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Ferritin M is involved in the regulation of fish immunity. In this study, open reading frame (ORF) sequences of ferritin M from hybrid fish and its parental species were 534 bp. Tissue-specific analysis indicated that the highest level of ferritin M from red crucian carp was observed in kidney, while peaked expressions of ferritin M from white crucian carp and hybrid carp were observed in gill. Elevated levels of ferritin M from hybrid carp and its parental species were detected in immune-related tissues following Aeromonas hydrophila infection or in cultured fish cell lines after lipopolysaccharide (LPS) challenge. Ferritin M overexpression could attenuate NF-κB and TNFα promoter activity in their respective fish cells. Purified ferritin M fusion proteins elicited in vitro binding activity to A. hydrophila and Edwardsiella tarda, lowered bacterial dissemination to tissues and alleviated inflammatory response. Furthermore, treatment with ferritin M fusion proteins could mitigate bacteria-induced liver damage and rescue antioxidant activity. These results suggested that ferritin M in hybrid fish showed a similar immune defense against bacteria infection in comparison with those of its parental species.

Aeromonas hydrophila is a common pathogen of freshwater fish. In this study, A. hydrophila infection was shown to cause tissue damage, trigger physiological changes as well as alter the expression profiles of immune- and metabolic-related genes in immune tissues of red crucian carp (RCC). Transcriptome analysis revealed that acute A. hydrophila infection exerted a profound effect on mitochondrial oxidative phosphorylation linking metabolic regulation to immune response. In addition, we further identified cellular senescence, apoptosis, necrosis and mitogen-activated protein kinase signal pathways as crucial signal pathways in the kidney of RCC subjected to A. hydrophila infection. These findings may have important implications for understanding modulation of immunometabolic response to bacterial infection.

Aeromonas hydrophila can pose a great threat to survival of freshwater fish. In this study, A. hydrophila infection could decrease blood cell numbers, promote blood cell damage as well as alter the levels of alkaline phosphatase (ALP), lysozyme (LZM), aspartate aminotransferase (AST), total antioxidant capacity (T-AOC), total superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) in immune-related tissues of red crucian carp (RCC, 2 N = 100) and triploid cyprinid fish (3 N fish, 3 N = 150). In addition, the significant alternation of antioxidant status was observed in PBMCs isolated from RCC and 3 N following LPS stimulation. The core differential expression genes (DEGs) involved in apoptosis, immunity, inflammation and cellular signals were co-expressed differentially in RCC and 3 N following A. hydrophila challenge. NOD-like receptor (NLR) signals appeared to play a critical role in A. hydrophila-infected fish. DEGs of NLR signals in RCCah vs RCCctl were enriched in caspase-1-dependent Interleukin-1β (IL-1β) secretion, interferon (IFN) signals as well as cytokine activation, while DEGs of NLR signals in 3Nah vs 3Nctl were enriched in caspase-1-dependent IL-1β secretion and antibacterial autophagy. These results highlighted the differential signal regulation of different ploidy cyprinid fish to cope with bacterial infection.

Combining sintering additive with field assisted sintering, stereolithographical dense Si3N4 ceramics was successfully fabricated. Owing to a large amount of polymer during the stereolithography, the green parts have the characteristics of low powder loading and high porosity. Adjusting the process parameters such as sintering temperature and soaking time can effectively improve the density of the specimens. The stress exponent n of all specimens is in a range of 1 and 2, which is derived from a modified sintering kinetics model. The apparent activation energy Qd of stereolithographic Si3N4 ceramics sintered with applied pressures of 30 MPa, 40 MPa, and 50 MPa is 384.75, 276.61 and 193.95 kJ/mol, respectively, suggesting that the densification dynamic process is strengthened by raising applied pressure. The grain boundary slipping plays a dominating role in the densification of stereolithographic Si3N4 ceramics. The Vickers hardness and fracture toughness of stereolithographic Si3N4 ceramics are HV10/10 (1347.9±2.4) and (6.57±0.07) MPa·m1/2, respectively.

