面向室内厘米级定位及单站定位技术难点,借助射频识别(Radio Frequency Identification,RFID)收发相位同步技术优势,建立基于跳频的多载波相位距离观测方程,计算各载波在不同整周下的链路距离,利用距离方差快速求解整周模糊度,提升整周...面向室内厘米级定位及单站定位技术难点,借助射频识别(Radio Frequency Identification,RFID)收发相位同步技术优势,建立基于跳频的多载波相位距离观测方程,计算各载波在不同整周下的链路距离,利用距离方差快速求解整周模糊度,提升整周求解的鲁棒性.利用跳频并改进多重信号分类(MUltiple SIgnal Classification,MUSIC)算法建立跳频测向求解模型,消除短距离测向不同天线来波方向不平行带来的误差,实现两天线短距离标签反射信号的精确测向.最后联合载波相位测距对双天线测向结果进行筛选,实现RFID标签的单站厘米级精确定位.通过测试验证,平均定位误差低于4 cm.展开更多
SiC MOSFET分立器件的并联已在中大功率的电力电子设备中广泛使用,为充分利用并联使用的优势,避免不当并联可能产生的电-热失衡现象,需提前预测开关管并联工作时的稳态电-热分布情况。而由于半导体器件在生产过程中的差异性不可避免,即...SiC MOSFET分立器件的并联已在中大功率的电力电子设备中广泛使用,为充分利用并联使用的优势,避免不当并联可能产生的电-热失衡现象,需提前预测开关管并联工作时的稳态电-热分布情况。而由于半导体器件在生产过程中的差异性不可避免,即使是同一厂商生产的同一型号SiC MOSFET,在关键参数如阈值电压U_(TH)和导通电阻R_(DS(ON))上都有所差异,而这些参数正是影响器件并联动静态电流分布和电-热分布的关键参数。本文研究了影响器件并联动静态电流分布和电-热分布的因素以及关键参数的温度分布特性,并在此基础上提出了一种电-热分布特性的预测模型,最后搭建了实验平台验证了预测模型的准确性。展开更多
Objective:To explore the mechanism of electroacupuncture(EA) in promoting recovery of the facial function with the involvement of autophagy,glial cell line-derived neurotrophic factor(GDNF),and phosphatidylinositol-3-...Objective:To explore the mechanism of electroacupuncture(EA) in promoting recovery of the facial function with the involvement of autophagy,glial cell line-derived neurotrophic factor(GDNF),and phosphatidylinositol-3-kinase(PI3K)/mammalian target of rapamycin(mTOR) signaling pathway.Methods:Seventy-two male Sprague-Dawley rats were randomly allocated into the control,sham-operated,facial nerve injury(FNI),EA,EA+3-methyladenine(3-MA),and EA+GDNF antagonist groups using a random number table,with 12 rats in each group.An FNI rat model was established with facial nerve crushing method.EA intervention was conducted at Dicang(ST 4),Jiache(ST 6),Yifeng(SJ 17),and Hegu(LI 4) acupoints for 2 weeks.The Simone’s 10-Point Scale was utilized to monitor the recovery of facial function.The histopathological evaluation of facial nerves was performed using hematoxylin-eosin(HE) staining.The levels of Beclin-1,light chain 3(LC3),and P62 were detected by immunohistochemistry(IHC),immunofluorescence,and reverse transcriptionpolymerase chain reaction,respectively.Additionally,IHC was also used to detect the levels of GDNF,Rai,PI3K,and mTOR.Results:The facial functional scores were significantly increased in the EA group than the FNI group(P<0.05 or P<0.01).HE staining showed nerve axons and myelin sheaths,which were destroyed immediately after the injury,were recovered with EA treatment.The expressions of Beclin-1 and LC3 were significantly elevated and the expression of P62 was markedly reduced in FNI rats(P<0.01);however,EA treatment reversed these abnormal changes(P<0.01).Meanwhile,EA stimulation significantly increased the levels of GDNF,Rai,PI3K,and mTOR(P<0.01).After exogenous administration with autophagy inhibitor 3-MA or GDNF antagonist,the repair effect of EA on facial function was attenuated(P<0.05 or P<0.01).Conclusions:EA could promote the recovery of facial function and repair the facial nerve damages in a rat model of FNI.EA may exert this neuroreparative effect through mediating the release of GDNF,activating the PI3K/mTOR signaling pathway,and further regulating the autophagy of facial nerves.展开更多
文摘面向室内厘米级定位及单站定位技术难点,借助射频识别(Radio Frequency Identification,RFID)收发相位同步技术优势,建立基于跳频的多载波相位距离观测方程,计算各载波在不同整周下的链路距离,利用距离方差快速求解整周模糊度,提升整周求解的鲁棒性.利用跳频并改进多重信号分类(MUltiple SIgnal Classification,MUSIC)算法建立跳频测向求解模型,消除短距离测向不同天线来波方向不平行带来的误差,实现两天线短距离标签反射信号的精确测向.最后联合载波相位测距对双天线测向结果进行筛选,实现RFID标签的单站厘米级精确定位.通过测试验证,平均定位误差低于4 cm.
基金Supported by the National Natural Science Foundation of China (No.81603706)。
文摘Objective:To explore the mechanism of electroacupuncture(EA) in promoting recovery of the facial function with the involvement of autophagy,glial cell line-derived neurotrophic factor(GDNF),and phosphatidylinositol-3-kinase(PI3K)/mammalian target of rapamycin(mTOR) signaling pathway.Methods:Seventy-two male Sprague-Dawley rats were randomly allocated into the control,sham-operated,facial nerve injury(FNI),EA,EA+3-methyladenine(3-MA),and EA+GDNF antagonist groups using a random number table,with 12 rats in each group.An FNI rat model was established with facial nerve crushing method.EA intervention was conducted at Dicang(ST 4),Jiache(ST 6),Yifeng(SJ 17),and Hegu(LI 4) acupoints for 2 weeks.The Simone’s 10-Point Scale was utilized to monitor the recovery of facial function.The histopathological evaluation of facial nerves was performed using hematoxylin-eosin(HE) staining.The levels of Beclin-1,light chain 3(LC3),and P62 were detected by immunohistochemistry(IHC),immunofluorescence,and reverse transcriptionpolymerase chain reaction,respectively.Additionally,IHC was also used to detect the levels of GDNF,Rai,PI3K,and mTOR.Results:The facial functional scores were significantly increased in the EA group than the FNI group(P<0.05 or P<0.01).HE staining showed nerve axons and myelin sheaths,which were destroyed immediately after the injury,were recovered with EA treatment.The expressions of Beclin-1 and LC3 were significantly elevated and the expression of P62 was markedly reduced in FNI rats(P<0.01);however,EA treatment reversed these abnormal changes(P<0.01).Meanwhile,EA stimulation significantly increased the levels of GDNF,Rai,PI3K,and mTOR(P<0.01).After exogenous administration with autophagy inhibitor 3-MA or GDNF antagonist,the repair effect of EA on facial function was attenuated(P<0.05 or P<0.01).Conclusions:EA could promote the recovery of facial function and repair the facial nerve damages in a rat model of FNI.EA may exert this neuroreparative effect through mediating the release of GDNF,activating the PI3K/mTOR signaling pathway,and further regulating the autophagy of facial nerves.
