Self-balance Principles and Formulae for Axle-linked Cable-car

Even if pulled by single wire rope, the axle-linked cable-car can under some conditions automatically balance the eccentric moment caused by the carried loads. This paper expounds the self-balance principles of the four-wheel axle-linked cable car, deduces the associated formulae and analyzes the conditions for its application, laying a theoretic foundation for the design of transverse container cable car.     

APPROXIMATION OF INVOLUTE PROFILE BY PEACH-SHAPED RING SECTION

By using the least pth min-max method, we find the best approximation of involute ptofile by peach-shaped ring section. The error of approximation is less than that of [ 1 ] and [2]. Thus we provide a new direction for dressing of a wheel for involute gear forming-grinding. In order to simplify calculation, we define the error function according to implicit equation of curve and as a result its rationalization is proved.     

APPROXIMATION OF INVOLUTE PROFILE BY MOON-SHAPED RING SECTION

In this paper,we study the approximation of involute profile by moor-shaped ring section. By using the minimax method, we find parameter of the best approximation moon-shaped ring section of invelute piofile. The error of approximation is 35% - 70% that of [1] and [2]. Thus the approximation precision of dressing a wheel for involute gear forming-grinding by approximating method has been greatly improved. In order to simplify calculation, the error function is defined according to the implicit equation of curve and its rationalization is proved.     

Improved Least Square Method for the Consolidation Coefficient Evaluation

At present, the logarithm of time and the square root of time methods are usually used to compute consolidation coefficient, from which only a few data were adopted for the consolidation coefficient. At the same time, the two solutions depend on the initial value from the curves and influenced the exactitude of consolidation coefficient directly. So, in this paper, an improved least square method is supposed to compute the consolidation coefficient with testing data. According to the derived formulae, a program is used to compute consolidation coefficient based on Matlab language and to eliminate human error. The computation results show a good effect and give a reduction of errors.     

The Mechanical Behaviors of Prestressed and Non-Prestressed Steel Rebars under High Temperature

In this paper ,21 pieces of ribbed rebar 16 in diameter,45 pieces of smooth circle rebar 12 and 8 in diameter and 24 pieces of high strength carbon steel wire s5 in diameter are tested on mechanical behaviors under high temperature.The laws of variation of mechanical behaviors with the temperature are investigated for prestressed steel and non_prestressed steel.The conclusions obtained in this paper are significant for research of the loading capacity of reinforced concrete members under the condition of fire catastrophe.     

Study on Dressing and Grinding Characteristics of Vitrified Bonded CBN Wheels

This paper describes the dressing principle and its grinding characteristics of vitrified bonded CBN wheels trued by cup truer.Analyzing experiment data of grinding workpiece,the influence factor on wear of CBN wheel has been obtained,which wear of CBN abrasives and chippings adhered is the main resons in grinding hard steel,and surface abrasives melted is the major factors in grinding soft steel.     

Rise Time Measurement System of Steep Pulse Based on Frequency Difference Multiply Technology

To accurately measure the ascendant time of a high-voltage steep pulse, the pace and precision of counter is highly challenged. The authors put forward the design of high-speed count system based on CPLD and DSP. In this system, the outer crystal oscillator of CPLD act as low-frequency clock whose frequency division and phase invertion are done by D-trigger group designed with CPLD, and finally,they get the counter with 200 MHz i. e. 5ns per period by the method of frequency difference multiply. The counting pace and precision are promoted, and meet the demand to measure the ascendant time of high-voltage steep pulse. It can be extended to measure the descendant time of pulse, pulse width and periods.     

The Development of Dynamic Measuring Instrument for Checking Lead Errors of Ball Screws of Steering Mechanism

A new type of measuring instrument which is used to measure lead errors of ballscrews has been developed. The principle of the inStrument,the system strucrure,the computer inter-face. The analyses of the instrument error and the experimental results are presented, The principleof comparing synchronous displacement is used to achieve absolute measurement. The errors correc-tion technique is adopted to correct the errors of the instrument so that the high measuring accuracycan be botained.     

