The quantum measurement incompatibility is a distinctive feature of quantum mechanics. We investigate the incompatibility of a set of general measurements and classify the incompatibility by the ...hierarchy of compatibilities of its subsets. By using the approach of adding noises to measurement operators, we present a complete classification of the incompatibility of a given measurement assemblage with
members. Detailed examples are given for the incompatibility of unbiased qubit measurements based on a semidefinite program.
Fifteen oil seepage and solid bitumen samples in the Southern Guizhou Depression were analyzed with GC-MS. Characteristics of molecular markers and carbon isotopes are discussed systemically. The ...results showed that the oil seepage and solid bitumen samples in the Southern Guizhou Depression could be divided into two families： Ordovician and Siluric samples, and Permian samples. The two families are different in alkanes distribution, biomarkers, aromatic hydrocarbon composition, and stable carbon isotopes; differences mainly caused by source rock variation.
Despite the recent significant progress reviewed in marine and continental shale gas reservoirs, there is no general investigation concerning marine–continental transitional shales, especially in the ...research of the pore structure and fractal characteristics of marine–continental shale reservoirs. In this study, the pore structure characteristics of 12 typical marine–continental transitional shale samples of the Upper Permian Longtan Formation collected from Southern Sichuan Basin were analyzed, combining techniques of total organic carbon (TOC) content determination, X-ray diffraction, field emission scanning electron microscopy, high-pressure mercury intrusion porosimetry, and low-pressure N2/CO2 adsorption. And the pore fractal characteristics of shales were also analyzed using the Frenkel–Halsey–Hill model with N2 adsorption data. Not only the effects of TOC content and mineralogical compositions for pore structure parameters and fractal dimensions were analyzed but also the relationships between pore structure parameters and fractal dimensions were discussed. The results showed that the macropores (>50 nm) mainly develop within or between clay minerals, while the micropores (<2 nm) and mesopores (2–50 nm) commonly develop within intraparticle pores and organic matter (OM) pores. Marine–continental Longtan shales develop with the characteristic of various pore types, complicated pore structure, and obvious heterogeneity, which mainly consist of silt-shaped pores and ink bottleneck pores. Micropores provide the dominant specific surface area (SSA), whereas meso- and macropores occupy the majority of the pore volume. Both uni- and multimodal pore-size distributions (PSDs) in shales were analyzed; the PSDs of macropores increase rapidly to above 5 μm or below 30 nm, but a flat trend is present within the range of 30 nm to 5 μm; the PSDs of mesopores develop with a peak around 4 nm; and the PSDs of micropores develop with a minor peak around 0.35–0.40 nm and two major peaks around 0.45–0.50 and 0.55–0.60 nm. Micropores and macropores were the most important storage space for shale gas, and the micropores play a pivotal role in shale gas adsorption by providing the dominated SSAs. Two fractal dimensions (D 1, 2.523–2.696; D 2, 2.754–2.886) are positively associated with the pore volumes and SSAs of shales, and the micropores are the dominant factor for controlling the pore structure heterogeneity. The small pores of marine–continental shales mainly consist of OM pores, which are considerably affected by TOC content; large pores are mainly produced in clay minerals. TOC content has a significant positive relationship not only with the pore volumes and special surface areas of micropores but also with the fractal dimensions; and the enrichment of the clay minerals will contribute to the production of macropores (including fractures) while the brittle ones play the reverse role.
One‐step direct conversion of biomass‐derived furfural to 2‐methyltetrahydrofuran was realized under atmospheric pressure over a dual solid catalyst based on two‐stage‐packed Cu–Pd in a reactor; this ...is the first report that one‐step conversion of furfural resulted in high yield of 2‐methyltetrahydrofuran (97.1 %) under atmospheric pressure. This strategy provided a successive hydrogenation process, which avoids high H2 pressure, uses the reactor efficiently, and eliminates the product‐separation step. Therefore, it could enhance the overall efficiency as a result of low cost and high yield.
Furfural in bed with two catalysts: One‐step conversion of biomass‐derived furfural to 2‐methyltetrahydrofuran (2‐MTHF) is realized over dual solid catalysts based on two‐stage‐packed Cu–Pd in a reactor. 2‐MTHF yield is as high as 97.1 % at atmospheric pressure and 180 °C, which is the highest value reported so far. This strategy provides a successive hydrogenation by avoiding high H2 pressure, using the reactor efficiently, and eliminating the product‐separation step.
