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In order to overcome the short battery life and poor long-distance maneuverability of Unmanned Aerial Vehicle (UAV) in power inspection operations, some provincial and municipal power companies promote a new mode of “UAV and operating vehicle (OV)” collaborative power inspection. This paper investigates into the actual problems in the cooperative inspection operations of the OV and multi-UAVs, and proposes a model of task allocation for the cooperative inspections of the OV and multi-UAVs, which includes four sub-problems: the division of a single operation circle, the location of parking spots, multi-UAVs task allocation, and the path planning of OV. The proposed model is solved by using improved K-means algorithm and genetic algorithm, and case analysis is carried out. The calculation results show that the model of task allocation for cooperative inspections proposed in this paper is practical and feasible, which can provide theoretical guidance for actual power inspections.

Transition metal-based nanoparticle-embedded carbon materials have received increasing attention for constructing next-generation electrochemical catalysts for energy storage and conversion. However, designing hybrid carbon materials with controllable hierarchical micro/mesoporous structures, excellent dispersion of metal nanoparticles, and multiple heteroatom-doping remains challenging. Here, a novel pyridinium-containing ionic hypercrosslinked micellar frameworks (IHMFs) prepared from the core-shell unimicelle of s-poly(tert-butyl acrylate)-b-poly(4-bromomethyl) styrene (s-PtBA-b-PBMS) and linear poly(4-vinylpyridine) were used as self-sacrificial templates for confined growth of molybdenum disulfide (MoS2 ) inside cationic IHMFs through electrostatic interaction. After pyrolysis, MoS2 -anchored nitrogen-doped porous carbons possessing tunable hierarchical micro/mesoporous structures and favorable distributions of MoS2 nanoparticles exhibited excellent electrocatalytic activity for hydrogen evolution reaction as well as small Tafel slope of 66.7 mV dec-1 , low onset potential, and excellent cycling stability under acidic condition. Crucially, hierarchical micro/mesoporous structure and high surface area could boost their catalytic hydrogen evolution performance. This approach provides a novel route for preparation of micro/mesoporous hybrid carbon materials with confined transition metal nanoparticles for electrochemical energy conversion.

Four-product dividing wall columns (FPDWCs) are considered as more energy-efficient than conventional column sequence for multi-product separation. The FPDWCs with two partition walls have the supe...

To improve the mechanical property of 2, 4-dinitroanisole (DNAN)/1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) melt-cast explosives, the effects of additives, N-methyl-4-nitroaniline(MNA), polyethyl...

In this paper, we introduce the dual $r$-rank decomposition of dual matrix, get its existence condition and equivalent form of the decomposition, as well as derive some characterizations of dual Moore-Penrose generalized inverse(DMPGI). Based on DMPGI, we introduce one special dual matrix(dual EP matrix). By applying the dual $r$-rank decomposition we derive several characterizations of dual EP matrix, dual idempotent matrix, dual generalized inverses, and the relationships among dual Penrose equations.

Auxin-dependent cell expansion is crucial for initiation of fiber cells in cotton (Gossypium hirsutum), which ultimately determines fiber yield and quality. However, the regulation of this process is far from being well understood. In this study, we demonstrate an antagonistic effect between cytokinin (CK) and auxin on cotton fiber initiation. In vitro and in planta experiments indicate that enhanced CK levels can reduce auxin accumulation in the ovule integument, which may account for the defects in the fiberless mutant xu142fl. In turn, supplementation with auxin can recover fiber growth of CK-treated ovules and mutant ovules. We further found that GhPIN3a is a key auxin transporter for fiber-cell initiation and is polarly localized to the plasma membranes of non-fiber cells, but not to those of fiber cells. This polar localization allows auxin to be transported within the ovule integument while specifically accumulating in fiber cells. We show that CKs antagonize the promotive effect of auxin on fiber cell initiation by undermining asymmetric accumulation of auxin in the ovule epidermis through down-regulation of GhPIN3a and disturbance of the polar localization of the protein.

