Dynamics Of Structure Research Articles

One-dimensional mechanism of gaseous deflagration-to-detonation transition

A one-dimensional mechanism of deflagration to detonation transition is identified and investigated by an asymptotic analysis in the double limit of large activation energy and small Mach number of the laminar flame velocity. The unsteady analysis concerns the self-accelerating tip of an elongated flame in a smooth walled tube. The flame on the tip, considered as plane and orthogonal to the tube axis, is pushed from behind by the longitudinal flow resulting from the cumulative effect of the radial flows of burned gas issued from the lateral flame of the finger-like front (called backflow in the following). The analysis of the one-dimensional dynamics is performed by coupling the flame structure with the downstream-running compression waves propagating in the external flows. A critical elongation is identified from which the slightest increase in elongation leads to a pressure runaway producing the flame blow-off. The dynamics of the inner structure of the laminar flame on the tip which is accelerated by the self-induced backflow is characterized by a finite-time singularity of the reacting flow in the form of a dynamical saddle-node bifurcation.

Interplay between Spatial Confinement of Thrombin Activity and Dense Granule Secretion Regulates Dynamics of Thrombus Formation

Background Thrombi formed in healthy murine microvessels have a heterogeneous structure, comprising a thrombin-dependent core and a shell supplied by platelet-derived agonists, such as ADP from dense granules. After the injury is inflicted, the core steadily grows until it reaches a plateau in size, while the shell follows three stage dynamics of rapid growth, shrinkage and stabilization. However, it is not clear how the complex dynamics of the overall thrombus structure is orchestrated by various cues. Aim We aimed to analyze whether spatiotemporal kinetics of thrombin-induced dense granule secretion is responsible for the observed dynamics of thrombus formation in microvessels. Methods We developed a multiscale computational model of thrombogenesis in response to a vessel wall injury. Platelets were modeled as two-dimensional particles, while platelet agonists were described as virtual particles, which induced platelet activation through affecting mechanical interactions between platelets and triggering platelet degranulation. As a platelet aggregate grew, the blood flow was recalculated. The model was built in a bottom-up manner and its description of single-cell processes was based on the experimental findings. Results The model showed that thrombin produced at the injury site was mostly confined to the innermost layers of the thrombus due to competing intrathrombus diffusion and flow-mediated dilution. Such spatial confinement of thombin resulted in the formation of a thrombus with a pronounced thrombin-activated core where platelets were able to secrete their dense granules. Released ADP recruited new platelets and triggered the formation of a thrombin-free thrombus shell. The thrombus grew until it ruptured under the hydrodynamic force and the growth repeated in cycles. However, our results predicted that if the propagation of thrombin along the flow was limited either by volumetric or surface inhibition, the cycles of thrombus formation stopped once the dense granule pool in the core was depleted. Without the supply of newly secreted ADP, the thrombus shell disassembled and the thrombus size was stabilized, in line with experimental findings. Conclusion Computational modelling predicts that thrombin-induced dense granule secretion is responsible for the rapid formation of the thrombus shell, which disintegrates once the granule pool is depleted due to intense secretion in the confined thrombus core. We suggest that this mechanism is responsible for the three-stage dynamics of thrombus growth in vivo.

Mass estimation of a simple hydraulic crane using discrete extended Kalman filter and inverse dynamics for online identification

