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This paper focuses on researching the softening resistance performance of Mg alloy under high temperature and the evolution of microstructure during high-temperature treatment. The results showed that, compared with Cu-0.39Cr-0.12Fe alloy, Cu-0.38Cr-0.04Fe-0.08Mg alloy has higher resistance to softening temperature, hardness and conductivity, which were 40 °C, 13 HV, 5% IACS higher than that of Cu-0.39Cr-0.12Fe alloy. Both of the aging precipitated phase of two alloys are nano-Cr phase. Mg can inhibit the growing of nano-Cr phase and the grain recrystallization process significantly. According to 3DAP analysis, the interface structure of Cr/Mg/Cu is formed, which might be the key factor that results in the excellent softening resistance performance of Cu–Cr–Fe–Mg alloy.

Using a simple hydrothermal strategy, the novel UiO-66-NH2/CdIn2S4 heterojunction connected by a coordination bond was constructed with high photocatalytic activity for water reduction.

This paper concerns a model of hierarchical neural network with D n × D n -symmetry and time delays. The linear stability of the steady state is obtained via an artful factorization technique of the characteristic equation corresponding to the linearized system. And we also perform a delay-induced Hopf bifurcation analysis involving spatio-temporal patterns of bifurcated periodic solutions relying on the equivariant Hopf bifurcation theory for retarded functional differential equations and the representation method of Lie groups. Some numerical simulations for a simple example are carried out to demonstrate the application of our theoretical conclusion that multiple periodic orbits could occur simultaneously from Hopf bifurcation in the model.

Postharvest deterioration of ginger rhizome caused by microorganisms or wound infections causes significant economic losses.

Cotton is the most important fiber crop and provides indispensable natural fibers for the textile industry. Micronaire (MIC) is determined by fiber fineness and maturity and is an important component of fiber quality. Gossypium barbadense L. possesses long, strong and fine fibers, while upland cotton (Gossypium hirsutum L.) is high yielding with high MIC and widely cultivated worldwide. To identify quantitative trait loci (QTLs) and candidate genes for MIC in G. barbadense, a population of 250 backcross inbred lines (BILs), developed from an interspecific cross of upland cotton CRI36 × Egyptian cotton (G. barbadense) Hai7124, was evaluated in 9 replicated field tests. Based on a high-density genetic map with 7709 genotyping-by-sequencing (GBS)-based single-nucleotide polymorphism (SNP) markers, 25 MIC QTLs were identified, including 12 previously described QTLs and 13 new QTLs. Importantly, two stable MIC QTLs (qMIC-D03-2 on D03 and qMIC-D08-1 on D08) were identified. Of a total of 338 genes identified within the two QTL regions, eight candidate genes with differential expression between TM-1 and Hai7124 were identified. Our research provides valuable information for improving MIC in cotton breeding.

Ticks, as obligate blood-sucking ectoparasites, feed on a broad range of vertebrates and transmit a great diversity of pathogenic microorganisms. Some tick-borne pathogens (TBPs) are endemic in China, whereas epidemiological studies are limited in Jiangxi, a forest province located in eastern China. Here, we have determined the positivity rates of TBPs in humans, rodents, dogs, goats and ticks, and performed the molecular characterization of TBPs in Jiangxi province. We found a high positivity rate of TBPs in the collected samples, demonstrating 23 (12.92%) samples positive for more than one TBPs. Of those, 11 (6.18%) samples were positive for Rickettsia spp., six (3.37%) Ehrlichia spp./Anaplasma spp., one (0.56%) Bartonella spp., two (1.12%) Borrelia spp., and five (2.81%) Babesia spp. The positivity rates of TBPs varied among ticks, animals, and humans as follow: goats (14/37, 37.84%), ticks (8/35, 22.86%), and dogs (1/11, 9.09%). Humans and rodents were negative for TBP presence. Phylogenetic analyses of these TBP sequences revealed the presence of Rickettsia japonica, Ehrlichia minasensis, and an unclassified Babesia spp. in goats, and Anaplasma phagocytophilum, Borrelia valaisiana, and an unclassified Bartonella spp. in ticks. Furthermore, R. japonica infection was exclusively found in goats with the positivity rate of 29.73%. Our study is the first report of R. japonica in goats around the world. These findings suggest high TBP positivity rates among goats, ticks, and dogs, and diverse TBPs in goats and ticks in the studied sites. Therefore, our results underscore the urgent need to assess TBP-tick-vertebrate-environment interactions and the risk of tick borne disease exposure in humans in the future.