Rayleigh convection has a significant effect on gas-liquid interfacial mass transfer. However, its intensified mechanism has not been clarified so far. In the present work, three-dimensional hybrid Lattice Boltzmann Method-Finite Difference Method (LBM-FDM) was employed to simulate the Rayleigh convection emerging in the CO2-ethanol absorption process. A gas phase random disturbance model was applied to represent the disturbances on the gas-liquid interface which effectively induces Rayleigh convection. Then the front view images obtained by three-dimensional simulation were compared to the Schlieren observations for validation. Finally, a theoretical mass transfer coefficient model based on dissipation rate of concentration variance was proposed, by analyzing the overhead view of concentration contour and dissipation rate of concentration variance contour. Compared to the small eddy model and surface divergence model, the proposed model shows its strength in determining molecular diffusion stage and convective mass transfer stage of Rayleigh convection process, as well as eliminating the phase difference in model prediction.

The Rayleigh convection could be induced by solute evaporation in dual solvents, such as acetone-ethyl acetate and isopropanol-water system. The onset of Rayleigh convection and its evolutionary characteristics were simulated using LBM-FDM hybrid method with liquid phase random disturbance model. And the simulation results were in reasonable agreement with experimental measurements in four aspects: Rayleigh convection onset time, concentration field acquired by Schlieren and velocity field acquired by PIV, average mass transfer coefficient, and statistical average velocity distribution along the gravitational direction. It proves that the LBM-FDM hybrid method is effective in capturing the key features in this mesoscale phenomenon. Then three mass transfer model including small eddy model, surface divergence model and the new model based on theoretical parameters concentration variance, its dissipation rate and Reynolds mass flux were proposed to predict the interfacial mass transfer coefficient, and the new developed model had advantages over other two models, in the onset time of Rayleigh convection, the peak of mass transfer coefficient and tackling the non-synchronism between velocity and concentration field in fully developed convective stage. The new developed model shows its strength in determining the mass transfer coefficient in a theoretical way.

BACKGROUND This study aimed to investigate the effects of repetitive transcranial magnetic stimulation (rTMS) and treadmill training (TT) on motor function recovery in rats with partial spinal cord injury (SCI). MATERIAL AND METHODS Sixty rats with moderate partial SCI at the 9th thoracic vertebral level induced by a Louisville Injury System Apparatus impactor were randomly allocated to 5 groups: Sham surgery (Intact); Sham rTMS without TT (S-rTMS/Non-TT); Sham rTMS with TT (S-rTMS/TT); rTMS without TT (rTMS/Non-TT); and rTMS with TT (rTMS/TT). Interventions commenced 8 days after SCI and continued for 8 weeks. Outcomes studied were Basso, Beattie, and Bresnahan locomotor scale scores, grid walking test, and biochemical analysis of the brain-derived neurotrophic factor (BDNF), synapsin I (SYN), and postsynaptic density protein-95 (PSD-95) in the motor cortex and spinal cord. RESULTS The rTMS/TT contributed to greater Basso, Beattie, and Bresnahan scores compared with the S-rTMS/Non-TT (P

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A mixture of taxols was prepared from 10-deacetyl-7-xylosyltaxanes by three-step reactions: redox, acetylation, and deacetylation. The mixture was separated by column chromatography on silica gel to afford Taxol, Taxol B (Cephalomannine) and Taxol C. The mixture of Taxol B and Taxol C was converted to Docetaxel by Schwartz's reagent. The structures of Taxol and Docetaxel were characterized by HPLC, 1 H-NMR, 13 C-NMR and MS. This synthetic process has expanded the source of biomass for the chemical semi-synthesis of Taxol and Docetaxel, reduced the production costs, and increased the biomass resource of taxanes.

In this paper, we introduce the m-core-EP inverse in Minkowski space, consider its properties, and get several sufficient and necessary conditions for the existence of the m-core-EP inverse. We give the m-core-EP decomposition in Minkowski space, and note that not every square matrix has the decomposition. Furthermore, by applying the m-core-EP inverse and the m-core-EP decomposition, we introduce the m-core-EP order and give some characterizations of it.

For separating some specific four component mixtures into four products, the four-product dividing wall column (FPDWC) with two partition walls can provide the same utility consumption with the extended Petlyuk configuration, although with structure simplicity. However, the reluctance to implement this kind of four product dividing wall column industrially also consists in the two uncontrollable vapor splits associated with it. The vapor split ratios are set at the design stage and might not be the optimal value for changed feed composition, thus minimum energy consumption could not be ensured. In the present work, a sequential iterative optimization approach was initially employed to determine the parameters of cost-effective FPDWC. Then the effect of maintaining the vapor split ratios at their nominal value on the energy penalty was investigated for the FPDWC with two partition walls, in case of feed composition disturbance. The result shows that no more than + 2% above the optimal energy requirements could be ensured for 20% feed composition disturbances, which is encouraging for industrial implementation.

