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The first corrosion detection for the large grounding grid of a 220kV substation was performed based on electrical impedance tomography (EIT) technology. The impedance value of grounding grid branch which represented the corrosion state of metal was calculated using the current and voltage data acquired on-site through injecting a direct current from one down conductor and collecting voltage data from other down conductors. The results indicated that the impedance increase ratio of the No.143 grounding grid branch in test area D was higher than the warning value (>15 times), indicating a breakage has occurred on this grounding grid branch. The two-dimension corrosion image of the whole underground grounding grid was calculated and drawn accurately and visually using the corrosion diagnosis software. The corrosion rate of carbon steel was monitored in the serious corrosion area later, to realize the online corrosion monitoring of grounding grid metal. EIT technology realized the underground grounding grid statues visible exhibition, and could be used to detect the corrosion state, corrosion area and failure location of the underground grounding grid rapidly and effectively. This could reduce the blindness of corrosion detection for grounding grid and provide guidelines on the corrosion maintenance of underground grounding grid in large substation.

In some coastal areas, the primary freshwater obtained through seawater desalination has been widely used as the feed water in high purity-water production. Due to its high conductivity, however, further lowering ionic species load is needed before the final polishing process such as the mixed bed ion exchange and electrodeionization. In this work, a new process called as chemical-free ion exchange (CFIE) was proposed to replace the conventional two-bed (cation–anion) ion exchange for the purpose above. Results demonstrated that the mixed resin regeneration was achieved mainly by electrically enhancing water split. After regeneration, the resins could resume their ability to desalinate. The conductivities of purified water were 0.8–1.5 μS/cm, and the energy consumption and water recovery were 0.29–1.04 kWh/m3 water and 81.8–94.7%, respectively. The neutral concentrate collected during regeneration could be returned to a pretreatment unit for recovery. No chemical was needed and no wastewater was produced. Repetitive experimental results showed that the CFIE system could run stably.

A promising membrane-free electrodeionization (MFEDI) process has been proposed for high purity water (HPW) production in our previous work. However, the employ of a large number of weak-acid resins in MFEDI limits this process for purifying the reverse osmosis (RO) permeate of tap water with a pH value below 6.0. In this work, a MFEDI system filled only with mixed strong-acid and strong-base resins was tested to desalinate the synthetic acidic RO permeate. Results demonstrated that the resins regeneration was achieved mainly by electrically enhancing water dissociation after a high current density was imposed to the resin layer. Both good purification and effective regeneration were achieved. The conductivity of effluent was 0.060–0.062 μS/cm only. The energy consumption fluctuated in the range of 0.35–0.41 kW h/m 3 water and the water recovery reached 93.1%. The mixed concentrate collected during regeneration, with an average conductivity of 145 μS/cm and a pH value of 6.5, could be returned to a pretreatment unit for recovery. No chemical was needed and no wastewater was produced. Repetitive experimental results showed the MFEDI system could work stably.

Bi2WO6 nanoplates with thickness of about 100 nm had been successfully synthesized by sol-gel method using egg white proteins (albumin) as a biotemplate. On the basis of results of morphologies observation, it was found that albumin was critical for controlling the morphologies of the final products. Photocatalytic activities of the samples were evaluated by the degradation of Rhodamine B (RhB) under visible light irradiation. Due to the combined effects of high specific area, high light absorption and efficient separation of photogenerated electron-hole pairs, Bi2WO6 photocatalyst synthesized in the presence of albumin exhibited better photocatalytic activity than that Bi2WO6 synthesized without using albumin.

(+)-Rutamarin inhibits EBV lytic DNA replication with an IC50 of 7.0 μM. (−)-Chalepin, a (−)-rutamarin derivative, was isolated from the whole plant of Ruta graveolens and used as a precursor of (−)-rutamarin. Altogether, 28 (−)-rutamarin derivatives were synthesized starting from (−)-chalepin. Of these, 16 compounds (2a–e, 3b–e, 3g, 4f, 4k, 4m–p) were found to be more potent against EBV lytic DNA replication than (−)-chalepin. Compounds 4m, 4n, and 4p exhibited IC50 values of 1.5, 0.32, and 0.83 μM and showed selectivity index values (SI) of 801, 211, and >120, respectively. Thus, compounds 4m, 4n, and 4p are considered promising leads for further laboratory investigation.

