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Thermally induced oscillatory rarefied gas flow inside a two-dimensional rectangular cavity is investigated based on the hybrid macro-/mesoscopic scheme. The effects of the Knudsen (Kn) numbers and the oscillation frequency of lid temperature on the flow parameters are analyzed. The Shakhov model equation is solved numerically based on the mesoscopic approach in the near-wall region, and the macroscopic approach is adopted in the bulk flow region to reduce the computational cost. To close the numerical iteration procedure, the velocity distribution functions serving as the pseudo boundary between macroscopic and mesoscopic methods are reconstructed using the high-order Hermite polynomials. Numerical simulations demonstrate that the temperature profile at the central vertical of the cavity predicted by the hybrid method is in good agreement with results from the mesoscopic method, with a maximum error of 0.23%. In addition, the computational memory cost can be saved up to about 69.91%. The hybrid approach is able to capture the nonlinear phenomenon in the thermally induced oscillatory rarefied gas flow under high Kn numbers, where the horizontal velocity no longer obeys the law of periodic oscillating cosine function, and the rise time of the horizontal velocity is much longer than the fall time. The thickness of the viscous penetration layer and the disturbed region increases as the Kn number increases and decreases as the Strouhal number increases. [ABSTRACT FROM AUTHOR]

We consider the Cauchy problem for the isentropic compressible Euler–Maxwell equations under general pressure laws in a three-dimensional periodic domain. For any smooth initial electron density away from the vacuum and smooth equilibrium-charged ion density, we could construct infinitely many α -Hölder continuous entropy solutions emanating from the same initial data for α < 1 7 . Especially, the electromagnetic field belongs to the Hölder class C 1 , α . Furthermore, we provide a continuous entropy solution satisfying the entropy inequality strictly. The proof relies on the convex integration scheme. Due to the constrain of the Maxwell equations, we propose a method of Mikado potential and construct new building blocks. [ABSTRACT FROM AUTHOR]

From the time-dependent Gross equation, we find the quasiparticle dispersion law for a one-dimensional weakly interacting Bose gas with a non-point interatomic potential and zero boundary conditions (BCs). The result coincides with the dispersion law for periodic BCs, i.e., the Bogoliubov law E B (k) = ħ 2 k 2 2 m 2 + n 0 ν (k) ħ 2 k 2 m . In the case of periodic BCs, the dispersion law can be easily derived from Gross' equation. However, for zero BCs, the analysis is not so simple. [ABSTRACT FROM AUTHOR]

For generalised SOS model with spin values from countable set on a Cayley tree we consider gradient Gibbs measures(GGMs). Such a measure corresponds to a boundary law (i.e. an infinite dimensional vector-valued function defined on vertices of the Cayley tree) satisfying an infinite system of functional equations. We give several concrete GGMs of boundary laws which are independent from vertices of the Cayley tree and have periodic and mirror-symmetric coordinates. Namely, in this paper the particular classes of height-periodic boundary laws of period q ≤ 3 are studied and solutions are classified by their period and mirror-symmetry. [ABSTRACT FROM AUTHOR]

Based on the current theory of sequence stratigraphy, this study employs stillstand normal regression (SNR) to replace the method of highstand normal regression (HNR) to establish shoreline trajectory and sediment supply models of off-lap and onlap-type sequences, respectively. The basic principle of the digital model-driven approach in this study is to decompose the shoreline trajectory (fst) and sediment supply trajectory (fss) into their vertical and horizontal projection vectors to establish periodic sufficient condition of shoreline trajectory and sediment supply trajectory, aiming to obtain a sequence model bounded by the remnant maximum flooding surface (RMFS) and/or its intersecting subaerial unconformity (ISU): HST (SNR)-FSST (FR)-LST (LNR)-TST (T). This model establishes the synchronic necessary condition of shoreline trajectory and sediment supply trajectory and obtains the periodic law patterns of sequence stratigraphy, proposed as "two rhombuses sandwiching one extension of subaerial unconformity". This study defines a sequence as: a sequence is a stratigraphic unit ("two rhombuses sandwiching one extension of subaerial unconformity") constrained by both periodic sufficient condition and synchronic necessary condition of shoreline and sediment supply trajectories, and is composed of a relatively conformable succession of genetically interrelated strata bounded at their top and base by RMFS and/or intersecting subaerial unconformities (ISU). Moreover, the periodic laws of sequence stratigraphy show that the RMFS is almost potentially correlative to the lower boundary of the stage B (global boundary stratotype section and point) of chronostratigraphic units and close to the biohorizon or first appearance datums (first appearance datums) of biostratigraphic units. [ABSTRACT FROM AUTHOR]

