Table of Content

28 February 2017, Volume 33 Issue 1

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Effect of Different Zr/Ti on the Microstructure and Dielectric Properties of PZT Ceramics

LI Yingjuan, SONG Qunling, ZHANG Wenli, ZHANG Jinliang, TENG Yu, CAI Chuanxiong

2017, 33(1):  1.  doi:10. 3969/j. issn. 1009一0479.2017.01.001

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Pb(Zr_xTi_1-x)O₃ (x=0.8, 0.7, 0.48, 0.3, 0.2) ceramics were prepared by solid state sintering. The thermal decomposition of powder,  the surface topography，the microstructure and the effect of different Zr/Ti on the properties of PZT piezoelectric ceramics were characterized by TG/DSC，XRD，SEM and LCR respectively.  PZT piezoelectric ceramic microstructure and morphology were also characterized; the influence of different Zr/Ti on dielectric properties of PZT ceramics were discussed in the paper. The result shows that Pb(Zr_xTi_1-x)O₃ (x=0.8, 0.7, 0.48, 0.3, 0.2) ceramic target at 850 ℃ is re-sinteringed for 2 hours，and PZT has been the main crystal phase formation. After being sinteringed at 1 050 ℃ for 8 hours，the grain boundaries are clear, the grain size distribution is more uniform and denser, and the PZT ceramics with pure perovskite structure are obtained.  It is found that the different Zr/Ti is important for preparing the microstructure and dielectric properties of PZT ceramics.  At the same time，the dielectric constant with different Zr/Ti at 1 kHz is investigated.  The dielectric constant reaches a maximum 534 when x=0. 48，and dielectric loss value is 0. 04.

Frontal Analysis of International Metallurgy Based on Knowledge Mapping

杜湘，张国飞

2017, 33(1):  6.  doi:10.3969/j. issn.1009-0479.2017.01.002

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A quantitative statistical and a qualitative analysis of metallurgy discipline research literature from 2010 to 2016，which were supported by the database of science citation index expanded (SCI-E)，with the methods of bibliometrics and knowledge mapping were made. The general situation of the research literature about metallurgy from several aspects:period sequences，key node documents，hot topics and frontal researches，countries and institutions was analyzed. It was tried to clarify research history and research focus of metallurgy discipline through the current study. 

On Utilizing Phosphorus Gypsum as Cement Retarder

HUANG Lan, ZHOU Guangbo, CHEN Zixiang

2017, 33(1):  13.  doi:10. 3969/j. issn. 1009一0479.2017.01.003

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An experiment was carried out by using phosphorus gypsum rather than natural gypsum as cement retarder in portland cement to test its physical properties such as the setting time and decide its feasibility in cement production. The result shows that phosphorus gypsum works effectively in setting time and retarding the setting process. Besides，its indexes of physical property meet the requirments of the national standard.

Exploration and Development Status of Shale Gas in China and Enlightenment from North American Prosperous Shale Gas

CHENG Yong, CHEN Guodong, YIN Qiong, XIA Caixing, WANG Falong, ZHOU Li, LU Ping, MA Lei

