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Dear Editor, Plague, a seriously infectious zoonotic disease caused by the Gram-negative bacterium Yersinia pestis, has claimed millions of lives during three major historic pandemics. Y. pestis, with a minimum infectious dose for mammals of less than 100 organisms (even less than 10 by the subcutaneous route), can proliferate in mammalian macrophages and migrate to internal organs within days. To date, with rodents as reservoirs and fleas as vectors, Y. pestis is widely and persistently distributed in natural foci on most continents (except Australia) and poses a high risk to humans. Therefore, surveillance and control of local plague hosts, including decomposed ones, are important in plague-endemic regions. Furthermore, inexpensive, convenient, and reliable point-of-care testing (POCT) is essential in resource-limited areas.

The cloud in the high altitude is usually in the gas-liquid mixed state, this paper simulates the environment of the cloud particle using bubble field in the liquid. The paper research the gas-liquid mixture via measuring the size and 3D position of the bubble using a digital in-line holographic imaging system. The design of the optical system and the algorithm of reconstruction, recognition and extraction about the digital hologram is presented. The digital holography deserves to be selected as the projection to measure the bubble field because of advantages such as being able to record and reconstruct the three-dimensional position information, avoiding disturbing the object and insuring the instantaneity during the measurement. The optical system and the algorithm about the digital program have been completed, the hologram of bubbles in the liquids recorded by CCD, the hologram reconstruction using the digital hologram after denoising processing is accomplished. The character of cloud particles can be measured by using holography after analyzing the parameter of the bubbles.

The extraction of the weakly excited anti-symmetric Lamb wave from a submerged thin spherical shell backscattering is very difficult if the carrier frequency of the incident short tone burst is not at its frequency of greatest enhancement. Based on a single channel iterative time reversal technique, a method for isolating the subsonic anti-symmetric Lamb wave is proposed in this paper. The approach does not depend on the form function of a thin shell and any other priori knowledge, and it is also robust in the presence of some stochastic noise. Both theoretical and numerical results show that the subsonic anti-symmetric Lamb wave can be identified, even when the carrier frequency of the incident short tone burst is away from the frequency of greatest enhancement. The phenomenon may also be observed even in the case that the subsonic anti-symmetric Lamb wave is submerged in the noise, other than the case with the Signal to Noise Ratio being less than 10 dB, when the amplitude of the noise is comparable with the specular wave. In this paper, each iteration process contains a traditional transmission and time reversal transmission steps. The two steps can automatically compensate the time delay of the subsonic anti-symmetric Lamb wave relative to the specular wave and within-mode dispersion in the forward wave propagation.

Adiabatic approximation (AP) combined with perturbation theory gives a fast normal-mode solution of temporal coherence for sound field in a two-dimensional deep water with time-varying random internal waves. Internal waves induced mode changes are deduced using the first-order perturbation theory [C. T. Tindle, L. M. O’Driscoll and C. J. Higham, Coupled mode perturbation theory of range dependence, J. Acoust. Soc. Am. 108(1) (2000) 76–83]. And mode perturbations in amplitude are neglected by the adiabatic method with wavenumber perturbations in phase merely considered. The AP expression of temporal coherence function is theoretically identical to the adiabatic transport equation theory [J. A. Colosi, T. K. Chandrayadula, A. G. Voronovich and V. E. Ostashev, Coupled mode transport theory for sound transmission through an ocean with random sound speed perturbations: Coherence in deep water environments, J. Acoust. Soc. Am. 134(4) (2013) 3119–3133]. Numerical results of the adiabatic temporal coherence function for several low frequencies and ranges up to 1000[Formula: see text]km are calculated. Then the coherence time scales obtained from the calculations are examined by a one-way coupled theory considering forward scattering [A. G. Voronovich, V. E. Ostashev and J. A. Colosi, Temporal coherence of acoustic signals in a fluctuating ocean, J. Acoust. Soc. Am. 129(6) (2011) 3590–3597]. Comparisons demonstrate that the range and frequency dependence of coherence time for both methods are quite close. And this shows good agreement with the well-known inverse frequency and inverse square root range laws. In addition, the internal wave energy dependence of coherence time is also studied.