Automatization of hydraulic machinery requires accurate information of the current dynamic state of the machinery but also information of the underlying dynamic model characterized by a set of parameters. Some of the parameters can be considered static and well defined, such as machinery dimensions, whereas a part of the parameter set is time varying and needs to be identified based on observations. Particularly, difficult parameters to estimate are the ones, from which no prior knowledge is available. Consequently, the parameter corrections cannot be assumed to be small, which is commonly required for the existing parameter estimation algorithms. This study creates an online capable identification algorithm for estimation of a load mass operated by a hydraulic crane. In the case of load mass estimation, the unknown parameter can be practically any positive value, which implies the parameter corrections to be large. In this study, the estimation problem is divided in two parts: First, the dynamical states of the system are estimated based on the system kinematic relationships and dynamics of the hydraulic circuit. Secondly, the unknown load mass is estimated based on the known hydraulic forces and kinematics using the inverse dynamics of the mechanical structure. The proposed algorithm is tested with both artificially created measurements and with an experimental setup. The results show that both the kinematics of the structure and hydraulic pressures can be accurately estimated using the proposed method. Moreover, the method can be used to further estimate the payload mass. A drawback related to inverse dynamics is that it produces biased estimates in static equilibrium because of the discontinuous nature of static friction force. However, this drawback can be avoided, in part, by not updating the payload estimate in the low-velocity region. The proposed estimation methodology is capable for online identification, and as such, it can be used to adapt the control laws of automated machinery. Moreover, the methodology can be useful to record and document the amount of payload being handled during a work cycle.

Spiral shocks induced in a galactic gaseous disk: Hydrodynamic understanding of observational properties of spiral galaxies

Context. We investigate the properties of spiral shocks in a steady, adiabatic, non-axisymmetric, self-gravitating, mass-outflowing accretion disk around a compact object. Aims. We obtained the accretion-ejection solutions in a galactic disk and applied them to spiral galaxies in order to investigate the possible physical connections between some observational quantities of galaxies. Methods. We considered the self-gravitating disk potential to examine the properties of the galactic gaseous disk. We obtained spiral shock-induced accretion-ejection solutions following the point-wise self-similar approach. Results. We observed that the self-gravitating disk profoundly affects the dynamics of the spiral structure of the disk and the properties of the spiral shocks. We find that the observational dispersion between the pitch angle and shear rate and between the pitch angle and star formation rate in spiral galaxies contains some important physical information. Conclusions. There are large differences among the star formation rates of galaxies with similar pitch angles. These differences may be explained by the different star formation efficiencies caused by distinct galactic ambient conditions.

A hybrid time/event-triggered interaction framework for multi-agent consensus with relative measurements

This paper is concerned with the output-feedback consensus problem of linear multi-agent systems on undirected graphs. Our focus is on reducing sensing and communication burdens between agents. Based on relative output measurements, a dynamic output-feedback (DOF) protocol is proposed, which, by leveraging the structure of the closed-loop dynamics, integrates a hybrid time/event-triggered sampling mechanism such that only intermittent interaction between agents is needed. Consensus conditions are established by the Lyapunov method and numerical simulations are provided for illustrating the effectiveness of the protocol. Compared with the existing results, the proposed DOF protocol has the following merits: (1) they rely on relative output measurements but do not need absolute measurements about agents; (2) they only require agents to intermittently interact with neighbors and thus can greatly reduce sensing and communication burdens between agents; and (3) the designed event-triggering conditions do not need to perform extra reconstruction operations that are computationally demanding.

Fractional-Order Composite Adaptive Control of Robot Manipulators

The branch of system identification and control theory concerned about robot manipulators is adaptive control of non-linear multi-input multi-output dynamic systems which study constitutes a mature and well-founded discipline; nevertheless, there are fundamental problems open to date, one of them is to obtain a control law that is rich enough to guarantee its persistent excitation and consequently that the parametric error converges asymptotically to zero, while the tracking error converges globally asymptotically to zero. An extension of a globally convergent adaptive scheme control for a robot manipulator in the tracking of a determined trajectories with no consideration of the interaction with its environment is proposed, based on the fact that the parameter uncertainty is involved in both the tracking error and the identification error. The first control task is achieved by a feedback linearization technique that takes advantage of the structure of manipulator dynamics. The second task is achieved by a fractional order filtering technique to avoid the joint acceleration and enrich the regressor matrix in such way that is persistently exciting. Finally, the control law is expressed as feedforward compensation and a simple PD controller.

