难以克服

This study analysised the condition of Xinjiang's petroleum resource and made an evaluation and it points out that the development of petroleum and natural gas of Xinjiang is still in the developing period in which it aims at discovering the petrol field and increasing its reserves.Although it has a great exploring potential,because of its geograghy limitation and a lack of exploring funds,the exploring level is till low,even lower than the everage level of the whole country. The study is based on theories of industry distributions,its concentration,macroscopic analysis,government regulations and continuing development.From microcosmic and macroscopic aspects,it scientifically and systematically analyses the problems in the development of petroleum industry in Xinjiang.It points that the developments of middle and upper reaches lack a balance and have no rational industry structures.So it is hard to form an integral industry chains.Moreover,the upper reach covers a too much large proportion in the development,so it can not give a strong impetus to other industries.Based it,the paper points the industrial concentration of Petroleum Chemical Products Manufacture of Xinjiang should be enhanced and Input to Petroleum Chemical Products Manufacture of Xinjiang should be increased.Due to a lack of an established fair and competitive market and government's perfect laws and regulations on petroleum industry,it points that the phenomenon of mixed operation has become common in monolopied business and competitive business,so the systems of petroleum industry needs to be restructured.It states clearly that the country should take the development and benefits of Xinjiang's economy into consideration when making strategies for petroleum development .Besides,the allocation of profits between the center and the local should be well arranged so that we can guarantee the profits of Xinjiang ,considered as a resource area.It also reveals that we should not only overcome limitations of resources,environment,economy and technology on continuring development,but also we should deal with some realistic problems well.For instance,contradictions between the concept of limited resource and continuing development,the relationship between petroleum industry's own features and continuing development,the contradictions between the limits on supply of petroleum and the need of future development of continuing resource ,outdated petroleum technology and the need of advanced technology for continuing development,tremendous damages to environment and requirements of environment protection for continuing development and Xinjiang continuing economic development,outdated policy of industry and continuing development,the relationship between continuing development of Xinjiang petroleum industry and continuing economic development of Xinjiang.

本研究以产业布局理论、产业集中度理论、灰关联分析理论、政府规制理论、可持续发展理论为依据，从微观、宏观两个层面，科学、系统、全面地分析新疆石油产业的发展问题，指出：新疆石油天然气目前仍处于油气田发现和增储的主要发展阶段，开发潜力巨大，但由于地质原因及勘探投入的不足，石油天然气探明程度偏低，低于全国平均水平；新疆石油产业产业结构布局不合理、上中下游发展不平衡，难以形成完整的产业链条，对工业的带动力与其本身具有的经济总量很不匹配；新疆石油开采业和石油加工业属于高度寡头垄断的市场类型，新疆石油化工业属于竞争型的市场结构，要想石油产业对新疆经济有较强的带动作用，新疆石油化工业必须上升到一定的层次和规模，在提高规模的基础上，提高新疆化工业的产业集中度；新疆石油加工业和化工业与农业呈现较高的关联度，加大对石油加工业和化工业的投入，对新疆经济的协调发展有着深远的影响；政府要从石油产业本质特征和发展趋势为着眼点，实施规制改革，分开政府规制政策的制定部门和监管部门职能，建立健全石油产业法律法规体系，对垄断性业务和竞争性业务实施分类规制；国家石油发展战略的制定应兼顾新疆区域经济的发展和利益，应切实处理好新疆与中央的利益分配，切实保证新疆作为资源产区合理的资源收益；新疆石油产业要想得以可持续发展，不仅要克服影响可持续发展的资源、环境、经济和技术等客观因素，还要处理好观念、需求、政策等诸多主观因素。

With the new concept,the problem of variable structure control of 2D discrete system is transferred to the problem of seeking a sliding model with good sporting character and attractability. The concrete design schemes of the imitative sliding model and variable structure controller are also put forward. And the concrete expression of the time T in ε-neighborhood of reaching switch manifold is obtained. The difficulty of applying the existing methods to MIMO systems is overcome.

