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The problem of target detection and localization in layered media can be solved by the mixed TR–RTM. The highlight of this paper is on multilayer media, where the target is harder to detect than in...

In order to further improve the predictive accuracy of low-frequency (LF) ground-wave propagation delay, it is necessary to establish a proper model that can take complex temporal variation properties of propagation delay into account. In this letter, we first analyze the relationship between measured propagation delay and five typical meteorological factors. It can be found that propagation delay has strong correlation with meteorological factors, for example, there is a positive linear correlation between propagation delay and temperature. Then, a theoretical model of propagation delay is established by using a backward propagation neural network (BPNN), and its accuracy is validated by the good agreement between predicted results with measured values. Finally, a detailed quantitative comparison shows that on one hand, the more meteorological factors are considered, the more accurate the predictive model is; on the other hand, the BPNN provides a very convenient approach to handle a large number of factors.

BACKGROUND The aim of this study was to determine multidetector computed tomography (MDCT) features and tumor markers for differentiating stage I serous borderline ovarian tumors (SBOTs) from stage I serous malignant ovarian tumors (SMOTs). MATERIAL AND METHODS In total, 48 patients with stage I SBOTs and 54 patients with stage I SMOTs who underwent MDCT and tumor markers analysis were analyzed. MDCT features included location, shape, margins, texture, papillary projections, vascular abnormalities, size, and attenuation value. Tumor markers included serum cancer antigen 125 (CA125), carbohydrate antigen 19-9 (CA19-9), carcinoembryonic antigen (CEA), and human epididymis protein 4 (HE4). Parameters of clinical characteristic, MDCT features, and tumor markers were compared using a chi-square test and Mann-Whitney U tests. A binary logistic regression analysis was performed to detect predictors for SMOTs. A receiver operating characteristic (ROC) curve analysis was used to assess the potential diagnostic value of the quantitative parameters. Kappa and intraclass correlation coefficients were used to evaluate interobserver reproducibility for MDCT features. RESULTS Median ages between patients with SBOTs and SMOTs were significantly different. Compared with SBOTs, vascular abnormalities were significantly more common in SMOTs. CA125, HE4, the maximum thickness of the wall, the maximum thickness of the septa, and the maximum diameter of the solid portions were significantly higher in patients with SMOTs. A binary logistic regression analysis revealed that age, vascular abnormalities, and the maximum diameter of the solid portion were independent factors of SMOTs. ROC analysis was used to assess the potential diagnostic value for predicting SMOTs. Moderate or good interobserver reproducibility for MDCT features were identified. CONCLUSIONS Age, vascular abnormalities, and the maximum diameter of the solid portion were independent factors for differentiating SBOTs from SMOTs. The combined analysis of age, vascular abnormalities, and the maximum diameter of the solid portion may allow better differentiation between SBOTs and SMOTs.

The problem of target detection and localization in two-layered media can be solved by time reversal and reverse time migration mixed method. This paper is extended from two-layer layered medium to three-layered media. Due to the interference of two interfacial reflection signals, three-layered media is more difficult to detect than two-layer media. The single prominent mountain like acoustic field distribution is obtained around the target. For interface reflected signal, it is a disordered and inhomogeneous acoustic field distribution with a smaller amplitude. The position of summit is the just position of the target, thus achieving the detection and positioning of the target.

Layered structures are widely used, and their safety in service will be severely affected by the existence of defects. The snapshot time reversal and reverse time migration mixed method with longitudinal wave is adopted to detect and locate the target or defect in layered media containing solids. A mountain-like acoustic field distribution is constructed through the numerical simulations, and the location of the summit is that of the target, which realizes the detection and location of the target in layered media containing solids. In addition, this method can obtain a better signal-to-interference ratio by suppressing the interference of the interface reflection.

Without prior knowledge of medium parameters, a method is proposed to detect and locate a target in layered media. Experiments were carried out for liquid/liquid and solid/liquid layered media, and the location of a target in them was obtained using three methods combined, i.e., the least-square method, the method of finding minimum dispersal degree of target distribution, and the snapshot time reversal and reverse time migration mixed method. The medium parameters, i.e., the acoustic velocities of upper and lower media as well as the thickness of the upper medium, were inversed simultaneously. The results show that the position of target is consistent with its actual position. Thus, the detection and location of a target in layered media are achieved without prior knowledge of medium parameters, and it overcomes the difficulty that the common time reversal method only detects the target, but cannot locate it.

