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Background The prevalence of allergic diseases is rapidly increasing among the global population, affecting 10%-40% of people worldwide. Allergic diseases often begin in childhood. So far, data for analyzing the trends in the incidence of pediatric allergic diseases in China over the past decade are scant. This study aims to provide an epidemiological support for the prevention and management of pediatric allergic diseases in China by mining electronic medical record data from a single-center institution. Objective To analyze the annual proportion and trend of outpatient visits for allergic diseases among children aged 0-18 years in the Beijing Children's Hospital, Capital Medical University from 2014 to 2021. Methods A retrospective analysis of outpatient electronic medical records from the hospital information system of Beijing Children's Hospital, Capital Medical University from 2014 to 2021 was conducted to examine the annual proportional composition and changes in the trend changes of allergic diseases. The gender- and age-based proportions of different allergic diseases including eczema, urticaria, allergic rhinitis, bronchial asthma, allergic cough, allergic conjunctivitis, food allergies, drug allergies, pollen allergy, and anaphylaxis were calculated. The trend of changes in the proportion of allergic diseases with stable annual composition ranking in the top 10 was further analyzed. Results From 2014 to 2021, there were a total of 1 231 890 outpatient visits for pediatric allergic diseases in our center. After excluding missing data, a total of 1 231 863 eligible cases were included, involving 727 082 (59.0%) boys and 504 781 (41.0%) girls. The majority of children visited for allergic diseases were under the age of 3 years (46.9%). Non-IgE mediated allergic diseases, such as henoch-schoenlein purpura, bronchitis, and respiratory tract infections were excluded, and the remaining 1 208 265 cases included in the disease spectrum analysis. From 2016 to 2021, the proportion of outpatient visits for pediatric allergic diseases in Beijing Children's Hospital, Capital Medical University showed an upward trend. From 2014 to 2017, the top 5 allergic diseases visited in the outpatient department were eczema, urticaria, allergic rhinitis, bronchial asthma, and allergic cough. From 2018 to 2021, allergic rhinitis, eczema, urticaria, allergic conjunctivitis, and bronchial asthma ranked the top 5. The trend analysis for an annual proportion of pediatric allergic diseases showed that the ratios of allergic rhinitis, allergic conjunctivitis, and food allergies among all allergic diseases from 2014 to 2021 showed an increasing trend, with peak ratios of 45.4%, 11.1% and 2.8%, respectively. The ratios of urticaria, eczema, and bronchial asthma showed a decreasing trend, with peak ratios of 46.5%, 24.9% and 11.3%, respectively. Conclusion From 2016 to 2021, the proportion of outpatient visits for pediatric allergic diseases in Beijing Children's Hospital, Capital Medical University showed an upward trend. Between 2014 and 2021, the annual proportions of allergic rhinitis, allergic conjunctivitis, and food allergies exhibited an increasing trend, while the annual proportions of eczema, urticaria, and bronchial asthma demonstrated a decreasing trend.

The supercritical carbon dioxide (SC-CO2) jet has a wide application prospect in drilling engineering, and its low coal breaking pressure threshold and high efficiency can improve drilling efficiency. But it has the problems of high coal breaking threshold pressure and system energy consumption, which limits its application. The high pulse pressure and resonance effect of the self-excited oscillation pulse SC-CO2 jet can effectively reduce the coal breaking threshold pressure and significantly improve the coal breaking efficiency. Based on this, the variation law and comprehensive effect of the self-oscillating pulse SC-CO2 jet pulse frequency and pulse pressure amplitude at different target distances were studied. Large eddy simulation was used to analyze the flow field structure of the jet, and the variation laws of the pulse frequency and pressure amplitude in the axial direction of the flow field were clarified. The effect of the target distance on the impact frequency and impact pressure of the jet was studied by pulse characteristics test experiment, and the comprehensive effect of pulse characteristics on coal breaking was studied by coal breaking experiment. It was concluded that the pulse frequency and pulse pressure amplitude of the self-oscillation pulsed SC-CO2 jet do not remain constant in the axial direction of the jet, and they gradually decrease with the increasing target distance. Considering only the pulse frequency cannot maximize the resonance effect, and it is necessary to comprehensively consider the influence of pulse frequency and pressure amplitude on the resonance effect. Using displacement response amplitude to characterize resonance effect can reflect the comprehensive influence of frequency and amplitude on resonance. When the target distance is small, from 0 mm to 15 mm, the main influencing factor of the displacement response amplitude is the pulse pressure amplitude. When the target distance is large, from 15 mm to 30 mm, the main influencing factor is pulse frequency. In addition, reducing the pulse frequency and increasing the pressure amplitude can effectively improve the displacement response amplitude. The transition positions of the main influencing factors of displacement response amplitude under different nozzle structure conditions are different, and the optimal target distance is also not the same. In this study, the optimal target distance for nozzle a is 22 mm, where the displacement response amplitude is the largest and the coal breaking effect is the best, while the optimal target distance for nozzle b is 26 mm.

Objective: To predict the mechanism of sea buckthorn in the treatment of alcoholic liver injury based on network pharmacology, and to verify the efficacy of sea buckthorn in the treatment of alcoholic liver injury by establishing an animal model of alcoholic liver injury in zebrafish. Methods: Through the traditional chinese medicine systems pharmacology (TCMSP) and Uniprot database, the effective components and their targets were collected. Venny2.1 was used to find the intersection targets. GeneCards and OMIM databases were used to collect and screen disease targets. STRING v12.0 database was used for PPI network analysis. PDB and PubChem were used to confirm protein structure and small molecular structure. The correlation network of sea buckthorn in the treatment of alcoholic liver injury was constructed by Cytoscape (Version 3.9.1) software network diagram. Gene ontology (GO) and Kyoto encyclopedia of genes (KEGG) database pathway enrichment analysis were performed on the common targets using the Metascape database. Functional verification was performed by zebrafish experiments: Wild-type AB strain zebrafish 3 days after fertilization (3 dpf) were selected. The normal group was fed with normal feeding water, and the other groups were fed in 2% anhydrous ethanol solution to establish an alcoholic liver injury model. Results: After screening, 33 active components of sea buckthorn were obtained, mainly including quercetin, sunflower, catechin and so on. There were 1434 potential targets for the treatment of alcoholic liver injury, including ADH1C, CTNNB1, TGFB1 and so on. The signaling pathways that regulate these core targets are mainly enriched in multiple signaling pathways such as lipid and atherosclerosis, fluid shear stress and atherosclerosis and PI3K-Akt signaling pathway. The results of animal experiments showed that sea buckthorn had the effect of reducing the opacity value of zebrafish liver in alcoholic liver injury model (P

Sjögren's syndrome (SS) is a prevalent systemic autoimmune disease, primarily affecting exocrine glands, characterized by lymphocyte and plasma cell infiltration. Patients typically exhibit dry mouth and eyes, with potential involvement of the digestive tract, lungs, and kidneys. In China, SS prevalence ranges from 0.29% to 0.77%, rising to 3.00%-4.00% among the elderly. In Europe, the prevalence is approximately 0.23%. The pathogenesis of SS involves interactions of multiple cells and cytokines, including salivary gland epithelial cells, T-cells, B-cells, dendritic cells, interferon (IFN), interleukin (IL), tumour necrosis factor (TNF) and inflammasomes. Currently, glandular therapy for SS is primarily localised, while treatment for systemic involvement is mainly borrowed from other autoimmune diseases, with no approved targeted drugs yet. Among the targeted therapeutic agents for SS, rituximab, a B-cell targeted therapy, is the most studied and has shown improved salivary efficacy in SS patients with cryoglobulin vasculitis. BAFF inhibitors, CD40 targeting agents, and mesenchymal stem cells have also demonstrated cartain therapeutic effects. For most systemic involvement, glucocorticoids (GCs) are the first-line treatment, while immunosuppressants and biologics serve as second-line options for GCs-tolerant or resistant patients. Although many potential therapeutic targets have been identified, few drugs have been clinically translated. Currently, there is a need to develop relatively safe and effective treatment regimens with minimal adverse effects through comprehensive patient assessment and multidisciplinary collaboration. Future SS drug research will focus on targeted therapies, adverse effects reduction, and multi-drug combinations.

