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[Objective] The rapid development of nuclear technology and the continuous expansion of nuclear energy applications have focused engineering research on the conceptual design and shielding calculations of advanced reactors. The development of third-generation advanced modular small reactors has elevated the requirements for the types of neutron-shielding materials, equipment quality, and compactness of design. For shielding, these materials must exhibit good neutron and y-ray slowing down and absorption performance and have excellent mechanical properties to ensure structural integrity during long-term operation. Traditional shielding materials mostly rely on simple high-hydrogen-content compounds, high-density metal, and boron-containing concrete materials. However, when shielding small solid-state reactors, they gradually exhibit shortcomings in physical and mechanical performances. Addressing the inadequacies in the design and application research of composite shielding solutions for current small solid-state reactors, lightweight materials with excellent composite shielding performance can effectively meet the radiation shielding needs in complex geometric structures and operational scenarios. [Methods] This study selected lightweight materials with excellent performance for a single-tube neutron radiation detection system and conducted relevant performance experiments. Theoretical values and experimental results were cross validated through uncertainty simulations. After a comprehensive comparison of the physical performances and processing costs of neutron slowing down and absorption materials, coupled with discussions on the feasibility of neutron-shielding experiments in an experimental environment, boron carbide, titanium hydride, and zirconium hydride were chosen as the shielding materials for this experiment. Special-sized containers were customized, and samples encapsulated in organic glass and PVC materials were prepared. Performance tests of the shielding materials were conducted by counting the number of neutrons at counter positions in the single-tube neutron radiation detection system. The experimental data, including counting averages (n/s), sample variance, and the characterized shielding effectiveness, were recorded, summarized, and analyzed in detail. Subsequently, the detection system was modeled using the independently developed reactor Monte Carlo code by the REAL team at Tsinghua University. Monte Carlo particle transport simulations were used to validate the consistency between experimental and theoretical data. [Results] The experimental results indicate the following findings: 1) The shielding enclosure device comprising PVC material has virtually no impact on background neutron counts, while the use of organic glass material leads to a substantial effect, reaching 5%-6%. 2) Under the experimental conditions, boron carbide exhibits a noticeable absorption effect on neutrons, with a 3 mm thickness already achieving a considerable absorption effect at nearly an order of magnitude. 3) Under equivalent experimental conditions, the shielding effectiveness of titanium hydride and zirconium hydride is unsubstantial. However, titanium hydride slightly outperforms zirconium hydride. This superiority is observed because, in hydrogen-containing materials, titanium hydride and zirconium hydride have the same proportion of hydrogen nuclei. Because of the slightly higher neutron absorption cross-section of titanium nuclei compared to zirconium nuclei, the absorption effect makes titanium hydride slightly better than zirconium hydride in overall shielding effectiveness. 4) The experimental data collected align well with Monte Carlo simulation calculations, indicating the correctness of the experimental approach in this study.[Conclusions] The data and conclusions obtained from this study on lightweight shielding materials with specific characteristics apply to other novel shielding systems and devices. The research indicates that under equivalent irradiation conditions, shielding effectiveness increases in the order of boron carbide, titanium hydride, and zirconium hydride. Simulations and experiments provide guidance and validation, establishing a solid theoretical foundation for introducing composite diffusive shielding materials into portable small nuclear power systems. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effect of methionine analogue 2-hydroxy-4-methylthiobutanoic acid isopropyl ester (HMBi) on the rumen microbial community, microbial carbohydrate-active enzymes (CAZy), and protein metabolism pathways in yak. Twenty-four male Maiwa yaks (252.79 ± 15.95 kg) were selected and randomly divided into groups that received the basal diet alone, or a diet supplemented with different amounts of HMBi (5 g, 10 g or 15 g). At the phylum level, the group receiving 5 g of HMBi showed a considerably higher relative abundance of Lentisphaerae than the other treatment groups (p < 0.05). The relative abundance of Actinobacteria decreased linearly with the increase in HMBi supplemental levels (p < 0.05). The relative abundance of Prevotella increased linearly with the increasing level of HMBi supplementation (p < 0.05). The relative abundance of Butyrivibrio linearly decreased (p < 0.05), and the relative abundance of Alistipes tended to linearly decrease (p = 0.084). The addition of HMBi had linear or quadratic effects on the relative abundance of CAZy enzymes and functional proteins in the rumen of yak (p < 0.05). Conclusively, these results indicated that feeding yaks a diet supplemented with HMBi is an excellent strategy to enhance carbohydrate breakdown, and improve rumen microbial structure and function. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is a malignant tumor leading cancer-associated high mortality worldwide. Unfortunately, the most commonly used drug therapeutics not only lack of target ability and efficiency, but also exhibit severe systemic toxicity to normal tissues. Thus, effective and targeted nanodrug of HCC therapy is emerging as a more important issue. Here, we design and develop the novel nanomicelles, namely Mannose-polyethylene glycol 600-Nitroimidazole (Man-NIT). This micelle compound with high purity comprise two parts, which can self-assemble into nanoscale micelle. The outer shell is selected mannose as hydrophilic moiety, while the inner core is nitroimidazole as hydrophobic moiety. In the cell experiment, Man-NIT was more cellular uptake by HCCLM3 cells due to the mannose modification. Mannose as a kind of glucose transporter 1 (GLUT1) substrate, can specifically recognize and bind to over-expressed GLUT1 on carcinoma cytomembrane. The nitroimidazole moiety of Man-NIT was reduced by the over-expressed nitroreductase with reduced nicotinamide adenine dinucleotide phosphate (NADPH) as the cofactor, resulting in transient deletion of NADPH and glutathione (GSH). The increase of reactive oxygen species (ROS) in HCCLM3 cells disturbed the balance of redox, and finally caused the death of tumor cells. Additional in vivo experiment was conducted using twenty-four male BALB/c nude mice to build the tumor model. The results showed that nanomicelles were accumulated in the liver of mice. The tumor size and pathological features were obviously improved after nanomicelles treatment. It indicates that namomicelles have a tumor inhibition effect, especially Man-NIT, which may be a potential nanodrug of chemotherapeutics for HCC therapy. [ABSTRACT FROM AUTHOR]