Financing innovations in the agricultural industry as a component of the digital development of Ukraine’s economy

Innovative development of the economy is a condition for stable growth, which holds particular importance for the agricultural sector, elevating the management of biological assets to a significantly higher level. This study aims to determine the potential for innovative development in the agricultural sector of Ukraine and investigate the peculiarities of its financing. General scientific methods and hermeneutic methods were applied, along with statistical and correlation methods, to identify the connection between influencing factors. Tabular and graphical methods were used to present the results, and generalization was employed for drawing conclusions. The study assessed Ukraine’s positions in the Global Innovation Index (2014-2022), which is relatively low, decreasing from 63 to 57 over the period. However, it shows potential in components like human capital, the business environment, and scientific research. The dependency of the growth of agricultural GDP on various factors was identified through correlation and variance analysis, particularly through the advancement of innovations. The structure of GDP dynamics reveals a decline in the agricultural sector by 28% in the wartime of 2022 compared to 2021, while the information and telecommunication sector only decreased by 7%. If the pre-war level of government spending on financing agricultural innovations was 80% of the total, covering only the reproduction of conditions for the formation of scientific products, even raising it to 90% during the wartime does not meet real needs. Scientific and educational expenditures of the Ministry of Agricultural Policy and Food from 2018 to 2023 decreased by 22% in terms of funds, while their share increased from 4.45% in 2018 to 8.57% in 2023 due to the overall decrease in funding by 67%. Based on the assessment of the state of financing innovations in the agricultural sector to enhance them, a systematic approach to choosing financing sources was proposed. An optimal financing scheme for agricultural innovations was built based on consolidated sources under the conditions of forming a financial cluster. The practical significance of the research lies in the possibility of using its results in developing a strategy for post-war recovery of the agricultural sector. This involves evaluating the effectiveness of models for financial support of innovative development

Linking seasonal plankton succession and cellular trace metal dynamics in marine assemblages

Factors affecting trace metal dynamics in marine plankton still need to be fully understood. Underlying mechanisms affecting cellular metal distribution, seasonal changes, and the influence of plankton community structure are poorly explored. This study comprehensively analyzed the seasonal changes in environmental factors, plankton community structure, and their impact on plankton cellular metal dynamics. Plankton samples were isolated, and trace metals (Cr, Mn, Fe, Co, Ni, Cu, As, Cd, Hg, and Pb) were analyzed with an inductively coupled plasma mass spectrometer (ICP-MS). Plankton community structure significantly changed with seasons (p < 0.05), which were mainly driven by temperature (seasonal change) and nutrients (eutrophication). Mean plankton cellular trace metals did not significantly change (p > 0.05) in the study area but were higher along estuaries likely due to differences in metal influx from rivers. However, their distribution patterns significantly differ between the wet and dry seasons, likely influenced by the changes in community structure and anthropogenic influx. Cellular trace metals, particularly in phytoplankton, strongly correlated with selected species suggesting the impacts of community structure in trace metal distribution. Hence, the influence of environmental factors in driving plankton succession may have caused a ripple effect on cellular trace metal distribution, especially in phytoplankton. However, both blooming species Skeletonema and Chaetoceros (diatoms) showed a contrasting relationship with cellular metals, suggesting the cooccurrence of bioaccumulation or biodilution mechanisms. This study shows the potential influence of community structure in cellular trace metal dynamics for marine plankton assemblages. However, more than plankton abundance and functional diversity, i.e., species diversity, might be needed to assess the community-level impacts on cellular metals.

