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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]

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]

A numerical model was established for calculation in this study on the basis of the standard k-epsilon turbulence model and the discrete phase model of the Euler-Lagrange equation. Results of the particle image velocimetry experiment were used to verify the reliability of the numerical model. The effects of the rotation speeds, slurry densities, and impeller structures on the flow field characteristics, including velocity distribution, ballast fluidity, and power loss, were also investigated. The results indicate that the increase of rotation speed has little influence on the flow field near the wall and bottom of the agitator, and the agitator performs well when the speed is set between 30 rpm and 40 rpm. The increase of the slurry density will increase the pressure loss between the inlet and the outlet, and it will also increase the load of the agitator. Hence, the slurry density must be less than 1400 kg/m3. The baffle can improve the velocity distribution of the flow field and the slag discharge capacity of the agitator. [ABSTRACT FROM AUTHOR]

NaY and Na13X zeolites were modified by different modification manners including H+ modification, metal ion modification (Cu2+, Ni2+, or Ce3+), and H+ modification followed by metal ion modification to investigate their deep desulfurization behavior in gasoline. The sorbents were characterized by X-ray diffraction, FTIR of chemisorbed pyridine, N2 adsorption, and scanning electron microscope (SEM). The desulfurization performance of these sorbents was evaluated in model gasoline containing thiophene and cyclohexane with thiophene concentration of 500 mg/L, and the results were analyzed to investigate the effect of preparation methods on adsorption desulfurization behavior. The result indicates that H+ modification or metal ion modification could all improve the desulfurization performance of both NaY and Na13X zeolites, except for Na13X modified by Cu2+ and Ni2+. For Cu2+ or Ni2+ ion exchanging, the crystal structure of Na13X would be destroyed, resulting in a much lower desulfurization efficiency than that of the parent Na13X. The desulfurization efficiency of sorbents prepared via H+ modification followed by metal ion modification is higher than that of sorbents prepared by single H+ modification or single metal ion modification, because the former is more conducive to improve the content of metal elements on the sorbents than the latter. In addition, the increase of the specific surface area and pore volume of the sorbents would directly lead to the improvement of desulfurization performance of the sorbents. Compared with Na13X, the H+ modification on NaY zeolite can significantly enhance the desulfurization performance of the sorbents. Among those prepared sorbents, the CuHY has the highest desulfurization efficiency. The influence of thiophene concentration (100–1000 mg/L) on desulfurization efficiency of CuHY sorbent was evaluated. The results indicate that the desulfurization efficiency of CuHY sorbent is nearly 100% at room temperature, when the thiophene concentration is lower than 300 mg/L. Moreover, its desulfurization behavior could be described by Langmuir isothermal equation. Graphic abstract. [ABSTRACT FROM AUTHOR]

Dendrobium officinale Kimura et Migo (D. officinale) is not only an ornamental plant with beautiful flowers but also a medicinal herb that is widely used in traditional Chinese medicine. We used start codon targeted (SCoT) polymorphism molecular markers to analyse eleven Dendrobium cultivars. Using 13 selected SCoT primers, 181 bands were generated, 157 (86.86%) of which were polymorphic. The eleven cultivars were clustered into two major groups based on a SCoT analysis by the unweighted pair-group method with arithmetic mean. Then, we developed SCoT-sequence-characterised amplified region (SCoT-SCAR) markers and SCoT-nested polymerase chain reactions as the complementary tools for the identification of high-polysaccharide-content D. officinale cultivars. A D. officinale 'Ruishen No.2'-specific band was detected in the PCR products. The primers, which were designed to target a specific band, amplified the target bands in D. officinale 'Ruishen No.2', but not in the ten other cultivars. The universal verification test showed that there were not any target bands being amplified with the primer SC1, SC2, and SC3 to the seventeen Dendrobium cultivars from all over the world, which more to prove the reliability of the experimental results using the SCoT-SCAR markers and the SCoT-nested PCR markers. This study provides guidelines for D. officinale 'Ruishen No.2' identification, for the breeding of D. officinale plants with a high content of active ingredients, and for industrial production. [ABSTRACT FROM AUTHOR]

