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This paper analyzed the horizontal distribution and limitation of DIN, PO4-P and SiO3-Si based on the four surveys of Miaodao Archipelago sea area in August and October of 2018, April and June of 2019. The results showed that the concentration of DIN ranged from 0.82 μmol/L to 95.14 μmol/L with an average value of 5.27 μmol/L and the maximum was in August of 2018. The concentration of PO4-P ranged from "not detected" to 2.12 μmol/L with an average value of 0.19 μmol/L and the maximum was in October of 2018. The concentration of SiO3-Si ranged from 0.25 μmol/L to 48.93 μmol/L with an average value of 5.38 μmol/L and the maximum was in August of 2018. In general, the concentration of nutrients was higher in summer and was relatively scarce in spring. PO4-P was the limiting factor in August and October of 2018, June of 2019, while SiO3-Si and PO4-P were the limiting factors in April of 2019. The PO4-P limitation would limit the primary productivity of sea area and the aquaculture could be influenced. The low content of SiO3-Si was not conducive to the growth of diatoms, which indirectly promoted the reproduction of dinoflagellates, so that this area was easy to cause red tide in spring.

Based on the environmental monitoring data of Laizhou Bay in May (spring) and October (autumn), 2020, this paper had studied the spatial distribution characteristics of inorganic nitrogen (DIN) and reactive phosphate (DIP), the condition of seawater quality and eutrophication in Laizhou Bay, and completed the correlation analysis of nutrient and environmental factors. The results showed that in spring, the concentration of DIN ranged from 0.115 mg/L to 1.830 mg/L, which was higher near shore than far shore and higher in the west than in the east. In autumn, the concentration of DIN ranged from 0.009 mg/L to 2.070 mg/L, and the high value area was located near the estuary of the Yellow River. The DIP concentration in spring and autumn ranged from not detected to 0.009 mg/L and form 0.000 4 mg/L to 0.012 9 mg/L, respectively. Due to the influence of phosphorus load reduction policies such as "phosphorus control" and "phosphorus limit", the DIP concentration had always been at a low level. Affected by DIN concentration, 35.7% and 30.7% of the survey sites exceeded the second-class seawater quality standard in spring and autumn, respectively. In spring, 1.4% of the survey sites were slightly eutrophicated, located near the estuary of Xiaoqing River. In autumn, 1.6% of the survey sites were slightly eutrophic, located near the estuary of the Yellow River. And the other sites did not reach eutrophication level. The distribution characteristics of nutrients in Laizhou Bay were significantly correlated with various environmental factors, and the spatial distribution was affected by many factors.

Based on 4 cruises in August and October 2018, February and May 2019,water quality and zooplankton at 59 stations in Miaodao Archipelago were investigated. The community structure, spatial and temporal distribution of zooplankton collected by type I net and the correlation with various environmental factors were analyzed statistically. The results showed that: a total of 93 species of zooplankton were identified in Miaodao Archipelago, including 13 categories, the species of copepods and planktonic larvae were 25 respectively, accounting for 53.8% in total. The dominant species in different seasons were different, and Calanus sinicus was dominant in all seasons. The abundance of zooplankton ranged from 3.0 to 2 720 ind/m3, with an average of 122.41 ind/m3, and the biomass ranged from 0.25 to 3 106.75 mg/m3, with an average of 172.15 mg/m3. The Shannon-Wiener index varied from 0.058 to 3.670, with an average of 1.431, the Pielou evenness index varied from 0.030 to 0.922, with an average of 0.467, and the Margalef index varied from 0.362 to 7.964, with an average of 2.358. The results of Pearson correlation analysis and canonical correspondence analysis showed that the distribution of zooplankton was influenced by various environmental factors, among which temperature and salinity were the most important factors.

Aiming at the efficiency problem of privacy data sharing in the Internet of vehicles (IoV), an efficient distributed model sharing strategy based on blockchain was proposed.In response to the data sharing requirements among multiple entities and roles in the IoV, a master-slave chain architecture was built between vehicles, roadside units, and base stations to achieve secure sharing of distributed models.An asynchronous federated learning algorithm based on motivate mechanism was proposed to encourage vehicles and roadside units to participate in the optimization process.An improved DPoS consensus algorithm with hybrid PBFT was constructed to reduce communication costs and improve consensus efficiency.Experimental analysis shows that the proposed mechanism can improve the efficiency of data sharing and has certain scalability.

Based on the survey data of surface sediments in Shandong coastal waters, the temporal and spatial variation characteristics of sediment granularity and its influencing factors were analyzed. The results showed that in 2020, the grain size of surface sediments in Shandong coastal waters gradually decreased from shore to sea, and silt content was the highest, with an average of 66.45%, sand content was the second, with an average of 26.78%, clay content was lower, with an average of 6.77%. There were significant differences in the spatial distribution of sediment grain fractions, including silty sand, sandy silty sand, silty sand and sand, and silty sand was dominant, accounting for 61.9% of the survey site. From 2016 to 2020, an overall coarsening trend of surface sediments in Shandong coastal waters was detected. And the trend was more obvious in the coastal waters of Rizhao, Qingdao, Weifang and Binzhou, followed by Dongying, and the lowest in Yantai and Weihai. The main influencing factors of the temporal and spatial characteristics of sediment granularity include provenance, regional hydrodynamic conditions (such as the Bohai Sea Current, Yellow Sea Current, Shandong Coastal Current, etc.), and coastal engineering construction, and furthermore, the specific influencing mechanism still needs further investigation and research. The research results could provide a reference for the analysis of changes in sediment types and the protection and utilization of coastal zones in the coastal waters of Shandong Province.