Stimulation of domestic goods sales

The strategy of import substitution in the national economic policy, which provides the creation of conditions for the domestic production development, is mainly based on production capabilities and is aimed at ensuring the socio-economic and security needs of the country. Much less emphasis was placed on the possibility of substituting domestically produced goods for the demand of the population. Much less emphasis was placed on the possibility of the population’s demand replacement with domesti­cally produced goods. However, in view of social security, especially in the conditions of martial law, when there are disruptions in the supply of products, in particular imported products, the correlation between the industrial and trade sectors within the policy of import substitution seems to be unfairly underestimated. So the issue of taking into account the parameters of retail trade when determining the priorities of the national policy of import substitution becomes relevant. Therefore, the purpose of the article is to investigate the potential impact of retail trade on the implementation of the policy of import substitution in the country and to determine the directions of trade business support for domestic production in wartime with the perspective of post-war recovery of Ukraine. Using the me­thods of analysis and synthesis, comparison, grouping and systematization, the article exa­mines the level of import dependence of the retail trade of Ukraine in the pre-war period, which gives an idea of the potential of import substitution in the industry. Evaluating the product structure of retail turnover according to the criterion of the ratio of domestic and imported products made it possible to establish product groups, the domestic production of which must be supported and developed. Using the analysis of the dynamics of the commodity structure of imports in the prewar and wartime period, commodity items were identified for which supply chains were restored and for which there is a sufficiently high domestic demand, reflecting the needs of the market under martial law. Also, based on the analytical assessment of the levers of influence of trade business on its supply chain partners – domestic suppliers, the directions of its support for domestic, import-substituting production have been determined. The involvement of trade enterprises in the implementation of the national strategy of import substitution with the perspective of post-war reproduction involves the transformation of approaches to the integrated management of supply chains.

Spatio-temporal dynamics of phytoplankton in a diversion reservoir and the major influencing factors: taxonomic versus functional groups classification.

Identifying factors affecting phytoplankton dynamics is crucial to the management of aquatic ecosystems. A lot of scholars have conducted intensive studies on phytoplankton in lake or reservoirs, but not many studies have been conducted on diversion reservoirs. To explore the seasonal and spatial variation of phytoplankton communities and their relationship with environmental factors in the context of water diversion, a case study was carried out at XiKeng (XK) reservoir in South China. In this study, month-by-month water samples and phytoplankton were collected from this reservoir from December, 2021, to July, 2022. The results showed that the phytoplankton community was characterized by significant spatial and temporal variations. There were significant differences in phytoplankton abundance and structure in the reservoirs in terms of time. The abundance of phytoplankton cells and the proportion of Cyanobacteria in the reservoir showed a trend of increasing from autumn to spring and then decreasing from spring to summer, while the functional group evolved from S1 in autumn to SN in spring and summer. The abundance of phytoplankton was influenced by the dynamic water division and the characteristics of the reservoir itself, resulting in a spatial distribution characteristic of AIII > AII > AI. Water temperature (WT) and nutrients were the key factors driving the changes in phytoplankton abundance and community structure in the reservoir. These findings will deepen our understanding of the spatial and temporal dynamics of phytoplankton community structure in diversion reservoirs and provide a basis for freshwater water ecological management strategies.

The state of the population of narrow-clawed crayfish in Lake Sevan (Armenia) under multiple stress conditions.

The narrow-clawed crayfish is a crayfish species that was accidentally introduced into the ecosystem of Lake Sevan in the 1980s. Soon it became one of the most preferred fisheries in the lake and an important link in the food chain by successfully replacing the endemic fish subspecies Sevan khramicarp (Capoeta sevangi, De Filippi, 1865) in the chain of detritivores. However, recently, the stock declines dramatically, associated with two main threats: the impact of burn-spot disease and an increase in fishing pressure on its population. To estimate the state of population under multiple stress conditions, we investigated the dynamics of stock, the size/age and sex structure, the fecundity, and the health status of the population. A comparative analysis of oxidative stress biomarkers (superoxide dismutase, catalase, glutathione-S-transferase activities and reduced glutathione, thiobarbituric acid reactive substance contents) showed significant differences between healthy and infected individuals. Another indirect effect of the disease, which probably leads to a decrease in the stock, was an increase in the proportion of immature females. Also, we observed some decrease in the infection rate along with the decline in the density of crayfish. However, stock reduction and some changes in the population may also be caused by a strong bloom of cyanobacteria.

