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This article used four types rock powder, including granite, gneiss, basalt and limestone, to replace 20% cement to prepare concrete with a water -to -binder of 0.47 or 0.32, and tested their workability and 3 ~1080 d strength, such as cube compressive strength and splitting tensile strength, when the fly ash concrete was selected as the reference sample. The testing results show that the rock powder will affect the concrete workability in different level, and the development model of concrete strength exhibit two-stage feature which contained the rapid development period at 3~180 d and the slow development period at 180 d to 1080 d. Compound exponential function can be used to accurately predict the strength development model of rock powder concrete. The compressive strength ratio of rock powder concrete and fly ash concrete was 0.7~0.9 while the splitting tensile strength ratio was 0.8~1.0. The relationship of compressive strength and splitting tensile strength of rock powder strength can be described by powder function. The 28~90d strength of rock powder concrete was 0.7~0.9 of long-age (1080 d) strength. [ABSTRACT FROM AUTHOR]

The wire cable soft drifting technique is a newly drifting operation mode that far different from the traditional one, which provides a novel technical means for underground drifting operation in oilfield. Work-over rig XJ-150 was improved and the tensile strength tests were performed on the matching equipment to form a set of new drifting operation process using wire cable instead of tube. Field application results showed that this technique could do the work to replace the tube, and this operation method solves the problems of multiple trips, high intensity of labor, long construction period, and High operating costs with a prosperous application. [ABSTRACT FROM AUTHOR]

Objective: To compare the effectiveness of the traditional center of tibial plateau as the entry point and digital technology in the design of intramedullary tibial nail point positioning method in total knee arthroplasty (TKA)., Methods: Between October 2011 and October 2012, 60 cases undergoing unilateral TKA and meeting the selection criteria were randomly divided into 2 groups: in group A (30 cases), the tibial plateau center as the entry point of tibial intramedullary positioning was used; in group B (30 cases), Mimics 10.01 software to simulate the guide rod point of tibial intramedullary positioning was used. There was no significant difference in gender, age, etiology, disease duration, sides, and preoperative knee range of motion, Hospital for Special Surgery (HSS) score, and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) between 2 groups (P > 0.05). Postoperative X-ray films were taken to measure the tibiofemoral angle and tibial angle; knee range of motion, and HSS and WOMAC scores were used to assess the activity of knee., Results: The entry point of group B was located in front of the center of tibial plateau, which was inconsistent with the traditional entry point. The incision healed by first intention in all patients of 2 groups. The patients were followed up 6 to 12 months (mean, 8.6 months). The X-ray measurement at 1 week after operation showed no significant difference in tibiofemoral angle between 2 groups (t = -6.65, P = 0.72), but the anteroposterior and lateral tibial angles of group A were significantly lower than those of group B (P < 0.05). The knee range of motion, HSS score, and WOMAC score of 2 groups were significantly higher at 3 and 6 months after operation when compared with preoperative values (P < 0.05), and the values at 6 months were significantly increased than those at 3 months after operation (P < 0.05). HSS score and WOMAC score had no significant difference between 2 groups at 3 months after operation (P > 0.05), but the scores of group B were significantly higher than those of group A at 6 months (P < 0.05). The knee range of motion of group B was significantly better than that of group A at 3 months after operation (t = 2.13, P = 0.04), but no significant difference was found between 2 groups at 6 months (t = 0.58, P = 0.56)., Conclusion: Compared with the traditional intramedullary guide rod insertion point positioning, digital individualized design of entry point positioning has the advantages of more accurate lower limb force line, better recovery of knee function, and earlier 90 degrees activities, but the long-term effectiveness needs further observation.