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[Objective] Research was conducted on understory litter and soil hydrological function for artificial forests in the forest protection station in the eastern section of the Kubuqi Desert. The comprehensive weight value of various indicators of the artificial forests in this area were scientifically calculated, and the hydrological effect and water conservation function of artificial forest litter and soil were determined in order to provide theoretical guidance for the directional tending of returning sand to forest in this area and related sandy areas. [Methods] Five common types of artificial shelterbelts were used in the Ordos afforestation station in the Kubuqi Desert. The water-holding capacity of litter and soil were determined using field measurements and the indoor immersion method, and the water conservation function of each forest was assessed using a combination of the analytic hierarchy process (AHP) and the entropy-weight method (EWM). [Results] ① The litter thickness in each stand ranged from 6.56 to 22.20 mm, and the litter accumulation ranged from 1.44 to 13.62 t/hm2. Interception capacity for the different forest stands followed the order of Salix matsudana-Populus × euramericana mixed forest > Populus × euramericana forest > Pinus sylvestris forest >3-year S. matsudana forest >8-year S. matsudana forest. ② The maximum water-holding depth of litter was linearly related to the dry mass, and the maximum storage was about 1.36~2.04 L of precipitation in each stand. These results showed that the maximum water-holding capacity of the litter depended mainly on the dry weight of the litter, while related factors such as tree species, age, and meteorology indirectly affected the water-holding capacity by influencing the dry weight of the litter. ③ Logarithmic and power functions provided good representations of the dynamic water-holding capacity and dynamic water uptake of litter, respectively. ④ The saturated water-holding rate, capillary water-holding rate, and total porosity basically showed decreasing trends as soil depth increased, and soil bulk density showed an increasing trend. ⑤ The S. matsudana-Populus × euramericana mixed forest exhibited a higher water conservation function than the other forests, the Populus × euramericana and Pinus sylvestris forests had similar water conservation functions, and the S. matsudana forests had the lowest water conservation functions. [Conclusion] Construction of future artificial shelterbelts in desert regions should prioritize the cultivation of mixed forests, and a more scientific plan for the return of sand to forests should be developed by considering differences in the water conservation function between tree species.

As basic structural components of the ship hull, stiffened plates suffer both thrust and shear loads while ships sail in rough sea environments. In order to guide the scaled model design effectively, the similarity law is investigated in this paper. The parameters that determine the nonlinear behaviour of the stiffened plate under compression and shear loading are defined and the nonlinear similarity method is improved. This method is applied to design a scaled model under combined bending and torsional moment, and the collapse test is conducted to research the collapse characteristics. The collapse behaviour of actual ship structures under combined loads predicted by the model test is compared with that obtained by the nonlinear finite element analysis. The good agreement represents the capability of the newly improved nonlinear similarity law. The present research provides a proper way to investigate the collapse characteristics of actual ship structures through a model test. [ABSTRACT FROM AUTHOR]

With the increasing development of high-speed, large-scale and light-weight ships, the demand for high-tensile steel in ship structures is continuously rising. This has promoted a decrease in plate thickness, which in turn contributes to the critical issue of structural stability. As ships navigate in waves, they are exposed to dynamic loads, making it crucial to investigate the dynamic stability behaviour of ship structures. In this research, the dynamic stability of plates was investigated theoretically, and the influences of boundary conditions and damping were discussed. Then, a numerical simulation system using MITC4 shell elements was developed to investigate the dynamic stability of stiffened plates. An experiment was conducted to validate the accuracy of the simulation system. Finally, the influences of various factors on the dynamic stability of stiffened plates were discussed in detail. This research has significant meaning for the safety and reliability design of ship structures. [ABSTRACT FROM AUTHOR]

In this study, the finite element method combined with the model test method are used to investigate the ultimate strength of a target ship reactor hull structure under a pure bending load. Based on the distortion similarity theory and nonlinear similarity method, a scale model of the actual ship reactor hull structure is designed and the model collapse test is conducted. The ultimate bending moment obtained by the model test is transformed to the actual ship through the similarity transformation relationship and compared with the nonlinear finite element analysis result of the actual structure. The results are consistent with each other, which indicates that the collapse characteristics of the actual ship reactor hull structure can be better forecasted using the model test results when the test model is designed based on the nonlinear similarity method and distortion similarity theory. [ABSTRACT FROM AUTHOR]

[Objectives] In order to achieve safe and lightweight structural design,structural optimization is usually performed.[Methods] In the present research,a structural optimization platform is developed based on ISIGHT platform and finite element method. A parameterized model of the objective deep-water drilling ship is generated and the structural optimization on transverse structures is carried out in the proposed optimization platform. The plate thickness and the stiffener size are considered as discrete variable in the optimization platform.[Results] The structural weight of the transverse components of deep-water drilling ship can be reduced by 11% after the optimization.[Conclusions] This paper shows that the structural weight can be effectively reduced by the optimized design of strong frame structure.

