Inversion Technique Research Articles

A Case Study Comparing Methods for Coal Thickness Identification in Complex Geological Conditions

This study compares the effectiveness of different methods for coal thickness identification, aiming to identify the most accurate approach and provide a reference for intelligent coalmine development. Focused on the No. 2 coal seam in a mining area in Shanxi, China, the analysis employs well log-constrained impedance inversion and seismic multi-attribute techniques. The results show that the back propagation (BP) neural network model, as part of the seismic multi-attribute approach, delivers prediction accuracy comparable to the well log-constrained inversion method. Specifically, after applying proper static corrections, a four-layer BP neural network was constructed using four optimized sensitive attributes as the input layer, achieving an error range of 0.11% to 1.36%, compared to 0.03% to 6.59% for the logging-based method. The BP neural network demonstrated strong applicability in complex geological environments. Empirical analysis further validated the BP neural network’s geological reliability and practicality in systematic coal thickness determination.

Can one hear the shape of a crystal?

Isospectrality is a general fundamental concept often involving whether various operators can have identical spectra, i.e., the same set of eigenvalues. In the context of the Laplacian operator, the famous question “Can one hear the shape of a drum?” concerns whether different shaped drums can have the same vibrational modes. The isospectrality of a lattice in d-dimensional Euclidean space Rd is a tantamount to whether it is uniquely determined by its theta series, i.e., the radial distribution function g2(r). While much is known about the isospectrality of Bravais lattices across dimensions, little is known about this question of more general crystal (periodic) structures with an n-particle basis (n≥2). Here, we ask what is nmin(d), the minimum value of n for inequivalent (i.e., unrelated by isometric symmetries) crystals with the same theta function in space dimension d? To answer these questions, we use rigorous methods as well as a precise numerical algorithm that enables us to determine the minimum multiparticle basis of inequivalent isospectral crystals. Our algorithm identifies isospectral four-, three- and two-particle bases in one, two, and three spatial dimensions, respectively. For many of these isospectral crystals, we rigorously show that they indeed possess identically the same g2(r)'s for all values of r. Based on our analyses, we conjecture that nmin(d)=4, 3, 2 for d=1, 2, 3, respectively. The identification of isospectral crystals enables one to study the degeneracy of the ground-state under the action of isotropic pair potentials. Indeed, using inverse statistical-mechanical techniques, we find an isotropic pair potential whose low-temperature configurations in two dimensions obtained via simulated annealing can lead to both of two isospectral crystal structures with n=3, the proportion of which can be controlled by the cooling rate. Our findings provide general insights into the structural and ground-state degeneracies of crystal structures as determined by radial pair information. Published by the American Physical Society 2024

Abstract 4138529: Acute Coronary Syndrome in a Patient with Situs Inversus Totalis

INTRODUCTION: Situs inversus totalis (SIT) occurs in 1 in 8000 births. 0.04% of cases involve ACS, posing a clinical challenge. We present a case of NSTE-ACS in a patient with SIT, where a universal diagnostic catheter was used to engage the coronary arteries. CASE PRESENTATION: 51-year-old Caucasian male with situs inversus totalis presented with worsening right-sided chest&right arm pain after shoveling snow. Initial examination was benign, but the EKG showed features of dextrocardia with T wave inversions in V2-V6. Laboratory results showed elevated CKMB (119.2)&up-trending troponin T 1.260 ng/ml. He was started on a Heparin drip and 81 mg of Aspirin with a plan for urgent cardiac catheterization. A coronary angiogram from the right radial with a 6 French Tiger Radial Catheter in the right anterior projection (RAO) 30 degrees showed minor luminal irregularities in the RCA, and 90% stenosis in the LAD. RCA was enganged anticlockwise and LCA clockwise. A 6 French XB 3.5 guide catheter was used to engage the LCA system, and the mid-LAD was stented. DAPT including Aspirin and Ticagrelor, was initiated. A TTE showed an EF of 25-30% with severe anterior, apical, and septal wall hypokinesis. The patient was discharged home with GDMT for coronary artery disease. DISCUSSION: CAD in dextrocardia can be challenging, requiring reversed limb and precordial leads and a right-sided ECG to show the extent of MI. Failure to recognize dextrocardia can lead to underestimating or missing MI. Typical findings include global negativity in lead I, positively deflected QRS in aVR, negative P-wave in lead II, reverse R-wave progression in precordial leads, and right-axis deviation. Our patient's EKG revealed polarity reversal in leads I and aVL, QS and rS patterns in precordial leads, and positive polarity in aVR, suggesting dextrocardia with T wave inversions, prompting further workup. Engaging the coronary arteries is challenging. We used a Tiger radial catheter with a reverse torque technique: anticlockwise for the RCA and clockwise for the LCA. Both arteries were engaged in the right anterior oblique view at 30 degrees. The cranial and caudal angulation remained the same, but the standard left anterior oblique view was switched with the right anterior oblique view and vice versa. The double inversion technique is useful during interventions when dealing with unfamiliar anatomy. It is not well-established whether dextrocardia is a risk factor for myocardial infarction.

