Антенны最新文献

{"title":"Analysis of technological gaps impact on radar cross-section of a collapsible corner reflector","authors":"K. P. Chemaev, E. O. Mozharov, E. V. Komissarova, K. V. Lyulyukin","doi":"10.18127/j03209601-202302-08","DOIUrl":"https://doi.org/10.18127/j03209601-202302-08","url":null,"abstract":"Corner reflectors used for calibration of radar stations, despite their apparent simplicity, have a number of disadvantages that manifest themselves both in the design and in their manufacture and operation. One of the main disadvantages is that in order to achieve high values of the radar cross-section (RCS), corner reflectors must have large linear dimensions. In addition, to ensure reliable electrical contact, their designs are usually non-separable. All of the above together complicates their operation and transportation, due to the large dimensions and weight of the products. The aim of the article is to develop and investigate by strict electrodynamic methods a corner reflector of a collapsible lightweight design, as well as to evaluate the influence of design features on RCS. The paper presents the results of modeling corner reflectors of a prefabricated structure by strict electrodynamic methods and investigates the influence of design features on its RCS. In particular, the influence of gaps at the top and between the edges of the reflector has been analyzed, the limits of the permissible sizes of these defects have been determined. Based on the results of the study, a lightweight collapsible layout of a corner reflector with square faces has been developed and manufactured. The correspondence of the RCS of the manufactured corner reflector layout to the calculated values has been experimentally confirmed. The performed studies have shown the practical feasibility of lightweight corner reflectors of collapsible design and confirmed the possibility of their use in radar system testing. Information about the impact of defects in the manufacture of corner reflectors on their RCS enables developers to use simpler and cheaper technological and design solutions in the development of corner reflectors.","PeriodicalId":485428,"journal":{"name":"Антенны","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136231642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Algorithm for forming a fan of identical beams in digital antenna arrays","authors":"P. N. Bashly, S. E. Mishchenko, V. V. Shatsky, A. V. Litvinov, S. A. Shelkoplyasov","doi":"10.18127/j03209601-202302-02","DOIUrl":"https://doi.org/10.18127/j03209601-202302-02","url":null,"abstract":"Digital antenna arrays allow you to implement multipath reception using a grid or a fan of beams. For multiple beams forming the linear phasing method is usually used. The disadvantage of this method is that the directional characteristics of each fan beam depend on the orientation direction of the maximum of the radiation pattern. When the beam deviates from the direction of the normal to the aperture, the following effects occur: expansion of the beam, a decrease in the directivity coefficient and a decrease in the norm of the radiation pattern. This feature of antennas in radar leads to a decrease in the accuracy of measurements of the angular coordinates of targets during electronic scanning. In this regard, it seems urgent to develop new methods and algorithms that ensure the formation of a grid of beams of a digital antenna array consisting of beams with the same directional characteristics. The goal of the article is to form a fan of identical receiving beams of a digital antenna array in a given angular sector. The problem of constructing a fan of beams in a given angular sector with close values of the directivity coefficient and the same beam width has been solved. The proposed algorithms increase the speed of spatial viewing by 20–25%, stabilize the level of the intersection of the beams in the entire sector of electronic scanning and reduce the side lobe level by 23 dB in the central part of the beam grid and by 5 dB for the extreme beams.","PeriodicalId":485428,"journal":{"name":"Антенны","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136231641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method of spatial-temporal coding of signals in the antenna array of millimeter-wave radar","authors":"A. V. Myakinkov, R. S. Fadeev, A. A. Kuzin, S. E. Kuznetsov, S. A. Shabalin","doi":"10.18127/j03209601-202302-03","DOIUrl":"https://doi.org/10.18127/j03209601-202302-03","url":null,"abstract":"Currently, most antenna systems are built based on MIMO technology. Its main advantage compared to classical antenna arrays is the possibility of a significant reduction of the number of physical transmitting and receiving channels keeping the resolution in angular coordinates. This feature is achieved due to the fact that the transmitting or receiving array is designed to be sparse, that is, the distance between the phase centers is significantly higher than