The SC-CO2 jet drilling and completion technology can ensure the stability of coalbed methane wells, improve drilling speed and rock breaking efficiency, and has a wide application prospect. However, the high energy consumption and complex system of coal breaking limit its engineering application. The impact frequency of self-excited oscillation pulse SC-CO2 jet is the same as the natural frequency of coal and rock mass or satisfies the phase relationship, which can give full play to the resonance effect and achieve a better coal breaking effect. The nozzle structure is the key to affect the jet impact frequency. The existing frequency modulation method of self-resonating pulsed water jet is not suitable for the SC-CO2 jet. In order to realize the modulation of the impact frequency of the SC-CO2 jet, a large eddy simulation was used to study the influence law of different nozzle structures on the impact frequency of self-excited oscillation pulse SC-CO2 jet, and the influence degree of different nozzle structure parameters on jet impact frequency was obtained by weight analysis. The influence rule of nozzle structure on the jet impact frequency and the reliability of jet impact frequency modulation method are verified by jet impact frequency measurement experiment and coal breaking experiment. The results show that the diameter and length of the oscillating cavity, and the angle of the collision wall are the key factors affecting the jet impact frequency. The jet impact frequency can be substantially modulated by adjusting the structure of the oscillating cavity, so as to achieve the resonance effect. By adjusting the oscillating cavity structure, the jet impact frequency forms resonance with the inherent frequency of coal, then the coal breaking effect is significantly improved, and the smaller the resonance multiplier, the better the coal breaking effect of the jet, which can effectively improve the coal breaking efficiency. When the natural frequency of coal is 25 Hz, the outlet diameter of the upstream and downstream nozzle is set as 2.5 mm and 3.0 mm, and the diameter, length and angle of the oscillating chamber are adjusted to 10 mm, 3 mm and 120° respectively. The jet impact frequency reaches 25051.83 Hz, which is 1002.0 times of the natural frequency of coal and forms a resonance effect with the natural frequency of coal, effectively improves the coal breaking efficiency.

BackgroundNonylphenol (NP) is a typical phenolic endocrine disruptor, and there are significant differences in NP concentration in different regions and water types. ObjectiveTo investigate the concentration of NP in three types (river, lake, and reservoir) of water sources in Hubei Province, and assess its ecological risk and population health risk. MethodsFifteen sampling points were set up at four river water sources (Liangtingshan Waterworks, Baishazhou Waterworks, Dijiao Waterworks, and Zongguan Waterworks), one lake water source (Liangzi Lake), and one reservoir water source (Fushui Reservoir). Water samples were collected from the 15 sampling points in June 2019 (wet season), October 2019 (level season), and December 2019 (dry season), respectively. The NP concentration in water samples was detected using ultra-high-performance liquid chromatography-tandem mass spectrometry, and the differences in NP concentration among groups were compared using variance analysis. The ecological risk and the health risk of NP were evaluated using risk quotient (RQ) and non-carcinogenic risk index (NCRI), respectively. ResultsThe detection rate of NP was 100%, with an average concentration of (18.10±15.00) ng·L−1 (5.45-92.71 ng·L−1). The average concentrations of NP during the level, wet, and dry seasons were (11.52±5.31) ng·L−1, (23.86±22.08) ng·L−1, and (18.93±9.51) ng·L−1, respectively, and the maximum concentrations were 24.62 ng·L−1, 92.71 ng·L−1, and 42.38 ng·L−1, respectively. The variance analysis showed no statistical difference in the NP concentration in the samples from rivers, lakes, and reservoirs in different periods (P>0.05). Only the water samples from the water source serving the Zongguan Waterworks showed an RQ (0.19) greater than 0.1 during the wet season, indicating a moderate risk. The RQ values of other water samples were all less than 0.1, indicating an overall relatively low ecological risk. The highest NCRI values during the level, wet, and dry seasons were 0.1459, 0.5492, and 0.2511, respectively, all less than 1, indicating an acceptable health risk level. ConclusionThe NP concentrations in all water sources in this study are at a relatively low level, which poses an acceptable risk level to human health.

To explore the metabolites differences of grilled fish in different packages, liquid chromatography-tandem mass spectrometry was used to analyze and compare the metabolite profile of prefabricated grilled fish in tray packaging, vacuum packaging and modified atmosphere packaging through non-targeted metabolomics. The results showed that 318 metabolites were identified under secondary mass spectrometry information in the prefabricated grilled fish with different packaging. In this study, 47 differential metabolites were identified, including 10 fatty acids, 10 nucleotides, 9 amino acids, 7 organic acids and derivatives, 3 benzene and derivatives, 2 alcohol amines, and 6 unconfirmed metabolites, based on the variable importance projection value (VIP, VIP>1) and P

Ship detection is one of the most important applications of polarimetric Synthetic Aperture Radar (SAR) systems. Current ship detection methods are susceptible to side flap interference, making it difficult to extract the target shape correctly. In addition, when ships are exceedingly dense and have different scales, adjacent ships may be considered as a single target because of the influence of strong sidelobes, causing missed detections. To address the issues of sidelobe interference and multi-scale dense ship detection, a ship detection method based on the polarimetric SAR gradient and the complex Wishart classifier is proposed. First, the Likelihood Ratio Test (LRT) gradient is introduced into the log-ratio gradient framework to apply it to the polarimetric SAR data. Then, a Constant False Alarm Rate (CFAR) detector is applied to the gradient image to map the ship boundaries accurately. Second, the complex Wishart iterative classifier is used to detect the strong scattering part of the ship, which can eliminate most clutter interference and maintain the ship’s shape details. Finally, the LRT detection and complex Wishart classifier detection results are fused. Thus, not only the strong sidelobe interference can be greatly suppressed, but the dense targets with different scales are also distinguished and accurately located. This study performs comparative experiments on three polarimetric SAR images from the ALOS-2 satellite. Experimental results show that compared with the existing methods, the proposed algorithm has fewer false alarms and missed detections and can effectively overcome the problems of sidelobe interference while maintaining the shape details.

Cereal foods are the primary source of daily energy, protein, and dietary fiber intake for humans. With the continuous improvement of people's living standards, cereal foods' nutritional value, safety, and food quality have attracted much attention. Cereal metabonomics, as a new and rapidly developing branch of "metabonomics", has made rapid progress in quantifying and analyzing various metabolites. This article reviews the analysis process of metabolomics technology, and its application in the detection of component identification, the identification of flavor substances, the traceability of origin, and the product of new developments in cereal foods, and the development trend of metabonomics in cereal food field has prospected, to provide a reference for the in-depth development and application of cereal foods.

Protection, dispersion and delivery of the functional components can implement in the emulsion-encapsulating systems. Among the stabilizers of the emulsion, specific structure of the cellulose may improve the stability of the system, and supplying the utilization of the bioactive substances on encapsulation and release. Therefore, the recent advances on stabilizing mechanism, cellulosic materials, properties of bioactive substances and factors affecting on the release of cellulosic emulsion-encapsulating systems are summarized in this review. In addition, the paper focuses on the release process and regulated mechanism of cellulose, which shows high length-diameter ratio and mechanical strength in the emulsion-delivery system of bioactive substances, and providing reference for the development of the food-grade delivery system. Studies indicates that cellulose-stabilized emulsion can improve the dispersion and oxidation stability of the bioactive substances, while controlling the release and improving the bioavailability of the functional factors. However, there is still vast research space for its safety evaluation in the food system, and related toxicological experiments urgently need to be carried out.

