英汉对照参考资料(8)

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     

航空物探技术的一次有益交流

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)     

Isozyme expression of Chinese and Japanese populations of Chlamys farreri and their reciprocal hybrids

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.     

基于国家新旧测量规范的GPS观测模式比较分析

GPS测量因其具有高精度、全天候、不受通视限制等优点,成为目前大地测量、工程测量及城市控制网测量的主要观测方法。为了规范GPS测量,2001年制定了《全球定位系统(GPS)测量规范》,2009年进行了修订。在比较新旧规范对GPS观测模式的规定后,通过对比目前通用的3种观测模式的观测效率、观测精度及其应用,得出一些有益的结论。     

3种绘制等值线方法的比较

等值线是为了反映地球局部变化趋势,将一组反映地球形状与特征的离散点通过内插和拟合方法绘制成具有同一数值或特性的封闭曲线。在分别介绍Global Mapper、GMT和Surfer这3种软件的基础上,对某地区2.5'×2.5'大地水准面模型(高程异常)数据分别采用这3种软件绘制等值线,因这3种软件采用的网格化方法不同,所生成的等值线也不尽相同,通过对比分析得出一些有益的结论。