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Aiming at a kind of multi-energy complementary isolated power system in Tibet ali area, which consists of photovoltaic (PV) station with storage device, hydro generator, and diesel generator, a new control strategy was presented. According to the power system characteristics, analyzed the new control strategy, it can realize the grid power output with zero steady-state error. In the DIgSILENT/PowerFactory simulation environment, building the multi-energy complementary isolated power system model and simulation based on the control strategy, the system can track the fast variation of the PV array output power or other output power. Two studied cases verify the control strategy.

In order to research the expansive deformation performance of shrinkage-compensating steel fiber reinforced shotcrete, orthogonal test was done in this paper with expansive agent content and steel fiber content as variable. And the test results showed that restrictive expansion ratio was gradually increased when curing in water, while reducing in air. The difference between restrictive expansion ratio and free expansion ratio used to make self stress by stretching steel bar and steel fiber. Meanwhile the maximum self stress is 0.58MPa, and the minimum self stress is 0.23 MPa in concrete. What’s more, both the maximum self stress and the minimum self stress could meet the requirements for self stress of shrinkage-compensating concrete.

Due to the easy cracking of shotcrete, shrinkage-compensating shotcrete is researched and its micro-structure and strength properties are analyzed. Firstly, cement slurry is made by CSA, accelerating agent and two different cements. When hydrated 3 days and 28 days , hydration products of cement slurry are analyzed by SEM and XRD in feature, crystal characteristics and mineral compositions. The compatibility of the two different cements and admixtures is studied in apparent characteristics, and the fact that Portland cement is more suitable for making shrinkage-compensating shotcrete is obtained. Then, mechanical properties of concrete which consists of Portland cement, expansive agent and steel fiber are did to analyze the influence of strength characteristics caused by mix amount of expansive agent and steel fiber. The results show that the compression strength and tensile strength of concrete improve with the increasing mix of steel fiber. Incorporation of the expansive agent is greater impact on concrete strength, when mix amount of expansive agent is 8%, strength properties are the best. When mix amount of steel fiber is 1.0% and expansive agent is 8%, the effect of cooperative enhancement is the best.

Using 6% HCSA, HEA and CSA equivalent replacement Slag Portland Cement add into the normal concrete, the compressive strength, splitting tensile strength and flexural strength at the age of 3d, 7d and 28d are researched. It is concluded that reinforcing effect of the three expensive agents are in order CSA, HEA and HCSA form the view of mechanics , expansive agents increase the bonding force between coarse aggregate and slurry, alleviate the development speed of cracks and increase the destruction deformability of concrete.

The flexural strength of shotcrete which prepared for cementitious material incorporated with cements,accelerating agents and expensive agents is studied.By changing the fraction of steel fibers by volume and the addition percentage of expensive agent in binding material,the influence on flexural strength of the two factors is investigated,the mechanism of steel fibers and expensive agents work together to reinforce the shotcrete and the strength development law are analyzed.The result shows that, the flexural strength of steel fiber reinforced shotcrete is improving with the volume fractions of steel fibers increasing.And the flexural strength of shrinkage-compensating shotcrete is decreasing with the addition percentage of expensive agent in binding material adding except 6%. The flexural strength of shotcrete is rather better when the fraction of steel fibers by volume is 1.2%~1.6% and the addition percentage of expensive agent in binding material is 8%,which indicates that the restriction effect of steel fibers can enhance the flexural strength of shrinkage-compensating shotcrete,embodies the effect of synergistic enhancement and compounding effect with steel fibers and expensive agents.

According to dry-mixed materials of shotcrete which composed of raw materials in mix proportion the concrete quality as field mixing were included. Through the experimental research on the storage period of using dry-mixed materials in shotcrete, variations of compressive strength were obtained. In according with the studies on the storage period of dry-mixed materials in 7d, 11d, 15d, 20d and 28d, compared with 0d, the loss of compressive strength were obtained under different sand water content (0%, 0.5% and 1.0%). The results shown that strength loss rate of C30 concrete was 6.7% when the sand water content was 0.5% in the 28d and while strength loss rate was 12.0% when the sand water content was 1.0%. The studies on storage period provide supports to the using of dry-mixed shotcrete in engineering application.

Bisphenol A poly(carbonate) (PC) pellets used for production of 5 gallon drink water bottles were reprocessed in a twin-screw extruder for three processing cycles which simulated to those of PC bottle processing conditions. The reprocessed PC pellets were characterized by its mechanical, rheological, thermal, and optical properties. It was found that the mechanical properties of the reprocessed PC samples are slightly decreased after reprocessed. Whereas no further change was observed for the rheological and thermal properties and molecule weight of the PC samples after the second reprocessing cycles. Moreover, the melt flow index, color, and optical properties changed obviously after two reprocessing cycles.