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The relays used in aviation electronic equipment are required to have extremely high reliability. Due to strong shock and vibration in the service process, premature failure of reeds in aviation relays is a common problem. Nonetheless, limited published investigations focus on reed failures. In this study, a reed in a force-balanced aviation relay was investigated, which comprised of internally oxidized Ag-Mg-Ni alloy. The fracture and microstructural investigation of the failed reed were conducted systematically, and the microhardness of the reed was also measured. The results indicated that the intergranular fracture occurred in the failed reed, and the failure of the reed was caused by severe Ni segregation. Abnormally large grains and remarkable difference in grain size for the core regions were observed in the failed reed, and the overall hardness of the failed reed was lower than the technical specification. The results indicated that Ni segregation led to inhomogeneous microstructure. In addition, secondary particles in the fracture surface were identified as Ni particles and oxides of Ni. Numerous nanoparticles were distributed in the grain boundaries, which led to intergranular brittle fracture of the reed. This study provides guidance on the evaluation of microstructure and failure analysis for Ag-Mg-Ni reeds.

We prepared a novel hemostatic material using chitosan (CS), alginate, and Bletilla striata, which showed good biocompatibility and hemostatic properties. Alginate-calcium porous microspheres (Alg) were prepared by emulsification/cross-linking methods, and Bletilla striata polysaccharide (Bsp) was extracted from the tubers by water extraction and alcohol precipitation. To improve the water absorption and accelerate the blood coagulation, Alg and Bsp were mixed with chitosan solution to form CS/Alg and CS/Alg/Bsp composite sponges by lyophilization. Based on SEM images, the microspheres exhibited good spherical shape, possessed many pores on the surface, and were well dispersed in the CS/Alg5 and CS/Alg10 composite sponges. The CS/Alg10 composite sponges showed higher water absorption and porosity. In addition, the cytotoxicity assay and hemostatic property of the CS/Alg and CS/Alg/Bsp composite sponges were tested by CCK-8 assay, in vitro blood clotting, red blood cell (RBC) adhesion, and rabbit ear artery bleeding. These ternary composite sponges could be used as potential novel hemostatic materials in surgical treatment.

Weakly-supervised semantic segmentation aims at tackling the dense labeling task using weak supervision so as to reduce human annotation efforts. For weakly-supervised semantic segmentation using only image-level annotation, we propose a novel model of Learning with Saliency and Incremental Supervision Updating (LSISU), in which both the guidances of saliency prior and class information are jointly used and the segmentation supervision is dynamically updated. In the proposed LSISU, we present an image saliency objective complementary to classification loss, by which the trained weakly-supervised deep network can effectively deal with object co-occurrence problem. Meanwhile, we make full use of the class-wise pooling strategy to generate initial mask estimation of high quality. Given an initial annotation, a segmentation network is learned along with incremental supervision updating, which plays a role of region expansion and corrects the falsely estimated supervision for training images. The incremental supervision updating is performed on the fly and involves repeated usage of a fully connected conditional random field algorithm. LSISU achieves superior segmentation performance in terms of mIoU metric on benchmark datasets, which are 62.5% on the PASCAL VOC 2012 test set and 30.1% on the COCO val set.

A novel portable and cost-effective multi-wavelength smartphone colorimetric reader (MW-SCR) was designed for the quantitation of liquid colorimetric assays. Six light-emitting diodes (LEDs) with different wavelengths were assembled in a roulette fashion to form the light detection source. An ambient light sensor of smartphone was applied as the detector. Using this MW-SCR, we detected six common serum analytes, including alkaline phosphatase(ALP), potassium(K+), chloride(Cl−), alanine aminotransaminase(ALT), glycated serum protein(GSP), and albumin, to evaluate the feasibility and reliability of the MW-SCR. Strong linear regression (R2>0.99) analysis with a wide linear range and good limits of detection were found for this device, detection limits as low as 0.37 U/L, 0.0083 mmol/L, 0.78 mmol/L, 4.49 KarU, 0.023 mmol/L and 2.23 g/L for ALP, K+,Cl−, ALT, GSP and albumin, respectively, were achieved. It also had high repeatability that ranged from 0.20 to 0.61 % relative standard deviations (RSD), and the precision ranged of MW-SCR were from 0.26 to 1.17 % RSDs. Results demonstrated that our device showed remarkable stability, accuracy, and repeatability, presenting excellent consistency with a professional microplate reader. It can be redesigned for multiple indications, such as clinical biochemical analyses, food safety testing, environmental monitoring and so on, because it is open source, user friendly and easy manufacturing.

Due to the excellent electrochemical characteristics, Sb4O5Cl2 has been potentially used in flame retardant, catalyst, and anode materials, etc. At the same time, it has broad application prospects in optics and optoelectronics because of its strong inoxidizability, high damage threshold and relatively high-photoelectric conversion efficiency. However, the application of Sb4O5Cl2 in ultra-fast photonics has not been reported so far. In this work, the structure characteristic and nonlinear optics property of Sb4O5Cl2 have been systematically studied. The result indicates saturation intensity and modulation depth are 402.5 MW/cm2 and 1.3%, which prove Sb4O5Cl2 could be utilized as a saturable absorber (SA) in ultrafast photonics. Especially, harmonic mode-locking with 850-fs pulse duration, 2.86-nm 3-dB bandwidth, 202.3-MHz maximum repetition rate in optical communication region is generated based on a tapered fiber incorporated with Sb4O5Cl2 for the first time to our knowledge. This work opens novel avenues toward optoelectronics device based on Sb4O5Cl2 in the fields of optical modulation, optical detection and optical communication, etc.

A promising technology for non-destructive fabricating microtapered long period fiber gratings (MT-LPFGs) is demonstrated by periodically slight tapering single-mode fiber. Owing to the optimized microtapering technique, high-quality LPFGs with dip attenuations of about 40 dB, insertion loss

When a debris flow joins a main river, it may block the river. The collapse of the block is often a sudden change that can be simplified into a phase transition. In this paper we study the problem on the model of percolation which is a second order phase transition. Rather than general random percolation model, we introduce a self-similar percolation model and develop it from two dimensions to three dimensions. Under this model, we conclude that a block made of grains (for example stone, sandy grains, clay grains, silt grains, etc.) with more different sizes has a better stability. Moreover, with the help of efflux theory, we explain why the joint on the other side of the block with the main river is easier to break than other places of the block.