Mutual Transformation Research Articles

Experimental study on flow characteristics of gas–solid two-phase flow in inclined pipes

In a fluid catalytic cracking unit, inclined pipes are mainly used for particle transportation and to maintain the pressure balance between the reactor and regenerator. In this experimental inclined pipe device, the characteristics of gas–solid two-phase flow were studied by measuring and analyzing the dynamic pressure and particle concentration parameters in different flow states. Corresponding relationships between pressure fluctuation and particle concentration on the one hand and flow patterns on the other were discovered. These were used for the quantitative identification of flow patterns. Measurement data from an analysis of bubble and particle velocities in an inclined pipe revealed a critical mass flow rate, Gs, in the mutual transformation of different particle flow patterns. The critical mass flow rate Gsc1 of lean-phase and dense-phase flows was 149 kg/(m2·s). The critical mass flow rate Gsc2 of packed-bed and dense-phase flows was 240 kg/(m2·s). This study enriches the basic theoretical knowledge on flow patterns in inclined pipes and provides a theoretical basis for the adjustment of inclined pipe operation in industrial fluid catalytic cracking units.

Temporal and spatial characteristics of carbon storage and its response to land-use change in Chengdu, China

The accurate monitoring of the dynamic relationship between land use and carbon storage can provide a scientific basis for the government to formulate carbon emission reduction policies and promote the green development of cities, achieving a win–win situation for both ecology and the economy. As a national central city in southwest China, Chengdu has experienced rapid land-use changes in the past decade due to the implementation of development strategies such as urban-rural integration and the construction of a “Park City.” To explore the spatial and temporal distribution characteristics of carbon storage in Chengdu during this period, three representative years (2010, 2015, and 2020) were selected to estimate the changes in carbon storage using the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model. From 2010 to 2020, the land-use changes in Chengdu primarily manifested in the mutual transformation between cultivated land, forest land, and construction land. The conversion between the high-carbon-density-land-use type and the low-carbon-density-land-use type was an important driving factor for the change in carbon storage in Chengdu, and it was also the main reason for the overall reduction of carbon storage in the city. The carbon source areas of Chengdu demonstrated an aggregated spatial pattern, with the northern and southern parts of the city being the main carbon source areas. In contrast, the carbon sink areas were mainly distributed in the western and eastern parts, as well as the ecological park around the expressway in Chengdu. This distribution was mainly due to increased efforts to restore inefficiently used cultivated land back to forest and grassland. The proposal of the “Park City” strategy has promoted the construction of green infrastructure in Chengdu and has effectively increased urban carbon sinks.

Effect of gamma irradiation on sensory and aroma compounds of soaked bayberry jiu

Soaked bayberry jiu is a homely fruit alcoholic beverage that produced by soaking bayberry in Baijiu, a traditional Chinese distilled spirit. To investigate the changes in the sensory and aroma compounds of soaked bayberry jiu following gamma irradiation, the sensory evaluation, electron nose, electron tongue, and headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) were conducted. The results showed that the different irradiation doses of samples could be well separated. The taste and smell of 6 kGy irradiated soaked bayberry jiu were significantly improved, but the color of irradiated samples was deteriorated. Moreover, a total of 53 differential products (21 decreased and 32 increased products) were detected compared 6 kGy irradiated soaked bayberry jiu to unirradiated sample, including some important aroma compounds of Baijiu, indicating that the active free radicals produced by gamma irradiation promote the oxidation-reduction reaction in soaked bayberry jiu and lead to the mutual transformation and equilibrium among the compounds. These findings suggest that gamma irradiation can improve the quality of soaked bayberry jiu.