Nowadays, the development of green and smart ships has become a trend in the global shipping industry. Some countries such as Japan and Korea, as well as several European countries, have already made some progress and advantages. In recent years, China has issued a series of policies to encourage and support the development of green and smart ships. Beyond that, the demonstration of green and smart ships has been promoted along with the trend of larger-sized and standardized inland vessels. The Chinese status and plans of green technologies are summarized including air layer drag reduction, efficient propulsion, DC networking, and clean energy. Some smart technologies have also been illustrated, for instance, intelligent driving, intelligent engine rooms, energy efficiency, hulls, cargo control, and information integration. Smart ship technologies need to be fully validated in order to improve industrialization applications. In the shipping industry, the development and application of smart ship technology need international and inter-regional cooperation, so as to achieve much higher energy savings, ensure environmental protection, achieve collaborative intelligence, and ensure safety and reliability. In turn, this will aid economic advances worldwide. [ABSTRACT FROM AUTHOR]

In order to effectively promote the construction of the Yangtze River economic belt, it has become China’s national strategy to vigorously develop the river-sea-going transportation. In the present paper, theoretical analysis, numerical simulation and model test are combined together to develop flat-type river-sea-going ship which is characterized with larger loading capacity, lower fuel consumption, better performance on energy-saving and environmental-friendly, excellent economy and higher transportation efficiency. Key technologies on hydrodynamic performance, structural safety, energy-saving technology and green ship technology are investigated to develop the river-sea-going ship. The developed “4E” level ship has great significance to the implementation of national strategic deployment.

The external loads and structural ultimate strength are two important aspects for the safety of ship hull girder. It may collapse in case the structural capacity is less than the external forces in extreme seas. In the present research, progressive collapse test is performed to investigate the collapse mechanism of ship structure in waves. External load with time history and corresponding structural collapse behavior are measured and discussed to demonstrate the interaction of fluid and structures.

This study presents experimental and finite element investigations on the ultimate strength of the funnel structure of a large passenger ship subjected to wind pressure. An experimental test is conducted using a similar model to analyze the failure characteristics of the funnel structure. The model is designed based on similar theories to simulate the progressive collapse behavior of an actual ship's funnel under wind load. Additionally, a simplified wind loading device is also developed to apply large wind loads. Practical insights are provided in the research to assess the opening's influence on reducing the ultimate strength of funnel structures when suffering wind pressure. Results represent the failure initiated at the edges of the large opening, with stress concentration primarily occurring at the stiffener end, showing good agreement with the simulated results performed using the finite element method. Furthermore, the effects of different parameters on the ultimate strength of the funnel structure are discussed by using the numerical method. This analysis provides an important guide for the design of funnel structures of passenger ships with openings. [ABSTRACT FROM AUTHOR]

Diffuse axonal injury (DAI), with high mortality and morbidity both in children and adults, is one of the most severe pathological consequences of traumatic brain injury. Currently, clinical diagnosis, disease assessment, disability identification, and postmortem diagnosis of DAI is mainly limited by the absent of specific molecular biomarkers. In this review, we first introduce the pathophysiology of DAI, summarized the reported biomarkers in previous animal and human studies, and then the molecular biomarkers such as β-Amyloid precursor protein, neurofilaments, S-100β, myelin basic protein, tau protein, neuron-specific enolase, Peripherin and Hemopexin for DAI diagnosis is summarized. Finally, we put forward valuable views on the future research direction of diagnostic biomarkers of DAI. In recent years, the advanced technology has ultimately changed the research of DAI, and the numbers of potential molecular biomarkers was introduced in related studies. We summarized the latest updated information in such studies to provide references for future research and explore the potential pathophysiological mechanism on diffuse axonal injury. [ABSTRACT FROM AUTHOR]

