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An experiment was conducted to investigate flow-induced vibration (FIV) in the control rods of a pressurized-water reactor (PWR). Control rods and a guide cylinder (full scale compared with the real structure) were installed on an FIV experiment platform, with which flow distributions were simulated according to actual situations. The vibration displacements of the control rods were observed in different flow rate ranges of transverse and vertical flows. Several FIV characteristics of the control rods under different transverse and vertical flows were determined by analyzing the experimental results. A formula was also proposed to predict vibration.Key words: flow-induced vibration, control rod, PWR, prediction, vertical flow, transverse flow.Nous procedons a une experience pour examiner la vibration induite par le flot (VIF) dans les tiges de controle d'un reacteur a eau pressurisee. Des tiges de controle et un cylindre guide (pleine echelle par rapport a la vraie structure) sont installes sur une plateforme experimentale, dans laquelle les distributions de flot sont simulees selon des situations reelles. Nous observons les deplacements vibrationnels des tiges de controle pour differents domaines de taux de flots transverses et verticaux. En analysant les resultats, nous determinons les caracteristiques des VIF des tiges de controle et nous proposons une formule pour predire ces vibrations. [Traduit par la Redaction]Mots-cles : dynamique des fluides, vibration induite par un flot, flot vertical, flot transverse, tige de controle., 1. IntroductionVarious flow-induced vibration (FIV) accidents have occurred since the operation of the first pressurized-water reactor (PWR) in the 1960s. Serious accidents caused by the FIV problem have elicited much [...]

Graphdiyne (g−CnH2n‐2), a novel two‐dimension carbon allotrope material composed of a sp‐ and sp2‐hybrid carbon network, has been widely explored since it was synthesized for the first time by Li's group in 2010. A series distinct and excellent properties bestow graphdiyne excellent performance in many fields. Here, an innovative progress for preparing graphdiyne by using Cu+ contained material as catalyst is reported and the composite CuI‐GD is coupled with flower‐like NiAl‐LDH to produce H2 from photocatalytic water splitting. The results of FTIR and Raman spectroscopy together reveal that graphdiyne nanosheets are synthesized successfully by employing a cross‐coupling method. Photocatalytic hydrogen evolution performance shows that the hydrogen production activity of CuI‐GD/NiAl‐LDH has a 15‐ and 216‐fold enhancement compared with CuI‐GD and NiAl‐LDH, respectively. A series of characterizations are carried out to expound the underlying reasons in the enhancement of the photocatalytic hydrogen production performance of CuI‐GD/NiAl‐LDH. Meanwhile, a possible mechanism for the photocatalytic hydrogen evolution process was proposed to understand the interaction among these materials. [ABSTRACT FROM AUTHOR]

We studied the effects of copper (Cu) phytoremediation on microbial community composition under laboratory conditions. A Cu accumulator, Commelina communis, was grown on a soil containing different gradients of Cu. Results showed that the biomass of C. communis grown with Cu differed from that of the control. Concentrations of Cu in the shoots of C. communis were 73.6, 160.9, and 319.1 mg kg-1 under 200, 500, and 1000 mg kg-1 Cu treatments, respectively. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprint analysis revealed that additions of Cu decreased the number of bands in the soil with C. communis or without plants. The principal component analysis explained 52.7% of the variance for the different rhizospheres of soil and Cu treatments in the soil samples. These results indicated significant effects on soil bacteria activity and community composition in the rhizosphere of C. communis and provided a basis for further studies of metal-accumulator plant effects on soil microorganisms. [ABSTRACT FROM AUTHOR]

Graphdiyne (g-C n H 2n-2 ), a novel two-dimension carbon allotrope material composed of a sp- and sp 2 -hybrid carbon network, has been widely explored since it was synthesized for the first time by Li's group in 2010. A series distinct and excellent properties bestow graphdiyne excellent performance in many fields. Here, an innovative progress for preparing graphdiyne by using Cu + contained material as catalyst is reported and the composite CuI-GD is coupled with flower-like NiAl-LDH to produce H 2 from photocatalytic water splitting. The results of FTIR and Raman spectroscopy together reveal that graphdiyne nanosheets are synthesized successfully by employing a cross-coupling method. Photocatalytic hydrogen evolution performance shows that the hydrogen production activity of CuI-GD/NiAl-LDH has a 15- and 216-fold enhancement compared with CuI-GD and NiAl-LDH, respectively. A series of characterizations are carried out to expound the underlying reasons in the enhancement of the photocatalytic hydrogen production performance of CuI-GD/NiAl-LDH. Meanwhile, a possible mechanism for the photocatalytic hydrogen evolution process was proposed to understand the interaction among these materials., (© 2021 Wiley-VCH GmbH.)

Objective: To investigate the effect of luteolin on cell growth and apoptosis of HepG2 cells in vitro., Methods: Cultured HepG2,HL60,A549 and LO2 cells were treated with luteolin for different doses (0 μg/ml,2.5 μg/ml,10 μg/ml and 20 μg/ml) and varied times (0 h,24 h,48 h and 72 h). Cell viability was measured with MTT assay and IC50 was calculated. The reactive oxygen species (ROS) levels in HepG2 cells treated with luteolin for 6 h and 12 h were measured with flow cytometry. Cell apoptosis of HepG2 cells treated with luteolin for 24h was examined with flow cytometry and Annexin V-FITC/PI. Expression levels of apoptosis pathway proteins (p53,ASPP2 and iASPP) in HepG2 cells were detected with western blot and the dose and time-effect was analyzed., Results: Luteolin effectively inhibited tumor cell proliferation in a dose-and time-dependent manner,and the inhibition rates of 20 μg/ml Luteolin for 72 h were 39.34%,62.90%,57.57% and 62.90% to LO2,HepG2, HL60 and A549 cells,respectively. The intracellular ROS level was decreased in HepG2 cells by 13.88% and 41.11% after being treated with luteolin for 6 h and 12 h,respectively. The apoptosis rate of HepG2 cells treated with luteolin for 24 h was 14.43%,and western blot showed that luteolin reduced the expression level of iASPP by 77.07% and up-regulated the expression of p53 by 179.37% and ASPP2 by 725.02% in HepG2 cells treated with luteolin for 12 h., Conclusion: Luteolin has ant-proliferative and pro-apoptotic activity on hepatoma HepG2 cells, which is associated with the altered expression of pro-apoptotic factors and decreased ROS level in HepG2 cells.

As a new DNA fingerprinting technique, denaturing gradient gel electrophoresis (DGGE) can be used to analyze the microbial diversity in different environmental samples. Three biofilters treating air loaded with ammonia will be studied with respect to microbial diversity by applying cultivation-independent molecular methods DGGE. The principal objectives of this paper include the development and application of a suitable set of molecular tools to deliver information about the possible microbial community changes within carriers during treatment of ammonia-contaminated gas. Carriers were sampled at different time during operation of biofilters. After extraction and purification of the genomic DNA, the 16S rRNA genes (V3 region) were amplified by using the specific primers. These amplified DNA fragments were then separated by paralleled DGGE. The profile of DGGE showed that the same carrier at different time had the different bands' patterns. The structural diversity of the microbial community was examined by the Shannon index of general diversity H. Shannon indexes of three kinds of carriers all showed a decrease with time, which had a similar trend to NH3 removal efficiency.