This paper focuses on obtaining fundamental data for optimizing the design of intelligent equipment for cutting natural rubber and its key components. It uses natural rubber bark as the research subject and employs specific experimental apparatus to measure the physical properties and contact coefficients of the rubber bark. The discrete element method, along with the Hertz–Mindlin model featuring bonding contacts, are employed to create a discrete element model of natural rubber bark. Parameters are calibrated, and model validation is performed. Subsequently, a one-factor simulation test is conducted to assess various cutting angles of the rubber cutter knife. A secondary Fourier fitting is applied to fit the curve to the average shear force values obtained from the simulation. The results indicate that the lowest average shear force, at 84.345 N, occurs within the range of cutting angles between 25° and 30°. The corresponding optimal cutting angle is 29.294°, suggesting that cutting with low resistance can be achieved at this angle, leading to reduced power consumption. Following a statistical analysis of field rubber-cutting tests conducted in a forest setting, it was found that the average power consumption for rubber-cutting operations under the optimal cutting angle is 0.96 W·h. Additionally, the volume of rubber discharged in the initial 5 min period is 6.53 mL. These findings hold significant importance for guiding the optimization and enhancement of the design of intelligent equipment for cutting natural rubber and its key components. [ABSTRACT FROM AUTHOR]

To address the problem that anechoic coatings frequently fall off from modern submersible hulls and are detrimental to the realization of underwater acoustic stealth, this paper focuses on the broadband sound absorbing of acoustic coverings in debonding states from fully bonded span to fully shedded conditions. Based on the non-uniform waveguide theory, subdomain splitting approach, and wave propagation theory in layered media, a global transfer matrix method (TMM) is developed for predicting the sound absorption of a composite overburden with periodic cavities in all peeling situations. Meanwhile, the corresponding acoustic-structure fully coupled finite element (FE) simulation and hydroacoustic impedance tube-based absorption experiment are sequentially performed for the lining in a semi-bonded state to comprehensively verify the accuracy and reliability of the present analytical methodology. Then, the influence laws of debonding states, material properties, and geometric parameters on the global absorption performance are investigated in depth to reveal the multiple energy dissipation mechanisms. The results show that the shedding state primarily affects the sound absorption characteristics of anechoic coatings in the low- to mid-frequency band below 7 kHz. [ABSTRACT FROM AUTHOR]

