Absorption Process Research Articles

Enhancement of pair production in oscillated overlapped fields

The electron-positron pair production has been investigated in two overlapped potential wells with varied widths and frequencies. Notably, specific multiphoton absorption processes exhibit distinct changes, the total number of created pairs increases linearly, and appears in periodic oscillation with the spatial extends of the potential wells. Furthermore, the investigation revealed the crucial impact of the smaller frequency on the pair production yield. The optimal combination of frequencies was determined to enhance the creation of pairs in overlapped fields. These findings provide valuable insights into the dynamics of multiphoton absorption processes and offer a pathway toward maximizing pair creation in complex potential landscapes. Published by the American Physical Society 2024

On multi-stage deformation and gradual energy absorption of 3D printed multi-cell tubes with varying cross-section

Thin-walled structures are widely used in passive safety systems due to their excellent lightweight and controllable progressive deformation performance. While designing to improve the energy absorption performance of thin-walled structures, it is also crucial to consider reducing the damage received by protected objects during accidental collisions. In this work, stepwise and continuous graded multi-cell tubes with varying cross-sections were proposed based on the fused deposition modeling technique to achieve a gradual energy absorption process. Compression responses and energy absorption characteristics of the graded multi-cell tubes were investigated by quasi-static compression tests. Experimental results showed that the stepwise graded multi-cell tubes produced obvious multi-stage deformation and energy absorption during axial compression. The specific energy absorption presented an upward trend with the increased number of stepwise segments. For the same ranges of cross-section variations, continuous graded multi-cell tubes exhibited more plastic hinges and better energy absorption performance due to the absence of discontinuous interfaces. In addition, continuous graded multi-cell tubes showed continuous folding deformation with the gradually decreasing folding wavelength. Thus, it exhibited a steadily increasing trend in crushing force and realized the gradual energy absorption mode.

An Overview of Carbon Dioxide Photo/Electrocatalyzed by Titanium Dioxide Catalyst

AbstractThis study provides a comprehensive review of recent advancements in photocatalytic and electrocatalytic carbon dioxide reduction using titanium dioxide catalysts. The basic concepts of light absorption, electron transport, and reduction processes are introduced in this paper, which also delves into the specifics of photocatalytic and electrocatalytic reduction of carbon dioxide. The paper highlights the key applications and benefits of titanium dioxide, including its strong stability, outstanding light absorption capacity, and good electron transport performance, in the photocatalytic and electrocatalytic reduction of carbon dioxide. Furthermore, it examines the impact of various surface modification techniques on catalytic performance, as well as the effects of various titanium dioxide catalyst forms on catalytic activity and selectivity in carbon dioxide reduction. The in‐depth analysis exhibit promising catalytic properties and hold significant potential for future advancements. However, some obstacles still need to be overcome, such as increasing catalytic activity and selectivity while minimizing energy dissipation. In order to improve catalytic performance and efficiency, future research should prioritize the optimization of structural design and surface modification techniques for catalysts. Additionally, the paper provides a scientific foundation for accomplishing sustainable carbon conversion, it also calls for additional experimental and theoretical research into the mechanism of action for titanium dioxide catalyst.

Heavy metals biosorption in unary, binary, and ternary systems onto bacteria in a moving bed biofilm reactor

Toxic and heavy metals cause direct and indirect damage to the environment and ultimately to humans. This study involved the isolation of indigenous bacteria from heavy metal-contaminated environments that have the ability to bioabsorb heavy metals such as cadmium, nickel, and lead. The bioabsorption process was optimized by varying parameters such as temperature, metal concentration, number of bacteria, pH, and more. The bacterial isolates were investigated in terms of morphology, biochemistry, and phylogeny, with 12 strains chosen in the initial stage and one strain chosen in the final stage. It should be remembered that the metal uptake capacity of all isolates was approximately calculated. A box and reactor were designed to house these optimized microorganisms. Based on biochemical, morphological, and molecular results, the isolated strain was found to be closely related to the Bacillus genus. In the first five steps of testing, the ideal pH for removing lead alone, lead with cadmium, lead with nickel, and lead ternary (with cadmium and nickel) by Bacillus bacteria was found to be 7, 6, 5.5, and 6.5, respectively. The absorption efficiencies for single lead (unary), lead together with nickel, cadmium (binary), and ternary (lead with cadmium and nickel) were found to be 0.36, 0.25, 0.22, and 0.21 mmol/g, respectively. The ideal temperature for lead removal was around 30 °C. The adsorption isotherm for each lead metal in different states was found to be similar to the Langmuir isotherm, indicating that the surface absorption process is a single-layer process. The kinetics of the process follow the second-order kinetic model. The amount of Bacillus bacteria biomass obtained during this process was approximately 1.5 g per liter.

