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Recent visual odometry (VO) methods incorporating geometric algorithm into deep-learning architecture have shown outstanding performance on the challenging monocular VO task. Despite encouraging results are shown, previous methods ignore the requirement of generalization capability under noisy environment and various scenes. To address this challenging issue, this work first proposes a novel optical flow network (PANet). Compared with previous methods that predict optical flow as a direct regression task, our PANet computes optical flow by predicting it into the discrete position space with optical flow probability volume, and then converting it to optical flow. Next, we improve the bundle adjustment module to fit the self-supervised training pipeline by introducing multiple sampling, ego-motion initialization, dynamic damping factor adjustment, and Jacobi matrix weighting. In addition, a novel normalized photometric loss function is advanced to improve the depth estimation accuracy. The experiments show that the proposed system not only achieves comparable performance with other state-of-the-art self-supervised learning-based methods on the KITTI dataset, but also significantly improves the generalization capability compared with geometry-based, learning-based and hybrid VO systems on the noisy KITTI and the challenging outdoor (KAIST) scenes., Comment: 35 pages, 6 figures

The effects of shear strength on aggregation flotation processes for fine spodumene (particle size less than 19 μm) were investigated in this study. Sodium oleate was used as a surfactant and collector. The shear strength was controlled by varying the agitation speed of a self-made stirring apparatus. The aggregation process was studied by measuring the continuous transformations in the size distribution and shape of flocs. The results showed that as the shear strength increased, the distribution of fine spodumene transformed from bimodal to unimodal mode. The flocs tended to bridge more branches with a high shear strength and form globule-like flocs with very high strengths. The parameter “aggregation degree” was introduced to evaluate the aggregation process as a function of shear strength. The flotation rate of flocs formed with different shear strengths was also studied. These results demonstrated that the flotation rate was closely related to shear strength and that there was a close correlation between this and aggregation degree. These results could be used to guide the actual production of fine particles via shear aggregation flotation. Aggregation process was divided into formation, growth, bridge, and breakage stage. A parameter named aggregation degree was proposed to elaborate floc growth under various shear conditions. Optimizing shear strength in aggregation stage further improved flotation efficiency.

Brightness and color are two basic visual features of the human visual system. In the retina, color-sensitive cells are sensitive to brightness and color information and exhibit salient direction selectivity. However, evidence from neurobiology indicates that apart from color features, the rod and cone cells of the retina are also sensitive to high or low luminance, respectively termed the light and dark adaptation mechanisms. Classical single-opponent and color-opponent contour detection model frameworks include the computational processes of single red (R), green (G), blue (B) and yellow (Y) channels and opponent R–GB–Y channels, respectively. Thus, to combine luminance cues and traditional color cues to improve boundary detection in natural scenes, we propose the use of a dark and a light channel to simulate light and dark adaptation mechanisms. The results of the proposed model considering three datasets (BSDS300, BSDS500, NYUD) demonstrate an improvement compared with current bio-inspired contour detection models.

Physiological studies have revealed that the center–surround mechanism widely exists in the primary stages of the human visual system, such as the retina, lateral geniculate nucleus (LGN), and primary visual cortex (V1). In retina ganglion cells (RGC) and the LGN, the mechanism is well known to have two types: center “on” and center “off.” However, this mechanism in V1 is shown as classical receptive field (CRF) stimulation and surrounding non-CRF suppression. Although these two manifestations differ in function and appear in different areas of the visual pathway, from the perspective of computational simulation, they simply compute the differences between the center and its surrounding information. In the past decade, many bio-inspired computational models have demonstrated that the center–surround mechanism is good at extracting salient contours while suppressing textures. Based on this mechanism, we propose a method for extracting local center–surround contrast information from nature images by using a normalized difference of Gaussian (DoG) function and a sigmoid activated function. Compared with previous contour detection models (especially bio-motivated ones), the proposed method can efficiently suppress textures more quickly and accurately. More importantly, the proposed algorithm yields even better contour detection, yet the computational complexity is similar to the classical Canny operator.

Sodium-ion batteries show promising candidate for next-generation battery due to the low cost and abundance of sodium sources. Here, we have successfully fabricated bimetallic cobalt/zinc sulfides (Co4S3/Co9S8/ZnS) microflowers via a facile solvothermal method, and further evaluated their sodium storage performance. Due to bimetallic compounds and pseudocapacitive effect, the composites exhibit excellent electrochemical performance including high specific capacity, high rate capability and long-term cyclic stability.

