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【Objective】The study was carried out to explore the spatial distribution characteristics of soil physical and chemical properties in Changli Gold Coast National Nature Reserve, with an aim to provide scientific references for establishing a virtuous cycle of vegetation ecosystem in the reserve.【Method】Fifty-seven sampling sites were determined by 1 000 m×1 000 m grid sampling method, and 0-10 cm and 10-20 cm soil samples were collected for physical and chemical properties determination. The kriging interpolation method was used for spatial mapping, and the main influencing factors were discussed according to correlation analysis and variance analysis.【Result】The soil physical and chemical properties of the reserve showed obvious spatial heterogeneity in the horizontal direction, and the farther away from the sea, the higher value of some physical and chemical property indexes. The soil texture was mainly divided into four categories: sand, loamy sand, sandy loam and silty loam, of which sand accounted for about 70%, with the sand content reaching 85%-100%. The western Qilihai experimental area was salinized with the total salt quantity of 5.22 g/kg. The coastal area was mainly non-salinized and mildly salinized. There were significant correlations among the indexes, soil bulk density was negatively correlated with water content and nutrient indexes. In addition to bulk density, soil water content was significantly positively correlated with the other six indexes. The four nutrient indexes were positively correlated with each other, and the pH value was significantly positively correlated with available phosphorus, available potassium and total salt quantity. In addition, the distribution pattern of soil physical and chemical properties was affected by factors such as the distance from the coastline, land use type and soil type. The distance from the soastline played a significant role. The water and nutrients content of farm land were significantly higher than those of wood land, grassland and unused land. Compared with tidal soil and coastal salt soil, coastal aeolian sand soil had higher soil bulk density, lower water content, organic matter content, total salt quantity and pH value.【Conclusion】In the western Qilihai experimental area, saline-alkali tolerant plants should be selected as the main species, and drought-tolerant and wind-resistant tolerant seedlings should be selected in the land buffer area, the southern land core area and the Jinshawan experimental area.

To efficiently develop deep shale gas in southern Sichuan Basin, under the guidance of “extreme utilization” theory, a basic idea and solutions for deep shale gas development are put forward and applied in practice. In view of multiple influencing factors of shale gas development, low single-well production and marginal profit of wells in this region, the basic idea is to establish “transparent geological body” of the block in concern, evaluate the factors affecting shale gas development through integrated geological-engineering research and optimize the shale gas development of wells in their whole life cycle to balance the relationship between production objectives and development costs. The solutions are as follows: (1) calculate the gold target index and pinpoint the location of horizontal well drilling target, and shale reservoirs are depicted accurately by geophysical and other means to build underground transparent geological body; (2) optimize the drilling and completion process, improve the adaptability of key tools by cooling, reducing density and optimizing the performance of drilling fluid, the “man-made gas reservoir” is built by comprehensively considering the characteristics of in-situ stress and fractures after the development well is drilled; (3) through efficient management, establishment of learning curve and optimization of drainage and production regime, the development quality and efficiency of the well are improved across its whole life cycle, to fulfil “extreme utilization” development of shale gas. The practice shows that the estimated ultimate recovery of single wells in southern Sichuan Basin increase by 10%-20% than last year.

The effects of adding different amounts (0.1%, 0.2%, 0.3%, 0.4% and 0.5%) of psyllium husk powder (PHP), gellan gum (GG) or konjac glucomannan (KGM) on the properties of phosphorylated surimi-crab meat mixed gels (MG) were investigated. The gel properties were improved by adding a small amount (0.1%) of PHP or GG. With increasing addition level of hydrophilic colloids, phase separation occurred, so that the gel properties did not significantly change and even began to decrease. However, the addition of KGM had no significant effect on the breaking force or gel strength, and no phase separation was observed under laser scanning confocal microscopy (LSCM). The addition of PHP and GG increased the temperature at which G’ began to decrease, which was beneficial to the improvement of gel properties. The denaturation of myosin required higher temperature and less energy in the phosphorylated MG system with hydrophilic colloids, and temperature may become a major influential factor in the denaturation process. The overall structural stability of proteins in MG was enhanced by adding a small amount of PHP or KGM. However, PHP and GG had a destructive effect on actin. On the contrary, the addition of a small amount of KGM could increase the structural stability of actin, which may be unfavorable for the formation of gels. The interaction between myosin and actin in the MG system was conducive to enhancing the overall structural stability of proteins. The three hydrophilic colloids, especially GG, at an addition level of 0.1% was beneficial to the improvement of gel properties. The incorporation of hydrophilic colloids may be a novel strategy to improve the quality of phosphorylated MG.