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In order to address the challenges of inefficiency and insufficient accuracy in the manual identification of young citrus fruits during thinning processes, this study proposes a detection methodology using the you only look once for complex backgrounds of young citrus fruits (YCCB-YOLO) approach. The method first constructs a dataset containing images of young citrus fruits in a real orchard environment. To improve the detection accuracy while maintaining the computational efficiency, the study reconstructs the detection head and backbone network using pointwise convolution (PWonv) lightweight network, which reduces the complexity of the model without affecting the performance. In addition, the ability of the model to accurately detect young citrus fruits in complex backgrounds is enhanced by integrating the fusion attention mechanism. Meanwhile, the simplified spatial pyramid pooling fast-large kernel separated attention (SimSPPF-LSKA) feature pyramid was introduced to further enhance the multi-feature extraction capability of the model. Finally, the Adam optimization function was used to strengthen the nonlinear representation and feature extraction ability of the model. The experimental results show that the model achieves 91.79% precision (P), 92.75% recall (R), and 97.32% mean average precision (mAP)on the test set, which were improved by 1.33%, 2.24%, and 1.73%, respectively, compared with the original model, and the size of the model is only 5.4 MB. This study could meet the performance requirements for citrus fruit identification, which provides technical support for fruit thinning.

As the core of park intelligence, the smart park energy control platform realizes the efficient management and optimal use of park energy by integrating and applying IoT technology. This study focuses on the research development and application of a smart park energy management and control platform using IoT technology, firstly constructing the IoT smart park platform, designing the login module, the park information module, and the energy consumption analysis module, and describing the steps of the smart park energy collection algorithm, and then designing the model of the energy prediction and planning algorithms, i.e.In the construction of the LSTM heating temperature prediction model and the GRU network modeling. Testing and research can be done by using a smart park as an example. The empirical study shows that the construction of the IoT smart park platform can improve the accuracy of monitoring, and the difference between the actual collection results and the system monitoring results is no more than 0.03 kW. After optimizing the configuration, the park’s energy supply system can meet the electric heating and cooling loads with optimal efficiency. Through the comprehensive evaluation of the operation of the extensive energy information monitoring platform, the environmental pollutant emissions are reduced by about 20%, and the platform has a remarkable effect on energy saving and emission reduction.

This paper first calculates carbon emissions based on the carbon emission factor method and other methods and constructs a linear programming model for low-carbon operation of smart parks with economy, independence, and carbon emissions as objective functions, and constrains them from four aspects: power grid, natural gas pipeline network, equipment output, and energy storage battery limit. The problem can be solved using the sparrow optimization algorithm. Finally, the carbon emissions, power dispatching, and power consumption of the sample parks under the low-carbon operation control mode were analyzed. The results show that the carbon emissions of the park are reduced by 2035.93kg, and the total operating cost is reduced by 1680.11 yuan during the typical daily operation in summer after the intelligent optimization algorithm is used. The park’s carbon emissions decreased by 1686.53kg, and the total operating cost decreased by 1582.42 yuan during the typical daily operation in winter. The importance of this study lies in the low-carbon and modernization of smart parks.

This paper focuses on the “Internet + education” model and describes the feasible strategy of using data mining technology to establish a teaching quality monitoring mechanism in colleges and universities. Through the study of teaching quality monitoring pathways, such as teachers’ teaching level, students’ academic status, and course learning effectiveness, this paper’s main content provides a directional guide. Based on the teaching quality monitoring pathway, we choose the related algorithms of data mining technology, such as cluster analysis, association rule, and factor analysis, to be applied to the various aspects of the teaching quality monitoring pathway. The clustering algorithm is used to classify 1500 teachers in a university into 4 categories, such as excellent teaching effect, good teaching effect, etc., as well as to cluster students into 6 categories, such as excellent in all the courses and low to medium level, according to the course grades. In addition, this paper analyzes students’ course learning effectiveness, academic level, and career guidance using association rule algorithms, factor algorithms, and decision tree algorithms, respectively. From teachers’ teaching to students’ learning and employment, this paper constructs an all-round teaching quality monitoring mechanism using data mining technology, which contributes to the improvement of teaching quality in colleges and universities.

