Dual Structure Research Articles

Dual structure on-demand release chitosan-based coating film for peach preservation

After harvest, fruits and vegetables go through the stages of storage, transportation and sales, and how to regulate the role of preservative in different stages is an urgent problem to be solved. Herein, chitosan-stearic acid is synthesized, then interacting with trans-2-hexenal (E2H) to prepare nanoclusters. Subsequently, the temperature-sensitive liposomes were designed to encase E2H by using the special temperature-responsive open-chain phospholipids, and then combined with chitosan to obtain chitosan-based coating film for peach preservation. The thermosensitive liposomes were uniformly distributed, highly dispersed and spherical, which has excellent temperature response characteristics, and the release of active substances could be regulated in the temperature range of 10 °C-40 °C to achieve the effect of on-demand release. In addition, thermosensitive liposomes also have excellent antioxidant and antibacterial activities. Therefore, the obtained chitosan-based coating could maintain the freshness of peaches, improve the quality and extend the storage period of peaches. The edible chitosan coating and active preservative prepared in this study have potential application value in responsive intelligent active packaging.

A Bis-Boron Amino Acid for Positron Emission Tomography and Boron Neutron Capture Therapy.

Trifluoroborate boronophenylalanine (BBPA) is a boron amino acid analog of 4‑boronophenylalanine (BPA) but with a trifluoroborate group (-BF3-) instead of a carboxyl group (-COOH). Clinical studies have shown that 18F-labeled BBPA ([18F]BBPA) can produce high-contrast tumor images in positron emission tomography (PET). Beyond PET imaging, BBPA is a theranostic agent for boron neutron capture therapy (BNCT). Because BBPA possesses an identical chemical structure to BNCT and PET, it can potentially predict the boron concentration for BNCT using [18F]BBPA-PET. The synthesis of BBPA was achieved by selectively fluorinating the α-aminoborate compound, taking advantage of the varying rates of solvolysis of the B-F bond. The study showcased the high-contrast [18F]BBPA-PET imaging in various tumor models, highlighting its broad applicability for both [18F]BBPA-PET and BBPA-BNCT. [18F]BBPA-PET tumor uptake remains consistent across various doses, including those used in BNCT. This enables accurate estimation of the boron concentration in tumors using [18F]BBPA-PET. With its dual boron structure, BBPA increases boron concentration in tumor cells and tumor tissues compared to BPA. Thus, less boron carrier is needed. This study introduces a new theranostic boron carrier that enhances boron accumulation in tumors, predicts boron concentration, and enhances the accuracy and effectiveness of BNCT.

A Bis‐Boron Amino Acid for Positron Emission Tomography and Boron Neutron Capture Therapy

Trifluoroborate boronophenylalanine (BBPA) is a boron amino acid analog of 4‑boronophenylalanine (BPA) but with a trifluoroborate group (‐BF3‐) instead of a carboxyl group (‐COOH). Clinical studies have shown that 18F‐labeled BBPA ([18F]BBPA) can produce high‐contrast tumor images in positron emission tomography (PET). Beyond PET imaging, BBPA is a theranostic agent for boron neutron capture therapy (BNCT). Because BBPA possesses an identical chemical structure to BNCT and PET, it can potentially predict the boron concentration for BNCT using [18F]BBPA‐PET. The synthesis of BBPA was achieved by selectively fluorinating the α‐aminoborate compound, taking advantage of the varying rates of solvolysis of the B‐F bond. The study showcased the high‐contrast [18F]BBPA‐PET imaging in various tumor models, highlighting its broad applicability for both [18F]BBPA‐PET and BBPA‐BNCT. [18F]BBPA‐PET tumor uptake remains consistent across various doses, including those used in BNCT. This enables accurate estimation of the boron concentration in tumors using [18F]BBPA‐PET. With its dual boron structure, BBPA increases boron concentration in tumor cells and tumor tissues compared to BPA. Thus, less boron carrier is needed. This study introduces a new theranostic boron carrier that enhances boron accumulation in tumors, predicts boron concentration, and enhances the accuracy and effectiveness of BNCT.

