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Screening is a key unit in the coal cleaning process. One of the most widely used screening technologies for solving the technical problems associated with coal accumulation is the multi-stage vari...

According to China’s second national survey of pollution sources, the contribution of agricultural non-point sources (ANS) to water pollution is still high. Risk prevention and control are the main means to control costs and improve the efficiency of ANS, but most studies directly take pollution load as the risk standard, leading to a considerable misjudgment of the actual pollution risk. To objectively reflect the risk of agricultural non-point source pollution (ANSP) in Chongqing, China, we investigated the influences of initial source input, intermediate transformation, and terminal absorption of pollutants via literature research and the Delphi method and built a PTA (pressure kinetic energy, transformation kinetic energy, and absorption kinetic energy) model that covers 12 factors, with the support of geographical information system (GIS) technology. The terrain factor calculation results and the calculation results of other factors were optimized by Python tools to reduce human error and workload. Via centroid migration analysis and Kernel density analysis, the risk level, spatial aggregation degree, and key prevention and control regions could be accurately determined. There was a positive correlation between the water quality of the rivers in Chongqing and the risk assessment results of different periods, indirectly reflecting the reliability of the assessment results by the proposed model. There was an obvious tendency for the low-risk regions transforming into high-risk regions. The proportion of high-risk regions and extremely high-risk regions increased from 17.82% and 16.63% in 2000 to 18.10% and 16.76% in 2015, respectively. And the risk level in the main urban areas was significantly higher than that in the southeastern and northeastern areas of Chongqing. The centroids of all grades of risky areas presented a successive distribution from west to east, and the centroids of high-risk and extremely high-risk regions shifted eastward. From 2000 to 2015, the centroids of high-risk and extremely high-risk regions moved 4.63 km (1.68°) and 4.48 km (12.08°) east by north, respectively. The kernel density analysis results showed that the high-risk regions were mainly concentrated in the main urban areas and that the distribution of agglomeration areas overall displayed a transition trend from contiguous distribution to decentralized concentration. The risk levels of the regions with a high proportion of cultivated land and artificial surface were significantly increased, and the occupation of cultivated land in the process of urbanization promoted the movement of the centroids of high-risk and extremely high-risk regions. The identification of key areas for risk prevention and control provides data scientific basis for the development of prevention and control strategies.

Making use of solar energy to fly is an up-and-coming technology in the human aviation field since solar energy is renewable and inexhaustible, and more and more attention and efforts have been directed to the development of high-altitude solar aircraft (HSA). Due to the technical constraints of the rechargeable battery, the HSA must carry sufficient batteries to meet the flight power consumption at night, which seriously limits the flight endurance of HSA. To solve this contradiction, the paper has proposed a new energy management strategy (EMS) of multiple flight phases for HSA based on the gravitational energy storage and mission altitude, which aims to achieve the goal of long-endurance flight for HSA. The integrated model of this new EMS includes the aerodynamic model, the kinematic model, the solar irradiation model, the battery model, and the energy management model. Compared with the current EMS of level flight, the flight path of HSA in the new EMS has been divided into five phases: the lower altitude level flight at night, the maximum power ascending for mission altitude, the level flight at mission altitude, the maximum power ascending for higher altitude, and the longest gliding endurance. At last, the calculation of the new EMS for Zephyr 7 is studied by MATLAB/Simulink, and the calculation results indicate that about 22.9% of energy surplus can be stored in battery with the new EMS for Zephyr 7 compared with the current EMS, which is equal to reducing the rechargeable battery weight from 16.0 kg to 12.3 kg. Besides, the results of simulation in the four seasons also show that the new EMS is a very promising way to achieve the long-endurance goal for high-altitude HSA when the flight conditions satisfy some constraints like the deficiency of solar flux and the limit of battery mass.

This paper is dedicated to developing high-efficiency face detection and tracking method for big dynamic crowds or numerous pedestrians. Three modules constitute the proposed method, i.e., face candidate generation, face candidate verification, and face target tracking. In this work, face candidates are localized using the features of the face area, edge information, and skin color. Non-face parts in the face candidates are further verified by the C-SVM learning model and then removed, by which the face targets can be generated with lower computation-complexity and satisfactory accuracy than other approaches. Finally, the face targets are tracked by an efficient and reliable searching scheme for improving the effective face detection rate. Experimental results show that the average face detection rate (FDR) of 85%, average effective FDR of 95%, a frame rate of 28–66 frames per second (fps), and about 30 faces detected per frame are obtained from various test videos with big dynamic crowds or numerous pedestrians, indicating the feasibility of the proposed method to achieve unconstrained face detection with high-efficiency and cost-effectiveness. This result makes the proposed method more attractive for the video surveillance system as compared to other approaches, especially in the high computational complexity-based methods.