On October 13, 2021, a tick infestation occurred in a home in rural area of Nanchang city, China, and we were asked to inspect the tick infestation. Ticks were collected in the largest number on courtyard door jambs, followed by living room and bedroom door jambs. Ticks were identified morphologically as Rhipicephalus sanguineus adults. The 16S rRNA analysis effectively distinguished the ticks in this study from other Rhipicephalus species, including R. sanguineus south-east, temperate and tropical lineages and identified genetically as R. sanguineus south China lineage. Tick samples were subjected to conventional PCR analysis and detected negative for the presence of tick-borne pathogens. Our findings indicate that there was low transmission risk of tick-borne pathogens to humans in the tick-infested home. Further studies are needed to proactively investigate the tick species in Nanchang, and determine the presence of tick-borne pathogens for assessing their threat to human health in the region.

Cotton is the most important fiber crop and provides indispensable natural fibers for the textile industry. Micronaire (MIC) is determined by fiber fineness and maturity and is an important component of fiber quality. Gossypium barbadense L. possesses long, strong and fine fibers, while upland cotton (Gossypium hirsutum L.) is high yielding with high MIC and widely cultivated worldwide. To identify quantitative trait loci (QTLs) and candidate genes for MIC in G. barbadense, a population of 250 backcross inbred lines (BILs), developed from an interspecific cross of upland cotton CRI36 × Egyptian cotton (G. barbadense) Hai7124, was evaluated in 9 replicated field tests. Based on a high-density genetic map with 7709 genotyping-by-sequencing (GBS)-based single-nucleotide polymorphism (SNP) markers, 25 MIC QTLs were identified, including 12 previously described QTLs and 13 new QTLs. Importantly, two stable MIC QTLs (qMIC-D03-2 on D03 and qMIC-D08-1 on D08) were identified. Of a total of 338 genes identified within the two QTL regions, eight candidate genes with differential expression between TM-1 and Hai7124 were identified. Our research provides valuable information for improving MIC in cotton breeding.

We consider a generalized Fisher-KPP equation with the growth function being time and space dependent in the form of “shifting with constant speed”. The main concerns are extinction and persistence, as well as spatial-temporal dynamics. By employing a new method relating to semigroup and some subtle estimates, we not only extend the main results in Li et al. [SIAM J. Appl. Math. 74 (2014), pp. 1397-1417] to a scenario when the growth function may have no sign change, but also improve the main results there by dropping some restrictions on the initial functions.

There are many reports indicating that biochar can promote growth; however, its mechanism of action remains unclear. The aim of this study was to show that organic molecules from biochar-extracted liquor affect the growth of rice seedlings. In this study, rice seedlings were cultured under water. Agronomic traits and growth-related genes and proteins were used as markers to describe more precisely the effects of biochar on specific growth parameters of rice seedlings. Our results demonstrated that the 3% biochar-extracted liquor amendment clearly promoted growth. The growth-related gene auxin binding protein 1 and its encoded protein were up-regulated. Molecular simulations revealed that 2-acetyl-5-methylfuran from biochar-extracted liquor could interact with auxin binding protein 1 in a similar way to indoleacetic acid binding. The growth of rice seedlings was therefore affected by biochar-extracted liquor, which acted on the ABP1 signalling pathway.