With the ready-to-heat prepared grilled fish as study subject, the moisture distribution and volatile flavor compounds of grilled fish under different electric grilling conditions were investigated by LF-NMR and HS-SPME-GC-MS detection technology. The results showed that the lowest processing loss and the highest water holding capacity were found in the grilled fish baked at 250 °C for 20 min. The main form of water in grilled fish was non-flowable water, with the lowest relaxation times T22 and T23 for grilled fish at 200 °C, followed by grilled fish at 250 °C. The T2 inversion spectrum shifted to the left overall, indicating that the degree of freedom of water molecules decreased. Grilled fish at 250 °C for 20 min had the highest percentage of peak area of non-flowable water (A22) that up to 94.03%, and had the lowest percentage of peak area of free water (A23) as low as 1.93%, indicating that muscle tissue hold water better. A total of 70 volatile compounds were identified in five groups of grilled fish, including aldehydes, ketones, alcohols and hydrocarbons. The key volatile flavor compounds were screened by their relative odor activity values as 12, 9, 11, 8 and 8, respectively. The flavor compounds that contributed significantly to the five groups of samples were hexanal, 1-octen-3-ol and nonanal, with guaiacol and 4-methylphenol being the key flavor compounds specific to charcoal grilled fish. The key volatile flavor compounds of grilled fish baked under different conditions differed significantly by principal component analysis. Correlation analysis showed that A22 was significant positively correlated with isovaleraldehyde, heptanal and 2,3-octanedione (P

In recent years, several small and rich lithologic oil and gas reservoirs have been discovered in the saline lacustrine beach bar sand in the Qaidam Basin. In order to expand the exploration scale of lithologic oil and gas reservoirs, find new exploration targets and zones, and increase storage and production of oilfields, based on coring, logging and seismic data, the controlling factors of oil and gas accumulation in lithologic reservoirs are defined, and some exploration succeeding fields of lithologic reservoirs are pointed out. The results show that: The southwestern Qaidam Basin has four favorable conditions for the formation of lithologic reservoirs. The first is the development of three stable ancient slopes, namely, the Qigequan-Hongliuquan, Shaxi-Yuejin, and Zahaquan-Wunan, which are inherited and conducive to the accumulation of oil and gas. The second is the proximity of two hydrocarbon generation centers, Hongshi and Zahaquan, with superior oil source conditions. The third is that the salt lake basin developed large braided river delta, widely distributed shoal-bar sand and algal hill-gray cloud flat deposits, forming two complementary types of reservoirs of clastic rock and carbonate rock. The fourth is the development of a variety of drainage systems, which can form several sets of oil-bearing strata vertically. Controlled by paleo-structural, sedimentary and diagenetic factors, there are four types of lithologic reservoirs in the southwestern Qaidam Basin: updip pinching out, sandstone lens, physical sealing and dolomitization trap. Lithologic reservoirs are controlled by three factors: paleo-structure, high-quality source rock and effective reservoir. Paleo-structure determines the type of lithologic traps and the direction of hydrocarbon migration. The high-quality source rock controls the distribution and scale of lithologic reservoirs and effective reservoir controls the accumulation of lithologic reservoirs. Comprehensive evaluation shows that the braided river delta front sand body is a favorable area for the exploration of lithologic reservoirs in the lower Ganchaigou Formation of the Lower Paleogene, mainly distributed in the basin dip end of Shaxi, Gasi, and Wunan. The dolomitization trap is a favorable area for exploration of lithologic reservoirs in the upper member of lower Ganchaigou Formation of Paleogene, mainly distributed around the Hongshi Sag. The widely distributed beach bar is a favorable area for lithologic oil exploration in the upper Ganchaigou Formation and lower Youshashan Formation of Neogene, mainly distributed in Yingxiongling, Gasi, Zhahaquan, Wunan, and other areas. This understanding supports a series of major breakthroughs in lithologic exploration, such as well Qietan 2 and the new series of Gasi, with important guiding significance for further exploration of lithologic reservoirs in the southwestern Qaidam Basin.

To address issues like edge collapse and subsurface damage during the cutting process of SiC wafers, a model for cutting SiC wafers with ultra-thin diamond blades was established by combining Python language and Abaqus finite element analysis software. The effects of cutting parameters on cutting force, cutting temperature, wafer cutting edge morphology, cutting edge damage width and subsurface damage depth of wafer were studied. The results show that cutting force and cutting temperature are positively correlated with cutting depth, and there is an optimal value for the damage degree of the cutting edge and the subsurface damage depth. When the cutting depth is 6 μm, the cutting effect of SiC wafer is the best. The surface cutting edge damage width is 8 μm, the damage area is 4 905.56 μm2, the subsurface damage depth is 10.67 μm and the damage area is 7 022.18 μm2. In the high-speed cutting stage, where the cutting speed ranges from 60 to 121 m/s, cutting speed has no significant effect on cutting force, wafer temperature, wafer cutting edge morphology or subsurface damage.

The medium and deep underground coal gasification (UCG) is a new technology of coal utilization, and there is still lack of criterions to evaluate recovery rate. The strength of remaining wall between the gasification chambers and the gas permeability are two important factors indicating the safety of the formation. To ensure the safety of the formation after gasification, the recovery rate was defined according to the wall strength and seam permeability theory. Firstly, the stress distribution of target coal seam under the influence of the multiple factors was analyzed through the finite element method, and the critical conditions of crack under different loads were analyzed. The minimum wall thickness between the gasification chambers was determined under different conditions, such as different shape of the gasification chamber, different thickness of the coal seam, and different formation pressure and working pressure. Secondly, the Darcy Law was used to analyze the coal seam permeability quantitatively. Thirdly, the amount of coal could be used by the underground coal gasification process was calculated, and the recovery rate of underground coal gasification was defined based on the mining rate of coal and the recovery rate of crude oil. Finally, the recovery rates of different formation thicknesses and different gasification chambers were calculated and analyzed. The research results reveal that the recovery rate of UCG cannot be measured by the mining rate. Due to the cylindrical/conical shape of the gasification chamber, the recovery rate is lower than that of coal mining. Because a wall between the gasification chambers is kept to support the roof rock, the recovery rate of UCG is reduced further. With the increase in the wall thickness, the recovery rate decreases. However, the influence of wall thickness on the thick coal seam is minor, while the influence on the thin coal seam is greater. The thicker the coal seam, the thicker the wall between the chambers. On the other hand, the recovery rate of thick coal seam is greater than that of thin coal seam, especially for the pear-shaped gasification chamber. Different from coal mining, the recovery factor of UCG is affected significantly by the thickness of the coal seam. If a pear-shaped gasification chamber is used, the mining value of thin coal seam is low. Underground coal gasification provides a solution for deep coal mining and utilization. Since no UCG recovery rate evaluation method has been established universally, the results of this work provide a reference for the site selection, resource evaluation and gasification process of underground coal gasification, as well as the formulation of UCG recovery rate criterions.

The postmortem interval （PMI） estimation is a key and difficult point in the practice of forensic medicine, and forensic scientists at home and abroad have been searching for objective, quantifiable and accurate methods of PMI estimation. With the development and combination of high-throughput sequencing technology and artificial intelligence technology, the establishment of PMI model based on the succession of the microbial community on corpses has become a research focus in the field of forensic medicine. This paper reviews the technical methods, research applications and influencing factors of microbial community in PMI estimation explored by using high-throughput sequencing technology, to provide a reference for the related research on the use of microbial community to estimate PMI.

