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In this paper, a compact and low-profile beam steering circularly polarized folded reflectarray antenna (CPFRA) with low scan loss for wide-angle coverage is proposed and designed. In order to obtain lower scan loss over a wider beam coverage range (BCR), a multibeam optimization method considering the illumination weighting factor is introduced to obtain minimum phase errors for the designed beam direction. To improve antenna compactness and alleviate the mutual couplings among multiple feeding sources, small-size substrate integrated waveguide (SIW) cavity-backed slot antennas are employed as the feeding sources, which are integrated with the single-layer reflector board. An incident angle insensitive circular polarizer is designed and integrated over the antenna aperture to achieve circularly polarized (CP) radiation over a wide BCR. At last, a 15-beam CPFRA working at Ka-band, with size 140 mm × 140 mm is designed, manufactured, and measured to validate the proposed design method. Measurement results show that the designed CPFRA can achieve a rather flat gain, with only a 2.1 dB scan loss, across the wide 3-dB BCR of ±29°. The good CP beams are formed over the entire coverage range without any blind zone. With the advantages of wide-angle coverage, low scan loss, and high integration, the proposed beam steering antenna is promising in applications such as 5G communication, radar imaging, and target recognition.

In this paper, a low-profile folded reflectarray (FRA) assembled by an anisotropic metasurface is proposed to generate high-efficiency and broadband orbital angular momentum (OAM) vortex waves in the Ka band. In order to suppress the mutual coupling and increase the polarization conversion efficiency, a dual-polarization phase matching method (DPPMM) for helical wavefront construction is developed to achieve minimum phase compensation error in the orthogonal direction. A compact subwavelength anisotropic meta-atom with orthogonal $|\big | |$ -shaped structure is designed to achieve flexible wavefront manipulation and high-resolution phase compensation for ${x}$ and ${y}$ -polarization incident waves. After the optimization design, nearly 100% cross-polarization conversion efficiency for the anisotropic metasurface can be achieved at the working frequency of 12 GHz. To validate the proposed design method, an OAM FRA with $24\times24$ meta-atoms is fabricated and measured. The measurement results show that the aperture efficiency of the proposed FRA carried with the OAM mode ${l} = 1$ is significantly improved and reaches 20.2%. Moreover, the OAM bandwidth and 3-dB gain bandwidth reach 22.5% and 25%, respectively.

In this article, an automatic and forward method is realized to establish attributed scattering center models directly from the computer-aided design (CAD) model of the complex target. The main steps include the preprocessing of the CAD model, the separation of scattering sources, the selection of strong scattering sources, and the automatic determination of model parameters. With the proposed method, the scattering sources, scattering mechanisms, and model parameters of the scattering centers can be identified and derived, such that the complicated manual intervention is completely avoided. Moreover, the method establishes the distributed scattering center models formed by curved surfaces with large curvature radii. Therefore, the formation mechanism of the distributed scattering center is extended from typical scattering structures to a general case. Thus, the model of the attributed scattering center is extended and can be applied to describe the scattering from the real structures of the complex target. The geometric shape of the scattering source is distinguished based on the principal curvature radii, which are calculated by differential geometry theory. Thus, the frequency dependence parameter is obtained according to its corresponding relationship with the geometric shape. In addition, based on the automatic method, a technology is studied to diagnose and correct the scattering center models of a target whose CAD model is unknown or partially known. Finally, parametric models of several targets in the Moving and Stationary Target Acquisition Recognition (MSTAR) program are established, and then compared with the measured data. The results validate the effectiveness of the proposed method.

