Comparison study on calculation methods of bending behavior of Chinese reinforced concrete beams from 1912 to 1949

In order to study the calculation methods of bending behavior of Chinese reinforced concrete beams from 1912 to 1949, tests on the mechanical performance of 66 rebars from different modem Chinese concrete buildings, the concrete compressive strength of 12 modem Chinese concrete buildings, and the concrete cover thickness of 9 modem Chinese concrete buildings are carried out; and the actual material properties and structural conformations of modem Chinese concrete buildings are obtained. Then, the comparison on calculation methods of bending behavior including the original Chinese calculation method, the present Chinese calculation method, the present American calculation method and the present European calculation method is studied. The results show that the original Chinese calculation method of bending behavior is based on the allowable stress calculation method, and the design safety factors are 3.55 to 4. 0. In term of the calculation area of longitudinal rebars of reinforced concrete beams, without considering earthquake action, the original Chinese structural calculation method is safer than the present Chinese structural calculation method, the present European structural calculation method, and the present American structural calculation method. The results can provide support for the structural safety assessments of modem Chinese reinforced concrete buildings.

SOME ASPECTS OF TWO AIRCRAFT COMBAT IN PLANE——A METHOD OF DEALING WITH TWO-TARGET PROBLEM

A method of dealing with two-target problem in terms of coordinate transformation and differential game is presented in this paper. It has analysed the capture region, escape region and danger region. This approach is helpful to a pilot to possess the favourable position in an air-to-air combat in plane.

Comparative Analysis of Improving Effects of 12 Maize Populations with Improved S_1 Selection Method

ln this study, 12 maize populations were improved with the improved S1 selection method, aiming to increase the improvement efficiency of maize popula-tions. The results showed that number of rows per spike, number of grains per row and 100-grain weight were the three important component traits of maize yield. The highest genetic increment was found in Mengqun 2, fol owed by Mengqun 4, Mengqun 1 and other 7 maize populations. Negative genetic increment was shown in Mengqun 3 and 3 introduced foreign maize populations. Some changes were shown in spikes, plant traits and genetic diversity of maize populations. Based on our results, we concluded that Mengqun 2, Mengqun 4, Zhongzong 7, Mengqun C and Mengqun A could be directly used for the line breeding by selfing for their higher genetic increment of yield and better improvement effects of other agricultural traits. Compared with these 5 populations, the improvement potential of other maize populations was limited for their lower genetic increment.

Compare and Contrast the Strengths and Weaknesses of Task-based Language Teaching Method and Audio Lingual Teaching Method and Study How They Impact Upon Both the Teachers and the Learners

This essay focused on comparing and contrasts audio lingual method and Task-based language teaching method,demonstrating the strengths and weaknesses of the two methods and discusses how they impact upon both the teachers and the learners.TBLT is the contemporary teaching method with a great number of strong points.It seems that if there is more relatively scientific and effective method,TBLT should give way to it.The ultimate goal is to advocate the comparatively successful teaching method in the field of foreign language education.

Taking Stock of Grammar-Translation Teaching Method in Developing Intercultural Pragmatic Competence

Grammar-translation teaching method(GTTM as a shorthand below) has long been a buzzword when it is adopted in the class of English as a foreign language.It has been universally acknowledged that such teaching method contradicts the development of communicative language competence advocated in recent decades.However,I positively argue that GTTM in English class,as a comparative and intercultural model,should be given a due reconsideration to improve L2 learners' pragmatic competence.

Comparative Studies on Calculation Methods of Shear Behavior of Reinforced Concrete Beams of Chinese Modern Reinforced Concrete Buildings

In order to study the calculation methods of shear behavior of reinforced concrete beams of Chinese modern reinforced concrete buildings,this paper carried out tests on the concrete compressive strength of 12 Chinese modern concrete buildings,the mechanical properties of 66 rebars from different Chinese modern concrete buildings,and the concrete cover thickness of 9 Chinese modern concrete buildings,and the actual material properties and structural configurations have been obtained. Then,the comparison on calculation methods include the Chinese original calculation method,the Chinese present calculation method,the American present calculation method and the European present calculation method is studied with case analysis method.The results show that the Chinese original calculation method of shear behavior of reinforced concrete beams is based on the allowable stress calculation method,and the design safety factors are 3. 55- 4. 00. The standard value of the compressive strength of concrete cubes is 8. 48 MPa,the standard value of the concrete tensile strength is 1.20 MPa,the standard value of the yield strength of rectangular rebars is 229. 56 MPa,and the standard value of the yield strength of round rebars is 276. 82 MPa. The average value of the concrete cover thickness of beams and columns is 35.96 mm. In term of calculation area of hoop rebars of reinforced concrete beams,without considering earthquake loads,the Chinese original structural calculation method is safer than the Chinese present structural calculation method,but is more unsafe than the American present structural calculation method and the European present structural calculation method. The results can provide the support for structural safety assessments and repair designs of Chinese modern reinforced concrete buildings.