Tick calreticulin (CRT) is a calcium-binding protein secreted into the host during blood feeding. It has been used as a biomarker of tick exposure and has potential as an anti-tick vaccine, but there is no information about these uses for Haemaphysalis longicornis CRT (HlCRT). We synthesized recombinant H. longicornis CRT (rHlCRT) and evaluated its potential for tick bite diagnosis and for disrupting tick infestations.The responses of mice and rabbits exposed to H. longicornis ticks were measured with ELISA to determine the antibody level against rHlCRT. To evaluate the effects of rHlCRT-induced anti-tick immunity, engorgement weight, tick engorgement index (TEI), feeding duration, ecdysis rate, and egg weight per engorged tick were compared between ticks fed on immunized and normal mice.Mean anti-tick CRT antibody levels in sera collected from mice at 1 and 15 days after primary tick exposure were not significantly different from the mean antibody levels in negative control mice that were not bitten by ticks (all P values0.05). No significant anti-HlCRT IgG responses developed in mice after second exposure to tick bites compared with the level of anti-HlCRT antibody response in negative control mice (all P values0.25). For rabbits, no significant differences in the antibody levels were observed in animals before challenge infestation and after tick exposures, and in animals after two tick exposures (all P values0.10). There were no significant differences in the body weight of ticks fed on immunized and normal mice (all P values0.15). No significant differences in TEI were observed between ticks fed on immunized mice and normal control mice (all P values0.50). There were no significant differences in feeding duration for female ticks, and feeding duration and ecdysis rate for nymphs in the experimental and control groups (all P values0.10 for feeding duration and P value = 0.19 for ecdysis rate). We did not observe a significant difference in egg weight per tick in the rHlCRT-immunized and the control groups (P = 0.88).HlCRT in H. longicornis tick saliva proteins appears to be nonimmunogenic to mammalian hosts like mice and rabbits. Vaccination with rHlCRT did not generate effective immunity against parthenogenetic and bisexual H. longicornis nymphs or female ticks. These results indicate that HlCRT is not a suitable molecular candidate for H. longicornis tick bite diagnosis and not effective for the disruption of tick infestations.

Detection of surface defects is an essential step to ensure the quality and reliability of rubber seal-ring products. Machine vision inspection methods have received attention from engineers because they are beneficial in terms of the detection speed or detection accuracy. It is important to simultaneously guarantee high speed and high accuracy of defect detection in practice production. Considering this problem, in this paper, we propose a YOLO-based (You Only Look Once) lightweight neural network with edge-attention fusion for defect detection of rubber rings. First, an edge-attention block is integrated into the network to improve the detection accuracy. The edge images are weighted with attention weights and summarized with feature maps in the block. Second, an involution-based feature pyramid structure is proposed to reduce the network size and computational cost by using a new involution operator, instead of a convolution operator, at the bottleneck of the feature pyramid. Comparison of the proposed network with popular YOLO networks was performed based on a rubber-ring-image dataset with 138 images. The network achieved the highest detection accuracy and fastest speed among selected lightweight networks, including YOLOv3-tiny, YOLOv5-s, and YOLOX-s. Moreover, compared with the large and highly accurate YOLOv3-spp network, the network size decreased by 93.45% and the computational cost decreased by 91.46%, while average precision only decreased by 3.41%. It can be concluded that the YOLO-based lightweight neural network reaches a good balance between detection speed and detection accuracy.

Internal CO2/H2S corrosion of gathering pipelines is a serious problem in natural gas plant. It is important for field engineers to assess the corrosion degree and control corrosion risk. A multi-kernel support-vector-machine (SVM) method is presented to rank internal corrosion of gathering pipelines according to the NACE RP-0775-91 standard. By considering the nonlinear indivisibility between data, we combined three kinds of kernels (linear kernel, polynomial kernel, and Gaussian kernel) into a multi-kernel SVM to rank the internal CO2/H2S corrosion of gathering pipelines. The method was applied to a natural gas field in northwest China. Corrosion data were collected and analyzed. The prediction accuracy of the multi-kernel SVM method for ranking CO2/H2S corrosion was 66%, which is higher than the results of the single-kernel SVM methods (linear kernel, polynomial kernel and Gaussian kernel), whose prediction accuracies are 50%, 48% and 54% respectively. These findings could help field engineers rank corrosion and reduce the corrosion risk.

Natural gas is a kind of high-quality and low-carbon energy and its demand is increasing rapidly year by year. The natural gas produced from the gas well contains some corrosive impurities like CO2, H2S, and H2O. Therefore, the gas needs to be purified in purification plants before it can be used. In the process of purification, the impurities in the natural gas will cause corrosion to the purification equipment, especially to the industrial pipeline, which will lead to perforation and leakage of the pipeline, and even cause poisoning, fire or explosion, and other serious safety accidents. In order to ensure the safe operation of the industrial pipeline in the purification plant, it is necessary to carry out effective inspection and maintenance measures for the pipelines. The traditional regular inspection method just inspects a certain proportion of the pipelines which are selected by on-site inspection personnel. But limited by technical level and work experience of the inspection personnel, some high-risk pipelines may be neglected. Therefore, some plants try to adopt risk-based inspection (RBI) to carry out a risk assessment and conduct a comprehensive inspection on high-risk pipelines, so as to improve inspection efficiency and reduce inspection cost. However, in practice, it was found that the pipeline risk levels are not in accordance with the actual inspection results. The reason is that the RBI method developed in the background of oil refining and chemical industry is not suitable for natural gas purification plants. In order to solve the problems, this paper analyzed the relationship between the influencing factors and pipeline corrosion behavior. The influencing factors include the impurity contents (CO2, H2S, H2O, and chlorides), pipeline materials (carbon steel and austenitic stainless steel), and service conditions (operating temperature, operating pressure and flow velocity). Meanwhile, the plant management status and maintenance factors were also considered as the influencing factors to pipelines. According to the analysis, a corrosion risk assessment method for the pipelines in the natural gas purification plant was developed based on fault tree and scoring method. Finally, the method was applied to the pipelines in purification plant to verify the accuracy of this method.

