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IntroductionMangroves are an important component of coastal ecosystems, and determining the spatial dispersion of prevalent mangrove species and the most suitable land-use source for mangrove growth is of great importance for judicious restoration and effective conservation approaches. Maximum entropy (MaxEnt) models are well suited for this task; however, the default parameterization such models for distribution prediction has limitations and may produce results with low accuracy, requiring elucidation of useful parameter settings. Further, a focus on predicting only the mangrove distribution is insufficient for mangrove restoration, and clarification of suitable habitats is required. Here, we examined the geographical distribution of six mangrove species in Beihai, China (Aricennia marina, Aegiceras corniculatum, Kandelia obovata, Rhizophora stylosa, Bruguiera gymnorrhiza, and Acanthus ilicifolius).MethodsWe used the ENMTools tool to select 16 variables from environmental factors, including bioclimate, terrain, sediment type, land-use classification, and sea-surface salinity and temperature. Using the selected variables and mangrove distribution data, a MaxEnt model optimized using the “kuenm” package in R was used to establish a mangrove prediction distribution model for Beihai City. Transition analyses of land-use types within suitable zones further clarified their current and potential functional roles.Results and discussionThe spatial occurrences of A. marina, A. corniculatum, and K. obovata were strongly driven by topographical features, those of R. stylosa and B. gymnorrhiza mostly depended on bioclimatic variables, and that of A. ilicifolius was driven mostly by edaphic conditions, notably the substrate type. The predicted optimal suitable area for mangrove growth in Beihai City was 50.76 km2, of which 55.04% are currently officially protected. Unprotected areas suitable for mangrove growth were mainly located in Lianzhou Bay, Tieshangang Bay, Dafengjiang, and Xicun Port. The majority of these regions were derived from land-use transitions from wetlands and aquaculture ponds to forested ecosystems. We suggest that careful development of selected wetland ecosystems and transmutation of aquaculture ponds into forested landscapes are crucial for effective mangrove restoration. Our results will assist in selecting suitable species for mangrove restoration sites and improving mangrove restoration efficiency.

Terrestrial shale oil resources in China are abundant. However, its development in China is still in the early stages. And its scale of transformation and production systems is still being explored. Currently, reservoir numerical simulation on shale oil reservoirs faces two main challenges: (1) multiscale flow of matrix–microfracture–hydraulic fractures in shale oil reservoirs and (2) bidirectional coupling of reservoir–wellbore–nozzle systems. This paper proposes a self-flow model for horizontal shale wells that describes multiscale fractures and production controlled by the nozzle. The model integrates the embedded discrete fracture model (EDFM), pipe flow model, and nozzle flow model. The accuracy of the model has been validated through comparisons with other reference models and field data. Then, this study analyzes the effects of different natural fracture densities, horizontal section lengths, number of fracturing stages, and nozzle diameters on the production capacity during the self-flow period. The results indicate that reservoirs with developed natural fractures can enhance the development efficiency during the self-flow period, and appropriate horizontal section lengths and fracturing stages contribute to achieving maximum economic benefits in development. Additionally, smaller nozzle diameters lead to longer self-flow periods and higher cumulative production. The research findings of this paper can be applied to simulate the production of hydraulic fractured horizontal shale wells.

We present a method to design polarization-independent multilayer dielectric gratings. In this method the reflection phases in transverse electric (TE) and transverse magnetic (TM) polarizations of the multilayer stack thread surface-relief grating at the top and the multilayer stack at the bottom together, allowing the two parts first to be designed separately and efficiently, and then to be combined to achieve simultaneously high diffraction efficiency and large fabrication tolerance. We find numerically that in general a periodic stack is unable to provide the top-grating-demanded phase difference between TM and TE polarizations; adequate aperiodic layers atop of a periodic stack are needed. The analytic diffraction efficiency formula of a recent work [J. Opt. Soc. Am. A 41, 252 (2024). https://doi.org/10.1364/JOSAA.511422] is used at various places of the presented optimization algorithm to save computation time. An example grating with rectangular surface-relief profile and another with trapezoidal profile were successfully designed, validating the effectiveness of this design method.