Experimental Study on Coupling Dynamics of a High Dimensional Nonlinear Riser Structure and Floating Platform by Truncated Equivalent Method

Experimental Study on Coupling Dynamics of a High Dimensional Nonlinear Riser Structure and Floating Platform by Truncated Equivalent Method

A new design mobile cabin hospital based on the Hoberman sphere

Mobile cabin hospitals have been established in many countries and regions to cope with the spread of the new crown epidemic. The feasibility and convenience of the model are analyzed in the context of practical situations. This paper examines and exploits the collapsibility and convenience of Hoberman spheres, their principles and methods of movement, and the dynamics of the scissor structure, which is the basic unit of movement of Hoberman spheres. The effect of changes in angle as well as the length of the scissor-like structure leading to the size of the sphere is analyzed. It was also studied and analyzed through specific model designs, what materials are more suitable for the lining material. The resulting design for the individual wards of the mobile cabin hospital was constructed from half of the Hoberman spherical shell and covered with protective material inside. The final optimization of the combination makes it innovative. The design objectives were simple, easy to install and transport, and reusable.

Geometry-informed dynamic mode decomposition in Kresling origami dynamics

Origami structures often serve as the building block of mechanical systems due to their rich static and dynamic behaviors. Experimental observation and theoretical modeling of origami dynamics have been reported extensively, whereas the data-driven modeling of origami dynamics is still challenging due to the intrinsic nonlinearity of the system. In this study, we show how the dynamic mode decomposition (DMD) method can be enhanced by integrating geometry information of the origami structure to model Kresling origami dynamics in an efficient and accurate manner. In particular, an improved version of DMD with control, that we term geometry-informed dynamic mode decomposition (giDMD), is developed and evaluated on the origami chain and dual Kresling origami structure to reveal the efficacy and interpretability. We show that giDMD can accurately predict the dynamics of an origami chain across frequencies, where the topological boundary state can be identified by the characteristics of giDMD. Moreover, the periodic intrawell motion can be accurately predicted in the dual origami structure. The type of dynamics in the dual origami structure can also be identified. The model learned by the giDMD also reveals the influential geometrical parameters in the origami dynamics, indicating the interpretability of this method. The accurate prediction of chaotic dynamics remains a challenge for the method. Nevertheless, we expect that the proposed giDMD approach will be helpful towards the prediction and identification of dynamics in complex origami structures, while paving the way to the application to a wider variety of lightweight and deployable structures.

Unveiling clinically significant PPARγ mutations for thiazolidinedione treatment responsiveness through atomistic simulations

In Type 2 diabetes, increased insulin sensitivity is induced by thiazolidinedione activation of the peroxisome proliferator-activated receptor gamma (PPARγ). Recent data indicate a relationship between SNPs in PPARγ and poor drug response. Therefore, understanding the pathogenic consequences of mutations in PPARγ-mediated protein-drug interactions will be prima-facie for establishing personalized medicine. The PPARG gene has 197 missense SNPs, 22 of which were determined to be both deleterious and destabilizing, employing in silico approaches. Molecular docking analysis suggested that the mutation influenced the binding energy of at least seven of the variants. The mutant R316H was identified as the most damaging and deleterious from the observed results. For a better understanding of the dynamic variation upon mutation at the atomic level, molecular dynamics simulations of the wild-type and R316H mutant PPARγ structure were performed. The analysis indicates that the mutation increased protein structural compactness while decreasing flexibility. The reduced dynamics in the mutant structure was further validated by principal component analysis. This mechanistic evaluation of the PPARγ protein variants provides insight into the relationship between genetic variation and interindividual variability of drug responsiveness and will facilitate the future studies for the development of tailored treatment regime for precision medicine.