Target or defect has been detected and located in the liquid-liquid layered media by using a time reversal (TR) - reverse time migration (RTM) mixed method that can better suppress the effects of reflection signal of interface. In this paper, this method is extended to the case of solid-solid and liquid-solid layered media and the detection and location of the target can be obtained by establishing the acoustic field distribution. Because solids are different from liquids, both longitudinal wave and shear wave exist in solids. Therefore, four kinds of scattered wave in solid-liquid or liquid-solid layered media are recorded by receivers. Time reversal (TR) and reversed time migration (RTM) mixed method is used to establish the acoustic field distributions of four waves, respectively. The location of the target is interpreted as the position of the maximum value in these acoustic field distributions.

A time reversal (TR) - reversed time migration (RTM) mixed method has recently been proposed for locating targets in two-layered media. The experimental results have showed that the TR-RTM method is an effective method for determining the target location in two-layered media. However, for targets in multi-layer media, it is more difficult to distinguish the target signal and the interface signal because of the existence of multiple interfaces. The detection and location of targets in multi-layered media are studied. Through numerical simulation analysis, this method has been proved to be effective method for determining the target location in multi-layered medium.

As a sensing device, microfiber knot resonator (MKR) has been widely used in sensing field due to its advantages of high sensitivity and fast response. It is important to analyze the spectrum of MKR for detecting environmental parameters in that the spectrum can reflect the change of ambient environment. In this paper, the relationship between spectrum of MKR and seawater temperature has been studied theoretically and experimentally. Firstly, the dependences of the propagation constants of fundamental mode (HE11) on the fiber diameter and the probing wavelength are studied theoretically in this paper, including two orthogonal polarization states of fundamental mode. The calculated results show that the propagation constant increases with the increasing fiber diameter and the decreasing probing wavelength. Simultaneously, the dependence of propagation constant of fundamental mode on seawater temperature is studied. The results show that the larger propagation constant corresponds to the higher seawater temperature, which indicates that the seawater temperature affect the mode propagation constant. Thus, the seawater temperature can be obtained by detecting the resonant spectrum. Secondly, the experimental system for seawater temperature sensing is set up, with which the resonant spectrum of MKR for seawater temperature sensing are obtained. The experimental results show that two sets of resonant peak exist on the spectrum, which are corresponding to TE and TM modes of fundamental mode. The sensing sensitivities of the two polarization modes are 5.54 pm/°C and 5.24pm/°C, respectively. Finally, the reason for resonant spectrum of the two polarization states is discussed, which is that the separation of the two modes resulting from the twisted coupler of the knot zone, and the resonant intensity of the two polarization modes is analyzed. The resonant intensities of the two modes are different and one increases while the other one decreases with the increasing probing wavelength. It is determined by the coupling coefficients and attenuations of the two coupled states，which are affected by the probing wavelength. The experimental and theoretical results agree well.

Aiming at multi directions analysis problem of surface feature extraction from point cloud data, Curvelet transform is introduced to multi directions analysis of point cloud data. Based on the preprocessing of location and expansion, second-generation discrete Curvelet transform is used to analyze point cloud data. Curvelet transform coefficients are processed to enhance the contour of point cloud data. Nonlinear function is used to process Curvelet transform coefficients of coarse layer. Compromise for soft and hard thresholds is used to process Curvelet transform coefficients of detail layer. Piecewise nonlinear function is used to process Curvelet transform coefficients of fine layer. The data point is reconstructed from the enhanced Curvelet transform coefficient with Curvelet inverse transformation. Initial surface feature is achieved with edge detection. The precise surface feature is achieved with morphological dilation and erosion to filter edge without real shape significance. Example of part point cloud data of brake shell shows the proposed surface feature extraction method can accurately extract surface feature from data point.