half the wavelength. The cost of simplifying the design is presence of energy losses. In addition, the presence of several transmitting signals leads to the need to separate them from each other at the receiving position. The most popular method for separating orthogonal signals in MIMO arrays is code division signal separation. To implement this method, various types of orthogonal sequences are used. The most common are the Walsh, Fourier, and pseudo-random sequences. The use of orthogonal codes leads to the arising of multiple maximums in two-dimensional spectrum of the signal reflected from the object, exactly in dimension of Doppler frequency, with regular intervals. The number of maximums corresponds to the number of orthogonal sequences. Moreover, these maximums are formed in both case when using a sequence decoder and in the absence of a decoder. This feature is explained by the fact that when the sum of signals modulated in phase by Walsh sequences is multiplied by one of these sequences, one of the signals is demodulated, and the rest receive additional phase modulation. The level of additional maximum corresponds to the level of the main maximum. As a result, the ambiguity in determining the Doppler frequency appears. The indicated problem is very actual at the present time. To solve this problem, in the present paper the method of spatial-temporal coding of signals in millimeter-wave antenna array has been considered, based on the simultaneous operation of all sparse transmitters encoded by Walsh or Fourier sequences and spatial selection of transmitting beams by receiving one. The geometry of the placement of the elements of the transmitting and receiving antenna arrays corresponds to the geometry of the elements of MIMO array. At the same time, in contrast to the classical approach of beam forming for MIMO array, when individual transmitting antennas radiate orthogonal signals, and the irradiation of the target by each of them is considered separately, in the proposed method, the target is irradiated with a beam formed for transmission due to coherent spatial addition of signals from individual sparse transmitting array elements shifted in phase in accordance with the required slope of the phase front. As a result, the directivity pattern (DP) of the transmitting and receiving antenna is formed, which is equal to the product of the DP of the transmitting and receiving arrays. In this case, the interference maxima of DP of the transmitting antenna are at the zeros of DP of the re","PeriodicalId":485428,"journal":{"name":"Антенны","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136231639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection range of airborne objects by broadband active-passive radar systems","authors":"A. V. Bogoslovsky, S. N. Razinkov, O. E. Razinkova","doi":"10.18127/j03209601-202302-04","DOIUrl":"https://doi.org/10.18127/j03209601-202302-04","url":null,"abstract":"In the interests of searching and observing aerial objects with low levels of background contrast of secondary electromagnetic radiation and signals of on-board radio-electronic means, it is required to use active-passive radar systems with identification of the belonging of unmasking signs identified by heterogeneous information sensors to one object. When constructing procedures for joint processing of information signals, the issues of determining the range of active and passive search (observation) channels become important when implementing measures to reduce the reflective properties and structural and energy secrecy of the operation of electronic equipment of aircraft. To establish the boundaries of the area controlled by the active-passive radar system, it is necessary to use energy equations for transmitting and receiving broadband signals with a priori indefinite arrival time in a radio channel with scattering and a direct radio channel. The equations are found by integrating spectral equations for inharmonic wave processes propagating in free space in the band of cyclic operating frequencies when approximating the partial directional coefficients of antennas and partial effective scattering areas of objects by power functions of cyclic frequencies. The goal of the article is identification of patterns of influence of object reflective properties and characteristics of airborne radio sources on the range of active-passive radar systems. Using energy equations of transmission-reception of non-harmonic wave processes in a radio channel with scattering and direct radio channel, analytical expressions for determining probabilistic characteristics of signal detection with a priori indefinite arrival time, the possibilities of detecting air objects by broadband active-passive radar systems have been investigated. Ratios of ranges of detection of objects have been found based on the results of receiving and processing of information signals of radar stations and intrinsic radiation of airborne radio-electronic