Abstract: In the Chinese Pharmacopoeia, the method of detecting heavy metals commonly uses thioglycolic acid. It is often used as a special method for the limit check of heavy metals in raw pharmaceutical or cosmetic raw materials. Traditional use of porcelain crucibles in sample pretreatment may result in false positive reactions. This study used quartz crucibles to replace the traditional porcelain crucibles to study the possibility of contamination. It was found that the false negative reactions caused by crucible material can be eliminated, and the precision of the method was verified by detecting three batches of samples. The method has good repeatability and accuracy. It can replace the use of traditional porcelain crucibles in the method of detecting heavy metals with thioglycolic acid. Read More

Abstract: In the wave of agricultural modernization, intelligent apple selection line technology is a key link in improving fruit quality and production efficiency. There are various methods for grading the external quality of apples, some of which focus on detecting single external features of apples, such as color, size, shape, texture, and visual defects; Other methods are based on deep learning techniques to grade the appearance quality of apples. However, these manual methods for extracting single external features of apples have certain limitations in terms of grading accuracy, and cannot comprehensively and objectively evaluate the external quality of apples. To improve the accuracy and stability of the lossless grading method for apples, this paper proposes a Yan'an apple grading method based on the DXNet model. The convolutional blocks of traditional convolutional neural networks are extracted as feature extractors for apple images, and the learned feature maps are subjected to global max pooling and global average pooling, respectively. The two one-dimensional vectors after pooling are concatenated and input into a classifier mainly composed of fully connected layers for classification. Read More

Abstract: 2017.4 The project team conducted an acoustic survey of fishery resources in the fish reef area of the South Yellow Sea using a scientific fish finder (EY60, SIMRAD) to obtain acoustic images of biological resources in the sea area passed by the survey vessel. In data processing, this survey used professional fishery resources acoustic survey data processing software (ECHOVIEW 7.9, MYRIAX, AUSTRIA), in particular, the software has a special background noise processing module, according to De Robertis, Higginbottom's research results of the preparation. The results of this survey showed that the average NASC in the target area of the reef zone was 42.85 m^2/nmi^2, with the largest NASC of 249.47 m^2/nmi^2 in one section, and 28.56 m^2/nmi^2 in the southernmost control area, with the smallest NASC of 25.11 m^2/nmi^2 and the largest of 35.37 m^2/nmi^2. Read More

Abstract: Addressing the impact of climate change on food security is now one of the most important challenges facing humanity in the twenty-first century. As one of the three major food crops in China, maize is widely planted on the Loess Plateau and is also a major source of local agricultural income. Therefore, accurately assessing the impacts of climate change on local maize production and formulating corresponding adaptive measures are of great theoretical and practical value in reducing the impacts of climate change and guaranteeing the sustainable development of local agriculture. In this study, we calibrated and validated the parameters of the APSIM model using maize field trial data from 2009 to 2012 in Yuzhong County to assess the applicability of the model in the local area. Effect of using measured climate data from 1979 to 2018 and changes in climate data based on measured data and different CO2 concentrations (350 ppm, 450 ppm, 550 ppm, 650 ppm and 750 ppm) on maize yield in the region. The results showed that under the same CO2 concentration gradient, with the increase of temperature, corn yield basically showed a decreasing trend, in which the CO2 concentration at 350 ppm corn yield decreased at the greatest rate, the temperature increased by 5 ℃ compared to the baseline yield decreased by 30%; at the same temperature, with the increase of CO2 concentration, corn yield had a small increase, in the baseline temperature case, CO2 concentration at At 750 ppm, corn yields increased by 9% compared to yields at 350 ppm. Read More

Abstract: Humic acid is a naturally occurring organic substance found extensively in soils, coal, and peat, characterized by a complex molecular structure with abundant functional groups. Recent advancements in activation and modification techniques, such as oxidation, alkalization, and biological modification, have significantly enhanced the solubility, stability, and bioactivity of humic acid. These techniques have broadened its applications in agricultural productivity, soil improvement, and environmental protection. This review summarizes the principles and effects of various activation and modification techniques and discusses their roles in agriculture and environmental management. It also highlights the current achievements and limitations in the field, as well as potential directions for future research on humic acid activation and modification. Read More