PH-dependent mechanisms of sulfadiazine degradation by natural pyrite-driven heterogeneous Fenton-like reactions

The development of a natural pyrite/peroxymonosulfate (PMS) system for the removal of antibiotic contamination from water represented an economic and green sustainable strategy. Yet, a noteworthy knowledge gap remained considering the underlying reaction mechanism of the system, particularly in relation to its pH sensitivity. Herein, this paper investigated the impacts of critical reaction parameters and initial pH levels on the degradation of sulfadiazine (SDZ, 3 mg/L) in the pyrite/PMS system, and elucidated the pH dependence of the reaction mechanism. Results showed that under optimal conditions, SDZ could be completely degraded within 5 min at a broad pH range of 3.0–9.0, with a pseudo-first-order reaction rate of >1.0 min−1. The low or high PMS doses could lower degradation rates of SDZ through the decreased levels of active species, while the amount of pyrite was positively correlated with the removal rate of SDZ. The diminutive concentrations of anions exerted minor impacts on the decomposition of SDZ within the pyrite PMS system. Mechanistic results demonstrated that the augmentation of pH levels facilitated the transition from the non-radical to the radical pathway within the natural pyrite/PMS system, while concurrently amplifying the role of •OH in the degradation process of SDZ. This could be attributed to the change in interface electrostatic repulsion induced by pH fluctuations, as well as the mutual transformation between active species. The stable presence of the relative content of Fe(II) in the used pyrite was ensured owing to the reduced sulfur species acting as electron donors, providing the pyrite/PMS system excellent reusability. This paper sheds light on the mechanism regulation of efficient removal of organic pollutants through pyrite PMS systems, contributing to practical application.

Tetraphenylethene-based mononuclear aggregation-induced emission (AIE)-active mechanofluorochromism gold(I) complexes with different auxiliary ligands

In this study, a series of tetraphenylethene-containing gold(I) complexes with different auxiliary ligands have been synthesized. These complexes were characterized using a variety of techniques including nuclear magnetic resonance spectroscopy, mass spectrometry, and single crystal X-ray diffraction. Their aggregation-induced emission (AIE) behaviors were investigated through ultraviolet/visible and photoluminescence spectrum analyses, and dynamic light scattering measurements. Meanwhile, their mechanofluorochromic properties were also studied via solid-state photoluminescence spectroscopy. Intriguingly, all these mononuclear gold(I) molecules functionalized by tetraphenylethene group demonstrated AIE phenomena. Furthermore, five gold(I) complexes possessing diverse auxiliary ligands exhibited distinct fluorescence changes in response to mechanical grinding. For luminogens 2–5, their solids showed reversible mechanofluorochromic behaviors triggered by the mutual transformation of crystalline and amorphous states, while for luminogen 1, blue-green-cyan three-color solid fluorescence conversion was realized by sequential mechanical grinding and solvent fumigation. Based on this stimuli-responsive tricolored fluorescence feature of 1, an information encryption system was successfully constructed.

Molecular dynamics simulation for nanometric cutting of NiTi shape memory alloys at elevated temperatures

In nanometric cutting, the deformation mechanism is closely related to the cutting temperature. This study investigates the cutting mechanism at elevated temperatures via molecular dynamics simulation of nanometric cutting on equiatomic NiTi SMAs. Mutual transformation between martensite and austenite during the indentation and cutting process, and effects of the cutting temperature are analyzed. The results indicate that the NiTi workpiece atoms experience martensite phase transformation and reverse phase transformation during the indentation and cutting process, with different orientation of martensite facilitating the transformation. Besides, the average resistance coefficient decreases with increasing cutting temperature due to the elevated temperature lubrication effect, and the cutting forces and phase transformation in the processing area also experience a gradual reduction. Some of the dislocations inside the NiTi workpiece show plugging and tangling phenomena at temperatures of 400 and 600 K. Cutting simulations reveal that fewer dislocation slips and less residual stress occur at elevated temperatures and lead to significantly reduce of residual martensite phase after cutting. From an atomic perspective, this investigation explains the cutting mechanism of difficult-to-machine materials NiTi SMAs at elevated temperatures and gives guidance for improving its machinability.