In hepatocytes, autophagy and ferroptosis, as important biological processes in cells, play important roles in maintaining lipid accumulation homeostasis, oxidative stress and lipid peroxidation balance. Here we reviewed the impact of autophagy on the abnormal lipids accumulation in the process of liver lipid metabolism, and its relationship with ferroptosis, which was marked by oxidative stress and lipid peroxidation. The impact of the interaction between autophagy and ferroptosis on the course of non-alcoholic fatty liver disease (NAFLD) might provide some new ideas for the treatment of NAFLD.

With industrial development and innovation, the demand for key metal minerals dominated by rare earth elements is increasing day by day. More experts believe that coal measures mineral resources have the potential to obtain key metal minerals, and such resources have therefore received high attention at home and abroad. Huaibei coalfield in China is rich in coal resources. In order to study the geochemical characteristics of trace elements in its coal and judge the industrial potential of rare metals, No. 5 coal, No. 8 coal and No. 10 coal in Zhuzhuang Coal Mine were selected as the research objects. The samples were analyzed by means of industrial analysis, XRF and ICP-MS. The results show that compared with the world coal, most trace elements in Zhuzhuang Coal Mine are highly enriched, such as Li, Cr, Co, etc. Compared with 5 coal and 8 coal, the concentration of trace elements in 10 coal is low, and the contents of V, Mn, Rb and Cs belong to the normal range. Through the analysis of w (Al2O3)/ w (TiO2) ratio and element geochemical characteristics, it is concluded that the sedimentary source area of the study area is felsic source rock, the paleosalinity from Shanxi formation to Lower Shihezi Formation changes from marine facies to saline water facies, and the paleoclimate is a warm and humid reduction environment. In addition, rare earth elements are enriched in light and medium rare earth elements, and Eu, Y positive anomalies and Ce negative anomalies all show that the sedimentary environment of Zhuzhuang mine is affected by seawater and magmatic hydrothermal solution. Therefore, the abnormal enrichment of trace elements in Zhuzhuang Coal Mine may be affected by the sedimentary environment, seawater and hydrothermal solution. In addition, the study area is relatively rich in rare earth elements, and its total content is close to or even higher than the industrial grade. Through the comparison of REY prospect coefficient (Coutl) and a variety of sediment minerals, it is considered that the rare earth elements of coal 5 and coal 8 in the sample of the study area are promising as REY raw materials, while the effect of coal 10 is poor.

Intelligent radar image recognition based on Deep Neural Networks (DNN) has become an important topic in radar information processing. However, DNN models are susceptible to adversarial attacks. Malicious attackers can cause intelligent image recognition models to make incorrect predictions, considerably reducing their recognition accuracy and robustness. This article reviews recent research progress on intelligent radar image recognition countermeasures. Then it summarizes the adversarial attack methods on one/two-dimensional radar image recognition models and adversarial defense methods. Finally, it discusses five open questions worthy of in-depth research in intelligent radar image recognition countermeasures.

Herein, a novel and effective method for detecting radar targets with a low signal-to-clutter ratio is proposed based on the information geometry theory. In the proposed method, the target detection problem is converted to distinguishing the target from a clutter background on a manifold. However, this is challenging when dealing with small and weak targets embedded in a complex and strong clutter background, which limits the detection performance. Therefore, to address this issue, an orthogonal projection based subband information geometry detection method is proposed. In this method, the received radar signal undergoes subband decomposition by a designed filter bank, and the robust estimation of clutter signal subspace in each subband is implemented on the matrix manifold. Subsequently, the suppression of the strong clutter is achieved through orthogonal projection based on the manifold, thereby improving the discrimination between the target and the clutter. Finally, the effectiveness of the proposed method is evaluated using simulated and real sea clutter data. The experimental results confirm that the proposed method effectively suppresses strong clutter and exhibits excellent detection performance.

Oxidation reaction in food is related to chronic diseases and rancidity, shortening the nutritional value and shelf life of products. In recent advances, the amino acid, sort order and spatial conformation of the antioxidant peptides is wildly reported. The structure-function relationship of antioxidant peptides has become the main factors on the determination of the antioxidant mechanisms. However, compared with the significant antioxidant effect of the peptides from land animals, such structure-function relationship of the antioxidant peptides in the fish, which is rich in proteins, is seldom reported. Therefore, antioxidant mechanisms of the peptides from fish, such as scavenging the intracellular reactive oxygen species in vivo, scavenging the free radicals in vitro and chelating the pro-oxidant metal ions is summarized in this review. The structure-function relationship between the primary structure and secondary structure on the antioxidant activity of fish peptides is provided. Moreover, the effects of non-polar amino acids, polar uncharged amino acids, polar positively charged amino acids and polar negatively charged amino acids are further reviewed. The review would provide a guide for the application of antioxidant peptides, and expand the food market for such products.

In order to extend the shelf life of Pleurotus eryngii in nanofilm vacuum packaging, the fresh postharvest Pleurotus eryngii was placed in TiO2 and SiO2 composite nanofilm fresh-keeping bags, the sample was precooled to below 4 ℃ under 0.07 MPa and then stored at 2 ℃. In order to evaluate the dynamic changes of flavor qualities during storage, the free amino acids and the volatile flavor compounds were analyzed at 0, 20, and 40 days. The results showed that 17 free amino acids were detected, including 7 essential amino acids. The total amount of amino acids was 1196.15 mg/100 g, 1425.26 and 1629.77 mg/100 g on day 0, 20 and 40, and the content of delicious amino acids increased with storage time. A total of 36 volatile compounds were detected. The alcohols and esters were the two main components, which accounting for about 90% of the total volatile compounds content. The Venn diagram of volatile compounds, the heat diagram of relative content, and the PCA load diagram of key volatile substances revealed that the types and contents of volatile flavor compounds of Pleurotus eryngii changed significantly (P

Spatio-temporal information is an important basis for the construction of intelligent coal mines. How to build the unified integrated control and decision-making platform of mining area based on multi-dimensional GIS is of significance to improve the practicability and operability of the intelligent system. Aiming at the problems existing in the construction process of intelligent mines and intelligent mining areas, such as the single management and application mode of mining area level GIS, the lack of research and application of full scene business in a multi-level control mode, the lack of spatial dimension fusion analysis in multi-source data applications, and the lack of multi-system spatial collaborative control mechanism in production equipment control, the overall frame-work design of intelligent mining area cloud platform based on 4DGIS was proposed. The three-level application fusion technology of “Cloud Edge Device” hierarchical architecture based on the data base of “4DGIS+ digital twin”, the application technology of cross-database multi-source data fusion based on big data, and the collaborative control technology of autonomous controllable equipment group based on 4DGIS were studied. The spatio-temporal graph reasoning model integrating multiple features, the decision support model application sub-platform based on big data, and the 4DGIS cooperative control sub-platform were developed. The intelligent mining cloud platform for the holographic visual production factors, collaborative control of production systems, and intelligent calculation of production management of “the group + mines” was constructed. The platform implemented the functions of one button intelligent patrol inspection under the coal mine based on the “4DGIS+digital twin” data base, collaborative control of the whole production process from “maintenance mode” to “production mode”, intelligent decision analysis based on big data and so on. The leap from the single system intelligent to the whole mining area intelligent systematization was completed. The related technology has been applied in Huangling Mining Company and its No.1 Coal Mine, No.2 Coal Mine, Shuanglong Coal Mine and Ruineng Coal Mine, which has improved the efficiency of mine safety production management and control and the intelligent decision-making level of the group company.

