1980 volumne 1卷 Issue 01
Ding Ziqiang
Abstract: In this paper, various factors affecting the resistance moment plasticity coefficient of reinforced concrete members section are described, the regulations on the plasticity coefficient are introduced, the calculation formula of the resistance moment plasticity coefficient of hydraulic reinforced concrete members section is derived, the value of the common section plasticity coefficient is proposed, and the height correction coefficient of the plasticity coefficient is given on the basis of the analysis of the test data.
Abstract: This paper introduces a differential transformer inductance dynamic micrometer with high accuracy, good stability, convenient manufacture and installation as a test method to study linear thermal expansion and thermal deformation of sand under high temperature.A simple device for studying high temperature compressive strength and thermal deformation of molding sand with hydraulic universal strength tester is also introduced.The thermal expansion and deformation characteristics of quartz feldspar sand are studied by the above instruments.Effect of different compactness, different amount of pulverized coal and wood chips on thermal expansion and thermal deformation.By comparing a series of test curves, the favorable conditions of quartz-feldspar sand to reduce the sand trapping tendency of castings are analyzed.It provides a further theoretical basis for the full exploitation and utilization of quartz-feldspar sand in Henan Province.Finally, the production of various types of high-quality cast iron by quartz-feldspar sand in some factories in recent years is introduced.
Abstract: Yu County belongs to the Xuchang region of Henan Province, located 80 kilometers southwest of the capital city of Zhengzhou.It is known as Junzhou and Yuzhou in ancient times and has a long history.Shenli Town in Chengguan West Mountain area of Yu County is the origin of Jun porcelain, one of the five famous porcelain in Song Dynasty.In order to meet the needs of receiving people from all over the world to live friendly, professional inspection and developing China’s tourism industry, a tourism building - Yu County Hotel was built in Yu County city Pass with investment from the provincial tourism department.After initial use, domestic and foreign tourists have responded well.The architectural design is summarized below for your criticism.In the design, we follow the party’s "application, economy, pay attention to beauty under possible conditions" principle, starting from the actual specific situation of the level of county-level foreign affairs reception, focusing on the following points:
Sun Tiande
Abstract: <正> 步进电机既能控制转速又能直接控制机械位置,是一种新型的特种电机。它的定子由几相绕组构成。各相绕组按一定顺序通电和断电,才能使它旋转。在控制系统中,要求步进电机受脉冲信号控制。每来一个控制脉冲,步进电机走一步,其转子转过一个步距角。实现用脉冲信号控制步进电机转动的电路,称为步进电机驱动器。驱动器一般分为环形分配器、驱动信号电路和主回路三部分。我们先介绍环形分配器的设计方法。
Wang Zhongtai
Abstract: Shock wave phenomenon The spillway of a reservoir is controlled by a five-hole gate.The gate chamber is 50 meters wide, and the gate hole (with parapet wall) is 10 meters high and 8 meters wide.The pier is 2.5 meters thick and the gate is a curved gate.Behind the gate is a trapezoidal section channel (about 300 meters long) followed by a run-off nose.The bottom slope of the original design channel was horizontal and the surface was lined with concrete.The slopes are 1:1.5 and 1:2.As shown in Figure 1.
Walker Gang
Abstract: Due to the production needs of the chemical plant of the chemical engineering department of our hospital, we hope to try to wash the crude chloroform containing a small amount of ethanol, so as to obtain industrial chloroform, and then provide production use: To this end, we must first obtain the liquid phase equilibrium relationship of this ternary system, and then further use the characteristics of low boiling point azeotrope to purify.Considering that the volume measurement is more convenient than the weight measurement in the industrial liquid material measurement, the volume percentage relationship is adopted in the experiment and the phase diagram is drawn.By referring to the weight composition of azeotrope, the volume percentage composition of azeotrope is also sought. Finally, the measure of how to extract and wash to obtain industrial chloroform is proposed by using the obtained phase diagram.
Jin Haijun
Abstract: For a long time, in some "general chemistry" or "Inorganic Chemistry" textbooks at home and abroad, there are two contradictory situations in the description of the order of the activity (also called "activeness") of sodium and calcium two metals, which is often one of the problems that students encounter in the process of learning this course, and it is necessary to discuss and solve.For example, when describing the chemical properties of metals in the previous high school Chemistry section (1), "...The more easily an atom of a metallic element loses electrons, the more chemically active it is.On the contrary, the less active it is.In fact, various metal atoms, due to their different structures, need to consume different amounts of energy when they lose electrons.Therefore, there is indeed a significant difference in the activity of metals.The order of activity of metals discovered by Bechtov (published in 1865 - author’s note) is related to the ease with which metals lose electrons.The order of metal activity is shown in Table 1:
Copyright © 2023 Editorial Board of Journal of Zhengzhou University (Engineering Science)