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Purposes The bimetallic modified Y zeolite is of great importance for the deep removal of thiophene in coking benzene. The influence of metal ion-exchange sequence on the desulfurization performance of zeolite is crucial. Methods A series of bimetallic modified sorbents were prepared by ion-exchange with Cu and Ce. The desulfurization performance of sorbents in thiophene-benzene solutions was evaluated by static adsorption experiments. The physical and chemical properties of sorbents were analyzed by XRD, Py-FTIR, XPS, H2-TPR, and N2 adsorption and desorption techniques. Findings The results show that metal ion-exchange sequence affects the relative crystallinity, ion-exchange degree, metal content, and L acid amount of sorbent. The correlations between the physical, chemical properties and the desulfurization performance of sorbent indicate that the higher the ion-exchange degree, the higher the desulfurization efficiency of sorbent. Meanwhile, the more Cu＋ and Ce4＋ in the sorbent, the more L acid sites formed and the higher its desulfurization efficiency. When Y zeolite is exchanged by Ce first and then Cu, the metal Ce affects the location of Cu and improves reduction performance of Cu. The desulfurization efficiency order of sorbents is CuCeY>CeCuY>Cu-CeY. The desulfurization efficiency of CuCeY is the highest, reaching 97.3%, and its relative crystallinity is the highest and ion-exchange degree is the largest. This work serves as a guide for the preparation of high efficiency desulfurization sorbents.

Cu6Sn5-xAg alloys (x = 0, 3, 6; %, mass fraction) were synthesized using Ag as a dopant through a high-temperature melting technique. The microstructure of the alloy was analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and other equipment, while the hardness of the alloy was measured to investigate the impact of Ag addition on the structure and microstructure of the Cu6Sn5 intermetallic compound. This study explored the influence of varying Ag contents on the properties of Cu6Sn5 intermetallic compounds, with calculations based on first principles revealing the mechanical properties and density of states of η′-Cu6Sn5 and its Ag-doped systems. The results indicated that Cu6Sn5-xAg alloys predominantly existed in three distinct forms, all exhibiting large masses without any impurities or precipitates. First-principle calculations demonstrated that Ag substitution in certain sites suppressed the anisotropy of the Young's modulus of Cu6Sn5, particularly in the Cu1, Cu3, Sn1, and Sn3 positions, while the effect was less significant at the Cu2, Cu4, and Sn2 sites. The introduction of Ag through doping enhanced the covalent bonding within the η′-Cu6Sn5 structure, promoting the formation of a stable (Cu, Ag)6Sn5 structure. [ABSTRACT FROM AUTHOR]

Previous studies have found that ionic surfactant micelles can induce depletion forces between oil droplets, whereas the depletion forces induced by nonionic surfactant micelles cannot be measured. Nonionic surfactants are usually mixed with ionic surfactants to induce depletion forces. Here, we report that mixing of nonionic polymer micelles and inorganic salt is also an effective method for inducing depletion between oil droplets. Optical tweezers are used to measure the interaction forces between oil droplets in the aqueous solution of polyoxyethylene–polyoxypropylene–polyoxyethylene nonionic polymer. Without salts, there is no depletion force between oil droplets regardless of whether the concentration of polymer is above or below the critical micelle concentration (CMC). This result is consistent with literature that the oil drops adsorbed by the nonionic polymers were stable against coalescence. However, the depletion force between oil droplets generates when NaCl is added, and the concentration of Pluronic F127 is above or equal to the CMC. This suggests that salts can enhance the depletion force induced by nonionic polymer micelles. These findings have significant implications for the stability of emulsions in the food, oilfield, and medicine industries. [ABSTRACT FROM AUTHOR]

A new type of special machine tool for stripper sleeve was developed according to the stripper sleeve process of composite board. In order to ensure the reliability of the mainframe structure and the performance of the linear guide mechanism, the static structural analysis and modal analysis of the mainframe are carried out. The results show that the maximum stress of the supporting beam under the main frame is about 48.18 MPa, the maximum strain is 0.00023, and the maximum stress of the four-legged column is about 5.35 MPa, which is full of strength and stiffness design requirements. The end-cutting mechanism is installed on the beam through the installation plate. The deformation of the beam has a great influence on the operation accuracy of the linear guide mechanism and the cutting accuracy of the end-cutting mechanism. The maximum displacement in the X and Y directions of the installation plate is 0.014 mm, 0.030 mm and 0.197 mm, respectively, which meets the normal use requirements and cutting accuracy requirements of the linear guide mechanism. The first six natural frequencies of the mainframe are 2.963 – 47.137 Hz. In order to make the mainframe have good dynamic characteristics, avoid resonance and meet the end-cutting requirements of the composite board, the motor speed should be controlled between 300 – 493 r / min.

The ultra-deep removal of thiophene is essential for the conversion of coke oven gas to methane and metal modified Y zeolite has excellent thiophene adsorption capacity. The effects of temperature on chemisorption between metal modified Y zeolite and thiophene and the reductive gases in coke oven gas on the thiophene adsorption performance still remains ambiguous. To address the aforementioned aims, series of NaMY (M = Ce, Ni, Zn and Ag) were prepared via ion-exchanged with Na+ of NaY, and two comparable sets of thiophene adsorption evaluation were conducted in a fixed bed reactor: (1) NaY and NaMY were evaluated at different temperatures in simulated coke oven gas, and (2) NaCeY was evaluated in N2 and different reductive atmospheres. The results show that NaNiY, NaZnY and NaAgY could adsorb thiophene via π-complexation, however, NaCeY mainly through S-Ce bond. Π complexation becomes weak above 150 °C, and the strength of S-Ce bond varies little when the temperature rises to 250 °C. Compared with that of other sorbents, the breakthrough adsorption capacity for thiophene (Qb-thiophene) of NaAgY reaches the highest 144 mg/g at 100 °C, but decreases sharply when temperature rises to 200 °C. NaCeY has relatively low variation in Qb-thiophene from 100 °C to 200 °C. Moreover, Ce(IV) in NaCeY is more favorable for thiophene adsorption than Ce(III) in coke oven gas and the presence of H2 and CO would reduce the desulfurization activity of NaCeY. For the industrial utilization of thiophene ultra-deep removal, NaAgY has an excellent potential below 150 °C, while NaCeY with more Ce(IV) has a good prospect at 150–250 °C. [ABSTRACT FROM AUTHOR]