2017, 33(1):  16.  doi:10. 3969/j. issn. 1009一0479.2017.01.004

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America's shale gas breakthrough，continues to cause shale gas development boom and strategic layout of the countries with abundant shale gas，and sets off an unprecedented “shale gas revolution" in the world. It is of great significance for improving energy structure and guaranteeing energy security to speed up the exploration and development of abundant shale gas resources in our country. On the basis of a large number of literature investigation，this paper introduces the exploration and development history and present situation of shale gas in our country，and analyzes the enlightenment from North American prosperous shale gas to our country. The researches about shale gas start late in our country. China basitally completes the mission of the third stag(2010一2015): industrialization production test of marine shale gas，and the exploration&evaluation of transitional and continental shale gas，after the first stage (before 2005): analysis of shale gas in North America as it develops，and the second stage(2005-2010): the geology research，"dessert" area selection，appraisal well drilling and preparation for exploration & development of shale gas. The fourth stage (after 2015) about exploitation on a large scale in marine shale gas and industrial mining experiment in transitional and continental shale gas is ongoing. Chinese proved geological reserves of shale gas is 5 441.29 ×10⁸ m³ at present. Three industrial production demonstration area of marine shale gas are established in Fuling，Weiyuan, Changning一Zhaotong，one production demonstration area of continental shale gas in Yanchang and Fushun一Yongchuan cooperative development region.  China's shale gas production is 12. 5 × 10⁸ m³ in 2014 which produced from Wufeng一Longmaxi Formation marine shale in Sichuan basin，and becomes the third largest country in shale gas production second only to America and Canada.  What's more，shale gas has been found in multiple series of strata in south china marine shale，but need to evaluation further.  Transitional shale gas shows a certain degree of exploration prospects.  Continental shale gas is not form a stable industrial production，whose exploration prospects is not clear.  Although the successful experience of North American
shale gas is worthy of reference，but shale gas in China has its own characteristics.  In order to achieve the shale gas development on a large scale，there still has a lot of things to do. First of all，technical difficulties of deep shale gas exploration&development must he overcome，and the breakthrough must he
made in the core technology and equipment.  In addition，the government's policy support and stringent environmental regulation is also crucial to the development of shale gas industry in China.

Techniques for the Safety Assessment Report Writing of Non-coal Open-pit or Underground Mine

XIA Jiabo, LIN You, LIN Jifei

2017, 33(1):  25.  doi:10. 3969/j. issn. 1009一0479.2017.01.005

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The writing techniques for the core content of non-coal mine safety assessment reports were discussed in this paper, which focuses on the major quality problems of safety assessment reports of non-coal mine. This paper mainly discussed writing skills of describing mining process system，identifying risks and harmful factors，determining the evaluation scope of each unit，making qualitative and quantitative assessment of each unit，devising safety countermeasures and compiling safety assessment conclusion. It can effectively improve the quality of non-coal mine safety assessment report writing and thus secure its positive effect on non-coal mines' safe production.

Explore the Direction of Open-pit Stripping Work Line in Tongjie and Manjiazhai Village

HUANG Zhibing，SONG Jianjun

2017, 33(1):  31.  doi:10. 3969/j. issn. 1009一0479.2017.01.006

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To reduce the mining cost and ensure the security of open pit slope, decrease the transportation distance in ore, increase production efficiency, etc., it was tried to improve the blasting effect through the analysis of some problems such as security, cost, and transporting distance in the process of mining. It aims to explore some new ways to reevaluate the relationship between stripping time and space based on the premise of normal productivity. The analysis tries to divide the mining spots into two types according to different mining methods, changing the current transverse propelling to vertical propelling. The implementation of the devise can further realize the optimization of mining, escalating its efficiency. It can also help solve the problem in transverse propelling with mixed mining ore-bearing rocks. While improving the blasting effect, the scheme could reduce ore loss and dilution, exposing large-area ore body and increasing the secondary ore ownership.

A Design of Automatic Cooling and Alarm Control Device for Oversize Vehicle Wheels

LI Yuan, WANG Aiguo

2017, 33(1):  37.  doi:10. 3969/j. issn. 1009一0479.2017.01.007

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Due to ensure the heavy load and fast speed，oversize vehicles could only use the safety when going downwards. The brake disc result  would rise
in temperature continuously,  which lead to the “thermal recession"  and finally，result in the brake failing to work. Based on the analysis of the existing technologies to reduce the temperature of the vehicle wheels, a new automatic cooling and alarm control device was designed. When the wheels are in high temperature，the microcontroller will receive the signal via temperature detector. Then it will give a voice warning to the driver who can use compressed air to cool the brake disc with the help of air blower.


 

Research and Implementation of Digital Filtering by Siemens S7 Control System#br#

TAO Min

2017, 33(1):  41.  doi:10. 3969/j. issn. 1009一0479.2017.01.008

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In the automatic control systems based on computer, the digital filter is often used to eliminate all kinds of noises and interferences in the signal detection channels.  This paper introduced the methods of programming the commonly used digital filtering in automatic control system and the filtering algorithm
on the SIEMENS S7 series controller. It also made a comparative analysis of the effect of computer simulation system on digital filtering.