Salix psammophila, classified under the Salicaceae family, is a deciduous, densely branched, and erect shrub. As a leading pioneer tree species in windbreak and sand stabilization, it has played a crucial role in combating desertification in northwestern China. However, different genetic sources of Salix psammophila exhibit significant variations in their effectiveness for windbreak and sand stabilization. Therefore, it is essential to establish a rapid and reliable method for identifying different Salix psammophila varieties. Visible and near-infrared (Vis-NIR) spectroscopy is currently a reliable non-destructive solution for origin traceability. This study introduced a novel feature selection strategy, called qualitative percentile weighted sampling (QPWS), based on the principle of the long tail effect for Vis-NIR spectroscopy. The core idea of QPWS combines weighted sampling and percentage wavelength selection to identify key wavelengths. By employing a multi-threaded parallel execution of multiple QPWS instances, we aimed to search for the optimal feature bands to address the instability issues that can arise during the feature selection process. To address the problem of reduced prediction performance in one-dimensional convolutional neural network (1D-CNN) models after feature selection, we have introduced convolutional autoencoders (CAEs) to reduce the dimensions of wavelengths that are discarded during feature selection. Subsequently, these reduced dimensions are fused with the selected wavelengths, thereby enhancing the model's performance. With our completed model, we selected outstanding models for model fusion and established a decision system for Salix psammophila. It is worth noting that all 1D-CNN models in this study were developed using Bayesian optimization methods. In comparison with principal component analysis (PCA) and full spectrum methods, QPWS exhibits superior predictive performance in the field of machine learning. In the realm of deep learning, the fusion of data combining QPWS with CAE demonstrated even greater potential with an improvement of average accuracy of approximately 2.13% when compared to QPWS alone and a 228% increase in operational speed compared to a model with full spectra. These results indicated that the combination of CAE with QPWS can be an effective tool for identifying the origin of Salix psammophila. [ABSTRACT FROM AUTHOR]

The demand for larger passenger capacity and more entertainment facilities has led to the rapid growth of the cruise tourism market. The superstructure of cruise ships is designed to be plumper, with numerous decks and complex structural forms. To control the weight and the center of gravity, the bending stiffness of the superstructure is always designed to be weaker than that of the main hull, resulting in a stiffness step. Currently, there is no satisfactory method to accurately estimate the influence of the stiffness step between the main hull and superstructure on the structural response of cruise ships. In the present research, an experimental analysis is conducted to investigate the stiffness step between the main hull and superstructure of a typical cruise ship. By comparing the longitudinal stress distribution characteristics with and without the stiffness step with the theoretical results, the influence of the stiffness step on the longitudinal strength is investigated. Furthermore, the maximum stress and the bending efficiency of the superstructure are also discussed. The present research is of reference significance for the structural safety and reliability design of cruise ships. [ABSTRACT FROM AUTHOR]

The Inner Mongolia reach of the Yellow River basin is suffering severe degradation as an ecological barrier at present. Analyzing its landscape pattern and ecological risk is of great significance for promoting the high-quality development of this reach. Based on the land use data of 1980, 2000, and 2020 of the study area, this study analyzed the spatial distribution and spatio - temporal evolution of the ecological risks by calculating the regional landscape pattern index and the ecological risk index. The results show that: (1) During 1980-2020, the land in the study area was dominated by grassland, which accounted for more than 50%. In this period, the areas of cultivated land, grassland, water areas, and unused land decreased by 578 km², 1 911 km², 383 km², and 255 km², respectively. By contrast, the areas of forest land and construction land increased by 1 055 km and 2 072 km, respectively. In terms of land use types, the land in the study area mainly shifted from grassland, cultivated land, and water areas to construction land and forest land. The comprehensive land use intensity during 2000-2020 was 0.85 percentage points higher than that during 1980-2000; (2) During 1980-2020, the patch number of all types of land decreased except for water areas and unused land; the degree of landscape fragmentation of all types of land increased except for construction land; the degree of landscape disturbance of all types of land decreased except for forest land; the degree of landscape loss of all types of land did not change significantly except for construction land, for which the degree of landscape loss decreased significantly; (3) The ecological risk value of the Inner Mongolia reach of the Yellow River basin showed a downward trend during 1980-2020. Areas with fairly low and low ecological risks increased by 9 000 km² in total and were primarily concentrated in the northern and central areas in this period. In contrast, areas with high and fairly high ecological risks decreased by 1 350 km² in total and were scattered on the eastern and northern edges. [ABSTRACT FROM AUTHOR]