Learning spatiotemporal lip dynamics in 3D point cloud stream for visual voice activity detection

Visual voice activity detection (V-VAD) aims at identifying speech activities and measuring start/end moments in visual signal streams generated from the speaking-related biological modality. The visual cue is important counterpart of audio modality in noisy scenarios. Most of existing methods rely on 2D sequences, which suffer from limited robustness to variations of illumination and facial pose. This paper proposes a 3D V-VAD method based on lip dynamics modeling and learning spatiotemporal speaking lip representation in point cloud streams. We construct a lightweight temporal speaking dynamics model DualDyn to represent dual dynamics of global lip structure and local lip context in 4D spatiotemporal domain. The activity moment detection is formulated as frame-level state classification and refined by behavior continuity. Our method was verified on a public dataset S3DFM and achieves a state-of-the-art accuracy of 22.6ms and higher efficiency in measuring activity moments. Ablation studies demonstrate the robustness and applicability of our method.

Two-sided effects of the organic phosphorus phytate on a globally important marine coccolithophorid phytoplankton.

Dissolved organic phosphorus (DOP) is a potential source of aquatic eutrophication and pollution because it can potentially stimulate growth in some species and inhibit growth in other species of algae, the foundation of the marine ecosystem. Inositol hexaphosphate (also named phytic acid or PA), an abundant organophosphate, is presumably ubiquitous in the marine environment, but how it affects marine primary producers is poorly understood. Here, we investigated the bioavailability of this DOP to the cosmopolitan coccolithophore Emiliania huxleyi. Our results showed that E. huxleyi cells can take up PA and dissolved inorganic phosphorus (DIP) simultaneously. Absorbed PA can efficiently support algal growth, producing cell yield between DIP and phosphorus (P)-depleted conditions. Accordingly, PA supply as the sole P source highly influences cellular metabolism and nutrient stoichiometry. Particularly, PA-grown cultures exhibited enhanced carbon fixation, increased lipid content, activated energy metabolism, and induced nitrogen assimilation. However, our data suggest that PA may also exert some levels of toxic effects on E. huxleyi. This study provides novel insights into the variable effects of a DOP on marine phytoplankton, which will inform new inquiries about how the complex DOP constituencies in the ocean will shape phytoplankton community structure and function. IMPORTANCE The dissolved organic phosphorus (DOP) utilization in phytoplankton plays vital roles in cellular P homeostasis, P-nutrient niche, and the dynamics of community structure in marine ecosystems, but its mechanisms, potentially varying with species, are far from clear. In this study, we investigated the utilization of a widespread DOP species, which is commonly produced by plants (land plants and marine macrophytes) and released into coastal areas, in a globally distributed bloom-forming coccolithophore species in various phosphorus environments. Using a combination of physiological and transcriptomic measurements and analyses, our experimental results revealed the complex mechanism and two-sided effects of DOP (major algal growth-supporting and minor toxic effects) in this species, providing a novel perspective on phytoplankton nutrient regulation.

New Father a Male Ally-ship in Women's Movement: Effects of Digital Feminism in Reshaping Patriarchal Behaviour

The study examines the involvement of men in the women's movement in Pakistan, which is a patriarchal society. The interviews with progressive men and women, who are actively engaged in the feminist movement in Pakistan reveal the changing dynamics of family structure in Pakistan, and discussed the emerging role of the liberal father as male allyship in women's emancipation and eliminating gender inequalities. The study discusses the effects of digital feminism in Pakistan in involving men in the women's movement as bridging social capital, producing responsible behavior among men, and challenging patriarchy through new fathers. In a patriarchal society, where the dominancy of the father is blindly followed, digital feminism is now altering the father's rule into male allies, producing a concept of new a father, which is challenging the patriarchal notions of masculinity and hegemony. The new father is a symbol of a new dominant figure, who is responsible and transforming the domestic patriarchy, to maintain equality at home and would bring change to the social structure at large.

Adaptation of rhizosphere bacterial communities of drought-resistant sugarcane varieties under different degrees of drought stress.