UML-based Evaluation System Analysis and Implementation for National Vocational College Students’ Originality Competition#br#

GUO Honghai

2017, 33(1):  48.  doi:10. 3969/j. issn. 1009一0479.2017.01.009

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The traditional way before to hold the national higher vocational college students’ originality competition concerning business administration by Ministry of Education was mainly by means of sending letters or faxes to the organizers，which has brought much inconvenience. In this society of encouraging frugality，it can't meet the needs of expanding the size of the competition. Therefore, developing a Web evaluation system in accordance with competition requirement is urgently needed. By using UML analysis and design，based on B/S structure，the researcher developed the asp. Net dynamic technology to realize the online review, the implementation of which makes the competition go smoothly, efficiently and cross-regionally.

Jpcap-based Method to Obtain the NIDS Data Source

XU Wei, XU Chenming, WANG Suqiong

2017, 33(1):  57.  doi:10. 3969/j. issn. 1009一0479.2017.01.010

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Network Intrusion Detection System(NIDS) is one of the most effective methods in Internet security protection.  Numerous researchers at home and abroad have focused on it and obtained tremendous achievements in detection model, detection methods and practical application.  Nowadays KDDCUP 99' data sets are still the preferable data source to he used in testing the experiments of NIDS.  However, as a static data source, it doesn't work well in dynamic situations. Therefore, this paper establishes a new method with some characteristics of KDDCUP 99, by the data packet of Jpcap of JAVA to capture network
IP and pick up the information.

On Entropy-based Comprehensive Evaluation of the Wenchuan Earthquake Disaster

CHEN Li

2017, 33(1):  61.  doi:10. 3969/j. issn. 1009一0479.2017.01.011

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A comprehensive analysis is conducted by entropy method via the software of MATLAB to disaster indicators in 36 serious disaster-stricken counties and cities in the Wenchuan Earthquake.  First, 8 indicators' proportion, entropy & entropy weight and comprehensive evaluation values of 36 counties and
cities are obtained from the original data.  Second, these 36 counties and cities are ranked and classified according to their comprehensive evaluation values.  Finally, the 36 counties and cities are classified according to their equalization values and the outcomes are consistent with the real situation.  The result shows that it is more scientific and objective to analyze the disaster using entropy method, which contributes to the effective aids and rebuilding work in disaster areas.


Working Mechanism of the Peak Shifting Class and Its Feasibility: a Case of City College, Kunming University of Science and Technology

LEI Chunya，ZHONG Jiayu，XIANG Qing，CHAT Jiajia

2017, 33(1):  67.  doi:10. 3969/j. issn. 1009一0479.2017.01.012

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The issue of the peak shifting class is very complicated in colleges and universities, in which conceptualized implementation may not achieve good effect but could cause conflicts in teaching resources and worsen the crowded dining situation. In this paper, the current situation of the peak shifting class in
China was reviewed，and its impact on the mechanism of dining system was analyzed.  As teaching arrangement in time and space are inter-connected-we designed a new peak shifting strategy, considering curriculum characteristics, class starting and ending time, and the number of students from each grade.
Mathematical model was established on the basis of analytic hierarchy process(AHP ), and the weight of evaluation for the peak shifting strategy was calculated to research the feasibility of this strategy. The strategy was implemented in City College，Kunming University of Science and Technology.  The result shows that the strategy adopted has optimized the structure system of teaching arrangement, teaching resources and students' dining, overcoming the bottleneck factor in teaching resources. Therefore, this strategy is worth to he promoted in other areas.


Selection and Application of Protection Scheme for Subgrade Close to High-voltage Transmission Tower

YANG Yuanhong

2017, 33(1):  75.  doi:10. 3969/j. issn. 1009一0479.2017.01.013

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A road project in Yunnan is part of urban special expressway, whose route in the vicinity of K10+520 is close to a 220 kV high-voltage transmission tower. The excavation of the subgrade poses a great threat to the safety of high-voltage transmission tower, and the construction risk is high. In order to ensure the safety of high-voltage transmission tower when excavating the subgrade, the scheme of sheet-pile wall in the paper was selected as the best from the angle of subgrade protection. The deformation observation of tower foundation was carried out in the construction. It is shown that sheet-pile wall can effectively control the accumulation settle-ment and uneven settlement of the tower foundation in subgrade excavation, and the tower deformation is in the allowable ranges. The use of sheet-pile wall has ensured the safety of high-voltage transmission tower, meanwhile, it verifies the rationality and feasibility of the scheme.

