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Performance of gear transmissions affects the performance of mechanical equipment. It is necessary to develop more reliable gear pitch and tooth thickness accuracy detection methods in order to evaluate gear transmission performance and detect gear pitch and tooth thickness accuracy more accurately. Based on the basic theory of gears, binocular vision technology, and statistical principles, a new method that measures gear pitch and tooth thickness using machine vision is proposed: coaxial multi-ring detection (MCD). There is no contact, no damage, and a high degree of efficiency with this method. Using this method, we are able to detect the pitch and thickness accuracy of each gear tooth multiple times within the tooth width range and in multiple directions perpendicular to the gear axis. We statistically analyze the measurement results to determine the gear's most accurate detection results. The measurement method for gear machining accuracy is investigated using the coaxial multi-ring detection method. The statistical analysis of multiple measurement results is carried out, and the measurement results obtained are highly consistent with those of the gear detection center. In conclusion, the measurement results of this method are highly reliable, and they can be used as a reliable basis for evaluating gear transmission performance. [ABSTRACT FROM AUTHOR]

HY-2C is the third satellite in China's ocean dynamic environment satellite series, and carries a correction microwave radiometer (CMR) to correct the wet tropospheric path delay for the aligned radar altimeter. To effectively use the brightness temperatures (TB) of CMR to retrieve path delay, an on-orbit calibration effort is required. In this study, an antenna pattern correction (APC) method and a neural network method are used to perform an on-orbit calibration for CMR's antenna temperatures and a model based on the Whale Optimization Algorithm (WOA), Levenberg–Marquardt (LM) algorithm, and Back-Propagation neural network (WOA–LM–BP) has been proposed to retrieve the wet tropospheric correction (WTC) of CMR. The on-orbit calibration results, compared with the simulated brightness temperatures calculated by the radiative transfer model (RTM), have shown that compared with the APC method, the neural network method can almost eliminate the latitude variation, and the total bias and standard deviation of the on-orbit calibrated TB at all channels have obviously decreased. The retrieved WTC results also have shown that the retrieved WTC of CMR has a good agreement with the corresponding ones from the model-derived WTC and Jason-3. [ABSTRACT FROM AUTHOR]

The Calibration Microwave Radiometer (CMR) is a three-band radiometer deployed on the HY-2C satellite in a near-Earth orbit, and since it launched, there are few studies presented on the performance of CMR to date. Therefore, this paper focuses on providing an assessment of HY-2C CMR brightness temperature and wet troposphere correction (WTC). CMR works at 18.7 GHz, 23.8 GHz and 37 GHz in a nadir-viewing direction, aligned with the HY-2C radar altimeter. The wet troposphere path delay of the radar altimeter signal caused by water vapour and cloud liquid water content can be monitored and corrected by CMR. In this paper, guided by the concept of antenna pattern correction algorithm and a purely statistical method, we directly establish the function between the CMR antenna temperature and the model-derived WTC calculated by the European Centre from Medium-Range Weather Forecasting (ECMWF) Reanalysis data, which can obtain the brightness temperature and the WTC of CMR simultaneously. Firstly, the algorithm principle of CMR to establish the function between the antenna temperature and the model-derived WTC is introduced, and then the brightness temperature of CMR is evaluated using reference brightness temperatures of the Advanced Microwave Radiometer 2 (AMR-2) on Jason-3 satellite at crossover points. Furthermore, the performance of the CMR WTC is validated in three ways: (1) directly comparing with the colocated WTC measured by Jason-3 AMR-2, (2) directly comparing with model-derived WTC from ECMWF, which allows a rapid check at a global scale, (3) comparing the standard deviation of the Sea Surface Height (SSH) difference at crossover points using different WTC retrieval methods. The linear fit with Jason-3 brightness temperature and WTC in all non-precipitation conditions demonstrated a good agreement with Jason-3. In addition, the WTC of CMR has an obvious decrease in the standard deviation of the SSH difference compared with model-derived WTC, indicating the CMR can significantly improve the accuracy of the HY-2C SSH measurements. All the assessments indicate that the CMR performances are satisfying the expectations and fulfilling the mission requirements. [ABSTRACT FROM AUTHOR]

