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Using the density functional theory calculations, we have studied the hydrogenated two dimensional (2D) orthorhombic diboron diphosphorus (O-B2P2). It is found that hydrogenation could transit the pristine O-B2P2 from tiny bandgap semiconductor to wide- and indirect-bandgap semiconductor, and the bandgaps are dependent on hydrogenation configurations. Moreover, our calculations have revealed three hydrogenated O-B2P2 nanostructures are both dynamically and thermally stable, and their bandgaps are estimated to be 2.8-4.2 eV according to hybrid potential calculation. They are predicated to possess strongly anisotropic mechanical and carrier transport properties, allowing potential applications for in-plane anisotropic device and high-performance electronic device. The hydrogenated O-B2P2 nanostructures exhibit strong absorbance to the ultraviolet light, and their bandgaps could be linearly modulated by tensile strain. Our findings have shown novel mechanical and electronic properties of the hydrogenated O-B2P2, combined with their excellent stabilities at ambient condition, suggesting that they could be promising candidates for strongly anisotropic electronics and sensor device.

The influence maximization problem in complex networks asks to identify a given size of seed spreaders set to maximize the number of expected influenced nodes at the end of the spreading process. This problem finds many practical applications in numerous areas such as information dissemination, epidemic immunity, and viral marketing. However, most existing influence maximization algorithms are limited by the “rich-club” phenomenon and are thus unable to avoid the influence overlap of seed spreaders. This work proposes a novel adaptive algorithm based on a new gravity centrality and a recursive ranking strategy, named AIGCrank, to identify a set of influential seeds. Specifically, the gravity centrality jointly employs the neighborhood, network location and topological structure information of nodes to evaluate each node’s potential of being selected as a seed. We also present a recursive ranking strategy for identifying seed nodes one-by-one. Experimental results show that our algorithm competes very favorably with the state-of-the-art algorithms in terms of influence propagation and coverage redundancy of the seed set.

Breast cancer is a malignant disease that seriously threatens women’s health. Studying the mechanism of cancer occurrence and development is an urgent problem to be solved. In this paper, the eigen-microstate method was used to study conversion of normal breast cells into breast cancer cells and the reason. The main conclusions are as follows: the microstates of normal breast cell and breast cancer cell are different. There is a state conversion when a normal breast cell transforms into a breast cancer cell. The main reason for this state conversion is the combined effect of tumor suppressor genes and oncogenes. By analyzing the function of key genes, it was found that these genes do play an important role in the development of breast cancer. The findings contribute to understanding the mechanism by which breast cancer occurs and progresses, and key genes can serve as potential biomarkers or target genes for breast cancer treatment.

When lightning intrudes into the over-voltage in the 500 kV substation, the lightning wave will be introduced into the substation along the line, which will seriously affect the insulation level of the equipment. In this paper, firstly, the working principle, characteristics, and lightning current simulation of the ZnO arrester are described. Then, the electromagnetic transient program (EMTP-ATP) used in a 500 kV GIS substation carried out the simulation research to the lightning over-voltage, specifically studied the lightning protection effect of metal oxide arrester, compared the lightning over-voltage under the different lightning locations and operation mode, and calculated the 500kV GIS Substation under the single in single out operation mode, 500kV. The influence of different positions of lightning arresters in GIS on the magnitude of lightning over-voltage and the lightning over-voltage on the substation equipment in GIS is also described.

A reinforcing method for developing a kind of shear wall with both excellent self-centering capacity and high energy dissipation was presented, in which carbon fiber reinforced polymer (CFRP) bars or steel strands were longitudinally placed to provide a restoring effect, while magnetorheological (MR) dampers were externally coupled with wall panels to provide extra energy dissipation. To verify the feasibility of this method, three slender concrete walls were tested under reversed cyclic lateral loading while subjected to constant axial compression with an axial load ratio of 0.26, of which one was reinforced with CFRP bars, the second one was reinforced with CFRP bars and two external MR dampers, and the third one was reinforced with steel strands and two external MR dampers. The results indicated that the test walls possessed remarkable load-resisting capacities even when the lateral drift was as large as 1.8% as well as a lateral deformation recovery rate of 74%–89% after unloading. Owing to external MR dampers, the initial stiffness and ductility were increased by 28.3% and 29.8%, respectively. In addition, a specific quantitative analysis showed that the dampers could increase the cumulative energy dissipation of shear walls by 16.6%, of which the contribution provided by MR damper was 64.8%, confirming the effectiveness of MR dampers in improving energy dissipation while preserving the self-centering capacity.

