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With the continuous exploitation of most reservoirs in China, the proportion of heavy oil reservoirs increases, and the development difficulty is greater than that of conventional reservoirs. In view of the important subject of how to improve the recovery factor of heavy oil reservoir, the thermal recovery technology (hot water flooding, steam flooding, steam assisted gravity drainage SAGD and steam huff and puff) and cold recovery technology (chemical flooding, electromagnetic wave physical flooding and microbial flooding) used in the development of heavy oil reservoir are summarized. The principle of action is analyzed, and the main problems restricting heavy oil recovery are analyzed The main technologies of heavy oil recovery are introduced from the aspects of cold recovery and hot recovery. Based on the study of a large number of literatures, and according to the development trend of heavy oil development, suggestions and prospects for the future development direction are put forward.

Study on ecological compensation ability of urban green space is the premise and foundation of scientific and reasonable urban ecological green space system planning. Taking Jinan as an example, the paper studies the ecological compensation ability of ecological green space system by applying RS and GIS technology, based on the principle of balance of carbon and oxygen and by using the green equivalent method. The results show: except Lixia District’s per-capita two-dimensional green biomass does not reach minimal standard(25m2 per person), the other four districts (Licheng, Tianqiao, Huaiyin and Shizhong) reach the underline of green equivalent which meets the needs of the normal life of residents. However, there exist some problems, such as scarcity of green space types and disproportion of ratio between trees and shrubs.

The study on the wetland plant species and their resistance is the key to ecological wastewater treatment technology. The study on the effects of wastewater duress on the physical and chemical properties of constructed wetland plants and the anti-stress capability of constructed wetland plants can provide theoretical basis and technical support for constructed wetland plant material selection. By adopting surface flow constructed wetland system, the effects are studied on MDA in 4 common plants in Shandong (Phragmites communis, Typha oriental, Arundo donax and Canna generalis) in different wastewater duress time. The results show: All in all, Phragmites communis and Canna generalis have stronger anti-stress capability, while Arundo donax and Typha oriental has weaker anti-stress capability; but as wastewater duress time increases, the anti-stress capability of Phragmites communis decreases, while the anti-stress capability of Canna generalis increases.

By adopting the constructed wetland system of surface flow, the purification effects of different residence time of wastewater, different constructed wetland plants and their synergistic effect are studied in DO disposal in living wastewater. The results show that the best plant combination in purifying DO is that of Phragmites communis and Typha oriental,followed by that of Phragmites communis, and that of Arundo donax and Typha oriental is lowest.

The study on the resistance of different wetland plants to wastewater duress is the key to ecological wastewater treatment technology. This paper studies the change of soluble protein content in 4 common wetland plants (Phragmites communis, Typha angustata, Arundo donax and Canna generalis) in Shandong in different wastewater duress time. The results show: when the wastewater duress time is 2 days and 4 days, soluble protein content in Phragmites communis has minimal change, and its anti-stress capability is the strongest; when the wastewater duress time is 6 days, soluble protein content in Canna generalis has minimal change, and its anti-stress capability is the strongest, followed by Typha angustata.

Abstract. Smooth shift and low shift shock are needed to improve power shift quality and comfort of construction vehicle. And higher dynamic performance of power shift clutch is needed. In this paper, the dynamic mathematical model and simulation model of the clutch engagement process were established, the factors affecting the shift quality were analyzed qualitatively and quantitatively. The simulation model of the transmission system was established based on the software AMESim, the corresponding vehicle tests were performed, and the shifting quality was improved by changing key parameters. Analysis results illustrate that the proposed mathematical model and simulation model are correct and effective and can be used to predict and evaluate construction vehicle shift-feel, which are the theoretical basis for analysis and research on the static and dynamic characteristics of the dynamic shifting process in the future.