Considering the inheritance and hereditary of product structure life cycle assessment, full life cycle assessment properties of structure is introduced into expression of design scheme. Scheme evolution design is presented based on gene model of full life cycle assessment properties of structure. The gene model of life cycle assessment properties of structure is established. The variable length coding is converted to equal length coding to realize the quantitative representation of structure information. The fitness function is established for life cycle assessment of structure by Analytic Hierarchy Process. The genetic operators are designed. Scheme evolution design is realized based on gene model of life cycle assessment of structure, reflecting life cycle assessment properties of design schemes, improving the efficiency of product design generation. The evolution design example of multi-rope diamond wire saw verifies the feasibility of the imposed method.

The remote monitoring system of elevator is an important tool to improve the service quality of safety operation of elevator. This paper studies the elevator monitoring system based on Zigbee, which uses MCU to control the operation of elevator model, transmits operation informations of the elevator model to the PC monitoring system with information transmission module of Zigbee, and displays and queries basic informations and operation status informations of elevator. The communication of the Zigbee module and MCU needs to convert the voltage value of transmission signal. In this paper, the design of remote monitoring system of elevator based on Zigbee has certain reference significance for the research on the elevator remote monitoring system.

A target in layered medium can be located by the ridge-like distribution time reversal and reverse time migration (TR-RTM) mixed method. However, this method cannot distinguish between acoustic field distributions of the interface and target for the wider acoustic pulse signals, which may result in inaccurate location of the target. A snapshot TR-RTM mixed method is proposed to solve this problem. The principle of snapshot TR-RTM mixed method is first given. Experiments are then carried out, and a mountain-like acoustic field distribution is obtained by processing experimental data. The results show that the location of the peak is that of the target, and the ratio of the scattered signal and interface reflection signal (signal-to-interference ratio) is improved by about four times after processing. Furthermore, this method can effectively suppress the interface reflection signal and enhance the target scattering signal. Therefore, it can achieve effective detection and location of a target in a layered medium.

With the development of society, the ecological risks continue to produce; ecological risk management is becoming urgent. This paper uses the literature research methods, focusing on the origin of ecological risks, the arising of ecological risk management, the ecological risk assessment model, and the relationship between ecological risk assessment and ecological risk management. Based on research at home and abroad, the paper proposes shortcomings of current research and three areas for further study in the future.

Land planning is plans and arrangements to a certain of areas the ahead of future land use, and involving social, economic, resource and environmental and other aspects of the planning area, to social economic development and ecological environment will have a profound impact,Land planning environmental impact assessment is analysis, pre-monitoring and evaluation after the implementation of land use planning producting the potential environmental impact, and on this basis from the environment point of view ,raised the best solution for planning and adjustment proposal, so it carried out environmental impact assessment to guarantee the correctness of decisions is essential as soon as possible.

Accelerating urbanization is China's "The Fifth" period of economic and social development of an important part of the overall strategy.Urbanization construction process speeded up in Guan- zhong region in recent years.At the same time, many problems appeared, Guanzhong area of farmland for construction land increased year by year, while the Guanzhong area in northern and central located in the Loess Plateau and the Weihe Plain, is the most serious soil erosion in China, the ecological envi- ronment of the most vulnerable areas. Urban sprawl compressed natural environment space, and destr- oyed undermined the balance of the ecosystem.To under the premise of ensuring food security and ecological security, only to improve land use efficiency. It adopts the PSR framework model to build urbanization index system of intensive use of land.It used the matter-element extension theory to evaluate, designed to evaluate land use efficiency and benefit, To find out the problems existing in the current land use and seek the most effective use way of land and to achieve sustainable land use.

Knowledge modeling and solving strategy are the key techniques of improving the innovation design ability of a complex product with design knowledge system. Aiming at a formal expression of product behavior knowledge, generalized variables are introduced from the bond graph theory. The attributes of motion behavior are used to realize the unity of dynamic behavior and static behavior. The ontology model of product design function, behavior, structure knowledge is constructed with the six-tuple structure. With the breadth first search FBS ontology mapping strategy, product design is realized by searching within product design knowledge base according to the name similarity. For the new function introduced by new demand in product design, concept learning based on variant space is proposed to get the general function unit or special function unit. Then the innovation design is realized through FBS ontology mapping strategy. The validity of the proposed method is verified by example of innovation design of multi-wire diamond saw.