X-ray microscope as an important nanoprobing tool plays a prevailing role in nano-inspections of materials. Despite the fast advances of high resolution focusing/imaging reported, the efficiency of existing high-resolution zone plates is mostly around 5% in soft x-ray and rapidly goes down to 1%–2% when the resolution approaches 10 nm. It is well known that the rectangular zone shape, beamstop, limited height/width ratios, material absorption of light and structural defects are likely responsible for the limited efficiency. Although zone plates with Kinoform profile are supposed to be efficient, progress for achieving both high resolution (5%) have hardly been addressed in soft x-ray. In this work, we propose a compound Kinoform/Fresnel zone plate (CKZP) by combing a dielectric Kinoform zone plate with a 15 nm resolution zone plate. Greyscale electron beam lithography was applied to form the 3D Kinoform zone plate and atomic layer deposition was carried out to form the binary zone plate. Optical characterizations demonstrated 15 nm resolution focusing/imaging with over 7.8% efficiency in soft x-ray. The origin of the efficiency improvement behind the proposed compound lens is theoretically analyzed and discussed.

Two-dimensional (2D) ferroelectric compounds are a special class of materials that meet the need for devices miniaturization, which can lead to a wide range of applications. Here, we investigate ferroelectric properties of monolayer group-IV monochalcogenides MX (M = Sn, Ge; X = Se, Te, S) via strain engineering, and their effects with contaminated hydrogen are also discussed. GeSe, GeTe, and GeS do not go through transition up to the compressive strain of –5%, and consequently have good ferroelectric parameters for device applications that can be further improved by applying strain. According to the calculated ferroelectric properties and the band gaps of these materials, we find that their band gap can be adjusted by strain for excellent photovoltaic applications. In addition, we have determined the most stable hydrogen occupancy location in the monolayer SnS and SnTe. It reveals that H prefers to absorb on SnS and SnTe monolayers as molecules rather than atomic H. As a result, hydrogen molecules have little effect on the polarization and electronic structure of monolayer SnTe and SnS.

The quantum transport properties of defective two-dimensional (2D) GeP semiconductor nanodevice consisting of typical point defects, such as antisite defect, substitutional defect, and Schottky defect, have been studied by using density functional theory combined with non-equilibrium Green’s function calculation. The antisite defect has indistinctive influences on electron transport. However, both substitutional and Schottky defect have introduced promising defect state at the Fermi level, indicating the possibility of improvement on the carrier transport. Our quantitative quantum transport calculations of I–V b behavior have revealed that the electrical characters are enhanced. Moreover, the P atom vacancy could induce significant negative differential resistance phenomenon, and the physical mechanism is unveiled by detailed analysis. The transfer characteristic properties could be prominently improved by substitutional defect and vacancy defect. Most importantly, we have proposed a computational design of GeP-based electronic device with improved electrical performance by introducing vacancy defect. Our findings could be helpful to the practical application of novel 2D GeP semiconductor nanodevice in future.

Chemical looping combustion (CLC) plays a vital role in coal combustion which released pure CO2 in the exhaust gas with low energy consumption. Researchers have developed over 1000 oxygen carriers (OCs) to enhance the properties of OCs. This study focus on the microstructural changes of coal during CLC process which could provide the performance improvement direction for OCs. Results showed that the phenolic -OH group can easily be removed by CuO while the free -OH group and the self-associating -OH group are hard to be consumed by the lattice oxygen in CuO at 800 °C, showing good stability in CLC process. Aliphatic hydrocarbons could be consumed in the gas phase rapidly. The functional group of C=O maintains high reactivity with CuO which explains why the addition of CO2 promotes the reaction rate in coal CLC. But C=C group was nonpolar bond and hard to be consumed while the -CH2 and -CH3 group and C-O-C group showed good reactivity with CuO. Higher reaction temperature affords higher reactivity of coal CLC process. But the -OH group changed slowly at higher temperature which could because that higher temperature makes the organic big molecular of the coal char decomposed and produce more -OH group.

The upper lock is a key component of the landing gear system, and its fatigue life affects its service life and reliability. In this paper, the modal analysis, random vibration analysis, and fatigue life calculation are carried out for the upper lock. According to the analysis results, the upper lock structure is optimized, and the optimization scheme is proposed. The natural frequency, stress, and fatigue life are analyzed, and the scheme meets the design requirements. Finally, the optimized structure is verified to be reasonable and feasible through experiments.