FerL, a multifunctional iron-storage polypeptide, not only exhibited a regulatory role in iron metabolism, but also participated in the regulation of fish immunity. In this study, ORF sequence of WR-FerL was 522 bp, encoding 173 amino acid residues. Tissue-specific analysis revealed that the highest expression of WR-FerL was detected in spleen. A. hydrophila challenge and LPS stimulation could sharply enhance WR-FerL mRNA expression in tissues and fish cells, respectively. Purified WR-FerL fusion peptide exhibited in vitro binding activity to A. hydrophila and endotoxin, limited bacterial dissemination to tissues as well as attenuated A. hydrophila-induced production of pro-inflammatory cytokines. Moreover, WR-FerL overexpression could abrogate NF-κB and TNFα promoter activity in fish cells. These results indicated that WR-FerL could play an important role in host defense against A. hydrophila infection.

Aeromonas hydrophila can threaten the survival of freshwater fish. In this study, A. hydrophila challenge could induce tissue damage, promote antioxidant imbalance as well as alter the transcript levels of oxidative stress indicators, apoptotic genes and metabolic enzyme genes in kidney of red crucian carp (RCC). Metabolomics analysis revealed that A. hydrophila challenge had a profound effect on amino acid metabolism and lipid metabolism. In addition, we further identified dipeptides, fatty acid derivatives, cortisol, choline and tetrahydrocortisone as crucial biomarkers in kidney of RCC subjected to A. hydrophila infection. These results highlighted the importance of metabolic strategy against bacterial infection.

To construct pcDNA3.1(+) eukaryotic expression plasmid of connective tissue growth factor(CTGF), and detected its expression in human osteoblast-like cells SaOS-2, which provides a technical support for further research on the mechanism of CTGF gene in bone development and bone repair process. ;Methods: The whole sequence of CTGF gene was cloned in vitro by polymerase chain reaction(PCR) method and connected to the linear pcDNA3.1(+) vector for constructing pcDNA3.1(+)-CTGF eukaryotic expression plasmid by homologous recombination technology. The plasmid was identified by sequencing. After identification, it was transfected into SaOS-2 cells and its expression was detected at 48 h. ;Results: pcDNA3.1(+)-CTGF eukaryotic expression recombinant plasmid was successfully constructed, which was confirmed by sequencing. Compared with the control group, CTGF expression level was significantly up-regulated after transfection of SaOS-2 cells for 48 h, up to five times as much as the control group. ;Conclusion: pcDNA3.1(+)-CTGF eukaryotic expression plasmid was successfully constructed and could be stably expressed in human osteoblasts-like cell SaOS-2, which laid a foundation for further study on the regulatory mechanism of CTGF gene on bone formation.

Bo Fu,1 Shao-Nan Wen,1 Bin Wang,1 Kun Wang,2 Ji-Yan Zhang,3 Xie-Chuan Weng,1 Shao-Jun Liu1 1State Key Laboratory of Proteomics, Department of Neurobiology, Institute of Military Cognitive and Brain Sciences, Academy of Military Medical Sciences, Beijing 100850, China; 2Department of Occupational Medicine, Tianjin Institute of Environmental and Occupational Medicine, Tianjin 300050, China; 3Department of Molecular Immunology, Institute of Military Cognitive and Brain Sciences, Academy of Military Medical Sciences, Beijing 100850, China Purpose: Ventral tegmental area (VTA) dopamine system plays an important role in depression and is also involved in pain experience. In this study, we investigated the VTA dopaminergic (DA) neuron firing and local field potential (LFP) in pain-related depression, and we try to explore the underlying relationship between pain and depression.Materials and methods: We used neuropathic pain model [spare nerve injury (SNI)] to induce pain-related depression. The Dixon up–down method was used to test mechanical hypersensitivity. Behavioral changes like open field test, sucrose preference test, and forced swim test were used to test depression-like behaviors. Gabapentin (GBP) was used to explore the chronic analgesic treatment that could reverse pain-related depression. To investigate the in vivo variations of VTA DA neuron firing and LFP, multichannel acquisition processor system was used.Results: We used SNI to induce depression-like behaviors. Repeated GBP treatment reversed these behaviors after 14 days of injection. An in vivo electrophysiological analysis of the firing characteristics of VTA DA neurons and LFP revealed that SNI increased the firing rate of DA neurons, but not the burst firing activity. Surprisingly, chronic GBP reversed the firing rate of DA neurons and reduced the burst firing activity. Moreover, SNI increased the LFP power in delta and theta oscillation and decreased it in beta oscillation. Repeated administration of GBP significantly suppressed theta oscillation. Above all, chronic GBP altered these characteristics to reverse depression-like behaviors.Conclusion: The present study confirmed that the tonic firing activity of VTA DA neurons, but not the burst firing activity, was the key factor in peripheral neuropathy–induced depression. Chronic GBP regulated the firing pattern of DA neurons and decreased theta oscillation in VTA to treat pain-related depression. This variation tendency of electrophysiological characteristics of VTA DA neurons and theta oscillation in VTA might represent an attempt to cope with pain-related negative mood disorder. Keywords: chronic neuropathic pain, depression, dopaminergic neuron, LFP, VTA

