Evolution and Simulation of Spatial-temporal Heterogeneities in Ecological Background Quality of Changsha City

By GIS and ENVI,TM/ETM remote sensing images of five districts(Yuelu District,Furong District,Yuhua District,Tianxin District and Kaifu District) in Changsha City center in 2005,2010 and 2015 were interpreted.Moreover,distribution chart for ecological background factors in 2020 was simulated by using CA-Markov module in IDRISI.Using principal component analysis,evaluation model for ecological background quality of the city was established.Via circle analysi s,GS+semi variance function analysis,hot spot area analysis and grey correlation analysis,integrated analysis and evaluation on spatial heterogeneity evolution of ecological background quality in research region were conducted.Results showed that firstly Changsha overall has formed ecological pattern of landscape island city,but ecological background started to show the evolution trend of high heterogeneity and fragmentation under the construction land expansion,and ecological background quality of the city declined from 0.300,6 to 0.257,1 during 2005-2020.Secondly,ecological background quality of Changsha City had typical circle and axial gradient structure,and "eco tone" had the most violent evolution.Thirdly,spatial structure of ecological background quality had region,time and direction heterogeneities,and spatial heterogeneity of region was the most important.Fourthly,hot spot area distribution of ecological background quality evolution showed the "frog jump" trend of gathering in marginal zone and diffusing to peripheral zone.Fifthly,in driving factors of ecological background quality,industrialization rate had the highest grey correlation degree(0.842,1),and grey absolute correlation degree between ecological background quality in Yuelu District and industrialization rate was the highest(0.603,1).     

产乙醇工程菌构建方法的研究进展

归纳了产乙醇工程菌的构建方法,包括原生质体融合技术、不同水平上的基因工程技术（包括经典基因工程、代谢工程、全局转录调控工程和进化工程）及低能离子束介导转基因技术,分析了各项技术的优缺点,指出低能离子束介导转基因技术在构建工程菌方面的巨大应用潜力,以期为构建能利用新型碳源发酵乙醇的工程菌提供思路和依据。     

Stability Analysis for the Excavation Engineering Under Coupling Effect of Seepage from Heavy Rain and River Fluctuation

The seepage accident is very easily occurred, when the excavation engineering has been constructed in rainy season and it is very easily influenced by the coupling effect of seepage duo to heavy rain and water level fluctuation of neighboring river. So a coupling seepage equation that based on the theory of Dupuit has been established for the ground water in the layered foundation. And then, the water table surrounding the excavation engineering has been determined on the consideration of the coupling effect of seepage duo to heavy rain and water level fluctuation of river. In the meantime, by means of the theory of coupling analysis of stress and seepage and the software of Midas, a model of coupling analysis of stress and seepage has been built for the specific excavation engineering and the seepage destroy characteristics of this project has been researched.     

Numeric Analysis of the Dynamic Performance of a Prestressed Concrete Beam

The finite element of a prestressed concrete (PSC) beam is analyzed in a case of diverse prestressing forces. The mechanical model applied is that advanced by Clough for a concrete beam bearing axial force. The results indicate that the beam frequencies decrease with increasing prestressing force. A dynamic experiment of a non bonded PSC beam was carried out to validate the veracity of the finite element analysis. Test beam frequencies increase with increasing prestressing force. The analysis model thus is unfit for frequency analysis of a PSC beam. The determinant factor of frequencies is analyzed, and the dynamic model is modified according to experimental results. The modified model analysis result shows that: the calculated frequencies of mode 1 agree with the test results well; the frequencies of mode 2 posses some errors; and, the modified model can reflect the direction of frequency change along with the change of prestressing force well.     

新型组合梁板连接中板的抗弯性能

在高层建筑结构设计中,由于上部荷载较大或梁的跨度较大,使得梁的截面高度较高,通常会影响建筑的有效层高和建筑的总体高度。为了减小各层梁板结构高度,有效增大各层净高,提出了一种钢箱梁嵌入现浇板的新型组合梁板连接方式。针对这种新型连接方式,对6个钢箱梁混凝土板组合连接区域进行了板承受支座负弯矩的单调加载试验,对比分析了采用钢箱梁嵌入混凝土板组合楼盖与传统栓钉连接组合楼盖中板抵抗支座负弯矩的性能差异;并利用ABAQUS对试件进行了有限元分析。试验与有限元分析结果表明：采用钢箱梁嵌入板连接组合方式,其混凝土板抵抗支座负弯矩的能力与传统连接方式板抵抗支座负弯矩能力没有明显差异。     

Torsion Vibration Test and Analysis of Main Transmission System of 1450 Rolling Mill

The torsion vibration of main transmission system of 1 450 rolling mill is tested:The torsion vibration frequency and amplification coefficient of torque are obtained.Basing on part of the measured date and theoretical analysis,the measure is developed for preventive method;it is of important theoretic sense and high engineering practical value for reducing accident and controlling torsion vibration.     

