28 June 2014, Volume 32 Issue 18

    

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Articles
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  Mode I Crack Tip Deformation Field for Stratopheric Airship Envelope

  LIU Longbin, LI Xue, LÜ Mingyun, MI Panpan, CAO Shuai

  journal1. 2014, 32(18): 15-21. https://doi.org/10.3981/j.issn.1000-7857.2014.18.001

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  The stratospheric airship is affected by the alternating high and low temperatures, the ozone, the ultraviolet radiation and other harsh conditions in the stratosphere environment. This paper studies the crack tip opening displacement (CTOD) fields and the strain distribution test method for the strain field in the stratospheric airship envelope material by uni-axial tensile experiments and the digital speckle correlation method (DSCM). For tearing tests of single edge notched (SEN) specimens, the initial weft crack is prefabricated to a length of 20 mm, and the typical brittle fracture is observed during the crack propagation process and the material specimen deformation field varies in a manner of steps. The calculation results of the displacement and the strain of the weft and warp fibers show that the mode I crack tip deformation field is accurately evaluated by the DSCM, which also displays the initial crack propagation law and the crack evolution characteristics of an SEN crack tip. The crack tip deformation curves for a large scale yielding length is obtained for the design and the deformation test of the high performance stratospheric airship envelope material.
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  A Method for Measuring Particle Concentration Based on Mie Scattering

  ZHOU Libin, ZHANG Dachen, JIANG Pengfei, DI Chuanyong, LI Sha, WANG Jiangnan

  journal1. 2014, 32(18): 22-25. https://doi.org/10.3981/j.issn.1000-7857.2014.18.002

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  Numerical simulation of particle scattering was realized using the continued fraction recursion method based on Mie scattering theory. An easy numerical simulation method was obtained by the aid of special function library in the Mie scattering theory, improving the computing speed. The extinction coefficient was obtained by numerical simulation with a different refractive index variation of particle diameters. The result revealed that light scattering effects of particles with different refractive index were similar to those of water and dust, when the particles' diameter is larger than a certain value. The light scattering experiment of aerosols in the atmosphere was simulated using hydrosol, while the dust samples collected in different areas were used as particles. Light scattering data of the dust sample at different wavelengths and different concentrations were obtained and compared with those of SiO₂ particles whose diameter is 400 nm. Three wavelength method was used to obtain an average particle size of the sample, which is verified by SiO₂ particles' experiment results. Using the average particle sizes of each sample, the relationships between particle concentration and light intensity variation were simulated according to the law of extinction. The experimental results are consistent with those obtained theoretically. It provides a good theoretical basis for measuring the concentration of particles in the air.
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  Effect of Nitrogen Injection Conditions on the Spontaneous Combustion “Three Zones” in Goafs

  HUANG Xianhua, GU Beifang, JIN Xiaohua

  journal1. 2014, 32(18): 26-30. https://doi.org/10.3981/j.issn.1000-7857.2014.18.003

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  This paper studies the theory concerning relationships between nitrogen injection parameters and distribution of the “three zones” in goafs, and uses fire source location software to analyze the effect of nitrogen injection on the spontaneous combustion “three zones”. The results show that reasonable nitrogen injection is locatedat the border of the heat dissipation zone and oxidation zone. Under general conditions, nitrogen injection is suggested to be located in the oxidation zone. When nitrogen injection became stable, oxygen distribution showed a retraction and overall forward lead, especially when the oxidation zone was significantly reduced in the wind side, showing an apparent nitrogen injection effect.
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  The Design of Vibration Point Load Tester

  ZHOU Zilong, WU Zhibo, ZHAO Yunlong

  journal1. 2014, 32(18): 31-35. https://doi.org/10.3981/j.issn.1000-7857.2014.18.004

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  A vibration point load tester is designed in this paper, for studying the mechanical properties of rock subjected to a cyclic point load, with different vibration frequencies and excitiong forces. The instrument consists of a static loading unit and a vibration loading unit. The former is a hydrostatic pressure device fixed on the bottom platform of the bracket. And the latter is a special vibration motor, installed on the top platform of the bracket. The upper loading cone and the special vibration motor are cast as a whole. The lower loading cone is connected with the upper pressurized piston of the hydrostatic pressure device, and can move up and down through the diaphragm hole. Different excitiong forces and frequencies can be assigned by adjusting the eccentric block's angle and the motor speed, then the point load and the acting time for reaching the failure point of the rock body under a given excitiong force and frequency can be determined. And the best combination of the vibration frequency and the excitiong force, with the best rock fragmentation efficiency and the least harm to boring machine cutters, can be obtained.
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  Intelligent Blasting-hole Design System in Tunnel Engineering

  WANG Liguan, DING Qiqi, BI Lin, LI Jing

  journal1. 2014, 32(18): 36-40. https://doi.org/10.3981/j.issn.1000-7857.2014.18.005