•Pore types and morphology were investigated using FE-SEM.•The MIP and N2/CO2 GA are used for quantitative characterization of full size pores.•An interpretation model was built for quantitative ...analysis of shale pore-fracture.•Nanometer pores dominate in volume while OM pores are the major pore structure.•Correlation between matrix porosities and pore structure parameters are analyzed.
Although significant progress has been achieved in characterizing marine shale reservoirs, studies that are associated with marine-continental shale reservoirs, particularly quantitative characterizations of shale pore–fracture, remain rare. In this study, 12 black organic-rich marine-continental shale samples were collected from seven wells that were recently drilled in the Upper Permian Longtan Formation in the Southern Sichuan Basin of southern China. X-ray diffraction revealed that clay minerals are the most prevalent component of shale, followed by quartz and calcite. Various pore types were classified and morphologically characterized from images that were obtained with field emission scanning electron microscopy. Shale total porosity, which was measured via mercury injection porosimetry, was between 3.1% and 7.5%. In addition, a pore-fracture interpretation model was built to calculate fractures and matrix porosity, including organic matter porosity, interparticle porosity of brittle minerals, and intraparticle porosity of clay minerals. The model was highly consistent with the measured porosity. Three key parameters were obtained to characterize the development of different types of matrix pores (VTOC>VBri>VClay). Low-pressure N2 and CO2 gas adsorption experiments were conducted to analyze pore volume, special surface area (SSA), and pore-size diameter. The results of the analyses revealed that micropores and macropores (including micro-fractures) are the dominant pores of the Longtan shale reservoir and that micropores provide the dominant shale gas adsorption space. Furthermore, the effects of shale components on pore development, as well as the correlation among different pore structural parameters, were discussed. The results showed that the enrichment of total organic carbon and clay mineral content will benefit the development of the Longtan shale pore–fracture system. Moreover, a good positive linear relationship existed among matrix porosity, pore volume, SSA, average pore diameter, and surface porosity.
Abstract
Establishing quantum correlations between two remote parties by sending an information carrier is an essential step of many protocols in quantum information processing. We obtain trade-off ...relations between discords and coherence within a bipartite system. Then we study the distribution of coherence in a bipartite quantum state by using the relations of relative entropy and mutual information. We show that the increase of the relative entropy of discord between two remote parties is bounded by the nonclassical correlations quantified by the relative entropy of coherence between the carrier and two remote parties, providing an optimal protocol for discord distribution and showing that quantum correlations are the essential resource for such tasks.
Data was acquired from both the drillings and core samples of the Lower Paleozoic Qiongzhusi and Longmaxi Formations' marine shale gas reservoirs in the southern Sichuan Basin by means of numerous ...specific experimental methods such as organic geochemistry, organic petrology, and pore analyses. Findings helped determine the characteristics of organic matter, total porosity, microscopic pore, and pore structure. The results show that the Lower Paleozoic marine shale in the south of the Sichuan Basin are characterized by high total organic carbon content (most TOC>2.0%), high thermal maturity level (RO = 2.3%–3.8%), and low total porosity (1.16%–6.87%). The total organic carbon content and thermal maturity level of the Qiongzhusi Formation shale are higher than those of the Longmaxi Formation shale, while the total porosity of the Qiongzhusi Formation shale is lower than that of the Longmaxi Formation shale. There exists intergranular pore, dissolved pore, crystal particle pore, particle edge pore, and organic matter pore in the Lower Paleozoic Qiongzhusi Formation and Longmaxi Formation shale. There are more micro-nano pores developed in the Longmaxi Formation shales than those in the Qiongzhusi Formation shales. Intergranular pores, dissolved pores, as well as organic matter pores, are the most abundant, these are primary storage spaces for shale gas. The microscopic pores in the Lower Paleozoic shales are mainly composed of micropores, mesopores, and a small amount of macropores. The micropore and mesopore in the Qiongzhusi Formation shale account for 83.92% of the total pore volume. The micropore and mesopore in the Longmaxi Formation shale accounts for 78.17% of the total pore volume. Thus, the micropores and mesopores are the chief components of microscopic pores in the Lower Paleozoic shale gas reservoirs in the southern Sichuan Basin.