The homotopy analysis method and Galerkin spectral method are applied to find the analytical solutions for the Gross-Pitaevskii equations, a set of nonlinear Schrodinger equation used in simulation of spin-1 Bose-Einstein condensates trapped in a harmonic potential. We investigate the one-dimensional case and get the approximate analytical solutions successfully. Comparisons between the analytical solutions and the numerical solutions have been made. The results indicate that they are in agreement well with each other when the atomic interaction is weakly. We also find a class of exact solutions for the stationary states of the spin-1 system with harmonic potential for a special case.

In view of the situation of shearing the scraper chain frequently and adjusting the pitch chain of the scraper conveyer in the coal mine, the project design a kind of hydraulic security shearing machine for the annulus chain of scraper conveyer, to solve the problem for high strength and heavy gauge annulus underground coal mine to cut off.

In water-deficient areas, water resource management requires evapotranspiration at high spatiotemporal resolution-an impossible situation given the trade-off between spatial and temporal resolutions in space-borne systems. Some researchers have suggested sharpening the Moderate Resolution Imaging Spectroradiometer (MODIS) land-surface temperature product with a resolution from 1 km to 250 m and a functional relationship between surface temperature (Tr) and normalized difference vegetation index (NDVI). Evapotranspiration at 250 m resolution can be obtained once every few days using this technique. Based on the interpretation of the triangular Tr-NDVI space and assuming uniform soil moisture conditions in a coarse pixel, this paper suggests an alternative algorithm-the triangle algorithm-for sharpening. The triangle algorithm was tested using Landsat 7 Enhanced Thematic Mapper Plus (ETM+) data from an arid zone. Sharpened surface temperatures and reference temperatures were compared at 60 m and 240 m resolutions. Root mean square errors with the triangle algorithm are smaller than those with a functional relationship between Tr and NDVI. This paper will also discuss the impact of soil moisture variations in the coarse pixel on the triangle algorithm. Finally we should mention that the triangle algorithm only applies to regions with non-stressed vegetation canopies.

Investigations for a dusty plasma with many different dust grain species are adopted, which varies self-consistently with the system parameters. Two cases have been studied. One is that the dust size distribution is given by Gaussian distribution. The other is that there is only one kind of dust grains (mono-sized dusty plasma) whose size is the average one of Gaussian distribution. The comparisons between them have been made and it is found that the linear phase velocity is different.

Osteoporosis is a systemic skeletal disease, which is more prevalent in postmenopausal women. Osteoporosis likely develops beginning with genetic risk. This study explored the relationships between polymorphisms of HLA-B gene and postmenopausal osteoporosis in a Chinese Han population. Polymerase chain reaction sequence-based typing (PCR-SBT) method was used for DNA typing at HLA-B locus in 70 patients with postmenopausal osteoporosis and 73 healthy controls in female Han population of Shaanxi Province, situated in north-western China. We found that 40 HLA-B alleles in postmenopausal osteoporosis patients and control subjects, respectively. Furthermore, the frequency of HLA-B* 3501 allele was significantly higher in postmenopausal osteoporosis patients than in the control group (P = 0.033), and the relative risk was 7.632 (95% CI: 0.927-62.850). Our results suggest that HLA-B* 3501 was likely an important risk factor for postmenopausal osteoporosis. As different populations have different HLA polymorphisms, further investigation of the relationship of various HLA genes and osteoporosis with larger sample size is still necessary in the future.

