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Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by joint inflammation. Macrophages accelerate the pathological process of RA through the continuous cell accumulation and secretion of cytokines. Therefore, multiscale visualization of macrophages is of great significance for the early diagnosis of RA. In this work, folate receptor‐targeted Cptnc‐4F nanoprobes, named FA‐CF‐NPs, are developed for dual‐model molecular imaging of macrophages in RA mouse models. FA‐CF‐NPs exhibit complementary imaging advantages with high fluorescence sensitivity and resolution in the second near‐infrared window (NIR‐II) and promising photoacoustic (PA) imaging contrast with deep tissue penetration. The high affinity of the folate ligand on the surface of FA‐CF‐NPs to macrophages with overexpressed folate receptors ensures the specific targeting function of the nanoprobes for imaging in vivo. FA‐CF‐NPs are employed to achieve NIR‐II fluorescence imaging to accurately localize macrophages in the joint, obtaining a high signal‐to‐background ratio (SBR) of 15.5. Meanwhile, PA imaging is also performed to observe macrophage distribution in the longitudinal section of the whole joint. Moreover, macrophage infiltration is detected in the joint of RA mice with the absence of RA pathologies such as synovitis and cartilage loss. The results provide an opportunity for in vivo macrophage tracking and early diagnosis of RA. [ABSTRACT FROM AUTHOR]

Wireless sensor networks (WSNs) are widely used in industrial applications. However, many of them have limited lifetimes, which has been a considerable constraint on their widespread use. As a typical application of WSNs, distributed measurement of the electric field under high-voltage direct-current (HVDC) transmission lines also suffers from this issue. This paper first introduces the composition of the electric-field measurement system (EFMS) and its working principle. Considering the actual power supply of the system, this paper mainly introduces the composition of the wireless sensor node (WSND) and analyzes the power consumption and potential working state transformation of the WSND, together with a comprehensive study on parameters affecting the power consumption of the wireless communication unit. Moreover, an energy-efficient scheduling approach is proposed after specially designing a working sequence and the study on system parameters. The proposed approach is verified by experiments on not only the experimental line of the national HVDC test base, but also a commercial operation HVDC transmission line with the challenge of long endurance, which is considered in this paper with a new strategy. The results show that the proposed method can greatly extend the lifetime of the WSND. [ABSTRACT FROM AUTHOR]

It is known that the distorted electric field is generated by a high-voltage alternating current (HVac) transmission line passing through a conductor, but few studies have accurately measured and analyzed it. In this article, we analyze the distorted electric field and distortion rate (DR) using a ZigBee-based optical measurement system. First, the key parameters of the integrated optical sensor (IOS) and the wireless module are discussed, respectively. Second, the plate–plate and ball–plate characteristics of the measurement system are studied, and the results show that the measurement system can accurately measure the uniform and nonuniform electric field within 25 kV/m. Third, the measurements are compared to the calculation values, and the results show that the relative error is within 12%. Finally, the distribution law of DRs when considering the grounded shielding wire and height of the obstacle is analyzed. The findings show that the DR varies with the height of the obstacle but is not affected by the grounded shielding wire. [ABSTRACT FROM AUTHOR]

A wireless sensor network-based distributed measurement system is designed for collecting and monitoring the electric field under the high voltage direct current (HVDC) transmission lines. The proposed system architecture is composed of a group of wireless nodes connected with electric field sensors and a base station. The electric field sensor based on Gauss's law is elaborated and developed. For the design of wireless node, the ARM microprocessor and Zigbee radio frequency module are employed. The proposed system has been used in China's state grid HVDC test base and the in situ power transmission projects. Based on the experimental results, the proposed measurement system demonstrates that it can adapt to the complex electromagnetic environment under the transmission lines and can accomplish the accurate, flexible, and stable demands of the electric field measurement. [ABSTRACT FROM AUTHOR]

It is generally acknowledged that high voltage direct current (HVDC) transmission line endures the drawback of large area, because of which the utilization of cable for space charge density monitoring system is of inconvenience. Compared with the traditional communication network, wireless sensor network (WSN) shows advantages in small volume, high flexibility and strong self-organization, thereby presenting great potential in solving the problem. Additionally, WSN is more suitable for the construction of distributed space charge density monitoring system as it has longer distance and higher mobility. A distributed wireless system is designed for collecting and monitoring the space charge density under HVDC transmission lines, which has been widely applied in both Chinese state grid HVDC test base and power transmission projects. Experimental results of the measuring system demonstrated its adaptability in the complex electromagnetic environment under the transmission lines and the ability in realizing accurate, flexible, and stable demands for the measurement of space charge density. [ABSTRACT FROM AUTHOR]

