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Ceramic nanofiber membrane (CNM) based on attapulgite (APT) without any intermediate layer neither any cracks was fabricated by a one-step dip-coating method. The effects of sintering temperature and dip-coating time on the physicochemical properties and performances of prepared CNMs were investigated. The increase of the sintering temperature up to 700 °C reduced the bending strength, porosity and chemical stability of APT-based CNMs. Meanwhile, with the dip-coating time increased, the membrane thickness increased thereafter reduced. The APT-based CNM fabricated at a sintering temperature of 600 °C and with a dip-coating time of 15 s had an average pore size of 20.4 nm, high porosity (above 60 %), good permeability of 118 L/m2 h bar and a rejection of 96.6 % polymers with a molecule weight of 600 kDa. All these properties clearly suggest the practicability of the one-step dip-coating method to prepare ceramic nanofiber membranes.

To solve the contradiction between particle size and color performance, an ultrafine V-ZrSiO4 pigment was successfully synthesized by sol–gel-microemulsion-hydrothermal (S-G-M-H) method in this paper. Meanwhile, the effects of hydrothermal time on the chromatic parameter, particle size distribution, phase composition, valence bond species and microstructure of the precursor and pigment were systematically investigated. Moreover, the color deterioration mechanism of V-ZrSiO4 nano-grain pigment was also revealed. The results demonstrate that the median diameter (D50) of the obtained V-ZrSiO4 pigment is only 0.972 μm. Besides, the synthesized pigment has vivid blue hue and superior tinting strength. As the increase of hydrothermal time, the particle size of V-ZrSiO4 pigment decreases, while the color performance of the pigment deteriorates. The color deterioration mechanism is attributed to the dual effects of the reduction of vanadium content in the outer layers of pigment particles and the enhancement of visible light reflection intensity.

The mechanism of ferrite nucleation induced by different oxide particles was studied in this article. The inclusion insertion experiment as a simulated experiment was carried out using different oxide powders on a thermal simulator under certain heat treatment conditions. The main results showed that the chemical influences of oxide particles on ferrite nucleation are difficult to occur under solid-phase transformation conditions. The change of microstructure near the oxide particles may be related to the effect of thermal properties of oxide particles. Heat conduction performance of oxide particles may cause slower heat dissipation around the oxide particles, resulting in the variation of temperature gradient near the oxide particles. This temperature gradient may lead to the increasing diffusion of carbon atoms, which increases the driving force of ferrite nucleation and growth. The effect of thermal properties of oxide particles on ferrite phase transformation seems to provide a new insight for the study of the mechanism of acicular ferrite nucleation induced by inclusions in low carbon steels.

Background Pancreaticobiliary reflux (PBR) causes chronic inflammation of the gallbladder mucosa and changes in the bile components, which are known to promote gallstone formation. This study aimed to investigate the bile biochemistry changes in gallstone patients with PBR and provide new clues for research on the involvement of PBR in gallstone formation. Methods Patients undergoing surgery for gallstones between December 2020 and May 2021 were eligible for inclusion. The bile biochemistry (including amylase, lipase, triglyceride, cholesterol, free fatty acids [FFAs], alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [ALP], and γ-glutamyl transferase [γ-GT]) of the included gallstone patients was analysed to determine correlations with PBR. Results In this study, 144 gallstone patients who underwent surgery were enrolled. Overall, 15.97 % of the patients had an increased bile amylase level, which was associated with older age and significantly higher bile levels of ALP, lipase, triglyceride, and FFAs. Positive correlations were observed between amylase and lipase, triglyceride, FFAs levels in the gallbladder bile. However, the bile levels of triglyceride, FFAs, and lipase were positively correlated with each other only in the PBR group and showed no significant correlation in the control (N) group. In addition, elevated bile FFAs levels were found to be an independent risk factor for gallbladder wall thickening. Conclusions In conclusion, PBR-induced increase in FFAs and triglyceride in the gallbladder bile is a cause of gallstone formation, and an increase in bile ALP suggests the presence of cholestasis in PBR.

We systematically investigate the plugging performance and oil-displacement efficiency of the novel bilayer-coating microspheres (BCMS) designed for in-depth conformance control within heterogeneous hydrocarbon reservoirs. Visualization experiments on various glass models, as well as one- and two-phase core floods have been carried out at reservoir temperature and fluid salinity. Our results demonstrate that the rigid outer layer of BCMS can successfully protect its adhesive inner coating, enabling BCMS to transport deeply into porous media. Increasing particle concentration yields higher collision probability, leading to the formation of particle assembly that could effectively block pore throats in high-permeability channels and achieve more oil recovery in the low-permeability zones. It is also shown that as the BCMS slug size increases, the oil recovery asymptotically reaches a maximum value. A larger slug size cannot highly enhance the plugging performance yet significantly increase the resistance factor. A smaller permeability ratio of parallel cores leads to a narrower difference between the fractional flow rates. When the permeability ratio is two or lower, the fractional flow rates of parallel cores are both around 50%, yielding the best oil-displacement efficiency. BCMS exhibits promising application potential in production enhancement under reservoir conditions.

