基于ADE优化的IPMSM全速域无传感器控制

为了实现内置式永磁同步电机(IPMSM)全速域的无传感器控制和切换速域的平滑过渡,提出了一种基于自适应差分进化(ADE)算法优化的复合控制方法。分别在零低速域、中高速域采用旋转高频电压注入法和滑模观测器法来对电机转速和转子位置进行估算,并在切换速域采用基于ADE算法的权重系数优化法来实现上述两种控制方法的平滑切换,从而实现IPMSM全速域无传感器控制。仿真结果表明:提出的复合控制方法能够实现电机全速域的无感控制和切换速域的平滑过渡,且具有良好的稳定性。

Rhabdomyolysis after midazolam administration in a cirrhotic patient treated with atorvastatin

The administration of statins in patients with liver disease is not an absolute contraindication. Hepatotoxicity is a rare and often dose-related event and in the literature there are only a few described cases of fatal rhab-domyolysis in patients with chronic liver disease after statin administration. During treatment with 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors,the factors responsible for myopathy may either be related to the patient,or due to interactions with other medications that are metabolic substrates of the same isozymes and therefore able to increase blood statin concentration. The most important side effects consist of increased transaminase levels,abdominal pain or muscle weakness,increased serum levels of creatine kinase and rhabdomyolysis. In this article we report a case of fatal rhabdomyolysis with acute renal failure after gastric endoscopy,where midazolam was used as a sedation agent in a patient with chronic liver disease treated with a high dose of atorvastatin. Therefore,we suggest paying particular attention to the potential risks of associating atorvastatin and midazolam in patients with chronic liver disease who need to undergo gastric endoscopy.

儿童维生素AD滴剂,这样吃才对

众所周知,维生素A、D对孩子的生长发育至关重要。而补充维生素A、D,最好选择专门的维生素AD制剂,比如维生素AD滴剂。但许多家长对其又不甚了解,有诸多疑问。以下,笔者将一一进行解答。

Midazolam dose is associated with recurrence of paradoxical reactions during endoscopy

BACKGROUND Midazolam is commonly used for sedation during gastrointestinal procedures.However,some patients experience paradoxical reactions characterized by excessive movement or excitement.AIM To investigate the rate of recurrence of paradoxical reactions to midazolam during an upper endoscopy.METHODS We retrospectively reviewed 122152 sedative endoscopies among a total of 58553 patients at the Seoul National University Hospital,Healthcare System Gangnam Center,from July 2013 to December 2018.Among them,361 patients with a history of paradoxical reaction during sedative upper endoscopy were enrolled.The characteristics of patients in the recurrent and non-recurrent groups were compared via multivariable analysis using logistic regression.RESULTS Paradoxical reactions occurred in 0.86%(1054/122152)of endoscopies,and in 1.51%(888/58553)of patients.Among the 361 subjects with previous paradoxical reactions in sedative endoscopies,111(30.7%)experienced further paradoxical reactions.Univariable analysis revealed that the total midazolam dose used was higher in the recurrent group(6.74±2.58 mg)than in the non-recurrent group(5.49±2.04 mg;P<0.0001).Patients were administered a lower dose of midazolam than previous doses:1 mg less in the recurrent group and 2 mg less in the non-recurrent group.Multivariable analysis showed that the midazolam dose difference was an independent risk factor for recurrent paradoxical reaction(odds ratio:1.213,95%CI:1.099-1.338,P=0.0001).CONCLUSION The rate of recurrence of paradoxical reactions is significantly associated with midazolam dosage.The dose of midazolam administered to patients with previous paradoxical reactions should be less than that previously used.