The concept of metamaterials offers a flexible pathway to manipulate the macroscopic behavior of light by delicately designed microscopic subwavelength structures, which has been recently introduced to integrated photonics to create devices with ultra-compact footprint, excellent performance or versatile functionalities. However, the conventional design approach of metamaterials, including two separated steps of subwavelength structure design and the assembly of unit cells, often encounters challenges when facing extreme design targets. In this work, we propose a hierarchical inverse design approach by cascading a conventional unit-cell-based design with a holistic topology optimization. As a proof-of-concept, we demonstrate ultra-short-range light focusing and mode-size conversion enabled by on-chip meta-lenses. The shortening of tapering region pushes higher numerical aperture of on-chip lenses, leading to the violation of locally periodic approximation used in meta-lens design and thus poor device performance, which fortunately, can be well compensated by the follow-up holistic optimization step. We experimentally realize mode-size squeezing by almost 20 times in a tapering region as short as 8 μm and 5 μm with low insertion loss and broadband performance. The proposed design scheme provides practical guidelines to design metamaterials as flexible on-chip wavefront control and light routing devices for various applications in fiber communication, sensing and optical computing.

The large scale construction of both military and civil infrastructures located in Nansha reefs and offshore marine areas, South China Sea, has raised the seismic safety a challenging issue for the projects in the region. The influences of fines content (FC) on the liquefaction characteristics of saturated terrestrial quartz sands have been extensively studied, but the corresponding research on saturated coral sands in reclaimed coral islands is less involved. Using the GDS hollow cylinder torsion shear apparatus, a series of isotropically consolidated undrained cyclic tests have been performed on saturated coral sand sampled from the Nansha Islands, South China Sea. The samples are prescribed with the stress path formed under the 90° jump rotation of principal stress with various cyclic loading directions. The influences of the inclination angle (αd) of the major principal stress and fines content FC on the liquefaction characteristics of saturated coral sand are investigated. It has been discovered that, regarding the zero effective stress state as initial liquefaction criterion, the liquefaction resistance of saturated coral sand decreases with the increase of αd for 0°≤αd≤45° and FC for 0%≤FC≤30%. The correlation among the generalized shear strain amplitude (γga), the fines content FC, and the revolution of residual excess pore water pressure of saturated coral soil has been clearified. By introducing a unit cyclic stress ratio USR as a new index for liquefaction resistance and based on binary medium theory, the expression between the unit cyclic stress ratio USR15, inducing initial liquefaction in 15 cycles, and the equivalent skeleton void ratio e*sk for the saturated sands is established for the test. The theory is validated by the experimental data in the literature.

To analyze mechanisms of action of glucocorticoid treatment for endoplasmic reticulum stress (ERS) in sensorineural hearing loss (SNHL), we aimed to evaluate the expression and activation status of the protein kinase RNA-like ER kinase (PERK)–C/EBP homologous protein (CHOP) pathway, which is the major pathway in the ERS.

Both collagen fibres and nanohydroxyapatite crystals have anisotropic magnetisation, which allows them to be oriented by a high magnetic field. Highly oriented nanohydroxyapatite/collagen composites were prepared using a high magnetic field combined with in situ synthesis. These highly oriented composites were investigated and compared with conventional composites. The results showed that the collagen fibres in the magnetically induced highly oriented nanohydroxyapatite/collagen composites had a preferred orientation and smaller molecular spacing, while the nanohydroxyapatite crystals were tightly adhered along the collagen fibre surface. The magnetically induced composites exhibited superior resistance to swelling and degradation along with high compressive strength. This artificial composite, with a structure and composition similar to natural bone, represents a new idea for improving materials for vertical or horizontal bone augmentation.

