A B S T R A C TIt is known that the time-domain induced-polarization decay curve for a shaly sand reservoir depends on the pore structure of the reservoir, and this curve can be used to estimate permeability, which is a determining factor in making production decisions in the petroleum industry. Compared with NMR logging tools, induced polarization has several advantages, such as a deep depth of investigation and a high signal-to-noise ratio. The purpose of this paper is to establish an appropriate model using induced polarization to estimate the permeability. The curve can be modelled as a weighted superposition of exponential relaxations. The plot of weight versus the relaxation time constant is defined as the relaxation time spectrum.Induced-polarization decay-curve measurements were performed on 123 samples from the Daqing oilfield using a four-electrode technique. A singular-value decomposition method was used to transform the induced-polarization decay data into a spectrum. Different models to estimate the permeability were discussed. The results of the research indicate that the induced-polarization measurements greatly improve the statistical significance of permeability correlations. Compared with the traditional forms, Aφ C and AF C , the forms, AT B φ C and AT B F C , have lower error factors, where T, and F are the geometric mean time constant of the induced-polarization relaxation time spectrum, the porosity and the resistivity formation factor, respectively, and A, B and C are constants. The mean time constant is the decisive parameter in the permeability estimation and it is not completely independent of the resistivity formation factor. The additional use of the porosity and the resistivity formation factor leads to an appreciable improvement. It is concluded that this new model will make it possible to estimate the permeability of a shaly sand reservoir downhole.

An appropriate form of induced polarization (IP) acts as a bridge between the structure of a water-saturated core plug and its transport properties. The induced-polarization decay curves of natural rocks can be modeled as a weighted superposition of exponential relaxations. A singular-value decomposition method makes it possible to transform the induced-polarization decay data of the shaley sands into relaxation-time spectrum, defined as plot of weight versus the relaxation-time constant. We measured the induced-polarization decay curves of core samples from a formation of Daqing oil field using a four-electrode method. The decay curves were transformed to relaxation-time spectra that were used to estimate the capillary-pressure curves, the pore-size distribution, and the permeability of the shaley sands. The results show that salinity ranges from [Formula: see text] have little effect on the IP relaxation-time spectra. A pseudocapillary pressure curve can be derived from the IP relaxation-time spectrum by matching the pseudocapillary curve with that from HgAir. The best-matching coefficients of the studied cores change slightly for the samples. Defined as the value of pressure at which the injected mercury saturation is 5%, entry pressures of the cores can be estimated well from IP-derived capillary-pressure curves. Pore-size distributions generated from induced polarization and mercury capillary-pressure curves are comparable. Permeability can be predicted from IP measurements in the form of [Formula: see text], where [Formula: see text] is the estimated permeability from IP relaxation spectrum in millidarcies (md), [Formula: see text] is the porosity in percentage, and [Formula: see text] is average time constant of IP relaxation-time spectra in millis (ms). The constants and exponents from various rock formations are slightly different.

Scintillators are widely used for nondestructive testing, nuclear medicine imaging, space exploration and security inspection. Recently, lead halide perovskite scintillation crystals have been brought into focus due to their effective atomic number, fast scintillation decay time, strong luminous efficiency, and tunable band gap. However, their application is limited by lead toxicity. Here we report that Cedoping can increase sensitivity in lead-free double perovskite crystals (Cs 2 NaTbCl 6 ) for X-ray detection and imaging. The introduction of Ce ions as sensitizer can be used to improve the radioluminescence of the crystals. The light output of Ce : Cs 2 NaTbCl 6 crystals is about 52153 ph/MeV, which is 25 % higher than that of un-doped crystal. The X-ray sensitivity is significantly enhanced. Based on our scintillation film X-ray detector the detection limit is 30 nGy • s À 1 , which is about 1/183 of the typical medical imaging dose. Our scintillating film has excellent imaging ability with spatial resolution of up to 10 lp/mm. This research shows that Ce : Cs 2 NaTbCl 6 perovskite crystal scintillators are promising materials for X-ray imaging application.

Background: Lung adenocarcinoma (LUAD), the most common subtype of non-small cell lung cancer (NSCLC), is associated with poor prognosis. However, current stage-based clinical methods are insufficient for survival prediction and decision-making. This study aimed to establish a novel model for evaluating the risk of LUAD based on hypoxia, immunity, and epithelial-mesenchymal transition (EMT) gene signatures.Methods: In this study, we used data from TCGA-LUAD for the training cohort and GSE68465 and GSE72094 for the validation cohorts. Immunotherapy datasets GSE135222, GSE126044, and IMvigor210 were obtained from a previous study. Using bioinformatic and machine algorithms, we established a risk model based on hypoxia, immune, and EMT gene signatures, which was then used to divide patients into the high and low risk groups. We analyzed differences in enriched pathways between the two groups, following which we investigated whether the risk score was correlated with stemness scores, genes related to m6A, m5C, m1A and m7G modification, the immune microenvironment, immunotherapy response, and multiple anti-cancer drug sensitivity.Results: Overall survival differed significantly between the high-risk and low-risk groups (HR = 4.26). The AUCs for predicting 1-, 3-, and 5-year survival were 0.763, 0.766, and 0.728, respectively. In the GSE68465 dataset, the HR was 2.03, while the AUCs for predicting 1-, 3-, and 5-year survival were 0.69, 0.651, and 0.618, respectively. The corresponding values in the GSE72094 dataset were an HR of 2.36 and AUCs of 0.653, 0.662, and 0.749, respectively. The risk score model could independently predict OS in patients with LUAD, and highly correlated with stemness scores and numerous m6A, m5C, m1A and m7G modification-related genes. Furthermore, the risk model was significantly correlated with multiple immune microenvironment characteristics. In the GSE135222 dataset, the HR was 4.26 and the AUC was 0.702. Evaluation of the GSE126044 and IMvigor210 cohorts indicated that PD-1/PD-LI inhibitor treatment may be indicated in patients with low risk scores, while anti-cancer therapy with various drugs may be indicated in patients with high risk scores.Conclusion: Our novel risk model developed based on hypoxia, immune, and EMT gene signatures can aid in predicting clinical prognosis and guiding treatment in patients with LUAD.

: Cane molasses is one of the main by-products of sugar refineries, which is rich in sucrose. In this work, low-cost cane molasses was introduced as an alternative substrate for isomaltulose production. Using the engineered Yarrowia lipolytica, the isomaltulose production reached the highest (102.6 g L−1) at flask level with pretreated cane molasses of 350 g L−1 and corn steep liquor of 1.0 g L−1. During fed-batch fermentation, the maximal isomaltulose concentration (161.2 g L−1) was achieved with 0.96 g g−1 yield within 80 h. Simultaneously, monosaccharides were completely depleted, harvesting the high isomaltulose purity (97.4%) and high lipid level (12.2 g L−1). Additionally, the lipids comprised of 94.29% C16 and C18 fatty acids, were proved suitable for biodiesel production. Therefore, the bioprocess employed using cane molasses in this study was low-cost and eco-friendly for high-purity isomaltulose production, coupling with valuable lipids.