ADS-B信号在对流层大气波导中的传播性能

对流层大气环境存在特殊大气结构“大气波导”,可形成电波超视距传播或产生雷达盲区等。目前,通过雷达、GNSS信号等可以对大气波导进行一定程度的反演探测,但均存在一定的不足。ADS-B信号具有应用范围广、信号密度大、实时性高等特点,为此提出利用ADS-B信号受到不同大气环境影响后能量损耗不同的特点对ADS-B信号与对流层大气环境关联性进行分析研究。以武汉地区ADS-B信号数据为例,基于抛物方程传播理论对路径损耗进行仿真分析,并进行了实验验证。结果表明:ADS-B接收信号与仿真结果存在线性相关性并给出线性表述,为后续利用ADS-B信号反演大气波导提供参考依据。

星基ADS-B系统空天链路的建模与仿真

星基广播式自动相关监视(ADS-B,automatic dependent surveillance-broadcast)系统是一种新型的航空器监视技术,在未来空中交通管理系统中具有广阔的应用前景。为了深入研究星基ADS-B系统中航空器到卫星的空天链路通信性能,将专业软件Matlab和STK(system tool kit)有效联合,构建符合国际标准的星基ADS-B空天链路完整模型;通过离散事件动态交互模拟ADS-B消息的发送与接收全过程,最后统计得出体现星基ADS-B空天链路通信性能的消息识别概率(POI,possibility of identify)、消息检测概率(POD,possibility of detective)、信号接收功率、信号冲突概率、卫星覆盖范围等指标。仿真结果表明,随着区域内航空器数量上升,POI、POD下降,消息冲突概率上升。

基于迁移学习-元学习的ADS-B攻击分类研究

准确分类通航领域ADS-B攻击类型,采取预防攻击措施,对保障通航运行安全性具有重要意义。针对通航领域ADS-B攻击数据样本少,提出一种基于迁移学习-元学习的ADS-B攻击分类模型。该模型将迁移学习与深度卷积自编码器相结合,建立ADS-B攻击特征提取模型,提取数据样本的攻击有效特征表示,并运用元学习策略在特征空间中实现ADS-B攻击准确分类。实例研究表明,基于迁移学习-元学习的攻击分类模型可有效分类小样本ADS-B攻击,且正确率在95%以上。

A clinical investigation of the relationship between different sedation depths and the restlessness after using midazolam as an adjuvant during regional anesthesia

Objective： To investigate the relationship between different sedation depth and the restlessness after using midazolam as an adjuvant during regional anesthesia. Methods ： One hundred and fifty patients undergoing regional anesthesia were randomly divided into three groups. In group A, the patients were sedated at the level of OAA/S IV with midazolam during regional anesthesia. In group B and C, the sedation depths were kept at the levels of Ⅲ and Ⅱrespectively. The changes of BP, HR and SpO2 were recorded before and after midazolam. The rate of restlessness was also evaluated. Results： Blood pressures decreased in certain degree at 5 and 10 min after midazolam compared with those before in all three groups. BP decreased over 20% of the baseline in 4 cases in group A, in 5 cases in group B, and in 5 cases in group C. There was no significant difference in BP dropping among three groups. Compared with group B and C SpO2 dropped significantly at 3 and 5 rain after midazolam in group C, in which SpO2 was less than 93% in 8 cases. The restlessness rate in group C was 22%, which was significantly higher than those in group A （2% ,P〈0.01） and group B（4% ,P〈0.05）. Conclusion： The sedation depth is related to the rate of restlessness when midazolam is used as an adjuvant during regional anesthesia. It is suggested that the appropriate sedation depth for the patients under regional anesthesia is OAA/S Ⅲ.

The Addition of Midazolam Reduces the Incidence of Early Postoperative Nausea and Vomiting in Short Time Gynecological Procedures

Background: If untreated, one third of patients who undergo surgery develop postoperative nausea and/or vomiting (PONV). The prevention of postoperative nausea and vomiting can improve satisfaction among vulnerable patients. We hypothesized that preoperative anxiety may increase the incidence of PONV. The objective was to assess whether administration of a benzodiazepine prior to surgery would reduce the incidence of PONV. Methods: 130 women (ASA I and II) scheduled to undergo dilatation and curettage comprised the study group. The women were allocated randomly to two study groups according to the type of anesthesia administered (with and without midazolam). Results: Sixty-eight women received midazolam and 62 did not. Patients treated with midazolam were feeling more comfortable (“friendliness”, p = 0.005 and “elation”, p = 0.01) and had less postoperative fatigue (p = 0.04) than non-midazolam-treated group. Patients treated with midazolam had significantly fewer emetic episodes during the first 4 hours after surgery than those without midazolam (0.1 ± 0.2 vs 0.3 ± 0.6, respectively, p = 0.003). Conclusions: Midazolam reduces the incidence of PONV and improves patient’s comfort. We suggest that midazolam has to be routinely included in the anesthesia protocol for short-term gynecological procedures (dilatation and curettage).