Discovering meaningful patterns in image data can help to better understand and search the visual contents that convey rich information. Unlike conventional pattern mining in transaction or text data, visual patterns usually contain complex spatial structures and exhibit large variations, thus making the image data mining task very challenging. This thesis is devoted to developing effective methods for visual pattern discovery, and has the following three contributions. The first contribution of this thesis is on spatial visual pattern discovery. We focus on the composition of visual patterns from visual primitives (e.g., local interest points or regions in images). Conventional clustering of visual primitives, e.g., bag-of-words, usually ignores the spatial and feature structure among the visual primitives, thus cannot discover high-level visual patterns of complex structure. To overcome this problem, we propose to consider both spatial and feature contexts among visual primitives for spatial pattern discovery. We formulate the pattern discovery problem as a regularized k-means clustering, and propose a self-learning procedure to gradually refine the result until it converges. Our experiments validate that by discovering both spatial co-occurrence patterns among visual primitives and feature co-occurrence patterns among different types of features, our method can effectively reduce the ambiguities of visual primitives. The second contribution of this thesis is on multi-feature clustering for visual pattern discovery. Given multiple-feature representation for each image, we propose a novel minimax formulation to reach a consensus clustering, without requiring to specify the weighting parameter to fuse the multiple feature modalities. Our objective of consensus clustering is to find a universal feature embedding, which not only fits each feature modality well, but also unifies different modalities by minimizing the pairwise disagreement between any two of them. The experiments with real image data show the advantages of the proposed multi-feature clustering method when compared with existing methods. The last contribution of this thesis is on semi-supervised visual pattern discovery. We study visual pattern classification using collaborative multi-feature fusion in a transductive learning framework, where the labelled data can transfer the labels to the unlabelled data. To enable transductive spectral learning, we formulate a new objective function with three objectives, namely the good quality of spectral clustering in individual feature types, the label smoothness of data samples in terms of their feature co-occurrence representations, and the fitness to the labels provided by the training data. However, the spectral clustering results in different feature types and the formed co-occurrence patterns influence each other under the transductive learning formulation, which makes the optimization of this objective function challenging. To address this problem, we propose an iterative optimization approach that can decouple these factors. During the iterations, the clustering results of individual feature types and the smoothness of the labelling of data samples will help each other, leading to a better transductive learning and a pattern classification result. The effectiveness of the proposed method is validated by both synthetic and real image data. DOCTOR OF PHILOSOPHY (EEE)

Recently, more and more unmanned aerial vehicles (UAVs) have been used in industry, public services and commercial fields. However, the UAV is generally limited by the battery capacity, and the operation radius is greatly limited. In this paper, to increase the flight time of the UAV, the recharging station by using wireless power transfer (WPT) technology is proposed. A new receiver magnetic coupler is given, the receiver coil is wound around the hollow ferrite core, and the proposed structure provides many benefits: 1) first, there is a large magnetic flux captured surface, which can improve the mutual coupling between the primary side and secondary side. 2) Second, own to the hollow ferrite core, the receiver side is light, which has little effect on the weight bearing of UAV. 3) Third, it is easy to be installed on the UAV, since the receiving coil is compact. 4) Moreover, the proposed WPT system provides enough anti misalignment capability for UAV.

In this study, the gradient grain induced by punching deformation and recovery treatment on a cupronickel alloy surface sample were investigated, and their effects on corrosion resistance were measured by atom force microscopy (AFM), X-ray diffraction (XRD), electrochemical measurement, electron work function (EWF), and contact electrical resistance (CER). The cupronickel alloy surface experienced punching deformation for 60 min and recovery at 300 °C for 1 h to produce gradient surface. The grain size measured by XRD is bigger than that measured by AFM, due to X-ray intensity of 95 % produced at the depth of 12–20 μm for the crystal planes of (111), (200), and (220). The gradient grain surface, compared to the original surface, shows a 13.7-fold decrease in passivation current density (i p), and corrosion potential (E C) increases by approximately 9.8 %. These results are attributable to the increase in EWF and formation of passivation film with better adhesion and compactness after treatment.

