期刊文献+
共找到1,193篇文章
< 1 2 60 >
每页显示 20 50 100
New Measuring Method for Colorless Liquid Level Based on CLC100 Level Sensor and Powercast Wireless Sensor Kit
1
作者 Guanlin Yan Gerhard Lindner Yuming Shen 《Engineering(科研)》 2015年第4期177-189,共13页
In this paper, a new wireless measuring method for colorless liquid level measurement was presented, based on latest CLC100 liquid level sensor and Powercast wireless sensor development kit. The wireless system is div... In this paper, a new wireless measuring method for colorless liquid level measurement was presented, based on latest CLC100 liquid level sensor and Powercast wireless sensor development kit. The wireless system is divided into two parts, level measurement and data transmission part as well as data receiving and display part. First part included the capacitive liquid level sensor CLC100 and the wireless senor board. CLC100 sensor was used for liquid level measurement. Wireless sensor kit from Powercast Corporation included one wireless sensor board, which was used for signal transmission. A built-in PIC microcontroller was embedded in the transmission module, for the purpose of processing and data transmitting. Due to CLC100 sensor’s output voltage exceeding the sensor board’s input limitation, a voltage convertor was designed to connect the sensor and the wireless sensor board. The final results were voltages corresponding to the liquid level, and were processed by an independent PIC development board, and then sent to PC’s hyper terminal via serial-port by this PIC microcontroller. Experiments showed that this wireless sensor node prototype worked well. 展开更多
关键词 CLC100 LIQUID level sensor Powercast WIRELESS sensor KIT COLORLESS LIQUID level Measurement WIRELESS sensor
在线阅读 下载PDF
Ultrasensitive liquid level sensor based on slice-shaped composite long period fiber grating 被引量:1
2
作者 Xiren Jin Zeju Rui +10 位作者 Zihang Xiang Chupeng Lu Shuo Zhang Xian Xu Mingyang Lü Yiwei Ma Cuiting Sun Xinghua Yang Tao Geng Weimin Sun Libo Yuan 《Chinese Optics Letters》 SCIE EI CAS CSCD 2022年第1期37-42,共6页
In this paper,a novel liquid level sensor with ultra-high sensitivity is proposed.The proposed sensor is configured by a sliceshaped composite long period fiber grating(SSC-LPFG).The SSC-LPFG is prepared by polishing ... In this paper,a novel liquid level sensor with ultra-high sensitivity is proposed.The proposed sensor is configured by a sliceshaped composite long period fiber grating(SSC-LPFG).The SSC-LPFG is prepared by polishing two opposite sides of a composite multimode-single-mode-multimode fiber structure using a CO;laser.The method improves the sensitivity of the sensor to external environment.Based on the simulation calculation,a liquid level sensor with a length of 3 mm is designed.The experimental transmission spectrum agrees well with the simulation result.The experimental results show that the sensitivity reaches 7080 pm/mm in the liquid level range of 0-1400 μm in water.The temperature sensitivity is24.52 pm/℃ in the range of 20℃-90℃.Due to the ultra-high sensitivity,good linearity,and compact structure,the SSC-LPFG has potential application in the field of high-Drecision liquid level measurement. 展开更多
关键词 liquid level sensor composite long period fiber grating ultra-high sensitivity
原文传递
Weighted Multi-sensor Data Level Fusion Method of Vibration Signal Based on Correlation Function 被引量:7
3
作者 BIN Guangfu JIANG Zhinong +1 位作者 LI Xuejun DHILLON B S 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第5期899-904,共6页