PyArc: A python package for computing absorption and radiative coefficients from first principles

Light absorption and radiative recombination are two critical processes in optoelectronic materials that characterize the energy conversion efficiency. The absorption and radiative coefficients are thus key properties for device optimization and design. Here, we develop a python package named pyArc that allows rigorous computation of absorption and radiative coefficients from first principles. By integrating several interpolation strategies to augment k-point sampling in reciprocal space, our code is accurate yet highly efficient. In addition to evaluation of the coefficients, our code is capable of intuitive analysis of carrier distribution, facilitating a deeper understanding of the microscopic mechanisms underlying the radiative coefficients. Utilizing GaAs as a prototypical example, we demonstrate how to employ our package to compute absorption and radiative coefficients and to investigate the key features in the electronic structure that give rise to these coefficients. Program SummaryProgram title: PyArcCPC Library link to program files:https://doi.org/10.17632/5x9g9bvhcv.1Licensing provisions: MIT licenseProgramming language: Python 3Nature of problem: Light absorption and radiative recombination processes in semiconductors critically impact the energy conversion efficiency of optoelectronic devices. Developing a method to calculate coefficients of the two processes based on first-principles theory is essential, which not only can help to obtain the key properties of those semiconductor materials and guide the device design, but also can unveil the underlying microscopic mechanisms.Solution method: PyArc, written in the Python language, implements first-principles methodologies for the computation of absorption and radiative coefficients of semiconductors based on Fermi's golden rule. This package takes the electronic eigenvalues and dipole matrix elements of a material computed from first-principles codes such as VASP as input. Dense k-point sampling for the Brillouin zone is achieved through efficient interpolation schemes implemented in our code to acquire well converged results. The functionality of cross-sectional visualization of carrier distribution in our code provides intuitive insights into the fundamental mechanism beneath the charge-carrier radiative recombination process.

Optimization and Tradeoff Analysis for Multiple Configurations of Bio-Energy with Carbon Capture and Storage Systems in Brazilian Sugarcane Ethanol Sector.

Bio-energy systems with carbon capture and storage (BECCS) will be essential if countries are to meet the gas emission reduction targets established in the 2015 Paris Agreement. This study seeks to carry out a thermodynamic optimization and analysis of a BECCS technology for a typical Brazilian cogeneration plant. To maximize generated net electrical energy (MWe) and carbon dioxide CO2 capture (Mt/year), this study evaluated six cogeneration systems integrated with a chemical absorption process using MEA. A key performance indicator (gCO2/kWh) was also evaluated. The set of optimal solutions shows that the single regenerator configuration (REG1) resulted in more CO2 capture (51.9% of all CO2 emissions generated by the plant), penalized by 14.9% in the electrical plant's efficiency. On the other hand, the reheated configuration with three regenerators (Reheat3) was less power-penalized (7.41%) but had a lower CO2 capture rate (36.3%). Results showed that if the CO2 capture rates would be higher than 51.9%, the cogeneration system would reach a higher specific emission (gCO2/kWh) than the cogeneration base plant without a carbon capture system, which implies that low capture rates (<51%) in the CCS system guarantee an overall net reduction in greenhouse gas emissions in sugarcane plants for power and ethanol production.