Neuropathic pain (NP) is a common complication that negatively affects the lives of patients with spinal cord injury (SCI). The disruption in the balance of excitatory and inhibitory neurons in the spinal cord dorsal horn contributes to the development of SCI and induces NP. The calcium-binding protein (CaBP) calbindin-D 28K (CaBP-28K) is highly expressed in excitatory interneurons, and the CaBP parvalbumin (PV) is present in inhibitory neurons in the dorsal horn. To better define the changes in the CaBPs contributing to the development of SCI-induced NP, we examined the changes in CaBP-28K and PV staining density in the lumbar (L4-6) lamina I and II, and their relationship with NP after mild spinal cord contusion injury in mice. We additionally examined the effects of alternate thermal stimulation (ATS). Compared with sham mice, injured animals developed mechanical allodynia in response to light mechanical stimuli and exhibited mechanical hyporesponsiveness to noxious mechanical stimuli. The decreased response latency to heat stimuli and increased response latency to cold stimuli at 7 days post injury suggested that the injured mice developed heat hyperalgesia and cold hypoalgesia, respectively. Temperature preference tests showed significant warm allodynia after injury. Animals that underwent ATS (15-18 and 35-40°C; +5 minutes/stimulation/day; 5 days/week) displayed significant amelioration of heat hyperalgesia, cold hypoalgesia, and warm allodynia after 2 weeks of ATS. In contrast, mechanical sensitivity was not influenced by ATS. Analysis of the CaBP-28K positive signal in L4-6 lamina I and II indicated an increase in staining density after SCI, which was associated with an increase in the number of CaBP-28K-stained L4-6 dorsal root ganglion (DRG) neurons. ATS decreased the CaBP-28K staining density in L4-6 spinal cord and DRG in injured animals, and was significantly and strongly correlated with ATS alleviation of pain behavior. The expression of PV showed no changes in lamina I and II after ATS in SCI animals. Thus, ATS partially decreases the pain behavior after SCI by modulating the changes in CaBP-associated excitatory-inhibitory neurons.

This paper is concerned with the forced traveling wave solution of a nonlocal dispersal Lotka-Volterra cooperation model under the habitat shifting with a constant speed. Particularly, we relax the condition of intrinsic production so that there may be no sign change. By constructing a pair of upper and lower solutions and using the method of monotone iteration, we prove the existence of traveling wave solution for any positive constant shifting speed.

The internal corrosion of a 90° elbow was found in a natural gas gathering pipeline in Northeast China. The welded joint between the elbow and the downstream pipe was also severely corroded. The 90° elbow was forged of 16Mn steel. The downstream pipe (Φ 76 mm × 9 mm) was made of 20G steel. To determine failure causes, the elbow and the welded joint were taken as a whole and investigated systematically. The influence of the flow disturbance induced by the elbow on the damage at the welded joint was considered. The internal damage at the elbow and that at the welded joint were studied using field investigation, visual examination, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray powder diffraction (XRD), hardness tests, and computational fluid dynamics (CFD) techniques. The results showed that erosion corrosion from solid particles and corrosive liquid droplets entrained in the natural gas flow was the main cause of the internal damage at the elbow and the welded joint. The welded joint was attacked by the particles with the highest velocity magnitudes and the most dangerous impact angles. The flow disturbance induced by the elbow, the special location of the welded joint, and the angular misalignment due to poor welding quality jointly caused the substantially more severe damage at the welded joint.

