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1.
Professor Venzo de Sabbata,working at World Laboratory,Lausanne,Switzerland,and Department of Physics,University of Bologna and Ferrara,Italy,is a famous Italy Physicist in the world.He is engaged with a series of creating research works about gravity quantization of General Relativity Theory in the real space-time which attract the attentions of the world.This paper pays the attention to introduce the works of this field,containing mainly:1.quantizing the general relativity theory in the sense of Einstem-Cartan theory,i.e., general relativity adds the torsion,which means introducing spin into the theory of gravity.2. building a compact mathematical tool for research of gravity quantization,the geometric algebra in the real space-time--multivector algebra,i.e.,developing a spinor manifold in the real space-time.  相似文献   

2.
Sandstone is sediment rock composed of many cemented sand particles, and corresponding particle constraint and force bearing capacity are greatly controlled by the cemented property. In order to better reflect the cemented property influencing on the mechanical characteristics of the sandstone, take the oil sandstone reservoir for instance, a numerical model based on 3Dimensional Particle Flow Code (PFC3D) considering the parallel bond model was brought forward to simulate the failure mechanism during shearing process. The sandstone cemented property is modeled based on random mathematics and advanced development of Particle Flow Code (PFC), and the relation of the stress ratio, volume strain, coordination number and bond-broken number and the axial strain is analyzed in detail, especially the contact network evolution indicated the force chain is important to transfer the external force, which verifies the feasibility of the numerical model. Based on the above PFC3D model, a series of researches on changing the cemented radius ratio, parallel bond stiffness and cemented volume of the particles have been done to clearly illuminate the importance of cemented property for the bearing capacity of the sandstone structure, which provides a scientific base for research on the failure mechanism of the sandstone under special conditions. Therefore, the above numerical method is more efficient and applicable for comparatively large scale and complex experiments, and the obtained research results can bring a new thought for the real cemented sandstone to research on its macro-micromechanical response and the structure failure mechanism, and also is significant for the sand production mechanism, sand volume prediction and sand control measures for the sandstone reservoir.  相似文献   

3.
Based on the real size and constrain of the wet clutch, the friction pair of temperature, stress fields coupling model, and the heat convection coefficient model are established. The transient thermal-structural coupling and the thermoelastic instability of the phenomenon of friction discs generated in overload tests are numerically simulated and analyzed with ANSYS/LS-DYNA. Additionally, the distribution of the hot spots in the circle direction and surface of the friction discs are revealed, the distribution of the stress and strain caused by the thermoelastic instability is analyzed and tested. The results show that hot spots and contact pressure are mutual promotion. The thermal expansion and stress concentration caused by temperature gradient lead to steel disc warp. The heat fading caused by the thermoelastic instability leads to steel disc failure.  相似文献   

4.
Through analysis of basic assumptions and limitations of the conventional real estate investment decision method, in this paper, its unconformity to the investment environment, which includes a great number of uncertain elements, is pointed out. By analyzing the real option and the price formula, the pattern of real option in real estate investment decision is put forward and this breaks through the limitations of the conventional investment decision method and makes the decision scientifically and reasonably, moreover, it has some directive significance to investment administration work of real estate corporation.  相似文献   

5.
Although it is not long since the Chinese real estate appraisal agencies appeared in China, they have been developing quickly. With the increase of real estate appraisal portfolio, the number of real estate appraisal agencies in the market also increases. However, because of the loose management in this field, there are many operation that are not standard and not allowed by the operating rules. This paper tackles this problem on the basis of the special relationship between real estate appraisal agencies and banks, analyzes the present situation in this field in detail and puts forward the strategies accordingly.  相似文献   

6.
The yandongkai' s 2-stories "v' shape sequence of natural number is generalized to 2-stories and n-stories "v" shape sequence of real number,and some very interesting properties are given.x  相似文献   

7.
According to the present research status and existing problems of hot continuous billet surface temperature non contact measurement technology, a real time temperature measurement model, which combines two-color(R,G) and monochrome (B) of surface radiation image, is established. The surface image is collected through tricolor charge coupled device (CCD) sensor, at the same time, the temperature dynamic response range of CCD can be improved by controlling integrated time and setting different apertures. Through computer image process technology, multi-point temperature can be measured simultaneously, and 2-D temperature field distribution on continuous casting billet surface can be realized. It is be proved by theory and application that the model and method can provide a theory and technology support for realizing surface temperature field on-line measurement for continuous casting billet.  相似文献   