在新概念之下，将2D离散系统的变结构控制问题转化为寻找一个既具有良好的运动品质又具有吸引性的滑动模问题，给出了滑动模及变结构控制器的设计方案，并且获得了达到切换流形的ε领域的时间T的具体表达式，克服了已有方法难以应用到多输入—多输出系统上的困难。

This method commendably solves the hard problem of computing the damage efficiency precisely, which is caused by overlapping of bomblet's damage areas; overcomes the flaw that the error of computing result is big, which is the result of using overlap coefficient and effective coefficient methods.

该方法较好的解决了射击幅员中子弹毁伤幅员重迭难以精确计算毁伤效能的难题，克服了解析评定法中采用的重迭系数和有效系统法带来计算结果误差大的缺点。

By the way of melting the filler will also bring the diffusion and the capillary attraction, and that the same or different kinds of metal can be welded well without melting the original material, especially the different ones and the complicated shapes.

利用真空硬焊制程来克服Al、Cu焊接时所产生的困难，藉由填料熔融产生原子扩散及毛细现象在不熔融母材的情况下结合同种或异种金属，尤以异种材质的接合或形状复杂难以接合的工件，皆可达到良好的接合效果。

Checkweigher is difficulty to use in high speed filling and the liquid shake to the vibration, is unable to monitor missing or mis-aligned Lid/Cap/Crown, filling the pressure Detection. X Ray inspector although can automatically find out the manufacture flaw: The greasy dirt, the liquid, the distortion and contaminant, the reject product will remove from on-line, but will need to liquid/foam differentiation and X

称重检测存在难以适应高速灌装要求和液体晃动对称量影响，无法判断瓶盖封口是否完好，灌装压力是否达到指标；X射线影像检测虽然能够自动查出以下制造缺陷：油污、液体、变形和异物，将不合格容器从线上剔除，但需要克服泡沫影响和X射线安全性。

In order to study the effect of Coriolis acceleration on the natural frequency and dynamic stress of high spinning steam turbine blades, a computational model of Coriolis force and dynamic stress induced by Coriolis acceleration in blades is presented using analytic method.

该模型克服了以往在叶片动态特性分析时难以考虑科氏力影响的问题，导出了科氏动应力和非稳态气流动应力比值的计算公式以及科氏力和离心力比值的计算公式，并进行了实例分析。

Based on the important idea of duality between plane and point geometries,two direct explicit methods of computer-aided design for developable surface s were proposed,the developable surface s were represented using control planes with appropriate basis functions.

为了克服传统方法在可展曲面设计上的缺陷，方便地解决工程中经常遇到的可展曲面位置和形状难以调整和控制的问题，基于3D射影空间中点和平面间的对偶性这一重要思想，提出了两种直接、简单的可展曲面设计方法。

This method can overcome the defects of traditional analytical optimization methods: they are hard to suit the conditions of discontinuous objective function and disconnected constrained domain. At the same time, the quantities measured by PMU can fully give play to maximum advantage while limited PMUs are placed.

该方法克服了传统解析优化方法难以适应不连续目标函数和不连通约束域等情况的缺点，同时，在配置有限PMU的情况下使PMU量测量发挥最大效益。

The complexity of a possible intervention -- and the political divisiveness it has wrought -- could be too great to overcome this week.

可能的干预措施的复杂程度以及由此产生的政治分歧恐怕都过于强大，难以在本周克服。

The key technique to realize the system such as: the establishment of electronic map database ^ the search of the best pattu gobal position, map match and coordinate alternate etc, are discussed. The database of road information and main targets which is of much benefit to the realization of the system are built to manage the information of roads and main targets.

在研究电子地图数据库的建立方法时，为了克服现有电子地图的图幅接边在接边处会出现扭曲错位、难以管理地图信息、信息量少且难以更新等缺点，采用路网数据库和物标上题数据库来管理地图上的路网信息和主要物标信息。

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。