Search

Abstract Chinese cooking is the primary treatment method for table food in China. The process is complex and large‐scale, which is important to the macroeconomy and national nutrition and health. First, this article puts forward the concept of thermal accumulation for Chinese cooking by taking pork tenderloin fried at different oil temperatures, explaining changes in moisture content, hardness, and color with different thermal accumulation conditions, and measuring kinetic parameters. The variations of L* and b* obtained by the experimental results belong to the first‐order reaction kinetic model, while the changes in water content and shear force belong to the zero‐order reaction kinetic model. Simultaneously, the superheat value is used as a thermal accumulation indicator, combined with sensory evaluation to determine that the Z value of the human sensory overheating of pork tenderloin is 99°C, and Os,max (Z = 99°C, the reference temperature is 110°C) is 5.86 min.

Under hypersonic flight conditions, the optical window external surface of a near-space remote sensing system generates a large thermal load due to aerodynamic friction, resulting in serious additional contact thermal stresses and deformation of the flat window. Consequently, the imaging performance of the optical remote sensing system (ORSS) is reduced. To overcome this issue, a flexible support combination structure (FSCS) for an optical window suitable for ultra-high temperature conditions was developed in this study, which ensures the optical imaging quality requirements of the system. Based on the external thermal environment characteristics of a hypersonic aircraft, an aerothermal simulation model of the aircraft with a window component was established. More importantly, the FSCS was optimized and a thermal–structural model of the window component was established, and the opto-mechanical-thermal analysis method was proposed for the ORSS. Finally, the thermal-optical properties of the deformed window were evaluated. The results show that the optimized window component satisfies the optical imaging design requirements, which guides engineers in ultra-high temperature thermal analysis and optical imaging.

Coal/oil co-processing is an efficient utilization process of coal and heavy oil by coupling direct coal liquefaction with heavy oil hydrogenation conversion. It is an important way for compensating the shortage of oil, balancing the energy structure, and ensuring the national energy security in China. Coal tar, FCC (fluid catalytic cracking) slurry and DCC (deep catalytic cracking) slurry were chosen as oil samples and a sub-bituminous coal was chosen as the coal sample to investigate their co-processing characteristics. The results show that the coal conversion in the co-processing of FCC and coal is the highest, followed by that of DCC and coal, and that of coal tar and coal is the lowest. Further analyses found that the difference of the coal conversion and product composition in coal/oil co-processing is mainly caused by the difference of the aromatic hydrocarbon types and content in the oil samples. The hydrogen donor capacity of the polycyclic aromatic hydrocarbons (PAHs) of the oil samples is the main route to stabilize and protect the free radicals generated in the co-processing technology. The PAHs is favored to combine with the active hydrogen atoms in the reaction system and generated hydrogenated aromatic hydrocarbons, for which has the ability to stabilize the free radicals. It could be deduced from the analysis of the content of the PAHs with 1−5 rings, the FCC with the highest content of 4 ring PAHs has a higher co-processing ability than of the DCC with the highest content of 3 ring PAHs. The aromatic hydrocarbons in coal tar mainly come from the broken bonds of the aromatic structure of the coal, which has good solubility with the coal sample. However, the content of the higher-ring-number PAHs in coal tar is low, and the hydrogen donor capacity is weak, which leads to relatively low coal conversion rate and liquid oil yield when coal tar is co-processed with coal. When FCC and coal tar are mixed as the oil sample for co-processing, the aromatic hydrocarbons in coal tar can ensure the good dispersion of coal, and the higher-ring-number PAHs in FCC slurry can guarantee the hydrogen donor capacity. The synergy of the FCC and coal tar promotes the coal conversion in the coal/oil co-processing.

Introduction: The wear failure of spindle will lead to a decrease in cotton harvesting rate of the cotton picker during field operation and serious wastage.Method: Three types of spindle samples at different installation positions and working areas were obtained through field experiments to explore the wear failure law of spindle hook teeth of cotton picker during field operation. Hardness of hook tooth coating and substrate of spindles were tested, surface and cross-section microstructure of the spindle hook teeth were characterized, and wear area and width of the spindle hook teeth were extracted.Results: Results showed that the hardness of the hook tooth coating is evidently higher than that of the substrate; the average coating hardness of the No. 3 spindle hook teeth reaches the maximum at 1033.6 HV0.1; defects, such as microcracks and micropores, exist in the coating of the three types of spindle hook teeth; and the thickness of the coating is between 70 and 130 μm. The wear area of spindle hook tooth changes exponentially and the wear width changes linearly with the increase of field operation area at the same installation position. The wear area and width of the spindle hook teeth gradually increase with the decrease of the installation height and the wear change of the hook teeth is negatively correlated with the installation height in the same field operation area.Discussion: The wear failure of spindle hook tooth is mainly caused by abrasive, fatigue, and oxidation wear. The results of this study can provide a reference for improving the wear resistance of spindle hook teeth.

