- 沈佳丽;何吉欢;
A novel catalyst, TiO_2 nanotubes(TiO_2 NTs) composite decorated by CuO and CeO_2 particles, was prepared by a simple and cost-effective method. The TiO_2 NTs were fabricated by the hydrothermal method, and CuO and CeO_2 particles loaded onto TiO_2 NTs(CuO/CeO_2@TiO_2 NTs) were prepared by the water bath heating method. The CuO/CeO_2@TiO_2 NTs were investigated and characterized by transmission electron microscope(TEM), energy dispersive spectrometer(EDS), photoluminescence(PL), X-ray diffractometer(XRD) and ultraviolet-visible light diffuse reflectance spectrum(UV-Vis DRS). Both the p-n heterojunction formed at the p-CuO and n-TiO_2 interfaces and the highly induced electron transfer of CeO_2 can greatly promote the separation of electrons-holes. Therefore, CuO/CeO_2@TiO_2 NTs show enhanced absorption and have potential applications in photocatalysis.
2019年02期 v.36 113-116页 [查看摘要][在线阅读][下载 3019K] [网刊下载次数:2 ] |[引用频次:0 ] |[阅读次数:11 ] |[下载次数:50 ] - 李中凯;苗磊;宋英;
Mine rescue capsule is a typical emergency equipment in a coal mine. It provides a safe and confined space for miners when mining disasters occurred. The length of the passenger survival cell is suitable to be adjusted with several predefined modular cells according to various numbers of passengers. Aiming at the shortage of guidance rules for the modular combination design of mine rescue capsule, the configuration situations of survival cells are experimented with static and impact load analysis in ANSYS Workbench. The length range of a single cell, the combination schemes of miner survival section, and the effectiveness proof of assembled rescue capsules were solved sequentially by simulated load analysis on constructed structural models. The modular combination rules of the survival section are developed for variant passenger number ranging from 8 to 20. It also provides a reference for the optimal selection of rescue capsules with the same capacity. The proposed modular rules are effective for the rapid configuration design for mine rescue capsule driven by the number of passengers.
2019年02期 v.36 117-128页 [查看摘要][在线阅读][下载 3540K] [网刊下载次数:2 ] |[引用频次:1 ] |[阅读次数:12 ] |[下载次数:50 ] - 安婧;薛罡;
To attain a low-cost and high-efficient adsorbent and Fenton catalyst, sludge biochar/nano-cobalt(Co-Biochar) and sludge biochar/nano-cobalt/iron(Co-Fe-Biochar) composites were prepared to use as raw materials, and iron and nano-cobalt as modifiers with a hydrothermal method at 180°C for 3 h. The adsorption effect of different composite materials on low concentration Congo red dyes and synergistic effect of adsorption and high oxidation on high concentration Congo red dyes were studied. The results show that Co-Fe-Biochar has not only adsorption to Congo red dyes but also strong advanced oxidation. The removal rate of Co-Fe-Biochar to high concentration Congo red dyes is as high as 82%. Co-Fe-Biochar were characterized by X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), scanning electron microscopy(SEM), nitrogen absorption and desorption(BET), hysteresis loop(VSM), and Fourier transform infrared spectrum(FTIR). It is known that the prepared composite material is a microsphere structure in which nano cobalt is the core and the iron carbon layer is the outer shell. Moreover, the addition of nano cobalt makes the composite have a porous morphology, with the specific surface area of the composite increased from 54.024 m~2/g to 117.753 m~2/g.
2019年02期 v.36 129-139页 [查看摘要][在线阅读][下载 4719K] [网刊下载次数:2 ] |[引用频次:0 ] |[阅读次数:11 ] |[下载次数:84 ] - 蔡加欣;钟然旭;李俊杰;
This paper proposes a framework for human action recognition based on procrustes analysis and Fisher vector coding(FVC). Firstly, we applied a pose feature extracted from silhouette image by employing Procrustes analysis and local preserving projection(LPP). Secondly, the extracted feature can preserve the discriminative shape information and local manifold structure of human pose and is invariant to translation, rotation and scaling. Finally, after the pose feature was extracted, a recognition framework based on FVC and multi-class supporting vector machine was employed to classify the human action. Experimental results on benchmarks demonstrate the effectiveness of the proposed method.