A new novel structure is proposed for cellular composite radar absorbing materials, and an equivalent method of electromagnetic scattering for the new material is also proposed for the first time. By covering the target surface with non-uniform medium cellular cell elements horizontally, the scattering characteristics of the coated target show strong surface anisotropy, leaving an imaginary space for optimizing the electromagnetic stealth performance of the coated target. In this paper, the equivalent dielectric tensor of horizontal directional composite honeycomb cell element has been calculated by using the equivalent method of electromagnetic scattering based on strong fluctuation theory (SFT) of anisotropic medium. Under the condition of plane wave irradiation with a frequency of 3 GHz, we use FEKO software to estimate the backscatter field of several typical models coated with this new structure. It has been proved that the strong fluctuation theory applied to the honeycomb composite absorbing material of the structure are effective for calculating the equivalent scattering. Based on the validity of the equivalent results, we further estimate the scattering characteristics of complex targets coated with the novel cellular medium.

Tuberculous peritonitis(TBP)is currently one of the common manifestations of extrapulmonary tuberculosis.Due to the atypical clinical features,diverse types of diseases to be distinguished,and limited detection methods,TBP is difficult to be diagnosed and the fatality caused by delayed diagnosis increases significantly.We studied the current research status of TBP and found that T cells spot test,abdominal CT,and laparoscopic biopsy were of high diagnostic value for TBP.However,the application of ascites Xpert-MTB/RIF-ultra assay,ascites ADA,and whole-body positron emission tomography/computed tomography remained to be studied.Serum CA125 helps to judge the efficacy of anti-tuberculosis treatment.

This paper proposes a fast target indexing method based on target geometric models and further conceives a forward method based coarse-to-fine hierarchical synthetic aperture radar (SAR) automatic target recognition (ATR) system. The proposed fast SAR target indexing method is employed for coarse classification before the implementation of fine classification and recognition, resulting in significant acceleration of target recognition. Furthermore, the fast SAR target indexing method is purely based on target geometric models without resorting to any time-consuming electromagnetic (EM) computation, which enables the online and real-time classification. The binary target region and shadow region are selected as the indexing features, and a forward feature prediction method based on optical visibility is developed to predict the features from the target geometric model in real time. Then, the features extracted from the testing SAR image are aligned with the predicted features to establish correlation ship and a fused similarity based on four types of complementary similarity criteria is designed to further implement target indexing. The effectiveness of the proposed fast SAR target indexing method is demonstrated by using the MSTAR dataset.

A novel forward method to establish the three-dimensional parametric scattering center models is developed to extract scattering centers from the combined target/rough surface models. Both scattering centers from the ship, including single-order and higher order scattering contributions, and from the multiple interactions between the ship and random rough sea surface would be described concisely with physically relevant parameters by this proposed method. Due to the statistical nature of the random rough surface for the Monte Carlo simulation, we acquire a large number of realizations for estimations of the amplitude and position parameters to overcome the problem that single realization cannot extract scattering centers effectively. This method is validated through parametric models of the ship in free space and on the sea surface, and a good agreement has been demonstrated between the constructed and simulated radar characteristics. Furthermore, we analyze the composite target/surface model's physics and feature stability in a visually spatial range and direct connections between scattering centers and scattering sources, which would be valuable to future target recognitions and classifications. Finally, we quantitatively calculate and analyze the coupling scattering centers from interactions between the ship and the ocean-like surface that provide more abundant contour information of the inverse synthetic aperture radar (ISAR) image to facilitate contour detections.

In this paper, we present a novel method that utilizes amplitude-only data of the electric field over a completely closed surface for the reconstruction of the spherical electric field, which represents a radiation source or an antenna under test (AUT) in the near-field (NF) region. The electric field exploiting genetic algorithm (GA) for global optimization is originally derived from a random initial estimate of field distribution and will gradually approximate to the exact value during iterations. When GA reaches the convergence criterion, we can calculate the far field (FF) by spherical NF-to-FF (NF-FF) transformation. The simulated and numerical results are in good agreement with each other, which shows that this method is effective over one or two closed surfaces. Furthermore, the related discussions corresponding to GA are given, confirming that the improved GA is feasible and efficient.

