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Online product recommendation and market segmentation are directly related to the consumer experience and the healthy development of the e-commerce market. In order to improve the selection of network products and the effect of market segmentation, this study introduced a wireless sensing system based on the recommendation of traditional network products and combined the operational conditions of the network commodity market to construct a personalized recommendation e-commerce system. Meanwhile, a series of representative WSN congestion control strategies are designed by dynamically adjusting the network topology, routing algorithm, channel allocation protocol, and channel resource utilization, and the system structural components and functions are implemented. The research shows that the proposed algorithm and system have certain practical effects and can provide theoretical reference for subsequent related research.

Thermal infrared (TIR) object tracking is one of the most challenging tasks in computer vision. This paper proposes a robust TIR tracker based on the continuous correlation filters and adaptive feature fusion (RCCF-TIR). Firstly, the Efficient Convolution Operators (ECO) framework is selected to build the new tracker. Secondly, an optimized feature set for TIR tracking is adopted in the framework. Finally, a new strategy of feature fusion based on average peak-to-correlation energy (APCE) is employed. Experiments on the VOT-TIR2016 (Visual Object Tracking-TIR2016) and PTB-TIR (A Thermal Infrared Pedestrian Tracking Benchmark) dataset are carried out and the results indicate that the proposed RCCF-TIR tracker combines good accuracy and robustness, performs better than the state-of-the-art trackers and has the ability to handle various challenges.

Cardiomyocyte death is a fundamental progress in cardiomyopathy. However, the mechanism of triggering the death of myocardial cells remains unclear. Ferroptosis, which is the nonapoptotic, iron-dependent, and peroxidation-driven programmed cell death pathway, that is abundant and readily accessible, was not discovered until recently with a pharmacological approach. New researches have demonstrated the close relationship between ferroptosis and the development of many cardiovascular diseases, and several ferroptosis inhibitors, iron chelators, and small antioxidant molecules can relieve myocardial injury by blocking the ferroptosis pathways. Notably, ferroptosis is gradually being considered as an important cell death mechanism in the animal models with multiple cardiomyopathies. In this review, we will discuss the mechanism of ferroptosis and the important role of ferroptosis in cardiomyopathy with a special emphasis on the value of ferroptosis as a potential novel diagnostic and therapeutic target for patients suffering from cardiomyopathy in the future.

At present, the one-stage detector based on the lightweight model can achieve real-time speed, but the detection performance is challenging. To enhance the discriminability and robustness of the model extraction features and improve the detector’s detection performance for small objects, we propose two modules in this work. First, we propose a receptive field enhancement method, referred to as adaptive receptive field fusion (ARFF). It enhances the model’s feature representation ability by adaptively learning the fusion weights of different receptive field branches in the receptive field module. Then, we propose an enhanced up-sampling (EU) module to reduce the information loss caused by up-sampling on the feature map. Finally, we assemble ARFF and EU modules on top of YOLO v3 to build a real-time, high-precision and lightweight object detection system referred to as the ARFF-EU network. We achieve a state-of-the-art speed and accuracy trade-off on both the Pascal VOC and MS COCO data sets, reporting 83.6% AP at 37.5 FPS and 42.5% AP at 33.7 FPS, respectively. The experimental results show that our proposed ARFF and EU modules improve the detection performance of the ARFF-EU network and achieve the development of advanced, very deep detectors while maintaining real-time speed.

Long QT syndrome (LQTS) is an arrhythmic heart disease caused by congenital genetic mutations, and results in increased occurrence rates of polymorphic ventricular tachyarrhythmias and sudden cardiac death (SCD). Clinical evidence from numerous previous studies suggested that beta blockers (BBs), including atenolol, propranolol, metoprolol, and nadolol, exhibit different efficacies for reducing the risk of cardiac events (CEs), such as syncope, arrest cardiac arrest (ACA), and SCD, in patients with LQTS. In this study, we identified relevant studies in MEDLINE, PubMed, embase, and Cochrane databases and performed a meta-analysis to assess the relationship between the rate of CEs and LQTS individuals with confounding variables, including different gender, age, and QTc intervals. Moreover, a network meta-analysis was not only established to evaluate the effectiveness of different BBs, but also to provide the ranked efficacies of BBs treatment for preventing the recurrence of CEs in LQT1 and LQT2 patients. In conclusion, nadolol was recommended as a relatively effective strategy for LQT2 in order to improve the prognosis of patients during a long follow-up period.

