Abstract:

Abstract: This article uses the state space to analyze the inferior parameter structure with the proclaimed element method. The secondary feature value problem of the reciprocating mode is used to the problem of one feature value problem. For the lata of the uncertain parameter in the neighborhood of a certain value, the finite element method using the second -order switch is obtained by a one or two -order switching formula of the status feature vector.

Abstract: Limited partition mixing cannot (referred to as mixed) is one of the effective methods for solving the problem of cracking of complex engineering structures. At present, it is mainly used for crack problems in homogeneous materials. This article will be legally promoted and applied to the interface cracks. It not only expands the legal application range of mixed legal application, but also solves the complex computing problem of interface cracks.

Abstract: This article first discusses the calculation of ordinary concrete beams and axis height and plastic coefficient. Based on this, based on the analysis of the bending performance of steel fiber concrete beams, it proposes a formula for computing formulas of steel fiber concrete beams and shaft heights, rigid cracking moment, and extreme bending momentum.

Abstract: The practical application of the steel concrete combination beam has been expanded from the building to the bridge. This article briefly discusses the design calculation of the static and dynamic (fatigue) loads of the nail connector and the calculation example.

Abstract: The accuracy of conventional physical fatigue test is too low and cannot determine the strength distribution law of the component in a given life. For this reason, this article will apply the lifting method to the physical fatigue test. Select the load as the control factor, and study the distribution rules of the fatigue strength of the 95 links under the life of a given life.

Abstract: This article was tested by the model test of the T -type tube wall thickness cracks and the non -fatigue T -type tube nodes with a model test of the T -type tube node. The performance of the two types of nodes was discussed through comparison.

Abstract: This article uses a pulse one-to-one response technology to determine the dual-dual-zone reactor (DRCB reactor) distribution (RTD) of the single-slot and dual-zone reactor (RTD) with curve-region reactor with Curvic Baffle-Plate. The reactor was determined using the mixing power and mixing time of the two -leaf paddles, and compared with the ordinary file grooves to provide some theoretical basis for the further development and research of the reactor.

Abstract: This article proposes a new method of synthetic chlorine chlorine -70 -70 -70 -70 -70 -70 -70 -70 -70 -70 -70 -chlorine chloride -70 -70 method of the reaction. Under this condition, it takes a short time to synthesize chlorine -70, which greatly improves the speed of chloride response and the production capacity of the reactor. The product color is good.

Abstract: This article discusses the new method of synthesizing L Burrary with NA water glass as raw materials. Use TEM, XRD, and electronic diffraction to determine its structure, and evaluate active evaluation of toluene directional chloride.

Abstract: The author proposes the best way to select the basic unit of the amount of substance -the minimum public multiple method, simple and practical, solve the key issues of the amount of such as the amount of SI and other substances in the analysis of chemical computing, and standardize the analytical chemistry calculation.

Abstract: For the first time, this article proposes the planetary cone interference and curve interference problems of the planetary cone -type transmission, so as to obtain the design guidelines.

Abstract: This article describes the mechanical properties of the cast -to -iron body tough ball iron, and analyzes the impact of the main process factors on the mechanical properties of the ball iron. In the production, MN <0.4 %, P <0.08 %, S <0.04 % of the raw iron; the heavenly furnace melt, use Fesimgbre7 intermediate alloy for ballization; use FESI75 silicon iron to strengthen the breeding technology multiple times. As a result, the Cafe test block and casting of the bottom 25mm, granite 1-3, graphite level 1-3, graphite, graphite, graphite, graphite The size of the ball is 5-7, the ratio of ferrite is more than 80 %, and the mechanical performance reaches the level of ISO400-18.

Abstract: This article detailed the basic concept of "trapezoidal four -fold box martial arts curved surface design". The overall structure is a trapezoidal box, and the stove surface is combined with four trapezoidal combinations. The ratio of trapezoidal waist to the bottom edge is close to 0.618. Calculation of the thickness of the box theory. It provides processing data for the manufacturing process by calculation.

Abstract: The transistor multiplier is a radio technology to obtain a high stability, broadband bias, and high -frequency circuit. The base wave and low harmonic in the multiplier process will severely interfere with the output waveform. This article effectively suppresses the base waves and the low -dimensional harmonic component. Analysis of the harmonic components, input and output circuit matching in the signal, analyzed it.

Abstract: In the audio device, the stability of the tape is directly related to the quality of the sound quality. At present, most of the domestic and foreign recorders use electronic steady speed circuits to ensure the stability of the lead. Therefore, it is necessary to study a simple and practical circuit. It is necessary to improve the stability indicator. This article proposes the simple design calculation method of the steady -speed circuit through a typical example. Level standard (speed error △ n <± 1.5 %, instantaneous shaking rate △ w <0.3 %). The design calculation method proposed for design and maintenance personnel reference.

Abstract: This article studies the relative error treatment of certain indirect measurement results in physical experiments. What kind of treatment method is scientific, and it is scientific, with example analysis and put forward personal views for discussions.

Abstract: Using the non -stable stream flow pump test data and a well -facing diagram of a well, according to the theory of interference pumping, combining the requirements of farmland irrigation, this article proposes a interference diagram solution method to determine the well distance.

Abstract: Urban groundwater is an important source of water for domestic water and industrial and agricultural water. Due to the pollution of urban environment, groundwater pollution has been universal. This article analyzes the types of industrial waste residues and the characteristics of groundwater pollution, and proposes preventive measures.

Abstract: This article studies the existence of non -linearly bi -songs, the existence of the overall solution of the small initial value problem of the parabolic coupling equation group and the gradual nature of T -→+∞ ∞.