Separation properties and fouling resistance of polyethersulfone membrane modified by fungal chitosan.

This research explores the enhancement of polyethersulfone (PES) membranes through the incorporation of chitosan derived from the lignicolous fungus Ganoderma sp. Utilizing wet phase inversion and solution casting techniques, chitosan was successfully integrated into the PES matrix, as confirmed by Fourier Transform Infrared Spectroscopy (FT-IR), which indicated a high deacetylation degree of 75.7%. The incorporation of chitosan significantly increased the membrane hydrophilicity, as evidenced by a reduction in the water contact angle and a substantial improvement in pure water permeability, from 17.9L m-2 h-1 bar-1 to 27.3L m-2 h-1 bar-1. The membrane anti-fouling properties were also notably enhanced, with the Flux Recovery Ratio (FRR) increasing from approximately 60-80%. Moreover, the chitosan-modified PES/CS membrane, particularly at a 5% chitosan concentration, demonstrated exceptional efficacy in pollutant removal, achieving over 90% elimination of total suspended solids, cadmium (Cd), and lead (Pb), alongside a 79% reduction in color during the treatment of textile wastewater.

Flow-dependent observation errors for greenhouse gas inversions in an ensemble Kalman smoother

Abstract. Atmospheric inverse modeling is the process of estimating emissions from atmospheric observations by minimizing a cost function, which includes a term describing the difference between simulated and observed concentrations. The minimization of this difference is typically limited by uncertainties in the atmospheric transport model rather than by uncertainties in the observations. In this study, we showcase how a temporally varying, flow-dependent atmospheric transport uncertainty can enhance the accuracy of emission estimation through idealized experiments using an ensemble Kalman smoother system. We use the estimation of European CH4 emissions from the in situ measurement network as an example, but we also demonstrate the additional benefits for trace gases with more localized sources, such as SF6. The uncertainty in flow-dependent transport is determined using meteorological ensemble simulations that are perturbed by physics and driven at the boundaries by an analysis ensemble from a global meteorology and a CH4 simulation. The impact of direct representation of temporally varying transport uncertainties in atmospheric inversions is then investigated in an observation system simulation experiment framework in various setups and for different flux signals. We show that the uncertainty in the transport model varies significantly in space and time and that it is generally highest during nighttime. We apply inversions using only afternoon observations, as is common practice, but also explore the option of assimilating hourly data irrespective of the hour of day using a filter based on transport uncertainty and taking into account the temporal covariances. Our findings indicate that incorporating flow-dependent uncertainties in inversion techniques leads to more accurate estimates of GHG emissions. Differences between estimated and true emissions could be reduced more effectively by 9 % to 82 %, with generally larger improvements for the SF6 inversion problem and for the more challenging setup with small flux signals.

Hybrid optimization for DC resistivity imaging via intelligible-in-time logic and the interior point method.

Geophysical DC resistivity imaging is crucial in subsurface exploration, environmental studies, and resource assessment. However, traditional inversion techniques face challenges in accurately resolving complex subsurface features because of the inherent nonlinearities in geophysical data. To overcome these challenges, we propose a hybrid optimization approach that combines incomprehensible but intelligible-in-time (IbI) logic with the interior point method (IPM). The IbI logic framework leverages complexity and temporal intelligibility, allowing for a dynamic interpretation of subsurface phenomena. By integrating IbI with IPM, our approach benefits from global exploration and local refinement, leading to improved convergence speed and solution quality. The objective function formulated for the inversion process includes data misfit and model regularization terms, which promote accurate and smooth solutions. Our methodology involves the use of the IbI logic algorithm (ILA) for initial global search, which identifies promising regions in the search space. This is followed by the application of IPM for local optimization. This synergy between the two algorithms ensures robustness and efficiency in handling large datasets and complex geological models. We conducted tests using synthetic and real DC resistivity data to validate our approach. The synthetic test demonstrated the accurate reconstruction of subsurface anomalies, whereas the real data test successfully identified fault zones, which is consistent with previous studies. The hybrid optimization algorithm significantly improves the resolution of subsurface structures and enhances geophysical data inversion practices. It balances the exploration and refinement phases effectively, optimizing the computation time and ensuring precise model delineation.