Cerebrovascular disease is increasing rapidly because of its high morbidity and high mortality, which is a serious threat to human health. For the early diagnosis and treatment of diseases, the CT vascular noise combined with high-resolution magnetic resonance angiography in acute cerebral apoplexy vascular disease is adopted. 150 patients with ischemic stroke were selected, which were admitted to the Department of Radiology, Huizhou Central People's Hospital, from January 2020 to December 2020. All patients accepted digital subtraction angiography (DSA), magnetic resonance angiography (MRA), and CT angiography (CTA) examination. Results. There were 76 cases of aneurysm in DSA examination, accounting for 46%; 69 cases with pulsating stenosis, accounting for 50.67%; and 5 cases of moyamoya disease, accounting for 3.33%. The number and proportion of cases of the above diseases in MRA examination were (75, 69, 71; 53.33%, 45.67%, 4%), and those in CTA examination were (71, 76, 3, 47.33%, 50.67%, 2%). Relative to the DSA gold standard, the sensitivity, specificity, and false positive rate of MRA were 81.51%, 95.19%, and 2.1, respectively, and those of CTA were 95.78%, 79.17%, and 11.0, respectively. The number of cases and accuracy of detection of cerebral aneurysms by MRA were (75, 96.57%), and those by CTA were (71, 91.2%), which was not statistically considerable, P > 0.05. For the number of cases and the detection accuracy of cerebrovascular malformations, MRA was (38, 92.68%) and CTA was (37, 90.24%), which was not statistically considerable, P > 0.05. Conclusion. The detection sensitivity and accuracy of MRA were better than those of CTA, while specific CTA was superior to MRA. The differences between the two detections were substantial (P < 0.05), while the sensitivity and false positive rate were not remarkably different (P > 0.05). Therefore, the combination of the two detections was of great significance to the diagnosis and treatment of stroke and other vascular diseases. [ABSTRACT FROM AUTHOR]

Polythiophene@Fe3O4 (PTh@Fe3O4) nanocomposites with different morphologies were prepared via in-situ oxidative polymerization by using Fe3O4 nanoparticles with spherical and flower-like morphologies, and thiophene as the feedstock. FTIR, TG, SEM, CV, GCD, and EIS were used to investigate the influence of the morphology of Fe3O4 nanoparticles on the structure and electrochemical performance of the PTh@Fe3O4 composites. The results show that Fe3O4 could significantly improve the electrical conductivity of PTh@Fe3O4 nanocomposites (up to 1.4 × 10−5 S/cm) which is obviously higher than the single PTh (1.2 × 10−8 S/cm). Moreover, PTh could inhibit the agglomeration of Fe3O4. Fe3O4 nanoparticles with spherical morphology (SA) would distribute more uniformly on the surface of PTh than the flower-like Fe3O4 (FA), so that the specific capacitance of PTh@SA nanocomposites (37.9 F/g) could be enhanced, which is about twice of PTh@FA nanocomposites (21.3 F/g). [ABSTRACT FROM AUTHOR]

The surface functional groups of lignite are thought to be the significant factor influencing the moisture re-adsorption behavior of dried coal. Several lignite samples with different surface functional groups were prepared by thermal treatment from 160 °C to 240 °C in N 2 and air. In situ FTIR and chemical titration methods were carried out to measure the functional groups of the raw coal and dried samples, and the results from these two methods were compared. FTIR spectra were deconvoluted to reveal the transformation of different functional groups, e.g. CH 3 , CH 2 , CH, anhydrides, esters, aldehydes, carboxylic acid, quinones, and ketones. The moisture re-adsorption behaviors of the heat-treated coals under relative humidity of 75% at 25 °C were measured, and the effect of functional groups on moisture re-adsorption property was investigated. The results showed that CH x functional groups decreased dramatically, especially in air, when heat-treating temperature was higher than 200 °C. For the CH, CH 2 , and CH 3 functional groups, their decomposition activation energies are 29.6, 44.2 and 19.3 kJ·mol−1, and their oxidation activation energies are 65.9, 36.1 and 36.5 kJ·mol−1, respectively. In air, when the heat-treating temperature raised to 240 °C, aromatic esters, aliphatic esters and anhydrides all sharply increased. The quinones were probably produced from the transformation of phenolic hydroxyl (Ar-OH) at 240 °C in air. Moreover, coal samples heat-treated in N 2 and air showed different equilibrium moisture capacity, which can be attributed to the different contents of hydrophilic groups. The contents of ketones, aldehydes, COOH and Ar-OH had a good linear relationship with equilibrium moisture capacity. The hydrophilic abilities of ketones, aldehydes, COOH and Ar-OH in lignite are higher than that of quinones, esters and anhydrides. Unlabelled Image • CH x decrease dramatically and oxygen-containing functional groups increase obviously in air than that in N 2. • The order of decomposition E a is CH 2 > CH > CH 3 , and oxidation E a is CH > CH 3 > CH 2. • Quinones, esters and anhydrides have sharp increase during thermal treatment. • Ketones, aldehydes and COOH in lignite have hydrophilic ability. [ABSTRACT FROM AUTHOR]