Sugarcane is highly sensitive to changes in moisture, and increased drought severely restricts its growth and productivity. Recent studies have shown that plant growth-promoting microorganisms are essential to reduce the adverse effects of environmental stresses, especially drought. However, our knowledge about the dynamics of rhizosphere microbial community structure in sugarcane under varying degrees of drought stress is limited. We analyzed the effects of different degrees of drought stress on the rhizosphere microbial communities of Zhongzhe 1(ZZ1) and Zhongzhe 6(ZZ6) with differences in drought resistance, by combining soil enzyme activity, nutrient content, and physiological and morphological characteristics of sugarcane roots. The results showed that rhizosphere bacterial community began to change at a field capacity of 50%, enriching the sugarcane rhizosphere with drought-resistant bacteria. The core strains of ZZ1 and ZZ6 rhizosphere enrichment were mainly Streptomycetales, Sphingomonadales, and Rhizobiales. However, compared to ZZ1, the changes in rhizosphere bacterial abundance in ZZ6 were primarily associated with the abundance of Streptomycetales as drought levels increased. Rhizobiales and Streptomycetales, enriched in the rhizosphere of ZZ6 under drought, were positively correlated with root tip number and total root length (TRL), increasing the distribution area of roots and, thus, improving water and nutrient uptake by the roots thereby enhancing the resistance of sugarcane to drought stress. This research enhances our understanding of the composition of the rhizosphere microbial community in sugarcane under different levels of drought stress and its interaction with the roots, thereby providing valuable insights for enhancing drought resistance in sugarcane. IMPORTANCE Drought stress is expected to further increase in intensity, frequency, and duration, causing substantial losses in sugarcane yields. Here, we exposed sugarcane to varying degrees of drought treatment during growth and quantified the eventual composition of the resulting sugarcane rhizosphere bacterial community groups. We found that sugarcane rhizosphere under mild drought began to recruit specific bacterial communities to resist drought stress and used the interactions of root tip number, total root length, and drought-resistant strains to improve sugarcane survival under drought. This research provides a theoretical basis for the rhizosphere microbiome to help sugarcane improve its resistance under different levels of drought stress.

Annual Dynamics of a Layered Phytoplankton Structure in a Meromictic Lagoon Partially Isolated from the White Sea

In a saline semi-isolated lagoon on Cape Zeleny (White Sea), the annual dynamics of the vertical hydrological structure and the seasonal dynamics of phytoplankton were traced. Species composition, vertical distribution, abundance, nutrition type, and biomass were analyzed. In total, 293 species and supraspecific taxa of algae and cyanobacteria were found. Most of the identified species are marine, and 38 species are freshwater. Taxonomic composition changed in the lagoon throughout the year. Dinoflagellates dominated in winter and early June; unidentified cocci and flagellates in July; diatoms, dinoflagellates, and unidentified cells in August; dinoflagellates in September; and unidentified cocci and flagellates in October–November. The abundance of algae also changed in the lagoon throughout the year. The integrated biomass in the water column varied from 0.01 g C/m2 in January to 0.78 g C/m2 in early September. According to the environmental parameters, the water column of the lagoon was subdivided into several zones with different environmental conditions and corresponding phytoplankton communities. The similarity between the communities of different horizons was 32–46% in summer and 7% in winter. The chemocline layer was the most populous. It contained a maximum of phytoplankton biomass, 1–2 orders of magnitude higher than that in the overlying horizons. Despite the connection to the sea, the phytoplankton structure in the surface water layer in the lagoon and in the sea differed significantly in composition, quantitative parameters, and seasonal dynamics. The similarity between the communities never exceeded 50%. In terms of biomass dynamics, the lagoon lagged behind the sea until mid-summer, but, starting from August, it outnumbered it, and the phytoplankton development in the lagoon lasted longer, until late autumn. According to sequential tests DistLM, the phytoplankton structure and dynamics in the lagoon and in the sea were related to the daylength, water salinity, oxygen content, and pH by 24.5%. At the same time, the PhP structure did not depend on water temperature, underwater illuminance, or depth. Oxygen content and pH were defined by PhP activity. Salinity serves as a vector of the vertical sequence of ecological niches. The day length seems to be the crucial factor of the seasonal PhP dynamics in the semi-isolated coastal stratified lakes and lagoons.