Conceptual advances in petrophysical inversion techniques: The synergy of machine learning and traditional inversion models

Petrophysical inversion techniques are essential for estimating reservoir properties such as porosity, permeability, and fluid saturation, which are critical for optimizing hydrocarbon recovery and reservoir management. Traditionally, deterministic and stochastic inversion methods have relied on well log data, core samples, and seismic information to generate models of subsurface properties. However, these techniques face limitations in handling large datasets, nonlinear relationships, and uncertainties in complex reservoir environments. Recent advances in machine learning (ML) offer an opportunity to enhance these traditional methods by providing a data-driven approach capable of learning patterns and refining inversion models. This review explores the potential synergy between traditional petrophysical inversion techniques and machine learning algorithms to create a new paradigm for reservoir parameter estimation and analysis. Machine learning’s ability to process large volumes of diverse data and capture nonlinear relationships complements the physics-based constraints of traditional inversion methods. By combining these two approaches, hybrid models can provide improved accuracy in predicting reservoir properties and handling data gaps or uncertainties. The review discusses specific case studies where machine learning-assisted inversion models have been successfully applied, such as the estimation of porosity and permeability, seismic inversion for lithology identification, and fluid saturation modeling. These hybrid models demonstrate enhanced predictive accuracy, faster computational efficiency, and real-time adaptability, transforming reservoir characterization and management. The integration of machine learning with traditional inversion techniques represents a major advancement in petrophysical analysis. This synergy holds the potential to revolutionize reservoir parameter estimation, making it more accurate, robust, and responsive to real-time data, ultimately improving decision-making in reservoir engineering and maximizing hydrocarbon recovery. Keywords: Petrophysical Inversion, Machine Learning, Traditional Inversion, Models.

One-way reflection waveform inversion with depth-dependent gradient preconditioning

Summary Reflection Waveform Inversion (RWI) is a technique that uses pure reflection data to estimate subsurface background velocity, relying on evolving seismic images. Conventional RWI operates in a cyclic workflow, with two key components in each cycle—migration and reflection tomography. Conventional RWI may result in suboptimal background velocity estimation, partly due to limited or unresolved resolution within each component in each cycle. While gradient preconditioning with the reciprocal of Hessian information helps resolve this issue in both components of RWI, it becomes impractical for a large number of model parameters. One-way reflection waveform inversion (ORWI) is a reflection waveform inversion technique in which the forward modeling scheme operates in one direction (downward and then upward) via virtual parallel depth levels within the medium. Leveraging the ORWI framework, we decompose and reduce the linear Hessian operator (also known as the approximate Hessian or Gauss-Newton Hessian) into multiple smaller sub-operators. In particular, the diagonal blocks of the mono-frequency approximate Hessian operators, each corresponding to a single depth level within the medium, are extracted and inverted to precondition the corresponding mono-frequency gradients in both the migration and reflection tomography components of ORWI. This depth-dependent gradient preconditioning transforms standard ORWI into a high-resolution, yet computationally feasible version aimed at addressing suboptimal velocity estimation, referred to as high-resolution ORWI (HR-ORWI). The effectiveness of the proposed approach is demonstrated through successful applications to synthetic data examples.

