Alot of noises accumulate on the upstream channel in HFC ( Hybrid Fiber-Coax ) system which caused the difficulty in bi directional operations Therefore suppressing them is very difficult .

HFC 上行通路汇集了大量的各类噪声，严重影响着其双向 业务的开通，如何对这些噪声进行抑制是个难题。

That is true for both upstream and downstream operations .

上 下游 业务均是如此。

It will unlock a range of associated Shell upstream projects and extinguish routine gas flaring in its Nigerian operations .

它将带来与壳牌相关的一系列 上游项目，并将消除尼日利亚工厂 运营中常规气体的放空。

They could concentrate on the upstream exploration and production side of their operations already the largest and most profitable and increasingly operate as suppliers to refiners and distributors in China and other emerging economies .

它们可以专注于 业务“ 上游”的勘探和开采部分这已经是规模最大、最有利可图的部分，并争取成为中国和其它新兴经济体炼油厂和经销商的供应商。