The micro-dynamic process of diamond tool micro-nanometric cutting single crystal nickel was studied by molecular dynamics software Lammps. The types of defects, the relationship between cutting force and damage, and the evolution of dislocation lines during micro-nanometric cutting of single crystal nickel under different cutting directions and depths were analyzed. The results show that the high pressure phase transition zone and amorphous zone are formed in the single crystal nickel workpiece due to the extrusion and shearing of the tool, and there are atomic clusters and dislocation slip in the subsurface layer. The cutting along the [100] crystal direction has the smallest cutting force and the minimum thickness of the dislocation damage layer is 2.15 nm. The cutting along the [111] crystal direction has the best surface layer quality, but the maximum thickness of the damage layer is 3.75 nm. In the cutting process, the total length of dislocation line presents an overall upward trend, and the atom region removed in [110] direction as well as the dislocation line length are the largest. The greater the cutting depth is, the more serious the dislocation slip and the amorphous in the crystal become.

[Objective] The value of ecological products from the perspectives of ecology and economy was studied with incorporate ecological benefits into cost-benefit analysis, in order to provide decision-making basis for ecological poverty alleviation work in relevant regions. [Methods] We used data from farmland returned to tea and walnut forests in Anhui and Sichuan Province, respectively. We used soil and water conservation (SWC) as the major product of GTGP. The universal soil loss equation was employed to quantify the amounts and values of SWC, and then these SWS values were incorporated as a part of the income in the economic analysis that we conducted. [Results] ① Compared with bare land, tea and walnut forests effectively reduced soil erosion, and the cumulative erosion reduction in 20 years was 30 600 t and 212 000 t, respectively; ② The soil and water conservation values per unit area of tea and walnut were 681.0 and 1 285.5 yuan/(ha·yr), respectively. After incorporating these values into the economic analysis, the average net income was 61.3 and 1.293 million yuan/yr, respectively. The average annual net income per unit area of tea and walnut was 184,300 and 97,500 yuan/ha respectively; ③ The GTGP subsidy standard had little impact on net income. After the subsidy standard for returning farmland to forest was doubled, the simulated net income value (NPV) only dropped by 2.1% and 4.6%, respectively, while simulated NPV dropped 68.1% and 77.1%, respectively, if tea and walnut prices decreased by 50%; ④ The ecological benefits of tea forest and walnut forest accounted for 4.4% and 6.8%, respectively, of the cost, with the highest proportion reaching 11.9%. [Conclusion] The ecological benefits of economic forests can offset part of the costs, and should be included in the calculation of net income value so that the value of ecological products can be accounted for.

ObjectiveThe purpose of this paper is to obtain the hydro-acoustic modulus of high-strength polyvinyl chloride (PVC) foam through an inversion algorithm based on the measured underwater acoustic insertion loss values of the composite samples, then improve the calculation accuracy of the insertion loss of the composites. MethodsFirst, the static elastic modulus of high-strength PVC foam is obtained through mechanical tests such as compression and tension, and then the insertion loss of the sandwich composite is calculated using the transfer-matrix method. The reason for the large difference in the calculated values and the measured values obtained by the acoustic pulse-based tube method is that the input value of the elastic modulus of the core material is low. Based on the measured insertion loss values, the underwater acoustic modulus values of five PVC foam samples are then calculated via genetic algorithm inversion. ResultsThe quantitative calculation results indicate that the hydro-acoustic modulus value of high-strength PVC foam is higher than the measured static elastic modulus values. The average ratio of hydro-acoustic modulus to compressive modulus is 1.24, and that to tensile modulus is 1.36. ConclusionWhen calculating the hydro-acoustic performance of sandwich composites containing high-strength PVC foam, the error can be reduced by positively correcting the input value of the material's elastic modulus on the basis of the measured value of the static modulus.

Text intelligence classification is the basic work in the field of intelligence analysis. At present, text intelligence classification work is usually oriented to a single language, and there are relatively few studies on cross-language text intelligence classification. A text intelligence deep learning classification model based on "XLM-R+TextCNN" is proposed for the problem of cross-language text intelligence classification. The vectorized representation of text information irrelevant to the specific language representation is obtained, and the text vector is input into the TextCNN model to learn the category features of text information, so as to realize the classification of cross-language text information. Based on open-source defense science and technology intelligence, we construct a cross-language text intelligence classification dataset and test the model. Experiments show that the model has achieved good results in several comparative evaluations, proving the feasibility and effectiveness of this method.

Objective: This study was aimed to compare the effects of different raw fishes on the volatile flavor substances of pre-cooked roast fish. Methods: Headspace-solid phase micro extraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze the volatile flavor substances. Results: The similarities and differences were found in the types, relative contents and key flavor substances of the six grilled fish species. Besides, the 31, 29, 27, 33, 28 and 30 kinds of volatile compounds were identified in tilapia, grass carp, common carp, crucian carp, pincer fish and Wuchang fish, respectively, including aldehydes, ketones, alcohols and hydrocarbons. The common key flavor substances were nonanal, 1-octen-3-ol, hexanal, 2-pentylfuran and 4-allyl-2-methoxyphenol. The five principal components were extracted by principal component analysis, and 24 potential differential volatiles were screened out by model construction via the orthogonal partial least squares discriminant. The cluster analysis revealed that the results of the six kinds of grilled fish were well clustered, and the volatile components of common carp were similar to grass carp, and were close to pincer fish, Wuchang fish and crucian carp, but far from tilapia. Conclusion: The analysis of the differences in volatile components of six species of pre-cooked roast fishes provides a reference for the utilization of freshwater fish resources and the diversified development of pre-cooked roast fish.

In order to meet the needs of people to supplement the element selenium, in this paper, rice with retained germ was used as raw material to prepare selenium-enriched rice with retained germ by ultrasonic soaking. The optimal process conditions were optimized by single factor experiment, principal component analysis and response surface experiment, and the quality characteristics such as cooking characteristics, texture characteristics, gelatinization characteristics and thermal characteristics of rice with retained germ were studied. The results showed that the optimal process conditions were ultrasonic soaking time 8.25 min, ultrasonic soaking temperature 40 ℃ and ultrasonic power 150 W. Under these conditions, the comprehensive score of selenium-enriched rice with retained germ was 97.31±0.12. The surface pores of rice with retained germ were uniformly formed, the content of immobilized water and free water was increased, the cooking characteristics of rice grains were good, the texture was loose, soft and non-sticky, the taste was smooth, and the nutritional quality was improved.

In order to design and prepare hard coating for the flue gas turbine transition ring，and to ensure the long-term stable operation of the flue gas turbine，three kinds of Cr3C2-NiCr hard coatings were designed and prepared on the surface of 304L alloy substrate by detonation gun spraying process.By means of X-ray diffraction (XRD)，scanning electron microscope (SEM)，energy dispersive X-ray analysis(EDXA)，microhardness tester，surface roughness tester，universal testing machine and contact angle measuring instrument，the microstructure of the coatings was analyzed and observed，and the hardness，porosity，bonding strength，roughness，thermal shock performance and surface free energy of the coatings were characterized respectively.Results showed that as the oxygen-fuel ratio increased，the hardness of the coating increased monotonously，and the porosity of the coating decreased first and then increased.When the oxygen-fuel ratio was 1.5，the quality of the as-prepared coating was the best，with a micro hardness of 810 HV3N，a porosity of 0.58%，a bonding strength of 72.1 MPa，a surface roughness of 4.78 μm and a surface free energy of 25.43 mJ/m2.After being kept at 800 ℃for 10 minutes and quenched with water at room temperature for 20 cycles，the coating had no warping，cracking or peelin.Besides，the oxygen-fuel ratio changed the surface free energy and its component in the coating，thus had an effect on the surface characteristics of the coating.