Purpose – The purpose of this study was to investigate the corrosion of rusted carbon steel in dilute NaCl solution, with the purpose of exploring the effect of the rust layer on metal corrosion and establishing a corrosion model for rusted iron. Design/methodology/approach – The corrosion behavior of rusted carbon steel in dilute NaCl solution was studied by means of weight-loss determinations, scanning electron microscopy, Raman spectrometry and electrochemical techniques. Findings – The results indicated that carbon steel had a similar corrosion behavior in all three NaCl solutions. The iron rust, which consisted of a thin γ-FeOOH layer and a thick Fe3O4 layer, can facilitate the corrosion process of carbon steel via reduction of γ-FeOOH and the large area cathode of Fe3O4. Hence, the corrosion rate of carbon steel was accelerated significantly and finally was determined by the limiting diffusion rate of oxygen. Originality/value – A corrosion model of rusted carbon steel was established, suggesting that iron rust formed in all slightly acidic waters with low alkalinity probably promotes the corrosion of carbon steel. Anti-corrosion measures for iron in this type of solution, such as desalination water, should be aimed to reduce the promotional effect of the rust layer on metal corrosion.

Purpose – The purpose of this investigation was to study the effects of sodium hexametaphosphate and zinc sulfate on the corrosion control of rusted iron in reverse osmosis (RO) product water of seawater. Design/methodology/approach – The synergistic effects and inhibition effects of corrosion inhibitors on rusted carbon steel were studied using the weight-loss method, electrochemical tests and surface analysis techniques. Findings – The results indicated that sodium hexametaphosphate could partly suppress the corrosion of rusted steel, but zinc sulfate used alone had no inhibition effect. Hexametaphosphate and zinc sulfate showed a strong synergistic effect and the optimal ratio of two chemicals was 1:1. The inhibition efficiency appeared to increase with increasing inhibitor concentration and the ideal dosage of inhibitors was set at 20 mg/L, when chemical cost and inhibition efficiency were taken into account. Surface analysis results proved that this compound inhibitor could make the rust layer much more compact. The inhibitive mechanism was to combine with rust and form a protective film, which consisted of iron oxide, polyphosphate and Zn(OH)2. Originality/value – It was found that the compound inhibitor consisting of sodium hexametaphosphate and zinc sulfate had a good inhibitive effect on rusted iron in RO product water. The research results can provide theoretical guidelines for corrosion control of rusted pipes in power plants.

In order to develop highly efficient visible-light-driven photocatalysts, bismuth tungstate (Bi2WO6) was incorporated with reduced graphene oxide (RGO) via an ionic liquid-assisted hydrothermal process. The photocatalytic activities of the as-prepared samples were evaluated by photocatalytic degradation of a rhodamine B aqueous solution under visible light irradiation. Compared with pure Bi2WO6, all the as-prepared RGO–Bi2WO6 composites exhibited significantly enhanced photocatalytic performances for the degradation of rhodamine B. Significantly, the optimum photocatalytic degradation efficiency of RGO–Bi2WO6 composites prepared in the presence of the ionic liquid was about 1.9 times higher than that of Bi2WO6–RGO composites prepared without using the ionic liquid. The excellent photocatalytic performances of RGO–Bi2WO6 composites were correlated with the surface area, light absorption and the separation efficiency of photoinduced electrons and holes. Moreover, the possible mechanism of the enhanced photocatalytic activity for the RGO–Bi2WO6 photocatalyst was proposed on the basis of the experimental results.

Tree peony is a perennial deciduous shrub with great ornamental and medicinal value. A limitation of its current functional genomic research is the lack of effective molecular genetic tools. Here, the first application of a Tobacco rattle virus (TRV)-based virus-induced gene silencing (VIGS) in the tree peony species Paeonia ostii is presented. Two different approaches, leaf syringe-infiltration and seedling vacuum-infiltration, were utilized for Agrobacterium-mediated inoculation. The vacuum-infiltration was shown to result in a more complete Agrobacterium penetration than syringe-infiltration, and thereby determined as an appropriate inoculation method. The silencing of reporter gene PoPDS encoding phytoene desaturase was achieved in TRV-PoPDS-infected triennial tree peony plantlets, with a typical photobleaching phenotype shown in uppermost newly-sprouted leaves. The endogenous PoPDS transcripts were remarkably down-regulated in VIGS photobleached leaves. Moreover, the green fluorescent protein (GFP) fluorescence was detected in leaves and roots of plants inoculated with TRV-GFP, suggesting the capability of TRV to silence genes in various tissues. Taken together, the data demonstrated that the TRV-based VIGS technique could be adapted for high-throughput functional characterization of genes in tree peony.