Straight bevel gears are widely used in mining equipment, ships, heavy industrial equipment, and other fields due to their high capacity and robust transmission. Accurate measurements are essential in order to determine the quality of bevel gears. We propose a method for measuring the accuracy of the top surface profile of the straight bevel gear teeth based on binocular visual technology, computer graphics, error theory, and statistical calculations. In our method, multiple measurement circles are established at equal intervals from the small end of the top surface of the gear tooth to the large end, and the coordinates of the intersection points of these circles with the tooth top edge lines of the gear teeth are extracted. The coordinates of these intersections are fitted to the top surface of the tooth based on NURBS surface theory. The surface profile error between the fitted top surface of the tooth and the designed surface is measured and determined based on the product use requirements, and if this is less than a given threshold, the product is acceptable. With a module of 5 and an eight-level precision, such as the straight bevel gear, the minimum surface profile error measured was −0.0026 mm. These results demonstrate that our method can be used to measure surface profile errors in the straight bevel gears, which will broaden the field of in-depth measurements for the straight bevel gears. [ABSTRACT FROM AUTHOR]

Ceramic adhesive structures have been increasingly used in aerospace applications. However, the peaks of the signal on the upper and lower surface of the adhesive layer are difficult to measure directly due to the thin thickness of the adhesive layer and the effect of the attenuation dispersion of the ceramic layer. Thus, the existing non-destructive testing techniques have been ineffective in detecting adhesive quality. In this paper, the thickness of the adhesive layer is measured using terahertz time-domain spectroscopy. A sparse deconvolution method is proposed for the terahertz time-domain spectral signal of ceramic adhesive structures with different adhesive layer thicknesses. The results show that the methods proposed in this paper can realize the separation of reflection signals for glue layers with a thickness of 0.20 mm. By comparing with a wavelet denoising method and a modified covariance method (AR/MCM), the effectiveness of the sparse deconvolution method in estimating the thickness of the glue layer is demonstrated. This work will provide the theoretical and experimental basis for using terahertz time-domain spectroscopy to detect the homogeneity of ceramic adhesive structures. [ABSTRACT FROM AUTHOR]

Wind is one of the major processes modifying the land surface in the Hami Basin, as evidenced by wind deflation gravel lags, yardangs, and gravel mantled eolian ripples. We report erosion rates for the Hami Basin using cosmogenic 10Be measurements. Bedrock erosion rates average 0.121 ± 0.0293 mm yr−1, which is similar to those of other wind‐eroded arid basins in East Asia, but is anomalously low when modern near‐surface wind speeds are considered. We posit that interglacial periods experienced lower erosion rates than glacial periods, and that the Hami Basin was likely once a larger dust producer than at present, with Pleistocene dust emissions driven by the eolian deflation of alluvial terrace deposits as well as bedrock weathering and abrasion. Wind erosion and dust production in the Hami Basin was largely regulated by the synoptically controlled spatial‐temporal distribution of precipitation and subsequent landscape evolution since at least the late Pleistocene. Plain Language Summary: The Hami Basin in Xinjiang, China is in the core of the >3 × 106 km2 arid to hyperarid dust generating corridor of the eastern Eurasian continental interior. Quantifying the wind abrasion of bedrock on long timescales, while challenging, is necessary to understand landscape evolution. Based on cosmogenic 10Be measurements of wind eroded bedrock features (i.e., yardangs) in the Hami Basin, we provide the first quantitative evaluation of bedrock erosion in the stony Hami Basin over the last ∼20 thousand years. Incorporating previous work with our erosion rates, the results indicate that wind erosion rates are lower now than over multiple previous glacial‐interglacial cycles in the Hami Basin. Key Points: Wind erosion rates in the Hami Basin were determined to be ∼0.121 mm yr−1 for the last ∼11–23 ky using cosmogenic 10Be measurementsInterglacial periods likely experienced lower erosion rates than glacial periods due to changes in atmospheric conditionsWind erosion and dust production were regulated by climate and landscape evolution since the late Pleistocene in the Hami Basin [ABSTRACT FROM AUTHOR]