The Periodic Law of Chemistry is one of the great discoveries in cultural history. Elements behaving chemically similar are empirically merged in groups G of a Periodic Table, each element with G valence electrons per neutral atom, and with upper limit G for the oxidation and valence numbers. Here, we report that among the usually mono- or di-valent s-block elements (G = 1 or 2), the heaviest members (87Fr, 88Ra, 119E, and 120E) with atomic numbers Z = 87, 88, 119, 120 form unusual 5- or 6-valent compounds at ambient conditions. Together with well-reported basic changes of valence at the end of the 6d-series, in the whole 7p-series, and for 5g6f-elements, it indicates that at the bottom of common Periodic Tables, the classic Periodic Law is not as straightforward as commonly expected. Specifically, we predict the feasible experimental synthesis of polyvalent [RaL− n] (n = 4, 6) compounds. [ABSTRACT FROM AUTHOR]

This paper proposes a co-design method of dynamic output feedback control law and periodic event-triggered control (PETC) strategy to tolerate a maximum allowable number of successive packet dropouts (MANSDs) in networked control systems (NCSs). For the purpose of striking a balance between saving limited communication resources and reducing complexity of the transmission implementation, we present the periodic event-triggering mechanism (PETM), in which the triggering conditions only needs to be monitored at each event-verifying instant. In NCSs, packets often suffer from some interference in network transmission, such as packet losses. For packet dropouts, we introduce a dropout variable and model the whole closed-loop systems as a hybrid system. Furthermore, some stability conditions for co-design are given by a novel Lyapunov function and stability theorems of hybrid systems, and the explicit designs parameters of controller and triggering conditions are presented to ensure L 2 stability. Finally, two illustrated examples are given to show the effectiveness of the proposed design methods. • A co-design method of PETM and control law is proposed to save network resource. • The method aims at achieving desired stability properties while tolerating a MANSD. • The method provides less conservation results than the emulation-based approach. • The overall system is modeled based on the hybrid system framework. • By using a modified Young's inequality, rigorous stability analysis is provided. [ABSTRACT FROM AUTHOR]

Consider chemical elements as a system, we create an undirected chemical network with 99 elements and 1916 edges from Chemspider, a website that provide search engines to collect compounds. Using this network and the network that we used in our previous work with 97 elements and 2198 edges, we found that RootedPageRank, a link prediction tool in complex network, can be used to predict potential binary compounds, because the changing trend of PageRank probability of each element in these networks all follow the periodic law, despite of the difference of scale of these networks. The accuracy test indicates that at least 7 among top 10 predicted compoundss in one network can be verified using the compoundss in the other network or in other chemical database, proving that this method can be used to provide guidance in finding potential binary compounds, suggesting that we can study chemical properties from the view of complex network. [ABSTRACT FROM AUTHOR]

Aiming at the wind power characteristics of temporality, periodicity and complexity, the periodic law of short-term and long-term repetitive patterns is studied, and an integrated dual-channel prediction model is proposed. A practical periodic characteristic extracting strategy is designed to show the hidden periodic law of the original signal. Combining the grid search algorithm with the variation trend of amplitude/period, the optimal periodic step is determined. Based on the above analysis, the original signal is decomposed into temporal and periodic components. Then the temporal attention network and the encoder-decoder attention network are schemed out to dispose the two components respectively. Finally, the linear regression attention network is adopted to realize data fitting. The integrated forecasting framework can deal with the long-term and short-term dependencies of the original data at the same time, and ensure the rapid convergence of training process, thereby improve the prediction accuracy and stability. The multi-dimensional experimental verification is carried out through the comparison of evaluation indicators, prediction trends, scatter plots and box plots. [ABSTRACT FROM AUTHOR]