Rationale & Objective We aimed to explore the associated factors of endothelial injury in chronic kidney disease (CKD) and the relationship between endothelial dysfunction and CKD prognosis. Study Design A prospective observational cohort study. Setting & Participants 77 adults with CKD stages 1-5 were enrolled January 2010 to December 2010 and followed up until December 2015. Exposure Serum asymmetric dimethylarginine (ADMA) level at baseline, α-klotho, sodium-phosphorus synergistic transporter, and dimethylarginine-dimethylamine hydrolase expression in kidney biopsy samples. Outcome Initiation of kidney replacement therapy (KRT). Analytical Approach Kaplan-Meier analysis was used for evaluation of the incidence rate of KRT. All tests were 2 tailed, and statistical significance was defined as P, Graphical abstract

A prediction model of the friction coefficient and wear of the spiral bevel gears in the mixed lubrication condition is proposed. Effect of a coupling thermo-elasto-hydrodynamic phenomenon on tooth surface should be considered comprehensively prior to the execution of tooth wear analysis. An effort is devoted to application of TEHL with rough surface contact to analyze the performance of spiral bevel gears in terms of the pressure, flash temperature, friction coefficient, and particularly wear rate. Wear mechanism and rules under a condition of the mixed lubrication are revealed to provide evidence for gear design and engineering application. And comparison of the prediction wear depth with the experimental measurements shows good agreement.

In order to determine the temperature rise of the tooth surface as a result of the friction heat in mixed EHL, a coupled thermo-elasto-hydrodynamic analysis is carried out in consideration of the load shearing, mixed lubrication characteristics, heat generation in the contact region. The procedure necessary to establish the model of a coupled thermo-elasto-hydrodynamic analysis is also described. Considering the lubrication condition of tooth surface, a great challenge of moving heat source applied on complex curved surface is solved to improve the present thermal analysis method of spiral bevel gear. Based on loaded tooth contact analysis of spiral bevel gears and EHL analysis of point contact, steady-state and transient thermal analyses are conducted. And the comparison of the analytical results with the experimental measurements shows good agreement. Effects of asperity contact on temperature rise in spiral bevel gear teeth surfaces were also discussed.

Adipose-derived mesenchymal stem cells (ADMSCs) have been used for treating tissue injury, and preactivation enhances their therapeutic effect. This study is aimed at investigating the therapeutic effect of activated ADMSCs by IL-1β on the intestinal ischaemia-reperfusion (IR) injury and exploring potential mechanisms. ADMSCs were pretreated with IL-1β in vitro, and activation of ADMSCs was assessed by α-SMA and COX-2 expressions and secretary function. Activated ADMSCs was transplanted into IR-injured intestine in a mouse model, and therapeutic effect was evaluated. In addition, to explore underlying mechanisms, COX-2 expression was silenced to investigate its role in activated ADMSCs for treatment of intestinal IR injury. When ADMSCs were pretreated with 50 ng/ml IL-1β for 24 hr, expressions of α-SMA and COX-2 were significantly upregulated, and secretions of PGE2, SDF-1, and VEGF were increased. When COX-2 was silenced, the effect of IL-1β treatment was abolished. Activated ADMSCs with IL-1β significantly suppressed inflammation and apoptosis and enhanced healing of intestinal IR injury in mice, and these effects were impaired by COX-2 silencing. The results of RNA sequencing suggested that compared with the IR injury group activated ADMSCs induced alterations in mRNA expression and suppressed the activation of the NF-κB-P65, MAPK-ERK1/2, and PI3K-AKT pathways induced by intestinal IR injury, whereas silencing COX-2 impaired the suppressive effect of activated ADMSCs on these pathway activations induced by IR injury. These data suggested that IL-1β pretreatment enhanced the therapeutic effect of ADMSCs on intestinal IR injury repairing via activating ADMSC COX-2-PGE2 signaling axis and via suppressing the NF-κB-P65, MAPK-ERK1/2, and PI3K-AKT pathways in the intestinal IR-injured tissue.