Metal-free halide materials have garnered significant attention. However, because of their large band gap, current metal-free materials are not suitable as solar cell absorbers. A metal-free semiconductor, DMEDA·I6, with a narrow band gap (∼1.36 eV) and strong light absorption, is a promising candidate for solar cell absorbers. Using the first-principles calculation method, a systematic investigation was conducted on the photovoltaic properties of DMEDA·I6, including electronic properties, variation trend of the band gap under strain, defect physics, and band alignments of solar cell interfaces. It was found that DMEDA·I6 crystallized in a one-dimensional I chain with alternating long and short I–I bond lengths. Although both the valence band maximum and conduction band minimum of DMEDA·I6 are derived from the I p states, their compositions are distinguishable owing to the abnormal I–I bond arrangement. The band gap of DMEDA·I6 increases when the lattice volume expands, which is similar to that of the popular lead-based perovskites and opposite to that of the conventional zincblende semiconductors. Among the intrinsic defects, only defect VI can produce a deep defect level in the band gap. The formation of VI can be suppressed under the I-rich preparation conditions; thus, I rich condition is proposed when preparing DMEDA·I6 solar cell absorbers. Commonly used hole transportation materials are suitable for DMEDA·I6-based solar cells, whereas electron transport materials (ETMs) with a lower lowest unoccupied molecular orbital than commonly used ETMs should be used.

The issue of toxicity and chemical stability are two concerns for organic–inorganic hybrid perovskites, impeding their further commercial applications. Double perovskite (CH3NH3)2SnI6 with a bandgap of 1.81 eV and stable chemical valence of Sn (+4) is considered as a promising alternative. By first-principles calculations, the electronic properties, defect physics, and interface engineering of the perovskite are investigated in this work. It is found that (i) MA2SnI6 has a direct bandgap with a large dispersion of a lower conduction band. Due to the direct I 5p–5p transition between band edges, the light absorption can be as high as 105 cm−1 in the visible range. (ii) An Sn rich and I poor condition is suggested when MA2SnI6 is used as an electron transporting material (ETM) because of its high n-type electronic conductivity. An Sn poor and I rich condition is proposed when MA2SnI6 is prepared for photovoltaic application, because it can suppress the formation of non-radiation centers. (iii) ICBA and Spiro are proposed to be suitable ETM and hole transporting material, respectively, in MA2SnI6 based solar cells.

Through first-principles calculations, the photovoltaic properties of Cs2PdI6 were investigated and found that (i) Cs2PdI6 has a quasi-direct band gap nature, and strong p–d coupling of lower conduction bands is responsible for light electrons; (ii) dominant Pdi and Ii defects would be produced at a deep level in the band gap which acts as charge trapping states. Thus, should be passivated by suitable external doping, if Cs2PdI6 works as a solar cell absorber; (iii) The Cs2Pd(I1-x Br x )6 alloy is highly miscible. Tunable band gap depending on composition x has a non-linear bowing behavior occurring a lowest band gap at composition Cs2Pd(I0.7Br0.3)6.

Lead halide perovskite has shown amazing optoelectronic performance, while the issues of its toxicity and the thermal instability remain to be intractable. Recently, lead-free halide perovskite Cs2PdBr6 as a narrow bandgap semiconductor with long-term stability has attracted great attention. Herein, through performing first-principles calculations, we find that (i) Cs2PdBr6 has a quasi-direct bandgap with an indirect bandgap of 1.71 eV and a 20 meV smaller direct bandgap. The bandgap increases when the lattice constant enlarges, which is opposite to that of the traditional zincblende semiconductors. (ii) Band offsets between Cs2PdBr6 and popular perovskites indicate that Cs2PdBr6 is more difficult to be doped p-type according to the doping limit rule. The commonly used electron transport materials such as TiO2, SnO2, ZnO, and C60 can also be suitable for Cs2PdBr6 solar cell devices, but the commonly used hole transport materials with a lower highest occupied molecular orbital is an alternative. (iii) Cs2PdBr6 is shown to be difficult to be intrinsic p-type. The electric conductivity would not be too high due to the charge compensation of the defects if there is no suitable external doping. Since the Pd poor and Br rich condition can suppress the formation of the defects with deep levels, this condition is proposed to synthesize Cs2PdBr6 as a solar cell absorber.

The purpose of semantic segmentation is to classify the pixels within the target contour. Edge detection is another major basic vision task in machine vision. Today’s most effective semantic segmentation models and contour edge detection models are isolated networks. The edge of the output of the semantic segmentation model is coarse and cannot be directly used. And the output of the edge detection network cannot output the classification information of the pixels inside the contour. In view of the above shortcomings of the existing network, we propose a semantic segmentation model based on edge constraint optimization, so that the output of the semantic segmentation model has more delicate edge information, and the network directly outputs accurate contour edge graphs. The edge information output by the network can be directly used for tasks such as corner detection and center point detection. Experiments show that the mIOU statistics obtained by our model on the validation set of PASCAL VOC2012 can reach 83.9%. At the same time, more detailed edge details can be obtained. This algorithm has high engineering and theoretical research value.

This paper presents a solar tracking system based on ARM, which mainly adopts the solar trajectory tracking mode, supplemented by the photoelectric sensor tracking mode according to the weather condition, and control the motor rotation to achieve all-time accurate solar tracking. The experimental results show that, the system performance is reliable, and all-weather tracking accuracy is maintained within 0.15 degrees. Therefore, the system can be widely used in solar photovoltaic power generation and lighting devices with solar energy utilization ratio improving greatly.