The hydrogen circulating pump (HCP) used for hydrogen recovery and utilization, affects the performance of the hydrogen fuel cell system. In this paper, aiming at the measurement research blank of the output pressure and flow high-frequency pulsation curve of the HCP, a pressure-based flow measurement method and an overlapping grid-based simulation calculation method are proposed and then compared in multiple directions for mutual verification. The research results show that the waveform errors of the pressure pulsation curves are under 2.4%, and that of the flow pulsation curves are 6.2% and 8.3%, comparing the experimental data and simulation data when the average outlet pressure is 9 kpa and 27 kpa respectively. Further study of the internal fluid characteristics, the pressure and the density change the same and produce the lowest value before the meshing point, the leakage flow rate at the rotor-rotor gap is greater than that at the rotor-pump casing gap, and the vortices show cyclical change of co-evolution and co-growth in the low-pressure area and the high-pressure area. The research results can optimize the structural design of the HCP itself, and can also refine the input conditions of the fuel cell system and contribute to performance improvement. • An indirect method for measuring real-time flow is proposed. • Overlapping grid simulation method is verified reliability by experimental data. • Compare and analyze the real-time flow curves of experiment and simulation. • The periodic variation law of fluid parameters in the pump chamber is revealed. [ABSTRACT FROM AUTHOR]

The underground roadway of the Buertai Coal Mine adopts the double-roadway layout. Double-roadway layout mode has a roadway that is affected by repeated mining, called reserved roadways. The reserved roadway is strongly affected by mining, and the strata behaviors appear violently. This paper studies the strata behaviors that occur in auxiliary haulage roadway (AHR) during the mining of panel 42106. By analyzing geological conditions, mining influencing factors, and roadway layout, the mechanism of strong rock behavior has been clarified. Then, based on the theoretical analysis, we put forward the treatment method for the manifestation of strong strata behaviors by using hydraulic fracturing technology to break the key stratum. In this way, the high stress of the surrounding rock can be reduced by forcing the hard roof to be broken. After the application of hydraulic fracturing technology, we monitored the deformation of roadways and the periodic weighting law of the working face. The strength of strata behaviors has significantly weakened, and the application of this technology ensures the safe production of coal mines. [ABSTRACT FROM AUTHOR]

The objective of this work is to elaborate a new version of a game used to teach periodic law. To accomplish this, it is necessary to make some decisions regarding two equally important aspects: the need to define what is to be taught about the disciplinary content, and to improve the mechanics of a game, which already has two previous versions. Aiming to decide the approach to teach, we searched the historical milestones from which the concepts: element, atom, periodic law, and periodic properties, underlying the representations of the law were modeled. Then, an analysis was carried out from the epistemological and ontological dimensions that allowed us to define which would be the periodic properties used in the game. The intention was to propose an approach that prioritizes chemical theories and models over physical ones without forgetting the contributions of this discipline that could facilitate the definitions and understanding of the concepts. Regarding the periodic tables to be used as game boards, the aesthetic sense of the idea underlying the different representations was defined as a selection criterion. Concerning the development of the new game mechanics, it was modified so that learning takes place during the game and not only at a later stage. [ABSTRACT FROM AUTHOR]

High-intensity longwall top coal caving (LTCC) mining of super-thick coal seam in high stress conditions often leads to significant movement and failure of overburden. The competent roof above the super-thick coal seam is easy to form large unstable structures, and the breaking and movement of the roof strata often induce high weighting strength and large dynamic disasters which severely affect the mine safety. The key to control the behavior of competent roof is to understand the fracturing law of the roof strata. In this paper, a case study based on microseismic (MS) monitoring was performed at LW8309 working face in Tongxin coal mine, where super-thick coal seam under competent sandstone roof in high stress conditions was mined by LTCC method. The spatial distribution characteristics of MS events were studied and four impact zones in the horizontal direction and 'four-zones' in the vertical direction were identified. Multifractal analysis of MS events was carried out to study the multifractal characteristics of the fracturing of competent overburden. In addition, a large and small periodic law of fracturing of competent roof was revealed from the temporal distribution of MS events and on-site monitoring of hydraulic support pressure. A key stratum (KS) structural model was then proposed to explain the strong behaviors of competent strata during high-intensity mining. The research results are of great significance for safe and efficient mining of super-thick coal seam under competent roof in high stress conditions. Highlights: The impact zones in front of the mining face and four vertical zones were identified and the fracture characteristics of the competent overburden in the impact zones and the vertical zones were revealed. Multifractal characteristics of the fracture of the competent overburden were obtained. A large and small periodic law of fracture of competent overburden was revealed from the temporal distribution of MS events and on-site monitoring of hydraulic support pressure. A key stratum (KS) structural model was proposed to explain the behavior of the fracture of competent overburden. [ABSTRACT FROM AUTHOR]