The discovery of pressure-induced superconductivity in helimagnets (CrAs, MnP) has attracted considerable interest in understanding the relationship between complex magnetism and unconventional superconductivity. However, the nature of the magnetism and magnetic interactions that drive the unusual double-helical magnetic order in these materials remains unclear. Here, we report neutron scattering measurements of magnetic excitations in CrAs single crystals at ambient pressure. Our experiments reveal well defined spin wave excitations up to about 150 meV with a pseudogap below 7 meV, which can be effectively described by the Heisenberg model with nearest neighbor exchange interactions. Most surprisingly, the spin excitations are largely quenched above the Neel temperature, in contrast to cuprates and iron pnictides where the spectral weight is mostly preserved in the paramagnetic state. Our results suggest that the helimagnetic order is driven by strongly frustrated exchange interactions, and that CrAs is at the verge of itinerant and correlation-induced localized states, which is therefore highly pressure-tunable and favorable for superconductivity., 6 pages, 4 figures

Accurate evaluation of the residual entropy of three-dimensional ice systems remains a difficult task. In this work, we estimate the residual entropy of ice Ih (ordinary ice) by an improvement of the Wang–Landau Monte Carlo algorithm, which directly calculates the density of states of the system. We define an effective three-dimensional Ising model with nearest-neighbour interactions, and introduce the mapping of the spin configurations of this Ising model into the hydrogen configurations of ice Ih. The ground states of this Ising model are equivalent with the hydrogen configurations obeying the ice rules, therefore the ground state degeneracy directly determines the residual entropy. Our estimate is in good agreement with the famous theoretical approximation by Nagle in 1966, and other results evaluated from various methods. The advantage of making use of the equivalent Ising model is discussed. It is convenient to extend our approach to other lattice systems.

The fully developed turbulence can be regarded as a nonlinear system, with wave coupling inside, which causes the nonlinear energy to transfer, and drives the turbulence to develop further or be suppressed. Spectral analysis is one of the most effective methods to study turbulence system. In order to apply it to the study of the nonlinear wave coupling process of edge plasma turbulence, an efficient algorithm based on spectral analysis technology is proposed to solve the nonlinear wave coupling equation. The algorithm is based on a mandatory temporal static condition with the nonideal spectra separated from the ideal spectra. The realization idea and programing flow are given. According to the characteristics of plasma turbulence, the simulation data are constructed and used to verify the algorithm and its implementation program. The simulation results and experimental results show the accuracy of the algorithm and the corresponding program, which can play a great role in the studying the energy transfer in edge plasma turbulences. As an application, the energy cascade analysis of typical edge plasma turbulence is carried out by using the results of a case calculation. Consequently, a physical picture of the energy transfer in a kind of fully developed turbulence is constructed, which confirms that the energy transfer in this turbulent system develops from lower-frequency region to higher-frequency region and from linear growing wave to damping wave.

The magnetic topological van der Waals materials family MnBi2Te4/(Bi2Te3) n have drawn markedly attention due to their novel multiple topological phases in different magnetic configurations. Recently, their close relative, the MnSb4Te7, was firstly synthesized in experiments (2021 Phys. Rev. Lett. 126 246601). To further explore the emergent properties of MnSb4Te7, we have systematically investigated the magnetic and topological characters under compressive strain and charge doping using first-principles calculations. We predict that MnSb4Te7 transits from an interlayer antiferromagnetic ground state to a ferromagnetic semimetal ground state with multiple Weyl points when compressive strained along c axis above 8% or charge doping before 0.1 hole/formula concentration. Notable anomalous Hall conductivity is also predicted. Meanwhile, the magnetic easy axis can be reoriented from out-of-plane to in-plane orientation when strain or electron doping is applied. The underlying magnetic exchange mechanism is also analyzed from our calculation results. Our work thus provides a feasible way to realize applications of the highly tunable magnetic-topological nature and a comprehensive theoretical understanding of this magnetic topological material.

Evaporation duct is a kind of special atmospheric stratification that frequently appears on the sea surface, which has an important influence on the propagation and attenuation of electromagnetic waves, and is an important factor affecting the efficiency of marine radars and communication equipment. After the development in more than half a century, evaporation duct height can be obtained by direct detection, theoretical model, inversion and machine learning. Machine learning can explore the hidden laws of data efficiently and has the potential to surpass the traditional theoretical model. In this paper, the Machine Learning methods in evaporation duct research are shown and prospects of machine learning methods in evaporation duct research are given.