Abstract: This thesis takes the braised beef meal kit as the experimental object, selects two freezing methods of refrigerator (-18℃) and liquid frozen sleep (-25℃) for processing and then stores it in the refrigerator (-18℃) for 30 days, aiming to study the preservation effect of liquid frozen sleep technology on prefabricated dishes under frozen storage conditions. Taking cold storage (4℃) as the blank, the changes of texture, color, water content, sensory quality, protein structure and volatile components of braised beef were determined on the 10th, 20th and 30th days. The main research conclusions are as follows: In terms of texture, the hardness, chewiness and elasticity of beef all show a downward trend during storage, and the range of the frozen sleep group is lower than that of the refrigerator group; in terms of color, the L* value shows a trend of first increasing and then decreasing during storage, and the a* and b* values show a downward trend, among which the changes of the frozen sleep group are all smaller than those of the refrigerator group; in terms of water content, the water content of beef in the refrigerator group decreased from 67% to 50%, and the water content of beef in the frozen sleep group decreased from 67% to 56%; in terms of the secondary structure of protein, with the extension of storage time, the hydrogen bonds of the highly ordered α-helix structure are broken, and gradually transformed to the disordered β-turn and random coil structure, while the contents of the regular and ordered structures of α-helix and β-fold in the frozen sleep group decrease less than those in the refrigerator group; in terms of volatile components, the content of volatile substances of both freezing methods increases with the extension of storage time, while the content of volatile substance components of the frozen sleep group increases less. Liquid frozen sleep technology can be applied to the storage of braised beef, which can make the meat products maintain … Read More

Abstract: As a transition zone of urban-rural integration, the construction of cultivated land quality in suburban areas is of great significance to ensure food security and promote regional sustainable development. This paper comprehensively analyzes the current situation, problems and influencing factors of suburban cultivated land quality, and proposes corresponding construction strategies. The results show that the construction of cultivated land quality in urban and suburban areas needs to comprehensively consider natural conditions, socio-economic factors and policy orientation, and realize the continuous improvement of cultivated land quality and multi-functional and coordinated development through scientific planning and comprehensive management. Read More

Abstract: The aim of this study was to investigate the effects of the contents of immunity-enhancing soft capsules with krill oil as the main active ingredient on the immune function of female ICR mice. Methods: A 30-day continuous gavage experiment was performed by setting different doses of subjects, including high, medium and low dose groups and edible vegetable oil control group. During the experiment, a variety of immunological detection methods including carbon clearance test, delayed-type allergic reaction (DTH) test, antibody-producing cell test (hemolytic plaque number) and serum hemolysin were used to comprehensively evaluate the effect of the test substance on the immune function of mice. Results: In the carbon clearance test, the optical density OD(2min and 10min), liver weight, spleen weight and phagocytic index A of mice in each dose group were significantly higher than those in the control group (P < 0.05), suggesting that the subjects could enhance the phagocytic function of mice. DTH test results showed that the weight ratio of left and right ears of mice in each dose group was increased, but there was a statistical difference compared with the control group (P<0.05), indicating that the subject could improve the delayed allergic reaction in mice. The results of antibody-producing cell assay showed that the amount of hemolytic plaque in each dose was greater than that in the normal control group (P<0.05), indicating that the subject could promote the normal growth of mouse antibody-producing cells. The results of serum hemolysin test also showed that the degree of hemagglutination of mice in each dose group in different dilutions of serum was higher than that in the control group (P < 0.05), further confirming the enhancing effect of the test object on the immune function of mice. Conclusion: The content of immunity-enhancing soft capsule (krill oil, Antarctica) can significantly improve the immune function of ICR female mice, which is manifested as enhanced … Read More