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Online since: November 2012
Authors: S.A. Kukushkin, A.V. Osipov
Let us turn to formula (8), which describes the magnitude of the fluctuations of the number of nuclei.
Calculating the number of these nuclei and predicting their future lives is the purpose of the kinetic theory of new phase nucleation.
The quantity i is understood here as the number of structural units of the old phase.
Let the temperature , and (i.e. the pore is semi-spherical and form on the boundary grain).
Rice, et al., Non-equilibrium models for diffusive cavitation of grain interfaces, Acta Met. 27 (1979) 265-284
Online since: February 2017
Authors: Chen Li, Hai Ren Wang, Yan An Miao, Li Zhao
In the finite deformation range, the numbers of orthotropic 2n order elastic constants are studied on the basis of tensor function and of its representation theorem.
Through the study of symmetry, we can deduce the number of independent components of the 2n order of the orthotropic materials.
The number of the 2n-order elastic tensor of orthotropic materials can be derived with symmetry study.
The formulation of independent component numbers of the orthotropic elastic tensor is: (6) When using the short way, the tensor independent component can be expressed: 4 order (n=2) There are 9 independent components of the orthotropic elastic tensor: 6 order (n=3) There are 20 independent components of the orthotropic elastic tensor: 8 order (n=4) There are 42 independent components of the orthotropic elastic tensor: Thermal Elastic Constitutive Equations of Orthotropic Materials Lemma 2.1 E is symmetric.
For specific orthotropic materials, minimum numbers of elastic constants should be adopted in experimental observation
Online since: March 2015
Authors: Rong Qun Zhang, Wen Jie Hou, Wei Wang, Jun Liu, Dong Ai
The flood and drought disasters are evaluated by LiuYaBin etc. in China's major grain producing areas[6].From the perspective of system theory, this paper considerate the interaction mechanism of disaster-inducing factors, hazard inducing environment and hazard-affected body comprehensively.
Serious flooding disasters often cause large areas of farmland and crops have been destroyed, and a large number of cultivated lands also had been destroyed.
For larger relief amplitude area, the secondary disasters such as landslides and debris flows caused by tiny change of underlying surface factors, destroying a large number of cultivated land.
Acknowledges: This work is supported by the special fund of the Ministry of Land and Resources of the PRC (Project Number: 201311002-01).
Risk assessment of flood and drought in major grain-producing areas based on information diffusion theory [J].
Online since: September 2012
Authors: Rosemary S. Gault, Keith Ridgway, Gustavo A. Escobar-Palafox
AWJ subsurface, as well as common machined features such as grain deformation, possess certain characteristics linked to the AWJ process which have been less explored.
The mathematical model, presented as regression coefficients in Fig. 1 had a good experimental design with a condition number of 1.15, an excellent fit as indicated by the R2 parameter (0.900) and a very good prediction power with a high Q2 (0.817).
A fast traverse rate does not allow the jet of water to penetrate the material and minimises the number of particles that strike the material, increasing the kerf width at the bottom of the sample.
The mathematical model had a good experimental design as evaluated by the low condition number (2.28), a very good fit (R2=0.859) and good prediction power (Q2=0.572).
Acknowledgement The authors acknowledge the support of the European Commission through the 7th Framework Programme Transport (including Aeronautics) Call, Project number 234325 - ADMAP-GAS.
Online since: February 2013
Authors: Shao Ping Zhang
Step 4: auxiliary iterative localization If the number of anchors within two hops of an unknown node is less than 3, the unknown node cannot be localized directly.
IF the number of anchor nodes≥3 THEN 13.
IF the number of beacons(include anchor nodes and localized nodes) ≥3 THEN 27.
The number of anchors is 20; we take the latter 20 nodes as anchors.
Srivastava: Dynamic fine-grained localization in ad-hoc networks of sensors, in ACM MOBICOM(2001) 166-179
Online since: May 2012
Authors: Shinji Sato, Kohei Matsui, Yusuke Zushi, Satoshi Tanimoto, Masato Takamori, Takashi Iseki, Yoshinori Murakami
We can see from this micrograph that the Zn-Al solder rigidly joined the SiC die to the Cu foil without any cracking and that an off-eutectoid structure containing big hcp-Zn grains formed in the solder layer, as expected from the Zn-Al binary phase diagram [6].