In this paper, we present a novel method that utilizes amplitude-only data of electric field over two hemispheres for the far-field reconstruction above the perfectly electrically conducting (PEC) ground plane by the iterative Fourier transformation algorithm (IFTA).When the IFTA reaches the maximum number of iterations, then we can calculate the far-field (FF) by hemispherical near-filed to far-field (NF-FF) transformation. The simulated and numerical results are in good agreement with each other, which shows that this method works effectively.

In this paper, a dual frequencies and bidirectional functional metasurface is presented. The functional metasurface can achieve bidirectional radiation with dual polarization at different frequencies. By independently adjusting the reflection and transmission phases, the forward and backward beam convergence can be achieved. The simulated results indicate that the gain of reflection beam can reach 24.9 dBi at 9 GHz and the gain of transmission beam can reach 26.1 dBi at 12 GHz, which is at least 13.5 dBi higher than the bare feeder.

Despite of various advantages, transmitarray antennas usually suffer from the limited bandwidth. In this paper, ultra-wideband polarization conversion elements are employed to design ultra-wideband linearly polarization transmitarray antennas. The proposed ultra-wideband transmissive polarization conversion element is a multilayered structure with asymmetric split circular ring structure in the middle layer and orthogonal metal gratings at the outermost layer. The element features ultra-wideband high efficiency transmission capability, a transmission phase coverage of 360° and good phase linearity. By employing the proposed elements, an ultra-wideband linearly polarized transmitarray antenna with dimensions of 180 mm × 180 mm is designed and its highly efficient radiation performance is demonstrated by simulation. The designed transmitarray achieves 3 dB gain bandwidth of 61 %, ranging from 12.83 GHz to 24.09 GHz. The peak simulated gain is 28.13dB at 16.5GHz. In addition, the maximum aperture efficiency of the antenna is 54.13 % and the aperture efficiency is greater than 40% from 12.4 GHz to 18.4 GHz.

We present a design of wideband, single-layer reflectarray antenna by using reflection elements operating in linear cross-polarization scheme. The split ring element can maintain high polarization conversion rate and approximately linearly phase properties at ultra-wide bandwidth. Moreover, the phase and amplitude of cross-polarized reflection can be separately controlled by its split angle and rotation angle, and the phase covers over 360 degrees. Based on these properties of the element, a reflectarray with central frequency at 15 GHz is designed, which has an aperture dimension of $120\ \text{mm} \times 120\ \text{mm}$ and a focal length of 84 mm. And the designed refelctarray antenna is demonstrated to have 3 dB gain bandwidth of 61%, ranging from 10.8 GHz to 20.3 GHz.

Based on target geometric model, this paper proposes a forward approach to establish scattering center models. Different from the conventional inverse approach, which estimates scattering center models from the measured or simulated SAR image, the forward approach clearly describes the formation process of scattering centers by component separation, ray tracing and clustering technologies, and determines the model parameters by forward derivation and calculation.

In this paper, we present a novel method that utilizes amplitude-only data of electric field over semi-closed surface for the reconstruction of the spherical electric field that represents radiation source or an antenna under test (AUT) in the near-field (NF) region above perfectly electrically conducting (PEC) plane. The electric field exploiting genetic algorithm(GA) for global optimization is originally derived from a random initial estimate of field distribution, the electric field will gradually approximate to the exact value during iterations. When GA reach the maximum number of iterations, then we can calculate the far-field (FF) by spherical near-filed to far-field (NF-FF) transformation. The simulated and numerical results are in good agreement with each other, which shows that this method is effective.

With the development of radar stealth technology, electromagnetic scattering has been widely used, and the strong scattering center of military targets has been effectively suppressed by various means. At this time, the secondary scattering becoming more and more important. In this paper, the scattering field of two-dimensional perfect conductive cylinder was studied, and the curved surface diffraction field is mainly investigated. Further more, the parametric model of the curved surface diffraction field is given by function fitting method. Combined with examples, the importance of secondary scattering in high frequency region is demonstrated and the accuracy of the parametric model derived in this paper is verified.