To evaluate the safety and efficacy of a system aiming to correct scoliosis called “electromagnetically controlled shape-memory alloy rods” (EC-SMAR) used in a rabbit model. We heat-treated shape-memory alloy (SMA) rods to achieve a transition temperature between 34 and 47 °C and a C-shape austenite phase. We then developed a water-cooled generator capable of generating an alternating magnetic field (100 kHz) for induction heating. We next studied the efficacy of this system in vitro and determined some parameters prior to proceeding with animal experiments. We then employed a rabbit model, in which we fixed a straight rod along the spinous processes intraoperatively, and conducted induction heating postoperatively every 4 days for 1 month, while performing periodic X-ray assessments. Significant kyphotic deformations with Cobb angles of about 45° (p

Background. Osteosarcoma is one of the most common bone tumors among children. Tumor-associated macrophages have been found to interact with tumor cells, secreting a variety of cytokines about tumor growth, metastasis, and prognosis. This study aimed to identify macrophage-associated genes (MAGs) signatures to predict the prognosis of osteosarcoma. Methods. Totally 384 MAGs were collected from GSEA software C7: immunologic signature gene sets. Differential gene expression (DGE) analysis was performed between normal bone samples and osteosarcoma samples in GSE99671. Kaplan–Meier survival analysis was performed to identify prognostic MAGs in TARGET-OS. Decision curve analysis (DCA), nomogram, receiver operating characteristic (ROC), and survival curve analysis were further used to assess our risk model. All genes from TARGET-OS were used for gene set enrichment analysis (GSEA). Immune infiltration of osteosarcoma sample was calculated using CIBERSORT and ESTIMATE packages. The independent test data set GSE21257 from gene expression omnibus (GEO) was used to validate our risk model. Results. 5 MAGs (MAP3K5, PML, WDR1, BAMBI, and GNPDA2) were screened based on protein-protein interaction (PPI), DGE, and survival analysis. A novel macrophage-associated risk model was constructed to predict a risk score based on multivariate Cox regression analysis. The high-risk group showed a worse prognosis of osteosarcoma ( p

To determine the risk state distribution, risk level, and risk evolution situation of agricultural non-point source pollution (AGNPS), we built an ‘Input-Translate-Output’ three-dimensional evaluation (ITO3dE) model that involved 12 factors under the support of GIS and analyzed the spatiotemporal evolution characteristics of AGNPS risks from 2005 to 2015 in Chongqing by using GIS space matrix, kernel density analysis, and Getis-Ord Gi* analysis. Land use changes during the 10 years had a certain influence on the AGNPS risk. The risk values in 2005, 2010, and 2015 were in the ranges of 0.40–2.28, 0.41–2.57, and 0.41–2.28, respectively, with the main distribution regions being the western regions of Chongqing (Dazu, Jiangjin, etc.) and other counties such as Dianjiang, Liangping, Kaizhou, Wanzhou, and Zhongxian. The spatiotemporal transition matrix could well exhibit the risk transition situation, and the risks generally showed no changes over time. The proportions of ‘no-risk no-change’, ‘low-risk no-change’, and ‘medium-risk no-change’ were 10.86%, 33.42%, and 17.25%, respectively, accounting for 61.53% of the coverage area of Chongqing. The proportions of risk increase, risk decline, and risk fluctuation were 13.45%, 17.66%, and 7.36%, respectively. Kernel density analysis was suitable to explore high-risk gathering areas. The peak values of kernel density in the three periods were around 1,110, suggesting that the maximum gathering degree of medium-risk pattern spots basically showed no changes, but the spatial positions of high-risk gathering areas somehow changed. Getis-Ord Gi* analysis was suitable to explore the relationships between hot and cold spots. Counties with high pollution risks were Yongchuan, Shapingba, Dianjiang, Liangping, northwestern Fengdu, and Zhongxian, while counties with low risks were Chengkou, Wuxi, Wushan, Pengshui, and Rongchang. High-value hot spot zones gradually dominated in the northeast of Chongqing, while low-value cold spot zones gradually dominated in the Midwest. Our results provide a scientific base for the development of strategies to prevent and control AGNPS in Chongqing.