The Sichuan-Yunnan-Guizhou Pb-Zn metallogenic province (SYGMP) is an important region for Pb-Zn resources in China. However, considerable controversy remains as to whether the Pb-Zn deposits are Mississippi Valley Type (MVT). The Maozu deposit, a typical example of the carbonate-hosted Pb-Zn deposits in the SYGMP, occurs in the late Ediacaran Dengying Formation and its ore bodies are divided into three types: lower layer (LL), vein layer (VL), and upper layer (UL) ore bodies based on their spatial relationship. In this study, laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) was used to systematically analyze the trace-element compositions of sphalerite and galena in these three ore bodies. The results show that sphalerite is characterized by Cd and Ge enrichment; Fe, Mn, and Co depletion; and local In and Sn enrichment. Most of these elements likely appear as solid solutions in sphalerite and show a wide compositional variation, which is probably related to the medium- and low-temperature mixing of the ore-forming fluids. The local enrichment of In and Sn is likely attributed to the long-distance migration of ore-forming fluids through In-Sn-bearing volcaniclastic rocks. In vs. Sn and (Cu + Sb) vs. (Ag + Ge) show strong correlations and similar element distribution in the mapped images, indicating that these elements may be incorporated into sphalerite via a coupled substitution for Zn as 2In3+ + Sn4+ + 2☐ ↔ 5Zn2+ (☐ = vacancies) and 4(Cu+ + Sb3+) + (Ge4+ + 2Ag+) + 2☐ ↔ 13Zn2+. Galena is enriched in Ag and Sb with minor Cd and Se and depleted in Bi, and most of the elements may occur as solid solutions. Ag vs. Sb in galena displays a strong positive correlation, implying the coupled substitution of Ag+ + Sb3+ ↔ 2Pb2+. Notably, the majority of the trace-element concentrations gradually decrease in the order LL → UL except Fe, Co, Cu, and Ge, while Fe, In, and Sn in sphalerite and Ag and Sb in galena have the highest concentration in the VL, indicating that the VL is a secondary migration channel for the ore-forming fluids. Furthermore, the trace-element compositions of the sulfides in the Maozu Pb-Zn deposit are consistent with the typical MVT deposit (hosted in the carbonate sequence) but are markedly different from sedimentary exhalative (SEDEX), volcanogenic massive sulfide (VMS) and skarn-type deposits. Based on these results, as well as the geological and geochemical characteristics of the deposit, the Maozu Pb-Zn deposit is an MVT deposit.

Oleic acid-modified titania (OA-TiO2) nanoparticles are synthesized for the application of enhanced oil recovery (EOR) in low-permeability reservoirs. The oleic acid is grafted onto the surface of ...

Catalytic performances of Mn2O3 nanoparticles for peroxymonosulfate (PMS) activation in bisphenol A (BPA) degradation were comprehensively investigated in this study. Experimental results showed that 10 mg/L BPA could be 100% degraded within 20 min with the dosages of 0.2 g/L Mn2O3 and 0.1 mM PMS. Moreover, Mn2O3 showed remarkable activity in activation of PMS and excellent adaptability in various real water matrices, including river water, tap water and secondary effluents. Based on the radical detection and scavenging experiments, it was found that both radical and non-radical oxidation contributed to the degradation of BPA and 1O2 was the dominant species in the degradation compared to •OH, SO4•− and O2•−. A total of 15 transformation products were identified by LC/MS-MS during BPA degradation in the Mn2O3/PMS system, and degradation pathways via three routes are proposed. Compared with lab-made catalysts reported in the literature, the Mn2O3 catalyst demonstrated its superiority in terms of its high TOC removal, low PMS consumption and fast degradation rate for BPA.

The Dongzigou Pb-Zn deposit is located in the south-eastern margin of Yangtze block, Midwest China. Ore bodies are hosted in Sinian carbonate rocks. The main metallic minerals are sphalerite and galena, while the non-metallic minerals are dolomite, barite, and quartz. Three stages of hydrothermal mineralization are an early quartz-pyrite stage (stage I), a middle sphalerite-galena stage (stage II), and a late sphalerite-barite stage (stage III). The main types of fluid inclusions for the Dongzigou deposit are liquid-rich inclusions (L0-type). Laser Raman analysis indicates that the fluid inclusions within the hosted minerals are dominated by H2O. Given the fluid inclusion data, the homogenization temperatures range from 220.0–300.0 °C (stage I), 126.7–243.9 °C (stage II), and 117.0–201.0 °C (stage III), respectively. Fluid salinities range from 3.4–11.8 wt% NaCl eq. (stage I), 3.6–10.7 wt% NaCl eq. (stage II), and 2.0–6.5 wt% NaCl eq. (stage III), respectively. Indicating that the ore-forming fluid of the Dongzigou deposit tends to decrease in salinity and homogenization temperature during the fluid evolution process. The δD (−63.4% to −49.8%) and δ18OH2O (0.6 to 13.7%) data from stage I to stage III which indicate that the ore-forming fluids derived from formation water, and in the late stage of hydrothermal mineralization mixed with meteoric water. The LA-ICPMS results show that sphalerite enriched Cd (1272–3437 ppm), Ge (201–717 ppm), and Ga (0.1–130 ppm), but poor in In (0.01–0.1 ppm). Through comparative studies with the trace elements of sphalerite from different types of Pb-Zn deposits, it is found that the trace element characteristics of the Dongzigou deposit are most similar to the MVT deposits. Overall, the Dongzigou Pb-Zn deposit is an atypical MVT deposit, and the salinity of fluid inclusions is lower than that of typical MVT deposits.

