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Oil-based mud is widely used in shale oil well drilling because of its good stability and high temperature resistance at high temperature. However, during the drilling process of shale oil wells, fluid displacement between the annulus and the formation occurs. The existing temperature field model cannot predict the temperature distribution of the wellbore annulus under this condition. Based on the equations of heat conduction and conservation of energy, a new model of wellbore heat transfer in shale oil wells considering the displacement between downhole fluids is established in this paper. By comparing the temperature distribution of annular fluid under normal circulation, lost circulation and overflow, the accuracy of this model is confirmed. Taking the parameters of a shale oil well in a certain area as an example, the factors that affect the temperature of the annular fluid are analyzed and solved. Numerical analysis and simulation results show that the flow rate remains unchanged, and the annular temperature decreases by about 1.42 °C/L when the flow rate of the annulus increases. As the specific heat capacity of shale oil increases, the annular temperature increases by about 0.0012 °C/J/(kg·°C). In addition, when displacement between fluids occurs in the upper open-hole segment, there is an inflection point on the temperature distribution curve of the annular fluid, and the location of the inflection point is consistent with the location of the fluid displacement point. The results can provide a theoretical reference for drilling in complex formations with frequent formation-annulus fluid displacement, leakage and overflow. [ABSTRACT FROM AUTHOR]

We consider the quasinormal modes, quasibound states and superradiant instability of a rotating hairy black hole, which possesses a Horndeski hair as deviation from Kerr black hole, under the perturbation of massive scalar field. With the use of the matrix method, we mainly calculate the eigenfrequencies related to those modes of the perturbation. Under the perturbation of the massless scalar field, the Horndeski hair and spin parameter have significant influences on the quasinormal frequency, but its imaginary part is always finite negative and no unstable mode is found. Under the perturbation of the massive scalar field, we focus on the eigenfrequencies of quasibound states and find the modes of which the imaginary part of eigenfrequencies is positive, indicating that the black hole undergoes superradiant instability. Then we scan the parameters and figure out a diagram in the space of Horndeski hair and spin parameters to distinguish the rotating hairy black hole with superradiant instability from the stable one. [ABSTRACT FROM AUTHOR]

ZSSG (ZnSSe/rGO) composites are prepared by a hydrothermal method. The structure, morphology and material properties are investigated by various tests. Compared to ZnSe, the diffraction peaks of ZnSSe are moved to a larger angle and located between cubic phase ZnSe and cubic phase ZnS. The photocurrent density of ZSSG20 with 20 wt.% graphene is 2.17×10−5 A cm−2, which is 8.9 times higher than that of pure ZnSSe. ZSSG20 has the minimum charge transfer resistance and highest carrier density. The decreased fluorescence intensity in PL spectra indicates that graphene can effectively prevent the recombination of electron‐hole pairs. [ABSTRACT FROM AUTHOR]

In this paper, we study the propagations of external fields in a specific black hole solution in Horndeski theory, including the scalar field, electromagnetic field and Dirac field. We extensively explore the quasinormal frequencies, time evolution, greybody factors and emission rates of those massless perturbing fields by solving the corresponding master equations in the specific Horndeski hairy black hole. With the use of both numerical and analytical methods, we disclose the competitive/promotional influences of the Horndeski hair, spin and quantum momentum number of the external fields on those phenomenal physics. Our results show that this specific Horndeski hairy black hole is stable under those perturbations. Moreover, a larger Horndeski hair could enhance the intensity of energy emission rate for Hawking radiation of various particles, indicating that comparing to the Schwarzschild black hole, this specific Horndeski hariy black hole could have longer or shorter lifetime depending on the sign of the Horndeski hair. [ABSTRACT FROM AUTHOR]

TiSi 2 and Ti 5 Si 3 ceramics are high-temperature coating materials that are mainly synthesized using high-purity Ti and Si. In this study, to determine the application potential of TiSi 2 and Ti 5 Si 3 ceramics prepared through Al reduction-electromagnetic directional crystallization (AR-EDC) from Ti-bearing blast furnace slag (TBFS), spent SCR catalysts (SSCs), and diamond wire saw Si powder (DWSSP) for high-temperature coating, the thermal conductivity of AR-EDC-prepared TiSi 2 and Ti 5 Si 3 ceramics was measured. In addition, the effect of dissolved W and Al on the thermal conductivities of TiSi 2 and Ti 5 Si 3 ceramics was investigated. Meanwhile, the thermal conductivities of AR-EDC-prepared TiSi 2 and Ti 5 Si 3 ceramics were compared with those of commercial TiSi 2 and Ti 5 Si 3 ceramics and typical high-temperature coating materials. Additionally, the thermal coefficient expansions of AR-EDC-prepared TiSi 2 and Ti 5 Si 3 ceramics were compared with those of typical high-temperature Ti alloys. The results showed that the heat transfer mode of TiSi 2 ceramics was phonon heat transfer, while that of the Ti 5 Si 3 ceramics was radiation heat transfer, and dissolved W and Al reduced their thermal conductivities. At the temperature range of 298–873K, the thermal conductivities of the TiSi 2 and Ti 5 Si 3 ceramics were 29–35 W/(m·K) and 6–11 W/(m·K), respectively, and their thermal expansion coefficients were 8 × 10−6–12 × 10−6 K−1 and 5 × 10−6 –10 × 10−6 K−1, respectively. These results indicate that the thermal conductivity and thermal expansion coefficient of AR-EDC-prepared TiSi 2 and Ti 5 Si 3 meet the requirements for high-temperature coating. This study shows that Ti 5 Si 3 and TiSi 2 ceramics prepared from Ti- and Si-rich wastes are promising high-temperature coating materials. [ABSTRACT FROM AUTHOR]

Melanoma is a melanocyte‐derived malignant cancer and is known for its early metastasis and high mortality rates. It is a highly cutaneous tumour disease that could be related to the abnormal immune microenvironment, and the identification of reliable diagnostic and prognostic markers is crucial for improving patient outcomes. In the search for biomarkers, various types of RNAs have been discovered and recognized as reliable prognostic markers. Among these, small nucleolar RNAs (snoRNAs) have emerged as a promising avenue for studying early diagnosis and prognostic markers in tumours due to their widespread presence in tissues, tumour specificity and stability. In our study, we analysed snoRNAs data from melanoma samples in the TCGA‐SKCM cohort and developed a prognostic model comprising 12 snoRNAs (SNORD9, SNORA31, SNORD14E, SNORA14A, SNORA5A, SNORD83A, SNORA75, AL096855, AC007684, SNORD14A, SNORA65 and AC004839). This model exhibited unique prognostic accuracy and demonstrated a significant correlation with the immune infiltration tumour microenvironment. Additionally, analysis of the GSE213145 dataset, which explored the sensitivity and resistance of immune checkpoint inhibitors, further supported the potential of snoRNAs as prognostic markers for immunotherapy. Overall, our study contributes reliable prognostic and immune‐related biomarkers for melanoma patients. These findings can offer valuable insights for the future discovery of novel melanoma treatment strategies and hold promise for improving clinical outcomes in melanoma patients. [ABSTRACT FROM AUTHOR]