Recent extensions are reported for the evaluation of electromagnetic scattering from electrically large perfect electric conductor target coated with uniaxial electric anisotropic multilayered media. First, the boundary conditions at the interfaces of the stratified anisotropic medium are employed to determine the complex amplitudes of the scattered fields in spectral domain, which involve a complicated coupling of type I and type II waves existing in uniaxial electric anisotropic medium. Then the scattering from the infinite coated substrate is asymptotically calculated by using the proposed spectral domain method combined with saddle point evaluation. Thereafter, the asymptotic solution is applied to derive the physical optics currents on the surface of the target. Ultimately, comparisons of the proposed asymptotic solution with the reference solutions calculated numerically confirm the validity and efficiency of the proposed solution. Employing the asymptotic solution, the evaluation of the scattering from an electrically large target coated with uniaxial electric anisotropic multi-layered media is realized.

The gaseous emissions of stage Ⅲ standard City bus with and without DOC+CDPF after-treatment fueled with biodiesel blends on real road in steady-state and transient conditions were studied using OBS-2200 gaseous portable emission measurement. The results showed that B20 led to a decrease of CO and THC emission rates compared with those of B0. In steady-state condition, CO and THC average mass emission rates of B20 decreased by 26.43% and 10.44% respectively and in transient condition the decrease rates were 22.78% and 4.95%. Meanwhile, B20 eventuated in higher CO

Based on the revolving drum test bench, an experimental study was conducted in heavy-duty diesel vehicle at China Stage Ⅲ with and without DOC+CDPF to investigate the effects of DOC+CDPF on the gaseous and particle emission characteristics under C-WTVC driving cycle. The results showed that from city circulation conditions to high way circulation conditions to high-speed circulation conditions, the CO, THC, CO

In this paper, split ring unit cells are proposed and designed for ultra-wideband RCS reduction. The split ring unit cell converts the incidence wave to its cross-polarization in wide bandwidth, and most importantly, the cross-polarized reflection phase and amplitude can be separately controlled by the cell geometry and rotation angle. Based on the diffuse reflection theory, reflection phase of the proposed split ring unit cells are tailored to form a ultrawide band RCS reduction metasurface. The designed metasurface demonstrate RCS reduction of 10 dB in the range of 8.75 GHz-24.7 GHz.

This paper proposes a forward approach to establish parametric scattering center models for complex dielectric targets. It proposes a space ray diversity method for complex medium targets based on ray splitting tracing method. Based on the high frequency electromagnetic mechanism of complex targets, a method of calculating the equivalent action point of internal coupling action ray is proposed. This solves the problem of the forward calculation of the three-dimensional position parameters of the scattering center. Finally, the decomposition and its quantitative characterization technique of strong scattering source for complex dielectric targets are obtained, and the target scattering center model with complex dielectric has been established with clear and accurate scattering mechanism. This method greatly expands the scope of target application in the forward modeling method of attribute scattering center. Finally, a simplified wing calculation example shows the feasibility and effectiveness of the proposed method.

To better link the scattering center with the target structure, this paper forwardly deduces and analyses the component-level 3-D scattering center position of radar target under the mechanisms of single and double scattering. The ray equivalent position under the double scattering mechanism is especially deduced. This position derivation process is then applied on the models of SLICY and T72 tank to deduce and analyze their scattering center positions. The corresponding measured SAR images are used for contrast to prove the validity of the position derivation.