To achieve higher detection rate and lower false alarm rate in dim and small target detection, this paper proposes a novel approach based on the Local Region Similarity Difference (LRSD). Then the regions where the true targets and suspected target areas exist in are extracted. To further eliminate the false target regions, we process the LRSD image with pipeline filter and then the true target is finally obtained. Experimental results on some real-life infrared (IR) images with different types of targets verify that the proposed method could effectively prove that the proposed method has satisfying detection effectiveness and robustness. Meanwhile, experimental results demonstrate its superior and reliable detection performance by high detection rate and low false alarm rate.

Long-term robust tracking remains a challenging problem in visual object tracking. Based on the popular tracking-by-detection framework, we propose an approach named real-time long-term correlation tracking by single-shot multibox detection (RLCT-SSD), in which tracking and detection work in parallel and cooperate together. Our algorithm consists of two parts: a tracking module is expected to track in real time and accurately, whereas a detection module is responsible for verifying the tracking results at intervals, and redetecting if necessary. The detector updates the tracking module when the tracking result is unreliable. We introduce a motion model on the basis of fast discriminative scale space tracker to design our tracking module. The detection module is based on the single-shot multibox detector algorithm. To further reduce the computational cost, we use the ShuffleNet as our base network of detection. The experimental results on OTB2013 and OTB2015 demonstrate that our RLCT-SSD performs favorably against most state-of-the-art trackers and achieves long-term accurate tracking running in real time.

Objective To investigate the short-term and long-term therapeutic efficacy of preoperative intra-arterial infusion chemoembolization on stage IB2-IIB uterine cervix cancer (UCC).

If we use computer to simulate simple form of three-dimensional dynamic process that is virtual or very difficult to achieve in reality directly in the two-dimensional space, we will reduce the development difficulty of simulation process. This paper introduces the simulation methods and key technologies by some relevant examples in “Audio and Video Electronic Textbook of Mechanical Drawing.” The examples include the formation process of gyration curved surface, the process of an object being cut by a plane, the decomposition process of a combined object. The Flash animation software is mainly used in the simulation process, and AutoCAD software and Photoshop software are the tools used for preparing materials. The results show that simple form of three-dimensional dynamic process can be simulated very realistically in the two-dimensional space, not using the tools of three-dimensional animation.

In order to solve the problem of rapid turning of missile vertical launch, the thrust vector control of jet vane is designed in this paper. By applying the force analysis to the jet vane, the mathematical model of the missile's pitch motion in the vertical plane is established. At the same time the jet vane controller is designed, which introducing the missile's pitch angle position control and rate control. The simulation results show that the jet vane controller with the PID control rule can make the missile fast turn within one second. The model of jet vane thrust vector control can effectively provide sufficient control torque for a missile's quick turn.

According to the needs of dim and small targetdetection, a new detection algorithm based on wavelet transform and image fusion is put forward in the paper. In this algorithm, firstly, the original image is decomposed and reconstructed by wavelet and it is separated into a low frequency image and some high frequency images., secondly, the low frequency image is removed and the high frequency images are fused into a new image , finally, the fused image is segmented with threshold and the target is detected and signed. After the flight test validation, this algorithm has better accuracy and stability.

This design of the demodulation system of the wavelength information of the FBG strain sensor was based on data acquisition system of DSP and FPGA, which can realize real-time detection and analysis of the multi-point strain. FBG strain sensor is an optical passive instrument. Through the demodulation analysis of the wavelength drift, the variation of corresponding strain can be calculated. This design includes: the demodulation principle of FBG strain sensor, the components of demodulation system, hardware design and analysis of experimental data.

Eating habits, smoking, drugs and chemicals can cause undesirable staining of teeth. Tooth bleaching has become a popular dental practice to remove stains from the tooth surface for aesthetic or therapeutic purposes. Clinical teeth-whitening involves the application of H 2 O 2 gel (35%), which might be harmful after prolonged use.

Formocresol and calcium hydroxide are commonly used as the clinical disinfectant of root canals. Although they have strong chemical disinfection properties, their cytotoxic effects have always been a concern. E. faecalis, which is responsible for root canal failure, can also cause life-threatening infections in humans, especially in the nosocomial (hospital) environment, where naturally high levels of antibiotic-resistance towards E. faecalis are found and contribute to its pathogenicity.

This paper proposes a scheme for nondestructive detection of blockboard. According to intensity differences of the x-ray through the blockboard, a lot of valuable target information such as bond quality, uniformity degree, and situations of filler were detected. First of all, x-ray nondestructive system was used to detect blockboard and the blockboard image was obtained. And then some image pre-processing methods just as function imadjust and value filter are employed to enhance the valuable target information in blockboard image. Then, mathematical morphology double-gradient algorithm was used in edge detection of blockboard image. Experimental results demonstrate that the method performs better in noise- suppression and edge detection than conventional edge detection operations. This study provides a new tool for nondestructive detection of blockboard.

D ) was applied in this paper. The MF D values of different regions in a medical image are normally different. According to the values of the MF D , small lesions in a medical x-ray image can be detected. This method has been applied to a digital bone fracture x-ray image. Experimental result showed that the MF D values of the background regions are between 0.005 and 0.020; the MF D values of the normal regions are between 0.040 and 0.070; and the MF D values of the