Simultaneous localization and mapping (SLAM) in rubber plantations is a challenging task for rubber-tapping robots. Due to the long-term stability of tree trunks in rubber plantations, a SLAM system based on semantic segmentation, called Se-LOAM, is proposed in this work. The 3D lidar point cloud datasets of trunks collected in rubber plantations of Hainan University are used to train the semantic model, and the model is used to extract features of trunk point clouds. After clustering the trunk point clouds, each single rubber tree instance is segmented based on the Viterbi algorithm. The point clouds of tree instances are fitted to the cylindrical trunk models for semantic cluster association and positional estimation, which are used for lidar odometry and mapping. The experimental results show that the present SLAM system is accurate in establishing online mapping, and the location of the trunk in the map is clearer. Specifically, the average relative pose error is 0.02 m, which is better than the positioning performance of LOAM and LeGO-LOAM. The average error of estimating the diameter at breast height (DBH) is 0.57 cm, and it only takes 401.4 kB to store a map of the area of approximately 500 m 2 , which is about 10% less than other classic methods. Therefore, Se-LOAM can meet the requirements of online mapping, providing a robust SLAM method for rubber-tapping robots. [ABSTRACT FROM AUTHOR]

With an increased inlet gas temperature and the homogenization of the combustion chamber outlet temperature, the endwalls of gas turbines are exposed to extremely high heat loads. The complex flow structure of turbine endwalls makes it difficult to cool some regions of the endwalls, which can easily cause endwall ablation, reducing turbine aerodynamic performance and threatening the turbine's safe operation. In order to improve the cooling and aerodynamic performance of gas turbines, the flow structure, heat transfer and film cooling characteristics of endwalls are analyzed in depth in this paper. This paper summarizes and analyzes the development of the aerodynamic heat transfer and film cooling of gas turbine endwalls in terms of geometric structures and flow boundary conditions and also presents new research directions. Based on the literature, the development and challenge of turbine endwall film cooling are also discussed. [ABSTRACT FROM AUTHOR]

This study introduces the fuzzy theory approach as an enhancement to the traditional failure mode, effect, and criticality analysis (FMECA) method in order to address its limitations, which primarily stem from subjectivity and a lack of quantitative analysis. The proposed method, referred to as FMECA improvement based on fuzzy comprehensive evaluation, aims to quantify the qualitative aspect of the analysis and provides a detailed outline of the analysis procedure. By applying the enhanced FMECA method to assess the reliability of an intelligent profiling progressive automatic rubber cutter, the hazard ranking for each failure mode of the cutter can be determined, thereby identifying areas that require reliability improvement. The analysis outcomes demonstrate that this method establishes a theoretical foundation for subsequent cutter improvement designs, enables early identification of potential failures, and consequently leads to a reduced failure rate and an enhanced reliability level for the intelligent profiling progressive automatic cutter. Furthermore, this innovative agricultural equipment reliability analysis and testing approach holds significant value in elevating the reliability standards of agricultural equipment as a whole and can be explored and implemented in other agricultural machinery contexts. [ABSTRACT FROM AUTHOR]

Conjugated polymers (CPs) represent a promising platform for photocatalytic CO2 fixation owing to their suitable band structures that meet the requirements of the reduction potential of CO2 to value‐added fuels. However, the photocatalytic performance of CPs is rather restrained by the low charge transfer efficiency. Herein, we rationally designed three CPs with a more delocalized electronic transmission channel and planar molecular structure, which are regarded to evidently reduce the exciton binding energy (Eb) and accelerate the internal charge transfer process. Besides, the assembly of suitable electron‐output "tentacles" and cocatalysts on the surface of CPs could effectively facilitate interfacial electron delivery. Accordingly, the optimal P‐2CN exhibits an apparent quantum yield of 4.6 % at 420 nm for photocatalytic CO2 to CO. Further adjusting the amounts of cyano groups and cocatalysts, the CO selectivity could be obtained in the range of 0–80.5 %. [ABSTRACT FROM AUTHOR]