A new accurate numerical algorithm is presented for creeping ray tracing on the arbitrarily shaped surfaces modeled by the Non-Uniform Rational B-spline (NURBS) surfaces. The main problem in calculating the uniform geometrical theory of diffraction (UTD) surface diffracted fields on NURBS surfaces lies in the difficulty in determining the geodesic paths which the creeping rays propagate along. In this paper, a novel method is developed based on the property of geodesic to compute geodesic paths on NURBS surfaces. Actually a complex object generally needs to be modeled as a combination of several connected NURBS patches. Therefore a transition method is presented to handle the transition of the creeping rays when the rays propagate from one patch to another. The proposed creeping ray tracing algorithm is efficient and accurate for ray tracing on arbitrarily shaped complex shapes. And the algorithm can also extend the applicability of UTD for practical engineering. The validity and efficiency of the algorithm is verified by numerical results.

A method for the calculation of the scattering of the stratified uniaxial electric anisotropic media (UEAM) under point source excitation with arbitrary orientation is presented. In this method, the total field is decomposed into three parts, the radiated field of the point source in free space, the reflected field from the top interface of the UEAM and the transmitted field after multiple reflections in the anisotropic layer. The three parts are derived in spectral domain respectively and can be expressed by using Fourier transform. Then the saddle point technique (SPT) is introduced to obtain an asymptotic solution of the scattered field. Results from the asymptotic solution are compared with the results calculated by the method of moments (MOM) and the comparison shows good agreement.

Model of the film-substrate interface of diamond coatings is built with the method of molecular dynamic, and the molecular dynamic simulation is applied to study the mechanical property of the model based on the Morse potential function and Tersoff potential function with temperature ranging from 0K to 800K. The results show that the adhesive strength of the interface between the diamond coatings and the cemented carbide substrate behaves a downward trend when the temperature rises from 0K to 800K and the downward trend is sharp when the temperature increases from 0K to 300K and the downward trend is smooth when the temperature rises from 300K to 800K. Meanwhile, the varying trend of the energy with the temperature is similar to the adhesive strength.

This paper briefly reviews the overseas and domestic research status of the mechanics of hetero film-substrate interface based on molecular dynamics simulation, on this basis building the accurate model of diamond coatings/WC interface and executing the molecular dynamic simulation, exactly measuring the adhesive strength of the diamond coatings/WC interface, finally exploring the influence of interface scales on the adhesive strength of the diamond coatings/WC interface and verifying the feasibility of studying the microscopic structure by molecular dynamics simulation to characterize the mechanical properties of macrostructure, which has important significance for optimizing deposition process of diamond coatings to improve the adhesive strength of the interface.

Effect of material mix proportion on strength of cement asphalt concrete (CAC) was studied based on 7d cleavage strength. Results indicate that the cleavage strength of CAC increase sharply with the increase of the cement content (0-6%), and the optimum content of added water and emulsified asphalt were 2% and 6% respectively while the cement content was 5%.

Electrolysis is the main method of refined copper smelting. In order to obtain high-quality refined copper, it needs to ensure that the negative plate in the electrolytic cell has a high flatness. The precise straightening device in roller leveler is the last step to ensure the negative plate of high quality flatness. Studying the influence of parameters of precise straightening in roller leveler on the flatness of the negative plate has an important significance. Precise straightening process were simulated in ANSYS/LS-DYNA. The results of simulation were analyzed, on the basis of better meeting the requirements of enterprise, the most reasonable set of matching parameters was chosen to provide a reference for the enterprise designing and studying the roller leveler.

Vertical planetary mill is a kind of efficient grinding equipment. Due to its unique design, the materials can suffer combined effects of squeezing, shearing and grinding. this paper developed the virtual prototype of vertical planetary grinding wheel sand reclamation equipment based on virtual prototyping technology, and did the dynamic simulation with this virtual prototype. It will use ADAMS to do the dynamic simulation, and it can provide reference price for staff.