Impact of the biogas impurities on the quality of the precipitated calcium carbonate in the regenaration stage of a chemical absorption biogas upgrading unit

Combining Carbon Capture and Storage (CCS) with producing competitive secondary raw materials is key to decarbonizing industry and reducing resource extraction. Biogas upgrading to biomethane stand out as an alternative, but a significant gap remains in integrating this process within a circular economy framework. This issue has been recently addressed by a process that integrates biogas upgrading via caustic absorption with the production of Precipitated Calcium Carbonate (PCC) and the recovery of sodium hydroxide from waste brine solution using membrane technologies. The profitability of this approach depends on the quality of the PCC, a critical factor that this work addresses. By characterizing PCC is determined whether trace compounds in biogas contaminate the PCC and potentially affect its commercial value. It also examines the CO2 absorption process and analyzes the aqueous samples from the filtration phase of the PCC slurry. Results confirm the high purity of PCC obtained from biogas treatment using Raman spectroscopy, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The analyses show that the PCC is pure calcium carbonate, mainly in the stable calcite form, with a typical tetrahedral morphology and no detectable impurities. Characterization of aqueous solutions revealed organic trace compounds from biogas, with TOC concentrations of 9.7 (± 6.4) and 16.0 (± 8) mg C/l. Silicon measurements showed similar concentrations in the absorbent solution and filtrated PCC slurry. Additionally, ammonia escapes as gas, and hydrogen sulfide in the biogas likely contributed to sulfate salt formation. Analysis of the CO₂ absorption shows a first-order reaction with OH-, where the amount of CO₂ absorbed (46.3–50.0 g) closely matches the theoretical value of 48 g. The study reveals that most of the biogas impurities dissolve into the aqueous solution, being crucial for future studies and downstream membrane treatments, and the PCC is unaffected by these impurities with a purity suitable for commercial applications.

β-Cyclodextrin enhanced bioavailability of petroleum hydrocarbons in industrially contaminated soil: A phytoremediation field study

Low remediation efficiency due to low bioavailability is a primary restrictive factor for phytoremediation applications. Specifically, this investigation examines whether Suaeda heteroptera Kitagawa (S. heteroptera) can be used in combination with β-cyclodextrin (β-CD) to remediate contaminated site. The study was conducted on the growth response of S. heteroptera, bioavailability and dissipation of petroleum hydrocarbons (PHs) in soil under the influence of β-CD Our preliminary studies confirmed that β-CD is effective in increasing the biomass and height of plants. The presence of β-CD could dramatically elevate polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in S. heteroptera. Moreover, a remarkable positive correlation between PHs levels in roots with the dosage of β-CD and a negative correlation between the PHs levels in roots with KOW of PHs have been observed. The dissipation of n-alkanes was estimated to be 38.73–62.27%, and the dissipation of PAHs was 36.59–60.10%. In addition, the dissipation behavior of n-alkanes and PAHs was well agreement with the first-order kinetic model. These results display that applying β-CD accelerated the desorption process of PHs from soil and promoted the absorption process of PHs onto the root epidermis. The enhancement of phytoremediation was achieved by increasing the bioavailability of PHs.

Quantification of seepage characteristics in shale oil reservoirs: A triple medium model-driven approach

Shale oil is an important unconventional oil and gas resource depicting a complex microstructure with various pore types and fluid distribution. In particular, the fluid flow mechanism and the associated percolation characterization theory have recently gained notable interest. Here we establish a mathematical model to describe non-wetting and wetting phase imbibition in shale oil formation. The model is based on the triple continuum medium theory taking into account the wetting characteristics of the shale/oil/brine system, the percolation processes in inorganic and organic pores, and the dynamic process of adsorption and absorption of crude oil in kerogen. The experimental results of oil and water imbibition were fitted thereby obtaining seepage physical parameters and validating the realiability of the proposed model. The impact of physical properties (e.g. inorganic and organic permeability, equivalent cross-flow coefficient, and diffusion coefficient) on the dynamic characteristics of the imbibition process was also evaluated. The results show that the inorganic permeability is between 10−7–10−4μm2 and the organic permeability is between 10−10–10−6μm2. The imbibition rate demonstrates a positive correlation with inorganic and organic permeability, equivalent cross-flow coefficient, and diffusion coefficient. The larger the difference between inorganic and organic permeability, the more pronounced the “bi-horizontal segment” feature of the shale oil imbibition saturation curve. The proposed model effectively calculates the reserves in both organic and inorganic pores, thereby addressing the time-consuming challenges associated with experimentally obtaining seepage parameters. This study thus provides a theoretical basis for precisely evaluating fluid flow in shale oil reservoirs.