Nonlinear joint inversion of Rayleigh and Love wave dispersion curves based on Pearson correlation coefficient and thickness mean sharing

AbstractThe joint inversion of Rayleigh and Love waves plays a crucial role in mitigating the non‐uniqueness of surface wave inversion results and enhancing the stability of these inversions. Existing approaches to the joint inversion of Rayleigh and Love wave dispersion curves, which rely on conventional objective functions, often struggle with complex stratigraphic configurations and yield results of limited accuracy. This study introduces two novel nonlinear joint inversion techniques for Rayleigh and Love waves: Pearson correlation coefficient and thickness mean sharing. The Pearson correlation coefficient approach employs the Pearson correlation coefficient and alternating iterative objective functions to synchronize the shear wave velocity structures derived from Rayleigh and Love waves, thereby enhancing the accuracy of the joint inversion. Conversely, the thickness mean sharing method computes an average of the thickness values obtained in each iteration of the inversion, utilizing the traditional joint inversion objective function. Tests on three distinct stratigraphic structures—characterized by increasing velocity, high‐speed hard interlayers and low‐speed soft interlayers—as well as on measured data, demonstrate that the proposed methods significantly improve the stability and accuracy of nonlinear joint inversion.

Penile inversion vulvo-vaginoplasty with scrotal graft for trans women: surgical technique and results of initial experience.

A significant proportion of trans women is demanding for a genital gender-affirming surgery, with vulvo-vaginoplasty being the most frequently requested procedure. The gold standard for primary vaginoplasty in trans women is the penile skin inversion technique with scrotal skin graft, which allows for increased depth of the vaginal cavity. The assessment of vulvo-vaginoplasty outcomes utilizing penile skin inversion and scrotal skin graft in individuals assigned male at birth in the surgeon's learning curve involves evaluating aesthetics, functionality, and sexual aspects. A total of 76 individuals assigned male at birth were included in 2 French university hospitals from 2020 to 2022. They underwent vulvo-vaginoplasty following 8 key steps: scrotal skin excision; bilateral orchiectomy; dissection between the rectum, bladder, and prostate; penile dissection; clitoroplasty; urethroplasty; penile skin inversion with scrotal skin graft; labioplasty. The average follow-up period was 12.4months, with participants averaging 35.7years of age. Each patient was invited to complete a questionnaire during follow-up. The study's outcomes encompassed the assessment of both early and late surgical complications, postoperative sexuality, aesthetic results, and voiding satisfaction. Of the total patients, 15.8% experienced major early postoperative complications, while 3% encountered major late postoperative complications. No complication was classified 4 or 5 in Clavien-Dindo scale. Most early complications were related to issues in vulvar healing, which did not compromise long-term aesthetic results. Patients-reported satisfaction was 82% after the procedure. Vulvo-vaginoplasty utilizing penile skin inversion and scrotal skin graft for individuals assigned male at birth is a reproductive surgery procedure that can be successfully performed by experienced urologist. It achieves high patient-reported satisfaction even during the learning curve. The surgical procedures were consistent, and the sizable cohort of patients accurately reflects the learning curve of both surgeons. However, extrapolating long-term complications is challenging due to the relatively brief follow-up period. Additionally, there is a lack of self-reported sexual function data, and the scales used to assess patient-reported quality of life and urinary satisfaction are not specifically validated for transgender patients. Vulvo-vaginoplasty utilizing penile skin inversion and scrotal skin graft for individuals assigned male at birth is a complex surgical procedure. It appears to be achievable by experienced urologists during their learning curve, resulting in similar functional and surgical outcomes, along with high patient satisfaction.

Timing of puberty suppression in transgender adolescents and sexual functioning after vaginoplasty.

Sexual function in transgender adolescents after puberty suppression has been a topic of recent clinical and scientific questions. This study aimed to explore the long-term effects of early treatment with puberty suppression on sexual functioning of transfeminine individuals after vaginoplasty. This retrospective cohort study included 37 transfeminine individuals treated with a gonadotropin-releasing hormone agonist (puberty suppression), estrogen, and vaginoplasty (penile inversion technique or intestinal vaginoplasty) at the Center of Expertise on Gender Dysphoria in Amsterdam, the Netherlands, between 2000 and 2016. Experiences regarding sexual functioning and difficulties were assessed with a self-developed questionnaire ~1.5years after genital gender-affirming surgery and compared between early (Tanner stage G2-3) and late (Tanner stage G4-5) treatment with puberty suppression. Following surgery, 91% of transfeminine individuals was able to experience sexual desire, 86% experienced arousal, and 78% could attain an orgasm. Seventy-five percent of transfeminine individuals who had not experienced an orgasm pre-surgery were able to experience one post-surgery. Of all participants, 62% reported having tried penile-vaginal intercourse post-surgery. The majority reported the presence of one or multiple sexual challenges. There were no significant differences in postoperative sexual function or sexual difficulties between groups treated with early versus late puberty suppression. With these findings, more adequate and tailored information on the expected effects of early endocrine gender-affirming treatment (including puberty suppression) can be given by healthcare professionals. This is the first study that has assessed sexual functioning of transgender individuals treated with puberty suppression, and has differentiated between the pubertal stage at treatment initiation. Limitations were the small cohort size and retrospective study design. This study focuses on sexual functioning, however, it is important to realize sexual wellbeing is multifactorial and encompasses more than genital functioning or the ability to have certain sexual experiences. This study found that post-vaginoplasty transfeminine individuals after both early and late suppression of puberty have the ability to experience sexual desire and arousal, and to achieve orgasms. Outcomes are comparable to previous findings in those who started treatment in adulthood.

