Dynamical Properties of a Delay Prey-Predator Model with Disease in the Prey Species Only

A three-dimensional ecoepidemiological model with delay is considered. We first investigate the existence and stability of the equilibria. We then study the effect of the time delay on the stability of the positive equilibrium. The existence of a Hopf bifurcation at the positive equilibrium is obtained through the study of an exponential polynomial equation with delay-dependent coefficients. Numerical simulation with a hypothetical set of data has been carried out to support the analytical findings

Foreign entry liberalization and export quality: evidence from China

This paper examines the impact of foreign entry deregulation in China on the export price and quality of manufacturing firms through input-output linkage. We create a unique dataset describing the extent of regulatory control over foreign entry across approximately 900 industries covering all primary, manufacturing and services sectors. Results suggest foreign entry deregulation encourages firms to improve product quality and increase export prices. Deregulation in the manufacturing sectors has more impact on downstream export price and quality, compared with services sectors. Moreover, firms having larger imported inputs benefit more from foreign entry deregulation. These effects are robust to alternative specifications

The Anneal Temperature Effect on the BTO and NZFO Flims and Their Capacitance - Inductance Integrated Device

In this paper, a novel capacitor-inductor integrated structure was proposed. The dielectric material BaTiO3 (BTO) and ferromagnetic material Ni0.5Zn0.5Fe2O4 (NZFO) was prepared by sol-gel method. Phase composition and morphology of the thin films were characterized by XRD, SEM and AFM. The effect of annealing temperature on film crystallinity, surface morphology, dielectric properties and ferromagnetism were investigated. When the annealing temperature was 700 °C, the BTO film and the NZFO film got the better dielectric properties and ferromagnetic properties. Then the BTO thin film was spin-coated on the substrate, and the NZFO thin film was in-situ sintered on the BTO thin film. The composite film possessed both ferromagnetism and dielectric properties. Finally, an inductive coil was fabricated on the BTO/NZFO composite film to produce a capacitance and inductance integrated device

Transportation inequalities: From Poisson to Gibbs measures

We establish an optimal transportation inequality for the Poisson measure on the configuration space. Furthermore, under the Dobrushin uniqueness condition, we obtain a sharp transportation inequality for the Gibbs measure on $\mathbb{N}^{\Lambda}$ or the continuum Gibbs measure on the configuration space.Comment: Published in at http://dx.doi.org/10.3150/00-BEJ268 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

Evaluation of Ecological Supply-demand Synergy of Park Green Space in the Main Urban Region of Zhengzhou City

As important types of green spaces in the urban green space system, park green spaces are closely related to the urban residents. Research on park green spaces mainly focuses on the functions and the accessibility, and the synergy between supply and demand of park green spaces remains to be studied. This paper aims to promote the synergistic development between park green spaces and residents, and provide a scientific basis for the construction of an efficient park green space system and sustainable urban development. Based on the perspective of the supply-demand synergy of the ecological function of park green spaces, this paper took the main urban region of Zhengzhou City as the study area. An evaluation system of synergy degree of supply and demand was constructed using network analysis method, quantitative model of supply-demand synergy and analytic hierarchy process to study the characteristics of synergistic evolution between park green spaces and residents in the space-time dimension. The results show that the overall synergy degree of the study area increased from 0.1522 to 0.4256 from 2000 to 2020, and the overall supply index was always lower than the overall demand index. According to the results above, the authors proposed the optimizing strategies of increasing the number and green area of parks and improving connectivity between parks. Based on the top-down planning system, this study suggests bottom-up supply and demand evaluation and synergistic optimization, which can promote the efficiency of the ecological function of park green spaces, and solve the mismatch of supply and demand resources between the old and new urban areas

Cement Degradation Caused Risks for Geological Carbon Sequestration Reservoirs

Geologic carbon sequestration (GCS), a process to capture and store CO2 in deep geologic formations, is considered an essential technique to reduce carbon emissions which are a main cause of global warming and climate change. Depleted oil and gas reservoirs are among the most appealing locations for GCS. However, the success of the strategy relies on the long-term integrity of the reservoirs, which is challenged by the carbonation reactions between the main reservoir sealing material, i.e., cement, and the stored CO2 and then the occurrence of fluid leakage. This work provides a concise review on the degradation of oil well cement and the interface between cement and casing/formation rock, with a special focus on the influence of different factors such as the curing, service conditions and contaminants. The mechanisms and the mitigation methods of the degradation process are also discussed. This work aims to summarise current research progress and identify some remaining challenges for future research

Study On Land Use Aggregation Pattern Of Luohe City Based On Spatial Heterogeneity

The spatial layout of land use can reflect the health of urban development and inform the construction of green infrastructure. Many layout measurements have been proposed for lands in homogeneous spaces. Researchers and planners have used them to describe the urban structure and identify current problems in pursuit of problem-oriented optimizations. Now, with the urban expansion and accessibility development, the urban space has gradually changed from homogeneous to heterogeneous. However, the study of land use layout based on heterogeneous space is insufficient. Different land use types are expected to be allocated more scientifically, so providing more objective evidence on the urban land layout is necessary. Among them, the Aggregation-Diffusion status of each type of land is the most basic and vital information. In this paper, the spectral, index, and inversion data of Landsat 8 and Sentinel2 were collected, combined with NPP/VIIRS, and the Weka-EM clustering method was used to determine the boundary of build-up area in Luohe City (China) to obtain our study area. Then, we improve the traditional RAD by measuring roads \u27Efficiency value\u27 using Space Syntax: the homogeneous space is weighted to describe the effect of spatial heterogeneity for each land type. Therefore, by comparing the differences in the aggregation-diffusion land layout of these two spaces, the results are as follows: first of all, RAD shows that there is a dense core in Luohe City, in which priority development of ecological land can achieve a multiplier effect with half the effort. Secondly, in AAD, the basic unit based on efficiency value shows apparent spatial heterogeneity in Luohe urban space, represented by the contour line. The benefits of the greenway will be more fully realized where the contours are dense. Thirdly, comparing the description of the Aggregation-Diffusion situation of each land type by RAD and AAD, it can be found that: each land type has a different sensitivity to spatial heterogeneity, and AAD is a more accurate way of spatial description; Both AAD and RAD indicate a significant radial differentiation of land use in Luohe, which means that the significance of greenway construction in this religion is further enhanced. In addition to the greenway’s fundamental ecological implications, it also plays a vital role in facilitating the material-energy flow as well as promoting integration and equitable urban development

Digital image processing technology applied in level measurement and control system

AbstractAs the diversity of industrial processes, the common level meter devices are more impacted by external factors. This paper presents a new type of digital image processing technology for the level control system, combining with CCD camera technology as one of the measurement method. The fixed beam for measuring needs generated by the laser measurements, shape a special light point on the object surface, We can measure according to the changing scope of these points, or moving distance. From the experiment we can see, the CCD-based level measurement method not only has strong anti-interference ability, good usability, easy adaptability, but also applies to variety of more complex industrial applications