As the differences of sensor's precision and some random factors are difficult to control,the actual measurement signals are far from the target signals that affect the reliability and precision of rotating machinery... As the differences of sensor's precision and some random factors are difficult to control,the actual measurement signals are far from the target signals that affect the reliability and precision of rotating machinery fault diagnosis.The traditional signal processing methods,such as classical inference and weighted averaging algorithm usually lack dynamic adaptability that is easy for trends to cause the faults to be misjudged or left out.To enhance the measuring veracity and precision of vibration signal in rotary machine multi-sensor vibration signal fault diagnosis,a novel data level fusion approach is presented on the basis of correlation function analysis to fast determine the weighted value of multi-sensor vibration signals.The approach doesn't require knowing the prior information about sensors,and the weighted value of sensors can be confirmed depending on the correlation measure of real-time data tested in the data level fusion process.It gives greater weighted value to the greater correlation measure of sensor signals,and vice versa.The approach can effectively suppress large errors and even can still fuse data in the case of sensor failures because it takes full advantage of sensor's own-information to determine the weighted value.Moreover,it has good performance of anti-jamming due to the correlation measures between noise and effective signals are usually small.Through the simulation of typical signal collected from multi-sensors,the comparative analysis of dynamic adaptability and fault tolerance between the proposed approach and traditional weighted averaging approach is taken.Finally,the rotor dynamics and integrated fault simulator is taken as an example to verify the feasibility and advantages of the proposed approach,it is shown that the multi-sensor data level fusion based on correlation function weighted approach is better than the traditional weighted average approach with respect to fusion precision and dynamic adaptability.Meantime,the approach is adaptable and easy to use,can be applied to other areas of vibration measurement. 展开更多
关键词 vibration signal MULTI-sensor data level fusion correlation function weighted value
在线阅读 下载PDF
Analysis of Lifetime of Large Wireless Sensor Networks Based on Multiple Battery Levels
4
作者 Ruihua ZHANG Zhiping JIA Dongfeng YUAN 《International Journal of Communications, Network and System Sciences》 2008年第2期136-143,共8页
Due to the limited transmission range, data sensed by each sensor has to be forwarded in a multi-hop fashion before being delivered to the sink. The sensors closer to the sink have to forward comparatively more messag... Due to the limited transmission range, data sensed by each sensor has to be forwarded in a multi-hop fashion before being delivered to the sink. The sensors closer to the sink have to forward comparatively more messages than sensors at the periphery of the network,and will deplete their batteries earlier. Besides the loss of the sensing capabilities of the nodes close to the sink, a more serious consequence of the death of the first tier of sensor nodes is the loss of connectivity between the nodes at the periphery of the network and the sink;it makes the wireless networks expire. To alleviate this undesired effect and maximize the useful lifetime of the network, we investigate the energy consumption of different tiers and the effect of multiple battery levels, and demonstrate an attractively simple scheme to redistribute the total energy budget in multiple battery levels by data traffic load. We show by theoretical analysis, as well as simulation, that this substantially improves the network lifetime. 展开更多