To obtain the ultrafine pigment for ink-jet printing, ultrafine spherical Pr-ZrSiO4 pigment was prepared by sol-gel-microemulsion method (S-G-M). In the emulsion, ZrO2 and SiO2 sols are used as water phase, cyclohexane serves as oil phase, Triton X-100 and 1-hexanol are chosen as surfactant and co-surfactant, respectively. The results show that without the introduction of demulsifier, the sol/oil microemulsion system is demulsified automatically due to the transformation of liquid/liquid to solid/liquid interface following the transformation from sol to gel. The obtained Pr-ZrSiO4 pigment owns uniform spherical particles with the average particle size of about 0.785 μm, which is suitable for the ink-jet printing. The CIE coordination of the pigment is L* = 87.63, a* = −3.82, b* = 65.68, which shows bright lemon yellow. Hence, the ultrafine pigment in this work has the good application prospects.

During micro-scale tracer flow in porous media, the permeability and fluid velocity significantly affect the fluid dispersion properties of the media. However, the relationships between the dispersion coefficient, permeability, and fluid velocity in core samples are still not clearly understood. Two sets of experiments were designed to study the effects of tracer fluid flow velocity and porous medium permeability on the dispersion phenomenon in a core environment, using natural and sand-filled cores, respectively. From experimental data-fitting by a mathematical model, the relationship between the dispersion coefficient, flow velocity, and permeability was identified, allowing the analysis of the underlying mechanism behind this phenomenon. The results show that a higher volumetric flow rate and lower permeability cause a delay in the tracer breakthrough time and an increase in the dispersion coefficient. The core experimental results show that the dispersion coefficient is negatively correlated with the permeability and positively correlated with the superficial velocity. The corresponding regression equations indicate linear relations between the dispersion coefficient, core permeability, and fluid velocity, resulting from the micron scale of grain diameters in cores. The combination of high velocity and low permeability yields a large dispersion coefficient. The effects of latitudinal dispersion in porous media cannot be ignored in low-permeability cores or formations. These findings can help to improve the understanding of tracer flow in porous media, the design of injection parameters, and the interpretation of tracer concentration distribution in inter-well tracer tests.

Foam-assisted steam flooding is a promising technique to alleviate gas channeling and enhance sweep efficiency in heterogeneous heavy-oil reservoirs. However, long-term foam stabilization remains problematic at high temperatures. Three-phase foam (TPF), containing dispersed solid particles, has been proposed to improve foam stability under harsh reservoir conditions. We fabricated a novel TPF system by adding ultrafine fly ash particles, as well as high-temperature resistant microspheres with an adhesive coating layer. This work aims at assessing the ability of the generated TPF in controlling steam channeling and enhancing oil recovery. Static and core flood tests were performed to evaluate foam strength and stability. Our results suggested a stronger foamability at a lower consolidation agent concentration, while a longer half-life period of foam and settling time of solid particles at a larger consolidation agent concentration were observed. Bubbles suspended independently in the liquid phase, with sizes varying from 10 to 100 μm, smaller than that of the conventional foam, suggesting a significant enhancement of foam dispersity and stability. The plugging rate was close to 90% when the temperature was as high as 300 °C, demonstrating a well-accepted plugging effect under high temperatures. A larger pore volume injection of TPF yielded a higher EOR in parallel cores, which substantiated the effectiveness of the three-phase foam system in sealing high-permeability channels.

Objectives This study was conducted to identify the significantly altered long noncoding RNAs (lncRNAs), messenger RNA (mRNA) and pathways in gastric cancer (GC). Methods We used microarray analysis to identify differentially expressed lncRNAs and mRNAs, whereas the obviously changed pathways were found by gene set enrichment analysis. The coexpression network of lncRNA and mRNA was constructed by Cytoscape, and their target relationships with miRNAs were predicted by miRcode and TargetScan. qRT-PCR and Western blot were performed to determine the expression levels of mRNAs and proteins in tissues and cell lines. Dual-luciferase reporter assay was applied to achieve the determination of the specific target relationships. Cell viability, migration, and apoptosis were detected by MTT assay, wound healing assay and flow cytometry, respectively. Through the xenograft assay, the gastric tumor was implanted into nude mice to investigate the influence of HOTAIRM1 in vivo. Results HOTAIRM1 and phosphatase and tensin homolog (PTEN) were both downregulated in GC, whereas miR-17-5p was upregulated. Moreover, the PI3K/AKT pathway was found activated in GC. HOTAIRM1 targeted miR-17-5p, whereas PTEN was the downstream target gene of miR-17-5p. HOTAIRM1 suppressed proliferation and migration of GC cell line and induced their apoptosis, whereas miR-17-5p played the opposite role on GC cell line. HOTAIRM1 also postponed tumor growth in vivo and inhibited the PI3K/AKT pathway in GC. Conclusions LncRNA HORAIRM1 suppressed the PI3K/AKT pathway in GC and inhibited the progression of GC by serving as a competing endogenous RNA of miR-17-5p, mediating the expression of PTEN.

