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1.
The rolling cone enveloping hourglass worm pair has been successfully developed, in which there is almost only rolling friction between the meshing tooth surfaces, and both the worm and wormwheel have hard surfaces. Such a new type of hourglass worm pair is particularly-favorable for power transmission. This paper presents the design. manufacting and testing of this worm pair.  相似文献   

2.
THis Paper derscribes a novel all-fiber compensation network with three access-couplers for improving the stability of amplitude modulated fiber optical sensors. and its optimumstructure which is indepent on environment effects. We also describe the sealing method of the com-pensation network and the experiment of its coupler parameter variation caused by tempertare andvibration. The expreiment results showed that the compe nsation network can effectivelv resist themeasurement error affected by the in tensity variation of the optieal souce and other transmission loss.  相似文献   

3.
This paper presents a reactive power optimization method which combines thelinear programming model with secure correction. In correction. this mOdel presents a new idea inwhich the feasible control region of con trol variables is resolved by over constrained state varlables. This method is quick and reliable and overcomes oscillation of a general linear programming model.  相似文献   

4.
The feasible control problem is presented for the day-operation of the Three-Gorge Caseade Hydropower Station. The significance of the problem is explained. Basic propetties ofthe problem and the approaches to study it are discussed. Two methfods are given for solving theproblem. which are calculus of variation and linear programming. In the former. the Euler equationwith time-lag and the generalised two-point boundary conditions are obtained and the correspondingpractical implication is interpreted. In the latter. the rationality for the discrete model is exptainedand the computalional details are given for the implement software. some questions which should bepaid much attentfon and the corresponding propeels are prasented based on the numerical results andtheoretical analysis  相似文献   

5.
The basic equations of wall plates of MAN' S dry gas holders are derived in this paper. According to the law of cylindrical bending given by the finite element results .we derive some approximate formula calculating the deflection and stresses of the wall plates from the basic equations. Compared with the known approximate calculating method.the method car. obviously increase the percision.  相似文献   

6.
In order to investigate the influence of concrete strength,horlzontal and verticalportions of anchorage length and cover thickness etc,upon the mechanical performance of 90-degreehooks of beam upper bars in exterior joints,static experiments of 40 beam- column subassemblagesare carried out. This study emphasizes the damage characteristics of the anchorage zone,measures thestrains of the bars along the anchorage length and analyzes the special anchorage mechanism of suchhooks of beam bars.  相似文献   

7.
The behavior of soft tissues of human musculoskeletal system can be describedwith the biphasic model based on a continuum theory of mktures. This paper. using Galerkin weight-ed residual method.obtains a mixed finite element formulation for the linear biphasic model of smalldeformation. and. in turn. gives out the iterative scheme solving the system equations. The results ofnumerical analysis for the constrained compression problem are consistent with those obtained bytheory. which illustrates the correctnas and feasibility of the derived mixed finite element formula-tion. concludingly. this formulation provides an effective means of numerical analysis for the motfonmechanism of human articulating joints.  相似文献   

8.
A probabilistic production costing method for multistates and multiblocks of units is presented in this paper. The mixtures of normal distributions are used to represent the power of the system and the load. The energy, reliability and production costs are calculated directly from the analytical formulae. Numeral examples demonstrate that the algorithm presented in the paper is accurate and efficient.  相似文献   

9.
considering the Combination of several typical rotor unbalance conditions andpossible arrangments of magnet damper. rotor unbalance vibration of a large BBC turbine-genera-tor set has been analyzed by finite element method. Lincar simplification of dynamical characteris-tics of journal bearing and magnet damper was taken into account in the analysis.Numerical resultsshow that the optimum vibration control effect could be achieved when the damper located at middlepressure stage.  相似文献   

10.
阴、阳生木芙蓉气体交换参数对光温的响应   总被引:1,自引:1,他引:0  
本文以木芙蓉为实验材料,研究阴、阳生木芙蓉气体交换参数对光、温的响应。测定了不同光温条件下,阴、阳生木芙蓉光合速率(Pn)、蒸腾速率(E)、胞间CO2浓度(Ci)、气孔导度(Gs)。结果表明,随着光强和温度的升高,阴、阳生木芙蓉的净光合速率、蒸腾速率逐渐升高,而胞间CO2浓度随光强和温度的的递增而递减;气孔导度随温度的的递增而递减,随光强的递增而递增。阳生木芙蓉的光合生理表现优于阴生木芙蓉。本研究结果发现木芙蓉更适于在阳生环境下栽培,为木芙蓉的园林绿化提供技术参考。  相似文献   