Understanding cottonseeds’ basic physical parameters and compressive mechanical properties is necessary in seed cotton packing and cottonseed processing. In this study, the basic physical parameters of three cottonseed varieties (Huiyuan 720, Xinluzao 61, and Xinluzao 74) under different moisture contents (6%, 9%, 12%, and 15%) were measured. These parameters include 1000-grain weight, triaxial dimension, and sphericity. The effects of different moisture, varieties, and compression orientation (horizontal and vertical) on the compressive mechanical properties of the cottonseed were studied, and the variance analysis of the experimental data showed that the triaxial dimension, 1000-grain weight, arithmetic mean diameter, and geometric mean diameter of cottonseeds of the same variety increased with an increase in moisture content. Extremely significant differences (p < 0.01) were found in the physical parameters among different varieties. The main factors affecting crushing force and apparent elastic modulus are moisture content, variety, and compression orientation. For deformation, the main factors are moisture content, compression orientation, and variety. Moreover, compression orientation, moisture content, and variety are the main factors affecting failure energy. The results obtained that the crushing force and apparent elastic modulus decreased, deformation increased, and failure energy decreased first and then increased with the increase in moisture content under the same cottonseed variety. The results also provided the basic physical parameters for the design parameter optimization of seed cotton harvesting and processing machinery.

This paper takes the frame as the research object and explores the vibration characteristics of the frame to address the vibration problem of a 1-MSD straw-crushing and residual film recycling machine in the field operation process, and an accurate identification of the modal parameters of the frame is carried out to solve the resonance problem of the machine, which can achieve cost reduction and increase income to a certain extent. The first six natural frequencies of the frame are extracted by finite element modal identification and modal tests, respectively. The rationality of the modal test results is verified using the comprehensive modal and frequency response confidences. The maximum frequency error of modal frequency results of the two methods is only 6.61%, which provides a theoretical basis for the optimal design of the frame. In order to further analyze the resonance problem of the machine, the external excitation frequency of the machine during normal operation in the field is solved and compared with the first six natural frequencies of the frame. The results show that the first natural frequency of the frame (18.89 Hz) is close to the external excitation generated by the stripping roller (16.67 Hz). The first natural frequency and the volume of the frame are set as the optimization objectives, and the optimal optimization scheme is obtained by using the Optistruct solver, sensitivity method, and grey correlation method. The results indicate the first-order natural frequency of the optimized frame is 21.89 Hz, an increase of 15.882%, which is much higher than the excitation frequency of 16.67 Hz, and resonance can be avoided. The corresponding frame volume is 9.975 × 107 mm3, and the volume reduction is 3.46%; the optimized frame has good dynamic performance, which avoids the resonance of the machine and conforms to the lightweight design criteria of agricultural machinery structures. The research results can provide some theoretical reference for this kind of machine in solving the resonance problem and carrying out related vibration characteristics research.

Target geolocation in long-range oblique photography (LOROP) is a challenging study due to the fact that measurement errors become more evident with increasing shooting distance, significantly affecting the calculation results. This paper introduces a novel high-accuracy target geolocation method based on multi-view observations. Unlike the usual target geolocation methods, which heavily depend on the accuracy of GNSS (Global Navigation Satellite System) and INS (Inertial Navigation System), the proposed method overcomes these limitations and demonstrates an enhanced effectiveness by utilizing multiple aerial images captured at different locations without any additional supplementary information. In order to achieve this goal, camera optimization is performed to minimize the errors measured by GNSS and INS sensors. We first use feature matching between the images to acquire the matched keypoints, which determines the pixel coordinates of the landmarks in different images. A map-building process is then performed to obtain the spatial positions of these landmarks. With the initial guesses of landmarks, bundle adjustment is used to optimize the camera parameters and the spatial positions of the landmarks. After the camera optimization, a geolocation method based on line-of-sight (LOS) is used to calculate the target geolocation based on the optimized camera parameters. The proposed method is validated through simulation and an experiment utilizing unmanned aerial vehicle (UAV) images, demonstrating its efficiency, robustness, and ability to achieve high-accuracy target geolocation.

Ticks and tick-borne diseases have negative impacts on the health of wild animals including endangered and vulnerable species. The giant panda (Ailuropoda melanoleuca), a vulnerable and iconic flagship species, is threatened by tick infestation as well. Not only can ticks cause anemia and immunosuppression in the giant panda, but also bacterial and viral diseases. However, previous studies regarding tick infestation on giant pandas were limited in scope as case reports from sick or dead animals. In this study, an investigation focusing on the tick infestation of a reintroduced giant panda at the Daxiangling Reintroduction Base in Sichuan, China was conducted. Ticks were routinely collected and identified from the ears of the giant panda from March to September in 2021. A linear model was used to test the correlation between tick abundance and climate factors. All ticks were identified as Ixodes ovatus. Tick abundance was significantly different among months. Results from the linear model showed temperature positively correlated to tick abundance, while air pressure had a negative correlation with tick abundance. To the best of our knowledge, this study is the first reported investigation of tick species and abundance on a healthy giant panda living in the natural environment, and provides important information for the conservation of giant pandas and other species sharing the same habitat.