Based on the data from an atmospheric electric field (AEF) meter at 500 m from the top of Canton Tower, dual-polarimetric radar in Guangzhou, Guangdong-Hong Kong-Macao lightning location system and ERA5 reanalysis data, this study comparatively investigates the characteristics of cloud-to-ground lightning (CG) activity and the relationship between CG activity and variation features of AEF in two thunderstorms in Guangzhou on August 15 and September 23, 2020. The results show that the"local Thunderstorm"caused by local thermal instability possesses is associated with less lightning frequency and weaker precipitation, while the"systematic Thunderstorm"caused by mesoscale system possesses is associated with higher lightning frequency and short-term heavy precipitation. The lightning frequency and variation of AEF in the two thunderstorm processes display the distributions with two peaks, and the peak of AEF variability and time-frequency domain energy correspond well to the lightning outbreak stage. In the decay of "systematic Thunderstorm", AEF fluctuates greatly and slowly between the positive and negative poles for a relatively long time, showing the characteristic of End of Storm-Oscillation (EOSO). However, such a characteristic of the oscillation of AEF does not occur in the decay of the"local Thunderstorm". The lightning often comes soon, when the AEF variability and time-frequency domain energy increase significantly. The thunderstorm is often dying out or moving away from the station, when the time-frequency domain energy decreases significantly and concentrates in the low frequency band. The variation characteristics of AEF in time domain and frequency domain play an indicative role in the occurrence and dissipation of thunderstorm. This can be considered as a reference for converged application of the atmospheric electric field data with other data in lightning risk early warning.

【Objective】A large amount of tobacco stems produced in China's tobacco production is a problem that needs to be solved urgently. We prepared biochar by treatment with pyrolysis carbonization technology, and characterized its physicochemical properties to explore its adsorption properties of heavy metal Cd2+, with a view to providing a pathway and data support for the demand of resource utilization of tobacco stems.【Method】Tobacco stems were used as raw materials for the preparation of biochar and pyrolyzed at five temperatures of 300 ℃, 400 ℃, 500 ℃, 600 ℃ and 700 ℃. The effects of pyrolysis temperatures and structural properties on Cd2+ adsorption were investigated by various characterization means, indoor batch adsorption tests and adsorption kinetics tests.【Result】There were significant differences in the properties and Cd2+ adsorption characteristics of tobacco stem biochar pyrolyzed at different temperatures. The pH increased from 9.05 to 11.54 when the pyrolysis temperature was increased from 300 ℃ to 700 ℃. The H, O and N contents and the atomic ratios of H/C, O/C and (O+N)/C also decreased with the increase of pyrolysis temperature, showing that the aromatic structure of hightemperature pyrolyzed biochar was more complex and stable; the specific surface area of low-temperature tobacco stem biochar was relatively large, however, the surface pore structure was more developed at high temperature. The quasi-second kinetic equation and intra-particle diffusion equation could well fit the adsorption process of Cd2+ by different temperatures of the straw biochar, indicating that the adsorption is heterogeneous chemisorption; the high temperature pyrolysis of stems had a strong adsorption capacity for Cd2+, and the rich pore structure of its surface enhances the adsorption of Cd2+, therefore, the removal rate of Cd2+ by T700 was as high as 99.01%; with Langmuir-Freundlich fitting, the maximum adsorption amounts (Qm) ranged from 54.40 to 106.16 mg/g, with the largest Qm values for 700 ℃ biochar, which were also much higher than those for rice straw, wheat and other crop straw biochar.【Conclusion】The biochar of tobacco stem prepared at different pyrolysis temperatures has a strong adsorption capacity for Cd2+ and has the potential to be applied for remediation of environmental Cd2+ pollution in the environment.

Tomato is an important vegetable crop in China, and its yield ranks the top among vegetables in the world. It has important nutritional value, with rich and varied tastes. Plant male sterility is caused by the abnormal development of stamens, which cannot produce pollen with normal function, while pistils develop normally and can be fertilized by foreign normal pollen. Tomato is a typical self-pollinated plant with obvious heterosis and strong disease resistance and stress resistance. At present, the production of tomato F1 hybrid seeds in China basically depends on artificial emasculation and pollination, therefore, a lot of manpower and material resources are needed in the process of seed production. In the use of tomato male sterile seed production, the seed production process can be simplified, costs be greatly reduced and and seed purity be improved, in this case, tomato yield and quality will be increased significantly. Therefore, the research and utilization of tomato male sterility is of great practical significance to tomato genetic breeding, and has always been an important research topic for the domestic and foreign scholars. This paper mainly outlines the current situation of male sterility of tomato in recent years, summarizes the types of tomato male sterility, the application of genetic engineering technology of tomato male sterility, the fine positioning and functional study of tomato male sterility gene, and the analysis of cell biological mechanism of tomato male sterility. The effect of temperature on tomato male sterility is expounded from the perspective of genetics, and the physiological and biochemical mechanism and the gene function and regulation mechanism in response temperature changes are discussed. Then, the heterosis of tomato male sterility and its utilization value in production and application are analyzed. On this basis, the problems existing in the current research work are put forward, and the innovation and basic research of tomato male sterility technology in the future are prospected.

Origin of authigenic dolomites in the dolomitic reservoir of the Permian Fengcheng Formation in the Mahu Sag of Junggar Basin is unclear. Occurrence and genetic evolution of the authigenic dolomites in dolomitic rock reservoir of the Fengcheng Formation in the Mahu Sag were analyzed by polarized and fluorescence thin sections, scanning electron microscope (SEM), electron microprobe (EMP), C, O and Sr isotopes analysis, and other techniques. (1) Dolomites were mainly precipitated in three stages: penecontemporaneous–shallow burial stage (early stage of the Middle Permian), middle burial stage (middle stage of the Middle Permian), and middle–deep burial stage, with the former two stages in dominance. (2) Dolomitization fluid was high-salinity brine originating from alkaline lake. In the penecontemporaneous–shallow burial stage, Mg2+ was mainly supplied by alkaline-lake fluid and devitrification of volcanic glass. In the middle burial stage, Mg2+ mainly came from the transformation of clay minerals, devitrification of volcanic glass and dissolution of aluminosilicates such as feldspar. (3) Regular changes of Mg, Mn, Fe, Sr, Si and other elements during the growth of dolomite were mainly related to the alkaline-lake fluid, and to different influences of devitrification and diagenetic alteration of volcanic materials during the burial. (4) In the penecontemporaneous stage, induced by alkaline-lake microorganisms, the micritic–microcrystalline dolomites were formed by primary precipitation, replacement of aragonite and high-Mg calcite, and other processes; in the shallow burial stage, the silt-sized dolomites were formed by continuous growth of micritic–microcrystalline dolomite and replacement of calcites, tuffs and other substances; in the middle burial stage, the dolomites, mainly silt- and fine-sized, were formed by replacement of volcanic materials. The research results are referential for investigating the formation mechanism and distribution patterns of tight dolomitic reservoirs in the Mahu Sag and other similar oil and gas bearing areas.

The generation and transport process of bombardment ions and the sputtering process of ions on target are important parts to realize double glow plasma metallization. In this paper, on the basis of the glow discharge theory and COMSOL Multiphysics software, a typical double glow plasma metalizing device was modeled, and the energy range of bombardment ions was analyzed. Combined with the classical scattering theory and Monte Carlo method, SRIM software was used to simulate the sputtering process of Ar+ on multiple metal targets. The results show that the position of sputtering atom is concentrated near the incident position of metal target, forming a circular sputtering crater. The energy of sputtered atoms is within 20 eV. With the increase of incident ion energy, some sputtered atoms with high energy and large angle appear. The sputtering yield increases with the increase of the electron filling degree of the d shell layer of target atom, and the sputtering yield mainly comes from the low-energy recoil atoms. The larger sputtering yield means that the more low energy recoil atoms, the more dispersed energy transfer and the lower sputtering atom energy.

