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MWD todayMeasurement-while-drilling (MWD) tools and tech-niques have made steady, if not spectacular, progressduring the year. Mud-pulse telemetry has become amature technology.Teleco Oilfleld Services, Inc., has successfully used itspositive-pulse MWD to 相似文献
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为了活跃学术研究空气,开扩眼界,更有针对性地学习国外先进航空物探方法与技术,地矿部航空物探总队于四月中旬先后邀请了来京参加“1985年国际石油及矿产开发展览会”的五家西方著名航空物探公司来队做报告,介绍他们在研制新仪器及开展航空物探测量方面的丰富经验。这些公司有加拿大肯廷(KENTING)公司、先达利(SCINTREX)公司、乌尔特克(URTEC) 相似文献
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Chinese and Japanese population of Chlamys farreri and their reciprocal hybrids were surveyed in isozyme variability at 13 loci by polyacrytamide gel electrophoresis (PAGE). Isozyme banding patterns indicated these hybrids were diploid. Loci that were observed as being monomorphic in inbred populations of C. farreri were also found to be monomorphic in filial progeny; loci that observed to be polymorphic in parental type generations were also polymorphic in hybrid generations. Differences existed among allelic frequency of the four types of cross. Within the reciprocal hybrids the expression of malic enzyme (ME) isozyme was sufficient to distinguishing individual hybrids because of the band, Rf=0.38. However, there were no noticeable variations among all the samples to differentiate one from another. Inbreeding was likely to be the main problem in aquaculture. The introduction of new broodstock can improve the genetic diversity. Hybrid vigor has manifested to a certain extent in the present study. 相似文献
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