关键词 WIRELESS sensor Networks Energy Efficient Network LIFETIME BATTERY level
在线阅读 下载PDF
Distributed High-Level Scheduling Concept for Synchronised, Wireless Sensor and Actuator Networks
5
作者 Matthias Vodel Mirko Caspar Mirko Lippmann Wolfram Hardt 《通讯和计算机(中英文版)》 2010年第11期27-35,共9页
关键词 无线传感器网络 网络调度 分布式调度 时间同步算法 执行器 传感器节点 测量系统 应用程序
在线阅读 下载PDF
Design and construction of a multi-sensor position monitoring system applied to key components of synchrotron sources 被引量:4
6
作者 Wei Wang Zheng Tang +1 位作者 Xiao-Ye He Qiang Zhang 《Nuclear Science and Techniques》 SCIE CAS CSCD 2016年第6期79-85,共7页
High-accuracy position monitoring of key components is required for modern synchrotron sources,such as free-electron lasers and diffraction-limited storage rings.Although various position monitoring sensors have been ... High-accuracy position monitoring of key components is required for modern synchrotron sources,such as free-electron lasers and diffraction-limited storage rings.Although various position monitoring sensors have been adopted to monitor the displacement of key components in each direction in real time,these monitoring systems are usually based on their own coordinate system.Data from such systems are meaningful when evaluating and examining the data from each positioning monitoring system in a unified coordinate system.This paper presents the design and construction of a multi-sensor position monitoring system(MPMS).A hydrostatic levelling system,a wire position sensor(WPS) and a tiltmeter are fixed to a stainless steel plate that has been calibrated by a coordinate-measurement machine.Several plates form the MPMS.The system must compensate for the sag of the stretched wires so that the WPSs create a straight line.The method of the coordinate transformation from the sensor coordinate system to the MPMS coordinate system was thoroughly studied.An experimental MPMS that includes five plates was setup in a 20-m tunnel,and a validation study to verify fully the feasibility of the MPMS was performed. 展开更多
关键词 实时监测系统 位置传感器 自由电子激光器 坐标系统 坐标变换方法 关键部件 不锈钢板 同步加速器
在线阅读 下载PDF
Fuzzy Based BEENISH Protocol for Wireless Sensor Network
7
作者 A. Devasena B. Sowmya 《Circuits and Systems》 2016年第8期1893-1905,共13页
The main parameter to be considered in the wireless sensor network is the amount of energy that is available in each sensor node. The lifetime of the sensor node (SN) depends on it. As the SNs are deployed in remote l... The main parameter to be considered in the wireless sensor network is the amount of energy that is available in each sensor node. The lifetime of the sensor node (SN) depends on it. As the SNs are deployed in remote locations, if the entire energy is consumed, it would be very difficult to replace or recharge the energy source immediately. Hence the energy consumed by each node is very important. If individual SNs send information directly to the base station (BS), then the availability of energy in such SN decreases very fast. This will lead to reduction in the life time of the SN. Instead, the SNs can send the data to the cluster head (CH), then the CH consolidates the received data. The CH sends it to the BS periodically. In this way, utilizing CH for sending the information to the BS increases the lifetime of the SN. The cluster head selection is very crucial in such networks. This paper proposes a novel fuzzy based BEENSIH protocol for CH selection. 展开更多
关键词 sensor Nodes CLUSTER Energy level Heterogeneous sensor Network Fuzzy Logic BEENISH
在线阅读 下载PDF
