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This study deeply explores the characteristics of the dolomite reservoir and its controlling factors in the Ordovician Majiagou Formation in the southern Gaoqiao area of the Jingbian gas field in the Ordos Basin, aiming to provide a more accurate scientific basis for oil and gas exploration. The study reveals the petrological characteristics and reservoir properties of the reservoir through core analysis, thin- section observation and porosity and permeability testing. The results show that the reservoir in this area is dominated by mud-crystalline dolomite and crystalline dolomite, especially mud-crystalline dolomite shows excellent storage and permeability performance due to the development of pore-soluble pores. The porosity mainly ranges from 2% to 6%, with an average porosity of 3.03%, and the permeability mainly ranges from 0.01 to 5 mD, with an average of 2.14 mD. The analysis of the main controlling factors of the reservoir shows that karst plays a decisive role in the development of dolomite reservoirs, and especially the formation and distribution of the paste-solution pores have a significant influence on the storage and seepage performance. The depositional characteristics of gypsum nodules and their distribution pattern during the rock-forming process have an important influence on the porosity and permeability of the reservoir. Differences in the physical properties of the reservoir in the sedimentary microphase environment have a significant impact on the reservoir performance, in which the microphase reservoir containing gypsum cloud ping exhibits higher porosity and permeability. In addition, reservoir destructive primary control factors, such as compaction and pressure-solubilization effects and cementation and filling effects, negatively affected reservoir properties. Taken together, this study provides important scientific support for understanding the formation mechanism of dolomite reservoirs in the region, assessing the hydrocarbon resource potential, and guiding future exploration activities. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Inappropriate design eye point (DEP) will lead to nonstandard sitting postures, including nonneutral head positions and other uncomfortable sitting postures, which are high risk factors for neck pain in fighter pilots exposed to high G forces. Therefore, application of a 3D measurement method to collect data regarding eye position while in the cruising sitting posture in the aircraft cockpit to guide the design eye point has been proposed. METHODS: A total of 304 male fixed wing aircraft pilots were divided into two groups. Subgroup A (N = 48) were studied to define the cruising posture during flight. Subgroup B (N = 256) were studied with Romer 3D measurement equipment to locate the cruising eye position of the pilots in a simulated cockpit. The 3D data were compared to DEP data in the current standard cockpit. RESULTS: According to 3D measurement, the vertical distance from the cruising eye point to the neutral seat reference point was 759 mm, which is 36 mm lower than that of the Chinese standard DEP and also lower than the U.S. military standard. The horizontal distance was 131 mm, which is 24 mm shorter than that of the Chinese standard. CONCLUSIONS: The current DEP data cannot fulfill the needs of fighter pilots and should be amended according to the results of the 3D measurement so that pilots can acquire the optimal cruising posture in flight. This new method has the value of practical application to investigate cockpit ergonomics and the measurement data can guide DEP design [ABSTRACT FROM AUTHOR]