Training on Making Local Microorganisms (MOL) based on Mimosa Roots to Farmers Group in Jubung Village

Jubung Village is the largest soybean producer in Sukorambi District. Partners in this service are farmer groups in Jubung with the name of the Farmer Group "Tani Mulyo". This partner has the problem of soybean production that cannot increase and the high price of fertilizer. The solution offered to solve the problem is the use of local Microorganisms (MOLs). MOL is useful for increasing plant production and bio activators and fermentation of animal feed. Mimosa has the potential as an antimicrobial food pathogen. Mimosa root can speed up the process of absorption of nutrients and water, as well as remodel organic matter in the soil. The purpose of the service activity is to introduce the technology of making root MOL to supporting organic farming. The solutions provided will be divided into several activities, including socialization, counseling about the role of PGPR and MOL, soybean cultivation according to GAP, practices for making Root MOL, monitoring and evaluation. The results of the activity showed that the participants participated in the activity enthusiastically, as evidenced by the discussion that went well. The indicators of the success of making MOL are indicated by the characteristics of cloudy color and have a fermentation smell

Study on Shipboard Carbon Capture Technology with the MEA-AMP-Mixed Absorbent Based on Ship Applicability Perspective.

Ocean-going ships powered by diesel engines were the main source of CO2 emissions in the marine environment, and it was imperative to study shipboard carbon capture technology. Based on this, the whole process of CO2 absorption and desorption was studied with a mixed amine (MEA + AMP). The effective cycle time, CO2 absorption capacity, desorption efficiency, energy consumption, foaming and volatilization characteristics, and other key parameters were compared and analyzed under the conditions of required capture efficiency by ships. The MEA20% + AMP10% solution showed good CO2 absorption performance. At 80% capture efficiency, the desorption efficiency was more than 50%. The absorption capacity was close to that of the MEA30% solution, and the cycle time was basically the same. The effective cycle time under the reaction time of 2 s was also determined, which was an important parameter for setting the desorption frequency and had a great effect on reducing the desorption energy consumption. This work can provide an important reference value for the real ship application of carbon capture devices.

MOF-801 enabled rapid-cycling atmospheric water harvester with vertically aligned photothermal channel

Sorption-based atmospheric water harvesting (SAWH) with metal–organic frameworks (MOFs) offer a promising solution to freshwater scarcity in arid regions. However, given the powder nature of MOFs, scaling-up such a concept with industrially favorable monolithic MOFs in bulky sizes remains challenging. In this study, a pore vertically aligned nanocomposite sorbent where MOF-801 is anchored at the polymeric structure surface was prepared via Fe3+-induced crosslinking and directional freezing methods. The continuous vertically aligned hierarchical pores not only offer sufficient sites for MOF-801 loading but also provide rapid moisture transport channels, as well as high solar-thermal conversion efficiency, resulting in a rapid ab/desorption duration of 2 h (including an absorption process for 1 h and a desorption process for 1 h under 1 sun irradiation) and multicycle daily water production of 1.40 L kg−1 at low RH of 20 % and 5.57 L kg−1 at higher RH of 80 %, respectively, which is outperformed most of the state-of-the-art MOFs based SAWH materials. This work provides a simple and effective way to shorten MOF-801 ab/desorption duration, which has great means for designing of high-performance solar-driven water harvesting materials.

Microfluidic fabrication of compound microfibers encapsulating nano-enhanced phase change material (PCM) for thermal regulation

This study presents a microfluidic approach for fabrication of compound phase change fibers (CPCFs) encapsulating nano-enhanced phase change material (PCM), RT25, for thermal regulation. The produced fibers are flexible and have strong compatibility and durable stability, with their size and the proportion of PCM can be precisely controlled by the microfluidic approach. Especially, a hydroxy surface modification method was used to uniformly disperse SiO2 nanoparticles into the RT25, aiming to enhance the thermal regulation performance of the CPCFs. Thermal performance test was conducted and it indicated that, compared with the compound phase change fiber (CPCF) with pure RT25, the CPCF incorporated with 2 wt% SiO2 nanoparticles presented a notable increase in thermal conductivity by 46.52 % and 45.51 % for solid-state and liquid-state enclosed PCM with a limited reduction in both melting and solidification enthalpies by 9.21 % and 10.1 %, respectively. Moreover, an experiment simulating the heat dissipation scenario of the electronic cabinet under intermittent running with short operation and long rest was conducted by using the CPCFs. It showed that adding SiO2 nanoparticles can improve the heat absorption process (solid-to-liquid phase) via the CPCFs with a smaller temperature increase (i.e., the maximum temperature of simulated inner electronic device in the cabinet for the repeated intermittent running) and it is also able to make the CPCFs renew (liquid-to-solid phase) more quickly and ready for heat absorption process in the next cycle. These CPCFs offer a promising alternative for more efficient and sustainable thermal management of the electrical/electronic equipment.

