Search

Abundant geothermal springs occur along the Moxi fault located in western Sichuan Province (the eastern edge of the Qinghai-Tibet plateau), highlighted by geothermal water outflow with an unusually high temperature of 218 °C at 21.5 MPa from a 2010-m borehole in Laoyulin, Kangding. Earthquake activity occurs relatively more frequently in the region and is considered to be related to the strong hydrothermal activity. Geothermal waters hosted by a deep fault may provide evidence regarding the deep underground; their aqueous chemistry and isotopic information can indicate the mechanism of thermal springs. Cyclical variations of geothermal water outflows are thought to work under the effect of solid earth tides and can contribute to understanding conditions and processes in underground geo-environments. This paper studies the origin and variations of the geothermal spring group controlled by the Moxi fault and discusses conditions in the deep ground. Flow variation monitoring of a series of parameters was performed to study the geothermal responses to solid tides. Geothermal reservoir temperatures are evaluated with Na-K-Mg data. The abundant sulfite content, dissolved oxygen (DO) and oxidation-reduction potential (ORP) data are discussed to study the oxidation-reduction states. Strontium isotopes are used to trace the water source. The results demonstrate that geothermal water could flow quickly through the Moxi fault the depth of the geothermal reservoir influences the thermal reservoir temperature, where supercritical hot water is mixed with circulating groundwater and can reach 380 °C. To the southward along the fault, the circulation of geothermal waters becomes shallower, and the waters may have reacted with metamorphic rock to some extent. Our results provide a conceptual deep heat source model for geothermal flow and the reservoir characteristics of the Moxi fault and indicate that the faulting may well connect the deep heat source to shallower depths. The approach of hot spring variation research also has potential benefits for earthquake monitoring and prediction.

A new pure rolling-type hole-forming machine for transplanting rapeseed has been developed in accordance with agricultural requirements. The motion of the pure rolling-type mechanism is analyzed to derive parametric equations for the hole-forming mechanism. Computer-aided design and MATLAB are then used to generate theoretical contours and outlines of the transplanting hole. Simulation analysis is conducted to obtain the contours of the transplanting hole, and the resulting structure and motion parameters are verified. Subsequently, a prototype is produced and field testing is performed. Experimental results indicate that, when the machine is in low gear, its forward speed is in the range 1.80–1.96 km/h, corresponding to an operational efficiency of 0.306–0.333 hm2/h. When tested in clay, loamy, and sandy soils, the average qualification rate of hole formation reaches 94.4%, 93.3%, and 90.4%, respectively. These results confirm that the transplanting hole-forming machine developed in this study satisfies the design requirements, representing a significant advance in the provision of technical support for new transplanter designs.

In order to realise high-efficiency hole-forming and pursue optimal forming hole parameters which satisfied agricultural requirements for awl-shaped punch transplanter, a optimally designed indigenously-developed pure rolling planting hole-forming machine's hole forming mechanism parts is proposed. The CAD software graphing method was used to study the effect of forming planting hole by structural parameters, with the numerical simulation method by MATLAB 7.0 software and CATIA software were used to verify the rationality of the hole-forming key parameters optimisation design. Subsequently, prototype trial-production was carried out, followed by field testing. The results showed that forming planting hole opening lengthwise shrank from originally 88.8 mm to 72.6 mm, lateral width was 41.2 mm, the effective depth reduced from 58.9 mm to 48.5 mm, qualified radio of forming planting hole reached to 95.1%, which 1.93% higher than the original prototype, which was significant for the provision of technical support for the design of new transplanter.

The integration of PV generation system in traction power supply system contributes to promote the nearby accommodation of PV energy and the energy- saving and emission-reduction of railway system. This paper proposed a back-to-back PV generation system for electrified railway and its control strategy. In the proposed system, PV energy was output using the DC side of back-to-back converter. The optimal power of the two individual converters was calculated dynamically according to the working conditions. Two converters were controlled independently and the PV energy could be output. In the meanwhile, the reactive power and negative sequence current of traction power supply system were compensated to a certain extent taking advantage of the redundant capacity of converters. Simulation model was built in Simulink and the simulation results verified the effectiveness of the proposed system and control strategy.

Test of bench performance to the power of tractor PTO (power take-off ) is a necessary way to evaluate the economic and dynamic performance. So the bracket of engine bench testing is essential equipment, and the effect of DC electric dynamometer used in PTO power test is investigated in this paper. Realizing the process to achieve automatic control and automatic recording, thus greatly reducing the labor intensity of testing personnel and the human error in the testing process, but also greatly increased the accuracy of the test results.

Recently, traditional rules of male sterile lines and restorer lines to regularization planting, with harvesting respectively, labor intensive, uneven pollination, and seriously affecting to the quality and yield of seeds, have been changed by the technology of Engineered Seeding Production, which can reduce the production cost and greatly raise the level of seeds breeding mechanization. But, there are also many problems, in particular, purity of the seeds and high working efficiency are hard to guarantee. So developing a separator is the crux of further popularization. On the basis of parents in different lengths, this paper designs a model Indent Cylinder Separator to study dynamics analysis, and obtains the factors influencing the results of separation are radius, angular velocity and rake angle of the cylinder. Meanwhile, mathematics models between structural, kinetic parameters of the cylinder and different lengths seeds are founded to provide theory basis for further study of structure and parameter design.

There is much difficulty in fault diagnosis because of lacking of system fault samples. So this paper presents a mixed strategy of combining differential evolution algorithm with local enhanced operator with the optimization of the parameters of support vector machine. For the diesel engine valve clearance fault diagnosis, the measured diesel engine valve vibration signals data after wavelet transform are used as the characteristic values of the diagnostic model. Then the diesel engine valve clearance fault diagnosis model of SVM based on MPDE is established and compared with the BPNN, SVM and IQPSO-RBF models, The results showed that the performance of the SVM optimized by MPDE algorithm is better than the models based on the other three algorithms. The method is practical and effective.