In this paper, the effects of high temperature deformation on the microstructure, mechanical properties and hydrogen embrittlement (HE) of the 2.25Cr–1Mo-0.25 V steel was investigated by a scanning electron microscope (SEM), a transmission electron microscope (TEM) and tensile tests. The SEM and TEM images demonstrated that high temperature plastic deformation (HTPD) led to the coarsening of carbides and the dislocation density increase. The tensile tests displayed that the HTPD resulted in the cracking susceptibility increase, as indicated by the increased numbers and sizes of cracks at the fractured surface. This was attributed to the coarsening of carbides during high temperature deformation. In contrast, the HTPD highly decreased the loss of ductility compared to the un-deformed specimens, although the amount of ductility losses (elongation or reduction of area) did not change significantly as the HTPD increased. The correlations among carbides, hydrogen and cracks were discussed.

This paper deals with the existence of traveling wave solutions of the Fisher equation with a shifting habitat representing a transition to a devastating environment. By constructing a pair of appropriate upper/lower solutions and using the method of monotone iteration, we prove that for any given speed of the shifting habitat edge, this reaction-diffusion equation admits a monotone traveling wave solution with the speed agreeing to the habitat shifting speed, which accounts for an extinction wave. This predicts not only how fast but also in what manner a biological species will die out in such a shifting habitat.

In this paper, weighted inequalities for a certain general commutator associated to a singular integral operator satisfying a variant of Ho¨ rmander’s condition on Lebesgue spaces are obtained. To do this, some weighted sharp maximal function inequalities for the commutator are proved.

The corrosion of mild carbon steel in a H2S aqueous environment without corrosion product layers is predicted using the computational fluid dynamics method. The Abe–Kondoh–Nagano low-Reynolds-numbe...

Background: Parecoxib is a selective cyclooxygenase (COX)-2 inhibitor widely used as an analgesia technique in perioperative period for its potent anti-inflammatory and analgesic effects. However, litter is known about its effect on postoperative cognitive dysfunction (POCD). The purpose of this meta-analysis of randomized controlled trials (RCTs) was to evaluate the effect of parecoxib in the treatment of postoperative cognitive dysfunction. Methods: We searched PubMed, Cochrane Library and Embase databases for relevant studies up to October 2017. We selected fixed-effect model for analysis of data heterogeneity. Statistical analyses were performed by using Review Manager Version 5.3 for Windows. Results: Four RCTs with 904 patients that underwent surgical operations were included. The meta-analysis demonstrated parecoxib could significantly decrease the incidence of POCD on postoperative day 1, day 3, day 5, and day 7 when compared with control treatment; IL-6 and S100β concentrations were lower up to postoperative day 2. The consumption of morphine, fentanyl and tramadol in parecoxib groups were lower than control groups. Conclusion: Our meta-analysis suggested that the administration of Parecoxib was effective in treating early POCD within 7 days and reducing IL-6 and S100β concentrations within 2 days after operations. Nevertheless, our current study with some limitations such as the small sample size only provided limited quality of evidence, confirmation from further meta-analysis with large-scale, well-designed RCTs is required.

In this paper, we are concerned with existence/non-existence of traveling waves of a diffusive SIR epidemic model with general incidence rate of the form of f ( S ) g ( I ) and infinitely distributed latency but without demography. We show that the existence of traveling waves only depends on the basic reproduction number of the corresponding spatial-homogeneous system of delay differential equations, which is determined by the recovery rate, the local properties of f and g and a minimal wave speed c ∗ that is affected by the distributed delay. The proof of existence of traveling waves is by employing Schauder’s fixed point theorem, and the proof of nonexistence is completed with the aid of the bilateral Laplace transform.

Boltzmann transform method, wetting front advancing method and instantaneous profile method are widely used in measuring hydraulic conductivity of unsaturated soils. However, all the three methods are based on relatively strong assumptions. In this study, a new Boltzmann variable was proposed based on the experimental observation that the wetting front advancing distance is not always proportional to the square of time. The improved Boltzmann transform method incorporating the new Boltzmann variable can significantly improve the accuracy of hydraulic conductivity determination. For the wetting front advancing method, a new formula for calculating the hydraulic gradient using central difference was proposed to reduce the fluctuation of determined hydraulic conductivity curve while using data recorded with small time intervals. A series of numerical tests including the horizontal absorption test, vertical ponding test and vertical capillary rise test were performed to verify the accuracy of hydraulic gradient and water flow rate calculated by wetting front advancing method. Results show that the calculated hydraulic gradients in low suction range are far from the real values except for the vertical ponding test and only the vertical ponding test can give reasonable hydraulic conductivity in both low and high suction ranges. For the instantaneous profile method applied in infiltration test with one end of soil column maintained at saturation, using the connected linear line with consideration of the location of wetting front to represent profiles of water content and suction can improve the accuracy significantly.