To investigate the dewatering kinetics and mechanism of low-rank coal, the dewatering behaviors of the Chinese lignite and its moisturized sample (prepared from dewatered coal moisturized under relative humidity of 75% at 303 K for 48 h) in nitrogen and the temperature range of 333–433 K were tested. Physical structure changes of raw coal and moisturized coal before and after drying were determined. The results indicate that drying process of lignite could be divided into four stages, which are increasing rate stage, constant rate stage, relatively fast decreasing rate stage, and relatively slow decreasing rate stage. Jander model and first-order kinetics model are favorite to describe the relatively fast decreasing rate stage and relatively slow decreasing rate stage, respectively, and the corresponding dewatering mechanism equations areandy = −ln(1 − α). The effective diffusion coefficients and diffusion activation energy were calculated by Fick’s second law. The diffusion activation energy of the dewatering stages, related to the relatively fast and slow decreasing rate stages, was 35.80, 40.75 kJ/mol for raw coal and 27.80, 37.34 kJ/mol for moisturized coal, respectively. The effective diffusion coefficient was significantly affected by drying temperature through the pore structure change of coal when other drying operation parameters were fixed. These prove that the forms of readsorbed water are not entirely the same as that in raw lignite, in which the former is relatively simple and the latter is more complex. [ABSTRACT FROM PUBLISHER]

Objective: To determine the prognostic CT and MR imaging features of extranodal non-Hodgkin lymphoma in the head and neck region. Methods: The clinical data and CT and MR imaging features of 59 patients with histologically confirmed extranodal non-Hodgkin lymphoma in the head and neck region were retrospectively reviewed. Subjects included 27 male and 32 female patients between 13 and 81 years of age, with a mean age of 60.3 years. The clinical outcomes were categorized according to whether relapse or metastasis occurred within 2 years after therapy. The association between the clinical outcome and radiologic factors including tumour size, margin, shape, local tumour invasiveness, regional lymph node involvement, number of involvement sites, and contrast enhancement patterns was determined using univariate and multiple logistic regression analysis. Results: Radiologic factors including tumour size, margin, shape, and local tumour invasiveness were associated with poor clinical outcomes, as determined by univariate analysis ( P < 0.05). Only the lesion margin category (ill-defined) remained an independent risk factor for clinical outcome in multivariate logistic regression analysis, with an OR of 8.14 ( P < 0.05). Conclusion: Ill-defined margin of the primary lesion was indicative of unfavourable survival outcome for patients with extranodal non-Hodgkin lymphoma of the head and neck region. Key Points: • Tumour size, margin, shape and local tumour invasiveness were prognostically relevant. • Tumour margin was an independent risk factor for clinical outcome. • Ill-defined margin of primary lesion was indicative of unfavourable survival outcome. [ABSTRACT FROM AUTHOR]

Pure benzene is an important chemical feedstock, and coking benzene is one of its sources. However, the industrialized coking benzene refining processes are not green and sustainable. To solve this problem, a green two-step process for the desulfurization of coking benzene with the advantages of easy operation, low environmental pollution and solid waste (sorbent/thiophene) recyclability was evaluated. The thiophene in coking benzene was first alkylated by the olefins present in it using a suitable AlCl3/silica gel catalyst to produce alkylthiophenes, which can be easily separated by distillation. The AlCl3/silica gel catalyst obtained by a novel green process was effective in catalyzing the alkylation of thiophene by 1-hexene with an efficiency of removing thiophene up to 94.2%. AlCl3 was grafted onto silica gel by reacting with hydroxyls on its surface, which could prevent the dissolution problem of AlCl3 in benzene. The residual thiophene with its concentration range of 100–1000 mg L−1 in benzene was then almost completely removed by adsorption using an ion-exchanged zeolite. The CeY zeolite sorbent showed excellent performance in deeply removing the residual thiophene in the benzene, in which the adsorption desulfurization over the CeY sorbent fits a Langmuir isotherm. The product met the requirements for a chemical feedstock, in that no thiophene was measured in the purified benzene by gas chromatography with a flame photometric detector. The CeY zeolite with adsorbed thiophene was used to prepare polythiophene–CeY composites by chemical oxidative polymerization using anhydrous FeCl3 as an oxidant at 0 °C. The decomposition temperature of the polythiophene–CeY composites is 480 °C, which is 60 °C higher than that of polythiophene. [ABSTRACT FROM AUTHOR]