The stabilized/solidified (S/S) sediments are supposed to be damaged by freeze–thaw cycles (FTs), and their deformation parameters such as void ratio, compression modulus and consolidation coefficient changed during FTs. The characteristics of pore structure of S/S sediments during FTs are critical for identifying the damage mechanisms, since these damages are primarily induced by the water-phase changes in the pores. Hence, FTs were first simulated in laboratory to prepare S/S sediments samples in different conditions. Then, oedometer tests were launched on these samples to observe the changing of the deformation parameters of S/S sediments in different FTs. After that, scanning electron microscopy analysis (SEM) was applied to observe the changing of the micro pore structure aspects of S/S sediments in different FTs. And finally, the combined application of mercury intrusion porosimetry analysis (MIP) and nitrogen adsorption porosimetry analysis (NAP) was conducted to ascertain the changing of the micro pore structure of S/S sediments in different FTs quantitatively, including the changing of pore-size distributions and pore surface roughness. The comprehensive analysis of pore structure of S/S sediments by SEM, MIP and NAP appropriately explained the changes of deformation parameters in the oedometer tests. Furthermore, the necessity and validity of combined application of MIP and NAP were proved, for full-scale pore structure analysis of S/S sediments during FTs.

In recent years, power departments have gradually utilized UAV to carry out regular inspections of transmission lines to ensure the safety and stability of power systems. However, a large number of images without useful information are usually captured during the UAV inspection. These images that contain no transmission line information are transmitted to the ground station with informative images, which leads to the surge of workload. To solve this problem, we propose an intelligent image filtering method based on the VGGNet, which is called Light-VGGNet. Firstly, this paper collects the aerial images captured by cameras during the UAV inspection and builds an aerial dataset of transmission line scenes. Then, the Light-VGGNet is proposed, which achieves much lower memory consumption and faster running speed than those of the VGGNet. We use the aerial image dataset to train the proposed network. Finally, the best weight is loaded and utilized to predict the label of the test dataset.

Zn-Cu-Al zinc alloy was prepared by metal mould casting. The effects of Al addition on the microstructure, electrical conductivity and wear resistance of Zn-Cu-Al alloy were studied. The results show that the structure of Zn-Cu-Al alloy is composed of Zn solid solution containing Cu and Al (η phase), eutectic phase (α+η) and CuZn5 (ε phase); Al0.4Zn0.6 phase appeared when Al addition content exceeded 2.0wt.%; With the increase of Al addition content, eutectic phase (α+η) content increased and η phase grain refined. Meanwhile, the hardness and electrical conductivity of the alloy increase with the increase of Al addition content. When the addition of Al is 5.0 wt.%, the hardness and electrical conductivity of the alloy reach the maximum, 151HV and 26.4% IACS, respectively. The wear mechanism of the alloy is mainly plastic deformation with a mixture mode of plastic deformation and adhesion.

Based on orthogonal experimental design, the key solidification controlling technology of Solidified/Stabilized (S/S) sludge with high total organic content (TOC) by cement, lime and metakaolin was explored by macroscopic tests, chemical components measurements and microscopic analysis. The macroscopic tests show that, the permeability coefficient is mainly affected by initial water content and lime content, and the unconfined compression strength is mainly affected by cement content and lime content. The chemical components measurements show that, the solidification effect of S/S sludge with high TOC is controlled by organic matter consumption, and organic matter consumption is determined by the alkaline environment from the cement and lime hydration reactions, which is mainly affect by the initial water content and lime-metakaolin content ratio. The microscopic analysis results show that, lime consumes parts of organic matter while excess lime produces weak Ca(OH)2 crystal fluffy sheet structure, matakaolin produces pozzolanic reactions with cement and lime instead of soil particles, and consumes the weak Ca(OH)2 crystal fluffy sheet structure produced by superfluous lime. The research has confirmed key controlling points of S/S sludge in case of high TOC, which will provide theoretical guidance and technical support for S/S sludge promotion with high TOC.

