Marx and Engels related and analyzed the relationship between humans and nature as early as more than 100 years ago. and they revealed the interdependent and indivisible relationship between humans and nature in the d...Marx and Engels related and analyzed the relationship between humans and nature as early as more than 100 years ago. and they revealed the interdependent and indivisible relationship between humans and nature in the development of the human society and history from the perspectives of the dialectical materialism and the historical materialism. The Communist Party of China has always attached great importance to the ecological problems. The ＂17th CPC National Congress＂ wrote for the first time the ＂ecological civilization＂ into the political report. The ＂18th CPC National Congress＂ placed the construction of the ecological civilization in a prominent position, emphasizing that the ecological construction should be integrated into all aspects and the whole process of the economic construction, the political construction, the cultural construction and the social construction. The report of ＂19th CPC National Congress＂ promoted the construction of the ecological civilization to a new strategic level, and made an Omni-directional discussion from a new height, the new goals. the new values, the new roles and the new initiatives and other aspects.展开更多
静电四级透镜具有优越的电子光学聚焦成像性能,单一静电四极透镜可实现电子束线聚焦,组合静电四极透镜系统拥有点聚焦的能力。文中对实现点聚焦的双静电四极透镜系统相关参数进行了计算,利用电子光学软件SIMION仿真发现,静电四极透镜之...静电四级透镜具有优越的电子光学聚焦成像性能,单一静电四极透镜可实现电子束线聚焦,组合静电四极透镜系统拥有点聚焦的能力。文中对实现点聚焦的双静电四极透镜系统相关参数进行了计算,利用电子光学软件SIMION仿真发现,静电四极透镜之间的畸变场与两端的边缘场引起的像差会严重影响系统聚焦成像质量。仿真分析了系统像差与发射电子初动能的关系。结果表明:系统在保证点聚焦的情况下,增加电子发射初动能可以有效减小系统像差;当电子初动能增加至1×105 e V时,最大发散角为2°的电子束在聚焦平面上的弥散斑减小至3.2μm×28μm。展开更多
文摘Marx and Engels related and analyzed the relationship between humans and nature as early as more than 100 years ago. and they revealed the interdependent and indivisible relationship between humans and nature in the development of the human society and history from the perspectives of the dialectical materialism and the historical materialism. The Communist Party of China has always attached great importance to the ecological problems. The ＂17th CPC National Congress＂ wrote for the first time the ＂ecological civilization＂ into the political report. The ＂18th CPC National Congress＂ placed the construction of the ecological civilization in a prominent position, emphasizing that the ecological construction should be integrated into all aspects and the whole process of the economic construction, the political construction, the cultural construction and the social construction. The report of ＂19th CPC National Congress＂ promoted the construction of the ecological civilization to a new strategic level, and made an Omni-directional discussion from a new height, the new goals. the new values, the new roles and the new initiatives and other aspects.
文摘静电四级透镜具有优越的电子光学聚焦成像性能,单一静电四极透镜可实现电子束线聚焦,组合静电四极透镜系统拥有点聚焦的能力。文中对实现点聚焦的双静电四极透镜系统相关参数进行了计算,利用电子光学软件SIMION仿真发现,静电四极透镜之间的畸变场与两端的边缘场引起的像差会严重影响系统聚焦成像质量。仿真分析了系统像差与发射电子初动能的关系。结果表明:系统在保证点聚焦的情况下,增加电子发射初动能可以有效减小系统像差;当电子初动能增加至1×105 e V时,最大发散角为2°的电子束在聚焦平面上的弥散斑减小至3.2μm×28μm。