Abstract The precipitation of wax crystals will lead to the formation of gelation structures in waxy crude oils, and the presence of asphaltenes will affect the gelation and flow process of waxy crude oils. In this work, five waxy oils with different asphaltene contents were formulated, and the effect of asphaltene on the gelation and flow behavior of wax-containing simulated oils was investigated. The results show that asphaltenes can improve the low-temperature rheology of wax-containing simulated oils to a certain extent. When the asphaltene contents in wax-containing simulated oils increased from 0 wt% to 0.5 wt%, the pour points decreased from 25 °C to below 0 °C, while the gelation temperatures and storage modulus were also decreased from the initial 29.01 °C to 25.64 °C and 33262 Pa to 5.9 Pa, respectively. The results were due to the fact that the increase of asphaltene contents weakened the gelation network structure strength of wax-containing simulated oils and inhibited gelation process. Meanwhile, in the range of low asphaltene contents, the apparent viscosity of wax-containing simulated oils at 10 °C decreased from 531.5 mPa·s to 7.6 mPa·s with the increase of asphaltene contents. [ABSTRACT FROM AUTHOR]

S‐graphene quantum dots (GQDs), N‐GQDs, P‐GQDs, and Cl‐GQDs are prepared by a solution chemistry method and further incorporated with ZnxCd1−xSe by one‐step hydrothermal method. In the previous study, ZnxCd1−xSe reached the optimal photoelectric performances at the Zn/Cd ratio of 0.9:0.1, so the Zn0.9Cd0.1Se were combined with doped GQDs (D‐GQDs) to form Zn0.9Cd0.1Se/doped‐GQDs. The influence of GQDs doped with different elements on the photoelectric properties of Zn0.9Cd0.1Se composites is discussed. Compared with pristine Zn0.9Cd0.1Se, Zn0.9Cd0.1Se/Cl‐GQDs, and Zn0.9Cd0.1Se/P‐GQDs can improve the photocurrent response and current intensity, therein, Zn0.9Cd0.1Se/Cl‐GQDs reaches the lowest interfacial charge transfer resistance and the highest photocurrent response of 5.48 × 10−6 A cm−2. Mott–Schottky analysis shows that the fitting slope of Zn0.9Cd0.1Se/Cl‐GQDs composites is significantly lower than that of Zn0.9Cd0.1Se/GQDs with other doped elements. The results indicate that Zn0.9Cd0.1Se/Cl‐GQDs composites has the largest carrier density, which is beneficial to charge conduction. [ABSTRACT FROM AUTHOR]

Background: To investigate the efficacy and safety of lymph nodes (LNs) dissection guided by carbon nanoparticles (CNs) in gastric cancer (GC) surgery. Materials and methods: We searched electronic databases such as PubMed, Web of Science, Embase, Cochrane Library, and Scopus for relevant articles up to September 2022 and collected all studies comparing the CNs group with blank controls group on the efficacy and safety of LN dissection in gastrectomy. A pooled analysis of the collected data was performed, including the number of retrieved LNs, the staining rate of LNs, the number of metastatic LNs dissection, various intraoperative outcomes, and postoperative complications. Results: A total of 9 studies including 1770 participants (502 in the CNs group and 1268 in the control group) were included. As compared to the blank control group, the CNs group detected 10.46 more LNs in each patient (WMD = 10.46, 95% CI: 6.63 ~ 14.28, p < 0.00001, I2 = 91%), and also significantly more metastatic LNs (WMD = 2.63, 95% CI: 1.43 ~ 3.83, p < 0.0001, I2 = 41%). However, there was no significant difference in the rate of metastatic LNs between the CNs and control groups (OR = 1.37, 95% CI: 0.94 ~ 2.00, P = 0.1, I2 = 89%). In addition, there was no increase in operative time, intraoperative blood loss, and postoperative complications associated with CNs-guided gastrectomy. Conclusion: CNs-guided gastrectomy is safe and effective, and can increase the efficiency of LN dissection without increasing the risk of surgery. [ABSTRACT FROM AUTHOR]

Practical application of direct methanol fuel cell (DMFC) technology is greatly hindered by the strong dependence of anodic methanol oxidation reaction (MOR) on precious Pt based catalyst and the unsatisfying performance of Pt. Therefore, increasing the utilization and the catalytic performance of Pt toward MOR in DMFC is urgent. Here in this work, CeO 2 is modified via a plasma-phosphating combing strategy and is invited as Frustrated Lewis Pair to assist the catalytic MOR process on Pt sites. Simultaneously, the plasma-phosphating combing strategy leads to negatively charged sites on CeO 2 surface, which can be functioned as host for Pt anchoring, facilitating the even dispersion of Pt nanocrystals. Besides, this strategy also has an effect on the Ce3+/Ce4+ ratio and vacancy oxygen ratio on CeO 2 surface, which are critical to the adsorbed OH generation and anti-CO poisoning ability, thus boosting the MOR catalytic activity of Pt. DMFC device therefore exhibits ca. 30% maximum power density enhancement compared with the commercial Pt/C based DMFC. Ce–P LFP, which is highly active toward water dissociation reaction, is constructed in CeO 2 substrate via the plasma-phosphating combing strategy for Pt loading and the MOR activity is significantly improved with the DMFC performance enhanced by 30%. [Display omitted] • Ce–P LFP is constructed substrate via the plasma-phosphating combing strategy. • Pt nanoparticles can be evenly distributed on Ce–P LFP rich CeO 2 substrate. • DMFC performance is enhanced by ca. 30%. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two wastes were recycled collaboratively. • Reveal the dissolution mechanism of Al 2 O 3 and MgO refractories in the Si reduction. • Reveal the effect of Al 2 O 3 and MgO refractories on slag-alloy separation. • Reveal the effect of Al 2 O 3 and MgO refractories on the extraction of Ti and Si. • Magnesia brick was suggested as a suitable refractory for recycling DWSSP and TBFS. The industrial wastes diamond wire saw silicon powder (DWSSP) and Ti–bearing blast furnace slag (TBFS) are important Si and Ti secondary resources, respectively. During the industrial application of recycling DWSSP and TBFS via reduction smelting, the refractories can dissolve into the molten slag, which can change the composition of the slag and influence the extraction of Si and Ti. Unfortunately, few studies on the reduction smelting of DWSSP and TBFS related to refractories have been reported, making such studies urgently needed. Therefore, the main purpose of this work was to reveal the dissolution mechanism of refractories (alumina and magnesia bricks) and the effect of refractory dissolution on Si-Ti alloy preparation. The results show that during the reduction smelting, the dissolution of alumina and magnesia bricks changed from direct dissolution into the molten slag to indirect dissolution, and the amount of magnesia bricks dissolved was less than that of aluminum bricks. Al3+ (aluminum brick) entering the slag could replace Si4+ in [Si n O 2n ] to form [Al x Si n–x O 2n ] x- , increasing the viscosity of the slag. The O2– (magnesia brick) entering the slag could dissociate [Al x Si n–x O 2n ] x- , decreasing the viscosity of the slag. Therefore, compared with alumina bricks, magnesia bricks can promote slag-alloy separation and improve the extraction ratios of Ti and Si. In the case of magnesia bricks, the maximum reduction ratio of TiO 2 was 98.4 %, and the maximum extraction ratio of Si was 95.8 %. This work provides essential experimental data for the Si-Ti alloys prepared via recycling DWSSP and TBFS. [ABSTRACT FROM AUTHOR]