Due to the mismatch of thermal expansion coefficients and effective moduli between fibers and matrix materials, local stress concentrations arise in composites during the curing process from the high preparation temperature to room temperature. To evaluate the effect of thermal residual stresses on local stress distributions in composites, a high-precision microscale model is established in this paper. The numerical results obtained indicate that the thermal residual stresses cannot give rise to plastic strains in the matrix. [ABSTRACT FROM AUTHOR]

In order to explore the tensile properties of VCM deep drawing steel plate and its relationship with constituent materials, ABAQUS finite element method was used to conduct numerical simulation of VCM deep drawing steel plate and its constituent materials, and the relevant mechanical parameters (tensile strength, upper yield strength, fracture strain and elongation after fracture) were compared and analyzed. The influence coefficient of steel plate substrate and VCM film on the mechanical properties of VCM deep drawing steel plate was introduced. The results showed that the strength and plasticity of VCM deep drawing steel plate were improved compared with that of steel plate substrate after the VCM film was bonded on the substrate surface. The steel plate substrate had a great influence on the tensile strength and upper yield strength of VCM deep drawing steel plate, and the VCM film had a great influence on the fracture strain and elongation after fracture of VCM deep drawing steel plate, that was, the steel plate substrate had a great influence on the strength of VCM deep drawing steel plate, and the VCM film had a great influence on the plasticity and ductility of VCM deep drawing steel plate. [ABSTRACT FROM AUTHOR]

Aims: Some studies investigated the association between nestin and the overall survival (OS) of nonsmall cell lung cancer (NSCLC). However, the results were conflicted and inconclusive. Therefore, we performed this meta-analysis to determine the association between nestin and OS of NSCLC.Materials and Methods: PubMed and EMBASE were searched to find relevant studies. The strength of the association was calculated with the hazard ratios (HRs) and respective 95% confidence intervals (CIs).Results: High expression of nestin was significantly associated with OS of NSCLC (HR = 2.09; 95% CI = 1.59-2.77). In the stratified analysis by race, we found that the expression of nestin was significantly associated with OS of NSCLC in Asians (HR = 3.02; 95% CI = 1.80-5.07) and Caucasians (HR = 1.81; 95% CI = 1.21-2.71). In addition, when we limited the meta-analysis to studies that controlled for clinical parameters, a significant association between nestin and OS of NSCLC remained (HR = 2.19; 95% CI = 1.54-3.11). A sensitivity analysis showed no substantial modification of the estimates after exclusion of individual studies.Conclusions: In conclusion, this meta-analysis suggested that high expression of nestin was significantly associated with OS of NSCLC. [ABSTRACT FROM AUTHOR]

In this paper, a high efficiency and high power 165–180 GHz balanced doubler based on the planar Schottky diode is presented. To maximize the efficiency of the doubler in the target frequency band, an in-band embedded impedance optimization method (IEIOM) is adopted. The method aims to extract the conjugate value of embedded impedances of the three-dimensional electromagnetic (3D-EM) model of the diode. Compared to the method of impedance optimization at a single frequency point using Load-Pull, the proposed method not only takes account for both conversion efficiency and bandwidth but also simplifies operation process. To verify the proposed concept, the doubler was fabricated and measured, which exhibits a conversion efficiency of 13%–46% at the 165–180 GHz band under 160–200 mW input power and a 90.88 mW peak output power with a 46% efficiency was measured at 178 GHz when the input power is 198 mW. [ABSTRACT FROM AUTHOR]