Gas drainage is an important measure to ensure energy safety in coal mines. However, for mines with high gas content and low permeability, the critical question is how to enhance the drainage effect of drilling. By using the self‐unloading pressure effect on the coal body in front of the mine, the permeability of the coal body can be improved, which facilitates gas drainage. Therefore, establishing the fluid–solid model of gas‐bearing coal mass under the influence of mining, this paper simulates the advanced self‐pressure‐relief range in front of the coal working face and the permeability of coal seam at different heights. Through simulations and field tests, the reasonableness of the advanced self‐pressure‐relief gas drainage was verified, and the spatial and temporal characteristics of the gas drainage from the borehole were quantified and analyzed. The results show that the width of the advanced self‐pressure‐relief zone after simulated mining is 25 m, the vertical permeability of the coal seam increases first and then decreases with the increase of the height from the floor, and the maximum permeability of the layer is 2.6 m from the floor, which is 8.62 times higher than the initial permeability; the gas drainage effect of test boreholes has a periodic law with the coal seam recovery, which, divided into the initial drainage stage, the scalar volume of gas drainage increase stage, and the scalar volume of gas drainage decay stage. At a distance from the working face 20–40 m, the boreholes' scalar volume of gas drainage increased by 3.89 times compared with the initial drainage stage, and the scalar drainage volume of the boreholes through the seam increased by 8.01 times compared with the initial drainage stage; in the section of increasing scalar volume of drainage, the gas drainage volume of the boreholes at different heights of the coal seam had obvious "stratification" phenomenon. The test boreholes were optimally placed in the middle of the seam at the lower end. The study provides a reference for self‐pressure‐relief gas drainage technology and optimization of borehole placement. [ABSTRACT FROM AUTHOR]

This paper deals with the global asymptotic stabilization problem for discontinuous nonlinear time‐varying switched systems in the sense of fractional‐order. Via the designed periodic switching law, some criteria are firstly developed. It is shown that the derivatives of the constructed Lyapunov functions are allowed to be indefinite. Several corollaries are further derived, and some existing results can be regarded as special cases of our obtained results. Finally, our findings are verified by three numerical examples and one experiment. [ABSTRACT FROM AUTHOR]

This article studies periodic switching control under quantized state feedback for discrete‐time linear systems. First, a novel necessary and sufficient condition is presented for the existence of stabilizing periodic switching law for the systems, by which the periodic switching law with shorter period is obtained. Second, based on this condition and by spherical polar coordinate quantizer, we give quantized state feedback control with infinite data rate for periodic switching law. From a practical point of view, we are more concerned with quantized feedback control with finite data rate, so a quantization method with finite data rate is designed for stabilizing periodic switching law under quantized state feedback. Simulation results illustrate the effectiveness of the approach. [ABSTRACT FROM AUTHOR]

Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to study the migration characteristics and strata behavior law of mining-induced rocks in fully mechanized caving face of coal mine, taking the actual geological mining of Longwanggou Coal Mine as the background, using computer software (KSPB) to identify the location of key strata. The physical similar material simulation test was used to monitor the movement characteristics of mining-induced rocks by using the internal displacement sensor (IDS) and distributed optical fiber sensor (DOFS). A three-dimensional physical model of 3.6 m × 2.0 m × 2.0 m was built; the internal displacement of rock was measured by IDS. BOTDA distributed optical fiber was used to monitor the dynamic movement and deformation law of coated rock. Finally, the two monitoring results were compared and analyzed. The results show that: (1) the displacement curve of the fractured rock mass in the key strata shows a "stepped" increase; (2) based on the analysis of displacement continuous monitoring results, the strata behavior law of working face is obtained. The first weighting interval of 61601 working face is 90 cm, and the periodic weighting steps are 105 cm, 115 cm, 135 cm, 150 cm, 165 cm, 180 cm, 215 cm, and 240 cm; (3) the average strain of fiber is proposed. The first weighting and periodic weighting laws of the working face are represented by the average strain, which are consistent with the experimental phenomena. The first weighting in the average strain curve shows the first mutation peak, and the periodic weighting shows the periodic mutation peak change of the average strain curve. [ABSTRACT FROM AUTHOR]

When an axial-flow pump is running, there is a very complex flow inside the runner. Based on the two-way fluid–structure coupling method, this paper simulated the forward and reverse operating conditions of an axial-flow pump and calculated the dynamic stress distribution on the blade surface. The stress load spectrum was loaded onto the blade, and fatigue characteristic analysis was carried out to obtain the fatigue life and damage of the blade. This research shows the following: under different working conditions, the dynamic stress is concentrated at the root of the blade, and its amplitude decreases with the increase in the flow rate; at the same time, the change in stress with time shows a periodic change law. Under the working conditions of the turbine, the main frequency is the rotational frequency, and the secondary frequency is composed of multipliers of the rotational frequency, which is obviously affected by the number of blades; the fatigue damage and stress distribution are consistent, and the damage is the most serious at the stress concentration point. The research results of this paper can provide theoretical guidance for the structural design and safe operation of axial-flow pumps. [ABSTRACT FROM AUTHOR]