Driving oscillatory flow around an obstacle generates, due to inertial rectification, a steady 'streaming' flow that is useful in a host of microfluidic applications. While theory has focused largely on two-dimensional flows, streaming in many practical microfluidic devices is three-dimensional due to confinement. We develop a three-dimensional streaming theory around an obstacle in a microchannel with a Hele-Shaw-like geometry, where one dimension (depth) is much shorter than the other two dimensions. Utilizing inertial lubrication theory, we demonstrate that the time-averaged streaming flow has a three-dimensional structure. Notably, the flow reverses direction across the depth of the channel, which is a feature not observed in less confined streaming set-ups. This feature is confirmed by our experiments of streaming around a cylinder sandwiched in a microchannel. Our theory also predicts that the streaming velocity decays as the inverse cube of the distance from the cylinder, faster than that expected from previous two-dimensional approaches. We verify this velocity decay quantitatively using particle tracking measurements from experiments of streaming around cylinders with different aspect ratios at different driving frequencies. [ABSTRACT FROM AUTHOR]

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by heterogeneous clinical phenotypes. Patients often experience abnormal sensory perception, which may further affect the ASD core phenotype, significantly and adversely affecting their quality of life. However, biomarkers for the diagnosis of ASD sensory perception abnormality are currently elusive. We sought to identify potential biomarkers related to ASD sensory perception abnormality to construct a prediction model that could facilitate the early identification of and screening for ASD. Differentially expressed genes in ASD were obtained from the Gene Expression Omnibus database and were screened for genes related to sensory perception abnormality. After enrichment analysis, the random forest method was used to identify disease-characteristic genes. A prediction model was constructed with an artificial neural network. Finally, the results were validated using data from the dorsal root ganglion, cerebral cortex, and striatum of the BTBR T+ Itpr3tf/J (BTBR) ASD mouse model. A total of 1869 differentially expressed genes in ASD were screened, among which 16 genes related to sensory perception abnormality were identified. According to enrichment analysis, these 16 genes were mainly related to actin, cholesterol metabolism, and tight junctions. Using random forest, 15 disease-characteristic genes were screened for model construction. The area under the curve of the training set validation result was 0.999, and for the model function validation, the result was 0.711, indicating high accuracy. The validation of BTBR mice confirmed the reliability of using these disease-characteristic genes for prediction of ASD. In conclusion, we developed a highly accurate model for predicting ASD sensory perception abnormality from 15 disease-characteristic genes. This model provides a new method for the early identification and diagnosis of ASD sensory perception abnormality. [ABSTRACT FROM AUTHOR]

Conjugated polymers (CPs) have garnered increasing attention in the field of photocatalysis due to their stability and molecular tunability. Understanding the structure–property relationship in CPs and addressing appropriate molecular design strategies are pivotal to improving the photocatalytic performance of CPs. Herein, a new efficient cyano (CN) engineering approach was proposed to promote the photocatalytic performance of CPs, and three representative CP‐based photocatalysts with different CN contents were tailor‐made to investigate the relationship between CN functionalization and photocatalytic activity. A series of systematically experimental and theoretical studies reveal that CN functionalization contributes to strengthening the donor‐acceptor (D‐A) interaction, enhancing the light absorption ability, charge separation/transfer efficiency, and hydrophilicity of CPs, and also facilitating the output of separated photoinduced electrons from CPs to Pt cocatalyst. Thus, the dicyano‐functionalized polymer (P‐2CN) manifests an attractive photocatalytic performance in hydrogen production. This study provides a facile strategy to develop excellent CP‐based photocatalysts for solar fuel production. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii (T.gondii) is a widespread protozoan with significant economic losses and public health importance. But so far, the protective effect of reported DNA-based vaccines fluctuates widely, and no study has demonstrated complete protection. This review provides an inclusive summary of T. gondii DNA vaccine antigens, adjuvants, and some other parameters. A total of 140 articles from 2000 to 2021 were collected from five databases. By contrasting the outcomes of acute and chronic challenges, we aimed to investigate and identify viable immunological strategies for optimum protection. Furthermore, we evaluated and discussed the impact of several parameters on challenge outcomes in the hopes of developing some recommendations to assist better future horizontal comparisons among research. In the coming five years of research, the exploration of vaccine cocktails combining invasion antigens and metabolic antigens with genetic adjuvants or novel DNA delivery methods may offer us desirable protection against this multiple stage of life parasite. In addition to finding a better immune strategy, developing better in silico prediction methods, solving problems posed by variables in practical applications, and gaining a more profound knowledge of T.gondii-host molecular interaction is also crucial towards a successful vaccine. [ABSTRACT FROM AUTHOR]

