选对内裤能够预防妇科病

近几年,越来越多的女性受到各种各样的妇科疾病的危险,最常见的就是阴道炎和生殖系统肿瘤等。一般情况下如果你的白带出现浑浊,甚至带红、色黄,这些都是疾病的信号。如果早期能发现这些现象而及早治疗,     

奥陶纪棘皮动物骨骼地球化学特征指示古海水Mg/Ca比的可靠性分析

显生宙棘皮动物骨骼均由高镁方解石组成,其骨骼的Mg/Ca比受海水Mg/Ca比、古海水温度、成岩作用等因素的影响.研究以华南扬子区下奥陶统棘皮动物海百合化石为主要测试对象,通过能谱仪及波谱仪等微区原位分析方法,获得其骨骼可靠的Mg/Ca比.化石骨骼显微构造和化学成分特征表明,扬子区下奥陶统海百合茎化石骨骼受到成岩作用的影响较弱,依旧保存有与壳体原始矿物有关的Mg含量特征.测试结果显示,根据棘皮动物骨骼的Mg/Ca比与海水Mg/Ca比的线性及指数关系,早奥陶世海水的Mg/Ca比分别在0.16~0.7或0.07~1.17之间变动.经过对其变化趋势的讨论,研究认为扬子区下奥陶统棘皮动物骨骼Mg/Ca比的逐渐增高主要受控于海水Mg/Ca比,而受温度的影响相对较小.研究表明,保存良好的棘皮动物化石可更广泛地应用于古代海洋Mg/Ca比的重建.     

Several Words and Expressions in XING Sill YAN

《型世言》是明代一部重要的短篇白话小说,它的语言自然清新,生活气息和地方色彩比较浓厚,历来有不少前贤时人对其词汇进行研究,这里选取未被论及的＂雪诗儿＂、＂咱伊＂、＂白老鼠＂、＂锅边秀＂等几个词语进行解析,并同时补充《汉语大词典》的书证。     

枸杞泡水3大惊人功效

<正>因为枸杞子天然健康,又含有多种利于人体的营养成分,因此枸杞子可以方便地泡水服下,可以很好地吸收枸杞子的营养物质,同时简单易行,不用担心过多服用枸杞子的副作用。下面就是枸杞子泡水的功效介绍:一、枸杞泡水3大惊人功效1、补肾     

国内外全新世环境考古研究的回顾与展望

环境考古旨在研究古代人类社会和其所处自然环境的相互关系,进而探讨由这种相互作用决定的人类生态系统。其认识论和方法论具有经验主义和实证主义相结合的特色,并以历史唯物主义为哲学基础。全新世以来持续多变的全球气候环境,人类进入新石器时代以后日趋复杂的人地关系,使全新世环境考古一开始就是环境考古重要的组成部分,并于近年来发展成为考古学、地球科学特别是地貌与第四纪环境和全球变化研究的主要方向。本文从科学引文检索结果分析入手,回顾了近年来全球各大洲全新世环境考古研究的主要内容及特色,以及地学考古、分子生物考古及多指标综合集成研究方法和技术手段方面的重要进展。未来全新世环境考古必须加强交叉尺度的综合集成研究和长周期模型的开发应用,深入开展农业起源与传播、史前及历史时期土地利用与资源开发等专题研究,注重在人地关系动态阐释中人文科学与自然科学理论的结合,藉以发挥全新世环境考古研究成果的科学指导作用。     

6kaBP中东亚气候对植被变化的响应

选取PMIP2计划中ECBilt-CLIO-VECODE模式的结果,对比中全新世(6 kaBP)气候对于现代气候的变化,探讨了植被在中全新世气候变化中的意义.中东亚干旱区受西风环流影响,而东亚地区6 kaBP季风深入,不同大气环流的影响导致两区域大尺度气候特征差异大,同时该时期植被的变化增强了气候系统对轨道参数变化的响应:一系列气候要素对植被的动态响应导致气温、降水都因植被反馈而发生较大变化,但是该模式的结果存在低估6 kaBP升温幅度的缺陷,尤其是对冬季温度的模拟;即使耦合植被后有所改善,但对6 kaBP气候变化的驱动因子及其相互关系的研究仍需深入,同时对局地气候变化的物理机制还需改进.     

科技期刊亮点

舟山北部海域海底赋存地下淡水资源上海陆地地区在第四纪早更新世时期(距今73万年—250万年)存在2条古河道——北部的浏河-南汇古河道(可能属于古长江水系)、南部的枫泾-奉城古河道(可能属于古钱塘江水系),2条古河道向海域延伸,北部的古河道自上海的南     

Northern Tibetan Plateau cooling and aridification linked to Cenozoic global cooling: Evidence from <Emphasis Type="Italic">n</Emphasis>-alkane distributions of Paleogene sedimentary sequences in the Xining Basin

The Xining Basin on the northeastern Tibetan Plateau holds the longest continuous Cenozoic stratigraphic record in China. The sequence record contains considerable information on the history of Tibetan uplift and associated climatic change. In particular, high resolution n-alkane biomarker proxy and pollen records have been obtained from the Paleogene sediments of the Xiejia section of the basin. A combination of the n-alkane and palynological records reveals that the paleoclimate in the Xining Basin experienced a long-term cooling trend from 50.2 to 28.2 Ma with a distinctive ecological event spanning 37.5 to 32.7 Ma. Since this ecological event, a vertical zonation of vegetation from lowland arid grasses, to middle-elevation subtropical broad-leaf plants, to high-elevation coniferous trees was established. We interpret that these changes in climate and vegetation were probably responses to a combination of long term global cooling since the Eocene climatic optimum and uplift of the surrounding mountains on the northern Tibetan Plateau in the early Cenozoic.     

The evolution of the atmosphere in the Archaean and early Proterozoic

Key steps in atmospheric evolution occurred in the Archaean. The Hadean atmosphere was created by the inorganic processes of volatile accretion from space and degassing from the interior, and then modified by chemical and photochemical processes. The air was probably initially anoxic, though there may have been a supply of oxidation power as a consequence of hydrodynamic escape to space of hydrogen from water. Early subduction may have removed CO₂ and the Hadean planet may have been icy. In the Archaean, as anoxygenic and then oxygenic photosynthesis evolved, biological activity remade the atmosphere. Sedimentological evidence implies there were liquid oceans despite the faint young Sun. These oceans may have been sustained by the greenhouse warming effect of biologically-made methane. Oxygenesis in the late Archaean would have released free O₂ into the water. This would have created oxic surface waters, challenging the methane greenhouse. After the Great Oxidation Event around 2.3 to 2.4 billion years ago, the atmosphere itself became oxic, perhaps triggering a glacial crisis by cutting methane-caused greenhouse warming. By the early Proterozoic, all the key biochemical processes that maintain the modern atmosphere were probably present in the microbial community.     

《型世言》方言量词和特殊量词研究

《型世言》中所用的语言保留了当时鲜活的口语资料。在对书中方言量词和特殊量词进行考察的基础上,探究其中量词“儿”尾、“子”尾的特点,进而管窥明代吴方言量词的面貌。