(Digital Presentation) Cooperative Quantum Dynamics of Excitons in Colloidal Quantum Dots for Novel Optoelectronic Applications

Colloidal semiconductor quantum dots (QDs) are excellent materials for combining photonics and nanoscience. They have been extensively studied to understand the photophysics of quantum confined excitons and to develop efficient optoelectronic devices such as QD solar cells and light-emitting diodes. The photophysical processes of QD devices are governed by a large number of QDs constructing the devices. Therefore, cooperative quantum dynamics of QDs, i.e., synchronous responses of QD ensembles, have a great potential for boosting optoelectronic device performances.Before the use of cooperative quantum dynamics in QD devices, the understanding of quantum dynamics of excitons, i.e., coherent properties of multiexcitons, is required to draw out quantum cooperativity from QD ensembles. In order to elucidate coherent dynamics of multiexcitons during resonant laser-pulse excitation, we performed a quantum interference spectroscopy of QD responses. We found that multiexcitons generate the high-frequency coherent oscillations with integer multiples of the exciton resonance frequency, which is called harmonic quantum coherence, and that the coherent responses govern the microscopic processes in the resonant multiphoton absorption [1-3]. Furthermore, it was demonstrated that the coherent responses were detectable as photocurrent signals in thin films of QD ensembles [4]. These developments build up an essential base of quantum cooperativities emerging in optoelectronics.Here, we report recent investigations of cooperative quantum dynamics in QDs. In optoelectronic devices, electronic couplings between QDs are expected to generate a new type of quantum cooperativities. To generate electronic coupling, we fabricated closely packed PbS QDs by using a ligand exchange method. We found that nonlinear photocurrent signals are strongly enhanced in the QD solids. The comparison analysis of different ligands clarified that the enhancement ratio increases monotonically with the decrease of the inter-QD distance [5]. This means that the signal enhancement originates from the electronic coupling and cooperative behavior of QDs. These findings show that the cooperative quantum dynamics provide a new route to advanced optoelectronic technology such as nonlinear amplifiers.Part of this work was supported by JSPS KAKENHI (JP19H05465, JP22H01990, and JP23K17877), JST PRESTO (JPMJPR23H3), and JST CREST (JPMJCR21B4).

Human Enteroid Monolayers: A Novel, Functionally-Stable Model for Investigating Oral Drug Disposition.

To further the development of an in vitro model which faithfully recapitulates drug disposition of orally administered drugs, we investigated the utility of human enteroid monolayers to simultaneously assess intestinal drug absorption and first-pass metabolism processes. We cultured human enteroid monolayers from three donors, derived via biopsies containing duodenal stem cells that were propagated and then differentiated atop permeable Transwell® inserts, and confirmed transformation into a largely enterocyte population via RNA-seq analysis and immunocytochemical (ICC) assays. Proper cell morphology was assessed and confirmed via bright field microscopy and ICC imaging of tight junction proteins and other apically and basolaterally localized proteins. Enteroid monolayer barrier integrity was demonstrated by elevated transepithelial electrical resistance (TEER) that stabilized after 10 days in culture and persisted for 42 days. These results were corroborated by low paracellular transport probe permeability at 7 and 21 days in culture. The activity of a prominent drug metabolizing enzyme, CYP3A, was confirmed at 7, 21, and 42 days culture under basal, 1α,25(OH)2 vitamin D3-induced, and 6',7'-dihydroxybergamottin-inhibited conditions. The duration of these experiments is particularly noteworthy, as this is the first study assessing drug metabolizing enzymes and transporters (DMET) expression/function for enteroids cultured for greater than 12 days. The sum of these results suggests enteroid monolayers are a promising ex vivo model to investigate and quantitatively predict an orally administered drug's intestinal absorption and/or metabolism. Significance Statement This study presents a novel ex vivo model of the human intestine, human intestinal organoid (enteroid) monolayers, that maintain barrier function and metabolic functionality for up to 42-days in culture. The incorporation of both barrier integrity and metabolic function over an extended period within the same model is an advancement over historically used in vitro systems, which either lack one or both of these attributes or have limited viability.