基于多时间特征融合网络的ADS-B实采信号分离

不同于以往单天线广播式自动相关监视(Automatic Dependent Surveillance-Broadcast,ADS-B)信号分离中利用仿真的ADS-B信号制作数据集,将单天线接收的真实飞机发射的ADS-B原始信号通过调整信号起始时间以及功率并人为增加噪声来制作数据集。为了提高信号分离的时域波形精度,提出一种多分辨率多时间特征融合重采样(Multi-Temporal fusion Resampling of Multi-Resolution Features,MTRM-RF)网络,通过卷积将信号转化成不同采样率的信号并分别使用多层堆叠逐渐膨胀的一维卷积提取不同时间间隔的特征,以获得更多的时间信息。对多种基于深度学习的语音分离网络进行比较发现,MTRM-RF网络能够有效地融合ADS-B信号的不同采样率、不同时间间隔采样点的特征进行训练。并且随着训练集数据量的增加,分离信号的平均解码正确率达到88.39%,证明该网络可有效分离单天线实采的ADS-B交织信号。

Impact of Adding Midazolam to Bupivacaine 0.5% in Regional Spinal Anesthesia on Maternal Middle Cerebral Artery Velocimetry in Parturients with Severe Preeclampsia

Severe preeclampsia is a challenging issue facing both intensivist and anesthetic team carrying both maternal and fetal morbidity and mortality. Termination of pregnancy after blood pressure control is the golden key in management. Cerebral complications due to diffuse cerebral vasospasm are most common and serious. Intrathecal midazolam with its gamma amino butyric action may antidote glutamate mediated sympathetic surge and decreasing cerebral vasospasm. Temporal view transcranial Doppler imaging maternal middle cerebral artery is used to examine blood flow indices namely pulsatility index and resistive index. One hundred ladies with severe preeclampsia scheduled for urgent caesarian section were recruited in 2 groups, both received 10 mg bupivacaine 0.5%, Midazolam group received 1 mg midazolam and the other group received 0.2 ml sterile saline 0.9% NaCl. All vascular indices were significantly better in midazolam group, less ICU stay.

Comparison of impact of adjuvant treatment of midazolam, fentanyl, and magnesium sulfate with intrathecal bupivacaine on block characteristics and postoperative analgesia in knee arthroplasty: A randomized clinical trial

Objective:To compare the efficacy of midazolam,fentanyl,and magnesium sulfate as adjuvants to intrathecal bupivacaine on both block characteristics and postoperative analgesia in knee arthroplasty.Methods:This randomized double-blind clinical trial recruited spinal anesthesia patients of the American Society of Anesthesiologists classⅠorⅡ,who needed knee arthroplasty.Patients were stratified into three intervention groups,including the midazolam group,the fentanyl group,and the magnesium sulfate group,and the patients were administered with midazolam,fentanyl,and magnesium sulfate,respectively.Hemodynamic parameters,sensory and motor block,and pain score(Visual Analogue Scale)were measured and compared among the three groups.Results:A total of 105 patients were included in this study with 35 patients in each group.There was no statistically significant difference in terms of oxygen saturation,mean blood pressure,duration of surgery,and postoperative complications,including nausea,vomiting,bradycardia,dizziness,and hypotension,as well as the time of opioid administration among the three groups(P>0.05).Statistically significant differences were found in terms of heart rate at 15,30,45,60,75,and 105 min after beginning of operation among the three groups,which was lower in the midazolam group(P<0.05).The midazolam group showed a shorter time to achieve sensory block after spinal anesthesia,sensory block to T8 or higher and sensory block to T12 and L1(P<0.05).Besides,the three groups showed significantly differences in terms of onset of motor block after spinal anesthesia and time to achieve motor block to T8 or higher or Bromage score 3(P=0.001).No significant difference was noted in pain scores among the three groups(P>0.05).Conclusion:Midazolam resulted in a shorter time to achieve sensory and motor block to T8 or higher,the onset of motor block and sensory block after spinal anesthesia,and time to achieve sensory block to T12 and L1,and the pain scores were not significantly different among the groups.Thus,midazolam can be highly underlined,if a shorter onset of sensory and motor blocks is targeted.[Funded by the research deputy of Arak University of Medical Sciences(No.99258);fa.irct.ir number,IRCT20141209020258N164].