Since the SARS-CoV-2 outbreak, pharmaceutical companies and researchers worldwide have worked hard to develop vaccines and drugs to end the SARS-CoV-2 pandemic. The potential pathogen responsible for Coronavirus Disease 2019 (COVID-19), SARS-CoV-2, belongs to a novel lineage of beta coronaviruses in the subgenus arbovirus. Antiviral drugs, convalescent plasma, monoclonal antibodies, and vaccines are effective treatments for SARS-CoV-2 and are beneficial in preventing infection. Numerous studies have already been conducted using the genome sequence of SARS-CoV-2 in comparison with that of other SARS-like viruses, and numerous treatments/prevention measures are currently undergoing or have already undergone clinical trials. We summarize these studies in depth in the hopes of highlighting some key details that will help us to better understand the viral origin, epidemiology, and treatments of the virus. [ABSTRACT FROM AUTHOR]

With lightweight, multifunctional, and designable characteristics, porous/lattice structures have started to be used in aerospace applications. Porous/lattice structures applied in the thermal management technology of aerospace vehicles have attracted much attention. In the past few years, many related numerical and experimental investigations on flow, heat transfer, modelling methodology, and manufacturing technology of porous/lattice structures applied in thermal management systems have been widely conducted. This paper lists the investigations and applications of porous/lattice structures applied in thermal management technology from two aspects, i.e., heat transfer enhancement by porous/lattice structures and transpiration cooling. In addition, future developments and challenges based on the previous investigations are analyzed and summarized. With the higher requirements of thermal protection for aerospace applications in the future, thermal management technology based on porous/lattice structures shows good prospects. [ABSTRACT FROM AUTHOR]

Autism spectrum disorder (ASD) is a neurodevelopmental disorder. Abnormal lipid metabolism has been suggested to contribute to its pathogenesis. Further exploration of its underlying biochemical mechanisms is needed. In a search for reliable biomarkers for the pathophysiology of ASD, hippocampal tissues from the ASD model BTBR T+ Itpr3tf/J (BTBR) mice and C57BL/6J mice were analyzed, using four-dimensional (4D) label-free proteomic analysis and bioinformatics analysis. Differentially expressed proteins were significantly enriched in lipid metabolic pathways. Among them, apolipoprotein A-I (ApoA-I) is a hub protein and its expression was significantly higher in the BTBR mice. The investigation of protein levels (using Western blotting) also confirmed this observation. Furthermore, expressions of SphK2 and S1P in the ApoA-I pathway both increased. Using the SphK inhibitor (SKI-II), ASD core phenotype and phenotype-related protein levels of P-CREB, P-CaMKII, and GAD1 were improved, as shown via behavioral and molecular biology experiments. Moreover, by using SKI-II, we found proteins related to the development and function of neuron synapses, including ERK, caspase-3, Bax, Bcl-2, CDK5 and KCNQ2 in BTBR mice, whose levels were restored to protein levels comparable to those in the controls. Elucidating the possible mechanism of ApoA-I in ASD-associated phenotypes will provide new ideas for studies on the etiology of ASD. [ABSTRACT FROM AUTHOR]

