mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Research on the falling film flow and heat transfer characteristics of FLNG spiral wound heat exchanger under sea conditions

As the key equipment of floating liquefied natural gas(FLNG) process, the performance of spiral wound heat exchanger(SWHE) influences operation costs and reliability of the whole system. The sea conditions destroy the falling film flow state of the refrigeration and then affect the heat transfer performance of FLNG SWHE. In order to design and optimize the SWHE, a cryogenic experimental device of FLNG process and a numerical model of falling film flow have been constructed to study the effects of sea conditions on the falling film flow and heat transfer characteristics of SWHE. The cryogenic experimental results show that the pitching conditions have larger effects on the heat transfer performance than yawing. Under the pitching angle of 7°, the natural gas temperature and gaseous refrigerant temperature increase by 3.22 °C and 7.42 °C, respectively. The flow rates of refrigerant and feed natural gas have a great impact on the heat transfer performance of SWHE under pitching and compound sloshing conditions. When the tilt angle increases to 9°, the tube structure with outer diameter D = 8 mm and pipe spacing S = 4 mm is recommended to reduce the drying area of the pipe wall surface.
Relative permeability estimation of oil-water two-phase flow in shale reservoir

Oil-water two-phase flow is ubiquitous in shale strata due to the existence of connate water and the injection of fracturing fluid. In this work, we propose a relative permeability model based on a modified Hagen-Poiseuille(HP) equation and shale reconstruction algorithm. The proposed model can consider the nanoconfined effects(slip length and spatially varying viscosity), oil-water distribution, pore size distribution(PSD), total organic matter content(TOC), and micro-fracture. The results show that the increasing contact angles of organic matters(OM) and inorganic minerals(iOM) increase the relative permeability of both oil and water. As the viscosity ratio increases, the relative permeability of oil phase increases while that of water phase decreases, due to the different water-oil distribution. The effective permeability of both oil and water decreases with the increasing TOC. However, the relative permeability of water phase increases while that of oil phase decreases. The increasing number and decreasing deviation angle of micro-fracture increase the effective permeability of oil and water. However, microfracture has a minor effect on relative permeability. Our model can help understand oil-water twophase flow in shale reservoirs and provide parameter characterization for reservoir numerical simulation.
Permeability and heterogeneity adaptability of surfactant-alternatinggas foam for recovering oil from low-permeability reservoirs

As the traditional polymer stabilizer is eliminated to improve the injectability of foam in lowpermeability reservoirs, the stability, plugging capacity, conformance control and oil recovery performance of the surfactant-alternating-gas(SAG) foam become significantly important for determining its adaptability to permeability and heterogeneity, which were focused and experimentally researched in this paper. Results show that the SAG bubbles are highly stable in micron-sized channels and porous media(than in the conventional unconstrained graduated cylinder), making it possible to use in enhanced oil recovery(EOR). Such bubbles formed in porous media could be passively adjusted to match their diameter with the size of the pore. This endows the SAG foam with underlying excellent injectability and deep migration capacity. Permeability adaptability results indicate a reduced plugging capacity, but, increased incremental oil recovery by the SAG foam with decreased permeability. This makes it a good candidate for EOR over a wide range of permeability, however, parallel core floods demonstrate that there is a limiting heterogeneity for SAG application, which is determined to be a permeability contrast of 12.0(for a reservoir containing oil of 9.9 mPa s). Beyond this limit, the foam would become ineffective.
A novel hybrid thermodynamic model for pore size distribution characterisation for shale