索承式桥梁吊索钢丝腐蚀疲劳寿命评估

根据吊索镀锌钢丝腐蚀疲劳破坏特点,把镀锌钢丝腐蚀疲劳纹形成和扩展过程分解成镀锌层腐蚀失效、蚀坑萌生、蚀坑形成、短裂纹扩展、长裂纹扩展和断裂破坏等阶段,建立各阶段时间表达式,得到镀锌钢丝疲劳寿命表达式,提出基于断裂力学的吊索钢丝腐蚀疲劳寿命评估研究结果方法。通过算例分析复杂运营条件下腐蚀环境和应力幅等因素对吊索钢丝腐蚀疲劳寿命的影响,研究结果表明：吊索钢丝腐蚀疲劳寿命主要由钢丝镀锌层腐蚀、蚀坑发展和短裂纹扩展等3个阶段组成,为了准确地评估吊索腐蚀疲劳寿命,需要掌握大桥的运营环境和交通荷载。     

Selection in Early Generations of Dried Peas, Pisum sativum L. II. Significance of the Environment of Selection

In early generations peas arc frequently grown widely-spaced against wire netting under growing conditions considerably different from the commercial cultivation practice of dense stands. In 1985 and 1986, five morphologically different pea varieties were grown both widely-spaced against wire and in dense stand in plots. In the plot stands no methods to prevent the peas from lodging were used. Grain yield and yield-related traits were recorded in both environments of selection, i.e. ‘wire netting’ and ‘plot stand’. Data were analyzed with respect to the suitibility of the environment ‘wire netting’ for selection for grain yield to be realized in commercial stands of the crop. Against wire, the grain yield, number of podded lateral branches, number of podded nodes/main stem, and the profile of grain yield/node on the main stem were the most responsive characters as compared to the standard plot with a dense stand. The relative increase differed between genotypes, which was also indicated by highly significant genotype × environment interactions. Only small changes consistent over genotypes were observed for thousand grain weight (slightly lower), number of seeds/pod (slightly increased) and grain yield/pod (slightly higher). Against wire, the expression of varietal variation was higher for most characters. In addition, single plant error was lower, so that at the wire heritability values based on individual plants were larger than in the plots. The significance of the present results and the effects of competition on selection in early generations in dried peas are discussed.     

水产养殖水质监测温度补偿系统

水产养殖水质的准确监测对保证水产品健康养殖至关重要,为了克服温度对溶解氧传感器、pH传感器的影响,重点对二者进行了温度补偿研究,采用三次多项式拟合法对溶解氧电极进行了温度补偿分析,采用最小二乘法对不同温度段的电压与pH 关系进行了线性分析,最后得出两者的温度补偿模型。试验结果表明,该温度补偿系统所测得溶解氧与pH平均相对误差分别为1.82%和1.72%,实现了对水产养殖水质因子的准确监测,对现代水产养殖业水质监测具有良好的应用前景。     

A comparison between 55CrSiA and JIS G3566-77 Oil Tempered Spring Steel Wires

The qualities of 55CrSiA oil tempered spring steel wire and not as good as that of JIS G3566-77. This conclusion resulted from the comparative tests which were for the valve springs of FM147 Engine being seperately made of the two kinds of spring steel wires mentioned above acording to the same processing and test methods.     

用于齿面扭曲消减的齿向修形曲线设计方法

针对蜗杆砂轮磨消减齿面扭曲时存在成本高、效率低等问题,探讨在设计阶段消减齿面扭曲的途径。首先,基于蜗杆砂轮磨齿时的接触迹分析,给出了一种齿面扭曲的计算方法,分析了鼓形量及螺旋角对扭曲量的影响;其次,提出一种常用鼓形齿修形曲线的改进设计方法,将修形曲线分成三段,分别计算齿向左右两段各处扭曲量。在满足齿轮设计要求的前提下,通过调整三段曲线的比例因子以及各处的鼓形量,实现齿面扭曲量的消减。计算实例表明,该方法可有效消减齿面扭曲现象,减小齿向修形误差。     

Laboratory similar model test investigation of prestressed anchor rope strengthened slope fractured rock mass

Now in the highway construction of the mountain area, fractured rock mass slope always strengthened by the anchor rope. In order to investigate the strengthen effect of the slope fractured rock mass strengthened by the prestressed anchor rope, laboratory similar model test was designed and preceded. By the self-made facilities, a new method of modeling prestressed anchor rope was used in the test. Nylon ropes and the aluminum flakes were used to model the anchor rope and discrete rock mass joints. Gypsum based mix material was used to model rock. According to the real slope engineering site circumstances, six sorts of different disposed prestressed nylon rope strengthened model specimens and the specimens without prestressed nylon rope were made by the similar theory. With the test results, the strength and deformation properties of different model specimens were investigated. Comparison to different anchor effects of the different model specimens was made. The final analysis shows that in order to make full use of the anchor rope's strengthen ability, anchor rope should be disposed perpendicularly to the fracture structure rock mass's main joint direction and should be placed in the upper or top area of the fractured rock mass slope.     