The characterization of the pore structure and shale gas content provides useful information for shale gas reservoir assessment and evaluation and guides the exploration and development of shale gas. ...Fresh core samples obtained from three different basin formations in China were analyzed by field-emission scanning electron microscopy, low-pressure CO2 and N2 gas adsorption–desorption, high-pressure mercury intrusion, and methane adsorption experiments to clarify the pore structure characteristics of coal-bearing shales and their effects on shale gas content. The inter- and intraparticle pores, organic matter pores, and microfractures were well developed in coal-bearing shales. These pores had different geneses, morphologies, and sizes with main diameters of <6.5 and 80–200 nm and the main shape of slit, taper, and ink bottle. Pores with diameters <10 nm dominated the shale pore networks. Shale gas content was directly influenced by shale pores, and small pores had a large surface area, which resulted in the high adsorption capacity of shale gas. Clay mineral and total organic carbon contents positively controlled the pore structures and shale gas adsorption, whereas brittle minerals were counterproductive. Coal-bearing shale gas content was lower than marine shale gas content, with an adsorption gas content percentage of 50–85%. The proportion of adsorbed gas decreased with the increase of pore size diameters, whereas the proportion of free gas increased. When the pore size diameter reached approximately 3.5 nm, the free and adsorption gases reached dynamic balance. The adsorption gas content would be slightly low with pore size ranges of >6.5 nm, whereas the free gas content would be stable and merely increase in the range of 100–300 nm.
The pore-throat structure and gas–water seepage behavior are important factors affecting reservoir quality and development efficiency. Sixteen tight sandstone samples from the He 8 and Shan 1 ...Formations in the Dingbian area of the Ordos Basin were analyzed using casting thin section, scanning electron microscopy, high-pressure mercury injection, and displacement experiments, integrated with the nuclear magnetic resonance technique, to clarify the pore-throat structure characteristics and their influence on the mobility of reservoir fluids. The results revealed four characteristic pore-throat structure combinations: large interparticle pore dominated pore-throat (LIPT), small interparticle and dissolution pore dominated pore-throat (SIPT), intercrystalline pore dominated pore-throat (IAPT), and nanopore dominated pore-throat (NPT). Among these, IAPT and SIPT are identified as the main spaces of movable fluids, and the number of IAPT and SIPT determines the seepage capacity of the tight sandstone. The best fluidity was observed in coarse-moderate sandstones in the riverine sedimentary phase with high IAPT and SIPT, while the worst fluidity was observed in siltstones in the NPT-dominated interfluvial bay phase. Linear correlation and gray relational analysis were used to examine the quantitative effects of nine factors on the flow of movable fluids with different pore-throat combinations. Among these factors, the average pore-throat radius exhibited the highest gray relational and weighting coefficient with movable fluid saturation, with values of 0.81 and 0.12, respectively, followed by the median radius and maximum mercury injection saturation. In general, the average pore-throat radius size and connectivity are key factors influencing the seepage behavior. Based on these findings, seepage patterns of movable fluids with four different pore-throat combinations were established in the context of the depositional environment. This can help in better evaluating the heterogeneity of tight sandstones and guide the exploration and development of tight oil and gas in shallow braided river delta front sedimentary environments.
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•Nest-like copper phyllosilicate (CuSi-N) precursor was fabricated through P123-assisted hydrothermal crystallization.•The reduced CuSi-N exhibits excellent catalytic performance ...toward gas hydrodeoxidation of furfural to 2-methylfuran.•Cu+ serves as the adsorption center of CO bond in furfural and CO bond in furfuryl alcohol intermediate.•The synergistic catalysis of Cu0-Cu+ dual sites plays a vital role in determining the catalytic behavior.
Furfural hydrodeoxygenation (HDO) to 2-methylfuran (2-MF) is one of the most momentous routes in upgrading of biomass platform molecules, where the most universally employed active metal—Cu often suffers from thermal sintering and poor stability in spite of its brilliant effect on the activation of carbonyl. In this study, we designed a highly active and stable Cu/SiO2 nanocatalyst by fabricating nest-like nanotubes (CuSi-N) through a two-step method: preparation of amorphous copper phyllosilicate through ammonia evaporation, followed by a further hydrothermal crystallization with the assistance of P123. Notably, the CuSi-N catalyst gives a 2-MF space–time yield of 46.6 mmol·gcat−1·h−1, which is much larger than CuSi-A prepared by the conventional ammonia-evaporation method. A combination study (Raman spectra, TEM, H2-TPR, XPS, CO-DRIFTS and NH3-TPD) verifies that the nest-like precursor enhances the CuOx-SiO2 interaction, which results in a promoted Cu+ abundance as well as thermal stability of the active sites. In situ FTIR spectra of adsorbed molecules, coupled with density functional theory calculations, prove that Cu+ sites are responsible for the adsorption and activation of both furfural (FAL) and intermediate furfuryl alcohol (FOL) while Cu0 sites account for H2 dissociation. This work discloses the significance of the synergy effect of Cu0-Cu+ dual sites of Cu/SiO2 catalysts which could be employed for the other HDO reactions in the upgrading process of biomass.
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