Based on elastoplastic mechanics and in accordance with defferential equation of stress equilibrium and coulomb criterion, the width of stress limit equilibrium zone of retained strip coal pillars is derived, and the width of yield regions of strip coal pillars is obtained using a complex functions model of theory of elasticity, deriving various theoretical formulas, which have proved to be able to meet the needs of practical projects.

The increasing production effects of N-P are also different at each location. 1 kg pure N can increase production 2 to 10 kg in higher basic yield regions and 17 to 24 kg in lower ones.

2. Based on the the FLAC-3D method, stability analysis is carried out for the underground caverns of Goupitan hydropower station, which imitate the construction process. At the same time, the deformation, the stress and the distribution of the yield regions are evaluated.

This paper uses principal component analysis and the ward's cluster method of squared euclielian distances of standard data to svaluate fertility grade synthetically for the 12 fertility indexes of 158 paddy soils from medium-low yield regions at Fujian.

The optimum comprehensive practices for high yield of the hybrid were, density of about 3500 plants, about 11.0 KG Navailable and about 5.0 KG P_2O_5 available per mu in the centre of the Sichuan Basin and around and in the high yield regions of the east, and density of 2813—3271 plants, 9.6—11.6 KG N available and 3.2—5.2 KG P_2O_5 available per mu in the lower yield regions of the east.

This paper outlines the situation of agricultural production situation in Chongqing Municipanity as well as the thinks and measures for stabilizing the rice planting area,improving the productive condition of the middle and low yield regions.

The result shows that the length of the plastic yield regions is not much affected by bonding, though its effect on the relative displacement between the lips of the yield regions is remarkable.

While degrees of relative homogeneity are apparent at many scales, the map was designed at a scale that would yield regions with sufficient homogeneity to be useful for lake management throughout the area.

Further it may be applied to other mechanical behaviour such as creep in the yield and post-yield regions and also the second order transition temperature that has been observed in stretched wool fibres in water.

This rising inequality can also be found where earlier low-yield regions are catching up because of improved technology.

Other high water yield regions are coastal Louisiana and Alabama and the Ouachita Mountains.

Based on both the calculating formula for J-integral determined by means of TPB type specimen and the experimental evidence of da/dN=C_1(ΔJ)~r ,an expression of subcritical fatigue crack growth rate characterized by AJ from TPB specimen from the linear elastic to complete yielding region has been derived as follows: For high-cycle fatigue crack, its approximate growth rate will be which seems to be identical with the Paris' relation. For high-stain fatigue crack, it may be which is analogous to the Coffin-Manson's...

Based on both the calculating formula for J-integral determined by means of TPB type specimen and the experimental evidence of da/dN=C_1(ΔJ)~r ,an expression of subcritical fatigue crack growth rate characterized by AJ from TPB specimen from the linear elastic to complete yielding region has been derived as follows: For high-cycle fatigue crack, its approximate growth rate will be which seems to be identical with the Paris' relation. For high-stain fatigue crack, it may be which is analogous to the Coffin-Manson's relation.

The purpose of this paper is to improve some of techniques in designing a piston cylinder, ultra-high pressure vessel.First it introduces the elastoplastic analysis of the twofold cylinder which has been autofretted after shrink on and presents the formulae of autofrettage pressure and its cha- racteristic values. Then it derives the formulae of stress distribution in different regions and the formulae of displacements and strains in the yield region. In addition it proposes the approximate calculation...

The purpose of this paper is to improve some of techniques in designing a piston cylinder, ultra-high pressure vessel.First it introduces the elastoplastic analysis of the twofold cylinder which has been autofretted after shrink on and presents the formulae of autofrettage pressure and its cha- racteristic values. Then it derives the formulae of stress distribution in different regions and the formulae of displacements and strains in the yield region. In addition it proposes the approximate calculation methods of fracture analyses.Based on the results, the strength and fracture analyses have been made for the vessel. In analysing, two cases have been considered: autofrettage after shrink on and shrink on after autofrettage. Adopted are: 1) the material used is perfectly elastoplastic and 2) the axial stress is independent of the coordinate, r.

Having been analysed the present situation about the grain production and supply as well as the major factors influencing the steady increase of grain production in Sichuan, the responding countermeasures are proposed in this paper. In the near future, must give more effective leadership to the grain production, stabilize the planting area of grain crops, build the bases of commodity grain better and make grain yields in the middle and low-yield regions increasing much more, increase the input into agriculture,...

Having been analysed the present situation about the grain production and supply as well as the major factors influencing the steady increase of grain production in Sichuan, the responding countermeasures are proposed in this paper. In the near future, must give more effective leadership to the grain production, stabilize the planting area of grain crops, build the bases of commodity grain better and make grain yields in the middle and low-yield regions increasing much more, increase the input into agriculture, perfect the systems for popularizing agricultural techniques, strenghthen the scientific research of grain, perfect the system of purchasing grain according to contract. From a long-term point of view, should take three countermeasures, that are establising a reasonable price system in rural economy, gradually forming a scale of moderate degree in grain production and strenghthening the agricultural scientific research strate-gically.