Significant progress has been made in boundary detection with the help of convolutional neural networks. Recent boundary detection models not only focus on real object boundary detection but also "crisp" boundaries (precisely localized along the object's contour). There are two methods to evaluate crisp boundary performance. One uses more strict tolerance to measure the distance between the ground truth and the detected contour. The other focuses on evaluating the contour map without any postprocessing. In this study, we analyze both methods and conclude that both methods are two aspects of crisp contour evaluation. Accordingly, we propose a novel network named deep refinement network (DRNet) that stacks multiple refinement modules to achieve richer feature representation and a novel loss function, which combines cross-entropy and dice loss through effective adaptive fusion. Experimental results demonstrated that we achieve state-of-the-art performance for several available datasets., 11 pages, 7 figures

Endoscopic retrograde cholangiopancreatography (ERCP) has been an important therapeutic measure for the treatment of pancreatobiliary diseases in the elderly, but limited data on the use of ERCP in the super-aged elderly are available. This study aimed to evaluate the efficacy and safety of ERCP in patients 80 years of age or older.All therapeutic ERCPs performed from January 2012 to December 2015 at our endoscopy unit were retrospectively reviewed to evaluate the clinical outcomes and ERCP-related complications in patients 80 years of age or older (group A) and in patients younger than 65 years of age (group B).A total of 141 patients (182 procedures) were 80 years of age or older (group A), and 513 patients (610 procedures) were 65 years old or younger (group B). Chronic concomitant diseases (73.05% vs. 31.19%, P0.01) and the use of antithrombotic drugs (25.53% vs. 15.01%, P0.01) were more frequent in group A than in group B. Common bile duct (CBD) stones were the most common indication for ERCP in both groups. The rate of a difficult cannulation was higher in group A than in group B (23.63% vs. 16.56%, P0.01). The mean procedure time was longer, and second ERCPs were performed more frequently in group A than in group B. In addition, periampullary diverticulum was observed significantly more frequently in group A (30.22% vs. 20%, P0.01) than in group B. The overall success rate (92.31% vs. 93.93%, P0.05) and the complication rate (6.59% vs. 5.25%, P0.05) were not significantly different between the 2 groups.ERCP is a safe and effective intervention in patients 80 years of age or older, although elderly patients had a high rate of concomitant chronic diseases and used antithrombotic drugs more frequently.

OBJECTIVE To investigate the protective effect of angiopoietin-1 (Ang-1) from capillary endothelial damage in rats with acute necrotizing pancreatitis (ANP). METHODS 96 male Sprague-Dawley rats were randomly averaged and divided into control group, ANP group, Si-Ang-1 group, and COMP (cartilage oligomeric matrix protein)-Ang-1 group. Animals were killed at 6, 12, and 24 hours after molding. Levels of serum amylase, porcine endothelin 1, C-reactive protein, and Ang-1 were detected; histopathological changes in the pancreas were observed; capillary permeability and Ang-1 expression of the pancreatic tissue were detected by Evans Blue extravasation assay, immunohistochemistry, Western blot, and quantitative polymerase chain reaction. RESULTS (1) Levels of serum amylase, C-reactive protein, and porcine endothelin-1 increased and level of Ang-1 decrease in the ANP group and Si-Ang-1 group compared with the control group, whereas COMP-Ang-1 group could improve the changes. (2) The order of pancreas pathological changes (mild to severe) is: control group, COMP-Ang-1 group, ANP group, and Si-Ang-1 group. (3) Capillary permeability of the pancreatic tissue in the COMP-Ang-1 group was lower than that in the ANP group. (4) Ang-1 mRNA and protein expression in the COMP-Ang-1 group was significantly higher than in the ANP group. CONCLUSIONS COMP-Ang-1 can upregulate the expression of Ang-1 protein to promote angiogenesis and improve early inflammatory and pathological damage in ANP group.

We report on the fabrication of a multifunctional polymeric prodrug covalently linked with an anticancer drug (bufalin, BUF) and tumor-targeting peptide (RGD) and investigate its anticancer performance against colon cancer in mice. The polymerizable monomer, 3-((2-(methacryloyloxy)ethyl) thio)propanoic acid (BSMA), was synthesized first. Atom radical transfer polymerization (ATRP) of BSMA and oligo(ethylene glycol) monomethyl ether methacrylate (OEGMA) afforded random copolymers, P(OEGMA-co-BSMA). The polymeric prodrug of BUF, P(OEGMA-co-BUF), was obtained by an esterification reaction between the carboxyl groups of P(OEGMA-co-BSMA) and the hydroxyl group of BUF. Finally, a tumor-targeting polymeric prodrug, P(OEGMA-co-BUF-co-RGD), was obtained via an aminolysis reaction of P(OEGMA-co-BUF) in the presence of RGD and the final drug content was determined to be ∼32.9 wt%. In aqueous media, P(OEGMA-co-BUF-co-RGD) self-assembles into micelles and the hydrodynamic diameter (Dh) of the micelles was determined to be ∼33.0 (±2.5) nm by dynamic laser light scattering (LLS). It was demonstrated that the tumor-targeting polymeric prodrug showed improved anticancer performance both in vitro and in vivo in comparison with that of free BUF.

In order to study the condition of structural integrity in the process of the solid propellant motor launching and transporting, the stress and strain field analysis were studied on a certain type of solid propellant motor. the vibration acceleration on the solid propellant motors’ transport process were monitored, then the original vibration data was eliminated the noise and the trend term efficiently, finally the characteristic frequency of vibration was got to the finite element analysis. Experiment and simulation results show that the monitored solid propellant motor mainly bear 0.2 HZ and 15 HZ low frequency vibration in the process of transportation; Under the low frequency vibration loading, solid propellant motor grain stress concentration position is respectively below the head and tail of the propellant/liner bonding surface and the grain roots.