基于AD与TRIZ的加工中心主轴松拉刀机构优化设计

数控加工中心在加工过程中常出现主轴松刀力不足或无法松刀的现象。针对此问题,通过TRIZ系统组件分析明确现有松拉刀机构各组件间作用关系,利用因果链分析得出影响松刀的根本原因,最终应用TRIZ理论中的物场模型分析方法和AD独立性原理提出优化设计方案。根据新方案计算出实际工况下的主轴松刀力和螺杆强度,并对松刀杆进行建模和仿真。结果表明:最大位移量为6.995μm,最大应力为45.24 MPa,符合结构设计要求。最后,经过现场实物测试,当液压力为5 MPa时,松刀行程、松刀力以及打刀量均符合生产要求,验证了优化设计方案的合理性。

白菜型冬油菜BrADS2基因的克隆、表达分析与亚细胞定位

【目的】探究白菜型冬油菜(Brassica rapa L.)脂肪酸去饱和酶ADS2(Δ9 fatty acid desaturase)基因与抗寒性的关系。【方法】基于前期转录组结果,采用一步定向克隆法得到BrADS2基因;构建GFP融合表达载体,通过注射法在烟草下表皮细胞进行瞬时转化,同时采用农杆菌侵染法侵染‘中双11号’;利用qRT-PCR技术,检测抗寒性不同的白菜型冬油菜品种叶片中ADS2基因的表达模式,并对低温下冬油菜的形态变化和抗氧化酶活性、电导率含量进行分析。【结果】白菜型冬油菜BrADS2基因可编码307个氨基酸,该基因编码的蛋白具有亲水性特性;qRT-PCR结果显示,BrADS2基因的表达量呈先升后降的单峰型变化,且在-4℃时表达量达到峰值;亚细胞定位结果显示BrADS2蛋白在细胞质和细胞膜上表达;低温处理下3个品种叶片的相对电导率、抗氧化物酶活性均显著上升,强抗寒品种抗氧化酶活性高于弱抗寒品种,电导率却相反;农杆菌介导侵染‘中双11号’下胚轴后获得15株转基因阳性苗,且转基因油菜阳性植株叶中的BrADS2基因表达量均显著高于野生型。【结论】推测BrADS2基因在白菜型冬油菜膜脂不饱和调节中起重要作用,揭示了ADS2基因与冬油菜抗低温胁迫的关系。

基于改进型多斜Ⅲ技术的7位半AD转换器设计

高精度测试仪器在环境试验中扮演着重要角色,而积分型AD转换器被广泛的应用在高精度测试仪器中。针对传统型积分型AD转换器转换速率较低的问题,提出了一种提高转换速率的改进型多斜ⅢAD转换器,详细的介绍了其原理和设计思路。该转换器以单片机与CPLD一同控制积分型ADC,在积分末尾利用单片机片内ADC测量积分器的残留电压,以达到提高转换速率的目的。经理论分析该AD转换器比传统型转换速率快836倍,分辨率可达到31位,在±10V直流电压测量中可实现7位半分辨率。