A three-dimensional (3D) digital image correlation (DIC) method is presented for measuring the deformations of vinyl chloride-coated metal (VCM) multilayer sheets and their composites. The calculations and the principle of strain and deformation measurements using the DIC method are described. A VCM multilayer sheet consists of a substrate [steel plate cold commercial (SPCC) and steel plate cold elongation (SPCE)] and a clad (a VCM film). The corresponding deformations of VCM deep-drawing multilayer sheets (SPCE as a substrate and a VCM film as a clad), VCM nondeep-drawing multilayer sheets (SPCC as a substrate and a VCM film as a clad), nondeep-drawing substrates (SPCC), deep-drawing substrates (SPCE) and clads (VCM films) were captured along the x- and y-directions in uniaxial tension experiments and using the DIC method. The maximal measured strains along the x-direction for the VCM deep-drawing multilayer sheets, VCM nondeep-drawing multilayer sheets, nondeep-drawing substrates, deep-drawing substrates and clads were, respectively, 637.835%, 132.210%, 31.688.632%, 107.102%, and 118.937%. The maximal measured strains along the y -direction were 739.028%, −11.174%, −9.678%, −13.273% and 12.120%, respectively. These data show that the mechanical properties of VCM multilayer sheets are better than those of their substrates and clads. The effectiveness and accuracy of the presented DIC method for VCM multilayer sheet measurements were confirmed in a series of experiments. [ABSTRACT FROM AUTHOR]

The paper applies dual BIE with crack opening displacements for the calculation of stress intensity factors of a 3D crack. A general transformation is introduced to remove the weak singularity no matter where the source point is located. A singular integration element is subdivided into several quadrilaterals and triangles with fine shapes to ensure the high accuracy of singular integrals. Two types of special crack front elements based on the quadrilateral discontinuous element are proposed to model the distribution of displacements in the vicinity of the crack tips. Results of our method are in very good agreement with the existing results. [ABSTRACT FROM AUTHOR]

A novel 3D optical method for measuring and evaluating the springback in sheet metal forming is presented and its principle, program and steps are studied. The optical method includes a measuring method and evaluation indexes. The point cloud, obtained using photogrammetry and surface scanning systems, is used as the workpiece shape after springback. The original mould is regarded as the CAD model before springback. The point cloud and CAD model are aligned in Geomagic Qualify. A cutting line for the point cloud or CAD model can be obtained at any point in any direction of their cross sections. The springback is calculated as the difference between any two corresponding key points on the two cutting lines. The evaluation index S consists of a 3D springback value w and its vectors along x , y and z directions. Feasibility of the optical method is verified by using a refrigerator door shell. [ABSTRACT FROM AUTHOR]

The atmospheric correction microwave radiometer (ACMR) is one of the main payloads for correcting atmospheric path delay in the radar altimeter on the Haiyang-2A (HY-2A) satellite. The ACMR is a three-band microwave radiometer operating at 18.7, 23.8, and 37.0 GHz. Calibration of the ACMR is important for applying its measurements to correct for atmospheric effects on the HY-2A altimeter signal transmission in the air. Therefore, a detailed introduction to the principles and specifications of the ACMR system is given first. The thermal vacuum calibration method of the ACMR is discussed and analysed, and the microwave transfer functions and related coefficients are given, especially the nonlinear coefficients derived from a test for correcting nonlinear responses between the input of antenna temperature and the output of voltage at each channel of the ACMR. Furthermore, antenna pattern correction algorithms for removing the effects of side lobe and cross-polarization are derived and their coefficients are used for in-orbit data processing. Primary calibration results are given by comparing with the similar spaceborne Jason microwave radiometer (JMR) on the Jason-1 satellite and with the advanced microwave radiometer (AMR) on Jason-2. The results of this comparison show that the data from the ACMR match well to those from the JMR and AMR. [ABSTRACT FROM AUTHOR]