A series of new charge transfer (CT) chromophores of "α-diimine-MII-catecholate" type (where M is 3d-row transition metals—Cu, Ni, Co) were derived from 4,4′-di-tert-butyl-2,2′-bipyridyl and 3,6-di-tert-butyl-o-benzoquinone (3,6-DTBQ) in accordance with three modified synthetic approaches, which provide high yields of products. A square-planar molecular structure is inherent for monomeric [CuII(3,6-Cat)(bipytBu)]∙THF (1) and NiII(3,6-Cat)(bipytBu) (2) chromophores, while dimeric complex [CoII(3,6-Cat)(bipytBu)]2∙toluene (3) units two substantially distorted heteroleptic D-MII-A (where D, M, A are donor, metal and acceptor, respectively) parts through a donation of oxygen atoms from catecholate dianions. Chromophores 1–3 undergo an effective photoinduced intramolecular charge transfer (λ = 500–715 nm, extinction coefficient up to 104 M−1·cm−1) with a concomitant generation of a less polar excited species, the energy of which is a finely sensitive towards solvent polarity, ensuring a pronounced negative solvatochromic effect. Special attention was paid to energetic characteristics for CT and interacting HOMO/LUMO orbitals that were explored by a synergy of UV-vis-NIR spectroscopy, cyclic voltammetry, and DFT study. The current work sheds light on the dependence of CT peculiarities on the nature of metal centers from various groups of the periodic law. Moreover, the "α-diimine-MII-catecholate" CT chromophores on the base of "late" transition elements with differences in d-level's electronic structure were compared for the first time. [ABSTRACT FROM AUTHOR]

The efficient estimation problem of a semi-parametric first-order periodic integer-valued autoregressive (PINAR(1)) model is considered. The unspecified distribution of the innovation process of this model is suposed to satisfy only some mild technical assumptions. We therefore provide efficient estimates for both parameters of the model, namely a periodic autoregressive parameter and a periodic probability law of the innovation non-negative integer values process which is seen as an infinite dimensional parameter. The performances of these efficient estimations are shown through intensive simulations studies and an application on real data set. [ABSTRACT FROM AUTHOR]

In philosophy, the empirical success of a science is often explained by the fact that it has managed to discover some law(s) of nature. This line of thought has not been thoroughly explored with respect to chemistry. The aim of this paper is to fill this gap by showing how we could think about laws in chemistry. Specifically, it briefly presents how laws of nature are understood in philosophy of science. It then discusses two case studies from chemistry—the periodic table and chemical reactions—and explains how general ideas about law-hood can be applied to these cases. Lastly, it presents research questions and philosophical problems that arise by considering chemistry from the perspective of laws. This analysis illustrates that there is value in thinking about laws in chemistry. [ABSTRACT FROM AUTHOR]

High Mountain Asia (HMA) is one of the main distribution areas of surging glaciers in the world. The glacier change represented by the Karakoram anomaly has been a topic of wide concern. Surging glaciers not only reshape the peri-glacial landscape, but may also directly or indirectly lead to disasters. Therefore, it is of great importance to understand the distribution characteristics, periodic laws, and occurrence mechanisms of surging glaciers. Based on Landsat TM/ETM+/OLI remote sensing images from 1986–2021, a total of 244 surging glaciers in HMA were identified, covering an area of 10974.25 km2, accounting for 11.25 % of the total area of glaciers in HMA. The Karakoram Range and Pamirs are the main mountain/plateau where 185 surging glaciers are more highly concentrated. Three basins, including Amu Darya, Tarim and Indus, have 208 surging glaciers comprising 85.25 % of the total amount of surging glaciers in HMA, covering an area of 10096.89 km2. From 1986–2021, these surging glaciers advanced at least 2802 times, and exhibited different temporal and spatial trends. Obvious differences exist in the surge phase and the quiescent phase of glaciers in different regions of HMA. The surge phase of surging glaciers in the Karakoram Range and Pamirs is generally short, mostly between 2~6a, the quiescent phase is 5~19a, and the surging period is 9~24a. The mechanism of surging glaciers in HMA is more complex, which is different from Svalbard and Alaska glaciers. [ABSTRACT FROM AUTHOR]