In this article, a type of adjustable blade angle control system was designed. The main role of the system was to achieve the function which made the blade angle follow with the change of the signal input. The article indicated the working principle of the adjustable blade angle control system combined with the relative math model. Aiming to the control target, a self-adapting fuzzy PID controller was designed. Mtalab7.0 was applied to carry out simulation and analysis on the cases that the step signals and sine signals were added to the controller, and it was validated that the self-adapting fuzzy PID controller had a good quality of dynamical characteristics, static characteristics and robust characteristics. Introduction To improve the aeroengine’s performance, widen the working range, the designers developed adjustable blade angle control technology. Nowadays the adjustable blade technology mainly achieved its blade angle following the given signal to carry out follow-up control function through adjustable blade angle control system. This article aimed to the requirements of aeroengine to the blade angle control, developed a set of adjustable blade angle control system. To realize the requirement for the adjustable blade technology as a fast and accuracy respond, this system took hydraulic control into use. Hydraulic control played a very important role in military affairs, aviation and industrial automation. In practical applications, general requirement was that the controller had fast respond and small overshoot characteristics. Considering that there were some uncertain factors in the hydraulic servo system, the time-changing characteristics of some parameters such as hydraulic nature frequency of the system, hydraulic damping ratio as well as nonlinearity of the servo valves and disturbance of exoteric load, traditional PID controllers could hardly satisfy the control’s need, sometimes even not able to be used, while self-adapting fuzzy PID controller was able to simplify the complexity of system design in an extreme degree, which was especially suitable to this kind of nonlinear system control. For this reason this system applied self-adapting fuzzy PID controller as governor [1] [2]. This article applied MATLAB7.0 to carry out simulation and analysis for the case with no disturbs to validate that the self-adapting fuzzy PID controller had better dynamical characteristics, static characteristics and robust characteristics. By practical application, the validity of the designed self-adapting fuzzy PID controller was proved and was able to satisfy the requirements of blade adjusting during the process of the tests. The working principle of the angle control system The control principle of the adjustable blade angle control system was shown in Fig.1. The computer exported the control signal to the A/D conversion module through the RS232 port and transformed it into voltage signal. The voltage signal and signal fed back by the displacement transducer were compared in the servo amplifier, the deviation signal was transformed into current signal after amplified, and transferred to the loop of the electro-hydraulic servo valve, in this way the opening control of the servo valve was achieved. After the servo valve opened, hydraulic oil 5th International Conference on Computer Sciences and Automation Engineering (ICCSAE 2015) © 2016. The authors Published by Atlantis Press 442 flowed into the actuating cylinder through the valve, made the actuating cylinder move and then achieved angle adjusting. The displacement transducer fixed on the actuating cylinder was used to measure the displacement of the actuating cylinder, and feedback to the servo amplifier. Fig.1. Control principle figure The mathematical model of angle control system Adjustable blade angle control system applied hydraulic pressure to control a pair of hydraulic actuating cylinders, this system included: servo amplifier, electro-hydraulic servo valve, displacement transducer, hydraulic pressure actuating cylinder, etc. The math models for these components were built up as followed: Servo amplifier When using current feedback amplifier, the output current 1 I and input voltage 1 U from the power amplifier were approximately proportioned and could be seen as scaled loop, the math model was: 1 1 1 ( ) ( ) I s K U s = (1) In the formula 1 K was servo amplifier increment, the enlargement factor of the servo amplifier 1 K =10mA/V. Electro-hydraulic servo valve Generally servo valve used current increment I ∆ as input, and no-load flow 0 Q as output, when the working frequency of the servo valve was nearly the same as hydraulic pressure natural frequency, the servo valve could be seen as a second order surge loop

Background After the earthquake on 14, April 2010 at Yushu in China, a plague epidemic hosted by Himalayan marmot (Marmota himalayana) became a major public health concern during the reconstruction period. A rapid assessment of the distribution of Himalayan marmot in the area was urgent. The aims of this study were to analyze the relationship between environmental factors and the distribution of burrow systems of the marmot and to predict the distribution of marmots. Methods Two types of marmot burrows (hibernation and temporary) in Yushu County were investigated from June to September in 2011. The location of every burrow was recorded with a global positioning system receiver. An ecological niche model was used to determine the relationship between the burrow occurrence data and environmental variables, such as land surface temperature (LST) in winter and summer, normalized difference vegetation index (NDVI) in winter and summer, elevation, and soil type. The predictive accuracies of the models were assessed by the area under the curve of the receiving operator curve. Results The models for hibernation and temporary burrows both performed well. The contribution orders of the variables were LST in winter and soil type, NDVI in winter and elevation for the hibernation burrow model, and LST in summer, NDVI in summer, soil type and elevation in the temporary burrow model. There were non-linear relationships between the probability of burrow presence and LST, NDVI and elevation. LST of 14 and 23 °C, NDVI of 0.22 and 0.60, and 4100 m were inflection points. A substantially higher probability of burrow presence was observed in swamp soil and dark felty soil than in other soil types. The potential area for hibernation burrows was 5696 km2 (37.7 % of Yushu County), and the area for temporary burrows was 7711 km2 (51.0 % of Yushu County). Conclusions The results suggested that marmots preferred warm areas with relatively low altitudes and good vegetation conditions in Yushu County. Based on these results, the present research is useful in understanding the niche selection and distribution pattern of marmots in this region.