LEAP-2, a multifunctional peptide, not only exhibits a regulatory role in pathogenic infection, but also participates in the regulation of teleostean immunity. In this study, ORF sequence of WR-LEAP-2 was 240 bp and encoded 79 amino acid residues. Tissue-specific analysis revealed that the highest expression of WR-LEAP-2 was observed in liver. Aeromonas hydrophila challenge can sharply increase WR-LEAP-2 mRNA expression in liver, kidney and spleen. The purified WR-LEAP-2 peptide can directly bind to A. hydrophila and S. agalactiae, reduce the relative bacterial activity and limit bacterial growth in vitro. In addition, the treatment of WR-LEAP-2 can restrict bacterial dissemination in vivo and reduce production of pro-inflammatory cytokines. These results indicated that WR-LEAP-2 can confer protection against A. hydrophila- or S. agalactiae-stimulated MyD88-dependent pro-inflammatory cytokines activation.

The wear characteristics of the deep-sea mining pump was investigated. The Euler-Lagrange coupling model, RNG k-e turbulence model and Finnie wear model were used to simulate the solid-liquid two phase flow in the pump. The influence of particle size on the wear characteristics of hydraulic components was analyzed when the particle volume concentration was 5.14%. The results demonstrate that the wear rate of the impeller is faster than that of the diffuser. The wear rate of the shroud is the fastest, followed by the blade and the wear rate of the hub is the last. The particle size of 10mm is appropriate for this model, resulting in less wear. Comparing the simulation results with the experimental results, it is found that the simulation results of the pump external characteristics are consistent with the experimental results in the same condition, indicating the validity and correctness of the simulation model. Finally, suggestions about the design of deep-sea mining pump are put forward.

As Hainan Island belonged to tropical monsoon influenced region, vegetation coverage was high. It is accessible to acquire the vegetation index information from remote sensing images, but predicting the average vegetation index in spatial distributing trend is not available. Under the condition that the average vegetation index values of observed stations in different seasons were known, it was possible to qualify the vegetation index values in study area and predict the NDVI (Normal Different Vegetation Index) change trend. In order to learn the variance trend of NDVI and the relationships between NDVI and temperature, precipitation, and land cover in Hainan Island, in this paper, the average seasonal NDVI values of 18 representative stations in Hainan Island were derived by a standard 10-day composite NDVI generated from MODIS imagery. ArcGIS Geostatistical Analyst was applied to predict the seasonal NDVI change trend by the Kriging method in Hainan Island. The correlation of temperature, precipitation, and land cover with NDVI change was analyzed by correlation analysis method. The results showed that the Kriging method of ARCGIS Geostatistical Analyst was a good way to predict the NDVI change trend. Temperature has the primary influence on NDVI, followed by precipitation and land-cover in Hainan Island.