Tricritical phenomenon appearing in multiple phases is a fundamental and attractive issue in condensed-matter physics. In this work, a field-modulated tricritical phenomenon is realized in single-crystal PrCu9Sn4. The magnetization under variable directions of field indicates strong magnetic anisotropy in PrCu9Sn4, which reveals ferromagnetic coupling for H//c. A paramagnetic-to-ferromagnetic magnetic transition occurs with H//c at T C = 11.7 K, which is evidenced to be of a first-ordered type. The systematical study of the critical behavior gives that β = 0.195(8), γ = 0.911(1), and δ = 0.0592(1) for H//c consistent with a tricritical mean-field model, which suggests a field-modulated tricritical phenomenon. A detailed H − T phase diagram around the tricritical point (TCP) is constructed for single-crystal PrCu9Sn4 for H//c, where ferromagnetic state, forced ferromagnetic phase and paramagnetic state meet at the TCP (H tr = 799 kOe, T tr = 11.3 K). The single-crystal PrCu9Sn4 supplies a platform to deep investigate the field-modulated magnetic couplings and tricritical phenomenon.

Objective. Subtype classification plays a guiding role in the clinical diagnosis and treatment of non-small-cell lung cancer (NSCLC). However, due to the gigapixel of whole slide images (WSIs) and the absence of definitive morphological features, most automatic subtype classification methods for NSCLC require manually delineating the regions of interest (ROIs) on WSIs. Approach. In this paper, a weakly supervised framework is proposed for accurate subtype classification while freeing pathologists from pixel-level annotation. With respect to the characteristics of histopathological images, we design a two-stage structure with ROI localization and subtype classification. We first develop a method called multi-resolution expectation-maximization convolutional neural network (MR-EM-CNN) to locate ROIs for subsequent subtype classification. The EM algorithm is introduced to select the discriminative image patches for training a patch-wise network, with only WSI-wise labels available. A multi-resolution mechanism is designed for fine localization, similar to the coarse-to-fine process of manual pathological analysis. In the second stage, we build a novel hierarchical attention multi-scale network (HMS) for subtype classification. HMS can capture multi-scale features flexibly driven by the attention module and implement hierarchical features interaction. Results. Experimental results on the 1002-patient Cancer Genome Atlas dataset achieved an AUC of 0.9602 in the ROI localization and an AUC of 0.9671 for subtype classification. Significance. The proposed method shows superiority compared with other algorithms in the subtype classification of NSCLC. The proposed framework can also be extended to other classification tasks with WSIs.

A new frustrated triangular lattice antiferromagnet Na2BaNi(PO4)2 was synthesized by high temperature flux method. The two-dimensional triangular lattice is formed by the Ni2+ ions with S = 1. Its magnetism is highly anisotropic with the Weiss constants θ CW = –6.615 K (H ⊥ c) and –43.979 K (H ∥ c). However, no magnetic ordering is present down to 0.3 K, reflecting strong geometric spin frustration. Our heat capacity measurements show substantial residual magnetic entropy existing below 0.3 K at zero field, implying the presence of low energy spin excitations. These results indicate that Na2BaNi(PO4)2 is a potential spin liquid candidate with spin-1.

Van der Waals magnet VI$_3$ demonstrates intriguing magnetic properties that render it great for use in various applications. However, its microscopic magnetic structure has not been determined yet. Here, we report neutron diffraction and susceptibility measurements in VI$_3$ that revealed a ferromagnetic order with the moment direction tilted from the $c$-axis by ~36{\deg} at 4 K. A spin reorientation accompanied by a structure distortion within the honeycomb plane is observed at a temperature of ~27 K, before the magnetic order completely disappears at $T_C$ = 50 K. The refined magnetic moment of ~1.3 $\mu_B$ at 4 K is considerably lower than the fully ordered spin moment of 2 $\mu_B$/ V$^{3+}$, suggesting the presence of a considerable orbital moment antiparallel to the spin moment and strong spin-orbit coupling in VI$_3$. This results in strong magnetoelastic interactions that make the magnetic properties of VI$_3$ easily tunable via strain and pressure., Comment: 8 pages, 4 figures

We report polarized neutron scattering measurements of the low energy spin fluctuations of the iron-selenide superconductor Li$_{0.8}$Fe$_{0.2}$ODFeSe below and above its superconducting transition temperature $T_c=41$ K. Our experiments confirmed that the resonance mode near 21 meV is magnetic. Moreover, the spin excitations are essentially isotropic in spin space at 5$\leq E\leq$ 29 meV in the superconducting and normal states. Our results suggest that the resonance mode in iron-based superconductors becomes isotropic when the influence of spin-orbit coupling and magnetic/nematic order is minimized, similar to those observed in cuprate superconductors., Comment: 10 pages, 4 figures