With the rapid reduction in NOx emissions and the end of various Al alloy products' lives in recent years, large amounts of spent SCR catalysts (SSCs) and Al alloy scrap (AAS) as important secondary Ti and Al resources have been discarded. The value-added reutilization of Ti and Al from the two wastes is necessary to develop sustainable Ti and Al resources. In this work, an environmentally friendly approach is proposed to simultaneously recycle Ti and Al from the two wastes and then prepare them into TiAl3 and low-Fe Al alloys. First, AAS (1.25 wt% Fe) was used as a reductant to extract Ti and W from the SSC to prepare raw W-containing Ti–Al alloys. The results showed that applying a MgO crucible and electromagnetic force can promote alloy–slag separation and a MgO crucible increased the extraction ratio of Ti and W. Next, the raw Ti–Al melt was separated by electromagnetic directional crystallization for the simultaneous preparation of the two high-value products: W-containing TiAl3 and low-Fe Al (0.41 wt% Fe) alloys. In the separation process, Ca, Mg, and Zn impurities in the alloys were removed via volatilization; Fe and Mn impurities were eliminated through agglomeration at the boundary between the TiAl3 and low-Fe Al alloys and at the top of the Ti–Al alloy. The entire process produces no waste liquid, gas, or slag. This method provides new environmentally friendly insights for sustainable recycling of secondary Ti and Al resources, and provides a new technology for preparing TiAl3 and low-Fe Al alloys. [ABSTRACT FROM AUTHOR]

WO 3 and N-GQDs were loaded in a two-dimensional graphene sheet layer by hydrothermal method, and then oxygen vacancy-rich WO 3 /N-GQDs/N-rGO composites were successfully prepared by calcination. The structures, morphologies and surface chemical states were characterized by XRD, TEM, XPS, FTIR, and the electrochemical properties were studied by EIS, i-t, LSV and M-S. The WO 3 /N-GQDs/N-rGO composites had a high carrier density of 5.88 × 1020 cm−3 and presented an instantaneous photocurrent density of 2.96 × 10−4 A/cm2 under 365 nm irradiation, which was 4.4 times larger than that of pure WO 3. The enhanced properties were mainly ascribed to the increased light absorption and carrier migration by the two-carbon modification of N-GQDs and N-rGO. Meanwhile, the presence of oxygen vacancies can improve the carrier lifetime, thus suppressing the recombination of photogenerated electron-hole pairs in the WO 3 /N-GQDs/N-rGO composites. The photoelectric properties of the composites were improved by the cooperative effect of double carbon modification and oxygen vacancies. [Display omitted] • WO 3 /N-GQDs/N-rGO with oxygen vacancies was prepared by a hydrothermal and calcination process. • Oxygen vacancies trap photoelectrons to suppress the recombination and improve the conductivity and lifetime. • The introduction of N-doped graphene provides doping atoms and defect sites for oxygen vacancies. • N-rGO acts as a transport channel to speed up the migration of photoelectrons and promote the charge carrier. • Combination of WO 3 with N-GQDs and N-rGO provides more defect sites and conductive ways for photoelectrons. [ABSTRACT FROM AUTHOR]

This paper conducts an in-depth study and analysis of the preservation of ancient village heritage and the restructuring and optimization of cultural industries in western Guangdong in the context of the current "Internet+." This study is problem-oriented and aims to improve the common rural environment in the less developed areas of western Guangdong from the perspective of sustainable development. This study conducts an objective investigation and understanding of villages, combining contemporary methods and techniques of quantitative analysis. This study aims to understand the regular characteristics of the evolution of the settlement space itself based on the characteristics of the interaction between the settlement space itself, especially with the local natural ecology and human society, to explore the localized decision making of the village settlement space, and to propose a specific and operable systematic approach from macro to micro, an approach that focuses on the village settlements established. This approach focuses on the optimization of the existing pattern, architecture, and surrounding vernacular landscape of rural settlements and is a critical inheritance based on the existing spatial pattern, emphasizing the coordination and unity of multiple factors related to the settlement space. Combining the background of the era of "Internet+" and the actual situation of the development of tourism in ancient villages in western Guangdong, a marketing 4Ps combination strategy suitable for the development of tourism in ancient villages in western Guangdong was formulated. The flexible and diverse forms of operation also determine the independence of the villagers in the distribution of benefits. The villagers take the family as the unit of self-employment, and the distribution of benefits is distributed by the villagers themselves within the family. The product strategy, product pricing strategy, marketing channels, and promotion strategy of "Internet+ rural tourism" are formulated. A study on the cultural renewal strategy of the Nanchang community in the context of rural revitalization strategy. Based on clarifying the idea of cultural renewal, the principles of cultural renewal are proposed based on the strategic planning of rural revitalization: the principle of overall protection and development, the principle of restoring the old as the old, and the principle of regional linkage renewal. Based on the conservation plan of the Nanchang community, the scope of its conservation and conservation framework is sorted out, and the cultural renewal strategy of the Nanchang community is elaborated in four aspects: optimization of the overall layout of the village, enhancement of public space, improvement of key buildings and living heritage of intangible cultural heritage. [ABSTRACT FROM AUTHOR]

In the work, CdS x Se 1-x /N-GQDs composites were fabricated via a simple one-step hydrothermal process and their tunable composition, structure and photoelectric properties were characterized by various techniques. The photoelectric properties of CdS x Se 1-x /N-GQDs could be adjusted by different Se/S ratios and tunable band-gaps. CdS x Se 1-x /N-GQDs composites reached the optimal photocurrent response and the lowest interfacial impedance at the Se/S ratio of 0.75:0.25. Mott-Schottky plots and LSV spectra showed that the n-type CdS 0.25 Se 0.75 /N-GQDs presented a higher carrier density under light illumination. The excellent properties of the composites could be attributed to the mechanism involved in the excitation and electron-transfer process. On one hand, the band-gap of CdS 0.25 Se 0.75 /N-GQDs was narrowed, and more electrons were excited by the lower band-gap energy to promote a superior electron separation and transportation. On the other hand, N-GQDs acted as charge carriers and conductive way providers for electron-transfer instead of electron-hole recombination in the composites. [ABSTRACT FROM AUTHOR]

Among all renewable energies, biomass has been receiving more attention because of its availability and economic advantages. In this study, a thermodynamic model was developed using a commercial simulator to analyze the gasification behavior of biomass (pine sawdust) particles in the presence of CaO as CO2 sorbent. The developed model was validated with the experimental results showed a good agreement. It was found that H2 and CO2 increased, as the SBR increased, while an opposite trend is obtained for CO and CH4. The simulated results also showed that the CO2 conversion ratio (CCR) increased from 31.12% to 59.45% increased as the SBR increased from 0.25 to 1.0. [ABSTRACT FROM AUTHOR]

• Hayduk-Minhas relationship underestimates wax molecular diffusion coefficient. • Develop a new diffusion laboratory apparatus coupled with differential scanning calorimeter. • Put forward a new wax molecular diffusion coefficient correlation. Wax molecular diffusion coefficient is a crucial factor determining the wax deposition rate of waxy crude oil, but the calculation accuracy of the traditional Hayduk-Minhas and Wilke-Chang relations is unclear. The Couette wax deposition experiments of Changqing crude oil under different operating conditions (oil temperature, wall temperature, rotation speed and deposition duration) were carry out and find the traditional Hayduk-Minhas relationship will underestimate the wax molecular diffusion coefficient. To increase the calculation accuracy of wax molecular diffusion coefficient, a newly-developed diffusion laboratory apparatus coupled with the Differential Scanning Calorimeter (DSC) were utilized to evaluate the diffusion coefficient of C 16 , C 18 , C 20 , C 22 , C 24 in n -alkane solutions at different temperatures (10, 15, 20, 25, 30,35, and 40 °C). Based on the experimental results, a novel high-precision correlation was put forward and the calculated results are in good agreement with the experimental results, the average relative error is within 3.0 %. The applied solvent of the n-alkane solutions is mineral oil and it has a complex composition. Therefore, the developed correlation can be used to evaluate the wax molecular diffusion coefficient in the real crude oil. The application of the new relationship will lead to more accurate wax deposition calculations. [ABSTRACT FROM AUTHOR]

