Shale oil is a kind of oil resource that occurs in shale strata in the form of adsorption and free phase. As an essential strategic replacement resource, shale oil has become the focus of global attention. Shale oil reservoirs’ formation and distribution characteristics are quite different from those of conventional reservoirs. The occurrence mechanism of shale oil reservoirs (including hydrocarbon generation, hydrocarbon expulsion, and hydrocarbon storage) restricts the enrichment of shale oil. Furthermore, the compactness of shale oil reservoir limits the recoverability (mobility and momentum) of shale oil, which is also the bottleneck factor restricting the effectiveness of shale oil exploration and development. The hydrocarbon generation, expulsion, storage, and movable hydrocarbon of shale oil are the key scientific problems in the research of shale oil. Understanding these key scientific problems and establishing an effective evaluation model is the key to improving the effectiveness of shale oil exploration and development. The shale oil resources in Jiyang Depression are of large scale and have the value of a commercial product, but the development effect is not ideal. Based on the research achievements of Jiyang Depression in recent years, this paper discusses the related research progress and the current situation around (1) hydrocarbon generation characteristics, (2) hydrocarbon expulsion characteristics, (3) hydrocarbon storage characteristics, and (4) movable hydrocarbon characteristics. This paper is expected to be beneficial to promote the substantial progress of shale oil exploration and development in Jiyang Depression.

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Grassland is the second green cover layer on the land surface of the earth after the forest. Grassland is not only a substantial production base of animal husbandry, but also plays a vital role in biodiversity protection, climate change, and human sustainable development. With the increasing impact of climate change and human activities on the grassland ecosystem, more and more attention has been paid to the degradation of the grassland ecosystem. The study of grassland ecosystems is of great significance. Based on previous studies, this paper summarizes the research progress of the grassland ecosystem in China in recent years from five aspects: (1) vegetation, (2) soil, (3) hydrology, (4) climate, and (5) soil animals. On this basis, the critical research direction in the future is put forward. The purpose of this paper is to provide references for grassland protection and effective utilization.

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