Morphologically Switchable Twin Photonic Hooks

A dual fan-shaped structure covered with Ag films was investigated for generating twin photonic hooks (t-PHs). The t-PH characteristics of this structure are studied using the Finite-Difference Time-Domain (FDTD) method. The results show that by designing appropriate fan-shaped opening angles and angles of Ag films coverage, the switching between t-PHs, S-shaped t-PHs, and W-shaped t-PHs can be achieved, along with controlling over the bending angles. The maximum first, second, and third bending angles for the obtained W-shaped t-PHs are 51.3°, 36.4°, and 41.8°, respectively, while the Ag films angle is 5°. The investigated tunable morphology t-PHs provide innovative applications in the fields of nanolithography and integrated optics.

On the patterns and mechanisms of residual currents and suspended sediment transport in the Lingdingyang of the Pearl River Delta

Tide-averaged current, i.e., Eulerian residual current (ERC), indicates net transport of sediment and pollutants in coastal and estuarine regions. In this paper, we examine the dynamics of tidal currents and associate residual currents (RCs), suspended sediment transport and its governing mechanisms in the Lingdingyang (LDY) of the Pearl River Delta based on field data and numerical modeling. Results indicate that seaward ERCs dominate throughout the LDY. The ERCs are greater in the wet seasons than that in the dry seasons. The ERCs are smaller in the middle layer of the water column over the shoals, whereas they ware are larger in the middle layers in deep channels. The ERCs mainly discharge into the sea through the deep channel and west shoal, forming a slack water zone in the middle shoal. Vertical circulation structures of ERCs are controlled by the channel-shoal structure. A dual ERC circulation structure was observed between the channels, which is characterized with seaward and landward ERCs at the surface and bottom layers, respectively. As a result, the residual sediment transports are seaward, with large rates at the shoal than in the channel. Seaward ERCs explain residual sediment transport in the deep channel. Both ERCs and Stokes RCs (SRCs) are important over the shoal. Tidal pumping is of secondary importance and its direction varies over time and in space. These findings provide a scientific basis for understanding the channel-shoal evolution and maintenance of the navigational waterway in the LDY.

Is It Reliable to Extract Gully Morphology Parameters Based on High-Resolution Stereo Images? A Case of Gully in a “Soil-Rock Dual Structure Area”

The gully morphology parameter is an important quantitative index for monitoring gully erosion development. Its extraction method and accuracy evaluation in the “soil-rock dual structure area” are of great significance to the evaluation of gully erosion in this type of area. In this study, unmanned aerial vehicle (UAV) tilt photography data were used to evaluate the accuracy of extracting gully morphology parameters from high-resolution remote sensing stereoscopic images. The images data (0.03 m) were taken as the reference in Zhangmazhuang and Jinzhongyu small river valleys in Yishui County, Shandong Province, China. The accuracy of gully morphology parameters were extracted from simultaneous high-resolution remote sensing stereo images data (0.5 m) was evaluated, and the parameter correction model was constructed. The results showed that (1) the average relative errors of circumference (P), area (A), linear length of bottom (L1), and curve length of bottom (L2) are mainly concentrated within 10%, and the average relative errors of top width (TW) are mainly within 20%. (2) The average relative error of three-dimensional (3D) parameters such as gully volume (V) and gully depth (D) is mainly less than 50%. (3) The larger the size of the gully, the smaller the 3D parameters extracted by visual interpreters, especially the absolute value of the mean relative error (Rmean) of V and D. (4) A relationship model was built between the V and D values obtained by the two methods. When V and D were extracted from high-resolution remote sensing stereo images, the relationship model was used to correct the measured parameter values. These findings showed that high-resolution remote sensing stereo images represents an efficient and convenient data source for monitoring gully erosion in a small watershed in a “soil-rock dual structure area”.

Design and Analysis of a Highly Reliable Permanent Magnet Synchronous Machine for Flywheel Energy Storage

This article aims to propose a highly reliable permanent magnet synchronous machine (PMSM) for flywheel energy-storage systems. Flywheel energy-storage systems are large-capacity energy storage technologies suitable for the short-term storage of electrical energy. PMSMs have been used in the flywheel energy-storage systems due to their advantages. One of the key requirements for PMSMs in flywheel energy-storage systems is high reliability. A double redundant winding structure is adopted to ensure fault-tolerant operation of the PMSM. The stator is designed with auxiliary teeth to reduce the short-circuit current. Moreover, the number of slots and poles is determined to ensure the winding factor, heat dissipation, and reduce losses. Moreover, the dual three-phase stator winding structure and auxiliary teeth are adopted on the PMSM to improve reliability. Afterward, the electromagnetic performance is analyzed, and the mechanical stress is investigated to ensure mechanical strength. Finally, a prototype is built and tested to verify the theoretical analysis and performance of the PMSM.