8.
Complex wavelet transform can characterize the partial feature of the PD signal in time-domain and frequency-domain,and provides the unique phasic information.In this paper,the PD pulse waveforms which are created by 4 typical insulated defects are transformed by complex wavelet,and then the complex wavelet coefficient's real part,imaginary part and compound coefficient are clustered by the Fuzzy c-means,the energy of the cluster is the feature of pattern recognition.Discharge samples are got through large number of experiments,and BPNN can identify the PD created by 4 typical insulated defects effectively.The results show that the feature extracted from compound coefficient is better than the feature extracted form the real part and imaginary part of complex wavelet coefficient or wavelet coefficient.  相似文献   

9.
Aiming at real time diagnostic knowledge accumulation and updating in intelligent diagnostic system, to simulate the process experts accumulate and update fault diagnostic knowledge, a new real time diagnostic knowledge self learning model is proposed based on pattern comparing and updating. Abnormal distribution test of hypothesis is used to compare real time equipment fault pattern to equipment normal pattern of contingent knowledge. The algorithm of sample size estimation algorithm is used to calculate the number of samples which is used to obtain necessary diagnostic efficiency. Real time model updating algorithm is used to adjust the diagnostic knowledge model to actual equipment on the spot. Analysis to actual test data of equipment shows that the method could achieve new diagnostic knowledge accumulation and be adaptive to actual equipment on the spot.  相似文献   

10.
B. Yu. Anoshenko 《Euphytica》1996,90(2):149-162
Summary Presented are the results of an application of the local adjustment Field-method in the analysis of the real field experiments without replications and in experiments with pseudo- and random replications. It was found that the local adjustment allowed a more precise estimation of the real values of genotypes in all kinds of experiments over a wide interval of spatial heterogeneity. The results obtained indicate that by simply using up to 5 random replications the decrease of the spatial effects is inadequate for fields with medium and high soil heterogeneity or with unsuccessful randomization. The Field-method which has sufficient precision in evaluating spatial heterogeneity, considerably increases the reliability of estimates in experiments even with a small number of replications or with unsuccessful randomization. Therefore, for all field experiments that have fulfilled the necessary requirements the Field-method is recommended as an obligatory statistical procedure for a prior data analysis as it allows an accurate estimation of the real character expression of genotypes, as well as the random variance in experiments without replication and the parameters of ANOVA in ones with pseudo- and random replications.  相似文献   

11.
The causal relationships between poverty in female-headed households with minor children and Aid to Families with Dependent Children (AFDC) transfer payments for the period from 1959 to 1988 were examined by means of the Granger causality test. This study found weak statistical evidence that receipt of AFDC “causes” poverty, but strong statistical evidence that the number of poor female-headed households with minor children is a “cause” of the number of recipients of AFDC, and that an increase in the real dollar amount of AFDC per recipient family “causes“ a reduction in the poverty rate of female-headed households with minor children.  相似文献   

12.
为了进一步探究高产杂交水稻新品种‘协优385’的高产潜力和高产途径,利用相关区域试验和生产试验资料,对高产品种‘协优385’全生育期、株高、有效穗、穗长、穗粒数、实粒数、结实率、千粒重、产量等性状进行了相关性分析和通径分析。相关性分析结果表明:与杂交水稻新品种‘协优385’产量相关性最大的因子是实粒数,r=0.53达到了显著水平;另外,穗粒数与实粒数相关系数r=0.77达到极显著水平。通径分析表明:有效穗和实粒数对产量的直接作用较大。因此,在新品种‘协优385’推广应用以及高产创建时要做到氮肥适当后移,倒三叶时增施粒肥,注重灌浆期水肥管理,以提高结实率进而增加穗粒数为实现高产奠定基础。  相似文献   

13.
遗传多样性是植物育种的基础,但“遗传侵蚀”现象十分严重。以长期技术供给为主要任务而形成的自上而下的农业研究和推广与需求相脱节,它在新的农村经济社会条件下已不适应。通过对广西玉米育种机构研究人员、科研管理人员及县、乡(镇)、村有关指导农业生产的管理干部和技术员进行访谈,对玉米种植的社区农户进行了深入的调查。运用系统科学的方法对广西玉米遗传多样性降低的影响因素进行分析得出结论和对策,同时通过《玉米种质遗传多样性与农民参与式育种研究》项目在广西实施为案例,进行调查和分析,以促进新的研究理念的形成。  相似文献   