The present study focuses on the decomposition behavior of biochar. The beta-d-glucoside was investigated as cellulose unit modeled compound by Py-GC/MS for fast pyrolysis. The results indicated that the main products consisted of acids, aldehydes, alcoholic hydroxyls, esters and ethers. The content of functional groups was changed with residence time and temperature but the distribution of beta-d-glucoside pyrolysis products did not vary.

In this study, we investigate the dynamic behavior on a system of neutral functional differential equations in critical case. Combining monotonicity techniques and functional methods, we develop the delicate monotonicity with the addressed system and show the convergence for every pre-compact solution with some initial condition, which improves and complements some existing ones.

Impact limiters are attached near to the top and the bottom of a spent fuel containment body as shock absorbers to maintain the structural integrity of the containment not only in normal condition but also in hypothetical accident condition of 9m falling. Ellipsoidal-head-like metallic impact limiters are used for a spent fuel containment which is designed to carry 26 spent fuel assemblies. Main geometry dimensions of the limiters, such as diameter, thickness of the shell, length of straight flange and fillet radius, are design variables. The LS-DYNA software is applied to simulate the acceleration of containment in a falling accident. Sensitivity analyses of the variables on acceleration of spent fuel containment in the 9m falling accident are carried out. By response surface method, the best geometry dimensions which minimize the acceleration of the containment in falling accident are achieved. As showed in results, ellipsoidal head shaped metallic impact limiters work very well in the 9m falling accident. They could significantly decrease load factor and provide more safety margin.

A hierarchical network composed of two interacting rings each of which consists of n identical cells with an unidirectional coupling is the topic of this paper. We present a detailed discussion about the linear stability of the equilibrium by analyzing the associated characteristic equation. The local Hopf bifurcation and spatio-temporal patterns of bifurcating periodic oscillations are also given by employing the symmetric Hopf bifurcation theory for delay differential equations. In particular, by using the normal form theory and the center manifold theorem, we derive the formula determining the direction of the Hopf bifurcation and the stability of the bifurcated periodic orbits. An example with numerical simulations is presented to illustrate our theoretical results.

Defects of pressure piping, especially cracks, are inevitable during the lifetime of pipe, which will result in the pipe failure. In order to ensure safe operation of pipe, failure assessment for the pressure pipe containing defects needs to be implemented. In fact, the assessment parameters would show two types of uncertainty: randomness and fuzziness, because of the errors of inspection and lack of precise information. In this paper, a fuzzy-probabilistic failure assessment method has been developed based on Failure Assessment Diagram (FAD) from API 579-1/ASME FFS-1 procedure. This method combines the probability theory with possibility theory to deal with fuzzy and random variables. Also, Monte Carlo simulation is used to calculate the failure probability of pipe. This method was applied to a pipe with a surface crack. The effects of variables and their uncertainties on failure probability were analyzed. The results show that the wall thickness and diameter of the pipe has the most important contribution to the pipe failure, followed by the fracture toughness, the yield strength, the operating pressure, the depth and length of the crack.

Natural gas transmission pipeline is prone to internal corrosion due to the combination of corrosive impurities in the pipe (such as CO2, H2S and chlorides) and applied pressure of the pipeline, which seriously affects the safe operation of the pipeline. In this work, the corrosion behavior of a typical X70 pipeline steel was investigated by using potentiodynamic polarization and electrochemical impendence spectroscopy (EIS). The polarization and EIS data under different CO2 partial pressures (0–1 atm), H2S concentrations (0–150 ppm), chloride concentrations (0–3.5 wt%) and tensile stress (0–400 MPa) were obtained. The results show that corrosion rate increases with the increase of CO2 partial pressure and chloride concentration, respectively, while first increases and then decreases with the increase H2S concentrations. The corrosion rate is less affected by elastic tensile stress. In addition, a quantitative prediction model for corrosion rate of natural gas pipeline based on adaptive neuro-fuzzy inference system (ANFIS) was established by fitting the experimental data which maps the relationship between the key influencing factors (i.e. CO2 partial pressure, H2S concentration, chloride concentration and tensile stress) and the corrosion rate. The prediction results show that the relative percentage errors of the predicted and experimental values are relatively small. The prediction accuracy of the model satisfies the engineering application requirement.