Objectives The purpose of this study was to evaluate the sonographic and pathologic features of littoral cell angioma of the spleen in 7 patients. Methods The sonographic appearance in 7 cases of littoral cell angioma confirmed by surgical pathologic examination was retrospectively reviewed. All underwent color Doppler imaging. Two underwent contrast-enhanced sonography. The sonographic appearance was compared with pathologic findings. Results Splenic lesions were solitary in 5 cases and multiple in 2 cases. The masses ranged from 10 to 64 mm in maximum diameter. Five hypoechoic and 2 hyperechoic lesions on grayscale sonography corresponded to few and multiple blood-filled spaces on pathologic examination, respectively. Four hypovascular lesions, 1 hypervascular lesion, and the other 2 hypervascular lesions full of color flow signals on color Doppler imaging corresponded to few, several, and multiple arteries on pathologic examination. On contrast-enhanced sonography, 1 hypervascular lesion full of color flow signals showed homogeneous hyperenhancement for 8 minutes during the arterial and parenchymal phases. One hypovascular lesion showed inhomogeneous isoenhancement transiently during the arterial phase and became hypoechoic later. Conclusions Littoral cell angioma is a primary vascular splenic neoplasm with variable features on grayscale sonography and color Doppler imaging as well as contrast-enhanced sonography. The sonographic appearance of littoral cell angioma mainly depends on the type and number of tumor vessels.

At present, due to a multitudes of equipment with intelligence and information have been put into operation in the intelligent substation, the ways of the information interaction are becoming complicated between intelligent devices in the stations. Consequently, the enormous amount of information and complexity of the correlation cause difficulties in data collection, management, analysis and evaluation. On the basis of the above, a method for implementation of high speed data reception and transmission is proposed based on the field programmable gate array (FPGA) in this paper, aimed at the auxiliary analysis of data collection issues in the operation and maintenance of the smart substation. This method uses the PCI-Express bus technology with high-speed serial point-to-point dual-channel high-bandwidth transmission and the Gigabit Ethernet physical layer chip 88E1111 to realize connect function between the optical interface and FPGA bus interface. Meanwhile, with the combination of the secondary generation double data rate synchronous dynamic random access technology and the DMA chaining technology, the full data channel is realized to facilitate the high-speed and real-time acquisition and analysis of data. Finally, the experiment results show that the proposed method is feasible and the performance is excellent.

With the increasing coupling of secondary system components in smart substation, the operation management becomes more and more difficult. This paper proposes a graphical display approach of secondary functional components based on “information-event-function” logics. The displayed layout as well as connection relationship, which is accomplished through automatic graphing, clearly describes the logical order and assists auxiliary analysis. Based on the reasoning of the logics of layout and routing, the automatic graphing accurately describes the functional correlation of the secondary components in a simple and intuitive way. The displayed graph can be further improved by comparing it with the actual functional circuit. Several practical examples are presented to demonstrate the feasibility of the proposed approach.

The high-frequency scattering of an electrically large target can be well approximated as a sum of response from individual scattering centers. The scattering center model can provide a concise and physically relevant description of the target radar signature. We use the attribute scattering center model to represent the targets' high frequency back scattering. In this model, the backscattered field of an individual scattering center is described as a function of frequency and aspect angle, and the total scattered field from a target is then modeled as the sum of these individual scattering centers. It provides a physical description of target scattering centers via a set of parameters. Based on the limited observation data, the problems about scattering centers diagnosis and parameters modification of the complex targets' geometry model are discussed. Firstly, by comprehensive analyzing the limited observation data, we can suppose a non-accurate geometric model. Secondly, the SAR image of the geometry model can be reconstructed using a forward approach to establish parametric scattering center model. The image is compared with the limited observation data, and then adjust the correctional components' position, size and shape. As follows, the parametric scattering center model of the adjusted model is established, the SAR image of the adjusted model is reconstructed, and compared with the limited observation data again We adjust the geometry models and establish parametric scattering center model several times like these. Finally, the scattering centers are diagnosed and the parameters are modified. The modeling method is applied to a tank target, it is proved to be effective.