Novel active chlorine based-mechanism for 1O2-dominated tetracycline hydrochloride electrocatalytic oxidation over N-doped MXene

Chloride ions (Cl−) as electrolyte contribute remarkably to electrocatalytic oxidation because of the by-production of active chlorine. Experiment and theoretical calculation were proposed to clarify the contribution of Cl− to TC degradation, the generation and contribution mechanism of active chlorine, and the mutual transformation of active species. DFT results showed the favorable adsorption and conversion of Cl− on Ti-N, Ti-O-N, and Ti-N-O sites of Ti3C2Tx@N-0.1, thereby facilitating the generation of active chlorine and improving the TC degradation. The limited effect of direct electrocatalytic degradation (leading to O2– and 1O2 accumulation) and active chlorine (e.g., HClO) oxidation was proved by quenching, EPR, and qualification test of active species. The secondary and dominant production of 1O2 from active chlorine conversion was greatly improved in Ti3C2Tx@N-0.1/electrocatalysis system and played a crucial role in TC removal. The mutual transformation of OH, O2–, and 1O2 from direct electrocatalysis and secondary active chlorine conversion also enriched the TC removal mechanism. This research provides novel insights into the influence of active chlorine on electrocatalytic oxidation and the underlying mechanism.

Experimental and numerical study on characteristics of wake and vortex structure of cluster personnel

The purpose of this study is to study the characteristics of unsteady flow field caused by human activities in crowded public space. This study analyses the wake and vortex structure characteristics of cluster personnel through experiments and numerical simulations. The wake velocity field and vortex structure of 2 (columns) × 5 (rows) human walking were analysed by experimental measurement and large eddy simulation (LES). Personnel movement is simulated by using the dynamic mesh model of computational fluid dynamics (CFD). The results show that the wake of the leg is fully developed, and the wake end presents a “swallow-tail shaped”. The rear row personnel will make a secondary disturbance to the wake of the front row personnel in the wake of the cluster personnel. Therefore, there will be a process of mutual transformation of large-scale vortices and small-scale vortices in the wake field. In addition, the wake flow significantly affects the diffusion and propagation of respiratory pollutants.

Enhancing mechanical properties of high Cr dual-phase FeCrNi medium-entropy alloy through mutual phase transformation and grain refinement

A high Cr Fe40Cr40Ni20 (at.%) medium-entropy alloy was prepared through vacuum arc melting. The alloy exhibited a dual-phase structure comprising face-centered-cubic (FCC) and body-centered-cubic (BCC) phases in a solid solution state. After annealing and cold rolling, two different heterogeneous structures emerged from the original FCC and BCC phases through mutual phase transformation. Moreover, the alloy exhibited a yield strength, ultimate tensile strength, and total elongation of 1.18 GPa, 1.25 GPa, and 13 %, respectively. The high strength of the alloy was mainly attributed to boundary strengthening and heterogeneous deformation-induced (HDI) strengthening within the two heterogeneous structures. Notably, the effectiveness of HDI strengthening was enhanced owing to the complete encapsulation and constraint of soft zones by hard zones in the heterogeneous structure originating from the BCC phase. Additionally, the deformation ability of the alloy mainly depended on dislocation slips and deformation twinning in recrystallized FCC grains and FCC strip phases, thereby ensuring satisfactory ductility.

Multi-functional photonic spin Hall effect sensor controlled by phase transition

Abstract Photonic spin Hall effect (PSHE), as a novel physical effect in light–matter interaction, provides an effective metrological method for characterizing the tiny variation in refractive index (RI). In this work, we propose a multi-functional PSHE sensor based on VO2, a material that can reveal the phase transition behavior. By applying thermal control, the mutual transformation into different phase states of VO2 can be realized, which contributes to the flexible switching between multiple RI sensing tasks. When VO2 is insulating, the ultrasensitive detection of glucose concentrations in human blood is achieved. When VO2 is in a mixed phase, the structure can be designed to distinguish between the normal cells and cancer cells through no-label and real-time monitoring. When VO2 is metallic, the proposed PSHE sensor can act as an RI indicator for gas analytes. Compared with other multi-functional sensing devices with the complex structures, our design consists of only one analyte and two VO2 layers, which is very simple and elegant. Therefore, the proposed VO2-based PSHE sensor has outstanding advantages such as small size, high sensitivity, no-label, and real-time detection, providing a new approach for investigating tunable multi-functional sensors.