Yellow-emitting long afterglow phosphors Sr3−xSiO5, xMF2: Eu2+, Dy3+ (0 ≤ x ≤ 0.15, M: Ba, Sr, Ca) have been prepared by high-temperature solid-state reaction method followed with rapid cooling process. Photoluminescence measurement reveals that the main emission of the phosphors locates at 575 nm, corresponding to the 4f65d1–4f7 transition of Eu2+. The introduction of alkaline earth metal fluoride effectively enhances the luminescence intensity and prolongs the afterglow time. Especially, the afterglow of the Sr2.95SiO5, 0.05BaF2: Eu2+, Dy3+ phosphor can last for 12 h. Thermal luminescence measurement shows that the trap density of Sr3SiO5: Eu2+, Dy3+ phosphor can be adjusted by adding different alkaline earth metal fluorides, which offers a feasible way to improve the afterglow properties of silicate phosphors. [ABSTRACT FROM AUTHOR]

Series sorbents of Cu, Zn, Ni, Ce and Ag metal components supported on γ-AlO carrier for removing thiophene from benzene were prepared by conventional and ultrasound-assisted incipient-wetness impregnation method. The static adsorption experiments were carried out in the thiophene-benzene solution with thiophene concentration of 500 mg/L. The results show that the desulfurization activity of all γ-AlO sorbents modified by different metal components obviously increase, among which the sorbent modified by silver nitrate has the best performance. The active components of sorbents from Cu, Zn, Ni, Ce nitrates loaded on γ-AlO carrier are their oxides. Besides AgO, the products of silver nitrate thermal decomposition in sorbent prepared still have Ag and Ag-O-Al species. The assistant ultrasound in the process of sorbent preparation can not only shorten the impregnation time, but also enrich the pore structure of sorbent and improve the size and distribution of the Ag species, which is favorable to the removal of thiophene from benzene. The desulfurization capacity of sorbent changes with the Ag content loaded. The sorbent with 15 % quality content of Ag prepared by ultrasound-assisted impregnation method has the highest desulfurization efficiency. It could reduce the thiophene concentration to 1.7 mg/L from 500 mg/L at room temperature and ambient pressure, with the desulfurization efficiency of more than 99 %, when the ratio of sorbent to solution was 1:4 (g/mL). [ABSTRACT FROM AUTHOR]

The commercial NaY zeolite with the Si/Al ratio of 5:1 was selected and modified for researching the adsorptive removal of thiophene from benzene. The zeolite was ion-exchanged in Ce(NO3)3 solution and then calcined in muffle to prepare the CeY sorbent. The results show that it is a suitable method to prepare the sorbent removing thiophene from benzene that NaY zeolite is ion-exchanged by cerium in Ce(NO3)3 solution. The desulfurization efficiency of CeY sorbent increases obviously comparing with NaY zeolite. The effects of the calcination temperature, calcination time, concentration of Ce(NO3)3 solution, ion-exchange time, and ion-exchange times on the desulfurization capacity of CeY sorbent were also studied. The results show that the optimal CeY sorbent can be obtained when NaY zeolite is ion-exchanged in 0.5 mol/L Ce(NO3)3 solution at 100°C for 4 h, calcined at 700°C for 2 h, and repeated the above steps two times. The results of XRD and BET characterization indicate that those preparation conditions mainly influence on the crystallinity, specific surface area of CeY sorbent. The best CeY sorbent can remove thiophene to 136.8 mg/L from 550.0 mg/L in thiophene-benzene solution at ambient temperature and pressure with the agent-liquid ratio of 1:16 (g/mL). [ABSTRACT FROM AUTHOR]