Three-Dimensional Subsurface Model of Luk-Ulo Melange Complex, Karangsambung, Indonesia: Insights from Gravity Modeling

The Luk-Ulo Melange Complex (LMC) is characterized by a chaotic assemblage of mixed rocks with a block-in-matrix fabric. The exposed blocks consist of various scattered rock types, trending in an ENE-WSW direction. In the case of Mt. Parang, the origin of the diabase remains uncertain, with ongoing debate as to whether it is associated with in situ volcanic activity or represents an exotic block within the melange deposit. Subsurface data obtained through geophysical investigation can aid in modeling the geometry of intrusive bodies using inverse modeling techniques. In this study, we conducted a gravity survey and performed 3D inverse modeling to investigate the subsurface beneath Karangsambung. A total of 818 gravity data points and 28 rock density measurements were integrated with existing geological data to construct an a priori 3D geological model. To ensure the results align with geological concepts, the 3D inversion utilized a stochastic approach, allowing for the incorporation of multiple geological constraints over fifty million iterative procedures. Ultimately, the inversion successfully reduced the misfit between observed and calculated data from 2.71 to 0.55 mGal. Based on the inverted 3D model, the diabase rock in Mt. Parang is identified as having an intrusive origin. The intrusion model exhibited minimal changes in density, volume, and shape during the inversion process. Additionally, the model suggests the presence of a solidified magma reservoir at a depth of approximately 3 km, potentially related to Dakah volcanism. The inverted model also reveals the block-in-matrix structure of the Luk-Ulo Melange Complex in the northern area.

Manipulation of Lipid Nanocapsules as an Efficient Intranasal Platform for Brain Deposition of Clozapine as an Antipsychotic Drug

Background/objectives: The blood–brain barrier (BBB) significantly limits the treatment of central nervous system disorders, such as schizophrenia, by restricting drug delivery to the brain. This study explores the potential of intranasal clozapine-loaded lipid nanocapsules (IN LNCsClo) as a targeted and effective delivery system to the brain. Methods: LNCsClo were prepared using the phase inversion technique and characterized in terms of size, zeta potential, entrapment efficiency (EE%), and in vitro drug release. The pharmacokinetic, safety, and pharmacodynamic effects of LNCsClo were then evaluated in a rat model through intranasal (IN) administration and compared with those of oral and intravenous (IV) Clo solutions. Results: LNCsClo were prepared using a phase inversion technique, resulting in a nanocarrier with a particle size of 28.6 ± 3.6 nm, homogenous dispersion, and high EE% (84.66 ± 5.66%). Pharmacokinetic analysis demonstrated that IN LNCsClo provided enhanced Clo brain bioavailability, rapid CNS targeting, and prolonged drug retention compared to oral and intravenous routes. Notably, the area under the curve (AUC) for brain concentration showed more than two-fold and eight-fold increases with LNCsClo, compared to IV and oral solutions, respectively, indicating improved brain-targeting efficiency. Safety assessments indicated that LNCsClo administration mitigated Clo-associated metabolic side effects, such as hyperglycemia, insulin imbalance, and liver enzyme alterations. Additionally, pharmacodynamic studies showed that LNCsClo significantly improved antipsychotic efficacy and reduced schizophrenia-induced hyperactivity, while preserving motor function. Conclusions: These results highlight the potential of IN LNCsClo as a novel drug delivery system, offering improved therapeutic efficacy, reduced systemic side effects, and better patient compliance in the treatment of schizophrenia and potentially other CNS disorders.