Free amino acids (FAAs) are key components of the global nitrogen cycle and important disinfection byproduct (DBP) precursors. The knowledge gap of FAA occurrence in source and engineered water is discussed in this paper. Solid phase extraction and post column derivatization was combined with gas chromatography&ndash, mass spectrometry to simultaneously detect &mu, g/L concentrations of FAAs. This method efficiently detects alanine (Ala), threonine (Thr), serine (Ser), valine (Val), leucine (Leu), isoleucine (Ile), proline (Pro), aspartic (Asp), phenylalanine (Phe), and glutamic acid (Glu) with good linearity, accuracy, and precision. An investigation of FAAs in surface waters in Zhejiang Province found concentrations of 1.48&ndash, 14.73 &mu, g/L Ala, 0.20&ndash, 2.39 &mu, g/L Thr, 0.41&ndash, 7.84 &mu, g/L Val, 0.21&ndash, 6.86 &mu, g/L Ser, 0.11&ndash, 4.16 &mu, g/L Leu, 0.57&ndash, 1.54 &mu, g/L Ile, 0.24&ndash, 8.06 &mu, g/L Pro, 0.42&ndash, 4.73 &mu, g/L Asp, 0.30&ndash, 3.01 &mu, g/L Phe, and 0.12&ndash, 3.83 &mu, g/L Glu. Phe and tyrosine (Tyr) exhibited higher trichloromethane (TCM) formation (1029&ndash, 1148 &mu, g/mmolAA) than dichloroacetonitrile (DCAN) formation (333&ndash, 347 &mu, g/mmolAA). Asp and Glu demonstrated the opposite trend: higher DCAN (570&ndash, 1106 &mu, g/mmolAA) formation than TCM (137&ndash, 506 &mu, g/mmolAA).

Abstract. Plant carbon (C) content is one of the most important plant traits and is critical in the assessment of global C cycle and ecological stoichiometry. However, the global variation in plant C content remains poorly understood. We conducted a global analysis of the plant C content by synthesizing data from 4318 species to provide specific values of C content and to assess their variation across plant organs and life forms. Our results showed that C content varied markedly across plant organs. Plant organ C content ranged from 45.01 % in reproductive organs to 47.88 % in stems at global scales, which were significantly lower than a canonical value of 50 % that has been widely employed in previous studies. Plant C content in leaves was higher than that in roots. Across life forms, woody plants exhibited higher C content than herbaceous plants. Conifers, relative to broad-leaved woody species, had higher C content in roots, leaves and stems. Plant C content tended to decrease with the increasing latitude. The life form explained more variation of the C content than climate due to plant structural requirements. Our findings suggest that specific C content values from different organs and life forms may be more suitable to evaluate global vegetation C stock and plant ecological stoichiometry.

Oxide superlattices often exhibit emergent physical properties that are desirable for future information device applications. The most common growth technique for fabrication of oxide superlattices is pulsed laser deposition (PLD), which is convenient yet powerful for the growth of various oxide superlattices. However, the sample size prepared by PLD is rather small confined by the plasmon plume, which greatly limits its potential for device applications. Here, we design a PLD system that is capable of fabricating large-sized oxide superlattices with high uniformity. Specifically, during growth, the laser beam scans the target surface by combining the pitch and yaw angle rotation of the high reflective mirror and the linear motion of the focus lens. A SiC susceptor is placed in between the sample holder and the substrate to improve the large area infrared heating efficiency. Using such a system, droplet-free 10 × 10 mm2 [(LSMO)12/(PCMO)6]7 superlattices are epitaxially grown with the same period of superlattices across the whole sample areas. The high uniformity of the superlattices is further illustrated by near identical physical properties of all regions of the superlattice films. The present PLD system can be used to grow various kinds of oxide superlattices with the area size as large as 2 in., which is highly useful for device applications of oxides.

As a globally important artificial sweetener, sucralose (SUC) is a persistent emerging contaminant in global aquatic environments. This research comprehensively track the fate and transport of SUC throughout an urban water cycle; to perform laboratory experiments to determine chlorinated disinfection by-products (DBPs) of SUC sebsequent to advanced oxidation with ozone; and to perform a risk evaluation of SUC related DBPs.; The results demonstrated that SUC was consistently present throughout the urban water cycle, including consumer's tap water. The inluent to the municipal wastewater treatment plant contained 1033.4-2626.3 ng/L SUC, and as expected for this non-biodegradable artificial sweetener, the concentration in the effluent was slightly reduced to 917.6-2031.2 ng/L. The concentration of SUC varied in surface waters with a peak value of 2070.0 ng/L. In finished drinking water 288.1–505.3 ng/L SUC was found, and values of 177.7–409.7 ng/L were present in the distribution system. Up to 16.3% of SUC concentration discharged as municipal wastewater was delivered to residents in their drinking water. While conventional treatment little removed SUC, the mean removal efficiency of SUC with ozonation followed by activated carbon filtration was 39.6% at a full-scale drinking water treatment plant. The fate and transformation of SUC in drinking water treated by ozonation and chlorination were investigated in laboratory experiments. Ozonation partially degraded SUC; however, intermediates reacted with chlorine to generate DBPs, including trichloromethane (TCM), dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA). Peak 7-days potential formation of TCM, DCAA and TCAA were 0.016, 0.51 and 23.34 μ g/mg SUC, respectively. DBP yields increased with increasing chlorine dosage, chlorination time, temperature, and solution pH. The presence of ammonia nitrogen in water facilitated dichloroacetonitrile (DCAN) production up to 0.78 μ g/mg SUC, while simultaneously reducing the yield of TCM, DCAA and TCAA. Human exposure analysis revealed that carcinogenic risks of DBPs caused only by SUC ozonation were in the range of 1.86 × 10−12-6.12 × 10−9, while non-carcinogenic risks were in the range of 6.0 × 10−9-4.37 × 10−6. The pervasive occurrence of SUC in an urban water cycle, couple to its resistance to biological and chemical treatment, confirms that SUC is a persistent contaminant in the aquatic system, including tap water.