Freezing and thawing processes can change the structure of frozen soil and reduce the mechanical properties, thus affecting the stability of engineering infrastructures built in frozen soil. Due to the different settings of freeze-thaw cycles, a large number of experimental results cannot be effectively compared and analyzed. In addition, estimating the soil mechanical characteristics under freeze-thaw action has also become a research difficulty. In this paper, based on the frozen soil genetic creep theory, a spherical indenter is developed, and a freeze-thaw cycle–physical time analogy method is proposed. Using the number of cycles (numbers of freeze-thaw cycles) and the duration time (physical time–minutes), we can obtain the long-term strength curve family of the frozen soil and mapping the curve family into the same stress space to achieve the normalized strength curve, and thus we can predict the long-term deformation and shear strength. Finally, two soil samples are selected for testing, and the relevant equations for predicting the long-term shear strength are obtained. This method has important theoretical significance for the comparative study on the mechanical behavior of frozen soils under freeze-thaw actions. It also has value for engineering practice and stability analysis of infrastructures built in cold regions.

Pollution of mycotoxigenic fungi and their toxins seriously affect the safety of grain, oil and food.The development and application of natural preservatives are important technologies and research areas in the field of food microbial control. Inhibitory effect of trans-2-methyl-2-pentenoic acid as a natural food flavor on the growth of Aspergillus flavus was determined in vitro by contact assay and in vivo in stored peanut seeds, with sorbic acid as a positive control. The results showed that trans-2-methyl-2-pentenoic acid exhibited a stronger inhibitory effect than sorbic acid. The MIC (Minimum Inhibition Concentration) values of trans-2-methyl-2-pentenoic acid and sorbic acid on A. flavus were 0.6 and 1.0 g/L, respectively. Moreover,trans-2-methyl-2-pentenoic acid had a 100% inhibitory effect on the control of A. flavus in stored peanut seeds at 10.0 g/L, while a higher concentration of 20.0 g/L was needed for sorbic acid to achieve the same control effect. The results indicate that trans-2-methyl-2-pentenoic acid as a natural food flavor shows significant antifungal effect, and has high potential for the development of natural food preservatives.

A degrading enzyme PADE produced during the degradation of aflatoxin B1 (AFB1) by the laboratory screening bacteria M19 was selected as the subject in this study. Thin layer chromatography and fluorescence spectrum analysis were performed to analyze possible structural changes of products in the AFB1 degradation solution. Mass spectrometric were further used to detect the AFB1 degradation products.The results of thin layer chromatography showed that no new fluorescent absorbent substance was detected in the organic phase degradation solution, and no absorbent substance was detected in the aqueous phase degradation solution, indicating that the degradation product did not have fluorescence absorption. The fluorescence spectrum detection results showed that the fluorescence of the AFB1 degradation product was decreased obviously. The mass spectrometry results showed that a substance P with a mass-to-charge ratio of 227.18 was found. Based on all the results, it can be concluded that the lactone bond was broken during the degradation of AFB1, and a degradation product P with a molecular weight of 226 was generated. The molecular formula was C14H10O3 as analyzed by Xcalibur software. The degradation pathway was hypothesized.

Zearalenone (ZEA) has strong reproductive toxicity, mutagenicity and teratogenicity. A rapid visual aptasensor for sensitive and specific detection of zearalenone (ZEA) was developed in this study based on gold nanoparticle (AuNP) aggregation induced by the competitive absorption of aptamer between gold nanoparticle and zearalenone. The results showed that a good linear correlation between the concentration of ZEA and the absorbance of AuNPs was found within the range of 5-200 ng·mL-1, the linear regression equation is y= 0.248 6+0.000 461 56x (R2=0.990 2). And the detection limit was 5 ng / ml with a good specificity. Furthermore, the sensitivity of the assay was further enhanced 50 times by combining with argentation amplification strategy. The reliability of the developed assay for detecting the actual corn and corn oil samples were verified by comparing with those detected by commercial ELISA kit. These results demonstrated that the developed assay has great potential in the rapid and specific detection of ZEA in foodstuffs.