Smart Class services have been touted as a promising tool to enhance teaching and learning interactions. Initiatives on education reformation and relevant information technology deployment have been carried out by universities worldwide. However, previous studies often overlook the user perceptions on such applications which may lead to uncertainties or failures in the implementation of Smart Class services as users may not always accept or adopt such technologies. This study examines student perceptions about the use of Smart Class services from various perspectives. Ten variables adapted from previously validated measurement scales were selected. They are enjoyment, perceived interaction, subjective norm, privacy concern, computer anxiety, self-efficacy, facilitating conditions, perceived usefulness, perceived ease of use, and attitude. A total of 335 students from local universities were recruited and returned 282 valid observations for data analysis. Our results showed that, regardless of the concerns on personal privacy and the relatively low ratings on enjoyment and subjective norm, Smart Class services appear to be a feasible tool for university students. Further research is needed to analyze the correlations among the examined variables and their quantitative effects on users’ technology acceptance behaviors.

The effect of carbon risk on the debt capital market has become increasingly prominent under carbon constraints. We use a panel regression model to examine the relationship between carbon risk and the cost of debt financing and the moderating effect of positive media attention on this relationship. Using a sample of 191 Chinese A‐share listed firms operating in high‐carbon industries covering the period 2011–15, we conduct an empirical study and find that the relationship between carbon risk and the cost of debt financing in China is a U‐shaped one. Thus, carbon risk exerts an “interval effect" on the cost of debt financing, which mainly exists in private firms rather than state‐owned firms. This relationship can be mitigated by positive media attention. Compared with private firms that receive low positive media attention, private firms with high positive media attention are more sensitive and less tolerant to environmental regulations. Our findings provide firms with practical advice on carbon risk management, particularly on improving carbon transparency and mitigating the cost of debt financing.

To eliminate the problems of large dimensional differences, big semantic gap, and mutual interference caused by hybrid features, in this paper, we propose a novel Multi-Features Guidance Network for partial-to-partial point cloud registration(MFG). The proposed network mainly includes four parts: keypoints' feature extraction, correspondences searching, correspondences credibility computation, and SVD, among which correspondences searching and correspondence credibility computation are the cores of the network. Unlike the previous work, we utilize the shape features and the spatial coordinates to guide correspondences search independently and fusing the matching results to obtain the final matching matrix. In the correspondences credibility computation module, based on the conflicted relationship between the features matching matrix and the coordinates matching matrix, we score the reliability for each correspondence, which can reduce the impact of mismatched or non-matched points. Experimental results show that our network outperforms the current state-of-the-art while maintaining computational efficiency., Comment: preprint version, the final version is accepted by Neural Computing and Applications and is available online at https://doi.org/10.1007/s00521-021-06464-y

With the rapid development of the automobile industry, the demand for autonomous driving becomes more and more urgent, and the traffic sign recognition technology in autonomous driving is an indispensable technology. This paper proposes a GoogLeNet based convolutional neural network for traffic signs. This convolutional neural network improves each of the underlying Inception Modules and adds the Batch Normalization layer, effectively avoiding over-fitting of the network. We use a sparse structure that conforms to the Hebbain principle to reduce the parameters and improve the generalization ability of the network, which can extract the features of the image more accurately. Meanwhile, the network also reduces the parameters of the full connection layer by 20 times through the continuous two-layer pooling layer, which greatly speeds up the network training. Finally, the network is trained using the GTSRB data set and the classification accuracy rate can reach 98%. At the same time, we also verified the validity of the network on the MNIST dataset and the pneumonia dataset. The classification accuracy rate can reach 100% on the above two datasets. Experimental results on the above data sets show the validity of the convolutional neural network.

Internet of things (IoT) integrates sensor, radio frequency identification, network and cloud computing technology into a large-scale monitoring area. Wireless sensor network (WSN), as the most suitable infrastructure for the Internet of Things, how to reduce its energy consumption has been a research hotspot. In hierarchical networks, cluster head nodes need to take on more energy consumption tasks. Therefore, reasonable cluster head selection scheme and normal node joining cluster mechanism become particularly important. This paper proposes a new clustering method to save energy and prolong network life. Firstly, in the cluster head selection phase, the influence of energy threshold, residual energy, node density and communication factor is considered. Secondly, in the ordinary node joining cluster phase, the residual energy and distance factor are considered to form the non-uniform cluster set of the network. Simulation results show that the algorithm has good performance in reducing and balancing energy consumption.