OBJECTIVE To investigate on Left ventricular ejection fraction value and aldosterone of two medicinals of Traditional Chinese Medicine (TCM) with the properties of warming Yang and tonifying Qi in terms of TCM theory. METHODS An animal model of coronary ligation of heart failure after myocardial infarction was employed to study the influence of these two kinds of drugs on three batches of rats. On the basis of the average score of left ventricle ejection fraction during the investigation, there were some different groups, including WenYang (the warming Yang) group, YiQi (tonifying Qi) group, WenYang and YiQi group, captopril group, digoxin group. In additional, an artificial operation group was set for comparison. The systemic intervention using these medicinal and drugs was taken effects on the 2nd day after the operation of myocardial infraction (MI) with once a day. At week one, two, and four after the MI treatment, evaluated were EF values, and ferritin, angiotensin-II and aldosterone in the rats’ plasma. RESULTS At week one and week two, the medicinal of WenYang, YiQi, WenYang pluse YiQi, and digoxin could improve left ventricular ejection fraction in rats with heart failure; Compared to the model group, captopril Left ventricular EF value increased, but there was not significant. At week four, heart failure and left ventricular EF values was improved in the intervention group and the other four captopril drug intervention. At week one in the rats with drug intervention, the medicinals of YiQi, WenYang plus YiQi, and captopril could inhibit activation in vivo hormone aldosterone in heart failure rats; aldosterone in WenYang group and digoxin group were not different from that in the model group at week two and four. CONCLUSION Chinese medicinals with properties of WenYang, YiQi have significant effect on improving left ventricular EF in rats with heart failure; compared to YiQi medicinals, WenYang medicinals that inhibit the effectiveness of the time required for the activation of the role of aldosterone. The medicinals of WenYang and YiQi seems better by inhibiting the activation of the hormone aldosterone after failing to inhibit ventricular remodeling to improve heart failure.

Ultra-trace detection from polluted solution makes great contribution to environmental monitoring, food safety and medical analysis. However, its common difficulty arises in concentrating analytes on easily accessible substrate for highly amplified detection intensity. Herein, a superhydrophobic Al-Mg alloy surface focusing on droplet condensation and analyte detection is fabricated by an environment-friendly, efficient and low-cost machining process for surface enhanced Raman scattering (SERS) analyses. The micro-scale craters covered with nano-scale terrace-like structures have been prepared by one-step wire electrical discharge machining (WEDM). Meanwhile, wet abilities of hierarchical structures have been investigated after stearic acid modification. Results show that the as-prepared surface exhibits excellent repellent ability to water and oil drops. The resultant superamphiphobic surface also displays a 3-fold higher SERS intensity over hydrophilic Al-Mg alloy substrate. The corresponding SERS signals also show well signal reproducibility. This work sheds positive insights into fabricating accessible and efficient active substrates for SERS detection and extending potential applications of Al-Mg alloys in ultra-trace analysis in the future.

The existing study and application of Prolate Spheroidal Wave Function (PSWF) primarily around the characteristics of PSWF in a single energy domain, the characteristics of PSWF in two-dimensional time-frequency energy domain have not been mining and using, from the perspective of signal time-frequency distribution, Wigner-Ville Distribution with higher time-frequency resolution was introduced to study the time-frequency characteristics of PSWF. The simulation results shows that the PSWF with different parameters with different time-frequency distribution characteristics; at the same time, through the comparison those different of time-frequency distribution, a deeper understanding of the characteristics of PSWF was known, which could further improve the foundation PSWF properties, look for efficient information loading and testing way, and significantly improve the application value of PSWF.

The performance of the polymer electrolyte membrane fuel cell (PEMFC) is greatly controlled by the structure of the catalyst layer. Low catalyst utilization is still a significant obstacle to the commercialization of the PEMFC. In order to get a fundamental understanding of the electrode structure and to find the limiting factor in the low catalyst utilization, it is necessary to develop the mechanical model on the effect of catalyst layer structure on the catalyst utilization and the performance of the PEMFC. In this work, the structure of the catalyst layer is studied based on the lattice model with the Monte Carlo simulation. The model can predict the effects of some catalyst layer components, such as Pt/C catalyst, electrolyte and gas pores, on the utilization of the catalyst and the cell performance. The simulation result shows that the aggregation of conduction grains can greatly affect the degree of catalyst utilization. The better the dispersion of the conduction grains, the larger the total effective area of the catalyst is. To achieve higher utilization, catalyst layer components must be distributed by means of engineered design, which can prevent aggregation.