Objectives: Despite the vast quantity of research among Chinese female sex workers (FSWs) to address concerns regarding HIV/sexually transmitted infection (STI) risk, there is a paucity of research on issues of sexual and gender-based violence (SGBV) and the missed opportunity for sexual and reproductive health (SRH) promotion among young FSWs. Our research aimed to assess the prevalence and correlates of SGBV among Chinese adolescent FSWs, and to explore SRH service utilisation. Design and methods: A cross-sectional study using a one-stage cluster sampling method was employed. A semistructured questionnaire was administered by trained peer educators or health workers. Multivariable logistic regression was conducted to determine individual and structural correlates of SGBV. Setting and participants: Between July and September 2012, 310 adolescent women aged 1520 years, and who self-reported having received money or gifts in exchange for sex in the past 6 months were recruited and completed their interview in Kunming, Yunnan Province, China. Results: Findings confirm the high prevalence of SGBV against adolescent FSWs in China, with 38% (118/310) of participants affected in the past year. Moreover, our study demonstrated the low uptake of public health services and high rates of prior unwanted pregnancy (52%; 61/118), abortion (53%; 63/118) and self-reported STI symptoms (84%; 99/118) in participants who were exposed to SGBV. Forced sexual debut was reported by nearly a quarter of FSWs (23%; 70/310) and was independently associated with having had a drug-using intimate partner and younger age (

To compare the difference of therapeutic effects between vessel pricking therapy and Prednisone for treatment of Henoch-Schonlein purpura nephritis.Seventy cases of acute purpura nephritis syndrome were randomly divided into an observation group (40 cases) and a control group (30 cases). Patients in observation group were differentiated into sthenia and asthenia syndromes. Vessel pricking therapy was applied at Hegu (LI 4), Quchi (LI 11), Xuehai (SP 10) etc. by triangular needle for sthenia symptom; shallow needling was used at Pishu (BL 20), Shenshu (BL 23), Zusanli (ST 36) etc. by filiform needle. The control group was treated with oral admi-nidtration of Prednisone. The symptom score of TCM, 24 h urinary protein, red blood cell count of urinary sediment of both groups were observed before and after treatment and therapeutic effects were compared.The total effective rate of 92.5% (37/40) in observation group was superior to that of 80.0% (24/30) in control group, and there was a significant difference between two groups (P0.05); the symptom score of TCM, 24 h urinary protein, red blood cell count of urinary sediment were all improved in both groups after treatment (all P0.05), and moreover, the improvement in observation group was superior to that of control group (all P0.05); after treatment, the symptom score of TCM of sthenia syndrome was lower than that of asthenia syndrome in observation group (P0.05).Vessel pricking therapy has a significant therapeutic effect for treatment of Henoch-Schonlein purpura nephritis, superior to that of oral administration of Prednisone, and the therapeutic effect is better for treating sthenia syndrome than for asthenia syndrome.

To isolate and purify corynoline and acetylcorynoline from Corydalis bungeana and develop a reversed-phase HPLC method of determining the two components in C. bungeana.Alkaloids were isolated from the ethanolic extract with column gel chromatography, and identified on the basis of spectral analysis (UV, 1H-NMR, 13C-NMR) and physicochemical properties. For quantitative analysis of the two components, samples were separated on an ODS column with mobile phase of methanol-15 mmol.L-1 potassium dihydrogen phosphate/potassium phosphate dibasic (pH 6.70, 70:30). The flow rate was 0.8 mL.min-1, and the detection was set at 289 nm.The purity was 99.5% and 99.1% for corynoline and acetylcorynoline respectively. The calibration curves were linear in the range of 6.9-110.4 mg.L-1 corynoline and 8.7-139.5 mg.L-1 acetylcorynoline. The RSD was 2.1% and 2.7%, and the average recovery was 97.3% and 97.2% respectively.The method of isolating and purifying corynoline and acetylcorynoline from Corydalis bungeana and the HPLC method of simultaneous determination of the two components have been developed. The HPLC method is simple, easy to perform and applicable to the content determination of corynoline and acetylcorynoline in C. bungeana of various origins.

We try to find the analytical solutions to the time-independent Gross-Pitaevskii equation, a nonlinear Schrodinger equation used in the simulation of Bose—Einstein condensates trapped in a harmonic potential. Both the homotopy analysis method and the Galerkin spectral method are applied. We investigate the one-dimensional case and obtain the approximate analytical solutions successfully. Comparison between the analytical solutions and the numerical solutions has been made. The results indicate that they agree very well with each other when the atomic interaction is not too strong.