Nitrogen plasma-induced phase engineering and titanium carbide/carbon nanotubes dual conductive skeletons endow molybdenum disulfide with significantly improved lithium storage performance

MoS2/Ti3C2 MXene composite has emerged as a promising anode material for lithium storage due to the synergistic combination of high specific capacity offered by MoS2 and conductive skeleton provided by Ti3C2 MXene. However, its two-dimensional/two-dimensional (2D/2D) structure is susceptible to collapse after long cycles, while the inherent low conductivity of MoS2 limits its rate performance. In this study, we developed a novel approach combining plasma-induced phase engineering with dual skeleton structure design to fabricate a unique P-MoS2/Ti3C2/CNTs anode material featuring highly conductive 1T phase MoS2 and a stable one-dimensional/two-dimensional (1D/2D) architecture. Within this architecture, growth of MoS2 nanosheets on the surface of Ti3C2 cross-linked by carbon nanotubes (CNTs) was achieved. The resulting Ti3C2/CNTs dual skeleton not only provides robust mechanical support to prevent structural collapse during long cycles but also offers increased specific surface area and additional Li+ storage space, thereby enhancing the lithium storage capacity of the composite. Subsequent N2 plasma treatment induced a phase transition in MoS2 from 2H to 1T configuration. Density functional theory (DFT) calculations confirmed that the induced 1T-MoS2 exhibits higher conductivity and lower Li+ diffusion barrier compared to 2H-MoS2. Benefiting from these synergistic effects, our P-MoS2/Ti3C2/CNTs anode demonstrated remarkable electrochemical performance including a high reversible specific capacity of 1120 mAh g−1 at 0.1 A g−1, excellent cycling stability with a specific capacity retention of 670 mAh g−1 after 600 cycles at 1 A/g, and superior rate performance with a specific capacity of 614 mAh g−1 at 2 A g−1. This combined modification strategy will serve as guidance for designing other energy storage materials.

Fractional spins, unfolding, and holography. Part I. Parent field equations for dual higher-spin gravity reductions

In this work and in the companion paper arXiv:2403.02301, we initiate an approach to holography based on the AKSZ formalism. As the first step, we refine Vasiliev’s holography proposal in arXiv:1203.5554 by obtaining 4D higher-spin gravity (HSG) and 3D coloured conformal higher-spin gravity (CCHSG) — i.e., coloured conformal matter fields coupled to conformal higher-spin gauge fields and colour gauge fields — as two distinct and classically consistent reductions of a single parent theory. The latter consists, on-shell, of a flat superconnection valued in a fractional-spin extension of Vasiliev’s higher-spin algebra. The HSG and CCHSG reductions are characterized by dual structure groups and two-form cohomology elements, and their embedding in a common parent model provides a rationale for deriving holographic relations from multi-dimensional AKSZ partition functions on cylinders with dual boundary conditions, to appear separately. In this work we i) construct the underlying non-commutative geometry as a metaplectic operator algebra represented in a Hermitian module of a pair of conformal particles; ii) identify a discrete modular group, arising from twisted boundary conditions of the first-quantized system, and connecting different boundary conditions of the second-quantized system; and iii) identify the holonomies, structure groups and two-form cohomology elements that characterize the HSG and CCHSG reductions, and equate the dual second Chern classes.