食品科学与工程专升本“食品工程原理实验”课程教改探索

通过分析课程教材、实验条件、教学方式、教师素质、考核方式等方面存在的问题,进行了“食品工程原理实验”课程的教学改革,以期培养专升本学生成为素质全面的高水平应用型食品科学与工程专业人才。     

Fast circle measurement of industrial CT images based on existence probability

The general methods in reverse engineering cannot measure the inside of close parts. Traditional methods like Capture Geometrical Inside (CGI) would destroy the part. We used the industrial computer tomography (ICT) method to obtain accurate measurements of close parts. Based on the acquired computer tomography images, the size of an internal part was obtained through image measurement and subsequently edited, amended, and dimensioned in CAD software. First, the position and the pixel size of the circle were determined based on existence probability. Next, the actual size of one pixel was obtained based on the image size and the purview diameter. Finally, the actual circle size was calculated by multiplying the pixel size and the actual size of one pixel. A real part was measured using the method. The results show that the relative error of the measured circle radius and the actual size is less than 0.5% and the measuring time is several seconds.     

Theoretical and Experimental Analysis of Bending Behavior of Composite Beam with Notched Web

A new kind of steel-concrete composite beam with notched web is proposed, and the bend and shear behaviors of this composite beam are investigated. First of all, the constitution, bearing characteristics and merits of the steel-concrete composite beam with notched web are introduced; then, a group of formulas about the bending capacity, slip between the steel beam and the concrete flange, and the deflection are introduced; after that, the bending behavior, slip effect and bearing characteristic of the steel-concrete composite beam with notched web are studied on 4 specimens, which are tested by applying two concreted vertical loads on the top of concrete flange. And the finite element model is adopted to analyze the results of the 4 specimens; finally, the reliabilities of the formulas are verified by comparing the results of theoretical formulas, the results of tests and that of finite element analysis. Study shows that the bend behavior and shear behavior are fine, and the popularization of this new kind of composite beam which can be broadly used in building engineering will save the consumption of steel.     

The Necessity of Establishing the Mechanism of RegulationStandards on Construction Engineering Quality

On the basis of quaility accident cases in engineering, this paper presents the necessity of establishing the mechanism of regulation standards on engineering quaility for whole construction work. This paper compares the technology standards with regulation standards on engineering quaility, puts forward the idea of regulation standards on engineering quaility for whole construction, analyses and studies the procedure norm, accounting system, management mechanism,auditing supervision and risk forecasting technique on engineering quaility in entity related with whole construction, under consideration with the reality of interaction relationship on engineering quaility and engineering financing in our county, finally ,explores and illustrates the positive appoarch which is used for establishing the mechanism of regulation standards on construction engineering quaility.     

“新工科”背景下“包装测试”课程教学改革与探索——以黑龙江八一农垦大学为例

在"新工科"背景下,从教学内容、教学方法、考核方式、实验设计等方面探索了"包装测试"课程的教学改革。通过以新技术成果扩充教学内容,实施"课堂教学+网络教学"的混合式教学模式、注重过程化考核方式,优化和创新实验设计,极大地提高了课程质量,为"新工科"背景下复合应用型包装工程专业人才培养途径提供参考。     

Study on the Key Construction Techniques about the Prestressed Transform Beam of Chongqing People''s Mansion

In order to ensure the construction quality of the massive prestressed transform beam, to prevent and control the cracking before tensioning ,the technology of casting ,methods of temperature and crack controlling are carefully analysed and theoretical calculation is carried out as well as the temperature inspection during construction ,all of which have effective results. Some prestressed construction points of transform beam are also introduced in this article, and reference advices are given at last.     