The thermal conductivity, specific heat, and total drying shrinkage test of slag blended OPC cement is conducted by using a Hotdisk-2500S thermal conductivity, and non-contact shrinkage deformation measurement apparatus based on ISO 22007-2 and GB/T50082-2009 test standards, respectively. The influence of replacement rates of slag cement (0, 30, 50, and 70%) and high-temperature exposure (21, 200, 400, 600, and 800 °C) on the thermal properties of concrete is analysed. The results show that for all three concretes, the thermal conductivity initially decreases with increasing temperature up to 400 °C, then after it remains almost constant between 400 and 600 °C, and gradually begins to decrease again up to 800 °C. Furthermore, thermal diffusivity of concrete group G-70, shows 21.4, 21.6, and 37.6% increment in 21, 200, and 600 °C temperature exposure respectively compared to concrete group G-0. Though, as the exposure temperature keeps rise to 800 °C, its value starts to decrease. Furthermore, the results indicated that high volume slag cement content in the concrete mix lessen the drying shrinkage of the concrete at later age. Test data is used as a function of temperature and slag replacement to establish high temperature relations for thermal properties. The proposed thermal property relationships can be used as input data for validation in computer programs and to evaluate the response of OPC and slag blended Portland cement concrete structures subjected to fire.

Two-dimensional transition metal dichalcogenide MnSe2 (2D-MnSe2) with Curie temperature approximate to 300 K has a significant spintronic application on thin-film devices. We demonstrate theoretically a tunable magnetic transition of 2D-MnSe2 between anti-ferromagnetic (AFM) metal and ferromagnetic (FM) half metal as strain increasing. Mechanism of that transition involves a competition between d–p–d through-bond and d–d direct interaction in 2D-MnSe2. Hole doping is an alternative way to enhance the stability of FM coupling. Adsorption (including Li, Na, Cl and F) and vacancy (Mn and Se) studies confirm that the controllable magnetism of 2D-MnSe2 is related to both interaction competition and charge doping. Tensile strains can greatly amplify through-bond interaction and exchange parameters, resulting in a sharp increase of Curie temperature.

Web application brings us convenience but also has some potential security problems. SQL injection attacks topped the list of Top 10 Network Security Problems released by OWASP, and the detection technology of SQL injection attacks has been one of the hotspots of network security research. In this paper, we propose a SQL injection detection method that does not rely on background rule base by using a natural language processing model and deep learning framework on the basis of comprehensive domestic and international research. The method can improve the accuracy and reduce the false alarm rate while allowing the machine to automatically learn the language model features of SQL injection attacks, greatly reducing human intervention and providing some defense against 0day attacks that never occur.

With the development of vehicular Ad hoc Networks (VANENTs) technology, application in VANENTs has becomes an important role in human life. In practice, the location information of not all vehicles in VANENTs contains sensitive information. But traditional publish algorithm for geospatial stream for VANENTs based on differential privacy assumes that all the data in the geospatial stream contain sensitive information of users. As a consequence, utility of the traditional algorithm has been decreased. In this paper, a novel algorithm is proposed to publish geospatial stream, denoted as PGSV. PGSV make used of one-sided differential privacy to guarantee sensitive information. In the end, we make used of public dataset to verify efficiency of PGSV. The result show that PGSV have increased utility of published result and guaranteed security of published result.

Imaging through multimode fibers (MMFs) is a challenging task. Some approaches, e.g. transmission matrix or digital phase conjugation, have been developed to realize imaging through MMF. However, all these approaches seem sensitive to the external environment and the condition of MMF, such as the bent condition and the movement of the MMF. In this paper, we experimentally demonstrate the high-fidelity imaging through a bent MMF by the conventional neural network (CNN). Two methods (accuracy and Pearson correlation coefficient) are employed to evaluate the reconstructed image fidelity. We focus on studying the influence of MMF conditions on the reconstructed image fidelity, in which MMF for imaging is curled to different diameters. It is found that as an object passes through a small bent diameter of the MMF, the information of the object may loss, resulting in little decrease of the reconstructed image fidelity. We show that even if MMF is curled to a very small diameter (e.g. 5 cm), the reconstructed image fidelity is still good. This novel imaging systems may find applications in endoscopy, etc.