The rapid and credible evaluations of the microbial stability of a drinking water distribution system (DWDS) are of great significance for ensuring the safety of drinking water and predicting microbial pollution. Conventional biostability assessment methods mainly focus on bacterial regrowth or evaluation of the level of nutrients that support bacterial regrowth. However, such methods are time-consuming and have many limitations. An adenosine triphosphate (ATP) assay can rapidly measure all active microorganisms and is known to be a useful method to assess the microbial activity of drinking water. The measurement of ATP has been used for more than a decade in the field of drinking water research. This article reviews the application of an ATP luminescence-based method to assess the biostability of drinking water and discusses the feasibility of ATP measurement as a parameter for quickly evaluating this criterion. ATP measurement will help researchers and water managers better monitor the biological stability of drinking water from the source to the consumer’s tap. This review covers the: (1) principle and application of the ATP measurement in drinking water quality assessment; (2) comparison of the merits and demerits of several methods for evaluating the biostability of drinking water; (3) discussions on using ATP measurement in evaluating biostability; and (4) improvements in the use of ATP measurement in evaluating biostability. At the end of this review, recommendations were given for better application of the ATP measurement as a parameter for monitoring the microbial quality of drinking water.

In this paper, vanadium ion (V4+) doped ZrO2 pigment (Vx-ZrO2) and vanadium/yttrium ions (V4+/Y3+) co-doped ZrO2 pigment (VxYy-ZrO2) were synthesized via inorganic sol-gel route. The Vx-ZrO2 and VxYy-ZrO2 pigments with the low V4+ content still have excellent color performance, because the gel network is conducive to immobilize coloring ions which to reduce the loss of coloring ions. The results show that the Vx-ZrO2 pigment has the optimal chromatic parameters of L∗ = 68.40, a∗ = 7.93, b∗ = 43.72 when the x-value is 0.04. The measurement of EDS indicates the actual doping amount of V4+ is up to 3.14 mol%. The introduction of Y3+ in a moderate amount can increase the doping amount of V4+ in the V–ZrO2 pigment, because of Y3+ can activate zirconia lattice. Therefore, with the introduction of 1 mol% Y3+ in the ZrO2 lattice, the chromatic parameter of the pigment (i.e. V0.04Y0.01-ZrO2) is optimized to L∗ = 58.57, a∗ = 19.39, b∗ = 40.02, where the actual doping amount of V4+ increased to 3.48 mol%. Meanwhile, there is a synergy/competition mechanism in the process of V4+ and Y3+ co-doped into ZrO2 lattice. After applying on high-temperature ceramic glaze, the V0.04-ZrO2 and V0.04Y0.01-ZrO2 pigment present superior tinting strength, high thermal stability and excellent chemical stability, indicating they are attractive application in ceramic decoration.

The artificial sweeteners (ASs) saccharin (SAC) and neotame (NEO) are widely used across the globe and are considered as emerging contaminants in surface, ground, and drinking waters. To degrade SAC and NEO, the metal organic framework material Co-based bio-MOF-11 was prepared by hydrothermal reaction and used with peroxymonosulfate (PMS) activator. The effects of the initial concentration of SAC and NEO, bio-MOF-11-Co dosage, PMS concentration, initial pH, temperature, and competitive anions were determined. The results revealed that bio-MOF-11-Co effectively catalyzed the degradation of SAC and NEO and possessed good stability and recycling efficiency. The degradation reaction was effective from pH 3.6–9.8 and followed quasi-first-order kinetics with degradation rate constants of 0.001–0.013 min−1 for SAC and 0.03–0.52 min−1 for NEO. Increased temperature was conducive to the degradation of both artificial sweeteners. The presence of Cl− inhibited the degradation of SAC and NEO, while the presence of CO32− promoted their degradation. Electron paramagnetic resonance (EPR) and free radical quenching demonstrated that the primary free radicals were sulfate radicals ( SO 4 − · ) and hydroxyl radicals (HO ). The change of cobalt oxidation state and electron transfer in bio-MOF-11-Co mainly induces the production of SO 4 − · . A plausible mechanism for degradation is SO 4 − · and HO attack on C S bonds, N S bonds, and benzene rings.

