川省4年来的食品安全监督抽检合格率较高,在该省流通销售的34类食品品质均保持在较高水平.食品生产者违规使用食品添加剂是该省食品不合格的最主要原因之一.用时空扫描统计量分析验证了各年度局部空间自相关分析的结果,前者的风险聚集区与后者的低聚集区基本一致,食品安全风险聚集在该省中偏东部区域.

HPLC-MS/MS法检测动物源性食品中喹诺酮类药物的基质效应及其补偿措施研究

目的 研究高效液相色谱-串联质谱法(HPLC-MS/MS)测定动物源性食品中15种喹诺酮类化合物的基质效应及其补偿措施。方法 以鱼肉、猪肉和鸡肉作为典型基质,采用提取后加入法和动态多反应监测方式评价基质效应。结果 在三种基质中,60%以上化合物受到中等及强的基质效应,恩诺沙星、培氟沙星和达氟沙星受到强的基质增强效应;氟罗沙星受到强的抑制效应。前处理方法、基质种类、化合物种类以及质量浓度是影响喹诺酮类化合物基质效应的主要因素。结论 日常监测过程中,在不改变检测标准前处理的条件下,采取基质匹配标准曲线、同位素内标、稀释样品以及改善分离度并结合动态多反应监测方式能有效补偿喹诺酮类化合物的基质效应,提高其检测结果的可靠性和准确性。

Efficacy of electroacupuncture stimulating Shenmen(HT7),Baihui(GV20),Sanyinjiao(SP6)on spatial learning and memory deficits in rats with insomnia induced by para-chlorophenylalanine:a single acupoint vs combined acupoints

OBJECTIVE:To investiage the effect of electroacupuncture(EA)at a single acupoint of Shenmen(HT7),Baihui(GV20),Sanyinjiao(SP6)and at combined acupoints of Shenmen(HT7)and Baihui(GV20)and Sanyinjiao(SP6)on the PKA/CREB and BDNF/TrkB signaling,as well as neuroapoptosis and neurogenesis in hippocampus and elucidate the underlying mechanism of single and combined acupoints on ameliorating spatial learning and memory deficits in a rat model of primary insomnia.METHODS:Primary insomnia was modeled by intraperitoneal injection of para-chlorophenylalanine(PCPA)once daily for 2 d.EA was applied at Shenmen(HT7),Baihui(GV20),Sanyinjiao(SP6),or Shenmen(HT7)+Baihui(GV20)+Sanyinjiao(SP6)(combined)for 30 min daily for 4 d.Spatial learning and memory function was evaluated by the Morris water maze(MWM)test.Protein expressions of hippocampal cAMP-dependent protein kinase(PKA)-Cβ,phosphorylated cAMP-responsive element-binding protein(p-CREB),brainderived neurotrophic factor(BDNF),and tyrosine kinase receptor B(TrkB)were evaluated by Western blotting.Neuronal apoptosis in the hippocampus was detected with the transferase-mediated dUTP-X nick end labeling assay.Endogenous neurogenesis was examined with bromodeoxyuridine staining.The MWM test and hippocampal p-CREB,BDNF,and TrkB protein levels in the combined acupoints group were evaluated after the administration of a PKA-selective inhibitor(H89).RESULTS:Spatial learning and memory were significantly impaired in rats with insomnia.The spatial learning deficits were ameliorated in the Shenmen(HT7),Baihui(GV20),Sanyinjiao(SP6),and combined groups;this improvement was significantly greater in the combined group than the single acupoint groups.The spatial memory impairment was improved in the combined,Baihui(GV20),and Shenmen(HT7)groups,but not the Sanyinjiao(SP6)group.The expressions of PKA-Cβ,p-CREB,BDNF,and TrkB were decreased in rats with insomnia.All these proteins were significantly upregulated in the combined group.PKA/p-CREB protein levels were elevated in the Baihui(GV20)and Shenmen(HT7)groups,whereas BDNF/TrkB expression was upregulated in the Sanyinjiao(SP6)group.The staining results showed significant attenuation of hippocampal cell apoptosis and increased numbers of proliferating cells in the combined group,whereas the single acupoint groups only showed decreased numbers of apoptotic cells.In the combined group,the PKA inhibitor reversed the improvement of spatial memory and upregulation of pCREB expression caused by EA,but did not affect its activation of BDNF/TrkB signaling.CONCLUSIONS:EA at the single acupoints Baihui(GV20),Shenmen(HT7),or Sanyinjiao(SP6)had an ameliorating effect on the spatial learning and memory deficits induced by insomnia.EA at combined acupoints exerted a synergistic effect on the improvements in spatial learning and memory impairment in rats with insomnia by upregulating the hippocampal PKA/CREB and BDNF/TrkB signaling,facilitating neurogenesis,and inhibiting neuronal apoptosis.These findings indicate that EA at combined acupoints[(Baihui(GV20),Shenmen(HT7),and Sanyinjiao(SP6)]achieves a more pronounced regulation of hippocampal neuroplasticity than EA at single acupoints,which may partly explain the underlying mechanisms by which EA at combined acupoints exerts a better ameliorative effect on the cognitive dysfunction caused by insomnia.