Discussion on the application prospect of the transient electromagnetic method based on the dual launcher and mine advanced detection

The dual transmitter implements the equivalent anti-magnetic flux transient electromagnetic method, which can effectively reduce the scope of the transient electromagnetic detection blind area. However, this method is rarely reported in the detection of pipelines in urban geophysical exploration and the application of coal mines. Based on this, this paper realizes the equivalent anti-magnetic flux transient electromagnetic method based on the dual launcher. The suppression effect of this method on the blind area is analyzed by physical simulation. And the detection experiment of underground pipelines is carried out outdoors. The results show that the dual launcher can significantly reduce the turn-off time, thereby effectively reducing the impact of the blind area on the detection results, and the pipeline detection results verify the device’s effectiveness. Finally, based on the ground experimental results, the application prospect of mine advanced detection is discussed. Compared with other detection fields, the formation of blind areas is mainly caused by the equipment. If the dual launcher can be used to reduce the blind area, the accuracy of advanced detection can be improved more effectively. The above research results are of great significance for improving the detection accuracy of the underground transient electromagnetic method.

POWER FLOW ANALYSIS AND APPLICATION SIMULATION OF ELECTROMAGNETIC CONTINUOUSLY VARIABLE TRANSMISSION

With the structure of two air gaps and two rotors, the electromagnetic continuously variable transmission（EMCVT） is a novel power-split continuously variable transmission（CVT）. There are two kinds of power flowing through the EMCVT, one is mechanical power and the other is electric power. In the mean time, there are three power ports in the EMCVT, one is the outer rotor named mechanical power port and the other two are the inner rotor and the stator named electric power ports. The mechanical power port is connected to the driving wheels through the final gear and the electric ports are connected to the batteries through the transducers. The two kinds of power are coupled on the outer rotor of the EMCVT. The EMCVT can be equipped on the conventional vehicle being regarded as the CVT and it also can be equipped on the hybrid electric vehicle（HEV） as the multi-energy sources assembly. The power flows of these two kinds of applications are analysed. The back electromotive force（EMF） equations are illatively studied and so the dynamic mathematic model is theorized. In order to certify the feasibility of the above theories, three simulations are carried out in allusion to the above two kinds of mentioned applications of the EMCVT and a five speed automatic transmission（AT） vehicle. The simulation results illustrate that the efficiency of the EMCVT vehicles is higher than that of the AT vehicle owed to the optimized operation area of the engine. Hence the fuel consumption of the EMCVT vehicles is knock-down.

Numerical Solution of the Weight Function for Electromagnetic Flowmeter

A numerical solution of the weight function for a two-electrode electromagnetic flowmeter was proposed. The solution was obtained by using the finite element method based on the basic equation of a traditional two-electrode electromagnetic flowmeter. The two-dimensional distribution of the weight function of the electromagnetic flowmeter obtained was verified by the analytical solution. Three-dimensional distribution of the weight function was also presented in the paper. It can be employed to analyze the sensitivity and linearity of the electromagnetic flowmeter with non-uniform magnetic field, and even to assist the design of the excitation coil pair.

Application system and data description of the China Seismo-Electromagnetic Satellite

The China Seismo-Electromagnetic Satellite, launched into orbit from Jiuquan Satellite Launch Centre on February 2 nd, 2018, is China's first space satellite dedicated to geophysical exporation. The satellite carries eight scientific payloads including high-precision magnetometers to detect electromagnetic changes in space, in particular changes associated with global earthquake disasters. In order to encourage and facilitate use by geophysical scientists of data from the satellite's payloads, this paper introduces the application systems developed for the China Seismo-Electromagnetic Satellite by the Institute of Crustal Dynamics, China Earthquake Administration;these include platform construction, data classification, data storage, data format, and data access and acquisition.

