The mechanism of the chemical reaction of H₂O with three stabilized Criegee intermediates (stabCI-OO, stabCI-CH₃-OO and stabCIx-OO) produced via the limonene ozonolysis reaction has been investigated using ab initio and DFT (Density Functional Theory) methods. It has been shown that the formation of the hydrogen-bonded complexes is followed by two different reaction pathways, leading to the formation of either OH radicals via water-catalyzed H migration or of α-hydroxy hydroperoxide. Both pathways were found to be essential sources of atmospheric OH radical and H₂O₂ making a significant contribution to the formation of secondary aerosols in the Earth’s atmosphere. The activation energies at the CCSD(T)/6-31G(d) + CF level of theory were found to be in the range of 14.70–21.98 kcal mol⁻¹. The formation of α-hydroxy hydroperoxide for the reaction of stabCIx-OO and H₂O with the activation energy of 14.70 kcal mol⁻¹ is identified as the most favorable pathway.

Paeonia rockii has been a traditional medicinal material from time immemorial. It is an important plant resource of ethnic medicine and chinese herbal medicine. It has unique effects on heat and cool blood, promoting blood circulation and dispersing blood stasis, analgesia and promoting menstruational flow. It is also a first-class protected plant. With the increasing demand for the bark and roots of P. rockii in China’s medicinal market, the continuous high-intensity and disorderly excavation has led to a sharp decline in wild resources. P. rockii is in imminent danger and needs to be saved and protected urgently. In this study, the distribution records of P. rockii in China, combined with environmental factors, are used to simulate the current potential distribution area of P. rockii through MaxEnt model. The environmental factors affecting the distribution of P. rockii are obtained by using the contribution rate of environmental factors and a jackknife test analysis, and the appropriate value of environmental factors is determined by using the response curve. The results show that the AUC value of test set data is 0.985 and that of training set data is 0.987. The prediction accuracy of the Maxent model is extremely high and the simulation effect is very good. At present, the high suitable areas of P. rockii are mainly distributed in the shape of cake in Southern Ningxia, southern Gansu and southern Shanxi, accounting for 15.58% of the total suitable areas. The most important environmental factor affecting the geographical distribution of P. rockii is the altitude; Under the future climate change scenario, the total suitable area of P. rockii shows a decreasing trend, among which the area of high suitable area shows an obvious decreasing trend, the mass center of high suitable area of P. rockii generally tends to migrate to the northwest, and the migration range is large under the scenario of high concentration emission. The research results can provide scientific data support for P. rockii to to cope with the changes in suitable areas caused by climate change and the establishment of effective protection, clarify the change and heterogeneity of P. rockii in different regions of China in the future, and clarify its ecological needs, which has certain practical significance.

Alien invasive algae along with ship ballast water have posed a serious threat to China’s marine ecological security. A clear understanding of the geographical distribution of invasive species and their response to climate change can provide a scientific basis for their prevention and control. In this study, combined with environmental variables and distribution data, MaxEnt was used to predict the potential geographical distribution and change trend of Alexandrium in the four major sea areas of China currently, 2040s (2040-2050) and 2090s (2090-2100), reveal the dominant environmental factors affecting the geographical distribution, analyze the migration trends of centroids the highly suitable area, and clarify the key control sea areas. The results showed that: 1) The AUC values of all models were significantly higher than random models, and the Kappa statistics of all models were higher than “general”, demonstrated that the prediction results were available. 2) The most important environmental variable affecting the geographical distribution of Alexandrium was the Temperature. Range (bio24), and its suitable range was 23.43-31.52ºC. 2) At present, in the corresponding sea areas of Nantong, Yancheng, Ningbo, Jiaxing, Dongying, Binzhou, Cangzhou, Tianjin, Tangshan, Qinhuangdao, Shenzhen, Dongguan and Zhongshan, special attention should be paid to the control of Alexandrium. 3) Under the future climate change scenarios, excepted in the South China Sea, the total and highly suitable area of Alexandrium showed an increasing trend. 4) Under climate change scenarios, in the Yellow Sea, the centroids of the highly suitable area would move to the southeast. In the Bohai Sea and the East China Sea, the centroid showed a trend of moving to different latitudes and directions. In the South China Sea, the centroids of of the highly suitable area and total suitable area of Alexandrium would both move to the southwest. Our results can provide a theoretical basis for the prevention and control of Alexandrium.