Fines migration involving particle detachment in natural reservoirs usually exhibits significant permeability damage. This occurs due to mobilization and migration of detached colloidal or suspended fines that were strained in thin pore throats. Numerous laboratory coreflood tests show that the time for permeability stabilization accounts for hundreds of injected pore volumes. However, classical filtration theory assumes that the released fines are transported by the bulk of the carrier fluid, thus stabilizing the permeability after the injection of one pore volume. The current paper attributes the stabilization delay to the slow drift of the mobilized fines near the pore walls. We propose basic flow equations for single-phase particle transport in porous media with velocity lower than the carrier fluid velocity. We derive an analytical model for one dimensional flow with particle release and straining under piecewise-constant increasing velocity. The laboratory data are in high agreement with the results of mathematical modelling. The effective particle speed is 500–1000 times lower than the water velocity.

Laboratory-based mathematical modelling of fines migration allows predicting well productivity reduction during the geothermal reservoir exploitation. The analytical model for one-dimensional flow with ionic strength alteration has been derived. Good adjustment of the permeability and breakthrough concentration data from coreflood test by the analytical model has been achieved, and the tuned model coefficients fall in the common ranges. The obtained maximum retention function of multi-sized fines allows calculating their size distribution. During the temperature rise, weakening of electrostatic attraction on fines attached to rock surface overwhelms the reduction of detaching drag force due to water viscosity decrease. It leads to increased fines detachment and more severe permeability decline at elevated temperatures, typical for geothermal fields.

Foam has been widely used as a proven technology in enhanced oil recovery by improving the mobility of the injected gas. However, its further application has been retarded owing to the limited stability in high salinity, high temperature and crude oil conditions. Traditional agents for foam stabilization including surfactants, polymers are unable to stabilize foam for long term under harsh conditions. In this work, the nanogel particles with high viscoelasticity were synthesized to stabilize foam for more than one year through a free radical reaction method using α-starch, acrylamide, N,N′-methylene bisacrylamide, potassium persulfate. The diameter of nanogel particles was 30 nm. The stability of foam stabilized by nanogel particles was evaluated by using foam volume and T90 as indicators at temperature of 30–120 °C, salinity of 0–240 g/L and oil percentage of 0–50 wt%. Moreover, the rheological properties of foam were also measured to study the mechanisms of foam stability under different conditions. The results demonstrated that foam stabilized by nanogel particles exhibited excellent resistance to high salinity, high temperature and crude oil. Thus, the synthesized nanogel particles can be used as a potential candidate for stabilizing foam in enhanced oil recovery.

Taste and odor (T & O) issues in drinking water have become serious problems which cannot be ignored by customers. Several studies have confirmed that microbes in water can biotransform halophenols (HPs) to haloanisoles (HAs) with earthy and musty flavors via microbial O-methylation. In this paper, the formation of 2-chloroanisole (2-CA), 2,4-dichloroanisole (2,4-DCA), 2,4,6-trichloroanisole (2,4,6-TCA), 2,3,6-trichloroanisole (2,3,6-TCA) and 2,4,6-tribromoanisole (2,4,6-TBA), and the microbial variation during the microbial O-methylation were investigated in annular reactors (ARs) with three coupon materials. For precursors, 42.5% of 2-CP and 68.9% of 2,4-DCP decayed during the reaction. Among the five HAs, the formation rate constant followed an order of 2,4,6-TCA > 2-CA > 2,4,6-TBA > 2,4-DCA ~ 2,3,6-TCA, while [HA]max followed a totally opposite one. The simulated flow velocity had no significant effect (p > 0.05) on HA formation. Ductile iron (DI) AR could produce more HAs than stainless steel (SS) and polyvinyl chloride (PVC) ARs. The final HA molar concentration followed an order of 2,3,6-TCA > 2,4-DCA > 2,4,6-TBA ~ 2,4,6-TCA > 2-CA, which might be explained by multiple factors including HP's dissociation degree, halogen atom's steric hindrance and specificity of HP O-methyltransferases. During the reaction, the microbial biomass dramatically increased 6.8–9.0 times in bulk water but dropped significantly on coupon biofilms. The effect of HPs significantly changed the bacterial communities on coupon in terms of composition and diversity, and declined the relative abundance of HA-producing bacteria, while fungi and their HA-producing genus showed better resistance ability towards HPs. By using Pearson correlation analysis, a significant correlation (p = 0.0003) was found between [HA]max and initial coupon biofilm biomass. Finally, a linear relationship was established between initial total biomass and HA formation potential.

Using the alumina powders with different average particle sizes as main raw materials, the tubular ceramic membrane support was prepared by extrusion method, and the membrane interlayer (thickness ~20 μm) and top layer (thickness ~5 μm) were deposited on the membrane support surface by dip coating process. In order to improve the separation performance of the membrane, it was modified with FAS, nano metal oxide or graphene oxide, respectively. During the oil/water treatment, the water flux of the modified membrane is higher about 27.8–43% than that of the original membrane. The modified membrane has higher oil rejection (99%) than that of the original membrane. The results show the modification has an important role on the oil/water separation performance of the membrane.