In this study, Indium oxide (In 2 O 3) and 3D reduced graphene oxide (3D rGO) composites were obtained by hydrothermal treatment. The structure composition, morphology, surface area and band gap of In 2 O 3 /3D rGO were analyzed by a series of techniques. The relationship between the photoelectric properties and capacitance of In 2 O 3 /3D rGO composites with various mass proportions was investigated, and the results indicated that the steady-state photocurrent density of In 2 O 3 /3D rGO increased and then started to drop with the increase of the specific capacitance. The current density of In 2 O 3 /3D rGO reached a maximum of 0.11 mA/cm2 at the intermediate specific capacitance (77.8 mF/cm2). This photocurrent trend of the composites was attributed to the positive and negative effects of capacitance. The proper capacitance might result in the low recombination rate of photogenerated carriers and holes, while the overlarge capacitance might limit the release of electrons, thus reducing the photocurrent generation. This research result was expected to provide favorable conditions for further applications of 3D graphene and new strategies to improve the photoelectric performance of In 2 O 3. [Display omitted] [ABSTRACT FROM AUTHOR]

Personalized drug therapy aims to provide tailored treatment for individual patient. Mass spectrometry (MS) is revolutionarily involved in this area because MS is a rapid, customizable, cost‐effective, and easy to be used high‐throughput method with high sensitivity, specificity, and accuracy. It is driving the formation of a new field, MS‐based personalized drug therapy, which currently mainly includes five subfields: therapeutic drug monitoring (TDM), pharmacogenomics (PGx), pharmacomicrobiomics, pharmacoepigenomics, and immunopeptidomics. Gas chromatography‐MS (GC‐MS) and liquid chromatography‐MS (LC‐MS) are considered as the gold standard for TDM, which can be used to optimize drug dosage. Matrix‐assisted laser desorption ionization‐time of flight‐MS (MALDI‐TOF‐MS) significantly improves the capability of detecting biomacromolecule, and largely promotes the application of MS in PGx. It is becoming an indispensable tool for genotyping, which is used to discover and validate genetic biomarkers. In addition, MALDI‐TOF‐MS also plays important roles in identity of human microbiome whose diversity can explain interindividual differences of drug response. Pharmacoepigenetics is to study the role of epigenetic factors in individualized drug treatment. MS can be used to discover and validate pharmacoepigenetic markers (DNA methylation, histone modification, and noncoding RNA). For the emerging cancer immunotherapy, personalized cancer vaccine has effective immunotherapeutic activity in the clinic. MS‐based immunopeptidomics can effectively discover and screen neoantigens. This article systematically reviewed MS‐based personalized drug therapy in the above mentioned five subfields. © 2020 John Wiley & Sons Ltd. Mass Spec Rev [ABSTRACT FROM AUTHOR]

In the present study, a heterostructure based on Zn 0·1 Cd 0·9 S, N-doped graphene quantum dots (N-GQDs), and graphene was successfully prepared by a simple method. Various analyses are conducted to determine the structure, morphology, and materials performance of the synthesized composite. The results exhibit that the Zn 0·1 Cd 0·9 S/N-GQDs/graphene heterostructure presents excellent photoelectric performance with a high photocurrent of 4.43 × 10−5 A/cm2 and 3.43 × 10−5 A/cm2 under light irradiation of 365 nm and 405 nm, respectively. It demonstrates a two-fold photocurrent enhancement in comparison to blank Zn 0·1 Cd 0.9 S. This remarkable improvement is ascribed to a mechanism in which the N-GQDs act as photosensitizers, enhancing the absorption ability. Concurrently, graphene serves as a carrier mobility substrate, facilitating the separation of the photogenerated electron–hole pairs. The synergetic effect between Zn 0·1 Cd 0·9 S, the N-GQDs, and graphene enhances the photoelectric performance. The Zn 0·1 Cd 0·9 S/N-GQDs/graphene heterostructure provides a new route for the enhancement of the photoelectric performance of a semiconductor under UV–visible light. [ABSTRACT FROM AUTHOR]

Unconventional rocks such as tight sandstone and shale usually develop multiscale complex pore structures, with dimensions ranging from nanometers to millimeters, and the full range can be difficult to characterize for natural samples. In this paper, we developed a new hybrid digital rock construction approach to mimic the pore space of tight sandstone by combining X-ray CT scanning and multiple-point geostatistics algorithm (MPGA). First, a three-dimensional macropore digital rock describing the macroscopic pore structure of tight sandstone was constructed by micro-CT scanning. Then, high-resolution scanning electron microscopy (SEM) was performed on the tight sandstone sample, and the three-dimensional micropore digital rock was reconstructed by MPGA. Finally, the macropore digital rock and the micropore digital rock were superimposed into the full-pore digital rock. In addition, the nuclear magnetic resonance (NMR) response of digital rocks is simulated using a random walk method, and seepage simulation was performed by the lattice Boltzmann method (LBM). The results show that the full-pore digital rock has the same anisotropy and good connectivity as the actual rock. The porosity, NMR response, and permeability are in good agreement with the experimental values. [ABSTRACT FROM AUTHOR]

The cellular internal ribosomal entry site (IRES) is one of the most important elements to mediate cap‐independent translational initiation, especially under conditions of stress and pathology. However, a high‐throughput method to discover IRESs in these conditions is still lacking. Here, a possible way IRES long‐read sequencing based on the latest high‐throughput technologies is proposed to solve this problem. Based on this design, diversity and integrity of the transcriptome from original samples can be kept. The micro‐environment that stimulates or inhibits IRES activity can also be mimicked. By using long read‐length sequencing technology, additional experiments that are essential for ruling out the cryptic promoters or splicing events in routine IRES identification processes can be circumvented. It is hoped that this proposed methodology may be adopted for IRES element discovery, hence uncovering the full extent of the role of IRESs in disease, development, and stress. Also see the video abstract here https://youtu.be/JuWBbMzWXS8 [ABSTRACT FROM AUTHOR]

Cadmium selenide and S, N co-doped graphene quantum dots (CdSe/S, N-GQDs) nanocomposites were synthesized via a solvothermal method. The results show that S, N-GQDs have a grain size of around 5 nm and an average height of 0.5 nm, which contains only 1–2 layers of graphene sheets. The CdSe/S, N-GQDs composites exhibit distinct lattice fringes with a layer spacing of 0.24 and 0.35 nm, corresponding to (1120) and (111) crystal planes of S, N-GQDs and the cubic CdSe, respectively. The photoelectric properties of CdSe/S, N-GQDs were evaluated under ultraviolet light (365 nm) irradiation. Compared with CdSe and CdSe/GQDs, CdSe/S, N-GQDs composites have the largest photocurrent density of 4.286 × 10–5 A cm−2, which is about 10.5 times and 7.5 times as high as that of CdSe and CdSe/GQDs, respectively. The increase in photocurrent density of CdSe/S, N-GQDs can be attributed to the incorporation of S and N to promote separation of photogenerated carriers. Moreover, S, N-GQDs are nano-fragments of graphene, which can provide a larger specific surface area and greatly increase the contact surface with CdSe. In addition, the photoelectric properties of CdSe/S, N-GQDs composites can be adjusted by varying the doping ratio. When the doping ratio is 1:1, CdSe/S, N-GQDs have the best photoelectric performance. [ABSTRACT FROM AUTHOR]