In order to optimize the parameters of the mechanism, reduce the pressure loss and improve the efficiency of pneumatic utilization, the principles and types of pneumatic loss in different areas were defined, and the key parameters, including the diameter of the horizontal air pipe, the angle of the air pipe, and the diameter of the negative pressure aperture, which affect the pressure loss, were analyzed. In addition, an orthogonal simulation experiment was carried out using Fluent software, and determined the best parameter combination, which is as follows: the diameter of the horizontal air pipe must be 15 mm, the angle of the air pipe must be 105°, and the diameter of the negative pressure aperture must be 34 mm. It can be concluded from the simulation results that the average airflow velocity of the seed-sucking hole is 102.59 m ⋅ s − 1 , the minimum airflow velocity of the seed-sucking hole is 101.58 m ⋅ s − 1 , and the airflow velocity standard deviation of the seed-sucking hole is 0.54 m ⋅ s − 1 . The trend of the test results was consistent with the simulation results, which verified the reliability of the numerical analysis. These results will provide theoretical guidance for research on the obstruction effect of complex airways on airflow. [ABSTRACT FROM AUTHOR]

Simple Summary: Yaks (Bos grunniens) are one of the most remarkable domestic animals; however, they generally suffer from malnutrition for almost 8 months of the year, which results in yaks displaying a circannual rhythm with seasonal changes. Yaks are ruminant animals whose utilization of dietary nitrogen efficiency is only about 15.9–19.0%; a large amount of N is excreted in feces and urine. A nutritional method could be taken to improve the utilization rate of dietary nutrients and regulate the synthesis of protein. Methionine makes up the first two limiting amino acids in a corn–soybean-meal-based diet for ruminants; therefore, we added the methionine analogues to the diet to investigate its role in yaks, eventually to find an efficient way to feed yaks. This experiment was conducted to investigate the effects of methionine analogues 2-hydroxy-4-methylthio butanoic acid isopropyl ester (HBMi) on growth performance, nutrient apparent digestibility, serum metabolite, serum free amino acids, and rumen fermentation parameters of yaks. Twenty-four male Maiwa yaks (252.79 ± 15.95 kg) were randomly allocated to four dietary treatments: basic diet (CON), or three HBMi (MetaSmart (MS); Adisseo Inc., Antony, France) supplementation treatments: MS1 (5 g), MS2 (10 g), and MS3 (15 g). The results showed that the increase in the supplemented MS levels linearly increased the average daily gain (p < 0.05), while the serum alkaline phosphatase activity and malondialdehyde content were increased when yaks were fed with 15 g/d MS (p < 0.05). The diet supplemented with MS linearly increased the percentages of glutamic acid and proline, and linearly or quadratically decreased the percentages of isoleucine, phenylalanine, and valine (p < 0.05). Furthermore, supplementation of 10 g/d and 15 g/d MS increased ruminal microbial crude protein (p < 0.05). The ratio of acetate to propionate in the MS2 group was lower than those in CON and MS1 groups (p < 0.05). In summary, a diet supplemented with 10 g/d MS could be an effective way to improve the growth performance of fattening yaks without negative effects. [ABSTRACT FROM AUTHOR]

In the past decade, intelligent technologies have advanced rapidly, particularly due to improvements in automatic control, which have had a significant impact on forestry, as well as animal husbandry and the future of farm management. However, the degree of production and management mechanization in natural rubber plantations is low, especially since the methods of tapping still rely heavily on labor. The decrease of skilled rubber tappers and the increase in labor costs have led to the development of the mechanization of rubber tapping operations. The application of emerging intelligent agricultural technologies could provide an alternative in order to maximize the potential productivity of natural rubber. Based on this vision, we reviewed the literature on rubber tapping from the past decade for system implementation in rubber plantations. In this review, selected references on rubber tapping were categorized into several directions of research, including rubber tapping machines, the key technologies applied in tapping operations, and some related protective research, analyzing research works from 2010 to 2022 that focused on tapping methods. The review also discusses the application of intelligent agricultural technologies, such as the recognition of tapping trajectory and tapping path planning. A summary of challenges and future trends is also provided in this study. Based on the relevant research, the use of intelligent technologies in rubber tapping machines is still in its initial stage and has broad prospects. Through this study, we aim to provide a reference for researchers in the field of rubber tapping machines and thus to play a positive role in future rubber tapping. [ABSTRACT FROM AUTHOR]