This study examined the temporal and spatial variations in the occurrence of major algae and algae-related taste and odour (T&O) compounds in Qingcaosha Reservoir, China. Water samples were collected monthly from seven sites in the reservoir and analysed using solid phase microextraction combined with gas chromatography-mass spectrometry. Results showed that green algae were dominant over the 9-month study. In addition, cyanobacteria in the summer and early autumn peaked at 3.2 ∼ 9.6 × 106 cell/L. Among the four most common algae-related T&O compounds, dimethyl trisulphide was undetectable at any of the sampling sites, and 2-methylisoborneol (2-MIB), geosmin and β -cyclocitral were frequently over their respective odour threshold levels from August through October. β -cyclocitral concentration was linearly correlated with the concentration of cyanobacteria ( R 2 = 0.9831). The peak β -cyclocitral concentrations varied from 452 to 1,293 ng/L and were observed close to the water table. In contrast, high concentrations of 2-MIB and geosmin occurred in the water overlying sediments, probably because some of the 2-MIB and geosmin came from the micro-organisms in the sediments. These results provide important information regarding algae and algae-related T&O compounds in a typical reservoir in estuary and coastal areas, and will be helpful for developing appropriate strategies to minimize undesirable T&O issues in water sources.

The graded proppant injection into a connected cleat system of coal bed methane (CBM) reservoir allows deeper particle penetration and straining in the remote open cleats yielding higher well productivity index. The analytical model for axisymmetric flow has been derived for exponential stress–permeability relationship and accounting for permeability variation outside the stimulated zone. Laboratory proppant injections into coal cores have been performed for different proppant sizes and water salinities. It is shown that the proppant suspension based on low salinity water prevents the particle–particle and particle–coal attraction with the consequent core inlet plugging and external cake formation. However, low salinity of the injected water may cause mobilisation, migration and straining of the natural reservoir fines resulting in high formation damage. The interval where salinity is low enough for the rock inlet not to be plugged by the injected proppant, and is high enough for large formation damage due to fine migration not to occur, is proposed for the cores under investigation. The analytical model is tuned from the laboratory data and used for well index prediction. Ignoring the model matching by the laboratory results causes the overestimation of the incremental productivity index, as achieved by the graded proppant injection into coal beds below the fracturing pressure.

Permeability decline during high rate flows has been widely reported for corefloods and for production wells. The phenomenon is attributed to mobilisation of fine particles at elevated velocities, their migration in porous space with the following straining in thin pores and attachment to pore walls. Sixteen sets of corefloods with piecewise constant rate have been performed under increasing flow rate. The particularities of this study are long injection periods, allowing estimating permeability stabilisation times, and pressure measurements in intermediate core points, permitting for evaluation of the permeability profile variation along the core. It was found out that the mobilised particles drift with speeds significantly lower than the carrier fluid velocity, resulting in long permeability stabilisation periods.

Cisplatin is widely used as the standard gastric cancer treatment, but the relapse and metastasis are common as intrinsic or acquired drug resistance. CD133 has been widely known to be associated with chemoresistance in various cancer cells. In this study, we focused on investigating the function and mechanism of CD133 underlying cisplatin resistance in gastric cancer cell line KATO-III. We detected CD133 expression by using quantitative real-time polymerase chain reaction and Western blot and found that expression of CD133 was upregulated in cisplatin resistance of KATO-III cells (Cis-KATO-III) compared with KATO-III cells, indicating the role of CD133 in regulating cisplatin resistance of KATO-III cells. Then we sorted the Cis-KATO-III cells into CD133-positive (CD133+) pools and measured the proliferation and apoptosis after the cell is transfected with pc-CD133 and sh-CD133 by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay and flow cytometry. The results showed that the inhibition of CD133 inhibited the cell viability and promoted the cell apoptosis after cisplatin treatment. Furthermore, we found that inhibition of CD133 downregulated the expression of PI3K/AKT and promoted the expression of mammalian target of rapamycin, thus inhibited the autophagic activity in the Cis-KATO-III cells after cisplatin treatment. Besides, we also verified the effects of CD133 in vivo. The results indicated that inhibition of CD133 enhanced the Cis-KATO-III cell sensitivity to cisplatin by regulating PI3K/AKT/mTOR signaling pathway. In summary, our data provide new insight that CD133 activates the PI3K/AKT/mTOR signaling transduction pathway, resulting in activation of autophagy and cisplatin resistance of Cis-KATO-III cells. These results may offer a novel therapeutic target in cisplatin-resistant gastric cancer.

Fines migration involving particle detachment in reservoirs often leads to severe permeability damage. It is the consequence of straining of the detached fines in relatively narrower pore throats. Many laboratory coreflood tests indicate that the time of permeability stabilisation can reach hundreds or thousands of pore volumes injected. However, the classical filtration theory assumes that the mobilised fines are transported by the bulk of the carrier fluid, thus the permeability stabilises after one pore volume injected. The current paper attributes the stabilisation delay to the slow drift of the released fines close to the rock surface. We propose the system of flow equations for fines migration in porous media taking into account the velocity of particles lower than that of the fluid. An analytical model for one-dimensional flow with particle mobilisation and straining during piecewise increasing flow rate is obtained. The laboratory data are in good agreement with the results of mathematical modelling. The effective particle speed is 500-1000 times lower than the water velocity.