Mutual modeling of sequential and parallel word computations

The work is devoted to the connection between parallel and sequential computing. On the one hand, we consider a class of word predicates based on sequential calculations, limited in memory by constants and having polynomial time complexity. On the other hand, we consider a class of word predicates that are computable on parallel alternating machines in logarithmic time. The coincidence of the corresponding classes is proven. The direction of using the obtained results for mutual transformation and combination of calculations on molecular biosimilar sequential machines and parallel calculations on vector-matrix computers is proposed. Intended applications: real-time image processing for control tasks, analysis of large texts and other big data.

Investigation of the Inhibitory Effects of Illicium verum Essential Oil Nanoemulsion on Fusarium proliferatum via Combined Transcriptomics and Metabolomics Analysis.

Fusarium proliferatum is the main pathogen that causes Panax notoginseng root rot. The shortcomings of strong volatility and poor water solubility of Illicium verum essential oil (EO) limit its utilization. In this study, we prepared traditional emulsion (BDT) and nanoemulsion (Bneo) of I. verum EO by ultrasonic method with Tween-80 and absolute ethanol as solvents. The chemical components of EO, BDT, and Bneo were identified by gas chromatography-mass spectrometry (GC-MS) and the antifungal activity and mechanism were compared. The results show that Bneo has good stability and its particle size is 34.86nm. The contents of (-) -anethole and estragole in Bneo were significantly higher than those in BDT. The antifungal activity against F. proliferatum was 5.8-fold higher than BDT. In the presence of I. verum EO, the occurrence of P. notoginseng root rot was significantly reduced. By combining transcriptome and metabolomics analysis, I. verum EO was found to be involved in the mutual transformation of pentose and glucuronic acid, galactose metabolism, streptomycin biosynthesis, carbon metabolism, and other metabolic pathways of F. proliferatum, and it interfered with the normal growth of F. proliferatum to exert antifungal effects. This study provide a theoretical basis for expanding the practical application of Bneo.

Civic integration and the negation of collective selfhood: A normative analysis through Paul Ricoeur’s notions of identity

ABSTRACT Requirements of immigrants to prove language skills, undertake knowledge tests, or complete courses of civic education, have become central in the process of attaining formal legal membership in the political community. However, while civic integration often is furthered as an emancipatory process and way to strengthen social cohesion, this article maintains that civic integration deviates from a notion of integration as the mutual transformation of migrant and receiving polity alike. Drawing on Paul Ricoeur’s discussion of ipse- and idem-identity, the article analyses the normative underpinnings of civic integration and argues that civic integration is conditioned on a community based in sameness rather than in an inclusive and reciprocal respect for diversity, meaning that civic integration will emerge as strikingly similar to the assimilationist practices it seeks to overcome. Thus, drawing on idem-identity, civic integration is seen to not only defeat its own goals of political emancipation of the migrant and the social cohesion of the community, but also to negate the very possibility of collective selfhood. By contrast, through exploring Ricoeur’s notion of identity as imbued with temporality, this article gestures towards how the normative standards of reflexivity, tolerance and mutuality ought to guide any idea of integration.