A new approach was proposed to prepare multi-products, high-purity Si powders, bulk Si, and Si/TiSi 2 materials (eutectic Si-Ti), simultaneously using inexpensive low-purity Si (99.3%) and metallurgical waste—Ti-bearing blast furnace slag. TiO 2 in Ti-bearing blast furnace slag was first reduced by Si to form a Si-Ti alloy which was then separated into high-purity bulk Si (99.97%) and Si/TiSi 2 materials (99.4%) using directional solidification. The bulk Si could be repeatedly recycled as a reductant, or further upgraded to prepare super-pure Si powders (99.995%) after acid leaching. The new approach shows many sustainable and economic benefits, such as no carbon gas emission, low acid consumption and Si loss, recyclable Si reductant, widely-used multi-products employing one approach, and rapid consumption of accumulated Ti-bearing blast furnace slag. • A new approach was proposed to clean up the Ti-bearing blast furnace slag. • Multi-products could be prepared simultaneously throughout one approach. • Most of Si could be recycled as reductant repeatedly. • Most of impurities could be removed to obtain high-purity Si and Ti materials. • Si-Ti alloy could be separated into bulk Si and eutectic Si-Ti alloy. [ABSTRACT FROM AUTHOR]

A series of graphene quantum dots-modified ZnCdS (ZnCdS/G) composites with different contents of graphene quantum dots (GQDs) were prepared by a solvothermal route and characterized via various measurements. GQDs have a type graphene height of 2 nm and exhibit an excitation-dependent PL behavior. GQDs-modified ZnCdS composites present good lattice fingers that can be assigned to the (110) plane of GQDs and (112) plane of ZnCdS. The effect of different GQDs contents on the photoelectric property of ZnCdS was investigated. The results show that the photocurrent density of ZnCdS/G first increases and achieves a maximum of 11.4 μA/cm2 with the addition of 0.06 wt% and then decreases as the GQDs content changes from 0.06 wt% to 0.12 wt%. Photocurrent counts as a function of time present a decrease of 10% and remains stable after 1600 s. [ABSTRACT FROM AUTHOR]

The long-term administration of acyclovir (ACV) for therapy against herpes simplex virus type 1 (HSV-1) infections can result in the emergence of ACV-resistant HSV strains. It is therefore urgent to develop new anti-herpetic compounds with mechanisms that differ from that of ACV. Cyanovirin-N (CV-N) is an antiviral agent that has an inhibitory effect on HSV-1 infections, and PEGylation of CV-N is potentially useful for pharmaceutical applications. Here, a (Gly4Ser)3 linker molecule was attached to the N-terminus of CV-N, and the resulting compound, linker-CV-N (LCV-N), was produced on a pilot scale with purity up to 95%. Then, PEG10k-LCV-N was synthesized by modifying at the α-amine group of the N-terminus of LCV-N with 10-kDa polyethylene glycol propionaldehyde (mPEG-ALD). CV-N, LCV-N and PEG10k-LCV-N were all found to have potent inhibitory activity against ACV-resistant HSV strains with IC50 values in the nM range. LCV-N was the most potent of these three compounds against both normal and ACV-resistant HSV strains. Although PEG10k-LCV-N showed less antiviral activity than CV-N and LCV-N, it still exhibited significant and universal virucidal activity against drug-resistant viruses. The toxicity and immunogenicity of PEG10k-LCV-N were dramatically lower than those of CV-N and LCV-N. In conclusion, we suggest that LCV-N and PEG10k-LCV-N are promising and safe microbicides for the control and/or treatment of ACV-resistant HSV infection. [ABSTRACT FROM AUTHOR]

Fluoroalkylated enaminones, such as trifluridine and 5-trifluoromethyluracil, have widespread applications in pharmaceuticals and agrochemicals. Although these kinds of pharmaceutical agent often bear CF3 and perfluoroalkyl motifs in the core structure, access to such analogues typically requires multi-step synthesis. Here, we report a mild, metal-free and operationally simple strategy for the direct perfluoroalkylation of uracils, cytosines and pyridinones through a visible-light induced pathway from perfluoroalkyl iodides. This photochemical transformation features synthetic simplicity, mild reaction conditions without any photoredox catalyst, and high functional group tolerance, providing a facile route for applications in medicinal chemistry. [ABSTRACT FROM AUTHOR]

Abstract Hf, Zr, or Ti was employed as additive to enhance removal of the main impurities from metallurgical-grade Si (MG–Si) during the Si–Sn alloy refining process. The microstructure of Si-Sn alloy without/with Zr, Hf, or Ti was observed and analyzed by electron probe microanalysis (EPMA) to investigate the distribution of impurities. Compositions of intermetallic phases precipitated in Sn or among the grain boundaries of Si were quantitatively analyzed using EPMA. The mechanisms of their formation and the removal of impurities are discussed. The results of Si refining showed that the addition of Hf or Zr slightly enhanced the removal of Al. The high refining temperature in the Si-Sn alloy refining process was responsible for the low extraction of B. Most of Zr, Hf, or Ti was removed simultaneously with other impurities during the Si–Sn alloy refining process. [ABSTRACT FROM AUTHOR]

Abstract Ti-bearing blast-furnace slag is a metallurgical waste but a promising Ti resource. In this study, Ti and Al–Si alloys can be prepared directly by separating a Ti–Si–Al alloy that was prepared by reducing Ti and Si from Ti-bearing blast-furnace slag with Al. The technology of directional solidification with electromagnetic force was employed to carry out the separation of the Ti–Si–Al alloy. When additions of CaO and Al were 24 wt% and 40 wt%, respectively, the composition of the obtained Ti–Si–Al alloy was 31.8 wt% Ti, 22.7 wt% Si, 28.5 wt% Al, and 10.2 wt% Fe. Ti 5 Si 4 , TiSi, Al–Si–Ti (τ 2), Al–Si–Fe (τ 4), and Al–Si alloys were prepared in sequence after separating the Ti–Si–Al alloy using directional solidification with electromagnetic force. However, when the composition of the Ti–Si–Al alloy was changed to 21.2 wt% Ti, 48.5 wt% Si, 19 wt% Al, and 6.8 wt% Fe, the TiSi 2 , Si, Al–Si–Fe and Al–Si alloys were prepared in sequence. This study will propose an approach to employ the metallurgical waste, titanium-bearing blast-furnace slag, to prepare Ti and Al–Si alloys. Highlights • An approach to employ Ti-bearing blast-furnace slag to prepare Ti and Al–Si alloys. • Ti and Al–Si alloys were prepared directly by separating a Ti–Si–Al alloy. • Electromagnetic directional solidification was employed to separate Ti–Si–Al alloy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Develop a series of pressurized laboratory apparatus for dissolved gas crude oil. • CH 4 can reduce wax deposition rate, but raise WAT and wax content of wax deposit. • Raising dissolved CH 4 pressure reduces deposit mass but raises mass of diffused wax. • Molecular diffusion, dynamic gelation and stripping effect are dominant mechanisms. In offshore oilfields, crude oils often contain dissolved gas, and are unavoidably transported under pressure. However, the flowability and wax deposition of crude oils with dissolved gas are rarely investigated. In this paper, Methane (CH 4) was used as a similar substitute for the dissolved gas in crude oils, and a series of pressurized laboratory apparatuses were developed to study the influencing mechanism of dissolved CH 4 on the flowability and wax deposition of Changqing waxy crude oil. It was found that with the increase of the dissolved CH 4 pressure, the crude oil flowability was improved, and the wax deposition rate was inhibited. However, the wax appearance temperature (WAT), the average wax content of wax deposits, and the mass of wax diffused into wax deposits all increased accordingly. This was mainly attributed to the influence of dissolved CH 4 , which can effectively increase the intermolecular distance between wax molecules, decrease the intermolecular forces, and weaken the strength of wax crystals to overlap each other. The improvement of rheological properties, on the one hand, promotes the diffusion of wax molecules, which leads to the increase in the mass of wax diffused into wax deposits; on the other hand, it increases the wax content required for the formation of wax deposits according to the dynamic gelation mechanism, thus resulting in the decrease of wax deposition rate. Also, the wax stripping effect during the deposition and depressurization processes cannot be ignored. The research results have guiding significance for the optimal design of the gathering and transportation pipeline network and the calculation of wax deposition. [ABSTRACT FROM AUTHOR]

