Search

Lithium-sulfur battery suffers from sluggish kinetics at low temperatures, resulting in serious polarization and reduced capacity. Here, this work introduces medium-entropy-alloy FeCoNi as catalysts and carbon nanofibers (CNFs) as hosts. FeCoNi nanoparticles are in suit synthesized in cotton-derived CNFs. FeCoNi with atomic-level mixing of each element can effectively modulate lithium polysulfides (LiPSs), multiple components making them promising to catalyze more LiPSs species. The higher configurational entropy endows FeCoNi@CNFs with extraordinary electrochemical activity, corrosion resistance, and mechanical properties. The fractal structure of CNFs provides a large specific surface area, leaving room for volume expansion and Li

Here a facile method to fabricate closed-cell alumina ceramics by binding hollow alumina spheres with high-temperature binder was introduced. Hollow alumina spheres as the pore-forming agent were bonded together by silica and phosphate binder to form closed-cell structure at the high temperatures. The mechanical properties of as-received closed-cell alumina ceramic can be tailored by the volume fraction of hollow alumina spheres and sintering schedule. Besides, the effects of fusing agent B 2 O 3 and chopped mullite fiber on bulk density and compressive strength of closed-cell alumina ceramics were investigated, respectively. The results indicated that the addition of chopped mullite fiber can effectively enhance the compressive strength of the closed-cell alumina ceramic without significant change in bulk density. The compressive strength of the closed-cell alumina ceramics with 62.5% total porosity was 11.97 MPa when 5 wt% B 2 O 3 and 6 wt% chopped mullite fibers were added in the sample.

A temperature resistance buoyancy material was fabricated through a tert-butyl alcohol gelcasting process with borosilicate glass (BG) and hollow glass microspheres (HGMs) as the matrix and filler, respectively. The effects of the mass ratio of HGMs to BG and sintering temperature on the microstructure, thermal conductivity, and mechanical properties of the composite were studied. The results show that HGMs were bonded together by the BG, and the sample sintered at 750 °C exhibited a broad pore size distribution, from several microns to more than one hundred microns. The thermal conductivity experimental values of all the samples were less than that of Hashin-Shtrikman upper bound (HS+) prediction but agreed well with that predicted from effective medium percolation theory. The relationship between compressive strength and relative density was predicted by the Gibson-Ashby model, with the calibration factor phi below 0.7. Young′s modulus values obtained from the experiment were below that of HS+ prediction. The modulus values of the four types of samples sintered at 650 °C agreed well with the Pabst model prediction, while the values of the samples sintered at 700 °C and 750 °C were distributed in a zone between Ashby-Gibson model and HS+ prediction.

It is classic to prepare nanoceramics by crystallization of amorphous solids; however, this method was seldom reported in the classic system of Al 2 O 3 –ZrO 2 . In present work, fine grained Al 2 O 3 –ZrO 2 (Y 2 O 3 ) ceramics were obtained through controlled crystallization of dense amorphous bulks by heat treatment. Phase composition, microstructure and mechanical property were investigated during heat treatment. Crystallization and densification were almost completed after heat treatment at 1400 °C for 2 h with relative density of 98.5%, and as-prepared sample exhibited homogenous mixture of Al 2 O 3 and ZrO 2 grains at about 440 nm. The fine grained ceramic exhibited high hardness of 15.5 GPa and fracture toughness of 5.2 MPa m 1/2 . This work may provide new guidance for preparing AZY nanoceramics through crystallization of amorphous phase in both experiment and theory.

Ceramics are hard and brittle due to the complex crystalline structure, and the plastic deformation in amorphous oxides at moderate temperature may provide new ideas for achieving plasticity in ceramic materials. In this article, deformations in bulk amorphous Al 2 O 3 –ZrO 2 –Y 2 O 3 precipitated with different amounts of nanocrystallite were investigated under moderate temperature compression. Almost no plastic deformation occurred in fully amorphous AZY at 500 °C; however, a large plastic strain of 10.5% was achieved in sample with 3.65 mol% nanocrystallite, and the plasticity degraded as the crystallinity increased to 24.80 mol%. Plasticity enhanced by nanocrystallite in bulk amorphous oxides was achieved at temperature as low as 500 °C, and the deformation exhibited an unusual behavior of brittle-plastic-brittle transition with increasing crystallinity. The plastic strain was mainly resulted from shear banding along with further densification, and shear banding was confirmed as the dominating mechanism. Shear banding as well as the brittle-plastic-brittle transition was explained in terms of free volume theory. This work might provide a profound understand of plastic deformation and shear banding in bulk amorphous oxides, and inspire new methods to improve plasticity in amorphous materials.