Summary This paper proposes a high‐power solid‐state power combining frequency multiplier source based on a waveguide magic‐T divider. The magic‐T has the merits of high isolation and reliability compared to conventional Y/T junction power dividers and wider bandwidth compared to 3 dB couplers. In the waveguide magic‐T, a two‐stage cuboid ridge is employed to reduce the difference‐port reflection and act as a matching element for the improved isolation port. Furthermore, two bent waveguides are connected with the output port of the magic‐T, which can achieve phase congruence. The reliability of the solid‐state power combining multiplier can be enhanced by this low‐loss, high‐isolation power divider. Moreover, the divider also facilitates the realization of a high‐power frequency multiplier. Measured results show that the multiplier has a maximum output power of 90.3 mW at 178 GHz with an input power of 448 mW. [ABSTRACT FROM AUTHOR]

Unconsolidated gravel surfaces, alluvial terraces, and yardangs are widespread in the Turpan-Hami topographical depression of NW China. These landscape features provide an opportunity to investigate the wind erosion history and landscape evolution of the Hami Basin. Along with anomalously high near-surface wind speeds, these features suggest that the Hami Basin was an important source of mineral dust during the Pleistocene. We present the results of an integrated geomorphologic, stratigraphic, and chronologic study on the genesis of unconsolidated gravel surfaces and yardang fields in the Hami Basin. Mobilization of silt- to sand-sized fractions from the surfaces of the Quaternary alluvial sediments occurred under generally dry conditions, leaving unconsolidated gravels to organize into inflationary-type desert pavement surfaces (Type-1) and deflationary-type desert pavements surfaces (Type-2). We propose that the Pleistocene alluvial terraces of the Hami Basin formed principally during wetter intervals, which are assumed to correspond with interglacial periods. The coarse-grained alluvium atop terraces protected underlying strata from wind erosion. The bedrock then began to be sculpted into yardangs after the removal of the coarse-grained armoring surfaces. With mostly sub-horizontal bedding, the geometries of yardangs was controlled by lithology, wind and water erosion. Based on UAV-3D models, optically-stimulated luminescence (OSL) and electron spin resonance (ESR) ages, we find an erosion rate of ~0.23 mm/yr since ~200 ka, This, combined with widespread uneroded strata armored by unconsolidated gravel surfaces, indicates that the Hami Basin had considerable dust emission potential in the past. • An integrated geomorphologic, stratigraphic and chronologic study on gravel surfaces. • Geometries and factors controlling yardang fields in deeply wind eroded strata. • Late Quaternary fluvial-eolian landscape evolution model for the Hami Basin. • A dust emission potential for the Hami Basin during the late Pleistocene. [ABSTRACT FROM AUTHOR]

With the arrival of 5G networks, cellular networks are moving in the direction of diversified, broadband, integrated, and intelligent networks. At the same time, the popularity of various smart terminals has led to an explosive growth in cellular traffic. Accurate network traffic prediction has become an important part of cellular network intelligence. In this context, this paper proposes a deep learning method for space-time modeling and prediction of cellular network communication traffic. First, we analyze the temporal and spatial characteristics of cellular network traffic from Telecom Italia. On this basis, we propose a hybrid spatiotemporal network (HSTNet), which is a deep learning method that uses convolutional neural networks to capture the spatiotemporal characteristics of communication traffic. This work adds deformable convolution to the convolution model to improve predictive performance. The time attribute is introduced as auxiliary information. An attention mechanism based on historical data for weight adjustment is proposed to improve the robustness of the module. We use the dataset of Telecom Italia to evaluate the performance of the proposed model. Experimental results show that compared with the existing statistics methods and machine learning algorithms, HSTNet significantly improved the prediction accuracy based on MAE and RMSE. [ABSTRACT FROM AUTHOR]