14.
A pipelined FFT processor designed for fast and real-time requirements with FPGA is introduced. This FFT processor can be used to real-time frequency analysis and its working frequency can reach to 75 MHz. The leakage error is reduced through multiply the sampled signal by a weighting window. In order to improve FFT's working frequency and economize FPGA resources, an algorithm of 1024-point complex to compute 2048-point real data is adopted. In addition, an approximate algorithm to compute module value of complex number is introduced.  相似文献   

15.
This paper proposed a fuzzy optimal model of rock classification, according to a number of controlling factors of rock classification. Satisfactory results are obtained by applying the model to the real rock mass classification.  相似文献   

16.
The contact analysis on the double enveloping hourglass worm gearing is very important to control its efficient contact zone and contact quality. Nevertheless, current meshing analysis under the rigid condition cannot really reflect its tooth-surface contact. In this paper, the contact Finite Element Method is used to analyze the tooth contact of double enveloping hourglass worm gearing under the manufacturing error and the elastic deformation caused by the load. The load sharing among the contact tooth pairs and variations of contact zone are investigated. As compared with the result of rigid analysis, the contact zone is obviously shifted. This analysis method can provide a base for the conjugating control of the double enveloping hourglass worm gearing.  相似文献   

17.
With the influence of the different gas Reynolds number and liquid Reynolds number on falling film heat and mass transfer of subway station plate evaporative cooler, the experiment was carried out by non contact infrared thermal imaging technology under gas liquid cross flow condition. The results indicated that during the increasing of liquid Reynolds number the thickness of liquid film increased and the temperature difference between liquid film inlet and outlet decreased in determined heating water temperature which weakened the heat transfer of liquid film. However, the increase of liquid Reynolds number strengthened the liquid film turbulence that enhanced heat transfer. Under the synergistic effect of these two factors, there was an optimal liquid Reynolds number which minimize thermal resistance and maximize heat and mass transfer coefficient of liquid film.  相似文献   

18.
As metal Belt CVT(Continuously Variable Trans mission) acts as a kind of friction transmission, friction coefficient is a key parameter of CVT. The friction characters of CVTF(Continuously Variable Transmission Fluid) are mainly determined by fluid and contact state. The contact between belt and pulley can be regarded as a kind of contact between cylinder and cone. As their contact line is short, the curvature change of pulley along the contact line can be neglected. Then the contact problem of belt and pulley was reasonably simplified as a contact between cylinder and cylinder. Under the state of equivalent maximum stress, the contact friction condition of metal belt and pulley was simulated by the contact of ring and block in Timken Friction Test Machine.  相似文献   

19.
Hydraulic system pressure, contact surface between grinding roller and materials and grinding roller force of roller mill are analyzed. A new roller pressure calculation method named average surface roller pressure calculation method is proposed,and the corresponding theoretical formula is derived from three different perspectives, including roller pressure numerical calculation, stress and strain of main components and mill power through the calculation of real samples. The average surface roller and traditional average material roller pressure are compared to verify the correctness and accuracy of the proposed method. Design parameters such as the grinding roller structure, material maximum size, layer height and working pressure of the hydraulic system on the influence of roller are analyzed according to the formula of roller pressure. The research results provide theoretical basis for the selection of design parameters and the design calculation of structural strength for roller mill.  相似文献   

20.
Contact temperature is one important working proprieties of friction pairs,there are no study on the contact temperature fields of rough surface contact at present.The methods of calculating the contact temperature fields are presented.On the basis of taking rough surface and debris effects into account,the temperature fields of sliding friction pairs are calculated.And the effect of temperature on the sliding friction pairs scuffing proprieties is discussed.The result shows that there are obvious enbance of the contact temperature comparing the smooth surface contact to the rough surface contact.If the coefficient of rough influence equal 0.1 and 0.5,the contact temperature will enhance by 14% and 103%.The contact temperature will enhance once again if the debris embed in the surface.If the material of the friction pairs is 45 # steel,Supposing the surface film has been destroyed,the temperature of debris embed point will come to the material welding temperature.  相似文献   

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