Heat-resistant syntactic foams with relative high compressive strength, elastic modulus and low density were successfully fabricated through binding hollow glass microsphere by phosphate adhesive. The effects of additive B4C on the mechanical behavior of syntactic foams were investigated. The bulk density, compressive strength and elastic modulus of the syntactic foams could be tailored by varying the content of additive and the sintering schedule. The results revealed that the additive B4C was useful in regulating the mechanical behavior of the syntactic foams due to the volume compensation from B4C's oxidation and the formation of glassy state B2O3, which promoted the bonding of hollow glass microspheres. The compressive strength, bulk density, and elastic modulus of the syntactic foams were 10.80–20.38 MPa, 0.525–1.198 g/cm3 and 0.81–1.23 GPa, respectively, when the samples containing 5–15 wt.% B4C sintered at 700–900 °C for 2 h. Therefore, the heat-resistant syntactic foams possess the potential application in aerospace, aviation and oil exploitation. Keywords: Hollow glass microsphere, Phosphate adhesive, B4C, Heat-resistant, Syntactic foam

A novel temperature resistance buoyancy material with hollow glass microspheres (HGMs) as the filler and borosilicate glass (BG, similar chemical composition to the HGMs) as the high temperature matrix was prepared by a tert-butyl alcohol based on gelcasting process. The effect of solid loading and sintering temperature on microstructure and mechanical properties were investigated. The results showed that HGMs were bonded together by borosilicate glass and 45 wt.% solid loading and 700 °C were the optimal processing parameters to fabricate the samples with the best mechanical and thermal properties, and the corresponding bulk density, compressive strength, thermal conductivity and Young’s modulus were 0.92 g/cm3, 14.46 MPa, 0.15 W/m K and 1.24 GPa, respectively. The exponent m value for the samples fabricated in this work was 1.18, lower than that of open- or closed-cell foams, because the sample possess both the closed and open pores. The experimental values of thermal conductivity from 0.07 to 0.16 W/m K were lower than the prediction with the Hashin–Shtrikman upper bound and almost close to that predicted by the Landauer’s relation. Only modulus value of SSL45 sample which possessed the maximum value was closer to Hashin–Shtrikman upper bound, while the modulus value of other samples agreed well with Ashby–Gibson model applied for a porosity ranging from 65% to 89%. The HGMs/BG composite exhibited a low density, low thermal conductivity and excellent temperature resistance, and can be used as the thermal insulation for undersea pipeline or submarine.

To investigate the effects of microRNA-210 (miRNA- 210) on the biological behaviors (proliferation and invasion) of EC109 cells of highly metastatic human esophageal cancer (EC).The EC109 genomic DNA of human EC was used as a template to amplify the precursor sequence of miRNA-210 by polymerase chain reaction (PCR). The precursor sequence of miRNA-210 was sub-cloned into the eukaryotic expression vector pcDNA3.1(-) via double digestion by BamH I and Hind III restriction enzymes. Then the pcDNA3.1 (-)-pri-miRNA-210 vector (named as p-miRNA-210) that was constructed successfully was transiently transfected into EC109 cells of human EC in vitro. Quantitative real-time PCR (qRT-PCR) was used to detect the expression level of mature miR-210. 3-(4,5-dimethyl-2-thiazolyl)-2,5- diphenyl-2-H-tetrazolium bromide (MTT) assay and scratch method were adopted to detect the proliferation and in vitro migration of EC109 cells, and flow cytometry was performed to detect the degree of cell apoptosis.The eukaryotic expression vector carrying miRNA- 210 was constructed successfully. Compared with that in the blank group (Mock) and the control group (P-Blank), miRNA-210 was overexpressed in the transfected EC109 cells. The cell apoptosis was significantly increased compared with that in the control group (p0.05); the inhibition of proliferation of EC109 cells in the p-miRNA-210 vector transfected group was remarkably elevated (p0.05), and wound healing ability was also significantly increased (p0.05).The overexpression of miRNA-210 can significantly inhibit the proliferation of EC109 cells of human EC and accelerate the migration ability and the rate of apoptosis, providing a potential strategy for the treatment of EC.