Polymer composite for antistatic application in aerospace

The pheno menon of static electricity is unpredictable,particulariy when an aircraft flying at high altitude that causes the accumulation of static charges beyond a threshold value leading to the failure of its parts and systems including severe explosion and radio communication failure.The accumulation of static charges on aircraft is generated by the virtue of interaction between the outer surface of aircraft and the external environmental attributes encompasses air particles,ice,hail,dust,volcanic ash in addition to its triboelectric charging.In the recent years,advanced polymer-based composites or nanocomposites are preferred structural constituents for aircrafts due to their light weight and comparable mechanical properties,but such composite systems do not render low impedance path for charge flow and are subsequently vulnerable to effect of lightning strike and precipitation static.In this context,it is essential to develop conductive composite systems from non-co nductive polymer natrix by nano fillerembodime nts.The advent of carbon-based nanocomposite/nano materials have adequately addressed such issues related to the nonco nductive polymer matrix and further turned into an avant-garde genre of materials.The current review envisioned to illustrate the detailed exploitation of various polymer nanocomposites in addition to especially mentioned epoxy composites based on carbon fillers like carbon black,carbon nanotube(single walled carbon nanotube and multi walled carbon nanotube) and graphene the development of antistatic application in aircra ft in addition to the static charge phenomenon and condition for its prevalence in avionic systems.

The Disk-Magnet Electromagnetic Induction Applied to Thermoelectric Energy Conversions

The thermoelectric energy conversion technique by employing the Disk-Magnet Electromagnetic Induction (DM-EMI) and improved DM-EMIs is shown, and possible applications to heat engines as one of the energy harvesting technologies are also discussed. The idea is induced by integrating irreversible thermodynamical mechanism of a water drinking bird with that of a Stirling engine, resulting in thermoelectric energy generation different from conventional heat engines. The current thermoelectric energy conversion with DM-EMI can be applied to wide ranges of temperature differences. The mechanism of DM-EMI energy converter is examined in terms of axial flux magnetic lines and categorized as the axial flux generator. It is useful for practical applications to macroscopic heat engines such as wind, geothermal, thermal and nuclear power turbines and heat-dissipation lines, for supporting thermoelectric energy conversions. The technique of DM-EMI will contribute to environmental problems to maintain clean and susceptible energy as one of the energy harvesting technologies.

特定电磁波治疗仪联合穴位敷贴改善腹腔镜肝切除术后肩痛的临床研究

目的观察特定电磁波(TDP)照射联合穴位敷贴在腹腔镜肝切除术后肩痛患者中的应用效果。方法选择2020年1月至2023年12月在我院进行腹腔镜肝切除术后肩痛患者160例作为研究对象,按随机数字表法分为观察组和对照组,每组80例。对照组给予常规护理,观察组在对照组的基础上给予TDP联合穴位敷贴干预,比较两组患者干预前及干预后1、3 d时的疼痛程度[视觉模拟评分法(VAS)]评分、疼痛介质[P物质(SP)、前列腺素E2(PGE2)]、临床疗效及护理满意度结果观察组干预后各个时间点的VAS评分均低于对照组,差异有统计学意义(均P<0.05)。观察组干预后1、3 d时的血清SP、PGE2水平均低于对照组,差异均有统计学意义(均P<0.05)。两组的治疗效果比较,观察组的治疗总有效率为93.8%,对照组为73.8%,两组比较差异具有统计学意义(P<0.05)。观察组的护理满意度评分高于对照组,差异具有统计学意义(P<0.05)。结论TDP联合穴位敷贴可有效减轻腹腔镜肝切除术后肩痛程度,降低疼痛介质水平,提高临床疗效和护理满意度。

电磁流量计在线校准方法的探讨

电磁流量计具有操作简单、精度高、适应性强、不影响被测流体的流态分布等优点,广泛应用于供水、化工、制药、水处理、环保、食品饮料等领域。对于不方便拆卸或者由于连续生产的要求无法拆卸的情况下,对电磁流量计进行在线校准不失为一种可行的方法,满足其溯源的要求。介绍了2种电磁流量计在线校准的方法,结果表明这2种方法对于在线校准电磁流量计均是可行的。在测量环境理想的条件下首选标准表法,在测量条件不理想的条件下,电参数法可定性评价电磁流量计的计量性能。