Fig. 6 The results of a thermal cycle test between –40°C and 200°C where the average shear strength is plotted as a function of the number of cycles.
Figure 6 shows the results of the thermal cycle tests, with the change in the average shear strength plotted as a function of the number of cycles.
Although the shear strength gradually declined with an increasing number of cycles, our attachment maintained a sufficient and acceptable strength level of 78 MPa even after 1500 cycles.
A considerable number of cracks and their length can be seen in the Zn-Al solder layer.
Online since: May 2004
Authors: M.José Matos, M. Fátima Vaz, Jorge Cruz Fernandes, Fernando A. Costa Oliveira
The quality of information is related to the possibility of focusing within a certain depth of field, which provides acquiring images in such a way that cells approach the volumic dimension; the higher accuracy of data is reflected in the lower standard deviations, for a similar number of measurements.
When the images are acquired by an electron microscope the grey levels represent either surface topography (secondary electron images) or phases with different mean atomic numbers (backscattered electron images); therefore electronic signals make it possible to discriminate a wider range of materials and/or features within a sample [3].
For this purpose, several parallel lines (equally spaced by 0.35 mm) were superposed on the micrographs and the number of cell walls intersected by unit length, PL, was determined.
Most cells possess faces with five edges and a number of closed faces, suggesting that they can be classified as semiclosed-cell type foams.
Vander Voort: Grain Size Measurement, in “Practical applications of quantitative metallography”, Ed.
Online since: October 2010
Authors: Yan Feng Wang, Jiang Yu, Chang Ming Qiu
After water toughening treatment at 1050℃, the organization of the manganese steel is even austenitic grains, the hardness reaches to 170 ~ 230HB.
The emerging of a large number of high-density twins decrease the casting defects such as gas holes and so on.
(a) (b) (c) (d) (e) (f) Fig.1 Typical microstructure of high manganese steel before and after asynchronous rolling a) structure with water toughening treatment b) with 8.51% cold rolling c) with 15.25% cold rolling d) with 18.83% cold rolling e) with 22.48% cold rolling f) with29.63% cold rolling It can be seen from Figure 2 that: in the small deformation case, a lot of flat deformation zone and deformation twins appear in the organization, dislocation configuration performance is the flat band; with deformation increase, the twins number increase significantly; when the deformation reaches a certain level, the organization appears stacking faults and twins crossing fracture or serious distortion and crystal division.
With the increase of deformation, a large number of high density deformation twins appear.
(3) After asynchronous rolling, a large number of high-density twins appear in the organization of the high manganese steel, which not only decrease gas holes and other casting defects, but also greatly improved the hardening performance.
Online since: September 2013
Authors: Gu Hua Li, Da Zhen Xu, Zhuang Zhi Liao, Hai Wei Yan
Table 2-1 Cumulative triage and fineness modulus of manufactured sand sand Number Cumulative triage(%) MX granite sand 4.75 2.36 1.18 0.6 0.3 0.15 2.462 4.45 20.64 34.74 43.90 73.15 85.08 Table 2-2 Performance index of manufactured sand sand Number Fineness modulus Loose bulk density(kg/m³) Voidage Bulk density(kg/m³) Performance density(g/cm³) Value of methylene blue Crusher dust content/% granite sand 2.67 1450 43% 1740 2.68 1.0 12.7 Fig. 2-1 Grading curve of granite sand (5)Fine Aggregate.