2019年02期 v.36 140-148页 [查看摘要][在线阅读][下载 290K] [网刊下载次数:1 ] |[引用频次:5 ] |[阅读次数:13 ] |[下载次数:44 ] - HICINTUKA Jean Philippe;周武能;
The devastating effects of wildland fire are an unsolved problem, resulting in human losses and the destruction of natural and economic resources. Convolutional neural network(CNN) is shown to perform very well in the area of object classification. This network has the ability to perform feature extraction and classification within the same architecture. In this paper, we propose a CNN for identifying fire in videos. A deep domain based method for video fire detection is proposed to extract a powerful feature representation of fire. Testing on real video sequences, the proposed approach achieves better classification performance as some of relevant conventional video based fire detection methods and indicates that using CNN to detect fire in videos is efficient. To balance the efficiency and accuracy, the model is fine-tuned considering the nature of the target problem and fire data. Experimental results on benchmark fire datasets reveal the effectiveness of the proposed framework and validate its suitability for fire detection in closed-circuit television surveillance systems compared to state-of-the-art methods.
2019年02期 v.36 149-157页 [查看摘要][在线阅读][下载 15740K] [网刊下载次数:1 ] |[引用频次:6 ] |[阅读次数:7 ] |[下载次数:96 ] - 曲连艺;罗忻;牛增元;叶曦雯;张丽;汤志旭;张林;朱平;
Liquid chromatography coupled to high resolution mass spectrometry(LC-HRMS) was used to establish a high throughput and sensitive method for 18 phthalic acid esters(PAEs) in textiles. The method was applied to screen PAEs in 413 textile samples and 7 434 pieces of test data were analyzed. Further discussion was conducted about specific compounds, textile materials, detected value distribution and positive rate of samples. Twenty-nine percent of samples were detected with PAEs, and no samples were detected beyond regulations. Diisobutyl phthalate(DiBP), Dibutyl phthalate(DBP) and Di-2-ethylhexyl phthalate(DEHP)were detected with high frequency, and most samples were fabrics with coating and printing. This study can be used to reflect distribution of phthalate residues in textiles on the market and provide data support for risk assessment of PAEs for textile producers and consumers.
2019年02期 v.36 158-162页 [查看摘要][在线阅读][下载 868K] [网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:10 ] |[下载次数:66 ] - 曹瑶煜;徐弘萱;张洋;朱雨霜;桂林;左健存;
A novel multi-point sensing scheme to improve the signal-to-noise ratio(SNR), temperature measurement range of the fiber Bragg grating(FBG) sensors is proposed. The new sensing scheme adopted a composite coding technique based on Simplex codes and Golay codes and time division multiplexing technique to enhance the performance of the sensing system. Simulation results, in good agreement with the theory, confirmed that the maximum SNR enhancement of the sensor system employing composite coding based on 15-bit Simplex codes and 16-bit Golay codes was approximately 6.01 dB in comparison to the conventional single pulse case.
2019年02期 v.36 163-169页 [查看摘要][在线阅读][下载 1195K] [网刊下载次数:2 ] |[引用频次:1 ] |[阅读次数:10 ] |[下载次数:39 ] - 罗通;练章华;谌贵辉;张强;
To find out and improve the flow characteristics inside the intake system of cylinder head, the application of computational fluid dynamics(CFD) in the evaluation and optimization of the reconstructed intake system based on slicing reverse method was proposed. The flow characteristics were found out through CFD, and the velocity vector field, pressure field and turbulent kinetic energy field for different valve lifts were discussed, which were in good agreement with experimental data, and the quality of reconstruction was evaluated. In order to improve its flow characteristic, an optimization plan was proposed. The results show that the flow characteristics after optimization are obviously improved. The results can provide a reference for the design and optimization of the intake system of cylinder head.
2019年02期 v.36 170-178页 [查看摘要][在线阅读][下载 17543K] [网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:8 ] |[下载次数:63 ] - 韩莎莎;陈群;李杰;戴一璟;
The accurate assessment of the quality can materially affect the safety and life of the prefabricated construction. In this paper, we studied the overall module of concealed water supply pipeline, and a new complex sequence quality evaluation model was established. By analyzing the small evaluation index elements of the model, the weight of the larger evaluation index could be deduced. The total quality evaluation score of the overall module could be obtained by calculating the weight value of the evaluation index, and then the quality standard of the overall module could be obtained.
2019年02期 v.36 179-186页 [查看摘要][在线阅读][下载 150K] [网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:8 ] |[下载次数:71 ] - 杨斌;徐玉康;靳向煜;
The effect of elongation of particles in dispersion powders on mechanical performance of polytetrafluoroethylene(PTFE) flat filament is analyzed. Morphology and elongation of particles in four different PTFE dispersion powders are analyzed. Meanwhile, the correlation between elongation and diameter of dispersion particles is discussed. Strength-elongation curves of PTFE flat filaments made of four different dispersion powders are obtained from measurements of mechanical behaviors. Experimental results show that PTFE flat filament manufactured with dispersion particles having appropriate elongation(0.55-0.60) shows excellent mechanical performance. This work could be regarded as a reference for manufacturing high performance PTFE flat filaments.