Agricultural non-point source pollution (AGNPS) risk prevention and control is more conducive to reducing costs than post-treatment. Therefore, how to effectively identify risks is a key problem to be solved. The study area is located in the NANTUO small watershed of the Three Gorges Reservoir Area in China, on the side of the Yangtze River, where agriculture is developed with many kinds of plantings. There is a water level fluctuation zone (WLFZ) with seasonal elevation difference up to 30 m due to the water level regulation of the Three Gorges reservoir, which is a hot area of AGNPS research. On the basis of daily water level observation in NANTUO small watershed, based on the theory of “source” and “sink”, this study explored the land use change in different seasons with the help of high-resolution remote sensing image (According to the change of water level, it can be divided into two periods: non-submergence period (low water level period from the beginning of June to the end of September) and submergence period (high water level period at other time)). With the help of “source” identification (Types of land use that produce pollutants) and resistance surface calculation index system (Minimum cumulative resistance model, MCR model), the risk level and risk transmission path (The easiest path for pollutants to move to water) of AGNPS in WLFZ were analyzed. Combined with the idea of ecological corridor construction and pollution control, the risk change of regional AGNPS under the optimization of land use mode (The cultivated land types within 50 m and 100 m (Landscape optimization zone) around the water area are adjusted to forest land respectively in two scenarios (Q1 and Q2)) was analyzed as well. Based on our results, 1) the difference in the water areas between the non-submergence and submergence periods was 3.79 km2, and the areas of grassland, farmland, and forest land in the non-submergence period increased by 0.62, 0.85, and 0.35 km2, respectively. The “source” land in this region was mainly sloping farmland with slope above 6°. 2) The calculation results of the minimum cumulative resistance base surface for each source land showed the characteristics of “high values in the west and dispersedly distributed, low values in the east and continuously distributed”. 3) The distribution of the resistance surface during the non-submergence and submergence periods was basically the same; the high-risk zones were widely distributed throughout the region, while the low-risk zones were mainly distributed in the eastern mountains. 4) The number of risk transmission paths followed the order of a4 (farmland with slopes between 6° and 15°) > a5 (farmland with slopes between 2° and 6°) > a1 (rural settlements) > a3 (farmland with slopes between 15° and 25°) > a6 (farmland with slopes ≤ 2°) > a2 (farmland with slopes above 25°), and about 90% of the risk transmission paths were distributed in the lower levels (i.e., level 1, level 2, level 3). The proportion of risk transmission paths in the lower levels during the submergence period was higher than that during the non-submergence period. 5) The proportions of high risk, relatively high risk, medium risk, low risk, and no risk in the study area varied respectively following the rules of 72.79%→70.07%→66.56%, 16.85%→18.16%→18.3%, 6.24%→7.21%→9.3%, 2.25%→2.36%→3.32%, and 1.87%→2.2%→2.52% under the intact status of non-submergence period (Q0), Q1 scenario, and Q2 scenario. 6)The maximum values of pollution transmission path resistance of “source” land under the intact status of non-submergence period (Q0), Q1 scenario, and Q2 scenario followed the order of Q0

As an important light absorbing material, space extinction black paint has been widely used for space stray light suppression structures. This is usually not compatible with the Lambert diffusion law. Therefore, in order to describe the light scattering characteristics of a stray light suppressed structure surface accurately, bidirectional reflection distribution data at different angles and wavelengths are obtained by experimental measurements. Then a multivariate and multiparameter spectral bidirectional reflection distribution function model is established according to the characteristics of experimental data, and the parameters of the model are fitted accurately based on the Newton descent method. The quantitative evaluation of model error is completed by comparatively analyzing the measured data and the model data. The calculated model error is 3.07%, which proves the accuracy of the proposed parametric model. This model can provide important technical support for the design and evaluation of a space stray light suppression system.