In this paper, a grey prediction model group is employed to quantitatively study the impact of COVID‐19 on natural gas consumption in Chongqing, China. First, a grey prediction model group suitable for the prediction of Chongqing's natural gas consumption is introduced, which consists of GM(1,1), TWGM(1,1), and the newly‐developed ODGM(1,1). Then, the model group is constructed to predict Chongqing's natural gas consumption in 2020. Finally, compare the predicted results of the model group with the actual consumption and quantitatively analyze the impact of the epidemic on natural gas in Chongqing. It is found that the impact of the epidemic on the consumption of natural gas in the first quarter of the year is very small, but relatively bigger in the second and third quarters. The study is of positive significance to maintain the supply and demand balance of natural gas consumption in Chongqing in the background of COVID‐19; and it enriches and develops the theoretical system of grey prediction models. [ABSTRACT FROM AUTHOR]

• Prediction of the effective thermal conductivity of the composite material. • Establishing representative numerical simulation models at multiple scales. • Heat transfer under the condition of conduction & radiation. • Effects of the porosity and fiber volume fraction on the effective thermal conductivity of the composite materials. Composite materials are widely used in the fields of aviation and space, where their thermal properties are of importance since they are often challenged by variations of environmental temperatures. However, thermal properties of composite materials under conditions of conduction & radiation (a key mode of heat transfer in space) remain elusive. In order to address this issue, in this study, numerical simulations of the glass/polyimide composite materials were conducted to determine its effective thermal conductivity under the conduction condition with and without radiation. More specifically, unit cell models of polyimide matrix, glass-fiber yarns, and the composite materials were constructed sequentially to study the effects of the porosity and the fiber volume fraction on the effective thermal conductivities of the composite materials. Simulation results revealed that 1) an increase in porosity can reduce the effective thermal conductivity of the polyimide matrix with the maximal decreasing ratio of 39.5%; 2) an increase in fiber volume fraction can increase the transverse effective thermal conductivity of the glass-fiber yarns with the maximal increasing ratio of 49.0%; 3) differences of 26.0% and 27.6% of the in-plane and out-of-plane effective thermal conductivities of the composite materials were located under the conduction condition with and without radiation. This study provided a simulation approach to investigate thermal properties of composite materials, paving ways for their applications in the fields of aviation and space. [Display omitted] [ABSTRACT FROM AUTHOR]

Chang'e-5 (CE-5) mission is expected to land and sample in the Rümker region, north of the Oceanus Procellarum. To select optimal sampling points, the microwave radiation features in this mare unit are analyzed, and the dielectric constant and thickness of lunar regolith are retrieved based on Chang'e lunar microwave sounder (CELMS) data. According to the microwave brightness temperature (TB) maps, TB varying with frequency at noon and midnight are different, in which noon TB increases with frequency, but midnight TB does not follow this rule. Moreover, there are differences among TB distributions at the three higher frequencies, especially in the southern part. In addition, a great TB difference between noon and midnight can be seen in Rümker E that shows higher daytime temperature but lower nighttime temperature The inversion results reveal that the dielectric constant is lower in the west and north, higher in the middle and east, and the largest value occurs in Rümker E. As for the regolith thickness, most areas are uniform and no more than 4 m, with the thickest and thinnest regolith appearing in the northwest and Rümker E, no less than 6 m and about 2.5 m, respectively. Considering the safety and operability of landing and sampling, the northwest with thick regolith is recommended, while the Rümker E should be eluded. [ABSTRACT FROM AUTHOR]