Starch is a kind of biodegradable biopolymer with a wide range of sources and low price. With the development of nanotechnology, starch nanoparticles have become a research hotspot due to their unique properties different from native starch. In this paper, the structure characteristics of different sources of starch is introduced, the preparation of starch nanoparticles of top-down and bottom-up method and the advantages and disadvantages of various preparation methods are summarized, the effects of starch nanoparticles on Pickering emulsion stability, performance improvement of composite material, delivery of targeted drug and adsorption of industrial waste water are reviewed, and the application prospect of starch nanoparticles in food, industry, medicine and other fields is prospected in order to provide the theoretical basis for the research of starch nanoparticles.

In order to study the influence rule of HVDC grounding electrode interference on the cathodic area and anodic area of the pipeline systematically,the Zheneng Jinliwen pipeline was taken as the research object to establish a HVDC interference model using CatPro software based on the real soil structure.The pipe-to-ground current density was calculated under conditions involving different ground polarity,interference current and soil resistivity,and the ranges of the cathodic area and anodic area of the pipeline under such conditions were analyzed.Results showed that after the locations of the grounding electrode and the pipeline were determined,the demarcation point between the cathodic area and anodic area of the pipeline resulting from HVDC interference was fixed and not affected by external conditions.

In order to improve the crush resistance of the traditional hexagonal honeycomb structures,based on the principle of bionics and considering the influence of hierarchical factors,a self-similar hierarchical quasi-honeycomb structure was proposed on the basis of the hexagonal honeycomb.With the specific energy absorption(SEA),initial peak crushing force(PCF) and crushing force efficiency(CFE) as the impact characteristics evaluation indicators,a theoretical model was established to predict the impact characteristics of the quasi-honeycomb structure according to the simplified super-folded unit theory.On the basis of this theoretical model,the effects of cell wall thickness t,cell wall length l and cell number n on the mean crushing force(MCF) and SEA of quasi-honeycomb structures under out-of-plane impact load were studied.The results show that under the condition of equal relative density,the SEA and CFE increase with the increase of the hierarchy.Among them,under the impact velocity of 10 m/s,compared with 0th order honeycomb,the CFE of the 1st order honeycomb and the 2nd order honeycomb increase by 21% and 40%,and the SEA increase by 11% and 28%,respectively.Under the condition of same wall thickness,the initial PCF increases obviously with the increasing of the hierarchy,but the improvement of SEA and CFE is more significant than PCF.Under the impact velocity of 10 m/s,compared with the 0th order honeycomb,the CFEs of the 1st order honeycomb and the 2nd order honeycomb increase by 77% and 115%,and the SEAs increase by 72% and 116%,respectively.The theoretical model can effectively predict the energy absorption performance parameters of quasi-honeycomb structures,thereby providing a theoretical reference for the study of honeycomb structure impact dynamics.

In order to study the the effect of laser quenching power on the microstructure and wear resistance of the 0Cr13Ni4Mo stainless steel of hydraulic mechinery flow passage component, semiconductor lasers with a laser quenching power of 2.5 kW, 3.0 kW, 3.5 kW respectively were used for surface quenching. The microhardness tester, impact toughness tester, friction and wear tester, and scanning electron microscope were used to analyze and test the microhardness, impact toughness and wear resistance of the three resulting quenched layers. By observing the wear microstructure of the coating, the wear mechanism of the coating was analyzed. Results showed that the microhardness, impact toughness and wear resistance of the laser quenched layer all increased with the rising of laser quenching power. The wear mechanism of the quenched layer was mainly adhesive wear. In general, laser quenching could improve the wear resistance of 0Cr13Ni4Mo stainless steel significantly and it had a prospect of wide application.

Objective: In order to solve the problem of inaccurate detection of alcohol accuracy due to manual "flower picking" in the segmented liquor picking process. Methods: Designed and built a segmented liquor taking system based on alcohol accuracy modeling. The research collected tuning fork frequency values, tuning fork built-in temperature values, alcohol solution temperature values and pump speed values under dynamic conditions in different modes of alcohol solutions with different concentrations, implemented adaptive tuning fork frequency filtering and dynamic compensation based on least mean square algorithm （LMS） and long short-term memory network （LSTM）, and built a liquor accuracy prediction model based on improved genetic algorithm optimized BP neural network （IGA-BP）. Results: The model outperformed the traditional genetic algorithm optimized BP neural network and BP neural network in terms of the number of iterations and prediction accuracy, and the average prediction error of the alcoholic beverages was 0.381. Conclusion: which verifies the reasonableness of the model. In order to solve the limitations of the current manual "flower picking", a method is proposed to improve the accuracy of alcohol detection in the segmented liquor taking process.

Moving target indication using space-based early warning radar is important in military applications. For the space-based early warning radar, complicated non-stationary clutter characteristics are induced due to the high-speed movement of the radar platform and Earth’s rotation, and more serious clutter non-homogeneity than the airborne radar scenario is caused by the large beam illumination region. Consequently, traditional Space-Time Adaptive Processing (STAP) methods, which have been widely used in airborne early warning radar, cannot be applied directly to the space-based early warning radar. In this study, we analyze the characteristic of clutter distribution and build a novel STAP framework, where high-resolution clutter spectra used to construct the adaptive weights is estimated via a Convolutional Neural Network (CNN). First, clutter data sets were randomly simulated with different ranges of bin, latitude, spatial error, internal clutter motion, and coefficients of surface scattering, where the radar and satellite parameters were utilized as a priori knowledge. Then, we designed a two-dimensional CNN with five layers that converted a low-resolution clutter spectrum into a high-resolution spectrum. Finally, a space-time adaptive filter was calculated using the estimated high-resolution space-time spectrum and employed for clutter suppression and target detection. The simulation results show that the proposed CNN STAP can achieve sub-optimal performance under limited sample conditions, and a smaller computational load compared with a state-of-the-art sparse recovery STAP method. Therefore, this framework is suitable for practical application in space-based early warning radar.

Radar emitter signal deinterleaving is a key technology for radar signal reconnaissance and an essential part of battlefield situational awareness. This paper systematically sorts out the mainstream technology of radar emitter signal deinterleaving. It summarizes the main research progress in radar emitter signal deinterleaving from three directions: interpulse modulation characteristics-based, intrapulse modulation characteristics-based, and machine learning-based research. Particularly, this paper focuses on explaining the principle and technical characteristics of the latest deinterleaving technology, such as neural network-based and data stream clustering-based techniques. Finally, the shortcomings of the current radar emitter deinterleaving technology are summarized, and the future trend is predicted.

The parameters such as pore size distribution, specific surface area and pore volume of shale rock samples are analyzed by low-temperature nitrogen adsorption experiment, and then the conversion coefficient between relaxation time (T2) and pore size is calibrated. Nuclear magnetic resonance experiments of CO2 huff and puff in shale samples are carried out to study the effects of gas injection pressure, soaking time and fractures on the oil production characteristics of shale pores from the micro scale. The recovery degrees of small pores (less than or equal to 50 nm) and large pores (greater than 50 nm) are quantitatively evaluated. The experimental results show that the recovery degree of crude oil in large pores increases rapidly with the increase of injection pressure under immiscible conditions, and the effect of injection pressure rise on recovery degree of large pores decreases under miscible conditions; whether miscible or not, the recovery degree of crude oil in small pores basically maintains a linear increase with the increase of injection pressure, and the lower size limit of pores in which oil can be recovered by CO2 decreases with the increase of gas injection pressure; with the increase of soaking time, the recovery degree of crude oil in large pores increases slowly gradually, while the recovery degree of crude oil in small pores increases faster and then decelerates, and the best soaking time in the experiments is about 10 h; the existence of fractures can enhance the recovery degrees of crude oil in small pores and large pores noticeably.