Brucellosis is a chronic infectious disease caused by brucellae or other bacteria directly invading human body. Brucellosis presents the aggregation characteristics and periodic law of infectious diseases in temporal and spatial distribution. Taking major European countries as an example, this study established the temporal and spatial distribution sequence of brucellosis, analyzed the temporal and spatial distribution characteristics of brucellosis, and quantitatively predicted its epidemic law by using different traditional or machine learning models. This paper indicates that the epidemic of brucellosis in major European countries has statistical periodic characteristics, and in the same cycle, brucellosis has the characteristics of piecewise trend. Through the comparison of the prediction results of the three models, it is found that the prediction effect of long short-term memory and convolutional long short-term memory models is better than autoregressive integrated moving average model. The first mock exam using Conv layer and data vectorizations predicted that the convolutional long short-term memory model outperformed the traditional long short-term memory model. Compared with the monthly scale, the prediction of the trend stage of brucellosis can achieve better results under the single model prediction. These findings will help understand the development trend and liquidity characteristics of brucellosis, provide corresponding scientific basis and decision support for potential risk assessment and brucellosis epidemic prevention and control, and reduce the loss of life and property. [ABSTRACT FROM AUTHOR]

For the SOS (solid-on-solid) model (with an external field) with spin values from the set of all integers on a Cayley tree we give gradient Gibbs measures (GGMs). Such a measure corresponds to a boundary law (a function defined on vertices of Cayley tree) satisfying an infinite system of functional equations. We give several concrete GGMs which correspond to periodic boundary laws. [ABSTRACT FROM AUTHOR]

Incentivizing businesses to lower carbon emissions and trade back excess carbon allowances paved the way for rapid growth in carbon credit ETFs. The use of carbon allowances as a hedging alternative fueled this rally further, causing a shift to speculation and forming repetitive bubbles. Speculative bubbles are born from euphoria, yet, they are relatively predictable, provided their pattern matches the log periodic power law (LPPL) with specific stylized facts. A "Minsky moment" identifies a clear speculative bubble as a signal of financial system instability, while a "Social bubble" is regarded as relatively positive, increasing in the long run, infrastructure spending and development. The aim of this paper is to investigate whether various carbon credit bubbles during the pandemic period caused financial instability or had a positive impact ("Minsky" or "Social"). Particularly, we investigate the carbon credit bubble behavior in the ETF prices of KRBN, GRN (Global Carbon Credit tracking ETFs), and the SOLCARBT index during the COVID-19 pandemic period by adopting the log-periodic power law model (LPPL) methodology, which has been widely used, over the past decade, for detecting bubbles and crashes in various markets. In conclusion, these bubbles are social and propelled by the newfound interest in carbon credit trading, for obvious reasons. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The law of bioethics defines the judicial framework for governing medical practices and research involving the human body and the embryo. To achieve this goal, a preliminary reflection is necessarry so as to define new equilibria which respect ethical principles. Since 2011, the CCNE is charged with organizing public debate, in the form of a general assembly of bioethics, with the support of regional spaces of ethical reflection. This extensive experience took place from January to June 2018 and lead to several lessons, notably the strong expression of a need for information and a critical vision of the notion of medical progress. Then, the parliamentary instruction, from 24 July 2019 to 2 August 2021, contributed developments to the initial bill. One of the main characteristics of this law concerns the promotion of solidarity with respect for the autonomy of each person. Moreover, the periodic review of the law of bioethics is now based on citizen participation in the construction of legislative arbitration, demonstrating the French way of social participation. However, this feature should be consolidated. [ABSTRACT FROM AUTHOR]

Copyright of Direito da Cidade is the property of Editora da Universidade do Estado do Rio de Janeiro (EdUERJ) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the field of frontier research, information security has received a lot of interest, but in the field of information security algorithm, the introduction of decimals makes it impossible to bypass the topic of calculation accuracy. This article creatively proposes the definition and related proofs of double parameters fractal sorting matrix (DPFSM). As a new matrix classification with fractal properties, DPFSM contains self-similar structures in the ordering of both elements and sub-blocks in the matrix. These two self-similar structures are determined by two different parameters. To verify the theory, this paper presents a type of $2\times 2$ DPFSM iterative generation method, as well as the theory, steps, and examples of the iteration. DPFSM is a space position transformation matrix, which has a better periodic law than a single parameter fractal sorting matrix (FSM). The proposal of DPFSM expands the fractal theory and solves the limitation of calculation accuracy on information security. The image encryption algorithm based on DPFSM is proposed, and the security analysis demonstrates the security. DPFSM has good application value in the field of information security. [ABSTRACT FROM AUTHOR]