A dual-layer nano dressing with enhanced antimicrobial and healing properties via sesame nanoemulgel with efficient levofloxacin delivery for wound management

Creating suitable wound dressings is considered a promising approach for treating severe skin injuries, as they can provide the environment for healing and protection against infection. The optimum wound dressing should possess biocompatibility, high absorbency, antimicrobial activity, breathability, and mechanical strength. So, in this study, we created a two-layer dressing that includes a surface layer composed of xanthan, polyvinyl alcohol, and sesame oil, as well as a nanofibrous sublayer that contains polyvinyl alcohol, collagen, levofloxacin, and sesame oil nanoemulsion (Video 1). This dual structure is designed to offer antimicrobial properties and facilitate wound healing while having suitable physical stability. The films showed desirable morphological features and significantly increased flexibility (less than 1000). These features were respectively proven through scanning electron microscopy and tensile strength. Laboratory investigations were conducted to examine the precise compatibility and anti-inflammatory features. According to the obtained results, the nanosystems showed compatibility with hemolysis below 5 percent and by adding sesame oil to the films, their anti-inflammatory properties (88 ± 0.19 %) and blood compatibility (1.3507 ± 0.20) increased. In-vivo studies using the rat skin defect model showed that the dressings significantly accelerate the closure of skin wounds and enhance the reconstruction of skin appendage structures. The therapeutic effect resulted from reducing inflammatory factors, and the film's antimicrobial properties effectively prevent the growth of harmful microorganisms. In conclusion, the study suggests that the new nano-biocomposite films suit wound management.

New training simulator for lumbar puncture base on magnetorheological

In response to the difficulties in accurately reproducing the resistance drop generated by puncturing key tissue layers with a needle and the poor experience in existing simulators, based on the continuous controllability and rapid response of magnetorheological fluid under the influence of a magnetic field, this paper proposes a lumbar puncture training simulator(LPTS) that can accurately simulate the puncture feedback force within tissues such as the skin, subcutaneous fat, and supraspinous ligament throughout the entire process. By using a dual rod structure and reasonably arranging the damping channel gap, the influence of mechanical friction and zero-field damping force on the feedback force during tissue progression is minimized. This paper introduces the acquisition and modeling analysis of raw data, and based on this, the design, simulation, and mechanical testing of the simulator are carried out. Finally, a performance testing platform for the simulator is established to evaluate its tracking performance of the expected puncture strength and the reproducibility of the puncture sensation. The results show that the experimental puncture strength deviates from the expected puncture strength by 0.35 N to 0.61 N in the crucial steps of breaking through the supraspinous ligament, interspinous ligament, ligamentum flavum, and dura mater, with a relative error below 10 %.

The Intervention and Impact of Digital Society on the Governance of Dual Equity Structure in Enterprises

The digital society has become a prominent feature of today's era. Its highly interconnected, transparent, and intelligent characteristics are profoundly changing the governance mode and operational logic of enterprises. This article aims to explore the intervention and impact of digital society on the governance of dual equity structure in enterprises, and provide practical guidance for the sustainable development of enterprises. The dual equity structure, as a special corporate governance model, is characterized by granting different voting rights to different types of shares, achieving absolute control over the company by the management. However, this structure has also sparked many controversies, such as the possibility of management using control to harm shareholder interests, leading to management dictatorship, and so on. In the context of the digital society, enterprises face new challenges and opportunities in terms of information transparency, decision-making efficiency, and governance mechanisms.

AgNPs with CNTs to construct multifunctional flexible sensor with dual conductive network structure

Flexible sensors play an important role in the field of smart devices. However, most flexible sensors suffer from poor sensing signal stability and monofunction. In this study, a multifunctional film (named PM) with dual conductive network structure was fabricated by nanocellulose crystal dispersed with silver nanoparticles and carbon nanotube. The PM film exhibited excellent conductivity (24.6 S/m) along with antimicrobial effects against Staphylococcus aureus and Escherichia coli. Furthermore, the PM sensor showed excellent electrothermal performance, reaching 133.1 °C within 50 s at 12 V, and an excellent temperature coefficient of resistance (TCR = −0.65 % °C−1) over a temperature range of 36–124 °C. More importantly, the PM sensor demonstrated a high strain sensitivity (GF = 1.66) and durability (320 cycles), capable of detecting minute human body movements at a strain as low as 1 %. Additionally, the PM sensor maintained a stable sensing performance even after 30 d of exposure to air. Therefore, the multifunctional integration of the PM sensor shows great potential for application in the field of flexible electronics.