Long-distance transmission pipelines with 3PE coating undergo a two-stage failure process, including the damage process of three-layer polyethylene coating and the failure process of metal pipelines. The two stages are random and independent of each other. A reliability model of transmission pipelines under periodic inspection is presented with the assumptions of delay-time concepts. Functions of maximum likelihood estimations and the goodness of model fit are given. The effect of the inspection interval on reliability is investigated. A case study of Xinqin natural gas transmission pipelines is presented. Data of the pitting depth are obtained at 43 excavation locations. Best estimations of distribution parameters are obtained in a genetic algorithm search. Results show that the average time of coating damage is around 1.04 years. The failure probability of a pipe segment after 36 years’ operation is 1.1E−3 if no inspections are carried out. The failure probability is around 5.5 times the failure probability of a pipe segment with a 6-year periodic inspection. The sensitivity of variance of distribution parameters to failure probability is presented.

This paper presents a numerical investigation into the macromechanical and micromechanical behavior of unsaturated structural loess under constant stress increment ratio compression using the distinct-element method (DEM). Loess is typically a kind of clayey silt with a metastable structure composed of interparticle bonding and large voids. To represent the interparticle bonding, a published bond contact model proposed by the authors was used. Three samples with different water contents were tested under six incremental stress ratios to study the influence of water content and stress increment ratio on the mechanical response of loess. The DEM results qualitatively agree with available experimental observations in the literature. The observed macromechanical properties can be explained by the velocity field, force-chain distribution, bond breakage events, and contact orientation at the microscopic scale. When the stress increment ratio is low, the force chains exhibit a column-like pattern. As the...

Interferons are multifunctional cytokines widely used in clinical settings as an anti-viral drug. In addition, interferon’s exhibit anti-cancer and anti-bacterial effects. Nearly two thousand papers related to interferon are published each year, which illustrates the importance placed by researchers on the study of interferon. This review focuses on recent advances in the study of interferon, particularly in the areas of its mechanism of anti-cancer effect and signal transduction. We also describe the tumor resistance to interferon and the side-effect of interferon-based therapy, which leads to an expectation of future research of interferon.

Components with multiple failure modes may encounter imperfect preventive maintenance triggered by inspections during their two-stage failure. Employing delay-time concepts and accumulative age, a new imperfect-maintenance model for these components is presented under the assumptions that failure modes are independent of each other and all kinds of defects will be dealt with in each maintenance task. Reliability and cost models are derived. Their characteristics are analyzed in numerical simulations. The results show components with more failure modes and worse imperfect inspection maintenance will have lower reliability, lower expected cycle cost and higher average cost per unit time. With an increasing inspection interval, the cycle cost will monotonically decrease while the average cost per unit time may have a local minimum. If inspection maintenance is insufficient, the minimum of the average cost per unit time will disappear, as does the best inspection interval.

Natural loess is a kind of under-consolidated and unsaturated loose granulates (silts) with its microstructure characterized with large voids and inter-particle cementation. This paper presents a distinct element method (DEM) to investigate its macro- and micro-mechanical behaviour (compression and collapse behaviour) under one-dimensional (1D) compression condition. A relationship between bond strength in DEM model and initial water content is used to develop a bond contact model for loess. Then, DEM structural loess samples are prepared by the multi-layer under-compaction method, and cemented with the bond contact model. The effect of water content and void ratio on compression and collapse behaviour of loess is numerically investigated by simulating 1D compression and wetting tests on the DEM material. The DEM results agree qualitatively with available experimental observations in literatures. The wetting-induced deformation is independent of the sequence of wetting and loading under 1D compression condition. The macroscopic yielding and collapse behaviours are associated with bond breakage on microscopic scale. Moreover, bonds break in one of the two failure types in the simulations, i.e. tensile failure and shear failure (compression-shear failure and tension-shear failure), with bonds broken firstly mainly due to tension followed by shear when the samples are compressed, while mainly due to shear when the samples are wetted under a certain pressure. In addition, the contact orientations and deviator fabrics of contacts under 1D compression and wetting were also investigated.