On Design and Research of Aluminum Alloy Formwork in Engineering

CHENG Yongwei，WU Yansheng，GAO Xiong，PAN Jie，PENG Yi

2017, 33(1):  79.  doi:10. 3969/j. issn. 1009一0479.2017.01.014

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The advantages in application and research contents of the aluminum alloy formwork were introduced firstly. Then the features and design contents，combined with some engineering cases were summarized.  Aluminum alloy formwork's advantages of environmental protection，simple construction and
reutilization，which result in its wide use in the field of construction were indicated finally.


Electrochemical Analysis of Zn on Inlaid Carbon Nanotubes Bismuth-film Electrode

LIU Qiong

2017, 33(1):  84.  doi:10. 3969/j. issn. 1009一0479.2017.01.015

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The embedded carbon nanotubes modified bismuth-film electrode was prepared and the electrochemical behaviors of Zn at the modified electrode
was studied with cyclic voltammetry in this work. The result shows that the oxidation peak of Zn at the modified electrode is single and irreversible. The oxidation peak potential (E_pa) and current (I_pa) are -0. 06V and 10. 90 μA respectively, with two protons in this process. Then, the optimum condition of copper differential potentiometric stripping is -1.1 V in accumulation potential, 0. 4 mg/L in bismuth concentrations, and pH 4.6 in the HAc-NaAc buffers. The situ-plate bismuth and standard addition method were used to calculate the concentration of samples. The height of peak is linear with the mass 0 to 50.0 μg/L under the best conditions. The detection limit is 0.84 μg/L. The RSD is 1. 56%∽7. 90% and the recovery rate is in the range between 94.6% and 104.0%.

Study and Practice of the Differentiated Teaching Strategy for Different Teaching Targets: a Case Study of Mine Ventilation Course

LIU Yingke，ZHOU Fubao，LIU Zhentang

2017, 33(1):  91.  doi:10. 3969/j. issn. 1009一0479.2017.01.016

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Based upon the fact that there is great diversity among the teaching targets in their knowledge base, familiarity with spots of coal mine, and career development upon graduation，a differentiated teaching strategy of mine ventilation for different teaching targets is investigated from such four aspects as course introduction，arrangement of emphasis upon teaching contents, knowledge extension, and course discussion. By actualizing this strategy，teaching objects are better educated in accordance with their aptitude. Besides，they also get activated and motivated，with a desirable teaching effect achieved.







On the Project Curriculum Reform of Spatial Database Technology Application

MA Juan, XIA Jianbo, SONG Qunling, YAO Zhiqi

2017, 33(1):  97.  doi:10. 3969/j. issn. 1009一0479.2017.01.017

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Based on the basic orientation of the vocational education curriculum reform，this paper first puts forward vocational ability oriented curriculum objectives of spatial database technology application，and then it analyzes the reform ideas of curriculum, work task, teaching project，teaching modules，teaching scheme. Finally，it expounds the content of project curriculum reform and evaluates the teaching outcomes.


Discussion on Teaching Reform of Water Supply and Drainage Pipe Network System

LI Jianping, HUANG Xiangyang

2017, 33(1):  104.  doi:10. 3969/j. issn. 1009一0479.2017.01.018

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Water supply and drainage pipe network system is a professional core course in water supply and drainage specialty.  Based on the questionnaire handed out to students of water supply and drainage major, the article analyzed some problems in the teaching. The paper brings forward some ways to reform
teaching such as reasonable selection of teaching materials，varied teaching materials，better teaching methods and examination methods.  It actively promotes teaching reform to ensure students have better theoretical knowledge and practical skills to lay a good foundation for their future career.