Biogenic components in total 66 surface sediments,which were taken in the western Arctic Ocean during the First and Second Chinese National Arctic Expedition cruises,are analyzed for probing into the relationship between surface productivity and water masses in area studied.
通过对中国首次和第二次北极科学考察在北冰洋西部所采取的66个表层沉积物中生源组分的分析,探讨了该海区表层生产力变化与水团的相互关系。
Quantitative analytic results of biogenic components in core B2-9 from the northern Bering Sea slope indicate that coarse fraction and opal content, serving as proxies of surface productivity, have increased stepwise since the MIS 5.
3期以来表层生产力指标的粗组分和蛋白石含量呈阶梯状增加,反映表层生产力阶段式的增长。
hard facing of tool joint
钻杆接头表面加硬层
hard banding of tool joint
钻杆接头表面加硬圈
shoulder dressing tool
钻杆接头端面整形工具
Cause Analyses of Pin Joint Fracture of 139.7 mm Heavy Weight Drill Pipe
139.7mm加重钻杆外螺纹接头断裂原因分析
A study of the surface crack at thread root of tool joint pins by the aid of finite element method.
石油钻杆公接头螺纹牙根部表面裂纹有限元计算
Tribological Properties of Sulfur-nitrade Layer on Drilling Joint Material 35CrMo Steel
钻杆接头材料35CrMo钢硫氮共渗层的摩擦学性能
Defects Analysis on 37CrMnMo4 Drill Pipe Joints
37CrMnMo4钻杆接头缺陷分析
Study on Dry Biological Properties of Drilling Pipe Joint Material with 35CrMo Sulphurized-nitrided Compound Layer
钻杆接头材料35CrMo硫氮复合处理层的干摩擦学性能研究
Study on Surface Nanocrystallization of 7A52 Superhard Aluminum Alloy Welded Joint
7A52超硬铝合金焊接接头表面纳米化的试验研究
Threads on rotary shouldered connections for petroleum industry
GB/T9253.1-1999石油钻杆接头螺纹
Petroleum equipment--Thread gages for rotary shouldered connections
GB/T4749-1993石油钻杆接头螺纹量规
Longitudinal-cracking Failure Analysis of Box
φ139.7mm钻杆内螺纹接头纵向开裂失效分析
Failure Analysis on Tool Joint Expansion of φ88.9mm×9.35mm G105 Drill Pipe
φ88.9mm×9.35mm G105钻杆内螺纹接头胀扣失效分析
Finite element analysis of the screw structure of the drill-stem junction
钻杆接头螺纹结构形式的有限元分析
Analysis of characteristics of PDC rock bits applied to the hard rock
适用于硬岩的PDC全面钻头特点分析
Machining quality is usually not a problem with the sealing surfaces of outlet connections, but it may impact the threads. This is especially true for the harder materials of construction.
排气口接头的密封表面的加工质量通常不是问题，但它会影响螺纹。对于较硬的建材更是如此。
Wear-resistant Properties of Plasma Sprayed WC-Co Coating On the Roller Bit Metal Seal Ring Surface
牙轮钻头金属密封环表面喷涂WC-Co涂层耐磨性研究
Study on Electroplated Diamond Bit for Extra-hard, Compact and Weak-abrasiveness Formation;
坚硬致密弱研磨性岩层电镀金刚石钻头研究