Sonodynamic therapy (SDT) has rapidly developed as a powerful alternative to traditional photodynamic therapy due to its intrinsically deeper tissue-penetration. However, single SDT dose is incapable of radical cure because the long-term hypoxia of tumor limits its therapeutic effect. Herein, we developed a biomimetic nanoplatform with dual pH/ultrasound response, homologous targeting and low phototoxicity for combined nitric oxide (NO) gas therapy with SDT to solve the problem. This nanoplatform is composed of zeolite imidazole framework-8 material embedded with nitrosoglutathione (GSNO) and chlorin e6 (Ce6) by one-step encapsulation, and then wrapped by homologous tumor cell membrane. In vitro and in vivo experiments indicate that the biomimetic nanoplatform has excellent biocompatibility and shows higher retention in tumor by homologous targeting. Importantly, it can sustainably release the encapsulated drug in acidic tumor microenvironment and accelerate degradation by ultrasound (US). Furthermore, NO released from GSNO and reactive oxygen species generated by Ce6, which are both triggered by US, react with each other to produce highly reactive peroxynitrite to inhibit the growth of tumor. Moreover, by repeated US irradiation, the tumor hypoxia can be relieved for a much-longer term, resulting in an effective gas-sonodynamic combined treatment. This study fully utilizes the advantages of US, providing a new strategy for high-performance cancer therapy.

To explore the underlying electrophysiological mechanism of depression induced by chronic pain in dopaminergic neurons in midbrain ventral tegmental area (VTA) of rats.Twenty-four healthy adult rats were divided into two groups randomly(①Comparing to sham rats, the paw withdrawalmechanical threshold of SNI rats was decreased significantly (Chronic pain could induce depression, and the increase of spontaneous firing rate of dopaminergic neurons in midbrain VTA might be contribute to the depression induced by the chronic neuropathic pain.

To explore the effects of hyperpolarization-activated cyclic nucleotide-gated channels 2(HCN2) in the formation of peripheral neuropathic pain in rats.Twenty-four healthy adult rats were divided into two groups randomly(The rat model of neuropathic pain was successfully established. Compared with saline group, GBPT group and ZD7288 group could significantly reduce the symptoms of neuropathic pain in rats after injection 1 h (HCN2 is involved in the development of peripheral neuropathic pain and is likely to be a potential new target for the treatment of neuropathic pain.

The medial prefrontal cortex is involved in the process of sensory discrimination. In this study, we examined the local field potential activity response to the different stages of pain in the prelimbic cortex (PrL) which is a sub-region of the medial prefrontal cortex. Recent studies revealed extensive information about neural oscillations, but there is limited information on the local field potential profiles for acute or chronic pain, particularly in freely moving animals. This study showed that acute mechanical pain increases alpha oscillation and decreases beta and gamma oscillations before spared nerve injury surgery. Delta oscillation was decreased by chronic pain and gamma oscillation varied with time. However, acute mechanical pain stimulus had no effects on local field potential in rats under mechanical allodynia. Together, our findings provide novel insights into the role of medial prefrontal cortex local field potential activity response to pain stimulus.

In this study, morphology observation and illumina sequencing were performed on two different coloration skins of crimson snapper (Lutjanus erythropterus), the black zone and the red zone. Three types of chromatophores, melanophores, iridophores and xanthophores, were organized in the skins. The main differences between the two colorations were in the amount and distribution of the three chromatophores. After comparing the two transcriptomes, 9200 unigenes with significantly different expressions (ratio change ≥ 2 and q-value ≤ 0.05) were found, of which 5972 were up-regulated in black skin and 3228 were up-regulated in red skin. Through the function annotation, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the differentially transcribed genes, we excavated a number of uncharacterized candidate pigment genes as well as found the conserved genes affecting pigmentation in crimson snapper. The patterns of expression of 14 pigment genes were confirmed by the Quantitative real-time PCR analysis between the two color skins. Overall, this study shows a global survey of the morphological characters and transcriptome analysis of the different coloration skins in crimson snapper, and provides valuable cellular and genetic information to uncover the mechanism of the formation of pigment patterns in snappers.