equipment. The revealed regularities of the influence of the object reflective properties and the characteristics of airborne radio sources on the range of radar stations and passive radar complexes allow us to make a rational choice of parameters of active-passive radar system designs in order to achieve the required indicators of the effectiveness of air space control. The energy equations of transmission and reception of broadband signals in radio channels form the basis for the development of proposals to ensure the covert use of aircraft.","PeriodicalId":485428,"journal":{"name":"Антенны","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136231640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development features of small-sized phased antenna arrays of millimeter wave band","authors":"E. V. Manaenkov","doi":"10.18127/j20700784-202001-04","DOIUrl":"https://doi.org/10.18127/j20700784-202001-04","url":null,"abstract":"Recently, a need has arisen for small-sized Ka-band phased antenna arrays (PAA) with electric beam scanning. In the development and study of phased arrays with small apertures not exceeding several tens of wavelengths, significant limitations were found on the accuracy of beam setting accuracy when its scanning in a wide angular sector. This leads to an increase in direction finding errors when using such phased arrays as part of small-sized monopulse radars for target tracking. The aim of the article is to investigate the causes of occurrence of various factors that affect the accuracy of the beam setting accuracy in the feedthrough phased arrays with spatial excitation by monopulse feeds, and also to note ways to eliminate or minimize this effect. The analysis of the main factors affecting the accuracy of the beam setting accuracy in the phased arrays, associated with the control algorithms of the phase shifters of the phased arrays, caused by the peculiarities of the circuitry implementation of the beam handling system of the phased arrays, and also having an electrodynamic nature and taking into account the excitation of the receiving antenna array by a monopulse feed, the mutual influence of emitters and edge effects in the antenna array. Recommendations on eliminating or mitigating the influence of these factors are given.","PeriodicalId":485428,"journal":{"name":"Антенны","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136328025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and measurements of 6 x 6 m collimator reflector with rounded edges","authors":"E. V. Korotetskiy, I. Yu. Tamaris","doi":"10.18127/j03209601-202301-05","DOIUrl":"https://doi.org/10.18127/j03209601-202301-05","url":null,"abstract":"Compact antenna test range (CATR) is designed to form a plane wave at a small distance from the aperture of the collimator reflector, which allows measurements to be made under far field conditions in a compact anechoic chamber. Currently, collimators are in demand due to the technical re-equipment of the industry for the production of 4G, 5G and Internet of Things stuff. The typical size of a quiet zone for these needs is 1–1.5 m. Along with antenna pattern measurements, collimators are widely used for RCS measurements. In the latter case, the measured objects may have dimensions several times larger than the average size of the quiet zone. Manufacturing, installation and adjustment of collimator reflector of several meters in size is a non-trivial task that requires separate study for each project. An incorrect choice of the reflector geometry can lead to an increase in mass and size, which entails an increase in production costs and the anechoic chamber designed for the CATR. In addition, increase in mass imposes additional requirements on the rigidity of the rack to which the reflector is attached, and the foundation under the collimator. As a rule, large-sized reflectors consist of a dozen fragments, which leads to the need to have special adjustment mechanisms for precision tuning of the reflector fragments. These and other problems need to be solved when developing large CATR. The article presents the issues faced by the LLC «RadioLine» in the process of manufacturing and setting up a collimator stand with a 6 x 6 m reflector. The issues of choosing the geometry of the reflector, its focal length have been highlighted. It has been shown how the agreement of the results of three-dimensional modeling of the reflector and production capabilities has been carried out. The features of the design of the reflector rack are touched upon, in particular, the appropriateness of using two materials: one for the base, and the second for the truss, which is connected to the reflector. After discussing the design features, a scheme for measuring the electromagnetic field distribution in a quiet zone, approaches to improving the quality of the RF characteristics of the CATR have been presented. It is noted that in the process of setting up the collimator, in order to determine