The temperature drift of measurement accuracy is one of the difficult problems in the practical process of optical voltage sensor. This paper presents a kind of self-healing optical voltage sensor technology to overcome above problem. The technology combines self-healing and optical voltage sensing techniques to realize the synchronous compensation of disturbing birefringence and the transistor half-wave voltage. This technology can realize the automatic compensation of temperature, improving the whole performance of sensor while ignoring the influence of ambient temperature. The experiments show that the linearity of the self-healing optical voltage sensor can reach to 0.2 grades in the room temperature. When the working intensity disturbances or sensor parameter drifts induced by temperature, the measurement accuracy of self-healing optical voltage sensor is improved largely compare to the conventional optical voltage sensor. The results show the validity of self-healing optical voltage sensor.

Most existing researches of FSO system are based on the assumption of plane wave or spherical wave, while the actual transmitting beam of FSO system is Gaussian beam, so the study of the effect of different transmitting beam on the performance of FSO system is important. Starting from the aperture averaging effect, without considering the impact of the turbulent inner and outer scale, the effect of turbulent strength on the aperture averaging effect is analyzed under the Gaussian beam condition, it's shown that aperture averaging effect get more obvious by increasing the turbulent strength. And then, under the weak turbulent condition, the effect of transmitting beam on the improvement of BER performance by aperture averaging effect is simulated analyzed. The results showed that Gaussian-beam wave has apparent impact on BER performance, and saturation is reached firstly, followed by spherical wave. Plane wave is relatively gentle.

Aim To explore the relationship between plasma total homocysteine concentration and diabetic neuropathy in Chinese patients with type 2 diabetes. Methods Chinese patients with type 2 diabetes ( n =249) were enrolled in a cross-sectional hospital based study. Diabetic neuropathy status was documented by presence of clinical signs and confirmed by electromyography. Plasma total homocysteine concentration was measured using fluorescence polarization immunoassay. Traditional risk factors for diabetic neuropathy were obtained from fasting blood samples and interviewer-questionnaire. Results Plasma total homocysteine levels were higher in subjects with diabetic neuropathy than without (12.8 (9.2–14.8)μmol/l vs. 8.0 (7.7–9.1)μmol/l, p =0.005). The association of homocysteine with diabetic neuropathy was independent of major traditional risk factors for diabetic neuropathy (duration of diabetes, HbA1c) and determinants of higher homocysteine concentration (age, gender, serum folate and vitamin B12, renal status, and Biguanide use) (OR: 1.12 (1.00–1.25), p =0.042). Furthermore, per increase of 4.0μmol/l plasma homocysteine was related to neuropathy, after controlling for per unit increase of other factors (OR: 1.17 (0.94–1.33), p =0.045). Conclusion Plasma total homocysteine concentration was independently associated with occurrence of diabetic neuropathy in Chinese people. Future prospective studies are warranted to clarify the relationship.

The information capacity model of M-ary PPM ultra-wideband communications is built over multiple-access and additive white Gaussian noise channel. The model extends the known capacity of PPM orthogonal pulses to incorporate specific UWB constraints. Based on Gaussian approximation for the multiple access interference, an expression of the UWB capacity is developed as a function of system parameter. The channel capacity of UWB communications using PSWF pulses subject to FCC spectral masks is computed, and the results is compared with that of 5th and 7th order Gauss pulse. The simulation results show that the UWB system with the PSWF pulses has more channel capacity than the system with Gaussian pulse. This conclusion presents a new view for the UWB pulse choice, which can facilitate system designers to improve the efficiency of UWB communications.

This paper presents a new method using principal component analysis (PCA) to eliminate data redundancy in loudspeaker fault detection. It uses wavelet packet transformation (WPT) to decompose the loudspeaker acoustics signal into 32 packet node signals. Then, get the mean, max, standard deviation and correlation coefficient of every node envelopment .With the way of observing, it gets 63 coefficients from 128 ones which are helpful for detection of fault. Using the new way above, 32 coefficients are removed from the 63. The failed loudspeaker can be found with the help of artificial neural network (ANN). It is proved that the method is very effective in experiment.