Zinc-air batteries offer a possible solution for large-scale energy storage due to their superhigh theoretical energy density, reliable safety, low cost, and long durability. However, their widespread application is hindered by low power density. Herein, a multiscale structural engineering of Ni-doped CoO nanosheets (NSs) for zinc-air batteries with superior high power density/energy density and durability is reported for the first time. In micro- and nanoscale, robust 2D architecture together with numerous nanopores inside the nanosheets provides an advantageous micro/nanostructured surface for O2 diffusion and a high electrocatalytic active surface area. In atomic scale, Ni doping significantly enhances the intrinsic oxygen reduction reaction activity per active site. As a result of controlled multiscale structure, the primary zinc-air battery with engineered Ni-doped CoO NSs electrode shows excellent performance with a record-high discharge peak power density of 377 mW cm-2 , and works stable for >400 h at 5 mA cm-2 . Rechargeable zinc-air battery based on Ni-doped CoO NSs affords an unprecedented small charge-discharge voltage of 0.63 V, outperforming state-of-the-art Pt/C catalyst-based device. Moreover, it is shown that Ni-doped CoO NSs assembled into all-solid-state coin cells can power 17 light-emitting diodes and charge an iPhone 7 mobile phone.

Soil arch plays an important role in the landslides reinforced by stabilizing piles . A method was presented to determine the range of soil arching ring. The method proposed was achieved by finite element program and the stress distribution of soil arch with different landslide thrust was analyzed. The results show that the thickness of soil arching ring is variable. The mid-span section of soil arching ring is the minimum. The arch ring becomes thicker from the mid-span axis to the arch feet. With the increase of landslide thrust, the soil arching ring becomes thicker and thicker. At last ,the monitoring data of a model test is studied and the results are consistent with that of numerical simulation.

New energy vehicles are becoming the future of auto industry and acquire considerable significance in many fields including energy conservation, CO2 emission reduction, environmental protection, oil dependence reduction, cultivation of new economic growth point, etc.. Based on international comparison and investigation to China’s two major auto industry bases----Changchun and Hubei, this paper discusses and analyzes, from economic point of view, the world new energy vehicle development and its experiences to China. Compares China’s new energy vehicle policies with relevant US policies. Analyzes the success of Belgian high tech and green plastic auto development. Illustrates, from consumers’ and companies’ view respectively, influence of China’s policies to the new energy vehicle development. Finally, summarizes the characteristics of China’s development, studies problems existing, and puts forward certain constructive suggestions.

In view of solar arrays applied in large-scale stratospheric airship, modular thinking was proposed by reasonable decomposition of solar array to design composite maximum power point tracking (MPPT) controller where the input and output are both in parallel, which ensures maximized solar energy output on a limited area. And each solar array sub-model was equipped with independent MPPT controller to control power tracking separately. Then, the solar array composed of three sub-models was used for simulation and its result indicates that MPPT controller of each sub-model can track the power quickly, and the output power can reach 93% of maximum input power when the efficiency loss of converter in reality is not considered . So, the model constructed in this paper can be used to optimize the design and analyze output characteristics quantitatively for the large-scale stratospheric airship's solar array.

Using only photovoltaic battery on solar-powered aircraft will waste energy because of its low conversion efficiency. For reusing the energy that converted into heat by photovoltaic cells, a hybrid power system is presented in this paper for solar-powered aircraft. Its a new electricity-generating method that spreading photovoltaic cells on the wing surface and arranging photothermal cells in the wing box section. Due to temperature of the back of photovoltaic battery is high, it can be used as high temperature heat source. And the lower wing surface can be a low temperature cooling source. A lightweight solar-powered UAV was used to analyze the relevant performances of pure photovoltaic powered aircraft and hybrid powered aircraft. The result shows that using hybrid system can reduce the area of wing by 4.6%, and solar-powered aircraft with a 6m or below-6m wingspan can raise the utilization rate of solar energy per unit area by adopting hybrid power system.

A coal mine in Chongqing +590m south four district 2443 working face as the research object, using the finite difference method (FLAC) which can solve the nonlinear large deformation problem, setting up the mechanical analysis model of the gob-side entry retaining, analyzing the structure characteristics of surrounding rock, and studying on the stability of surrounding rock of the gob-side entry retaining under the mining. the results showed that:(1) After the coal mining, the maximum displacement of roof has occurred on the edge of the roadway upper side near the filling body. The floor heave at the beginning mining, the floor has a downward displacement after the mining;(2)After the coal mining, the surrounding rock of the gob-side entry retaining has a larger range of shear failure, a strong tensile damage was occurred in filling body, big horizontal displacement was happened in the middle of filling body. Research results can provide reference for similar coal mining..