the directions to the sources of diffraction, it is useful to apply the recalculation of the measured electromagnetic field in the quiet zone into the plane wave spectrum. At the end of the article, quiet zone cuts have been shown at frequencies of 0.75 GHz, 8.2 GHz and 50 GHz. Average peak-to-peak ripple of the amplitude-phase distribution in the operating frequency range of the CATR is 1 dB in amplitude and 10 degrees in phase.","PeriodicalId":485428,"journal":{"name":"Антенны","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136328024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Practical approach of measuring of angular bearing errors for radiotransparent radomes with complex shape in the “antenna – radome” system in the entire possible scanning ar-ea of the airborne radar antenna system","authors":"I. E. Makushkin, A. E. Dorofeev, A. N. Gribanov","doi":"10.18127/j03209601-202301-02","DOIUrl":"https://doi.org/10.18127/j03209601-202301-02","url":null,"abstract":"A nose radiotransparent radome (RTR) plays the role of a dielectric lens of a complex shape, which can significantly affect the radiation characteristics of the airborne radar antenna of an aircraft located under it. Modern radars, as a rule, are built on the basis of antenna systems with electronic beam control – phased antenna arrays. The phasing of the array is carried out in the most different (available for a given phased array) spatial directions. One of the parameters that define the operation of the radar under the RTR is the error in determining the angular position of the targets found by the radar. With complex forms (with one plane of symmetry) of the nose RTR, the resulting angular bearing errors (ABE) depend significantly on the spatial position in which the radar antenna is currently phased. In some cases, bearing errors must be taken into account when operating the radar. This becomes especially important in direction finding and tracking of targets remote to the limit for radar aircraft. In this case, the data on the values of the ABE depending on the current coordinates of the array phasing become relevant. The aim of the article is to present a simple technique that makes it possible to practically measure the ABE in the system “antenna – RTR” in a significant area of electronic scanning by the antenna beam. The technique for measuring the ABE has been developed, which was tested on the basis of an antenna-measuring collimator complex (“compact test site”). Mathematical expressions have been given for calculating both components of ABE (in the phased antenna array angular coordinate system) based on the measured data. At the initial stage, the technique has been tested on the basis of a specially made quick-detachable model-simulator of the radome, which has the ability to introduce arbitrary ABE. With the help of this model, a comparison of the results of measurements obtained on the basis of the proposed method and the method associated with the measurement of dynamic spatial radiation patterns (RP) has been performed. A good correlation of data has been noted for different methods, but on one physical model-simulator of the RTR, which allows us to speak about the correctness of the chosen approach. Subsequently, the correctness of the proposed method has been confirmed by the data collected when working with the system “phased antenna array – RTR” (teardrop shape). In this case, the calculated components of the ABE have been compared with the results of direct measurements by the difference method, when each of the orthogonal components is calculated by measuring the angle of displacement of the minimum of the corresponding difference pattern, obtained before and after the installation of the RTR. The developed technique of preliminary measurement of angular bearing errors over a significant part of the surface of a real RTR makes it possible, if necessary, to compensate the measured ABE in aircraft radar computers, thereby ","PeriodicalId":485428,"journal":{"name":"Антенны","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136329819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ionosonde antenna system for combined ionospheric sounding","authors":"D. S. Korlyakov, S. V. Litvinov","doi":"10.18127/j03209601-202301-03","DOIUrl":"https://doi.org/10.18127/j03209601-202301-03","url":null,"abstract":"The article is devoted to new and promising directions of development of ionosonde antenna systems, which have appeared in recent years and are able to conduct vertical and oblique sounding of ionosphere. A brief historical overview of ionosphere research has been given. The principles of vertical sounding of ionosphere and formation of ionograms in the frequency range from 1 to 30 MHz have been considered. The most widespread ionosondes of Russia and the world (DPS-4 (USA), CADI (Canada), Parus-A, Tomion, Raduga) have been studied. The analysis of antenna systems of these ionosondes (delta antennas, large and small