Boosted peroxymonosulfate activation by bimetallic organometallic frameworks via by-produced and dominated H2O2 generation

Verifying the role of H2O2 is a critical challenge for deepening the understanding of the mechanism of peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs). In this research, Co, Fe bimetallic organometallic frameworks (ZIF-L@Fe28) were prepared, and their ultrahigh activities via H2O2 generation at Fe and Co sites were experimentally and theoretically verified. The important contribution of H2O2 to 1O2 production was identified through the quantifications of the mutual transformation of active species. Co sites were identified as the most active positions for PMS activation because of they strongly triggered 1O2, SO4·−, ⋅O2−, ·OH, and H2O2. However, the self-quenching of active species suppressed the efficiency and selectivity of 1O2 generation at Co sites. In contrast to Co sites, Fe sites had selective preference for H2O2 generation, and the transformation of H2O2 to 1O2 further enhanced the performance of ZIF-L@Fe28. The supplementary discussion from the perspective of H2O2 will enable the further application of the PMS activation mechanism.

K-Space Approach in Optical Coherence Tomography: Rigorous Digital Transformation of Arbitrary-Shape Beams, Aberration Elimination and Super-Refocusing beyond Conventional Phase Correction Procedures.

For the most popular method of scan formation in Optical Coherence Tomography (OCT) based on plane-parallel scanning of the illuminating beam, we present a compact but rigorous K-space description in which the spectral representation is used to describe both the axial and lateral structure of the illuminating/received OCT signals. Along with the majority of descriptions of OCT-image formation, the discussed approach relies on the basic principle of OCT operation, in which ballistic backscattering of the illuminating light is assumed. This single-scattering assumption is the main limitation, whereas in other aspects, the presented approach is rather general. In particular, it is applicable to arbitrary beam shapes without the need for paraxial approximation or the assumption of Gaussian beams. The main result of this study is the use of the proposed K-space description to analytically derive a filtering function that allows one to digitally transform the initial 3D set of complex-valued OCT data into a desired (target) dataset of a rather general form. An essential feature of the proposed filtering procedures is the utilization of both phase and amplitude transformations, unlike conventionally discussed phase-only transformations. To illustrate the efficiency and generality of the proposed filtering function, the latter is applied to the mutual transformation of non-Gaussian beams and to the digital elimination of arbitrary aberrations at the illuminating/receiving aperture. As another example, in addition to the conventionally discussed digital refocusing enabling depth-independent lateral resolution the same as in the physical focus, we use the derived filtering function to perform digital "super-refocusing." The latter does not yet overcome the diffraction limit but readily enables lateral resolution several times better than in the initial physical focus.

Investigation of pore structure evolution and damage characteristics of high temperature rocks subjected to liquid nitrogen cooling shock

Liquid nitrogen (LN2) can be utilized in the development of enhanced geothermal systems, as well as for deep/ultra-deep hydrocarbon reservoir stimulation, fire suppression, and other high-temperature geological projects. It is a crucial issue in the utilization of LN2 to investigate the pore structure evolution, permeability, and damage characteristics of high-temperature rocks under the influence of LN2 cooling shock. These rocks were first slowly heated to 150∼600°C and held for 2 h, followed by LN2 or natural cooling. The evolution of pore volume in high-temperature rocks affected by liquid nitrogen cooling was quantified. T2 cutoff values were determined through centrifugal tests, while the contents of irreducible and mobile fluids were estimated. Based on the aforementioned analysis as well as changes in irreducible fluid saturation, pore throat, tortuosity, and permeability, this study examines the closure and development of pores along with permeability behavior. The findings suggest that, despite a more pronounced decrease in porosity at lower heating temperatures, LN2 cooling specimens exhibit superior pore connectivity and permeability compared to those cooled naturally. LN2 stimulation not only induces crack initiation and propagation but also results in further cooling induced densification based on heating densification. 225°C is considered to be the optimal temperature for cooling contraction induced densification in this study. At higher heating temperatures, the damage to rock cooled with LN2 is more severe than that of naturally cooled. This results in a greater increase in porosity, movable fluid content and proportion, and permeability of LN2 cooled specimens compared to naturally cooled specimens. The damage mechanism can be better understood by the constructed damage model that coordinates the pore increase/decrease and mutual pore transformation from the perspective of pore evolution.