2019年02期 v.36 187-191页 [查看摘要][在线阅读][下载 8301K] [网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:11 ] |[下载次数:32 ] - 刘建;朱平;陈兵;王曙光;董朝红;
An excellent and novel flame retardant and antimicrobial agent, monochlorotriazine triethylphosphite guaridine(MCTPG), which made in the laboratory could treat cotton fabrics and dyeing with reactive dyes at the same time. The dyeing and functional property of treated cotton fabrics is characterized by five variables, each with a different effect on the final product. The best dyeing and flame retardant finishing process of reactive red K and MCTPG:2%(owf)reactive red K, 250 g/L MCTPG, 40 g/L NaCl, and 60 g/L Na_2CO_3, the fixation temperature is 90 ℃, and the fixation time is controlled at 60 min, with a bath ratio of 1:30. The percentage of dye uptake rate can reach 61.9% and the fixation rate is 52.8%. The treated cotton fabric has better flame retardancy and antibacterial property. The limited oxygen index(LOI) reached 26.3%, the after-flame time was 7.1 s, the char length was 65 mm, and the width of the bacteriostatic band of Escherichia coli and Staphylococcus aureus both reached 2.0 mm.
2019年02期 v.36 192-197页 [查看摘要][在线阅读][下载 935K] [网刊下载次数:1 ] |[引用频次:0 ] |[阅读次数:8 ] |[下载次数:79 ] - 侯凤仙;
Sorting and collecting the data by questionnaire survey and literature analysis, the childrenswear brand elemental analysis is completed. The development goal of differentiated positioning of Chinese childrenswear brands is decided. Four modules which influence the brand differentiated development were extracted to establish the hierarchical analysis framework for the differentiated positioning development of Chinese childrenswear brand. Judgment matrix diagram is constructed by using the analytic hierarchy process(AHP). According to the data analysis and judgment, the core elements, basic elements and auxiliary elements are identified which support the development of differentiated positioning of Chinese childrenswear brands. The clear development path of differentiated positioning of Chinese childrenswear brands is formed, namely to enhance the core essential factors as the key point, to grasp the elements' spirit exactly in differentiated positioning of brand style, childrenswear color feature, green and security of products quality and retail prices which influence the brand differentiated development. The Chinese existing technical advantages was given full play by providing the basic support for the differentiated development of childrenswear brands. Auxiliary elements were heleped to grow by making auxiliary elements play a greater role. The goal was achieved to improve the market competitiveness by development of differentiated positioning of Chinese childrenswear brands.
2019年02期 v.36 198-204页 [查看摘要][在线阅读][下载 242K] [网刊下载次数:1 ] |[引用频次:0 ] |[阅读次数:8 ] |[下载次数:28 ] - 牟琳;赵欲晓;
In order to reveal the appearance of the clothing prototype on the human body, the characteristics of the human body's structure above the waist section were studied. Based on the experimental data of the fit prototype, three-dimensional prototypes features were comparatively analyzed. And then objectively evaluating the relationship was conducted between the planar structure lines of different prototypes and the human body. The results showed that the prototypes analyzed basically conformed to the size of the human body. However, when they were worn on the human body, there were problems in the structure and forming. The main reason was that the side seam was skewed to different degrees. The results of this study provide reference for many practitioners to choose prototypes.
2019年02期 v.36 205-211页 [查看摘要][在线阅读][下载 13126K] [网刊下载次数:2 ] |[引用频次:0 ] |[阅读次数:10 ] |[下载次数:33 ] - 洪海燕;
The spectral theory of graph is an important branch of graph theory, and the main part of this theory is the connection between the spectral properties and the structural properties, characterization of the structural properties of graphs. We discuss the problems about singularity, signature matrix and spectrum of mixed graphs. Without loss of generality, parallel edges and loops are permitted in mixed graphs. Let G_1 and G_2 be connected mixed graphs which are obtained from an underlying graph G. When G_1 and G_2 have the same singularity, the number of induced cycles in G_i(i=1, 2) is l(l=1,l>1), the length of the smallest induced cycles is 1, 2, at least 3. According to conclusions and mathematics induction, we find that the singularity of corresponding induced cycles in G_1 and G_2 are the same if and only if there exists a signature matrix D such that L(G_2)=D~TL(G_1)D. D may be the product of some signature matrices. If L(G_2)=D~TL(G_1)D, G_1 and G_2 have the same spectrum.
2019年02期 v.36 212-214页 [查看摘要][在线阅读][下载 100K] [网刊下载次数:2 ] |[引用频次:0 ] |[阅读次数:7 ] |[下载次数:14 ] 下载本期数据