In the study, a novel sensing strategy based on dual-probe mode, which involved two groups of 2′-fluoro ribonucleic acid (2′-F RNA) modified probes, was designed for the detection of synthetic target double-strand DNA (dsDNA) of PML/RARα fusion genes in APL. And each pair of probes contained a thiolated capture probe (C1 or C2) immobilized on one of electrode surfaces in the dual-channel electrochemical biosensor and a biotinylated reporter probe (R1 or R2). The two groups of 2′-F RNA modified probes were separately complementary with the corresponding strand (Sa or Sb) from target dsDNA in order to prevent renaturation of target dsDNA. Through flanking target dsDNA, two “sandwitch” complexes (C1/Sa/R1 and C2/Sb/R2) were separately shaped by capture probes (C1 and C2) and free reporter probes (R1 and R2) in hybridization solution on the surfaces of different electrodes after the thermal denaturation. The biotin-modified enzyme which produced the measurable electrochemical current signal was localized to the surface by affinity binding between biotin with streptavidin. Under the optimal condition, the biosensor was able to detect 84 fM target dsDNA and showed a good specificity in PBS hybridization solution. Otherwise, the investigations of the specificity and sensitivity of the biosensor were carried out further in the mixed hybridization solution containing different kinds of mismatch sequences as interference background. It can be seen that under a certain interference background, the method still exhibited excellent selectivity and specificity for the discrimination between the fully-complementary and the mismatch sequences. The results of our research laid a good basis of further detection research in practical samples. [ABSTRACT FROM AUTHOR]

Poorly water soluble drugs often show low oral bioavailability due to their low dissolution rate. In the present study, cross-linked poly(vinyl alcohol) hydrogel microspheres were prepared. Nanocrystals of fenofibrate as a model of poorly water soluble drugs were dispersed within the poly(vinyl alcohol) hydrogel microspheres by swelling the microspheres with fenofibrate/methanol solution, followed by evaporation of the solvent methanol. The fenofibrate dissolution rate from the fenofibrate-loaded hydrogel microspheres in a medium simulating gastrointestinal tract conditions was much higher than the dissolution rate of free fenofibrate. And the dissolution assay also showed that fenofibrate released from the hydrogel in a sustained manner. In vivo pharmacokinetic study showed that the fenofibrate-loaded hydrogel microspheres showed much higher bioavailability compared with free fenofibrate, and similar bioavailability but longer half-lives and mean residence time and lower maximum plasma concentration compared with a marked fenofibrate formulation Lipanthyl® after oral administration in rats, indicating that the fenofibrate-loaded PVA hydrogel exhibited lower fluctuation in plasma drug concentration and more sustained release behavior. [ABSTRACT FROM AUTHOR]

In order to discuss the effects of transition metals such as Zr, Hf, and Ti on the removal of impurities (B, P, Fe, Al, Ca, Ti, V, Cu, Ni, Mn, Zr, and Hf) in the purification of metallurgical-grade Si (MG-Si) with Al–Si alloy, the impurity phases formed after solidification were investigated by electron probe microanalysis (EPMA) and their removal by acid leaching was performed. EPMA investigation showed that β-Al 5 FeSi was the main impurity phase aside from Al in the sample without additives. However, after adding Zr, Hf, or Ti, the ZrSi 2 , HfSi 2 , or TiSi 2 compound dissolved in small amounts of Al was the most observed phase besides β-Al 5 FeSi and Al. Impurities such as V, Ni, and Mn were more likely to coexist with β-Al 5 FeSi when Hf or Zr was employed as the impurity getter. However, V preferentially coexisted with TiSi 2 when Ti was added. The leaching results showed that the addition of Zr, Hf, or Ti significantly enhanced the extraction of B and slightly enhanced that of other impurities. The added Zr, Hf, and Ti were eliminated efficiently with the other impurities, reaching extraction ratios of 99.998%, 99.9994%, and 99.997%, respectively. [ABSTRACT FROM AUTHOR]

Compared with various malignant tumors, lung cancer has high incidence and the highest mortality worldwide. Non-small-cell lung cancer (NSCLC), the most common kind of lung cancer, is still a great threat to the world, including China. Surgery, platinum-based chemotherapy, and radiotherapy are still the primary treatments for NSCLC patients in the clinic, whereas immunotherapy and targeted therapy are gradually playing more important roles. A next-generation tyrosine kinase inhibitor (TKI), afatinib, was developed as a targeted reagent for epidermal growth factor receptor (EGFR). This targeted drug was effective in a series of trials. The US Food and Drug Administration then approved afatinib as a new first-line treatment for EGFR L858R and exon 19 deletion mutant patients in 2013. This review focused on current clinical studies of afatinib. Although this TKI was not widely available in China until recently, we aim to provide a reference for its future use in China. [ABSTRACT FROM AUTHOR]

Vacuum refining is a green technology for separating Ca from Si–Ti alloys. This study investigated the kinetics of Ca evaporation from Si–Ti melts in vacuum refining, including the effect of holding time and melt temperature and composition. Although the Ca activity in Si–Ti melts is an essential thermodynamic property that affects the Ca evaporation kinetics, it has not been measured to date. Consequently, another objective of this study was to determine the Ca activity using a chemical equilibration technique and investigate its effect on Ca evaporation. The results show that the activity of Ca in the Si–Ti melt decreased gradually with increasing Ti content in the melt, which reduced the Ca removal ratio. The removal ratio of Ca increased with the temperature and holding time. The apparent evaporation rate of Ca was consistent with the first-order law, and the apparent evaporation rate constants of Ca in 15%Si–Ti melt at 1673 and 1773 K were 2.1 × 10−6 and 2.8 × 10−6 m/s, respectively. The apparent activation energy for Ca evaporation from Si–15 wt%Ti melt was determined to be 68.2 kJ/mol, and the rate-determining step to be Ca mass transfer at the melt boundary layer. • Determine the activity of Ca in Si–Ti alloys for the first time. • The Kinetics of Ca evaporation from Si–Ti melts were studied for the first time. • The evaporation rate and rate-determining step of Ca evaporation were determined. • Systematic elucidation of factors affecting Ca evaporation from Si–Ti melts. [ABSTRACT FROM AUTHOR]

The stress field is a critical factor for fracture propagation in hydraulic fracturing. Attention should be paid to fracture propagation with the nonuniform stress field. A stress field with gradient was established to investigate the influence of the nononuniform stress on fracture propagation. Based on the three‐dimensional block distinct element model the fracture propagation law with nononuniform stress was obtained. The mechanism of stress gradient and magnitude of uneven fracture propagation was revealed. Aiming at the uneven propagation, the influence of elastic modulus and construction parameters was analyzed. The results show that the influence of the elastic modulus follows the χ2 distribution equation and the influence of construction parameters can be expressed by the product of the injection rate and fluid viscosity. This conclusion is of theoretical significance for fracturing with nonuniform in situ stress. [ABSTRACT FROM AUTHOR]

