低渗透油藏动态渗吸机理实验研究及数字岩心模拟

在低渗油藏的开发过程中,渗吸作用对于产量提升起到重要作用。传统的岩心渗流实验难以从微观的角度较为清晰地描述岩石物性、孔喉分布、岩石组分构成等特征。利用数字岩心技术建立孔隙网络模型,对真实岩心孔隙结构进行渗吸模拟分析具有重要意义。对松辽盆地某区域岩心样品通过综合微计算机断层扫描技术(micro computed tomography,Micro-CT)、数字岩心分析技术,实现低渗储层数字岩心渗吸过程的模拟,与实验室岩心自发渗吸实验对照,结果表明,利用数字岩心技术模拟得到的孔隙度、渗透率参数与实验室测量结果相差较小,提取的孔隙网络模型与真实岩心误差较小,从而可以保证数字岩心得到的两相渗流模拟结果具有较高的可信度,为油藏渗吸作用的机理研究提供了新的思路,对指导实际油藏开发具有重要意义。

RNA interference in Colorado potato beetle(Leptinotarsa decemlineata): A potential strategy for pest control

Colorado potato beetle(CPB),Leptinotarsa decemlineata,is a notorious destructive pest that mainly feeds on the leaves of potato and several other solanaceous plants.CPB is widely recognized for its adaptation to a remarkable variety of host plants and diverse climates,and its high resistance to insecticides and Bacillus thuringiensis toxins.RNA interference(RNAi)is a sequence-specific,endogenous gene silencing mechanism evoked by small RNA molecules that is used as a robust tool for virus and pest control.RNAi has been extensively tested for CPB management by employing various target genes and delivery methods.This article reviews the screening of RNAi target genes,efficient RNAi delivery systems,and factors affecting RNAi efficiency in CPB,which may help understand the mechanisms of RNAi and its application in CPB control strategy.

钛合金精铸熔模材料及其成形脱除技术

系统阐述了常见钛合金精密铸造熔模材料:光敏树脂(SLA)、高分子聚合物、蜡基及树脂基模料其组元、性能、成形及脱除工艺对熔模质量及灰分残留的影响,并就未来模料研发和脱模工艺的研究进行了展望。为钛合金精密铸造的发展提供有益参考。