In this paper, a transcritical carbon dioxide power generation system based on a vortex tube is studied, which has the advantage of the self-condensation of carbon dioxide. The thermodynamic performance of the system was investigated by establishing a mathematical model. The results showed that under fundamental working conditions, the system could output a net power of 271.72 kW, and the thermal efficiency as well as the exergy efficiency of the system could reach 7.38% and 27.09%, respectively. Exergy analysis showed that the turbine had the greatest exergy loss among the system’s components, followed by the vortex tube, pump, heater and cooler. Parameter analysis showed that increasing the outlet pressure and inlet temperature of the vortex tube can improve the thermal efficiency and exergy efficiency of the system. In addition, the improvement in the turbine component’s efficiency is the most beneficial to the system’s performance, among which the turbine’s efficiency has the greatest impact. Carbon dioxide can be effectively liquified by expanding it in the vortex tube, and its liquefaction ratio increases with the decrease in the vortex tube’s inlet temperature and the increase in the vortex tube’s inlet pressure.

A 56-year-old man underwent stenting for treatment of coarctation of the aorta. He subsequently developed severe abdominal pain and paradoxical postoperative hypertension. Abdominal computed tomography revealed two long mesenteric artery lesions. After potent antihypertensive therapy, he did not develop intestinal necrosis, and he was discharged with no recurrent abdominal pain. Although postcoarctectomy syndrome is rare in the current era of nonsurgical intervention for coarctation of the aorta, it can still occur and should be carefully managed to prevent intestinal necrosis.

Neuroglial cells have a high level of plasticity, and many types of these cells are present in the nervous system. Neuroglial cells provide diverse therapeutic targets for neurological diseases and injury repair. Cell reprogramming technology provides an efficient pathway for cell transformation during neural regeneration, while transcription factor-mediated reprogramming can facilitate the understanding of how neuroglial cells mature into functional neurons and promote neurological function recovery.

Separation is the primary consideration in cloud computing security. A series of security and safety problems would arise if a separation mechanism is not deployed appropriately, thus affecting the confidence of cloud end-users. In this paper, together with characteristics of cloud computing, the separation issue in cloud computing has been analyzed from the perspective of information flow. The process of information flow in cloud computing systems is formalized to propose corresponding separation rules. These rules have been verified in this paper and it is shown that the rules conform to non-interference security, thus ensuring the security and practicability of the proposed rules.

Network evasions can bypass network intrusion detection/prevention systems to deliver exploits, attacks, or malware to victims without being detected. This paper presents a novel method for the detection and recognition of atomic network evasions by the classification of a transmission control protocol (TCP) stream's packet behavior. The syntax for the conversion of TCP streams to codeword streams is proposed to facilitate the extraction of statistical features while preserving the evasion behavior attributes of original network flows. We developed a feature extraction method of employing the normalized term frequencies of codewords to characterize intra and inter packet attribute patterns hidden in actual TCP streams. A TCP stream is then transformed to a fixed length numeric feature vector. Supervised multi-class classifiers are built on the extracted feature vectors to differentiate different types of evasions from normal streams. The quantitative evaluations on an evasion dataset consisting of normal network flows and eight types of atomic evasion flows demonstrated that the proposed approach achieved an encouraging performance with an accuracy of 98.95%.

Introduction: The extremely high genetic variation and the continuously emerging variants of foot-and-mouth disease virus (FMDV) of Southern African Territory (SAT) serotypes including SAT1, SAT2, and SAT3 make it necessary to develop a new RT-PCR for general use for monitoring viruses based on the updated genome information.

The dust control basis of fully mechanized mining face is clear dust source characteristics. In view of the problem of unclear dust source and unknown distribution characteristics in the working area of 7.8 m large fully mechanized mining face, the fully mechanized mining face of Shendong Bulianta Coal Mine is selected as the The research object adopts the method of combining numerical simulation and field measurement to study the dust migration law based on the single action and joint action of the two main dust sources of shearer cutting coal and column moving frame, and obtains the dust migration law. According to the characteristics, the distribution of respirable dust concentration in the breathing zone of personnel in the vicinity of the shearer was further analyzed. The results show that the dust produced by dropping the column and moving the frame has the greatest impact on the dust concentration in the operator’s area. The maximum value of the respirable dust concentration in the operator’s area when cutting coal downwind and upwind is in the middle of the shearer, and originates from the shearer cutting coal. The proportions of dust source and column-moving dust source were 44.50% and 76.69%, respectively. The dust traceability research can provide a theoretical basis for the targeted management of dust in fully mechanized mining face with large mining height.