Objective To investigate the relationship between serum miR-199a-5p and miR-378a-3p levels and the recurrence of infants with proliferative facial hemangioma relapsed after propranolol withdrawal in infants. Methods Ninety-three infants with proliferative facial hemangioma were selected, all of whom received propranolol treatment. The recurrence of the hemangioma after treatment was followed up, and the children were divided into a recurrence group (23 patients) and a nonrecurrence group (70 patients). Venous blood was collected before and after treatment, and the serum levels of miR-199a-5p and miR-378a-3p were detected by qRT-PCR, and the relationship between the serum levels of miR-199a-5p and miR-378a-3p and the recurrence of proliferative facial hemangioma relapsed after propranolol withdrawal in infants was analyzed. Results The serum expressions levels of miR-199a-5p and miR-378a-3p in non-relapsed group were increased after treatment compared with before treatment (P < 0.05), and there was no significant difference in the levels of miR-199a-5p and miR-378a-3p in the serum of the recurrence group after treatment compared with before treatment (P > 0.05). After treatment, the levels of miR-199a-5p and miR-378a-3p in the serum of the recurrence group were lower than those of the nonrecurrence group (P < 0.05). After treatment, the serum levels of miR-199a-5p and miR-378a-3p in patients with Ⅲ ~Ⅳ Norm grade hemangioma were higher than those in patients with Ⅰ~Ⅱ Norm grade hemangioma (P < 0.05). Logistic regression analysis showed that the low expression of miR-199a-5p, low expression of miR-378a-3p and tumor grade Ⅰ~Ⅱ after treatment were risk factors for the recurrence of proliferative facial hemangioma after propranolol withdrawal in infants (P < 0.05). Conclusion Low serum levels of miR-199a-5p and miR-378a-3p are associated with the recurrence of proliferative facial hemangioma after propranolol withdrawal in infants.

Harsh environments such as alternating wet and dry conditions and cyclic loading cause erosion in steel bars, leading to severe damage to structures. Steel bars are also prone to bending under long-term fatigue loads. This paper establishes the bending performance test of corroded reinforced concrete (RC) beam under fatigue load based on the mathematical–statistical algorithm. It investigates the influence of heavy load on the fatigue performance of damaged RC beams, the influence of corrosive environment on the fatigue performance of RC beams, the degree of corrosion of steel bars in concrete beams under fatigue loading, and the distribution of chloride ions. The study results found that the stress ratio has a significant effect on the maximum crack width of the specimen beam. The greater is the stress ratio, the longer the fatigue life. This directly affects the performance of the specimen beam under fatigue loading. For this reason, we should pay special attention to the impact of corrosion on the fatigue performance of a structure during the design of steel bars.

Using high temperature gas heating equipment, lignite is heated at different temperatures. The failure forms on the surface were observed by scanning electron microscopy, and the samples were X-ray scanning with high-precision CT. The failure forms were obtained macroscopically and the CT images were processed in binarization to obtain the porosity of lignite and the length and width of cracks in different temperature sections. The results showed that under the action of temperature, thermal stress generated between solid particles of lignite resulted in the pyrolysis of organic matter, which is thermal fracture. The thermal fracture effect is obvious when the temperature is higher than 200 ℃. Below 200 ℃, the evolution of lignite pores and fractures is mainly caused by internal free water and gas loss. After 200 ℃, thermal fracture played a dominant role, and the growth rate of pores and fissures increased greatly, and the porosity increased by 6.83% compared with normal temperature. In the low temperature stage of thermal damage, the destruction of lignite is dominated by long and thin cracks. When the temperature is higher than 200 ℃, the failure form is dominated by irregular ellipses.

The work started 20 years ago [Appl. Opt. 42, 6255 (2003)] investigating the physical mechanism of multilayer dielectric reflection gratings to achieve 100% diffraction efficiency is extended to offer much deeper insight than before. How different diffraction amplitudes of the top surface corrugation contribute to the −1st-order efficiency of such a grating is shown analytically using a minimum set of real parameters. The two diffraction amplitudes transmitted through the corrugation play a dominant role in enabling DE = 100%. The necessary and sufficient condition for 100% efficiency is derived, and a very simple sufficient condition is also given. Moreover, the role of the reflection phase of the perfect-reflector, including the contribution due to optical path between the corrugation and the reflector, is emphasized.