Detached eddy simulation was used to numerically compute the leeward vortex flow field on a blunt-headed rotating body. The effects of changes in the angle of attack and flight velocity on the evolutionary law of the counter-rotating vortexes and the fluctuation characteristics of the lateral force coefficient were analyzed. The results show that the counter-rotating vortexes on the leeward surface of the blunt-headed rotating body gradually separate from the wall along the direction from the tail to the head of the projectile as the angle of attack increases. In addition, it shows a periodic variation law of alternating expansion and detachment of the unilateral separated vortex. When the angle of attack is greater than 30°, the fluctuation amplitude of the lateral force coefficient initially rises and then drops with an increase in the angle of attack, while the fluctuation frequency keeps increasing. The maximum amplitude and corresponding frequency of the lateral force coefficient under the main fluctuation remain in the range of 100–230 Hz and have a linear positive feedback relationship with the flight Mach number. With the angle of attack and flight velocity as independent variables, the fittings were performed on the varying laws of maximum amplitude and the corresponding frequency of the lateral force coefficient under the main fluctuation. An unsteady calculation equation for the lateral force coefficient under the change in coupling with the angle of attack and flight velocity was established. [ABSTRACT FROM AUTHOR]

For new medical β titanium implants, the surface micro texture processing technology is a difficult problem. To solve this problem, a new method of ultrasonic elliptical vibration cutting (UEVC) is adopted in this paper. The mechanism of material removal in ultrasonic elliptical vibration cutting is explored for different cutting paths. By means of simulation and experimentation, the material removal mechanism of ultrasonic elliptical vibration cutting medical β titanium alloy is revealed with respect to the aspects of cutting deformation, stress distribution, force and thermal variation, and chip formation mechanism. The results show that: (1) The cutting temperature and cutting force in the UEVC process obey the law of periodic change, and the maximum point of cutting force appears ahead of the maximum point of cutting temperature. (2) The material removal process of UEVC is a "press–shear–pull" composite cutting process. The tool squeezes the material to form the chips. Under the action of high temperature, the material is removed by adiabatic shear. (3) The difference of UEVC paths will affect the removal mode of materials and form different surface morphology. (4) For different cutting paths, compressive stress is distributed at the lowest point of the machining pit, and tensile stress is distributed at the protrusion position. [ABSTRACT FROM AUTHOR]

The concept of agricultural innovation ecosystem in county areas was defined by reviewing the literature on agricultural innovation systems and innovation ecosystems. Combined with the urgent demand for agricultural innovation-driven development, a multidimensional agricultural innovation ecosystem was established in county areas. From the life-cycle perspective, the evolution law of agricultural innovation ecosystems in county areas was analyzed, and the evaluation system was constructed from four aspects: subjects, network, resources, and the environment. Then, the fuzzy technique for order preference by similarity to an ideal solution approach was used to determine the evolution stage of the system. It was found that the agricultural innovation ecosystem in county areas includes three ecological layers of microsubjects, meso-interfaces, and the macroenvironment. The microsubjects exchange material, energy, and information, with the macroenvironment more effectively depending on the carrier function of meso-interfaces. The system shows periodic laws in the process of spiraling evolution, gestation, growth, maturity, and recession, where different stages of the system exhibit different characteristics. Through an empirical analysis of the apple industry of Neiqiu County, Shunping County, and Yi County in Hebei province, the innovation ecosystems formed around the apple industry in the three counties were judged to be in the maturity stage, growth stage, and growth stage, respectively. The evaluation results are consistent with the actual situation, which effectively verified the scientific nature and effectiveness of the theoretical model and the evolutionary evaluation index system. [ABSTRACT FROM AUTHOR]

Consideration has been given to laminar flow of a liquid with constant properties in a channel on whose surface the temperature or density of the heat flux vary with time by a periodic law. An analytical solution to the problem of convective heat transfer in general form has been obtained, using which it has been established that heat transfer ceases to depend on the axial coordinate away from the inlet of the heated portion. Relations have been found to calculate stabilized heat transfer. It has been shown that at a high frequency of the process, a nonstationary stabilized heat-transfer coefficient varies noticeably over the period, however, its stabilization with time occurs as the frequency is reduced. Data on fully stabilized heat transfer have been given for various shapes of the channel, flow regimes, and boundary conditions. [ABSTRACT FROM AUTHOR]

