科创中国

陕西省铧厂沟金矿床位于勉略缝合带以南,矿体受控于近东西向逆冲断层和韧脆性剪切带。本文以细碧岩矿带为例,系统研究了围岩蚀变分带及蚀变矿物组合,总结了矿床的蚀变分带模式。围岩蚀变以穿切细碧岩透镜体的剪切带为中心向外依次可划分为黄铁绢英岩化带、绢云碳酸盐化带和绿泥赤铁矿化带。蚀变矿物组合分别为黄铁矿+铁白云石+铬云母+绢云母+钠长石+石英+方解石、铁白云石+绢云母+钠长石+石英±黄铁矿、(铁)绿泥石+钠长石+铁白云石+赤铁矿+钛铁氧化物+石英±绿帘石。蚀变岩石组分迁移分析表明,在围岩蚀变过程中, SiO2、Na2O、Fe2O3T、MgO与Y等组分发生不同程度的迁出, K2O、CaO、Ba、Rb、Sr、Cr、Cu、Pb和挥发组分等迁入,并以黄铁绢英岩化带最为显著。金在成矿流体中以Au(HS)–2络合物迁移,成矿流体与富铁细碧岩之间的反应是金沉淀重要机制。

英语和法语同属于印欧语系,在语音、词汇和句法和时态上有很多相似之处.英语对法语的学习同时具有正迁移和负迁移.是回避还是直面语言迁移?其实,回避是回避不了的.直面迁移,明晰英语和法语的相似点和相异点,有助于强化其正迁移和克服负迁移.因此,英法互译可以成为法语教学的重要手段.

综述了纳米复合食品包装材料中纳米成分检测与迁移的国内外研究进展,重点就纳米复合包装材料中纳米成分检测的前处理方法、形貌检测和含量检测方法以及迁移研究进展进行了总结,为进一步的理论和实验研究提供参考.

中华民族有五千年的文化历程,各族人民在缔造统一的多民族国家的同时,充分发挥了他们的聪明才智.创造了灿烂悠久的民族文化,这段历史本身也成了中国文化的一部分.在现代社会之前,历史文化的传承主要依靠的是文化自身的生命力和发展惯性.而在我们现代化发生之后,相应地给历史文化的表达带来了一些现代化的特性.本文将在现代化的背景之下探讨历史文化的现代表达途径,发现其中的问题并提出自己的建议.

通过腐蚀模拟试验,研究了在3.5%NaCl溶液中样品表面熔敷硫条件下,腐蚀时间对X52钢元素硫腐蚀类型、腐蚀速率的影响,分析硫沉积条件下腐蚀产物膜的发展规律.结果表明,60℃条件下X52钢腐蚀速率逐渐升高并趋于稳定,90℃条件下初期腐蚀速率很高,随后逐渐降低,并最终都趋于稳定.在单质硫覆盖下样品表面的腐蚀产物随时间的演化是影响腐蚀速率在不同温度下趋于接近的重要原因.

以当前出现的食品包装安全问题为背景,从传统食品包装中汲取"纯朴"元素,分析其特征,探求其所蕴藏的文化内涵,发掘它的审美价值和功能,发现新的设计理念及方法,从而实现低碳环境下"纯朴"元素与现代食品包装设计的完美结合.

1.需要大写的外文字母:(1)来源于人名的单位首字母,如单位Pa、Gy、Hz等.(2)化学元素符号首字母,如Cl、Fe等.(3)西方人的名字、姓及头衔的首字母.

介绍了灰铸铁、球墨铸铁中微量杂质元素的不利影响及其限量,并对Sn、Sb、Cr、Mo、V、Ti、Al等元素作了补充说明.简述了铸造用高纯生铁的含义:一种Mn、P、S、Ti含量低、特定微量元素含量很低的生铁,指出铸造用高纯生铁中微量元素含量明显低于铸铁中微量杂质元素的限量.

我们经常遇到这样的情况,学生在学习物理知识时轻松、愉快,学习兴趣浓厚,可在解决实际问题时,往往一筹莫展,束手无策.究其原因是,在教学中重知识轻能力、学不致用.这种反差现象使我意识到:学生仅仅是懂得了物理知识还不足够,还要培养学生应用知识解决实际问题的能力,特别是知识迁移的能力.学生在学习过程中通过举一反三、触类旁通,把学到的某些物理原理、物理知识应用到学习新的知识或解决问题的活动中去,这就实现了知识的迁移.

Satellite-tracking technology has allowed scientists to make a quantum leap in the field of migration ecology. Nowadays, the basic description of migratory routes of many species of birds has been reported. However, the investigation of bird migration at individual level (i.e. repeatability in migratory routes and timing) still remains seldom explored. Here, we investigated repeated migratory trips of a trans-Saharan endangered migratory raptor, the Egyptian Vulture Neophron percnopterus, tracked by GPS satellite telemetry. We compared between- and within-individual variation in migratory routes and timing in order to assess the degree of repeatability (or conversely, the flexibility) in migration. To this end, we analysed a dataset of 48 trips (23 springs and 25 autumns) recorded for six adult birds during 2007-2013. Our results showed consistent migration timing at the individual level, both in spring and autumn. Interestingly, there was a high degree of flexibility in the routes followed by the same individual in different years, probably due to variations in meteorological conditions. Contrary to expectations of a faster migration in spring than in autumn owing to a time-minimization strategy for breeding, birds spent less time in autumn migration (13 ± 2 days, range = 9-18 d) than in spring migration (19 ± 3 days, range = 13-26 d), which can be explained by differences in environmental con- ditions en route. Egyptian vultures showed a consistent clockwise loop migration through western Africa, following more easterly routes in autumn than in spring. Finally, our results provide supporting evidence of low phenotypic plasticity in timing of migration (i.e. strong endogenous control of migration) and high flexibility in routes [Current Zoology 60 (5): 642-652, 2014].