rhombus antennas, etc.), their designs, directional patterns, conditions of application has been carried out. Proposals for modernizing the antennas, which have been put forward by foreign and Russian scientists, have been reviewed. A proposal to create a new, original design of the antenna system for combined sounding of the ionosphere has been given. The presented results create a basis for modernization and industrial production of promising antenna arrays.","PeriodicalId":485428,"journal":{"name":"Антенны","volume":"228 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136328027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of macros for automated performance of the same type operations when simulating SIW-based slotted waveguide antennas in Ansys HFSS CAD","authors":"M. M. Migalin, V. G. Koshkid'ko, V. V. Demshevsky","doi":"10.18127/j03209601-202301-04","DOIUrl":"https://doi.org/10.18127/j03209601-202301-04","url":null,"abstract":"SIW slotted waveguide antennas contain numerous equidistantly spaced vias and many slots distributed following a particular field distribution. Ansys HFSS CAD user must manually repeat the same type of operations when creating slots or vias. Automating these routine operations is advisable to eliminate design errors and speed up model construction. This paper aims at complete automation of SIW resonant slotted waveguide antenna arrays modelling in CAD Ansys HFSS, including model construction, running simulations and displaying simulation results. There are multiple procedures for slotted waveguide antenna synthesis. For small waveguide antenna arrays with a number of elements less than 15, the internal and external slots coupling consideration is beneficial, while for large waveguide antennas, no mutual coupling assumption can be made (so-called “energy method”). The energy method has been used to determine the coordinates of the longitudinal slots on the broad wall of the SIW based on a given side lobe level. The slot resonant length has been determined using substrate permittivity and operating frequency. The number of slots has been obtained based on the required half-power beamwidth. SIW dimensions have been calculated using the given operating frequency and the dimensions of the filled rectangular waveguide. An IronPython script has been developed to automate the antenna's model construction, automatic simulation and determination of its characteristics. All script commands have been taken from the “HFSS Scripting Guide” document integrated into Ansys HFSS. The tangible outcome of this work is the development of the IronPython script for fully automated modelling of SIW resonant slotted waveguide antennas. The script builds an antenna model from scratch based on a given antenna characteristics, assigns excitation port and radiation boundary conditions, and displays the simulation results – a radiation pattern at a fixed frequency. The script significantly reduces the antenna design time by eliminating the need to repeat the object creation operations.","PeriodicalId":485428,"journal":{"name":"Антенны","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136328026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Algorithm for beam grid forming in digital antenna arrays with an asymmetric envelope of side lobes","authors":"P. N. Bashly, S. E. Mishchenko, V. V. Shatsky, A. V. Litvinov, S. A. Shelkoplyasov","doi":"10.18127/j03209601-202301-01","DOIUrl":"https://doi.org/10.18127/j03209601-202301-01","url":null,"abstract":"In digital antenna arrays with a parallel view of space, the linear phasing method is usually used to distribute beams in space. At the same time, the requirements for the side lobe level are sufficiently fulfilled if the amplitude distribution falling to the edges of the opening is used. In this case, the envelope of the side lobes does not take into account the distribution of noise temperature in space. For different orientation of the beams in space, the noise quality of the antenna depends on the spatial orientation of the formed beams. In this regard, the problem of forming a beam grid taking into account the spatial distribution of the noise temperature is of interest. The aim of the article is to increase the noise quality of the antenna in conditions of uneven distribution of noise temperature in space. The algorithm for forming a beam grid with a uniform angular pitch and a constant directivity has been proposed, taking into account the uneven distribution of noise temperature in space based on previously developed methods for the synthesis of antenna arrays: with a simplified gradient procedure and according to the requirements for the envelope of the side lobes. The proposed algorithm makes it possible in the considered example to achieve a gain in noise quality by 1.5 dB.","PeriodicalId":485428,"journal":{"name":"Антенны","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136328028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}