Most of the construction machinery for vibro-sinking stone columns, which are widely used in China, needs to be improved in terms of degree of automation. Engineering quality control is mainly carried out post-inspection; consequently, it is difficult to control the construction quality in real time. According to the construction characteristics of traditional stone column machines, we established the theory and model for the real-time monitoring of stone column construction, as well as put forward an intelligent monitoring method for stone column machines. With the comprehensive application of critical technologies such as the Global Navigation Satellite System (GNSS) measurement technology, laser ranging sensors, and massive data processing, an intelligent data acquisition technique and associated monitoring equipment for stone column construction machines are developed. The data acquisition and storage of crucial construction parameters, such as pile depth, pile point co-ordinates, bearing layer current, and reverse insertion times, are realized. A large number of actual construction data are collected and the construction quality parameters of stone column machines are obtained. By comparison with third-party detection data, it is verified that the intelligent monitoring technique for stone column machines proposed in this paper is feasible. [ABSTRACT FROM AUTHOR]

It is known that the high-voltage direct-current (HVdc) transmission projects are increasingly used in actual electrical power transmission and the ion-flow field at ground level has been systematically studied. However, few studies focused on the research of the consistency among ion-flow density measurement systems (IDMS). IDMS should keep good concordance to discover the distribution law of ion-flow density in HVdc research. This study proposes an improved gray relational analysis (IGRA) method for consistency test of IDMS by introducing an entropy weight method and interval estimation method. Using this method, the consistency among IDMS is analyzed. The calibration assessment experiment was conducted and the results can be used for calibration assessment. The fault diagnosis experiment with +120 kV was also performed and findings show that the IGRA method is effective in finding potential fault for IDMS compared to the GRA method. Overall, results demonstrate that the IGRA method presented in this paper is useful for discovering distribution law of ion-flow density in HVdc research. [ABSTRACT FROM AUTHOR]

Overhead lines are important parts of distribution networks at present. Assessment and prediction of their health status is of great significance to ensure the reliable operation of distribution network. This paper presents a method for assessing and predicting the health status of overhead lines based on health index (HI). First, the key features set of overhead lines including ontological and nonontological factors is determined. Then, a calculation method for evaluating HI based on analytic hierarchy process and technique for order preference by similarity to an ideal solution is proposed. Subsequently, the health assessment results of the actual 110 and 10 kV overhead lines located in China show that the proposed method could reflect the actual situation of overhead lines well. Finally, based on the proposed method, this paper takes two areas of China, Beijing and Nanjing, which have different climatic conditions, as research objects, and studies the influence of natural factors on the health status of overhead lines, respectively. Based on the analysis results, the health statuses of the overhead lines in the two regions are predicted. The research results of this paper can provide guidance for the operation and maintenance of overhead lines. [ABSTRACT FROM AUTHOR]

Corona current is an important parameter to characterise the corona discharge on high‐voltage direct current (HVDC) transmission lines. The spectral components of corona current are closely related to a variety of corona effects, such as audible noise. It is of great significance to study the frequency‐domain characteristics of corona current. Here, the relationship between DC component and spectral components of corona current on HVDC transmission lines in the band of 2–20 kHz was analysed. First, a lot of corona current data were measured in two HVDC experiment bases. Then, the expression representing the correlation between DC component and spectral components of corona current within 2–20 kHz was established with the maximum surface nominal electric field intensity of conductor as an intermediate variable. Finally, the correctness and universality of the relationship found were verified. The research results here not only reveal the characteristics of corona discharge but can also provide a new way for obtaining the spectral components of corona current in 2–20 kHz with its DC component, and can lay the foundation to provide a new way to get audible noise indirectly based on the DC component of corona current in the future. [ABSTRACT FROM AUTHOR]

An ISO/IEC/IEEE21451 smart sensor network for distributed measurement of pavement structural temperature (PST) is proposed in this paper. The proposed network architecture is a star network based on GPRS communication, adapting to the measurement environment of PST. The proposed network node consists of autonomous power supply system, network capable application processor (NCAP), and smart transducer interface module (STIM). The design of hardware and software is based on ISO/IEC/IEEE21451-1 and ISO/IEC/IEEE21451-2 standards. A human-computer interaction website is designed based on B/S three-layer architecture. Users having access rights can access the PST data using a browser connected to the internet. The proposed system has been used in the experimental research of the PST distribution of asphalt and cement pavement. The experimental results demonstrate that the proposed smart sensor network can adapt to the distributed fieldwork and unattended measurement environment of PST. The validity and reliability of the system have also been verified. [ABSTRACT FROM AUTHOR]