The Design Liquid-level Monitoring System of Adopting the Ultrasonic Sensing Technology
8
作者 LI JING YAO YANZHI ZHAO MINGBO CHEN PING 《微计算机信息》 北大核心 2007年第34期70-72,85,共4页
Utilizing the technology of Ultrasonic wave,relevant test arithmetic and the PC to carry on monitoring,controlling and cen-tralized management of the liquid-level in the liquid container. It can prevent from keeping i... Utilizing the technology of Ultrasonic wave,relevant test arithmetic and the PC to carry on monitoring,controlling and cen-tralized management of the liquid-level in the liquid container. It can prevent from keeping in touch with the examined liquid,not only has increased the continuous working time of the system greatly,simplifying maintenance of the sensor conveniently,can also realize overhauling in producing and boost the productivity and management level. The working principle,hardware structure of the instrument and the design method are presented,and the selection of sensor and MCU is discussed in detail in this paper. MCU are used to control the emission and receiving. Then the liquid-level are calculated,which makes the design more intelligent. 展开更多
关键词 超声波传感器 液位监控 液位测量 温度补偿 MSP430 群罐
在线阅读 下载PDF
基于F-P腔的地浸采铀水位实时监测传感器研制
9
作者 张翀 詹洋 +4 位作者 张志伟 贾皓 王译那 郭迎庆 卢泓方 《光通信技术》 北大核心 2025年第1期71-77,共7页
为了实时监控我国地浸铀矿山井场群井水位,设计了一种基于法布里-珀罗腔(F-P)腔的地浸采铀水位实时监测传感器。该传感器的腔长由电动精密位移平台和定制夹具进行控制,传感头由硅片、基座、陶瓷插芯经胶粘耦合工艺加工而成,并在内蒙古... 为了实时监控我国地浸铀矿山井场群井水位,设计了一种基于法布里-珀罗腔(F-P)腔的地浸采铀水位实时监测传感器。该传感器的腔长由电动精密位移平台和定制夹具进行控制,传感头由硅片、基座、陶瓷插芯经胶粘耦合工艺加工而成,并在内蒙古某地浸采铀矿山进行了实地验证实验。实验结果表明,该传感器的压力测量范围为0~1.5 MPa,压力灵敏度为1.68μm/MPa,线性度为0.998,实现了地浸生产井水位参数在线监测。 展开更多
关键词 水位实时监测 光纤传感器 水位传感器 法布里-珀罗 地浸采铀
在线阅读 下载PDF
一种轨道弹性垫板关键尺寸的多点测量方法
10
作者 汤亮 蔡凯翼 +1 位作者 龚发云 杨敏 《机械设计与制造》 北大核心 2025年第6期46-49,54,共5页
在利用激光位移传感器对轨道减震弹性垫板尺寸进行测量的场合,为了解决激光位移传感器单点测量速度难以满足生产要求这一问题,提出了一种激光位移传感器线扫描测量方法。通过激光位移传感器对弹性垫板的宽度数据和厚度数据进行采集,利... 在利用激光位移传感器对轨道减震弹性垫板尺寸进行测量的场合,为了解决激光位移传感器单点测量速度难以满足生产要求这一问题,提出了一种激光位移传感器线扫描测量方法。通过激光位移传感器对弹性垫板的宽度数据和厚度数据进行采集,利用拉以达法则去检测采集中的异常数据,并使用BP神经网络模型对其进行修复,最后将各数据进行长度匹配达到弹性垫板检测的目的。实验表明:经过神经网络训练后的预测值和实际值具有高度吻合度,各模型的回归拟合值均达到0.98以上,该方法宽度重复测量精度在0.036mm以内,厚度重复测量精度在0.028mm以内,平均测量时间为4.0493s,满足实际生产要求。 展开更多
关键词 线扫描测量 激光位传感器 弹性垫板 BP神经网络 拉以达准则 尺寸测量
在线阅读 下载PDF
基于MSF和I-InceptionNet的变工况滚动轴承故障诊断
11
作者 王进花 曹文宝 +1 位作者 周德义 曹洁 《华中科技大学学报(自然科学版)》 北大核心 2025年第5期24-30,共7页
针对滚动轴承在故障数据有限且在不同工况下采集的信号存在不同的分布特性,导致现有故障诊断方法在表现出较低的故障诊断准确率低、鲁棒性差,提出一种基于多传感器融合(MSF)和改进的InceptionNet网络(IInceptionNet)的故障诊断方法.该... 针对滚动轴承在故障数据有限且在不同工况下采集的信号存在不同的分布特性,导致现有故障诊断方法在表现出较低的故障诊断准确率低、鲁棒性差,提出一种基于多传感器融合(MSF)和改进的InceptionNet网络(IInceptionNet)的故障诊断方法.该方法首先利用多相抗混叠滤波器对采集的多种信号进行重采样,转换为红绿蓝(RGB)图像作为模型的输入,保留信号的多维信息;然后,采用注意力特征融合(AFF)方法改进InceptionNet网络的连接层,融合多传感器图像特征,提高模型的分类性能;最后,对融合后的图像进行故障状态分类.实验结果表明:所提方法在变工况条件下的故障诊断性能显著优于单一信号源及其他对比方法,特别是在数据量有限的情况下,平均诊断准确率达到98.5%,具有优越的诊断精度和鲁棒性. 展开更多
关键词 滚动轴承 故障诊断 InceptionNet网络 特征级融合 多传感器
原文传递
一种应用于大面阵CMOS图像传感器的斜坡发生器
12
作者 祝晓笑 吴治军 +1 位作者 翟江皞 张艺潇 《半导体光电》 北大核心 2025年第3期449-455,共7页
为满足大面阵CMOS图像传感器(CIS)的应用需求,提出一种斜率可调、可配合列并行ADC实现普通采样与相关双采样模式的斜坡发生器电路的实现方案。基于90 nm(1.2 V/2.8 V)1P5M CIS工艺,完成了电路设计、仿真验证及版图实现。测试结果表明,... 为满足大面阵CMOS图像传感器(CIS)的应用需求,提出一种斜率可调、可配合列并行ADC实现普通采样与相关双采样模式的斜坡发生器电路的实现方案。基于90 nm(1.2 V/2.8 V)1P5M CIS工艺,完成了电路设计、仿真验证及版图实现。测试结果表明,该斜坡发生电路结构简单、面积较小,斜坡幅度大于0.5 V,复位时间小于70 ns,微分非线性为+0.018 LSB/-0.012 LSB,积分非线性为+0.37 LSB/-0.013 LSB。在保证低功耗和小面积的同时,实现了高线性度和快速响应,满足超大面阵CIS的设计和工程应用需求。 展开更多
关键词 CMOS图像传感器 列级ADC 相关双采样 斜坡发生器
原文传递
A Novel Approach for Fault Diagnosis in Wireless Sensor Networks
13
作者 Boul Chandra Garai Priyanka Das 《Communications and Network》 2013年第2期169-177,共9页
The following article has been retracted due to special reason of the author. This paper published in Vol.5 No. 2, 2013, has been removed from this site.