11.
12.
A kind of synthetical control algorithms is presented in this paper.The controlstratege achieved by com bination cloed-lcop pole assignment and modified Smith predictor as wellas self-tuning control is useful to reailze extensive adapability and satisfactory prformence-robust-ness. Digital simulation experiment demonstrated the availability.  相似文献   

13.
Some results are presen ted which related fault-tolerance degrees of a multibussystem with the con nectivity of the bipartite graph induced by the system. Using the best con nectivi-ty bipartitegraph. we also present two classes of multibus systems which have the best degree of busfault tolerance and the best degree of bus-processor fault toferance as well as better degree of proces-sor fault tolerance.  相似文献   

14.
A set of coal samples are characterized by FT-i.r. spectroscopy, and the assignment of the frequencies observed in coal spectra is analysed and discussed in delail in this paper. At the same time, the law of the variation of the groups in the macromolecule of coal with the increase in the rank of coal is researched.  相似文献   

15.
The dynamic behaviour of a new reinforced concerte hollow plate using the medium strength(800 MPa yield strength)ribbed bar as prestressed wire has been studied experimentaly under various concentrated impact loads.The test results on the inherent characteristics,frequency,damping,dynamic rigidity etc.are presented.Meanwhile the important points in respect to the strength,deformation,cracking under impact loads and earthquake response of plate have discussed.  相似文献   

16.
在人工控制条件下研究了在15小时长光照下减数分裂期的不同温度(23.3~30.3℃)对籼稻光敏不育系W6154S和5460S育性转换的影响。结果表明,温度对育性的影响因温度的高低及处理持续时间长短而异,不同的材料对温度的反应不同。5460S从不育转为可育的临界温度在26.4℃左右,而W6154S在处理温度范围内均出现自交结实现象,表明供试的W6154S株系育性转换的临界温度可能超过30.3℃。提出了深入研究影响籼稻光敏不育系育性转换的临界温度的建议。  相似文献   

17.
光敏核不育水稻的光温反应研究   总被引:9,自引:1,他引:9  
在人工控制条件下研究了在15小时长光照下减数分裂期的不同温度(23.3-30.3℃)对籼稻光敏不育系W6154S和5460S育性转换的影响。结果表明,温度对育性的影响因温度的高低及处理持续时间长短而异,不同的材料对温度的反应不同。5460S从不育的临界温度在26.4℃左右,而W6154S在处理温度范围内均出现自交结实现象,表明供试的W61  相似文献   

18.
An A. C. load flow analysis of the reliability evaluation of composite generation and transmission systems is presented on the basis of a fast outage simulation algorithm and an optimal model of active and reactive power adjustment after outage contingencies. The information of the first -level outage events is utilized for simulating higher -level outage events in the fast outage simulation algorithm ; the optimal model is satisfactory in speed and accuracy with the application of concentric relaxation and linear increment constraint on the comprehensive adjustment of active and reactive power. As an example. the IEEE Reliability Test System is tested and the results show that the method is accurate and well-matched in speed with the method studied by R. Bllinton, et al.  相似文献   

19.
Based on the analysis of chloride ion-induced erosion mechanism of reinforced concrete and the Fick’s second law, a multi-factor model of the chloride ion erosion is established. In this model, the influences of water-cement ratio, humidity, time, temperature, and chloride ion binding capacity of concrete are taken into consideration, and the mathematic solution to the new model is provided by considering the boundary conditions. The new model is verified by analyzing the long-term exposed experiment data. Compared with the traditional model of Fick's second law, the model can indicate the development trend of the structure eroded by chloride and the chloride ion concentration in different depth, and at the same time, it can predicate the chlorine ion concentration on rebar surface in different corrosion periods and the initiation corrosion time of reinforcement.  相似文献   

20.
Mixed mode fracture in rock subjected to compressive loading has many differ-ent features in fracture hehaviour from those subjected to tensile loading,especially when the aper-ture is partly or fully closed.The traditional theory of elastic fracttire mechanics can not be used tosolove compressive-shear fracture problem. Based on fracture characteristics of rock under compres-sion,the formulas to calculate stress intensity factor are updated so that the new strength criterion isevolved to evaluate the crack initiation streilgth.The stress distribution and the relative displacementof crack surface in central slit is confirmed by FEM analysis.  相似文献   

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