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  Based on the Dimine digital mining software, an intelligent tunnel excavation engineering blast-hole design system was developed by using computer graphics and object-oriented technology to solve the problems of low efficiency and tedious modification of conventional manual and CAD blasting-hole design methods. According to the blast plan and tunnel excavation data, the type and location of blast-hole can be determined by using the quadtree algorithm, the blast-hole can be modified, numbered, lined and charged through data editing, the coordinate dimension of the blast-hole can be achieved and the overlap dimension can be avoided by using coordinate transformation. Finally, the blasting-hole layout charts and blasting parameter charts which are adjusted to practical engineering are output. Its application shows that this system improved the design efficiency of both blasting-hole and blasting charts in tunnel excavation engineering.
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  Mathematical Model of Thermal Effect of Magma Intrusion into Porous Reservoir and Its Application

  YU Shui

  journal1. 2014, 32(18): 41-47. https://doi.org/10.3981/j.issn.1000-7857.2014.18.006

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  In this paper, a mathematical model is proposed for the thermal effect of intrusion of magma into porous reservoir to simulate the geological system of magma intrusion and the heat effect in solidification by using an equivalent algorithm, based on the equivalence principle of the physical and mathematical equations. The transient finite element analysis transforms the original rock magma solidification boundary movement into a physical equivalent heat source boundary with no new movement, namely, a singlestep solidification model and a multi step (three step) solidification model. The main advantages of the proposed algorithm is that the finite element mesh size is fixed, the varied time step is used to simulate the intruding magma solidification thermal effect through the traditional finite element analysis. Comparing various thermal effect models, it is shown that the numerical single-step solidification model solution and the multi step (three step) numerical model solution enjoy similar accuracy, so the single-step solidification model can effectively simulate the thermal effect of the magma intrusion in the porous rock. Single and multi step (three step) solidification models are compared with the Wang Min model and the Zhao model, and it is shown that the single and multi step (three step) models give solidification results more consistent with those of the Zhao model, which theoretically are closer to the actual geological data. The diabase intrusive analysis of Shang 56 sha 3 pool is carried out to simulate the thermal field, and it is shown that the Shang 56 Sha 3 pool thermal cracking volume is 9.02×10⁴ m³, and the preservation conditions of the reservoir is poor, with a large amount of oil and gas leakage, to which is attributed mostly the loss of crude oil.
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  Extraction of Sectional Contour Lines of Goafs using Triangulation Model

  LUO Zhouquan, ZHANG Wenfen, LUO Zhenyan, XU Shimin

  journal1. 2014, 32(18): 48-53. https://doi.org/10.3981/j.issn.1000-7857.2014.18.007

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  Goafs are one of the main hazards for mine safety and production. Accurate information of goaf profile is an important basis for safe exploitation of mining resources and prevention of goafs' disasters. Contour line extraction by using goaf triangulation model is the premise for accurately obtaining the profile by visual method. The defects of currently used triangulation sectional contour extraction methods are analyzed, including the minimum distance method, fan-shaped regional method and convex hull algorithm applied to extract the sectional contour line of goafs which have complex boundaries. This paper aims to improve the conventional methods and proposes an advanced extraction method named convex hull penetration method for the extraction. First, it extracts the convex hull line of unordered point set obtained in the plane vertical to arbitrary axis using the triangulation model; then it obtains a complete cross-section contour line by putting points of the initial contour line into the contour line following the principle of maximum opening angle; finally it forms the profile of the goaf. The application shows that this method has practical values in efficiently extracting the sectional contour lines of complex goafs and accurately obtaining the profile.
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  The Design and Test of the Warm Tuner for Multi-Cell Medium β SRF Cavity

  ZHANG Xinrong, XUE Peipei, ZHANG Liping, SUN An

  journal1. 2014, 32(18): 54-57. https://doi.org/10.3981/j.issn.1000-7857.2014.18.008

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  In order to correct the field frequency deviation caused by the machining error and the welding shrinkage in the manufacturing process of the multi-cell medium β SRF cavity, a regulating mechanism-warm tuner is designed based on the multicell medium β SRF cavity's characteristics and the field flatness principle. The tuner contains five parts, which are the activity carriage, the gearbox carriage, the tailstock, the activity tailstock and the bed body. The warm tuner is used in the test of the field flatness and the field frequency of a medium β SRF cavity. Finally, the test system of the RF superconducting cavity field flatness is set, detailed analyses and designs of the bead-pulling system, the network analyzer and the microcomputer control system are carried out. The microcomputer control system uses the virtual instrument Lab VIEW software as the platform to control the other parts in the test system, and to analyze the test results, to present the test results. The results show that the medium β SRF cavity warm tuner can be successfully used for the test and modulation.
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  A Monotonic Optimization Approach for Solving Globally Generalized Quadratic Programming

  SHEN Peiping, LI Weimin, TANG Chong

  journal1. 2014, 32(18): 58-61. https://doi.org/10.3981/j.issn.1000-7857.2014.18.009