Table 2-3 Mix calculation of high performance manufactured sand concrete Number Water cement ratio Water consumption Cb Cement Coal ash Silica fume Sand ratio Sand Cobble Water reducer C2 0.55 165 300 180 120 42% 801 1098 0.72% C4 0.47 157 334 200 134 41% 766 1120 0.86% C6 0.42 150 357 214 143 39% 741 1139 0.94% C8 0.38 145 382 229 153 38% 716 1152 1.00% C6 0.42 150 357 214 143 39% 741 1139 1.16% C8 0.38 145 382 229 153 38% 716 1152 1.08% C10 0.3 143 477 286 191 35% 617 1157 0.87% C12 0.3 143 477 286 191 35% 617 1157 1.99% D1 0.36 143 397 238 159 41% 764 1104 1.04% D2 0.32 141 441 264 176 39% 720 1109 0.94% D3 0.28 139 496 298 199 37% 664 1114 0.83% D4 0.26 137 527 316 211 36% 633 1120 0.78% E1 0.36 143 397 258 119 20 41% 769 1104 1.04% E2 0.32 141 441 286 132 22 40% 726 1109 0.94% E3 0.28 139 496 323 149 25 38% 670 1114 0.83% E4 0.26 137 527 343 158 26 36% 639 1120 0.78% F1 0.36 143 397 397 46% 882 1036 1.83% F2 0.32 141 441 441 44% 829 1055 2.27% F3 0.28 139 496
Table 3-1 Test data of carbonation depth Number Water-binder ratio Admixture type 56d's strength Carbonation depth 3d 7d 14d 28d C2 0.55 Ⅱgrade ash of 40% 33.7 6.7 9.2 14.9 21.3 C4 0.47 34.6 6.3 10.6 14.4 15.6 C6 0.42 45.7 6.0 8.3 9.3 11.5 C8 0.38 56.0 3.2 3.6 5.3 7.3 C10 0.3 60.3 3.6 3.2 6.0 6.5 C12 0.26 65.7 2.0 3.2 3.4 5.2 D1 0.36 Ⅰgrade ash of 40% 55.0 1.6 3.3 3.4 6.2 D2 0.32 73.6 0.3 1.9 2.4 3.4 D3 0.28 79.6 0.2 1.1 1.1 1.4 D4 0.26 70.6 0.0 0.7 0.8 1.0 E1 0.36 Ⅰgrade ash of 30%+silica fume of 5% 64.9 0.4 1.9 2.2 3.0 E2 0.32 66.3 0.0 0.7 09 1.4 E3 0.28 77.9 0.0 0.0 0.0 0.0 E4 0.26 81.8 0.0 0.0 0.0 0.0 F1 0.36 No admixture 69.9 0.0 0.0 0.0 0.0 F2 0.32 78.0 0.0 0.0 0.0 0.0 F3 0.28 71.5 0.0 0.0 0.0 0.0 F4 0.26 76.5 0.0 0.0 0.0 0.0 Test Result Analysis.
According to figure 3-1, figure 3-2 and figure 3-3, when water cement ratio is smaller, carbonation resistance is better, because carbonation speed is mainly associated with compactness of concrete, with the decrease of water-cement ratio and increase of cementations material consumption, the concrete is more close-grained.
Online since: February 2012
Authors: Xiao Bo Yao, Li Yang, Mu Qing Qiu
Introduction In recent decades, the development of modern agriculture in China has made remarkable achievements, 22% of the world basically solved the problem of feeding the population[1], but in order to improve grain yield, chemical fertilizers and pesticides in the production process into a rapid increase in agricultural non-point source pollution is getting serious pollution of the water environment is particularly serious, it is estimated that China's water pollution in about 1/3 from agricultural non-point source pollution.
Pesticides and the loss of one hand, a large number of application resulted in ecological imbalance, on the other hand the soil, surface water, groundwater, air pollution and so on, can directly lead to excessive pesticide residues in agricultural products, harm to human health.
However, manure used in our country has not been reasonable, according to the survey, only 49% of the manure to be used, the rest were either randomly stacked, or sewage directly into the form of ditches, sinks into the river, causing a large number of nutrients, of rural non-point source pollution is the main pollutant causing eutrophication.
With the rapid economic development in rural areas, sewage and solid waste pollution, the number is growing, and traditional agricultural solid waste re-use patterns and gradually weakening, a lot of vegetables, straw and other garbage is dumped at random, littered, the waste directly in the rain washed into the river, increasing the deterioration of ecological environment in rural areas, the formation of a more serious point source pollution.
In addition, the rice-frog can also significantly increase the number of natural enemies of pests, the increase of the natural enemies also promoted the pest control of the field[10].
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