Hepatocyte nuclear factor 6 (HNF6), as a transcription factor, has been reported to be involved in cell proliferation, carcinogenesis, and tumor metastasis. Here, we demonstrated the role of HNF6 in tumor growth and liver metastasis in colorectal cancer (CRC). Through bioinformatics and clinical samples analysis, we found HNF6 messenger RNA was upregulated both in CRC primary sites and liver metastases, and its high expression indicated poor survival in CRC patients. In vitro studies confirmed that HNF6 promoted cell proliferation and colony formation. What is more, in mouse models, the xenografts grew significantly faster and liver metastasis rate was nearly 45% higher in mice injected with HNF6-overexpressing cells. Further mechanism exploration showed that HNF6 expression affected cell adhesion and conferred resistance to anoikis in CRC cells. Taken together, HNF6 expression was upregulated in CRC and closely correlated with poor survival. HNF6 promoted CRC cell proliferation and tumor growth, and may contribute to liver metastasis via conferring cell resistance to anoikis.

Existing eccentric zonal water injection techniques cannot meet the requirements of separated layer water injection, testing and adjustment in highly-deviated wells, because of their low fishing success rate of down-hole nozzles, low efficiency of connection between instruments and nozzles, and low precision of zonal flow rate test. A new concentric zonal water injection technique is proposed for highly-deviated wells. This technique adopts concentric testing and adjustment, i.e., the test instrument is concentrically connected with the down-hole regulator, with high success rate of connection. The down-hole regulator uses bridge-type channel to effectively eliminate inter-layer interference and thereby improving testing and adjustment efficiency. Water flow rate is adjusted with an eccentric valve, which features small loss in full-off state, small adjustment torque and easier water adjustment. This technique is functional for both collected flow test and non-collected flow test, so it is workable for low flow rate test. It can achieve packer seal test on line by cable, the status of seal balls can be monitored and all seal test operations can be completed in one trip. This technique can obtain flow rate, pressure, temperature and other parameters of any layer on line and automatic testing and adjustment of injection allocation rate, without fishing, significantly improving testing and adjustment efficiency. Until now, this technique has been tested in 11 wells (maximum well deviation of 55°), with tested flow rate error of less than 5%, and three-layer seal check and adjustment time of less than one day. Compared with the existing techniques, this new technique has advantages such as high testing and adjustment efficiency, high precision and low cost. Key words: highly-deviated well, concentric zonal water injection, cable test and adjustment, cable seal test, automatic water allocation, testing and adjustment efficiency

A SiC whisker reinforced phosphate adhesive was developed for bonding carbon/carbon composites. A kind of spine-like SiCw with a large specific surface area was synthesized at first and then was chosen as the reinforcement phase. It was found that the mechanical performance of adhesive was promoted by the appropriate amount (1 wt.%) of SiCw within the whole heat-treatment temperature range, while the excessive whisker content caused a side effect. With the temperature increasing, the variation of composition and structure of adhesive was closely related to the reinforcing effect of whiskers at different temperatures. Moreover, the reinforcement effect from 900 °C to 1500 °C was better than that below 900 °C. At 1300 °C, the fracture displacement could be extended by 100%, which was attributed to the influence of both spine-like SiCw and the newly-formed slender SiCw.