SAMControl: Controlling Pose and Object for Image Editing with Soft Attention Mask

To achieve content-consistent results in text-conditioned image editing, existing methods typically employ a reconstruction branch to capture the source image details via diffusion inversion and a generation branch to synthesize the target image based on the given textual prompt and the masked source image details. However, accurately segmenting source details is challenging with the current fixed-threshold mask strategy. Additionally, the inadequacies in the inversion process can lead to insufficient retention of source details. In this paper, we propose a method called SAMControl ( S oft A ttention M ask) to adaptively control the pose and object details for image editing. SAMControl dynamically learns flexible attention masks for different images at various diffusion steps. Furthermore, in the reconstruction branch, we utilize a direct inversion technique to ensure the fidelity of source details within SAM. Extensive qualitative and quantitative results demonstrate the effectiveness of the proposed method.

Prediction of Thin Shoal Reservoirs Under Reef Controlled by Isochronous Stratigraphic Framework

Despite the great success in the global exploration and development of reef reservoirs, research on bioclastic shoals under reefs is still in its infancy. Bioclastic shoal reservoirs are very thin, with multiple vertical levels and fast lateral changes, which makes accurate prediction of the reservoir’s location much tougher. To further implement the reservoir distribution, under the guidance of sequence stratigraphy, the prediction of thin shoals under the control of an isochronous stratigraphic framework was established. Using the combination of spectrum shaping and F-X domain noise suppression techniques and utilizing the signal-to-noise ratio spectrum set as the reference, logging curve as supervision, and well seismic calibration and isochronal amplitude slicing as quality control, the seismic frequency band was extended, and the seismic data resolution and signal-to-noise ratio were improved. After frequency extension, the global optimal seismic automatic interpretation technique was used to construct an isochronal stratigraphic framework model. Through waveform facies-controlled inversion and waveform facies-controlled simulation techniques, the elastic properties of the shoal reservoir were obtained, from which the planar distribution of the reservoir was accurately predicted. The above methods were applied to the prediction of the bioclastic shoal reservoir in the lower submember of the Changxing formation in the Yuanba gas field (China). The plane distribution of bioclastic shoal in the first and second levels was identified, which provides a guideline for the prediction of thin shoal reservoirs.

Development of a Negatively Charged Polyether Sulfone Membrane Enriched with MIL-101(Cr)-Modified Magnetic Activated Pyrolytic Coke for Enhanced Dye Removal, Permeability, and Antifouling Properties

Developing high-performance nanofiltration membranes for effectively treating wastewater contaminated with organic pollutants has become increasingly important. Given the hazardous nature of these contaminants, proper treatment of wastewater is crucial before it is released into natural water bodies. This study synthesized a novel composite membrane by incorporating Fe3O4@APC@MIL-101(Cr) nanocomposites into a polyether sulfone (PES) matrix using a phase inversion technique. The inclusion of 0.5wt.% Fe3O4@APC@MIL-101(Cr) significantly enhanced the membrane's hydrophilicity, porosity, and surface characteristics. The optimized membrane achieved an impressive pure water flux (PWF) of 90.24L/m²h, reflecting a 400% improvement over pristine PES membranes. Moreover, it exhibited excellent rejection rates of 97.21% for crystal violet (CV) and 99.43% for methylene blue (MB), alongside a rejection efficiency of 57.73% for the anionic dye methyl orange (MO). The antifouling performance was notably improved, as evidenced by an increase in the flux recovery ratio (FRR) from 46% for bare PES membranes to 81.11% for hybrid membranes. Additionally, the effects of various salt types on the membrane's separation performance were investigated. The Fe3O4@APC@MIL-101(Cr) modified PES membranes demonstrate significant potential as effective candidates for treating wastewater contaminated with dye pollutants.