α-MnO2 nanostructures with different morphologies including nanoparticles, flower-like nanostructures and nanorods have been successfully prepared and used in the heterogeneous oxidation of naproxen in water. It has been found out that the heterogeneous oxidation process is highly pH dependent, with higher efficiency at lower pH values. The oxidation kinetics of naproxen were modeled by Langmuir–Hinshelwood equations. Based on the kinetic constants (k), the oxidation efficiency follows the order of commercial particles

Macroporous TiO2 microspheres have been synthesized on a large scale by a facile hydrothermal process using titanium tetrachloride (TiCl4) as the titanium source, ammonium fluoride (NH4F) and hydrogen peroxide (H2O2) as the etchant. X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) studies show that the anatase TiO2 microspheres are well-crystalline with an average diameter of 5.43 μm. N2 adsorption–desorption and mercury intrusion porosimetry analysis reveal that the as-prepared TiO2 microspheres are composed of numerous pore networks with an average pore diameter of 274 nm and porosity of 39.8%. In addition, the formation mechanisms of macroporous TiO2 microspheres were also investigated.

The meso-2,3-butanediol dehydrogenase (meso-BDH) from S. marcescens H30 is responsible for converting acetoin into 2,3-butanediol during sugar fermentation. Inactivation of the meso-BDH encoded by budC gene does not completely abolish 2,3-butanediol production, which suggests that another similar enzyme involved in 2,3-butanediol formation exists in S. marcescens H30. In the present study, a glycerol dehydrogenase (GDH) encoded by gldA gene from S. marcescens H30 was expressed in Escherichia coli BL21(DE3), purified and characterized for its properties. In vitro conversion indicated that the purified GDH could catalyze the interconversion of (3S)-acetoin/meso-2,3-butanediol and (3R)-acetoin/(2R,3R)-2,3-butanediol. (2S,3S)-2,3-Butanediol was not a substrate for the GDH at all. Kinetic parameters of the GDH enzyme showed lower K m value and higher catalytic efficiency for (3S/3R)-acetoin in comparison to those for (2R,3R)-2,3-butanediol and meso-2,3-butanediol, implying its physiological role in favor of 2,3-butanediol formation. Maximum activity for reduction of (3S/3R)-acetoin and oxidations of meso-2,3-butanediol and glycerol was observed at pH 8.0, while it was pH 7.0 for diacetyl reduction. The enzyme exhibited relative high thermotolerance with optimum temperature of 60 °C in the oxidation–reduction reactions. Over 60 % of maximum activity was retained at 70 °C. Additionally, the GDH activity was significantly enhanced for meso-2,3-BD oxidation in the presence of Fe2+ and for (3S/3R)-acetoin reduction in the presence of Mn2+, while several cations inhibited its activity, particularly Fe2+ and Fe3+ for (3S/3R)-acetoin reduction. The properties provided potential application for single configuration production of acetoin and 2,3-butanediol .

Hydrangea-like F-doped TiO2microspheres have been synthesized on a large scale by a simple hydrothermal process using potassium titanium oxalate as the titanium source, ammonium fluoride and hydrogen peroxide as the etchant. The photocatalytic activities were evaluated using carbamazepine as the target organic molecule under UV and visible light irradiation. Structural characterization indicates that the hydrangea-like TiO2microspheres, with an average diameter of 2.80 μm, are composed of numerous anatase TiO2petals. Moreover, it is found that both the NH4F and H2O2dosages have important effects on the formation of the hydrangea-like structures. In addition, photocatalytic experiments show that the hydrangea-like TiO2microspheres calcined at 500°C exhibit high photocatalytic efficiency under both UV and visible light irradiation. The enhanced photocatalytic activity can be attributed to the successful fluorine doping, good crystallinity, and the unique nanostructures.

The new method to assess permeability damage in geothermal reservoirs and predict well productivity decline is presented. The laboratory methodology developed aims to determine permeability decline from mobilisation, migration and straining of natural reservoir fines. Laboratory coreflood testing with constant and stepwise decreasing ionic strength has been performed with measurements of the pressure drop along the core and accumulated effluent particle concentration. Stabilisation of rock permeability occurs after injection of numerous pore volumes, suggesting slow drift of mobilised particles if compared with the carrier water velocity. Low ionic strength water increases electrostatic repulsion forces between clay particles and sand grain surfaces, further mobilising particles and resulting in formation damage. Kaolinite and illite/chlorite mixed layer clay minerals are identified by SEM-EDAX analysis and are the minerals primarily responsible for the permeability damage. The competitive effects of decreasing water viscosity and weakening electrostatic attraction on the attached particle concentration during temperature increase have been observed. The micro-modeling of the fine particle mechanical equilibrium shows that the water viscosity effect on the fine particle attachment dominates. It results in decreased fines detachment and permeability decline at high temperatures.

Fines migration causes significant permeability damage, due to mobilisation of particles at increased velocities, their migration in pores followed by straining at pore throats and attachment to pore walls. Numerous coreflooding tests with piecewise increasing rates are conducted. There are two main features of these tests: the first is long-term injection, which allows calculating permeability stabilisation time; the second is pressure measurement at intermediate points, allowing for evaluating the permeability profile along the core. The impedance data obtained from experiments are matched with the results from analytical model. It shows that the mobilised particles move with velocity much smaller than the carrier fluid, yielding long time for permeability stabilisation. It contradicts the classical filtration theory, which indicates the fines are transported with the carrier fluid velocity.