Objective To study the genotype of the members of a Chinese family with spinocerebellar ataxia (SCA). Methods The peripheral blood samples of 6 patients and 40 asymptomatic people belonged to the family were collected. Referring to the clinical manifestations of the proband and second-generation sequencing results, the CAG trinucleotide repeats of the pathogenic gene ATXN2 were amplified by polymerase chain reaction (PCR). The repeated times of the trinucleotide in normally and abnormally amplified alleles were defined by agarose gel electrophoresis and PCR products sequencing. Results Autosomal dominant heredity was the cause of the SCA in this family. Six out of 46 in the fourth-generation were SCA2 patients, 7 were the carriers of pathogenic allele. The repeated times of CAG trinucleotide were within the normal range in one of the two alleles of ATXN2, but they were in abnormal range in the another one. The repeated times of CAG trinucleotide were 40-46 in abnormal alleles of patients. Conclusion Autosomal dominant heredity SCA2 has been diagnosed in this family caused by the dynamic nutation of CAG trinucleotide repeats, and 7 pathogenic allele carriers in this family were confirmed by genetic diagnosis. DOI: 10.11855/j.issn.0577-7402.2015.08.07

To complete the contact fatigue reliability analysis of spur gear under elastohydrodynamic lubrication (EHL) efficiently and accurately, an intelligent method is proposed. Oil film pressure is approximated using quadratic polynomial with intercrossing term and then mapped into the Hertz contact zone. Considering the randomness of the EHL, material properties and fatigue strength correction factors, the probabilistic reliability analysis model is established using artificial neural network (ANN). Genetic algorithm (GA) is employed to search the minimum reliability index and the design point by introducing an adjusting factor in penalty function. Reliability sensitivity analysis is completed based on the advanced first order second moment (AFOSM). Numerical example shows that the established probabilistic reliability analysis model could correctly reflect the effect of EHL on contact fatigue of spur gear, and the proposed intelligent method has an excellent global search capability as well as a highly efficient computing performance compared with the traditional Monte Carlo method (MCM).

In order to consider the effects of elastohydrodynamic lubrication (EHL) on contact fatigue reliability of spur gear, an accurate and efficient method that combines with response surface method (RSM) and first order second moment method (FOSM) was developed for estimating the contact fatigue reliability of spur gear under EHL. The mechanical model of contact stress analysis of spur gear under EHL was established, in which the oil film pressure was mapped into hertz contact zone. Considering the randomness of EHL, material properties and fatigue strength correction factors, the proposed method was used to analyze the contact fatigue reliability of spur gear under EHL. Compared with the results of 1.5×105 by traditional Monte-Carlo, the difference between the two failure probability results calculated by the above mentioned methods is 2.2×10−4, the relative error of the failure probability results is 26.8%, and time-consuming only accounts for 0.14% of the traditional Monte-Carlo method (MCM). Sensitivity analysis results are in very good agreement with practical cognition. Analysis results show that the proposed method is precise and efficient, and could correctly reflect the influence of EHL on contact fatigue reliability of spur gear.

Deepwater deployment of offshore structures in different sea states was investigated. The whole deployment system was modeled as a lumped mass model, and discretization scheme for cable geometry and methodology for calculating the internal and external force acting on deploying cable were presented. The deployment model suitable for the time-varying length of deploying cable was specified. The free-surface flow fields together with the ship motions were used to calculate dynamic tension in the deploying cable during deployment of the structure. The deployment of deep sea mining system which was a typical subsea working system was employed. Based on lumped mass analysis model and parameters of deep sea mining system, numerical simulations were performed, and dynamic load and dynamic amplification factor (DAF) with different cable parameters, deploying velocities and sea states were obtained. It is shown that cable parameters and amplitudes of ocean waves can significantly influence the dynamic load and DAF, and the time-varying natural period of deploying system is a dominant factor, while the effect of deploying velocity is not obvious.

Equipment for deep sea mining has risen from a position of virtual non-existence to a major industrial significance and in deep sea bed mining, the miner is the key equipment of the whole system that charges with the most complex and dangerous task. Evaluation of trafficability for tracked vehicles for deep sea mining is essential. Rare earth elements (REEs) are used in a wide range of modern applications. These applications are highly specific and substitutes are inferior or unknown. One possible source of the REE could be the poly-metallic nodule, at present explored in the tropical part of the Pacific Ocean. In developing miners of high performance, dynamic behaviour should be investigated under various traveling conditions. The mechanics of tracked vehicles is of continuing interest to organizations and agencies that specify design and operate tracked vehicles. Most works done are on the complete track vehicle system but in this work the research activity is aimed only at the track system with the basic aim of optimizing the track system design so that it can be manufactured by using the minimum resources. Equations and models are developed for the track system of a miner during steering motion. These equations and models could further be used for design optimization of the track system.