Dust plays an important role in climate, and while our current representation of dust production includes shifts in vegetation, soil moisture, and ice cover, it does not account for the role of landscape evolution. Here, we use the Weather Research and Forecasting model coupled to an aerosol chemistry model to quantify the effects of arid landscape evolution on boundary layer conditions, dust production, and radiative properties in the Hami Basin, China, a dynamic stony desert in eastern Asia. Relative to today, altered surface roughness, sediment erodibility, and albedo combine to produce up to a ~44% increase in wind speeds (mean ≈ 15%), up to a ~59% increase in dust loading (mean ≈ 30%), and up to a ~4.4 W m−2 increase in downwelling radiation (mean ≈ 2.4 W m−2) over the Hami Basin. Our modeling results, along with geomorphological data for the western Gobi Desert, provide evidence that stony deserts acted as important Plio‐Pleistocene dust sources. Plain Language Summary: Dust from the breakdown of rocks and minerals plays an important role in Earth's atmosphere by absorbing or scattering incoming solar radiation, and by seeding clouds. Once deposited, iron‐rich dust can fertilize surface ocean waters and terrestrial soils for the growth of organisms, making dust important in the global carbon cycle. Because of its role in modifying Earth's climate, we must accurately understand ancient dust production. To test the hypothesis that past changes in dust production impacted climate, we altered the surface properties of the western Gobi Desert, a location that had a very different landscape thousands to millions of years ago, and simulated changes in wind and dust using a regional climate model. We found that this area would have experienced increased wind speeds by up to ~40%, increased dust loading by up to ~60%, and substantially altered incoming solar radiation in response to land surface evolution. Key Points: In arid regions, consideration of landscape evolution is necessary to accurately reconstruct dust production and regional climateWe use a regional climate model to quantify the effect of arid landscape evolution on dust production in the Hami Basin, ChinaRepresentative Plio‐Pleistocene surface conditions lead to enhanced winds and dust production in the Hami Basin relative to today [ABSTRACT FROM AUTHOR]

• A kernel separation method is proposed to compute the singular integral accurately. • Four singular integrals with different ordered kernel are computed directly with the help of the kernel separation method. • A patch subdivision scheme is developed based on the relation between the product of wave velocity, time and the distance. In the implementation of time-domain boundary element method for elasto-dynamic problems, there are two types of singularities: the wave front singularity arising when the product of wave velocity and time is equal to the distance between the source point and the field point, and the spatial singularity arising when the source point coincides with the field point. In this paper, the singularity of the first type in the integrand is eliminated by an analytical integration over time, Cauchy principal value and Hadamard finite part integral. Four types of singularities with different orders appear in the integrand after analytical time integration. In order to accurately calculate the integral, in which the integrand is piecewise continuous, the integral domain is subdivided into several patches based on the relation between the product of wave velocity and time and the distance. In singular patches, the integrands are separated into a regular part and a singular part. The regular part can be computed by traditional numerical integration method such as Gaussian integration, while the singular part can be analytically integrated. Using the proposed method, the spatial singular integrals can be calculated directly. Numerical examples using various kinds of elements are presented to verify the proposed method. [ABSTRACT FROM AUTHOR]

Iron-based soft magnetic composites insulated with parylene C film were prepared via chemical vapor deposition polymerization, and their morphologies, magnetic properties, and corrosive resistance were investigated. Scanning electron microscopy and Fourier transform infrared spectrum confirmed that the surface of the iron particle was completely uniform insulated with parylene C, resulting in reducing the core loss of the synthetic compacts. The results show that compressed pressure has an important influence on the magnetic properties of the soft magnetic composites, enhance the magnetic induction value from 0.64 to 1.01 T and is obtained with increased the compressed pressure from 300 to 650 MPa. The loss separation results show that the hysteresis loss coefficient of 4 wt% parylene C insulated samples decreased from 1.743 to 1.657 and eddy current loss coefficient decreased from 0.019 to 0.012 as compared with uncoated compacts under the same compress pressure. The acid and salt corrosion resistance of the iron particles is apparently enhanced when the chemically stable parylene C layer was exited in the surface. [ABSTRACT FROM AUTHOR]