Detecting of the auto parts solder joints quality is always a technological difficulty in the production line, the key point is how to exact the parts feature which is tested. New quality detection method for the auto parts soldered joints is presented based on biology vision feature. First the Gabor filter banks which have the emulation of biological vision is used to filter the detected image with eight different directions. Then the biggest powers of all pixel points are chosen to be the solder joints feature and classified by support vector machine (SVM). The experimental results show that the algorithm has higher accuracy as an effective quality detection method. It can be a useful reference to the auto parts solder joints quality testing of engineering application.

In order to study the effects of shipboard environment on solid motor grain, the ambient temperature in multi-launch containers were monitored. The temperature and stress fields of solid propellant grain under different ambient temperature were obtained using three-dimensional viscoelastic finite element method. It is shown by the results that the changed trend of temperature, stress and strain of motors in multi-container is similar to the environment temperature. The stress and strain were largest at the star tip of grain, and the stress and strain were closer in the upper and bottom layer containers.

Aim at high-to-float high-ash fine coal with large content of granules, in order to reduce pollution of carried fine slime to quality of concentrate coal, soluble glass, sodium hexametaphosphate and cornstarch these three kinds of regulators were choosen to carry out flotation reducing ash experiment. Result showed that, cause of poor selectivity of fine coal is mainly small quality, big surface area and the poor dispersion of fine coal. When sodium hexametaphosphate dosage is 1500g/t, the kerosene dosage is 370g/t, the foam beater GF dosage is 150g/t, production rate of concentrate coal is 57.69%，and ash content of concentrate coal is 12.04%. Under the same condition, separation index of sodium hexametaphosphate as regulator is superior to cornstarch and soluble glass.

As for certain high ash and difficult floatable fine coal, the coal quality characteristic is the frangible and easyly-clayed main gangue mineral kaolinite, and the high content of fine-grade and intermediate density grade materials. In order to reduce tiny slimes pollution and to increase quality and recovery rate of concentrate, we used cyclonic-static micro-bubble flotation column and XFD-3 flotation machine to experiment on separation process. It probed into re-concentration after grinding rough refined coal, classified flotation process and selective agglomeration-flotation process these three technical processes. The comparison of flotation machine test result showed that, using the flotation column as separation equipment, process of re-concentration after grinding rough refined coal could obtain the best refined coal accumulation index. When medicaments dosage is kerosene 800 g/t, GF 300 g/t, and sodium hexametaphosphate 1500g/t, refined coal production rate of flotation column is 59.47% and ash content is 10.63%.

As certain refractory molybdenum with degree high oxidation and high argillization, on the premise of molybdenum concntrate recovery rate, in order to increase tenor of molybdenum concntrate, we use cyclonic static micro-bubble flotation column as concentration equipment. We used two concentrate courses to replace flotation machine eight concentrate courses. It showed that, in the condition of same recovery rate, tenor of molybdenum concntrate was 26.16%, rising by 8%. Using processes of flotation machine eight concentrate courses - concentrate regrinding - flotation column two concentrate courses, tenor of molybdenum concntrate was 39.33% and the recovery rate was of 8%. The results showed that, by increasing the degree of monomer dissociation of molybdenum ores, cyclonic static micro-bubble flotation column has higher capability in recovering and selecting ores of -400 mm size fraction. The high argillization resulting from the regrinding and unsuppressed gangue minerals are the main factors affecting the tenor of ore concentrate.

In this paper, carbon materials with solid and hollow sphere morphologies, have been prepared by reduction of hexachlorobenzene with metallic sodium at temperatures of 400-500°C for 6-10h. Characterized by XRD, TEM, SAED and Raman spectrum, the composition and morphology of the products are confirmed. The possible formation mechanism has also been proposed.

Schwannomas are rarely observed in the gastrointestinal tract. The most common symptoms of a gastric schwannoma are abdominal pain or dyspepsia, gastrointestinal bleeding, and an abdominal mass. Many gastric schwannomas are asymptomatic and are discovered incidentally or at postmortem. The diagnosis of a schwannoma is based on immunohistochemical positivity for S-100 protein. We present a case report of a rare complication of gastric schwannoma causing gastroduodenal intussusception that was successfully managed by a Billroth II distal gastrectomy. In this rare case, the patient had intermittent, colicky abdominal pain, nausea, and vomiting for over 4 wk accompanied by a weight loss. A diagnosis of gastric intussusception was made by computed tomography. A Billroth II distal gastrectomy was then performed, and complete en bloc removal (R0 resection) was achieved. Pathology confirmed a gastric schwannoma through positive immunohistochemical staining for S-100 protein.

One mild multiple emulsions was used for the fabrication of hollow polystyrene (PS) spheres. Polystyrene was dissolved in a volatile organic solvent to form the O phase, then an aqueous phase containing a surfactant was transferred into above phase to form an oil-in-water (W in /O) emulsion, followed by addition of W in /O emulsion in the external W out phase, and solvent evaporation. Final product with diameter of 150 μm, surface roughness of 30 nm, and sphericity of 98.0% was obtained. The possible influences on the formation of PS hollow sphere were also discussed.