Considering the effect of vacuum tightness on the performance of condensers, the influence of various operating parameters on condenser pressure and terminal difference was studied by establishing a calculation model of variable operating conditions of condensers. The results show that the change of heat load has a greater impact on the vacuum, and the effect is more pronounced when the initial temperature of the cooling water is higher. Therefore, it is necessary to strictly control the internal leakage of the valve, reasonably adjust the steam parameters of the shaft seal, and minimize the additional heat load on the condenser. The cooling water flow and initial temperature directly affect the condenser vacuum and have a greater impact. The initial temperature of the cooling water is not easy to control. When the initial temperature is high, most power plants use a method of increasing the flow to increase the condenser vacuum. The cleaning coefficient and air leakage have a great impact on the quality of the vacuum. Therefore, regular operation of the rubber ball cleaning system and timely vacuum leak detection are necessary measures to ensure the vacuum of the unit, which can effectively improve the economic efficiency of the unit.

Near-net-shaped hierarchical structure-adjustable short mullite fibers/mullite whiskers frameworks (MF/MW frameworks) were prepared by slurry-filtration and heat-treating method. The main structure of MF/MW framework was constituted by lap-jointed mullite fibers. Every single fiber in the framework was densely covered by mullite whiskers which formed through fluorine-catalyzed gas-phase reaction, and the fibers actually served as curved substrates for the mullite whiskers' growth. The lap-jointing points of the fibers were served by movable intersected mullite whiskers. Moreover, the microstructure of the frameworks could be adjusted by tailoring the raw materials mass ratio. The volume densities, the apparent porosities and the thermal conductivities of the MF/MW frameworks in different raw materials mass ratios were 0.459–0.487 g/cm 3 , 79.7–82.8% and 0.1356–0.1965 W/k m, respectively. The compression–resilience property of the samples was tested under 0.4 MPa at room temperature. The compression ratio and resilience ratio of the MF/MW frameworks in different raw materials mass ratios were 1.63–2.25% and 92.67–98.16%, respectively. The MF/MW frameworks with advanced thermal and mechanical properties were considered to be promising high-temperature heat-insulation material.

An enhanced anti-apoptotic capacity of tumor cells plays an important role in the process of breakpoint cluster region/Abelson tyrosine kinase gene (BCR/ABL)-independent imatinib resistance. We have previously demonstrated that brain expressed X-linked 1 (BEX1) was silenced in secondary imatinib-resistant K562 cells and that re-expression of BEX1 can restore imatinib sensitivity resulting in the induction of apoptosis. However, the mechanism by which BEX1 executes its pro-apoptotic function remains unknown. We identified B-cell lymphoma 2 (BCL-2) as a BEX1-interacting protein using a yeast two-hybrid screen. The interaction between BEX1 and BCL-2 was subsequently confirmed by co-immunoprecipitation assays. Like BCL-2, BEX1 was localized to the mitochondria. The region between 33K and 64Q on BEX1 is important for its localization to the mitochondria and its ability to interact with BCL-2. Additionally, we found that this region is essential for BEX1-regulated imatinib-induced apoptosis. Furthermore, we demonstrated that the interaction between BCL-2 and BEX1 promotes imatinib-induced apoptosis by suppressing the formation of anti-apoptotic BCL-2/BCL-2-associated X protein (BAX) heterodimers. Our results revealed an interaction between BEX1 and BCL-2 and a novel mechanism of imatinib resistance mediated by the BEX1/BCL-2 pathway.

To construct a recombinant lentiviral vector that stably express hepatocyte nuclear factor 6 (HNF6) in colorectal cancer cell line and examine its effects on the invasive ability of SW620 cells.The lentiviral vector pLeno-DCE-HA-HNF6 was constructed and transfected into 293T cells. The supernatant containing the lentivirus particles was harvested to determine the virus titer. A stable cell line was established by infecting SW620 cells with the lentivirus particles, and the transfection efficiency was examined by fluorescence microscopy and flow cytometry. The invasion ability of the transfected SW620-HNF6 cells was assessed by wound healing and transwell assays.The recombinant lentiviral vector was correctly constructed and verified by sequencing. SW620-HNF6 cell line with stable HNF6 expression was established successfully, and the transfection efficiency reached 82.3%. Western blotting and quantitative PCR demonstrated significantly upregulated HNF6 expression in SW620-HNF6 cells, which showed obviously suppressed invasive ability in wound healing and transwell assays.We have successfully established a colorectal cancer cell line SW620-HNF6 stably expressing HNF6, which shows a lowered migration activity in vitro.