必要条件

This, however, is where the more abstract and general characterization of the necessary and sufficient conditions for Humean skepticism pays off.

无论如何，这是给出的对Hume式怀疑论的充分、必要条件更理论和一般性的刻画。

According to the variation in the components of intermediateacid igneous rocks coming from the lower crust, it is possible to restrain the depth of the source area and the minimum thickness of the crust, and thus to provide important information for the study of the deep process of the continental intraplate mineralizationGlobally, many world level porphyry copper deposits and metallogenic systems formed by hypabyssal hot liquid have their close relationship with the synchronous adakite in spacetime and genesis; domestically, the adakitelike rocks have been identified to be related to the metallogenesis in the main metallogenic areas in ChinaThe recognition of adakitelike rocks having no relationship with the process of subduction makes it possible to construct a metallogenic model of continental intraplate porphyry metal deposits by combining other geological evidences, and this model is totally different from the metallogenic model of porphyry copper deposits with Bsubduction setting constructed by Sillitoe (1972)The existence of adakitelike rocks may be the necessary condition but not the sufficient one for forming the largescale porphyry deposits and the hypabyssal hotliquid deposits, whose metallogenic elements mainly came from the mantleThe metallogenic potential of adakitelike rocks is achieved by the entering of the mantle material, and the metallogenic specialization of adakitelike rocks is decided by the distribution characteristics of the metallogenic elements in the upper mantleAn important reason for the adakitelike magma related to subduction being advantageous to mineralization is that there were abundant high pressure and high temperature liquid coming from the subducted platepieces and the magma of high fO2 coming from the melting of subducted platepiecesHowever, for those adakitelike rocks, whose occurrence has continental plate background but does not relate to the subduction, their metallogenic mechanism is not clear yetBased on the concept of modern mineral exploration and combined with the analysis of integrated geological information, we may better realize the practical prospecting significance of the adakitelike rocks

根据起源于下地壳的中酸性岩浆岩的成分变化，可以约束其源区深度以及地壳最小厚度，为大陆板内成矿作用的深部过程研究提供重要信息。全球范围内，许多世界级斑岩铜矿和浅成热液矿化系统与同期的埃达克质岩存在密切的时空与成因联系，在国内主要成矿区带也识别出与金属成矿作用有关的埃达克岩。与俯冲过程无关的埃达克质岩的识别，使我们有可能结合其他地质证据构建完全不同于Sillitoe(1972)B型俯冲环境的斑岩铜矿成矿模式的大陆板内斑岩型金属矿床成矿模式。对于规模巨大、矿质主要源自地幔的热液矿床的形成，埃达克岩可能是必要条件，但不是充分条件。埃达克岩的成矿潜力通过地幔物质加入而获取，埃达克岩的成矿专属性由上地幔成矿元素分布特征决定。与俯冲有关的埃达克质岩浆之所以有利于成矿，重要的原因是存在大量来自俯冲板片的高压、高温流体以及俯冲板片熔融形成高氧逸度(fO2)的熔体，但产出在大陆板内背景、与俯冲无关的埃达克岩的成矿机制还不清楚。根据现代资源勘查理念，结合综合地质信息分析，埃达克质岩具有实际找矿意义。

Spheroidization annealing of hypoeutectoid steel is a must of cutting-less processing.

亚共析钢球化退火是满足无切削加工的必要条件，文中列举了3种实用的热处理工艺。

Lenin thinks that publicity is a indiscerptible aspect of socialist democratic politics ,and a necessary condition of constructing socialist democratic politics and realizing independent and master of the people.

列宁认为，公开性是社会主义民主政治不可分割的一方面，是建设社会主义民主政治、实现人民当家作主的必要条件。

It provides a significant condition for data management of digital human body , multi-data introject and imitation and virtual technique .

为数字人体的数据管理，多种数据融合与仿真虚拟技术提供了必要条件。

This dissertation gives necessary and sufficient conditions for 2-torus parabolic maps to be invertible,which improves P.

本文首先给出了二维环面上抛物型映射可逆的充分必要条件，完善了P。

It is demonstrated that existence of inflection point on velocity profile is a sufficient condition, but not a necessary condition for flow instability, for both inviscid and viscous flows.

它表明存在速度剖面拐点充分条件，但不是必要条件流不稳定，都粘和粘性流动。

In addition to a theory being logically self-referentially inconsistent, a theory can be inconsistent by virtue of itself denying or implying the contrary of one of its justificatory, semantic, or pragmatic presuppositions. Performative inconsistency derives from the self-referential denial of semantic or pragmatic presuppositions--in other words, a performatively self-falsifying proposition denies a necessary condition if its being meaningfully affirmed.27 The affirmation of a self-stultifying proposition, by contrast, denies one of its justificatory presuppositions.

除了'一个理论能在逻辑上自指不一致'外，一个理论能依据'自己被拒绝'或'内含其辩护性/语义性/语用性预设的反对'而得到不一致；换句话说，如果其被有意义地肯定，则是一个performatively self-falsifying的命题拒绝了一个必要条件。27 （作为对比，对self-stultifying命题的肯定，拒绝了部分其辩护性预设。

Moreover, a criterion is introduced, which is necessary and sufficient for liveness.

进一步，给出了判定合成系统有活性的充分必要条件。

It is shown that the whole system is managerially effective if and only if that all sub-processes are managerially effective.

理论分析表明：链型组织系统管理有效的充分必要条件是系统内的每个子系统均管理有效。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。