Scholars often see the gas adsorption technique as a straight-to-interpret technique and adopt the pore size distribution(PSD) given by the gas adsorption technique directly to interpret pore-structure-related issues. The oversimplification of interpreting shale PSD based on monogeometric thermodynamic models leads to apparent bias to the realistic pore network. This work aims at establishing a novel thermodynamic model for shale PSD interpretation. We simplified the pore space into two geometric types-cylinder-shaped and slit-shaped. Firstly, Low-temperature Nitrogen Adsorption data were analyzed utilizing two monogeometric models(cylindrical and slit) to generate PSD_(cyl). and PSD_(slit); Secondly, pore geometric segmentation was carried out using Watershed by flooding on typical SEM images to obtain the ratio of slit-shaped(∅_s) and cylinder-shaped pores(∅_c). Combining the results of the two, we proposed a novel hybrid model. We performed pyrolysis, XRD, FE-SEM observation, quantitative comparison with the results obtained by the DFT model, and fractal analysis to discuss the validity of the obtained PSD_(Hybrid). The results showed that: the hybrid model proposed in this work could better reflect the real geometry of pore space and provide a more realistic PSD; compared with thermodynamic monogeometric models, PSD obtained from the hybrid model are closer to that from the DFT model, with an improvement in the deviation from the DFT model from 5.06% to 68.88%. The proposed hybrid model has essential application prospects for better interpretation of shale pore space. It is also worth noting that we suggest applying the proposed hybrid model for PSD analysis in the range of 5 -100 nm.
Diesel molecular composition and blending modeling based on SUBEM framework

Diesel molecular compositional model has important application for diesel quality prediction, blending, and molecular-level process model development. In this paper, different types of diesel molecular compositional and blending models were constructed based on the SU-BEM framework. More than 1500 representative molecules were selected to form the molecular structure library. The probability density functions(PDFs) combination was determined by experimental data and experience. A quadratic optimization strategy combining genetic algorithm with local optimization algorithm was adopted to improve the accuracy of the compositional model. The model results show good agreement with the experimental data. The diesel blending model was constructed at the molecular-level based on the above diesel compositional models. The properties of the blending model accord with the experimental regulations. It is proved that the compositional models and blending model constructed have high accuracy and strong prediction capability, and are applicable to the industrial process.
Construction of complex digital rock physics based on full convolution network

Digital rock physics(DRP) is a paramount technology to improve the economic benefits of oil and gas fields, devise more scientific oil and gas field development plans, and create digital oil and gas fields. Currently, a significant gap is present between DRP theory and practical applications. Conventional digital-core construction focuses only on simple cores, and the recognition and segmentation effect of fractures and pores of complex cores is poor. The identification of rock minerals is inaccurate, which leads to the difference between the digital and actual cores. To promote the application of DRP in developing oil and gas fields, based on the high-precision X-ray computed tomography scanning technology, the U-Net deep learning model of the full convolution neural network is used to segment the pores, fractures, and matrix from the complex rock core with natural fractures innovatively. Simultaneously, the distribution of rock minerals is divided, and the distribution of rock conditions is corrected by X-ray diffraction. A pore-fracture network model is established based on the equivalent radius, which lays the foundation for fluid seepage simulation. Finally, the accuracy of the established a digital core is verified by the porosity measured via nuclear magnetic resonance technology, which is of great significance to the development and application of DRP in oil and gas fields.
Comments on "Acupoint Catgut Embedding Alleviates Insomnia in Different Chinese Medicine Syndrome Types: A Randomized Controlled Trial"

We recently read the paper entitled "Acupoint catgut embedding alleviates insomnia in different Chinese medicine syndrome types: a randomized controlled trial" by XU, et al. The article elaborated on the effect and safety evaluation of acupoint catgut embedding for different Chinese medicine (CM) syndrome types of insomnia. As a randomized controlled trial article, it has rigorous design, clear inclusion and exclusion criteria, reasonable grouping, and sufficient sample size. By comparing the 3 methods of treating insomnia, it concluded that the acupoint catgut embedding had better curative effect. We admire their huge workload and explicit trial conclusions.
Evolution of gas kick and overflow in wellbore and formation pressure inversion method under the condition of failure in well shut-in during a blowout