MATHEMATICAL THEORY OF THE INCLINED PLANE

The laws of mutual transformation of statistical and dynamic effects on an inclined plane are shown, a mathematical justification is given for obtaining a gain from the action or the possibility of saving the main useful action and facilitating the actions of Gravity. All the above statements are carried out using the basic elements of the theories of dynamics, statics and trigonometric calculations. The influence of the geometric dimensions of the inclined plane on the transformation of actions is estimated. The mechanism of statistical and dynamic equilibrium of actions on an inclined plane is substantiated through mathematical expressions of the conservation law and the relationship between the components of the vector.

Style transfer for converting images into Chinese landscape painting based on CycleGAN

Chinese landscape painting is a prevalent and unique mode of artistic expression within traditional Chinese art. It boasts intricate techniques and demands a relatively high level of artistic skill. Recent advancements in artificial intelligence have ushered in the era of image style transfer techniques, making it feasible to convert landscape photographs into stunning Chinese landscape paintings. In this study, the author has developed an image translation model that enables mutual transformation between images of landscapes and Chinese landscape paintings. This technology significantly reduces the difficulty of creating Chinese landscape paintings, allowing more ordinary people in China to experience and appreciate the joy brought by traditional Chinese art. Experimental results indicate that the style transfer model based on CycleGAN has achieved significant success in this scenario. The generated artworks successfully integrate the style of Chinese landscape painting into the original images without altering the original composition and details. As a result, the original photos gain a certain level of artistic value. Additionally, this study innovatively explores the goal of reverse restoration of Chinese landscape paintings into images, highlighting both the similarities and differences with the current research, thus laying the foundation for future studies.

Identification and bioactivity evaluation of ring-opening and lactone forms of enterolactone from sheep fed flaxseed cake

The previously undescribed lactone ring-opening enterolactone and its sulphate were purified along with the lactone counterparts from the urine of dairy sheep fed flaxseed cake. The structures were determined by NMR and MS analyses. The ring-opening and lactone forms underwent mutual transformation with changes in pH and milk could protect the lactone form. Enterolactone exhibited more effective anti-proliferation activity on MDA-MB-231 breast cancer cells than its ring-opening counterpart, while the ring-opening enterolactone demonstrated more effective anti-osteoporosis activity than the lactone form. The results indicated the potential for targeting biological functions through pH and medium manipulation.

The Impact of Territorial Spatial Transformation on Carbon Storage: A Case Study of Suqian, East China

The carbon storage of terrestrial ecosystems plays a crucial role in mitigating climate change, and the transformation of territorial space has a significant impact on the carbon cycle of a country’s terrestrial ecosystems. Therefore, evaluating the impact of space transformation on carbon storage is essential for enhancing regional carbon storage potential and reducing carbon emissions. We use the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model to analyze the dynamic changes in territorial spatial transformation and carbon storage from 2000 to 2020 in Suqian, as well as their relationship. On this basis, the optimization strategy and specific path for improving territorial space carbon storage capacity were determined. The results show the following: that (1) from 2000 to 2020, territorial spatial transformation in Suqian was dramatic, with the most significant changes occurring between 2005 and 2010. The scale of mutual transformation between agricultural production space and urban–rural construction space was the largest. (2) Carbon storage gradually decreased in Suqian City, with a total reduction of 1.23 × 106 tons over 20 years and an annual decrease of 1.46%. The carbon density of forested space was significantly higher than that of other spaces. The conversion of agricultural production space and forestland space to urban–rural construction space was the main factor driving a decrease in carbon storage. (3) Territorial spatial transformation is a spatial manifestation of the evolution of human–land relationships. Regulating the function, scale, structure and layout of territorial space as a whole and implementing differentiated management of specific space will be beneficial to optimize carbon storage in Suqian.