A Model for Harm Impact Evaluation of Crude Water Pollution Accident

The harm impact evaluation was studied for pollution accident happened in urban crude water system characterized of fetching crude water from reservoir through channel.The relevant direct and indirect factors to harm impact of crude water pollution accident were analyzed.Furthermore, the attribute reduction method in rough set theory was applied to eliminate the redundancy of indirect factors.Integrating the direct and indirect factors effects, an emergent evaluation model for the Harm Impact was established with the similarity analysis by vague sets theory.Taking crude water system in Chengdu as a case study, a designed nitrobenzene pollution accident was simulated in different working conditions.Moreover, the Harm Impact extent of the accident was calculated with the proposed model.The sensitivity analysis indicates that the proposed model is reasonable and valid in the emergent evaluation for the pollution accident happened in the urban crude water system.     

The method of dynamic aperture control technology based on ultrasound imaging system

Dynamic aperture control technology is one of the most important parts in ultrasonic imaging system. Excellent control technology of dynamic aperture can effectively improve the quality of ultrasonic imaging. Based on deep analysis of ultrasonic beam distribution, a control method for dynamic aperture which can eliminate the scanning dead zone of focused beam is presented. The detection region is even divided according to the number of probe array elements. The desired focused beam width is calculated between the next two scan lines at different depths, and then according to the beam width, the required aperture size for different depths is determined. The method is not affected by the probe parameters or detection objects, and it can be widely employed in ultrasonic imaging system. The simulation experiments indicate that the proposed method can effectively improve the whole quality of ultrasonic imaging.     

RETAINING WALL ON A SLIP BODY STABILIZED BY THE AID OF PRESSURE-GROUTED LITTLE PILES

This paper introduces pressur-grouted little piles and analyses mainly a serious engineering accident of retaining wall built on a slip body in Sichuan. That is stabilized by the aid of pressur-grouted little pile and a good result is obtained.     

基于OBE理念的“食品工厂设计”教学改革与实践

基于OBE理念,进行了“食品工厂设计”课程教学改革。围绕学生取得的学习成果提出了“食品工厂设计”课程建设基本思路,从构建课程目标、优化理论教学、提高实践能力、完善考评体系等4个方面进行了教学研究。以期提高理论和实践教学效果和质量,为我国新时代工程人才培养和形成世界水平的工程教育体系提供思路及方法。     

Deformation Analysis of Thermo Elastic Plastic on ReinforcedConcrete Structure Subjected to Fire

To investigate the mechanical behavior of reinforced concrete structure subjected to fire, the incremental thermo elastic plastic creep constitutive equations of steel and concrete in consideration of temperature and creep deformation were obtained based on different yield rules and the elastic plastic theories. The nonlinear analysis for reinforced concrete simply supported slab was carried out with consideration the variation of the mechanical properties of steel and concrete with temperature. The effectiveness and applicability of the constitutive equations were verified with the test results from relevant literature. The nonlinear analysis was employed for one bay one storey reinforced concrete frame under fire and the variation of displacement at partial nodes was analysed. It was found that the reinforced concrete structure at a high temperature would have a significant deformation. And the displacement change curves of beam column joints of reinforced concrete frame were not monotonous trend and there were inflexion points. The vertical displacement values of beam column joints were less than those at midspan of cross beam.     

食品科学与工程专业实践教学改革探索

实践教学是本科教学的重要组成部分,是提高学生综合素质、培养学生创新精神与实践动手能力的重要途径。从改革实践教学方法、改进实验教学内容、加强实验教学条件和实习基地建设、抓好毕业实习和毕业论文(设计)等环节对食品科学与工程专业实践教学改革进行探讨,以期为高校食品科学与工程及相关专业开展实践教学改革提供参考。     

Experimental Analysis for Steel Box Concrete Composite Beam of Arch Bridge

A new steel concrete composite structure was proposed which composed of steel box beam, PC beam and PBH Shear connection. Bend test was carried out for the performance study of deformation and stress. It was found that Material advantages of steel and concrete were fully used and crack of concrete and local instability of steel box were avoided. And the deformation between steel box and concrete can be smoothed with PBH shear connection. As the calculated values showed good agreements with the test results, the proposed formulas can be reliably applied to the practice analysis. With the different parameters analysis, mechanic performance of the composite was obtained.     

Control System of Construction Quality of Building Engineering

Through construction market survey, the paper proposes the way of the control system of construction quality of building engineering and establishes objective system of its on becoming core of quality control spot. It puts forward many grade control and evaluation net and expounds the method to produce quality evaluation form, control system of quality ordinary question and quality analysis. It determines technology way and movement foundation on system development. The paper introduces the model and its function on the control system of construction quality of building engineering. This system is a opening system, it may be filled and complemented with new content at any time. It has better adaptable to change of construction code.