An enhanced electromagnetic energy harvester based on dual ratchet structure with secondary energy recovery

Abstract With the continuous advancement of ultra-low-power electronic devices, capturing energy from the surrounding environment to power these smart devices has emerged as a new direction. However, most of the mechanical energy available for harvesting in the environment exhibits ultra-low frequencies. Therefore, the feasibility of self-powering low-power devices largely depends on the effective utilization of this ultra-low-frequency mechanical energy. Consequently, this work proposes an enhanced electromagnetic energy harvester based on a dual ratchet structure with secondary energy recovery. It converts ultra-low frequency vibrations into fast rotational movements by means of a rack and pinion mechanism, thus achieving high power output while maintaining a simple structure. Experimental tests demonstrate that the proposed harvester exhibits excellent power output under ultra-low-frequency external excitation. Under external excitation with a frequency of 1.5 Hz and an amplitude of 22 mm, with the optimal load matched at 20 Ω, the maximum power output reaches 598 mW, with a power density of 1572.65 μW/cm³. The secondary energy recovery power accounts for 34.4 %, resulting in a 52.56 % enhancement in the energy harvester's output performance. Additionally, hand-cranking tests indicate that the fabricated prototype of the electromagnetic energy harvester can power some common electronic devices, including smartphones, showcasing significant application potential.

Research of a 0.14 THz Dual-Cavity Parallel Structure Extended Interaction Oscillator.

This paper presents a method to enhance extended interaction oscillator (EIO) output power based on a dual-cavity parallel structure (DCPS). This stucture consists of two conventional ladder-line structures in parallel through a connecting structure, which improves the coupling efficiency between the cavities. The dual output power fusion structure employs an H-T type combiner as the output coupler, which can effectively combine the two input waves in phase to further increase the output power. The dispersion characteristics, coupling impedance, and field distribution of the DCPS are investigated through numerical and simulation calculations, and the optimal operating parameters and output structure are obtained by PIC simulation. At an operating voltage of 12.6 kV, current density of 200 A/cm2, and longitudinal magnetic field of 0.5 T, the DCPS EIO exhibits an output power exceeding 600 W at a frequency of 140.6 GHz. This represents a nearly three-fold enhancement compared with the 195 W output of the conventional ladder-line EIO structure. These findings demonstrate the significant improvement in output power and interaction efficiency achieved by the DCPS for the EIO device.

Does Longer Tenure Mean Greater Ability? Deep-Rooted Politics and Migration in Rural China

This study examines the political motivations behind changes in labor migration rates in Chinese villages. Using data from the China village survey, we estimate the impact of the tenure gap between the village committee director and party branch secretary on village labor migration rates. We find that within the dual power structure of villages, a longer political tenure for the secretary relative to the director significantly suppresses village labor migration rates, while a shorter tenure significantly promotes them. IV estimation supports the causal interpretation found by OLS estimation. This mechanism of causality is associated with vested interests stemming from ambiguous ownership, having a director or secretary with a longer political tenure tends to bias these interests towards villagers or township authorities. Other accompanying effects of the tenure gap should not be ignored, including the amplification effect of the non-laboring population, the feedback effect of labor, and the shrinkage effect of outsiders. This causal relationship is heterogeneous, the dual role analysis shows that the structure and stance of village leaders will affect the strength of the causal relationship, and the regional heterogeneity analysis shows that economic factors that drive village labor migration may be more important than political factors.

Five Volts Lithium Batteries with Advanced Carbonate-Based Electrolytes: A Rational Design via a Trio-Functional Addon Materials.

Lithium metal batteries paired with high-voltage LiNi0.5Mn1.5O4 (LNMO) cathodes are a promising energy storage source for achieving enhanced high energy density. Forming durable and robust solid-electrolyte interphase (SEI) and cathode-electrolyte interface (CEI) and the ability to withstand oxidation at high potentials are essential for long-lasting performance. Herein, advanced electrolytes are designed via trio-functional additives to carbonate-based electrolytes for 5V Li||LNMO and graphite||LNMO cells achieving 88.3% capacity retention after 500 charge-discharge cycles. Theoretical calculations reveal that adding adiponitrile facilitates the presence of more hierarchical DFOB- and PF6 - dual anion structure in the solvation sheath, leading to a faster de-solvation of the Li cation. By combining both fluorine and nitrile additives, an efficient synergistic effect is obtained, generating robust thin inorganic SEI and CEI films, respectively. These films enhance microstructural stability; Li dendrite growth on the Li electrode is being suppressed at the anode side and transition-metals dissolution from the cathode is being mitigated, as evidenced by cryo-transmission electron microscopy and synchrotron studies.