(Invited) Near-Infrared Triggered Theranostics

In the last decade, the field of luminescent lanthanide doped nanoparticles has had a meteoric rise, progressing from the basic understanding of the photophysical properties governing their nanoscale luminescence, in particular upconversion, to their use in a plethora of applications, with considerable focus in biology and medicine. This interest stems primarily from the ability to stimulate these luminescent nanoparticles with near-infrared (NIR) light as well as their diverse emission wavelengths spanning the UV to the NIR. Therefore, with a single NIR excitation wavelength, it is possible to observe higher energy multiphoton luminescence, known as upconversion, or single photon NIR emission (known as down-shifted luminescence). The former upconversion process proceeds through the sequential absorption of multiple NIR photons through the long-lived 4f electronic energy states of the tri-positive lanthanide ions. As a result, upconversion is several of orders more efficient than conventional multiphoton absorption processes. This is especially interesting for applications in theranostics (therapy + diagnostics on the same platform) where the upconverted light can be used to trigger another light activated modality (therapy) while the NIR luminescence can be used for bioimaging and nanothermometry (diagnostics). Here, we present our work on the synthesis and development of various NIR excited (and emitting) core/shell lanthanide-doped nanostructures/nanoplatforms and demonstrate how their various emissions could be harnessed for applications in biology and nanomedicine.

Knowledge arbitrage: what are the risks, and do they matter?

Purpose It is largely acknowledged that arbitrating the flow of knowledge can help firms strategically leverage tacit and explicit internal knowledge. However, despite the apparent scholarly and managerial acceptance of the criticality of the flow of knowledge between various stakeholders, the academic understanding of knowledge arbitrage remains coarse-grained. There are practically no empirical insights available to unravel the consequences of firms’ knowledge arbitrage choices regarding rewards and risks. This study aims to identify the risks that emerge as firms channel the flow of knowledge from surplus to deficit areas within organizational boundaries. To this end, the authors investigate several subsumed subprocesses in knowledge arbitrage to map the associated risks. Design/methodology/approach This study used an exploratory qualitative approach to examine the risks that emerge as firms attempt to support knowledge flows within their organizational boundaries. The data were collected through open-ended essays via an online research platform from 45 full-time employees of firms operating in different sectors. The collected data were analyzed inductively through open, axial and selective coding. Findings The research findings identified three key subprocesses of knowledge arbitrage: knowledge diffusion, knowledge brokering and knowledge absorption. These subprocesses are susceptible to various risks arising the form of channels, champions, sharers and receivers of knowledge flows. In general, the study showed that a firm’s decision regarding knowledge flows, such as structured or random flows, or the presence or absence of designated coordinators to broker the flow carries specific risks for both sharers and receivers. In particular, while the risks of knowledge hiding, misinformation and disinformation manifest in all three subprocesses, low employee engagement, loss of knowledge and information overload also emerged as key risks in any two of the three subprocesses. Originality/value This study offers valuable insights by uncovering the hitherto unexplored risks in intrafirm knowledge arbitrage. Given that knowledge is a crucial organizational tool for driving performance, innovation and competitive advantage, understanding the risks associated with intrafirm arbitrated knowledge flows can help firms anticipate and mitigate the associated adverse consequences. The findings make a novel contribution by offering (a) a comprehensive categorization of the risks associated with knowledge arbitrage rooted in processes, people and structures and (b) a macro overview of knowledge arbitrage risks associated with the processes of knowledge diffusion, knowledge brokering and knowledge absorption.