A 2-DOF spatial 8R parallel mechanism is proposed for hip joint rehabilitation. The model of spatial 8R parallel mechanism is established， and the initial configuration and general configuration of the mechanism are analyzed by using screw theory. The geometric model and kinematics equations of the spatial 8R parallel mechanism are established by D-H method， and the kinematics equations of the mechanism are obtained. The correctness of the kinematics equation of the spatial 8R parallel mechanism is verified by Adams software and theoretical calculation， and the variation law of the angular displacement of the mechanism in one period under different motions is obtained. This spatial 8R parallel mechanism has stable performance and can carry out smooth movement， which can effectively improve the rehabilitation effect of hip joint.

Long-term cumulative rise of sea level will exacerbate disasters such as storm surges, soil salinization and coastal erosion. However, there are obvious regional differences in the natural characteristics and socio-economic development levels of the coast. The impact of the natural environment and the socio-economic risks caused by sea level rise has shown regional differences. The paper analyzed the risk of sea level rise impact in Tianjin Binhai New Area. It was assessed that the southern part of Tianjin Binhai New Area would have the highest level of sea level rise risk and the northern part would have the lowest level of risk.

Based on the understanding of the basic geological conditions of shale gas from the Upper Ordovician Wufeng Formation to the Lower Silurian Longmaxi Formation in Dingshan area of the southeastern Sichuan Basin, the occurrence, migration mode and intensity of natural gas in the shale gas system were discussed according to the results of drilling, logging, fracturing test, laboratory test and structural interpretation, moreover, a shale gas enrichment mode suitable for the study area was proposed. In shale gas systems, high-angle fractures extend for a short distance, while horizontal fractures such as bedding-parallel detachment and interlayer bedding fractures extend for a long distance. As a result, the permeability in the bedding direction is much greater than that in the vertical direction. These characteristics together determined that natural gas in shale gas system was usually transported horizontally, and sometimes both horizontally and vertically. For the Qiyueshan fault zone, the burial depth of shale reservoir and the distance to Qiyueshan fault zone are the major constrains for shale gas enrichment in the Wufeng-Longmaxi formations in the study area. The Qiyueshan fault zone is a basin-controlling fault zone with fractures and associated fractures developed, and is a shale gas escaping area. In the shallow-buried area in the southeastern part, high-angle fractures were relatively developed, by which horizontal fractures were opened. The proportion of free gas was less than 60%. A normal pressure system indicates a semi-retention area for shale gas. In the middle-to deep-buried area in the northwest, high-angle fractures were relatively undeveloped, and horizontal fractures were closed. The vertical and horizontal migrations were blocked, and most of shale gas was trapped in shale reservoirs. The proportion of free gas is more than 60%. A high-to ultra-high pressure system indicates a shale gas accumulation area.

During gait rehabilitation training， patients with hemiplegia or stroke are prone to muscle cramps， which can cause them to lose their balance due to their inability to support their weight and cause secondary injuries. In response to the above problems， a six-degree-of-freedom parallel rehabilitation robot driven by eight cables is designed， which can not only perform gait training on patients but also implement effective anti-fall protection for patients. Firstly， the configuration of the robot is described， and its kinematics model is established by using the closed vector quadrilateral method. Secondly， combined with the characteristics of cable-driven， a concept of a robot force control workspace and its solution method are proposed based on the statics analysis. In order to avoid secondary injuries to patients after losing their balance， a space trajectory safety wall is further proposed based on the force-controlled working space， which classified the possible shapes to be protected for patients and studied the space trajectory path planning method for their return to the safety wall. Finally， two different types of to-be-protected profiles are selected to study the changes in cable length and tension as they moved along the regression trajectory which verified the effectiveness and rationality of the trajectory planning method for the return safety wall.

Taking the down-slope with weak strata in the south of Fushun west open-pit mine as the reference prototype, numerical simulations of the down-slope with weak strata were conducted through FLAC3D software, which included the simulation of actual ground motion and ground motion input, the boundary conditions of slope model, rock mass parameters, and grid model division. The response rule of down-slope with weak strata under an earthquake was investigated by analyzing the acceleration and velocity of the monitoring points. The results revealed that: (1) The thickness of the weak layer is a critical factor affecting the response characteristics of the slope with a single weak layer under an earthquake, and it has a greater impact on the stability of the slope under earthquake load than the dip angle of a single weak layer. (2) Based on the horizontal velocity of monitoring point 2# at the intersection of the weak layer and the slope surface, it was concluded that the thickness has a significant influence on the velocity in the X direction. (3) The failure response law at the intersection of weak layers and slope changes with an increase in slope height when analyzing the response law of the double weak layer characteristic slope under an earthquake. The acceleration amplitude and velocity change degree of monitoring point 3# with double weak layers are more noticeable than that of monitoring point 2#. The response law of the down-slope under an earthquake is related to the dip angle, thickness, number, and location of weak layers. Therefore, the coupling effect of earthquake and weak layer characteristics on slope stability should be thoroughly considered in the process of slope treatment and protection. [ABSTRACT FROM AUTHOR]

Using WRF V4.1.3 model and ERA5 reanalysis data, analyses and numerical simulation tests were conducted for a weather event of Meiyu front torrential rainfall occurred in central China on 7 July 2020 to explore the effects of the combinations of different vertical and horizontal resolutions on the rainfall simulation. Based on results from the above analyses, then investigations are carried out on whether applying cumulus parameterization at a horizontal resolution of 3 km would influence on the simulation of precipitation. The simulated results show that the features of circulation at middle and low levels, characteristics of rain clusters and rainfall distribution largely conform to the actual situations, although there are some differences among different combinations of tests. For the evolution of hourly precipitation at 3 selected relatively heavy precipitation areas, the simulation results of each simulation test are greatly deviated from the actual situation. Results from tests with the same horizontal resolution and cumulus parameterization are closer to each other. According to TS, ETS, BS and SAL scores, the simulation results of the 3 km tests were generally better than those of the 12 km tests, indicating that finer horizontal resolution of the model could improve the precipitation forecasts. Turning off cumulus parameterization at horizontal resolution of 3 km obviously reduces the forecasting skill, especially for events with the magnitude of heavy rain and above. However, for precipitation prediction with different threshold values, the influence of cumulus parameterization is different. The effect of changing vertical resolution on prediction skills is not as significant as that of changing horizontal resolution and the inclusion of cumulus parameterization. In the 3 km horizontal resolution model, the adoption of cumulus parameterization scheme can significantly improve the prediction skill of rainfall intensity.

To scientifically measure and accurately evaluate the spatial quality within the station area and realize effective optimization, seventy-three subway stations in Chengdu City were selected to support multi-source big data such as street network, POI(point of interest), street view pictures, etc., then machine learning and spatial design network analysis(sDNA) and other technologies were used to construct an evaluation system with convenience, functionality and comfort as the core. Large-scale quantitative evaluation of street space quality within the station area was carried out, and guidance and control strategies for different levels of stations were proposed. The results show that 68.03% of the station area streets score is lower than the medium level, the street function and comfort are generally good, and the convenience is poor; at the station level, the street space quality shows the distribution characteristics of high in the South and low in the north, high in the West and low in the East, and high in the inside and low in the outside. The proposed method takes into account the analysis accuracy of human-oriented scale, the analysis depth of site scale and the analysis breadth of urban scale, which is helpful to create an efficient dynamic feedback mechanism of urban management.