Atherosclerosis is chronic inflammatory disease tightly related with defective efferocytosis of apoptotic cells (ACs) in the plaques. The strategy of efferocytosis reactivation using Atorvastatin (AT) and Metformin (Met) has attracted increasing attention for atherosclerosis treatment. Although these drug-based therapies could stimulate the phagocytic clearance of ACs, the rapid drug clearance and poor bioavailability limited their efficacy. In this study, by co-loading AT and Met into poly(lactic-co-glycolic) acid nanoparticles (PLGA NPs), we developed a biomimetic nanocomplexes for targeted atherosclerosis treatment. Macrophages membrane-coated nanocomplexes efficiently avoided the clearance of NPs from immune system and achieved targeting ability to the atherosclerotic plaques. Moreover, modified hyaluronic acid (HA) delivered NPs into the dysfunctional efferocytic cells of plaques, and achieved the plaques-macrophages-targeted therapy. In vitro results indicated that the biomimetic nanocomplexes reactivated efferocytosis by facilitating macrophages polarization from M1 to M2 phenotype through enhancing ERK5/MerTK pathway and inhibiting cellular senescence through inhibiting p53-p16/pRB pathway. In vivo study indicated that this biomimetic nanocomplexes accumulated in the atherosclerotic plaques, resulting in reduction of necrotic core area and protection against plaque rupture by reactivating efferocytosis. These findings indicated that reactivation of efferocytosis by AT and Met co-delivered nanocomplexes provided a novel promising strategy for targeted atherosclerosis treatment.

Machine-harvested seed cotton was taken as the research object to further clarify its creep performance, minimize its power consumption during the loading process, and obtain a better loading method. The uniaxial compression creep test was carried out using the Instron universal material test bench to apply cyclic loading treatment. The test factors included cyclic loading times, cyclic stress peak, and cyclic loading frequency. The energy consumption curve of the machine-harvested seed cotton during cyclic loading was obtained through OriginPro 2019b software, and its energy change law was analyzed. Creep strain was divided into two parts, namely, initial creep strain and creep strain increment, to elucidate the creep mechanism. The Burgers model was chosen to describe the creep strain increment. Results show that machine-harvested seed cotton exhibits energy consumption hysteresis during cyclic loading. The compression energy rapidly decreases with increasing cyclic loading times and then stabilizes. Meanwhile, the compression energy increases with increasing cyclic stress peak and cyclic loading frequency. The creep strain mechanism is also the same, which first rapidly increases and then levels off. Cyclic loading times, cyclic stress peak, and cyclic loading frequency have different effects on creep strain increment, instantaneous elastic modulus, hysteresis elastic modulus, viscosity coefficient, delay time, and relative deformation index. Finally, disregarding power consumption and interaction, extending the cyclic loading time, and increasing the cyclic stress peak while simultaneously minimizing the cyclic loading frequency can reduce the relative deformation index in the creeping stage. Accordingly, the deformation retention ability in the creep is improved, but the compression energy in the cyclic loading increases. The results can provide theoretical and data support for studying the theoretical basis of the rheological properties of machine-harvested seed cotton, the design of seed cotton baling devices, and the study of bale (mold) forming quality.

This study investigated the impact of compression molding parameters on the post-molding characteristics of machine-harvested seed cotton and aimed to determine the optimal compression molding parameters. The closed compression test of seed cotton and force analysis on a single cottonseed clarified the boundary conditions for cottonseed crushing and the relationship between crushing rate and compressive force. A seed cotton compression test bench facilitated single-factor and four-factor, three-level quadratic regression orthogonal experiments, varying the moisture content, initial density, compression force, and holding time. Variance analysis revealed each factor’s influence on the dimensional stability coefficient. Utilizing Design Expert 13.0.5, the optimal compression molding parameter ranges were identified: 6–11.7% moisture content, 47.87–74.84 kg/m3 initial density, 3–5.32 kN compression force, and 50–239.75 s holding time. Software predictions within this range indicated an optimal cottonseed crushing rate and dimensional stability coefficient of 2.853% and 3.274, respectively. Further verification experiments yielded a cottonseed crushing rate and dimensional stability coefficient of 2.888% and 3.282, respectively, with a maximum error of 3.85%, validating the model and optimized parameters. Therefore, strictly controlling seed cotton compression molding parameters was shown to reduce the cottonseed crushing rate and dimensional stability coefficient. These findings offer crucial theoretical insights for developing seed cotton compression processes and selecting parameters for cotton harvesting and packing devices.