基于混合优化算法的电磁监测裂缝参数识别

压裂实时监测是水力压裂效果评价和工程参数优化的重要保障措施之一。传统电磁监测裂缝参数识别方法的准确性和精度难以保证,影响了监测效果。为了提高裂缝参数识别能力,提出了一种基于海洋捕食者密度聚类混合优化算法的电磁监测裂缝参数识别方法。利用海洋捕食者算法(MPA)进行多次寻优,以每次寻优结果作为初始数据集,然后,利用密度聚类算法(DBSCAN)进行聚类,构建中间样本数据集,最后,抽取该样本数据中值作为最终输出结果。采用Rastrigin函数进行测试,分析混合优化算法寻优能力。测试结果表明,相对粒子群优化算法(PSO),MPA算法单次寻优效果较佳。但两种算法寻优结果均具有较强随机性,其中,PSO和MPA算法50次寻优精度分别为10^(-7)~10^(2)和10^(-10)~10^(-2),而改进的混合优化算法寻优效果更稳定,寻优精度达10^(-7)。构建缝长、方位压裂模型并进行了数值模拟实验,结果表明,在噪声低于15%时,缝长和方位识别平均绝对误差分别小于1 m和1°。利用改进的算法对四川盆地某井页岩气压裂电磁监测实测数据进行分析,确定了裂缝改造的长度(缝长)与方位。实例分析结果验证了改进算法的可行性和有效性。

瞬变电磁法在地下水勘查中应用研究

瞬变电磁技术(Transient Electromagnetic Method,简称TEM)是近年发展较快并得到广泛应用的一种勘探方法。由于其观测的是二次场,可在近区观测,对低阻含水体反应灵敏,而且体积效应小、纵横向分辨率高,施工也很方便、快捷,所以效率很高。将该方法利用在贵州省兴义市清水河镇发大地下水勘查中,勘查效果极佳,所得成果接近真实,故提出将瞬变电磁法可以作为浅层水文地质勘探的重要手段。

电磁流量计结构与干扰抑制发展与趋势

电磁流量计量程宽、结构简单、应用广泛。以电磁流量计的结构演变与干扰抑制技术为线索,介绍了两个大方向下的各个重点研究方向的电磁流量计最新技术,并分析了其未来研究发展方向和趋势,在电子技术不断发展与流量计量方法呈现多样化基础上,未来电磁流量计仍以提高线圈励磁精度来抑制噪声干扰为主,同时又不断改变自身结构和组合方法测量,以适应越来越复杂的流体测量环境。

电磁频谱空间应用及发展趋势综述

近年来,电磁频谱空间已逐步发展成为大国博弈的必争领域,成为国家的战略稀缺资源。在民用电磁频谱领域,电磁频谱拥挤、应用业务激增,在宽带频谱监测、频谱安全、频谱大数据及智能化应用方面面临着巨大挑战;军用电磁频谱博弈对抗愈加激烈,电磁频谱感知、监测及影响效应评估面临感知手段有限、频谱管控和协同应用能力不足等难题。该文首先回顾了典型电磁频谱应用现状、面临的挑战及国外发展趋势。然后,分析了国内电磁频谱空间总体设计和规划管理、典型工程实践和关键技术突破情况。最后,给出了我国电磁频谱空间应用的发展思路。

形状记忆聚合物及其复合材料空间辐照环境效应研究进展

形状记忆聚合物及其复合材料具有密度低、可回复变形大、刺激方式可控、成本低等优点,可应用于空间可展开结构,但空间辐照环境对其在轨安全带来了严重的威胁。首先介绍了形状记忆聚合物及其复合材料的分类,接着总结了基于形状记忆聚合物的空间可展开结构应用现状,然后分析了高能电磁辐射、高能粒子辐射和原子氧等空间环境对形状记忆聚合物及其复合材料性能的影响,最后对形状记忆材料空间辐照环境效应的研究成果进行了总结并对未来发展方向进行了展望。

电磁触发锁紧释放机构设计与试验研究

近年来发展的以形状记忆合金驱动、热刀为代表的空间应用低冲击锁紧释放装置,解决了火工品解锁器的冲击和污染等问题,但同时引入了解锁同步性差、温度环境适应性不足等问题。为解决上述问题,提出了一种电磁触发锁紧释放机构设计方案,完成了工程样机的研制,并进行了锁紧力加载、最短加电时间、解锁同步性、解锁冲击及真空热环境下解锁等功能性测试。结果表明:加载10000 N锁紧力工况下,最短加电时长为0.05 s时可以正常解锁,2000 Hz范围内解锁冲击加速度不大于100g(g为重力加速度),可以兼容0.104 s星载火工品电源,多台解锁器解锁同步性小于0.02 s,热真空过程中低温为-50℃、常温为28℃和高温为90℃这3种工况下均可以正常解锁。该产品质量轻、尺寸小、解锁响应快、可重复使用、解锁冲击小、解锁同步性和环境适应性好,具有很大的工程应用潜力。