To balance the supply and demand in China's beef market, beef consumption must be scientifically and effectively forecasted. Beef consumption is affected by many factors and is characterized by gray uncertainty. Therefore, gray theory can be used to forecast the beef consumption, In this paper, the structural defects and unreasonable parameter design of the traditional gray model are analyzed. Then, a new gray model termed, EGM(1,1,r), is built, and the modeling conditions and error checking methods of EGM(1,1,r) are studied. Then, EGM(1,1,r) is used to simulate and forecast China’s beef consumption. The results show that both the simulation and prediction precisions of the new model are better than those of other gray models. Finally, the new model is used to forecast China’s beef consumption for the period from 2019–2025. The findings will serve as an important reference for the Chinese government in formulating policies to ensure the balance between the supply and demand for Chinese beef. [ABSTRACT FROM AUTHOR]

This study presents a design of a tri-band dual polarisation common aperture feed horn used for the radiometer. The proposed feeding system is made up of a corrugated horn, an orthomode transducer (OMT) and two pairs of a high-pass filter (HPF) and a band-pass filter (BPF). The broadband profiled corrugated horn loaded with teeth (rings) is adopted as the feed of the radiometer. Wideband finline OMT is developed to realise a bandwidth ratio in excess of 2:1. Two different HPFs and BPFs are employed to block and pass waves of different frequencies. The feeding structure is then simulated, fabricated and tested. The measured results show that the radiation patterns possess good symmetry at all three working frequencies of interest (18.7, 23.8 and 37 GHz). Furthermore, the cross-polarisation levels are below -23 dB and voltage standing-wave ratios are lower than 1.5 throughout all working bands. [ABSTRACT FROM AUTHOR]

Iron-based soft magnetic composites with silicone resin coating have been designed to reduce the core loss and improve the magnetic properties of cores. The silicone resin serving as electrical insulating layer was modified by 3-glycidoxypropyltrimethoxy silane, and the effect of silicone resin content, coupling agent, annealing treatment, and thermal cycling on the magnetic properties of composites was investigated in the frequency range from DC to 150 kHz. The coated silicone resin insulating layer was characterized by scanning electron microscopy and energy dispersive spectroscopy. The results showed that the optimum coating content of silicone resin to attain the acceptable permeability and the minimum magnetic loss for the prepared composites is 4 wt%. The sample with silicone resin coat exhibited better DC-bias superposition characteristics compared to the uncoated sample, 6 wt% silicone resin coating sample have excellent percentage effective permeability (84.8%) under 50 Oe applied field. AC magnetic properties evaluated at 1 and 100 kHz do not vary with a 95% confidence interval with the number of thermal cycles; therefore, the properties of the silicone resin-insulating composites are stable under thermal cycling. [ABSTRACT FROM AUTHOR]

To support the microwave brightness data retrieval of future China space-borne lunar exploration microwave radiometer, based on the collection of plentiful terrestrial basalts and anorthosites and their chemical compositions got by X-ray fluorescence, nine lunar soil simulators were prepared and made respectively into 0.8, 1.0, 1.2, 1.4 and 1.6 g/cm³ five densities each. We measured their relative dielectric constants over the range of 0.5–20 GHz with open-ended coaxial line model on the HP8722C Network Analyzer and then processed and analyzed the measurement data. This study shows that among the three parameters of density, frequency and composition, density has the strongest effect on the relative dielectric constants, frequency comes second, composition the least. The three parameters account for 45%, 33% and 22% respectively of the changed real part of a relative dielectric constant, and 55%, 27% and 19% respectively of the changed imaginary part. The real parts of the relative dielectric constants are linearly linearly correlated with density or frequency, and the imaginary parts have a linear relation with both approximately over the range of 0.5–10 GHz and tend to be poorly correlated with them in 10–20 GHz. The effect of composition on a relative dielectric constant seems very complicated, both probably do not follow a simple function relation, with the least correlation. Multiple regression analysis indicates that major element oxides SiO2, Al2O3, CaO, MgO, TiO2 and ΔFe are correspondent to a one-order polynomial, and TiO2 or ΔFe or TiO2+ΔFe has not been proven to be the indicators in the contribution to the relative dielectric constants. [ABSTRACT FROM AUTHOR]