The model of airborne radar reconnaissance is one of key models for joint campaign level wargame. On the one hand the joint campaign level wargame system often needs to simulate hundreds of aircraft in once combat simulation which requires high computing capability. On the other hand, a few aircraft can affect the progress of the war in the information war age sometimes, therefore, modern joint campaign level wargame systems need to simulate single aircraft now. In this paper, we proposes a model of airborne radar reconnaissance for joint campaign level wargame based on EBI(Entity, Behavior, Interaction) modeling framework, which can satisfy both the hardware computing capability constraints and simulation granularity requirement for single aircraft. We also give some key mathematical models and algorithms.

Due to the coaxial connection of engine, motor and pump, the dynamic characteristics of hybrid construction machinery are changed, which generates a new torsional vibration problem of multi-power sources. To reduce the torsional vibration of the hybrid construction machinery complex shafting, torsional vibration active control was proposed. The three-mass model of coaxial shafting of hybrid construction machinery was established. The PID control and the fuzzy sliding mode control were chosen to weaken torsional vibration by controlling the motor speed and torque. The simulation results show that the fuzzy sliding mode control has 12% overshoot of the PID control when the engine torque changes. The active control is effective and can realize smooth power switch.

Seafloor polymetallic sulfide specimens were developed according to engineering rock test method standard (GB/T 50266-2013). Seafloor polymetallic sulfide wet density and dry density were tested. Uniaxial compressive strength and triaxial compression strength of seafloor polymetallic sulfide were tested using rock mechanics test system MTS 815. Elasticity modulus and Poisson's ratio of seafloor polymetallic sulfide were calculated based on specimens stress-strain curves. Cohesion and internal friction angle were calculated based on specimens triaxial test Mohr stress circle. Test results show that seafloor polymetallic sulfide dry density average value is 2.6 g/cm3, wet density average value is 2.94 g/cm3. Uniaxial compressive strength and triaxial compression strength of seafloor polymetallic sulfide are unstable. Average value of the uniaxial compressive strength is 10.243MPa. Average value of triaxial compression strength test peak load is 47.166KN. Cohesion is 2.447MPa and internal friction angle is 38.04o.

A numerical wave load model based on two-phase (water-air) Reynolds-Averaged Navier Stokes (RANS) type equations is used to evaluate hydrodynamic forces exerted on flatted-bottom seafloor mining tool during its entering ocean waves of deploying process. The discretization of the RANS equations is achieved by a finite volume approach (FV). The volume of fluid method (VOF) is employed to track the complicated free surface. A numerical wave tank is built to generate the ocean waves which are suitable for deploying seafloor mining tool. A typical deploying condition is employed to reflect the process of flatted-bottom body impacting with waves, and the pressure distribution of bottom is also presented. Four different lowering velocities are applied to obtain the time histories of maximum pressure of bottom, and it can be concluded that the pressure coefficient decreases with water velocity increasing, which is similar with ordinary water entry case. The numerical results clearly demonstrate the characteristics of flatted-bottom body entering ocean waves.

There are a great amount of electronic meters equipped in the distribution substations, which were traditionally monitored by operators. On-site monitoring for risk assessment of these meters is very important. In this paper, we presented an advanced machine vision based automatic meter detection method toward the development of an online automatic meter reading intelligent inspection robot in substation. Firstly, the image received from the inspection robot was enhanced using histogram equalization. Then, the image was segmented into two parts based on the threshold obtained by Otsu’s method. Using these two parts, and the whole enhanced image, circular Hough transformation was applied on these three images and detected the circle with highest probability on them. The normalized correlation coefficients were calculated between the corresponding areas of those three circles from three images and the template image of SF6meter. Finally, the circle with highest correlation coefficient, which was higher than a certain threshold, was determined to be the meter. If it is lower than the threshold, the algorithm would decide that no meter was found in the image. The method was tested with 222 images obtained in one substation in Xi’an, Shanxi, China, and an 87.4% accuracy was achieved using these images, which indicated the potential of this method.