关键词 System-level Fault DIAGNOSIS Testing by Comparison Wireless sensor Networks Distributed DIAGNOSIS INTERMITTENT and PERMANENT FAULTS MESSAGE Complexity IDENTIFIABILITY
在线阅读 下载PDF
多传感器自动调平履带车体设计
14
作者 丁华忠 徐勇智 +3 位作者 曾庆辉 韩健 解志在 彭涛 《煤矿机械》 2025年第7期21-24,共4页
煤矿智能化钻孔机器人在施工作业前需要根据钻孔设计进行开孔姿态调整。煤矿井下钻场路面不平整,为保证钻孔机器人的稳定性,需实现钻孔机器人自动调平功能。以STM32控制器为主控核心,利用双轴倾角传感器及内置磁致伸缩位移传感器稳固油... 煤矿智能化钻孔机器人在施工作业前需要根据钻孔设计进行开孔姿态调整。煤矿井下钻场路面不平整,为保证钻孔机器人的稳定性,需实现钻孔机器人自动调平功能。以STM32控制器为主控核心,利用双轴倾角传感器及内置磁致伸缩位移传感器稳固油缸搭建一套自动调平控制系统。实际应用表明,该系统能够实现自动、安全、高效、精确调平,具有较好的稳定性。 展开更多
关键词 钻孔机器人 自动调平 车体平台 多传感器
原文传递
煤矿井下智能排水系统中液位传感器与泵站联动控制技术分析 被引量:1
15
作者 吕惠林 《仪器仪表用户》 2025年第6期31-33,共3页
基于某煤矿井下智能排水系统的需求,针对井下排水系统的复杂性,本研究提出了一种液位传感器与泵站联动控制策略,包括液位实时监测、阈值控制、变频调速优化等技术方案;结合无线数据传输、云计算和物联网,实现了远程监控与智能调度。研... 基于某煤矿井下智能排水系统的需求,针对井下排水系统的复杂性,本研究提出了一种液位传感器与泵站联动控制策略,包括液位实时监测、阈值控制、变频调速优化等技术方案;结合无线数据传输、云计算和物联网,实现了远程监控与智能调度。研究结果表明,该联动控制技术能够提高排水系统的自动化水平和可靠性,有效降低能耗,增强安全性,为煤矿井下排水系统的智能化改造提供了技术支持。 展开更多
关键词 煤矿井下排水系统 液位传感器 泵站联动控制 智能控制 远程监测
在线阅读 下载PDF
基于石墨烯/金属异质结的SF_(6)分解产物特性研究
16
作者 林露 曹志刚 +2 位作者 向英瀚 张强 刘晓波 《高压电器》 北大核心 2025年第3期200-204,共5页
文中详细探讨了石墨烯/金属这种异质结结构对SF_(6)分解产物H2S和SO_(2)的吸附行为的影响。实验结果显示,石墨烯/金和石墨烯/铂异质结结构在吸附H2S或SO_(2)气体时,电阻率变化率出现峰值或出现电阻率变化率下降现象。进一步研究表明,这... 文中详细探讨了石墨烯/金属这种异质结结构对SF_(6)分解产物H2S和SO_(2)的吸附行为的影响。实验结果显示,石墨烯/金和石墨烯/铂异质结结构在吸附H2S或SO_(2)气体时,电阻率变化率出现峰值或出现电阻率变化率下降现象。进一步研究表明,这种异质结电阻率变化率曲线吸附峰的具体位置由石墨烯与金属之间的费米能级差异决定,而气敏响应强度则由两者之间的费米能级差异及金属的功函数共同作用。该研究基于相关理论基础,为开发新型石墨烯气体传感器在检测SF_(6)分解产物方面的应用提供了理论指导和参考。 展开更多
关键词 石墨烯/金属异质结 SF_(6)分解气体 吸附峰 费米能级差 气体传感器
在线阅读 下载PDF
碳纳米管功能纤维的可控制备与性能调控研究进展
17
作者 李润 常梓洋 张如范 《纺织学报》 北大核心 2025年第5期30-40,共11页