Over the past decade, Unmanned Aerial Vehicles (UAVs) have emerged as essential tools for landslide studies, particularly in on-site investigations. This paper reviews UAV applications in landslide studies, with a focus on static geological characteristics, monitoring temporal and spatial dynamics, and responses post-events. We discuss the functions and limitations of various types of UAVs and sensors (RGB cameras, multi-spectral cameras, thermal IR cameras, SAR, LiDAR), outlining their roles and data processing methods in landslide applications. This review focuses on the UAVs’ roles in landslide geology surveys, emphasizing landslide mapping, modeling and characterization. For change monitoring, it provides an overview of the temporal and spatial evolution through UAV-based monitoring, shedding light on dynamic landslide processes. Moreover, this paper underscores UAVs’ crucial role in emergent response scenarios, detailing strategies and automated detection using machine learning algorithms. The discussion on challenges and opportunities highlights the need for ongoing UAV technology advancements, addressing regulatory hurdles, hover time limitations, 3D reconstruction accuracy and potential integration with technologies like UAV swarms.

In this study, the influence of different ionic composition in aqueous solution on the minerals surface wettability was studied. The differences effect of monovalent ion and divalent ions onto the wettability alteration were studied. The anions were Cl- and SO42-. The SO42- could make the minerals surface more hydrophilic. Besides, the influence of NaCl, MgCl2, CaCl2, Na2SO4, K2SO4 and MgSO4 on the mineral wettability alteration were studied. The results indicated that divalent ions showed significant impact on the minerals wettability alteration, compared with monovalent ion. The reasons were due to the fact that divalent ions showed higher ions adsorption than monovalent ion, and divalent ions have higher effect on compressing the electric double layer. The static contact angle and dynamic contact angle were measured. Different heavy oils were studied, including heavy oil with 100 ppm, heavy oil, heavy oil without resins, heavy oil without asphaltenes. The results showed that the asphaltenes would make it difficult for the heavy oils to liberate from minerals, thus decreasing the oil drops contact angle. Then the resins would decrease the heavy oil contact angles. CaCl2/MgCl2 and K2SO4 have synergistic effect on the change of the minerals surface wettability. Atomic force microscope (AFM) measurement indicated that the ions would effectively decrease the interaction force on the surface of heavy oil-minerals, which was beneficial to the heavy oil liberation. The roughness measurement indicated that the different ions would effectively increase the minerals surface wettability.

Cardiovascular disease (CVD) caused by atherosclerosis has become a main threaten for human health. As an independent risk factor, hyperhomocysteinemia (HHcy) played an important role in the pathogenesis of atherosclerosis by regulating DNA methylation modification and autophagy of macrophages. In this study, we constructed a new kind of macro-liposome nanoparticle by hybridizing liposome with macrophages membranes (Møm) to encapsulate hydroxysafflower yellow A (HSYA). Assertion of Hyaluronic acid (HA) on the macro-liposome NPs was adopted to endow nanodrug targeting ability. In vitro results showed that the prepared macro-liposome nanoparticles can significantly inhibit Atg13 DNA methylation, while enhance autophagy of macrophages to promote cholesterol efflux, as well. In vivo studies have shown that the HA modification made the macro-liposome NPs an ideal decoy for targeting plaques. Thus, the macro-liposome NPs with prolonged blood circulation time, and improved targeting ability can achieve optimal HSYA accumulation at the region of atherosclerotic plaques to obtain high efficacy. According to our point, the nano-drug delivery system with high immune escape capability provided a feasible therapeutic strategy for efficient atherosclerosis therapy.

For traditional imaging systems, high imaging quality and system miniaturization are often contradictory. In order to meet the requirements of high imaging quality and system miniaturization, this paper proposes a method to correct the aberration of coherent imaging optical systems. The method is based on the idea of phase recovery and the imaging principle of a coherent imaging system to recover the aberrations at the exit pupil of the system. According to the recovered aberrations, conjugate filters are constructed to correct the image quality in the frequency domain. The imaging quality of the system is improved without changing the original optical path, and the simplicity of the system is guaranteed. To solve the pupil frequency domain aberration more accurately, this paper adopts the dual competition and parallel recombination strategy based on the genetic algorithm and introduces the disaster model. The improved genetic algorithm can effectively restrain the appearance of the “precocity” phenomenon. Finally, the paraxial imaging optical path is simulated and verified by experiments. The results show that, after aberration correction, the image sharpness is improved and the edge information is richer, which verifies the feasibility of the coherent imaging system image quality enhancement method proposed in this paper.