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101.
Through technological research of foundation treatments in the collapsible loess areas, we recommend a method of treating foundations in collapsible loess with quicklime piles. We set forth the basic principle of this expansive method. When a very thick foundation in collapsible loess is treated, the computational formula for the volume of expanding material in a quicklime pile is deduced based on cavity expansion theory. This theory is applied to engineering practice. Physical and mechanical properties of the compacted soil are tested. The result shows that the collapsibility of a foundation in loess has been eliminated, its physico mechanical indexes have been improved, and the soil compressibility and the modulus of compressibility also increase remarkably, demonstrating the correctness of the computation theory. The feasibility of the expansive method for very thick collapsible loess areas is further established. 相似文献
102.
To create a model for recycling technology, a waste FR 4 printed circuit board (PCB) recycling process employing supercritical fluid CO2 (SCF CO2) is studied using central composite design. The influence of temperature and treatment time on the PCB delamination ratio, latitudinal tensile strength of glass fiber sheets, and their synthesized effect are analyzed. The optimal temperature and treatment time for FR 4 PCB recycling with SCF CO2 are found by building a quadratic polynomial equation model of output parameters in recycling technology. The accuracy of the derived optimal temperature and treatment time is validated by a series of experiments. 相似文献
103.
A good method for creating a surface borehole for withdrawing coal strata methane is to build before excavation and use during the whole process. But the excavation greatly affects the overlying rock strata, and when the excavation face passes through the 相似文献
104.
To address the problems of low carrying capacity and short life of bearings in current ring reducers, a new type of ring reducer is proposed which consists of a two stepped transmission. One is a planetary transmission, and the other is an N type planetary transmission with a low tooth number difference. Based on the analysis of structural features, the transmission principle, and a transmission load situation, a contact finite element model of the new type of ring reducer is set up, and the stress value and the actual pairs of meshing teeth are derived by calculation. Based on gear modification research theory, the second stage transmission gear pairs of the new reducer are modified on its teeth profiles. Results demonstrate that the load capacity of transmission gear pairs have been enhanced greatly. 相似文献
105.
To improve the energy efficiency of solar cells in wireless sensor networks nodes, the energy relationship between solar cells and the wireless sensor networks nodes is studied. An adaptive algorithm is adopted to ensure the wireless sensor networks work normally at different sunlight intensities. An energy model is designed that reveals the energy relationship between the output power of the solar cells and the power of nodes working normally at a standard sunlight intensity. The experimental results show that the model represents the adaptive energy relationship between the solar cells and the nodes, ensures that the nodes work stably in a long term, and extends the life cycle of the sensor networks as long as possible. The model has important guiding significance for wireless sensor networks designation. 相似文献
106.
For the large span and flat, together with the interaction effect of construction and disturbance of surrounding rock, the mechanical of large span and flat multi arch tunnel is very complicated, and the time space effect is different from that of two lane multi arch tunnel or separated tunnel. Adopting the “CTSSSRH”, the 3 D dynamic process of the tunnel construction was simulated. Analyzing the rule of surrounding rock displacement and stress with excavation, the time space effect of large span and flat multi arch tunnel was proposed. 相似文献
107.
By means of discovering crosscutting concerns from legacy systems, aspect mining intends to help migrate the systems to an aspect oriented design. An improved method based on maximum tree method for aspect mining is presented. The method uses aspect ideas to capture the runtime method call information by mining crosscutting concerns from dynamic behaviors, and then constructs a method call relationship data matrix. Based on fuzzy similarity relation theory, by introducing the similarity, an object similarity matrix is constructed, and the maximum tree method is used to identify the crosscutting concerns in the system. The method can provide a basis for system’s software reconstruction and reusability. An experiment is conducted to verify the validity of the method. Compared with the existing typical mining methods, the method shows the virtue of clear implementation and high efficiency. 相似文献
108.
通过对两个刺槐无性系苗木在光照培养箱内进行盆栽,采用正交试验设计的方法,研究不同水分胁迫水平下增施氮磷对两个刺槐无性系苗木光合特性的影响。对光合光响应曲线、最大净光合速率、光饱和点、光补偿点和叶绿素含量进行分析,结果表明:随干旱程度加深,干旱前期氮磷交互作用对刺槐叶片光饱和点和光补偿点影响显著,干旱后期差异不显著。比较两个刺槐无性系苗木的光合特性得出,L1(鲁刺一号)比W1(皖刺一号)更为耐旱。 相似文献
109.
To recycle wet discharged fly ash and carbide lime effectively, a highly activated mineral admixture slurry consisting of both these components was investigated. The preparation technology of mineral admixture slurry made from a composite of wet discharged fly ash and carbide lime and the strengths, hydration products change (XRD, SEM) of cement paste made by the slurry were studied. The results indicate that the optimal proportion between wet discharged fly ash and carbide lime (solid content) is 75:25 in the process of wet milling preparation. The alkaline environment provided by carbide lime with high Ca(OH)2content and cement hydration accelerated by modified agents can promote early activation of fly ash, and accelerate its secondary hydration reaction. 相似文献
110.
The microbiology was introduced in foundation treatment. Several Carbonate mineralization microorganisms and polysaccharides viscose microorganisms were screened and the microorganisms No.ATCC 6453,3,polysaccharides viscose microorganisms 5 and 6 were used in silt modification. The engineering properties of silt before and after modification were compared by unconfined compressive strength test and indoor seepage test. The microstructures of silt incorporating different microorganisms were analysed by mean of scanning electron microscope and energy dispersive X ray (EDX) analysis. And the modification mechanism of silt has been revealed. These studies indicate that certain engineering properties of silt can be improved by incorporating microorganisms. 相似文献