BACKGROUND: Gastric cancer has been the second cause of cancer death worldwide. Chemical comprehensive treatment programs primarily were the main therapy method with modest efficacy to gastric cancer. Traditional Chinese medicine (TCM) has been reported to alleviate adverse events induced by chemotherapy, but has not yet developed clinical trials to test and needs scientific evidence for making policy. Single-patient (N-of-1) trials might be an eligible study design for TCM since it well represented the individualized treatment philosophy of TCM. The aim of this study is to obtain information necessary to design a more series trial. METHODS: Individuals who underwent gastrectomy were included. Each patient suffered 3-week standard chemotherapy and 3-day treatment periods (decoction with Astragalus mongholicus and Semen Cuscutae or placebo: decoction without Astragalus mongholicus and Semen Cuscutae). Each trial lasted up to a maximum of 30 weeks or a minimum of 20 weeks. Staffs and participants were blinded to the randomization. This study was approved by Ethics Committee of First Hospital, Lanzhou University in November, 2014. RESULTS: From August, 2014 to March, 2015, 6 participants were included. There were 16 cycles compared between intervention and control decoction (2.28, 95% CI: 1.24–5.47), P

PurposeThe purpose of this paper is to explore the long‐term corrosion behavior of carbon steel in 3% NaCl solution and evaluate the effect of rust layer on the corrosion process.Design/methodology/approachThe corrosion behavior of rusted carbon steel in 3% NaCl solution was studied by means of infrared spectroscopy (IR) and electrochemical impedance spectroscopy (EIS).FindingsThe results indicated that the corrosion of carbon steel was affected by chloride ion in initial immersion and then controlled by the rust layer. The rust layer consisted of a thin outer layer (γ‐FeOOH layer) and a thick inner layer (Fe3O4 layer). The outer rust layer facilitated the cathodic process via reduction of γ‐FeOOH, while the inner rust layer provided a large cathode area and oxygen could be reduced on its surface. As a result, the corrosion rate of carbon steel was determined by the limiting diffusion rate of oxygen and stabilized at a high value.Originality/valueThe corrosion model of rusted carbon steel in 3% NaCl solution was established. It is probable that the iron rust in all slightly acidic water with low alkalinity can promote the corrosion process via reduction of γ‐FeOOH. Anti‐corrosion measures for iron in this type of solutions should be aimed to reduce the promoting effect of rust layer on the metal corrosion. The NaCl solution prepared from tap water is more suitable for the substitution of artificial water than that prepared from deionized water.

PurposeThe purpose of this paper is to set out a study of the film‐forming characteristics of octadecylamine (ODA), estimate the feasibility of shutdown protection using ODA at high temperatures, and determine the optimum process condition of shutdown protection for units under full load if ODA has a good film‐forming effect at high temperatures.Design/methodology/approachAn autoclave was used to simulate the water‐vapor environments at 350‐560°C in the water‐steam system of power plants. The decomposition test of ODA was investigated and the ODA film‐forming characteristics were studied for furnace tube materials used in gas‐fired power plants.FindingsResults showed that ODA had a decomposition equilibrium and the decomposition products did not contain harmful organic substances such as low molecular organic acids. ODA would form a satisfactory protective film in the range of 350‐560°C with the best film at 480°C. The protection effect of the film formed by ODA at 560°C was much stronger than was that of its oxide film, which showed the feasibility of shutdown protection using ODA for gas‐fired power plants operating under full load. The optimal conditions of shutdown protection under full load were as follows: the temperature was 560°C, the concentration of ODA was 80 mg/L, the pH was 9.5 and the exposure time was 2 h. From the experimental results of X‐ray photoelectron spectroscopy, it was known that the surface film on the specimens was composed of a compound of ferroferric oxide and ODA, and the film‐forming mechanism was chemical adsorption between N in the ODA and Fe.Originality/valueIt was found that ODA has a good film‐forming effect at high temperatures and it is practicable to implement shutdown protection for base‐load units. The research results can provide theoretical guidelines for shutdown protection of gas‐fired power plants.