碳纳米管纤维因其优异的物理和化学性能,在纤维传感器、纤维储能器件、柔性电子及显示器件等领域具有广泛的应用潜力。为充分利用和开发单根碳纳米管的本征优异性能,综述了碳纳米管纤维的可控制备和功能化策略。碳纳米管纤维的可控制备... 碳纳米管纤维因其优异的物理和化学性能,在纤维传感器、纤维储能器件、柔性电子及显示器件等领域具有广泛的应用潜力。为充分利用和开发单根碳纳米管的本征优异性能,综述了碳纳米管纤维的可控制备和功能化策略。碳纳米管纤维的可控制备技术包括湿法纺丝技术、阵列抽丝技术、以及目前主流应用的浮动催化直接纺丝技术,其功能化策略包括与其它功能材料的复合及多级结构设计;介绍了碳纳米管纤维在传感、储能等领域的应用进展,碳纳米管纤维在物理传感器、化学传感器等领域均得到了研究与应用,在储能领域可作为超级电容器和电化学电池的电极;最后总结了碳纳米管功能纤维领域面临的科学和技术挑战,对其未来的发展方向进行了讨论与展望。 展开更多
关键词 碳纳米管纤维 可控制备方法 性能调控 多级结构设计 传感器件 储能器件
在线阅读 下载PDF
千米级水平定向钻孔压水试验设备研发与应用 被引量:1
18
作者 张祥祥 杨栋 +3 位作者 朱贤 王军朝 李勇 张佳敏 《钻探工程》 2025年第3期77-83,共7页
传统压水试验设备在数据采集和试验操作上存在诸多局限,难以满足高精度工程需求。本文介绍了一套适用于千米级水平定向孔的压水试验方法及设备,压水试验设备引入先进的自动采集系统,集成了高精度传感器和智能控制模块,创新设计了止水栓... 传统压水试验设备在数据采集和试验操作上存在诸多局限,难以满足高精度工程需求。本文介绍了一套适用于千米级水平定向孔的压水试验方法及设备,压水试验设备引入先进的自动采集系统,集成了高精度传感器和智能控制模块,创新设计了止水栓塞结构。该套设备可直接测定试验段实际压力,获取的试段压力排除了管路损失;判别试验段密封性,提高试验可靠性;可对试验过程中的关键参数进行实时、连续、准确的记录,避免了人工操作误差和数据采集不及时的问题;新型止水栓塞的设计降低了事故率。与之配套的试验方法,依据智能化成套设备的特点进行优化,实现了试验的自动化运行和高效管理,并且根据试验所得数据可准确计算压水试验在水平孔中试验段的水位高程。经实际工程应用验证,该新型压水试验设备及试验方法显著提高了试验数据的可靠性和精度,提升了工作效率,为岩土工程、水利水电工程等领域的地质勘察和工程设计提供了更为科学、准确的基础数据,具有重要的工程应用价值和推广意义。 展开更多
关键词 千米级水平定向钻孔 压水试验 传感器 智能控制模块 止水栓塞
在线阅读 下载PDF
雷达液位传感器的研制与钻井现场应用
19
作者 张良 谢平 许铁成 《录井工程》 2025年第3期52-57,共6页
针对油气田井场钻井液出口缓冲罐液位监测中出现的超声波液位传感器易受环境干扰、测量精度不足等问题,提出了一种采用78 GHz调频连续波(FMCW)的雷达液位传感器改进方案。通过波束角优化设计与抗干扰信号处理算法,实现了毫米级测量精度... 针对油气田井场钻井液出口缓冲罐液位监测中出现的超声波液位传感器易受环境干扰、测量精度不足等问题,提出了一种采用78 GHz调频连续波(FMCW)的雷达液位传感器改进方案。通过波束角优化设计与抗干扰信号处理算法,实现了毫米级测量精度(误差为±3.2 mm)与窄波束(≤6°)覆盖特性。在西南油气田W 204HX⁃X井的应用表明,该传感器在剧烈液面波动场景下较超声波传感器准确性提高79.6%、数据稳定性提升16.2%,有效克服了高温烟、水雾等环境干扰导致的测量偏差并提升了监测稳定性。研究结果揭示并扩展了高频雷达技术在复杂工业环境中的适用边界,无论从成本还是功效上比较,都可以替代传统的超声波液位传感器,为钻探过程中钻井液液面智能监测装备的研发应用提供了新的技术路径。 展开更多
关键词 雷达 抗干扰 液位传感器 出口流量 钻井液 液面监测
在线阅读 下载PDF
上一页 1 2 60 下一页 到第
使用帮助 返回顶部