Hf was employed as an impurity getter to enhance the removal of impurities from metallurgical-grade Si (MG-Si) via the solidification of Si or a Si-33 wt% Al solvent. The leaching behaviors of the impurities (B, Fe, Al, Ca, P, Zr, Ti, V, Mn, Hf, and Ni) within MG-Si, in the presence of 5 wt% Hf, were investigated using various leaching approaches. Compared with aqua regia and HF, HCl + HF was determined to be the optimal lixiviant for the elimination of impurities from Hf-containing MG-Si. The use of a combination of HCl + HF and aqua regia reduced the quantity of impurities from 6126 ppmw to 94 ppmw. Eh-pH diagrams were calculated to discuss the leaching of HfSi 2 in aqua regia and HF solutions. The presence of Hf in the MG-Si enhanced the removal of impurities, especially P, which cannot be efficiently removed via solidification refining and hydrometallurgical treatments. Hf-containing Si-Al solvent refining is considered the most efficient approach for the elimination of impurities (except Al). The removal fractions of B and P were 94.2% and 86.2%, respectively, achieved via the solidification of the Si-33 wt% Al solvent. Moreover, 99.94% and 99.9996% of the Hf, used as an impurity getter, could be eliminated through the solidification of the Si and Si-33wt% Al solvent, respectively, decreasing from 50,000 ppmw, to 28 ppmw and 0.2 ppmw, respectively. [ABSTRACT FROM AUTHOR]

Zr was employed as an impurity getter to enhance removal of impurities from MG-Si because of its strong affinity for a wide range of impurities. Different lixiviants, HCl + HF, HF and aqua regia, were employed to investigate the leaching behavior of MG-Si at 348 K for 2.5 h with and without Zr addition. Typical precipitates at Si grain boundaries before and after acid leaching were observed and analyzed via scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS). The leaching results show that the order of efficiency of the lixiviants, from highest to lowest, is HCl + HF > HF > aqua regia. HCl + HF is the optimal lixiviant for purification of MG-Si with and without Zr addition. The presence of Zr in MG-Si can significantly enhance the efficient extraction of impurities, especially P and Al, which cannot be removed efficiently using conventional hydrometallurgical technologies. The total fraction of impurities removed (Fe, Al, Ca, B, P, Zr, Ti, V, Mn, Cu and Ni) increased from 94.2 to 97.5% after HCl + HF leaching. In addition, 99.9% of the impurity getter Zr was removed, with its concentration decreasing from 50,000 ppmw to 49 ppmw after HCl + HF leaching. The residual amount of Zr in the refined Si can be further removed by directional-solidification purification because of its extremely small segregation coefficient. [ABSTRACT FROM AUTHOR]

A small amount of Hf was employed as a new additive to improve B removal in the electromagnetic solidification refinement of Si with an Al–Si melt, because Hf has a very strong affinity for B. The segregation ratio of Hf between the solid Si and Al–Si melt was estimated to range from 4.9 × 10−6to 8.8 × 10−7for Al concentrations of 0 to 64 at.%, respectively. The activity coefficient of Hf in solid Si at its infinite dilution was also estimated. A small addition of Hf (<1025 parts per million atoms, ppma) significantly improved the B removal. It was confirmed that the use of an increased Hf addition, slower cooling rate, and Al-rich Al–Si melt as the refining solvent removed B more efficiently. B in Si could be removed as much as 98.2% with 410 ppma Hf addition when the liquidus temperature of the Al–Si melt was 1173 K and the cooling rate was 4.5–7.6 K min–1. The B content in Si could be controlled from 153 ppma to 2.7 ppma, which meets the acceptable level for solar-grade Si. [ABSTRACT FROM PUBLISHER]

[Display omitted] • The quantitative analysis of microstructure of wax crystals was discussed. • The fractal dimension and unit cell structure of wax crystals were studied. • Existence state of asphaltenes can affect the structural integrity of wax crystals. The influence of asphaltenes on the wax crystallization has long been studied, yet the quantitative analysis of microstructure of wax crystals are rarely involved. In this research work, paraffin (C20∼C40) and n-heptane asphaltenes were used to prepare model oils containing varying amounts of asphaltenes. By means of the Fourier transform infrared spectroscopy (FTIR), microscopy and X-ray diffraction (XRD), the influence of asphaltenes on the microstructure of wax crystals was systematically analyzed focusing on the fractal dimension (area box dimension, perimeter box dimension and average size) and unit cell. Four main findings were made: (1) The influence of asphaltenes on microstructure of wax crystals mainly depends on its existence state, that is, the dispersed asphaltenes and aggregated asphaltenes. (2) As the asphaltene concentration increases, asphaltenes gradually transform from dispersed to aggregated state, and the area box dimension of waxy crystals increases firstly and then decreases, and the maximum occurs at the transition of asphaltenes state, while asphaltenes have no significant effect on the perimeter box dimension of wax crystals. (3) At lower temperatures, the average size of wax crystals without asphaltenes is significantly larger than that cases with asphaltenes, but it can be ignored as the temperatures increase. (4) Existence state of asphaltenes can affect the structural integrity of wax crystals. When the asphaltenes are well dispersed, XRD shows that the structure of wax crystals is relatively intact, but when the asphaltenes are aggregated state, wax crystals show more defects. This study is expected to provide guidance for the control of flow assurance in the coexistence of wax and asphaltenes from the mechanism level. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu, Co and Sn in copper converter slags were recovered in a Cu-Co-Sn-Fe alloy. • Excessive coke or CaO worsened metal-slag separation and decreased metal yield. • Pig iron addition raised Co yield due to the enrichment of Co in an Fe–Co alloy phase. • Cu, Co and Sn yields from converter slag reached 94.4%, 90.1% and 95.0% respectively. Massive amounts of waste copper converter slags have been produced from pyrometallurgical extraction of copper from copper concentrates, and the disposal of them in landfills creates serious environmental problems. However, this converter slag contains numerous valuable heavy metals, including copper, cobalt and tin etc. In this research, due to similar properties of iron and cobalt, pig iron with a low melting point was creatively used as capturing agent for cobalt recycling in a smelting reduction. The recovery of copper and tin was also studied. The phase transformation during reduction process was clarified by X-ray diffraction and Scanning electron microscope-energy dispersive spectrometer analyses. After the reduction performed at 1250 °C, the copper, cobalt and tin were recovered in a copper-cobalt-tin-iron alloy. The addition of pig iron improved cobalt yield, which was ascribed to the enrichment of cobalt in an iron–cobalt alloy phase. This decreased activity of the reduced cobalt and promoted reduction of cobalt oxide. As a result, the cobalt yield had a significant increase from 66.2% to 90.1% by adding 2% pig iron. Similarly, the copper also accelerated tin recovery through the formation of a copper–tin alloy. The copper and tin yields reached 94.4% and 95.0%, respectively. This work provided a high efficiency method to recover copper, cobalt and tin from waste copper converter slags. [ABSTRACT FROM AUTHOR]

A new electrochemical DNA biosensor based on double-probe mode and enzyme-mediated multiple signal electrocatalysis is constructed for the highly sensitive determination of double-stranded (ds-) PML/RARα fusion gene. Through the ingenious design of two groups of detection probes, including two thiolated capture probes anchored on dual standalone detection units integrated into one customized gold electrode and four biotinylated reporter probes, hybridizing with different segments of the same target single-stranded DNA (ssDNA) simultaneously, the hybridization efficiency between the probes and target is improved by preventing the reannealing of the two separate target ssDNA. Compared with a single reporter probe, this method can dramatically increase the amount of biotin and introduce numerous streptavidin-labelled horseradish peroxidase (HRP), thereby significantly amplifying electrochemical signals with low background signals. The combination of the dual-probe mode, multiple signal amplification strategy, and the inherent electrocatalytic activity of the HRP results in the prominent electrochemical sensing performance in detecting large-fragment target dsDNA with a detection limit as low as 71 fM. Furthermore, taking advantage of the new detection strategy, polymerase chain reaction (PCR) products and enzyme-digested PCR products from NB4 cells can be effectively analysed, showing great promise for the development of a new class of point-of-care platforms for disease-/drug-related genes. [Display omitted] • An E-DNA biosensor based on dual-probe mode and enzyme-mediated multiple signal electrocatalysis is constructed. • The dual-probe E-DNA biosensor exhibits excellent selectivity and specificity for detection of a larger dsDNA segment. • The practicability of this biosensor is well proven by determining both PCR products and enzyme-digested PCR products. • The dual-probe biosensor provides an alternative method for the development of rapid and sensitive diagnostic platform. [ABSTRACT FROM AUTHOR]