Based on spectral domain method (SDM), an asymptotic approach to the investigation of the reflection of electromagnetic waves from a metal plane interface separating a vacuum half-space and a anisotropic plasmas layer is presented. Firstly, the spectral formulas of type I and type II waves existing in the plasmas are deduced. Then the boundary conditions at the top and bottom interfaces of the plasmas slab are employed to determine the complex amplitudes of the scattered fields in spectral domain. By means of saddle point technique (SPT), the scattered fields in space domain are asymptotically solved out, which degrade to the reflected fields. The asymptotic solution is validated by the comparisons between the reflection coefficients obtained from the proposed solution and Titchener's method.

Handover management with Quality of Service (QoS) provision is the major challenge for the seamless mobility across heterogeneous wireless networks. In this paper, we propose the context-aware vertical handoff (VHO) management architecture with QoS provision, based on the extension of IEEE 802.21. In this proposed architecture, context information is collection from all layers of the protocol stack both mobile node side and network side as most as possible. Context-aware Adaptive Analytic Hierarchy Process Method (CAAHP) method is chosen to identify the most suitable network for the optimization of handover decision mechanism. For QoS provision, QoS Management Module is carefully designed to provide the various functionalities, especially, Dynamic QoS negotiation mechanism and Dynamic QoS Mapping mechanism to provide the QoS service continuity and adaptation. Finally, the Mobile-initiated Handover scheme integrating with our proposed architecture is detailedly illustrated through the messages and procedures.

In this paper, a scalable dispersion management approach for microstructured fibers (MSFs) is proposed and applied to the design of zero-dispersion fibers and ultrawideband dispersion-flattened fibers. The proposed method can predict the dispersion of MSFs accurately by taking secondary dispersion into account, this being the interactive contribution from both the material and the geometrical effects. The secondary dispersion is modeled as a function of the propagation index difference and wavelength, and the model can be exploited to predict the secondary dispersion of scaled structures. This method of predicting dispersion is then combined with the scalable property of the geometrical dispersion to form a scalable dispersion-tailoring approach. This new design approach is applied to the design of zero-dispersion MSFs working at 1.55 m and 1.3 m, respectively. It is then shown that the method can be used for the design of ultrawideband zero-dispersion fibers. A MSF with predicted dispersion as low as 0.2 ps/(kmnm) over the range 1.3-1.6 m is described.

Aiming at the treatment of difficult-to-handle oily wastewater, the ceramics filter mediums made from the iron and steel plant sludge were adopted to surface lipophilic modification so as to remove oil efficiently. The hydrolysis technique by FTIR and conductivity test indicated that under acid conditions hydrogen silicon oil did not hydrolyze but release hydrogen by chemical reaction under alkaline conditions. The results of the experiments including contact angle measurement, FTIR analysis, and SEM analysis illustrate that a layer of lipophile coating indeed exists evenly on the surface of filter mediums after modification. Furthermore, the hydrogen-containing silicone oil was combined through dehydration of Si-H bond with the -OH on the surface of ceramic filter medium.

This paper proposes a single-mode Bragg fiber design method based on a modal filtering technique and applies it to the design of a hollow-core single-mode Bragg fiber, which can achieve low loss by avoiding material loss. The proposed method exploits the Brewster phenomenon to filter out the TM01 mode so that only the fundamental HE11 mode exists. Consequently, this proposed method maintains a balance between single-mode propagation and low-loss propagation so that it is specially suitable for terahertz single-mode Bragg fiber design. An explicit relationship between the first bandgap width and the layer thickness is derived. As a result, for a certain design bandwidth requirement, the Bragg fiber parameters can be determined. The proposed design strategy is applied to a hollow-core single HE11-mode Bragg fiber operating in the 0.65-1.35-THz range with a calculated loss ranging from 0.2 to 1 dB/m.