基于FPGA与AD9786的调制解调电路的设计

谐振式光学陀螺因其高理论精度、小型化以及高稳定性受到了国内外的强烈关注。针对于谐振式光学陀螺检测信号微弱的特点,需要对该信号进行调制解调,以实现陀螺的稳定输出,设计了一种基于FPGA和AD9786的高精度模拟信号源,该信号以FPGA作为核心控制单元,AD9786作为数模转换器,实现16位的高精度DA转换,通过上位机实现指令的通信过程,可实现不同频率的交流信号。该实验结果表明,该系统符合陀螺测试系统调制解调要求,通过上位机对不同输出信号进行测试,且测试结果无纹波时输出噪声Vrms269μV,交流信号精度达到0.01%,最高频率可达到2M,稳定性高。

基于AD7616的16通道数据采集系统设计

针对传统数据采集系统因通道不足或数据量过大,无法满足多通道同步采集的问题,设计了一种基于AD7616的16通道数据采集系统。系统以Xilinx系列FPGA作为主控芯片,ADI公司的AD7616作为模数转换芯片,DDR3 SDRAM作为缓存单元。介绍了各个模块硬件的设计思路,重点介绍了FPGA控制AD7616模数转换模块、DDR3 SDRAM缓存模块的软件程序设计,并对系统的多通道采样功能、同步性能以及实际水下超声信号的采集能力进行了实验验证,结果表明,系统可以完成水下超声信号的多通道同步采集。

脉冲电流对轧辊用AD180高碳半钢材料力学性能及组织的影响

为分析电流处理对轧辊材料的影响规律,通过改变电流密度和处理时间来调整AD180高碳半钢的微观组织和力学性能。使用万能拉伸试验机对电流处理后的试样进行单轴拉伸实验,并对试样进行SEM断口截面分析和EBSD微观表征,研究其力学性能和微观组织的变化规律。拉伸结果表明,在电流密度11.88 A·mm-2、通电5 min时,试样的综合性能最好,屈服强度提高6.5%,抗拉强度提高12.1%,伸长率提高了25.4%。通过断口截面分析发现,拉伸试样均为脆性断裂,未通电试样存在大量孔洞缺陷,而合适的电流密度和通电时间可以促进试样内部孔洞缺陷的“愈合”,其中,电流密度为11.88 A·mm^(-2)、通电5 min时,试样断口上的缺陷最少。EBSD微观表征结果表明,脉冲电流使试样在较低温度下发生了再结晶,细化了晶粒。由此可见,脉冲电流可以改善试样内部的组织结构和治愈微缺陷,提高其综合力学性能。

基于动态离散模型的机场ADS-B攻击威胁影响研究

随着航空业信息技术的发展,空中交通管制系统面临着多种网络攻击的威胁。广播式自动相关监视(ADS-B)系统因其明文广播的数据传输方式,存在着被网络攻击的安全问题。依据“等待降落-降落-停泊-排队起飞-起飞”的航班运行全流程,建立了WLPQD动态离散模型,研究机场流量和航班延误。模型引入了系统冗余能力、处理速率等参数,模拟了攻击场景;通过受影响飞机数量和延误时间等指标研究了机场航班延误的传播影响。模型展示了ADS-B消息注入攻击对降落、起飞航班造成的延误,提出了两种攻击缓解方法。结果表明,延误规模的大小与攻击强度呈现正相关,且攻击对起飞航班的延误影响更大;提升对“幽灵飞机”和合法飞机的处理速率都可提升机场系统的抗毁性,但前者对提升机场系统冗余能力的效果更加显著。所做研究为机场系统抵御网络攻击、增强抗毁性提供了决策分析的参考依据。

采用AD654芯片的直流电压传感器及其温度漂移补偿

提出一种基于电压-频率变换的光电式电压传感器及电压传感信号温度漂移的补偿方法。电压传感系统主要包括电阻分压器、电压-频率变换芯片、发光二极管、光纤、光电探测与信号处理单元等。利用两块AD654型芯片分别作为被测电压和温度传感单元,通过对两路光传感信号进行非线性数据拟合等方式实现了对电压传感信号温度漂移的实时补偿。实验测量了0.6 kV~5.0 kV范围内的直流电压,并实现了电压传感信号的温度漂移补偿,在-40℃~+60℃的温度范围内,电压传感信号温度漂移的平均相对误差约为±0.7%。