This paper summarizes the experimental work done on the wax deposition in a waxy crude oil, considering the impact of the dispersion degree of asphaltene. Asphaltene from Venezuela residue was added into the waxy crude oil at several concentrations, and the dispersion degree of asphaltene was determined by the size distribution of asphaltene measured with microscopic observation and software analysis. Based on the size distribution of asphaltene, it shows two types of asphaltenes: dispersed asphaltenes (< 2 μm) and aggregated asphaltenes (> 2 μm). By using a differential scanning calorimeter (DSC) measurements and coldfinger experiments, it is shown that the dispersed asphaltenes can inhibit the wax precipitation, and the concentration gradient of wax molecules between the bulk and deposit surface is increased, favoring wax deposition. The aggregated asphaltenes can provide crystal cores, promote wax molecules to precipitate in advance, and decrease the concentration gradient of wax molecules, depressing the wax deposition. Additionally, it is found that the dispersed asphaltenes play little role in hindering wax molecule diffusion towards the deposition surface. Furthermore, the idea that the n-paraffin component in deposits is a function of the dispersion degree of asphaltene is supported by the high-temperature gas chromatography (HTGC) measurements. [ABSTRACT FROM AUTHOR]

Small amounts of Ti (<2037 ppma) were employed as an additive to enhance B removal from Si in electromagnetic solidification refining with an Al–Si alloy. The B removal process was investigated by varying the initial concentration of Ti, the cooling rate, and the liquidus temperature of the Al–Si alloy. Experimental results show that the small amounts of Ti were primarily responsible for enhancing B removal. This B removal process was more efficient at lower cooling rates combined with the use of Al–Si alloy solvents having lower liquidus temperatures. With the addition of 2037 ppma Ti, the residual B in the refined Si could be controlled to 1.2 ppma, which meets the requirements for manufacturing solar cells. The added Ti could be simultaneously removed because of its extremely low segregation coefficient between solid Si and liquid Al–Si alloy. Although trace amounts of Ti and Al were present in the refined Si, they are expected to be removed in the next processing step, which is directional solidification in vacuum. Finally, the mechanism of this B removal process is discussed. [ABSTRACT FROM AUTHOR]

In order to strengthen B removal during purification of Si with Al–Si solvent, small amounts (<1100 ppma) of transition metals (Hf, Zr, Ti, and Nb) were employed as additives because of their strong affinity for B. The results showed that the B removal process can be significantly improved by adding small amounts of Hf, Zr, and Ti and that Hf and Zr are more efficient for strengthening B removal than Ti or Nb. Nb had no effect on B removal. These additives could be also efficiently removed because of their extremely small segregation coefficients. [ABSTRACT FROM AUTHOR]

A novel polyaniline/α-cyclodextrin (PANI/α-CD) composite coated stir bar was prepared by sol–gel process for the analysis of polychlorinated biphenyls (PCBs) in this work. The preparation reproducibility of the PANI/α-CD-coated stir bar was good, with relative standard deviations (RSDs) ranging from 2.3% to 3.7% ( n =7) and 2.0% to 3.8% ( n =7) for bar to bar and batch to batch, respectively. Based on it, a novel method of PANI/α-CD-coated stir bar sorptive extraction (SBSE) followed by high performance liquid chromatography-ultraviolet (HPLC-UV) detection was developed for the determination of trace PCBs in environmental waters. To obtain the best extraction performance for target PCBs, several parameters affecting SBSE, such as extraction time, stirring rate, and ionic strength were investigated. Under optimal experimental conditions, the limits of detection (LODs) of the proposed method for seven PCBs were in the range of 0.048–0.22 μg/L, and the RSDs were 5.3–9.8% ( n =7, c =1 μg/L). Enrichment factors (EFs) ranging from 39.8 to 68.4-fold (theoretical EF, 83.3-fold) for target analytes were achieved. The proposed method was successfully applied for the determination of seven target PCBs in Yangtze River water and East Lake water, and the recoveries were in the range of 73.0–120% for the spiked East Lake water samples and 82.7–121% for the spiked Yangtze River water samples, respectively. [ABSTRACT FROM AUTHOR]

CdSe/graphene composites with different contents of graphene were prepared by the solvothermal method. The composites were characterized by X-ray diffraction, scanning electron microscope and further investigated by transient photocurrent responses and electrochemical impedance spectroscopy. Compared with pure CdSe particles, CdSe/graphene composites show improved photocurrent responses and decreased electron-transfer resistance due to the presence of graphene, which acts as an electron collector and transporter as well as the supporting matrix for CdSe particles. The composites were synthesized by varying the graphene content from 0.5 wt% to 6 wt%, which has been experienced to exert great influence on the photoelectric characteristics of CdSe/graphene composites. A higher photocurrent density and smaller arc radius can be observed for 0.5% CdSe/graphene composites. [ABSTRACT FROM AUTHOR]

Ternary Zn X Cd 1− X S particles were directly immobilized on graphene sheets by a facile solvothermal route with zinc acetate, cadmium acetate and thiourea as precursors, ethylene glycol as reaction solvent and graphene oxide as support. The value of x could be adjusted by controlling the molar ratio of Zn and Cd precursors. The products were characterized by X-ray diffraction, scanning electron microscope and ultraviolet–visible absorption. The photoelectric properties of the graphene-Zn X Cd 1− X S composites were investigated by transient photocurrent responses and electrochemical impedance spectra, and the results show that the obvious increase in the photocurrent density and decrease in electron-transfer resistance can be seen for graphene-Zn 0.8 Cd 0.2 S composites as compared to graphene-Zn X Cd 1− X S composites with other Zn/Cd ratios. [ABSTRACT FROM AUTHOR]

The solidification refining of Si using a Si–Sn solvent was investigated under various cooling conditions: (1) slow cooling, (2) slow cooling with electromagnetic stirring, and (3) directional solidification with the aim of developing a novel low-cost route for solar-grade Si production. The separation efficiency of refined Si achieved by combining slow cooling and electromagnetic stirring was much higher than that achieved using directional solidification; in addition, the purification efficiency of the refined Si in both methods was similar. The separation mechanism of refined Si from a Si–Sn melt is also discussed. Purification testing of the refined Si revealed that more than 96% of the metallic impurities, approximately 60% B, and over 70% P were removed. [ABSTRACT FROM AUTHOR]

CdS x Se 1− x –graphene composites were prepared by a solvothermal process using cadmium acetate as Cd precursors, sulfourea as S precursors and selenium powder as Se precursors. CdS x Se 1− x –graphene composites were characterized by X-ray diffraction, scanning electron microscope and ultraviolet–visible absorption spectroscopy. The photoelectric properties of CdS x Se 1- x –graphene and bare CdS x Se 1- x were investigated by transient photocurrent responses and three-electrode cyclic voltammetry. Compared with bare CdS x Se 1− x , CdS x Se 1− x –graphene composites show the improved photoelectric characteristics in the presence of graphene. [ABSTRACT FROM AUTHOR]