With ongoing development of oil exploration and techniques, there is a significant need for improved well control strategies and formation pressure prediction methods. In this paper, a gas-liquid transient drift flow model was established according to the gas-liquid two-phase flow characteristics during the gas kick. A Roe scheme was used for numerical calculation based on the finite volume method. The changes of bottom-hole pressure, casing pressure, the development law of cross-sectional gas holdup, and gas velocity, along with the vertical well depth, were analyzed through simulation examples. The time-series characteristics of mud pit gain were obtained by adjusting the formation parameter. The complex nonlinear mapping relationship between the formation parameters and the mud pit gain was established. The long short-term memory network(LSTM) of deep learning was used to obtain a formation pressure inversion when the blowout is out of control and the well cannot be shut-in. Experimental data from a well were used to verify the gas-liquid two-phase transient drift flow model based on the finite volume method, demonstrating that this method is reliable, with greatly improved prediction accuracy. This approach provides theoretical support for the early monitoring of gas kick during drilling, and for well-killing design and construction after uncontrolled blowout.
Porosity of gas shale: Is the NMR-based measurement reliable?

Aiming at obtaining an accurate porosity of gas shale, various approaches are attempted. Therein, nuclear magnetic resonance(NMR), being treated as a kind of new-developed technique, possesses the representative significance. However, as a booming technique, the reliability of NMR-based porosity of shale is not exactly defined. Depending on NMR device, this work measured the porosity of shale experiencing different water soaking time, accordingly, judging the reliability of NMR-based porosity. Results indicate the NMR outcomes vary with the water soaking time, making a doubt about the objectivity of NMRbased porosity in reflecting the real shale porosity. Furthermore, some supplementary means were adopted to verify the water soaking-induced variation in the pore system of shale sample, which intensities the suspicion if the NMR-based porosity is reliable or not. To sum up, this work considers that the NMR-based porosity of shale is not reliable enough when water is used as the probe. Besides, this work also offers some suggestions on how to enhance the reliability of NMR-based porosity of shale sample. Basically, this work selects a fresh perspective to analyze the NMR approach in determining shale porosity, which is hopefully helpful in promoting the development of NMR technique in the shale-related field.
Pore structure evolution of lacustrine organic-rich shale from the second member of the Kongdian formation in the Cangdong Sag, Bohai Bay Basin, China

Pyrolysis experiments were conducted on lacustrine organic-rich shale from Cangdong Sag in Bohai Bay Basin, China, to investigate the impact of hydrocarbon generation on shale pore structure evolution. Thermal evolution is found to control the transformation of organic matter, hydrocarbon products characteristics, and pore structure changes. Furthermore, pore volume and specific surface area increase with increasing maturity. In low-mature stage, the retained oil content begins to increase, pore volumes show slight changes, and primary pores are occluded by the generated crude oil of high molecular weight and density. In the oil-window stage, the retained oil content rapidly increases and reaches maximum, and pore volumes gradually increase with increasing thermal maturity. At high mature stage, the retained oil content begins to decrease, and the pore volume increases considerably owing to the expulsion of liquid hydrocarbon. In over mature stage, natural gas content significantly increases and kerogen transforms to asphalt. Numerous organic pores are formed and the pore size gradually increases, resulting from the connection of organic pores caused the increasing thermal stress. This study lays a foundation for understanding variation of hydrocarbon products during the thermal evolution of lacustrine shales and its relationship with the evolution of shale reservoirs.
High Order Mixed Finite Elements with Mass Lumping for Elasticity on Triangular Grids

A family of conforming mixed finite elements with mass lumping on triangular grids are presented for linear elasticity. The stress field is approximated by symmetric H(div) - P_k (k ≥ 3) polynomial tensors enriched with higher order bubbles so as to allow mass lumping, and the displacement field is approximated by C~(-1) - P_(k-1) polynomial vectors enriched with higher order terms. For both the proposed mixed elements and their mass lumping schemes, optimal error estimates are derived for the stress and displacement in H(div) norm and L~2 norm, respectively. Numerical results confirm the theoretical analysis.
Comparison of sampling designs for calibrating digital soil maps at multiple depths