Automobile anti lock braking system control based on a least squares support vector machine

Using the referenced slip rate and angle acceleration of the wheel as input vectors and the braking pressure as an output vector, an automobile anti lock braking system (ABS) controller based on a least squares support vector machine (LS SVM) was designed. Training the LS SVM controller using the supporting vector, the parameter of the controller was calculated. An anti lock braking system was designed that includes an input layer, a control layer, and an output layer. Using wheel speed as an input, the braking pressure of each wheel was calculated. The pulse width modulation (PWM) method was used to control the braking pressure, and thereby to bring ABS control. An automotive ABS test and control system was constructed. Road tests under different conditions were completed according to international standards. Test results show that an anti lock braking control method based on LS SVM has good braking stability and adaptability. It is an effective new ABS control method.     

Breaking incompatibility of Brassica oleracea L. by steel-brush pollination

Summary A method is described of breaking self-incompatibility in Brussels sprouts by mutilating the stigmata during pollination with a brush of which the hair had been replaced by steel wire. The results are similar to those obtained with bud pollination and the method opens up prospects for practical use.     

Development of a sub-nanosecond steep pulse generatorfor simulating weak PD UHF signal

In need of ultra-high frequency partial discharge location and correction of electrical equipment, we designed a sub-nanosecond steep pulse generator, and constructed the corresponding circuit model through the circuit simulation software Pspice. The influence of the storage capacitor and the supply voltage to the pulse waveform is analyzed. When the storage capacitor is 10 pF and 20pF respectively, the output pulse waveforms have been measured in the conditions of pulse rise time being 0.68 ns and 0.90 ns, pulse width being 0.98 ns and 1.18 ns, pulse peek being 8.72 V and 12.2 V respectively, and partical discharge capacity of charge being 320 pC and 600 pC. The picked multi-pulse singnals are steady with the developped sleeve monopole antenna, the error is less than 70 ps. It can be used for the experimental study of ultra-high frequency partial discharge location and correction of electrical equipment.     

Accurate mathematical models for relief grinding of gear hob cutters

A mathematical model for accurate relief grinding of gear hob cutters along radial directions is presented based on the analysis of grinding geometry. Both the design and manufacturing models of gear hob cutters are carefully derived and presented. By employing the plane envelope theory, the reference contour of the grinding wheel is determined in order to attain the design tool profile precisely. The tooth profile error model after regrinding is also given to confirm the grinding parameters. The model provides accurate solutions for both the tool profile and the sectional contour of the grinding wheel. It is simple and straightforward and can be used to produce high precision hob cutters systematically. Two numerical examples are presented to illustrate the effectiveness of the proposed method. The model computing results indicate that the proposed method is practical, precise and reliable. The method provides valuable reference for the design and machining of hob cutters.     

Design of Reef- blasting Project and Analysis of Regulation Effect for Fuling to Tongluo Canyon Reach in Three Gorges Reservoir Region

After the completion of the Three Gorges project,the navigation conditions of the reservoir region will be improved evidently,which has laid the foundation for straight run of the 10,000-ton-class fleet to Chongqing Port,and is the promotion of the development of shipping in Yangtze River.But according to the standard of the 10,000-ton-class fleet,there are still some reaches of the reservoir region can not meet the requirements of the waterway on smooth and safe navigation.Therefore,some regulation measures should be adopted to eliminate these obstructions.It is one of the important parts in the reservoir region waterway regulation work for the Fuling to Tongluo canyon reach blasting project.30 reef obstacle blocks of 14 reaches in this project were removed by blasting.Based on the analysis of obstruct features of various rocks,according to the standard of the 10,000-ton-class fleet,the design parameters and blasting regulation program were put forward,and the regulation effect is analyzed and forecasted.     

Numerical simulation for the residual stress of U-rib welding onto the flat steel box girder

The flat steel box girder is commonly used for long-span cable-stayed bridges. the structural complexity, construction details and manufactures cause damage to the bridge and the damages seriously grow overtime. The main reason for these damages is that welding technology of flat steel box girder with thin plates and rib elements produces residual stress and strain fields during the welding process, and further more welding cracks commonly appear. In this study, thermal-structural couple methods was adopted to numerically simulate the welding high temperature fields and the stress fields at the joint of U rid and decks of a flat steel box. The welding residual stress distribution was studied as well for further analyzing on the structural damage and strengthening design strategies.