基于电磁瞬态过程的GIS隔离开关分合位置确认方法研究

GIS隔离开关在电力系统中扮演着重要角色,但分合闸不到位故障会威胁系统安全。传统的状态检测方法所反映的腔体内部信息有限,文中提出了一种基于电磁瞬态过程的新方法。利用在GIS隔离开关带电分合过程中产生的电磁瞬态信息,通过分析电磁瞬态信号的起止时间与开关动静触头位置关系,反演GIS隔离开关腔体内动静触头状态。同时,还提出了一种低采样频率下提取高频电磁瞬态信号特征的方法,并开发了相应的采集装置。不仅有效降低了数据采集量,同时可以成功确认GIS隔离开关的分合位置。最后通过实验证明了文中提出方法的有效性。

空间目标远距离磁控方法及应用分析

星间电磁力/力矩作用相对于传统航天器操控方式,具有不消耗推进剂、无羽流污染、可控能力强等优势。因此,在交会对接、编队集群、失效卫星消旋等方面得到了广泛关注。然而,电磁力/力矩的数值与场源作用距离的3到4次方成反比,导致电磁力/力矩的有效作用空间有限。磁化同轴枪强流脉冲放电装置可产生高传输速度(~1000 km/s)、高电子密度(~10^(16)cm^(-3))、高能量密度(~1 MJ/m^(2))、具有球马克位形的等离子体环,且等离子体环的放电电流可产生强度可观的环向磁场和极向磁场(~1 T)。此外,等离子体环的生成和输运环境与空间真空环境高度契合。基于磁化同轴枪生成具有球马克位形的等离子体环并将等离子体环所携带磁场远距投送的新型磁控方式,本文研究可控等离子体环远距投送对空间目标的磁控能力以及对空间目标消旋/回收的应用潜力等,并通过初步仿真算例予以验证结论的正确性。

仪表检定证书在泵试验台的应用

为保证泵试验台准确地测量试验泵的水力性能,泵试验台所有的测量仪表均由相关检定机构进行了检定,并出具了相应的检定证书。选取压力变送器、电磁流量计和扭矩仪的检定证书进行论述,探讨如何将这三种仪表的检定证书应用到泵试验台的水力测量中,以提高泵试验台的准确度。其他仪表检定证书的应用方法可以参照执行。

电磁脉冲引起人体血脑屏障开放的生物电磁剂量学

目的:对电磁脉冲引起人体血脑屏障开放的生物电磁剂量学进行研究。方法:基于典型暴露平台建立人体脑部剂量学研究环境,利用三维数字化人体模型并结合电磁仿真方法对生物电磁剂量进行仿真评估。结果:头部中心的电场峰值为1.49 kV/m,与激励电场相比衰减41.6 dB;鼻尖皮肤表面处空气中最大电场幅值为1795 kV/m;一次脉冲下头部空间的平均吸收率为4.16×10^(-8)J/kg;重复频率1 000 s^(-1)的极端条件下的头部平均比吸收率为4.16×10^(-5)W/kg。结论:局部高强度电场是临床应用中重要的安全隐患,需要结合血脑屏障开放的量效关系研究抑制局部高强度电场的手段,本研究的人体脑部生物电磁剂量数据可用于临床效应的可行性评估。

“电磁场与电磁波”课程教学改革研究

通过分析“电磁场与电磁波”教学过程中出现的典型问题,首先将教学内容具体化,通过案例分析其中蕴含的思政意义。其次,将理论内容与马克思主义的基本原理相结合,达到以教育人的效果。之后,通过补充“电磁场与电磁波”在生活中的应用,使学生能够从身边案例中寻找所学知识点的踪迹,温故知新。最后,对传统的单一化读写教材的教学方式进行了全新的教学改革,增加了CDIO教学法,解决了原理性强、内容繁多的问题;增加了对分课堂PAD教学法,解决了教学时长受限、课本局限的问题;增加了PBL教学法,解决了教学设施有限、高数学能力要求等问题。