Two new integrated processes, gas-energy-management (GEM)—electrochemical catalytic oxidation (ECO)—membrane bioreactor (MBR) and ultrafiltration (UF)—ECO—MBR, in industrial-scale test for treating cold-rolling mill emulsion wastewater with water quantity of 200 L/h to 3000 L/h were studied. The former was put forward firstly and the latter was applied initially in this field. The operation conditions and mechanisms of each module in the integrated processes were analyzed and the influences of operational parameters of two processes on chemical oxygen demand (CODCr) removal efficiency were comparatively investigated. The test results showed that the ultimate water quality from the two processes after treatment could meet the requirement for reuse. However, the quality of effluent treated by GEM—ECO—MBR was more stable than that of UF—ECO—MBR.

We report results of a search for light weakly interacting massive particle (WIMP) dark matter from the CDEX-1 experiment at the China Jinping Underground Laboratory (CJPL). Constraints on WIMP-nucleon spin-independent (SI) and spin-dependent (SD) couplings are derived with a physics threshold of 160 eVee, from an exposure of 737.1 kg-days. The SI and SD limits extend the lower reach of light WIMPs to 2 GeV and improve over our earlier bounds at WIMP mass less than 6 GeV., Comment: 10 pages, 10 figures

The numerical implementation of traditional discrete complex image method (DCIM) approach for spatial-domain Green's functions (GFs) is limited to low values of ρ (ρ is the distance between the source and the field points of the GFs). Although recently a direct DCIM was introduced to obtain both near- and far-field region accurately, the direct DCIM was limited to choose the paths of kz plane in free-space layer. In this paper, an improved DCIM is introduced without any quasistatic and surface-wave extraction. We choose a novel path of kz plane. The improved DCIM works in both the near- and far-field region for multilayered media as direct DCIM does. And the method is applicable to choose the paths of kz plane in the layer where the source and field points are. The improvement makes it feasible to accelerate the calculation of spatial-domain GFs of electrically large buried objects in multilayered media. In this paper, the method developed for the computation of GFs is used for planar structures containing both lossless and lossy media. The CPU time used to perform the improved DCIM is less than 1 s for computing the fields, with a horizontal source-field separation from 1.6 × 103λ0 to 16λ0 (λ0 is the free-space wavelength). © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1337–1340, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22412

An accurate and efficient numerical algorithm is presented for creeping ray tracing on the arbitrarily shaped surfaces modeled by the Non-Uniform Rational B-spline (NURBS) surfaces. The main problem in calculating the UTD surface diffracted fields on NURBS surfaces is due to the difficulty in determining the geodesic paths which the creeping rays propagate along. In this paper, an efficient method is developed based on the property of geodesic to compute geodesic paths on NURBS surfaces. And the algorithm can extend the applicability of UTD for practical engineering. The validity and efficiency of the algorithm is verified by numerical results.

This work presents a new technique based on ray tracing to extract and analyze scattering centers from complex targets, which is called ray clustering. The input of this method is the target CAD model and the output is the dominant scattering centers. This method can separate the echoes from different components by clustering rays owning the different paths and establish relationship between target components and the scattering source, thus it can provide an effective approach to analyze the target characteristics. After introducing the implementation procedure of the extracting method, we present an example to demonstrate its application in characteristic analysis.

Although the uniform theory of diffraction (UTD) could be theoretically applied to arbitrarilyshaped convex objects modeled by nonuniform rational B-splines (NURBS), one of the great challenges in calculation of the UTD surface diffracted fields is the difficulty in determining the geodesic paths along which the creeping waves propagate on arbitrarilyshaped NURBS surfaces. In differential geometry, geodesic paths satisfy geodesic differential equation (GDE). Hence, in this paper, a general and efficient adaptive variable step Euler method is introduced for solving the GDE on arbitrarilyshaped NURBS surfaces. In contrast with conventional Euler method, the proposed method employs a shape factor (SF)ξto efficiently enhance the accuracy of tracing and extends the application of UTD for practical engineering. The validity and usefulness of the algorithm can be verified by the numerical results.