Its most celebrated use has been Mendeleev's detailed prediction of three elements - discussed in Jensen's as well as Orna and Fontani's chapters - which led Mendeleev to be almost universally associated with the system. 150 Years of the Periodic Table: A Commemorative Symposium: Edited by CARMEN J. GIUNTA, VERA V. MAINZ, AND GREGORY S. GIROLAMI. This follows from the widespread idea that similar elements are grouped together in columns of the conventional periodic table, when, for instance, rare earths and fourth-period elements clearly indicate otherwise. [Extracted from the article]

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This paper studies the exponential stabilization on the infinite dimensional system with impulse controls, where the impulse instants appear periodically. The first main result shows that the exponential stabilizability of the control system with a periodic feedback law is equivalent to one kind of weak observability inequalities. The second main result presents that, in the setting of a discrete LQ problem, the exponential stabilizability of control system with a periodic feedback law is equivalent to the solvability of an algebraic Riccati-type equation which was built up in Qin et al. (2021) [18] for finite dimensional system. As an application, some sufficient and necessary condition for the exponential stabilization of an impulse controlled system governed by coupled heat equations is given. [ABSTRACT FROM AUTHOR]

As an important water source, groundwater profoundly influences global human survival and production. The spatiotemporal characteristics of groundwater and the periodic variation law of different time scales must be analyzed to understand the dynamic situation of this resource and to provide scientific guidance for its rational utilization and management. In this study, the temporal and spatial variability and periodicity of groundwater level in the Xining region of eastern Qinghai–Tibet Plateau in China were studied using the traditional statistical method, geographic information system, and Morlet wavelet analysis. Results show that the groundwater dynamics in the study area are mainly controlled by three factors, namely, the amount of river water infiltration, discharge from groundwater, and artificial exploitation. These factors can be divided into three dynamic types, namely, hydrological, hydrological exploitation, and runoff discharge, according to their combination relationship. From 1980 to 2020, the groundwater depth in Xining initially increased before stabilizing and eventually decreasing. As revealed in the spatial variability analysis, groundwater depth demonstrates a huge spatial difference with a moderate spatial variation intensity across different periods. Moreover, the spatial correlation of groundwater in the abundant season is lower than that in the dry season mainly due to increasing artificial exploitation. Meanwhile, the Kriging interpolation of the spherical model in the geographic information system reveals that the groundwater in Xining is deep in the south and east and shallow in the north and west. From the 1960s to 2000s, the inter-annual groundwater in the region continuously declined due to chronic overexploitation, with a maximum cumulative depth of 15 m. Afterward, the amount groundwater extraction was further reduced, and the amount of rainfall significantly increased in recent years. Accordingly, the cone of depression underwent an evolutionary process involving periods of expansion, stability, and shrinkage. The annual groundwater level in most monitoring wells within the study area demonstrated the same multi-year scale time-variation characteristics with an evident regular periodic variation on the 9-14a and 17-25a time scales according to the results of the Morlet wavelet transform analysis. The temporal sequence of groundwater from 1980 to 2020 had two main periods, namely, 12a and 21a. According to these time scales, the groundwater level in Xining will continue to increase in the short term, which provides a scientific theoretical basis for the long-term sustainable development of groundwater resources and government decision-making. [ABSTRACT FROM AUTHOR]

The presented work is devoted to the analysis of the modern stage of development of the theory periodic properties of chemical elements as a fundamental aspect of scientific worldpicture. Studying of the phenomenon of periodic properties of chemical elements has gone far beyond chemistry. It should be taken into account that even today, after the creation of two quantum theories of the electronic structure of the atom, after a century of experience in the study of chemical elements and the experimental discovery of antihydrogen, this problem is far from being exhausted. The generalization of theoretical and experimental studies of the quantum-mechanical aspects of the chemical properties of matter, the first results of the study of antimatter made it possible to set a hypothesis of the existence of a new fundamental characteristic of chemical element and to formulate the Periodic Law adequately – in keeping with modern concepts.

The author expresses critical remarks regarding the article by O.V. Mikhailov on teaching the topic “Mendeleev’s Periodic law” by at the national research University. Some specific errors of O.V. Mikhailov relating to historical-scientific and quantum-chemical issues are indicated. The article also presents a general critical assessment of his approach to teaching.