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Objectives Because radiotherapy is indispensible for treating cervical cancer, it is critical to accurately and efficiently delineate the radiation targets. We evaluated a deep learning (DL)-based auto-segmentation algorithm for automatic contouring of clinical target volumes (CTVs) in cervical cancers. Methods Computed tomography (CT) datasets from 535 cervical cancers treated with definitive or postoperative radiotherapy were collected. A DL tool based on VB-Net was developed to delineate CTVs of the pelvic lymph drainage area (dCTV1) and parametrial area (dCTV2) in the definitive radiotherapy group. The training/validation/test number is 157/20/23. CTV of the pelvic lymph drainage area (pCTV1) was delineated in the postoperative radiotherapy group. The training/validation/test number is 272/30/33. Dice similarity coefficient (DSC), mean surface distance (MSD), and Hausdorff distance (HD) were used to evaluate the contouring accuracy. Contouring times were recorded for efficiency comparison. Results The mean DSC, MSD, and HD values for our DL-based tool were 0.88/1.32 mm/21.60 mm for dCTV1, 0.70/2.42 mm/22.44 mm for dCTV2, and 0.86/1.15 mm/20.78 mm for pCTV1. Only minor modifications were needed for 63.5% of auto-segmentations to meet the clinical requirements. The contouring accuracy of the DL-based tool was comparable to that of senior radiation oncologists and was superior to that of junior/intermediate radiation oncologists. Additionally, DL assistance improved the performance of junior radiation oncologists for dCTV2 and pCTV1 contouring (mean DSC increases: 0.20 for dCTV2, 0.03 for pCTV1; mean contouring time decrease: 9.8 min for dCTV2, 28.9 min for pCTV1). Conclusions DL-based auto-segmentation improves CTV contouring accuracy, reduces contouring time, and improves clinical efficiency for treating cervical cancer.

Detection of organic materials or heavy ions using the surface plasmon resonance (SPR) effect of the MoS2/Ag system was studies. We found that the reflectivity of the SPR system was sensitive to the incident angle of light, dielectric constant of the detected samples, wavelength of light, and thickness of the Ag film. It reached an extreme minimal value (EMV) at an extreme angle θ. As the dielectric constant of the samples was increased from 1.0 to 3.25, θ increased, enabling high-resolution detection. θ slightly decreased with the thickness of the Ag film changed from 300 to 700 nm for a given detected sample while the EMV of reflectivity increased. Moreover, the reflectivity curves were overlapped when the wavelength of light and the thickness, d of the Ag film both increased from 400 to 700 nm, showing synchronous effect. The results showed that MoS2 was a suitable material for the detection of a wide range of samples and could replace the prism.

Molybdenum disulfide (MoS2) thin films, layered quasi-two dimensional (2D) materials, have excellent optical and electronic properties for its special structure. In this paper, the surface morphologies, crystals structures and optical characteristics of MoS2 and Er3+-doped MoS2 (Er: MoS2) thin film samples fabricated on the quartz substrates by sol-gel method were investigated. The result indicated that annealing made the crystallinity and optical absorption characteristics of MoS2 thin films better. The light absorption and photoluminescence intensity was enhanced by doping Er3+. Moreover, the photoluminescence intensity increased with increasing doping concentration, but appears saturation tendency.

It has been widely accepted that tensile strength plays a dominant role in the failure mechanism of rock or rock-like material. Tensile strength is determined mainly via two methods: the direct tension test and Brazilian test. Due to the strictness of preparing the specimen and difficulty of conducting the direct tension test, Brazilian test has been widely applied to determine the tensile strength of geo-materials. However, there is no exact standard for Brazilian test specimen. Moreover, Brazilian tensile strength (BTS) is affected by many factors, such as loading rate, loading platen width, model size. So far, most parametric studies of geo-materials have involved compression tests, but few studies have systematically focused on Brazilian test. The continuum methods have difficulty reproducing the failure process of Brazilian test, and 2D discrete element methods can not reflect the real mechanical behavior of a 3D cylindrical disk specimen. Moreover, the standard bonded-particle model has intrinsic problems in simulating geo-materials. This paper, using a 3D flat-joint model (FJM3D), investigates the effects of micro-structure and micro-parameters on BTS. The micro-structure consists of model size, model resolution, and degree of heterogeneity. The micro-parameters include the average coordination number, crack density, and bond strength. The effects on BTS are summarized, and this summary will be useful for guiding future Brazilian tests. Finally, FJM3D is used to calibrate Brisbane tuff by Brazilian test and the uniaxial compression test. The simulation results are in good agreement with those measured from experiments, and the failure process of Brazilian test is analyzed in detail at the microscale. Because of the heterogeneity of rock, cracks initiate near the loading platen instead of the center of the specimen. Even so, BTS can be an useful tensile index for geo-materials in a triaxial stress state, which is similar to the physical situations, and Brazilian test is helpful for further understanding the failure mechanism of geo-materials.