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  The generalized quadratic programming (GQP) is an important class of global optimization problems with wide applications in the fields of financial management, statistics and design engineering, with multiple local optimal solutions differing from the global solution. Thus, it is very difficult to obtain a global optimal solution for the GQP. Many solution methods were developed for globally solving the GQPs in a special form and the general form. However, these approaches may sometimes provide an infeasible solution, or one far from the true optimum. To overcome these limitations, a monotonic optimization approach is proposed for the GQP. In the approach, the original problem is first converted into an equivalent monotonic optimization problem, whose objective function is just a simple univariate by exploiting the particular features of this problem. Then, a range division and compression approach is used to reduce the range of each variable. Tightening variable bounds iteratively allows the proposed method to reach an approximate solution within an acceptable error by using monotonic functions, in which such solution is adequately guaranteed to be feasible and to be close to the actual global optimal solution. At last, several numerical examples are given to illustrate the feasibility and efficiency of the present algorithm.
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  Correlation Analysis of Plasma Fatty Acid Levels in Patients with Tumor and Abnormal Savda in Uyghur Medicine

  MAMTIMIN Batur, SUN Feng, KELIMU Alimujiang, KONG Bin, GONG Can, UPUR Halmurat

  journal1. 2014, 32(18): 62-66. https://doi.org/10.3981/j.issn.1000-7857.2014.18.010

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  To investigate the plasma fatty acid metabolism of different cancer patients with abnormal Savda in Uyghur medicine and analyze its common features, the plasma fatty acid concentration was tested by the gas chromatography (GC) from 122 cases of cancer patients with abnormal Savda including 25 cases of esophageal cancer, 20 cases of colorectal cancer, 33 cases of lung cancer, 20 cases of breast cancer and 24 cases of gastric cancer, and 35 healthy volunteers as a control group. The spectral profiles were subjected to a t-test for statistical significance. The results show that compared to the healthy group, the patients of esophageal cancer, colorectal cancer, lung cancer, breast cancer and gastric cancer with abnormal Savda suffer a high concentration of myristic acid; the patients of esophageal cancer, lung cancer, breast cancer and gastric cancer with abnormal Savda suffer a high concentration of palm acid; the patients of colorectal cancer, lung cancer and breast cancer with abnormal Savda suffer a high concentration of palmitic acid; the patients of esophageal cancer, lung cancer and gastric cancer with abnormal Savda suffer a low concentration of linoleic acid; the patients of esophageal cancer, colorectal cancer, lung cancer and breast cancer with abnormal Savda suffer a high concentration of oleic acid; the patients of breast cancer patients with abnormal Savda suffer a low concentration of stearic acid; the patients of esophageal cancer and gastric cancer with abnormal Savda suffer a low concentration of arachidonic acid; the patients of breast cancer patients with abnormal Savda suffer a high concentration of EPA, but the patients of gastric cancer with abnormal Savda suffer a low concentration of EPA; the patients of esophageal cancer, lung cancer and breast cancer with abnormal Savda suffer a high concentration of arachidic acid; the patients of esophageal cancer and gastric cancer with abnormal Savda suffer a high concentration of DHA. It is concluded that these findings suggest that different tumor patients with abnormal Savda see some common characteristics, and also significant differences.
Reviews
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  Review on Casing Corrosion Testing Techniques outside China

  WANG Lichen, ZHEN Jian, ZHU Guiqing

  journal1. 2014, 32(18): 67-72. https://doi.org/10.3981/j.issn.1000-7857.2014.18.011

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  Corrosion phenomena are widespread during the process of oil and gas exploration and production. Corrosion prevention and control are necessary in protection of oil-gas exploitation facilities, such as the casing, tubing and wellhead, to guarantee economic and production efficiency. Corrosion testing techniques are important means to deal with corrosion problems with high resolution and good continuity. This paper mainly addresses the casing corrosion problems by introducing the current status and development trend of casing corrosion testing techniques outside China.
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  Review on Transient Operation Optimization of Gas Pipelines

  ZUO Lili, LIU Huan, ZHANG Xiaorui, Feng Liang

  journal1. 2014, 32(18): 73-78. https://doi.org/10.3981/j.issn.1000-7857.2014.18.012

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  When the gas flows through the pipeline, compressors are used to compensate the pressure loss due to the friction by consuming the fuel gas. For the fuel gas used by compressors constitutes a significant part (about 3%~5% of the gas running through the pipeline), it is quite necessary to study how to optimize the operation of the gas pipeline in a better way that the consumer's demands are satisfied and the compressors are set cost-efficiently. The paper summarizes related typical transient operation issues. The mathematical model for optimizing the gas pipeline operation in a transient flow is built, and the commonly used algorithms and the relevant results are analyzed in detail.
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  Review on Car Engine Mounting System

  YIN Zhixin, LIANG Wenbo, WEI Qifeng

  journal1. 2014, 32(18): 79-83. https://doi.org/10.3981/j.issn.1000-7857.2014.18.013

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  The car engine mounting system is the key to the improvement of the NVH (Noise, Vibration, Harshness) properties. The development aiming to higher speed, more power and less weight makes the vibration isolation property an important issue. Therefore, the car engine mounting system becomes one of the key factors to achieve the driving comfort, the riding comfort and the good NVH properties of the automobiles. This paper discusses some rubber unit optimal designs of the engine mounting system and their shortcomings. The future direction of the research is pointed out to provide a reference for the car engine mounting system research.