Explicit formulations and performance of LSFD method on Cartesian mesh

Performance of the LSFD method is compared with conventional FD schemes. Generally, 9-point stencils for 2D cases and 27-point stencils for 3D cases are used for the approximation of the first and second order derivatives obtained with conventional central difference schemes. When the same stencils are used, explicit LSFD formulations for approximation of the first and second order derivatives are presented. The LSFD formulations are actually a combination of conventional central difference schemes along relevant mesh lines. It has been found that LSFD formulations need much less iteration steps than the conventional FD schemes to converge, and the ratio of mesh spacing in the x and y directions is an important parameter in the LSFD application, with a great impact on stability of LSFD computation.

Synthesis of Au nanorods in a low pH solution via seed-media method

The gold （Au） nanorods with various aspect ratios are obtained by a seed-media method in low pH growth solution. Transmission electron microscopy （TEM） and UV-visible spectrophotometry are utilized to characterize the Au nanorods, and the longitudinal absorption peak positions of Au nanorods show different shifting trends of the growth evolutions in various low pH （1~3） solutions. Other influential factors on the shape of Au nanorod are also systematically studied under low pH reaction condition. The positions of longitudinal peak shift between 600 nm and 900 nm, with the aspect ratios of Au nanorods varying from 2 to 5 both in the simulation and experimental results. The simulation results are in agreement with experimental ones.

Progress of Land Engineering Discipline and Comparative Study on Teaching Methods

This paper introduces the origin and development of land engineering.Taking the course Introduction to Land Engineering as an example,this paper makes a comparative analysis of the teaching effects of traditional teaching method and task-driven teaching method.The results show that the task-driven teaching method is more suitable for the teaching task of land engineering,the students’learning effect is remarkable,and the degree of realization of teaching goal is high.

Agile Software Development Methodologies: Survey of Surveys

Agile software design and development methodologies have been gaining rigorous attention in the software engineering research community since their early introduction in the mid-nineties in addition to being highly adopted by the software development industry. In the last 15 years, an excessive number of research studies have been conducted on agile methods, a great number of notable methods have been proposed and various surveys have been presented by many researchers. In this study, the authors intend to conduct a literature survey study of the surveys of the different agile methodologies ranging from January 2000 to December 2015 using an intuitive research methodology called “Compare and Review” (CR). Furthermore, these survey papers were classified into four major categories according to their area of study. Additionally, the newly proposed agile methodologies that have not been addressed yet in any other literature review were reviewed and compared in terms of where the changes that they proposed lay on the SDLC.

Three-dimensional modeling and porosity calculation of coal rock pore structure

Coal rock is a type of dual-porosity medium,which is composed of matrix pores and fracture-cutting matrix.They play different roles in the seepage and storage capacity of coal rock.Therefore,constructing the micropore structure of coal rock is very important in the exploration and development of coalbed methane.In this study,we use a coal rock digital core and three-dimensional modeling to study the pore structure of coal rock.First,the micropore structure of coal rock is quantitatively analyzed using a two-dimensional thin-section image,and the quantitative information of the pore and fracture(cleat)structure in the coal rock is extracted.The mean value and standard deviation of the face porosity and pore radius are obtained using statistical analysis.The number of pores is determined using dichotomy and spherical random-packing methods based on compression.By combining with the results of the petrophysical analysis,the single-porosity structure model of the coal rock is obtained using a nonequal-diameter sphere to represent the pores of the coal rock.Then,an ellipsoid with an aspect ratio that is very much lesser than one is used to represent the fracture(cleat)in the coal rock,and a dual-pore structure model of the coal rock is obtained.On this basis,the relationship between the different pore aspect ratios and porosity is explored,and a fitting relationship is obtained.The results show that a nonlinear relationship exists between them.The relationship model can provide a basis for the prediction of coal rock pore structure and the pore structure parameters and provide a reference for understanding the internal structure of coalbed methane reservoirs.

Comparing High-resistance Grounding Method with Resonance Grounding Method for Large Generators

For large generators, the problem of high-resistance grounding method and the advantages of resonance, grounding method are discussed in detail, and an overall comparison is given in this paper. It is recommended that the latter should be adopted so as to increase the operation reliability of large generators and power systems.