Through a lot of investigation, many times of demonstrating scheme, the in-depth theoretic analysis, a large scale numeric simulation tests and the field tests, the operating line of the rapid excavation is equipped which are consisting of the way of the drilling and blasting, the bolt-mesh-spurting supporting and the trackless transportation. The key technology which includes the stable technology of controling the surrounding rock, the optimization technology of transportation system, the excavating technology of layered drilling and the technology of parallel and cross operation develops the integral management framework and the advanced technology framework with the operating line, which realizes the safe and efficient construction and provides rich experience for the similar mines.

Availability is essential index for strategic weapons in storage mission. Spare parts replacement is an effective way to improve system storage availability. Normally, the performance degradation of spare parts before replacement is hardly considered in traditional instantaneous availability model. We established a instantaneous availability model using backward equation of semi-Markov Process (SMP) when considering the degradation time of spare parts before replacement. Our analysis indicated that availability had been great effect on when the performance degradation of spare parts is considered. An example is shown to express that this model could help policymakers to choose more suitable supporting plan.

Long Period Fiber Gratings(LPFGs) were inscribed by using a 800 nm femtosecond laser and their high-temperature properties were verified in this paper.Firstly,an inscription system for the laser into fiber cores was designed using a camera and an electric moving platform.With controlling a pulse laser of 1.3 mW,a LPFG was inscribed in a non-hydrogen-loaded bare fiber using point by point technique,and the resonant peak of the LPFG is about-17 dB in the 1 200~1 700 nm band.Then,high temperature sensing experiments were performed on the LPFG by a high temperature box,obtained results show that the linearity of the resonance peak changes is about 0.992 and temperature sensitivity is 0.056 nm/℃ at 300-800 ℃.It demonstrates that the inscription technology for LPFGs by using the 800 nm femtosecond laser is feasible and obtained LPFGs have good response characteristics and stability,and are suitable for the high-temperature measurement.

Based on a wavelength scanning technique and the characteristics of ultra-narrow-linewidth laser,a kind of cavity enhanced absorption gas detection system with high sensitivity is designed.A semiconductor laser with ultra-narrow-linewidth and tunable wavelength is used as a light source,and an optical cavity which consisted of two mirrors with high reflectivity is also used as an absorption cell in this system.The laser frequency overlaps with one of cavity modes via scanning the cavity length and the input laser is switched off by using the laser detuning technique.Then,the ring-down detection of acetylene with low concentration is achieved.With the cavity enhanced absorption technology,spectra of acetylene near the region of 6 518.824 cm-1 and laser ring-down time at different concentrations are measured and also analyzed.The experiments for concentration measurement indicate that the relative error is less than 2.5%,relevance coefficient is 0.999 and the lowest detection limit is 2×10-6.By filling a volume of acetylene into the gas cell gradually,the system dynamic response time is less than 10 s.Obtained results show that the system has advantages of good accuracy,high sensitivity and quick response,which can be used in the fault gas on-line monitoring for power transformers in real time.

On the basis of the wavelength scanning and spectrum modulation techniques of an ultra-narrow-linewidth semiconductor laser,a kind of multi-component gas online detection system with high precision was designed.A semiconductor laser with ultra-narrow-bandwidth and tunable wavelength was utilized as a light source and a novel series gas cell was also used to compress the horizontal space and increase the optical path of the system.By taking the sawtooth signal to modulate the spectrum of laser and using space division multiplexing(SDM) and time division multiplexing(TDM) techniques,the detection of multi-component gases(CO,CO2,CH4) based on ultra-narrow-linewidth laser characteristics was achieved.The experiments indicate that the relative measurement error is less than 2% and linearity relevance coefficient is 0.99 for the three kinds of gases.Furthermore,the system dynamic response time is less than 10 s by filling a volume of multi-component gas into the gas cell gradually.Finally,the result of long time stability monitoring shows that the maximum concentration fluctuation is less than 0.02%.The system has advantages of high accuracy,good stability and quick response,and is suitable for the fault gas monitoring of power transformers in real time.

Safe landing for spacecraft on moon or the other planets is the basic premise for carrying on field survey and sampling research. When it comes to the spacecraft safe landing, the environment the spacecraft confronts becomes more complex. So the selection of landing area would influence the success landing probability of the spacecraft directly. The paper stands in reality and takes the factors such as craters and stones into account abundantly, which affect safe landing for spacecraft. Considering of the radiuses of obstacle spots (craters and stones) and the edge conditions of predestination landing area, we could find out the optimal landing area with the help of Delaunay Triangulation.