TaMYB-CC5 gene specifically expressed in root improve tolerance of phosphorus deficiency and drought stress in wheat

Phosphate deficiency and drought are significant environmental constraints that impact both the productivity and quality of wheat. The interaction between phosphorus and water facilitates their mutual absorption processes in plants. Under conditions of both phosphorus deficiency and drought stress, we observed a significant upregulation in the expression of wheat MYB-CC transcription factors through the transcriptome analysis. 52 TaMYB-CC genes in wheat were identified and analyzed their evolutionary relationships, structures, and expression patterns. The TaMYB-CC5 gene exhibited specific expression in roots and demonstrated significant upregulation under phosphorus deficiency and drought stress compared to other TaMYB-CC genes. The overexpression of TaMYB-CC5A in Arabidopsis resulted in a significant increase of root length under stress conditions, thereby enhancing tolerance to phosphate starvation and drought stress. The wheat lines with silenced TaMYB-CC5 genes exhibited reduced root length under stress conditions and increased sensitivity to phosphate deficiency and drought stress. In addition, silencing the TaMYB-CC5 genes resulted in altered phosphorus content in leaves but did not lead to a reduction in phosphorus content in roots. Enrichment analysis the co-expression genes of TaMYB-CC5 transcription factors, we found the zinc-induced facilitator-like (ZIFL) genes were prominent associated with TaMYB-CC5 gene. The TaZIFL1, TaZIFL2, and TaZIFL5 genes were verified specifically expressed in roots and regulated by TaMYB-CC5 transcript factor. Our study reveals the pivotal role of the TaMYB-CC5 gene in regulating TaZIFL genes, which is crucial for maintaining normal root growth under phosphorus deficiency and drought stress, thereby enhanced resistance to these abiotic stresses in wheat.

One- and Two-Photon Photophysical Properties, Ultrafast Dynamics, and DFT Study of Three Modified Zinc Phthalocyanines.

As two-photon absorption (TPA) materials, phthalocyanine molecules have promising application prospects due to their large TPA absorption cross-section, high third-order nonlinear optical susceptibility, and ultrafast response characteristics. In this work, optical properties and the ultrafast response of three modified zinc phthalocyanine molecules (P-HPcZn, Pc-P-Pc, and (DR1)4PcZn) were analyzed. No obvious side-shoulder absorption peaks in the Q-band can be observed from the steady-state absorption spectra of the three molecules, confirming the lack of aggregation products in the solutions of our measurement. Open-aperture Z-scan results show relatively large TPA cross-section values of 136.4 and 55.3 GM for Pc-P-Pc and (DR1)4PcZn, respectively. The nonlinear optical results show that the absorption process observed under the excitation of femtosecond pulses is a reverse saturable absorption (RSA) mechanism. Up-conversion fluorescence spectra of (DR1)4PcZn in THF solution indicate that the fluorescence emission mechanism is TPA. In the study of ultrafast dynamics, the transient absorption spectra were investigated and the decay lifetime of the dynamic traces corresponding to some representative probe wavelengths was obtained through data fitting with a multi-exponential function. Finally, the charge transfer and excited state properties of the modified zinc phthalocyanine molecules were discussed in depth by the DFT method. The energy gaps of P-HPcZn, Pc-P-Pc, and (DR1)4PcZn are 2.16, 1.39, and 2.13 eV, respectively. The results indicate that the Pc-P-Pc of donor-acceptor-donor (D-A-D) structure has the smallest energy gap as well as the best charge transfer properties.

Infrared photodetectors based on wide bandgap two-dimensional transition metal dichalcogenides via efficient two-photon absorption

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted considerable attention due to their outstanding optoelectronic properties and ease of integration, making them ideal candidates for high-performance photodetectors. However, the excessive width of the bandgap in some 2D TMDs presents a challenge for achieving infrared photodetection. One approach to broaden the photoresponse wavelength range of TMDs is through the utilization of two-photon absorption (TPA) process. Unfortunately, the inefficiency of TPA hinders its application in infrared photodetection. In this study, we propose the design of two photodetectors utilizing high TPA coefficient materials, specifically ReSe2 and MoS2, to exploit their TPA capability and extend the photoresponse to the near-infrared region at 1550 nm. The ReSe2 photodetector demonstrates an unprecedented responsivity of 43 μA W−1, surpassing that of current single-material TPA photodetectors. Similarly, the MoS2 photodetector achieves a responsivity of 18 μA W−1, comparable to state-of-the-art TPA photodetectors. This research establishes the potential of high TPA coefficient 2D TMDs for infrared photodetection.