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Dynamic compaction is one of the densification techniques of ground improvement and extensive theoretical, experimental and in-situ tests have been used to clarify its mechanism. In this paper, a literature review about the dynamic compaction is carried out and the emphasis is put on the reinforcement mechanism, effective reinforcement depth and influence range of vibration to give a reference for the ongoing researches of dynamic compaction method.

Setting of insulation layer is widely recognized to prevent frost damage for tunnels constructed in cold region. Optimization design of insulation layers, however, still need deeply investigate. In this paper, taking Houanshan tunnel as example, two-dimensional finite element analysis on the optimization design of insulation layers has been carried out by ABAQUS. The tunnel temperature fields due to various thickness and length of insulation layer are numerically analyzed. It shows that ,1)4.85°C increased at backside of insulation layer with thickness of 5cm, while 5.8°C increased for thickness of 7cm;2) frozen depth of surrounding rock decrease with the increase of insulation layer thickness. The farther distance to tunnel portal, the smaller thickness of insulation layer required to prevent the surrounding rock from freezing;3)According to analysis, frost penetration length should be 450~500m before tunnel holing-through ,while 720m~830m after tunnel holing-through.

Aiming at the petrochemical wastewater activated sludge system, using the Elman neural network modeling technology, through the improvement structure to improve the dynamic performance of the network, check and repair etc data preprocessing methods, combined with object characteristics selected input variable, construct the neural network model. The simulation results show that the neural network based on the activated sludge system model has good convergence and prediction accuracy, and can meet the control sewage treatment system reliable and stable operation of the engineering application demand.

This paper examines research on sustainable tourism policies formulation and implementation and the role of government and industry policy makers. This document explains classification of China’s tourism development policies and present sustainable research progress. At the end, the article points out future development directions of sustainable tourism policies formulation : Establishing the theory system of policy research for tourism sustainable development; Deepening the policy thinking of sustainable development——industry transformation; Enriching the theory contents of tourism policy research.

This paper introduces a new position method based on phase difference. The electrocircuits are designed to meet the position demand. The signal produced, phase demodulation, drive circuit are described. Lots of experiments are performed to test the linear error, hysteresis error, repeatability error and stability error. The uncertainty is synthesized based on testing data and the results show that the displacement error form electrocircuits is less than 11.2nm.

Activated carbon fibers supported TiO2 nanoparticle photocatalyst was prepared by immersing activated carbon fibers in water suspended with TiO2 nanoparticles under sonication. X-ray diffraction and scanning electron microscopy were applied to characterize the crystallinity and morphology of the photocatalyst. The photocatalytic activity of the prepared photocatalyst was evaluated by the photodegradation of formaldehyde for indoor air purification. The result showed that the low-concentration formaldehyde in the polluted indoor air could be photocatalytically degraded over the prepared photocatalyst, with the formaldehyde concentration in the product air falling into the standard range that is specified by the Chinese Indoor Quality Standard.

The concentration error of standard gas in different locations of calibration system will have different degrees of impact on accuracy of calibration results. Among them, concentration of standard gas in gas mantle that combine detection sensors and gas transmission pipelines show the greatest impact on calibration results. In order to realize monitoring and analysis of the overall calibration process, this paper simulated gas concentration change status during calibration process of indoor environmental monitor gas mantle by FLUENT software. Gas concentration change status and sensor measurement accuracy at situations of different size sensors placed in the same gas mantle at the same location and same sensor placed in the same gas mantle at different location were analysed. Simulation results show that to make gas most quickly and evenly filled gas mantle, gas mantle size should be slightly larger than sensor and sensor should be placed in the top of the mantle as far as possible. On this condition, it can ensure gas concentrations error range between sensor workface and the inlet are within ±2%, thereby ensuring the accuracy of calibration results.

Quality control of plastic for avoiding environmental pollution and food poisoning is of utmost relevance and it is a common requirement in national norms for health and safety reasons. Among series of factors, trademark plays an integral role in the procedure which must be properly classified in order to reduce risk loss of distinctiveness. As most norms rely on chemical or physical experiment, chemometric classification models from NIRS spectra were tested for sampling polyethylene that presents potential effect of trademark by using Soft Independent Modeling of Class Analogy (SIMCA) and Factor Analysis in this paper. The classification models were carried out with two kinds of trademarks (F410-3 and LA0710) of 50 test samples from Singapore and Qatar respectively. And the experimental results show that the SIMCA classification obtained 88% accurate identifications, while Factor Analysis gives 100%. By using this strategy, it was feasible to conclude a better method to classify plastic quickly and nondestructively without the need for various analytical determinations.

Ram-compaction gravel pile with end expansion is widely adopted in the treatment of silty clay foundations. In this paper, the bearing properties of rammed gravel pile reinforced foundations and soil between piles were investigated by use of static load tests and heavy-duty dynamic penetration test. It is demonstrated that the settlement curves (P-S curve) of ram-compaction gravel pile with end expansion reinforced foundation and soil between piles were monotonic, without turning point being observed. With the increases of pile length, the bearing capacity of pile increases. According to the experimental results from heavy dynamic penetration tests and static load test, the strength of soil between piles is improved, which also have effects on the elimination of the uneven settlements. Comparison the results between heavy-duty dynamic penetration tests and over-heavy dynamic penetration tests shows that the later one is suitable on testing of the soil properties between piles. In addition, from in-situ measurements of uplift deformation of different depths, it is found that uplift behavior occurs with depth more than 0.5m, whit largest uplift value of 21cm. The result provides a reference for the design and construction of rammed gravel pile reinforced foundation.

The work presented in this paper focuses on support time for tunnel, which has much effect on stability of tunnel. Based on loess tunnel of Zhengzhou-Xi’an high-speed passenger rail line in China, large scale model test with geometric proportion 1: 20 was applied to study on different support time. Supplemental numerical analysis was carried out to investigate the effect of release ratio of stress which cannot be covered by model test. It is revealed that it is asynchronous change for deformation, strain and stress of surround rock. If the supporting constructs prematurely, internal force of support would be excessive greatly and if the supporting constructs too late, it will bring excessive slack pressure which leads to the plastic zone unfavorable, even tunnel collapse. The reasonable support time can improve self-bearing capability of surrounding rock and reduce the cost. The limited displacements about 17.8 cm for crown and 12.9 for horizontal convergence are gained. The research results can act as reference for similar materials tunnel and underground engineering construction.

The flood of spam has caused more serious harm in society. In this paper, we bring forward an anti-spam system based on the service grid, which can dynamically organize the mail servers on the Internet together to against the spam. We discuss the working model and system architecture of the anti-spam grid and design the core algorithm for the status monitoring and load distribution of a dispatch server. And In this paper, we implement the system performance evaluation, and the experiment results show that the system is stable, efficient and scalable.

The flood of spam promotes the development of anti-spam technology. In this paper, we bring forward the Bayesian filter technology based on the distributed architecture, which can realize the sharing of the Bayesian learning outcomes among servers within the system, so as to increase the accuracy of spam recognition. We, in the paper, discuss the sharing model of information with spam features under the distributed architecture and the spam identification process; analyze the Bayes algorithm and carry out the relevant improvements; design the Bayes Filter based on distributed architecture on the above basis and verify the effect of the filter by experiments.