Use Taiping coal mines second horizontal (+1100m~+900 m level ) 1#, 3# and 5# coal seam in Panzhihua Baoding as the research object, apply the problem solving nonlinear large deformation finite difference method (FLAC), to research the steep multi-seam mining of pressure distribution and characteristics of fracture zone. The results show that: (1)During the course of three coal mining extraction, the stress of goaf surrounding rocks will be changed. (2)When the nearby coal is mining, the coal pillar come into being stress concentration near the area. when the mining work continues, the goaf will have an effect on the protection pillar, which is similar to the "liberate". the effect of coal pillar and stress concentration nearby will be eased; (3)After the coal mining, plastic failure has occurred over the protection pillar, forming a water guide channel. Research results can be as a reference for similar steep seam mining.

As one of the key technic of achieving high-altitude and long-time flight, the stratospheric airship energy system in stratosphere is always the important point but also very difficult. In this paper, the stratospheric airship geometry analysis as a starting point, through a series analysis as follow: the stratospheric airship surface mesh model, the sun vector, the relationship between the sun vector and the body coordinate system, and the solar radiation model, we have accomplished the characteristics analysis of the radiation receiving on stratospheric airship. The analysis result show that: Although different flight direction corresponding to different distribution of light intensity, the light changes from sunrise to sunset is symmetrical when the stratospheric airship on the condition of level flight. Airship for east heading of region resides, the maximum energy can be obtained when the solar array laying in the installation of 0 β π / 4. With the changing of heading angle and pitch angle, the radiation receiving of the solar array can also transform, but the influence of pitch angle greater than heading angle.

Cell temperature can reach as high as 70 oC while working, using only photovoltaic battery in the solar plane will result in a waste of energy. Combined with the wing configuration, a hybrid energy design method with higher efficiency is presented: photovoltaic cells will be distributed on the wing surface and photothermal cells will be arranged in the wing box section. The back of photovoltaic battery can be used as high temperature heat source and the lower wing surface can be a low temperature cooling source. Through the research of photovoltaic cells maximum power output, the envelope method ensures the output power, improves the power tracking reliability, and reduces difficulty in the design. The structure design of thermoelectric battery P-N junction is optimized by using the maximum power and maximum power to-mass ratio as objective function. The optimal solution of P-N junction structure of a certain type thermoelectric battery is given for acquiring maximum power-to-mass ratio.

Ship wrecks in the sea has many dangerous to enviroment, especially there are fuel and oil in them. To protect sea enviroment and improve the removal of wreckage, the use of the commercialization can solve the problem, have a reality meaning for the high cost of salvaging problem. The thesis analyses the situation and problem of our wreck removal actuality, then introduce Bertrend game model of the market to illustrate competition of the removal work, which can reduce the cost of salvage , our government should actively support the development of dive salvaging and private enterprise and make them strong and better.

The injecton pulsed bending bump magnets of Rapid Cycling Synchrotron (RCS) in China Spallation Neutron Source (CSNS) consist of four horizontal bending (BH) magnets and four vertical bending (BV) magnets. The BH magnets are operated at a repetition rate of 25 Hz and are excited with a trapezoid rectangle waveform with about 1.6 milliseconds duration. The eddy current is induced in BH magnets and in the end plates it is expected to be large, so the heat generation is of our great concern. In this paper, the eddy current loss of the BH magnet has been investigated and calculated by using a coupling method of 3D electromagnetic and thermal analysis. The accuracy of the analysis is confirmed by testing the prototype BH magnet. The end plate temperature of the BH magnet provided with slit cuts has been decreased obviously and met the requirements.

This paper try to analyze the rheological behavior during the wax injection, and build a mathematical model to simulate the wax injection process. By using Moldflow, simulate a wax pattern with different ingate configurations to optimize the injection modeling product design. This study helps to improve the model design quality, shorten the development cycles, lower down the overall cost and enhanced competition in market.

Investment casting method can fabricate the impeller slots with non-uniform thickness and distorted surface. The process of investment casting can be simulated by employing ProCAST software. The mesh of the casting was introduced in the article. The influence about the initial temperature of shell on the defects of the casting and the pouring temperature and the pouring speed on the effective stress of the casting was studied in this article. When the initial temperature of shell was 400°C,there was no defect in the casting. The pouring temperature of the casting, will produce a very strong influence on the effective stress. When the pouring temperature in this article was 800°C, the maximum effective stress of the casting was 108MPa.