高海拔铁路隧道施工安全风险管理策略研究

为弥补组织安全风险管理漏洞、提高高海拔地区铁路隧道施工安全风险管理绩效,采用扎根理论构建管理层面的高海拔地区铁路隧道施工安全风险管理策略框架,然后通过fsQCA方法构建策略选择组态模型,探讨安全风险管理能力与策略对于安全风险管理绩效影响的组态效应。研究结果表明:通过扎根理论分析识别出17条安全风险管理策略,基于Reason模型将其分为“组织规范策略”、“安全监督策略”、“前提保障策略”以及“行为规范策略”4个类别;在决策能力较强时,管理者需要将精力和资源着重偏向“安全监督策略”、“前提保障策略”以及“行为规范策略”;在决策能力较弱时,则需要注重全部4个类别所对应的安全风险管理策略的实施落实情况。研究结果可为提高高海拔隧道安全管理者的决策效率、保障施工安全进行提供一定参考。

两地无花果微量元素及总放射性物质分析与质量评估

目的评估新疆阿图什与江苏南通两地无花果产品质量。方法运用电感耦合等离子体质谱仪和总放测量仪,分别对新疆阿图什和江苏南通两地无花果微量元素和总放射性物质进行分析检测。结果新疆阿图什无花果与江苏南通本地无花果微量元素相比,铝、钾、钙、钒、锰、钴、镍、铜、锌、硒、钡等11种微量元素含量明显较高,镁和钼元素略低,铬元素较低。两地无花果的总α放射性物质和总β放射性物质均合格。结论新疆阿图什无花果产品质量优于江苏南通本地的无花果,具有较高的产品开发价值。

基于FMEA方法的射线检测实验室风险管理

射线检测是无损检测的主要方法,广泛应用于产品缺陷检测。X射线、γ射线是能量较高的电磁辐射,这使得射线检测实验室的管理不同于一般的实验室。基于此,应用故障模式及影响分析(FMEA)方法,参考质量、环境、职业健康安全国际管理体系标准的要求,对射线检测实验室的质量、环境、职业健康安全三大风险进行识别、分析、评价及控制。通过设计适用于三大风险的FMEA表和评分表对射线检测实验室的质量因素、环境因素、危险源开展识别及评价,通过计算风险优先数(RPN)获得重要质量因素、环境因素、危险源,并提出有效控制措施。研究结果对高等院校射线检测实验室的风险分析、评价及管理具有一定的参考价值。

比较法提升实训课堂教学效果的实践探索——以高职会计专业增值税纳税申报实训项目为例

比较法是把内容或形式上有一定联系的事物加以比较,辨别异同或优劣,在教学过程中,“知同”可以帮助学生更好地理解和掌握事物的本质,“辨异”才能知悉差别,触类旁通。教师将比较法运用于高职会计专业纳税申报实训中,比较知识点之间的区别与联系,比较理论与实践的辩证关系,从而帮助学生更好地理解会计业务、法规条款与纳税申报的本质和规律。在提高课堂教学效果的同时,培养学生对知识的梳理能力以及学会摸索实际业务脉络的能力。

比较教育与人类发展:新世纪的进展

在促进人类发展的共同使命下,发展研究需以比较教育研究为基础。研究以《比较教育》期刊为主线,结合比较教育领域的整体进展,对比较涉及的国别、类型以及涌现出的概念、理论进行分析,发现新世纪比较教育研究开始关注“全球南方”,对南美洲、亚洲、非洲的教育研究开始增多,对欧洲的研究数量略有降低。比较教育对人类社会的发展保持着深切的关注,“全球南方”与“全球北方”被重新概念化;国际组织出现了新的治理形式,并参与到未来建构中;全球化与本土化在理论对话中有了新的内涵与关系;作为教育现象与社会现象的学习在话语上迎合了不同国家的发展需求;而比较教育中的隐喻和流动的身份为知识生产和实践提供了另一种视角;比较教育研究方法也有了进一步的争鸣与发展,这些均有助于比较教育完善自我,为人类发展贡献更多的智慧。

不同液化判别方法在下辽河地区的对比分析

结合海城地震液化资料,选取四种具有代表性的液化判别方法,通过判别结果与地震液化资料的对比分析,得出各种判别方法的优劣。四种方法可归纳为利用规范和室内实验两大类。结果表明:规范方法,判定结果的准确率为42.8%;调整的规范方法,准确率为88%;室内实验的输入正弦波方法,准确率为88%;室内实验的地震波法,准确率为77%。规范方法优点方便快捷,缺点是利用规范提供参数准确率有限;室内实验方法优点是物理原理清楚,缺点是需要进行土层地震反应计算。由此说明,利用规范方法,并适当调整参数,可以有效提高液化判定准确率。

构造法在比大小中的应用探索

构造法是一种重要的比较数与式大小的方法。常见的构造法包括构造图形与构造函数及不等式。用举例的方式分别介绍了常见的几种方法,重点是构造函数法。构造函数法又分利用同构式构建函数、利用等价关系比较大小、利用差商式构建函数、常值换元构造函数、根据凹凸性构造函数、利用不等式特点构建函数等方法。