The object detection algorithm is one of the core technologies of the intelligent rubber tapping robot, but most of the existing detection algorithms cannot effectively meet the tapping trajectory detection of natural rubber trees in the complex forest environment. This paper proposes a tapping trajectory detection method for natural rubber trees based on an improved YOLOv5 model to accomplish fast and accurate detection. Firstly, the coordinate attention (CA) mechanism is added to the Backbone network to embed the location information into the channel attention, which effectively improves the detection accuracy. Secondly, a module called convolution and GhostBottleneck (CGB) is designed, based on the Ghost module, to substitute the Cross Stage Partial Network (CSP) module in the Neck network, which ensures the detection accuracy while reducing model parameters. Finally, the EIoU loss function is introduced to enable a more accurate regression of the model. The experimental results show that the overall performance of the YOLOv5-CCE model outperforms the original YOLOv5 and other classical lightweight detection algorithms. Compared with the original YOLOv5 model, the YOLOv5-CCE model has a 2.1% improvement in mAP value, a 2.5% compression of model parameters, and a 7.0% reduction in the number of floating point operations (FLOPs). Therefore, the improved model can fully meet the requirements of real-time detection, providing a robust detection method for rubber tapping robots. [ABSTRACT FROM AUTHOR]

Aiming at the unsatisfactory sound transmission loss (STL) of thin-plate structures in the low-mid frequency range, this paper proposes an acoustic insulation metamaterial with distributed piezoelectric resonators. A complete acoustic prediction model is established based on the effective medium method and classical plate theory, and the correctness is verified by the STL simulation results of the corresponding acoustic-structure fully coupled finite-element model. Moreover, the intrinsic relationship between the dual equivalent negative properties and STLs is investigated to reveal the insulation mechanisms of this metamaterial. Then, the influence of the geometric and material parameters on the double equivalent negative characteristics is studied to explore the broadband STL for distributed multi-modal resonant energy-dissipation modes in the frequency band of interest. The results show that the two acoustic insulation crests correspond to the dual equivalent negative performances, and the sound insulation in the low-mid frequency range is improved by more than 5 dB compared with that of the substrate, even up to 44.49 dB. [ABSTRACT FROM AUTHOR]

Conservation tillage is becoming increasingly attractive to farmers because it involves lower production costs than does conventional tillage. The long-term effects of sub-soiling tillage (ST), no tillage (NT), and conventional tillage (CT) on soil properties and crop yields were investigated over an 8-year period (2000-07). The study was conducted in a 2-crop-a-year region (Daxing) and a 1-crop-a-year region (Changping) of the Beijing area in China. At 0-0.30 m soil depth, water stability of macro-aggregates (>0.25 mm) was much greater for ST (22.1%) and NT (12.0%) than for CT in Daxing, and the improvements in Changping were 18.9% and 9.5%, respectively. ST and NT significantly (P< 0.05) improved aeration porosity by 14.5% and 10.6%, respectively, at Daxing and by 17.0% and 8.6% at Changping compared with CT treatment. Soil bulk density after 8 years was 0.8-1.5% lower in ST and NT treatments than in CT at both sites. Soil organic matter and available N and P followed the same order ST ≅ NT > CT at both sites. Consequently, crop yields in ST and NT plots were higher than in CT plots due to improved soil physical and chemical properties. Within the conservation tillage treatments, despite similar economic benefit, the effects on crop yields for ST were better than for NT. Mean (2000-07) crop yields for ST were 0.2% and 1.5% higher than for NT at Daxing and Changping, respectively. We therefore conclude that ST is the most suitable conservation tillage practice for annual 2-crop-a-year and 1-crop-a- year regions in the Beijing area. Additional keywords: sub-soiling tillage, soil fertility, aggregate stability, soil porosity, bulk density, yield., Introduction Conventional tillage has been practiced for centuries in China. This method is believed to reduce compaction, provide a favourable seed bed, increase root growth and development, control weeds, and [...]