Laser Shock Processing (LSP) is a kind of new surface hardening technology, which can increase fatigue life obviously. Due to the LSP, the residual stress is generated and dislocations increase obviously in the surface of specimen, so the fatigue life of specimen processed by LSP increases. Thanks to the finite element programs, it is able to simulate the fatigue life. The simulation of fatigue life has important significance, which not only can reduce the costs of fatigue test and research, but also further study the effect of LSP on fatigue life. The results of fatigue test coincide with the results of simulation.

In order to satisfy the stringent requirements for edge location accuracies in such fields as medical image analysis and satellite remote sensing, an approach based on orthogonal Fourier-Mellin moments is proposed to use the lower radial orders and the rotation invariance of these moments to describe small objects in images, and edge location is accomplished by setting the edge in the vertical direction and analyzing the interrelationships among the orthogonal Fourier-Mellin moments with different orders and degrees, and consequently the specific characteristics of the edge can be fully extracted. Experimental results show that the proposed method can be used to achieve an edge location accuracy of 0.16 pixel for straight lines with noise and 0.23 pixel for curves with noise. It can therefore be concluded that the proposed method is an efficient approach to satisfy the stringent requirements for higher edge location accuracies in such fields as medical image analysis and satellite remote sensing.

The necessity to drastically reduce the space-heating (SH) needs of residential buildings in Europe has prompted the emergence of building concepts based on a super-insulated building envelope, such as the passive house (PH) standard. In these envelopes, the SH distribution system can be simplified because it is theoretically not necessary anymore to place a heat emitter in each room, or in front of each window. There is lack of fundamental knowledge to support this simplification of the SH distribution system. The present contribution especially focuses on apartment buildings heated using a reduced number of radiators. It aims at comparing the balance between energy efficiency, thermal comfort and user satisfaction using simplified SH distribution. For this purpose, two flats built according to the Norwegian PH standard have been investigated using building simulations (using IDA-ICE), field measurements and occupant interviews. With a simplified distribution, one may suspect that occupants experience the thermal environment of rooms without heat emitter as too cold, typically bedrooms. On the contrary, the super-insulation and the high-efficiency heat recovery prevent significant temperature zoning to takes place between rooms. Even though the SH distribution is simplified, occupants rather complain about the bedroom temperature which is too warm if they do not open windows. Unfortunately, this way to control indoor temperature has a strong adverse influence on the space-heating needs, which is here investigated for different control strategies. Another limitation is the time needed to heat a bedroom only using internal door opening. It takes several hours to adjust to a higher set-point temperature; an aspect that can be critical if the bedroom temperature should be changed between daytime and nighttime. © 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

The response speed of in‐plane switching mode liquid crystal displays with three initial director configurations—homogeneous, twisted nematic and 180° super twisted nematic—was investigated via simulations. These simulations studied the relationship between the change in the optical axis and the optical transmission in the three configurations, allowing us to calculate the optical response times. The time‐dependent change in the director was calculated using the Erickson–Leslie equations and these two results combined. These results predict that the response time during both the rise and decay periods of a super twist cell is about four times faster than the other two configurations.

The rubbing angle effect on transmissive in‐plane switching liquid crystal displays is analysed by the Jones matrix method. Simulation results show that the optimum rubbing angle is around 30°–40°; the cell gap/birefringence product (dΔn) is about 0.33 µm. Increasing the rubbing angle can shorten the rise time and enlarge the grey scale voltage intervals. The optical characteristics are similar in two cells with different rubbing angles. These effects are particularly attractive for liquid crystal TV applications.

The technical feasibility analysis of an aircraft design scheme directly influences the design proposal, which determines whether scheme can satisfy the maximum design requirements or we can continue the detailed design. Conventional design evaluation of a new technical influence is insufficient, because the weight evaluation (analytic hierarchy process, AHP) is usually subjective. This paper proposes a new impact analysis method based on probability theory, and the comprehensive information including the data envelopment analysis (DEA) and the interval number AHP is referred to as a comprehensive empowerment of the appraisal criterion. According to the proposed method, the best selection method of an aircraft conceptual/preliminary scheme based on probability and integration judgment is established. Finally, some examples are presented to demonstrate the validity of the method.

To investigate the vesicle shapes of the area difference elasticity (ADE) model, the shooting method and mathematica software were used to calculate the shapes of vesicles. Results not only several corresponding shapes of vesicles, such as oblate and prolate shapes were obtained but also some new shapes of vesicles were gained by limiting some parameters in the ADE model. Studies have shown that the shape equations of axisymmetrical in the ADE model can be simplified to the shapes of axisymmetrical in the spontaneous curvature model (SC).