A three dimensional (3D) measurement method for train wheel surface is proposed based on S-transform profilometry. This method is based on S-transform in fringe analysis. A fringe pattern with a carrier frequency component is projected onto the wheel tread, the deformed fringe patterns caused by the height distribution of wheel surface is recorded as an image, and the fundamental spectrum of S-transform spectra from the image is abstracted by use of weighting filters, then the wrapped phase is obtained by IFFT of the fundamental spectrum. 2D-SRNCP (sorting by reliability following a non-continuous path) phase unwrapping algorithm is used to unwrap phase, which can be used to reconstruct the surface distribution of wheel. Simulation and testing experiment is taken and the result shows that, comparing with light-section method, this method can realize a faster inspection and a higher accuracy measurement of 3D wheel surface.

Phase unwrapping is a common problem in many phase measuring techniques. Glodstein’s branch-cut algorithm is one of classic ways of phase unwrapping, but it need rectifying. First the paper introduces the characteristics of residual points and describes Glodstein’s branch-cut algorithm in detail. Then the paper discusses the improvements on the algorithm by changing branch setting and adding pretreatment. Last the paper summarizes the new algorithm and gets the better result by using computer emulation mode and validation test.

Summary Recent progress in single DNA manipulation with atomic force microscope has proved its potential in analysing genetic information at the molecular level instead of macro ensemble approach. However, current manipulation of DNA is mainly carried out by manual operations, which is labour-intensive and time-consuming, thus limits the further applications in other fields. In this paper, an optimized DNA manipulation method is successfully established. An image correlation technique is introduced to realize automatic thermal drift compensation. Combined with elaborately designed tip movement control for different manipulation purposes, accurate and efficient DNA manipulations such as dissection, folding and picking are realized. The efficiency has been improved for an order of magnitude compare to manual manipulations, whereas the performance is demonstrated to be the same. This newly developed method has shed light on high-efficiency nanomanipulation of small molecules with complex structures, and thus provides the possibility of deeply understanding the intrinsic properties of single biomolecules.

With the wide use of reverse osmosis technology in power plants, many produce water distribution networks of first-order reverse osmosis of seawater have severe corrosion, which is a threat for the normal and efficient operation of power plant. This paper studied the effect of corrosion factors such as dissolved oxygen, chloride ion, flow velocity, temperature on first-order reverse osmosis corrosion by carrying out coupon tests, explored the measure of adding corrosion inhibitors to produce water in order to reduce product water corrosion on the based of the above research results, and then proposed a useful anticorrosive method which suits for power plant. The research result of this paper can provide operation guidance to power plant and has obvious social benefits and practical application value.

Prediction of breakdown voltage of transformer oil has a great significance to the fault diagnosis and daily maintenance of transformer. Based on the correlation of performance parameters of transformer oil and the prominent fault-tolerance, non-linear approximation, and self-learning capabilities of BP neural network, this paper constructed a prediction method of breakdown voltage via multi-parameter correlation under the development environment of Matlab. Through examining the routine monitoring data of transformer oil by gray correlation analysis, this paper excavated some parameters which have strong correlation with breakdown voltage. Then a relational model of breakdown voltage and those parameters was further constructed using BP neural network. The clustering centers used to train network were acquired through clustering the original monitoring data samples with fuzzy C-means clustering algorithm. This method which uses clustering centers to train network can resolve natural problems of neural networks caused by large sample capacity, such as complication of net structure, inferior astringency, poor generalization ability, and so on. Test results show that the relative errors between predicted values and real values are all less than 10%, which indicates the significant practical values of this model.

Prediction of breakdown voltage of transformer oil facilitates the early fault diagnosis, prevention and treatment of transformer. In this article, a prediction method of breakdown voltage via multi-parameter correlation was proposed considering the lack of research in this field. Through examining the routine monitoring data of transformer oil by gray correlation analysis, some parameters which have strong correlation with breakdown voltage were excavated, then a relational model of breakdown voltage and those parameters was further constructed using back-propagation neural network, since BP neural network has prominent fault-tolerant, non-linear approximation, and self-learning capabilities. The clustering centers which were used to train network were acquired through clustering the original monitoring data samples with fuzzy C-means clustering algorithm. The adoption of this method can resolve natural problems of neural networks caused by large sample capacity, such as complication of net construction, inferior astringency, poor generalization ability, and so on. Test results show that the precision of the prediction model is high and that the relative prediction errors of test samples are all less than 10%, which indicates the significant practical value of the model.