Alexandrium spp., globally recognized as harmful algal bloom (HAB) species, pose severe threats to marine ecosystems, fisheries, and public health. Based on 469 occurrence records and 24 marine environmental variables, this study employed the Biomod2 ensemble modeling framework to predict the potential distribution of Alexandrium spp. under current and future climate scenarios, and to assess the role of key environmental factors and the spatiotemporal dynamics of habitat centroid shifts. The results revealed that (1) the ensemble model outperformed single models (AUC = 0.998, TSS = 0.977, Kappa = 0.978), providing higher robustness and reliability in prediction; (2) salinity range (bio18, 19.1%) and mean salinity (bio16, 5.8%) were the dominant factors, while minimum temperature (bio23) also showed strong constraints, indicating that salinity determines “whether persistence is possible,” while temperature influences “whether blooms occur”; (3) under present conditions, high-suitability habitats are concentrated in Bohai Bay, the Yangtze River estuary to the Fujian coast, and parts of Guangdong; (4) climate change is predicted to drive a southward shift of suitable habitats, with the most pronounced expansion under the high-emission scenario (RCP8.5), leading to the emergence of new high-risk areas in the South China coast and adjacent South China Sea; (5) centroid analysis further indicated a pronounced southward migration under RCP8.5 by 2100, highlighting a regional reconfiguration of ecological risks. Collectively, salinity and temperature are identified as the core drivers shaping the ecological niche of Alexandrium spp., and future warming is likely to exacerbate HAB risks in southern China. This study delineates key prevention regions and proposes a shift from reactive to proactive management strategies, providing scientific support for HAB monitoring and marine ecological security in China’s coastal waters.

This paper analyzes the harm of invasion of alien species caused by ship activities, and expounds the necessity and urgency of carrying out relevant research in China. This paper summarizes the research progress at home and abroad, analyzes the research defects, and proposes that the research on the invasion mechanism of alien species caused by ship activities in China should focus on solving the major scientific problems such as the process and evolution of the invasion disaster, the interaction between the invasion and the offshore ecological environment security. In addition, it is necessary to consider the different invasion stages of alien species, such as invasion-escape period, population establishment period, latent-lag period and spread-outbreak(disaster) period. Finally, the key technologies and implementation plans to solve major scientific problems are proposed. The results show that, the interpretation of the model is generally consistent with the actual situation. Through database construction and typical species experiments, the theoretical model of alien invasion mechanism introduced by ship activities is interpreted and proved.

In this paper, a quantitative risk assessment method of packaged cargoes carried by ship based on online dynamic big data fusion technology was researched. In recent years, major accidents such as oil spill, fire, explosion and ship loss occurred frequently in shipborne cargo transportation. Due to the lack of real-time dynamic risk analysis, both early warning and emergency handling of those accidents are extremely difficult. In this paper, a risk transmission model was built, which based on the flow chain for cargo transportation. A system including the analysis of cargo transportation risk and quantitative assessment model based on real-time dynamic big data fusion technology was built. Finally, a scientific quantitative assessment method was formed. And a container ship passing through Shenzhen waters was taken as an example in order to verify the practicality of the method. In this way, it can realize the quantitative assessment of risk (especially the risk of dangerous packaged cargoes)in the waterage. What's more, according to the assessment results, it can analyze the high-risk factors and high-risk parts in the process of waterage, and then realize the informationalized and modernized intelligent supervision in a whole process and all round way, which will effectively improve the level of accident prevention in China.