Digital soil mapping (DSM) aims to produce detailed maps of soil properties or soil classes to improve agricultural management and soil quality assessment. Optimized sampling design can reduce the substantial costs and efforts associated with sampling, profile description, and laboratory analysis. The purpose of this study was to compare common sampling designs for DSM, including grid sampling (GS), grid random sampling (GRS), stratified random sampling (StRS), and conditioned Latin hypercube sampling (cLHS). In an agricultural field (11 ha) in Quebec, Canada, a total of unique 118 locations were selected using each of the four sampling designs (45 locations each), and additional 30 sample locations were selected as an independent testing dataset (evaluation dataset). Soil visible near-infrared (Vis-NIR) spectra were collected in situ at the 148 locations (1 m depth), and soil cores were collected from a subset of 32 locations and subdivided at 10-cm depth intervals, totaling 251 samples. The Cubist model was used to elucidate the relationship between Vis-NIR spectra and soil properties (soil organic matter (SOM) and clay), which was then used to predict the soil properties at all 148 sample locations. Digital maps of soil properties at multiple depths for the entire field (148 sample locations) were prepared using a quantile random forest model to obtain complete model maps (CM-maps). Soil properties were also mapped using the samples from each of the 45 locations for each sampling design to obtain sampling design maps (SD-maps). The SD-maps were evaluated using the independent testing dataset (30 sample locations), and the spatial distribution and model uncertainty of each SD-map were compared with those of the corresponding CM-map. The spatial and feature space coverage were compared across the four sampling designs. The results showed that GS resulted in the most even spatial coverage, cLHS resulted in the best coverage of the feature space, and GS and cLHS resulted in similar prediction accuracies and spatial distributions of soil properties. The SOM content was underestimated using GRS, with large errors at 0-50 cm depth, due to some values not being captured by this sampling design, whereas larger errors for the deeper soil layers were produced using StRS. Predictions of SOM and clay contents had higher accuracy for topsoil (0-30 cm) than for deep subsoil (60-100 cm). It was concluded that the soil sampling designs with either good spatial coverage or feature space coverage can provide good accuracy in 3D DSM, but their performances may be different for different soil properties.
Dual-metal zeolite imidazolate framework for efficient lithium storage boosted by synergistic effects and self-assembly 2D nanosheets

Metal-organic framework materials (MOFs), such as zeolitic imidazolate framework (ZIF), have been widely used in energy storage due to their advantages such as high structural stability, large specific surface, more active sites and skeleton structures. Herein, a novel two-dimensional (2D) CoCu-ZIF was synthesized by a facile solvothermal method. The as-prepared CoCu-ZIF nanosheets exhibit an ultrahigh reversible capacity of 2287.4 mAh/g and remains at 1172.1 mAh/g after 300 cycles at a current density of 100 mA/g, far better than that of the single Co-ZIF and Cu-ZIF. Additionally, the specific discharge capacity of CoCu-ZIF nanosheets can maintain at about 590 mAh/g after 10 0 0 cycles at the current density of 2 A/g. Owing to the synergistic effect of two metals, function of nitrogen in the molecular and selfassembly 2D nanosheets, our research can provide strong support for the practical application of CoCu-ZIF materials in lithium ion batteries.
Opportunities and challenges of high-pressure ion exchange chromatography for nuclide separation and enrichment

With the rapid development of the nuclear industry, more-stringent requirements are proposed for highlevel radioactive waste liquid treatment and the enrichment of isotope products. High-pressure ion exchange chromatography has been widely accepted for the fine separation of elements and nuclides due to its advantages, such as high efficiency, environmental friendliness, ease of operation, and feasibility for large-scale industrial applications. Here, we summarized the evolution of high-pressure ion exchange chromatography and the relevant research progress in ion exchange equilibrium and related separation technology. The prospects for application of high-pressure ion exchange chromatography to rare earth elements, actinide elements and isotope separation were discussed. High-pressure ion exchange chromatography represents a promising strategy for the extraction of rare earth elements and actinide elements from high-level radioactive waste liquid, as well as being an effective method for the automated production of high purity isotope products with great environmental benefits.
Enhancing the process of CO_2 reduction reaction by using CTAB to construct contact ion pair in Li-CO_2 battery