Morphology and properties of carbon black‐filled thermoplastic vulcanizate (TPV) composites based on hydrogenated acrylonitrile butadiene rubber and thermoplastic polyester elastomer

AbstractThe unique morphology of thermoplastic vulcanizates (TPVs) reveals a significant correlation between the microstructure and performance, and the development of high‐performance TPV composites for specialized applications has become a current research priority. This study is devoted to developing heat‐ and oil‐resistant TPV composites filled with carbon black (CB) based on hydrogenated acrylonitrile butadiene rubber (HNBR) and thermoplastic polyester elastomer (TPEE) following the masterbatch procedure of dynamic vulcanization. Herein, it focuses on the effects of CB content on the morphology, filler network structure, and properties of the TPV/CB composites. As observed by morphological studies, CB nanoparticles are interconnected and aggregated to form a dual network structure of rubber and CB particles in the composite. With the increasing CB content, it's demonstrated that dual networks have enhanced and shifted to rigid. Consequently, the hardness, thermal stability, and oil resistance of TPV/CB composites are improved, with a 104% elevation in the stress at 300% strain. The flowability in the molten state, toughness (the elongation at break decreased from 690% to 310%), and elasticity deteriorated by oversized (0.5 ~ 1.2 μm) CB agglomerates and rigid rubber particles. This study gives new insight into the microstructure‐properties relationship of TPVs, offering theoretical guidance for fabricating HNBR‐based TPV composites.

Investigation of the substitution of mercury by silver in Ag2S-HgS-GeS2 glasses: Macroscopic, electrical and vibrational properties

The evolution of structure and physical properties was investigated in the (Ag2S)x(HgS)50-x(GeS2)50 system. It was found that the density increases with increasing silver sulfide. The DSC data show a non-monotonic change of the glass transition temperature, Tg, from 243 °C (x = 0) to 301 °C (x = 50) with the minimum at 231 °C for x = 10 sample. The dual structure of HgS, which consists of the presence of dimorphic tetrahedral and chain forms of HgS, is found to be responsible for the non-monotonic change of the Tg. An increase in silver content leads to a significant enhancement of ionic conductivity from ∼10−14 S.cm−1 (x = 0) to ∼10−3 S.cm−1 (x = 50). The gradual structural evaluation is evidenced by the disappearance of the main Raman feature at ≈300 cm−1 related to the Hg-S stretching and the emergence of two contributions for silver-rich glasses at ≈370 cm−1 and at ≈400 cm−1.

Technological progress, fiscal policy, and economic fluctuations in China: Evidence from the heterogeneous firm DSGE model during the COVID-19 pandemic

Against the backdrop of the global COVID-19 pandemic and the deepening structural changes in the Chinese economy, this study presents a four-sector dual Dynamic Stochastic General Equilibrium (DSGE) model that incorporates households, heterogeneous firms, capitalists, and the government, taking into account the current domestic "dual economic structure." The model is used to simulate and analyze the impacts of fiscal policies and technological progress on diverse economic entities during the pandemic. The study reveals several key findings: (1) the pandemic outbreak has a significant short-term impact on the economy, disproportionately affecting small and microenterprises but with higher natural recovery rates compared with large and medium-sized enterprises; (2) unbiased fiscal policies have positive effects on output and capital, with larger output recovery effects observed for large and medium-sized enterprises, while capital recovery effects are less favorable; (3) technological progress contributes to rapid and stable economic growth, yielding overall benefits for large and medium-sized enterprises, but leading to significant crowding-out effects on small and microenterprises; and (4) solely increasing tax support for small and microenterprises, assuming constant tax revenue sources, does not enhance the overall resilience of the economy. These research findings provide policymakers with a dynamic microeconomic foundation within a macroeconomic framework, thereby enhancing the efficacy and precision of policies.