The antibacterial activity and mechanism of rhamnolipids (RLs) against Bacillus cereus spores were analyzed from the aspects of appearance, morphology, and cell membrane state. The results showed that minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of RLs were 80.0 and 160.0 mg/L, respectively. Both concentrations of RLs caused severe shrinkage and depression on the surface of spores, and disrupted the integrity and permeability of the spore cell membrane, leading to the leakage of intracellular electrolytes, DNA and proteins. In addition, RLs inhibited and inactivated B. cereus spores by various mechanisms such as decreasing heat resistance, generating oxidative stress, reducing surface adhesion, and binding to and interfering with DNA molecules. The results of this study will contribute to the development and application of RLs in the field of food safety.

为了提高牦牛酥油的品质，以青藏高原牦牛乳为原料制得牦牛酥油后，采用水化脱胶和碱炼脱酸法对其进行精炼处理。通过单因素试验研究50%柠檬酸添加量、脱胶温度和脱胶时间对脱胶率的影响，并通过正交试验优化脱胶工艺；通过单因素试验研究脱酸温度、超碱量、碱液质量分数和脱酸时间对脱酸率的影响，同时通过响应面试验优化脱酸工艺。采用气质联用技术（GC-MS）分析精炼前后牦牛酥油的脂肪酸组成和挥发性成分。结果表明：最佳的脱胶工艺条件为50%柠檬酸添加量0.6%、脱胶温度60 ℃、脱胶时间30 min，在此条件下脱胶率可达94.12%；最佳的脱酸工艺条件为超碱量0.4%、碱液质量分数10%、脱酸温度60 ℃、脱酸时间30 min，在此条件下脱酸率达91.85%；经脱胶和脱酸处理后牦牛酥油磷脂含量、过氧化值和酸值均显著降低，色泽呈黄色且透明，不饱和脂肪酸含量显著增加，挥发性成分中醛类、酮类化合物含量均显著增加，酸类化合物含量显著减少。综上，经脱胶和脱酸精炼处理后，牦牛酥油色泽和风味明显改善，品质得到提高。 In order to improve the quality of yak ghee, the yak ghee was prepared from the yak milk from Qinghai Tibet plateau, and then was refined by hydration degumming and alkali deacidification. The effects of 50% citric acid addition, degumming temperature and degumming time on degumming rate were investigated by single factor experiment, and the degumming process was optimized by orthogonal experiment. The effects of deacidification temperature, excess alkali quantity, alkali mass fraction and deacidification time on deacidification rate were investigated by single factor experiment, and the deacidification process was optimized by response surface methodology. The fatty acid composition and volatile components of yak ghee were analyzed by GC-MS. The results showed that the optimal degumming process conditions were 50% citric acid addition 0.6%, degumming temperature 60 ℃ and degumming time 30 min, and the degumming rate could reach 94.12%. The optimal deacidification process conditions were excess alkali quantity 0.4%, alkali mass fraction 10%, deacidification temperature 60 ℃ and deacidification time 30 min, and the deacidification rate could reach 91.85%. After degumming and deacidification, the content of phospholipid, peroxide value and acid value of yak ghee decreased significantly, the color was yellow and transparent, the content of unsaturated fatty acids increased significantly, the content of volatile components aldehydes and ketones increased significantly, while the content of acid compounds decreased significantly. In conclusion, after degumming and deacidification, the color and flavor of yak ghee improved obviously, and the quality of yak ghee improved.

Objective: To detect the molecular characterization of polysaccharide purified from Amusium pleuronectes , so as to investigate its role of intervention to the formation of hepatic fibrosis caused by Schistosoma japonicum infection., Methods: The crude polysaccharide from A. pleuronectes was extracted and further purified, and the molecular weight and monosaccharide composition were determined by the high pressure size exclusion chromatography and PMP pre-column derivatization method, respectively. A total of 50 female BALB/c mice were randomly divided into five groups：A (normal group), B (experimental group), C (polysaccharide group), D (praziquantel), and E (polysaccharide + praziquantel group). The mice in B, C, D, or E groups were attacked on the abdominal skin by using the cercariae of S. japonicum (30 ± 2 for each mouse) respectively. After 8 weeks, the mice in C, D, and E groups were administrated by polysaccharide and/or praziquantel, and the mice in B group were instead of saline. All the livers and sera were collected after 16 weeks. HE staining was employed for the livers, and serum IFN-γ and IL-13 were measured by using ELISA kits., Results: The molecular weight of purified polysaccharide from A. pleuronectes was 11.7 kDa. Compared with A and B groups, the serum levels of IFN-γ in C, D, and E groups were significantly increased ( F = 63.525, P < 0.01). However, the serum levels of IL-13 in C, D, and E groups were significantly decreased ( F = 99.788, P < 0.01) compared with that in B group. HE staining showed that the egg nodules and hepatic fibrosis were observed in B, C, D, and E groups. The number of egg nodules and fibrosis degree in E group were milder than those in B group (χ 2 = 7.875, P < 0.05)., Conclusions: The polysaccharide from A. pleuronectes has an obvious effect in preventing hepatic fibrosis process induced by S. japonicum infection, particularly combining with the administration of praziquantel.