Bioinspired multi-functional modified PVDF membrane for efficient oil-water separation

The pervasive issue of oily wastewater presents a critical environmental challenge, necessitating the development of advanced membranes that offer high purification efficiency, durability, and versatility. In this study, we introduce a novel bioinspired multifunctional membrane, synthesized by modifying polyvinylidene fluoride (PVDF) with fibrous two-dimensional carbides and nitrides (MXene) and silica (SiO2) nanoparticles, drawing inspiration from the complex structure of coral stones. The membrane was fabricated using the phase inversion technique, producing a robust material that achieves over 99% separation efficiency for oil–water mixtures. Beyond oil–water separation, the membrane exhibited exceptional performance in removing various contaminants from complex oily wastewater, including heavy metals, dyes, and phenol. Remarkably, the membrane maintained its high purification efficiency even after 5 consecutive cycles of oil–water separation and pollutant adsorption. This bioinspired multifunctional modified PVDF (MMP) membrane represents a major advancement in wastewater treatment technology, with significant potential for widespread application in the purification of complex oily wastewater.

Transmission characteristics of vortex light superposition in atmospheric turbulence disturbed by plane acoustic waves

Herein, we derive the expression for the atmospheric refractive index structure constant under the influence of planar acoustic wave perturbations under the influence of the acoustic field on the refractive index and energy of the atmosphere. Utilizing the low-frequency compensated power spectrum inversion technique, we simulate the refractive index power spectrum of atmospheric turbulence perturbed by a planar acoustic wave. Numerical analysis is conducted on the transmission characteristics of the vortex light superposition states in atmospheric turbulence perturbed by a plane acoustic wave under different acoustic wave transmission heights, acoustic pressure amplitudes, and frequencies. Results indicate that introducing an acoustic field induces fluctuations in the atmospheric refractive index structure constant, with a more pronounced impact on the refractive index than on energy. Compared with the sole consideration of the impact of the acoustic field on the atmospheric refractive index, incorporating its effect on atmospheric energy results in a decrease in the atmospheric refractive index structure constant. The impact of the acoustic field on atmospheric turbulence is directly proportional to both acoustic pressure amplitude and frequency. The influence of the acoustic field on the transmission properties of the vortex optical superposition state varies with different acoustic transmission distances. Consequently, the transmission characteristics of the vortex light superposition state can be actively modulated according to varying acoustic wave transmission distances. This study offers a theoretical basis for modulating the optical field transmission characteristics via acoustic fields.

Isotopic and Geophysical Investigations of Groundwater in Laiyuan Basin, China.

Due to the complex intersection and control of multiple structural systems, the hydrogeological conditions of the Laiyuan Basin in China are complex. The depth of research on the relationship between geological structure and groundwater migration needs to be improved. The supply relationship of each aquifer is still uncertain. This paper systematically conducts research on the characteristics of hydrogen and oxygen isotopes, and combines magnetotelluric impedance tensor decomposition and two-dimensional fine inversion technology to carry out fine exploration of the strata and structures in the Laiyuan Basin, as well as comprehensive characteristics of groundwater migration and replenishment. The results indicate the following: (i) The hydrogen and oxygen values all fall near the local meteoric water line, indicating that precipitation is the main groundwater recharge source. (ii) The excess deuterium decreased gradually from karst mountain to basin, and karst water and pore water experienced different flow processes. (iii) The structure characteristics of three main runoff channels are described by MT fine processing and inversion techniques. Finally, it is concluded that limestone water moved from the recharge to the discharge area, mixed with the deep dolomite water along the fault under the control of fault F2, and eventually rose to the surface of the unconsolidated sediment blocked by fault F1 to emerge into an ascending spring.

Inverse design of polaritonic devices

Polaritons, arising from the strong coupling between excitons and photons within microcavities, hold promise for optoelectronic and all-optical devices. They have found applications in various domains, including low-threshold lasers and quantum information processing. To realize complex functionalities, non-intuitive designs for polaritonic devices are required. In this contribution, we use finite-difference time-domain simulations of the dissipative Gross–Pitaevskii equation, written in a differentiable manner, and combine it with an adjoint formulation. Such a method allows us to use topology optimization to engineer the potential landscape experienced by polariton condensates to tailor its characteristics on demand. The potential directly translates to a blueprint for a functional device, and various fabrication and optical control techniques can experimentally realize it. We inverse-design a selection of polaritonic devices, i.e., a structure that spatially shapes the polaritons into a flat-top distribution, a metalens that focuses a polariton, and a nonlinearly activated isolator. The functionalities are preserved when employing realistic fabrication constraints such as minimum feature size and discretization of the potential. Our results demonstrate the utility of inverse design techniques for polaritonic devices, providing a stepping stone toward future research in optimizing systems with complex light–matter interactions.