Entanglement witnesses (EWs) are a fundamental tool for the detection of entanglement. We study the inertias of EWs, i.e., the triplet of the numbers of negative, zero, and positive eigenvalues respectively. We focus on the EWs constructed by the partial transposition of states with non-positive partial transposes. We provide a method to generate more inertias from a given inertia by the relevance between inertias. Based on that we exhaust all the inertias for EWs in each qubit-qudit system. We apply our results to propose a separability criterion in terms of the rank of the partial transpose of state. We also connect our results to tripartite genuinely entangled states and the classification of states with non-positive partial transposes. Additionally, the inertias of EWs constructed by X-states are clarified., Comment: similar to the accepted version, to appear in the journal of physics a

Three isostructural pillared-layer frameworks with M-BDC-X layers supported by ditopic HL connectors, [M(HL)(BDC)0.5X] n (HL = 4′-(4-hydroxyphenyl)-4,2′:6′,4″-terpyridine, BDC = terephthalate, M = Cd, X = Cl for (1), M = Cd, X = formate for (2), and M = Co, X = formate for (3)), were solvothermally synthesized, and used as photocatalysts for Pt-assisted visible-light-initiated hydrogen evolution from water splitting. These water-durable frameworks exhibit varied hydrogen production rates of 361.2, 271.3, and 327.5 μmol · g−1 · h−1 in 12 h due to their slightly different donor environments of the octahedral CdII and CoII ions. Further experimental and theoretical investigations reveal that the metal ions and the local coordination surroundings have essentially dominated the conduction band minimum and electric resistance of the charge transport, which play highly important roles for the improved catalytic hydrogen evolution ability. These findings demonstrate the electronic effect of the slightly ligand field modifications on the boosting hydrogen generation activity in the noble metal-assisted MOF photocatalytic systems.

Nowadays, the collection of electrical energy measurement data is mainly completed by smart meters, electrical energy data monitoring equipment and electrical energy data management equipment. Due to system defects, equipment failures and human factors, it is prone to abnormal data collection. The design concept of online early warning system for extracting abnormal features of electrical energy data based on multi- node real-time computing framework is proposed in the paper to analyze the hardware and software of the online early warning system for extracting abnormal features of electrical energy data.

By applying the first principles calculations combined with density functional theory (DFT), this study explored the optical properties, electronic structure, and structure stability of triangular borophene decorated chemically, B3 X (X = F, Cl) in a systematical manner. As revealed from the results of formation energy, phonon dispersion, and molecular dynamics simulation study, all the borophene decorated chemically were superior and able to be fabricated. In the present study, triangular borophene was reported to be converted into Dirac-like materials when functionalized by F and Cl exhibiting narrow direct band gaps as 0.19 eV and 0.17 eV, separately. Significant light absorption was assessed in the visible light and ultraviolet region. According the mentioned findings, these two-dimensional (2D) materials show large and wide promising applications for future nanoelectronics and optoelectronics.

Ali in Tibet, 5100 m above sea level, is one of the most suitable locations in the world for infrared spectral observations. The atmospheric transmittances at Ali Observatory and Mauna Kea Observatory were calculated by MODTRAN using radiosonde data. The results were 0.848 and 0.789 respectively which indicated better conditions at Ali Observatory. A self-made instrument with a 320×256-pixel HgCdTe infrared focal plane array and a 7.5-cm diameter telescope was utilized for the actual measurements. Without the help of standard stars, the on-site and real-time atmospheric transmittance can be obtained as 0.831 by fitting the relation between the measured atmospheric radiation intensity and the zenith angle based on radiation transfer equations. This paper firstly reports the atmospheric transmittance in the M’ band (4.605–4.755 μm) at the 5100 m-altitude Ali observatory by actual measurement. It shows that the high-altitude Ali observatory with sufficiently low water vapor content is suitable for observation in the mid-infrared bands.

Aiming at the problems and shortcomings of the current electronic intelligence reconnaissance system effectiveness evaluation methods, an ELINT system effectiveness evaluation algorithm based on grey correlation optimization algorithm is proposed. The algorithm firstly combines the principle of ELINT system to build its evaluation index system. Then, based on the subjective and objective attributes of the index, the algorithm combines the G1 sequence subjective weighting method with the CRITIC objective weighting method to obtain the combined weight of each index. Finally, the improved gray correlation optimization algorithm model is used to analyze the correlation of the index value of the system under test, and the system performance is determined by comparing each distance with the optimal system. Theoretical analysis and simulation results show that the method effectively combines qualitative and quantitative analysis and is feasible in the performance evaluation of ELINT system.