Aprotic Li-CO_2 batteries have attracted growing interest due to their high theoretical energy density and its ability to use green house gas CO_2 for energy storage. However, the poor ability of activating CO_2 in organic electrolyte often leads to the premature termination of CO_2 reduction reaction (CO_2 RR) directly. Here in this work, cetyl trimethyl ammonium bromide (CTAB) was introduced into a dimethyl sulfoxide (DMSO) based Li-CO_2 battery for the first time to enhance the CO_2 RR. Significantly improved electrochemical performances, including reduced discharge over-potential and increased discharge capacity, can be achieved with the addition of CTAB. Ab initio molecular dynamics (AIMD) simulations show that quaternary ammonium group CTA~+ can accelerate CO_2 reduction process by forming more stable contact ion pair (CIP) with CO_2-, reducing the energy barrier for CO_2 RR, thus improving the CO_2 reduction process. In addition, adding CTA + is also favorable for the solution-phase growth of discharge products because of the improved migration ability of stable CTA~+ -CO_2-CIP in the electrolyte, which is beneficial for improving the utilization ratio of cathode. This work could facilitate the development of CO_2 RR by providing a novel understanding of CO_2 RR mechanism in organic system.
An alternative method to reduce process-induced deformation of CFRP by introducing prestresses

Process-induced deformation is an important limiting factor to the application of high performance composite structures. An alternative method to reduce process-induced deformation is proposed by introducing prestress to a single layer or part of the layers instead of all the applicable layers. In this method, the necessary prestress level that applied to the single layer was in the reasonable range. Two kinds of unsymmetric laminates are manufactured at varying prestress levels. The experimental results described that the curing deformation is changed rapidly with the growing prestress level and flipped after a certain prestress level. Moreover, there is a good linear relationship between prestress level and final curing deformation, which gives a convenient way to calculate the prestress level that can fully counteract the curing deformation. The numerical model to predict the curing deformation was built. A good agreement between the numerical and the experimental results shows the effectiveness of the numerical model. To predict the prestress level that can fully counteract the curing deformation, an analytical model is also proposed. Theoretically, the prestress method can fully counteract the curing deformation of the specimens, while the experimental results show that the prestressing layer reduces more than 80% of the curing deformation.
How do inundation provoke the release of phosphorus in soil-originated sediment due to nitrogen reduction after reclaiming lake from polder

Different N and P fractions in microcosm incubation experiment was measured using highresolution in-situ Peeper and DGT techniques combining with sequential extraction procedure. The results showed the synchronous desorption and release of PO_4~(3-), S~(2-) and Fe~(2+) from the solid soil-originated sediment. This trend indicated that the significant reduction of Fe-P and SO_4~(2-)occurred in the pore water during the inundation. The concentrations of PO_4~(3-)in the overlying water and pore water increased to more than 0.1 and 0.2 mg/L at the beginning of the incubation experiment. Decreased NO_3 concentrations from more than 1.5 mg/L to less than 0.5 mg/L combining with increasing NH_4~+ concentrations from less than 1 mg/L to more than 5 mg/L suggested the remarkable NO_3 reduction via dissimilatory nitrate reduction to ammonia (DNRA) pathway over time. High NH_4~+ concentrations in the pore water aggravated the release of Fe~(2+) through reduction of Fe(III)-P as electric acceptors under anaerobic conditions. This process further stimulated the remarkable releasing of labile PO_4~(3-) from the solid phase to the solution and potential diffusion into overlying water. Additionally, high S~(2-)concentration at deeper layer indicated the reduction and releasing of S~(2-) from oxidation states, which can stimulated the NO_3 reduction and the accumulation of NH_4~+ in the pore water. This process can also provoke the reduction of Fe-P as electric acceptors following the release of labile PO_4~(3-)into pore water. Generally, inundation potentially facilitate the desorption of labile P and attention should be paid during the reclaiming lake from polder.