Stratospheric airship is capable of station-keeping at high altitude in precondition of the balance of buoyancy and weight, thrust and drag. Based on specific computation process, when some hypotheses are given, the length of airship can be calculated and it is emphasized to analyze the impacts on payload capability performance and conceptual parameters (such as length, surface area and volume) with altitude, latitude of station-keeping and pressure difference, temperature difference, helium purity. It is shown from the analyses that pressure difference, temperature difference and helium purity have fewer effects on payload capability and length of airship, and in contrast, altitude and latitude of station-keeping have the larger effects. On the other hand, effects on payload capability and length with each technology guideline are also discussed when specified operation parameters keep constant, such as altitude and design wind of station-keeping. It is concluded that the benefit to length and payload capability is the largest with improvement of envelope mass/area ratio but the least with improvement of propeller system efficiency.

The paper proposes an artificial intelligence method to trace inherence leakage current between power line and Earth, which can be used in history records of only one residual current (RC) detection point. Firstly, it gives the common topology structure of residual current detection in Low voltage power line and defines three ingredients in TLCE (Total Leakage Current to Earth): ILCE (Inherence Leakage Current to Earth), TLCES (Total Leakage Current to Earth after Sub-switch) and BLCE (Burst Leakage Current to Earth). Then the paper analyzes the features of those three ingredients of leakage current. Finally, it gives out an artificial intelligence method to trace inherence leakage current which can be used in leakage current alarm threshold adjustment of electric fire prevention system.

In the course of capturing vein images from image capturing devices, displacement deviation, angle deviation and scale changes are inherent. In order to overcome these problems arosed by above factors, an approach to vein image recognition using the angle matrixes of feature points is presented in this paper. In the phase of feature extraction, all feature points and multisection points between them are obtained first, then the angle matrix of the feature points are calculated and arranged to form an angle matrix sequence. In the matching phase, the type and number of the feature points were first compared, if they mach, the angle matrix sequence was compared. Experimental results show the method is feasible.

We numerically investigate the electromagnetic properties of tellurium dielectric resonator metamaterial at the infrared wavelengths. The transmission spectra, effective permittivity and permeability of the periodic tellurium metamaterial structure are investigated in detail. The linewidth of the structure in the direction of magnetic field Wx has effects on the position and strength of the electric resonance and magnetic resonance modes. With appropriately optimizing the geometric dimensions of the designed structure, the proposed tellurium metamaterial structure can provide electric resonance mode and high order magnetic resonance mode in the same frequency band. This would be helpful to analyze and design low-loss negative refraction index metamaterials at the infrared wavelengths.

Room-temperature operation of a GaSb based laterally coupled distributed feedback quantum-well laser diode emitting at 2 μm is demonstrated. The device exhibits single longitudinal mode characteristic as a result of the first order Cr-Bragg gratings alongside the narrow ridge waveguide. We design the laser structure to obtain a critical coupling condition corresponding to a coupling coefficient of 12 cm−1. For a 1-mm-long uncoated laser diode with a 3-μm-wide stripe, a single mode output spectrum with side mode suppression ratio as high as 28.5 dB is achieved, and the maximum single mode continuous-wave output power is about 11 mW at room temperature.

Out of 1346 newborns screened for congenital hypothyroidism, 31 non-hypothyroid infants were summoned because of a thyroid stimulating hormone (TSH) level above 10 microU/ml. False-positive TSH levels were significantly more frequent in the babies treated with povidone-iodine (4.6%) than in those treated with either alcohol or triple dye (0.7%). CONCLUSION. Iodine containing solutions should be avoided in umbilical cord care of the newborn.

We investigate the sensitivity and figure of merit (FOM) of a localized surface plasmon (LSP) sensor with gold nanograting on the top of planar metallic film. The sensitivity of the localized surface plasmon sensor is 317 nm/RIU, and the FOM is predicted to be above 8, which is very high for a localized surface plasmon sensor. By employing the rigorous coupled-wave analysis (RCWA) method, we analyze the distribution of the magnetic field and find that the sensing property of our proposed system is attributed to the interactions between the localized surface plasmon around the gold nanostrips and the surface plasmon polarition on the surface of the gold planar metallic film. These findings are important for developing high FOM localized surface plasmon sensors.