Background Plague, a zoonotic disease caused by Yersinia pestis, is characterized by its ability to persist in the plague natural foci. Junggar Basin plague focus was recently identified in China, with Rhombomys opimus (great gerbils) and Xenopsylla skrjabini as the main reservoir and vector for plague. No transmission efficiency data of X. skrjabini for Y. pestis is available till now. Methods In this study, we estimated the median infectious dose (ID50) and the blockage rates of X. skrjabini with Y. pestis, by using artificial feeders. We then evaluated the flea transmission ability of Y. pestis to the mice and great gerbils via artificial bloodmeal feeding. Finally, we investigated the transmission of Y. pestis to mice with fleas fed by infected great gerbils. Results ID50 of Y. pestis to X. skrjabini was estimated as 2.04 × 105 CFU (95% CI, 1.45 × 105 – 3.18 × 105 CFU), around 40 times higher than that of X. cheopis. Although fleas fed by higher bacteremia bloodmeal had higher infection rates for Y. pestis, they lived significantly shorter than their counterparts. X. skrjabini could get fully blocked as early as day 3 post of infection (7.1%, 3/42 fleas), and the overall blockage rate of X. cheopis was estimated as 14.9% (82/550 fleas) during the 14 days of investigation. For the fleas infected by artificial feeders, they seemed to transmit plague more efficiently to great gerbils than mice. Our single flea transmission experiments also revealed that, the transmission capacity of naturally infected fleas (fed by infected great gerbils) was significantly higher than that of artificially infected ones (fed by artificial feeders). Conclusion Our results indicated that ID50 of Y. pestis to X. skrjabini was higher than other fleas like X. cheopis, and its transmission efficiency to mice might be lower than other flea vectors in the artificial feeding modes. We also found different transmission potentials in the artificially infected fleas and the naturally infected ones. Further studies are needed to figure out the role of X. skrjabini in the plague epidemiological cycles in Junggar Basin plague focus. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-0852-z) contains supplementary material, which is available to authorized users.

In the long-term process of use, due to the influence of various factors as material aging, load effect and environmental change, a certain degree of deformation will occur to the foundation and superstructure of the brige, the long-term monitoring for the deformation of the bridge as well as its influencing factors and the establishment of mathematical models for predicting deformation will contribute to the maintenance and management of large bridge. According to the complex characteristics of factors influencing, the improved algorithm of radial basis function neural network and network parameters was studied, and a software based on MATLAB was developed for bridge deformation predication. Combined with the monitoring data of Nanjing second Yangtze river bridge, a RBF network deformation forecasting model that based on 9 # measure point affected by many factors was established, and the deformation forecast and analysis were carried out. Research methods and the calculation and analysis results show that improved radial basis function neural network has higher prediction accuracy and can provide an important reference for the management of bridge.

Affected by many factors, deformation of large bridge will take place in the course of usage, so the development of deformation prediction system will contribute to the maintenance and management of large bridge. As the multiple-input and multiple-output characteristic of the RBF neural network, which also has the nature of universal approximation and optimal approximation, MATLAB combined with RBF network was choosed to develope the deformation prediction system of large bridge. The improved algorithm of RBF network parameters was studied, some key issues in the system development were solved, the choice of input factors and the preprocessing method of sampled data were discussed, the main function of the system was elaborated. This system has some popularization and application values to the deformation prediction and safety supervising of other similar projects.

Internal wave induce the decreasing of temporal coherence of sound field. The scale of temporal coherence is related with strength of the internal wave and frequency of the sound wave; meanwhile, it has the definite spatial structure. Spatial structures of the temporal coherence are not same under the different propagation conditions. It is related with the structure of the sound field.